Merge pull request #8543 from volta-networks/fix_bgp_invalid_nexthop

[mirror_frr.git] / lib / bfd.c

/**
 * bfd.c: BFD handling routines
 *
 * @copyright Copyright (C) 2015 Cumulus Networks, Inc.
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * GNU Zebra is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; see the file COPYING; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <zebra.h>

#include "command.h"
#include "memory.h"
#include "prefix.h"
#include "thread.h"
#include "stream.h"
#include "vrf.h"
#include "zclient.h"
#include "table.h"
#include "vty.h"
#include "bfd.h"

DEFINE_MTYPE_STATIC(LIB, BFD_INFO, "BFD info");

static int bfd_debug = 0;
static struct bfd_gbl bfd_gbl;

/*
 * bfd_gbl_init - Initialize the BFD global structure
 */
void bfd_gbl_init(void)
{
        memset(&bfd_gbl, 0, sizeof(struct bfd_gbl));
}

/*
 * bfd_gbl_exit - Called when daemon exits
 */
void bfd_gbl_exit(void)
{
        SET_FLAG(bfd_gbl.flags, BFD_GBL_FLAG_IN_SHUTDOWN);
}

/*
 * bfd_info_create - Allocate the BFD information
 */
struct bfd_info *bfd_info_create(void)
{
        struct bfd_info *bfd_info;

        bfd_info = XCALLOC(MTYPE_BFD_INFO, sizeof(struct bfd_info));
        assert(bfd_info);

        bfd_info->status = BFD_STATUS_UNKNOWN;
        bfd_info->type = BFD_TYPE_NOT_CONFIGURED;
        bfd_info->last_update = 0;
        return bfd_info;
}

/*
 * bfd_info_free - Free the BFD information.
 */
void bfd_info_free(struct bfd_info **bfd_info)
{
        XFREE(MTYPE_BFD_INFO, *bfd_info);
}

/*
 * bfd_validate_param - Validate the BFD paramter information.
 */
int bfd_validate_param(struct vty *vty, const char *dm_str, const char *rx_str,
                       const char *tx_str, uint8_t *dm_val, uint32_t *rx_val,
                       uint32_t *tx_val)
{
        *dm_val = strtoul(dm_str, NULL, 10);
        *rx_val = strtoul(rx_str, NULL, 10);
        *tx_val = strtoul(tx_str, NULL, 10);
        return CMD_SUCCESS;
}

/*
 * bfd_set_param - Set the configured BFD paramter values
 */
void bfd_set_param(struct bfd_info **bfd_info, uint32_t min_rx, uint32_t min_tx,
                   uint8_t detect_mult, const char *profile, int defaults,
                   int *command)
{
        if (!*bfd_info) {
                *bfd_info = bfd_info_create();
                *command = ZEBRA_BFD_DEST_REGISTER;
        } else {
                if (((*bfd_info)->required_min_rx != min_rx)
                    || ((*bfd_info)->desired_min_tx != min_tx)
                    || ((*bfd_info)->detect_mult != detect_mult)
                    || ((*bfd_info)->profile[0] == 0 && profile)
                    || ((*bfd_info)->profile[0] && profile == NULL)
                    || (profile && (*bfd_info)->profile[0]
                        && strcmp((*bfd_info)->profile, profile)))
                        *command = ZEBRA_BFD_DEST_UPDATE;
        }

        if (*command) {
                (*bfd_info)->required_min_rx = min_rx;
                (*bfd_info)->desired_min_tx = min_tx;
                (*bfd_info)->detect_mult = detect_mult;
                if (profile)
                        strlcpy((*bfd_info)->profile, profile,
                                BFD_PROFILE_NAME_LEN);
                else
                        (*bfd_info)->profile[0] = '\0';
        }

        if (!defaults)
                SET_FLAG((*bfd_info)->flags, BFD_FLAG_PARAM_CFG);
        else
                UNSET_FLAG((*bfd_info)->flags, BFD_FLAG_PARAM_CFG);
}

/*
 * bfd_peer_sendmsg - Format and send a peer register/Unregister
 *                    command to Zebra to be forwarded to BFD
 *
 * DEPRECATED: use zclient_bfd_command instead
 */
void bfd_peer_sendmsg(struct zclient *zclient, struct bfd_info *bfd_info,
                      int family, void *dst_ip, void *src_ip, char *if_name,
                      int ttl, int multihop, int cbit, int command,
                      int set_flag, vrf_id_t vrf_id)
{
        struct bfd_session_arg args = {};
        size_t addrlen;

        /* Individual reg/dereg messages are suppressed during shutdown. */
        if (CHECK_FLAG(bfd_gbl.flags, BFD_GBL_FLAG_IN_SHUTDOWN)) {
                if (bfd_debug)
                        zlog_debug(
                                "%s: Suppressing BFD peer reg/dereg messages",
                                __func__);
                return;
        }

        /* Check socket. */
        if (!zclient || zclient->sock < 0) {
                if (bfd_debug)
                        zlog_debug(
                                "%s: Can't send BFD peer register, Zebra client not established",
                                __func__);
                return;
        }

