[mirror_frr.git] / zebra / zebra_ptm.c

/* Kernel routing table updates using netlink over GNU/Linux system.
 * Copyright (C) 1997, 98, 99 Kunihiro Ishiguro
 *
 * 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 <sys/un.h> /* for sockaddr_un */
#include <net/if.h>

#include "bfd.h"
#include "buffer.h"
#include "command.h"
#include "if.h"
#include "network.h"
#include "ptm_lib.h"
#include "rib.h"
#include "stream.h"
#include "lib/version.h"
#include "vrf.h"
#include "vty.h"
#include "lib_errors.h"

#include "zebra/debug.h"
#include "zebra/interface.h"
#include "zebra/zebra_errors.h"
#include "zebra/zebra_ptm.h"
#include "zebra/zebra_ptm_redistribute.h"
#include "zebra/zebra_router.h"
#include "zebra_vrf.h"

/*
 * Choose the BFD implementation that we'll use.
 *
 * There are two implementations:
 * - PTM BFD: which uses an external daemon;
 * - bfdd: FRR's own BFD daemon;
 */
#if HAVE_BFDD == 0

#define ZEBRA_PTM_RECONNECT_TIME_INITIAL 1 /* initial reconnect is 1s */
#define ZEBRA_PTM_RECONNECT_TIME_MAX     300

#define PTM_MSG_LEN     4
#define PTM_HEADER_LEN  37

const char ZEBRA_PTM_GET_STATUS_CMD[] = "get-status";
const char ZEBRA_PTM_BFD_START_CMD[] = "start-bfd-sess";
const char ZEBRA_PTM_BFD_STOP_CMD[] = "stop-bfd-sess";
const char ZEBRA_PTM_BFD_CLIENT_REG_CMD[] = "reg-bfd-client";
const char ZEBRA_PTM_BFD_CLIENT_DEREG_CMD[] = "dereg-bfd-client";

const char ZEBRA_PTM_CMD_STR[] = "cmd";
const char ZEBRA_PTM_CMD_STATUS_STR[] = "cmd_status";
const char ZEBRA_PTM_PORT_STR[] = "port";
const char ZEBRA_PTM_CBL_STR[] = "cbl status";
const char ZEBRA_PTM_PASS_STR[] = "pass";
const char ZEBRA_PTM_FAIL_STR[] = "fail";
const char ZEBRA_PTM_BFDSTATUS_STR[] = "state";
const char ZEBRA_PTM_BFDSTATUS_UP_STR[] = "Up";
const char ZEBRA_PTM_BFDSTATUS_DOWN_STR[] = "Down";
const char ZEBRA_PTM_BFDDEST_STR[] = "peer";
const char ZEBRA_PTM_BFDSRC_STR[] = "local";
const char ZEBRA_PTM_BFDVRF_STR[] = "vrf";
const char ZEBRA_PTM_INVALID_PORT_NAME[] = "N/A";
const char ZEBRA_PTM_INVALID_SRC_IP[] = "N/A";
const char ZEBRA_PTM_INVALID_VRF[] = "N/A";

const char ZEBRA_PTM_BFD_DST_IP_FIELD[] = "dstIPaddr";
const char ZEBRA_PTM_BFD_SRC_IP_FIELD[] = "srcIPaddr";
const char ZEBRA_PTM_BFD_MIN_RX_FIELD[] = "requiredMinRx";
const char ZEBRA_PTM_BFD_MIN_TX_FIELD[] = "upMinTx";
const char ZEBRA_PTM_BFD_DETECT_MULT_FIELD[] = "detectMult";
const char ZEBRA_PTM_BFD_MULTI_HOP_FIELD[] = "multiHop";
const char ZEBRA_PTM_BFD_CLIENT_FIELD[] = "client";
const char ZEBRA_PTM_BFD_SEQID_FIELD[] = "seqid";
const char ZEBRA_PTM_BFD_IFNAME_FIELD[] = "ifName";
const char ZEBRA_PTM_BFD_MAX_HOP_CNT_FIELD[] = "maxHopCnt";
const char ZEBRA_PTM_BFD_SEND_EVENT[] = "sendEvent";
const char ZEBRA_PTM_BFD_VRF_NAME_FIELD[] = "vrfName";
const char ZEBRA_PTM_BFD_CBIT_FIELD[] = "bfdcbit";

static ptm_lib_handle_t *ptm_hdl;

struct zebra_ptm_cb ptm_cb;

static int zebra_ptm_socket_init(void);
int zebra_ptm_sock_read(struct thread *);
static void zebra_ptm_install_commands(void);
static int zebra_ptm_handle_msg_cb(void *arg, void *in_ctxt);
void zebra_bfd_peer_replay_req(void);
void zebra_ptm_send_status_req(void);
void zebra_ptm_reset_status(int ptm_disable);
static int zebra_ptm_bfd_client_deregister(struct zserv *client);

