Evgeny
6aedf5fe91
- Add lib/getmyip.c/h with get_outgoing_local_ip() using UDP connect+getsockname - Update etcp_socket_add() to use new function for 0.0.0.0 and :: bindings - Support both IPv4 (8.8.8.8) and IPv6 (2001:4860:4860::8888) auto-detection - Remove broken get_default_route_ip() from platform_compat (it returned gateway IP, not local IP) - Keep get_interface_ip_by_index() for explicit interface bindings - Update Makefile.am to include new getmyip module
103 lines
3.8 KiB
C
103 lines
3.8 KiB
C
/**
|
|
* getmyip.c - Определение локального IP-адреса для исходящих соединений
|
|
*
|
|
* Использует временный UDP-сокет с connect() для определения
|
|
* локального IP, который ОС выберет для заданного маршрута.
|
|
*/
|
|
|
|
#include "getmyip.h"
|
|
#include "socket_compat.h"
|
|
#include "debug_config.h"
|
|
|
|
#ifdef _WIN32
|
|
#include <winsock2.h>
|
|
#include <ws2tcpip.h>
|
|
#else
|
|
#include <unistd.h>
|
|
#include <arpa/inet.h>
|
|
#include <errno.h>
|
|
#endif
|
|
|
|
int get_outgoing_local_ip(const struct sockaddr_storage *local_addr,
|
|
const struct sockaddr_storage *remote_addr,
|
|
struct sockaddr_storage *result)
|
|
{
|
|
if (!local_addr || !remote_addr || !result) {
|
|
DEBUG_ERROR(DEBUG_CATEGORY_CONNECTION, "get_outgoing_local_ip: NULL argument");
|
|
return -1;
|
|
}
|
|
|
|
int family = local_addr->ss_family;
|
|
if (family != AF_INET && family != AF_INET6) {
|
|
DEBUG_ERROR(DEBUG_CATEGORY_CONNECTION, "get_outgoing_local_ip: unsupported family %d", family);
|
|
return -1;
|
|
}
|
|
|
|
if (remote_addr->ss_family != family) {
|
|
DEBUG_ERROR(DEBUG_CATEGORY_CONNECTION, "get_outgoing_local_ip: family mismatch");
|
|
return -1;
|
|
}
|
|
|
|
socket_t sock = socket_create_udp(family);
|
|
if (sock == SOCKET_INVALID) {
|
|
DEBUG_ERROR(DEBUG_CATEGORY_CONNECTION, "get_outgoing_local_ip: socket_create_udp failed");
|
|
return -1;
|
|
}
|
|
|
|
// Bind на local_addr, но порт ставим 0 чтобы не конфликтовать с основным сокетом
|
|
struct sockaddr_storage bind_addr;
|
|
memcpy(&bind_addr, local_addr, sizeof(bind_addr));
|
|
if (family == AF_INET) {
|
|
((struct sockaddr_in *)&bind_addr)->sin_port = 0;
|
|
} else {
|
|
((struct sockaddr_in6 *)&bind_addr)->sin6_port = 0;
|
|
}
|
|
|
|
socklen_t bind_len = (family == AF_INET) ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6);
|
|
if (bind(sock, (struct sockaddr *)&bind_addr, bind_len) != 0) {
|
|
int err = socket_get_error();
|
|
DEBUG_ERROR(DEBUG_CATEGORY_CONNECTION, "get_outgoing_local_ip: bind failed: %s", socket_strerror(err));
|
|
socket_close_wrapper(sock);
|
|
return -1;
|
|
}
|
|
|
|
// Connect к remote_addr — ядро вычислит маршрут и выберет source IP
|
|
socklen_t remote_len = (family == AF_INET) ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6);
|
|
if (connect(sock, (struct sockaddr *)remote_addr, remote_len) != 0) {
|
|
int err = socket_get_error();
|
|
DEBUG_ERROR(DEBUG_CATEGORY_CONNECTION, "get_outgoing_local_ip: connect failed: %s", socket_strerror(err));
|
|
socket_close_wrapper(sock);
|
|
return -1;
|
|
}
|
|
|
|
// Получаем выбранный локальный адрес
|
|
struct sockaddr_storage local;
|
|
socklen_t local_len = sizeof(local);
|
|
if (getsockname(sock, (struct sockaddr *)&local, &local_len) != 0) {
|
|
int err = socket_get_error();
|
|
DEBUG_ERROR(DEBUG_CATEGORY_CONNECTION, "get_outgoing_local_ip: getsockname failed: %s", socket_strerror(err));
|
|
socket_close_wrapper(sock);
|
|
return -1;
|
|
}
|
|
|
|
socket_close_wrapper(sock);
|
|
|
|
// Копируем только IP (без порта)
|
|
memset(result, 0, sizeof(*result));
|
|
if (family == AF_INET) {
|
|
struct sockaddr_in *sin = (struct sockaddr_in *)result;
|
|
struct sockaddr_in *src = (struct sockaddr_in *)&local;
|
|
sin->sin_family = AF_INET;
|
|
sin->sin_addr = src->sin_addr;
|
|
sin->sin_port = 0;
|
|
} else {
|
|
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)result;
|
|
struct sockaddr_in6 *src6 = (struct sockaddr_in6 *)&local;
|
|
sin6->sin6_family = AF_INET6;
|
|
sin6->sin6_addr = src6->sin6_addr;
|
|
sin6->sin6_port = 0;
|
|
}
|
|
|
|
return 0;
|
|
}
|