/*
* 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.
*/
/*
* Query the kernel to find network interfaces that are multicast-capable
* and install them in the uvifs array.
*/
void
config_vifs_from_kernel(void)
{
struct ifaddrs *ifa, *ifap;
struct uvif *v;
vifi_t vifi;
u_int32_t addr, mask, subnet;
short flags;
if (getifaddrs(&ifap) < 0)
logit(LOG_ERR, errno, "getifaddrs");
for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
/*
* Ignore any interface for an address family other than IP.
*/
if (ifa->ifa_addr->sa_family != AF_INET)
continue;
/*
* Ignore loopback interfaces and interfaces that do not support
* multicast.
*/
flags = ifa->ifa_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}.
*/
mask = ((struct sockaddr_in *)ifa->ifa_netmask)->sin_addr.s_addr;
subnet = addr & mask;
if (!inet_valid_subnet(subnet, mask) ||
addr == subnet ||
addr == (subnet | ~mask)) {
logit(LOG_WARNING, 0,
"ignoring %s, has invalid address (%s) and/or mask (%s)",
ifa->ifa_name, inet_fmt(addr),
inet_fmt(mask));
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) {
logit(LOG_WARNING, 0, "ignoring %s, same subnet as %s",
ifa->ifa_name, v->uv_name);
break;
}
}
if (vifi != numvifs)
continue;
/*
* If there is room in the uvifs array, install this interface.
*/
if (numvifs == MAXVIFS) {
logit(LOG_WARNING, 0, "too many vifs, ignoring %s", ifa->ifa_name);
continue;
}
v = &uvifs[numvifs];
v->uv_flags = 0;
v->uv_metric = DEFAULT_METRIC;
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;
strlcpy(v->uv_name, ifa->ifa_name, sizeof(v->uv_name));
v->uv_groups = NULL;
v->uv_neighbors = NULL;
v->uv_acl = NULL;
v->uv_addrs = NULL;
logit(LOG_INFO,0,"installing %s (%s on subnet %s) as vif #%u - rate=%d",
v->uv_name, inet_fmt(addr),
inet_fmts(subnet, mask),
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;
}
}
