/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 1983, 1988, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgment:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD: src/sbin/routed/output.c,v 1.7 2000/08/11 08:24:38 sheldonh Exp $
 */

#include "defs.h"
#include <md5.h>
#include <alloca.h>

uint_t update_seqno;


/*
 * walk the tree of routes with this for output
 */
static  struct {
        struct sockaddr_in to;
        in_addr_t       to_mask;
        in_addr_t       to_net;
        in_addr_t       to_std_mask;
        in_addr_t       to_std_net;
        struct interface *ifp;          /* usually output interface */
        struct auth     *a;
        uint8_t         metric;         /* adjust metrics by interface */
        uint32_t        npackets;
        uint32_t        gen_limit;
#define WS_GEN_LIMIT_MAX        1024
        uint16_t        state;
#define WS_ST_FLASH     0x001   /* send only changed routes */
#define WS_ST_RIP2_ALL  0x002   /* send full featured RIPv2 */
#define WS_ST_AG        0x004   /* ok to aggregate subnets */
#define WS_ST_SUPER_AG  0x008   /* ok to aggregate networks */
#define WS_ST_QUERY     0x010   /* responding to a query */
#define WS_ST_TO_ON_NET 0x020   /* sending onto one of our nets */
#define WS_ST_DEFAULT   0x040   /* faking a default */
} ws;

/* A buffer for what can be heard by both RIPv1 and RIPv2 listeners */
struct ws_buf v12buf;
static  union pkt_buf ripv12_buf;

/* Another for only RIPv2 listeners */
static  struct ws_buf v2buf;
static  union pkt_buf rip_v2_buf;



void
bufinit(void)
{
        ripv12_buf.rip.rip_cmd = RIPCMD_RESPONSE;
        v12buf.buf = &ripv12_buf.rip;
        v12buf.base = &v12buf.buf->rip_nets[0];

        rip_v2_buf.rip.rip_cmd = RIPCMD_RESPONSE;
        rip_v2_buf.rip.rip_vers = RIPv2;
        v2buf.buf = &rip_v2_buf.rip;
        v2buf.base = &v2buf.buf->rip_nets[0];
}


/*
 * Send the contents of the global buffer via the non-multicast socket
 */
int                                     /* <0 on failure */
output(enum output_type type,
    struct sockaddr_in *dst,            /* send to here */
    struct interface *ifp,
    struct rip *buf,
    int size)                   /* this many bytes */
{
        struct sockaddr_in sin;
        int flags;
        const char *msg;
        int res;
        int ifindex;
        struct in_addr addr;

        sin = *dst;
        if (sin.sin_port == 0)
                sin.sin_port = htons(RIP_PORT);

        flags = 0;

        if (ifp == NULL && type == OUT_MULTICAST) {
                msglog("Cannot send RIP message to %s",
                    inet_ntoa(sin.sin_addr));
                return (-1);
        }

        switch (type) {
        case OUT_QUERY:
                msg = "Answer Query";
                break;
        case OUT_UNICAST:
                msg = "Send";
                flags = MSG_DONTROUTE;
                break;
        case OUT_BROADCAST:
                msg = "Send bcast";
                break;
        case OUT_MULTICAST:
                msg = "Send mcast";
                break;

        case NO_OUT_MULTICAST:
        case NO_OUT_RIPV2:
        default:
#ifdef DEBUG
                abort();
#endif
                return (-1);
        }

        /*
         * IP_PKTINFO overrides IP_MULTICAST_IF, so we don't set ifindex
         * for multicast traffic.
         */
        ifindex = (type != OUT_MULTICAST && type != OUT_QUERY &&
            ifp != NULL && ifp->int_phys != NULL) ?
            ifp->int_phys->phyi_index : 0;

        if (rip_sock_interface != ifp) {
                /*
                 * For multicast, we have to choose the source
                 * address.  This is either the local address
                 * (non-point-to-point) or the remote address.
                 */
                if (ifp != NULL) {
                        addr.s_addr = (ifp->int_if_flags & IFF_POINTOPOINT) ?
                            ifp->int_dstaddr : ifp->int_addr;
                        if (type == OUT_MULTICAST &&
                            setsockopt(rip_sock, IPPROTO_IP,
                            IP_MULTICAST_IF, &addr, sizeof (addr)) == -1) {
                                LOGERR("setsockopt(rip_sock, IP_MULTICAST_IF)");
                                return (-1);
                        }
                }
                rip_sock_interface = ifp;
        }

