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 #elif defined(__FreeBSD__)
  10         #include <netinet/in.h>
  11         #include <sys/socket.h>
  12 #endif
  13
  14 #include "../util.h"
  15
  16 static const char *
  17 ip(const char *interface, unsigned short sa_family)
  18 {
  19         struct ifaddrs *ifaddr, *ifa;
  20         int s;
  21         char host[NI_MAXHOST];
  22
  23         if (getifaddrs(&ifaddr) < 0) {
  24                 warn("getifaddrs:");
  25                 return NULL;
  26         }
  27
  28         for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
  29                 if (!ifa->ifa_addr) {
  30                         continue;
  31                 }
  32                 s = getnameinfo(ifa->ifa_addr, sizeof(struct sockaddr_in6),
  33                                 host, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
  34                 if (!strcmp(ifa->ifa_name, interface) &&
  35                     (ifa->ifa_addr->sa_family == sa_family)) {
  36                         freeifaddrs(ifaddr);
  37                         if (s != 0) {
  38                                 warn("getnameinfo: %s", gai_strerror(s));
  39                                 return NULL;
  40                         }
  41                         return bprintf("%s", host);
  42                 }
  43         }
  44
  45         freeifaddrs(ifaddr);
  46
  47         return NULL;
  48 }
  49
  50 const char *
  51 ipv4(const char *interface)
  52 {
  53         return ip(interface, AF_INET);
  54 }
  55
  56 const char *
  57 ipv6(const char *interface)
  58 {
  59         return ip(interface, AF_INET6);
  60 }