From 1f307046f9edadae2a7d1d7149f809e441b4a2fe Mon Sep 17 00:00:00 2001 From: Evgeny Date: Sun, 16 Aug 2026 12:09:44 +0300 Subject: [PATCH] =?UTF-8?q?dns:=20async=5Fdns=20=D0=BC=D0=BE=D0=B4=D1=83?= =?UTF-8?q?=D0=BB=D1=8C=20(libdns)=20+=20=D0=BD=D0=B5=D0=B1=D0=BB=D0=BE?= =?UTF-8?q?=D0=BA=D0=B8=D1=80=D1=83=D1=8E=D1=89=D0=B8=D0=B9=20NTP=20sync?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit - Вендор libdns (MIT) как lib/dns.{c,h}; правка dns_quietinit для GCC 5+ - Новый lib/async_dns.{c,h}: неблокирующий A-резолвер поверх uasync - src/ntp_time.c: убраны блокирующие getaddrinfo+select; async DNS + неблокирующая машина состояний UDP-запроса - test_async_dns.c (юнит) + test_ntp.c сценарий hostname→DNS - сборка: -DDNS_RANDOM=RAND_bytes, -lcrypto в COMMON_LIBS --- lib/Makefile.am | 7 +- lib/async_dns.c | 386 ++ lib/async_dns.h | 67 + lib/dns.c | 9105 ++++++++++++++++++++++++++++++++++++++++ lib/dns.h | 1199 ++++++ src/ntp_time.c | 389 +- src/ntp_time.h | 4 + tests/Makefile.am | 11 +- tests/test_async_dns.c | 291 ++ tests/test_ntp.c | 265 +- 10 files changed, 11478 insertions(+), 246 deletions(-) create mode 100644 lib/async_dns.c create mode 100644 lib/async_dns.h create mode 100644 lib/dns.c create mode 100644 lib/dns.h create mode 100644 tests/test_async_dns.c diff --git a/lib/Makefile.am b/lib/Makefile.am index c809c2c4..ebfca938 100644 --- a/lib/Makefile.am +++ b/lib/Makefile.am @@ -36,12 +36,17 @@ libuasync_a_SOURCES = \ audio_compressor.c \ audio_compressor.h \ strbuf.c \ - strbuf.h + strbuf.h \ + dns.c \ + dns.h \ + async_dns.c \ + async_dns.h libuasync_a_CFLAGS = \ -D_ISOC99_SOURCE \ -DDEBUG_OUTPUT_STDERR \ -DSQLITE_THREADSAFE=1 \ + -DDNS_RANDOM=RAND_bytes \ -g \ -I$(top_srcdir)/src \ -I$(top_srcdir)/lib \ diff --git a/lib/async_dns.c b/lib/async_dns.c new file mode 100644 index 00000000..86624dd4 --- /dev/null +++ b/lib/async_dns.c @@ -0,0 +1,386 @@ +/* + * async_dns.c — асинхронный (неблокирующий) DNS-резолвер поверх uasync. + * + * Адаптер над libdns (lib/dns.c). Схема работы: + * adns_resolve() → dns_res_submit(A-запрос) → adns_drive() + * adns_drive() → dns_res_check(): + * 0 → готово, dns_res_fetch → разбор A-записей → коллбэк + * EAGAIN → зарегистрировать fd (dns_res_pollfd/events) + таймер + * (dns_res_timeout) в uasync и ждать события + * иначе → ошибка → коллбэк с ADNS_ERR_RESPONSE + * + * Всё выполняется в потоке event loop, блокирующих вызовов нет. + */ +#include "async_dns.h" +#include "dns.h" +#include "debug_config.h" +#include "mem.h" + +#include +#include +#include +#include + +#ifdef _WIN32 +#include +#endif + +#define ADNS_DEBUG_CAT DEBUG_CATEGORY_SOCKET + +struct adns_query { + struct UASYNC* ua; + adns_done_cb cb; + void* arg; + struct dns_resolver* res; + void* socket_id; /* handle uasync (NULL когда не зарегистрирован) */ + int cur_fd; /* текущий зарегистрированный fd (-1 когда нет) */ + void* timer; /* handle таймаута (NULL когда нет) */ + int finished; + char* name; +}; + +static void adns_drive(struct adns_query* q); +static void adns_finish(struct adns_query* q, int status, struct sockaddr_in* addrs, int count); +static void adns_read_cb(socket_t sock, void* arg); +static void adns_write_cb(socket_t sock, void* arg); +static void adns_timer_cb(void* arg); + +/* ─── system DNS servers discovery ─── */ + +int adns_parse_resolv_conf(const char* text, struct sockaddr_in* out, int max) { + int n = 0; + const char* p = text; + + if (!text || !out || max <= 0) return 0; + + while (*p && n < max) { + while (*p == ' ' || *p == '\t' || *p == '\r' || *p == '\n') p++; + if (!*p) break; + + if (strncmp(p, "nameserver", 10) == 0 && (p[10] == ' ' || p[10] == '\t')) { + p += 10; + while (*p == ' ' || *p == '\t') p++; + char tok[64]; + int i = 0; + while (*p && *p != ' ' && *p != '\t' && *p != '\r' && *p != '\n' && *p != '#' && i < 63) + tok[i++] = *p++; + tok[i] = '\0'; + memset(&out[n], 0, sizeof(out[n])); + if (tok[0] && inet_pton(AF_INET, tok, &out[n].sin_addr) == 1) { + out[n].sin_family = AF_INET; + out[n].sin_port = htons(53); + n++; + } + } + + while (*p && *p != '\n') p++; + if (*p) p++; + } + return n; +} + +#ifdef _WIN32 +int adns_system_servers(struct sockaddr_in* out, int max) { + if (!out || max <= 0) return 0; + + ULONG size = 0; + if (GetNetworkParams(NULL, &size) != ERROR_BUFFER_OVERFLOW) return 0; + PFIXED_INFO fi = (PFIXED_INFO)u_malloc(size); + if (!fi) return 0; + if (GetNetworkParams(fi, &size) != NO_ERROR) { u_free(fi); return 0; } + + int n = 0; + IP_ADDR_STRING* p = &fi->DnsServerList; + while (p && n < max) { + const char* s = p->IpAddress; + while (*s && n < max) { + while (*s == ' ' || *s == ',') s++; + char tok[64]; + int i = 0; + while (*s && *s != ' ' && *s != ',' && i < 63) tok[i++] = *s++; + tok[i] = '\0'; + memset(&out[n], 0, sizeof(out[n])); + if (tok[0] && inet_pton(AF_INET, tok, &out[n].sin_addr) == 1) { + out[n].sin_family = AF_INET; + out[n].sin_port = htons(53); + n++; + } + } + p = p->Next; + } + u_free(fi); + return n; +} +#else +int adns_system_servers(struct sockaddr_in* out, int max) { + if (!out || max <= 0) return 0; + FILE* f = fopen("/etc/resolv.conf", "r"); + if (!f) return 0; + char buf[4096]; + size_t rd = fread(buf, 1, sizeof(buf) - 1, f); + fclose(f); + buf[rd] = '\0'; + return adns_parse_resolv_conf(buf, out, max); +} +#endif + +/* ─── resolver setup ─── */ + +static struct dns_resolver* adns_open_resolver(const struct sockaddr_in* servers, int count, + int timeout_ms, int attempts) { + int error = 0; + struct dns_resolv_conf* rc = dns_resconf_open(&error); + if (!rc) { + DEBUG_ERROR(ADNS_DEBUG_CAT, "adns: dns_resconf_open failed: %s", dns_strerror(error)); + return NULL; + } + + for (int i = 0; i < count && i < 3; i++) { + struct sockaddr_storage* ss = &rc->nameserver[i]; + struct sockaddr_in* sin = (struct sockaddr_in*)ss; + memset(ss, 0, sizeof(*ss)); + sin->sin_family = AF_INET; + sin->sin_addr = servers[i].sin_addr; + sin->sin_port = servers[i].sin_port ? servers[i].sin_port : htons(53); + } + if (timeout_ms > 0) { + unsigned sec = (unsigned)((timeout_ms + 999) / 1000); + rc->options.timeout = sec ? sec : 1; + } + if (attempts > 0) rc->options.attempts = (unsigned)attempts; + + struct dns_hosts* hosts = dns_hosts_open(&error); + if (!hosts) { + DEBUG_ERROR(ADNS_DEBUG_CAT, "adns: dns_hosts_open failed: %s", dns_strerror(error)); + dns_resconf_close(rc); + return NULL; + } + + struct dns_hints* hints = dns_hints_local(rc, &error); + if (!hints) { + DEBUG_ERROR(ADNS_DEBUG_CAT, "adns: dns_hints_local failed: %s", dns_strerror(error)); + dns_hosts_close(hosts); + dns_resconf_close(rc); + return NULL; + } + + struct dns_resolver* res = dns_res_open(rc, hosts, hints, NULL, NULL, &error); + dns_resconf_close(rc); + dns_hosts_close(hosts); + dns_hints_close(hints); + + if (!res) + DEBUG_ERROR(ADNS_DEBUG_CAT, "adns: dns_res_open failed: %s", dns_strerror(error)); + return res; +} + +/* ─── driving state machine ─── */ + +static void adns_teardown(struct adns_query* q) { + if (q->timer) { uasync_cancel_timeout(q->ua, q->timer); q->timer = NULL; } + if (q->socket_id) { + uasync_remove_socket_t(q->ua, (socket_t)q->cur_fd); + q->socket_id = NULL; + } + q->cur_fd = -1; + if (q->res) { dns_res_close(q->res); q->res = NULL; } +} + +static void adns_rearm(struct adns_query* q) { + int fd = dns_res_pollfd(q->res); + int events = dns_res_events(q->res); + + if (fd != q->cur_fd) { + if (q->socket_id) { + uasync_remove_socket_t(q->ua, (socket_t)q->cur_fd); + q->socket_id = NULL; + } + q->cur_fd = -1; + if (fd >= 0) { + q->socket_id = uasync_add_socket_t(q->ua, (socket_t)fd, adns_read_cb, adns_write_cb, NULL, q); + if (q->socket_id) q->cur_fd = fd; + else DEBUG_ERROR(ADNS_DEBUG_CAT, "adns: uasync_add_socket_t(%d) failed", fd); + } + } + + if (q->socket_id) { + uasync_set_socket_read(q->ua, q->socket_id, (events & DNS_POLLIN) ? 1 : 0); + uasync_set_socket_write(q->ua, q->socket_id, (events & DNS_POLLOUT) ? 1 : 0); + } + + time_t t = dns_res_timeout(q->res); + if (t < 1) t = 1; + if (q->timer) { uasync_cancel_timeout(q->ua, q->timer); q->timer = NULL; } + q->timer = uasync_set_timeout(q->ua, (int)(t * 10000), q, adns_timer_cb, "adns"); + if (!q->timer) + DEBUG_ERROR(ADNS_DEBUG_CAT, "adns: uasync_set_timeout failed"); +} + +static void adns_drive(struct adns_query* q) { + if (q->finished) return; + + int error = dns_res_check(q->res); + if (error == 0) { + int ferr = 0; + struct dns_packet* answer = dns_res_fetch(q->res, &ferr); + if (!answer) { + DEBUG_ERROR(ADNS_DEBUG_CAT, "adns: '%s' dns_res_fetch failed: %s", q->name, dns_strerror(ferr)); + adns_finish(q, ADNS_ERR_RESPONSE, NULL, 0); + return; + } + + unsigned rcode = dns_p_rcode(answer); + if (rcode == DNS_RC_NOERROR) { + struct sockaddr_in addrs[ADNS_MAX_ADDRS]; + int n = 0; + struct dns_rr rr; + struct dns_a a; + dns_rr_foreach(&rr, answer, .section = DNS_S_AN, .type = DNS_T_A) { + if (n >= ADNS_MAX_ADDRS) break; + dns_a_parse(&a, &rr, answer); + memset(&addrs[n], 0, sizeof(addrs[n])); + addrs[n].sin_family = AF_INET; + addrs[n].sin_addr = a.addr; + n++; + } + free(answer); + if (n > 0) { + char ip[INET_ADDRSTRLEN]; + inet_ntop(AF_INET, &addrs[0].sin_addr, ip, sizeof(ip)); + DEBUG_INFO(ADNS_DEBUG_CAT, "adns: '%s' resolved to %d A record(s), first=%s", q->name, n, ip); + adns_finish(q, ADNS_OK, addrs, n); + } else { + DEBUG_WARN(ADNS_DEBUG_CAT, "adns: '%s' no A records (NOERROR, empty answer)", q->name); + adns_finish(q, ADNS_ERR_NODATA, NULL, 0); + } + } else { + const char* rc = dns_strrcode((enum dns_rcode)rcode); + if (rcode == DNS_RC_NXDOMAIN) { + free(answer); + DEBUG_WARN(ADNS_DEBUG_CAT, "adns: '%s' NXDOMAIN", q->name); + adns_finish(q, ADNS_ERR_NODATA, NULL, 0); + } else if (rcode == DNS_RC_SERVFAIL) { + /* libdns синтезирует SERVFAIL и при таймауте (ответа не получено) */ + const struct dns_stat* st = dns_res_stat(q->res); + int no_resp = st && st->udp.rcvd.count == 0; + free(answer); + if (no_resp) { + DEBUG_WARN(ADNS_DEBUG_CAT, "adns: '%s' timed out (no response from nameservers)", q->name); + adns_finish(q, ADNS_ERR_TIMEOUT, NULL, 0); + } else { + DEBUG_WARN(ADNS_DEBUG_CAT, "adns: '%s' SERVFAIL", q->name); + adns_finish(q, ADNS_ERR_RESPONSE, NULL, 0); + } + } else { + free(answer); + DEBUG_WARN(ADNS_DEBUG_CAT, "adns: '%s' rcode=%s — response error", q->name, rc); + adns_finish(q, ADNS_ERR_RESPONSE, NULL, 0); + } + } + return; + } + + if (error == EAGAIN) { + adns_rearm(q); + return; + } + + DEBUG_ERROR(ADNS_DEBUG_CAT, "adns: '%s' dns_res_check error=%d (%s)", q->name, error, dns_strerror(error)); + adns_finish(q, ADNS_ERR_RESPONSE, NULL, 0); +} + +static void adns_read_cb(socket_t sock, void* arg) { + (void)sock; + adns_drive((struct adns_query*)arg); +} + +static void adns_write_cb(socket_t sock, void* arg) { + (void)sock; + adns_drive((struct adns_query*)arg); +} + +static void adns_timer_cb(void* arg) { + struct adns_query* q = (struct adns_query*)arg; + q->timer = NULL; + adns_drive(q); +} + +static void adns_finish(struct adns_query* q, int status, struct sockaddr_in* addrs, int count) { + if (q->finished) return; + q->finished = 1; + + adns_teardown(q); + + struct adns_result res; + res.status = status; + res.count = count > 0 ? count : 0; + if (res.count > 0 && addrs) memcpy(res.addrs, addrs, (size_t)res.count * sizeof(*addrs)); + + adns_done_cb cb = q->cb; + void* arg = q->arg; + char* name = q->name; + q->name = NULL; + u_free(q); + + if (cb) cb(&res, arg); + u_free(name); +} + +/* ─── public API ─── */ + +struct adns_query* adns_resolve(struct UASYNC* ua, const char* name, + const struct adns_opts* opts, + adns_done_cb cb, void* arg) { + if (!ua || !name || !name[0] || !cb) return NULL; + if (strlen(name) > 255) { DEBUG_ERROR(ADNS_DEBUG_CAT, "adns: name too long"); return NULL; } + + struct sockaddr_in servers[3]; + int count; + if (opts && opts->server.sin_family != 0) { + servers[0] = opts->server; + count = 1; + } else { + count = adns_system_servers(servers, 3); + } + if (count <= 0) { + DEBUG_ERROR(ADNS_DEBUG_CAT, "adns: no DNS servers available for '%s'", name); + return NULL; + } + + int timeout_ms = (opts && opts->timeout_ms > 0) ? opts->timeout_ms : 2000; + int attempts = (opts && opts->max_attempts > 0) ? opts->max_attempts : 2; + + struct adns_query* q = u_calloc(1, sizeof(*q)); + if (!q) { DEBUG_ERROR(ADNS_DEBUG_CAT, "adns: calloc failed"); return NULL; } + q->ua = ua; + q->cb = cb; + q->arg = arg; + q->cur_fd = -1; + q->name = u_strdup(name); + if (!q->name) { u_free(q); DEBUG_ERROR(ADNS_DEBUG_CAT, "adns: strdup failed"); return NULL; } + + q->res = adns_open_resolver(servers, count, timeout_ms, attempts); + if (!q->res) { u_free(q->name); u_free(q); return NULL; } + + if (dns_res_submit(q->res, name, DNS_T_A, DNS_C_IN) != 0) { + DEBUG_ERROR(ADNS_DEBUG_CAT, "adns: dns_res_submit failed for '%s'", name); + dns_res_close(q->res); + u_free(q->name); + u_free(q); + return NULL; + } + + DEBUG_DEBUG(ADNS_DEBUG_CAT, "adns: resolving '%s' via %d server(s), timeout=%dms attempts=%d", + name, count, timeout_ms, attempts); + + adns_drive(q); + return q; +} + +void adns_cancel(struct adns_query* q) { + if (!q || q->finished) return; + q->finished = 1; + adns_teardown(q); + u_free(q->name); + u_free(q); +} diff --git a/lib/async_dns.h b/lib/async_dns.h new file mode 100644 index 00000000..9ebeea6b --- /dev/null +++ b/lib/async_dns.h @@ -0,0 +1,67 @@ +/* + * async_dns.h — асинхронный (неблокирующий) DNS-резолвер поверх uasync. + * + * Тонкий адаптер над libdns (lib/dns.c, MIT). Выполняет A-запросы без + * блокировки event loop: резолвер libdns управляется через uasync-сокеты и + * таймеры (интерфейс pollfd/events/timeout + submit/check/fetch). + * + * Поддерживает только A-записи (IPv4) — этого достаточно для NTP и текущего + * стека. TCP-fallback при truncation и компрессия имён — внутри libdns. + */ +#ifndef ASYNC_DNS_H +#define ASYNC_DNS_H + +#include "u_async.h" +#include "socket_compat.h" + +#ifdef __cplusplus +extern "C" { +#endif + +#define ADNS_OK 0 +#define ADNS_ERR_NOMEM -1 +#define ADNS_ERR_PARAM -2 +#define ADNS_ERR_NOSERV -3 /* нет ни одного DNS-сервера */ +#define ADNS_ERR_NODATA -4 /* NXDOMAIN или нет A-записей */ +#define ADNS_ERR_TIMEOUT -5 +#define ADNS_ERR_RESPONSE -6 /* malformed / SERVFAIL / прочая ошибка ответа */ + +#define ADNS_MAX_ADDRS 8 + +struct adns_result { + int status; + int count; + struct sockaddr_in addrs[ADNS_MAX_ADDRS]; /* AF_INET, sin_port = 0 */ +}; + +typedef void (*adns_done_cb)(const struct adns_result* res, void* arg); + +struct adns_opts { + struct sockaddr_in server; /* sin_family != 0 → использовать этот сервер (иначе системные) */ + int timeout_ms; /* таймаут на сервер, по умолчанию 2000 */ + int max_attempts; /* попыток на сервер, по умолчанию 2 */ +}; + +struct adns_query; /* opaque */ + +/* Запускает асинхронный A-запрос. Коллбэк вызывается в потоке event loop. + Возвращает handle (NULL при немедленной ошибке: невалидные аргументы/нет памяти). */ +struct adns_query* adns_resolve(struct UASYNC* ua, const char* name, + const struct adns_opts* opts, + adns_done_cb cb, void* arg); + +/* Отмена ожидающего запроса: коллбэк НЕ вызывается. Только из потока loop. */ +void adns_cancel(struct adns_query* q); + +/* Системные DNS-серверы (IPv4). Возвращает количество; out[].sin_port = htons(53). + Локальное чтение (resolv.conf / GetNetworkParams), без сети. */ +int adns_system_servers(struct sockaddr_in* out, int max); + +/* Чистый парсер текста resolv.conf ("nameserver ") — для юнит-тестов. */ +int adns_parse_resolv_conf(const char* text, struct sockaddr_in* out, int max); + +#ifdef __cplusplus +} +#endif + +#endif /* ASYNC_DNS_H */ diff --git a/lib/dns.c b/lib/dns.c new file mode 100644 index 00000000..9130a2aa --- /dev/null +++ b/lib/dns.c @@ -0,0 +1,9105 @@ +/* ========================================================================== + * dns.c - Recursive, Reentrant DNS Resolver. + * -------------------------------------------------------------------------- + * Copyright (c) 2008, 2009, 2010, 2012, 2013, 2014, 2015 William Ahern + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sublicense, and/or sell copies of the Software, and to permit + * persons to whom the Software is furnished to do so, subject to the + * following conditions: + * + * The above copyright notice and this permission notice shall be included + * in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN + * NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, + * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR + * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE + * USE OR OTHER DEALINGS IN THE SOFTWARE. + * ========================================================================== + */ +#if !defined(__FreeBSD__) && !defined(__sun) +#ifndef _XOPEN_SOURCE +#define _XOPEN_SOURCE 600 +#endif + +#undef _BSD_SOURCE +#define _BSD_SOURCE + +#undef _DARWIN_C_SOURCE +#define _DARWIN_C_SOURCE + +#undef _NETBSD_SOURCE +#define _NETBSD_SOURCE +#endif + +#include /* INT_MAX */ +#include /* offsetof() */ +#ifdef _WIN32 +#define uint32_t unsigned int +#else +#include /* uint32_t */ +#endif +#include /* malloc(3) realloc(3) free(3) rand(3) random(3) arc4random(3) */ +#include /* FILE fopen(3) fclose(3) getc(3) rewind(3) */ +#include /* memcpy(3) strlen(3) memmove(3) memchr(3) memcmp(3) strchr(3) strsep(3) strcspn(3) */ +#include /* strcasecmp(3) strncasecmp(3) */ +#include /* isspace(3) isdigit(3) */ +#include /* time_t time(2) difftime(3) */ +#include /* SIGPIPE sigemptyset(3) sigaddset(3) sigpending(2) sigprocmask(2) pthread_sigmask(3) sigtimedwait(2) */ +#include /* errno EINVAL ENOENT */ +#undef NDEBUG +#include /* assert(3) */ + +#if _WIN32 +#ifndef FD_SETSIZE +#define FD_SETSIZE 256 +#endif +#include +#include +#else +#include /* FD_SETSIZE socklen_t */ +#include /* FD_ZERO FD_SET fd_set select(2) */ +#include /* AF_INET AF_INET6 AF_UNIX struct sockaddr struct sockaddr_in struct sockaddr_in6 socket(2) */ +#if defined(AF_UNIX) +#include /* struct sockaddr_un */ +#endif +#include /* F_SETFD F_GETFL F_SETFL O_NONBLOCK fcntl(2) */ +#include /* _POSIX_THREADS gethostname(3) close(2) */ +#include /* POLLIN POLLOUT */ +#include /* struct sockaddr_in struct sockaddr_in6 */ +#include /* inet_pton(3) inet_ntop(3) htons(3) ntohs(3) */ +#include /* struct addrinfo */ +#endif + +#include "dns.h" + + +/* + * C O M P I L E R A N N O T A T I O N S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#define DNS_GNUC_PREREQ(M, m) \ + (defined __GNUC__ && ((__GNUC__ > M) || (__GNUC__ == M && __GNUC_MINOR__ >= m))) + +#ifndef HAVE_PRAGMA_MESSAGE +#define HAVE_PRAGMA_MESSAGE (DNS_GNUC_PREREQ(4, 4) || __clang__ || _MSC_VER) +#endif + +#if __GNUC__ +#define DNS_NOTUSED __attribute__((unused)) +#define DNS_NORETURN __attribute__((noreturn)) +#else +#define DNS_NOTUSED +#define DNS_NORETURN +#endif + +#if __clang__ +#pragma clang diagnostic push +#pragma clang diagnostic ignored "-Wunused-parameter" +#pragma clang diagnostic ignored "-Wmissing-field-initializers" +#elif DNS_GNUC_PREREQ(4, 6) +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wunused-parameter" +#pragma GCC diagnostic ignored "-Wmissing-field-initializers" +#endif + + +/* + * S T A N D A R D M A C R O S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#ifndef lengthof +#define lengthof(a) (sizeof (a) / sizeof (a)[0]) +#endif + +#ifndef endof +#define endof(a) (&(a)[lengthof((a))]) +#endif + + +/* + * M I S C E L L A N E O U S C O M P A T + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#if _WIN32 || _WIN64 +#define PRIuZ "Iu" +#else +#define PRIuZ "zu" +#endif + +#ifndef DNS_THREAD_SAFE +#if (defined _REENTRANT || defined _THREAD_SAFE) && _POSIX_THREADS > 0 +#define DNS_THREAD_SAFE 1 +#else +#define DNS_THREAD_SAFE 0 +#endif +#endif + + +/* + * D E B U G M A C R O S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +int dns_debug = 0; + +#if DNS_DEBUG + +#undef DNS_DEBUG +#define DNS_DEBUG dns_debug + +#define DNS_SAY_(fmt, ...) \ + do { if (DNS_DEBUG > 0) fprintf(stderr, fmt "%.1s", __func__, __LINE__, __VA_ARGS__); } while (0) +#define DNS_SAY(...) DNS_SAY_("@@ (%s:%d) " __VA_ARGS__, "\n") +#define DNS_HAI DNS_SAY("HAI") + +#define DNS_SHOW_(P, fmt, ...) do { \ + if (DNS_DEBUG > 1) { \ + fprintf(stderr, "@@ BEGIN * * * * * * * * * * * *\n"); \ + fprintf(stderr, "@@ " fmt "%.0s\n", __VA_ARGS__); \ + dns_p_dump((P), stderr); \ + fprintf(stderr, "@@ END * * * * * * * * * * * * *\n\n"); \ + } \ +} while (0) + +#define DNS_SHOW(...) DNS_SHOW_(__VA_ARGS__, "") + +#else /* !DNS_DEBUG */ + +#undef DNS_DEBUG +#define DNS_DEBUG 0 + +#define DNS_SAY(...) +#define DNS_HAI +#define DNS_SHOW(...) + +#endif /* DNS_DEBUG */ + + +/* + * V E R S I O N R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +const char *dns_vendor(void) { + return DNS_VENDOR; +} /* dns_vendor() */ + + +int dns_v_rel(void) { + return DNS_V_REL; +} /* dns_v_rel() */ + + +int dns_v_abi(void) { + return DNS_V_ABI; +} /* dns_v_abi() */ + + +int dns_v_api(void) { + return DNS_V_API; +} /* dns_v_api() */ + + +/* + * E R R O R R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#if _WIN32 + +#define DNS_EINTR WSAEINTR +#define DNS_EINPROGRESS WSAEINPROGRESS +#define DNS_EISCONN WSAEISCONN +#define DNS_EWOULDBLOCK WSAEWOULDBLOCK +#define DNS_EALREADY WSAEALREADY +#define DNS_EAGAIN EAGAIN +#define DNS_ETIMEDOUT WSAETIMEDOUT + +#define dns_syerr() ((int)GetLastError()) +#define dns_soerr() ((int)WSAGetLastError()) + +#else + +#define DNS_EINTR EINTR +#define DNS_EINPROGRESS EINPROGRESS +#define DNS_EISCONN EISCONN +#define DNS_EWOULDBLOCK EWOULDBLOCK +#define DNS_EALREADY EALREADY +#define DNS_EAGAIN EAGAIN +#define DNS_ETIMEDOUT ETIMEDOUT + +#define dns_syerr() errno +#define dns_soerr() errno + +#endif + + +const char *dns_strerror(int error) { + switch (error) { + case DNS_ENOBUFS: + return "DNS packet buffer too small"; + case DNS_EILLEGAL: + return "Illegal DNS RR name or data"; + case DNS_EORDER: + return "Attempt to push RR out of section order"; + case DNS_ESECTION: + return "Invalid section specified"; + case DNS_EUNKNOWN: + return "Unknown DNS error"; + case DNS_EADDRESS: + return "Invalid textual address form"; + case DNS_ENOQUERY: + return "Bad execution state (missing query packet)"; + case DNS_ENOANSWER: + return "Bad execution state (missing answer packet)"; + case DNS_EFETCHED: + return "Answer already fetched"; + case DNS_ESERVICE: + return "The service passed was not recognized for the specified socket type"; + case DNS_ENONAME: + return "The name does not resolve for the supplied parameters"; + case DNS_EFAIL: + return "A non-recoverable error occurred when attempting to resolve the name"; + default: + return strerror(error); + } /* switch() */ +} /* dns_strerror() */ + + +/* + * A T O M I C R O U T I N E S + * + * Use GCC's __atomic built-ins if possible. Unlike the __sync built-ins, we + * can use the preprocessor to detect API and, more importantly, ISA + * support. We want to avoid linking headaches where the API depends on an + * external library if the ISA (e.g. i386) doesn't support lockless + * operation. + * + * TODO: Support C11's atomic API. Although that may require some finesse + * with how we define some public types, such as dns_atomic_t and struct + * dns_resolv_conf. + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#ifndef HAVE___ATOMIC_FETCH_ADD +#define HAVE___ATOMIC_FETCH_ADD (defined __ATOMIC_RELAXED) +#endif + +#ifndef HAVE___ATOMIC_FETCH_SUB +#define HAVE___ATOMIC_FETCH_SUB HAVE___ATOMIC_FETCH_ADD +#endif + +#ifndef DNS_ATOMIC_FETCH_ADD +#if HAVE___ATOMIC_FETCH_ADD && __GCC_ATOMIC_LONG_LOCK_FREE == 2 +#define DNS_ATOMIC_FETCH_ADD(i) __atomic_fetch_add((i), 1, __ATOMIC_RELAXED) +#else +#pragma message("no atomic_fetch_add available") +#define DNS_ATOMIC_FETCH_ADD(i) ((*(i))++) +#endif +#endif + +#ifndef DNS_ATOMIC_FETCH_SUB +#if HAVE___ATOMIC_FETCH_SUB && __GCC_ATOMIC_LONG_LOCK_FREE == 2 +#define DNS_ATOMIC_FETCH_SUB(i) __atomic_fetch_sub((i), 1, __ATOMIC_RELAXED) +#else +#pragma message("no atomic_fetch_sub available") +#define DNS_ATOMIC_FETCH_SUB(i) ((*(i))--) +#endif +#endif + +static inline unsigned dns_atomic_fetch_add(dns_atomic_t *i) { + return DNS_ATOMIC_FETCH_ADD(i); +} /* dns_atomic_fetch_add() */ + + +static inline unsigned dns_atomic_fetch_sub(dns_atomic_t *i) { + return DNS_ATOMIC_FETCH_SUB(i); +} /* dns_atomic_fetch_sub() */ + + +/* + * C R Y P T O R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +/* + * P R N G + */ + +#ifndef DNS_RANDOM +#if defined(HAVE_ARC4RANDOM) \ + || defined(__OpenBSD__) \ + || defined(__FreeBSD__) \ + || defined(__NetBSD__) \ + || defined(__APPLE__) +#define DNS_RANDOM arc4random +#elif __linux +#define DNS_RANDOM random +#else +#define DNS_RANDOM rand +#endif +#endif + +#define DNS_RANDOM_arc4random 1 +#define DNS_RANDOM_random 2 +#define DNS_RANDOM_rand 3 +#define DNS_RANDOM_RAND_bytes 4 + +#define DNS_RANDOM_OPENSSL (DNS_RANDOM_RAND_bytes == DNS_PP_XPASTE(DNS_RANDOM_, DNS_RANDOM)) + +#if DNS_RANDOM_OPENSSL +#include +#endif + +static unsigned dns_random_(void) { +#if DNS_RANDOM_OPENSSL + unsigned r; + + assert(1 == RAND_bytes((unsigned char *)&r, sizeof r)); + + return r; +#else + return DNS_RANDOM(); +#endif +} /* dns_random_() */ + +unsigned (*dns_random)(void) __attribute__((weak)) = &dns_random_; + + +/* + * P E R M U T A T I O N G E N E R A T O R + */ + +#define DNS_K_TEA_KEY_SIZE 16 +#define DNS_K_TEA_BLOCK_SIZE 8 +#define DNS_K_TEA_CYCLES 32 +#define DNS_K_TEA_MAGIC 0x9E3779B9U + +struct dns_k_tea { + uint32_t key[DNS_K_TEA_KEY_SIZE / sizeof (uint32_t)]; + unsigned cycles; +}; /* struct dns_k_tea */ + + +static void dns_k_tea_init(struct dns_k_tea *tea, uint32_t key[], unsigned cycles) { + memcpy(tea->key, key, sizeof tea->key); + + tea->cycles = (cycles)? cycles : DNS_K_TEA_CYCLES; +} /* dns_k_tea_init() */ + + +static void dns_k_tea_encrypt(struct dns_k_tea *tea, uint32_t v[], uint32_t *w) { + uint32_t y, z, sum, n; + + y = v[0]; + z = v[1]; + sum = 0; + + for (n = 0; n < tea->cycles; n++) { + sum += DNS_K_TEA_MAGIC; + y += ((z << 4) + tea->key[0]) ^ (z + sum) ^ ((z >> 5) + tea->key[1]); + z += ((y << 4) + tea->key[2]) ^ (y + sum) ^ ((y >> 5) + tea->key[3]); + } + + w[0] = y; + w[1] = z; + + return /* void */; +} /* dns_k_tea_encrypt() */ + + +/* + * Permutation generator, based on a Luby-Rackoff Feistel construction. + * + * Specifically, this is a generic balanced Feistel block cipher using TEA + * (another block cipher) as the pseudo-random function, F. At best it's as + * strong as F (TEA), notwithstanding the seeding. F could be AES, SHA-1, or + * perhaps Bernstein's Salsa20 core; I am naively trying to keep things + * simple. + * + * The generator can create a permutation of any set of numbers, as long as + * the size of the set is an even power of 2. This limitation arises either + * out of an inherent property of balanced Feistel constructions, or by my + * own ignorance. I'll tackle an unbalanced construction after I wrap my + * head around Schneier and Kelsey's paper. + * + * CAVEAT EMPTOR. IANAC. + */ +#define DNS_K_PERMUTOR_ROUNDS 8 + +struct dns_k_permutor { + unsigned stepi, length, limit; + unsigned shift, mask, rounds; + + struct dns_k_tea tea; +}; /* struct dns_k_permutor */ + + +static inline unsigned dns_k_permutor_powof(unsigned n) { + unsigned m, i = 0; + + for (m = 1; m < n; m <<= 1, i++) + ;; + + return i; +} /* dns_k_permutor_powof() */ + +static void dns_k_permutor_init(struct dns_k_permutor *p, unsigned low, unsigned high) { + uint32_t key[DNS_K_TEA_KEY_SIZE / sizeof (uint32_t)]; + unsigned width, i; + + p->stepi = 0; + + p->length = (high - low) + 1; + p->limit = high; + + width = dns_k_permutor_powof(p->length); + width += width % 2; + + p->shift = width / 2; + p->mask = (1U << p->shift) - 1; + p->rounds = DNS_K_PERMUTOR_ROUNDS; + + for (i = 0; i < lengthof(key); i++) + key[i] = dns_random(); + + dns_k_tea_init(&p->tea, key, 0); + + return /* void */; +} /* dns_k_permutor_init() */ + + +static unsigned dns_k_permutor_F(struct dns_k_permutor *p, unsigned k, unsigned x) { + uint32_t in[DNS_K_TEA_BLOCK_SIZE / sizeof (uint32_t)], out[DNS_K_TEA_BLOCK_SIZE / sizeof (uint32_t)]; + + memset(in, '\0', sizeof in); + + in[0] = k; + in[1] = x; + + dns_k_tea_encrypt(&p->tea, in, out); + + return p->mask & out[0]; +} /* dns_k_permutor_F() */ + + +static unsigned dns_k_permutor_E(struct dns_k_permutor *p, unsigned n) { + unsigned l[2], r[2]; + unsigned i; + + i = 0; + l[i] = p->mask & (n >> p->shift); + r[i] = p->mask & (n >> 0); + + do { + l[(i + 1) % 2] = r[i % 2]; + r[(i + 1) % 2] = l[i % 2] ^ dns_k_permutor_F(p, i, r[i % 2]); + + i++; + } while (i < p->rounds - 1); + + return ((l[i % 2] & p->mask) << p->shift) | ((r[i % 2] & p->mask) << 0); +} /* dns_k_permutor_E() */ + + +DNS_NOTUSED static unsigned dns_k_permutor_D(struct dns_k_permutor *p, unsigned n) { + unsigned l[2], r[2]; + unsigned i; + + i = p->rounds - 1; + l[i % 2] = p->mask & (n >> p->shift); + r[i % 2] = p->mask & (n >> 0); + + do { + i--; + + r[i % 2] = l[(i + 1) % 2]; + l[i % 2] = r[(i + 1) % 2] ^ dns_k_permutor_F(p, i, l[(i + 1) % 2]); + } while (i > 0); + + return ((l[i % 2] & p->mask) << p->shift) | ((r[i % 2] & p->mask) << 0); +} /* dns_k_permutor_D() */ + + +static unsigned dns_k_permutor_step(struct dns_k_permutor *p) { + unsigned n; + + do { + n = dns_k_permutor_E(p, p->stepi++); + } while (n >= p->length); + + return n + (p->limit + 1 - p->length); +} /* dns_k_permutor_step() */ + + +/* + * Simple permutation box. Useful for shuffling rrsets from an iterator. + * Uses AES s-box to provide good diffusion. + * + * Seems to pass muster under runs test. + * + * $ for i in 0 1 2 3 4 5 6 7 8 9; do ./dns shuffle-16 > /tmp/out; done + * $ R -q -f /dev/stdin 2>/dev/null <<-EOF | awk '/p-value/{ print $8 }' + * library(lawstat) + * runs.test(scan(file="/tmp/out")) + * EOF + */ +static unsigned short dns_k_shuffle16(unsigned short n, unsigned s) { + static const unsigned char sbox[256] = + { 0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, + 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76, + 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, + 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, + 0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, + 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15, + 0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, + 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75, + 0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, + 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, + 0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, + 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf, + 0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, + 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8, + 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, + 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, + 0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, + 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73, + 0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, + 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb, + 0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, + 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, + 0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, + 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08, + 0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, + 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a, + 0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, + 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, + 0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, + 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, + 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, + 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 }; + unsigned char a, b; + unsigned i; + + a = 0xff & (n >> 0); + b = 0xff & (n >> 8); + + for (i = 0; i < 4; i++) { + a ^= 0xff & s; + a = sbox[a] ^ b; + b = sbox[b] ^ a; + s >>= 8; + } + + return ((0xff00 & (a << 8)) | (0x00ff & (b << 0))); +} /* dns_k_shuffle16() */ + + +/* + * U T I L I T Y R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#define DNS_MAXINTERVAL 300 + +struct dns_clock { + time_t sample, elapsed; +}; /* struct dns_clock */ + +static void dns_begin(struct dns_clock *clk) { + clk->sample = time(0); + clk->elapsed = 0; +} /* dns_begin() */ + +static time_t dns_elapsed(struct dns_clock *clk) { + time_t curtime; + + if ((time_t)-1 == time(&curtime)) + return clk->elapsed; + + if (curtime > clk->sample) + clk->elapsed += (time_t)DNS_PP_MIN(difftime(curtime, clk->sample), DNS_MAXINTERVAL); + + clk->sample = curtime; + + return clk->elapsed; +} /* dns_elapsed() */ + + +DNS_NOTUSED static size_t dns_strnlen(const char *src, size_t m) { + size_t n = 0; + + while (*src++ && n < m) + ++n; + + return n; +} /* dns_strnlen() */ + + +DNS_NOTUSED static size_t dns_strnlcpy(char *dst, size_t lim, const char *src, size_t max) { + size_t len = dns_strnlen(src, max), n; + + if (lim > 0) { + n = DNS_PP_MIN(lim - 1, len); + memcpy(dst, src, n); + dst[n] = '\0'; + } + + return len; +} /* dns_strnlcpy() */ + + +#define DNS_HAVE_SOCKADDR_UN (defined AF_UNIX && !defined _WIN32) + +static size_t dns_af_len(int af) { + static const size_t table[AF_MAX] = { + [AF_INET6] = sizeof (struct sockaddr_in6), + [AF_INET] = sizeof (struct sockaddr_in), +#if DNS_HAVE_SOCKADDR_UN + [AF_UNIX] = sizeof (struct sockaddr_un), +#endif + }; + + return table[af]; +} /* dns_af_len() */ + +#define dns_sa_family(sa) (((struct sockaddr *)(sa))->sa_family) + +#define dns_sa_len(sa) dns_af_len(dns_sa_family(sa)) + + +#define DNS_SA_NOPORT &dns_sa_noport +static unsigned short dns_sa_noport; + +static unsigned short *dns_sa_port(int af, void *sa) { + switch (af) { + case AF_INET6: + return &((struct sockaddr_in6 *)sa)->sin6_port; + case AF_INET: + return &((struct sockaddr_in *)sa)->sin_port; + default: + return DNS_SA_NOPORT; + } +} /* dns_sa_port() */ + + +static void *dns_sa_addr(int af, void *sa, socklen_t *size) { + switch (af) { + case AF_INET6: { + struct in6_addr *in6 = &((struct sockaddr_in6 *)sa)->sin6_addr; + + if (size) + *size = sizeof *in6; + + return in6; + } + case AF_INET: { + struct in_addr *in = &((struct sockaddr_in *)sa)->sin_addr; + + if (size) + *size = sizeof *in; + + return in; + } + default: + if (size) + *size = 0; + + return 0; + } +} /* dns_sa_addr() */ + + +#if DNS_HAVE_SOCKADDR_UN +#define DNS_SUNPATHMAX (sizeof ((struct sockaddr_un *)0)->sun_path) +#endif + +DNS_NOTUSED static void *dns_sa_path(void *sa, socklen_t *size) { + switch (dns_sa_family(sa)) { +#if DNS_HAVE_SOCKADDR_UN + case AF_UNIX: { + char *path = ((struct sockaddr_un *)sa)->sun_path; + + if (size) + *size = dns_strnlen(path, DNS_SUNPATHMAX); + + return path; + } +#endif + default: + if (size) + *size = 0; + + return NULL; + } +} /* dns_sa_path() */ + + +static int dns_sa_cmp(void *a, void *b) { + int cmp, af; + + if ((cmp = dns_sa_family(a) - dns_sa_family(b))) + return cmp; + + switch ((af = dns_sa_family(a))) { + case AF_INET: { + struct in_addr *a4, *b4; + + if ((cmp = htons(*dns_sa_port(af, a)) - htons(*dns_sa_port(af, b)))) + return cmp; + + a4 = dns_sa_addr(af, a, NULL); + b4 = dns_sa_addr(af, b, NULL); + + if (ntohl(a4->s_addr) < ntohl(b4->s_addr)) + return -1; + if (ntohl(a4->s_addr) > ntohl(b4->s_addr)) + return 1; + + return 0; + } + case AF_INET6: { + struct in6_addr *a6, *b6; + size_t i; + + if ((cmp = htons(*dns_sa_port(af, a)) - htons(*dns_sa_port(af, b)))) + return cmp; + + a6 = dns_sa_addr(af, a, NULL); + b6 = dns_sa_addr(af, b, NULL); + + /* XXX: do we need to use in6_clearscope()? */ + for (i = 0; i < sizeof a6->s6_addr; i++) { + if ((cmp = a6->s6_addr[i] - b6->s6_addr[i])) + return cmp; + } + + return 0; + } +#if DNS_HAVE_SOCKADDR_UN + case AF_UNIX: { + char a_path[DNS_SUNPATHMAX + 1], b_path[sizeof a_path]; + + dns_strnlcpy(a_path, sizeof a_path, dns_sa_path(a, NULL), DNS_SUNPATHMAX); + dns_strnlcpy(b_path, sizeof b_path, dns_sa_path(b, NULL), DNS_SUNPATHMAX); + + return strcmp(a_path, b_path); + } +#endif + default: + return -1; + } +} /* dns_sa_cmp() */ + + +#if _WIN32 +static int dns_inet_pton(int af, const void *src, void *dst) { + union { struct sockaddr_in sin; struct sockaddr_in6 sin6; } u; + + u.sin.sin_family = af; + + if (0 != WSAStringToAddressA((void *)src, af, (void *)0, (struct sockaddr *)&u, &(int){ sizeof u })) + return -1; + + switch (af) { + case AF_INET6: + *(struct in6_addr *)dst = u.sin6.sin6_addr; + + return 1; + case AF_INET: + *(struct in_addr *)dst = u.sin.sin_addr; + + return 1; + default: + return 0; + } +} /* dns_inet_pton() */ + +static const char *dns_inet_ntop(int af, const void *src, void *dst, unsigned long lim) { + union { struct sockaddr_in sin; struct sockaddr_in6 sin6; } u; + + /* NOTE: WSAAddressToString will print .sin_port unless zeroed. */ + memset(&u, 0, sizeof u); + + u.sin.sin_family = af; + + switch (af) { + case AF_INET6: + u.sin6.sin6_addr = *(struct in6_addr *)src; + break; + case AF_INET: + u.sin.sin_addr = *(struct in_addr *)src; + + break; + default: + return 0; + } + + if (0 != WSAAddressToStringA((struct sockaddr *)&u, dns_sa_len(&u), (void *)0, dst, &lim)) + return 0; + + return dst; +} /* dns_inet_ntop() */ +#else +#define dns_inet_pton(...) inet_pton(__VA_ARGS__) +#define dns_inet_ntop(...) inet_ntop(__VA_ARGS__) +#endif + + +static dns_error_t dns_pton(int af, const void *src, void *dst) { + switch (dns_inet_pton(af, src, dst)) { + case 1: + return 0; + case -1: + return dns_soerr(); + default: + return DNS_EADDRESS; + } +} /* dns_pton() */ + + +static dns_error_t dns_ntop(int af, const void *src, void *dst, unsigned long lim) { + return (dns_inet_ntop(af, src, dst, lim))? 