/* Настоящие UDP/router-пакеты; сетевые потери и задержка вводятся на границе sendto. * Подмена наблюдения отдельно проверяет применение подписанных mapping-отчётов. */ #include "nat_fixture.h" #include "test_clock.h" enum fault_mode { FAULT_NONE, FAULT_NO_PONG, FAULT_FILTERED, FAULT_LATE_PRE, FAULT_CONTACT, FAULT_DEPENDENT, FAULT_UNSTABLE, FAULT_NO_REPORT, FAULT_INGRESS_BLOCKED, FAULT_NO_ANCHOR }; static struct { struct nat_fixture *fixture; struct UTUN_INSTANCE *owner, *observer, *helper; struct ETCP_SOCKET *socket; enum fault_mode mode; unsigned dropped, altered, direct_received, observations; int contacted, injected; socket_t delayed_fd; uint8_t delayed[1600]; size_t delayed_length; struct sockaddr_storage delayed_target; socklen_t delayed_target_length; } fault; ssize_t __real_socket_sendto(socket_t, const void *, size_t, const struct sockaddr *, socklen_t); void __real_nat_detection_record_observation(struct NAT_DETECTION *, struct ETCP_SOCKET *, const uint8_t *, const struct sockaddr_storage *, const uint8_t *, size_t); static void ignored_ping(int success, uint16_t rtt, void *arg, uint64_t nonce, const uint8_t *data, size_t length) { (void)success; (void)rtt; (void)arg; (void)nonce; (void)data; (void)length; } /* Расшифровываем только PING/PONG с публичным хвостом, используя настоящие ключи участников стенда. */ static size_t decode_ping(struct ETCP_SOCKET *socket, const uint8_t *packet, size_t length, uint8_t plain[1600]) { if (length <= SC_PUBKEY_ENC_SIZE || length > 1600) return 0; const uint8_t *salt = packet + length - SC_PUBKEY_ENC_SIZE; for (unsigned i = 0; i < fault.fixture->node_count; i++) { struct UTUN_INSTANCE *peer = fault.fixture->nodes[i]; uint8_t obfuscated[SC_PUBKEY_SIZE]; sc_obfuscate_pubkey(salt, peer->my_keys.public_key, socket->instance->my_keys.public_key, obfuscated); if (memcmp(obfuscated, salt + SC_PUBKEY_ENC_SALT_SIZE, sizeof(obfuscated))) continue; sc_context_t crypto; assert(sc_init_ctx(&crypto, &socket->instance->my_keys) == SC_OK); assert(sc_set_peer_public_key(&crypto, peer->my_keys.public_key, SC_PEER_PUBKEY_BIN) == SC_OK); size_t size = 0; assert(sc_decrypt(&crypto, packet, length - SC_PUBKEY_ENC_SIZE, plain, &size) == SC_OK); return size >= 23 && (plain[3] == ETCP_PING || plain[3] == ETCP_PONG) ? size : 0; } return 0; } ssize_t __wrap_socket_sendto(socket_t fd, const void *packet, size_t length, const struct sockaddr *target, socklen_t target_length) { if (!fault.fixture) return __real_socket_sendto(fd, packet, length, target, target_length); struct ETCP_SOCKET *source = NULL; for (unsigned i = 0; i < fault.fixture->node_count && !source; i++) for (struct ETCP_SOCKET *socket = fault.fixture->nodes[i]->etcp_sockets; socket; socket = socket->next) if (socket->fd == fd) { source = socket; break; } uint8_t plain[1600]; size_t size = source ? decode_ping(source, packet, length, plain) : 0; if (!size) return __real_socket_sendto(fd, packet, length, target, target_length); struct sockaddr_storage destination = {0}; assert(target_length <= sizeof(destination)); memcpy(&destination, target, target_length); int to_owner = route_ping_addr_equal(&destination, &fault.socket->local_addr, 1); if ((fault.mode == FAULT_NO_PONG || fault.mode == FAULT_NO_ANCHOR) && to_owner && plain[3] == ETCP_PONG) { fault.dropped++; return length; } if (source == fault.socket && plain[3] == ETCP_PING && (plain[4] & ETCP_PING_FLAG_OBSERVE) && !route_ping_addr_equal(&destination, &test_etcp_bound_socket(fault.observer, "udp")->local_addr, 0)) { fault.contacted = 1; ssize_t result = __real_socket_sendto(fd, packet, length, target, target_length); if (fault.delayed_length) { assert(__real_socket_sendto(fault.delayed_fd, fault.delayed, fault.delayed_length, (const struct sockaddr *)&fault.delayed_target, fault.delayed_target_length) == (ssize_t)fault.delayed_length); DEBUG_INFO(DEBUG_CATEGORY_NAT, "fault fixture: delayed PRE delivered after outgoing contact"); fault.delayed_length = 0; fault.injected = 1; } return result; } if (to_owner && plain[3] == ETCP_PING && (plain[4] & ETCP_PING_FLAG_ADDRESS_CHECK)) { if (fault.mode == FAULT_CONTACT && !fault.injected) { fault.injected = 1; assert(!etcp_send_ping_to_socket(fault.owner, fault.socket, source->instance->my_keys.public_key, &source->local_addr, 500, ignored_ping, NULL, NULL, 0, 0)); DEBUG_INFO(DEBUG_CATEGORY_NAT, "fault fixture: real outgoing PING contaminates PRE source IP"); } if (fault.mode == FAULT_INGRESS_BLOCKED || ((fault.mode == FAULT_FILTERED || fault.mode == FAULT_LATE_PRE || fault.mode == FAULT_NO_ANCHOR) && !fault.contacted)) { if (fault.mode == FAULT_LATE_PRE && !fault.delayed_length && !fault.injected) { memcpy(fault.delayed, packet, length); fault.delayed_length = length; fault.delayed_fd = fd; fault.delayed_target = destination; fault.delayed_target_length = target_length; } fault.dropped++; return length; } fault.direct_received++; } return __real_socket_sendto(fd, packet, length, target, target_length); } void __wrap_nat_detection_record_observation(struct NAT_DETECTION *detector, struct ETCP_SOCKET *socket, const uint8_t *key, const struct sockaddr_storage *source, const uint8_t *tag, size_t length) { if (!fault.fixture || socket->instance != fault.helper || memcmp(key, fault.owner->my_keys.public_key, 32) || length != ROUTE_OBSERVE_TAG_SIZE + 9) { __real_nat_detection_record_observation(detector, socket, key, source, tag, length); return; } fault.observations++; if (fault.mode == FAULT_NO_REPORT) { fault.dropped++; return; } struct sockaddr_storage observed = *source; if (fault.mode == FAULT_DEPENDENT || (fault.mode == FAULT_UNSTABLE && fault.observations == 1)) { struct sockaddr_in *address = (struct sockaddr_in *)&observed; address->sin_port = htons(ntohs(address->sin_port) == 65535 ? 65534 : ntohs(address->sin_port) + 1); fault.altered++; DEBUG_INFO(DEBUG_CATEGORY_NAT, "fault fixture: observed mapping changed from=%s to=%s", sockaddr_storage_to_str(source).str, sockaddr_storage_to_str(&observed).str); } __real_nat_detection_record_observation(detector, socket, key, &observed, tag, length); } static void run_case(enum fault_mode mode, uint8_t mapping, uint8_t inbound) { struct nat_fixture fixture; nat_fixture_init(&fixture); struct UTUN_INSTANCE *owner = nat_fixture_node(&fixture, "127.0.0.2", NULL, NULL); struct UTUN_INSTANCE *observer = nat_fixture_node(&fixture, "127.0.0.3", NULL, NULL); struct UTUN_INSTANCE *helper = nat_fixture_node(&fixture, "127.0.0.4", NULL, NULL); nat_detection_set_automatic(observer->nat_det, 0); nat_detection_set_automatic(helper->nat_det, 0); nat_fixture_connect(&fixture, observer, "udp", helper); nat_fixture_connect(&fixture, owner, "udp", observer); nat_detection_set_automatic(owner->nat_det, 0); memset(&fault, 0, sizeof(fault)); fault.fixture = &fixture; fault.owner = owner; fault.observer = observer; fault.helper = helper; fault.socket = test_etcp_bound_socket(owner, "udp"); fault.mode = mode; assert(!nat_detection_request_check_socket(owner->nat_det, fault.socket, observer->node_id)); struct nat_check_status status = {0}; uint64_t end = get_time_tb() + 400000; do { test_clock_poll(fixture.ua, 1000); assert(!nat_detection_get_status(owner->nat_det, fault.socket, &status)); } while (get_time_tb() < end && (!status.rounds || status.phase || status.cycling)); DEBUG_INFO(DEBUG_CATEGORY_NAT, "fault fixture result mode=%d mapping=%s inbound=%s phase=%u cycling=%u reason=%s dropped=%u observations=%u", mode, address_mapping_name(fault.socket->address_profile.mapping), address_inbound_name(fault.socket->address_profile.inbound), status.phase, status.cycling, nat_check_reason_name(status.reason), fault.dropped, fault.observations); assert(!status.phase && !status.cycling); assert(fault.socket->address_profile.mapping == mapping && fault.socket->address_profile.inbound == inbound); if (mode == FAULT_NO_PONG || mode == FAULT_FILTERED || mode == FAULT_LATE_PRE || mode == FAULT_NO_REPORT) assert(fault.dropped); if (mode == FAULT_LATE_PRE || mode == FAULT_CONTACT) assert(fault.injected); if (mode == FAULT_DEPENDENT || mode == FAULT_UNSTABLE) assert(fault.altered); fault.fixture = NULL; nat_fixture_cleanup(&fixture); DEBUG_INFO(DEBUG_CATEGORY_NAT, "PASS NAT fault mode=%d", mode); } /* Разные ключи не означают разные IP: неподходящего помощника отклоняет получатель. */ static void run_alias(const char *alias_ip) { struct nat_fixture fixture; nat_fixture_init(&fixture); struct SC_MYKEYS first, second; assert(sc_generate_keypair(&first) == SC_OK && sc_generate_keypair(&second) == SC_OK); if (sc_derive_node_id_from_pubkey(first.public_key) > sc_derive_node_id_from_pubkey(second.public_key)) { struct SC_MYKEYS swap = first; first = second; second = swap; } struct UTUN_INSTANCE *owner = nat_fixture_node(&fixture, "127.0.0.2", NULL, NULL); struct UTUN_INSTANCE *observer = nat_fixture_node(&fixture, "127.0.0.3", NULL, NULL); struct UTUN_INSTANCE *alias = nat_fixture_node(&fixture, alias_ip, &first, NULL); struct UTUN_INSTANCE *helper = nat_fixture_node(&fixture, "127.0.0.4", &second, NULL); nat_detection_set_automatic(observer->nat_det, 0); nat_detection_set_automatic(alias->nat_det, 0); nat_detection_set_automatic(helper->nat_det, 0); nat_fixture_connect(&fixture, observer, "udp", alias); nat_fixture_connect(&fixture, observer, "udp", helper); nat_fixture_connect(&fixture, owner, "udp", observer); nat_detection_set_automatic(owner->nat_det, 0); struct ETCP_SOCKET *socket = test_etcp_bound_socket(owner, "udp"); assert(!nat_detection_request_check_socket(owner->nat_det, socket, observer->node_id)); struct nat_check_status status = {0}; uint64_t end = get_time_tb() + 