test/ifconf/ifconf.c

   1 #include <sys/types.h>
   2 #include <sys/ioctl.h>
   3 #include <sys/socket.h>
   4
   5 #include <arpa/inet.h>
   6 #include <netinet/in.h>
   7 #include <net/if.h>
   8 #include <net/if_dl.h>
   9
  10 #include <err.h>
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14 #include <unistd.h>
  15
  16 #define NADDRS          128
  17
  18 /* XXX _SIZEOF_ADDR_IFREQ should accept ptr */
  19 #define _SIZEOF_ADDR_IFREQ1(ifr) \
  20         ((ifr)->ifr_addr.sa_len > sizeof(struct sockaddr) ? \
  21          (sizeof(struct ifreq) - sizeof(struct sockaddr) + \
  22           (ifr)->ifr_addr.sa_len) : sizeof(struct ifreq))
  23
  24 static void
  25 usage(const char *cmd)
  26 {
  27         fprintf(stderr, "%s [-n naddrs]\n", cmd);
  28         exit(1);
  29 }
  30
  31 int
  32 main(int argc, char *argv[])
  33 {
  34         struct ifconf ifc;
  35         struct ifreq *ifr;
  36         caddr_t pos;
  37         int s, naddrs, opt;
  38
  39         naddrs = NADDRS;
  40
  41         while ((opt = getopt(argc, argv, "n:")) != -1) {
  42                 switch (opt) {
  43                 case 'n':
  44                         naddrs = strtol(optarg, NULL, 10);
  45                         break;
  46                 default:
  47                         usage(argv[0]);
  48                 }
  49         }
  50         if (naddrs <= 0)
  51                 usage(argv[0]);
  52
  53         s = socket(AF_INET, SOCK_DGRAM, 0);
  54         if (s < 0)
  55                 err(2, "socket failed");
  56
  57         memset(&ifc, 0, sizeof(ifc));
  58         ifc.ifc_len = sizeof(struct sockaddr_storage) * naddrs;
  59         ifc.ifc_buf = malloc(ifc.ifc_len);
  60         if (ifc.ifc_buf == NULL)
  61                 err(2, "malloc failed");
  62
  63         if (ioctl(s, SIOCGIFCONF, &ifc, sizeof(ifc)) < 0)
  64                 err(2, "ioctl failed");
  65
  66         pos = ifc.ifc_buf;
  67         while (ifc.ifc_len >= (int)sizeof(*ifr)) {
  68                 int len;
  69
  70                 ifr = (struct ifreq *)pos;
  71                 len = _SIZEOF_ADDR_IFREQ1(ifr);
  72                 if (ifc.ifc_len < len)
  73                         err(2, "invalid ifc.ifc_len");
  74
  75                 if (ifr->ifr_addr.sa_family == AF_UNSPEC) {
  76                         printf("%s: no address\n", ifr->ifr_name);
  77                 } else if (ifr->ifr_addr.sa_family == AF_INET ||
  78                     ifr->ifr_addr.sa_family == AF_INET6) {
  79                         char addr_str[INET6_ADDRSTRLEN];
  80                         const void *src;
  81                         const char *ret;
  82
  83                         if (ifr->ifr_addr.sa_family == AF_INET) {
  84                                 const struct sockaddr_in *in =
  85                                     (const struct sockaddr_in *)&ifr->ifr_addr;
  86                                 src = &in->sin_addr;
  87                         } else {
  88                                 const struct sockaddr_in6 *in6 =
  89                                     (const struct sockaddr_in6 *)&ifr->ifr_addr;
  90                                 src = &in6->sin6_addr;
  91                         }
  92
  93                         ret = inet_ntop(ifr->ifr_addr.sa_family, src,
  94                             addr_str, sizeof(addr_str));
  95                         if (ret == NULL)
  96                                 err(2, "inet_ntop failed");
  97                         printf("%s: inet%c %s\n", ifr->ifr_name,
  98                             ifr->ifr_addr.sa_family == AF_INET ? '4' : '6',
  99                             ret);
 100                 } else if (ifr->ifr_addr.sa_family == AF_LINK) {
 101                         const struct sockaddr_dl *dl =
 102                             (const struct sockaddr_dl *)&ifr->ifr_addr;
 103
 104                         printf("%s: link%d\n", ifr->ifr_name, dl->sdl_index);
 105                 } else {
 106                         printf("%s: unknown family %d\n", ifr->ifr_name,
 107                             ifr->ifr_addr.sa_family);
 108                 }
 109
 110                 ifc.ifc_len -= len;
 111                 pos += len;
 112         }
 113         if (ifc.ifc_len != 0)
 114                 printf("ifc_len left %d\n", ifc.ifc_len);
 115
 116         exit(0);
 117 }