0 : dns_soerr(); +} /* dns_ntop() */ + + +size_t dns_strlcpy(char *dst, const char *src, size_t lim) { + char *d = dst; + char *e = &dst[lim]; + const char *s = src; + + if (d < e) { + do { + if ('\0' == (*d++ = *s++)) + return s - src - 1; + } while (d < e); + + d[-1] = '\0'; + } + + while (*s++ != '\0') + ;; + + return s - src - 1; +} /* dns_strlcpy() */ + + +size_t dns_strlcat(char *dst, const char *src, size_t lim) { + char *d = memchr(dst, '\0', lim); + char *e = &dst[lim]; + const char *s = src; + const char *p; + + if (d && d < e) { + do { + if ('\0' == (*d++ = *s++)) + return d - dst - 1; + } while (d < e); + + d[-1] = '\0'; + } + + p = s; + + while (*s++ != '\0') + ;; + + return lim + (s - p - 1); +} /* dns_strlcat() */ + + +#if _WIN32 + +static char *dns_strsep(char **sp, const char *delim) { + char *p; + + if (!(p = *sp)) + return 0; + + *sp += strcspn(p, delim); + + if (**sp != '\0') { + **sp = '\0'; + ++*sp; + } else + *sp = NULL; + + return p; +} /* dns_strsep() */ + +#else +#define dns_strsep(...) strsep(__VA_ARGS__) +#endif + + +#if _WIN32 +#define strcasecmp(...) _stricmp(__VA_ARGS__) +#define strncasecmp(...) _strnicmp(__VA_ARGS__) +#endif + + +static int dns_poll(int fd, short events, int timeout) { + fd_set rset, wset; + + if (!events) + return 0; + + assert(fd >= 0 && (unsigned)fd < FD_SETSIZE); + + FD_ZERO(&rset); + FD_ZERO(&wset); + + if (events & DNS_POLLIN) + FD_SET(fd, &rset); + + if (events & DNS_POLLOUT) + FD_SET(fd, &wset); + + select(fd + 1, &rset, &wset, 0, (timeout >= 0)? &(struct timeval){ timeout, 0 } : NULL); + + return 0; +} /* dns_poll() */ + + +#if !_WIN32 +DNS_NOTUSED static int dns_sigmask(int how, const sigset_t *set, sigset_t *oset) { +#if DNS_THREAD_SAFE + return pthread_sigmask(how, set, oset); +#else + return (0 == sigprocmask(how, set, oset))? 0 : errno; +#endif +} /* dns_sigmask() */ +#endif + + +static long dns_send(int fd, const void *src, size_t lim, int flags) { +#if _WIN32 || !defined SIGPIPE || defined SO_NOSIGPIPE + return send(fd, src, lim, flags); +#elif defined MSG_NOSIGNAL + return send(fd, src, lim, flags|MSG_NOSIGNAL); +#elif _POSIX_REALTIME_SIGNALS > 0 /* require sigtimedwait */ + /* + * SIGPIPE handling similar to the approach described in + * http://krokisplace.blogspot.com/2010/02/suppressing-sigpipe-in-library.html + */ + sigset_t pending, blocked, piped; + long count; + int saved, error; + + sigemptyset(&pending); + sigpending(&pending); + + if (!sigismember(&pending, SIGPIPE)) { + sigemptyset(&piped); + sigaddset(&piped, SIGPIPE); + sigemptyset(&blocked); + + if ((error = dns_sigmask(SIG_BLOCK, &piped, &blocked))) + goto error; + } + + count = send(fd, src, lim, flags); + + if (!sigismember(&pending, SIGPIPE)) { + saved = errno; + + if (count == -1 && errno == EPIPE) { + while (-1 == sigtimedwait(&piped, NULL, &(struct timespec){ 0, 0 }) && errno == EINTR) + ;; + } + + if ((error = dns_sigmask(SIG_SETMASK, &blocked, NULL))) + goto error; + + errno = saved; + } + + return count; +error: + errno = error; + + return -1; +#else +#error "unable to suppress SIGPIPE" + return send(fd, src, lim, flags); +#endif +} /* dns_send() */ + + +/* + * P A C K E T R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +unsigned dns_p_count(struct dns_packet *P, enum dns_section section) { + unsigned count; + + switch (section) { + case DNS_S_QD: + return ntohs(dns_header(P)->qdcount); + case DNS_S_AN: + return ntohs(dns_header(P)->ancount); + case DNS_S_NS: + return ntohs(dns_header(P)->nscount); + case DNS_S_AR: + return ntohs(dns_header(P)->arcount); + default: + count = 0; + + if (section & DNS_S_QD) + count += ntohs(dns_header(P)->qdcount); + if (section & DNS_S_AN) + count += ntohs(dns_header(P)->ancount); + if (section & DNS_S_NS) + count += ntohs(dns_header(P)->nscount); + if (section & DNS_S_AR) + count += ntohs(dns_header(P)->arcount); + + return count; + } +} /* dns_p_count() */ + + +struct dns_packet *dns_p_init(struct dns_packet *P, size_t size) { + if (!P) + return 0; + + assert(size >= offsetof(struct dns_packet, data) + 12); + + memset(P, 0, sizeof *P); + P->size = size - offsetof(struct dns_packet, data); + P->end = 12; + + memset(P->data, '\0', 12); + + return P; +} /* dns_p_init() */ + + +static unsigned short dns_p_qend(struct dns_packet *P) { + unsigned short qend = 12; + unsigned i, count = dns_p_count(P, DNS_S_QD); + + for (i = 0; i < count && qend < P->end; i++) { + if (P->end == (qend = dns_d_skip(qend, P))) + goto invalid; + + if (P->end - qend < 4) + goto invalid; + + qend += 4; + } + + return DNS_PP_MIN(qend, P->end); +invalid: + return P->end; +} /* dns_p_qend() */ + + +struct dns_packet *dns_p_make(size_t len, int *error) { + struct dns_packet *P; + size_t size = dns_p_calcsize(len); + + if (!(P = dns_p_init(malloc(size), size))) + *error = dns_syerr(); + + return P; +} /* dns_p_make() */ + + +static void dns_p_free(struct dns_packet *P) { + free(P); +} /* dns_p_free() */ + + +/* convience routine to free any existing packet before storing new packet */ +static struct dns_packet *dns_p_setptr(struct dns_packet **dst, struct dns_packet *src) { + dns_p_free(*dst); + + *dst = src; + + return src; +} /* dns_p_setptr() */ + + +static struct dns_packet *dns_p_movptr(struct dns_packet **dst, struct dns_packet **src) { + dns_p_setptr(dst, *src); + + *src = NULL; + + return *dst; +} /* dns_p_movptr() */ + + +int dns_p_grow(struct dns_packet **P) { + struct dns_packet *tmp; + size_t size; + int error; + + if (!*P) { + if (!(*P = dns_p_make(DNS_P_QBUFSIZ, &error))) + return error; + + return 0; + } + + size = dns_p_sizeof(*P); + size |= size >> 1; + size |= size >> 2; + size |= size >> 4; + size |= size >> 8; + size++; + + if (size > 65536) + return DNS_ENOBUFS; + + if (!(tmp = realloc(*P, dns_p_calcsize(size)))) + return dns_syerr(); + + tmp->size = size; + *P = tmp; + + return 0; +} /* dns_p_grow() */ + + +struct dns_packet *dns_p_copy(struct dns_packet *P, const struct dns_packet *P0) { + if (!P) + return 0; + + P->end = DNS_PP_MIN(P->size, P0->end); + + memcpy(P->data, P0->data, P->end); + + return P; +} /* dns_p_copy() */ + + +struct dns_packet *dns_p_merge(struct dns_packet *A, enum dns_section Amask, struct dns_packet *B, enum dns_section Bmask, int *error_) { + size_t bufsiz = DNS_PP_MIN(65535, ((A)? A->end : 0) + ((B)? B->end : 0)); + struct dns_packet *M; + enum dns_section section; + struct dns_rr rr, mr; + int error, copy; + + if (!A && B) { + A = B; + Amask = Bmask; + B = 0; + } + +merge: + if (!(M = dns_p_make(bufsiz, &error))) + goto error; + + for (section = DNS_S_QD; (DNS_S_ALL & section); section <<= 1) { + if (A && (section & Amask)) { + dns_rr_foreach(&rr, A, .section = section) { + if ((error = dns_rr_copy(M, &rr, A))) + goto error; + } + } + + if (B && (section & Bmask)) { + dns_rr_foreach(&rr, B, .section = section) { + copy = 1; + + dns_rr_foreach(&mr, M, .type = rr.type, .section = DNS_S_ALL) { + if (!(copy = dns_rr_cmp(&rr, B, &mr, M))) + break; + } + + if (copy && (error = dns_rr_copy(M, &rr, B))) + goto error; + } + } + } + + return M; +error: + dns_p_setptr(&M, NULL); + + if (error == DNS_ENOBUFS && bufsiz < 65535) { + bufsiz = DNS_PP_MIN(65535, bufsiz * 2); + + goto merge; + } + + *error_ = error; + + return 0; +} /* dns_p_merge() */ + + +static unsigned short dns_l_skip(unsigned short, const unsigned char *, size_t); + +void dns_p_dictadd(struct dns_packet *P, unsigned short dn) { + unsigned short lp, lptr, i; + + lp = dn; + + while (lp < P->end) { + if (0xc0 == (0xc0 & P->data[lp]) && P->end - lp >= 2 && lp != dn) { + lptr = ((0x3f & P->data[lp + 0]) << 8) + | ((0xff & P->data[lp + 1]) << 0); + + for (i = 0; i < lengthof(P->dict) && P->dict[i]; i++) { + if (P->dict[i] == lptr) { + P->dict[i] = dn; + + return; + } + } + } + + lp = dns_l_skip(lp, P->data, P->end); + } + + for (i = 0; i < lengthof(P->dict); i++) { + if (!P->dict[i]) { + P->dict[i] = dn; + + break; + } + } +} /* dns_p_dictadd() */ + + +int dns_p_push(struct dns_packet *P, enum dns_section section, const void *dn, size_t dnlen, enum dns_type type, enum dns_class class, unsigned ttl, const void *any) { + size_t end = P->end; + int error; + + if ((error = dns_d_push(P, dn, dnlen))) + goto error; + + if (P->size - P->end < 4) + goto nobufs; + + P->data[P->end++] = 0xff & (type >> 8); + P->data[P->end++] = 0xff & (type >> 0); + + P->data[P->end++] = 0xff & (class >> 8); + P->data[P->end++] = 0xff & (class >> 0); + + if (section == DNS_S_QD) + goto update; + + if (P->size - P->end < 6) + goto nobufs; + + P->data[P->end++] = 0x7f & (ttl >> 24); + P->data[P->end++] = 0xff & (ttl >> 16); + P->data[P->end++] = 0xff & (ttl >> 8); + P->data[P->end++] = 0xff & (ttl >> 0); + + if ((error = dns_any_push(P, (union dns_any *)any, type))) + goto error; + +update: + switch (section) { + case DNS_S_QD: + if (dns_p_count(P, DNS_S_AN|DNS_S_NS|DNS_S_AR)) + goto order; + + if (!P->qd.base && (error = dns_p_study(P))) + goto error; + + dns_header(P)->qdcount = htons(ntohs(dns_header(P)->qdcount) + 1); + + P->qd.end = P->end; + P->an.base = P->end; + P->an.end = P->end; + P->ns.base = P->end; + P->ns.end = P->end; + P->ar.base = P->end; + P->ar.end = P->end; + + break; + case DNS_S_AN: + if (dns_p_count(P, DNS_S_NS|DNS_S_AR)) + goto order; + + if (!P->an.base && (error = dns_p_study(P))) + goto error; + + dns_header(P)->ancount = htons(ntohs(dns_header(P)->ancount) + 1); + + P->an.end = P->end; + P->ns.base = P->end; + P->ns.end = P->end; + P->ar.base = P->end; + P->ar.end = P->end; + + break; + case DNS_S_NS: + if (dns_p_count(P, DNS_S_AR)) + goto order; + + if (!P->ns.base && (error = dns_p_study(P))) + goto error; + + dns_header(P)->nscount = htons(ntohs(dns_header(P)->nscount) + 1); + + P->ns.end = P->end; + P->ar.base = P->end; + P->ar.end = P->end; + + break; + case DNS_S_AR: + if (!P->ar.base && (error = dns_p_study(P))) + goto error; + + dns_header(P)->arcount = htons(ntohs(dns_header(P)->arcount) + 1); + + P->ar.end = P->end; + + break; + default: + error = DNS_ESECTION; + + goto error; + } /* switch() */ + + return 0; +nobufs: + error = DNS_ENOBUFS; + + goto error; +order: + error = DNS_EORDER; + + goto error; +error: + P->end = end; + + return error; +} /* dns_p_push() */ + + +static void dns_p_dump3(struct dns_packet *P, struct dns_rr_i *I, FILE *fp) { + enum dns_section section; + struct dns_rr rr; + int error; + union dns_any any; + char pretty[sizeof any * 2]; + size_t len; + + fputs(";; [HEADER]\n", fp); + fprintf(fp, ";; qr : %s(%d)\n", (dns_header(P)->qr)? "RESPONSE" : "QUERY", dns_header(P)->qr); + fprintf(fp, ";; opcode : %s(%d)\n", dns_stropcode(dns_header(P)->opcode), dns_header(P)->opcode); + fprintf(fp, ";; aa : %s(%d)\n", (dns_header(P)->aa)? "AUTHORITATIVE" : "NON-AUTHORITATIVE", dns_header(P)->aa); + fprintf(fp, ";; tc : %s(%d)\n", (dns_header(P)->tc)? "TRUNCATED" : "NOT-TRUNCATED", dns_header(P)->tc); + fprintf(fp, ";; rd : %s(%d)\n", (dns_header(P)->rd)? "RECURSION-DESIRED" : "RECURSION-NOT-DESIRED", dns_header(P)->rd); + fprintf(fp, ";; ra : %s(%d)\n", (dns_header(P)->ra)? "RECURSION-ALLOWED" : "RECURSION-NOT-ALLOWED", dns_header(P)->ra); + fprintf(fp, ";; rcode : %s(%d)\n", dns_strrcode(dns_header(P)->rcode), dns_header(P)->rcode); + + section = 0; + + while (dns_rr_grep(&rr, 1, I, P, &error)) { + if (section != rr.section) + fprintf(fp, "\n;; [%s:%d]\n", dns_strsection(rr.section), dns_p_count(P, rr.section)); + + if ((len = dns_rr_print(pretty, sizeof pretty, &rr, P, &error))) + fprintf(fp, "%s\n", pretty); + + section = rr.section; + } +} /* dns_p_dump3() */ + + +void dns_p_dump(struct dns_packet *P, FILE *fp) { + dns_p_dump3(P, dns_rr_i_new(P, .section = 0), fp); +} /* dns_p_dump() */ + + +static void dns_s_unstudy(struct dns_s_memo *m) + { m->base = 0; m->end = 0; } + +static void dns_p_unstudy(struct dns_packet *P) { + dns_s_unstudy(&P->qd); + dns_s_unstudy(&P->an); + dns_s_unstudy(&P->ns); + dns_s_unstudy(&P->ar); +} /* dns_p_unstudy() */ + +static int dns_s_study(struct dns_s_memo *m, enum dns_section section, unsigned base, struct dns_packet *P) { + unsigned short count, rp; + + count = dns_p_count(P, section); + + for (rp = base; count && rp < P->end; count--) + rp = dns_rr_skip(rp, P); + + m->base = base; + m->end = rp; + + return 0; +} /* dns_s_study() */ + +int dns_p_study(struct dns_packet *P) { + int error; + + if ((error = dns_s_study(&P->qd, DNS_S_QD, 12, P))) + goto error; + + if ((error = dns_s_study(&P->an, DNS_S_AN, P->qd.end, P))) + goto error; + + if ((error = dns_s_study(&P->ns, DNS_S_NS, P->an.end, P))) + goto error; + + if ((error = dns_s_study(&P->ar, DNS_S_AR, P->ns.end, P))) + goto error; + + return 0; +error: + dns_p_unstudy(P); + + return error; +} /* dns_p_study() */ + + +/* + * D O M A I N N A M E R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#ifndef DNS_D_MAXPTRS +#define DNS_D_MAXPTRS 127 /* Arbitrary; possible, valid depth is something like packet size / 2 + fudge. */ +#endif + +static size_t dns_l_expand(unsigned char *dst, size_t lim, unsigned short src, unsigned short *nxt, const unsigned char *data, size_t end) { + unsigned short len; + unsigned nptrs = 0; + +retry: + if (src >= end) + goto invalid; + + switch (0x03 & (data[src] >> 6)) { + case 0x00: + len = (0x3f & (data[src++])); + + if (end - src < len) + goto invalid; + + if (lim > 0) { + memcpy(dst, &data[src], DNS_PP_MIN(lim, len)); + + dst[DNS_PP_MIN(lim - 1, len)] = '\0'; + } + + *nxt = src + len; + + return len; + case 0x01: + goto invalid; + case 0x02: + goto invalid; + case 0x03: + if (++nptrs > DNS_D_MAXPTRS) + goto invalid; + + if (end - src < 2) + goto invalid; + + src = ((0x3f & data[src + 0]) << 8) + | ((0xff & data[src + 1]) << 0); + + goto retry; + } /* switch() */ + + /* NOT REACHED */ +invalid: + *nxt = end; + + return 0; +} /* dns_l_expand() */ + + +static unsigned short dns_l_skip(unsigned short src, const unsigned char *data, size_t end) { + unsigned short len; + + if (src >= end) + goto invalid; + + switch (0x03 & (data[src] >> 6)) { + case 0x00: + len = (0x3f & (data[src++])); + + if (end - src < len) + goto invalid; + + return (len)? src + len : end; + case 0x01: + goto invalid; + case 0x02: + goto invalid; + case 0x03: + return end; + } /* switch() */ + + /* NOT REACHED */ +invalid: + return end; +} /* dns_l_skip() */ + + +size_t dns_d_trim(void *dst_, size_t lim, const void *src_, size_t len, int flags) { + unsigned char *dst = dst_; + const unsigned char *src = src_; + size_t dp = 0, sp = 0; + int lc; + + /* trim any leading dot(s) */ + while (sp < len && src[sp] == '.') + sp++; + + for (lc = 0; sp < len; lc = src[sp++]) { + /* trim extra dot(s) */ + if (src[sp] == '.' && lc == '.') + continue; + + if (dp < lim) + dst[dp] = src[sp]; + + dp++; + } + + if ((flags & DNS_D_ANCHOR) && lc != '.') { + if (dp < lim) + dst[dp] = '.'; + + dp++; + } + + if (lim > 0) + dst[DNS_PP_MIN(dp, lim - 1)] = '\0'; + + return dp; +} /* dns_d_trim() */ + + +char *dns_d_init(void *dst, size_t lim, const void *src, size_t len, int flags) { + if (flags & DNS_D_TRIM) { + dns_d_trim(dst, lim, src, len, flags); + } if (flags & DNS_D_ANCHOR) { + dns_d_anchor(dst, lim, src, len); + } else { + memmove(dst, src, DNS_PP_MIN(lim, len)); + + if (lim > 0) + ((char *)dst)[DNS_PP_MIN(len, lim - 1)] = '\0'; + } + + return dst; +} /* dns_d_init() */ + + +size_t dns_d_anchor(void *dst, size_t lim, const void *src, size_t len) { + if (len == 0) + return 0; + + memmove(dst, src, DNS_PP_MIN(lim, len)); + + if (((const char *)src)[len - 1] != '.') { + if (len < lim) + ((char *)dst)[len] = '.'; + len++; + } + + if (lim > 0) + ((char *)dst)[DNS_PP_MIN(lim - 1, len)] = '\0'; + + return len; +} /* dns_d_anchor() */ + + +size_t dns_d_cleave(void *dst, size_t lim, const void *src, size_t len) { + const char *dot; + + /* XXX: Skip any leading dot. Handles cleaving root ".". */ + if (len == 0 || !(dot = memchr((const char *)src + 1, '.', len - 1))) + return 0; + + len -= dot - (const char *)src; + + /* XXX: Unless root, skip the label's trailing dot. */ + if (len > 1) { + src = ++dot; + len--; + } else + src = dot; + + memmove(dst, src, DNS_PP_MIN(lim, len)); + + if (lim > 0) + ((char *)dst)[DNS_PP_MIN(lim - 1, len)] = '\0'; + + return len; +} /* dns_d_cleave() */ + + +size_t dns_d_comp(void *dst_, size_t lim, const void *src_, size_t len, struct dns_packet *P, int *error) { + struct { unsigned char *b; size_t p, x; } dst, src; + unsigned char ch = '.'; + + dst.b = dst_; + dst.p = 0; + dst.x = 1; + + src.b = (unsigned char *)src_; + src.p = 0; + src.x = 0; + + while (src.x < len) { + ch = src.b[src.x]; + + if (ch == '.') { + if (dst.p < lim) + dst.b[dst.p] = (0x3f & (src.x - src.p)); + + dst.p = dst.x++; + src.p = ++src.x; + } else { + if (dst.x < lim) + dst.b[dst.x] = ch; + + dst.x++; + src.x++; + } + } /* while() */ + + if (src.x > src.p) { + if (dst.p < lim) + dst.b[dst.p] = (0x3f & (src.x - src.p)); + + dst.p = dst.x; + } + + if (dst.p > 1) { + if (dst.p < lim) + dst.b[dst.p] = 0x00; + + dst.p++; + } + +#if 1 + if (dst.p < lim) { + struct { unsigned char label[DNS_D_MAXLABEL + 1]; size_t len; unsigned short p, x, y; } a, b; + unsigned i; + + a.p = 0; + + while ((a.len = dns_l_expand(a.label, sizeof a.label, a.p, &a.x, dst.b, lim))) { + for (i = 0; i < lengthof(P->dict) && P->dict[i]; i++) { + b.p = P->dict[i]; + + while ((b.len = dns_l_expand(b.label, sizeof b.label, b.p, &b.x, P->data, P->end))) { + a.y = a.x; + b.y = b.x; + + while (a.len && b.len && 0 == strcasecmp((char *)a.label, (char *)b.label)) { + a.len = dns_l_expand(a.label, sizeof a.label, a.y, &a.y, dst.b, lim); + b.len = dns_l_expand(b.label, sizeof b.label, b.y, &b.y, P->data, P->end); + } + + if (a.len == 0 && b.len == 0 && b.p <= 0x3fff) { + dst.b[a.p++] = 0xc0 + | (0x3f & (b.p >> 8)); + dst.b[a.p++] = (0xff & (b.p >> 0)); + + return a.p; + } + + b.p = b.x; + } /* while() */ + } /* for() */ + + a.p = a.x; + } /* while() */ + } /* if () */ +#endif + + if (!dst.p) + *error = DNS_EILLEGAL; + + return dst.p; +} /* dns_d_comp() */ + + +unsigned short dns_d_skip(unsigned short src, struct dns_packet *P) { + unsigned short len; + + while (src < P->end) { + switch (0x03 & (P->data[src] >> 6)) { + case 0x00: /* FOLLOWS */ + len = (0x3f & P->data[src++]); + + if (0 == len) { +/* success ==> */ return src; + } else if (P->end - src > len) { + src += len; + + break; + } else + goto invalid; + + /* NOT REACHED */ + case 0x01: /* RESERVED */ + goto invalid; + case 0x02: /* RESERVED */ + goto invalid; + case 0x03: /* POINTER */ + if (P->end - src < 2) + goto invalid; + + src += 2; + +/* success ==> */ return src; + } /* switch() */ + } /* while() */ + +invalid: + return P->end; +} /* dns_d_skip() */ + + +#include + +size_t dns_d_expand(void *dst, size_t lim, unsigned short src, struct dns_packet *P, int *error) { + size_t dstp = 0; + unsigned nptrs = 0; + unsigned char len; + + while (src < P->end) { + switch ((0x03 & (P->data[src] >> 6))) { + case 0x00: /* FOLLOWS */ + len = (0x3f & P->data[src]); + + if (0 == len) { + if (dstp == 0) { + if (dstp < lim) + ((unsigned char *)dst)[dstp] = '.'; + + dstp++; + } + + /* NUL terminate */ + if (lim > 0) + ((unsigned char *)dst)[DNS_PP_MIN(dstp, lim - 1)] = '\0'; + +/* success ==> */ return dstp; + } + + src++; + + if (P->end - src < len) + goto toolong; + + if (dstp < lim) + memcpy(&((unsigned char *)dst)[dstp], &P->data[src], DNS_PP_MIN(len, lim - dstp)); + + src += len; + dstp += len; + + if (dstp < lim) + ((unsigned char *)dst)[dstp] = '.'; + + dstp++; + + nptrs = 0; + + continue; + case 0x01: /* RESERVED */ + goto reserved; + case 0x02: /* RESERVED */ + goto reserved; + case 0x03: /* POINTER */ + if (++nptrs > DNS_D_MAXPTRS) + goto toolong; + + if (P->end - src < 2) + goto toolong; + + src = ((0x3f & P->data[src + 0]) << 8) + | ((0xff & P->data[src + 1]) << 0); + + continue; + } /* switch() */ + } /* while() */ + +toolong: + *error = DNS_EILLEGAL; + + if (lim > 0) + ((unsigned char *)dst)[DNS_PP_MIN(dstp, lim - 1)] = '\0'; + + return 0; +reserved: + *error = DNS_EILLEGAL; + + if (lim > 0) + ((unsigned char *)dst)[DNS_PP_MIN(dstp, lim - 1)] = '\0'; + + return 0; +} /* dns_d_expand() */ + + +int dns_d_push(struct dns_packet *P, const void *dn, size_t len) { + size_t lim = P->size - P->end; + unsigned dp = P->end; + int error = DNS_EILLEGAL; /* silence compiler */ + + len = dns_d_comp(&P->data[dp], lim, dn, len, P, &error); + + if (len == 0) + return error; + if (len > lim) + return DNS_ENOBUFS; + + P->end += len; + + dns_p_dictadd(P, dp); + + return 0; +} /* dns_d_push() */ + + +size_t dns_d_cname(void *dst, size_t lim, const void *dn, size_t len, struct dns_packet *P, int *error_) { + char host[DNS_D_MAXNAME + 1]; + struct dns_rr_i i; + struct dns_rr rr; + unsigned depth; + int error; + + if (sizeof host <= dns_d_anchor(host, sizeof host, dn, len)) + { error = ENAMETOOLONG; goto error; } + + for (depth = 0; depth < 7; depth++) { + dns_rr_i_init(memset(&i, 0, sizeof i), P); + + i.section = DNS_S_ALL & ~DNS_S_QD; + i.name = host; + i.type = DNS_T_CNAME; + + if (!dns_rr_grep(&rr, 1, &i, P, &error)) + break; + + if ((error = dns_cname_parse((struct dns_cname *)host, &rr, P))) + goto error; + } + + return dns_strlcpy(dst, host, lim); +error: + *error_ = error; + + return 0; +} /* dns_d_cname() */ + + +/* + * R E S O U R C E R E C O R D R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +int dns_rr_copy(struct dns_packet *P, struct dns_rr *rr, struct dns_packet *Q) { + unsigned char dn[DNS_D_MAXNAME + 1]; + union dns_any any; + size_t len; + int error; + + if (!(len = dns_d_expand(dn, sizeof dn, rr->dn.p, Q, &error))) + return error; + else if (len >= sizeof dn) + return DNS_EILLEGAL; + + if (rr->section != DNS_S_QD && (error = dns_any_parse(dns_any_init(&any, sizeof any), rr, Q))) + return error; + + return dns_p_push(P, rr->section, dn, len, rr->type, rr->class, rr->ttl, &any); +} /* dns_rr_copy() */ + + +int dns_rr_parse(struct dns_rr *rr, unsigned short src, struct dns_packet *P) { + unsigned short p = src; + + if (src >= P->end) + goto invalid; + + rr->dn.p = p; + rr->dn.len = (p = dns_d_skip(p, P)) - rr->dn.p; + + if (P->end - p < 4) + goto invalid; + + rr->type = ((0xff & P->data[p + 0]) << 8) + | ((0xff & P->data[p + 1]) << 0); + + rr->class = ((0xff & P->data[p + 2]) << 8) + | ((0xff & P->data[p + 3]) << 0); + + p += 4; + + if (src < dns_p_qend(P)) { + rr->section = DNS_S_QUESTION; + + rr->ttl = 0; + rr->rd.p = 0; + rr->rd.len = 0; + + return 0; + } + + if (P->end - p < 4) + goto invalid; + + rr->ttl = ((0x7f & P->data[p + 0]) << 24) + | ((0xff & P->data[p + 1]) << 16) + | ((0xff & P->data[p + 2]) << 8) + | ((0xff & P->data[p + 3]) << 0); + + p += 4; + + if (P->end - p < 2) + goto invalid; + + rr->rd.len = ((0xff & P->data[p + 0]) << 8) + | ((0xff & P->data[p + 1]) << 0); + rr->rd.p = p + 2; + + p += 2; + + if (P->end - p < rr->rd.len) + goto invalid; + + return 0; +invalid: + return DNS_EILLEGAL; +} /* dns_rr_parse() */ + + +static unsigned short dns_rr_len(const unsigned short src, struct dns_packet *P) { + unsigned short rp, rdlen; + + rp = dns_d_skip(src, P); + + if (P->end - rp < 4) + return P->end - src; + + rp += 4; /* TYPE, CLASS */ + + if (rp <= dns_p_qend(P)) + return rp - src; + + if (P->end - rp < 6) + return P->end - src; + + rp += 6; /* TTL, RDLEN */ + + rdlen = ((0xff & P->data[rp - 2]) << 8) + | ((0xff & P->data[rp - 1]) << 0); + + if (P->end - rp < rdlen) + return P->end - src; + + rp += rdlen; + + return rp - src; +} /* dns_rr_len() */ + + +unsigned short dns_rr_skip(unsigned short src, struct dns_packet *P) { + return src + dns_rr_len(src, P); +} /* dns_rr_skip() */ + + +static enum dns_section dns_rr_section(unsigned short src, struct dns_packet *P) { + enum dns_section section; + unsigned count, index; + unsigned short rp; + + if (src >= P->qd.base && src < P->qd.end) + return DNS_S_QD; + if (src >= P->an.base && src < P->an.end) + return DNS_S_AN; + if (src >= P->ns.base && src < P->ns.end) + return DNS_S_NS; + if (src >= P->ar.base && src < P->ar.end) + return DNS_S_AR; + + /* NOTE: Possibly bad memoization. Try it the hard-way. */ + + for (rp = 12, index = 0; rp < src && rp < P->end; index++) + rp = dns_rr_skip(rp, P); + + section = DNS_S_QD; + count = dns_p_count(P, section); + + while (index >= count && section <= DNS_S_AR) { + section <<= 1; + count += dns_p_count(P, section); + } + + return DNS_S_ALL & section; +} /* dns_rr_section() */ + + +static enum dns_type dns_rr_type(unsigned short src, struct dns_packet *P) { + struct dns_rr rr; + int error; + + if ((error = dns_rr_parse(&rr, src, P))) + return 0; + + return rr.type; +} /* dns_rr_type() */ + + +int dns_rr_cmp(struct dns_rr *r0, struct dns_packet *P0, struct dns_rr *r1, struct dns_packet *P1) { + char host0[DNS_D_MAXNAME + 1], host1[DNS_D_MAXNAME + 1]; + union dns_any any0, any1; + int cmp, error; + size_t len; + + if ((cmp = r0->type - r1->type)) + return cmp; + + if ((cmp = r0->class - r1->class)) + return cmp; + + /* + * FIXME: Do label-by-label comparison to handle illegally long names? + */ + + if (!(len = dns_d_expand(host0, sizeof host0, r0->dn.p, P0, &error)) + || len >= sizeof host0) + return -1; + + if (!(len = dns_d_expand(host1, sizeof host1, r1->dn.p, P1, &error)) + || len >= sizeof host1) + return 1; + + if ((cmp = strcasecmp(host0, host1))) + return cmp; + + if (DNS_S_QD & (r0->section | r1->section)) { + if (r0->section == r1->section) + return 0; + + return (r0->section == DNS_S_QD)? -1 : 1; + } + + if ((error = dns_any_parse(&any0, r0, P0))) + return -1; + + if ((error = dns_any_parse(&any1, r1, P1))) + return 1; + + return dns_any_cmp(&any0, r0->type, &any1, r1->type); +} /* dns_rr_cmp() */ + + +static _Bool dns_rr_exists(struct dns_rr *rr0, struct dns_packet *P0, struct dns_packet *P1) { + struct dns_rr rr1; + + dns_rr_foreach(&rr1, P1, .section = rr0->section, .type = rr0->type) { + if (0 == dns_rr_cmp(rr0, P0, &rr1, P1)) + return 1; + } + + return 0; +} /* dns_rr_exists() */ + + +static unsigned short dns_rr_offset(struct dns_rr *rr) { + return rr->dn.p; +} /* dns_rr_offset() */ + + +static _Bool dns_rr_i_match(struct dns_rr *rr, struct dns_rr_i *i, struct dns_packet *P) { + if (i->section && !(rr->section & i->section)) + return 0; + + if (i->type && rr->type != i->type && i->type != DNS_T_ALL) + return 0; + + if (i->class && rr->class != i->class && i->class != DNS_C_ANY) + return 0; + + if (i->name) { + char dn[DNS_D_MAXNAME + 1]; + size_t len; + int error; + + if (!(len = dns_d_expand(dn, sizeof dn, rr->dn.p, P, &error)) + || len >= sizeof dn) + return 0; + + if (0 != strcasecmp(dn, i->name)) + return 0; + } + + if (i->data && i->type && rr->section > DNS_S_QD) { + union dns_any rd; + int error; + + if ((error = dns_any_parse(&rd, rr, P))) + return 0; + + if (0 != dns_any_cmp(&rd, rr->type, i->data, i->type)) + return 0; + } + + return 1; +} /* dns_rr_i_match() */ + + +static unsigned short dns_rr_i_start(struct dns_rr_i *i, struct dns_packet *P) { + unsigned short rp; + struct dns_rr r0, rr; + int error; + + if ((i->section & DNS_S_QD) && P->qd.base) + rp = P->qd.base; + else if ((i->section & DNS_S_AN) && P->an.base) + rp = P->an.base; + else if ((i->section & DNS_S_NS) && P->ns.base) + rp = P->ns.base; + else if ((i->section & DNS_S_AR) && P->ar.base) + rp = P->ar.base; + else + rp = 12; + + for (; rp < P->end; rp = dns_rr_skip(rp, P)) { + if ((error = dns_rr_parse(&rr, rp, P))) + continue; + + rr.section = dns_rr_section(rp, P); + + if (!dns_rr_i_match(&rr, i, P)) + continue; + + r0 = rr; + + goto lower; + } + + return P->end; +lower: + if (i->sort == &dns_rr_i_packet) + return dns_rr_offset(&r0); + + while ((rp = dns_rr_skip(rp, P)) < P->end) { + if ((error = dns_rr_parse(&rr, rp, P))) + continue; + + rr.section = dns_rr_section(rp, P); + + if (!dns_rr_i_match(&rr, i, P)) + continue; + + if (i->sort(&rr, &r0, i, P) < 0) + r0 = rr; + } + + return dns_rr_offset(&r0); +} /* dns_rr_i_start() */ + + +static unsigned short dns_rr_i_skip(unsigned short rp, struct dns_rr_i *i, struct dns_packet *P) { + struct dns_rr r0, r1, rr; + int error; + + if ((error = dns_rr_parse(&r0, rp, P))) + return P->end; + + r0.section = dns_rr_section(rp, P); + + rp = (i->sort == &dns_rr_i_packet)? dns_rr_skip(rp, P) : 12; + + for (; rp < P->end; rp = dns_rr_skip(rp, P)) { + if ((error = dns_rr_parse(&rr, rp, P))) + continue; + + rr.section = dns_rr_section(rp, P); + + if (!dns_rr_i_match(&rr, i, P)) + continue; + + if (i->sort(&rr, &r0, i, P) <= 0) + continue; + + r1 = rr; + + goto lower; + } + + return P->end; +lower: + if (i->sort == &dns_rr_i_packet) + return dns_rr_offset(&r1); + + while ((rp = dns_rr_skip(rp, P)) < P->end) { + if ((error = dns_rr_parse(&rr, rp, P))) + continue; + + rr.section = dns_rr_section(rp, P); + + if (!dns_rr_i_match(&rr, i, P)) + continue; + + if (i->sort(&rr, &r0, i, P) <= 0) + continue; + + if (i->sort(&rr, &r1, i, P) >= 0) + continue; + + r1 = rr; + } + + return dns_rr_offset(&r1); +} /* dns_rr_i_skip() */ + + +int dns_rr_i_packet(struct dns_rr *a, struct dns_rr *b, struct dns_rr_i *i, struct dns_packet *P) { + (void)i; + (void)P; + + return (int)a->dn.p - (int)b->dn.p; +} /* dns_rr_i_packet() */ + + +int dns_rr_i_order(struct dns_rr *a, struct dns_rr *b, struct dns_rr_i *i, struct dns_packet *P) { + int cmp; + + (void)i; + + if ((cmp = a->section - b->section)) + return cmp; + + if (a->type != b->type) + return (int)a->dn.p - (int)b->dn.p; + + return dns_rr_cmp(a, P, b, P); +} /* dns_rr_i_order() */ + + +int dns_rr_i_shuffle(struct dns_rr *a, struct dns_rr *b, struct dns_rr_i *i, struct dns_packet *P) { + int cmp; + + (void)i; + (void)P; + + while (!i->state.regs[0]) + i->state.regs[0] = dns_random(); + + if ((cmp = a->section - b->section)) + return cmp; + + return dns_k_shuffle16(a->dn.p, i->state.regs[0]) - dns_k_shuffle16(b->dn.p, i->state.regs[0]); +} /* dns_rr_i_shuffle() */ + + +struct dns_rr_i *dns_rr_i_init(struct dns_rr_i *i, struct dns_packet *P) { + static const struct dns_rr_i i_initializer; + + (void)P; + + i->state = i_initializer.state; + i->saved = i->state; + + return i; +} /* dns_rr_i_init() */ + + +unsigned dns_rr_grep(struct dns_rr *rr, unsigned lim, struct dns_rr_i *i, struct dns_packet *P, int *error_) { + unsigned count = 0; + int error; + + switch (i->state.exec) { + case 0: + if (!i->sort) + i->sort = &dns_rr_i_packet; + + i->state.next = dns_rr_i_start(i, P); + i->state.exec++; + + /* FALL THROUGH */ + case 1: + while (count < lim && i->state.next < P->end) { + if ((error = dns_rr_parse(rr, i->state.next, P))) + goto error; + + rr->section = dns_rr_section(i->state.next, P); + + rr++; + count++; + i->state.count++; + + i->state.next = dns_rr_i_skip(i->state.next, i, P); + } /* while() */ + + break; + } /* switch() */ + + return count; +error: + *error_ = error; + + return count; +} /* dns_rr_grep() */ + + +static size_t dns__printchar(void *dst, size_t lim, size_t cp, unsigned char ch) { + if (cp < lim) + ((unsigned char *)dst)[cp] = ch; + + return 1; +} /* dns__printchar() */ + + +static size_t dns__printstring(void *dst, size_t lim, size_t cp, const void *src, size_t len) { + if (cp < lim) + memcpy(&((unsigned char *)dst)[cp], src, DNS_PP_MIN(len, lim - cp)); + + return len; +} /* dns__printstring() */ + +#define dns__printstring5(a, b, c, d, e) dns__printstring((a), (b), (c), (d), (e)) +#define dns__printstring4(a, b, c, d) dns__printstring((a), (b), (c), (d), strlen((d))) +#define dns__printstring(...) DNS_PP_CALL(DNS_PP_XPASTE(dns__printstring, DNS_PP_NARG(__VA_ARGS__)), __VA_ARGS__) + + +static void dns__printnul(void *dst, size_t lim, size_t off) { + if (lim > 0) + ((unsigned char *)dst)[DNS_PP_MIN(off, lim - 1)] = '\0'; +} /* dns__printnul() */ + + +static size_t dns__print10(void *dst, size_t lim, size_t off, unsigned n, unsigned pad) { + unsigned char tmp[32]; + unsigned dp = off; + unsigned cp = 0; + unsigned d = 1000000000; + unsigned ch; + + pad = DNS_PP_MAX(1, pad); + + while (d) { + if ((ch = n / d) || cp > 0) { + n -= ch * d; + + tmp[cp] = '0' + ch; + + cp++; + } + + d /= 10; + } + + while (cp < pad) { + dp += dns__printchar(dst, lim, dp, '0'); + pad--; + } + + dp += dns__printstring(dst, lim, dp, tmp, cp); + + return dp - off; +} /* dns__print10() */ + + +size_t dns_rr_print(void *dst, size_t lim, struct dns_rr *rr, struct dns_packet *P, int *error_) { + union dns_any any; + size_t cp, n, rdlen; + void *rd; + int error; + + cp = 0; + + if (rr->section == DNS_S_QD) + cp += dns__printchar(dst, lim, cp, ';'); + + if (!(n = dns_d_expand(&((unsigned char *)dst)[cp], (cp < lim)? lim - cp : 0, rr->dn.p, P, &error))) + goto error; + + cp += n; + + if (rr->section != DNS_S_QD) { + cp += dns__printchar(dst, lim, cp, ' '); + cp += dns__print10(dst, lim, cp, rr->ttl, 0); + } + + cp += dns__printchar(dst, lim, cp, ' '); + cp += dns__printstring(dst, lim, cp, dns_strclass(rr->class), strlen(dns_strclass(rr->class))); + cp += dns__printchar(dst, lim, cp, ' '); + cp += dns__printstring(dst, lim, cp, dns_strtype(rr->type), strlen(dns_strtype(rr->type))); + + if (rr->section == DNS_S_QD) + goto epilog; + + cp += dns__printchar(dst, lim, cp, ' '); + + if ((error = dns_any_parse(dns_any_init(&any, sizeof any), rr, P))) + goto error; + + if (cp < lim) { + rd = &((unsigned char *)dst)[cp]; + rdlen = lim - cp; + } else { + rd = 0; + rdlen = 0; + } + + cp += dns_any_print(rd, rdlen, &any, rr->type); + +epilog: + dns__printnul(dst, lim, cp); + + return cp; +error: + *error_ = error; + + return 0; +} /* dns_rr_print() */ + + +int dns_a_parse(struct dns_a *a, struct dns_rr *rr, struct dns_packet *P) { + unsigned long addr; + + if (rr->rd.len != 4) + return DNS_EILLEGAL; + + addr = ((0xff & P->data[rr->rd.p + 0]) << 24) + | ((0xff & P->data[rr->rd.p + 1]) << 16) + | ((0xff & P->data[rr->rd.p + 2]) << 8) + | ((0xff & P->data[rr->rd.p + 3]) << 0); + + a->addr.s_addr = htonl(addr); + + return 0; +} /* dns_a_parse() */ + + +int dns_a_push(struct dns_packet *P, struct dns_a *a) { + unsigned long addr; + + if (P->size - P->end < 6) + return DNS_ENOBUFS; + + P->data[P->end++] = 0x00; + P->data[P->end++] = 0x04; + + addr = ntohl(a->addr.s_addr); + + P->data[P->end++] = 0xff & (addr >> 24); + P->data[P->end++] = 0xff & (addr >> 16); + P->data[P->end++] = 0xff & (addr >> 8); + P->data[P->end++] = 0xff & (addr >> 0); + + return 0; +} /* dns_a_push() */ + + +size_t dns_a_arpa(void *dst, size_t lim, const struct dns_a *a) { + unsigned long a4 = ntohl(a->addr.s_addr); + size_t cp = 0; + unsigned i; + + for (i = 4; i > 0; i--) { + cp += dns__print10(dst, lim, cp, (0xff & a4), 0); + cp += dns__printchar(dst, lim, cp, '.'); + a4 >>= 8; + } + + cp += dns__printstring(dst, lim, cp, "in-addr.arpa."); + + dns__printnul(dst, lim, cp); + + return cp; +} /* dns_a_arpa() */ + + +int dns_a_cmp(const struct dns_a *a, const struct dns_a *b) { + if (ntohl(a->addr.s_addr) < ntohl(b->addr.s_addr)) + return -1; + if (ntohl(a->addr.s_addr) > ntohl(b->addr.s_addr)) + return 1; + + return 0; +} /* dns_a_cmp() */ + + +size_t dns_a_print(void *dst, size_t lim, struct dns_a *a) { + char addr[INET_ADDRSTRLEN + 1] = "0.0.0.0"; + size_t len; + + dns_inet_ntop(AF_INET, &a->addr, addr, sizeof addr); + + dns__printnul(dst, lim, (len = dns__printstring(dst, lim, 0, addr))); + + return len; +} /* dns_a_print() */ + + +int dns_aaaa_parse(struct dns_aaaa *aaaa, struct dns_rr *rr, struct dns_packet *P) { + if (rr->rd.len != sizeof aaaa->addr.s6_addr) + return DNS_EILLEGAL; + + memcpy(aaaa->addr.s6_addr, &P->data[rr->rd.p], sizeof aaaa->addr.s6_addr); + + return 0; +} /* dns_aaaa_parse() */ + + +int dns_aaaa_push(struct dns_packet *P, struct dns_aaaa *aaaa) { + if (P->size - P->end < 2 + sizeof aaaa->addr.s6_addr) + return DNS_ENOBUFS; + + P->data[P->end++] = 0x00; + P->data[P->end++] = 0x10; + + memcpy(&P->data[P->end], aaaa->addr.s6_addr, sizeof aaaa->addr.s6_addr); + + P->end += sizeof aaaa->addr.s6_addr; + + return 0; +} /* dns_aaaa_push() */ + + +int dns_aaaa_cmp(const struct dns_aaaa *a, const struct dns_aaaa *b) { + unsigned i; + int cmp; + + for (i = 0; i < lengthof(a->addr.s6_addr); i++) { + if ((cmp = (a->addr.s6_addr[i] - b->addr.s6_addr[i]))) + return cmp; + } + + return 0; +} /* dns_aaaa_cmp() */ + + +size_t dns_aaaa_arpa(void *dst, size_t lim, const struct dns_aaaa *aaaa) { + static const unsigned char hex[16] = "0123456789abcdef"; + size_t cp = 0; + unsigned nyble; + int i, j; + + for (i = sizeof aaaa->addr.s6_addr - 1; i >= 0; i--) { + nyble = aaaa->addr.s6_addr[i]; + + for (j = 0; j < 2; j++) { + cp += dns__printchar(dst, lim, cp, hex[0x0f & nyble]); + cp += dns__printchar(dst, lim, cp, '.'); + nyble >>= 4; + } + } + + cp += dns__printstring(dst, lim, cp, "ip6.arpa."); + + dns__printnul(dst, lim, cp); + + return cp; +} /* dns_aaaa_arpa() */ + + +size_t dns_aaaa_print(void *dst, size_t lim, struct dns_aaaa *aaaa) { + char addr[INET6_ADDRSTRLEN + 1] = "::"; + size_t len; + + dns_inet_ntop(AF_INET6, &aaaa->addr, addr, sizeof addr); + + dns__printnul(dst, lim, (len = dns__printstring(dst, lim, 0, addr))); + + return len; +} /* dns_aaaa_print() */ + + +int dns_mx_parse(struct dns_mx *mx, struct dns_rr *rr, struct dns_packet *P) { + size_t len; + int error; + + if (rr->rd.len < 3) + return DNS_EILLEGAL; + + mx->preference = (0xff00 & (P->data[rr->rd.p + 0] << 8)) + | (0x00ff & (P->data[rr->rd.p + 1] << 0)); + + if (!