local ip with checking

    printf("Retrieving data for %s...\n",hostname);
    short i, j, ifd_num = 0, hst_num = 0;

    char *host_chk[20];
    char *ifad_chk[20];

    struct hostent * h_local_chk;
    char *host = (char *)malloc(255);
    gethostname(host, 255);
    if ((h_local_chk = gethostbyname(host)) < 0) die_with_signal("hostname");
    free(host);
    for (i=0; i < h_local_chk->h_length; i++) {
        host_chk[i] = calloc(1, INET_ADDRSTRLEN+1);
        inet_ntop(AF_INET, (struct in_addr *)h_local_chk->h_addr_list[i], host_chk[i], INET_ADDRSTRLEN);
        hst_num++;
    }
    struct ifaddrs *ifa = (struct ifaddrs *)malloc(sizeof(*ifa));
    if (getifaddrs(&ifa)) die_with_signal("local retr.");
    i = 0;
    for (; ifa != NULL; ifa = ifa->ifa_next) {
        if (!memcmp(ifa->ifa_name, syn->device, strlen(syn->device))) {
            ifad_chk[i] = calloc(1, INET_ADDRSTRLEN+1);
            inet_ntop(AF_INET, (void *)&((struct sockaddr_in *)ifa->ifa_addr)->sin_addr, ifad_chk[i], INET_ADDRSTRLEN);
            ifd_num++, i++;
        }
    }
    free(ifa);
    for (i = 0; i < hst_num; i++) {
        for (j = 0; j < ifd_num; j++) {
            if (!(memcmp(host_chk[i], ifad_chk[j], 10))) {
                syn->syn_data.p_src = (char *)malloc(16);
                memcpy( syn->syn_data.p_src, host_chk[i], INET_ADDRSTRLEN);
                printf("Got local IP: %s\n",syn->syn_data.p_src);
                free(host_chk[i]);
                free(ifad_chk[j]);
                break;
            }
        }
        if (syn->syn_data.p_src) break;
    }