/*      $OpenBSD: rde_mfc.c,v 1.12 2025/12/15 23:38:34 jsg Exp $ */

/*
 * Copyright (c) 2009 Michele Marchetto <michele@openbsd.org>
 * Copyright (c) 2006 Esben Norby <norby@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 <sys/socket.h>
#include <sys/tree.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <err.h>
#include <stdlib.h>
#include <string.h>

#include "igmp.h"
#include "dvmrp.h"
#include "dvmrpd.h"
#include "log.h"
#include "dvmrpe.h"
#include "rde.h"

/* multicast forwarding cache */

void                     mfc_send_prune(struct rt_node *, struct mfc_node *);
void                     mfc_add_prune(struct mfc_node *, struct prune *);
struct prune_node       *mfc_find_prune(struct mfc_node *, struct prune *);
void                     mfc_delete_prune(struct mfc_node *,
                            struct prune_node *);

int     prune_compare(struct mfc_node *, struct rt_node *, int);
void    prune_expire_timer(int, short, void *);
int     mfc_reset_prune_expire_timer(struct prune_node *);


void     mfc_expire_timer(int, short, void *);
int      mfc_start_expire_timer(struct mfc_node *);
int      mfc_reset_expire_timer(struct mfc_node *);
void     mfc_prune_timer(int, short, void *);
int      mfc_start_prune_timer(struct mfc_node *);
int      mfc_reset_prune_timer(struct mfc_node *);

int      mfc_compare(struct mfc_node *, struct mfc_node *);

RB_HEAD(mfc_tree, mfc_node)      mfc;
RB_PROTOTYPE(mfc_tree, mfc_node, entry, mfc_compare)
RB_GENERATE(mfc_tree, mfc_node, entry, mfc_compare)

extern struct dvmrpd_conf       *rdeconf;

/* timers */
void
mfc_expire_timer(int fd, short event, void *arg)
{
        struct mfc_node *mn = arg;
        struct mfc       nmfc;

        log_debug("mfc_expire_timer: group %s", inet_ntoa(mn->group));

        /* remove route entry */
        nmfc.origin = mn->origin;
        nmfc.group = mn->group;
        rde_imsg_compose_parent(IMSG_MFC_DEL, 0, &nmfc, sizeof(nmfc));

        event_del(&mn->expiration_timer);
        mfc_remove(mn);
}

int
mfc_reset_expire_timer(struct mfc_node *mn)
{
        struct timeval  tv;

        timerclear(&tv);
        tv.tv_sec = ROUTE_EXPIRATION_TIME;
        return (evtimer_add(&mn->expiration_timer, &tv));
}

int
mfc_start_expire_timer(struct mfc_node *mn)
{
        struct timeval  tv;

        log_debug("mfc_start_expire_timer: group %s", inet_ntoa(mn->group));

        timerclear(&tv);
        tv.tv_sec = ROUTE_EXPIRATION_TIME;
        return (evtimer_add(&mn->expiration_timer, &tv));
}

void
mfc_prune_timer(int fd, short event, void *arg)
{
        struct mfc_node *mn = arg;

        log_debug("mfc_prune_timer: group %s", inet_ntoa(mn->group));

        event_del(&mn->prune_timer);
}

int
mfc_start_prune_timer(struct mfc_node *mn)
{
        struct timeval  tv;

        log_debug("mfc_start_prune_timer: group %s", inet_ntoa(mn->group));

        timerclear(&tv);
        tv.tv_sec = MAX_PRUNE_LIFETIME;
        return (evtimer_add(&mn->prune_timer, &tv));
}

int
mfc_reset_prune_timer(struct mfc_node *mn)
{
        struct timeval  tv;

        timerclear(&tv);
        tv.tv_sec = MAX_PRUNE_LIFETIME;
        return (evtimer_add(&mn->prune_timer, &tv));
}

/* route table */
void
mfc_init(void)
{
        RB_INIT(&mfc);
}

int
mfc_compare(struct mfc_node *a, struct mfc_node *b)
{
        if (ntohl(a->origin.s_addr) < ntohl(b->origin.s_addr))
                return (-1);
        if (ntohl(a->origin.s_addr) > ntohl(b->origin.s_addr))
                return (1);
        if (ntohl(a->group.s_addr) < ntohl(b->group.s_addr))
                return (-1);
        if (ntohl(a->group.s_addr) > ntohl(b->group.s_addr))
                return (1);
        return (0);
}

struct mfc_node *
mfc_find(in_addr_t origin, in_addr_t group)
{
        struct mfc_node s;

        s.origin.s_addr = origin;
        s.group.s_addr = group;

        return (RB_FIND(mfc_tree, &mfc, &s));
}

int
mfc_insert(struct mfc_node *m)
{
        if (RB_INSERT(mfc_tree, &mfc, m) != NULL) {
                log_warnx("mfc_insert failed for group %s",
                    inet_ntoa(m->group));
                free(m);
                return (-1);
        }

        return (0);
}

int
mfc_remove(struct mfc_node *m)
{
        if (RB_REMOVE(mfc_tree, &mfc, m) == NULL) {
                log_warnx("mfc_remove failed for group %s",
                    inet_ntoa(m->group));
                return (-1);
        }

        free(m);
        return (0);
}

void
mfc_clear(void)
{
        struct mfc_node *m;

        while ((m = RB_MIN(mfc_tree, &mfc)) != NULL)
                mfc_remove(m);
}

void
mfc_dump(pid_t pid)
{
        static struct ctl_mfc    mfcctl;
        struct timespec          now;
        struct timeval           tv, now2, res;
        struct mfc_node         *mn;
        int                      i;

        clock_gettime(CLOCK_MONOTONIC, &now);