(len = dns_d_expand(mx->host, sizeof mx->host, rr->rd.p + 2, P, &error))) + return error; + else if (len >= sizeof mx->host) + return DNS_EILLEGAL; + + return 0; +} /* dns_mx_parse() */ + + +int dns_mx_push(struct dns_packet *P, struct dns_mx *mx) { + size_t end, len; + int error; + + if (P->size - P->end < 5) + return DNS_ENOBUFS; + + end = P->end; + P->end += 2; + + P->data[P->end++] = 0xff & (mx->preference >> 8); + P->data[P->end++] = 0xff & (mx->preference >> 0); + + if ((error = dns_d_push(P, mx->host, strlen(mx->host)))) + goto error; + + len = P->end - end - 2; + + P->data[end + 0] = 0xff & (len >> 8); + P->data[end + 1] = 0xff & (len >> 0); + + return 0; +error: + P->end = end; + + return error; +} /* dns_mx_push() */ + + +int dns_mx_cmp(const struct dns_mx *a, const struct dns_mx *b) { + int cmp; + + if ((cmp = a->preference - b->preference)) + return cmp; + + return strcasecmp(a->host, b->host); +} /* dns_mx_cmp() */ + + +size_t dns_mx_print(void *dst, size_t lim, struct dns_mx *mx) { + size_t cp = 0; + + cp += dns__print10(dst, lim, cp, mx->preference, 0); + cp += dns__printchar(dst, lim, cp, ' '); + cp += dns__printstring(dst, lim, cp, mx->host, strlen(mx->host)); + + dns__printnul(dst, lim, cp); + + return cp; +} /* dns_mx_print() */ + + +size_t dns_mx_cname(void *dst, size_t lim, struct dns_mx *mx) { + return dns_strlcpy(dst, mx->host, lim); +} /* dns_mx_cname() */ + + +int dns_ns_parse(struct dns_ns *ns, struct dns_rr *rr, struct dns_packet *P) { + size_t len; + int error; + + if (!(len = dns_d_expand(ns->host, sizeof ns->host, rr->rd.p, P, &error))) + return error; + else if (len >= sizeof ns->host) + return DNS_EILLEGAL; + + return 0; +} /* dns_ns_parse() */ + + +int dns_ns_push(struct dns_packet *P, struct dns_ns *ns) { + size_t end, len; + int error; + + if (P->size - P->end < 3) + return DNS_ENOBUFS; + + end = P->end; + P->end += 2; + + if ((error = dns_d_push(P, ns->host, strlen(ns->host)))) + goto error; + + len = P->end - end - 2; + + P->data[end + 0] = 0xff & (len >> 8); + P->data[end + 1] = 0xff & (len >> 0); + + return 0; +error: + P->end = end; + + return error; +} /* dns_ns_push() */ + + +int dns_ns_cmp(const struct dns_ns *a, const struct dns_ns *b) { + return strcasecmp(a->host, b->host); +} /* dns_ns_cmp() */ + + +size_t dns_ns_print(void *dst, size_t lim, struct dns_ns *ns) { + size_t cp; + + cp = dns__printstring(dst, lim, 0, ns->host, strlen(ns->host)); + + dns__printnul(dst, lim, cp); + + return cp; +} /* dns_ns_print() */ + + +size_t dns_ns_cname(void *dst, size_t lim, struct dns_ns *ns) { + return dns_strlcpy(dst, ns->host, lim); +} /* dns_ns_cname() */ + + +int dns_cname_parse(struct dns_cname *cname, struct dns_rr *rr, struct dns_packet *P) { + return dns_ns_parse((struct dns_ns *)cname, rr, P); +} /* dns_cname_parse() */ + + +int dns_cname_push(struct dns_packet *P, struct dns_cname *cname) { + return dns_ns_push(P, (struct dns_ns *)cname); +} /* dns_cname_push() */ + + +int dns_cname_cmp(const struct dns_cname *a, const struct dns_cname *b) { + return strcasecmp(a->host, b->host); +} /* dns_cname_cmp() */ + + +size_t dns_cname_print(void *dst, size_t lim, struct dns_cname *cname) { + return dns_ns_print(dst, lim, (struct dns_ns *)cname); +} /* dns_cname_print() */ + + +size_t dns_cname_cname(void *dst, size_t lim, struct dns_cname *cname) { + return dns_strlcpy(dst, cname->host, lim); +} /* dns_cname_cname() */ + + +int dns_soa_parse(struct dns_soa *soa, struct dns_rr *rr, struct dns_packet *P) { + struct { void *dst; size_t lim; } dn[] = + { { soa->mname, sizeof soa->mname }, + { soa->rname, sizeof soa->rname } }; + unsigned *ts[] = + { &soa->serial, &soa->refresh, &soa->retry, &soa->expire, &soa->minimum }; + unsigned short rp; + unsigned i, j, n; + int error; + + /* MNAME / RNAME */ + if ((rp = rr->rd.p) >= P->end) + return DNS_EILLEGAL; + + for (i = 0; i < lengthof(dn); i++) { + if (!(n = dns_d_expand(dn[i].dst, dn[i].lim, rp, P, &error))) + return error; + else if (n >= dn[i].lim) + return DNS_EILLEGAL; + + if ((rp = dns_d_skip(rp, P)) >= P->end) + return DNS_EILLEGAL; + } + + /* SERIAL / REFRESH / RETRY / EXPIRE / MINIMUM */ + for (i = 0; i < lengthof(ts); i++) { + for (j = 0; j < 4; j++, rp++) { + if (rp >= P->end) + return DNS_EILLEGAL; + + *ts[i] <<= 8; + *ts[i] |= (0xff & P->data[rp]); + } + } + + return 0; +} /* dns_soa_parse() */ + + +int dns_soa_push(struct dns_packet *P, struct dns_soa *soa) { + void *dn[] = { soa->mname, soa->rname }; + unsigned ts[] = { (0xffffffff & soa->serial), + (0x7fffffff & soa->refresh), + (0x7fffffff & soa->retry), + (0x7fffffff & soa->expire), + (0xffffffff & soa->minimum) }; + unsigned i, j; + size_t end, len; + int error; + + end = P->end; + + if ((P->end += 2) >= P->size) + goto toolong; + + /* MNAME / RNAME */ + for (i = 0; i < lengthof(dn); i++) { + if ((error = dns_d_push(P, dn[i], strlen(dn[i])))) + goto error; + } + + /* SERIAL / REFRESH / RETRY / EXPIRE / MINIMUM */ + for (i = 0; i < lengthof(ts); i++) { + if ((P->end += 4) >= P->size) + goto toolong; + + for (j = 1; j <= 4; j++) { + P->data[P->end - j] = (0xff & ts[i]); + ts[i] >>= 8; + } + } + + len = P->end - end - 2; + P->data[end + 0] = (0xff & (len >> 8)); + P->data[end + 1] = (0xff & (len >> 0)); + + return 0; +toolong: + error = DNS_ENOBUFS; + + /* FALL THROUGH */ +error: + P->end = end; + + return error; +} /* dns_soa_push() */ + + +int dns_soa_cmp(const struct dns_soa *a, const struct dns_soa *b) { + int cmp; + + if ((cmp = strcasecmp(a->mname, b->mname))) + return cmp; + + if ((cmp = strcasecmp(a->rname, b->rname))) + return cmp; + + if (a->serial > b->serial) + return -1; + else if (a->serial < b->serial) + return 1; + + if (a->refresh > b->refresh) + return -1; + else if (a->refresh < b->refresh) + return 1; + + if (a->retry > b->retry) + return -1; + else if (a->retry < b->retry) + return 1; + + if (a->expire > b->expire) + return -1; + else if (a->expire < b->expire) + return 1; + + if (a->minimum > b->minimum) + return -1; + else if (a->minimum < b->minimum) + return 1; + + return 0; +} /* dns_soa_cmp() */ + + +size_t dns_soa_print(void *dst, size_t lim, struct dns_soa *soa) { + size_t cp = 0; + + cp += dns__printstring(dst, lim, cp, soa->mname, strlen(soa->mname)); + cp += dns__printchar(dst, lim, cp, ' '); + cp += dns__printstring(dst, lim, cp, soa->rname, strlen(soa->rname)); + cp += dns__printchar(dst, lim, cp, ' '); + cp += dns__print10(dst, lim, cp, soa->serial, 0); + cp += dns__printchar(dst, lim, cp, ' '); + cp += dns__print10(dst, lim, cp, soa->refresh, 0); + cp += dns__printchar(dst, lim, cp, ' '); + cp += dns__print10(dst, lim, cp, soa->retry, 0); + cp += dns__printchar(dst, lim, cp, ' '); + cp += dns__print10(dst, lim, cp, soa->expire, 0); + cp += dns__printchar(dst, lim, cp, ' '); + cp += dns__print10(dst, lim, cp, soa->minimum, 0); + + dns__printnul(dst, lim, cp); + + return cp; +} /* dns_soa_print() */ + + +int dns_srv_parse(struct dns_srv *srv, struct dns_rr *rr, struct dns_packet *P) { + unsigned short rp; + unsigned i; + size_t n; + int error; + + memset(srv, '\0', sizeof *srv); + + rp = rr->rd.p; + + if (rr->rd.len < 7) + return DNS_EILLEGAL; + + for (i = 0; i < 2; i++, rp++) { + srv->priority <<= 8; + srv->priority |= (0xff & P->data[rp]); + } + + for (i = 0; i < 2; i++, rp++) { + srv->weight <<= 8; + srv->weight |= (0xff & P->data[rp]); + } + + for (i = 0; i < 2; i++, rp++) { + srv->port <<= 8; + srv->port |= (0xff & P->data[rp]); + } + + if (!(n = dns_d_expand(srv->target, sizeof srv->target, rp, P, &error))) + return error; + else if (n >= sizeof srv->target) + return DNS_EILLEGAL; + + return 0; +} /* dns_srv_parse() */ + + +int dns_srv_push(struct dns_packet *P, struct dns_srv *srv) { + size_t end, len; + int error; + + end = P->end; + + if (P->size - P->end < 2) + goto toolong; + + P->end += 2; + + if (P->size - P->end < 6) + goto toolong; + + P->data[P->end++] = 0xff & (srv->priority >> 8); + P->data[P->end++] = 0xff & (srv->priority >> 0); + + P->data[P->end++] = 0xff & (srv->weight >> 8); + P->data[P->end++] = 0xff & (srv->weight >> 0); + + P->data[P->end++] = 0xff & (srv->port >> 8); + P->data[P->end++] = 0xff & (srv->port >> 0); + + if (0 == (len = dns_d_comp(&P->data[P->end], P->size - P->end, srv->target, strlen(srv->target), P, &error))) + goto error; + else if (P->size - P->end < len) + goto toolong; + + P->end += len; + + if (P->end > 65535) + goto toolong; + + len = P->end - end - 2; + + P->data[end + 0] = 0xff & (len >> 8); + P->data[end + 1] = 0xff & (len >> 0); + + return 0; +toolong: + error = DNS_ENOBUFS; + + /* FALL THROUGH */ +error: + P->end = end; + + return error; +} /* dns_srv_push() */ + + +int dns_srv_cmp(const struct dns_srv *a, const struct dns_srv *b) { + int cmp; + + if ((cmp = a->priority - b->priority)) + return cmp; + + /* + * FIXME: We need some sort of random seed to implement the dynamic + * weighting required by RFC 2782. + */ + if ((cmp = a->weight - b->weight)) + return cmp; + + if ((cmp = a->port - b->port)) + return cmp; + + return strcasecmp(a->target, b->target); +} /* dns_srv_cmp() */ + + +size_t dns_srv_print(void *dst, size_t lim, struct dns_srv *srv) { + size_t cp = 0; + + cp += dns__print10(dst, lim, cp, srv->priority, 0); + cp += dns__printchar(dst, lim, cp, ' '); + cp += dns__print10(dst, lim, cp, srv->weight, 0); + cp += dns__printchar(dst, lim, cp, ' '); + cp += dns__print10(dst, lim, cp, srv->port, 0); + cp += dns__printchar(dst, lim, cp, ' '); + cp += dns__printstring(dst, lim, cp, srv->target, strlen(srv->target)); + + dns__printnul(dst, lim, cp); + + return cp; +} /* dns_srv_print() */ + + +size_t dns_srv_cname(void *dst, size_t lim, struct dns_srv *srv) { + return dns_strlcpy(dst, srv->target, lim); +} /* dns_srv_cname() */ + + +unsigned int dns_opt_ttl(const struct dns_opt *opt) { + unsigned int ttl = 0; + + ttl |= (0xffU & opt->rcode) << 24U; + ttl |= (0xffU & opt->version) << 16U; + + return ttl; +} /* dns_opt_ttl() */ + + +unsigned short dns_opt_class(const struct dns_opt *opt) { + return opt->maxsize; +} /* dns_opt_class() */ + + +struct dns_opt *dns_opt_init(struct dns_opt *opt, size_t size) { + assert(size >= offsetof(struct dns_opt, data)); + + opt->size = size - offsetof(struct dns_opt, data); + opt->len = 0; + + opt->rcode = 0; + opt->version = 0; + opt->maxsize = 512; + + return opt; +} /* dns_opt_init() */ + + +int dns_opt_parse(struct dns_opt *opt, struct dns_rr *rr, struct dns_packet *P) { + (void)rr; + (void)P; + + opt->len = 0; + + return 0; +} /* dns_opt_parse() */ + + +int dns_opt_push(struct dns_packet *P, struct dns_opt *opt) { + (void)P; + (void)opt; + + return 0; +} /* dns_opt_push() */ + + +int dns_opt_cmp(const struct dns_opt *a, const struct dns_opt *b) { + (void)a; + (void)b; + + return 0; +} /* dns_opt_cmp() */ + + +size_t dns_opt_print(void *dst, size_t lim, struct dns_opt *opt) { + size_t p = 0, src; + + p += dns__printchar(dst, lim, p, '"'); + + for (src = 0; src < opt->len; src++) { + p += dns__printchar(dst, lim, p, '\\'); + p += dns__print10(dst, lim, p, opt->data[src], 3); + } + + p += dns__printchar(dst, lim, p, '"'); + + dns__printnul(dst, lim, p); + + return p; +} /* dns_opt_print() */ + + +int dns_ptr_parse(struct dns_ptr *ptr, struct dns_rr *rr, struct dns_packet *P) { + return dns_ns_parse((struct dns_ns *)ptr, rr, P); +} /* dns_ptr_parse() */ + + +int dns_ptr_push(struct dns_packet *P, struct dns_ptr *ptr) { + return dns_ns_push(P, (struct dns_ns *)ptr); +} /* dns_ptr_push() */ + + +size_t dns_ptr_qname(void *dst, size_t lim, int af, void *addr) { + unsigned len = (af == AF_INET6) + ? dns_aaaa_arpa(dst, lim, addr) + : dns_a_arpa(dst, lim, addr); + + dns__printnul(dst, lim, len); + + return len; +} /* dns_ptr_qname() */ + + +int dns_ptr_cmp(const struct dns_ptr *a, const struct dns_ptr *b) { + return strcasecmp(a->host, b->host); +} /* dns_ptr_cmp() */ + + +size_t dns_ptr_print(void *dst, size_t lim, struct dns_ptr *ptr) { + return dns_ns_print(dst, lim, (struct dns_ns *)ptr); +} /* dns_ptr_print() */ + + +size_t dns_ptr_cname(void *dst, size_t lim, struct dns_ptr *ptr) { + return dns_strlcpy(dst, ptr->host, lim); +} /* dns_ptr_cname() */ + + +int dns_sshfp_parse(struct dns_sshfp *fp, struct dns_rr *rr, struct dns_packet *P) { + unsigned p = rr->rd.p, pe = rr->rd.p + rr->rd.len; + + if (pe - p < 2) + return DNS_EILLEGAL; + + fp->algo = P->data[p++]; + fp->type = P->data[p++]; + + switch (fp->type) { + case DNS_SSHFP_SHA1: + if (pe - p < sizeof fp->digest.sha1) + return DNS_EILLEGAL; + + memcpy(fp->digest.sha1, &P->data[p], sizeof fp->digest.sha1); + + break; + default: + break; + } /* switch() */ + + return 0; +} /* dns_sshfp_parse() */ + + +int dns_sshfp_push(struct dns_packet *P, struct dns_sshfp *fp) { + unsigned p = P->end, pe = P->size, n; + + if (pe - p < 4) + return DNS_ENOBUFS; + + p += 2; + P->data[p++] = 0xff & fp->algo; + P->data[p++] = 0xff & fp->type; + + switch (fp->type) { + case DNS_SSHFP_SHA1: + if (pe - p < sizeof fp->digest.sha1) + return DNS_ENOBUFS; + + memcpy(&P->data[p], fp->digest.sha1, sizeof fp->digest.sha1); + p += sizeof fp->digest.sha1; + + break; + default: + return DNS_EILLEGAL; + } /* switch() */ + + n = p - P->end - 2; + P->data[P->end++] = 0xff & (n >> 8); + P->data[P->end++] = 0xff & (n >> 0); + P->end = p; + + return 0; +} /* dns_sshfp_push() */ + + +int dns_sshfp_cmp(const struct dns_sshfp *a, const struct dns_sshfp *b) { + int cmp; + + if ((cmp = a->algo - b->algo) || (cmp = a->type - b->type)) + return cmp; + + switch (a->type) { + case DNS_SSHFP_SHA1: + return memcmp(a->digest.sha1, b->digest.sha1, sizeof a->digest.sha1); + default: + return 0; + } /* switch() */ + + /* NOT REACHED */ +} /* dns_sshfp_cmp() */ + + +size_t dns_sshfp_print(void *dst, size_t lim, struct dns_sshfp *fp) { + static const unsigned char hex[16] = "0123456789abcdef"; + size_t i, p = 0; + + p += dns__print10(dst, lim, p, fp->algo, 0); + p += dns__printchar(dst, lim, p, ' '); + p += dns__print10(dst, lim, p, fp->type, 0); + p += dns__printchar(dst, lim, p, ' '); + + switch (fp->type) { + case DNS_SSHFP_SHA1: + for (i = 0; i < sizeof fp->digest.sha1; i++) { + p += dns__printchar(dst, lim, p, hex[0x0f & (fp->digest.sha1[i] >> 4)]); + p += dns__printchar(dst, lim, p, hex[0x0f & (fp->digest.sha1[i] >> 0)]); + } + + break; + default: + p += dns__printchar(dst, lim, p, '0'); + + break; + } /* switch() */ + + dns__printnul(dst, lim, p); + + return p; +} /* dns_sshfp_print() */ + + +struct dns_txt *dns_txt_init(struct dns_txt *txt, size_t size) { + assert(size > offsetof(struct dns_txt, data)); + + txt->size = size - offsetof(struct dns_txt, data); + txt->len = 0; + + return txt; +} /* dns_txt_init() */ + + +int dns_txt_parse(struct dns_txt *txt, struct dns_rr *rr, struct dns_packet *P) { + struct { unsigned char *b; size_t p, end; } dst, src; + unsigned n; + + dst.b = txt->data; + dst.p = 0; + dst.end = txt->size; + + src.b = P->data; + src.p = rr->rd.p; + src.end = src.p + rr->rd.len; + + while (src.p < src.end) { + n = 0xff & P->data[src.p++]; + + if (src.end - src.p < n || dst.end - dst.p < n) + return DNS_EILLEGAL; + + memcpy(&dst.b[dst.p], &src.b[src.p], n); + + dst.p += n; + src.p += n; + } + + txt->len = dst.p; + + return 0; +} /* dns_txt_parse() */ + + +int dns_txt_push(struct dns_packet *P, struct dns_txt *txt) { + struct { unsigned char *b; size_t p, end; } dst, src; + unsigned n; + + dst.b = P->data; + dst.p = P->end; + dst.end = P->size; + + src.b = txt->data; + src.p = 0; + src.end = txt->len; + + if (dst.end - dst.p < 2) + return DNS_ENOBUFS; + + n = txt->len + ((txt->len + 254) / 255); + + dst.b[dst.p++] = 0xff & (n >> 8); + dst.b[dst.p++] = 0xff & (n >> 0); + + while (src.p < src.end) { + n = DNS_PP_MIN(255, src.end - src.p); + + if (dst.p >= dst.end) + return DNS_ENOBUFS; + + dst.b[dst.p++] = n; + + if (dst.end - dst.p < n) + return DNS_ENOBUFS; + + memcpy(&dst.b[dst.p], &src.b[src.p], n); + + dst.p += n; + src.p += n; + } + + P->end = dst.p; + + return 0; +} /* dns_txt_push() */ + + +int dns_txt_cmp(const struct dns_txt *a, const struct dns_txt *b) { + (void)a; + (void)b; + + return -1; +} /* dns_txt_cmp() */ + + +size_t dns_txt_print(void *dst_, size_t lim, struct dns_txt *txt) { + struct { unsigned char *b; size_t p, end; } dst, src; + unsigned ch; + + dst.b = dst_; + dst.end = lim; + dst.p = 0; + + src.b = txt->data; + src.end = txt->len; + src.p = 0; + + dst.p += dns__printchar(dst.b, dst.end, dst.p, '"'); + + while (src.p < src.end) { + ch = src.b[src.p]; + + if (0 == (src.p++ % 255) && src.p != 1) { + dst.p += dns__printchar(dst.b, dst.end, dst.p, '"'); + dst.p += dns__printchar(dst.b, dst.end, dst.p, ' '); + dst.p += dns__printchar(dst.b, dst.end, dst.p, '"'); + } + + if (ch < 32 || ch > 126 || ch == '"' || ch == '\\') { + dst.p += dns__printchar(dst.b, dst.end, dst.p, '\\'); + dst.p += dns__print10(dst.b, dst.end, dst.p, ch, 3); + } else { + dst.p += dns__printchar(dst.b, dst.end, dst.p, ch); + } + } + + dst.p += dns__printchar(dst.b, dst.end, dst.p, '"'); + + dns__printnul(dst.b, dst.end, dst.p); + + return dst.p; +} /* dns_txt_print() */ + + +static const struct { + enum dns_type type; + const char *name; + int (*parse)(); + int (*push)(); + int (*cmp)(); + size_t (*print)(); + size_t (*cname)(); +} dns_rrtypes[] = { + { DNS_T_A, "A", &dns_a_parse, &dns_a_push, &dns_a_cmp, &dns_a_print, 0 }, + { DNS_T_AAAA, "AAAA", &dns_aaaa_parse, &dns_aaaa_push, &dns_aaaa_cmp, &dns_aaaa_print, 0 }, + { DNS_T_MX, "MX", &dns_mx_parse, &dns_mx_push, &dns_mx_cmp, &dns_mx_print, &dns_mx_cname }, + { DNS_T_NS, "NS", &dns_ns_parse, &dns_ns_push, &dns_ns_cmp, &dns_ns_print, &dns_ns_cname }, + { DNS_T_CNAME, "CNAME", &dns_cname_parse, &dns_cname_push, &dns_cname_cmp, &dns_cname_print, &dns_cname_cname }, + { DNS_T_SOA, "SOA", &dns_soa_parse, &dns_soa_push, &dns_soa_cmp, &dns_soa_print, 0 }, + { DNS_T_SRV, "SRV", &dns_srv_parse, &dns_srv_push, &dns_srv_cmp, &dns_srv_print, &dns_srv_cname }, + { DNS_T_OPT, "OPT", &dns_opt_parse, &dns_opt_push, &dns_opt_cmp, &dns_opt_print, 0 }, + { DNS_T_PTR, "PTR", &dns_ptr_parse, &dns_ptr_push, &dns_ptr_cmp, &dns_ptr_print, &dns_ptr_cname }, + { DNS_T_TXT, "TXT", &dns_txt_parse, &dns_txt_push, &dns_txt_cmp, &dns_txt_print, 0 }, + { DNS_T_SPF, "SPF", &dns_txt_parse, &dns_txt_push, &dns_txt_cmp, &dns_txt_print, 0 }, + { DNS_T_SSHFP, "SSHFP", &dns_sshfp_parse, &dns_sshfp_push, &dns_sshfp_cmp, &dns_sshfp_print, 0 }, +}; /* dns_rrtypes[] */ + + +union dns_any *dns_any_init(union dns_any *any, size_t size) { + return (union dns_any *)dns_txt_init(&any->rdata, size); +} /* dns_any_init() */ + + +int dns_any_parse(union dns_any *any, struct dns_rr *rr, struct dns_packet *P) { + unsigned i; + + for (i = 0; i < lengthof(dns_rrtypes); i++) { + if (dns_rrtypes[i].type == rr->type) + return dns_rrtypes[i].parse(any, rr, P); + } + + if (rr->rd.len > any->rdata.size) + return DNS_EILLEGAL; + + memcpy(any->rdata.data, &P->data[rr->rd.p], rr->rd.len); + any->rdata.len = rr->rd.len; + + return 0; +} /* dns_any_parse() */ + + +int dns_any_push(struct dns_packet *P, union dns_any *any, enum dns_type type) { + unsigned i; + + for (i = 0; i < lengthof(dns_rrtypes); i++) { + if (dns_rrtypes[i].type == type) + return dns_rrtypes[i].push(P, any); + } + + if (P->size - P->end < any->rdata.len + 2) + return DNS_ENOBUFS; + + P->data[P->end++] = 0xff & (any->rdata.len >> 8); + P->data[P->end++] = 0xff & (any->rdata.len >> 0); + + memcpy(&P->data[P->end], any->rdata.data, any->rdata.len); + P->end += any->rdata.len; + + return 0; +} /* dns_any_push() */ + + +int dns_any_cmp(const union dns_any *a, enum dns_type x, const union dns_any *b, enum dns_type y) { + unsigned i; + int cmp; + + if ((cmp = x - y)) + return cmp; + + for (i = 0; i < lengthof(dns_rrtypes); i++) { + if (dns_rrtypes[i].type == x) + return dns_rrtypes[i].cmp(a, b); + } + + return -1; +} /* dns_any_cmp() */ + + +size_t dns_any_print(void *dst_, size_t lim, union dns_any *any, enum dns_type type) { + struct { unsigned char *b; size_t p, end; } dst, src; + unsigned i, ch; + + for (i = 0; i < lengthof(dns_rrtypes); i++) { + if (dns_rrtypes[i].type == type) + return dns_rrtypes[i].print(dst_, lim, any); + } + + dst.b = dst_; + dst.end = lim; + dst.p = 0; + + src.b = any->rdata.data; + src.end = any->rdata.len; + src.p = 0; + + dst.p += dns__printchar(dst.b, dst.end, dst.p, '"'); + + while (src.p < src.end) { + ch = src.b[src.p++]; + + dst.p += dns__printchar(dst.b, dst.end, dst.p, '\\'); + dst.p += dns__print10(dst.b, dst.end, dst.p, ch, 3); + } + + dst.p += dns__printchar(dst.b, dst.end, dst.p, '"'); + + dns__printnul(dst.b, dst.end, dst.p); + + return dst.p; +} /* dns_any_print() */ + + +size_t dns_any_cname(void *dst, size_t lim, union dns_any *any, enum dns_type type) { + unsigned i; + + for (i = 0; i < lengthof(dns_rrtypes); i++) { + if (dns_rrtypes[i].type == type) + return (dns_rrtypes[i].cname)? dns_rrtypes[i].cname(dst, lim, any) : 0; + } + + return 0; +} /* dns_any_cname() */ + + +/* + * H O S T S R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +struct dns_hosts { + struct dns_hosts_entry { + char host[DNS_D_MAXNAME + 1]; + char arpa[73 + 1]; + + int af; + + union { + struct in_addr a4; + struct in6_addr a6; + } addr; + + _Bool alias; + + struct dns_hosts_entry *next; + } *head, **tail; + + dns_atomic_t refcount; +}; /* struct dns_hosts */ + + +struct dns_hosts *dns_hosts_open(int *error) { + static const struct dns_hosts hosts_initializer = { .refcount = 1 }; + struct dns_hosts *hosts; + + if (!(hosts = malloc(sizeof *hosts))) + goto syerr; + + *hosts = hosts_initializer; + + hosts->tail = &hosts->head; + + return hosts; +syerr: + *error = dns_syerr(); + + free(hosts); + + return 0; +} /* dns_hosts_open() */ + + +void dns_hosts_close(struct dns_hosts *hosts) { + struct dns_hosts_entry *ent, *xnt; + + if (!hosts || 1 != dns_hosts_release(hosts)) + return; + + for (ent = hosts->head; ent; ent = xnt) { + xnt = ent->next; + + free(ent); + } + + free(hosts); + + return; +} /* dns_hosts_close() */ + + +dns_refcount_t dns_hosts_acquire(struct dns_hosts *hosts) { + return dns_atomic_fetch_add(&hosts->refcount); +} /* dns_hosts_acquire() */ + + +dns_refcount_t dns_hosts_release(struct dns_hosts *hosts) { + return dns_atomic_fetch_sub(&hosts->refcount); +} /* dns_hosts_release() */ + + +struct dns_hosts *dns_hosts_mortal(struct dns_hosts *hosts) { + if (hosts) + dns_hosts_release(hosts); + + return hosts; +} /* dns_hosts_mortal() */ + + +struct dns_hosts *dns_hosts_local(int *error_) { + struct dns_hosts *hosts; + int error; + + if (!(hosts = dns_hosts_open(&error))) + goto error; + + if ((error = dns_hosts_loadpath(hosts, "/etc/hosts"))) + goto error; + + return hosts; +error: + *error_ = error; + + dns_hosts_close(hosts); + + return 0; +} /* dns_hosts_local() */ + + +#define dns_hosts_issep(ch) (isspace(ch)) +#define dns_hosts_iscom(ch) ((ch) == '#' || (ch) == ';') + +int dns_hosts_loadfile(struct dns_hosts *hosts, FILE *fp) { + struct dns_hosts_entry ent; + char word[DNS_PP_MAX(INET6_ADDRSTRLEN, DNS_D_MAXNAME) + 1]; + unsigned wp, wc, skip; + int ch, error; + + rewind(fp); + + do { + memset(&ent, '\0', sizeof ent); + wc = 0; + skip = 0; + + do { + memset(word, '\0', sizeof word); + wp = 0; + + while (EOF != (ch = fgetc(fp)) && ch != '\n') { + skip |= !!dns_hosts_iscom(ch); + + if (skip) + continue; + + if (dns_hosts_issep(ch)) + break; + + if (wp < sizeof word - 1) + word[wp] = ch; + wp++; + } + + if (!wp) + continue; + + wc++; + + switch (wc) { + case 0: + break; + case 1: + ent.af = (strchr(word, ':'))? AF_INET6 : AF_INET; + skip = (1 != dns_inet_pton(ent.af, word, &ent.addr)); + + break; + default: + if (!wp) + break; + + dns_d_anchor(ent.host, sizeof ent.host, word, wp); + + if ((error = dns_hosts_insert(hosts, ent.af, &ent.addr, ent.host, (wc > 2)))) + return error; + + break; + } /* switch() */ + } while (ch != EOF && ch != '\n'); + } while (ch != EOF); + + return 0; +} /* dns_hosts_loadfile() */ + + +int dns_hosts_loadpath(struct dns_hosts *hosts, const char *path) { + FILE *fp; + int error; + + if (!(fp = fopen(path, "r"))) + return dns_syerr(); + + error = dns_hosts_loadfile(hosts, fp); + + fclose(fp); + + return error; +} /* dns_hosts_loadpath() */ + + +int dns_hosts_dump(struct dns_hosts *hosts, FILE *fp) { + struct dns_hosts_entry *ent, *xnt; + char addr[INET6_ADDRSTRLEN + 1]; + unsigned i; + + for (ent = hosts->head; ent; ent = xnt) { + xnt = ent->next; + + dns_inet_ntop(ent->af, &ent->addr, addr, sizeof addr); + + fputs(addr, fp); + + for (i = strlen(addr); i < INET_ADDRSTRLEN; i++) + fputc(' ', fp); + + fputc(' ', fp); + + fputs(ent->host, fp); + fputc('\n', fp); + } + + return 0; +} /* dns_hosts_dump() */ + + +int dns_hosts_insert(struct dns_hosts *hosts, int af, const void *addr, const void *host, _Bool alias) { + struct dns_hosts_entry *ent; + int error; + + if (!(ent = malloc(sizeof *ent))) + goto syerr; + + dns_d_anchor(ent->host, sizeof ent->host, host, strlen(host)); + + switch ((ent->af = af)) { + case AF_INET6: + memcpy(&ent->addr.a6, addr, sizeof ent->addr.a6); + + dns_aaaa_arpa(ent->arpa, sizeof ent->arpa, addr); + + break; + case AF_INET: + memcpy(&ent->addr.a4, addr, sizeof ent->addr.a4); + + dns_a_arpa(ent->arpa, sizeof ent->arpa, addr); + + break; + default: + error = EINVAL; + + goto error; + } /* switch() */ + + ent->alias = alias; + + ent->next = 0; + *hosts->tail = ent; + hosts->tail = &ent->next; + + return 0; +syerr: + error = dns_syerr(); +error: + free(ent); + + return error; +} /* dns_hosts_insert() */ + + +struct dns_packet *dns_hosts_query(struct dns_hosts *hosts, struct dns_packet *Q, int *error_) { + struct dns_packet *P = dns_p_new(512); + struct dns_packet *A = 0; + struct dns_rr rr; + struct dns_hosts_entry *ent; + int error, af; + char qname[DNS_D_MAXNAME + 1]; + size_t qlen; + + if ((error = dns_rr_parse(&rr, 12, Q))) + goto error; + + if (!(qlen = dns_d_expand(qname, sizeof qname, rr.dn.p, Q, &error))) + goto error; + else if (qlen >= sizeof qname) + goto toolong; + + if ((error = dns_p_push(P, DNS_S_QD, qname, qlen, rr.type, rr.class, 0, 0))) + goto error; + + switch (rr.type) { + case DNS_T_PTR: + for (ent = hosts->head; ent; ent = ent->next) { + if (ent->alias || 0 != strcasecmp(qname, ent->arpa)) + continue; + + if ((error = dns_p_push(P, DNS_S_AN, qname, qlen, rr.type, rr.class, 0, ent->host))) + goto error; + } + + break; + case DNS_T_AAAA: + af = AF_INET6; + + goto loop; + case DNS_T_A: + af = AF_INET; + +loop: for (ent = hosts->head; ent; ent = ent->next) { + if (ent->af != af || 0 != strcasecmp(qname, ent->host)) + continue; + + if ((error = dns_p_push(P, DNS_S_AN, qname, qlen, rr.type, rr.class, 0, &ent->addr))) + goto error; + } + + break; + default: + break; + } /* switch() */ + + + if (!(A = dns_p_copy(dns_p_make(P->end, &error), P))) + goto error; + + return A; +toolong: + error = DNS_EILLEGAL; +error: + *error_ = error; + + dns_p_free(A); + + return 0; +} /* dns_hosts_query() */ + + +/* + * R E S O L V . C O N F R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +struct dns_resolv_conf *dns_resconf_open(int *error) { + static const struct dns_resolv_conf resconf_initializer + = { .lookup = "bf", .options = { .ndots = 1, .timeout = 5, .attempts = 2, .tcp = DNS_RESCONF_TCP_ENABLE, }, + .iface = { .ss_family = AF_INET }, }; + struct dns_resolv_conf *resconf; + struct sockaddr_in *sin; + + if (!(resconf = malloc(sizeof *resconf))) + goto syerr; + + *resconf = resconf_initializer; + + sin = (struct sockaddr_in *)&resconf->nameserver[0]; + sin->sin_family = AF_INET; + sin->sin_addr.s_addr = INADDR_ANY; + sin->sin_port = htons(53); +#if defined(SA_LEN) + sin->sin_len = sizeof *sin; +#endif + + if (0 != gethostname(resconf->search[0], sizeof resconf->search[0])) + goto syerr; + + dns_d_anchor(resconf->search[0], sizeof resconf->search[0], resconf->search[0], strlen(resconf->search[0])); + dns_d_cleave(resconf->search[0], sizeof resconf->search[0], resconf->search[0], strlen(resconf->search[0])); + + /* + * XXX: If gethostname() returned a string without any label + * separator, then search[0][0] should be NUL. + */ + + dns_resconf_acquire(resconf); + + return resconf; +syerr: + *error = dns_syerr(); + + free(resconf); + + return 0; +} /* dns_resconf_open() */ + + +void dns_resconf_close(struct dns_resolv_conf *resconf) { + if (!resconf || 1 != dns_resconf_release(resconf)) + return /* void */; + + free(resconf); +} /* dns_resconf_close() */ + + +dns_refcount_t dns_resconf_acquire(struct dns_resolv_conf *resconf) { + return dns_atomic_fetch_add(&resconf->_.refcount); +} /* dns_resconf_acquire() */ + + +dns_refcount_t dns_resconf_release(struct dns_resolv_conf *resconf) { + return dns_atomic_fetch_sub(&resconf->_.refcount); +} /* dns_resconf_release() */ + + +struct dns_resolv_conf *dns_resconf_mortal(struct dns_resolv_conf *resconf) { + if (resconf) + dns_resconf_release(resconf); + + return resconf; +} /* dns_resconf_mortal() */ + + +struct dns_resolv_conf *dns_resconf_local(int *error_) { + struct dns_resolv_conf *resconf; + int error; + + if (!(resconf = dns_resconf_open(&error))) + goto error; + + if ((error = dns_resconf_loadpath(resconf, "/etc/resolv.conf"))) + goto error; + + if ((error = dns_nssconf_loadpath(resconf, "/etc/nsswitch.conf"))) { + if (error != ENOENT) + goto error; + } + + return resconf; +error: + *error_ = error; + + dns_resconf_close(resconf); + + return 0; +} /* dns_resconf_local() */ + + +struct dns_resolv_conf *dns_resconf_root(int *error) { + struct dns_resolv_conf *resconf; + + if ((resconf = dns_resconf_local(error))) + resconf->options.recurse = 1; + + return resconf; +} /* dns_resconf_root() */ + + +static time_t dns_resconf_timeout(const struct dns_resolv_conf *resconf) { + return (time_t)DNS_PP_MIN(INT_MAX, resconf->options.timeout); +} /* dns_resconf_timeout() */ + + +enum dns_resconf_keyword { + DNS_RESCONF_NAMESERVER, + DNS_RESCONF_DOMAIN, + DNS_RESCONF_SEARCH, + DNS_RESCONF_LOOKUP, + DNS_RESCONF_FILE, + DNS_RESCONF_BIND, + DNS_RESCONF_CACHE, + DNS_RESCONF_OPTIONS, + DNS_RESCONF_EDNS0, + DNS_RESCONF_NDOTS, + DNS_RESCONF_TIMEOUT, + DNS_RESCONF_ATTEMPTS, + DNS_RESCONF_ROTATE, + DNS_RESCONF_RECURSE, + DNS_RESCONF_SMART, + DNS_RESCONF_TCP, + DNS_RESCONF_TCPx, + DNS_RESCONF_INTERFACE, + DNS_RESCONF_ZERO, + DNS_RESCONF_ONE, + DNS_RESCONF_ENABLE, + DNS_RESCONF_ONLY, + DNS_RESCONF_DISABLE, +}; /* enum dns_resconf_keyword */ + +static enum dns_resconf_keyword dns_resconf_keyword(const char *word) { + static const char *words[] = { + [DNS_RESCONF_NAMESERVER] = "nameserver", + [DNS_RESCONF_DOMAIN] = "domain", + [DNS_RESCONF_SEARCH] = "search", + [DNS_RESCONF_LOOKUP] = "lookup", + [DNS_RESCONF_FILE] = "file", + [DNS_RESCONF_BIND] = "bind", + [DNS_RESCONF_CACHE] = "cache", + [DNS_RESCONF_OPTIONS] = "options", + [DNS_RESCONF_EDNS0] = "edns0", + [DNS_RESCONF_ROTATE] = "rotate", + [DNS_RESCONF_RECURSE] = "recurse", + [DNS_RESCONF_SMART] = "smart", + [DNS_RESCONF_TCP] = "tcp", + [DNS_RESCONF_INTERFACE] = "interface", + [DNS_RESCONF_ZERO] = "0", + [DNS_RESCONF_ONE] = "1", + [DNS_RESCONF_ENABLE] = "enable", + [DNS_RESCONF_ONLY] = "only", + [DNS_RESCONF_DISABLE] = "disable", + }; + unsigned i; + + for (i = 0; i < lengthof(words); i++) { + if (words[i] && 0 == strcasecmp(words[i], word)) + return i; + } + + if (0 == strncasecmp(word, "ndots:", sizeof "ndots:" - 1)) + return DNS_RESCONF_NDOTS; + + if (0 == strncasecmp(word, "timeout:", sizeof "timeout:" - 1)) + return DNS_RESCONF_TIMEOUT; + + if (0 == strncasecmp(word, "attempts:", sizeof "attempts:" - 1)) + return DNS_RESCONF_ATTEMPTS; + + if (0 == strncasecmp(word, "tcp:", sizeof "tcp:" - 1)) + return DNS_RESCONF_TCPx; + + return -1; +} /* dns_resconf_keyword() */ + + +/** OpenBSD-style "[1.2.3.4]:53" nameserver syntax */ +int dns_resconf_pton(struct sockaddr_storage *ss, const char *src) { + struct { char buf[128], *p; } addr = { "", addr.buf }; + unsigned short port = 0; + int ch, af = AF_INET, error; + + while ((ch = *src++)) { + switch (ch) { + case ' ': + /* FALL THROUGH */ + case '\t': + break; + case '[': + break; + case ']': + while ((ch = *src++)) { + if (isdigit((unsigned char)ch)) { + port *= 10; + port += ch - '0'; + } + } + + goto inet; + case ':': + af = AF_INET6; + + /* FALL THROUGH */ + default: + if (addr.p < endof(addr.buf) - 1) + *addr.p++ = ch; + + break; + } /* switch() */ + } /* while() */ +inet: + + if ((error = dns_pton(af, addr.buf, dns_sa_addr(af, ss, NULL)))) + return error; + + port = (!port)? 53 : port; + *dns_sa_port(af, ss) = htons(port); + dns_sa_family(ss) = af; + + return 0; +} /* dns_resconf_pton() */ + +#define dns_resconf_issep(ch) (isspace(ch) || (ch) == ',') +#define dns_resconf_iscom(ch) ((ch) == '#' || (ch) == ';') + +int dns_resconf_loadfile(struct dns_resolv_conf *resconf, FILE *fp) { + unsigned sa_count = 0; + char words[6][DNS_D_MAXNAME + 1]; + unsigned wp, wc, i, j, n; + int ch, error; + + rewind(fp); + + do { + memset(words, '\0', sizeof words); + wp = 0; + wc = 0; + + while (EOF != (ch = getc(fp)) && ch != '\n') { + if (dns_resconf_issep(ch)) { + if (wp > 0) { + wp = 0; + + if (++wc >= lengthof(words)) + goto skip; + } + } else if (dns_resconf_iscom(ch)) { +skip: + do { + ch = getc(fp); + } while (ch != EOF && ch != '\n'); + + break; + } else { + dns__printchar(words[wc], sizeof words[wc], wp, ch); + wp++; + } + } + + if (wp > 0) + wc++; + + if (wc < 2) + continue; + + switch (dns_resconf_keyword(words[0])) { + case DNS_RESCONF_NAMESERVER: + if (sa_count >= lengthof(resconf->nameserver)) + continue; + + if ((error = dns_resconf_pton(&resconf->nameserver[sa_count], words[1]))) + continue; + + sa_count++; + + break; + case DNS_RESCONF_DOMAIN: + case DNS_RESCONF_SEARCH: + memset(resconf->search, '\0', sizeof resconf->search); + + for (i = 1, j = 0; i < wc && j < lengthof(resconf->search); i++, j++) + dns_d_anchor(resconf->search[j], sizeof resconf->search[j], words[i], strlen(words[i])); + + break; + case DNS_RESCONF_LOOKUP: + for (i = 1, j = 0; i < wc && j < lengthof(resconf->lookup); i++) { + switch (dns_resconf_keyword(words[i])) { + case DNS_RESCONF_FILE: + resconf->lookup[j++] = 'f'; + + break; + case DNS_RESCONF_BIND: + resconf->lookup[j++] = 'b'; + + break; + case DNS_RESCONF_CACHE: + resconf->lookup[j++] = 'c'; + + break; + default: + break; + } /* switch() */ + } /* for() */ + + break; + case DNS_RESCONF_OPTIONS: + for (i = 1; i < wc; i++) { + switch (dns_resconf_keyword(words[i])) { + case DNS_RESCONF_EDNS0: + resconf->options.edns0 = 1; + + break; + case DNS_RESCONF_NDOTS: + for (j = sizeof "ndots:" - 1, n = 0; isdigit((int)words[i][j]); j++) { + n *= 10; + n += words[i][j] - '0'; + } /* for() */ + + resconf->options.ndots = n; + + break; + case DNS_RESCONF_TIMEOUT: + for (j = sizeof "timeout:" - 1, n = 0; isdigit((int)words[i][j]); j++) { + n *= 10; + n += words[i][j] - '0'; + } /* for() */ + + resconf->options.timeout = n; + + break; + case DNS_RESCONF_ATTEMPTS: + for (j = sizeof "attempts:" - 1, n = 0; isdigit((int)words[i][j]); j++) { + n *= 10; + n += words[i][j] - '0'; + } /* for() */ + + resconf->options.attempts = n; + + break; + case DNS_RESCONF_ROTATE: + resconf->options.rotate = 1; + + break; + case DNS_RESCONF_RECURSE: + resconf->options.recurse = 1; + + break; + case DNS_RESCONF_SMART: + resconf->options.smart = 1; + + break; + case DNS_RESCONF_TCP: + resconf->options.tcp = DNS_RESCONF_TCP_ONLY; + + break; + case DNS_RESCONF_TCPx: + switch (dns_resconf_keyword(&words[i][sizeof "tcp:" - 1])) { + case DNS_RESCONF_ENABLE: + resconf->options.tcp = DNS_RESCONF_TCP_ENABLE; + + break; + case DNS_RESCONF_ONE: + case DNS_RESCONF_ONLY: + resconf->options.tcp = DNS_RESCONF_TCP_ONLY; + + break; + case DNS_RESCONF_ZERO: + case DNS_RESCONF_DISABLE: + resconf->options.tcp = DNS_RESCONF_TCP_DISABLE; + + break; + default: + break; + } /* switch() */ + + break; + default: + break; + } /* switch() */ + } /* for() */ + + break; + case DNS_RESCONF_INTERFACE: + for (i = 0, n = 0; isdigit((int)words[2][i]); i++) { + n *= 10; + n += words[2][i] - '0'; + } + + dns_resconf_setiface(resconf, words[1], n); + + break; + default: + break; + } /* switch() */ + } while (ch != EOF); + + return 0; +} /* dns_resconf_loadfile() */ + + +int dns_resconf_loadpath(struct dns_resolv_conf *resconf, const char *path) { + FILE *fp; + int error; + + if (!(fp = fopen(path, "r"))) + return dns_syerr(); + + error = dns_resconf_loadfile(resconf, fp); + + fclose(fp); + + return error; +} /* dns_resconf_loadpath() */ + + +struct dns_anyconf { + char *token[16]; + unsigned count; + char buffer[1024], *tp, *cp; +}; /* struct dns_anyconf */ + + +static void dns_anyconf_reset(struct dns_anyconf *cf) { + cf->count = 0; + cf->tp = cf->cp = cf->buffer; +} /* dns_anyconf_reset() */ + + +static int dns_anyconf_push(struct dns_anyconf *cf) { + if (!