        /* Fill in all arguments. */
        args.ttl = ttl;
        args.cbit = cbit;
        args.family = family;
        args.mhop = multihop;
        args.vrf_id = vrf_id;
        args.command = command;
        args.set_flag = set_flag;
        args.bfd_info = bfd_info;
        if (args.bfd_info) {
                args.min_rx = bfd_info->required_min_rx;
                args.min_tx = bfd_info->desired_min_tx;
                args.detection_multiplier = bfd_info->detect_mult;
                if (bfd_info->profile[0]) {
                        args.profilelen = strlen(bfd_info->profile);
                        strlcpy(args.profile, bfd_info->profile,
                                sizeof(args.profile));
                }
        }

        addrlen = family == AF_INET ? sizeof(struct in_addr)
                                    : sizeof(struct in6_addr);
        memcpy(&args.dst, dst_ip, addrlen);
        if (src_ip)
                memcpy(&args.src, src_ip, addrlen);

        if (if_name)
                args.ifnamelen =
                        strlcpy(args.ifname, if_name, sizeof(args.ifname));

        zclient_bfd_command(zclient, &args);
}

/*
 * bfd_get_command_dbg_str - Convert command to a debug string.
 */
const char *bfd_get_command_dbg_str(int command)
{
        switch (command) {
        case ZEBRA_BFD_DEST_REGISTER:
                return "Register";
        case ZEBRA_BFD_DEST_DEREGISTER:
                return "Deregister";
        case ZEBRA_BFD_DEST_UPDATE:
                return "Update";
        default:
                return "Unknown";
        }
}

/*
 * bfd_get_peer_info - Extract the Peer information for which the BFD session
 *                     went down from the message sent from Zebra to clients.
 */
struct interface *bfd_get_peer_info(struct stream *s, struct prefix *dp,
                                    struct prefix *sp, int *status,
                                    int *remote_cbit,
                                    vrf_id_t vrf_id)
{
        unsigned int ifindex;
        struct interface *ifp = NULL;
        int plen;
        int local_remote_cbit;

        /*
         * If the ifindex lookup fails the
         * rest of the data in the stream is
         * not read.  All examples of this function
         * call immediately use the dp->family which
         * is not good.  Ensure we are not using
         * random data
         */
        memset(dp, 0, sizeof(*dp));
        memset(sp, 0, sizeof(*sp));

        /* Get interface index. */
        STREAM_GETL(s, ifindex);

        /* Lookup index. */
        if (ifindex != 0) {
                ifp = if_lookup_by_index(ifindex, vrf_id);
                if (ifp == NULL) {
                        if (bfd_debug)
                                zlog_debug(
                                        "zebra_interface_bfd_read: Can't find interface by ifindex: %d ",
                                        ifindex);
                        return NULL;
                }
        }

        /* Fetch destination address. */
        STREAM_GETC(s, dp->family);

        plen = prefix_blen(dp);
        STREAM_GET(&dp->u.prefix, s, plen);
        STREAM_GETC(s, dp->prefixlen);

        /* Get BFD status. */
        STREAM_GETL(s, (*status));

        STREAM_GETC(s, sp->family);

        plen = prefix_blen(sp);
        STREAM_GET(&sp->u.prefix, s, plen);
        STREAM_GETC(s, sp->prefixlen);

        STREAM_GETC(s, local_remote_cbit);
        if (remote_cbit)
                *remote_cbit = local_remote_cbit;
        return ifp;

stream_failure:
        return NULL;
}

/*
 * bfd_get_status_str - Convert BFD status to a display string.
 */
const char *bfd_get_status_str(int status)
{
        switch (status) {
        case BFD_STATUS_DOWN:
                return "Down";
        case BFD_STATUS_UP:
                return "Up";
        case BFD_STATUS_ADMIN_DOWN:
                return "Admin Down";
        case BFD_STATUS_UNKNOWN:
        default:
                return "Unknown";
        }
}

/*
 * bfd_last_update - Calculate the last BFD update time and convert it
 *                   into a dd:hh:mm:ss display format.
 */
static void bfd_last_update(time_t last_update, char *buf, size_t len)
{
        time_t curr;
        time_t diff;
        struct tm tm;
        struct timeval tv;

        /* If no BFD satatus update has ever been received, print `never'. */
        if (last_update == 0) {
                snprintf(buf, len, "never");
                return;
        }

        /* Get current time. */
        monotime(&tv);
        curr = tv.tv_sec;
        diff = curr - last_update;
        gmtime_r(&diff, &tm);

        snprintf(buf, len, "%d:%02d:%02d:%02d", tm.tm_yday, tm.tm_hour,
                 tm.tm_min, tm.tm_sec);
}

