#define _GNU_SOURCE
#include <dlfcn.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <net/if.h>
#include <errno.h>

static int (*real_socket)(int domain, int type, int protocol) = NULL;

__attribute__((constructor)) void init(void) {
    real_socket = dlsym(RTLD_NEXT, "socket");
    if (!real_socket) {
        fprintf(stderr, "Error loading original socket function\n");
        exit(1);
    }
}

int socket(int domain, int type, int protocol) {
    int sockfd = real_socket(domain, type, protocol);
    if (sockfd == -1) {
        return -1;
    }

    char *interface = getenv("SOCKET_INTERFACE");
    if (interface) {
        FILE *log = fopen("/tmp/socket_bind.log", "a");
        if (log) {
            fprintf(log, "Binding socket %d to interface %s\n", sockfd, interface);
            fflush(log);  // Ensure the log is written immediately
            fclose(log);
        }

        if (setsockopt(sockfd, SOL_SOCKET, SO_BINDTODEVICE, interface, strlen(interface)) < 0) {
            FILE *log = fopen("/tmp/socket_bind.log", "a");
            if (log) {
                fprintf(log, "Failed to bind socket to interface %s: %s\n", interface, strerror(errno));
                fflush(log);  // Ensure the log is written immediately
                fclose(log);
            }
            close(sockfd);
            return -1;
        }
    }

    return sockfd;
}