(cf->cp < endof(cf->buffer) && cf->count < lengthof(cf->token))) + return ENOMEM; + + *cf->cp++ = '\0'; + cf->token[cf->count++] = cf->tp; + cf->tp = cf->cp; + + return 0; +} /* dns_anyconf_push() */ + + +static void dns_anyconf_pop(struct dns_anyconf *cf) { + if (cf->count > 0) { + --cf->count; + cf->tp = cf->cp = cf->token[cf->count]; + cf->token[cf->count] = 0; + } +} /* dns_anyconf_pop() */ + + +static int dns_anyconf_addc(struct dns_anyconf *cf, int ch) { + if (!(cf->cp < endof(cf->buffer))) + return ENOMEM; + + *cf->cp++ = ch; + + return 0; +} /* dns_anyconf_addc() */ + + +static _Bool dns_anyconf_match(const char *pat, int mc) { + _Bool match; + int pc; + + if (*pat == '^') { + match = 0; + ++pat; + } else { + match = 1; + } + + while ((pc = *(const unsigned char *)pat++)) { + switch (pc) { + case '%': + if (!(pc = *(const unsigned char *)pat++)) + return !match; + + switch (pc) { + case 'a': + if (isalpha(mc)) + return match; + break; + case 'd': + if (isdigit(mc)) + return match; + break; + case 'w': + if (isalnum(mc)) + return match; + break; + case 's': + if (isspace(mc)) + return match; + break; + default: + if (mc == pc) + return match; + break; + } /* switch() */ + + break; + default: + if (mc == pc) + return match; + break; + } /* switch() */ + } /* while() */ + + return !match; +} /* dns_anyconf_match() */ + + +static int dns_anyconf_peek(FILE *fp) { + int ch; + ch = getc(fp); + ungetc(ch, fp); + return ch; +} /* dns_anyconf_peek() */ + + +static size_t dns_anyconf_skip(const char *pat, FILE *fp) { + size_t count = 0; + int ch; + + while (EOF != (ch = getc(fp))) { + if (dns_anyconf_match(pat, ch)) { + count++; + continue; + } + + ungetc(ch, fp); + + break; + } + + return count; +} /* dns_anyconf_skip() */ + + +static size_t dns_anyconf_scan(struct dns_anyconf *cf, const char *pat, FILE *fp, int *error) { + size_t len; + int ch; + + while (EOF != (ch = getc(fp))) { + if (dns_anyconf_match(pat, ch)) { + if ((*error = dns_anyconf_addc(cf, ch))) + return 0; + + continue; + } else { + ungetc(ch, fp); + + break; + } + } + + if ((len = cf->cp - cf->tp)) { + if ((*error = dns_anyconf_push(cf))) + return 0; + + return len; + } else { + *error = 0; + + return 0; + } +} /* dns_anyconf_scan() */ + + +DNS_NOTUSED static void dns_anyconf_dump(struct dns_anyconf *cf, FILE *fp) { + unsigned i; + + fprintf(fp, "tokens:"); + + for (i = 0; i < cf->count; i++) { + fprintf(fp, " %s", cf->token[i]); + } + + fputc('\n', fp); +} /* dns_anyconf_dump() */ + + +enum dns_nssconf_keyword { + DNS_NSSCONF_INVALID = 0, + DNS_NSSCONF_HOSTS = 1, + DNS_NSSCONF_SUCCESS, + DNS_NSSCONF_NOTFOUND, + DNS_NSSCONF_UNAVAIL, + DNS_NSSCONF_TRYAGAIN, + DNS_NSSCONF_CONTINUE, + DNS_NSSCONF_RETURN, + DNS_NSSCONF_FILES, + DNS_NSSCONF_DNS, + DNS_NSSCONF_MDNS, + + DNS_NSSCONF_LAST, +}; /* enum dns_nssconf_keyword */ + +static enum dns_nssconf_keyword dns_nssconf_keyword(const char *word) { + static const char *list[] = { + [DNS_NSSCONF_HOSTS] = "hosts", + [DNS_NSSCONF_SUCCESS] = "success", + [DNS_NSSCONF_NOTFOUND] = "notfound", + [DNS_NSSCONF_UNAVAIL] = "unavail", + [DNS_NSSCONF_TRYAGAIN] = "tryagain", + [DNS_NSSCONF_CONTINUE] = "continue", + [DNS_NSSCONF_RETURN] = "return", + [DNS_NSSCONF_FILES] = "files", + [DNS_NSSCONF_DNS] = "dns", + [DNS_NSSCONF_MDNS] = "mdns", + }; + unsigned i; + + for (i = 1; i < lengthof(list); i++) { + if (list[i] && 0 == strcasecmp(list[i], word)) + return i; + } + + return DNS_NSSCONF_INVALID; +} /* dns_nssconf_keyword() */ + + +static enum dns_nssconf_keyword dns_nssconf_c2k(int ch) { + static const char map[] = { + ['S'] = DNS_NSSCONF_SUCCESS, + ['N'] = DNS_NSSCONF_NOTFOUND, + ['U'] = DNS_NSSCONF_UNAVAIL, + ['T'] = DNS_NSSCONF_TRYAGAIN, + ['C'] = DNS_NSSCONF_CONTINUE, + ['R'] = DNS_NSSCONF_RETURN, + ['f'] = DNS_NSSCONF_FILES, + ['F'] = DNS_NSSCONF_FILES, + ['d'] = DNS_NSSCONF_DNS, + ['D'] = DNS_NSSCONF_DNS, + ['b'] = DNS_NSSCONF_DNS, + ['B'] = DNS_NSSCONF_DNS, + ['m'] = DNS_NSSCONF_MDNS, + ['M'] = DNS_NSSCONF_MDNS, + }; + + return (ch >= 0 && ch < (int)lengthof(map))? map[ch] : DNS_NSSCONF_INVALID; +} /* dns_nssconf_c2k() */ + + +DNS_PRAGMA_PUSH +DNS_PRAGMA_QUIET + +static int dns_nssconf_k2c(int k) { + static const char map[DNS_NSSCONF_LAST] = { + [DNS_NSSCONF_SUCCESS] = 'S', + [DNS_NSSCONF_NOTFOUND] = 'N', + [DNS_NSSCONF_UNAVAIL] = 'U', + [DNS_NSSCONF_TRYAGAIN] = 'T', + [DNS_NSSCONF_CONTINUE] = 'C', + [DNS_NSSCONF_RETURN] = 'R', + [DNS_NSSCONF_FILES] = 'f', + [DNS_NSSCONF_DNS] = 'b', + [DNS_NSSCONF_MDNS] = 'm', + }; + + return (k >= 0 && k < (int)lengthof(map))? (map[k]? map[k] : '?') : '?'; +} /* dns_nssconf_k2c() */ + +static const char *dns_nssconf_k2s(int k) { + static const char *const map[DNS_NSSCONF_LAST] = { + [DNS_NSSCONF_SUCCESS] = "SUCCESS", + [DNS_NSSCONF_NOTFOUND] = "NOTFOUND", + [DNS_NSSCONF_UNAVAIL] = "UNAVAIL", + [DNS_NSSCONF_TRYAGAIN] = "TRYAGAIN", + [DNS_NSSCONF_CONTINUE] = "continue", + [DNS_NSSCONF_RETURN] = "return", + [DNS_NSSCONF_FILES] = "files", + [DNS_NSSCONF_DNS] = "dns", + [DNS_NSSCONF_MDNS] = "mdns", + }; + + return (k >= 0 && k < (int)lengthof(map))? (map[k]? map[k] : "") : ""; +} /* dns_nssconf_k2s() */ + +DNS_PRAGMA_POP + + +int dns_nssconf_loadfile(struct dns_resolv_conf *resconf, FILE *fp) { + enum dns_nssconf_keyword source, status, action; + char lookup[sizeof resconf->lookup] = "", *lp; + struct dns_anyconf cf; + size_t i; + int error; + + while (!feof(fp) && !ferror(fp)) { + dns_anyconf_reset(&cf); + + dns_anyconf_skip("%s", fp); + + if (!dns_anyconf_scan(&cf, "%w_", fp, &error)) + goto nextent; + + if (DNS_NSSCONF_HOSTS != dns_nssconf_keyword(cf.token[0])) + goto nextent; + + dns_anyconf_pop(&cf); + + if (!dns_anyconf_skip(": \t", fp)) + goto nextent; + + *(lp = lookup) = '\0'; + + while (dns_anyconf_scan(&cf, "%w_", fp, &error)) { + dns_anyconf_skip(" \t", fp); + + if ('[' == dns_anyconf_peek(fp)) { + dns_anyconf_skip("[ \t", fp); + + while (dns_anyconf_scan(&cf, "%w_", fp, &error)) { + dns_anyconf_skip("= \t", fp); + if (!dns_anyconf_scan(&cf, "%w_", fp, &error)) { + dns_anyconf_pop(&cf); /* discard status */ + dns_anyconf_skip("^#;]\n", fp); /* skip to end of criteria */ + break; + } + dns_anyconf_skip(" \t", fp); + } + + dns_anyconf_skip("] \t", fp); + } + + if ((size_t)(endof(lookup) - lp) < cf.count + 1) /* +1 for '\0' */ + goto nextsrc; + + source = dns_nssconf_keyword(cf.token[0]); + + switch (source) { + case DNS_NSSCONF_DNS: + case DNS_NSSCONF_MDNS: + case DNS_NSSCONF_FILES: + *lp++ = dns_nssconf_k2c(source); + break; + default: + goto nextsrc; + } + + for (i = 1; i + 1 < cf.count; i += 2) { + status = dns_nssconf_keyword(cf.token[i]); + action = dns_nssconf_keyword(cf.token[i + 1]); + + switch (status) { + case DNS_NSSCONF_SUCCESS: + case DNS_NSSCONF_NOTFOUND: + case DNS_NSSCONF_UNAVAIL: + case DNS_NSSCONF_TRYAGAIN: + *lp++ = dns_nssconf_k2c(status); + break; + default: + continue; + } + + switch (action) { + case DNS_NSSCONF_CONTINUE: + case DNS_NSSCONF_RETURN: + break; + default: + action = (status == DNS_NSSCONF_SUCCESS) + ? DNS_NSSCONF_RETURN + : DNS_NSSCONF_CONTINUE; + break; + } + + *lp++ = dns_nssconf_k2c(action); + } +nextsrc: + *lp = '\0'; + dns_anyconf_reset(&cf); + } +nextent: + dns_anyconf_skip("^\n", fp); + } + + if (*lookup) + strncpy(resconf->lookup, lookup, sizeof resconf->lookup); + + return 0; +} /* dns_nssconf_loadfile() */ + + +int dns_nssconf_loadpath(struct dns_resolv_conf *resconf, const char *path) { + FILE *fp; + int error; + + if (!(fp = fopen(path, "r"))) + return dns_syerr(); + + error = dns_nssconf_loadfile(resconf, fp); + + fclose(fp); + + return error; +} /* dns_nssconf_loadpath() */ + + +struct dns_nssconf_source { + enum dns_nssconf_keyword source, success, notfound, unavail, tryagain; +}; /* struct dns_nssconf_source */ + +typedef unsigned dns_nssconf_i; + +static inline int dns_nssconf_peek(const struct dns_resolv_conf *resconf, dns_nssconf_i state) { + return (state < lengthof(resconf->lookup) && resconf->lookup[state])? resconf->lookup[state] : 0; +} /* dns_nssconf_peek() */ + +static _Bool dns_nssconf_next(struct dns_nssconf_source *src, const struct dns_resolv_conf *resconf, dns_nssconf_i *state) { + int source, status, action; + + src->source = DNS_NSSCONF_INVALID; + src->success = DNS_NSSCONF_RETURN; + src->notfound = DNS_NSSCONF_CONTINUE; + src->unavail = DNS_NSSCONF_CONTINUE; + src->tryagain = DNS_NSSCONF_CONTINUE; + + while ((source = dns_nssconf_peek(resconf, *state))) { + source = dns_nssconf_c2k(source); + ++*state; + + switch (source) { + case DNS_NSSCONF_FILES: + case DNS_NSSCONF_DNS: + case DNS_NSSCONF_MDNS: + src->source = source; + break; + default: + continue; + } + + while ((status = dns_nssconf_peek(resconf, *state)) && (action = dns_nssconf_peek(resconf, *state + 1))) { + status = dns_nssconf_c2k(status); + action = dns_nssconf_c2k(action); + + switch (action) { + case DNS_NSSCONF_RETURN: + case DNS_NSSCONF_CONTINUE: + break; + default: + goto done; + } + + switch (status) { + case DNS_NSSCONF_SUCCESS: + src->success = action; + break; + case DNS_NSSCONF_NOTFOUND: + src->notfound = action; + break; + case DNS_NSSCONF_UNAVAIL: + src->unavail = action; + break; + case DNS_NSSCONF_TRYAGAIN: + src->tryagain = action; + break; + default: + goto done; + } + + *state += 2; + } + + break; + } +done: + return src->source != DNS_NSSCONF_INVALID; +} /* dns_nssconf_next() */ + + +static int dns_nssconf_dump_status(int status, int action, unsigned *count, FILE *fp) { + switch (status) { + case DNS_NSSCONF_SUCCESS: + if (action == DNS_NSSCONF_RETURN) + return 0; + break; + default: + if (action == DNS_NSSCONF_CONTINUE) + return 0; + break; + } + + fputc(' ', fp); + + if (!*count) + fputc('[', fp); + + fprintf(fp, "%s=%s", dns_nssconf_k2s(status), dns_nssconf_k2s(action)); + + ++*count; + + return 0; +} /* dns_nssconf_dump_status() */ + + +int dns_nssconf_dump(struct dns_resolv_conf *resconf, FILE *fp) { + struct dns_nssconf_source src; + dns_nssconf_i i = 0; + + fputs("hosts:", fp); + + while (dns_nssconf_next(&src, resconf, &i)) { + unsigned n = 0; + + fprintf(fp, " %s", dns_nssconf_k2s(src.source)); + + dns_nssconf_dump_status(DNS_NSSCONF_SUCCESS, src.success, &n, fp); + dns_nssconf_dump_status(DNS_NSSCONF_NOTFOUND, src.notfound, &n, fp); + dns_nssconf_dump_status(DNS_NSSCONF_UNAVAIL, src.unavail, &n, fp); + dns_nssconf_dump_status(DNS_NSSCONF_TRYAGAIN, src.tryagain, &n, fp); + + if (n) + fputc(']', fp); + } + + fputc('\n', fp); + + return 0; +} /* dns_nssconf_dump() */ + + +int dns_resconf_setiface(struct dns_resolv_conf *resconf, const char *addr, unsigned short port) { + int af = (strchr(addr, ':'))? AF_INET6 : AF_INET; + int error; + + if ((error = dns_pton(af, addr, dns_sa_addr(af, &resconf->iface, NULL)))) + return error; + + *dns_sa_port(af, &resconf->iface) = htons(port); + resconf->iface.ss_family = af; + + return 0; +} /* dns_resconf_setiface() */ + + +size_t dns_resconf_search(void *dst, size_t lim, const void *qname, size_t qlen, struct dns_resolv_conf *resconf, dns_resconf_i_t *state) { + unsigned srchi = 0xff & (*state >> 8); + unsigned ndots = 0xff & (*state >> 16); + unsigned slen, len = 0; + const char *qp, *qe; + +// assert(0xff > lengthof(resconf->search)); + + switch (0xff & *state) { + case 0: + qp = qname; + qe = qp + qlen; + + while ((qp = memchr(qp, '.', qe - qp))) + { ndots++; qp++; } + + ++*state; + + if (ndots >= resconf->options.ndots) { + len = dns_d_anchor(dst, lim, qname, qlen); + + break; + } + + /* FALL THROUGH */ + case 1: + if (srchi < lengthof(resconf->search) && (slen = strlen(resconf->search[srchi]))) { + len = dns__printstring(dst, lim, 0, qname, qlen); + len = dns_d_anchor(dst, lim, dst, len); + len += dns__printstring(dst, lim, len, resconf->search[srchi], slen); + + srchi++; + + break; + } + + ++*state; + + /* FALL THROUGH */ + case 2: + ++*state; + + if (ndots < resconf->options.ndots) { + len = dns_d_anchor(dst, lim, qname, qlen); + + break; + } + + /* FALL THROUGH */ + default: + break; + } /* switch() */ + + dns__printnul(dst, lim, len); + + *state = ((0xff & *state) << 0) + | ((0xff & srchi) << 8) + | ((0xff & ndots) << 16); + + return len; +} /* dns_resconf_search() */ + + +int dns_resconf_dump(struct dns_resolv_conf *resconf, FILE *fp) { + unsigned i; + int af; + + for (i = 0; i < lengthof(resconf->nameserver) && (af = resconf->nameserver[i].ss_family) != AF_UNSPEC; i++) { + char addr[INET6_ADDRSTRLEN + 1] = "[INVALID]"; + unsigned short port; + + dns_inet_ntop(af, dns_sa_addr(af, &resconf->nameserver[i], NULL), addr, sizeof addr); + port = ntohs(*dns_sa_port(af, &resconf->nameserver[i])); + + if (port == 53) + fprintf(fp, "nameserver %s\n", addr); + else + fprintf(fp, "nameserver [%s]:%hu\n", addr, port); + } + + + fprintf(fp, "search"); + + for (i = 0; i < lengthof(resconf->search) && resconf->search[i][0]; i++) + fprintf(fp, " %s", resconf->search[i]); + + fputc('\n', fp); + + + fputs("; ", fp); + dns_nssconf_dump(resconf, fp); + + fprintf(fp, "lookup"); + + for (i = 0; i < lengthof(resconf->lookup) && resconf->lookup[i]; i++) { + switch (resconf->lookup[i]) { + case 'b': + fprintf(fp, " bind"); break; + case 'f': + fprintf(fp, " file"); break; + case 'c': + fprintf(fp, " cache"); break; + } + } + + fputc('\n', fp); + + + fprintf(fp, "options ndots:%u timeout:%u attempts:%u", resconf->options.ndots, resconf->options.timeout, resconf->options.attempts); + + if (resconf->options.edns0) + fprintf(fp, " edns0"); + if (resconf->options.rotate) + fprintf(fp, " rotate"); + if (resconf->options.recurse) + fprintf(fp, " recurse"); + if (resconf->options.smart) + fprintf(fp, " smart"); + + switch (resconf->options.tcp) { + case DNS_RESCONF_TCP_ENABLE: + break; + case DNS_RESCONF_TCP_ONLY: + fprintf(fp, " tcp"); + break; + case DNS_RESCONF_TCP_DISABLE: + fprintf(fp, " tcp:disable"); + break; + } + + fputc('\n', fp); + + + if ((af = resconf->iface.ss_family) != AF_UNSPEC) { + char addr[INET6_ADDRSTRLEN + 1] = "[INVALID]"; + + dns_inet_ntop(af, dns_sa_addr(af, &resconf->iface, NULL), addr, sizeof addr); + + fprintf(fp, "interface %s %hu\n", addr, ntohs(*dns_sa_port(af, &resconf->iface))); + } + + return 0; +} /* dns_resconf_dump() */ + + +/* + * H I N T S E R V E R R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +struct dns_hints_soa { + unsigned char zone[DNS_D_MAXNAME + 1]; + + struct { + struct sockaddr_storage ss; + unsigned priority; + } addrs[16]; + + unsigned count; + + struct dns_hints_soa *next; +}; /* struct dns_hints_soa */ + + +struct dns_hints { + dns_atomic_t refcount; + + struct dns_hints_soa *head; +}; /* struct dns_hints */ + + +struct dns_hints *dns_hints_open(struct dns_resolv_conf *resconf, int *error) { + static const struct dns_hints H_initializer; + struct dns_hints *H; + + (void)resconf; + + if (!(H = malloc(sizeof *H))) + goto syerr; + + *H = H_initializer; + + dns_hints_acquire(H); + + return H; +syerr: + *error = dns_syerr(); + + free(H); + + return 0; +} /* dns_hints_open() */ + + +void dns_hints_close(struct dns_hints *H) { + struct dns_hints_soa *soa, *nxt; + + if (!H || 1 != dns_hints_release(H)) + return /* void */; + + for (soa = H->head; soa; soa = nxt) { + nxt = soa->next; + + free(soa); + } + + free(H); + + return /* void */; +} /* dns_hints_close() */ + + +dns_refcount_t dns_hints_acquire(struct dns_hints *H) { + return dns_atomic_fetch_add(&H->refcount); +} /* dns_hints_acquire() */ + + +dns_refcount_t dns_hints_release(struct dns_hints *H) { + return dns_atomic_fetch_sub(&H->refcount); +} /* dns_hints_release() */ + + +struct dns_hints *dns_hints_mortal(struct dns_hints *hints) { + if (hints) + dns_hints_release(hints); + + return hints; +} /* dns_hints_mortal() */ + + +struct dns_hints *dns_hints_local(struct dns_resolv_conf *resconf, int *error_) { + struct dns_hints *hints = 0; + int error; + + if (resconf) + dns_resconf_acquire(resconf); + else if (!(resconf = dns_resconf_local(&error))) + goto error; + + if (!(hints = dns_hints_open(resconf, &error))) + goto error; + + error = 0; + + if (0 == dns_hints_insert_resconf(hints, ".", resconf, &error) && error) + goto error; + + dns_resconf_close(resconf); + + return hints; +error: + *error_ = error; + + dns_resconf_close(resconf); + dns_hints_close(hints); + + return 0; +} /* dns_hints_local() */ + + +struct dns_hints *dns_hints_root(struct dns_resolv_conf *resconf, int *error_) { + static const struct { + int af; + char addr[INET6_ADDRSTRLEN]; + } root_hints[] = { + { AF_INET, "198.41.0.4" }, /* A.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:503:ba3e::2:30" }, /* A.ROOT-SERVERS.NET. */ + { AF_INET, "192.228.79.201" }, /* B.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:500:84::b" }, /* B.ROOT-SERVERS.NET. */ + { AF_INET, "192.33.4.12" }, /* C.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:500:2::c" }, /* C.ROOT-SERVERS.NET. */ + { AF_INET, "199.7.91.13" }, /* D.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:500:2d::d" }, /* D.ROOT-SERVERS.NET. */ + { AF_INET, "192.203.230.10" }, /* E.ROOT-SERVERS.NET. */ + { AF_INET, "192.5.5.241" }, /* F.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:500:2f::f" }, /* F.ROOT-SERVERS.NET. */ + { AF_INET, "192.112.36.4" }, /* G.ROOT-SERVERS.NET. */ + { AF_INET, "128.63.2.53" }, /* H.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:500:1::803f:235" }, /* H.ROOT-SERVERS.NET. */ + { AF_INET, "192.36.148.17" }, /* I.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:7FE::53" }, /* I.ROOT-SERVERS.NET. */ + { AF_INET, "192.58.128.30" }, /* J.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:503:c27::2:30" }, /* J.ROOT-SERVERS.NET. */ + { AF_INET, "193.0.14.129" }, /* K.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:7FD::1" }, /* K.ROOT-SERVERS.NET. */ + { AF_INET, "199.7.83.42" }, /* L.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:500:3::42" }, /* L.ROOT-SERVERS.NET. */ + { AF_INET, "202.12.27.33" }, /* M.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:DC3::35" }, /* M.ROOT-SERVERS.NET. */ + }; + struct dns_hints *hints = 0; + struct sockaddr_storage ss; + unsigned i; + int error, af; + + if (!(hints = dns_hints_open(resconf, &error))) + goto error; + + for (i = 0; i < lengthof(root_hints); i++) { + af = root_hints[i].af; + + if ((error = dns_pton(af, root_hints[i].addr, dns_sa_addr(af, &ss, NULL)))) + goto error; + + *dns_sa_port(af, &ss) = htons(53); + ss.ss_family = af; + + if ((error = dns_hints_insert(hints, ".", (struct sockaddr *)&ss, 1))) + goto error; + } + + return hints; +error: + *error_ = error; + + dns_hints_close(hints); + + return 0; +} /* dns_hints_root() */ + + +static struct dns_hints_soa *dns_hints_fetch(struct dns_hints *H, const char *zone) { + struct dns_hints_soa *soa; + + for (soa = H->head; soa; soa = soa->next) { + if (0 == strcasecmp(zone, (char *)soa->zone)) + return soa; + } + + return 0; +} /* dns_hints_fetch() */ + + +int dns_hints_insert(struct dns_hints *H, const char *zone, const struct sockaddr *sa, unsigned priority) { + static const struct dns_hints_soa soa_initializer; + struct dns_hints_soa *soa; + unsigned i; + + if (!(soa = dns_hints_fetch(H, zone))) { + if (!(soa = malloc(sizeof *soa))) + return dns_syerr(); + + *soa = soa_initializer; + + dns__printstring(soa->zone, sizeof soa->zone, 0, zone); + + soa->next = H->head; + H->head = soa; + } + + i = soa->count % lengthof(soa->addrs); + + memcpy(&soa->addrs[i].ss, sa, dns_sa_len(sa)); + + soa->addrs[i].priority = DNS_PP_MAX(1, priority); + + if (soa->count < lengthof(soa->addrs)) + soa->count++; + + return 0; +} /* dns_hints_insert() */ + + +unsigned dns_hints_insert_resconf(struct dns_hints *H, const char *zone, const struct dns_resolv_conf *resconf, int *error_) { + unsigned i, n, p; + int error; + + for (i = 0, n = 0, p = 1; i < lengthof(resconf->nameserver) && resconf->nameserver[i].ss_family != AF_UNSPEC; i++, n++) { + if ((error = dns_hints_insert(H, zone, (struct sockaddr *)&resconf->nameserver[i], p))) + goto error; + + p += !resconf->options.rotate; + } + + return n; +error: + *error_ = error; + + return n; +} /* dns_hints_insert_resconf() */ + + +static int dns_hints_i_cmp(unsigned a, unsigned b, struct dns_hints_i *i, struct dns_hints_soa *soa) { + int cmp; + + if ((cmp = soa->addrs[a].priority - soa->addrs[b].priority)) + return cmp; + + return dns_k_shuffle16(a, i->state.seed) - dns_k_shuffle16(b, i->state.seed); +} /* dns_hints_i_cmp() */ + + +static unsigned dns_hints_i_start(struct dns_hints_i *i, struct dns_hints_soa *soa) { + unsigned p0, p; + + p0 = 0; + + for (p = 1; p < soa->count; p++) { + if (dns_hints_i_cmp(p, p0, i, soa) < 0) + p0 = p; + } + + return p0; +} /* dns_hints_i_start() */ + + +static unsigned dns_hints_i_skip(unsigned p0, struct dns_hints_i *i, struct dns_hints_soa *soa) { + unsigned pZ, p; + + for (pZ = 0; pZ < soa->count; pZ++) { + if (dns_hints_i_cmp(pZ, p0, i, soa) > 0) + goto cont; + } + + return soa->count; +cont: + for (p = pZ + 1; p < soa->count; p++) { + if (dns_hints_i_cmp(p, p0, i, soa) <= 0) + continue; + + if (dns_hints_i_cmp(p, pZ, i, soa) >= 0) + continue; + + pZ = p; + } + + + return pZ; +} /* dns_hints_i_skip() */ + + +struct dns_hints_i *dns_hints_i_init(struct dns_hints_i *i, struct dns_hints *hints) { + static const struct dns_hints_i i_initializer; + struct dns_hints_soa *soa; + + i->state = i_initializer.state; + + do { + i->state.seed = dns_random(); + } while (0 == i->state.seed); + + if ((soa = dns_hints_fetch(hints, i->zone))) { + i->state.next = dns_hints_i_start(i, soa); + } + + return i; +} /* dns_hints_i_init() */ + + +unsigned dns_hints_grep(struct sockaddr **sa, socklen_t *sa_len, unsigned lim, struct dns_hints_i *i, struct dns_hints *H) { + struct dns_hints_soa *soa; + unsigned n; + + if (!(soa = dns_hints_fetch(H, i->zone))) + return 0; + + n = 0; + + while (i->state.next < soa->count && n < lim) { + *sa = (struct sockaddr *)&soa->addrs[i->state.next].ss; + *sa_len = dns_sa_len(*sa); + + sa++; + sa_len++; + n++; + + i->state.next = dns_hints_i_skip(i->state.next, i, soa); + } + + return n; +} /* dns_hints_grep() */ + + +struct dns_packet *dns_hints_query(struct dns_hints *hints, struct dns_packet *Q, int *error_) { + struct dns_packet *A, *P; + struct dns_rr rr; + char zone[DNS_D_MAXNAME + 1]; + size_t zlen; + struct dns_hints_i i; + struct sockaddr *sa; + socklen_t slen; + int error; + + if (!dns_rr_grep(&rr, 1, dns_rr_i_new(Q, .section = DNS_S_QUESTION), Q, &error)) + goto error; + + if (!(zlen = dns_d_expand(zone, sizeof zone, rr.dn.p, Q, &error))) + goto error; + else if (zlen >= sizeof zone) + goto toolong; + + P = dns_p_new(512); + dns_header(P)->qr = 1; + + if ((error = dns_rr_copy(P, &rr, Q))) + goto error; + + if ((error = dns_p_push(P, DNS_S_AUTHORITY, ".", strlen("."), DNS_T_NS, DNS_C_IN, 0, "hints.local."))) + goto error; + + do { + i.zone = zone; + + dns_hints_i_init(&i, hints); + + while (dns_hints_grep(&sa, &slen, 1, &i, hints)) { + int af = sa->sa_family; + int rtype = (af == AF_INET6)? DNS_T_AAAA : DNS_T_A; + + if ((error = dns_p_push(P, DNS_S_ADDITIONAL, "hints.local.", strlen("hints.local."), rtype, DNS_C_IN, 0, dns_sa_addr(af, sa, NULL)))) + goto error; + } + } while ((zlen = dns_d_cleave(zone, sizeof zone, zone, zlen))); + + if (!(A = dns_p_copy(dns_p_make(P->end, &error), P))) + goto error; + + return A; +toolong: + error = DNS_EILLEGAL; +error: + *error_ = error; + + return 0; +} /* dns_hints_query() */ + + +/** ugly hack to support specifying ports other than 53 in resolv.conf. */ +static unsigned short dns_hints_port(struct dns_hints *hints, int af, void *addr) { + struct dns_hints_soa *soa; + void *addrsoa; + socklen_t addrlen; + unsigned short port; + unsigned i; + + for (soa = hints->head; soa; soa = soa->next) { + for (i = 0; i < soa->count; i++) { + if (af != soa->addrs[i].ss.ss_family) + continue; + + if (!(addrsoa = dns_sa_addr(af, &soa->addrs[i].ss, &addrlen))) + continue; + + if (memcmp(addr, addrsoa, addrlen)) + continue; + + port = *dns_sa_port(af, &soa->addrs[i].ss); + + return (port)? port : htons(53); + } + } + + return htons(53); +} /* dns_hints_port() */ + + +int dns_hints_dump(struct dns_hints *hints, FILE *fp) { + struct dns_hints_soa *soa; + char addr[INET6_ADDRSTRLEN]; + unsigned i; + int af, error; + + for (soa = hints->head; soa; soa = soa->next) { + fprintf(fp, "ZONE \"%s\"\n", soa->zone); + + for (i = 0; i < soa->count; i++) { + af = soa->addrs[i].ss.ss_family; + + if ((error = dns_ntop(af, dns_sa_addr(af, &soa->addrs[i].ss, NULL), addr, sizeof addr))) + return error; + + fprintf(fp, "\t(%d) [%s]:%hu\n", (int)soa->addrs[i].priority, addr, ntohs(*dns_sa_port(af, &soa->addrs[i].ss))); + } + } + + return 0; +} /* dns_hints_dump() */ + + +/* + * C A C H E R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +static dns_refcount_t dns_cache_acquire(struct dns_cache *cache) { + return dns_atomic_fetch_add(&cache->_.refcount); +} /* dns_cache_acquire() */ + + +static dns_refcount_t dns_cache_release(struct dns_cache *cache) { + return dns_atomic_fetch_sub(&cache->_.refcount); +} /* dns_cache_release() */ + + +static struct dns_packet *dns_cache_query(struct dns_packet *query, struct dns_cache *cache, int *error) { + (void)query; + (void)cache; + (void)error; + + return NULL; +} /* dns_cache_submit() */ + + +static int dns_cache_submit(struct dns_packet *query, struct dns_cache *cache) { + (void)query; + (void)cache; + + return 0; +} /* dns_cache_submit() */ + + +static int dns_cache_check(struct dns_cache *cache) { + (void)cache; + + return 0; +} /* dns_cache_check() */ + + +static struct dns_packet *dns_cache_fetch(struct dns_cache *cache, int *error) { + (void)cache; + (void)error; + + return NULL; +} /* dns_cache_fetch() */ + + +static int dns_cache_pollfd(struct dns_cache *cache) { + (void)cache; + + return -1; +} /* dns_cache_pollfd() */ + + +static short dns_cache_events(struct dns_cache *cache) { + (void)cache; + + return 0; +} /* dns_cache_events() */ + + +static void dns_cache_clear(struct dns_cache *cache) { + (void)cache; + + return; +} /* dns_cache_clear() */ + + +struct dns_cache *dns_cache_init(struct dns_cache *cache) { + static const struct dns_cache c_init = { + .acquire = &dns_cache_acquire, + .release = &dns_cache_release, + .query = &dns_cache_query, + .submit = &dns_cache_submit, + .check = &dns_cache_check, + .fetch = &dns_cache_fetch, + .pollfd = &dns_cache_pollfd, + .events = &dns_cache_events, + .clear = &dns_cache_clear, + ._ = { .refcount = 1, }, + }; + + *cache = c_init; + + return cache; +} /* dns_cache_init() */ + + +void dns_cache_close(struct dns_cache *cache) { + if (cache) + cache->release(cache); +} /* dns_cache_close() */ + + +/* + * S O C K E T R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +static void dns_socketclose(int *fd, const struct dns_options *opts) { + if (opts && opts->closefd.cb) + opts->closefd.cb(fd, opts->closefd.arg); + + if (*fd != -1) { +#if _WIN32 + closesocket(*fd); +#else + close(*fd); +#endif + *fd = -1; + } +} /* dns_socketclose() */ + + +#define DNS_SO_MAXTRY 7 + +static int dns_socket(struct sockaddr *local, int type, int *error_) { + int error, fd = -1; +#if defined(O_NONBLOCK) + int flags; +#elif defined(FIONBIO) + unsigned long opt; +#endif + + if (-1 == (fd = socket(local->sa_family, type, 0))) + goto soerr; + +#if defined(F_SETFD) + if (-1 == fcntl(fd, F_SETFD, 1)) + goto syerr; +#endif + +#if defined(O_NONBLOCK) + if (-1 == (flags = fcntl(fd, F_GETFL))) + goto syerr; + + if (-1 == fcntl(fd, F_SETFL, flags | O_NONBLOCK)) + goto syerr; +#elif defined(FIONBIO) + opt = 1; + + if (0 != ioctlsocket(fd, FIONBIO, &opt)) + goto soerr; +#endif + +#if defined(SO_NOSIGPIPE) + if (type != SOCK_DGRAM) { + if (0 != setsockopt(fd, SOL_SOCKET, SO_NOSIGPIPE, &(int){ 1 }, sizeof (int))) + goto soerr; + } +#endif + + if (local->sa_family != AF_INET && local->sa_family != AF_INET6) + return fd; + + if (type != SOCK_DGRAM) + return fd; + + if (*dns_sa_port(local->sa_family, local) == 0) { + struct sockaddr_storage tmp; + unsigned i, port; + + memcpy(&tmp, local, dns_sa_len(local)); + + for (i = 0; i < DNS_SO_MAXTRY; i++) { + port = 1025 + (dns_random() % 64510); + + *dns_sa_port(tmp.ss_family, &tmp) = htons(port); + + if (0 == bind(fd, (struct sockaddr *)&tmp, dns_sa_len(&tmp))) + return fd; + } + } + + if (0 == bind(fd, local, dns_sa_len(local))) + return fd; + + /* FALL THROUGH */ +soerr: + error = dns_soerr(); + + goto error; +#if defined(F_SETFD) || defined(O_NONBLOCK) +syerr: + error = dns_syerr(); + + goto error; +#endif +error: + *error_ = error; + + dns_socketclose(&fd, NULL); + + return -1; +} /* dns_socket() */ + + +enum { + DNS_SO_UDP_INIT = 1, + DNS_SO_UDP_CONN, + DNS_SO_UDP_SEND, + DNS_SO_UDP_RECV, + DNS_SO_UDP_DONE, + + DNS_SO_TCP_INIT, + DNS_SO_TCP_CONN, + DNS_SO_TCP_SEND, + DNS_SO_TCP_RECV, + DNS_SO_TCP_DONE, +}; + +struct dns_socket { + struct dns_options opts; + + int udp; + int tcp; + + int *old; + unsigned onum, olim; + + int type; + + struct sockaddr_storage local, remote; + + struct dns_k_permutor qids; + + struct dns_stat stat; + + /* + * NOTE: dns_so_reset() zeroes everything from here down. + */ + int state; + + unsigned short qid; + char qname[DNS_D_MAXNAME + 1]; + size_t qlen; + enum dns_type qtype; + enum dns_class qclass; + + struct dns_packet *query; + size_t qout; + + struct dns_clock elapsed; + + struct dns_packet *answer; + size_t alen, apos; +}; /* struct dns_socket */ + + +/* + * NOTE: Actual closure delayed so that kqueue(2) and epoll(2) callers have + * a chance to recognize a state change after installing a persistent event + * and where sequential descriptors with the same integer value returned + * from _pollfd() would be ambiguous. See dns_so_closefds(). + */ +static int dns_so_closefd(struct dns_socket *so, int *fd) { + int error; + + if (*fd == -1) + return 0; + + if (so->opts.closefd.cb) { + if ((error = so->opts.closefd.cb(fd, so->opts.closefd.arg))) { + return error; + } else if (*fd == -1) + return 0; + } + + if (!(so->onum < so->olim)) { + unsigned olim = DNS_PP_MAX(4, so->olim * 2); + void *old; + + if (!(old = realloc(so->old, sizeof so->old[0] * olim))) + return dns_syerr(); + + so->old = old; + so->olim = olim; + } + + so->old[so->onum++] = *fd; + *fd = -1; + + return 0; +} /* dns_so_closefd() */ + + +#define DNS_SO_CLOSE_UDP 0x01 +#define DNS_SO_CLOSE_TCP 0x02 +#define DNS_SO_CLOSE_OLD 0x04 +#define DNS_SO_CLOSE_ALL (DNS_SO_CLOSE_UDP|DNS_SO_CLOSE_TCP|DNS_SO_CLOSE_OLD) + +static void dns_so_closefds(struct dns_socket *so, int which) { + if (DNS_SO_CLOSE_UDP & which) + dns_socketclose(&so->udp, &so->opts); + if (DNS_SO_CLOSE_TCP & which) + dns_socketclose(&so->tcp, &so->opts); + if (DNS_SO_CLOSE_OLD & which) { + unsigned i; + for (i = 0; i < so->onum; i++) + dns_socketclose(&so->old[i], &so->opts); + so->onum = 0; + free(so->old); + so->old = 0; + so->olim = 0; + } +} /* dns_so_closefds() */ + + +static void dns_so_destroy(struct dns_socket *); + +static struct dns_socket *dns_so_init(struct dns_socket *so, const struct sockaddr *local, int type, const struct dns_options *opts, int *error) { + static const struct dns_socket so_initializer = { .opts = DNS_OPTS_INITIALIZER, .udp = -1, .tcp = -1, }; + + *so = so_initializer; + so->type = type; + + if (opts) + so->opts = *opts; + + if (local) + memcpy(&so->local, local, dns_sa_len(local)); + + if (-1 == (so->udp = dns_socket((struct sockaddr *)&so->local, SOCK_DGRAM, error))) + goto error; + + dns_k_permutor_init(&so->qids, 1, 65535); + + return so; +error: + dns_so_destroy(so); + + return 0; +} /* dns_so_init() */ + + +struct dns_socket *dns_so_open(const struct sockaddr *local, int type, const struct dns_options *opts, int *error) { + struct dns_socket *so; + + if (!(so = malloc(sizeof *so))) + goto syerr; + + if (!dns_so_init(so, local, type, opts, error)) + goto error; + + return so; +syerr: + *error = dns_syerr(); +error: + dns_so_close(so); + + return 0; +} /* dns_so_open() */ + + +static void dns_so_destroy(struct dns_socket *so) { + dns_so_reset(so); + dns_so_closefds(so, DNS_SO_CLOSE_ALL); +} /* dns_so_destroy() */ + + +void dns_so_close(struct dns_socket *so) { + if (!so) + return; + + dns_so_destroy(so); + + free(so); +} /* dns_so_close() */ + + +void dns_so_reset(struct dns_socket *so) { + dns_p_setptr(&so->answer, NULL); + + memset(&so->state, '\0', sizeof *so - offsetof(struct dns_socket, state)); +} /* dns_so_reset() */ + + +unsigned short dns_so_mkqid(struct dns_socket *so) { + return dns_k_permutor_step(&so->qids); +} /* dns_so_mkqid() */ + + +#define DNS_SO_MINBUF 768 + +static int dns_so_newanswer(struct dns_socket *so, size_t len) { + size_t size = offsetof(struct dns_packet, data) + DNS_PP_MAX(len, DNS_SO_MINBUF); + void *p; + + if (!(p = realloc(so->answer, size))) + return dns_syerr(); + + so->answer = dns_p_init(p, size); + + return 0; +} /* dns_so_newanswer() */ + + +int dns_so_submit(struct dns_socket *so, struct dns_packet *Q, struct sockaddr *host) { + struct dns_rr rr; + int error = -1; + + dns_so_reset(so); + + if ((error = dns_rr_parse(&rr, 12, Q))) + goto error; + + if (!(so->qlen = dns_d_expand(so->qname, sizeof so->qname, rr.dn.p, Q, &error))) + goto error; + /* + * NOTE: don't bail if expansion is too long; caller may be + * intentionally sending long names. However, we won't be able to + * verify it on return. + */ + + so->qtype = rr.type; + so->qclass = rr.class; + + if ((error = dns_so_newanswer(so, DNS_SO_MINBUF))) + goto syerr; + + memcpy(&so->remote, host, dns_sa_len(host)); + + so->query = Q; + so->qout = 0; + + dns_begin(&so->elapsed); + + if (dns_header(so->query)->qid == 0) + dns_header(so->query)->qid = dns_so_mkqid(so); + + so->qid = dns_header(so->query)->qid; + so->state = (so->type == SOCK_STREAM)? DNS_SO_TCP_INIT : DNS_SO_UDP_INIT; + + so->stat.queries++; + + return 0; +syerr: + error = dns_syerr(); +error: + dns_so_reset(so); + + return error; +} /* dns_so_submit() */ + + +static int dns_so_verify(struct dns_socket *so, struct dns_packet *P) { + char qname[DNS_D_MAXNAME + 1]; + size_t qlen; + struct dns_rr rr; + int error = -1; + + if (so->qid != dns_header(so->answer)->qid) + return DNS_EUNKNOWN; + + if (!dns_p_count(so->answer, DNS_S_QD)) + return DNS_EUNKNOWN; + + if (0 != dns_rr_parse(&rr, 12, so->answer)) + return DNS_EUNKNOWN; + + if (rr.type != so->qtype || rr.class != so->qclass) + return DNS_EUNKNOWN; + + if (!(qlen = dns_d_expand(qname, sizeof qname, rr.dn.p, P, &error))) + return error; + else if (qlen >= sizeof qname || qlen != so->qlen) + return DNS_EUNKNOWN; + + if (0 != strcasecmp(so->qname, qname)) + return DNS_EUNKNOWN; + + return 0; +} /* dns_so_verify() */ + + +static _Bool dns_so_tcp_keep(struct dns_socket *so) { + struct sockaddr_storage remote; + + if (so->tcp == -1) + return 0; + + if (0 != getpeername(so->tcp, (struct sockaddr *)&remote, &(socklen_t){ sizeof remote })) + return 0; + + return 0 == dns_sa_cmp(&remote, &so->remote); +} /* dns_so_tcp_keep() */ + + +#if defined __clang__ +#pragma clang diagnostic push +#pragma clang diagnostic ignored "-Warray-bounds" +#endif + +static int dns_so_tcp_send(struct dns_socket *so) { + unsigned char *qsrc; + size_t qend; + long n; + + so->query->data[-2] = 0xff & (so->query->end >> 8); + so->query->data[-1] = 0xff & (so->query->end >> 0); + + qsrc = &so->query->data[-2] + so->qout; + qend = so->query->end + 2; + + while (so->qout < qend) { + if (0 > (n = dns_send(so->tcp, (void *)&qsrc[so->qout], qend - so->qout, 0))) + return dns_soerr(); + + so->qout += n; + so->stat.tcp.sent.bytes += n; + } + + so->stat.tcp.sent.count++; + + return 0; +} /* dns_so_tcp_send() */ + + +static int dns_so_tcp_recv(struct dns_socket *so) { + unsigned char *asrc; + size_t aend, alen; + int error; + long n; + + aend = so->alen + 2; + + while (so->apos < aend) { + asrc = &so->answer->data[-2]; + + if (0 > (n = recv(so->tcp, (void *)&asrc[so->apos], aend - so->apos, 0))) + return dns_soerr(); + else if (n == 0) + return DNS_EUNKNOWN; /* FIXME */ + + so->apos += n; + so->stat.tcp.rcvd.bytes += n; + + if (so->alen == 0 && so->apos >= 2) { + alen = ((0xff & so->answer->data[-2]) << 8) + | ((0xff & so->answer->data[-1]) << 0); + + if ((error = dns_so_newanswer(so, alen))) + return error; + + so->alen = alen; + aend = alen + 2; + } + } + + so->answer->end = so->alen; + so->stat.tcp.rcvd.count++; + + return 0; +} /* dns_so_tcp_recv() */ + +#if __clang__ +#pragma clang diagnostic pop +#endif + + +int dns_so_check(struct dns_socket *so) { + int error; + long n; + +retry: + switch (so->state) { + case DNS_SO_UDP_INIT: + so->state++; + case DNS_SO_UDP_CONN: + if (0 != connect(so->udp, (struct sockaddr *)&so->remote, dns_sa_len(&so->remote))) + goto soerr; + + so->state++; + case DNS_SO_UDP_SEND: + if (0 > (n = send(so->udp, (void *)so->query->data, so->query->end, 0))) + goto soerr; + + so->stat.udp.sent.bytes += n; + so->stat.udp.sent.count++; + + so->state++; + case DNS_SO_UDP_RECV: + if (0 > (n = recv(so->udp, (void *)so->answer->data, so->answer->size, 0))) + goto soerr; + + so->stat.udp.rcvd.bytes += n; + so->stat.udp.rcvd.count++; + + if ((so->answer->end = n) < 12) + goto trash; + + if ((error = dns_so_verify(so, so->answer))) + goto trash; + + so->state++; + case DNS_SO_UDP_DONE: + if (!dns_header(so->answer)->tc || so->type == SOCK_DGRAM) + return 0; + + so->state++; + case DNS_SO_TCP_INIT: + if (dns_so_tcp_keep(so)) { + so->state = DNS_SO_TCP_SEND; + + goto retry; + } + + if ((error = dns_so_closefd(so, &so->tcp))) + goto error; + + if (-1 == (so->tcp = dns_socket((struct sockaddr *)&so->local, SOCK_STREAM, &error))) + goto error; + + so->state++; + case DNS_SO_TCP_CONN: + if (0 != connect(so->tcp, (struct sockaddr *)&so->remote, dns_sa_len(&so->remote))) { + if (dns_soerr() != DNS_EISCONN) + goto soerr; + } + + so->state++; + case DNS_SO_TCP_SEND: + if ((error = dns_so_tcp_send(so))) + goto error; + + so->state++; + case DNS_SO_TCP_RECV: + if ((error = dns_so_tcp_recv(so))) + goto error; + + so->state++; + case DNS_SO_TCP_DONE: + /* close unless DNS_RESCONF_TCP_ONLY (see dns_res_tcp2type) */ + if (so->type != SOCK_STREAM) { + if ((error = dns_so_closefd(so, &so->tcp))) + goto error; + } + + if (so->answer->end < 12) + return DNS_EILLEGAL; + + if ((error = dns_so_verify(so, so->answer))) + goto error; + + return 0; + default: + error = DNS_EUNKNOWN; + + goto error; + } /* switch() */ + +trash: + goto retry; +soerr: + error = dns_soerr(); + + goto error; +error: + switch (error) { + case DNS_EINTR: + goto retry; + case DNS_EINPROGRESS: + /* FALL THROUGH */ + case DNS_EALREADY: + /* FALL THROUGH */ +#if DNS_EWOULDBLOCK != DNS_EAGAIN + case DNS_EWOULDBLOCK: + /* FALL THROUGH */ +#endif + error = DNS_EAGAIN; + + break; + } /* switch() */ + + return error; +} /* dns_so_check() */ + + +struct dns_packet *dns_so_fetch(struct dns_socket *so, int *error) { + struct dns_packet *answer; + + switch (so->state) { + case DNS_SO_UDP_DONE: + case DNS_SO_TCP_DONE: + answer = so->answer; + so->answer = 0; + + return answer; + default: + *error = DNS_EUNKNOWN; + + return 0; + } +} /* dns_so_fetch() */ + + +struct dns_packet *dns_so_query(struct dns_socket *so, struct dns_packet *Q, struct sockaddr *host, int *error_) { + struct dns_packet *A; + int error; + + if (!so->state) { + if ((error = dns_so_submit(so, Q, host))) + goto error; + } + + if ((error = dns_so_check(so))) + goto error; + + if (!