/*
 * bfd_show_param - Show the BFD parameter information.
 */
void bfd_show_param(struct vty *vty, struct bfd_info *bfd_info, int bfd_tag,
                    int extra_space, bool use_json, json_object *json_obj)
{
        json_object *json_bfd = NULL;

        if (!bfd_info)
                return;

        if (use_json) {
                if (bfd_tag)
                        json_bfd = json_object_new_object();
                else
                        json_bfd = json_obj;

                json_object_int_add(json_bfd, "detectMultiplier",
                                    bfd_info->detect_mult);
                json_object_int_add(json_bfd, "rxMinInterval",
                                    bfd_info->required_min_rx);
                json_object_int_add(json_bfd, "txMinInterval",
                                    bfd_info->desired_min_tx);
                if (bfd_tag)
                        json_object_object_add(json_obj, "peerBfdInfo",
                                               json_bfd);
        } else {
                vty_out(vty,
                        "  %s%sDetect Multiplier: %d, Min Rx interval: %d, Min Tx interval: %d\n",
                        (extra_space) ? "  " : "", (bfd_tag) ? "BFD: " : "  ",
                        bfd_info->detect_mult, bfd_info->required_min_rx,
                        bfd_info->desired_min_tx);
        }
}

/*
 * bfd_show_status - Show the BFD status information.
 */
static void bfd_show_status(struct vty *vty, struct bfd_info *bfd_info,
                            int bfd_tag, int extra_space, bool use_json,
                            json_object *json_bfd)
{
        char time_buf[32];

        if (!bfd_info)
                return;

        bfd_last_update(bfd_info->last_update, time_buf, 32);
        if (use_json) {
                json_object_string_add(json_bfd, "status",
                                       bfd_get_status_str(bfd_info->status));
                json_object_string_add(json_bfd, "lastUpdate", time_buf);
        } else {
                vty_out(vty, "  %s%sStatus: %s, Last update: %s\n",
                        (extra_space) ? "  " : "", (bfd_tag) ? "BFD: " : "  ",
                        bfd_get_status_str(bfd_info->status), time_buf);
        }
}

/*
 * bfd_show_info - Show the BFD information.
 */
void bfd_show_info(struct vty *vty, struct bfd_info *bfd_info, int multihop,
                   int extra_space, bool use_json, json_object *json_obj)
{
        json_object *json_bfd = NULL;

        if (!bfd_info)
                return;

        if (use_json) {
                json_bfd = json_object_new_object();
                if (multihop)
                        json_object_string_add(json_bfd, "type", "multi hop");
                else
                        json_object_string_add(json_bfd, "type", "single hop");
        } else {
                vty_out(vty, "  %sBFD: Type: %s\n", (extra_space) ? "  " : "",
                        (multihop) ? "multi hop" : "single hop");
        }

        bfd_show_param(vty, bfd_info, 0, extra_space, use_json, json_bfd);
        bfd_show_status(vty, bfd_info, 0, extra_space, use_json, json_bfd);

        if (use_json)
                json_object_object_add(json_obj, "peerBfdInfo", json_bfd);
        else
                vty_out(vty, "\n");
}

/*
 * bfd_client_sendmsg - Format and send a client register
 *                    command to Zebra to be forwarded to BFD
 */
void bfd_client_sendmsg(struct zclient *zclient, int command,
                        vrf_id_t vrf_id)
{
        struct stream *s;
        enum zclient_send_status ret;

        /* Check socket. */
        if (!zclient || zclient->sock < 0) {
                if (bfd_debug)
                        zlog_debug(
                                "%s: Can't send BFD client register, Zebra client not established",
                                __func__);
                return;
        }

        s = zclient->obuf;
        stream_reset(s);
        zclient_create_header(s, command, vrf_id);

        stream_putl(s, getpid());

        stream_putw_at(s, 0, stream_get_endp(s));

        ret = zclient_send_message(zclient);

        if (ret == ZCLIENT_SEND_FAILURE) {
                if (bfd_debug)
                        zlog_debug(
                                "bfd_client_sendmsg %ld: zclient_send_message() failed",
                                (long)getpid());
                return;
        }

        return;
}

int zclient_bfd_command(struct zclient *zc, struct bfd_session_arg *args)
{
        struct stream *s;
        size_t addrlen;

        /* Individual reg/dereg messages are suppressed during shutdown. */
        if (CHECK_FLAG(bfd_gbl.flags, BFD_GBL_FLAG_IN_SHUTDOWN)) {
                if (bfd_debug)
                        zlog_debug(
                                "%s: Suppressing BFD peer reg/dereg messages",
                                __func__);
                return -1;
        }

        /* Check socket. */
        if (!zc || zc->sock < 0) {
                if (bfd_debug)
                        zlog_debug("%s: zclient unavailable", __func__);
                return -1;
        }

        s = zc->obuf;
        stream_reset(s);

        /* Create new message. */
        zclient_create_header(s, args->command, args->vrf_id);
        stream_putl(s, getpid());

        /* Encode destination address. */
        stream_putw(s, args->family);
        addrlen = (args->family == AF_INET) ? sizeof(struct in_addr)
                                            : sizeof(struct in6_addr);
        stream_put(s, &args->dst, addrlen);