        trace_rip(msg, "to", &sin, ifp, buf, size);

        res = sendtoif(rip_sock, buf, size, flags, &sin, ifindex);
        if (res < 0 && (ifp == NULL || !(ifp->int_state & IS_BROKE))) {
                writelog(LOG_WARNING, "%s sendto(%s%s%s.%d): %s", msg,
                    ifp != NULL ? ifp->int_name : "",
                    ifp != NULL ? ", " : "",
                    inet_ntoa(sin.sin_addr),
                    ntohs(sin.sin_port),
                    rip_strerror(errno));
        }

        return (res);
}

/*
 * Semantically identical to sendto(), but sends the message through a
 * specific interface (if ifindex is non-zero) using IP_PKTINFO.
 */
int
sendtoif(int fd, const void *buf, uint_t bufsize, uint_t flags,
    struct sockaddr_in *sinp, uint_t ifindex)
{
        struct iovec iov;
        struct msghdr msg;
        struct cmsghdr *cmsgp;
        struct in_pktinfo *ipip;

        iov.iov_base = (void *)buf;
        iov.iov_len = bufsize;

        (void) memset(&msg, 0, sizeof (struct msghdr));
        msg.msg_name = (struct sockaddr *)sinp;
        msg.msg_namelen = sizeof (struct sockaddr_in);
        msg.msg_iov = &iov;
        msg.msg_iovlen = 1;

        if (ifindex != 0) {
                /*
                 * We can't precisely predict the alignment padding we'll
                 * need, so we allocate the maximum alignment and then
                 * use CMSG_NXTHDR() to fix it up at the end.
                 */
                msg.msg_controllen = sizeof (*cmsgp) + _MAX_ALIGNMENT +
                    sizeof (*ipip) + _MAX_ALIGNMENT + sizeof (*cmsgp);
                msg.msg_control = alloca(msg.msg_controllen);

                cmsgp = CMSG_FIRSTHDR(&msg);
                ipip = (void *)CMSG_DATA(cmsgp);
                (void) memset(ipip, 0, sizeof (struct in_pktinfo));
                ipip->ipi_ifindex = ifindex;
                cmsgp->cmsg_len = (caddr_t)(ipip + 1) - (caddr_t)cmsgp;
                cmsgp->cmsg_type = IP_PKTINFO;
                cmsgp->cmsg_level = IPPROTO_IP;

                /*
                 * Correct the control message length.
                 */
                cmsgp = CMSG_NXTHDR(&msg, cmsgp);
                msg.msg_controllen = (caddr_t)cmsgp - (caddr_t)msg.msg_control;
        }

        return (sendmsg(fd, &msg, flags));
}

/*
 * Find the first key for a packet to send.
 * Try for a key that is eligible and has not expired, but settle for
 * the last key if they have all expired.
 * If no key is ready yet, give up.
 */
struct auth *
find_auth(struct interface *ifp)
{
        struct auth *ap, *res = NULL;
        int i;


        if (ifp == NULL)
                return (NULL);

        if ((ap = ifp->int_auth) == NULL)
                return (NULL);

        for (i = 0; i < MAX_AUTH_KEYS; i++, ap++) {
                /* stop looking after the last key */
                if (ap->type == RIP_AUTH_NONE)
                        break;

                /* ignore keys that are not ready yet */
                if ((ulong_t)ap->start > (ulong_t)clk.tv_sec)
                        continue;

                if ((ulong_t)ap->end < (ulong_t)clk.tv_sec) {
                        /* note best expired password as a fall-back */
                        if (res == NULL ||
                            (((ulong_t)ap->end > (ulong_t)res->end)) &&
                            ((ulong_t)res->end < (ulong_t)clk.tv_sec))
                                res = ap;
                        continue;
                }

                /* note key with the best future */
                if (res == NULL || (ulong_t)res->end < (ulong_t)ap->end)
                        res = ap;
        }
        return (res);
}


void
clr_ws_buf(struct ws_buf *wb, struct auth *ap)
{
        struct netauth *na;

        wb->lim = wb->base + NETS_LEN;
        wb->n = wb->base;
        (void) memset(wb->n, 0, NETS_LEN*sizeof (*wb->n));

