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/*
* 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
*/
#include "defs.h"
#ifndef lint
static char rcsid[] = "@(#) $Id: \
config.c,v 3.8.4.10 1998/01/06 01:57:41 fenner Exp $";
#endif
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);
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;
}
}
}
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