        /*
         * For more BFD integration protocol details, see function
         * `_ptm_msg_read` in `bfdd/ptm_adapter.c`.
         */
#if HAVE_BFDD > 0
        /* Session timers. */
        stream_putl(s, args->min_rx);
        stream_putl(s, args->min_tx);
        stream_putc(s, args->detection_multiplier);

        /* Is multi hop? */
        stream_putc(s, args->mhop != 0);

        /* Source address. */
        stream_putw(s, args->family);
        stream_put(s, &args->src, addrlen);

        /* Send the expected TTL. */
        stream_putc(s, args->ttl);

        /* Send interface name if any. */
        stream_putc(s, args->ifnamelen);
        if (args->ifnamelen)
                stream_put(s, args->ifname, args->ifnamelen);

        /* Send the C bit indicator. */
        stream_putc(s, args->cbit);

        /* Send profile name if any. */
        stream_putc(s, args->profilelen);
        if (args->profilelen)
                stream_put(s, args->profile, args->profilelen);
#else /* PTM BFD */
        /* Encode timers if this is a registration message. */
        if (args->command != ZEBRA_BFD_DEST_DEREGISTER) {
                stream_putl(s, args->min_rx);
                stream_putl(s, args->min_tx);
                stream_putc(s, args->detection_multiplier);
        }

        if (args->mhop) {
                /* Multi hop indicator. */
                stream_putc(s, 1);

                /* Multi hop always sends the source address. */
                stream_putw(s, args->family);
                stream_put(s, &args->src, addrlen);

                /* Send the expected TTL. */
                stream_putc(s, args->ttl);
        } else {
                /* Multi hop indicator. */
                stream_putc(s, 0);

                /* Single hop only sends the source address when IPv6. */
                if (args->family == AF_INET6) {
                        stream_putw(s, args->family);
                        stream_put(s, &args->src, addrlen);
                }

                /* Send interface name if any. */
                stream_putc(s, args->ifnamelen);
                if (args->ifnamelen)
                        stream_put(s, args->ifname, args->ifnamelen);
        }
#endif /* HAVE_BFDD */

        /* Finish the message by writing the size. */
        stream_putw_at(s, 0, stream_get_endp(s));

        /* Send message to zebra. */
        if (zclient_send_message(zc) == ZCLIENT_SEND_FAILURE) {
                if (bfd_debug)
                        zlog_debug("%s: zclient_send_message failed", __func__);
                return -1;
        }

        /* Write registration indicator into data structure. */
        if (args->bfd_info && args->set_flag) {
                if (args->command == ZEBRA_BFD_DEST_REGISTER)
                        SET_FLAG(args->bfd_info->flags, BFD_FLAG_BFD_REG);
                else if (args->command == ZEBRA_BFD_DEST_DEREGISTER)
                        UNSET_FLAG(args->bfd_info->flags, BFD_FLAG_BFD_REG);
        }

        return 0;
}

/**
 * BFD protocol integration configuration.
 */

/** Events definitions. */
enum bfd_session_event {
        /** Remove the BFD session configuration. */
        BSE_UNINSTALL,
        /** Install the BFD session configuration. */
        BSE_INSTALL,
};

/**
 * Data structure to do the necessary tricks to hide the BFD protocol
 * integration internals.
 */
struct bfd_session_params {
        /** Contains the session parameters and more. */
        struct bfd_session_arg args;
        /** Contains the session state. */
        struct bfd_session_status bss;
        /** Protocol implementation status update callback. */
        bsp_status_update updatecb;
        /** Protocol implementation custom data pointer. */
        void *arg;

        /**
         * Next event.
         *
         * This variable controls what action to execute when the command batch
         * finishes. Normally we'd use `thread_add_event` value, however since
         * that function is going to be called multiple times and the value
         * might be different we'll use this variable to keep track of it.
         */
        enum bfd_session_event lastev;
        /**
         * BFD session configuration event.
         *
         * Multiple actions might be asked during a command batch (either via
         * configuration load or northbound batch), so we'll use this to
         * install/uninstall the BFD session parameters only once.
         */
        struct thread *installev;

        /** BFD session installation state. */
        bool installed;

        /** Global BFD paramaters list. */
        TAILQ_ENTRY(bfd_session_params) entry;
};

struct bfd_sessions_global {
        /**
         * Global BFD session parameters list for (re)installation and update
         * without code duplication among daemons.
         */
        TAILQ_HEAD(bsplist, bfd_session_params) bsplist;

        /** Pointer to FRR's event manager. */
        struct thread_master *tm;
        /** Pointer to zebra client data structure. */
        struct zclient *zc;

        /** Debugging state. */
        bool debugging;
        /** Is shutting down? */
        bool shutting_down;
};

/** Global configuration variable. */
static struct bfd_sessions_global bsglobal;

/** Global empty address for IPv4/IPv6. */
static const struct in6_addr i6a_zero;

struct bfd_session_params *bfd_sess_new(bsp_status_update updatecb, void *arg)
{
        struct bfd_session_params *bsp;

        bsp = XCALLOC(MTYPE_BFD_INFO, sizeof(*bsp));