const char ZEBRA_PTM_SOCK_NAME[] = "\0/var/run/ptmd.socket";

void zebra_ptm_init(void)
{
        char buf[64];

        memset(&ptm_cb, 0, sizeof(struct zebra_ptm_cb));

        ptm_cb.out_data = calloc(1, ZEBRA_PTM_SEND_MAX_SOCKBUF);
        if (!ptm_cb.out_data) {
                zlog_debug("%s: Allocation of send data failed", __func__);
                return;
        }

        ptm_cb.in_data = calloc(1, ZEBRA_PTM_MAX_SOCKBUF);
        if (!ptm_cb.in_data) {
                zlog_debug("%s: Allocation of recv data failed", __func__);
                free(ptm_cb.out_data);
                return;
        }

        ptm_cb.pid = getpid();
        zebra_ptm_install_commands();

        snprintf(buf, sizeof(buf), "%s", FRR_PTM_NAME);
        ptm_hdl = ptm_lib_register(buf, NULL, zebra_ptm_handle_msg_cb,
                                   zebra_ptm_handle_msg_cb);
        ptm_cb.wb = buffer_new(0);

        ptm_cb.reconnect_time = ZEBRA_PTM_RECONNECT_TIME_INITIAL;

        ptm_cb.ptm_sock = -1;

        hook_register(zserv_client_close, zebra_ptm_bfd_client_deregister);
}

void zebra_ptm_finish(void)
{
        buffer_flush_all(ptm_cb.wb, ptm_cb.ptm_sock);

        free(ptm_hdl);

        if (ptm_cb.out_data)
                free(ptm_cb.out_data);

        if (ptm_cb.in_data)
                free(ptm_cb.in_data);

        /* Cancel events. */
        thread_cancel(&ptm_cb.t_read);
        thread_cancel(&ptm_cb.t_write);
        thread_cancel(&ptm_cb.t_timer);

        if (ptm_cb.wb)
                buffer_free(ptm_cb.wb);

        if (ptm_cb.ptm_sock >= 0)
                close(ptm_cb.ptm_sock);
}

static int zebra_ptm_flush_messages(struct thread *thread)
{
        ptm_cb.t_write = NULL;

        if (ptm_cb.ptm_sock == -1)
                return -1;

        errno = 0;

        switch (buffer_flush_available(ptm_cb.wb, ptm_cb.ptm_sock)) {
        case BUFFER_ERROR:
                flog_err_sys(EC_LIB_SOCKET, "%s ptm socket error: %s", __func__,
                             safe_strerror(errno));
                close(ptm_cb.ptm_sock);
                ptm_cb.ptm_sock = -1;
                zebra_ptm_reset_status(0);
                ptm_cb.t_timer = NULL;
                thread_add_timer(zrouter.master, zebra_ptm_connect, NULL,
                                 ptm_cb.reconnect_time, &ptm_cb.t_timer);
                return -1;
        case BUFFER_PENDING:
                ptm_cb.t_write = NULL;
                thread_add_write(zrouter.master, zebra_ptm_flush_messages, NULL,
                                 ptm_cb.ptm_sock, &ptm_cb.t_write);
                break;
        case BUFFER_EMPTY:
                break;
        }

        return 0;
}

static int zebra_ptm_send_message(char *data, int size)
{
        errno = 0;
        switch (buffer_write(ptm_cb.wb, ptm_cb.ptm_sock, data, size)) {
        case BUFFER_ERROR:
                flog_err_sys(EC_LIB_SOCKET, "%s ptm socket error: %s", __func__,
                             safe_strerror(errno));
                close(ptm_cb.ptm_sock);
                ptm_cb.ptm_sock = -1;
                zebra_ptm_reset_status(0);
                ptm_cb.t_timer = NULL;
                thread_add_timer(zrouter.master, zebra_ptm_connect, NULL,
                                 ptm_cb.reconnect_time, &ptm_cb.t_timer);
                return -1;
        case BUFFER_EMPTY:
                thread_cancel(&ptm_cb.t_write);
                break;
        case BUFFER_PENDING:
                thread_add_write(zrouter.master, zebra_ptm_flush_messages, NULL,
                                 ptm_cb.ptm_sock, &ptm_cb.t_write);
                break;
        }

        return 0;
}

int zebra_ptm_connect(struct thread *t)
{
        int init = 0;

        if (ptm_cb.ptm_sock == -1) {
                zebra_ptm_socket_init();
                init = 1;
        }

        if (ptm_cb.ptm_sock != -1) {
                if (init) {
                        ptm_cb.t_read = NULL;
                        thread_add_read(zrouter.master, zebra_ptm_sock_read,
                                        NULL, ptm_cb.ptm_sock, &ptm_cb.t_read);
                        zebra_bfd_peer_replay_req();
                }
                zebra_ptm_send_status_req();
                ptm_cb.reconnect_time = ZEBRA_PTM_RECONNECT_TIME_INITIAL;
        } else if (ptm_cb.reconnect_time < ZEBRA_PTM_RECONNECT_TIME_MAX) {
                ptm_cb.reconnect_time *= 2;
                if (ptm_cb.reconnect_time > ZEBRA_PTM_RECONNECT_TIME_MAX)
                        ptm_cb.reconnect_time = ZEBRA_PTM_RECONNECT_TIME_MAX;

