/*      $OpenBSD: update.c,v 1.6 2016/09/02 16:46:29 renato Exp $ */

/*
 * Copyright (c) 2015 Renato Westphal <renato@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip6.h>

#include <stdlib.h>

#include "eigrpd.h"
#include "eigrpe.h"
#include "log.h"

/* update packet handling */

void
send_update(struct eigrp_iface *ei, struct nbr *nbr, uint32_t flags,
    struct rinfo_head *rinfo_list)
{
        struct eigrp            *eigrp = ei->eigrp;
        struct ibuf             *buf;
        struct rinfo_entry      *re;
        int                      size;
        int                      route_len;

        do {
                if ((buf = ibuf_dynamic(PKG_DEF_SIZE,
                    IP_MAXPACKET - sizeof(struct ip))) == NULL)
                        fatal("send_update");

                /* EIGRP header */
                if (gen_eigrp_hdr(buf, EIGRP_OPC_UPDATE, flags,
                    eigrp->seq_num, eigrp->as))
                        goto fail;

                if (rinfo_list == NULL)
                        break;

                switch (eigrp->af) {
                case AF_INET:
                        size = sizeof(struct ip);
                        break;
                case AF_INET6:
                        size = sizeof(struct ip6_hdr);
                        break;
                default:
                        fatalx("send_update: unknown af");
                }
                size += sizeof(struct eigrp_hdr);

                while ((re = TAILQ_FIRST(rinfo_list)) != NULL) {
                        route_len = len_route_tlv(&re->rinfo);
                        /* don't exceed the MTU to avoid IP fragmentation */
                        if (size + route_len > ei->iface->mtu) {
                                rtp_send(ei, nbr, buf);
                                break;
                        }
                        size += route_len;

                        if (gen_route_tlv(buf, &re->rinfo))
                                goto fail;
                        TAILQ_REMOVE(rinfo_list, re, entry);
                        free(re);
                }
        } while (!TAILQ_EMPTY(rinfo_list));

        rtp_send(ei, nbr, buf);
        return;
fail:
        log_warnx("%s: failed to send message", __func__);
        if (rinfo_list)
                message_list_clr(rinfo_list);
        ibuf_free(buf);
        return;
}

void
recv_update(struct nbr *nbr, struct rinfo_head *rinfo_list, uint32_t flags)
{
        struct rinfo_entry      *re;

        rtp_ack_start_timer(nbr);

        if (flags & EIGRP_HDR_FLAG_INIT) {
                log_debug("%s: INIT flag is set", __func__);

                if (nbr->flags & F_EIGRP_NBR_PENDING)
                        nbr_init(nbr);

                /*
                 * The INIT flag instructs us to advertise all of our routes,
                 * even if the neighbor is not pending.
                 */
                eigrpe_imsg_compose_rde(IMSG_RECV_UPDATE_INIT, nbr->peerid,
                    0, NULL, 0);
                return;
        }

        TAILQ_FOREACH(re, rinfo_list, entry)
                eigrpe_imsg_compose_rde(IMSG_RECV_UPDATE, nbr->peerid,
                    0, &re->rinfo, sizeof(re->rinfo));
}