        /* Save application data. */
        bsp->updatecb = updatecb;
        bsp->arg = arg;

        /* Set defaults. */
        bsp->args.detection_multiplier = BFD_DEF_DETECT_MULT;
        bsp->args.ttl = BFD_SINGLE_HOP_TTL;
        bsp->args.min_rx = BFD_DEF_MIN_RX;
        bsp->args.min_tx = BFD_DEF_MIN_TX;
        bsp->args.vrf_id = VRF_DEFAULT;

        /* Register in global list. */
        TAILQ_INSERT_TAIL(&bsglobal.bsplist, bsp, entry);

        return bsp;
}

static bool _bfd_sess_valid(const struct bfd_session_params *bsp)
{
        /* Peer/local address not configured. */
        if (bsp->args.family == 0)
                return false;

        /* Address configured but invalid. */
        if (bsp->args.family != AF_INET && bsp->args.family != AF_INET6) {
                if (bsglobal.debugging)
                        zlog_debug("%s: invalid session family: %d", __func__,
                                   bsp->args.family);
                return false;
        }

        /* Invalid address. */
        if (memcmp(&bsp->args.dst, &i6a_zero, sizeof(i6a_zero)) == 0) {
                if (bsglobal.debugging) {
                        if (bsp->args.family == AF_INET)
                                zlog_debug("%s: invalid address: %pI4",
                                           __func__,
                                           (struct in_addr *)&bsp->args.dst);
                        else
                                zlog_debug("%s: invalid address: %pI6",
                                           __func__, &bsp->args.dst);
                }
                return false;
        }

        /* Multi hop requires local address. */
        if (bsp->args.mhop
            && memcmp(&i6a_zero, &bsp->args.src, sizeof(i6a_zero)) == 0) {
                if (bsglobal.debugging)
                        zlog_debug(
                                "%s: multi hop but no local address provided",
                                __func__);
                return false;
        }

        /* Check VRF ID. */
        if (bsp->args.vrf_id == VRF_UNKNOWN) {
                if (bsglobal.debugging)
                        zlog_debug("%s: asked for unknown VRF", __func__);
                return false;
        }

        return true;
}

static int _bfd_sess_send(struct thread *t)
{
        struct bfd_session_params *bsp = THREAD_ARG(t);
        int rv;

        /* Validate configuration before trying to send bogus data. */
        if (!_bfd_sess_valid(bsp))
                return 0;

        if (bsp->lastev == BSE_INSTALL) {
                bsp->args.command = bsp->installed ? ZEBRA_BFD_DEST_UPDATE
                                                   : ZEBRA_BFD_DEST_REGISTER;
        } else
                bsp->args.command = ZEBRA_BFD_DEST_DEREGISTER;

        /* If not installed and asked for uninstall, do nothing. */
        if (!bsp->installed && bsp->args.command == ZEBRA_BFD_DEST_DEREGISTER)
                return 0;

        rv = zclient_bfd_command(bsglobal.zc, &bsp->args);
        /* Command was sent successfully. */
        if (rv == 0) {
                /* Update installation status. */
                if (bsp->args.command == ZEBRA_BFD_DEST_DEREGISTER)
                        bsp->installed = false;
                else if (bsp->args.command == ZEBRA_BFD_DEST_REGISTER)
                        bsp->installed = true;
        } else {
                struct ipaddr src, dst;

                src.ipa_type = bsp->args.family;
                src.ipaddr_v6 = bsp->args.src;
                dst.ipa_type = bsp->args.family;
                dst.ipaddr_v6 = bsp->args.dst;

                zlog_err(
                        "%s: BFD session %pIA -> %pIA interface %s VRF %s(%u) was not %s",
                        __func__, &src, &dst,
                        bsp->args.ifnamelen ? bsp->args.ifname : "*",
                        vrf_id_to_name(bsp->args.vrf_id), bsp->args.vrf_id,
                        bsp->lastev == BSE_INSTALL ? "installed"
                                                   : "uninstalled");
        }

        return 0;
}

static void _bfd_sess_remove(struct bfd_session_params *bsp)
{
        /* Not installed, nothing to do. */
        if (!bsp->installed)
                return;

        /* Cancel any pending installation request. */
        THREAD_OFF(bsp->installev);

        /* Send request to remove any session. */
        bsp->lastev = BSE_UNINSTALL;
        thread_execute(bsglobal.tm, _bfd_sess_send, bsp, 0);
}

void bfd_sess_free(struct bfd_session_params **bsp)
{
        if (*bsp == NULL)
                return;

        /* Remove any installed session. */
        _bfd_sess_remove(*bsp);

        /* Remove from global list. */
        TAILQ_REMOVE(&bsglobal.bsplist, (*bsp), entry);