                ptm_cb.t_timer = NULL;
                thread_add_timer(zrouter.master, zebra_ptm_connect, NULL,
                                 ptm_cb.reconnect_time, &ptm_cb.t_timer);
        } else if (ptm_cb.reconnect_time >= ZEBRA_PTM_RECONNECT_TIME_MAX) {
                ptm_cb.reconnect_time = ZEBRA_PTM_RECONNECT_TIME_INITIAL;
        }

        return (errno);
}

DEFUN (zebra_ptm_enable,
       zebra_ptm_enable_cmd,
       "ptm-enable",
       "Enable neighbor check with specified topology\n")
{
        struct vrf *vrf;
        struct interface *ifp;
        struct zebra_if *if_data;

        ptm_cb.ptm_enable = ZEBRA_IF_PTM_ENABLE_ON;

        RB_FOREACH (vrf, vrf_name_head, &vrfs_by_name)
                FOR_ALL_INTERFACES (vrf, ifp)
                        if (!ifp->ptm_enable) {
                                if_data = (struct zebra_if *)ifp->info;
                                if (if_data
                                    && (if_data->ptm_enable
                                        == ZEBRA_IF_PTM_ENABLE_UNSPEC)) {
                                        ifp->ptm_enable =
                                                ZEBRA_IF_PTM_ENABLE_ON;
                                }
                                /* Assign a default unknown status */
                                ifp->ptm_status = ZEBRA_PTM_STATUS_UNKNOWN;
                        }

        zebra_ptm_connect(NULL);

        return CMD_SUCCESS;
}

DEFUN (no_zebra_ptm_enable,
       no_zebra_ptm_enable_cmd,
       "no ptm-enable",
       NO_STR
       "Enable neighbor check with specified topology\n")
{
        ptm_cb.ptm_enable = ZEBRA_IF_PTM_ENABLE_OFF;
        zebra_ptm_reset_status(1);
        return CMD_SUCCESS;
}

DEFUN (zebra_ptm_enable_if,
       zebra_ptm_enable_if_cmd,
       "ptm-enable",
       "Enable neighbor check with specified topology\n")
{
        VTY_DECLVAR_CONTEXT(interface, ifp);
        struct zebra_if *if_data;
        int old_ptm_enable;
        int send_linkdown = 0;

        if_data = ifp->info;
        if_data->ptm_enable = ZEBRA_IF_PTM_ENABLE_UNSPEC;

        if (ifp->ifindex == IFINDEX_INTERNAL) {
                return CMD_SUCCESS;
        }

        old_ptm_enable = ifp->ptm_enable;
        ifp->ptm_enable = ptm_cb.ptm_enable;

        if (if_is_no_ptm_operative(ifp))
                send_linkdown = 1;

        if (!old_ptm_enable && ptm_cb.ptm_enable) {
                if (!if_is_operative(ifp) && send_linkdown) {
                        if (IS_ZEBRA_DEBUG_EVENT)
                                zlog_debug("%s: Bringing down interface %s",
                                           __func__, ifp->name);
                        if_down(ifp);
                }
        }

        return CMD_SUCCESS;
}

DEFUN (no_zebra_ptm_enable_if,
       no_zebra_ptm_enable_if_cmd,
       "no ptm-enable",
       NO_STR
       "Enable neighbor check with specified topology\n")
{
        VTY_DECLVAR_CONTEXT(interface, ifp);
        int send_linkup = 0;
        struct zebra_if *if_data;

        if ((ifp->ifindex != IFINDEX_INTERNAL) && (ifp->ptm_enable)) {
                if (!if_is_operative(ifp))
                        send_linkup = 1;

                ifp->ptm_enable = ZEBRA_IF_PTM_ENABLE_OFF;
                if (if_is_no_ptm_operative(ifp) && send_linkup) {
                        if (IS_ZEBRA_DEBUG_EVENT)
                                zlog_debug("%s: Bringing up interface %s",
                                           __func__, ifp->name);
                        if_up(ifp);
                }
        }

        if_data = ifp->info;
        if_data->ptm_enable = ZEBRA_IF_PTM_ENABLE_OFF;

        return CMD_SUCCESS;
}


void zebra_ptm_write(struct vty *vty)
{
        if (ptm_cb.ptm_enable)
                vty_out(vty, "ptm-enable\n");

        return;
}

static int zebra_ptm_socket_init(void)
{
        int ret;
        int sock;
        struct sockaddr_un addr;

        ptm_cb.ptm_sock = -1;

        sock = socket(PF_UNIX, SOCK_STREAM, 0);
        if (sock < 0)
                return -1;
        if (set_nonblocking(sock) < 0) {
                if (IS_ZEBRA_DEBUG_EVENT)
                        zlog_debug("%s: Unable to set socket non blocking[%s]",
                                   __func__, safe_strerror(errno));
                close(sock);
                return -1;
        }