        /*
         * (start to) install authentication if appropriate
         */
        if (ap == NULL)
                return;

        na = (struct netauth *)wb->n;
        if (ap->type == RIP_AUTH_PW) {
                na->a_family = RIP_AF_AUTH;
                na->a_type = RIP_AUTH_PW;
                (void) memcpy(na->au.au_pw, ap->key, sizeof (na->au.au_pw));
                wb->n++;

        } else if (ap->type ==  RIP_AUTH_MD5) {
                na->a_family = RIP_AF_AUTH;
                na->a_type = RIP_AUTH_MD5;
                na->au.a_md5.md5_keyid = ap->keyid;
                na->au.a_md5.md5_auth_len = RIP_AUTH_MD5_LEN;
                na->au.a_md5.md5_seqno = htonl(clk.tv_sec);
                wb->n++;
                wb->lim--;              /* make room for trailer */
        }
}


void
end_md5_auth(struct ws_buf *wb, struct auth *ap)
{
        struct netauth *na, *na2;
        MD5_CTX md5_ctx;
        int len;

        na = (struct netauth *)wb->base;
        na2 = (struct netauth *)wb->n;
        len = (char *)na2-(char *)wb->buf;
        na2->a_family = RIP_AF_AUTH;
        na2->a_type = RIP_AUTH_TRAILER;
        na->au.a_md5.md5_pkt_len = htons(len);
        MD5Init(&md5_ctx);
        /* len+4 to include auth trailer's family/type in MD5 sum */
        MD5Update(&md5_ctx, (uchar_t *)wb->buf, len + 4);
        MD5Update(&md5_ctx, ap->key, RIP_AUTH_MD5_LEN);
        MD5Final(na2->au.au_pw, &md5_ctx);
        wb->n++;
}


/*
 * Send the buffer
 */
static void
supply_write(struct ws_buf *wb)
{
        /*
         * Output multicast only if legal.
         * If we would multicast and it would be illegal, then discard the
         * packet.
         */
        switch (wb->type) {
        case NO_OUT_MULTICAST:
                trace_pkt("skip multicast to %s because impossible",
                    naddr_ntoa(ws.to.sin_addr.s_addr));
                break;
        case NO_OUT_RIPV2:
                break;
        default:
                if (ws.a != NULL && ws.a->type == RIP_AUTH_MD5)
                        end_md5_auth(wb, ws.a);
                if (output(wb->type, &ws.to, ws.ifp, wb->buf,
                    ((char *)wb->n - (char *)wb->buf)) < 0 && ws.ifp != NULL)
                        if_sick(ws.ifp, _B_FALSE);
                ws.npackets++;
                break;
        }

        clr_ws_buf(wb, ws.a);
}


/*
 * Put an entry into the packet
 */
static void
supply_out(struct ag_info *ag)
{
        uint32_t dstcount;
        in_addr_t mask, v1_mask, dst_h, ddst_h = 0;
        struct ws_buf *wb;


        /*
         * Skip this route if doing a flash update and it and the routes
         * it aggregates have not changed recently.
         */
        if (ag->ag_seqno < update_seqno && (ws.state & WS_ST_FLASH))
                return;

        dst_h = ag->ag_dst_h;
        mask = ag->ag_mask;
        v1_mask = ripv1_mask_host(htonl(dst_h),
            (ws.state & WS_ST_TO_ON_NET) ? ws.ifp : NULL);
        dstcount = 0;

        /*
         * If we are sending RIPv2 packets that cannot (or must not) be
         * heard by RIPv1 listeners, do not worry about sub- or supernets.
         * Subnets (from other networks) can only be sent via multicast.
         * A pair of subnet routes might have been promoted so that they
         * are legal to send by RIPv1.
         * If RIPv1 is off, use the multicast buffer.
         */
        if ((ws.state & WS_ST_RIP2_ALL) ||
            ((ag->ag_state & AGS_RIPV2) && v1_mask != mask)) {
                /* use the RIPv2-only buffer */
                wb = &v2buf;

        } else {
                /*
                 * use the RIPv1-or-RIPv2 buffer
                 */
                wb = &v12buf;

                /*
                 * Convert supernet route into corresponding set of network
                 * routes for RIPv1, but leave non-contiguous netmasks
                 * to ag_check().
                 */
                if (v1_mask > mask &&
                    mask + (mask & -mask) == 0) {
                        ddst_h = v1_mask & -v1_mask;
                        dstcount = (v1_mask & ~mask)/ddst_h;

