PeerStreamer

/*

 *  Copyright (c) 2010 Luca Abeni

 *  Copyright (c) 2010 Csaba Kiraly

 *

 *  This is free software; see gpl-3.0.txt

 */

#include <sys/types.h>

#include <ifaddrs.h>

#include <sys/ioctl.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <net/if.h>     /* For struct ifreq */

#include <unistd.h>

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <netdb.h>

#include "net_helpers.h"

char *iface_addr(const char *iface)

{

    int s, res;

    struct ifreq iface_request;

    struct sockaddr_in *sin;

    char buff[512];

    s = socket(AF_INET, SOCK_DGRAM, 0);

    if (s < 0) {

        return NULL;

    }

    memset(&iface_request, 0, sizeof(struct ifreq));

    sin = (struct sockaddr_in *)&iface_request.ifr_addr;

    strcpy(iface_request.ifr_name, iface);

    /* sin->sin_family = AF_INET); */

    res = ioctl(s, SIOCGIFADDR, &iface_request);

    if (res < 0) {

        perror("ioctl(SIOCGIFADDR)");

        close(s);

        return NULL;

    }

    close(s);

    inet_ntop(AF_INET, &sin->sin_addr, buff, sizeof(buff));

    return strdup(buff);

}

/*

char *default_ip_addr()

{

  char hostname[256];

  struct hostent *host_entry;

  char *ip;

  fprintf(stderr, "Trying to guess IP ...");

  if (gethostname(hostname, sizeof hostname) < 0) {

    fprintf(stderr, "can't get hostname\n");

    return NULL;

  }

  fprintf(stderr, "hostname is: %s ...", hostname);

  host_entry = gethostbyname(hostname);

  if (! host_entry) {

    fprintf(stderr, "can't resolve IP\n");

    return NULL;

  }

  inet_ntop(AF_INET, &sin->sin_addr, buff, sizeof(buff));

  ip = inet_ntoa(host_entry->h_addr);

  fprintf(stderr, "IP is: %s ...", ip);

  return ip;

}

*/

const char *autodetect_ip_address() {

#ifndef __linux__

        return NULL;

#endif

        static char addr[128] = "";

        char iface[IFNAMSIZ] = "";

        char line[128] = "x";

        struct ifaddrs *ifAddrStruct = NULL;

        FILE *r = fopen("/proc/net/route", "r");

        if (!r) return NULL;

        while (1) {

                char dst[32];

                char ifc[IFNAMSIZ];

                fgets(line, 127, r);

                if (feof(r)) break;

                if ((sscanf(line, "%s\t%s", iface, dst) == 2) && !strcpy(dst, "00000000")) {

                        strcpy(iface, ifc);

                         break;

                }

        }

        if (iface[0] == 0) return NULL;

        if (getifaddrs(&ifAddrStruct) < 0) return NULL;

        while (ifAddrStruct) {

                if (ifAddrStruct->ifa_addr && ifAddrStruct->ifa_addr->sa_family == AF_INET && 

                        ifAddrStruct->ifa_name && !strcmp(ifAddrStruct->ifa_name, iface))  {

                        void *tmpAddrPtr=&((struct sockaddr_in *)ifAddrStruct->ifa_addr)->sin_addr;

                        return inet_ntop(AF_INET, tmpAddrPtr, addr, 127);

                }

        ifAddrStruct=ifAddrStruct->ifa_next;

        }

        return NULL;

}

const char *hostname_ip_addr()

{

  const char *ip;

  char hostname[256];

  struct addrinfo * result;

  struct addrinfo * res;

  int error;

  if (gethostname(hostname, sizeof hostname) < 0) {

    fprintf(stderr, "can't get hostname\n");

    return NULL;

  }

  fprintf(stderr, "hostname is: %s ...", hostname);

  /* resolve the domain name into a list of addresses */

  error = getaddrinfo(hostname, NULL, NULL, &result);

  if (error != 0) {

    fprintf(stderr, "can't resolve IP: %s\n", gai_strerror(error));

    return NULL;

  }

  /* loop over all returned results and do inverse lookup */

  for (res = result; res != NULL; res = res->ai_next) {

    ip = inet_ntoa(((struct sockaddr_in*)res->ai_addr)->sin_addr);

    fprintf(stderr, "IP is: %s ...", ip);

    if ( strncmp("127.", ip, 4) == 0) {

      fprintf(stderr, ":( ...");

      ip = NULL;

    } else {

      break;

    }

  }

  freeaddrinfo(result);

  return ip;

}

char *default_ip_addr()

{

  const char *ip = NULL;

  fprintf(stderr, "Trying to guess IP ...");

  //ip = hostname_ip_addr();

  if (!ip) {

    ip = autodetect_ip_address();

  }

  if (!ip) {

    fprintf(stderr, "cannot detect IP!\n");

    return NULL;

  }

  fprintf(stderr, "IP is: %s ...\n", ip);

  return strdup(ip);

}