components/ip.c

   1 /* See LICENSE file for copyright and license details. */
   2 #if defined(__linux__)
   3 #include <errno.h>
   4 #include <ifaddrs.h>
   5 #include <netdb.h>
   6 #include <stdio.h>
   7 #include <string.h>
   8
   9 #include "../util.h"
  10
  11 const char *
  12 ipv4(const char *iface)
  13 {
  14         struct ifaddrs *ifaddr, *ifa;
  15         int s;
  16         char host[NI_MAXHOST];
  17
  18         if (getifaddrs(&ifaddr) == -1) {
  19                 fprintf(stderr, "getifaddrs: %s\n", strerror(errno));
  20                 return NULL;
  21         }
  22
  23         for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
  24                 if (ifa->ifa_addr == NULL) {
  25                         continue;
  26                 }
  27                 s = getnameinfo(ifa->ifa_addr, sizeof(struct sockaddr_in), host, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
  28                 if ((strcmp(ifa->ifa_name, iface) == 0) && (ifa->ifa_addr->sa_family == AF_INET)) {
  29                         if (s != 0) {
  30                                 fprintf(stderr, "getnameinfo: %s\n", gai_strerror(s));
  31                                 return NULL;
  32                         }
  33                         return bprintf("%s", host);
  34                 }
  35         }
  36
  37         freeifaddrs(ifaddr);
  38
  39         return NULL;
  40 }
  41
  42 const char *
  43 ipv6(const char *iface)
  44 {
  45         struct ifaddrs *ifaddr, *ifa;
  46         int s;
  47         char host[NI_MAXHOST];
  48
  49         if (getifaddrs(&ifaddr) == -1) {
  50                 fprintf(stderr, "getifaddrs: %s\n", strerror(errno));
  51                 return NULL;
  52         }
  53
  54         for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
  55                 if (ifa->ifa_addr == NULL) {
  56                         continue;
  57                 }
  58                 s = getnameinfo(ifa->ifa_addr, sizeof(struct sockaddr_in6), host, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
  59                 if ((strcmp(ifa->ifa_name, iface) == 0) && (ifa->ifa_addr->sa_family == AF_INET6)) {
  60                         if (s != 0) {
  61                                 fprintf(stderr, "getnameinfo: %s\n", gai_strerror(s));
  62                                 return NULL;
  63                         }
  64                         return bprintf("%s", host);
  65                 }
  66         }
  67
  68         freeifaddrs(ifaddr);
  69
  70         return NULL;
  71 }
  72 #endif