usr.sbin/mrouted/config.c

   1 /*      $NetBSD: config.c,v 1.12 2003/05/16 18:10:38 itojun Exp $       */
   2
   3 /*
   4  * The mrouted program is covered by the license in the accompanying file
   5  * named "LICENSE".  Use of the mrouted program represents acceptance of
   6  * the terms and conditions listed in that file.
   7  *
   8  * The mrouted program is COPYRIGHT 1989 by The Board of Trustees of
   9  * Leland Stanford Junior University.
  10  */
  11
  12 #include "defs.h"
  13 #include <net/if.h>
  14 #include <ifaddrs.h>
  15
  16
  17 /*
  18  * Query the kernel to find network interfaces that are multicast-capable
  19  * and install them in the uvifs array.
  20  */
  21 void
  22 config_vifs_from_kernel(void)
  23 {
  24     struct ifaddrs *ifa, *ifap;
  25     struct uvif *v;
  26     vifi_t vifi;
  27     u_int32_t addr, mask, subnet;
  28     short flags;
  29
  30     if (getifaddrs(&ifap) < 0)
  31         logit(LOG_ERR, errno, "getifaddrs");
  32
  33     for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
  34         /*
  35          * Ignore any interface for an address family other than IP.
  36          */
  37         if (ifa->ifa_addr->sa_family != AF_INET)
  38             continue;
  39
  40         addr = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr;
  41
  42         /*
  43          * Ignore loopback interfaces and interfaces that do not support
  44          * multicast.
  45          */
  46         flags = ifa->ifa_flags;
  47         if ((flags & (IFF_LOOPBACK|IFF_MULTICAST)) != IFF_MULTICAST)
  48             continue;
  49
  50         /*
  51          * Ignore any interface whose address and mask do not define a
  52          * valid subnet number, or whose address is of the form {subnet,0}
  53          * or {subnet,-1}.
  54          */
  55         mask = ((struct sockaddr_in *)ifa->ifa_netmask)->sin_addr.s_addr;
  56         subnet = addr & mask;
  57         if (!inet_valid_subnet(subnet, mask) ||
  58             addr == subnet ||
  59             addr == (subnet | ~mask)) {
  60             logit(LOG_WARNING, 0,
  61                 "ignoring %s, has invalid address (%s) and/or mask (%s)",
  62                 ifa->ifa_name, inet_fmt(addr),
  63                 inet_fmt(mask));
  64             continue;
  65         }
  66
  67         /*
  68          * Ignore any interface that is connected to the same subnet as
  69          * one already installed in the uvifs array.
  70          */
  71         for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
  72             if ((addr & v->uv_subnetmask) == v->uv_subnet ||
  73                 (v->uv_subnet & mask) == subnet) {
  74                 logit(LOG_WARNING, 0, "ignoring %s, same subnet as %s",
  75                     ifa->ifa_name, v->uv_name);
  76                 break;
  77             }
  78         }
  79         if (vifi != numvifs)
  80             continue;
  81
  82         /*
  83          * If there is room in the uvifs array, install this interface.
  84          */
  85         if (numvifs == MAXVIFS) {
  86             logit(LOG_WARNING, 0, "too many vifs, ignoring %s", ifa->ifa_name);
  87             continue;
  88         }
  89         v  = &uvifs[numvifs];
  90         v->uv_flags       = 0;
  91         v->uv_metric      = DEFAULT_METRIC;
  92         v->uv_rate_limit  = DEFAULT_PHY_RATE_LIMIT;
  93         v->uv_threshold   = DEFAULT_THRESHOLD;
  94         v->uv_lcl_addr    = addr;
  95         v->uv_rmt_addr    = 0;
  96         v->uv_subnet      = subnet;
  97         v->uv_subnetmask  = mask;
  98         v->uv_subnetbcast = subnet | ~mask;
  99         strlcpy(v->uv_name, ifa->ifa_name, sizeof(v->uv_name));
 100         v->uv_groups      = NULL;
 101         v->uv_neighbors   = NULL;
 102         v->uv_acl         = NULL;
 103         v->uv_addrs       = NULL;
 104
 105         logit(LOG_INFO,0,"installing %s (%s on subnet %s) as vif #%u - rate=%d",
 106             v->uv_name, inet_fmt(addr),
 107             inet_fmts(subnet, mask),
 108             numvifs, v->uv_rate_limit);
 109
 110         ++numvifs;
 111
 112         /*
 113          * If the interface is not yet up, set the vifs_down flag to
 114          * remind us to check again later.
 115          */
 116         if (!(flags & IFF_UP)) {
 117             v->uv_flags |= VIFF_DOWN;
 118             vifs_down = TRUE;
 119         }
 120     }
 121
 122     freeifaddrs(ifap);
 123 }