        /* Free the memory and point to NULL. */
        XFREE(MTYPE_BFD_INFO, (*bsp));
}

static bool bfd_sess_address_changed(const struct bfd_session_params *bsp,
                                     uint32_t family,
                                     const struct in6_addr *src,
                                     const struct in6_addr *dst)
{
        size_t addrlen;

        if (bsp->args.family != family)
                return true;

        addrlen = (family == AF_INET) ? sizeof(struct in_addr)
                                      : sizeof(struct in6_addr);
        if ((src == NULL && memcmp(&bsp->args.src, &i6a_zero, addrlen))
            || (src && memcmp(src, &bsp->args.src, addrlen))
            || memcmp(dst, &bsp->args.dst, addrlen))
                return true;

        return false;
}

void bfd_sess_set_ipv4_addrs(struct bfd_session_params *bsp,
                             struct in_addr *src, struct in_addr *dst)
{
        if (!bfd_sess_address_changed(bsp, AF_INET, (struct in6_addr *)src,
                                      (struct in6_addr *)dst))
                return;

        /* If already installed, remove the old setting. */
        _bfd_sess_remove(bsp);

        bsp->args.family = AF_INET;

        /* Clean memory, set zero value and avoid static analyser warnings. */
        memset(&bsp->args.src, 0, sizeof(bsp->args.src));
        memset(&bsp->args.dst, 0, sizeof(bsp->args.dst));

        /* Copy the equivalent of IPv4 to arguments structure. */
        if (src)
                memcpy(&bsp->args.src, src, sizeof(struct in_addr));

        assert(dst);
        memcpy(&bsp->args.dst, dst, sizeof(struct in_addr));
}

void bfd_sess_set_ipv6_addrs(struct bfd_session_params *bsp,
                             struct in6_addr *src, struct in6_addr *dst)
{
        if (!bfd_sess_address_changed(bsp, AF_INET, (struct in6_addr *)src,
                                      (struct in6_addr *)dst))
                return;

        /* If already installed, remove the old setting. */
        _bfd_sess_remove(bsp);

        bsp->args.family = AF_INET6;

        /* Clean memory, set zero value and avoid static analyser warnings. */
        memset(&bsp->args.src, 0, sizeof(bsp->args.src));

        if (src)
                bsp->args.src = *src;

        assert(dst);
        bsp->args.dst = *dst;
}

void bfd_sess_set_interface(struct bfd_session_params *bsp, const char *ifname)
{
        if ((ifname == NULL && bsp->args.ifnamelen == 0)
            || (ifname && strcmp(bsp->args.ifname, ifname) == 0))
                return;

        /* If already installed, remove the old setting. */
        _bfd_sess_remove(bsp);

        if (ifname == NULL) {
                bsp->args.ifname[0] = 0;
                bsp->args.ifnamelen = 0;
                return;
        }

        if (strlcpy(bsp->args.ifname, ifname, sizeof(bsp->args.ifname))
            > sizeof(bsp->args.ifname))
                zlog_warn("%s: interface name truncated: %s", __func__, ifname);

        bsp->args.ifnamelen = strlen(bsp->args.ifname);
}

void bfd_sess_set_profile(struct bfd_session_params *bsp, const char *profile)
{
        if (profile == NULL) {
                bsp->args.profile[0] = 0;
                bsp->args.profilelen = 0;
                return;
        }

        if (strlcpy(bsp->args.profile, profile, sizeof(bsp->args.profile))
            > sizeof(bsp->args.profile))
                zlog_warn("%s: profile name truncated: %s", __func__, profile);

        bsp->args.profilelen = strlen(bsp->args.profile);
}

void bfd_sess_set_vrf(struct bfd_session_params *bsp, vrf_id_t vrf_id)
{
        if (bsp->args.vrf_id == vrf_id)
                return;

        /* If already installed, remove the old setting. */
        _bfd_sess_remove(bsp);

        bsp->args.vrf_id = vrf_id;
}

void bfd_sess_set_mininum_ttl(struct bfd_session_params *bsp, uint8_t min_ttl)
{
        assert(min_ttl != 0);

        if (bsp->args.ttl == ((BFD_SINGLE_HOP_TTL + 1) - min_ttl))
                return;

        /* If already installed, remove the old setting. */
        _bfd_sess_remove(bsp);

        /* Invert TTL value: protocol expects number of hops. */
        min_ttl = (BFD_SINGLE_HOP_TTL + 1) - min_ttl;
        bsp->args.ttl = min_ttl;
        bsp->args.mhop = (min_ttl > 1);
}

void bfd_sess_set_hop_count(struct bfd_session_params *bsp, uint8_t min_ttl)
{
        if (bsp->args.ttl == min_ttl)
                return;