        /* Make server socket. */
        memset(&addr, 0, sizeof(struct sockaddr_un));
        addr.sun_family = AF_UNIX;
        memcpy(&addr.sun_path, ZEBRA_PTM_SOCK_NAME,
               sizeof(ZEBRA_PTM_SOCK_NAME));

        ret = connect(sock, (struct sockaddr *)&addr,
                      sizeof(addr.sun_family) + sizeof(ZEBRA_PTM_SOCK_NAME)
                              - 1);
        if (ret < 0) {
                if (IS_ZEBRA_DEBUG_EVENT)
                        zlog_debug("%s: Unable to connect to socket %s [%s]",
                                   __func__, ZEBRA_PTM_SOCK_NAME,
                                   safe_strerror(errno));
                close(sock);
                return -1;
        }
        ptm_cb.ptm_sock = sock;
        return sock;
}

static void zebra_ptm_install_commands(void)
{
        install_element(CONFIG_NODE, &zebra_ptm_enable_cmd);
        install_element(CONFIG_NODE, &no_zebra_ptm_enable_cmd);
        install_element(INTERFACE_NODE, &zebra_ptm_enable_if_cmd);
        install_element(INTERFACE_NODE, &no_zebra_ptm_enable_if_cmd);
}

/* BFD session goes down, send message to the protocols. */
static void if_bfd_session_update(struct interface *ifp, struct prefix *dp,
                                  struct prefix *sp, int status,
                                  vrf_id_t vrf_id)
{
        if (IS_ZEBRA_DEBUG_EVENT) {
                char buf[2][INET6_ADDRSTRLEN];

                if (ifp) {
                        zlog_debug(
                                "MESSAGE: ZEBRA_INTERFACE_BFD_DEST_UPDATE %s/%d on %s %s event",
                                inet_ntop(dp->family, &dp->u.prefix, buf[0],
                                          INET6_ADDRSTRLEN),
                                dp->prefixlen, ifp->name,
                                bfd_get_status_str(status));
                } else {
                        struct vrf *vrf = vrf_lookup_by_id(vrf_id);

                        zlog_debug(
                                "MESSAGE: ZEBRA_INTERFACE_BFD_DEST_UPDATE %s/%d with src %s/%d and vrf %s(%u) %s event",
                                inet_ntop(dp->family, &dp->u.prefix, buf[0],
                                          INET6_ADDRSTRLEN),
                                dp->prefixlen,
                                inet_ntop(sp->family, &sp->u.prefix, buf[1],
                                          INET6_ADDRSTRLEN),
                                sp->prefixlen, VRF_LOGNAME(vrf), vrf_id,
                                bfd_get_status_str(status));
                }
        }

        zebra_interface_bfd_update(ifp, dp, sp, status, vrf_id);
}

static int zebra_ptm_handle_bfd_msg(void *arg, void *in_ctxt,
                                    struct interface *ifp)
{
        char bfdst_str[32];
        char dest_str[64];
        char src_str[64];
        char vrf_str[64];
        struct prefix dest_prefix;
        struct prefix src_prefix;
        vrf_id_t vrf_id;

        ptm_lib_find_key_in_msg(in_ctxt, ZEBRA_PTM_BFDSTATUS_STR, bfdst_str);

        if (bfdst_str[0] == '\0') {
                return -1;
        }

        ptm_lib_find_key_in_msg(in_ctxt, ZEBRA_PTM_BFDDEST_STR, dest_str);

        if (dest_str[0] == '\0') {
                zlog_debug("%s: Key %s not found in PTM msg", __func__,
                           ZEBRA_PTM_BFDDEST_STR);
                return -1;
        }

        ptm_lib_find_key_in_msg(in_ctxt, ZEBRA_PTM_BFDSRC_STR, src_str);

        if (src_str[0] == '\0') {
                zlog_debug("%s: Key %s not found in PTM msg", __func__,
                           ZEBRA_PTM_BFDSRC_STR);
                return -1;
        }

        ptm_lib_find_key_in_msg(in_ctxt, ZEBRA_PTM_BFDVRF_STR, vrf_str);

        if (vrf_str[0] == '\0') {
                zlog_debug("%s: Key %s not found in PTM msg", __func__,
                           ZEBRA_PTM_BFDVRF_STR);
                return -1;
        }

        if (IS_ZEBRA_DEBUG_EVENT)
                zlog_debug(
                        "%s: Recv Port [%s] bfd status [%s] vrf [%s] peer [%s] local [%s]",
                        __func__, ifp ? ifp->name : "N/A", bfdst_str, vrf_str,
                        dest_str, src_str);

