components/ip.c

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