                        if (dstcount > ws.gen_limit) {
                                /*
                                 * Punt if we would have to generate an
                                 * unreasonable number of routes.
                                 */
                                if (TRACECONTENTS)
                                        trace_misc("sending %s-->%s as 1"
                                            " instead of %d routes",
                                            addrname(htonl(dst_h), mask, 1),
                                            naddr_ntoa(ws.to.sin_addr.s_addr),
                                            dstcount + 1);
                                dstcount = 0;

                        } else {
                                mask = v1_mask;
                                ws.gen_limit -= dstcount;
                        }
                }
        }

        do {
                wb->n->n_family = RIP_AF_INET;
                wb->n->n_dst = htonl(dst_h);
                /*
                 * If the route is from router-discovery or we are
                 * shutting down, or this is a broken/sick interface,
                 * admit only a bad metric.
                 */
                wb->n->n_metric = ((stopint || ag->ag_metric < 1 ||
                    (ag->ag_ifp && (ag->ag_ifp->int_state &
                    (IS_BROKE|IS_SICK)))) ? HOPCNT_INFINITY : ag->ag_metric);
                wb->n->n_metric = htonl(wb->n->n_metric);
                /*
                 * Any non-zero bits in the supposedly unused RIPv1 fields
                 * cause the old `routed` to ignore the route.
                 * That means the mask and so forth cannot be sent
                 * in the hybrid RIPv1/RIPv2 mode.
                 */
                if (ws.state & WS_ST_RIP2_ALL) {
                        if (ag->ag_nhop != 0 &&
                            ((ws.state & WS_ST_QUERY) ||
                            (ag->ag_nhop != ws.ifp->int_addr &&
                            on_net(ag->ag_nhop, ws.ifp->int_net,
                            ws.ifp->int_mask)) &&
                            ifwithaddr(ag->ag_nhop, _B_FALSE, _B_FALSE) ==
                            NULL))
                                wb->n->n_nhop = ag->ag_nhop;
                        wb->n->n_mask = htonl(mask);
                        wb->n->n_tag = ag->ag_tag;
                }
                dst_h += ddst_h;

                if (++wb->n >= wb->lim)
                        supply_write(wb);
        } while (dstcount-- > 0);
}


/*
 * Supply one route from the table
 */
/* ARGSUSED */
static int
walk_supply(struct radix_node *rn, void *argp)
{
#define RT ((struct rt_entry *)rn)
        ushort_t ags;
        uint8_t metric, pref;
        in_addr_t dst, nhop;
        struct rt_spare *rts;
        uint_t sparecount;


        /*
         * Do not advertise external remote interfaces or passive interfaces.
         */
        if ((RT->rt_state & RS_IF) && RT->rt_ifp != NULL &&
            (RT->rt_ifp->int_state & IS_PASSIVE) &&
            !(RT->rt_state & RS_MHOME))
                return (0);
        /*
         * Do not advertise routes learnt from /etc/gateways.
         */
        if (RT->rt_spares[0].rts_origin == RO_FILE)
                return (0);

        /*
         * Do not advertise routes which would lead to forwarding on a
         * non-forwarding interface.
         */
        if (RT->rt_state & RS_NOPROPAGATE)
                return (0);

        /*
         * If being quiet about our ability to forward, then
         * do not say anything unless responding to a query,
         * except about our main interface.
         */
        if (!should_supply(NULL) && !(ws.state & WS_ST_QUERY) &&
            !(RT->rt_state & RS_MHOME))
                return (0);

        dst = RT->rt_dst;

        /*
         * do not collide with the fake default route
         */
        if (dst == RIP_DEFAULT && (ws.state & WS_ST_DEFAULT))
                return (0);

        if (RT->rt_state & RS_NET_SYN) {
                if (RT->rt_state & RS_NET_INT) {
                        /*
                         * Do not send manual synthetic network routes
                         * into the subnet.
                         */
                        if (on_net(ws.to.sin_addr.s_addr,
                            ntohl(dst), RT->rt_mask))
                                return (0);

                } else {
                        /*
                         * Do not send automatic synthetic network routes
                         * if they are not needed because no RIPv1 listeners
                         * can hear them.
                         */
                        if (ws.state & WS_ST_RIP2_ALL)
                                return (0);

                        /*
                         * Do not send automatic synthetic network routes to
                         * the real subnet.
                         */
                        if (on_net(ws.to.sin_addr.s_addr,
                            ntohl(dst), RT->rt_mask))
                                return (0);
                }
                nhop = 0;