        if (str2prefix(dest_str, &dest_prefix) == 0) {
                flog_err(EC_ZEBRA_PREFIX_PARSE_ERROR,
                         "%s: Peer addr %s not found", __func__, dest_str);
                return -1;
        }

        memset(&src_prefix, 0, sizeof(struct prefix));
        if (strcmp(ZEBRA_PTM_INVALID_SRC_IP, src_str)) {
                if (str2prefix(src_str, &src_prefix) == 0) {
                        flog_err(EC_ZEBRA_PREFIX_PARSE_ERROR,
                                 "%s: Local addr %s not found", __func__,
                                 src_str);
                        return -1;
                }
        }

        if (!strcmp(ZEBRA_PTM_INVALID_VRF, vrf_str) && ifp) {
                vrf_id = ifp->vrf->vrf_id;
        } else {
                struct vrf *pVrf;

                pVrf = vrf_lookup_by_name(vrf_str);
                if (pVrf)
                        vrf_id = pVrf->vrf_id;
                else
                        vrf_id = VRF_DEFAULT;
        }

        if (!strcmp(bfdst_str, ZEBRA_PTM_BFDSTATUS_DOWN_STR)) {
                if_bfd_session_update(ifp, &dest_prefix, &src_prefix,
                                      BFD_STATUS_DOWN, vrf_id);
        } else {
                if_bfd_session_update(ifp, &dest_prefix, &src_prefix,
                                      BFD_STATUS_UP, vrf_id);
        }

        return 0;
}

static int zebra_ptm_handle_cbl_msg(void *arg, void *in_ctxt,
                                    struct interface *ifp, char *cbl_str)
{
        int send_linkup = 0;

        if (IS_ZEBRA_DEBUG_EVENT)
                zlog_debug("%s: Recv Port [%s] cbl status [%s]", __func__,
                           ifp->name, cbl_str);

        if (!strcmp(cbl_str, ZEBRA_PTM_PASS_STR)
            && (ifp->ptm_status != ZEBRA_PTM_STATUS_UP)) {

                if (ifp->ptm_status == ZEBRA_PTM_STATUS_DOWN)
                        send_linkup = 1;
                ifp->ptm_status = ZEBRA_PTM_STATUS_UP;
                if (ifp->ptm_enable && if_is_no_ptm_operative(ifp)
                    && send_linkup)
                        if_up(ifp);
        } else if (!strcmp(cbl_str, ZEBRA_PTM_FAIL_STR)
                   && (ifp->ptm_status != ZEBRA_PTM_STATUS_DOWN)) {
                ifp->ptm_status = ZEBRA_PTM_STATUS_DOWN;
                if (ifp->ptm_enable && if_is_no_ptm_operative(ifp))
                        if_down(ifp);
        }

        return 0;
}

/*
 * zebra_ptm_handle_msg_cb - The purpose of this callback function is to handle
 *  all the command responses and notifications received from PTM.
 *
 * Command responses: Upon establishing connection with PTM, Zebra requests
 *  status of all interfaces using 'get-status' command if global ptm-enable
 *  knob is enabled. As a response to the get-status command PTM sends status
 *  of all the interfaces as command responses. All other type of command
 *  responses with cmd_status key word  are dropped. The sole purpose of
 *  registering this function as callback for the command responses is to
 *  handle the responses to get-status command.
 *
 * Notifications: Cable status and BFD session status changes are sent as
 *  notifications by PTM. So, this function is also the callback function for
 *  processing all the notifications from the PTM.
 *
 */
static int zebra_ptm_handle_msg_cb(void *arg, void *in_ctxt)
{
        struct interface *ifp = NULL;
        char port_str[128];
        char cbl_str[32];
        char cmd_status_str[32];

        ptm_lib_find_key_in_msg(in_ctxt, ZEBRA_PTM_CMD_STATUS_STR,
                                cmd_status_str);

        /* Drop command response messages */
        if (cmd_status_str[0] != '\0') {
                return 0;
        }

        ptm_lib_find_key_in_msg(in_ctxt, ZEBRA_PTM_PORT_STR, port_str);

        if (port_str[0] == '\0') {
                zlog_debug("%s: Key %s not found in PTM msg", __func__,
                           ZEBRA_PTM_PORT_STR);
                return -1;
        }

        if (strcmp(ZEBRA_PTM_INVALID_PORT_NAME, port_str)) {
                struct vrf *vrf;
                int count = 0;