        RB_FOREACH(mn, mfc_tree, &mfc) {
                mfcctl.origin.s_addr = mn->origin.s_addr;
                mfcctl.group.s_addr = mn->group.s_addr;
                mfcctl.uptime = now.tv_sec - mn->uptime;
                mfcctl.ifindex = mn->ifindex;

                for (i = 0; i < MAXVIFS; i ++) {
                        mfcctl.ttls[i] = mn->ttls[i];
                }

                gettimeofday(&now2, NULL);
                if (evtimer_pending(&mn->expiration_timer, &tv)) {
                        timersub(&tv, &now2, &res);
                        mfcctl.expire = res.tv_sec;
                } else
                        mfcctl.expire = -1;

                rde_imsg_compose_dvmrpe(IMSG_CTL_SHOW_MFC, 0, pid, &mfcctl,
                    sizeof(mfcctl));
        }
}

struct rt_node *
mfc_find_origin(struct in_addr group)
{
        struct mfc_node *mn;

        RB_FOREACH(mn, mfc_tree, &mfc)
                if (group.s_addr == mn->group.s_addr)
                        return (rt_match_origin(mn->origin.s_addr));

        return (NULL);
}

void
mfc_send_prune(struct rt_node *rn, struct mfc_node *mn)
{
        struct prune    p;

        memset(&p, 0, sizeof(p));

        p.origin.s_addr = (mn->origin.s_addr &
            htonl(prefixlen2mask(rn->prefixlen)));
        p.netmask.s_addr = htonl(prefixlen2mask(rn->prefixlen));
        p.group.s_addr = mn->group.s_addr;
        p.nexthop.s_addr = rn->nexthop.s_addr;
        p.ifindex = mn->ifindex;

        rde_imsg_compose_dvmrpe(IMSG_SEND_PRUNE, 0, 0, &p, sizeof(p));

        mfc_start_prune_timer(mn);
}

void
mfc_update_source(struct rt_node *rn)
{
        struct mfc_node         *mn;
        struct mfc               m;
        int                      i;
        u_int8_t                 found;

        RB_FOREACH(mn, mfc_tree, &mfc) {
                if (rn->prefix.s_addr == (mn->origin.s_addr &
                    htonl(prefixlen2mask(rn->prefixlen)))) {
                        mn->ifindex = rn->ifindex;

                        found = 0;

                        for (i = 0; i < MAXVIFS; i++) {
                                mn->ttls[i] = rn->ttls[i];
                                if (mn->ttls[i] != 0)
                                        found = 1;
                        }

                        m.origin.s_addr = mn->origin.s_addr;
                        m.group.s_addr = mn->group.s_addr;
                        m.ifindex = mn->ifindex;

                        for (i = 0; i < MAXVIFS; i++)
                                m.ttls[i] = mn->ttls[i];

                        rde_imsg_compose_parent(IMSG_MFC_ADD, 0, &m, sizeof(m));

                        mfc_reset_expire_timer(mn);

                        if (!found && !rn->connected)
                                mfc_send_prune(rn, mn);
                }
        }
}

void
mfc_update(struct mfc *nmfc)
{
        struct mfc_node         *mn;
        struct rt_node          *rn;
        struct timespec          now;
        int                      i;
        u_int8_t                 found = 0;

        clock_gettime(CLOCK_MONOTONIC, &now);

        if ((mn = mfc_find(nmfc->origin.s_addr, nmfc->group.s_addr)) == NULL) {
                if ((mn = calloc(1, sizeof(struct mfc_node))) == NULL)
                        fatalx("mfc_update");

                mn->origin.s_addr = nmfc->origin.s_addr;
                mn->group.s_addr = nmfc->group.s_addr;
                mn->ifindex = nmfc->ifindex;
                mn->uptime = now.tv_sec;
                for (i = 0; i < MAXVIFS; i++) {
                        mn->ttls[i] = nmfc->ttls[i];
                        if (mn->ttls[i] != 0)
                                found = 1;
                }

                if (mfc_insert(mn) == 0) {
                        rde_imsg_compose_parent(IMSG_MFC_ADD, 0, nmfc,
                            sizeof(*nmfc));
                }

                evtimer_set(&mn->expiration_timer, mfc_expire_timer, mn);
                evtimer_set(&mn->prune_timer, mfc_expire_timer, mn);
                mfc_start_expire_timer(mn);

                if (!found) {
                        /* We removed all downstream interfaces,
                           start the pruning process */
                        rn = rt_match_origin(mn->origin.s_addr);
                        if (rn == NULL) {
                                fatal("mfc_update: cannot find information "
                                    " about source");
                        }