        } else {
                /*
                 * Advertise the next hop if this is not a route for one
                 * of our interfaces and the next hop is on the same
                 * network as the target.
                 * The final determination is made by supply_out().
                 */
                if (!(RT->rt_state & RS_IF) && !(RT->rt_state & RS_MHOME) &&
                    RT->rt_gate != loopaddr)
                        nhop = RT->rt_gate;
                else
                        nhop = 0;
        }

        metric = RT->rt_metric;
        ags = 0;

        if (!RT_ISHOST(RT)) {
                /*
                 * Always suppress network routes into other, existing
                 * network routes
                 */
                ags |= AGS_SUPPRESS;

                /*
                 * Generate supernets if allowed.
                 * If we can be heard by RIPv1 systems, we will
                 * later convert back to ordinary nets.
                 * This unifies dealing with received supernets.
                 */
                if ((ws.state & WS_ST_AG) && ((RT->rt_state & RS_SUBNET) ||
                    (ws.state & WS_ST_SUPER_AG)))
                        ags |= AGS_AGGREGATE;
        } else if (!(RT->rt_state & RS_MHOME)) {
                /*
                 * We should always suppress (into existing network routes)
                 * the host routes for the local end of our point-to-point
                 * links.
                 * If we are suppressing host routes in general, then do so.
                 * Avoid advertising host routes onto their own network,
                 * where they should be handled by proxy-ARP.
                 */
                if ((RT->rt_state & RS_LOCAL) || ridhosts ||
                    on_net(dst, ws.to_net, ws.to_mask))
                        ags |= AGS_SUPPRESS;

                /*
                 * Aggregate stray host routes into network routes if allowed.
                 * We cannot aggregate host routes into small network routes
                 * without confusing RIPv1 listeners into thinking the
                 * network routes are host routes.
                 */
                if ((ws.state & WS_ST_AG) && (ws.state & WS_ST_RIP2_ALL))
                        ags |= AGS_AGGREGATE;
        }

        /*
         * Do not send RIPv1 advertisements of subnets to other
         * networks. If possible, multicast them by RIPv2.
         */
        if ((RT->rt_state & RS_SUBNET) && !(ws.state & WS_ST_RIP2_ALL) &&
            !on_net(dst, ws.to_std_net, ws.to_std_mask))
                ags |= AGS_RIPV2 | AGS_AGGREGATE;


        /*
         * Do not send a route back to where it came from, except in
         * response to a query.  This is "split-horizon".  That means not
         * advertising back to the same network and so via the same interface.
         *
         * We want to suppress routes that might have been fragmented
         * from this route by a RIPv1 router and sent back to us, and so we
         * cannot forget this route here.  Let the split-horizon route
         * suppress the fragmented routes and then itself be forgotten.
         *
         * Include the routes for both ends of point-to-point interfaces
         * among those suppressed by split-horizon, since the other side
         * should knows them as well as we do.
         *
         * Notice spare routes with the same metric that we are about to
         * advertise, to split the horizon on redundant, inactive paths.
         */
        if (ws.ifp != NULL && !(ws.state & WS_ST_QUERY) &&
            (ws.state & WS_ST_TO_ON_NET) && (!(RT->rt_state & RS_IF) ||
            (ws.ifp->int_if_flags & IFF_POINTOPOINT))) {
                for (rts = RT->rt_spares, sparecount = 0;
                    sparecount < RT->rt_num_spares; sparecount++, rts++) {
                        if (rts->rts_metric > metric || rts->rts_ifp != ws.ifp)
                                continue;

                        /*
                         * If we do not mark the route with AGS_SPLIT_HZ here,
                         * it will be poisoned-reverse, or advertised back
                         * toward its source with an infinite metric.
                         * If we have recently advertised the route with a
                         * better metric than we now have, then we should
                         * poison-reverse the route before suppressing it for
                         * split-horizon.
                         *
                         * In almost all cases, if there is no spare for the
                         * route then it is either old and dead or a brand
                         * new route. If it is brand new, there is no need
                         * for poison-reverse. If it is old and dead, it
                         * is already poisoned.
                         */
                        if (RT->rt_poison_time < now_expire ||
                            RT->rt_poison_metric >= metric ||
                            RT->rt_spares[1].rts_gate == 0) {
                                ags |= AGS_SPLIT_HZ;
                                ags &= ~AGS_SUPPRESS;
                        }
                        metric = HOPCNT_INFINITY;
                        break;
                }
        }