        /* If already installed, remove the old setting. */
        _bfd_sess_remove(bsp);

        bsp->args.ttl = min_ttl;
        bsp->args.mhop = (min_ttl > 1);
}


void bfd_sess_set_cbit(struct bfd_session_params *bsp, bool enable)
{
        bsp->args.cbit = enable;
}

void bfd_sess_set_timers(struct bfd_session_params *bsp,
                         uint8_t detection_multiplier, uint32_t min_rx,
                         uint32_t min_tx)
{
        bsp->args.detection_multiplier = detection_multiplier;
        bsp->args.min_rx = min_rx;
        bsp->args.min_tx = min_tx;
}

void bfd_sess_install(struct bfd_session_params *bsp)
{
        bsp->lastev = BSE_INSTALL;
        thread_add_event(bsglobal.tm, _bfd_sess_send, bsp, 0, &bsp->installev);
}

void bfd_sess_uninstall(struct bfd_session_params *bsp)
{
        bsp->lastev = BSE_UNINSTALL;
        thread_add_event(bsglobal.tm, _bfd_sess_send, bsp, 0, &bsp->installev);
}

enum bfd_session_state bfd_sess_status(const struct bfd_session_params *bsp)
{
        return bsp->bss.state;
}

uint8_t bfd_sess_minimum_ttl(const struct bfd_session_params *bsp)
{
        return ((BFD_SINGLE_HOP_TTL + 1) - bsp->args.ttl);
}

uint8_t bfd_sess_hop_count(const struct bfd_session_params *bsp)
{
        return bsp->args.ttl;
}

const char *bfd_sess_profile(const struct bfd_session_params *bsp)
{
        return bsp->args.profilelen ? bsp->args.profile : NULL;
}

void bfd_sess_addresses(const struct bfd_session_params *bsp, int *family,
                        struct in6_addr *src, struct in6_addr *dst)
{
        *family = bsp->args.family;
        if (src)
                *src = bsp->args.src;
        if (dst)
                *dst = bsp->args.dst;
}

const char *bfd_sess_interface(const struct bfd_session_params *bsp)
{
        if (bsp->args.ifnamelen)
                return bsp->args.ifname;

        return NULL;
}

const char *bfd_sess_vrf(const struct bfd_session_params *bsp)
{
        return vrf_id_to_name(bsp->args.vrf_id);
}

vrf_id_t bfd_sess_vrf_id(const struct bfd_session_params *bsp)
{
        return bsp->args.vrf_id;
}

bool bfd_sess_cbit(const struct bfd_session_params *bsp)
{
        return bsp->args.cbit;
}

void bfd_sess_timers(const struct bfd_session_params *bsp,
                     uint8_t *detection_multiplier, uint32_t *min_rx,
                     uint32_t *min_tx)
{
        *detection_multiplier = bsp->args.detection_multiplier;
        *min_rx = bsp->args.min_rx;
        *min_tx = bsp->args.min_tx;
}

void bfd_sess_show(struct vty *vty, struct json_object *json,
                   struct bfd_session_params *bsp)
{
        json_object *json_bfd = NULL;
        char time_buf[64];

        if (!bsp)
                return;

        /* Show type. */
        if (json) {
                json_bfd = json_object_new_object();
                if (bsp->args.mhop)
                        json_object_string_add(json_bfd, "type", "multi hop");
                else
                        json_object_string_add(json_bfd, "type", "single hop");
        } else
                vty_out(vty, "  BFD: Type: %s\n",
                        bsp->args.mhop ? "multi hop" : "single hop");

        /* Show configuration. */
        if (json) {
                json_object_int_add(json_bfd, "detectMultiplier",
                                    bsp->args.detection_multiplier);
                json_object_int_add(json_bfd, "rxMinInterval",
                                    bsp->args.min_rx);
                json_object_int_add(json_bfd, "txMinInterval",
                                    bsp->args.min_tx);
        } else {
                vty_out(vty,
                        "  Detect Multiplier: %d, Min Rx interval: %d, Min Tx interval: %d\n",
                        bsp->args.detection_multiplier, bsp->args.min_rx,
                        bsp->args.min_tx);
        }

        bfd_last_update(bsp->bss.last_event, time_buf, sizeof(time_buf));
        if (json) {
                json_object_string_add(json_bfd, "status",
                                       bfd_get_status_str(bsp->bss.state));
                json_object_string_add(json_bfd, "lastUpdate", time_buf);
        } else
                vty_out(vty, "  Status: %s, Last update: %s\n",
                        bfd_get_status_str(bsp->bss.state), time_buf);

        if (json)
                json_object_object_add(json, "peerBfdInfo", json_bfd);
        else
                vty_out(vty, "\n");
}

/*
 * Zebra communication related.
 */

/**
 * Callback for reinstallation of all registered BFD sessions.
 *
 * Use this as `zclient` `bfd_dest_replay` callback.
 */
static int zclient_bfd_session_reply(ZAPI_CALLBACK_ARGS)
{
        struct bfd_session_params *bsp;

        /* Do nothing when shutting down. */
        if (bsglobal.shutting_down)
                return 0;

        if (bsglobal.debugging)
                zlog_debug("%s: sending all sessions registered", __func__);

        /* Send the client registration */
        bfd_client_sendmsg(zclient, ZEBRA_BFD_CLIENT_REGISTER, vrf_id);

        /* Replay all activated peers. */
        TAILQ_FOREACH (bsp, &bsglobal.bsplist, entry) {
                /* Skip not installed sessions. */
                if (!bsp->installed)
                        continue;