                RB_FOREACH (vrf, vrf_id_head, &vrfs_by_id) {
                        ifp = if_lookup_by_name_vrf(port_str, vrf);
                        if (ifp) {
                                count++;
                                if (!vrf_is_backend_netns())
                                        break;
                        }
                }

                if (!ifp) {
                        flog_warn(EC_ZEBRA_UNKNOWN_INTERFACE,
                                  "%s: %s not found in interface list",
                                  __func__, port_str);
                        return -1;
                }
                if (count > 1) {
                        flog_warn(EC_ZEBRA_UNKNOWN_INTERFACE,
                                  "%s: multiple interface with name %s",
                                  __func__, port_str);
                        return -1;
                }
        }

        ptm_lib_find_key_in_msg(in_ctxt, ZEBRA_PTM_CBL_STR, cbl_str);

        if (cbl_str[0] == '\0') {
                return zebra_ptm_handle_bfd_msg(arg, in_ctxt, ifp);
        } else {
                if (ifp) {
                        return zebra_ptm_handle_cbl_msg(arg, in_ctxt, ifp,
                                                        cbl_str);
                } else {
                        return -1;
                }
        }
}

int zebra_ptm_sock_read(struct thread *thread)
{
        int sock;
        int rc;

        errno = 0;
        sock = THREAD_FD(thread);

        if (sock == -1)
                return -1;

        /* PTM communicates in CSV format */
        do {
                rc = ptm_lib_process_msg(ptm_hdl, sock, ptm_cb.in_data,
                                         ZEBRA_PTM_MAX_SOCKBUF, NULL);
        } while (rc > 0);

        if (((rc == 0) && !errno)
            || (errno && (errno != EWOULDBLOCK) && (errno != EAGAIN))) {
                flog_err_sys(EC_LIB_SOCKET,
                             "%s routing socket error: %s(%d) bytes %d",
                             __func__, safe_strerror(errno), errno, rc);

                close(ptm_cb.ptm_sock);
                ptm_cb.ptm_sock = -1;
                zebra_ptm_reset_status(0);
                ptm_cb.t_timer = NULL;
                thread_add_timer(zrouter.master, zebra_ptm_connect, NULL,
                                 ptm_cb.reconnect_time,
                                 &ptm_cb.t_timer);
                return -1;
        }

        ptm_cb.t_read = NULL;
        thread_add_read(zrouter.master, zebra_ptm_sock_read, NULL,
                        ptm_cb.ptm_sock, &ptm_cb.t_read);

        return 0;
}

/* BFD peer/dst register/update */
void zebra_ptm_bfd_dst_register(ZAPI_HANDLER_ARGS)
{
        struct stream *s;
        struct prefix src_p;
        struct prefix dst_p;
        uint8_t multi_hop;
        uint8_t multi_hop_cnt;
        uint8_t detect_mul;
        unsigned int min_rx_timer;
        unsigned int min_tx_timer;
        char if_name[INTERFACE_NAMSIZ];
        uint8_t len;
        void *out_ctxt;
        char buf[INET6_ADDRSTRLEN];
        char tmp_buf[64];
        int data_len = ZEBRA_PTM_SEND_MAX_SOCKBUF;
        unsigned int pid;
        uint8_t cbit_set;

        if (hdr->command == ZEBRA_BFD_DEST_UPDATE)
                client->bfd_peer_upd8_cnt++;
        else
                client->bfd_peer_add_cnt++;

        if (IS_ZEBRA_DEBUG_EVENT)
                zlog_debug("bfd_dst_register msg from client %s: length=%d",
                           zebra_route_string(client->proto), hdr->length);

        if (ptm_cb.ptm_sock == -1) {
                ptm_cb.t_timer = NULL;
                thread_add_timer(zrouter.master, zebra_ptm_connect, NULL,
                                 ptm_cb.reconnect_time, &ptm_cb.t_timer);
                return;
        }

        ptm_lib_init_msg(ptm_hdl, 0, PTMLIB_MSG_TYPE_CMD, NULL, &out_ctxt);
        snprintf(tmp_buf, sizeof(tmp_buf), "%s", ZEBRA_PTM_BFD_START_CMD);
        ptm_lib_append_msg(ptm_hdl, out_ctxt, ZEBRA_PTM_CMD_STR, tmp_buf);
        snprintf(tmp_buf, sizeof(tmp_buf), "%s",
                 zebra_route_string(client->proto));
        ptm_lib_append_msg(ptm_hdl, out_ctxt, ZEBRA_PTM_BFD_CLIENT_FIELD,
                           tmp_buf);

        s = msg;

        STREAM_GETL(s, pid);
        snprintf(tmp_buf, sizeof(tmp_buf), "%d", pid);
        ptm_lib_append_msg(ptm_hdl, out_ctxt, ZEBRA_PTM_BFD_SEQID_FIELD,
                           tmp_buf);

        STREAM_GETW(s, dst_p.family);

        if (dst_p.family == AF_INET)
                dst_p.prefixlen = IPV4_MAX_BYTELEN;
        else
                dst_p.prefixlen = IPV6_MAX_BYTELEN;

        STREAM_GET(&dst_p.u.prefix, s, dst_p.prefixlen);
        if (dst_p.family == AF_INET) {
                inet_ntop(AF_INET, &dst_p.u.prefix4, buf, sizeof(buf));
                ptm_lib_append_msg(ptm_hdl, out_ctxt,
                                   ZEBRA_PTM_BFD_DST_IP_FIELD, buf);
        } else {
                inet_ntop(AF_INET6, &dst_p.u.prefix6, buf, sizeof(buf));
                ptm_lib_append_msg(ptm_hdl, out_ctxt,
                                   ZEBRA_PTM_BFD_DST_IP_FIELD, buf);
        }