        /*
         * Keep track of the best metric with which the
         * route has been advertised recently.
         */
        if (RT->rt_poison_metric >= metric ||
            RT->rt_poison_time < now_expire) {
                RT->rt_poison_time = now.tv_sec;
                RT->rt_poison_metric = metric;
        }

        /*
         * Adjust the outgoing metric by the cost of the link.
         * Avoid aggregation when a route is counting to infinity.
         */
        pref = RT->rt_poison_metric + ws.metric;
        metric += ws.metric;

        /*
         * If this is a static route pointing to the same interface
         * upon which we are sending out the RIP RESPONSE
         * adjust the preference so that we don't aggregate into this
         * route. Note that the maximum possible hop count on a route
         * per RFC 2453 is 16 (HOPCNT_INFINITY)
         */
        if ((RT->rt_state & RS_STATIC) && (ws.ifp == RT->rt_ifp))
                pref = (HOPCNT_INFINITY+1);

        /*
         * Do not advertise stable routes that will be ignored,
         * unless we are answering a query.
         * If the route recently was advertised with a metric that
         * would have been less than infinity through this interface,
         * we need to continue to advertise it in order to poison it.
         */
        if (metric >= HOPCNT_INFINITY) {
                if (!(ws.state & WS_ST_QUERY) && (pref >= HOPCNT_INFINITY ||
                    RT->rt_poison_time < now_garbage))
                        return (0);

                metric = HOPCNT_INFINITY;
        }

        /*
         * supply this route out on the wire- we only care about dest/mask
         * and so can ignore all rt_spares[i] with i > 0
         */
        ag_check(dst, RT->rt_mask, 0, RT->rt_ifp, nhop, metric, pref,
            RT->rt_seqno, RT->rt_tag, ags, supply_out);
        return (0);
#undef RT
}


/*
 * Supply dst with the contents of the routing tables.
 * If this won't fit in one packet, chop it up into several.
 */
void
supply(struct sockaddr_in *dst,
    struct interface *ifp,      /* output interface */
    enum output_type type,
    int flash,                  /* 1=flash update */
    int vers,                   /* RIP version */
    boolean_t passwd_ok)        /* OK to include cleartext password */
{
        struct rt_entry *rt;
        uint8_t def_metric;


        ws.state = 0;
        ws.gen_limit = WS_GEN_LIMIT_MAX;

        ws.to = *dst;
        ws.to_std_mask = std_mask(ws.to.sin_addr.s_addr);
        ws.to_std_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_std_mask;

        if (ifp != NULL) {
                ws.to_mask = ifp->int_mask;
                ws.to_net = ifp->int_net;
                if (on_net(ws.to.sin_addr.s_addr, ws.to_net, ws.to_mask) ||
                    type == OUT_MULTICAST)
                        ws.state |= WS_ST_TO_ON_NET;

        } else {
                ws.to_mask = ripv1_mask_net(ws.to.sin_addr.s_addr, NULL);
                ws.to_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_mask;
                rt = rtfind(dst->sin_addr.s_addr);
                if (rt != NULL)
                        ifp = rt->rt_ifp;
                else
                        return;
        }

        ws.npackets = 0;
        if (flash)
                ws.state |= WS_ST_FLASH;

        ws.ifp = ifp;

        /*
         * Routes in the table were already adjusted by their respective
         * destination interface costs (which are zero by default) on
         * input.  The following is the value by which each route's metric
         * will be bumped up on output.
         */
        ws.metric = 1;

        ripv12_buf.rip.rip_vers = vers;

        switch (type) {
        case OUT_MULTICAST:
                if (ifp->int_if_flags & IFF_MULTICAST)
                        v2buf.type = OUT_MULTICAST;
                else
                        v2buf.type = NO_OUT_MULTICAST;
                v12buf.type = OUT_BROADCAST;
                break;

        case OUT_QUERY:
                ws.state |= WS_ST_QUERY;
                /* FALLTHROUGH */
        case OUT_BROADCAST:
        case OUT_UNICAST:
                v2buf.type = (vers == RIPv2) ? type : NO_OUT_RIPV2;
                v12buf.type = type;
                break;

        case NO_OUT_MULTICAST:
        case NO_OUT_RIPV2:
                return;                 /* no output */
        }

        if (vers == RIPv2) {
                /* full RIPv2 only if cannot be heard by RIPv1 listeners */
                if (type != OUT_BROADCAST)
                        ws.state |= WS_ST_RIP2_ALL;
                if ((ws.state & WS_ST_QUERY) || !(ws.state & WS_ST_TO_ON_NET)) {
                        ws.state |= (WS_ST_AG | WS_ST_SUPER_AG);
                } else if (ifp == NULL || !(ifp->int_state & IS_NO_AG)) {
                        ws.state |= WS_ST_AG;
                        if (type != OUT_BROADCAST && (ifp == NULL ||
                            !(ifp->int_state & IS_NO_SUPER_AG)))
                                ws.state |= WS_ST_SUPER_AG;
                }