                /* We are reconnecting, so we must send installation. */
                bsp->installed = false;

                /* Cancel any pending installation request. */
                THREAD_OFF(bsp->installev);

                /* Ask for installation. */
                bsp->lastev = BSE_INSTALL;
                thread_execute(bsglobal.tm, _bfd_sess_send, bsp, 0);
        }

        return 0;
}

static int zclient_bfd_session_update(ZAPI_CALLBACK_ARGS)
{
        struct bfd_session_params *bsp, *bspn;
        size_t sessions_updated = 0;
        struct interface *ifp;
        int remote_cbit = false;
        int state = BFD_STATUS_UNKNOWN;
        time_t now;
        size_t addrlen;
        struct prefix dp;
        struct prefix sp;
        char ifstr[128], cbitstr[32];

        /* Do nothing when shutting down. */
        if (bsglobal.shutting_down)
                return 0;

        ifp = bfd_get_peer_info(zclient->ibuf, &dp, &sp, &state, &remote_cbit,
                                vrf_id);
        /*
         * When interface lookup fails or an invalid stream is read, we must
         * not proceed otherwise it will trigger an assertion while checking
         * family type below.
         */
        if (dp.family == 0 || sp.family == 0)
                return 0;

        if (bsglobal.debugging) {
                ifstr[0] = 0;
                if (ifp)
                        snprintf(ifstr, sizeof(ifstr), " (interface %s)",
                                 ifp->name);

                snprintf(cbitstr, sizeof(cbitstr), " (CPI bit %s)",
                         remote_cbit ? "yes" : "no");

                zlog_debug("%s: %pFX -> %pFX%s VRF %s(%u)%s: %s", __func__, &sp,
                           &dp, ifstr, vrf_id_to_name(vrf_id), vrf_id, cbitstr,
                           bfd_get_status_str(state));
        }

        switch (dp.family) {
        case AF_INET:
                addrlen = sizeof(struct in_addr);
                break;
        case AF_INET6:
                addrlen = sizeof(struct in6_addr);
                break;

        default:
                /* Unexpected value. */
                assert(0);
                break;
        }

        /* Cache current time to avoid multiple monotime clock calls. */
        now = monotime(NULL);

        /* Notify all matching sessions about update. */
        TAILQ_FOREACH_SAFE (bsp, &bsglobal.bsplist, entry, bspn) {
                /* Skip not installed entries. */
                if (!bsp->installed)
                        continue;
                /* Skip different VRFs. */
                if (bsp->args.vrf_id != vrf_id)
                        continue;
                /* Skip different families. */
                if (bsp->args.family != dp.family)
                        continue;
                /* Skip different interface. */
                if (bsp->args.ifnamelen && ifp
                    && strcmp(bsp->args.ifname, ifp->name) != 0)
                        continue;
                /* Skip non matching destination addresses. */
                if (memcmp(&bsp->args.dst, &dp.u, addrlen) != 0)
                        continue;
                /*
                 * Source comparison test:
                 * We will only compare source if BFD daemon provided the
                 * source address and the protocol set a source address in
                 * the configuration otherwise we'll just skip it.
                 */
                if (sp.family && memcmp(&bsp->args.src, &i6a_zero, addrlen) != 0
                    && memcmp(&sp.u, &i6a_zero, addrlen) != 0
                    && memcmp(&bsp->args.src, &sp.u, addrlen) != 0)
                        continue;
                /* No session state change. */
                if ((int)bsp->bss.state == state)
                        continue;

                bsp->bss.last_event = now;
                bsp->bss.previous_state = bsp->bss.state;
                bsp->bss.state = state;
                bsp->bss.remote_cbit = remote_cbit;
                bsp->updatecb(bsp, &bsp->bss, bsp->arg);
                sessions_updated++;
        }

        if (bsglobal.debugging)
                zlog_debug("%s:   sessions updated: %zu", __func__,
                           sessions_updated);

        return 0;
}

void bfd_protocol_integration_init(struct zclient *zc, struct thread_master *tm)
{
        /* Initialize data structure. */
        TAILQ_INIT(&bsglobal.bsplist);

        /* Copy pointers. */
        bsglobal.zc = zc;
        bsglobal.tm = tm;

        /* Install our callbacks. */
        zc->interface_bfd_dest_update = zclient_bfd_session_update;
        zc->bfd_dest_replay = zclient_bfd_session_reply;

        /* Send the client registration */
        bfd_client_sendmsg(zc, ZEBRA_BFD_CLIENT_REGISTER, VRF_DEFAULT);
}

void bfd_protocol_integration_set_debug(bool enable)
{
        bsglobal.debugging = enable;
}

void bfd_protocol_integration_set_shutdown(bool enable)
{
        bsglobal.shutting_down = enable;
}

bool bfd_protocol_integration_debug(void)
{
        return bsglobal.debugging;
}

bool bfd_protocol_integration_shutting_down(void)
{
        return bsglobal.shutting_down;
}