        STREAM_GETL(s, min_rx_timer);
        snprintf(tmp_buf, sizeof(tmp_buf), "%d", min_rx_timer);
        ptm_lib_append_msg(ptm_hdl, out_ctxt, ZEBRA_PTM_BFD_MIN_RX_FIELD,
                           tmp_buf);
        STREAM_GETL(s, min_tx_timer);
        snprintf(tmp_buf, sizeof(tmp_buf), "%d", min_tx_timer);
        ptm_lib_append_msg(ptm_hdl, out_ctxt, ZEBRA_PTM_BFD_MIN_TX_FIELD,
                           tmp_buf);
        STREAM_GETC(s, detect_mul);
        snprintf(tmp_buf, sizeof(tmp_buf), "%d", detect_mul);
        ptm_lib_append_msg(ptm_hdl, out_ctxt, ZEBRA_PTM_BFD_DETECT_MULT_FIELD,
                           tmp_buf);

        STREAM_GETC(s, multi_hop);
        if (multi_hop) {
                snprintf(tmp_buf, sizeof(tmp_buf), "%d", 1);
                ptm_lib_append_msg(ptm_hdl, out_ctxt,
                                   ZEBRA_PTM_BFD_MULTI_HOP_FIELD, tmp_buf);
                STREAM_GETW(s, src_p.family);

                if (src_p.family == AF_INET)
                        src_p.prefixlen = IPV4_MAX_BYTELEN;
                else
                        src_p.prefixlen = IPV6_MAX_BYTELEN;

                STREAM_GET(&src_p.u.prefix, s, src_p.prefixlen);
                if (src_p.family == AF_INET) {
                        inet_ntop(AF_INET, &src_p.u.prefix4, buf, sizeof(buf));
                        ptm_lib_append_msg(ptm_hdl, out_ctxt,
                                           ZEBRA_PTM_BFD_SRC_IP_FIELD, buf);
                } else {
                        inet_ntop(AF_INET6, &src_p.u.prefix6, buf, sizeof(buf));
                        ptm_lib_append_msg(ptm_hdl, out_ctxt,
                                           ZEBRA_PTM_BFD_SRC_IP_FIELD, buf);
                }

                STREAM_GETC(s, multi_hop_cnt);
                snprintf(tmp_buf, sizeof(tmp_buf), "%d", multi_hop_cnt);
                ptm_lib_append_msg(ptm_hdl, out_ctxt,
                                   ZEBRA_PTM_BFD_MAX_HOP_CNT_FIELD, tmp_buf);

                if (zvrf_id(zvrf) != VRF_DEFAULT)
                        ptm_lib_append_msg(ptm_hdl, out_ctxt,
                                           ZEBRA_PTM_BFD_VRF_NAME_FIELD,
                                           zvrf_name(zvrf));
        } else {
                if (dst_p.family == AF_INET6) {
                        STREAM_GETW(s, src_p.family);

                        if (src_p.family == AF_INET)
                                src_p.prefixlen = IPV4_MAX_BYTELEN;
                        else
                                src_p.prefixlen = IPV6_MAX_BYTELEN;

                        STREAM_GET(&src_p.u.prefix, s, src_p.prefixlen);
                        if (src_p.family == AF_INET) {
                                inet_ntop(AF_INET, &src_p.u.prefix4, buf,
                                          sizeof(buf));
                                ptm_lib_append_msg(ptm_hdl, out_ctxt,
                                                   ZEBRA_PTM_BFD_SRC_IP_FIELD,
                                                   buf);
                        } else {
                                inet_ntop(AF_INET6, &src_p.u.prefix6, buf,
                                          sizeof(buf));
                                ptm_lib_append_msg(ptm_hdl, out_ctxt,
                                                   ZEBRA_PTM_BFD_SRC_IP_FIELD,
                                                   buf);
                        }
                }
                STREAM_GETC(s, len);
                STREAM_GET(if_name, s, len);
                if_name[len] = '\0';

                ptm_lib_append_msg(ptm_hdl, out_ctxt,
                                   ZEBRA_PTM_BFD_IFNAME_FIELD, if_name);
        }
        STREAM_GETC(s, cbit_set);
        snprintf(tmp_buf, sizeof(tmp_buf), "%d", cbit_set);
        ptm_lib_append_msg(ptm_hdl, out_ctxt,
                           ZEBRA_PTM_BFD_CBIT_FIELD, tmp_buf);

        snprintf(tmp_buf, sizeof(tmp_buf), "%d", 1);
        ptm_lib_append_msg(ptm_hdl, out_ctxt, ZEBRA_PTM_BFD_SEND_EVENT,
                           tmp_buf);

