/* * 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. * * * config.c,v 3.8.4.10 1998/01/06 01:57:41 fenner Exp */ #ifndef lint static const char rcsid[] = "$Id: config.c,v 1.12 1998/06/09 05:01:29 imp Exp $"; #endif /* not lint */ #include "defs.h" struct ifconf ifc; /* * 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 *ifrp, *ifend; register struct uvif *v; register vifi_t vifi; int n; u_int32 addr, mask, subnet; short flags; int num_ifreq = 32; ifc.ifc_len = num_ifreq * sizeof(struct ifreq); ifc.ifc_buf = malloc(ifc.ifc_len); while (ifc.ifc_buf) { if (ioctl(udp_socket, SIOCGIFCONF, (char *)&ifc) < 0) log(LOG_ERR, errno, "ioctl SIOCGIFCONF"); /* * If the buffer was large enough to hold all the addresses * then break out, otherwise increase the buffer size and * try again. * * The only way to know that we definitely had enough space * is to know that there was enough space for at least one * more struct ifreq. ??? */ if ((num_ifreq * sizeof(struct ifreq)) >= ifc.ifc_len + sizeof(struct ifreq)) break; num_ifreq *= 2; ifc.ifc_len = num_ifreq * sizeof(struct ifreq); ifc.ifc_buf = realloc(ifc.ifc_buf, ifc.ifc_len); } if (ifc.ifc_buf == NULL) log(LOG_ERR, 0, "config_vifs_from_kernel: ran out of memory"); ifrp = (struct ifreq *)ifc.ifc_buf; ifend = (struct ifreq *)(ifc.ifc_buf + ifc.ifc_len); /* * Loop through all of the interfaces. */ for (; ifrp < ifend; ifrp = (struct ifreq *)((char *)ifrp + n)) { struct ifreq ifr; #ifdef HAVE_SA_LEN 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 (strcmp(v->uv_name, ifr.ifr_name) == 0) { log(LOG_DEBUG, 0, "skipping %s (%s on subnet %s) (alias for vif#%u?)", v->uv_name, inet_fmt(addr, s1), inet_fmts(subnet, mask, s2), vifi); break; } 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]; zero_vif(v, 0); v->uv_lcl_addr = addr; v->uv_subnet = subnet; v->uv_subnetmask = mask; v->uv_subnetbcast = subnet | ~mask; strncpy(v->uv_name, ifr.ifr_name, IFNAMSIZ); v->uv_name[IFNAMSIZ-1] = '\0'; if (flags & IFF_POINTOPOINT) v->uv_flags |= VIFF_REXMIT_PRUNES; 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; } } }