ip.c

   1 #include <err.h>
   2 #include <ifaddrs.h>
   3 #include <netdb.h>
   4 #include <stdio.h>
   5 #include <string.h>
   6
   7 #include "util.h"
   8
   9 const char *
  10 ipv4(const char *iface)
  11 {
  12         struct ifaddrs *ifaddr, *ifa;
  13         int s;
  14         char host[NI_MAXHOST];
  15
  16         if (getifaddrs(&ifaddr) == -1) {
  17                 warn("Failed to get IPv4 address for interface %s", iface);
  18                 return NULL;
  19         }
  20
  21         for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
  22                 if (ifa->ifa_addr == NULL) {
  23                         continue;
  24                 }
  25                 s = getnameinfo(ifa->ifa_addr, sizeof(struct sockaddr_in), host, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
  26                 if ((strcmp(ifa->ifa_name, iface) == 0) && (ifa->ifa_addr->sa_family == AF_INET)) {
  27                         if (s != 0) {
  28                                 warnx("Failed to get IPv4 address for interface %s", iface);
  29                                 return NULL;
  30                         }
  31                         return bprintf("%s", host);
  32                 }
  33         }
  34
  35         freeifaddrs(ifaddr);
  36
  37         return NULL;
  38 }
  39
  40 const char *
  41 ipv6(const char *iface)
  42 {
  43         struct ifaddrs *ifaddr, *ifa;
  44         int s;
  45         char host[NI_MAXHOST];
  46
  47         if (getifaddrs(&ifaddr) == -1) {
  48                 warn("Failed to get IPv6 address for interface %s", iface);
  49                 return NULL;
  50         }
  51
  52         for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
  53                 if (ifa->ifa_addr == NULL) {
  54                         continue;
  55                 }
  56                 s = getnameinfo(ifa->ifa_addr, sizeof(struct sockaddr_in6), host, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
  57                 if ((strcmp(ifa->ifa_name, iface) == 0) && (ifa->ifa_addr->sa_family == AF_INET6)) {
  58                         if (s != 0) {
  59                                 warnx("Failed to get IPv6 address for interface %s", iface);
  60                                 return NULL;
  61                         }
  62                         return bprintf("%s", host);
  63                 }
  64         }
  65
  66         freeifaddrs(ifaddr);
  67
  68         return NULL;
  69 }