/* * The mrouted program is covered by the license in the accompanying file * named "LICENSE". Use of the mrouted program represents acceptance of * the terms and conditions listed in that file. * * The mrouted program is COPYRIGHT 1989 by The Board of Trustees of * Leland Stanford Junior University. * * * $Id: config.c,v 3.8.1.1 1996/08/09 22:46:16 fenner Exp $ */ #include "defs.h" /* * Query the kernel to find network interfaces that are multicast-capable * and install them in the uvifs array. */ void config_vifs_from_kernel() { struct ifreq ifbuf[32]; struct ifreq *ifrp, *ifend; struct ifconf ifc; register struct uvif *v; register vifi_t vifi; int n; u_int32 addr, mask, subnet; short flags; ifc.ifc_buf = (char *)ifbuf; ifc.ifc_len = sizeof(ifbuf); if (ioctl(udp_socket, SIOCGIFCONF, (char *)&ifc) < 0) log(LOG_ERR, errno, "ioctl SIOCGIFCONF"); ifrp = (struct ifreq *)ifbuf; ifend = (struct ifreq *)((char *)ifbuf + ifc.ifc_len); /* * Loop through all of the interfaces. */ for (; ifrp < ifend; ifrp = (struct ifreq *)((char *)ifrp + n)) { struct ifreq ifr; #if BSD >= 199006 n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name); if (n < sizeof(*ifrp)) n = sizeof(*ifrp); #else n = sizeof(*ifrp); #endif /* * Ignore any interface for an address family other than IP. */ if (ifrp->ifr_addr.sa_family != AF_INET) continue; addr = ((struct sockaddr_in *)&ifrp->ifr_addr)->sin_addr.s_addr; /* * Need a template to preserve address info that is * used below to locate the next entry. (Otherwise, * SIOCGIFFLAGS stomps over it because the requests * are returned in a union.) */ bcopy(ifrp->ifr_name, ifr.ifr_name, sizeof(ifr.ifr_name)); /* * Ignore loopback interfaces and interfaces that do not support * multicast. */ if (ioctl(udp_socket, SIOCGIFFLAGS, (char *)&ifr) < 0) log(LOG_ERR, errno, "ioctl SIOCGIFFLAGS for %s", ifr.ifr_name); flags = ifr.ifr_flags; if ((flags & (IFF_LOOPBACK|IFF_MULTICAST)) != IFF_MULTICAST) continue; /* * Ignore any interface whose address and mask do not define a * valid subnet number, or whose address is of the form {subnet,0} * or {subnet,-1}. */ if (ioctl(udp_socket, SIOCGIFNETMASK, (char *)&ifr) < 0) log(LOG_ERR, errno, "ioctl SIOCGIFNETMASK for %s", ifr.ifr_name); mask = ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr.s_addr; subnet = addr & mask; if (!inet_valid_subnet(subnet, mask) || addr == subnet || addr == (subnet | ~mask)) { log(LOG_WARNING, 0, "ignoring %s, has invalid address (%s) and/or mask (%s)", ifr.ifr_name, inet_fmt(addr, s1), inet_fmt(mask, s2)); continue; } /* * Ignore any interface that is connected to the same subnet as * one already installed in the uvifs array. */ for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) { if ((addr & v->uv_subnetmask) == v->uv_subnet || (v->uv_subnet & mask) == subnet) { log(LOG_WARNING, 0, "ignoring %s, same subnet as %s", ifr.ifr_name, v->uv_name); break; } } if (vifi != numvifs) continue; /* * If there is room in the uvifs array, install this interface. */ if (numvifs == MAXVIFS) { log(LOG_WARNING, 0, "too many vifs, ignoring %s", ifr.ifr_name); continue; } v = &uvifs[numvifs]; v->uv_flags = 0; v->uv_metric = DEFAULT_METRIC; v->uv_admetric = 0; v->uv_rate_limit = DEFAULT_PHY_RATE_LIMIT; v->uv_threshold = DEFAULT_THRESHOLD; v->uv_lcl_addr = addr; v->uv_rmt_addr = 0; v->uv_subnet = subnet; v->uv_subnetmask = mask; v->uv_subnetbcast = subnet | ~mask; strncpy(v->uv_name, ifr.ifr_name, IFNAMSIZ); v->uv_groups = NULL; v->uv_neighbors = NULL; v->uv_acl = NULL; v->uv_addrs = NULL; log(LOG_INFO,0,"installing %s (%s on subnet %s) as vif #%u - rate=%d", v->uv_name, inet_fmt(addr, s1), inet_fmts(subnet, mask, s2), numvifs, v->uv_rate_limit); ++numvifs; /* * If the interface is not yet up, set the vifs_down flag to * remind us to check again later. */ if (!(flags & IFF_UP)) { v->uv_flags |= VIFF_DOWN; vifs_down = TRUE; } } }