                /* See if this packet needs authenticating */
                ws.a = find_auth(ifp);
                if (!passwd_ok && ws.a != NULL && ws.a->type == RIP_AUTH_PW)
                        ws.a = NULL;
                if (ws.a != NULL && (ulong_t)ws.a->end < (ulong_t)clk.tv_sec &&
                    !ws.a->warnedflag) {
                        /*
                         * If the best key is an expired one, we may as
                         * well use it.  Log this event.
                         */
                        writelog(LOG_WARNING,
                            "Using expired auth while transmitting to %s",
                            naddr_ntoa(ws.to.sin_addr.s_addr));
                        ws.a->warnedflag = 1;
                }
        } else {
                ws.a = NULL;
        }

        clr_ws_buf(&v12buf, ws.a);
        clr_ws_buf(&v2buf, ws.a);

        /*
         * Fake a default route if asked and if there is not already
         * a better, real default route.
         */
        if (should_supply(NULL) && (def_metric = ifp->int_d_metric) != 0) {
                if (NULL == (rt = rtget(RIP_DEFAULT, 0)) ||
                    rt->rt_metric+ws.metric >= def_metric) {
                        ws.state |= WS_ST_DEFAULT;
                        ag_check(0, 0, 0, NULL, 0, def_metric, def_metric,
                            0, 0, 0, supply_out);
                } else {
                        def_metric = rt->rt_metric+ws.metric;
                }

                /*
                 * If both RIPv2 and the poor-man's router discovery
                 * kludge are on, arrange to advertise an extra
                 * default route via RIPv1.
                 */
                if ((ws.state & WS_ST_RIP2_ALL) &&
                    (ifp->int_state & IS_PM_RDISC)) {
                        ripv12_buf.rip.rip_vers = RIPv1;
                        v12buf.n->n_family = RIP_AF_INET;
                        v12buf.n->n_dst = htonl(RIP_DEFAULT);
                        v12buf.n->n_metric = htonl(def_metric);
                        v12buf.n++;
                }
        }

        (void) rn_walktree(rhead, walk_supply, NULL);
        ag_flush(0, 0, supply_out);

        /*
         * Flush the packet buffers, provided they are not empty and
         * do not contain only the password.
         */
        if (v12buf.n != v12buf.base &&
            (v12buf.n > v12buf.base+1 ||
            v12buf.base->n_family != RIP_AF_AUTH))
                supply_write(&v12buf);
        if (v2buf.n != v2buf.base && (v2buf.n > v2buf.base+1 ||
            v2buf.base->n_family != RIP_AF_AUTH))
                supply_write(&v2buf);

        /*
         * If we sent nothing and this is an answer to a query, send
         * an empty buffer.
         */
        if (ws.npackets == 0 && (ws.state & WS_ST_QUERY)) {
                supply_write(&v2buf);
                if (ws.npackets == 0)
                        supply_write(&v12buf);
        }
}


/*
 * send all of the routing table or just do a flash update
 */
void
rip_bcast(int flash)
{
        static struct sockaddr_in dst = {AF_INET};
        struct interface *ifp;
        enum output_type type;
        int vers;
        struct timeval rtime;


        need_flash = _B_FALSE;
        intvl_random(&rtime, MIN_WAITTIME, MAX_WAITTIME);
        no_flash = rtime;
        timevaladd(&no_flash, &now);

        if (!rip_enabled)
                return;

        trace_act("send %s and inhibit dynamic updates for %.3f sec",
            flash ? "dynamic update" : "all routes",
            rtime.tv_sec + ((double)rtime.tv_usec)/1000000.0);

        for (ifp = ifnet; ifp != NULL; ifp = ifp->int_next) {
                /*
                 * Skip interfaces not doing RIP or for which IP
                 * forwarding isn't turned on.  Skip duplicate
                 * interfaces, we don't want to generate duplicate
                 * packets.  Do try broken interfaces to see if they
                 * have healed.
                 */
                if (IS_RIP_OUT_OFF(ifp->int_state) ||
                    (ifp->int_state & IS_DUP) ||
                    !IS_IFF_ROUTING(ifp->int_if_flags))
                        continue;