400000; do { test_clock_poll(fixture.ua, 1000); assert(!nat_detection_get_status(owner->nat_det, socket, &status)); } while (get_time_tb() < end && (!status.rounds || status.phase || status.cycling)); assert(socket->address_profile.mapping == ADDRESS_MAP_UNCHANGED && socket->address_profile.inbound == ADDRESS_IN_OPEN); assert(status.helper == helper->node_id && status.helper_reselections); nat_fixture_cleanup(&fixture); DEBUG_INFO(DEBUG_CATEGORY_NAT, "PASS NAT receiver rejects helper source=%s", alias_ip); } /* У наблюдателя первый UDP listener недоступен, но управление по TCP и второй IP работают. */ static void run_endpoint_retry(void) { struct nat_fixture fixture; nat_fixture_init(&fixture); struct UTUN_INSTANCE *owner = nat_fixture_node(&fixture, "127.0.0.2", NULL, "[server:tcp]\naddr=127.0.0.2:0\ntransport=tcp\ntype=public\n"); struct UTUN_INSTANCE *observer = nat_fixture_node(&fixture, "127.0.0.3", NULL, "[server:other]\naddr=127.0.0.8:0\ntype=public\n[server:tcp]\naddr=127.0.0.3:0\ntransport=tcp\ntype=public\n"); struct UTUN_INSTANCE *helper = nat_fixture_node(&fixture, "127.0.0.4", NULL, "[server:tcp]\naddr=127.0.0.4:0\ntransport=tcp\ntype=public\n"); nat_detection_set_automatic(observer->nat_det, 0); nat_detection_set_automatic(helper->nat_det, 0); struct ETCP_SOCKET *bad = test_etcp_bound_socket(observer, "udp"); assert(!uasync_remove_socket_t(fixture.ua, bad->fd)); bad->socket_id = NULL; nat_fixture_connect(&fixture, observer, "tcp", helper); nat_fixture_connect(&fixture, owner, "tcp", observer); nat_detection_set_automatic(owner->nat_det, 0); struct ETCP_SOCKET *socket = test_etcp_bound_socket(owner, "udp"); assert(!nat_detection_request_check_socket(owner->nat_det, socket, observer->node_id)); struct nat_check_status status = {0}; uint64_t end = get_time_tb() + 400000; do { test_clock_poll(fixture.ua, 1000); assert(!nat_detection_get_status(owner->nat_det, socket, &status)); } while (get_time_tb() < end && (!status.rounds || status.phase || status.cycling)); assert(socket->address_profile.mapping == ADDRESS_MAP_UNCHANGED && socket->address_profile.inbound == ADDRESS_IN_OPEN); assert(status.helper_reselections && status.observer == observer->node_id); nat_fixture_cleanup(&fixture); DEBUG_INFO(DEBUG_CATEGORY_NAT, "PASS NAT retries another observer IP after timeout"); } int main(void) { debug_config_init(); debug_set_level(DEBUG_LEVEL_WARN); debug_set_category_level(DEBUG_CATEGORY_NAT, DEBUG_LEVEL_DEBUG); test_clock_init(1000); run_case(FAULT_NO_PONG, ADDRESS_MAP_UNCHANGED, ADDRESS_IN_OPEN); run_case(FAULT_FILTERED, ADDRESS_MAP_UNCHANGED, ADDRESS_IN_CONTACT); run_case(FAULT_LATE_PRE, ADDRESS_MAP_UNCHANGED, ADDRESS_IN_CONTACT); run_case(FAULT_CONTACT, ADDRESS_MAP_UNCHANGED, ADDRESS_IN_UNKNOWN); run_case(FAULT_DEPENDENT, ADDRESS_MAP_DEPENDENT, ADDRESS_IN_OPEN); run_case(FAULT_UNSTABLE, ADDRESS_MAP_UNKNOWN, ADDRESS_IN_UNKNOWN); run_case(FAULT_NO_REPORT, ADDRESS_MAP_UNKNOWN, ADDRESS_IN_UNKNOWN); run_case(FAULT_INGRESS_BLOCKED, ADDRESS_MAP_UNCHANGED, ADDRESS_IN_UNKNOWN); run_case(FAULT_NO_ANCHOR, ADDRESS_MAP_UNCHANGED, ADDRESS_IN_UNKNOWN); run_alias("127.0.0.3"); run_alias("127.0.0.2"); run_endpoint_retry(); test_clock_finish(); return 0; }