                        mfc_send_prune(rn, mn);
                }
        }
}

void
mfc_delete(struct mfc *nmfc)
{
        struct mfc_node *mn;

        if ((mn = mfc_find(nmfc->origin.s_addr, nmfc->group.s_addr)) == NULL)
                return;

        /* XXX decide if it should really be removed */
        mfc_remove(mn);

        /* XXX notify parent */
}

int
mfc_check_members(struct rt_node *rn, struct iface *iface)
{
        struct mfc_node         *mn;

        RB_FOREACH(mn, mfc_tree, &mfc) {
                if (mn->origin.s_addr == rn->prefix.s_addr) {
                        if (rde_group_list_find(iface, mn->group) != 0)
                                return (1);
                }
        }

        return (0);
}

void
mfc_recv_prune(struct prune *p)
{
        struct rt_node          *rn;
        struct mfc_node         *mn;
        struct prune_node       *pn;
        struct iface            *iface;
        struct mfc               m;

        iface = if_find_index(p->ifindex);
        if (iface == NULL) {
                log_debug("mfc_recv_prune: unknown interface");
                return;
        }

        rn = rt_match_origin(p->origin.s_addr);
        if (rn == NULL) {
                log_debug("mfc_recv_prune: no information for %s\n",
                    inet_ntoa(p->origin));
                return;
        }

        if (srt_find_ds(rn, p->nexthop.s_addr) == NULL) {
                log_debug("mfc_recv_prune: prune received from a "
                    "non downstream neighbor\n");
                return;
        }

        mn = mfc_find(p->origin.s_addr, p->group.s_addr);
        if (mn) {
                log_debug("mfc_recv_prune: no information for %s\n",
                    inet_ntoa(p->origin));
                return;
        }

        pn = mfc_find_prune(mn, p);
        if (pn == NULL) {
                mfc_add_prune(mn, p);
                if (prune_compare(mn, rn, p->ifindex) &&
                    !rde_group_list_find(iface, p->group)) {
                        mn->ttls[p->ifindex] = 0;

                        m.ifindex = p->ifindex;
                        m.origin.s_addr = p->origin.s_addr;
                        m.group.s_addr = p->group.s_addr;
                        mfc_update(&m);
                }
        } else
                mfc_reset_prune_expire_timer(pn);
}

void
mfc_add_prune(struct mfc_node *mn, struct prune *p)
{
        struct prune_node       *pn;
        struct timeval           tv;

        pn = calloc(1, sizeof(*pn));
        if (pn == NULL)
                fatal("prune_add");

        timerclear(&tv);
        tv.tv_sec = MAX_PRUNE_LIFETIME;

        pn->nbr.s_addr = p->nexthop.s_addr;
        pn->ifindex = p->ifindex;
        pn->parent = mn;

        evtimer_set(&pn->lifetime_timer, prune_expire_timer, pn);
        evtimer_add(&pn->lifetime_timer, &tv);

        LIST_INSERT_HEAD(&mn->prune_list, pn, entry);

        mn->prune_cnt[p->ifindex]++;
}

struct prune_node *
mfc_find_prune(struct mfc_node *mn, struct prune *p)
{
        struct prune_node       *pn;

        LIST_FOREACH(pn, &mn->prune_list, entry) {
                if (p->nexthop.s_addr == pn->nbr.s_addr)
                        return (pn);
        }

        return (NULL);
}

void
mfc_delete_prune(struct mfc_node *mn, struct prune_node *pn)
{
        unsigned int    ifindex = pn->ifindex;

        if (evtimer_pending(&pn->lifetime_timer, NULL))
                if (evtimer_del(&pn->lifetime_timer) == -1)
                        fatal("mfc_delete_prune");

        LIST_REMOVE(pn, entry);
        free(pn);
        mn->prune_cnt[ifindex]--;
}

int
prune_compare(struct mfc_node *mn, struct rt_node *rn, int ifindex)
{
        if (mn->prune_cnt[ifindex] == rn->ds_cnt[ifindex])
                return (1);

        return (0);
}

int
mfc_reset_prune_expire_timer(struct prune_node *pn)
{
        struct timeval  tv;

        timerclear(&tv);
        tv.tv_sec = MAX_PRUNE_LIFETIME;

        return (evtimer_add(&pn->lifetime_timer, &tv));
}

void
prune_expire_timer(int fd, short event, void *arg)
{
        struct prune_node       *pn = arg;

        LIST_REMOVE(pn, entry);

        pn->parent->prune_cnt[pn->ifindex]--;
        pn->parent->ttls[pn->ifindex] = 1;

        free(pn);
}