components/ip.c

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