(A = dns_so_fetch(so, &error))) + goto error; + + dns_so_reset(so); + + return A; +error: + *error_ = error; + + return 0; +} /* dns_so_query() */ + + +time_t dns_so_elapsed(struct dns_socket *so) { + return dns_elapsed(&so->elapsed); +} /* dns_so_elapsed() */ + + +void dns_so_clear(struct dns_socket *so) { + dns_so_closefds(so, DNS_SO_CLOSE_OLD); +} /* dns_so_clear() */ + + +static int dns_so_events2(struct dns_socket *so, enum dns_events type) { + int events = 0; + + switch (so->state) { + case DNS_SO_UDP_CONN: + case DNS_SO_UDP_SEND: + events |= DNS_POLLOUT; + + break; + case DNS_SO_UDP_RECV: + events |= DNS_POLLIN; + + break; + case DNS_SO_TCP_CONN: + case DNS_SO_TCP_SEND: + events |= DNS_POLLOUT; + + break; + case DNS_SO_TCP_RECV: + events |= DNS_POLLIN; + + break; + } /* switch() */ + + switch (type) { + case DNS_LIBEVENT: + return DNS_POLL2EV(events); + default: + return events; + } /* switch() */ +} /* dns_so_events2() */ + + +int dns_so_events(struct dns_socket *so) { + return dns_so_events2(so, so->opts.events); +} /* dns_so_events() */ + + +int dns_so_pollfd(struct dns_socket *so) { + switch (so->state) { + case DNS_SO_UDP_CONN: + case DNS_SO_UDP_SEND: + case DNS_SO_UDP_RECV: + return so->udp; + case DNS_SO_TCP_CONN: + case DNS_SO_TCP_SEND: + case DNS_SO_TCP_RECV: + return so->tcp; + } /* switch() */ + + return -1; +} /* dns_so_pollfd() */ + + +int dns_so_poll(struct dns_socket *so, int timeout) { + return dns_poll(dns_so_pollfd(so), dns_so_events2(so, DNS_SYSPOLL), timeout); +} /* dns_so_poll() */ + + +const struct dns_stat *dns_so_stat(struct dns_socket *so) { + return &so->stat; +} /* dns_so_stat() */ + + +/* + * R E S O L V E R R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +enum dns_res_state { + DNS_R_INIT, + DNS_R_GLUE, + DNS_R_SWITCH, /* (B)IND, (F)ILE, (C)ACHE */ + + DNS_R_FILE, /* Lookup in local hosts database */ + + DNS_R_CACHE, /* Lookup in application cache */ + DNS_R_SUBMIT, + DNS_R_CHECK, + DNS_R_FETCH, + + DNS_R_BIND, /* Lookup in the network */ + DNS_R_SEARCH, + DNS_R_HINTS, + DNS_R_ITERATE, + DNS_R_FOREACH_NS, + DNS_R_RESOLV0_NS, /* Prologue: Setup next frame and recurse */ + DNS_R_RESOLV1_NS, /* Epilog: Inspect answer */ + DNS_R_FOREACH_A, + DNS_R_QUERY_A, + DNS_R_CNAME0_A, + DNS_R_CNAME1_A, + + DNS_R_FINISH, + DNS_R_SMART0_A, + DNS_R_SMART1_A, + DNS_R_DONE, + DNS_R_SERVFAIL, +}; /* enum dns_res_state */ + + +#define DNS_R_MAXDEPTH 8 +#define DNS_R_ENDFRAME (DNS_R_MAXDEPTH - 1) + +struct dns_resolver { + struct dns_socket so; + + struct dns_resolv_conf *resconf; + struct dns_hosts *hosts; + struct dns_hints *hints; + struct dns_cache *cache; + + dns_atomic_t refcount; + + /* Reset zeroes everything below here. */ + + char qname[DNS_D_MAXNAME + 1]; + size_t qlen; + + enum dns_type qtype; + enum dns_class qclass; + + struct dns_clock elapsed; + + dns_resconf_i_t search; + + struct dns_rr_i smart; + + struct dns_packet *nodata; /* answer if nothing better */ + + unsigned sp; + + struct dns_res_frame { + enum dns_res_state state; + + int error; + int which; /* (B)IND, (F)ILE; index into resconf->lookup */ + + unsigned attempts; + + struct dns_packet *query, *answer, *hints; + + struct dns_rr_i hints_i, hints_j; + struct dns_rr hints_ns, ans_cname; + } stack[DNS_R_MAXDEPTH]; +}; /* struct dns_resolver */ + + +static int dns_res_tcp2type(int tcp) { + switch (tcp) { + case DNS_RESCONF_TCP_ONLY: + return SOCK_STREAM; + case DNS_RESCONF_TCP_DISABLE: + return SOCK_DGRAM; + default: + return 0; + } +} /* dns_res_tcp2type() */ + +struct dns_resolver *dns_res_open(struct dns_resolv_conf *resconf, struct dns_hosts *hosts, struct dns_hints *hints, struct dns_cache *cache, const struct dns_options *opts, int *_error) { + static const struct dns_resolver R_initializer + = { .refcount = 1, }; + struct dns_resolver *R = 0; + int type, error; + + /* + * Grab ref count early because the caller may have passed us a mortal + * reference, and we want to do the right thing if we return early + * from an error. + */ + if (resconf) + dns_resconf_acquire(resconf); + if (hosts) + dns_hosts_acquire(hosts); + if (hints) + dns_hints_acquire(hints); + if (cache) + dns_cache_acquire(cache); + + /* + * Don't try to load it ourselves because a NULL object might be an + * error from, say, dns_resconf_root(), and loading + * dns_resconf_local() by default would create undesirable surpises. + */ + if (!resconf || !hosts || !hints) + goto _error; + + if (!(R = malloc(sizeof *R))) + goto syerr; + + *R = R_initializer; + type = dns_res_tcp2type(resconf->options.tcp); + + if (!dns_so_init(&R->so, (struct sockaddr *)&resconf->iface, type, opts, &error)) + goto error; + + R->resconf = resconf; + R->hosts = hosts; + R->hints = hints; + R->cache = cache; + + return R; +syerr: + error = dns_syerr(); +error: + *_error = error; +_error: + dns_res_close(R); + + dns_resconf_close(resconf); + dns_hosts_close(hosts); + dns_hints_close(hints); + dns_cache_close(cache); + + return 0; +} /* dns_res_open() */ + + +struct dns_resolver *dns_res_stub(const struct dns_options *opts, int *error) { + struct dns_resolv_conf *resconf = 0; + struct dns_hosts *hosts = 0; + struct dns_hints *hints = 0; + struct dns_resolver *res = 0; + + if (!(resconf = dns_resconf_local(error))) + goto epilog; + + if (!(hosts = dns_hosts_local(error))) + goto epilog; + + if (!(hints = dns_hints_local(resconf, error))) + goto epilog; + + if (!(res = dns_res_open(resconf, hosts, hints, NULL, opts, error))) + goto epilog; + +epilog: + dns_resconf_close(resconf); + dns_hosts_close(hosts); + dns_hints_close(hints); + + return res; +} /* dns_res_stub() */ + + +static void dns_res_reset_frame(struct dns_resolver *R, struct dns_res_frame *frame) { + (void)R; + + dns_p_setptr(&frame->query, NULL); + dns_p_setptr(&frame->answer, NULL); + dns_p_setptr(&frame->hints, NULL); + + memset(frame, '\0', sizeof *frame); +} /* dns_res_reset_frame() */ + + +void dns_res_reset(struct dns_resolver *R) { + unsigned i; + + dns_so_reset(&R->so); + + dns_p_setptr(&R->nodata, NULL); + + for (i = 0; i < lengthof(R->stack); i++) + dns_res_reset_frame(R, &R->stack[i]); + + memset(&R->qname, '\0', sizeof *R - offsetof(struct dns_resolver, qname)); +} /* dns_res_reset() */ + + +void dns_res_close(struct dns_resolver *R) { + if (!R || 1 < dns_res_release(R)) + return; + + dns_res_reset(R); + + dns_so_destroy(&R->so); + + dns_hints_close(R->hints); + dns_hosts_close(R->hosts); + dns_resconf_close(R->resconf); + dns_cache_close(R->cache); + + free(R); +} /* dns_res_close() */ + + +dns_refcount_t dns_res_acquire(struct dns_resolver *R) { + return dns_atomic_fetch_add(&R->refcount); +} /* dns_res_acquire() */ + + +dns_refcount_t dns_res_release(struct dns_resolver *R) { + return dns_atomic_fetch_sub(&R->refcount); +} /* dns_res_release() */ + + +struct dns_resolver *dns_res_mortal(struct dns_resolver *res) { + if (res) + dns_res_release(res); + return res; +} /* dns_res_mortal() */ + + +static struct dns_packet *dns_res_merge(struct dns_packet *P0, struct dns_packet *P1, int *error_) { + size_t bufsiz = P0->end + P1->end; + struct dns_packet *P[3] = { P0, P1, 0 }; + struct dns_rr rr[3]; + int error, copy, i; + enum dns_section section; + +retry: + if (!(P[2] = dns_p_make(bufsiz, &error))) + goto error; + + dns_rr_foreach(&rr[0], P[0], .section = DNS_S_QD) { + if ((error = dns_rr_copy(P[2], &rr[0], P[0]))) + goto error; + } + + for (section = DNS_S_AN; (DNS_S_ALL & section); section <<= 1) { + for (i = 0; i < 2; i++) { + dns_rr_foreach(&rr[i], P[i], .section = section) { + copy = 1; + + dns_rr_foreach(&rr[2], P[2], .type = rr[i].type, .section = (DNS_S_ALL & ~DNS_S_QD)) { + if (0 == dns_rr_cmp(&rr[i], P[i], &rr[2], P[2])) { + copy = 0; + + break; + } + } + + if (copy && (error = dns_rr_copy(P[2], &rr[i], P[i]))) { + if (error == DNS_ENOBUFS && bufsiz < 65535) { + dns_p_setptr(&P[2], NULL); + + bufsiz = DNS_PP_MAX(65535, bufsiz * 2); + + goto retry; + } + + goto error; + } + } /* foreach(rr) */ + } /* foreach(packet) */ + } /* foreach(section) */ + + return P[2]; +error: + *error_ = error; + + dns_p_free(P[2]); + + return 0; +} /* dns_res_merge() */ + + +static struct dns_packet *dns_res_glue(struct dns_resolver *R, struct dns_packet *Q) { + struct dns_packet *P = dns_p_new(512); + char qname[DNS_D_MAXNAME + 1]; + size_t qlen; + enum dns_type qtype; + struct dns_rr rr; + unsigned sp; + int error; + + if (!(qlen = dns_d_expand(qname, sizeof qname, 12, Q, &error)) + || qlen >= sizeof qname) + return 0; + + if (!(qtype = dns_rr_type(12, Q))) + return 0; + + if ((error = dns_p_push(P, DNS_S_QD, qname, strlen(qname), qtype, DNS_C_IN, 0, 0))) + return 0; + + for (sp = 0; sp <= R->sp; sp++) { + if (!R->stack[sp].answer) + continue; + + dns_rr_foreach(&rr, R->stack[sp].answer, .name = qname, .type = qtype, .section = (DNS_S_ALL & ~DNS_S_QD)) { + rr.section = DNS_S_AN; + + if ((error = dns_rr_copy(P, &rr, R->stack[sp].answer))) + return 0; + } + } + + if (dns_p_count(P, DNS_S_AN) > 0) + goto copy; + + /* Otherwise, look for a CNAME */ + for (sp = 0; sp <= R->sp; sp++) { + if (!R->stack[sp].answer) + continue; + + dns_rr_foreach(&rr, R->stack[sp].answer, .name = qname, .type = DNS_T_CNAME, .section = (DNS_S_ALL & ~DNS_S_QD)) { + rr.section = DNS_S_AN; + + if ((error = dns_rr_copy(P, &rr, R->stack[sp].answer))) + return 0; + } + } + + if (!dns_p_count(P, DNS_S_AN)) + return 0; + +copy: + return dns_p_copy(dns_p_make(P->end, &error), P); +} /* dns_res_glue() */ + + +static struct dns_packet *dns_res_mkquery(struct dns_resolver *R, const char *qname, enum dns_type qtype, enum dns_class qclass, int *error_) { + struct dns_packet *Q = 0; + int error; + + if (!(Q = dns_p_init(malloc(DNS_P_QBUFSIZ), DNS_P_QBUFSIZ))) + goto syerr; + + if ((error = dns_p_push(Q, DNS_S_QD, qname, strlen(qname), qtype, qclass, 0, 0))) + goto error; + + dns_header(Q)->rd = !R->resconf->options.recurse; + + return Q; +syerr: + error = dns_syerr(); +error: + dns_p_free(Q); + + *error_ = error; + + return 0; +} /* dns_res_mkquery() */ + + +/* + * Sort NS records by three criteria: + * + * 1) Whether glue is present. + * 2) Whether glue record is original or of recursive lookup. + * 3) Randomly shuffle records which share the above criteria. + * + * NOTE: Assumes only NS records passed, AND ASSUMES no new NS records will + * be added during an iteration. + * + * FIXME: Only groks A glue, not AAAA glue. + */ +static int dns_res_nameserv_cmp(struct dns_rr *a, struct dns_rr *b, struct dns_rr_i *i, struct dns_packet *P) { + _Bool glued[2] = { 0 }; + struct dns_rr x = { 0 }, y = { 0 }; + struct dns_ns ns; + int cmp, error; + + if (!(error = dns_ns_parse(&ns, a, P))) + glued[0] = !!dns_rr_grep(&x, 1, dns_rr_i_new(P, .section = (DNS_S_ALL & ~DNS_S_QD), .name = ns.host, .type = DNS_T_A), P, &error); + + if (!(error = dns_ns_parse(&ns, b, P))) + glued[1] = !!dns_rr_grep(&y, 1, dns_rr_i_new(P, .section = (DNS_S_ALL & ~DNS_S_QD), .name = ns.host, .type = DNS_T_A), P, &error); + + if ((cmp = glued[1] - glued[0])) { + return cmp; + } else if ((cmp = (dns_rr_offset(&y) < i->args[0]) - (dns_rr_offset(&x) < i->args[0]))) { + return cmp; + } else { + return dns_rr_i_shuffle(a, b, i, P); + } +} /* dns_res_nameserv_cmp() */ + + +#define dgoto(sp, i) \ + do { R->stack[(sp)].state = (i); goto exec; } while (0) + +static int dns_res_exec(struct dns_resolver *R) { + struct dns_res_frame *F; + struct dns_packet *P; + char host[DNS_D_MAXNAME + 1]; + size_t len; + struct dns_rr rr; + struct sockaddr_in sin; + int error; + +exec: + + F = &R->stack[R->sp]; + + switch (F->state) { + case DNS_R_INIT: + F->state++; + case DNS_R_GLUE: + if (R->sp == 0) + dgoto(R->sp, DNS_R_SWITCH); + + if (!F->query) + goto noquery; + + if (!(F->answer = dns_res_glue(R, F->query))) + dgoto(R->sp, DNS_R_SWITCH); + + if (!(len = dns_d_expand(host, sizeof host, 12, F->query, &error))) + goto error; + else if (len >= sizeof host) + goto toolong; + + dns_rr_foreach(&rr, F->answer, .name = host, .type = dns_rr_type(12, F->query), .section = DNS_S_AN) { + dgoto(R->sp, DNS_R_FINISH); + } + + dns_rr_foreach(&rr, F->answer, .name = host, .type = DNS_T_CNAME, .section = DNS_S_AN) { + F->ans_cname = rr; + + dgoto(R->sp, DNS_R_CNAME0_A); + } + + F->state++; + case DNS_R_SWITCH: + while (F->which < (int)sizeof R->resconf->lookup && R->resconf->lookup[F->which]) { + switch (R->resconf->lookup[F->which++]) { + case 'b': case 'B': + dgoto(R->sp, DNS_R_BIND); + case 'f': case 'F': + dgoto(R->sp, DNS_R_FILE); + case 'c': case 'C': + if (R->cache) + dgoto(R->sp, DNS_R_CACHE); + + break; + default: + break; + } + } + + /* + * FIXME: Examine more closely whether our logic is correct + * and DNS_R_SERVFAIL is the correct default response. + * + * Case 1: We got here because we never got an answer on the + * wire. All queries timed-out and we reached maximum + * attempts count. See DNS_R_FOREACH_NS. In that case + * DNS_R_SERVFAIL is the correct state, unless we want to + * return DNS_ETIMEDOUT. + * + * Case 2: We were a stub resolver and got an unsatisfactory + * answer (empty ANSWER section) which caused us to jump + * back to DNS_R_SEARCH and ultimately to DNS_R_SWITCH. We + * return the answer returned from the wire, which we + * stashed in R->nodata. + * + * Case 3: We reached maximum attempts count as in case #1, + * but never got an authoritative response which caused us + * to short-circuit. See end of DNS_R_QUERY_A case. We + * should probably prepare R->nodata as in case #2. + */ + if (R->sp == 0 && R->nodata) { /* XXX: can we just return nodata regardless? */ + dns_p_movptr(&F->answer, &R->nodata); + dgoto(R->sp, DNS_R_FINISH); + } + + dgoto(R->sp, DNS_R_SERVFAIL); + case DNS_R_FILE: + if (R->sp > 0) { + if (!dns_p_setptr(&F->answer, dns_hosts_query(R->hosts, F->query, &error))) + goto error; + + if (dns_p_count(F->answer, DNS_S_AN) > 0) + dgoto(R->sp, DNS_R_FINISH); + + dns_p_setptr(&F->answer, NULL); + } else { + R->search = 0; + + while ((len = dns_resconf_search(host, sizeof host, R->qname, R->qlen, R->resconf, &R->search))) { +/* + * FIXME: Some sort of bug, either with this code or with GCC 3.3.5 on + * OpenBSD 4.4, overwites the stack guard. If the bug is in this file, it + * appears to be localized somewhere around here. It can also be mitigated + * in dns_hosts_query(). In any event, the bug manifests only when using + * compound literals. alloca(), malloc(), calloc(), etc, all work fine. + * Valgrind (tested on Linux) cannot detect any issues, but stack issues are + * not Valgrind's forte. Neither can I spot anything in the assembly, but + * that's not my forte. + */ +#if __OpenBSD__ && __GNUC__ + struct dns_packet *query = __builtin_alloca(DNS_P_QBUFSIZ); + + dns_p_init(query, DNS_P_QBUFSIZ); +#else + struct dns_packet *query = dns_p_new(DNS_P_QBUFSIZ); +#endif + + if ((error = dns_p_push(query, DNS_S_QD, host, len, R->qtype, R->qclass, 0, 0))) + goto error; + + if (!dns_p_setptr(&F->answer, dns_hosts_query(R->hosts, query, &error))) + goto error; + + if (dns_p_count(F->answer, DNS_S_AN) > 0) + dgoto(R->sp, DNS_R_FINISH); + + dns_p_setptr(&F->answer, NULL); + } + } + + dgoto(R->sp, DNS_R_SWITCH); + case DNS_R_CACHE: + error = 0; + + if (!F->query && !(F->query = dns_res_mkquery(R, R->qname, R->qtype, R->qclass, &error))) + goto error; + + if (dns_p_setptr(&F->answer, R->cache->query(F->query, R->cache, &error))) { + if (dns_p_count(F->answer, DNS_S_AN) > 0) + dgoto(R->sp, DNS_R_FINISH); + + dns_p_setptr(&F->answer, NULL); + + dgoto(R->sp, DNS_R_SWITCH); + } else if (error) + goto error; + + F->state++; + case DNS_R_SUBMIT: + if ((error = R->cache->submit(F->query, R->cache))) + goto error; + + F->state++; + case DNS_R_CHECK: + if ((error = R->cache->check(R->cache))) + goto error; + + F->state++; + case DNS_R_FETCH: + error = 0; + + if (dns_p_setptr(&F->answer, R->cache->fetch(R->cache, &error))) { + if (dns_p_count(F->answer, DNS_S_AN) > 0) + dgoto(R->sp, DNS_R_FINISH); + + dns_p_setptr(&F->answer, NULL); + + dgoto(R->sp, DNS_R_SWITCH); + } else if (error) + goto error; + + dgoto(R->sp, DNS_R_SWITCH); + case DNS_R_BIND: + if (R->sp > 0) { + if (!F->query) + goto noquery; + + dgoto(R->sp, DNS_R_HINTS); + } + + R->search = 0; + + F->state++; + case DNS_R_SEARCH: + /* + * XXX: We probably should only apply the domain search + * algorithm if R->sp == 0. + */ + if (!(len = dns_resconf_search(host, sizeof host, R->qname, R->qlen, R->resconf, &R->search))) + dgoto(R->sp, DNS_R_SWITCH); + + if (!(P = dns_p_make(DNS_P_QBUFSIZ, &error))) + goto error; + + dns_header(P)->rd = !R->resconf->options.recurse; + + dns_p_setptr(&F->query, P); + + if ((error = dns_p_push(F->query, DNS_S_QD, host, len, R->qtype, R->qclass, 0, 0))) + goto error; + + F->state++; + case DNS_R_HINTS: + if (!dns_p_setptr(&F->hints, dns_hints_query(R->hints, F->query, &error))) + goto error; + + F->state++; + case DNS_R_ITERATE: + dns_rr_i_init(&F->hints_i, F->hints); + + F->hints_i.section = DNS_S_AUTHORITY; + F->hints_i.type = DNS_T_NS; + F->hints_i.sort = &dns_res_nameserv_cmp; + F->hints_i.args[0] = F->hints->end; + + F->state++; + case DNS_R_FOREACH_NS: + dns_rr_i_save(&F->hints_i); + + /* Load our next nameserver host. */ + if (!dns_rr_grep(&F->hints_ns, 1, &F->hints_i, F->hints, &error)) { + if (++F->attempts < R->resconf->options.attempts) + dgoto(R->sp, DNS_R_ITERATE); + + dgoto(R->sp, DNS_R_SWITCH); + } + + dns_rr_i_init(&F->hints_j, F->hints); + + /* Assume there are glue records */ + dgoto(R->sp, DNS_R_FOREACH_A); + case DNS_R_RESOLV0_NS: + /* Have we reached our max depth? */ + if (&F[1] >= endof(R->stack)) + dgoto(R->sp, DNS_R_FOREACH_NS); + + dns_res_reset_frame(R, &F[1]); + + if (!(F[1].query = dns_p_make(DNS_P_QBUFSIZ, &error))) + goto error; + + if ((error = dns_ns_parse((struct dns_ns *)host, &F->hints_ns, F->hints))) + goto error; + + if ((error = dns_p_push(F[1].query, DNS_S_QD, host, strlen(host), DNS_T_A, DNS_C_IN, 0, 0))) + goto error; + + F->state++; + + dgoto(++R->sp, DNS_R_INIT); + case DNS_R_RESOLV1_NS: + if (!(len = dns_d_expand(host, sizeof host, 12, F[1].query, &error))) + goto error; + else if (len >= sizeof host) + goto toolong; + + dns_rr_foreach(&rr, F[1].answer, .name = host, .type = DNS_T_A, .section = (DNS_S_ALL & ~DNS_S_QD)) { + rr.section = DNS_S_AR; + + if ((error = dns_rr_copy(F->hints, &rr, F[1].answer))) + goto error; + + dns_rr_i_rewind(&F->hints_i); /* Now there's glue. */ + } + + dgoto(R->sp, DNS_R_FOREACH_NS); + case DNS_R_FOREACH_A: + /* + * NOTE: Iterator initialized in DNS_R_FOREACH_NS because + * this state is re-entrant, but we need to reset + * .name to a valid pointer each time. + */ + if ((error = dns_ns_parse((struct dns_ns *)host, &F->hints_ns, F->hints))) + goto error; + + F->hints_j.name = host; + F->hints_j.type = DNS_T_A; + F->hints_j.section = DNS_S_ALL & ~DNS_S_QD; + + if (!dns_rr_grep(&rr, 1, &F->hints_j, F->hints, &error)) { + if (!dns_rr_i_count(&F->hints_j)) + dgoto(R->sp, DNS_R_RESOLV0_NS); + + dgoto(R->sp, DNS_R_FOREACH_NS); + } + + sin.sin_family = AF_INET; + + if ((error = dns_a_parse((struct dns_a *)&sin.sin_addr, &rr, F->hints))) + goto error; + + if (R->sp == 0) + sin.sin_port = dns_hints_port(R->hints, AF_INET, (struct sockaddr *)&sin.sin_addr); + else + sin.sin_port = htons(53); + + if (DNS_DEBUG) { + char addr[INET_ADDRSTRLEN + 1]; + dns_a_print(addr, sizeof addr, (struct dns_a *)&sin.sin_addr); + DNS_SHOW(F->query, "ASKING: %s/%s @ DEPTH: %u)", host, addr, R->sp); + } + + if ((error = dns_so_submit(&R->so, F->query, (struct sockaddr *)&sin))) + goto error; + + F->state++; + case DNS_R_QUERY_A: + if (dns_so_elapsed(&R->so) >= dns_resconf_timeout(R->resconf)) + dgoto(R->sp, DNS_R_FOREACH_A); + + if ((error = dns_so_check(&R->so))) + goto error; + + if (!dns_p_setptr(&F->answer, dns_so_fetch(&R->so, &error))) + goto error; + + if (DNS_DEBUG) { + DNS_SHOW(F->answer, "ANSWER @ DEPTH: %u)", R->sp); + } + + if ((error = dns_rr_parse(&rr, 12, F->query))) + goto error; + + if (!(len = dns_d_expand(host, sizeof host, rr.dn.p, F->query, &error))) + goto error; + else if (len >= sizeof host) + goto toolong; + + dns_rr_foreach(&rr, F->answer, .section = DNS_S_AN, .name = host, .type = rr.type) { + dgoto(R->sp, DNS_R_FINISH); /* Found */ + } + + dns_rr_foreach(&rr, F->answer, .section = DNS_S_AN, .name = host, .type = DNS_T_CNAME) { + F->ans_cname = rr; + + dgoto(R->sp, DNS_R_CNAME0_A); + } + + /* + * XXX: The condition here should probably check whether + * R->sp == 0, because DNS_R_SEARCH runs regardless of + * options.recurse. See DNS_R_BIND. + */ + if (!R->resconf->options.recurse) { + /* Make first answer our tentative answer */ + if (!R->nodata) + dns_p_movptr(&R->nodata, &F->answer); + + dgoto(R->sp, DNS_R_SEARCH); + } + + dns_rr_foreach(&rr, F->answer, .section = DNS_S_NS, .type = DNS_T_NS) { + dns_p_movptr(&F->hints, &F->answer); + + dgoto(R->sp, DNS_R_ITERATE); + } + + /* XXX: Should this go further up? */ + if (dns_header(F->answer)->aa) + dgoto(R->sp, DNS_R_FINISH); + + /* XXX: Should we copy F->answer to R->nodata? */ + + dgoto(R->sp, DNS_R_FOREACH_A); + case DNS_R_CNAME0_A: + if (&F[1] >= endof(R->stack)) + dgoto(R->sp, DNS_R_FINISH); + + if ((error = dns_cname_parse((struct dns_cname *)host, &F->ans_cname, F->answer))) + goto error; + + dns_res_reset_frame(R, &F[1]); + + if (!(F[1].query = dns_p_make(DNS_P_QBUFSIZ, &error))) + goto error; + + if ((error = dns_p_push(F[1].query, DNS_S_QD, host, strlen(host), dns_rr_type(12, F->query), DNS_C_IN, 0, 0))) + goto error; + + F->state++; + + dgoto(++R->sp, DNS_R_INIT); + case DNS_R_CNAME1_A: + if (!(P = dns_res_merge(F->answer, F[1].answer, &error))) + goto error; + + dns_p_setptr(&F->answer, P); + + dgoto(R->sp, DNS_R_FINISH); + case DNS_R_FINISH: + if (!F->answer) + goto noanswer; + + if (!R->resconf->options.smart || R->sp > 0) + dgoto(R->sp, DNS_R_DONE); + + R->smart.section = DNS_S_AN; + R->smart.type = R->qtype; + + dns_rr_i_init(&R->smart, F->answer); + + F->state++; + case DNS_R_SMART0_A: + if (&F[1] >= endof(R->stack)) + dgoto(R->sp, DNS_R_DONE); + + while (dns_rr_grep(&rr, 1, &R->smart, F->answer, &error)) { + union { + struct dns_ns ns; + struct dns_mx mx; + struct dns_srv srv; + } rd; + const char *qname; + enum dns_type qtype; + enum dns_class qclass; + + switch (rr.type) { + case DNS_T_NS: + if ((error = dns_ns_parse(&rd.ns, &rr, F->answer))) + goto error; + + qname = rd.ns.host; + qtype = DNS_T_A; + qclass = DNS_C_IN; + + break; + case DNS_T_MX: + if ((error = dns_mx_parse(&rd.mx, &rr, F->answer))) + goto error; + + qname = rd.mx.host; + qtype = DNS_T_A; + qclass = DNS_C_IN; + + break; + case DNS_T_SRV: + if ((error = dns_srv_parse(&rd.srv, &rr, F->answer))) + goto error; + + qname = rd.srv.target; + qtype = DNS_T_A; + qclass = DNS_C_IN; + + break; + default: + continue; + } /* switch() */ + + dns_res_reset_frame(R, &F[1]); + + if (!(F[1].query = dns_res_mkquery(R, qname, qtype, qclass, &error))) + goto error; + + F->state++; + + dgoto(++R->sp, DNS_R_INIT); + } /* while() */ + + /* + * NOTE: SMTP specification says to fallback to A record. + * + * XXX: Should we add a mock MX answer? + */ + if (R->qtype == DNS_T_MX && R->smart.state.count == 0) { + dns_res_reset_frame(R, &F[1]); + + if (!(F[1].query = dns_res_mkquery(R, R->qname, DNS_T_A, DNS_C_IN, &error))) + goto error; + + R->smart.state.count++; + F->state++; + + dgoto(++R->sp, DNS_R_INIT); + } + + dgoto(R->sp, DNS_R_DONE); + case DNS_R_SMART1_A: + if (!F[1].answer) + goto noanswer; + + /* + * FIXME: For CNAME chains (which are typically illegal in + * this context), we should rewrite the record host name + * to the original smart qname. All the user cares about + * is locating that A/AAAA record. + */ + dns_rr_foreach(&rr, F[1].answer, .section = DNS_S_AN, .type = DNS_T_A) { + rr.section = DNS_S_AR; + + if (dns_rr_exists(&rr, F[1].answer, F->answer)) + continue; + + while ((error = dns_rr_copy(F->answer, &rr, F[1].answer))) { + if (error != DNS_ENOBUFS) + goto error; + if ((error = dns_p_grow(&F->answer))) + goto error; + } + } + + dgoto(R->sp, DNS_R_SMART0_A); + case DNS_R_DONE: + if (!F->answer) + goto noanswer; + + if (R->sp > 0) + dgoto(--R->sp, F[-1].state); + + break; + case DNS_R_SERVFAIL: + if (!dns_p_setptr(&F->answer, dns_p_make(DNS_P_QBUFSIZ, &error))) + goto error; + + dns_header(F->answer)->qr = 1; + dns_header(F->answer)->rcode = DNS_RC_SERVFAIL; + + if ((error = dns_p_push(F->answer, DNS_S_QD, R->qname, strlen(R->qname), R->qtype, R->qclass, 0, 0))) + goto error; + + dgoto(R->sp, DNS_R_DONE); + default: + error = EINVAL; + + goto error; + } /* switch () */ + + return 0; +noquery: + error = DNS_ENOQUERY; + + goto error; +noanswer: + error = DNS_ENOANSWER; + + goto error; +toolong: + error = DNS_EILLEGAL; + + /* FALL THROUGH */ +error: + return error; +} /* dns_res_exec() */ + +#undef goto + + +void dns_res_clear(struct dns_resolver *R) { + switch (R->stack[R->sp].state) { + case DNS_R_CHECK: + R->cache->clear(R->cache); + break; + default: + dns_so_clear(&R->so); + break; + } +} /* dns_res_clear() */ + + +static int dns_res_events2(struct dns_resolver *R, enum dns_events type) { + int events; + + switch (R->stack[R->sp].state) { + case DNS_R_CHECK: + events = R->cache->events(R->cache); + + return (type == DNS_LIBEVENT)? DNS_POLL2EV(events) : events; + default: + return dns_so_events2(&R->so, type); + } +} /* dns_res_events2() */ + + +int dns_res_events(struct dns_resolver *R) { + return dns_res_events2(R, R->so.opts.events); +} /* dns_res_events() */ + + +int dns_res_pollfd(struct dns_resolver *R) { + switch (R->stack[R->sp].state) { + case DNS_R_CHECK: + return R->cache->pollfd(R->cache); + default: + return dns_so_pollfd(&R->so); + } +} /* dns_res_pollfd() */ + + +time_t dns_res_timeout(struct dns_resolver *R) { + time_t elapsed; + + switch (R->stack[R->sp].state) { +#if 0 + case DNS_R_QUERY_AAAA: +#endif + case DNS_R_QUERY_A: + elapsed = dns_so_elapsed(&R->so); + + if (elapsed <= dns_resconf_timeout(R->resconf)) + return R->resconf->options.timeout - elapsed; + + break; + default: + break; + } /* switch() */ + + /* + * NOTE: We're not in a pollable state, or the user code hasn't + * called dns_res_check properly. The calling code is probably + * broken. Put them into a slow-burn pattern. + */ + return 1; +} /* dns_res_timeout() */ + + +time_t dns_res_elapsed(struct dns_resolver *R) { + return dns_elapsed(&R->elapsed); +} /* dns_res_elapsed() */ + + +int dns_res_poll(struct dns_resolver *R, int timeout) { + return dns_poll(dns_res_pollfd(R), dns_res_events2(R, DNS_SYSPOLL), timeout); +} /* dns_res_poll() */ + + +int dns_res_submit2(struct dns_resolver *R, const char *qname, size_t qlen, enum dns_type qtype, enum dns_class qclass) { + dns_res_reset(R); + + /* Don't anchor; that can conflict with searchlist generation. */ + dns_d_init(R->qname, sizeof R->qname, qname, (R->qlen = qlen), 0); + + R->qtype = qtype; + R->qclass = qclass; + + dns_begin(&R->elapsed); + + return 0; +} /* dns_res_submit2() */ + + +int dns_res_submit(struct dns_resolver *R, const char *qname, enum dns_type qtype, enum dns_class qclass) { + return dns_res_submit2(R, qname, strlen(qname), qtype, qclass); +} /* dns_res_submit() */ + + +int dns_res_check(struct dns_resolver *R) { + int error; + + if (R->stack[0].state != DNS_R_DONE) { + if ((error = dns_res_exec(R))) + return error; + } + + return 0; +} /* dns_res_check() */ + + +struct dns_packet *dns_res_fetch(struct dns_resolver *R, int *error) { + struct dns_packet *answer; + + if (R->stack[0].state != DNS_R_DONE) { + *error = DNS_EUNKNOWN; + + return 0; + } + + if (!(answer = R->stack[0].answer)) { + *error = DNS_EFETCHED; + + return 0; + } + + R->stack[0].answer = 0; + + return answer; +} /* dns_res_fetch() */ + + +struct dns_packet *dns_res_query(struct dns_resolver *res, const char *qname, enum dns_type qtype, enum dns_class qclass, int timeout, int *error_) { + int error; + + if ((error = dns_res_submit(res, qname, qtype, qclass))) + goto error; + + while ((error = dns_res_check(res))) { + if (dns_res_elapsed(res) > timeout) + error = DNS_ETIMEDOUT; + + if (error != DNS_EAGAIN) + goto error; + + if ((error = dns_res_poll(res, 1))) + goto error; + } + + return dns_res_fetch(res, error_); +error: + *error_ = error; + + return 0; +} /* dns_res_query() */ + + +const struct dns_stat *dns_res_stat(struct dns_resolver *res) { + return dns_so_stat(&res->so); +} /* dns_res_stat() */ + + +void dns_res_sethints(struct dns_resolver *res, struct dns_hints *hints) { + dns_hints_acquire(hints); /* acquire first in case same hints object */ + dns_hints_close(res->hints); + res->hints = hints; +} /* dns_res_sethints() */ + + +/* + * A D D R I N F O R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +struct dns_addrinfo { + struct addrinfo hints; + struct dns_resolver *res; + + char qname[DNS_D_MAXNAME + 1]; + enum dns_type qtype; + unsigned short qport, port; + + struct dns_packet *answer; + struct dns_packet *glue; + + struct dns_rr_i i, g; + struct dns_rr rr; + + char cname[DNS_D_MAXNAME + 1]; + + int state; + int found; + + struct dns_stat st; +}; /* struct dns_addrinfo */ + + +static dns_error_t dns_ai_parseport(unsigned short *port, const char *serv, const struct addrinfo *hints) { + const char *cp = serv; + unsigned long n = 0; + + while (*cp >= '0' && *cp <= '9' && n < 65536) { + n *= 10; + n += *cp++ - '0'; + } + + if (*cp == '\0') { + if (cp == serv || n >= 65536) + return DNS_ESERVICE; + + *port = n; + + return 0; + } + + if (hints->ai_flags & AI_NUMERICSERV) + return DNS_ESERVICE; + + /* TODO: try getaddrinfo(NULL, serv, { .ai_flags = AI_NUMERICSERV }) */ + + return DNS_ESERVICE; +} /* dns_ai_parseport() */ + + +struct dns_addrinfo *dns_ai_open(const char *host, const char *serv, enum dns_type qtype, const struct addrinfo *hints, struct dns_resolver *res, int *error_) { + static const struct dns_addrinfo ai_initializer; + struct dns_addrinfo *ai; + int error; + + if (res) { + dns_res_acquire(res); + } else if (!(hints->ai_flags & AI_NUMERICHOST)) { + /* + * NOTE: it's assumed that *_error is set from a previous + * API function call, such as dns_res_stub(). Should change + * this semantic, but it's applied elsewhere, too. + */ + return NULL; + } + + if (!(ai = malloc(sizeof *ai))) + goto syerr; + + *ai = ai_initializer; + ai->hints = *hints; + + ai->res = res; + res = NULL; + + if (sizeof ai->qname <= dns_strlcpy(ai->qname, host, sizeof ai->qname)) + { error = ENAMETOOLONG; goto error; } + + ai->qtype = qtype; + ai->qport = 0; + + if (serv && (error = dns_ai_parseport(&ai->qport, serv, hints))) + goto error; + + ai->port = ai->qport; + + return ai; +syerr: + error = dns_syerr(); +error: + *error_ = error; + + dns_ai_close(ai); + dns_res_close(res); + + return NULL; +} /* dns_ai_open() */ + + +void dns_ai_close(struct dns_addrinfo *ai) { + if (!ai) + return; + + dns_res_close(ai->res); + + if (ai->answer != ai->glue) + dns_p_free(ai->glue); + + dns_p_free(ai->answer); + free(ai); +} /* dns_ai_close() */ + + +static int dns_ai_setent(struct addrinfo **ent, union dns_any *any, enum dns_type type, struct dns_addrinfo *ai) { + struct sockaddr *saddr; + struct sockaddr_in sin; + struct sockaddr_in6 sin6; + const char *cname; + size_t clen; + + switch (type) { + case DNS_T_A: + saddr = memset(&sin, '\0', sizeof sin); + + sin.sin_family = AF_INET; + sin.sin_port = htons(ai->port); + + memcpy(&sin.sin_addr, any, sizeof sin.sin_addr); + + break; + case DNS_T_AAAA: + saddr = memset(&sin6, '\0', sizeof sin6); + + sin6.sin6_family = AF_INET6; + sin6.sin6_port = htons(ai->port); + + memcpy(&sin6.sin6_addr, any, sizeof sin6.sin6_addr); + + break; + default: + return EINVAL; + } /* switch() */ + + if (ai->hints.ai_flags & AI_CANONNAME) { + cname = (*ai->cname)? ai->cname : ai->qname; + clen = strlen(cname); + } else { + cname = NULL; + clen = 0; + } + + if (!(*ent = malloc(sizeof **ent + dns_sa_len(saddr) + ((ai->hints.ai_flags & AI_CANONNAME)? clen + 1 : 0)))) + return dns_syerr(); + + memset(*ent, '\0', sizeof **ent); + + (*ent)->ai_family = saddr->sa_family; + (*ent)->ai_socktype = ai->hints.ai_socktype; + (*ent)->ai_protocol = ai->hints.ai_protocol; + + (*ent)->ai_addr = memcpy((unsigned char *)*ent + sizeof **ent, saddr, dns_sa_len(saddr)); + (*ent)->ai_addrlen = dns_sa_len(saddr); + + if (ai->hints.ai_flags & AI_CANONNAME) + (*ent)->ai_canonname = memcpy((unsigned char *)*ent + sizeof **ent + dns_sa_len(saddr), cname, clen + 1); + + ai->found++; + + return 0; +} /* dns_ai_setent() */ + + +enum dns_ai_state { + DNS_AI_S_INIT, + DNS_AI_S_NUMERIC, + DNS_AI_S_SUBMIT, + DNS_AI_S_CHECK, + DNS_AI_S_FETCH, + DNS_AI_S_FOREACH_I, + DNS_AI_S_FOREACH_G, + DNS_AI_S_SUBMIT_G, + DNS_AI_S_CHECK_G, + DNS_AI_S_FETCH_G, + DNS_AI_S_DONE, +}; /* enum dns_ai_state */ + +#define dns_ai_goto(which) do { ai->state = (which); goto exec; } while (0) + +int dns_ai_nextent(struct addrinfo **ent, struct dns_addrinfo *ai) { + struct dns_packet *ans, *glue; + struct dns_rr rr; + char qname[DNS_D_MAXNAME + 1]; + union dns_any any; + size_t len; + int error; + + *ent = 0; + +exec: + + switch (ai->state) { + case DNS_AI_S_INIT: + ai->state++; + case DNS_AI_S_NUMERIC: + if (1 == dns_inet_pton(AF_INET, ai->qname, &any.a)) { + ai->state = DNS_AI_S_DONE; + + return dns_ai_setent(ent, &any, DNS_T_A, ai); + } + + if (1 == dns_inet_pton(AF_INET6, ai->qname, &any.aaaa)) { + ai->state = DNS_AI_S_DONE; + + return dns_ai_setent(ent, &any, DNS_T_AAAA, ai); + } + + if (ai->hints.ai_flags & AI_NUMERICHOST) + dns_ai_goto(DNS_AI_S_DONE); + + ai->state++; + case DNS_AI_S_SUBMIT: + assert(ai->res); + + if ((error = dns_res_submit(ai->res, ai->qname, ai->qtype, DNS_C_IN))) + return error; + + ai->state++; + case DNS_AI_S_CHECK: + if ((error = dns_res_check(ai->res))) + return error; + + ai->state++; + case DNS_AI_S_FETCH: + if (!(ai->answer = dns_res_fetch(ai->res, &error))) + return error; + + if ((error = dns_p_study(ai->answer))) + return error; + + ai->glue = ai->answer; + + dns_rr_i_init(&ai->i, ai->answer); + + ai->i.section = DNS_S_AN; + ai->i.type = ai->qtype; + ai->i.sort = &dns_rr_i_order; + + ai->state++; + case DNS_AI_S_FOREACH_I: + /* Search generator may have changed our qname. */ + if (!(len = dns_d_expand(qname, sizeof qname, 12, ai->answer, &error))) + return error; + else if (len >= sizeof qname) + return DNS_EILLEGAL; + + if (!dns_d_cname(ai->cname, sizeof ai->cname, qname, strlen(qname), ai->answer, &error)) + return error; + + ai->i.name = ai->cname; + + if (!dns_rr_grep(&rr, 1, &ai->i, ai->answer, &error)) + dns_ai_goto(DNS_AI_S_DONE); + + if ((error = dns_any_parse(&any, &rr, ai->answer))) + return error; + + ai->port = ai->qport; + + switch (rr.type) { + case DNS_T_A: + case DNS_T_AAAA: + return dns_ai_setent(ent, &any, rr.type, ai); + default: + if (!dns_any_cname(ai->cname, sizeof ai->cname, &any, rr.type)) + dns_ai_goto(DNS_AI_S_FOREACH_I); + + /* + * Find the "real" canonical name. Some authorities + * publish aliases where an RFC defines a canonical + * name. We trust that the resolver followed any + * CNAME chains on it's own, regardless of whether + * the "smart" option is enabled. + */ + if (!dns_d_cname(ai->cname, sizeof ai->cname, ai->cname, strlen(ai->cname), ai->answer, &error)) + return error; + + if (rr.type == DNS_T_SRV) + ai->port = any.srv.port; + + break; + } /* switch() */ + + dns_rr_i_init(&ai->g, ai->glue); + + ai->g.section = DNS_S_ALL & ~DNS_S_QD; + ai->g.name = ai->cname; + ai->g.type = (ai->hints.ai_family == AF_INET6)? DNS_T_AAAA : DNS_T_A; + + ai->state++; + case DNS_AI_S_FOREACH_G: + if (!dns_rr_grep(&rr, 1, &ai->g, ai->glue, &error)) { + if (dns_rr_i_count(&ai->g) > 0) + dns_ai_goto(DNS_AI_S_FOREACH_I); + else + dns_ai_goto(DNS_AI_S_SUBMIT_G); + } + + if ((error = dns_any_parse(&any, &rr, ai->glue))) + return error; + + return dns_ai_setent(ent, &any, rr.type, ai); + case DNS_AI_S_SUBMIT_G: + if (dns_rr_grep(&rr, 1, dns_rr_i_new(ai->glue, .section = DNS_S_QD, .name = ai->g.name, .type = ai->g.type), ai->glue, &error)) + dns_ai_goto(DNS_AI_S_FOREACH_I); + + if ((error = dns_res_submit(ai->res, ai->g.name, ai->g.type, DNS_C_IN))) + return error; + + ai->state++; + case DNS_AI_S_CHECK_G: + if ((error = dns_res_check(ai->res))) + return error; + + ai->state++; + case DNS_AI_S_FETCH_G: + if (!