/*      $NetBSD: config.c,v 1.6 1995/12/10 10:06:58 mycroft Exp $       */

/*
 * 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.
 */

#include "defs.h"
#include <net/if.h>
#include <ifaddrs.h>


/*
 * 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) == -1)
        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;

        addr = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr;

        /*
         * 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, 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) {
                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, 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;
        }
    }

    freeifaddrs(ifap);
}