                /* skip turned off interfaces */
                if (!IS_IFF_UP(ifp->int_if_flags))
                        continue;

                /* skip interfaces we shouldn't use */
                if (IS_IFF_QUIET(ifp->int_if_flags))
                        continue;

                vers = (ifp->int_state & IS_NO_RIPV1_OUT) ? RIPv2 : RIPv1;
                dst.sin_addr.s_addr = ifp->int_ripout_addr;

                /*
                 * Ignore the interface if it's not broadcast,
                 * point-to-point, or remote.  It must be non-broadcast
                 * multiaccess, and therefore unsupported.
                 */
                if (!(ifp->int_if_flags & (IFF_BROADCAST | IFF_POINTOPOINT)) &&
                    !(ifp->int_state & IS_REMOTE))
                        continue;

                type = (ifp->int_if_flags & IFF_BROADCAST) ?
                    OUT_BROADCAST : OUT_UNICAST;
                if (vers == RIPv2 && (ifp->int_if_flags & IFF_MULTICAST) &&
                    !(ifp->int_state & IS_NO_RIP_MCAST))
                        type = OUT_MULTICAST;

                supply(&dst, ifp, type, flash, vers, _B_TRUE);
        }

        update_seqno++;                 /* all routes are up to date */
}


/*
 * Ask for routes
 * Do it only once to an interface, and not even after the interface
 * was broken and recovered.
 */
void
rip_query(void)
{
        static struct sockaddr_in dst = {AF_INET};
        struct interface *ifp;
        struct rip buf;
        enum output_type type;


        if (!rip_enabled)
                return;

        (void) memset(&buf, 0, sizeof (buf));

        for (ifp = ifnet; ifp; ifp = ifp->int_next) {
                /*
                 * Skip interfaces those already queried.  Do not ask
                 * via interfaces through which we don't accept input.
                 * Do not ask via interfaces that cannot send RIP
                 * packets.  Don't send queries on duplicate
                 * interfaces, that would generate duplicate packets
                 * on link.  Do try broken interfaces to see if they
                 * have healed.
                 */
                if (IS_RIP_IN_OFF(ifp->int_state) ||
                    (ifp->int_state & IS_DUP) ||
                    ifp->int_query_time != NEVER)
                        continue;

                /* skip turned off interfaces */
                if (!IS_IFF_UP(ifp->int_if_flags))
                        continue;

                /* skip interfaces we shouldn't use */
                if (IS_IFF_QUIET(ifp->int_if_flags))
                        continue;

                /*
                 * Ignore the interface if it's not broadcast,
                 * point-to-point, or remote.  It must be non-broadcast
                 * multiaccess, and therefore unsupported.
                 */
                if (!(ifp->int_if_flags & (IFF_BROADCAST | IFF_POINTOPOINT)) &&
                    !(ifp->int_state & IS_REMOTE))
                        continue;

                buf.rip_cmd = RIPCMD_REQUEST;
                buf.rip_nets[0].n_family = RIP_AF_UNSPEC;
                buf.rip_nets[0].n_metric = htonl(HOPCNT_INFINITY);

                /*
                 * Send a RIPv1 query only if allowed and if we will
                 * listen to RIPv1 routers.
                 */
                if ((ifp->int_state & IS_NO_RIPV1_OUT) ||
                    (ifp->int_state & IS_NO_RIPV1_IN)) {
                        buf.rip_vers = RIPv2;
                } else {
                        buf.rip_vers = RIPv1;
                }

                dst.sin_addr.s_addr = ifp->int_ripout_addr;

                type = (ifp->int_if_flags & IFF_BROADCAST) ?
                    OUT_BROADCAST : OUT_UNICAST;
                if (buf.rip_vers == RIPv2 &&
                    (ifp->int_if_flags & IFF_MULTICAST) &&
                    !(ifp->int_state & IS_NO_RIP_MCAST))
                        type = OUT_MULTICAST;

                ifp->int_query_time = now.tv_sec+SUPPLY_INTERVAL;
                if (output(type, &dst, ifp, &buf, sizeof (buf)) < 0)
                        if_sick(ifp, _B_FALSE);
        }
}