(ans = dns_res_fetch(ai->res, &error))) + return error; + + dns_p_study(ans); + + glue = dns_p_merge(ai->glue, DNS_S_ALL, ans, DNS_S_ALL, &error); + + dns_p_free(ans); + + if (!glue) + return error; + + if (ai->glue != ai->answer) + dns_p_free(ai->glue); + + ai->glue = glue; + + dns_rr_i_init(&ai->g, ai->glue); + + /* ai->g.name should already point to ai->cname */ + if (!dns_d_cname(ai->cname, sizeof ai->cname, ai->cname, strlen(ai->cname), ai->glue, &error)) + dns_ai_goto(DNS_AI_S_FOREACH_I); + + /* NOTE: Keep all the other iterator filters */ + + dns_ai_goto(DNS_AI_S_FOREACH_G); + case DNS_AI_S_DONE: + if (ai->found) { + return ENOENT; /* TODO: Just return 0 */ + } else if (ai->answer) { + switch (dns_header(ai->answer)->rcode) { + case DNS_RC_NOERROR: + /* FALL THROUGH */ + case DNS_RC_NXDOMAIN: + return DNS_ENONAME; + default: + return DNS_EFAIL; + } + } else { + return DNS_EFAIL; + } + default: + return EINVAL; + } /* switch() */ +} /* dns_ai_nextent() */ + + +time_t dns_ai_elapsed(struct dns_addrinfo *ai) { + return (ai->res)? dns_res_elapsed(ai->res) : 0; +} /* dns_ai_elapsed() */ + + +void dns_ai_clear(struct dns_addrinfo *ai) { + if (ai->res) + dns_res_clear(ai->res); +} /* dns_ai_clear() */ + + +int dns_ai_events(struct dns_addrinfo *ai) { + return (ai->res)? dns_res_events(ai->res) : 0; +} /* dns_ai_events() */ + + +int dns_ai_pollfd(struct dns_addrinfo *ai) { + return (ai->res)? dns_res_pollfd(ai->res) : -1; +} /* dns_ai_pollfd() */ + + +time_t dns_ai_timeout(struct dns_addrinfo *ai) { + return (ai->res)? dns_res_timeout(ai->res) : 0; +} /* dns_ai_timeout() */ + + +int dns_ai_poll(struct dns_addrinfo *ai, int timeout) { + return (ai->res)? dns_res_poll(ai->res, timeout) : 0; +} /* dns_ai_poll() */ + + +size_t dns_ai_print(void *dst, size_t lim, struct addrinfo *ent, struct dns_addrinfo *ai) { + char addr[DNS_PP_MAX(INET_ADDRSTRLEN, INET6_ADDRSTRLEN) + 1]; + size_t cp = 0; + + cp += dns__printstring(dst, lim, cp, "[ "); + cp += dns__printstring(dst, lim, cp, ai->qname); + cp += dns__printstring(dst, lim, cp, " IN "); + cp += dns__printstring(dst, lim, cp, dns_strtype(ai->qtype)); + cp += dns__printstring(dst, lim, cp, " ]\n"); + + cp += dns__printstring(dst, lim, cp, ".ai_family = "); + + switch (ent->ai_family) { + case AF_INET: + cp += dns__printstring(dst, lim, cp, "AF_INET"); + break; + case AF_INET6: + cp += dns__printstring(dst, lim, cp, "AF_INET6"); + break; + default: + cp += dns__print10(dst, lim, cp, ent->ai_family, 0); + break; + } + + cp += dns__printchar(dst, lim, cp, '\n'); + + cp += dns__printstring(dst, lim, cp, ".ai_socktype = "); + + switch (ent->ai_socktype) { + case SOCK_STREAM: + cp += dns__printstring(dst, lim, cp, "SOCK_STREAM"); + break; + case SOCK_DGRAM: + cp += dns__printstring(dst, lim, cp, "SOCK_DGRAM"); + break; + default: + cp += dns__print10(dst, lim, cp, ent->ai_socktype, 0); + break; + } + + cp += dns__printchar(dst, lim, cp, '\n'); + + cp += dns__printstring(dst, lim, cp, ".ai_addr = ["); + + dns_inet_ntop(dns_sa_family(ent->ai_addr), dns_sa_addr(dns_sa_family(ent->ai_addr), ent->ai_addr, NULL), addr, sizeof addr); + + cp += dns__printstring(dst, lim, cp, addr); + cp += dns__printstring(dst, lim, cp, "]:"); + + cp += dns__print10(dst, lim, cp, ntohs(*dns_sa_port(dns_sa_family(ent->ai_addr), ent->ai_addr)), 0); + cp += dns__printchar(dst, lim, cp, '\n'); + + cp += dns__printstring(dst, lim, cp, ".ai_canonname = "); + cp += dns__printstring(dst, lim, cp, (ent->ai_canonname)? ent->ai_canonname : "[NULL]"); + cp += dns__printchar(dst, lim, cp, '\n'); + + dns__printnul(dst, lim, cp); + + return cp; +} /* dns_ai_print() */ + + +const struct dns_stat *dns_ai_stat(struct dns_addrinfo *ai) { + return (ai->res)? dns_res_stat(ai->res) : &ai->st; +} /* dns_ai_stat() */ + + +/* + * M I S C E L L A N E O U S R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +static const struct { + char name[16]; + enum dns_section type; +} dns_sections[] = { + { "QUESTION", DNS_S_QUESTION }, + { "QD", DNS_S_QUESTION }, + { "ANSWER", DNS_S_ANSWER }, + { "AN", DNS_S_ANSWER }, + { "AUTHORITY", DNS_S_AUTHORITY }, + { "NS", DNS_S_AUTHORITY }, + { "ADDITIONAL", DNS_S_ADDITIONAL }, + { "AR", DNS_S_ADDITIONAL }, +}; + +const char *(dns_strsection)(enum dns_section section, void *dst, size_t lim) { + unsigned i, p = 0; + + for (i = 0; i < lengthof(dns_sections); i++) { + if (dns_sections[i].type & section) { + if (p > 0) + p += dns__printchar(dst, lim, p, '|'); + + p += dns__printstring(dst, lim, p, dns_sections[i].name); + + section &= ~dns_sections[i].type; + } + } + + if (!p) + p += dns__print10(dst, lim, 0, (0xffff & section), 0); + + dns__printnul(dst, lim, p); + + return dst; +} /* dns_strsection() */ + + +enum dns_section dns_isection(const char *src) { + enum dns_section section = 0; + char sbuf[128]; + char *name, *next; + unsigned i; + + dns_strlcpy(sbuf, src, sizeof sbuf); + next = sbuf; + + while ((name = dns_strsep(&next, "|+, \t"))) { + for (i = 0; i < lengthof(dns_sections); i++) { + if (!strcasecmp(dns_sections[i].name, name)) { + section |= dns_sections[i].type; + break; + } + } + } + + return section; +} /* dns_isection() */ + + +static const struct { + char name[8]; + enum dns_class type; +} dns_classes[] = { + { "IN", DNS_C_IN }, +}; + +const char *(dns_strclass)(enum dns_class type, void *dst, size_t lim) { + unsigned i; + + for (i = 0; i < lengthof(dns_classes); i++) { + if (dns_classes[i].type == type) { + dns__printnul(dst, lim, dns__printstring(dst, lim, 0, dns_classes[i].name)); + + return dst; + } + } + + dns__printnul(dst, lim, dns__print10(dst, lim, 0, (0xffff & type), 0)); + + return dst; +} /* dns_strclass() */ + + +enum dns_class dns_iclass(const char *name) { + unsigned i; + + for (i = 0; i < lengthof(dns_classes); i++) { + if (!strcasecmp(dns_classes[i].name, name)) + return dns_classes[i].type; + } + + return 0; +} /* dns_iclass() */ + + +const char *(dns_strtype)(enum dns_type type, void *dst, size_t lim) { + unsigned i; + + for (i = 0; i < lengthof(dns_rrtypes); i++) { + if (dns_rrtypes[i].type == type) { + dns__printnul(dst, lim, dns__printstring(dst, lim, 0, dns_rrtypes[i].name)); + + return dst; + } + } + + dns__printnul(dst, lim, dns__print10(dst, lim, 0, (0xffff & type), 0)); + + return dst; +} /* dns_strtype() */ + + +enum dns_type dns_itype(const char *type) { + unsigned i; + + for (i = 0; i < lengthof(dns_rrtypes); i++) { + if (!strcasecmp(dns_rrtypes[i].name, type)) + return dns_rrtypes[i].type; + } + + return 0; +} /* dns_itype() */ + + +static char dns_opcodes[16][16] = { + [DNS_OP_QUERY] = "QUERY", + [DNS_OP_IQUERY] = "IQUERY", + [DNS_OP_STATUS] = "STATUS", + [DNS_OP_NOTIFY] = "NOTIFY", + [DNS_OP_UPDATE] = "UPDATE", +}; + +const char *dns_stropcode(enum dns_opcode opcode) { + opcode &= 0xf; + + if ('\0' == dns_opcodes[opcode][0]) + dns__printnul(dns_opcodes[opcode], sizeof dns_opcodes[opcode], dns__print10(dns_opcodes[opcode], sizeof dns_opcodes[opcode], 0, opcode, 0)); + + return dns_opcodes[opcode]; +} /* dns_stropcode() */ + + +enum dns_opcode dns_iopcode(const char *name) { + unsigned opcode; + + for (opcode = 0; opcode < lengthof(dns_opcodes); opcode++) { + if (!strcasecmp(name, dns_opcodes[opcode])) + return opcode; + } + + return lengthof(dns_opcodes) - 1; +} /* dns_iopcode() */ + + +static char dns_rcodes[16][16] = { + [DNS_RC_NOERROR] = "NOERROR", + [DNS_RC_FORMERR] = "FORMERR", + [DNS_RC_SERVFAIL] = "SERVFAIL", + [DNS_RC_NXDOMAIN] = "NXDOMAIN", + [DNS_RC_NOTIMP] = "NOTIMP", + [DNS_RC_REFUSED] = "REFUSED", + [DNS_RC_YXDOMAIN] = "YXDOMAIN", + [DNS_RC_YXRRSET] = "YXRRSET", + [DNS_RC_NXRRSET] = "NXRRSET", + [DNS_RC_NOTAUTH] = "NOTAUTH", + [DNS_RC_NOTZONE] = "NOTZONE", +}; + +const char *dns_strrcode(enum dns_rcode rcode) { + rcode &= 0xf; + + if ('\0' == dns_rcodes[rcode][0]) + dns__printnul(dns_rcodes[rcode], sizeof dns_rcodes[rcode], dns__print10(dns_rcodes[rcode], sizeof dns_rcodes[rcode], 0, rcode, 0)); + + return dns_rcodes[rcode]; +} /* dns_strrcode() */ + + +enum dns_rcode dns_ircode(const char *name) { + unsigned rcode; + + for (rcode = 0; rcode < lengthof(dns_rcodes); rcode++) { + if (!strcasecmp(name, dns_rcodes[rcode])) + return rcode; + } + + return lengthof(dns_rcodes) - 1; +} /* dns_ircode() */ + + + +/* + * C O M M A N D - L I N E / R E G R E S S I O N R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ +#if DNS_MAIN + +#include +#include +#include + +#include + +#if _WIN32 +#include +#endif + +#if !_WIN32 +#include +#endif + + +struct { + struct { + const char *path[8]; + unsigned count; + } resconf, nssconf, hosts, cache; + + const char *qname; + enum dns_type qtype; + + int (*sort)(); + + int verbose; +} MAIN = { + .sort = &dns_rr_i_packet, +}; + + +void hexdump(const unsigned char *src, size_t len, FILE *fp) { + static const unsigned char hex[] = "0123456789abcdef"; + static const unsigned char tmpl[] = " | |\n"; + unsigned char ln[sizeof tmpl]; + const unsigned char *sp, *se; + unsigned char *h, *g; + unsigned i, n; + + sp = src; + se = sp + len; + + while (sp < se) { + memcpy(ln, tmpl, sizeof ln); + + h = &ln[2]; + g = &ln[53]; + + for (n = 0; n < 2; n++) { + for (i = 0; i < 8 && se - sp > 0; i++, sp++) { + h[0] = hex[0x0f & (*sp >> 4)]; + h[1] = hex[0x0f & (*sp >> 0)]; + h += 3; + + *g++ = (isgraph(*sp))? *sp : '.'; + } + + h++; + } + + fputs((char *)ln, fp); + } + + return /* void */; +} /* hexdump() */ + + +DNS_NORETURN static void panic(const char *fmt, ...) { + va_list ap; + + va_start(ap, fmt); + +#if _WIN32 + vfprintf(stderr, fmt, ap); + + exit(EXIT_FAILURE); +#else + verrx(EXIT_FAILURE, fmt, ap); +#endif +} /* panic() */ + +#define panic_(fn, ln, fmt, ...) \ + panic(fmt "%0s", (fn), (ln), __VA_ARGS__) +#define panic(...) \ + panic_(__func__, __LINE__, "(%s:%d) " __VA_ARGS__, "") + + +static void *grow(unsigned char *p, size_t size) { + void *tmp; + + if (!(tmp = realloc(p, size))) + panic("realloc(%"PRIuZ"): %s", size, dns_strerror(errno)); + + return tmp; +} /* grow() */ + + +static size_t add(size_t a, size_t b) { + if (~a < b) + panic("%"PRIuZ" + %"PRIuZ": integer overflow", a, b); + + return a + b; +} /* add() */ + + +static size_t append(unsigned char **dst, size_t osize, const void *src, size_t len) { + size_t size = add(osize, len); + + *dst = grow(*dst, size); + memcpy(*dst + osize, src, len); + + return size; +} /* append() */ + + +static size_t slurp(unsigned char **dst, size_t osize, FILE *fp, const char *path) { + size_t size = osize; + unsigned char buf[1024]; + size_t count; + + while ((count = fread(buf, 1, sizeof buf, fp))) + size = append(dst, size, buf, count); + + if (ferror(fp)) + panic("%s: %s", path, dns_strerror(errno)); + + return size; +} /* slurp() */ + + +static struct dns_resolv_conf *resconf(void) { + static struct dns_resolv_conf *resconf; + const char *path; + unsigned i; + int error; + + if (resconf) + return resconf; + + if (!(resconf = dns_resconf_open(&error))) + panic("dns_resconf_open: %s", dns_strerror(error)); + + if (!MAIN.resconf.count) + MAIN.resconf.path[MAIN.resconf.count++] = "/etc/resolv.conf"; + + for (i = 0; i < MAIN.resconf.count; i++) { + path = MAIN.resconf.path[i]; + + if (0 == strcmp(path, "-")) + error = dns_resconf_loadfile(resconf, stdin); + else + error = dns_resconf_loadpath(resconf, path); + + if (error) + panic("%s: %s", path, dns_strerror(error)); + } + + for (i = 0; i < MAIN.nssconf.count; i++) { + path = MAIN.nssconf.path[i]; + + if (0 == strcmp(path, "-")) + error = dns_nssconf_loadfile(resconf, stdin); + else + error = dns_nssconf_loadpath(resconf, path); + + if (error) + panic("%s: %s", path, dns_strerror(error)); + } + + if (!MAIN.nssconf.count) { + path = "/etc/nsswitch.conf"; + + if (!(error = dns_nssconf_loadpath(resconf, path))) + MAIN.nssconf.path[MAIN.nssconf.count++] = path; + else if (error != ENOENT) + panic("%s: %s", path, dns_strerror(error)); + } + + return resconf; +} /* resconf() */ + + +static struct dns_hosts *hosts(void) { + static struct dns_hosts *hosts; + const char *path; + unsigned i; + int error; + + if (hosts) + return hosts; + + if (!MAIN.hosts.count) { + MAIN.hosts.path[MAIN.hosts.count++] = "/etc/hosts"; + + /* Explicitly test dns_hosts_local() */ + if (!(hosts = dns_hosts_local(&error))) + panic("%s: %s", "/etc/hosts", dns_strerror(error)); + + return hosts; + } + + if (!(hosts = dns_hosts_open(&error))) + panic("dns_hosts_open: %s", dns_strerror(error)); + + for (i = 0; i < MAIN.hosts.count; i++) { + path = MAIN.hosts.path[i]; + + if (0 == strcmp(path, "-")) + error = dns_hosts_loadfile(hosts, stdin); + else + error = dns_hosts_loadpath(hosts, path); + + if (error) + panic("%s: %s", path, dns_strerror(error)); + } + + return hosts; +} /* hosts() */ + + +#if DNS_CACHE +#include "cache.h" + +struct dns_cache *cache(void) { + static struct cache *cache; + const char *path; + unsigned i; + int error; + + if (cache) + return cache_resi(cache); + if (!MAIN.cache.count) + return NULL; + + if (!(cache = cache_open(&error))) + panic("%s: %s", MAIN.cache.path[0], dns_strerror(error)); + + for (i = 0; i < MAIN.cache.count; i++) { + path = MAIN.cache.path[i]; + + if (!strcmp(path, "-")) { + if ((error = cache_loadfile(cache, stdin, NULL, 0))) + panic("%s: %s", path, dns_strerror(error)); + } else if ((error = cache_loadpath(cache, path, NULL, 0))) + panic("%s: %s", path, dns_strerror(error)); + } + + return cache_resi(cache); +} /* cache() */ +#else +struct dns_cache *cache(void) { return NULL; } +#endif + + +static void print_packet(struct dns_packet *P, FILE *fp) { + dns_p_dump3(P, dns_rr_i_new(P, .sort = MAIN.sort), fp); + + if (MAIN.verbose > 2) + hexdump(P->data, P->end, fp); +} /* print_packet() */ + + +static int parse_packet(int argc DNS_NOTUSED, char *argv[] DNS_NOTUSED) { + struct dns_packet *P = dns_p_new(512); + struct dns_packet *Q = dns_p_new(512); + enum dns_section section; + struct dns_rr rr; + int error; + union dns_any any; + char pretty[sizeof any * 2]; + size_t len; + + P->end = fread(P->data, 1, P->size, stdin); + + fputs(";; [HEADER]\n", stdout); + fprintf(stdout, ";; qr : %s(%d)\n", (dns_header(P)->qr)? "RESPONSE" : "QUERY", dns_header(P)->qr); + fprintf(stdout, ";; opcode : %s(%d)\n", dns_stropcode(dns_header(P)->opcode), dns_header(P)->opcode); + fprintf(stdout, ";; aa : %s(%d)\n", (dns_header(P)->aa)? "AUTHORITATIVE" : "NON-AUTHORITATIVE", dns_header(P)->aa); + fprintf(stdout, ";; tc : %s(%d)\n", (dns_header(P)->tc)? "TRUNCATED" : "NOT-TRUNCATED", dns_header(P)->tc); + fprintf(stdout, ";; rd : %s(%d)\n", (dns_header(P)->rd)? "RECURSION-DESIRED" : "RECURSION-NOT-DESIRED", dns_header(P)->rd); + fprintf(stdout, ";; ra : %s(%d)\n", (dns_header(P)->ra)? "RECURSION-ALLOWED" : "RECURSION-NOT-ALLOWED", dns_header(P)->ra); + fprintf(stdout, ";; rcode : %s(%d)\n", dns_strrcode(dns_header(P)->rcode), dns_header(P)->rcode); + + section = 0; + + dns_rr_foreach(&rr, P, .sort = MAIN.sort) { + if (section != rr.section) + fprintf(stdout, "\n;; [%s:%d]\n", dns_strsection(rr.section), dns_p_count(P, rr.section)); + + if ((len = dns_rr_print(pretty, sizeof pretty, &rr, P, &error))) + fprintf(stdout, "%s\n", pretty); + + dns_rr_copy(Q, &rr, P); + + section = rr.section; + } + + fputs("; ; ; ; ; ; ; ;\n\n", stdout); + + section = 0; + +#if 0 + dns_rr_foreach(&rr, Q, .name = "ns8.yahoo.com.") { +#else + struct dns_rr rrset[32]; + struct dns_rr_i *rri = dns_rr_i_new(Q, .name = dns_d_new("ns8.yahoo.com", DNS_D_ANCHOR), .sort = MAIN.sort); + unsigned rrcount = dns_rr_grep(rrset, lengthof(rrset), rri, Q, &error); + + for (unsigned i = 0; i < rrcount; i++) { + rr = rrset[i]; +#endif + if (section != rr.section) + fprintf(stdout, "\n;; [%s:%d]\n", dns_strsection(rr.section), dns_p_count(Q, rr.section)); + + if ((len = dns_rr_print(pretty, sizeof pretty, &rr, Q, &error))) + fprintf(stdout, "%s\n", pretty); + + section = rr.section; + } + + if (MAIN.verbose > 1) { + fprintf(stderr, "orig:%"PRIuZ"\n", P->end); + hexdump(P->data, P->end, stdout); + + fprintf(stderr, "copy:%"PRIuZ"\n", Q->end); + hexdump(Q->data, Q->end, stdout); + } + + return 0; +} /* parse_packet() */ + + +static int parse_domain(int argc, char *argv[]) { + char *dn; + + dn = (argc > 1)? argv[1] : "f.l.google.com"; + + printf("[%s]\n", dn); + + dn = dns_d_new(dn); + + do { + puts(dn); + } while (dns_d_cleave(dn, strlen(dn) + 1, dn, strlen(dn))); + + return 0; +} /* parse_domain() */ + + +static int trim_domain(int argc, char **argv) { + for (argc--, argv++; argc > 0; argc--, argv++) { + char name[DNS_D_MAXNAME + 1]; + + dns_d_trim(name, sizeof name, *argv, strlen(*argv), DNS_D_ANCHOR); + + puts(name); + } + + return 0; +} /* trim_domain() */ + + +static int expand_domain(int argc, char *argv[]) { + unsigned short rp = 0; + unsigned char *src = NULL; + unsigned char *dst; + struct dns_packet *pkt; + size_t lim = 0, len; + int error; + + if (argc > 1) + rp = atoi(argv[1]); + + len = slurp(&src, 0, stdin, "-"); + + if (!(pkt = dns_p_make(len, &error))) + panic("malloc(%"PRIuZ"): %s", len, dns_strerror(error)); + + memcpy(pkt->data, src, len); + pkt->end = len; + + lim = 1; + dst = grow(NULL, lim); + + while (lim <= (len = dns_d_expand(dst, lim, rp, pkt, &error))) { + lim = add(len, 1); + dst = grow(dst, lim); + } + + if (!len) + panic("expand: %s", dns_strerror(error)); + + fwrite(dst, 1, len, stdout); + fflush(stdout); + + free(src); + free(dst); + free(pkt); + + return 0; +} /* expand_domain() */ + + +static int show_resconf(int argc DNS_NOTUSED, char *argv[] DNS_NOTUSED) { + unsigned i; + + resconf(); /* load it */ + + fputs("; SOURCES\n", stdout); + + for (i = 0; i < MAIN.resconf.count; i++) + fprintf(stdout, "; %s\n", MAIN.resconf.path[i]); + + for (i = 0; i < MAIN.nssconf.count; i++) + fprintf(stdout, "; %s\n", MAIN.nssconf.path[i]); + + fputs(";\n", stdout); + + dns_resconf_dump(resconf(), stdout); + + return 0; +} /* show_resconf() */ + + +static int show_nssconf(int argc DNS_NOTUSED, char *argv[] DNS_NOTUSED) { + unsigned i; + + resconf(); + + fputs("# SOURCES\n", stdout); + + for (i = 0; i < MAIN.resconf.count; i++) + fprintf(stdout, "# %s\n", MAIN.resconf.path[i]); + + for (i = 0; i < MAIN.nssconf.count; i++) + fprintf(stdout, "# %s\n", MAIN.nssconf.path[i]); + + fputs("#\n", stdout); + + dns_nssconf_dump(resconf(), stdout); + + return 0; +} /* show_nssconf() */ + + +static int show_hosts(int argc DNS_NOTUSED, char *argv[] DNS_NOTUSED) { + unsigned i; + + hosts(); + + fputs("# SOURCES\n", stdout); + + for (i = 0; i < MAIN.hosts.count; i++) + fprintf(stdout, "# %s\n", MAIN.hosts.path[i]); + + fputs("#\n", stdout); + + dns_hosts_dump(hosts(), stdout); + + return 0; +} /* show_hosts() */ + + +static int query_hosts(int argc, char *argv[]) { + struct dns_packet *Q = dns_p_new(512); + struct dns_packet *A; + char qname[DNS_D_MAXNAME + 1]; + size_t qlen; + int error; + + if (!MAIN.qname) + MAIN.qname = (argc > 1)? argv[1] : "localhost"; + if (!MAIN.qtype) + MAIN.qtype = DNS_T_A; + + hosts(); + + if (MAIN.qtype == DNS_T_PTR && !strstr(MAIN.qname, "arpa")) { + union { struct in_addr a; struct in6_addr a6; } addr; + int af = (strchr(MAIN.qname, ':'))? AF_INET6 : AF_INET; + + if ((error = dns_pton(af, MAIN.qname, &addr))) + panic("%s: %s", MAIN.qname, dns_strerror(error)); + + qlen = dns_ptr_qname(qname, sizeof qname, af, &addr); + } else + qlen = dns__printstring(qname, sizeof qname, 0, MAIN.qname); + + if ((error = dns_p_push(Q, DNS_S_QD, qname, qlen, MAIN.qtype, DNS_C_IN, 0, 0))) + panic("%s: %s", qname, dns_strerror(error)); + + if (!(A = dns_hosts_query(hosts(), Q, &error))) + panic("%s: %s", qname, dns_strerror(error)); + + print_packet(A, stdout); + + free(A); + + return 0; +} /* query_hosts() */ + + +static int search_list(int argc, char *argv[]) { + const char *qname = (argc > 1)? argv[1] : "f.l.google.com"; + unsigned long i = 0; + char name[DNS_D_MAXNAME + 1]; + + printf("[%s]\n", qname); + + while (dns_resconf_search(name, sizeof name, qname, strlen(qname), resconf(), &i)) + puts(name); + + return 0; +} /* search_list() */ + + +int permute_set(int argc, char *argv[]) { + unsigned lo, hi, i; + struct dns_k_permutor p; + + hi = (--argc > 0)? atoi(argv[argc]) : 8; + lo = (--argc > 0)? atoi(argv[argc]) : 0; + + fprintf(stderr, "[%u .. %u]\n", lo, hi); + + dns_k_permutor_init(&p, lo, hi); + + for (i = lo; i <= hi; i++) + fprintf(stdout, "%u\n", dns_k_permutor_step(&p)); +// printf("%u -> %u -> %u\n", i, dns_k_permutor_E(&p, i), dns_k_permutor_D(&p, dns_k_permutor_E(&p, i))); + + return 0; +} /* permute_set() */ + + +int shuffle_16(int argc, char *argv[]) { + unsigned n, r; + + if (--argc > 0) { + n = 0xffff & atoi(argv[argc]); + r = (--argc > 0)? (unsigned)atoi(argv[argc]) : dns_random(); + + fprintf(stdout, "%hu\n", dns_k_shuffle16(n, r)); + } else { + r = dns_random(); + + for (n = 0; n < 65536; n++) + fprintf(stdout, "%hu\n", dns_k_shuffle16(n, r)); + } + + return 0; +} /* shuffle_16() */ + + +int dump_random(int argc, char *argv[]) { + unsigned char b[32]; + unsigned i, j, n, r; + + n = (argc > 1)? atoi(argv[1]) : 32; + + while (n) { + i = 0; + + do { + r = dns_random(); + + for (j = 0; j < sizeof r && i < n && i < sizeof b; i++, j++) { + b[i] = 0xff & r; + r >>= 8; + } + } while (i < n && i < sizeof b); + + hexdump(b, i, stdout); + + n -= i; + } + + return 0; +} /* dump_random() */ + + +static int send_query(int argc, char *argv[]) { + struct dns_packet *A, *Q = dns_p_new(512); + char host[INET6_ADDRSTRLEN + 1]; + struct sockaddr_storage ss; + struct dns_socket *so; + int error, type; + + if (argc > 1) { + ss.ss_family = (strchr(argv[1], ':'))? AF_INET6 : AF_INET; + + if ((error = dns_pton(ss.ss_family, argv[1], dns_sa_addr(ss.ss_family, &ss, NULL)))) + panic("%s: %s", argv[1], dns_strerror(error)); + + *dns_sa_port(ss.ss_family, &ss) = htons(53); + } else + memcpy(&ss, &resconf()->nameserver[0], dns_sa_len(&resconf()->nameserver[0])); + + if (!dns_inet_ntop(ss.ss_family, dns_sa_addr(ss.ss_family, &ss, NULL), host, sizeof host)) + panic("bad host address, or none provided"); + + if (!MAIN.qname) + MAIN.qname = "ipv6.google.com"; + if (!MAIN.qtype) + MAIN.qtype = DNS_T_AAAA; + + if ((error = dns_p_push(Q, DNS_S_QD, MAIN.qname, strlen(MAIN.qname), MAIN.qtype, DNS_C_IN, 0, 0))) + panic("dns_p_push: %s", dns_strerror(error)); + + dns_header(Q)->rd = 1; + + if (strstr(argv[0], "udp")) + type = SOCK_DGRAM; + else if (strstr(argv[0], "tcp")) + type = SOCK_STREAM; + else + type = dns_res_tcp2type(resconf()->options.tcp); + + fprintf(stderr, "querying %s for %s IN %s\n", host, MAIN.qname, dns_strtype(MAIN.qtype)); + + if (!(so = dns_so_open((struct sockaddr *)&resconf()->iface, type, dns_opts(), &error))) + panic("dns_so_open: %s", dns_strerror(error)); + + while (!(A = dns_so_query(so, Q, (struct sockaddr *)&ss, &error))) { + if (error != DNS_EAGAIN) + panic("dns_so_query: %s (%d)", dns_strerror(error), error); + if (dns_so_elapsed(so) > 10) + panic("query timed-out"); + + dns_so_poll(so, 1); + } + + print_packet(A, stdout); + + dns_so_close(so); + + return 0; +} /* send_query() */ + + +static int print_arpa(int argc, char *argv[]) { + const char *ip = (argc > 1)? argv[1] : "::1"; + int af = (strchr(ip, ':'))? AF_INET6 : AF_INET; + union { struct in_addr a4; struct in6_addr a6; } addr; + char host[DNS_D_MAXNAME + 1]; + + if (1 != dns_inet_pton(af, ip, &addr) || 0 == dns_ptr_qname(host, sizeof host, af, &addr)) + panic("%s: invalid address", ip); + + fprintf(stdout, "%s\n", host); + + return 0; +} /* print_arpa() */ + + +static int show_hints(int argc, char *argv[]) { + struct dns_hints *(*load)(struct dns_resolv_conf *, int *); + const char *which, *how, *who; + struct dns_hints *hints; + int error; + + which = (argc > 1)? argv[1] : "local"; + how = (argc > 2)? argv[2] : "plain"; + who = (argc > 3)? argv[3] : "google.com"; + + load = (0 == strcmp(which, "local")) + ? &dns_hints_local + : &dns_hints_root; + + if (!(hints = load(resconf(), &error))) + panic("%s: %s", argv[0], dns_strerror(error)); + + if (0 == strcmp(how, "plain")) { + dns_hints_dump(hints, stdout); + } else { + struct dns_packet *query, *answer; + + query = dns_p_new(512); + + if ((error = dns_p_push(query, DNS_S_QUESTION, who, strlen(who), DNS_T_A, DNS_C_IN, 0, 0))) + panic("%s: %s", who, dns_strerror(error)); + + if (!(answer = dns_hints_query(hints, query, &error))) + panic("%s: %s", who, dns_strerror(error)); + + print_packet(answer, stdout); + + free(answer); + } + + dns_hints_close(hints); + + return 0; +} /* show_hints() */ + + +static int resolve_query(int argc DNS_NOTUSED, char *argv[]) { + _Bool recurse = !!strstr(argv[0], "recurse"); + struct dns_hints *(*hints)() = (recurse)? &dns_hints_root : &dns_hints_local; + struct dns_resolver *R; + struct dns_packet *ans; + const struct dns_stat *st; + int error; + + if (!MAIN.qname) + MAIN.qname = "www.google.com"; + if (!MAIN.qtype) + MAIN.qtype = DNS_T_A; + + resconf()->options.recurse = recurse; + + if (!(R = dns_res_open(resconf(), hosts(), dns_hints_mortal(hints(resconf(), &error)), cache(), dns_opts(), &error))) + panic("%s: %s", MAIN.qname, dns_strerror(error)); + + if ((error = dns_res_submit(R, MAIN.qname, MAIN.qtype, DNS_C_IN))) + panic("%s: %s", MAIN.qname, dns_strerror(error)); + + while ((error = dns_res_check(R))) { + if (error != DNS_EAGAIN) + panic("dns_res_check: %s (%d)", dns_strerror(error), error); + if (dns_res_elapsed(R) > 30) + panic("query timed-out"); + + dns_res_poll(R, 1); + } + + ans = dns_res_fetch(R, &error); + print_packet(ans, stdout); + free(ans); + + st = dns_res_stat(R); + putchar('\n'); + printf(";; queries: %"PRIuZ"\n", st->queries); + printf(";; udp sent: %"PRIuZ" in %"PRIuZ" bytes\n", st->udp.sent.count, st->udp.sent.bytes); + printf(";; udp rcvd: %"PRIuZ" in %"PRIuZ" bytes\n", st->udp.rcvd.count, st->udp.rcvd.bytes); + printf(";; tcp sent: %"PRIuZ" in %"PRIuZ" bytes\n", st->tcp.sent.count, st->tcp.sent.bytes); + printf(";; tcp rcvd: %"PRIuZ" in %"PRIuZ" bytes\n", st->tcp.rcvd.count, st->tcp.rcvd.bytes); + + dns_res_close(R); + + return 0; +} /* resolve_query() */ + + +static int resolve_addrinfo(int argc DNS_NOTUSED, char *argv[]) { + _Bool recurse = !!strstr(argv[0], "recurse"); + struct dns_hints *(*hints)() = (recurse)? &dns_hints_root : &dns_hints_local; + struct dns_resolver *res = NULL; + struct dns_addrinfo *ai = NULL; + struct addrinfo ai_hints = { .ai_family = PF_UNSPEC, .ai_socktype = SOCK_STREAM, .ai_flags = AI_CANONNAME }; + struct addrinfo *ent; + char pretty[512]; + int error; + + if (!MAIN.qname) + MAIN.qname = "www.google.com"; + if (!MAIN.qtype) + MAIN.qtype = DNS_T_A; + + resconf()->options.recurse = recurse; + + if (!(res = dns_res_open(resconf(), hosts(), dns_hints_mortal(hints(resconf(), &error)), cache(), dns_opts(), &error))) + panic("%s: %s", MAIN.qname, dns_strerror(error)); + + if (!(ai = dns_ai_open(MAIN.qname, "80", MAIN.qtype, &ai_hints, res, &error))) + panic("%s: %s", MAIN.qname, dns_strerror(error)); + + do { + switch (error = dns_ai_nextent(&ent, ai)) { + case 0: + dns_ai_print(pretty, sizeof pretty, ent, ai); + + fputs(pretty, stdout); + + free(ent); + + break; + case ENOENT: + break; + case DNS_EAGAIN: + if (dns_ai_elapsed(ai) > 30) + panic("query timed-out"); + + dns_ai_poll(ai, 1); + + break; + default: + panic("dns_ai_nextent: %s (%d)", dns_strerror(error), error); + } + } while (error != ENOENT); + + dns_res_close(res); + dns_ai_close(ai); + + return 0; +} /* resolve_addrinfo() */ + + +static int echo_port(int argc DNS_NOTUSED, char *argv[] DNS_NOTUSED) { + union { + struct sockaddr sa; + struct sockaddr_in sin; + } port; + int fd; + + memset(&port, 0, sizeof port); + port.sin.sin_family = AF_INET; + port.sin.sin_port = htons(5354); + port.sin.sin_addr.s_addr = inet_addr("127.0.0.1"); + + if (-1 == (fd = socket(PF_INET, SOCK_DGRAM, 0))) + panic("socket: %s", strerror(errno)); + + if (0 != bind(fd, &port.sa, sizeof port.sa)) + panic("127.0.0.1:5353: %s", dns_strerror(errno)); + + for (;;) { + struct dns_packet *pkt = dns_p_new(512); + struct sockaddr_storage ss; + socklen_t slen = sizeof ss; + ssize_t count; +#if defined(MSG_WAITALL) /* MinGW issue */ + int rflags = MSG_WAITALL; +#else + int rflags = 0; +#endif + + count = recvfrom(fd, (char *)pkt->data, pkt->size, rflags, (struct sockaddr *)&ss, &slen); + + if (!count || count < 0) + panic("recvfrom: %s", strerror(errno)); + + pkt->end = count; + + dns_p_dump(pkt, stdout); + + (void)sendto(fd, (char *)pkt->data, pkt->end, 0, (struct sockaddr *)&ss, slen); + } + + return 0; +} /* echo_port() */ + + +static int isection(int argc, char *argv[]) { + const char *name = (argc > 1)? argv[1] : ""; + int type; + + type = dns_isection(name); + name = dns_strsection(type); + + printf("%s (%d)\n", name, type); + + return 0; +} /* isection() */ + + +static int iclass(int argc, char *argv[]) { + const char *name = (argc > 1)? argv[1] : ""; + int type; + + type = dns_iclass(name); + name = dns_strclass(type); + + printf("%s (%d)\n", name, type); + + return 0; +} /* iclass() */ + + +static int itype(int argc, char *argv[]) { + const char *name = (argc > 1)? argv[1] : ""; + int type; + + type = dns_itype(name); + name = dns_strtype(type); + + printf("%s (%d)\n", name, type); + + return 0; +} /* itype() */ + + +static int iopcode(int argc, char *argv[]) { + const char *name = (argc > 1)? argv[1] : ""; + int type; + + type = dns_iopcode(name); + name = dns_stropcode(type); + + printf("%s (%d)\n", name, type); + + return 0; +} /* iopcode() */ + + +static int ircode(int argc, char *argv[]) { + const char *name = (argc > 1)? argv[1] : ""; + int type; + + type = dns_ircode(name); + name = dns_strrcode(type); + + printf("%s (%d)\n", name, type); + + return 0; +} /* ircode() */ + + +#define SIZE1(x) { DNS_PP_STRINGIFY(x), sizeof (x) } +#define SIZE2(x, ...) SIZE1(x), SIZE1(__VA_ARGS__) +#define SIZE3(x, ...) SIZE1(x), SIZE2(__VA_ARGS__) +#define SIZE4(x, ...) SIZE1(x), SIZE3(__VA_ARGS__) +#define SIZE(...) DNS_PP_CALL(DNS_PP_XPASTE(SIZE, DNS_PP_NARG(__VA_ARGS__)), __VA_ARGS__) + +static int sizes(int argc DNS_NOTUSED, char *argv[] DNS_NOTUSED) { + static const struct { const char *name; size_t size; } type[] = { + SIZE(struct dns_header, struct dns_packet, struct dns_rr, struct dns_rr_i), + SIZE(struct dns_a, struct dns_aaaa, struct dns_mx, struct dns_ns), + SIZE(struct dns_cname, struct dns_soa, struct dns_ptr, struct dns_srv), + SIZE(struct dns_sshfp, struct dns_txt, union dns_any), + SIZE(struct dns_resolv_conf, struct dns_hosts, struct dns_hints, struct dns_hints_i), + SIZE(struct dns_options, struct dns_socket, struct dns_resolver, struct dns_addrinfo), + SIZE(struct dns_cache), SIZE(size_t), SIZE(void *), SIZE(long) + }; + unsigned i, max; + + for (i = 0, max = 0; i < lengthof(type); i++) + max = DNS_PP_MAX(max, strlen(type[i].name)); + + for (i = 0; i < lengthof(type); i++) + printf("%*s : %"PRIuZ"\n", max, type[i].name, type[i].size); + + return 0; +} /* sizes() */ + + +static const struct { const char *cmd; int (*run)(); const char *help; } cmds[] = { + { "parse-packet", &parse_packet, "parse binary packet from stdin" }, + { "parse-domain", &parse_domain, "anchor and iteratively cleave domain" }, + { "trim-domain", &trim_domain, "trim and anchor domain name" }, + { "expand-domain", &expand_domain, "expand domain at offset NN in packet from stdin" }, + { "show-resconf", &show_resconf, "show resolv.conf data" }, + { "show-hosts", &show_hosts, "show hosts data" }, + { "show-nssconf", &show_nssconf, "show nsswitch.conf data" }, + { "query-hosts", &query_hosts, "query A, AAAA or PTR in hosts data" }, + { "search-list", &search_list, "generate query search list from domain" }, + { "permute-set", &permute_set, "generate random permutation -> (0 .. N or N .. M)" }, + { "shuffle-16", &shuffle_16, "simple 16-bit permutation" }, + { "dump-random", &dump_random, "generate random bytes" }, + { "send-query", &send_query, "send query to host" }, + { "send-query-udp", &send_query, "send udp query to host" }, + { "send-query-tcp", &send_query, "send tcp query to host" }, + { "print-arpa", &print_arpa, "print arpa. zone name of address" }, + { "show-hints", &show_hints, "print hints: show-hints [local|root] [plain|packet]" }, + { "resolve-stub", &resolve_query, "resolve as stub resolver" }, + { "resolve-recurse", &resolve_query, "resolve as recursive resolver" }, + { "addrinfo-stub", &resolve_addrinfo, "resolve through getaddrinfo clone" }, + { "addrinfo-recurse", &resolve_addrinfo, "resolve through getaddrinfo clone" }, +/* { "resolve-nameinfo", &resolve_query, "resolve as recursive resolver" }, */ + { "echo", &echo_port, "server echo mode, for nmap fuzzing" }, + { "isection", &isection, "parse section string" }, + { "iclass", &iclass, "parse class string" }, + { "itype", &itype, "parse type string" }, + { "iopcode", &iopcode, "parse opcode string" }, + { "ircode", &ircode, "parse rcode string" }, + { "sizes", &sizes, "print data structure sizes" }, +}; + + +static void print_usage(const char *progname, FILE *fp) { + static const char *usage = + " [OPTIONS] COMMAND [ARGS]\n" + " -c PATH Path to resolv.conf\n" + " -n PATH Path to nsswitch.conf\n" + " -l PATH Path to local hosts\n" + " -z PATH Path to zone cache\n" + " -q QNAME Query name\n" + " -t QTYPE Query type\n" + " -s HOW Sort records\n" + " -v Be more verbose (-vv show packets; -vvv hexdump packets)\n" + " -V Print version info\n" + " -h Print this usage message\n" + "\n"; + unsigned i, n, m; + + fputs(progname, fp); + fputs(usage, fp); + + for (i = 0, m = 0; i < lengthof(cmds); i++) { + if (strlen(cmds[i].cmd) > m) + m = strlen(cmds[i].cmd); + } + + for (i = 0; i < lengthof(cmds); i++) { + fprintf(fp, " %s ", cmds[i].cmd); + + for (n = strlen(cmds[i].cmd); n < m; n++) + putc(' ', fp); + + fputs(cmds[i].help, fp); + putc('\n', fp); + } + + fputs("\nReport bugs to William Ahern \n", fp); +} /* print_usage() */ + + +static void print_version(const char *progname, FILE *fp) { + fprintf(fp, "%s (dns.c) %.8X\n", progname, dns_v_rel()); + fprintf(fp, "vendor %s\n", dns_vendor()); + fprintf(fp, "release %.8X\n", dns_v_rel()); + fprintf(fp, "abi %.8X\n", dns_v_abi()); + fprintf(fp, "api %.8X\n", dns_v_api()); +} /* print_version() */ + + +int main(int argc, char **argv) { + extern int optind; + extern char *optarg; + const char *progname = argv[0]; + unsigned i; + int ch; + + while (-1 != (ch = getopt(argc, argv, "q:t:c:n:l:z:s:vVh"))) { + switch (ch) { + case 'c': + assert(MAIN.resconf.count < lengthof(MAIN.resconf.path)); + + MAIN.resconf.path[MAIN.resconf.count++] = optarg; + + break; + case 'n': + assert(MAIN.nssconf.count < lengthof(MAIN.nssconf.path)); + + MAIN.nssconf.path[MAIN.nssconf.count++] = optarg; + + break; + case 'l': + assert(MAIN.hosts.count < lengthof(MAIN.hosts.path)); + + MAIN.hosts.path[MAIN.hosts.count++] = optarg; + + break; + case 'z': + assert(MAIN.cache.count < lengthof(MAIN.cache.path)); + + MAIN.cache.path[MAIN.cache.count++] = optarg; + + break; + case 'q': + MAIN.qname = optarg; + + break; + case 't': + for (i = 0; i < lengthof(dns_rrtypes); i++) { + if (0 == strcasecmp(dns_rrtypes[i].name, optarg)) + { MAIN.qtype = dns_rrtypes[i].type; break; } + } + + if (MAIN.qtype) + break; + + for (i = 0; isdigit((int)optarg[i]); i++) { + MAIN.qtype *= 10; + MAIN.qtype += optarg[i] - '0'; + } + + if (!MAIN.qtype) + panic("%s: invalid query type", optarg); + + break; + case 's': + if (0 == strcasecmp(optarg, "packet")) + MAIN.sort = &dns_rr_i_packet; + else if (0 == strcasecmp(optarg, "shuffle")) + MAIN.sort = &dns_rr_i_shuffle; + else if (0 == strcasecmp(optarg, "order")) + MAIN.sort = &dns_rr_i_order; + else + panic("%s: invalid sort method", optarg); + + break; + case 'v': + dns_debug = ++MAIN.verbose; + + break; + case 'V': + print_version(progname, stdout); + + return 0; + case 'h': + print_usage(progname, stdout); + + return 0; + default: + print_usage(progname, stderr); + + return EXIT_FAILURE; + } /* switch() */ + } /* while() */ + + argc -= optind; + argv += optind; + + for (i = 0; i < lengthof(cmds) && argv[0]; i++) { + if (0 == strcmp(cmds[i].cmd, argv[0])) + return cmds[i].run(argc, argv); + } + + print_usage(progname, stderr); + + return EXIT_FAILURE; +} /* main() */ + + +#endif /* DNS_MAIN */ + + +/* + * pop file-scoped compiler annotations + */ +#if __clang__ +#pragma clang diagnostic pop +#elif DNS_GNUC_PREREQ(4, 6) +#pragma GCC diagnostic pop +#endif + diff --git a/lib/dns.h b/lib/dns.h new file mode 100644 index 00000000..2949cb33 --- /dev/null +++ b/lib/dns.h @@ -0,0 +1,1199 @@ +/* ========================================================================== + * dns.h - Recursive, Reentrant DNS Resolver. + * -------------------------------------------------------------------------- + * Copyright (c) 2009, 2010, 2012, 2013, 2014, 2015 William Ahern + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sublicense, and/or sell copies of the Software, and to permit + * persons to whom the Software is furnished to do so, subject to the + * following conditions: + * + * The above copyright notice and this permission notice shall be included + * in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN + * NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, + * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR + * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE + * USE OR OTHER DEALINGS IN THE SOFTWARE. + * ========================================================================== + */ +#ifndef DNS_H +#define DNS_H + +#include /* size_t offsetof() */ +#include /* FILE */ + +#include /* strlen(3) */ + +#include /* time_t */ + +#if _WIN32 +#include +#include +#else +#include /* BYTE_ORDER BIG_ENDIAN _BIG_ENDIAN */ +#include /* socklen_t */ +#include /* struct socket */ + +#include /* POLLIN POLLOUT */ + +#include /* struct in_addr struct in6_addr */ + +#include /* struct addrinfo */ +#endif + + +/* + * V E R S I O N + * + * Vendor: Entity for which versions numbers are relevant. (If forking + * change DNS_VENDOR to avoid confusion.) + * + * Three versions: + * + * REL Official "release"--bug fixes, new features, etc. + * ABI Changes to existing object sizes or parameter types. + * API Changes that might effect application source. + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#define DNS_VENDOR "william@25thandClement.com" + +#define DNS_V_REL 0x20150630 +#define DNS_V_ABI 0x20150612 +#define DNS_V_API 0x20150612 + + +const char *dns_vendor(void); + +int dns_v_rel(void); +int dns_v_abi(void); +int dns_v_api(void); + + +/* + * E R R O R S + * + * Errors and exceptions are always returned through an int. This should + * hopefully make integration easier in the majority of circumstances, and + * also cut down on useless compiler warnings. + * + * System and library errors are returned together. POSIX guarantees that + * all system errors are positive integers. Library errors are always + * negative integers in the range DNS_EBASE to DNS_ELAST, with the high bits + * set to the three magic ASCII characters "dns". + * + * dns_strerror() returns static English string descriptions of all known + * errors, and punts the remainder to strerror(3). + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#define DNS_EBASE -(('d' << 24) | ('n' << 16) | ('s' << 8) | 64) + +#define dns_error_t int /* for documentation only */ + +enum dns_errno { + DNS_ENOBUFS = DNS_EBASE, + DNS_EILLEGAL, + DNS_EORDER, + DNS_ESECTION, + DNS_EUNKNOWN, + DNS_EADDRESS, + DNS_ENOQUERY, + DNS_ENOANSWER, + DNS_EFETCHED, + DNS_ESERVICE, /* EAI_SERVICE */ + DNS_ENONAME, /* EAI_NONAME */ + DNS_EFAIL, /* EAI_FAIL */ + DNS_ELAST, +}; /* dns_errno */ + +const char *dns_strerror(dns_error_t); + +extern int dns_debug; + + +/* + * C O M P I L E R A N N O T A T I O N S + * + * GCC with -Wextra, and clang by default, complain about overrides in + * initializer lists. Overriding previous member initializers is well + * defined behavior in C. dns.c relies on this behavior to define default, + * overrideable member values when instantiating configuration objects. + * + * dns_quietinit() guards a compound literal expression with pragmas to + * silence these shrill warnings. This alleviates the burden of requiring + * third-party projects to adjust their compiler flags. + * + * NOTE: If you take the address of the compound literal, take the address + * of the transformed expression, otherwise the compound literal lifetime is + * tied to the scope of the GCC statement expression. + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#if defined __clang__ +#define DNS_PRAGMA_PUSH _Pragma("clang diagnostic push") +#define DNS_PRAGMA_QUIET _Pragma("clang diagnostic ignored \"-Winitializer-overrides\"") +#define DNS_PRAGMA_POP _Pragma("clang diagnostic pop") + +#define dns_quietinit(...) \ + DNS_PRAGMA_PUSH DNS_PRAGMA_QUIET __VA_ARGS__ DNS_PRAGMA_POP +#elif (__GNUC__ == 4 && __GNUC_MINOR__ >= 6) || __GNUC__ > 4 +#define DNS_PRAGMA_PUSH _Pragma("GCC diagnostic push") +#define DNS_PRAGMA_QUIET _Pragma("GCC diagnostic ignored \"-Woverride-init\"") +#define DNS_PRAGMA_POP _Pragma("GCC diagnostic pop") + +/* GCC 5+: the trailing _Pragma inside the statement expression yields void, + * so &dns_quietinit(...) fails with "lvalue required". Emit the compound + * literal directly; -Woverride-init suppression is not needed in this build. */ +#define dns_quietinit(...) __VA_ARGS__ +#else +#define DNS_PRAGMA_PUSH +#define DNS_PRAGMA_QUIET +#define DNS_PRAGMA_POP +#define dns_quietinit(...) __VA_ARGS__ +#endif + +#if defined __GNUC__ +#define DNS_PRAGMA_EXTENSION __extension__ +#else +#define DNS_PRAGMA_EXTENSION +#endif + + +/* + * E V E N T S I N T E R F A C E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#if defined(POLLIN) +#define DNS_POLLIN POLLIN +#else +#define DNS_POLLIN 1 +#endif + +#if defined(POLLOUT) +#define DNS_POLLOUT POLLOUT +#else +#define DNS_POLLOUT 2 +#endif + + +/* + * See Application Interface below for configuring libevent bitmasks instead + * of poll(2) bitmasks. + */ +#define DNS_EVREAD 2 +#define DNS_EVWRITE 4 + + +#define DNS_POLL2EV(set) \ + (((set) & DNS_POLLIN)? DNS_EVREAD : 0) | (((set) & DNS_POLLOUT)? DNS_EVWRITE : 0) + +#define DNS_EV2POLL(set) \ + (((set) & DNS_EVREAD)? DNS_POLLIN : 0) | (((set) & DNS_EVWRITE)? DNS_POLLOUT : 0) + + +/* + * E N U M E R A T I O N I N T E R F A C E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +enum dns_section { + DNS_S_QD = 0x01, +#define DNS_S_QUESTION DNS_S_QD + + DNS_S_AN = 0x02, +#define DNS_S_ANSWER DNS_S_AN + + DNS_S_NS = 0x04, +#define DNS_S_AUTHORITY DNS_S_NS + + DNS_S_AR = 0x08, +#define DNS_S_ADDITIONAL DNS_S_AR + + DNS_S_ALL = 0x0f +}; /* enum dns_section */ + + +enum dns_class { + DNS_C_IN = 1, + + DNS_C_ANY = 255 +}; /* enum dns_class */ + + +enum dns_type { + DNS_T_A = 1, + DNS_T_NS = 2, + DNS_T_CNAME = 5, + DNS_T_SOA = 6, + DNS_T_PTR = 12, + DNS_T_MX = 15, + DNS_T_TXT = 16, + DNS_T_AAAA = 28, + DNS_T_SRV = 33, + DNS_T_OPT = 41, + DNS_T_SSHFP = 44, + DNS_T_SPF = 99, + + DNS_T_ALL = 255 +}; /* enum dns_type */ + + +enum dns_opcode { + DNS_OP_QUERY = 0, + DNS_OP_IQUERY = 1, + DNS_OP_STATUS = 2, + DNS_OP_NOTIFY = 4, + DNS_OP_UPDATE = 5, +}; /* dns_opcode */ + + +enum dns_rcode { + DNS_RC_NOERROR = 0, + DNS_RC_FORMERR = 1, + DNS_RC_SERVFAIL = 2, + DNS_RC_NXDOMAIN = 3, + DNS_RC_NOTIMP = 4, + DNS_RC_REFUSED = 5, + DNS_RC_YXDOMAIN = 6, + DNS_RC_YXRRSET = 7, + DNS_RC_NXRRSET = 8, + DNS_RC_NOTAUTH = 9, + DNS_RC_NOTZONE = 10, +}; /* dns_rcode */ + + +/* + * NOTE: These string functions need a small buffer in case the literal + * integer value needs to be printed and returned. UNLESS this buffer is + * SPECIFIED, the returned string has ONLY BLOCK SCOPE. + */ +#define DNS_STRMAXLEN 47 /* "QUESTION|ANSWER|AUTHORITY|ADDITIONAL" */ + +const char *dns_strsection(enum dns_section, void *, size_t); +#define dns_strsection3(a, b, c) \ + dns_strsection((a), (b), (c)) +#define dns_strsection1(a) dns_strsection((a), (char [DNS_STRMAXLEN + 1]){ 0 }, DNS_STRMAXLEN + 1) +#define dns_strsection(...) DNS_PP_CALL(DNS_PP_XPASTE(dns_strsection, DNS_PP_NARG(__VA_ARGS__)), __VA_ARGS__) + +enum dns_section dns_isection(const char *); + +const char *dns_strclass(enum dns_class, void *, size_t); +#define dns_strclass3(a, b, c) dns_strclass((a), (b), (c)) +#define dns_strclass1(a) dns_strclass((a), (char [DNS_STRMAXLEN + 1]){ 0 }, DNS_STRMAXLEN + 1) +#define dns_strclass(...) DNS_PP_CALL(DNS_PP_XPASTE(dns_strclass, DNS_PP_NARG(__VA_ARGS__)), __VA_ARGS__) + +enum dns_class dns_iclass(const char *); + +const char *dns_strtype(enum dns_type, void *, size_t); +#define dns_strtype3(a, b, c) dns_strtype((a), (b), (c)) +#define dns_strtype1(a) dns_strtype((a), (char [DNS_STRMAXLEN + 1]){ 0 }, DNS_STRMAXLEN + 1) +#define dns_strtype(...) DNS_PP_CALL(DNS_PP_XPASTE(dns_strtype, DNS_PP_NARG(__VA_ARGS__)), __VA_ARGS__) + +enum dns_type dns_itype(const char *); + +const char *dns_stropcode(enum dns_opcode); + +enum dns_opcode dns_iopcode(const char *); + +const char *dns_strrcode(enum dns_rcode); + +enum dns_rcode dns_ircode(const char *); + + +/* + * A T O M I C I N T E R F A C E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +typedef unsigned long dns_atomic_t; + +typedef unsigned long dns_refcount_t; /* must be same value type as dns_atomic_t */ + + +/* + * C R Y P T O I N T E R F A C E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +extern unsigned (*dns_random)(void); + + +/* + * P A C K E T I N T E R F A C E + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +struct dns_header { + unsigned qid:16; + +#if (defined BYTE_ORDER && BYTE_ORDER == BIG_ENDIAN) || (defined __sun && defined _BIG_ENDIAN) + unsigned qr:1; + unsigned opcode:4; + unsigned aa:1; + unsigned tc:1; + unsigned rd:1; + + unsigned ra:1; + unsigned unused:3; + unsigned rcode:4; +#else + unsigned rd:1; + unsigned tc:1; + unsigned aa:1; + unsigned opcode:4; + unsigned qr:1; + + unsigned rcode:4; + unsigned unused:3; + unsigned ra:1; +#endif + + unsigned qdcount:16; + unsigned ancount:16; + unsigned nscount:16; + unsigned arcount:16; +}; /* struct dns_header */ + +#define dns_header(p) (&(p)->header) + + +#ifndef DNS_P_QBUFSIZ +#define DNS_P_QBUFSIZ dns_p_calcsize(256 + 4) +#endif + +#ifndef DNS_P_DICTSIZE +#define DNS_P_DICTSIZE 16 +#endif + +struct dns_packet { + unsigned short dict[DNS_P_DICTSIZE]; + + struct dns_s_memo { + unsigned short base, end; + } qd, an, ns, ar; + + struct { struct dns_packet *cqe_next, *cqe_prev; } cqe; + + size_t size, end; + + int:16; /* tcp padding */ + + DNS_PRAGMA_EXTENSION union { + struct dns_header header; + unsigned char data[1]; + }; +}; /* struct dns_packet */ + +#define dns_p_calcsize(n) (offsetof(struct dns_packet, data) + DNS_PP_MAX(12, (n))) + +#define dns_p_sizeof(P) dns_p_calcsize((P)->end) + +/** takes size of maximum desired payload */ +#define dns_p_new(n) (dns_p_init((struct dns_packet *)&(union { unsigned char b[dns_p_calcsize((n))]; struct dns_packet p; }){ { 0 } }, dns_p_calcsize((n)))) + +/** takes size of entire packet structure as allocated */ +struct dns_packet *dns_p_init(struct dns_packet *, size_t); + +/** takes size of maximum desired payload */ +struct dns_packet *dns_p_make(size_t, int *); + +int dns_p_grow(struct dns_packet **); + +struct dns_packet *dns_p_copy(struct dns_packet *, const struct dns_packet *); + +#define dns_p_opcode(P) (dns_header(P)->opcode) + +#define dns_p_rcode(P) (dns_header(P)->rcode) + +unsigned dns_p_count(struct dns_packet *, enum dns_section); + +int dns_p_push(struct dns_packet *, enum dns_section, const void *, size_t, enum dns_type, enum dns_class, unsigned, const void *); + +void dns_p_dictadd(struct dns_packet *, unsigned short); + +struct dns_packet *dns_p_merge(struct dns_packet *, enum dns_section, struct dns_packet *, enum dns_section, int *); + +void dns_p_dump(struct dns_packet *, FILE *); + +int dns_p_study(struct dns_packet *); + + +/* + * D O M A I N N A M E I N T E R F A C E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#define DNS_D_MAXLABEL 63 /* + 1 '\0' */ +#define DNS_D_MAXNAME 255 /* + 1 '\0' */ + +#define DNS_D_ANCHOR 1 /* anchor domain w/ root "." */ +#define DNS_D_CLEAVE 2 /* cleave sub-domain */ +#define DNS_D_TRIM 4 /* remove superfluous dots */ + +#define dns_d_new3(a, b, f) dns_d_init(&(char[DNS_D_MAXNAME + 1]){ 0 }, DNS_D_MAXNAME + 1, (a), (b), (f)) +#define dns_d_new2(a, f) dns_d_new3((a), strlen((a)), (f)) +#define dns_d_new1(a) dns_d_new3((a), strlen((a)), DNS_D_ANCHOR) +#define dns_d_new(...) DNS_PP_CALL(DNS_PP_XPASTE(dns_d_new, DNS_PP_NARG(__VA_ARGS__)), __VA_ARGS__) + +char *dns_d_init(void *, size_t, const void *, size_t, int); + +size_t dns_d_anchor(void *, size_t, const void *, size_t); + +size_t dns_d_cleave(void *, size_t, const void *, size_t); + +size_t dns_d_comp(void *, size_t, const void *, size_t, struct dns_packet *, int *); + +size_t dns_d_expand(void *, size_t, unsigned short, struct dns_packet *, int *); + +unsigned short dns_d_skip(unsigned short, struct dns_packet *); + +int dns_d_push(struct dns_packet *, const void *, size_t); + +size_t dns_d_cname(void *, size_t, const void *, size_t, struct dns_packet *, int *error); + + +/* + * R E S O U R C E R E C O R D I N T E R F A C E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +struct dns_rr { + enum dns_section section; + + struct { + unsigned short p; + unsigned short len; + } dn; + + enum dns_type type; + enum dns_class class; + unsigned ttl; + + struct { + unsigned short p; + unsigned short len; + } rd; +}; /* struct dns_rr */ + + +int dns_rr_copy(struct dns_packet *, struct dns_rr *, struct dns_packet *); + +int dns_rr_parse(struct dns_rr *, unsigned short, struct dns_packet *); + +unsigned short dns_rr_skip(unsigned short, struct dns_packet *); + +int dns_rr_cmp(struct dns_rr *, struct dns_packet *, struct dns_rr *, struct dns_packet *); + +size_t dns_rr_print(void *, size_t, struct dns_rr *, struct dns_packet *, int *); + + +#define dns_rr_i_new(P, ...) \ + dns_rr_i_init(&dns_quietinit((struct dns_rr_i){ 0, __VA_ARGS__ }), (P)) + +struct dns_rr_i { + enum dns_section section; + const void *name; + enum dns_type type; + enum dns_class class; + const void *data; + + int follow; + + int (*sort)(); + unsigned args[2]; + + struct { + unsigned short next; + unsigned short count; + + unsigned exec; + unsigned regs[2]; + } state, saved; +}; /* struct dns_rr_i */ + +int dns_rr_i_packet(struct dns_rr *, struct dns_rr *, struct dns_rr_i *, struct dns_packet *); + +int dns_rr_i_order(struct dns_rr *, struct dns_rr *, struct dns_rr_i *, struct dns_packet *); + +int dns_rr_i_shuffle(struct dns_rr *, struct dns_rr *, struct dns_rr_i *, struct dns_packet *); + +struct dns_rr_i *dns_rr_i_init(struct dns_rr_i *, struct dns_packet *); + +#define dns_rr_i_save(i) ((i)->saved = (i)->state) +#define dns_rr_i_rewind(i) ((i)->state = (i)->saved) +#define dns_rr_i_count(i) ((i)->state.count) + +unsigned dns_rr_grep(struct dns_rr *, unsigned, struct dns_rr_i *, struct dns_packet *, int *); + +#define dns_rr_foreach_(rr, P, ...) \ + for (struct dns_rr_i DNS_PP_XPASTE(i, __LINE__) = *dns_rr_i_new((P), __VA_ARGS__); dns_rr_grep((rr), 1, &DNS_PP_XPASTE(i, __LINE__), (P), &(int){ 0 }); ) + +#define dns_rr_foreach(...) dns_rr_foreach_(__VA_ARGS__) + + +/* + * A R E S O U R C E R E C O R D + */ + +struct dns_a { + struct in_addr addr; +}; /* struct dns_a */ + +int dns_a_parse(struct dns_a *, struct dns_rr *, struct dns_packet *); + +int dns_a_push(struct dns_packet *, struct dns_a *); + +int dns_a_cmp(const struct dns_a *, const struct dns_a *); + +size_t dns_a_print(void *, size_t, struct dns_a *); + + +/* + * AAAA R E S O U R C E R E C O R D + */ + +struct dns_aaaa { + struct in6_addr addr; +}; /* struct dns_aaaa */ + +int dns_aaaa_parse(struct dns_aaaa *, struct dns_rr *, struct dns_packet *); + +int dns_aaaa_push(struct dns_packet *, struct dns_aaaa *); + +int dns_aaaa_cmp(const struct dns_aaaa *, const struct dns_aaaa *); + +size_t dns_aaaa_print(void *, size_t, struct dns_aaaa *); + + +/* + * MX R E S O U R C E R E C O R D + */ + +struct dns_mx { + unsigned short preference; + char host[DNS_D_MAXNAME + 1]; +}; /* struct dns_mx */ + +int dns_mx_parse(struct dns_mx *, struct dns_rr *, struct dns_packet *); + +int dns_mx_push(struct dns_packet *, struct dns_mx *); + +int dns_mx_cmp(const struct dns_mx *, const struct dns_mx *); + +size_t dns_mx_print(void *, size_t, struct dns_mx *); + +size_t dns_mx_cname(void *, size_t, struct dns_mx *); + + +/* + * NS R E S O U R C E R E C O R D + */ + +struct dns_ns { + char host[DNS_D_MAXNAME + 1]; +}; /* struct dns_ns */ + +int dns_ns_parse(struct dns_ns *, struct dns_rr *, struct dns_packet *); + +int dns_ns_push(struct dns_packet *, struct dns_ns *); + +int dns_ns_cmp(const struct dns_ns *, const struct dns_ns *); + +size_t dns_ns_print(void *, size_t, struct dns_ns *); + +size_t dns_ns_cname(void *, size_t, struct dns_ns *); + + +/* + * CNAME R E S O U R C E R E C O R D + */ + +struct dns_cname { + char host[DNS_D_MAXNAME + 1]; +}; /* struct dns_cname */ + +int dns_cname_parse(struct dns_cname *, struct dns_rr *, struct dns_packet *); + +int dns_cname_push(struct dns_packet *, struct dns_cname *); + +int dns_cname_cmp(const struct dns_cname *, const struct dns_cname *); + +size_t dns_cname_print(void *, size_t, struct dns_cname *); + +size_t dns_cname_cname(void *, size_t, struct dns_cname *); + + +/* + * SOA R E S O U R C E R E C O R D + */ + +struct dns_soa { + char mname[DNS_D_MAXNAME + 1]; + char rname[DNS_D_MAXNAME + 1]; + unsigned serial, refresh, retry, expire, minimum; +}; /* struct dns_soa */ + +int dns_soa_parse(struct dns_soa *, struct dns_rr *, struct dns_packet *); + +int dns_soa_push(struct dns_packet *, struct dns_soa *); + +int dns_soa_cmp(const struct dns_soa *, const struct dns_soa *); + +size_t dns_soa_print(void *, size_t, struct dns_soa *); + + +/* + * PTR R E S O U R C E R E C O R D + */ + +struct dns_ptr { + char host[DNS_D_MAXNAME + 1]; +}; /* struct dns_ptr */ + +int dns_ptr_parse(struct dns_ptr *, struct dns_rr *, struct dns_packet *); + +int dns_ptr_push(struct dns_packet *, struct dns_ptr *); + +int dns_ptr_cmp(const struct dns_ptr *, const struct dns_ptr *); + +size_t dns_ptr_print(void *, size_t, struct dns_ptr *); + +size_t dns_ptr_cname(void *, size_t, struct dns_ptr *); + + +/* + * SRV R E S O U R C E R E C O R D + */ + +struct dns_srv { + unsigned short priority; + unsigned short weight; + unsigned short port; + char target[DNS_D_MAXNAME + 1]; +}; /* struct dns_srv */ + +int dns_srv_parse(struct dns_srv *, struct dns_rr *, struct dns_packet *); + +int dns_srv_push(struct dns_packet *, struct dns_srv *); + +int dns_srv_cmp(const struct dns_srv *, const struct dns_srv *); + +size_t dns_srv_print(void *, size_t, struct dns_srv *); + +size_t dns_srv_cname(void *, size_t, struct dns_srv *); + + +/* + * OPT R E S O U R C E R E C O R D + */ + +#define DNS_OPT_MINDATA 512 + +#define DNS_OPT_BADVERS 16 + +struct dns_opt { + size_t size, len; + + unsigned char rcode, version; + unsigned short maxsize; + + unsigned char data[DNS_OPT_MINDATA]; +}; /* struct dns_opt */ + +unsigned int dns_opt_ttl(const struct dns_opt *); + +unsigned short dns_opt_class(const struct dns_opt *); + +struct dns_opt *dns_opt_init(struct dns_opt *, size_t); + +int dns_opt_parse(struct dns_opt *, struct dns_rr *, struct dns_packet *); + +int dns_opt_push(struct dns_packet *, struct dns_opt *); + +int dns_opt_cmp(const struct dns_opt *, const struct dns_opt *); + +size_t dns_opt_print(void *, size_t, struct dns_opt *); + + +/* + * SSHFP R E S O U R C E R E C O R D + */ + +struct dns_sshfp { + enum dns_sshfp_key { + DNS_SSHFP_RSA = 1, + DNS_SSHFP_DSA = 2, + } algo; + + enum dns_sshfp_digest { + DNS_SSHFP_SHA1 = 1, + } type; + + union { + unsigned char sha1[20]; + } digest; +}; /* struct dns_sshfp */ + +int dns_sshfp_parse(struct dns_sshfp *, struct dns_rr *, struct dns_packet *); + +int dns_sshfp_push(struct dns_packet *, struct dns_sshfp *); + +int dns_sshfp_cmp(const struct dns_sshfp *, const struct dns_sshfp *); + +size_t dns_sshfp_print(void *, size_t, struct dns_sshfp *); + + +/* + * TXT R E S O U R C E R E C O R D + */ + +#ifndef DNS_TXT_MINDATA +#define DNS_TXT_MINDATA 1024 +#endif + +struct dns_txt { + size_t size, len; + unsigned char data[DNS_TXT_MINDATA]; +}; /* struct dns_txt */ + +struct dns_txt *dns_txt_init(struct dns_txt *, size_t); + +int dns_txt_parse(struct dns_txt *, struct dns_rr *, struct dns_packet *); + +int dns_txt_push(struct dns_packet *, struct dns_txt *); + +int dns_txt_cmp(const struct dns_txt *, const struct dns_txt *); + +size_t dns_txt_print(void *, size_t, struct dns_txt *); + + +/* + * ANY R E S O U R C E R E C O R D + */ + +union dns_any { + struct dns_a a; + struct dns_aaaa aaaa; + struct dns_mx mx; + struct dns_ns ns; + struct dns_cname cname; + struct dns_soa soa; + struct dns_ptr ptr; + struct dns_srv srv; + struct dns_opt opt; + struct dns_sshfp sshfp; + struct dns_txt txt, spf, rdata; +}; /* union dns_any */ + +#define DNS_ANY_INIT(any) { .rdata = { .size = sizeof *(any) } } + +union dns_any *dns_any_init(union dns_any *, size_t); + +int dns_any_parse(union dns_any *, struct dns_rr *, struct dns_packet *); + +int dns_any_push(struct dns_packet *, union dns_any *, enum dns_type); + +int dns_any_cmp(const union dns_any *, enum dns_type, const union dns_any *, enum dns_type); + +size_t dns_any_print(void *, size_t, union dns_any *, enum dns_type); + +size_t dns_any_cname(void *, size_t, union dns_any *, enum dns_type); + + +/* + * H O S T S I N T E R F A C E + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +struct dns_hosts; + +struct dns_hosts *dns_hosts_open(int *); + +void dns_hosts_close(struct dns_hosts *); + +dns_refcount_t dns_hosts_acquire(struct dns_hosts *); + +dns_refcount_t dns_hosts_release(struct dns_hosts *); + +struct dns_hosts *dns_hosts_mortal(struct dns_hosts *); + +struct dns_hosts *dns_hosts_local(int *); + +int dns_hosts_loadfile(struct dns_hosts *, FILE *); + +int dns_hosts_loadpath(struct dns_hosts *, const char *); + +int dns_hosts_dump(struct dns_hosts *, FILE *); + +int dns_hosts_insert(struct dns_hosts *, int, const void *, const void *, _Bool); + +struct dns_packet *dns_hosts_query(struct dns_hosts *, struct dns_packet *, int *); + + +/* + * R E S O L V . C O N F I N T E R F A C E + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +struct dns_resolv_conf { + struct sockaddr_storage nameserver[3]; + + char search[4][DNS_D_MAXNAME + 1]; + + /* (f)ile, (b)ind, (c)ache */ + char lookup[4 * (1 + (4 * 2))]; + + struct { + _Bool edns0; + + unsigned ndots; + + unsigned timeout; + + unsigned attempts; + + _Bool rotate; + + _Bool recurse; + + _Bool smart; + + enum { + DNS_RESCONF_TCP_ENABLE, + DNS_RESCONF_TCP_ONLY, + DNS_RESCONF_TCP_DISABLE, + } tcp; + } options; + + struct sockaddr_storage iface; + + struct { /* PRIVATE */ + dns_atomic_t refcount; + } _; +}; /* struct dns_resolv_conf */ + +struct dns_resolv_conf *dns_resconf_open(int *); + +void dns_resconf_close(struct dns_resolv_conf *); + +dns_refcount_t dns_resconf_acquire(struct dns_resolv_conf *); + +dns_refcount_t dns_resconf_release(struct dns_resolv_conf *); + +struct dns_resolv_conf *dns_resconf_mortal(struct dns_resolv_conf *); + +struct dns_resolv_conf *dns_resconf_local(int *); + +struct dns_resolv_conf *dns_resconf_root(int *); + +int dns_resconf_pton(struct sockaddr_storage *, const char *); + +int dns_resconf_loadfile(struct dns_resolv_conf *, FILE *); + +int dns_resconf_loadpath(struct dns_resolv_conf *, const char *); + +int dns_nssconf_loadfile(struct dns_resolv_conf *, FILE *); + +int dns_nssconf_loadpath(struct dns_resolv_conf *, const char *); + +int dns_resconf_dump(struct dns_resolv_conf *, FILE *); + +int dns_nssconf_dump(struct dns_resolv_conf *, FILE *); + +int dns_resconf_setiface(struct dns_resolv_conf *, const char *, unsigned short); + +typedef unsigned long dns_resconf_i_t; + +size_t dns_resconf_search(void *, size_t, const void *, size_t, struct dns_resolv_conf *, dns_resconf_i_t *); + + +/* + * H I N T S E R V E R I N T E R F A C E + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +struct dns_hints; + +struct dns_hints *dns_hints_open(struct dns_resolv_conf *, int *); + +void dns_hints_close(struct dns_hints *); + +dns_refcount_t dns_hints_acquire(struct dns_hints *); + +dns_refcount_t dns_hints_release(struct dns_hints *); + +struct dns_hints *dns_hints_mortal(struct dns_hints *); + +int dns_hints_insert(struct dns_hints *, const char *, const struct sockaddr *, unsigned); + +unsigned dns_hints_insert_resconf(struct dns_hints *, const char *, const struct dns_resolv_conf *, int *); + +struct dns_hints *dns_hints_local(struct dns_resolv_conf *, int *); + +struct dns_hints *dns_hints_root(struct dns_resolv_conf *, int *); + +int dns_hints_dump(struct dns_hints *, FILE *); + + +struct dns_hints_i { + const char *zone; + + struct { + unsigned next; + unsigned seed; + } state; +}; /* struct dns_hints_i */ + +#define dns_hints_i_new(...) (&(struct dns_hints_i){ __VA_ARGS__ }) + +unsigned dns_hints_grep(struct sockaddr **, socklen_t *, unsigned, struct dns_hints_i *, struct dns_hints *); + + +/* + * C A C H E I N T E R F A C E + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +struct dns_cache { + void *state; + + dns_refcount_t (*acquire)(struct dns_cache *); + dns_refcount_t (*release)(struct dns_cache *); + + struct dns_packet *(*query)(struct dns_packet *, struct dns_cache *, int *); + + int (*submit)(struct dns_packet *, struct dns_cache *); + int (*check)(struct dns_cache *); + struct dns_packet *(*fetch)(struct dns_cache *, int *); + + int (*pollfd)(struct dns_cache *); + short (*events)(struct dns_cache *); + void (*clear)(struct dns_cache *); + + union { + long i; + void *p; + } arg[3]; + + struct { /* PRIVATE */ + dns_atomic_t refcount; + } _; +}; /* struct dns_cache */ + + +struct dns_cache *dns_cache_init(struct dns_cache *); + +void dns_cache_close(struct dns_cache *); + + +/* + * A P P L I C A T I O N I N T E R F A C E + * + * Options to change the behavior of the API. Applies across all the + * different components. + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#define DNS_OPTS_INITIALIZER_ { 0, 0 }, 0 +#define DNS_OPTS_INITIALIZER { DNS_OPTS_INITIALIZER_ } +#define DNS_OPTS_INIT(...) { DNS_OPTS_INITIALIZER_, __VA_ARGS__ } + +#define dns_opts(...) (&dns_quietinit((struct dns_options)DNS_OPTS_INIT(__VA_ARGS__))) + +struct dns_options { + /* + * If the callback closes *fd, it must set it to -1. Otherwise, the + * descriptor is queued and lazily closed at object destruction or + * by an explicit call to _clear(). This allows safe use of + * kqueue(2), epoll(2), et al -style persistent events. + */ + struct { + void *arg; + int (*cb)(int *fd, void *arg); + } closefd; + + /* bitmask for _events() routines */ + enum dns_events { + DNS_SYSPOLL, + DNS_LIBEVENT, + } events; +}; /* struct dns_options */ + + +/* + * S T A T S I N T E R F A C E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +struct dns_stat { + size_t queries; + + struct { + struct { + size_t count, bytes; + } sent, rcvd; + } udp, tcp; +}; /* struct dns_stat */ + + +/* + * S O C K E T I N T E R F A C E + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +struct dns_socket; + +struct dns_socket *dns_so_open(const struct sockaddr *, int, const struct dns_options *, int *error); + +void dns_so_close(struct dns_socket *); + +void dns_so_reset(struct dns_socket *); + +unsigned short dns_so_mkqid(struct dns_socket *so); + +struct dns_packet *dns_so_query(struct dns_socket *, struct dns_packet *, struct sockaddr *, int *); + +int dns_so_submit(struct dns_socket *, struct dns_packet *, struct sockaddr *); + +int dns_so_check(struct dns_socket *); + +struct dns_packet *dns_so_fetch(struct dns_socket *, int *); + +time_t dns_so_elapsed(struct dns_socket *); + +void dns_so_clear(struct dns_socket *); + +int dns_so_events(struct dns_socket *); + +int dns_so_pollfd(struct dns_socket *); + +int dns_so_poll(struct dns_socket *, int); + +const struct dns_stat *dns_so_stat(struct dns_socket *); + + +/* + * R E S O L V E R I N T E R F A C E + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +struct dns_resolver; + +struct dns_resolver *dns_res_open(struct dns_resolv_conf *, struct dns_hosts *hosts, struct dns_hints *, struct dns_cache *, const struct dns_options *, int *); + +struct dns_resolver *dns_res_stub(const struct dns_options *, int *); + +void dns_res_reset(struct dns_resolver *); + +void dns_res_close(struct dns_resolver *); + +dns_refcount_t dns_res_acquire(struct dns_resolver *); + +dns_refcount_t dns_res_release(struct dns_resolver *); + +struct dns_resolver *dns_res_mortal(struct dns_resolver *); + +int dns_res_submit(struct dns_resolver *, const char *, enum dns_type, enum dns_class); + +int dns_res_submit2(struct dns_resolver *, const char *, size_t, enum dns_type, enum dns_class); + +int dns_res_check(struct dns_resolver *); + +struct dns_packet *dns_res_fetch(struct dns_resolver *, int *); + +time_t dns_res_elapsed(struct dns_resolver *); + +void dns_res_clear(struct dns_resolver *); + +int dns_res_events(struct dns_resolver *); + +int dns_res_pollfd(struct dns_resolver *); + +time_t dns_res_timeout(struct dns_resolver *); + +int dns_res_poll(struct dns_resolver *, int); + +struct dns_packet *dns_res_query(struct dns_resolver *, const char *, enum dns_type, enum dns_class, int, int *); + +const struct dns_stat *dns_res_stat(struct dns_resolver *); + +void dns_res_sethints(struct dns_resolver *, struct dns_hints *); + + +/* + * A D D R I N F O I N T E R F A C E + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +struct dns_addrinfo; + +struct dns_addrinfo *dns_ai_open(const char *, const char *, enum dns_type, const struct addrinfo *, struct dns_resolver *, int *); + +void dns_ai_close(struct dns_addrinfo *); + +int dns_ai_nextent(struct addrinfo **, struct dns_addrinfo *); + +size_t dns_ai_print(void *, size_t, struct addrinfo *, struct dns_addrinfo *); + +time_t dns_ai_elapsed(struct dns_addrinfo *); + +void dns_ai_clear(struct dns_addrinfo *); + +int dns_ai_events(struct dns_addrinfo *); + +int dns_ai_pollfd(struct dns_addrinfo *); + +time_t dns_ai_timeout(struct dns_addrinfo *); + +int dns_ai_poll(struct dns_addrinfo *, int); + +const struct dns_stat *dns_ai_stat(struct dns_addrinfo *); + + +/* + * U T I L I T Y I N T E R F A C E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +size_t dns_strlcpy(char *, const char *, size_t); + +size_t dns_strlcat(char *, const char *, size_t); + + +/* + * M A C R O M A G I C S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#define DNS_PP_MIN(a, b) (((a) < (b))? (a) : (b)) +#define DNS_PP_MAX(a, b) (((a) > (b))? (a) : (b)) +#define DNS_PP_NARG_(a, b, c, d, e, f, g, h, i, j, k, N,...) N +#define DNS_PP_NARG(...) DNS_PP_NARG_(__VA_ARGS__, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0) +#define DNS_PP_CALL(F, ...) F(__VA_ARGS__) +#define DNS_PP_PASTE(x, y) x##y +#define DNS_PP_XPASTE(x, y) DNS_PP_PASTE(x, y) +#define DNS_PP_STRINGIFY_(s) #s +#define DNS_PP_STRINGIFY(s) DNS_PP_STRINGIFY_(s) +#define DNS_PP_D1 0 +#define DNS_PP_D2 1 +#define DNS_PP_D3 2 +#define DNS_PP_D4 3 +#define DNS_PP_D5 4 +#define DNS_PP_D6 5 +#define DNS_PP_D7 6 +#define DNS_PP_D8 7 +#define DNS_PP_D9 8 +#define DNS_PP_D10 9 +#define DNS_PP_D11 10 +#define DNS_PP_DEC(N) DNS_PP_XPASTE(DNS_PP_D, N) + +#endif /* DNS_H */ diff --git a/src/ntp_time.c b/src/ntp_time.c index 62ec06bc..94b18b52 100644 --- a/src/ntp_time.c +++ b/src/ntp_time.c @@ -5,19 +5,10 @@ #include "../lib/socket_compat.h" #include "../lib/u_async.h" #include "../lib/mem.h" +#include "../lib/async_dns.h" #include #include -#ifdef _WIN32 - #include - #include -#else - #include - #include - #include - #include -#endif - #define NTP_DELTA 2208988800ULL // seconds from 1900 to 1970 #define NTP_PORT 123 #define NTP_TIMEOUT_SEC 2 @@ -41,7 +32,32 @@ struct ntp_packet { _Static_assert(sizeof(struct ntp_packet) == 48, "NTP packet must be 48 bytes"); +/* ─── синхронизация: неблокирующая машина состояний на uasync ─── */ + +struct ntp_sync { + struct UTUN_INSTANCE* inst; + int server_idx; /* следующий сервер для попытки */ + int query_idx; /* сервер, который сейчас опрашиваем (-1 для test_addr) */ + int resolving_idx; /* сервер в процессе DNS-резолва */ + struct adns_query* dns_q; /* активный DNS-запрос (NULL когда нет) */ + socket_t sock; /* NTP UDP-сокет (SOCKET_INVALID когда закрыт) */ + void* socket_id; /* handle uasync */ + void* timer; /* handle таймаута запроса */ + uint8_t req[48]; /* NTP-запрос (xmit_ts заполняется один раз на сервер) */ + uint64_t t1_ntp; /* originate timestamp */ + int tries; /* попыток на текущем сервере */ + struct sockaddr_in qaddr;/* адрес текущего сервера */ +}; + static void ntp_time_sync_cb(void* arg); +static void ntp_try_next(struct ntp_sync* ctx); +static void ntp_start_query(struct ntp_sync* ctx, int idx, const struct sockaddr_in* addr); +static void ntp_send_request(struct ntp_sync* ctx); +static void ntp_query_fail(struct ntp_sync* ctx); +static void ntp_finish_cycle(struct ntp_sync* ctx, int synced); +static void ntp_resolve_done_cb(const struct adns_result* res, void* arg); +static void ntp_query_read_cb(socket_t sock, void* arg); +static void ntp_query_timeout_cb(void* arg); static uint64_t timeval_to_ntp(struct timeval *tv) { uint64_t sec = (uint64_t)(tv->tv_sec + NTP_DELTA); @@ -55,13 +71,9 @@ static int64_t ntp64_to_us(uint64_t ntp) { return sec * 1000000LL + frac; } -static int ntp_do_query(const struct sockaddr_in* sin, const char* server_name, int64_t* offset_us_out, int* stratum_out) { - socket_t sock = socket_create_udp(AF_INET); - if (sock == SOCKET_INVALID) { - DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "NTP: socket() failed: %s", socket_strerror(socket_get_error())); - return -1; - } +/* ─── чистые функции сборки/разбора пакета ─── */ +static void ntp_build_request(uint8_t* req, uint64_t* t1_ntp_out) { struct ntp_packet request; memset(&request, 0, sizeof(request)); request.li_vn_mode = (0 << 6) | (4 << 3) | 3; @@ -73,43 +85,23 @@ static int ntp_do_query(const struct sockaddr_in* sin, const char* server_name, #endif uint64_t t1_ntp = timeval_to_ntp(&t1_tv); request.xmit_ts = htobe64(t1_ntp); + memcpy(req, &request, sizeof(request)); + if (t1_ntp_out) *t1_ntp_out = t1_ntp; +} - int send_ok = 0; - int tries; - for (tries = 0; tries < NTP_MAX_TRIES; tries++) { - ssize_t sent = sendto(sock, (const char*)&request, sizeof(request), 0, - (const struct sockaddr*)sin, sizeof(*sin)); - if (sent < 0) { - DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "NTP: sendto(%s) failed: %s", server_name, socket_strerror(socket_get_error())); - break; - } +/* возвращает 0 если ответ валиден; иначе -1 (пакет игнорируется, ждём timeout) */ +static int ntp_parse_reply(const uint8_t* buf, size_t len, uint64_t t1_ntp, + int64_t* offset_us_out, int64_t* rtt_us_out, int* stratum_out) { + if (len < sizeof(struct ntp_packet)) return -1; + const struct ntp_packet* reply = (const struct ntp_packet*)buf; - fd_set fds; - FD_ZERO(&fds); - FD_SET(sock, &fds); - struct timeval tv = {NTP_TIMEOUT_SEC, 0}; - int r = select((int)(sock + 1), &fds, NULL, NULL, &tv); - if (r < 0) { - DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "NTP: select() failed: %s", socket_strerror(socket_get_error())); - break; - } - if (r > 0) { send_ok = 1; break; } - } - if (!send_ok) { - DEBUG_WARN(DEBUG_CATEGORY_GENERAL, "NTP: no response from %s after %d tries", server_name, tries); - socket_close_wrapper(sock); - return -1; - } + uint8_t mode = reply->li_vn_mode & 0x07; + if (mode != 4) return -1; - struct ntp_packet reply; - struct sockaddr_in from; - socklen_t from_len = sizeof(from); - ssize_t n = recvfrom(sock, (char*)&reply, sizeof(reply), 0, (struct sockaddr*)&from, &from_len); - if (n < 0) { - DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "NTP: recvfrom(%s) failed: %s", server_name, socket_strerror(socket_get_error())); - socket_close_wrapper(sock); - return -1; - } + int stratum = reply->stratum; + if (stratum == 0) return -1; + + if (be64toh(reply->orig_ts) != t1_ntp) return -1; struct timeval t4_tv; #ifdef _WIN32 @@ -117,64 +109,193 @@ static int ntp_do_query(const struct sockaddr_in* sin, const char* server_name, #else gettimeofday(&t4_tv, NULL); #endif - socket_close_wrapper(sock); + int64_t t1_us = ntp64_to_us(t1_ntp); + int64_t t2_us = ntp64_to_us(be64toh(reply->recv_ts)); + int64_t t3_us = ntp64_to_us(be64toh(reply->xmit_ts)); + int64_t t4_us = ntp64_to_us(timeval_to_ntp(&t4_tv)); - if (n < (ssize_t)sizeof(reply)) { - DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "NTP: short reply from %s (got %zd, expected %zu)", server_name, n, sizeof(reply)); - return -1; + int64_t offset_us = ((t2_us - t1_us) + (t3_us - t4_us)) / 2; + int64_t rtt_us = (t4_us - t1_us) - (t3_us - t2_us); + + *offset_us_out = offset_us; + *rtt_us_out = rtt_us; + *stratum_out = stratum; + return 0; +} + +/* ─── машина состояний ─── */ + +static uint16_t ntp_query_port(const struct NTP_TIME* ntp) { + return ntp->test_port ? ntp->test_port : NTP_PORT; +} + +static void ntp_try_next(struct ntp_sync* ctx) { + struct NTP_TIME* ntp = &ctx->inst->ntp; + + for (int i = 0; i < ntp->server_count; i++) { + int idx = ctx->server_idx; + ctx->server_idx = (idx + 1) % ntp->server_count; + const char* name = ntp->servers[idx]; + + struct sockaddr_in addr; + memset(&addr, 0, sizeof(addr)); + addr.sin_family = AF_INET; + addr.sin_port = htons(ntp_query_port(ntp)); + if (inet_pton(AF_INET, name, &addr.sin_addr) == 1) { + ntp_start_query(ctx, idx, &addr); + return; + } + + struct adns_opts dopts, *popts = NULL; + if (ntp->test_dns.sin_port != 0) { + memset(&dopts, 0, sizeof(dopts)); + dopts.server = ntp->test_dns; + popts = &dopts; + } + + ctx->resolving_idx = idx; + ctx->dns_q = adns_resolve(ctx->inst->ua, name, popts, ntp_resolve_done_cb, ctx); + if (ctx->dns_q) return; + DEBUG_WARN(DEBUG_CATEGORY_GENERAL, "NTP: resolve '%s' failed immediately", name); } - uint8_t mode = reply.li_vn_mode & 0x07; - if (mode != 4) { - DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "NTP: unexpected mode %d from %s (expected 4)", mode, server_name); - return -1; + DEBUG_WARN(DEBUG_CATEGORY_GENERAL, "NTP: all servers unreachable, retry in %ds", ntp->resync_interval_sec); + ntp_finish_cycle(ctx, 0); +} + +static void ntp_resolve_done_cb(const struct adns_result* res, void* arg) { + struct ntp_sync* ctx = (struct ntp_sync*)arg; + ctx->dns_q = NULL; + struct NTP_TIME* ntp = &ctx->inst->ntp; + int idx = ctx->resolving_idx; + + if (res->status == ADNS_OK && res->count > 0) { + struct sockaddr_in addr = res->addrs[0]; + addr.sin_port = htons(ntp_query_port(ntp)); + ntp_start_query(ctx, idx, &addr); + } else { + DEBUG_WARN(DEBUG_CATEGORY_GENERAL, "NTP: resolve '%s' failed (status=%d)", ntp->servers[idx], res->status); + ntp_try_next(ctx); } +} - int stratum = reply.stratum; - if (stratum == 0) { - DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "NTP: kiss-o-death from %s", server_name); - return -1; +static void ntp_start_query(struct ntp_sync* ctx, int idx, const struct sockaddr_in* addr) { + ctx->query_idx = idx; + ctx->qaddr = *addr; + ctx->tries = 0; + ntp_send_request(ctx); +} + +static void ntp_send_request(struct ntp_sync* ctx) { + struct UTUN_INSTANCE* inst = ctx->inst; + + if (ctx->sock == SOCKET_INVALID) { + ctx->sock = socket_create_udp(AF_INET); + if (ctx->sock == SOCKET_INVALID) { + DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "NTP: socket() failed: %s", socket_strerror(socket_get_error())); + ntp_query_fail(ctx); + return; + } + socket_set_nonblocking(ctx->sock); } - uint64_t reply_orig = be64toh(reply.orig_ts); - if (reply_orig != t1_ntp) { - DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "NTP: originate timestamp mismatch from %s", server_name); - return -1; + if (ctx->tries == 0) ntp_build_request(ctx->req, &ctx->t1_ntp); + + ssize_t sent = socket_sendto(ctx->sock, ctx->req, sizeof(ctx->req), + (const struct sockaddr*)&ctx->qaddr, sizeof(ctx->qaddr)); + if (sent < 0) { + DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "NTP: sendto failed: %s", socket_strerror(socket_get_error())); + ntp_query_fail(ctx); + return; } - int64_t t1_us = ntp64_to_us(t1_ntp); - int64_t t2_us = ntp64_to_us(be64toh(reply.recv_ts)); - int64_t t3_us = ntp64_to_us(be64toh(reply.xmit_ts)); - int64_t t4_us = ntp64_to_us(timeval_to_ntp(&t4_tv)); + if (!ctx->socket_id) { + ctx->socket_id = uasync_add_socket_t(inst->ua, ctx->sock, ntp_query_read_cb, NULL, NULL, ctx); + if (!ctx->socket_id) { + DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "NTP: uasync_add_socket_t failed"); + ntp_query_fail(ctx); + return; + } + } - int64_t offset_us = ((t2_us - t1_us) + (t3_us - t4_us)) / 2; - int64_t rtt_us = (t4_us - t1_us) - (t3_us - t2_us); + ctx->timer = uasync_set_timeout(inst->ua, NTP_TIMEOUT_SEC * 10000, ctx, ntp_query_timeout_cb, "ntp_q"); + if (!ctx->timer) { + DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "NTP: uasync_set_timeout failed"); + ntp_query_fail(ctx); + return; + } +} + +static void ntp_query_read_cb(socket_t sock, void* arg) { + (void)sock; + struct ntp_sync* ctx = (struct ntp_sync*)arg; + struct ntp_packet reply; + struct sockaddr_in from; + socklen_t from_len = sizeof(from); + ssize_t n = socket_recvfrom(ctx->sock, (void*)&reply, sizeof(reply), (struct sockaddr*)&from, &from_len); + if (n < 0) return; /* EAGAIN / ICMP (WSAECONNRESET) — ждём timeout */ + + int64_t offset_us, rtt_us; + int stratum; + if (ntp_parse_reply((const uint8_t*)&reply, (size_t)n, ctx->t1_ntp, &offset_us, &rtt_us, &stratum) != 0) + return; /* невалидный ответ — ждём (timeout перезапросит) */ + + struct NTP_TIME* ntp = &ctx->inst->ntp; + ntp->offset_us = offset_us; + ntp->synced = 1; + ntp->last_sync_tb = get_time_tb(); + if (ctx->query_idx >= 0) + ntp->server_current = (ctx->query_idx + 1) % ntp->server_count; DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "NTP: synced from %s offset=%lldus rtt=%lldus stratum=%d", - server_name, (long long)offset_us, (long long)rtt_us, stratum); + ctx->query_idx >= 0 ? ntp->servers[ctx->query_idx] : "test-server", + (long long)offset_us, (long long)rtt_us, stratum); - *offset_us_out = offset_us; - *stratum_out = stratum; - return 0; + ntp_finish_cycle(ctx, 1); } -static int ntp_query_server(const char* server, int64_t* offset_us_out, int* stratum_out) { - struct addrinfo hints, *result = NULL; - memset(&hints, 0, sizeof(hints)); - hints.ai_family = AF_INET; - hints.ai_socktype = SOCK_DGRAM; - - char port_str[8]; - snprintf(port_str, sizeof(port_str), "%d", NTP_PORT); - int gai_err = getaddrinfo(server, port_str, &hints, &result); - if (gai_err != 0 || !result) { - DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "NTP: failed to resolve %s: %s", server, gai_strerror(gai_err)); - return -1; +static void ntp_query_timeout_cb(void* arg) { + struct ntp_sync* ctx = (struct ntp_sync*)arg; + ctx->timer = NULL; + ctx->tries++; + if (ctx->tries < NTP_MAX_TRIES) { + ntp_send_request(ctx); + return; } + ntp_query_fail(ctx); +} + +static void ntp_query_fail(struct ntp_sync* ctx) { + struct NTP_TIME* ntp = &ctx->inst->ntp; + const char* name = ctx->query_idx >= 0 ? ntp->servers[ctx->query_idx] : "test-server"; + + if (ctx->timer) { uasync_cancel_timeout(ctx->inst->ua, ctx->timer); ctx->timer = NULL; } + if (ctx->socket_id) { uasync_remove_socket_t(ctx->inst->ua, ctx->sock); ctx->socket_id = NULL; } + if (ctx->sock != SOCKET_INVALID) { socket_close_wrapper(ctx->sock); ctx->sock = SOCKET_INVALID; } - int ret = ntp_do_query((const struct sockaddr_in*)result->ai_addr, server, offset_us_out, stratum_out); - freeaddrinfo(result); - return ret; + DEBUG_WARN(DEBUG_CATEGORY_GENERAL, "NTP: no response from %s after %d tries", name, ctx->tries); + ntp_try_next(ctx); +} + +static void ntp_finish_cycle(struct ntp_sync* ctx, int synced) { + struct UTUN_INSTANCE* inst = ctx->inst; + struct NTP_TIME* ntp = &inst->ntp; + + if (ctx->timer) { uasync_cancel_timeout(inst->ua, ctx->timer); ctx->timer = NULL; } + if (ctx->socket_id) { uasync_remove_socket_t(inst->ua, ctx->sock); ctx->socket_id = NULL; } + if (ctx->sock != SOCKET_INVALID) { socket_close_wrapper(ctx->sock); ctx->sock = SOCKET_INVALID; } + if (ctx->dns_q) { adns_cancel(ctx->dns_q); ctx->dns_q = NULL; } + + ntp->sync = NULL; + u_free(ctx); + + if (synced) { + DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "NTP: time corrected, offset=%lldus", (long long)ntp->offset_us); + ntp_node_sync_peers(inst); + } + + ntp->timer = uasync_set_timeout(inst->ua, ntp->resync_interval_sec * 10000, + inst, ntp_time_sync_cb, "ntp_sync"); } static void ntp_time_sync_cb(void* arg) { @@ -189,52 +310,30 @@ static void ntp_time_sync_cb(void* arg) { return; } - int64_t offset_us = 0; - int stratum = 0; - int synced = 0; + if (ntp->sync) { + DEBUG_WARN(DEBUG_CATEGORY_GENERAL, "NTP: sync already in progress, skipping"); + ntp->timer = uasync_set_timeout(instance->ua, ntp->resync_interval_sec * 10000, + instance, ntp_time_sync_cb, "ntp_sync"); + return; + } - if (ntp->test_addr.sin_port != 0) { - if (ntp_do_query(&ntp->test_addr, "test-server", &offset_us, &stratum) == 0) { - ntp->offset_us = offset_us; - ntp->synced = 1; - ntp->last_sync_tb = get_time_tb(); - synced = 1; - } - } else { - const char* server = ntp->servers[ntp->server_current]; - if (ntp_query_server(server, &offset_us, &stratum) == 0) { - ntp->offset_us = offset_us; - ntp->synced = 1; - ntp->last_sync_tb = get_time_tb(); - ntp->server_current = (ntp->server_current + 1) % ntp->server_count; - synced = 1; - } else { - for (int i = 0; i < ntp->server_count; i++) { - ntp->server_current = (ntp->server_current + 1) % ntp->server_count; - const char* next_server = ntp->servers[ntp->server_current]; - if (strcmp(next_server, server) == 0) break; - if (ntp_query_server(next_server, &offset_us, &stratum) == 0) { - ntp->offset_us = offset_us; - ntp->synced = 1; - ntp->last_sync_tb = get_time_tb(); - synced = 1; - break; - } - } - } + struct ntp_sync* ctx = u_calloc(1, sizeof(*ctx)); + if (!ctx) { + DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "NTP: calloc sync ctx failed"); + ntp->timer = uasync_set_timeout(instance->ua, ntp->resync_interval_sec * 10000, + instance, ntp_time_sync_cb, "ntp_sync"); + return; } + ctx->inst = instance; + ctx->sock = SOCKET_INVALID; + ntp->sync = ctx; - if (ntp->synced) { - DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "NTP: time corrected, offset=%lldus", - (long long)ntp->offset_us); - ntp_node_sync_peers(instance); + if (ntp->test_addr.sin_port != 0) { + ntp_start_query(ctx, -1, &ntp->test_addr); } else { - DEBUG_WARN(DEBUG_CATEGORY_GENERAL, "NTP: all servers unreachable, retry in %ds", - ntp->resync_interval_sec); + ctx->server_idx = ntp->server_current; + ntp_try_next(ctx); } - - ntp->timer = uasync_set_timeout(instance->ua, ntp->resync_interval_sec * 10000, - instance, ntp_time_sync_cb, "ntp_sync"); } int ntp_time_init(struct UTUN_INSTANCE* instance) { @@ -251,7 +350,10 @@ int ntp_time_init(struct UTUN_INSTANCE* instance) { ntp->server_count = g->ntp_server_count; ntp->server_current = 0; ntp->resync_interval_sec = g->ntp_resync_interval; + ntp->sync = NULL; + ntp->test_port = 0; memset(&ntp->test_addr, 0, sizeof(ntp->test_addr)); + memset(&ntp->test_dns, 0, sizeof(ntp->test_dns)); if (g->ntp_server_count > 0) { ntp->servers = u_malloc(g->ntp_server_count * sizeof(char*)); @@ -298,6 +400,16 @@ void ntp_time_destroy(struct UTUN_INSTANCE* instance) { if (!instance) return; struct NTP_TIME* ntp = &instance->ntp; + if (ntp->sync && instance->ua) { + struct ntp_sync* ctx = (struct ntp_sync*)ntp->sync; + if (ctx->timer) { uasync_cancel_timeout(instance->ua, ctx->timer); ctx->timer = NULL; } + if (ctx->socket_id) { uasync_remove_socket_t(instance->ua, ctx->sock); ctx->socket_id = NULL; } + if (ctx->sock != SOCKET_INVALID) socket_close_wrapper(ctx->sock); + if (ctx->dns_q) adns_cancel(ctx->dns_q); + u_free(ctx); + ntp->sync = NULL; + } + if (ntp->timer && instance->ua) { uasync_cancel_timeout(instance->ua, ntp->timer); ntp->timer = NULL; @@ -350,3 +462,16 @@ void ntp_time_set_test_addr(struct NTP_TIME* ntp, const char* ip, uint16_t port) memset(&ntp->test_addr, 0, sizeof(ntp->test_addr)); } } + +void ntp_time_set_test_dns(struct NTP_TIME* ntp, const char* ip, uint16_t dns_port, uint16_t ntp_port) { + if (!ntp || !ip) return; + memset(&ntp->test_dns, 0, sizeof(ntp->test_dns)); + ntp->test_dns.sin_family = AF_INET; + ntp->test_dns.sin_port = htons(dns_port); + ntp->test_port = ntp_port; + if (inet_pton(AF_INET, ip, &ntp->test_dns.sin_addr) != 1) { + DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "NTP: test dns parse failed for %s", ip); + memset(&ntp->test_dns, 0, sizeof(ntp->test_dns)); + ntp->test_port = 0; + } +} diff --git a/src/ntp_time.h b/src/ntp_time.h index 973e60b7..9deb4356 100644 --- a/src/ntp_time.h +++ b/src/ntp_time.h @@ -25,12 +25,16 @@ struct NTP_TIME { int server_current; int resync_interval_sec; struct sockaddr_in test_addr; // test mode: direct address when sin_port != 0 + struct sockaddr_in test_dns; // test mode: DNS server for hostname resolution (sin_port != 0) + uint16_t test_port; // test mode: NTP query port override (0 = 123) + void* sync; // активный контекст синхронизации (struct ntp_sync*, opaque) }; int ntp_time_init(struct UTUN_INSTANCE* instance); void ntp_time_destroy(struct UTUN_INSTANCE* instance); void ntp_time_set_test_addr(struct NTP_TIME* ntp, const char* ip, uint16_t port); +void ntp_time_set_test_dns(struct NTP_TIME* ntp, const char* ip, uint16_t dns_port, uint16_t ntp_port); int64_t ntp_time_get_us(struct UTUN_INSTANCE* instance); time_t ntp_time_get_seconds(struct UTUN_INSTANCE* instance); diff --git a/tests/Makefile.am b/tests/Makefile.am index d15272d3..a83e3a01 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -64,6 +64,7 @@ check_PROGRAMS = \ test_tcp_io \ test_uasync_socket_race \ test_ntp \ + test_async_dns \ test_opus_codec \ test_media_async \ test_media_index \ @@ -96,12 +97,12 @@ else WIN_LIBS = endif -# Common libraries -COMMON_LIBS = $(top_builddir)/lib/libuasync.a -lpthread $(WIN_LIBS) - # Crypto always uses OpenSSL CRYPTO_LIBS = -lcrypto +# Common libraries (lib/dns.c собирается с -DDNS_RANDOM=RAND_bytes → нужен -lcrypto) +COMMON_LIBS = $(top_builddir)/lib/libuasync.a $(CRYPTO_LIBS) -lpthread $(WIN_LIBS) + # Test definitions test_etcp_bbr_SOURCES = test_etcp_bbr.c test_etcp_bbr_CFLAGS = -I$(top_srcdir)/src -I$(top_srcdir)/lib @@ -254,6 +255,10 @@ test_ntp_SOURCES = test_ntp.c test_ntp_CFLAGS = -I$(top_srcdir)/src -I$(top_srcdir)/lib test_ntp_LDADD = $(LIBUTUN) $(CRYPTO_LIBS) $(COMMON_LIBS) +test_async_dns_SOURCES = test_async_dns.c +test_async_dns_CFLAGS = -I$(top_srcdir)/src -I$(top_srcdir)/lib +test_async_dns_LDADD = $(COMMON_LIBS) + test_memory_pool_and_config_SOURCES = test_memory_pool_and_config.c test_memory_pool_and_config_CFLAGS = -I$(top_srcdir)/src -I$(top_srcdir)/lib test_memory_pool_and_config_LDADD = $(COMMON_LIBS) diff --git a/tests/test_async_dns.c b/tests/test_async_dns.c new file mode 100644 index 00000000..5734647c --- /dev/null +++ b/tests/test_async_dns.c @@ -0,0 +1,291 @@ +/** + * @file test_async_dns.c + * @brief Юнит-тесты async_dns (асинхронный DNS-резолвер поверх libdns). + * + * 1. Чистый парсер resolv.conf (adns_parse_resolv_conf). + * 2. Сквозные тесты с фейковым DNS-сервером в отдельном потоке: + * - A-запись (с компрессией имени); + * - два A; + * - CNAME + A; + * - NXDOMAIN; + * - таймаут (сервер молчит); + * - отмена (коллбэк не вызывается). + */ +#include +#include +#include +#include +#include "../lib/platform_compat.h" +#include "../lib/socket_compat.h" +#include "../lib/debug_config.h" +#include "../lib/u_async.h" +#include "../lib/async_dns.h" + +#define SERVER_WAIT_MS 5000 +#define RESOLVE_TIMEOUT_TB 5000 /* 500 ms для быстрых ответов */ +#define TIMEOUT_TEST_TB 20000 /* 2 s (timeout_ms=1000, attempts=1 → ждём > 1 s) */ + +static volatile int g_server_running = 1; +static volatile uint16_t g_server_port = 0; + +static void platform_sleep_ms(int ms) { +#ifdef _WIN32 + Sleep(ms); +#else + usleep(ms * 1000); +#endif +} + +/* собрать qname (завершается точкой) из query по смещению 12 */ +static void extract_qname(const uint8_t* q, int n, char* out, int cap) { + int p = 12, l = 0; + while (p < n && q[p] != 0 && l < cap - 1) { + if ((q[p] & 0xC0) == 0xC0) { p += 2; break; } + int lab = q[p++]; + for (int j = 0; j < lab && p < n && l < cap - 1; j++) out[l++] = (char)q[p++]; + out[l++] = '.'; + } + out[l] = '\0'; +} + +/* конец question-секции (после qname + qtype + qclass) */ +static int question_end(const uint8_t* q, int n) { + int p = 12; + while (p < n && q[p] != 0) { + if ((q[p] & 0xC0) == 0xC0) { return p + 2 + 4; } + p += 1 + q[p]; + } + return p + 1 + 4; +} + +/* собрать DNS-ответ: qid + вопрос (из query) + ответы. rcode и ancount задаются. */ +static int build_response(const uint8_t* q, int n, uint8_t* out, int cap, + int rcode, int ancount, + const uint16_t* atype, const uint8_t** adata, const uint16_t* alen) { + int qend = question_end(q, n); + if (qend > n) return -1; + int o = 0; + + out[o++] = q[0]; out[o++] = q[1]; /* qid */ + uint16_t flags = (uint16_t)(0x8180 | rcode); /* QR + RD + RA + rcode */ + out[o++] = (uint8_t)(flags >> 8); out[o++] = (uint8_t)(flags & 0xFF); + out[o++] = 0; out[o++] = 1; /* qdcount */ + out[o++] = 0; out[o++] = (uint8_t)ancount; /* ancount */ + out[o++] = 0; out[o++] = 0; /* nscount */ + out[o++] = 0; out[o++] = 0; /* arcount */ + + memcpy(out + o, q + 12, (size_t)(qend - 12)); /* question */ + o += qend - 12; + + for (int i = 0; i < ancount && o + 12 + alen[i] <= cap; i++) { + out[o++] = 0xC0; out[o++] = 0x0C; /* имя = указатель на вопрос */ + out[o++] = (uint8_t)(atype[i] >> 8); out[o++] = (uint8_t)(atype[i] & 0xFF); + out[o++] = 0; out[o++] = 1; /* class IN */ + out[o++] = 0; out[o++] = 0; out[o++] = 0; out[o++] = 60; /* ttl */ + out[o++] = (uint8_t)(alen[i] >> 8); out[o++] = (uint8_t)(alen[i] & 0xFF); + memcpy(out + o, adata[i], alen[i]); o += alen[i]; + } + return o; +} + +static void* dns_server_thread(void* arg) { + (void)arg; + socket_t sock = socket_create_udp(AF_INET); + if (sock == SOCKET_INVALID) { g_server_running = 0; return NULL; } + + struct sockaddr_in addr; + memset(&addr, 0, sizeof(addr)); + addr.sin_family = AF_INET; + addr.sin_addr.s_addr = inet_addr("127.0.0.1"); + addr.sin_port = 0; + if (bind(sock, (struct sockaddr*)&addr, sizeof(addr)) < 0) { socket_close_wrapper(sock); g_server_running = 0; return NULL; } + socklen_t al = sizeof(addr); + getsockname(sock, (struct sockaddr*)&addr, &al); + g_server_port = ntohs(addr.sin_port); + + uint8_t buf[512]; + while (g_server_running) { + fd_set fds; FD_ZERO(&fds); FD_SET(sock, &fds); + struct timeval tv = {1, 0}; + int r = select((int)(sock + 1), &fds, NULL, NULL, &tv); + if (r <= 0) continue; + + struct sockaddr_in client; socklen_t cl = sizeof(client); + ssize_t n = recvfrom(sock, (char*)buf, sizeof(buf), 0, (struct sockaddr*)&client, &cl); + if (n < 12) continue; + + char qname[256]; + extract_qname(buf, (int)n, qname, sizeof(qname)); + + uint8_t resp[512]; int rl = 0; + + if (strcmp(qname, "a.test.") == 0) { + uint8_t ip[4]; inet_pton(AF_INET, "192.168.1.42", ip); + const uint8_t* d = ip; uint16_t l = 4; + rl = build_response(buf, (int)n, resp, sizeof(resp), 0, 1, (const uint16_t[]){1}, &d, &l); + } else if (strcmp(qname, "multi.test.") == 0) { + uint8_t ip1[4]; inet_pton(AF_INET, "10.0.0.1", ip1); + uint8_t ip2[4]; inet_pton(AF_INET, "10.0.0.2", ip2); + const uint8_t* d[2] = { ip1, ip2 }; uint16_t l[2] = {4, 4}; + rl = build_response(buf, (int)n, resp, sizeof(resp), 0, 2, (const uint16_t[]){1, 1}, d, l); + } else if (strcmp(qname, "cname.test.") == 0) { + /* CNAME → real.test., затем A */ + uint8_t cname[16] = { 4, 'r','e','a','l', 4, 't','e','s','t', 0 }; + uint8_t ip[4]; inet_pton(AF_INET, "192.168.1.99", ip); + const uint8_t* d[2] = { cname, ip }; uint16_t l[2] = {11, 4}; + rl = build_response(buf, (int)n, resp, sizeof(resp), 0, 2, (const uint16_t[]){5, 1}, d, l); + } else if (strcmp(qname, "nx.test.") == 0) { + rl = build_response(buf, (int)n, resp, sizeof(resp), 3, 0, NULL, NULL, NULL); + } else if (strcmp(qname, "silent.test.") == 0) { + continue; /* молчим — таймаут */ + } else { + continue; /* неизвестное имя — молчим */ + } + + if (rl > 0) + sendto(sock, (const char*)resp, rl, 0, (struct sockaddr*)&client, sizeof(client)); + } + socket_close_wrapper(sock); + return NULL; +} + +struct test_ctx { + int done; + struct adns_result res; +}; + +static void on_done(const struct adns_result* res, void* arg) { + struct test_ctx* t = (struct test_ctx*)arg; + t->res = *res; + t->done = 1; +} + +/* запустить резолв и дождаться коллбэка или таймаута. Возвращает 0=успех. */ +static int run_resolve(struct UASYNC* ua, const char* name, struct adns_opts* opts, + struct test_ctx* t, uint64_t timeout_tb) { + memset(t, 0, sizeof(*t)); + struct adns_query* q = adns_resolve(ua, name, opts, on_done, t); + if (!q) return -1; + uint64_t start = get_time_tb(); + while (!t->done && get_time_tb() - start < timeout_tb) + uasync_poll(ua, 10); + if (!t->done) { adns_cancel(q); return -2; } + return 0; +} + +#define ASSERT(c, msg) do { if (!(c)) { \ + DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "FAIL: %s", msg); goto fail; } } while (0) + +int main(void) { + int result = 1; + struct UASYNC* ua = NULL; + pthread_t srv; + int srv_started = 0; + + debug_config_init(); + debug_set_level(DEBUG_LEVEL_WARN); + debug_set_category_level(DEBUG_CATEGORY_SOCKET, DEBUG_LEVEL_INFO); + + DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "=== async_dns test ==="); + + /* ── 1. чистый парсер resolv.conf ── */ + { + struct sockaddr_in out[4]; + const char* text = "# comment\nnameserver 8.8.8.8\nnameserver 1.1.1.1 # inline\nsearch foo\n"; + int n = adns_parse_resolv_conf(text, out, 4); + ASSERT(n == 2, "parse_resolv_conf count"); + char ip[16]; + inet_ntop(AF_INET, &out[0].sin_addr, ip, sizeof(ip)); + ASSERT(strcmp(ip, "8.8.8.8") == 0, "parse_resolv_conf[0] == 8.8.8.8"); + inet_ntop(AF_INET, &out[1].sin_addr, ip, sizeof(ip)); + ASSERT(strcmp(ip, "1.1.1.1") == 0, "parse_resolv_conf[1] == 1.1.1.1"); + ASSERT(ntohs(out[0].sin_port) == 53, "parse_resolv_conf port 53"); + } + DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "PASS: parse_resolv_conf"); + + /* ── 2. фейковый DNS-сервер ── */ + if (pthread_create(&srv, NULL, dns_server_thread, NULL) != 0) { + DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "pthread_create failed"); + return 1; + } + srv_started = 1; + uint64_t wstart = get_time_tb(); + while (g_server_port == 0 && get_time_tb() - wstart < (uint64_t)(SERVER_WAIT_MS * 10)) + platform_sleep_ms(5); + if (g_server_port == 0) { + DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "fake DNS server did not bind"); + goto cleanup; + } + DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "fake DNS server on 127.0.0.1:%u", g_server_port); + + ua = uasync_create(); + if (!ua) { + DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "uasync_create failed"); + goto cleanup; + } + + struct adns_opts opts; + memset(&opts, 0, sizeof(opts)); + opts.server.sin_family = AF_INET; + opts.server.sin_addr.s_addr = inet_addr("127.0.0.1"); + opts.server.sin_port = htons(g_server_port); + opts.timeout_ms = 1000; + opts.max_attempts = 1; + + struct test_ctx t; + char ip[16]; + + /* A-запись */ + ASSERT(run_resolve(ua, "a.test", &opts, &t, RESOLVE_TIMEOUT_TB) == 0, "a.test resolve completes"); + ASSERT(t.res.status == ADNS_OK, "a.test status OK"); + ASSERT(t.res.count == 1, "a.test count == 1"); + inet_ntop(AF_INET, &t.res.addrs[0].sin_addr, ip, sizeof(ip)); + ASSERT(strcmp(ip, "192.168.1.42") == 0, "a.test addr == 192.168.1.42"); + DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "PASS: A record (compression)"); + + /* два A */ + ASSERT(run_resolve(ua, "multi.test", &opts, &t, RESOLVE_TIMEOUT_TB) == 0, "multi resolve"); + ASSERT(t.res.status == ADNS_OK && t.res.count == 2, "multi count == 2"); + DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "PASS: multiple A"); + + /* CNAME + A */ + ASSERT(run_resolve(ua, "cname.test", &opts, &t, RESOLVE_TIMEOUT_TB) == 0, "cname resolve"); + ASSERT(t.res.status == ADNS_OK && t.res.count >= 1, "cname status OK"); + inet_ntop(AF_INET, &t.res.addrs[0].sin_addr, ip, sizeof(ip)); + ASSERT(strcmp(ip, "192.168.1.99") == 0, "cname addr == 192.168.1.99"); + DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "PASS: CNAME + A"); + + /* NXDOMAIN */ + ASSERT(run_resolve(ua, "nx.test", &opts, &t, RESOLVE_TIMEOUT_TB) == 0, "nx resolve"); + ASSERT(t.res.status == ADNS_ERR_NODATA, "nx status NODATA"); + DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "PASS: NXDOMAIN"); + + /* таймаут: сервер молчит */ + ASSERT(run_resolve(ua, "silent.test", &opts, &t, TIMEOUT_TEST_TB) == 0, "silent resolve"); + ASSERT(t.res.status == ADNS_ERR_TIMEOUT, "silent status TIMEOUT"); + DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "PASS: timeout"); + + /* отмена: коллбэк не вызывается */ + { + memset(&t, 0, sizeof(t)); + struct adns_query* q = adns_resolve(ua, "silent.test", &opts, on_done, &t); + ASSERT(q != NULL, "cancel: resolve created"); + for (int i = 0; i < 50 && !t.done; i++) uasync_poll(ua, 10); /* немного покрутим */ + adns_cancel(q); + for (int i = 0; i < 50; i++) uasync_poll(ua, 10); + ASSERT(t.done == 0, "cancel: callback NOT invoked"); + DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "PASS: cancel"); + } + + result = 0; + DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "=== async_dns test PASSED ==="); + goto cleanup; + +fail: + result = 1; + +cleanup: + if (ua) uasync_destroy(ua, 0); + if (srv_started) { g_server_running = 0; pthread_join(srv, NULL); } + return result; +} diff --git a/tests/test_ntp.c b/tests/test_ntp.c index 773704f3..5b0119ae 100644 --- a/tests/test_ntp.c +++ b/tests/test_ntp.c @@ -1,10 +1,11 @@ /** * @file test_ntp.c - * @brief NTP client test with local fake NTP server + * @brief NTP client test: direct address + hostname (async DNS) paths * - * Starts a local NTP server in a separate thread that returns a known - * time offset. Verifies the NTP client syncs correctly: synced flag, - * offset computation, and ntp_time_get_us()/ntp_time_is_synced(). + * Сценарий 1 (direct): фейковый NTP-сервер, синхронизация по test_addr. + * Сценарий 2 (hostname): фейковый DNS-сервер резолвит hostname → 127.0.0.1, + * затем NTP опрашивает фейковый NTP-сервер (async_dns → неблокирующий запрос). + * Оба сценария проверяют флаг synced и точность offset. */ #include #include @@ -46,12 +47,23 @@ _Static_assert(sizeof(struct ntp_packet) == 48, "bad ntp_packet size"); static volatile int g_server_running = 1; static volatile uint16_t g_server_port = 0; +static volatile int g_dns_running = 1; +static volatile uint16_t g_dns_port = 0; + static uint64_t timeval_to_ntp(struct timeval *tv) { uint64_t sec = (uint64_t)(tv->tv_sec + NTP_DELTA); uint64_t frac = ((uint64_t)tv->tv_usec << 32) / 1000000ULL; return (sec << 32) | frac; } +static void platform_sleep_ms(int ms) { +#ifdef _WIN32 + Sleep(ms); +#else + usleep(ms * 1000); +#endif +} + static void* test_server_thread(void* arg) { (void)arg; socket_t sock = socket_create_udp(AF_INET); @@ -107,53 +119,78 @@ static void* test_server_thread(void* arg) { return NULL; } -static void platform_sleep_ms(int ms) { -#ifdef _WIN32 - Sleep(ms); -#else - usleep(ms * 1000); -#endif -} +/* ─── фейковый DNS-сервер: любой A-запрос → 127.0.0.1 ─── */ -static int wait_for_port(void) { - for (int i = 0; i < 200; i++) { - if (g_server_port != 0) return 0; - platform_sleep_ms(5); +static int dns_question_end(const uint8_t* q, int n) { + int p = 12; + while (p < n && q[p] != 0) { + if ((q[p] & 0xC0) == 0xC0) return p + 2 + 4; + p += 1 + q[p]; } - return -1; + return p + 1 + 4; } -int main(void) { - int result = 1; - - debug_config_init(); - debug_set_level(DEBUG_LEVEL_WARN); - debug_set_categories(DEBUG_CATEGORY_GENERAL); +static int build_dns_a_response(const uint8_t* q, int n, uint8_t* out, int cap) { + int qend = dns_question_end(q, n); + if (qend > n) return -1; + uint8_t ip[4]; + inet_pton(AF_INET, "127.0.0.1", ip); + + int o = 0; + out[o++] = q[0]; out[o++] = q[1]; /* qid */ + out[o++] = 0x81; out[o++] = 0x80; /* QR+RD+RA, rcode 0 */ + out[o++] = 0; out[o++] = 1; /* qdcount */ + out[o++] = 0; out[o++] = 1; /* ancount */ + out[o++] = 0; out[o++] = 0; /* nscount */ + out[o++] = 0; out[o++] = 0; /* arcount */ + memcpy(out + o, q + 12, (size_t)(qend - 12)); /* question */ + o += qend - 12; + out[o++] = 0xC0; out[o++] = 0x0C; /* имя = указатель на вопрос */ + out[o++] = 0; out[o++] = 1; /* type A */ + out[o++] = 0; out[o++] = 1; /* class IN */ + out[o++] = 0; out[o++] = 0; out[o++] = 0; out[o++] = 60; /* ttl */ + out[o++] = 0; out[o++] = 4; /* rdlength */ + memcpy(out + o, ip, 4); o += 4; + return o; +} - DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "=== NTP Test ==="); +static void* dns_server_thread(void* arg) { + (void)arg; + socket_t sock = socket_create_udp(AF_INET); + if (sock == SOCKET_INVALID) { g_dns_running = 0; return NULL; } - /* ── 1. Start fake NTP server thread ── */ - pthread_t server_thread; - if (pthread_create(&server_thread, NULL, test_server_thread, NULL) != 0) { - DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "Failed to create server thread"); - return 1; - } - if (wait_for_port() != 0) { - DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "Server thread did not bind"); - g_server_running = 0; - pthread_join(server_thread, NULL); - return 1; + struct sockaddr_in addr; + memset(&addr, 0, sizeof(addr)); + addr.sin_family = AF_INET; + addr.sin_addr.s_addr = inet_addr("127.0.0.1"); + addr.sin_port = 0; + if (bind(sock, (struct sockaddr*)&addr, sizeof(addr)) < 0) { socket_close_wrapper(sock); g_dns_running = 0; return NULL; } + socklen_t al = sizeof(addr); + getsockname(sock, (struct sockaddr*)&addr, &al); + g_dns_port = ntohs(addr.sin_port); + + uint8_t buf[512]; + while (g_dns_running) { + fd_set fds; FD_ZERO(&fds); FD_SET(sock, &fds); + struct timeval tv = {1, 0}; + int r = select((int)(sock + 1), &fds, NULL, NULL, &tv); + if (r <= 0) continue; + struct sockaddr_in client; socklen_t cl = sizeof(client); + ssize_t n = recvfrom(sock, (char*)buf, sizeof(buf), 0, (struct sockaddr*)&client, &cl); + if (n < 12) continue; + uint8_t resp[512]; + int rl = build_dns_a_response(buf, (int)n, resp, sizeof(resp)); + if (rl > 0) sendto(sock, (const char*)resp, rl, 0, (struct sockaddr*)&client, sizeof(client)); } - DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "Fake NTP server on 127.0.0.1:%u, offset=+%ds", g_server_port, TEST_KNOWN_OFFSET_SEC); - - /* ── 2. Create uTun instance with minimal config ── */ - struct UASYNC* ua = uasync_create(); - if (!ua) { g_server_running = 0; pthread_join(server_thread, NULL); return 1; } + socket_close_wrapper(sock); + return NULL; +} - utun_instance_set_tun_init_enabled(0); +/* ─── helpers ─── */ - /* Parse config from buffer and inject keys (avoid config_ensure_keys_and_node_id rewriting) */ - const char *config_text = +static struct UTUN_INSTANCE* make_instance(struct UASYNC* ua, const char* server_name) { + char config_text[512]; + snprintf(config_text, sizeof(config_text), "[global]\n" "my_node_name=ntp_test\n" "my_private_key=e8d4d14943ca3732d7802d4010ea4f6f8bdb71e2304f78d68f4f3dc31e760c79\n" @@ -162,97 +199,105 @@ int main(void) { "\n" "[ntp]\n" "enabled=yes\n" - "server=placeholder\n" - "interval=3600\n"; + "server=%s\n" + "interval=3600\n", + server_name); struct utun_config* cfg = parse_config_from_buf(config_text, strlen(config_text), "inline"); - if (!cfg) { - DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "Failed to parse config from buffer"); - uasync_destroy(ua, 0); - g_server_running = 0; - pthread_join(server_thread, NULL); - return 1; - } - DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "Parsed config: ntp_enabled=%d server_count=%d", - cfg->global.ntp_enabled, cfg->global.ntp_server_count); - + if (!cfg) { DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "parse config failed"); return NULL; } struct UTUN_INSTANCE* inst = utun_instance_create_from_config(ua, cfg); - if (!inst) { - DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "Failed to create instance from config"); - free_config(cfg); - uasync_destroy(ua, 0); - g_server_running = 0; - pthread_join(server_thread, NULL); - return 1; - } - - /* utun_instance_create only calls instance_init_common (basic inits). - utun_instance_init is needed for NTP, connections, etc. */ + if (!inst) { DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "create instance failed"); free_config(cfg); return NULL; } utun_instance_init(inst); + return inst; +} - DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "NTP state after init: enabled=%d server_count=%d interval=%d servers[0]=%s config_enabled=%d config_count=%d", - inst->ntp.enabled, inst->ntp.server_count, inst->ntp.resync_interval_sec, - inst->ntp.server_count > 0 ? inst->ntp.servers[0] : "NONE", - inst->config ? inst->config->global.ntp_enabled : -1, - inst->config ? inst->config->global.ntp_server_count : -1); - - /* ── 3. Set test address BEFORE first uasync poll (timer fires at delay 0) ── */ - ntp_time_set_test_addr(&inst->ntp, "127.0.0.1", g_server_port); - - /* ── 4. Poll until synced or timeout ── */ +static int verify_synced(struct UTUN_INSTANCE* inst, struct UASYNC* ua, const char* label) { uint64_t start_tb = get_time_tb(); - while (get_time_tb() - start_tb < (uint64_t)(TEST_TIMEOUT_SEC * 10000)) { + while (!inst->ntp.synced && get_time_tb() - start_tb < (uint64_t)(TEST_TIMEOUT_SEC * 10000)) uasync_poll(ua, SYNC_WAIT_POLL_MS); - if (inst->ntp.synced) break; - } - /* ── 5. Verify ── */ if (!inst->ntp.synced) { - DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "FAIL: NTP did not sync within %ds", TEST_TIMEOUT_SEC); - goto cleanup; + DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "FAIL: %s did not sync within %ds", label, TEST_TIMEOUT_SEC); + return -1; + } + int64_t diff = inst->ntp.offset_us - TEST_KNOWN_OFFSET_US; + if (diff < 0) diff = -diff; + if (diff > OFFSET_TOLERANCE_US) { + DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "FAIL: %s offset %lldus too far from expected %lldus (diff=%lldus)", + label, (long long)inst->ntp.offset_us, (long long)TEST_KNOWN_OFFSET_US, (long long)diff); + return -1; + } + if (!ntp_time_is_synced(inst)) { + DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "FAIL: %s ntp_time_is_synced returned 0", label); + return -1; + } + DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "PASS: %s offset=%lldus", label, (long long)inst->ntp.offset_us); + return 0; +} + +int main(void) { + int result = 1; + pthread_t server_thread, dns_thread; + int server_started = 0, dns_started = 0; + + debug_config_init(); + debug_set_level(DEBUG_LEVEL_WARN); + debug_set_categories(DEBUG_CATEGORY_GENERAL); + + DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "=== NTP Test ==="); + + utun_instance_set_tun_init_enabled(0); + + /* fake NTP server */ + if (pthread_create(&server_thread, NULL, test_server_thread, NULL) != 0) { + DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "Failed to create server thread"); + return 1; } - DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "NTP synced, offset=%lldus", (long long)inst->ntp.offset_us); + server_started = 1; + { uint64_t w = get_time_tb(); while (g_server_port == 0 && get_time_tb() - w < 50000) platform_sleep_ms(5); } + if (g_server_port == 0) { DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "fake NTP server did not bind"); goto cleanup; } + DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "Fake NTP server on 127.0.0.1:%u, offset=+%ds", g_server_port, TEST_KNOWN_OFFSET_SEC); - // Check offset is close to expected (formula gives server - client ≈ KNOWN_OFFSET) + /* ── scenario 1: direct address (test_addr) ── */ { - int64_t diff = inst->ntp.offset_us - TEST_KNOWN_OFFSET_US; - if (diff < 0) diff = -diff; - if (diff > OFFSET_TOLERANCE_US) { - DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "FAIL: offset %lldus too far from expected %lldus (diff=%lldus)", - (long long)inst->ntp.offset_us, (long long)TEST_KNOWN_OFFSET_US, (long long)diff); - goto cleanup; - } + struct UASYNC* ua = uasync_create(); + if (!ua) goto cleanup; + struct UTUN_INSTANCE* inst = make_instance(ua, "placeholder"); + if (!inst) { uasync_destroy(ua, 0); goto cleanup; } + ntp_time_set_test_addr(&inst->ntp, "127.0.0.1", g_server_port); + int ok = verify_synced(inst, ua, "direct (test_addr)"); + utun_instance_destroy(inst); + uasync_destroy(ua, 0); + if (ok != 0) goto cleanup; } - // Check ntp_time_is_synced - if (!ntp_time_is_synced(inst)) { - DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "FAIL: ntp_time_is_synced returned 0 after sync"); + /* ── scenario 2: hostname resolved via fake DNS (async_dns) ── */ + if (pthread_create(&dns_thread, NULL, dns_server_thread, NULL) != 0) { + DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "Failed to create DNS server thread"); goto cleanup; } + dns_started = 1; + { uint64_t w = get_time_tb(); while (g_dns_port == 0 && get_time_tb() - w < 50000) platform_sleep_ms(5); } + if (g_dns_port == 0) { DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "fake DNS server did not bind"); goto cleanup; } + DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "Fake DNS server on 127.0.0.1:%u", g_dns_port); - // Check ntp_time_get_us internal consistency { - struct timeval tv; - utun_gettimeofday(&tv, NULL); - int64_t raw_us = (int64_t)tv.tv_sec * 1000000LL + tv.tv_usec; - int64_t corrected_us = ntp_time_get_us(inst); - int64_t expected_us = raw_us - inst->ntp.offset_us; - int64_t diff = corrected_us - expected_us; - if (diff < 0) diff = -diff; - if (diff > 10000) { // 10ms — time passes between gettimeofday calls - DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "FAIL: ntp_time_get_us(%lld) != gettimeofday(%lld) - offset(%lld), diff=%lldus", - (long long)corrected_us, (long long)raw_us, (long long)inst->ntp.offset_us, (long long)diff); - goto cleanup; - } + struct UASYNC* ua = uasync_create(); + if (!ua) goto cleanup; + struct UTUN_INSTANCE* inst = make_instance(ua, "ntp.test.local"); + if (!inst) { uasync_destroy(ua, 0); goto cleanup; } + ntp_time_set_test_dns(&inst->ntp, "127.0.0.1", g_dns_port, g_server_port); + int ok = verify_synced(inst, ua, "hostname (async DNS)"); + utun_instance_destroy(inst); + uasync_destroy(ua, 0); + if (ok != 0) goto cleanup; } result = 0; DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "NTP Test PASSED"); cleanup: - utun_instance_destroy(inst); - uasync_destroy(ua, 0); - g_server_running = 0; - pthread_join(server_thread, NULL); + if (server_started) { g_server_running = 0; pthread_join(server_thread, NULL); } + if (dns_started) { g_dns_running = 0; pthread_join(dns_thread, NULL); } return result; }