        ptm_lib_complete_msg(ptm_hdl, out_ctxt, ptm_cb.out_data, &data_len);

        if (IS_ZEBRA_DEBUG_SEND)
                zlog_debug("%s: Sent message (%d) %s", __func__, data_len,
                           ptm_cb.out_data);
        zebra_ptm_send_message(ptm_cb.out_data, data_len);

        return;

stream_failure:
        ptm_lib_cleanup_msg(ptm_hdl, out_ctxt);
}

/* BFD peer/dst deregister */
void zebra_ptm_bfd_dst_deregister(ZAPI_HANDLER_ARGS)
{
        struct stream *s;
        struct prefix src_p;
        struct prefix dst_p;
        uint8_t multi_hop;
        char if_name[INTERFACE_NAMSIZ];
        uint8_t len;
        char buf[INET6_ADDRSTRLEN];
        char tmp_buf[64];
        int data_len = ZEBRA_PTM_SEND_MAX_SOCKBUF;
        void *out_ctxt;
        unsigned int pid;

        client->bfd_peer_del_cnt++;

        if (IS_ZEBRA_DEBUG_EVENT)
                zlog_debug("bfd_dst_deregister msg from client %s: length=%d",
                           zebra_route_string(client->proto), hdr->length);

        if (ptm_cb.ptm_sock == -1) {
                ptm_cb.t_timer = NULL;
                thread_add_timer(zrouter.master, zebra_ptm_connect, NULL,
                                 ptm_cb.reconnect_time, &ptm_cb.t_timer);
                return;
        }

        ptm_lib_init_msg(ptm_hdl, 0, PTMLIB_MSG_TYPE_CMD, NULL, &out_ctxt);

        snprintf(tmp_buf, sizeof(tmp_buf), "%s", ZEBRA_PTM_BFD_STOP_CMD);
        ptm_lib_append_msg(ptm_hdl, out_ctxt, ZEBRA_PTM_CMD_STR, tmp_buf);

        snprintf(tmp_buf, sizeof(tmp_buf), "%s",
                 zebra_route_string(client->proto));
        ptm_lib_append_msg(ptm_hdl, out_ctxt, ZEBRA_PTM_BFD_CLIENT_FIELD,
                           tmp_buf);

        s = msg;

        STREAM_GETL(s, pid);
        snprintf(tmp_buf, sizeof(tmp_buf), "%d", pid);
        ptm_lib_append_msg(ptm_hdl, out_ctxt, ZEBRA_PTM_BFD_SEQID_FIELD,
                           tmp_buf);

        STREAM_GETW(s, dst_p.family);

        if (dst_p.family == AF_INET)
                dst_p.prefixlen = IPV4_MAX_BYTELEN;
        else
                dst_p.prefixlen = IPV6_MAX_BYTELEN;

        STREAM_GET(&dst_p.u.prefix, s, dst_p.prefixlen);
        if (dst_p.family == AF_INET)
                inet_ntop(AF_INET, &dst_p.u.prefix4, buf, sizeof(buf));
        else
                inet_ntop(AF_INET6, &dst_p.u.prefix6, buf, sizeof(buf));
        ptm_lib_append_msg(ptm_hdl, out_ctxt, ZEBRA_PTM_BFD_DST_IP_FIELD, buf);


        STREAM_GETC(s, multi_hop);
        if (multi_hop) {
                snprintf(tmp_buf, sizeof(tmp_buf), "%d", 1);
                ptm_lib_append_msg(ptm_hdl, out_ctxt,
                                   ZEBRA_PTM_BFD_MULTI_HOP_FIELD, tmp_buf);

                STREAM_GETW(s, src_p.family);

                if (src_p.family == AF_INET)
                        src_p.prefixlen = IPV4_MAX_BYTELEN;
                else
                        src_p.prefixlen = IPV6_MAX_BYTELEN;

                STREAM_GET(&src_p.u.prefix, s, src_p.prefixlen);
                if (src_p.family == AF_INET)
                        inet_ntop(AF_INET, &src_p.u.prefix4, buf, sizeof(buf));
                else
                        inet_ntop(AF_INET6, &src_p.u.prefix6, buf, sizeof(buf));
                ptm_lib_append_msg(ptm_hdl, out_ctxt,
                                   ZEBRA_PTM_BFD_SRC_IP_FIELD, buf);

                if (zvrf_id(zvrf) != VRF_DEFAULT)
                        ptm_lib_append_msg(ptm_hdl, out_ctxt,
                                           ZEBRA_PTM_BFD_VRF_NAME_FIELD,
                                           zvrf_name(zvrf));
        } else {
                if (dst_p.family == AF_INET6) {
                        STREAM_GETW(s, src_p.family);

                        if (src_p.family == AF_INET)
                                src_p.prefixlen = IPV4_MAX_BYTELEN;
                        else
                                src_p.prefixlen = IPV6_MAX_BYTELEN;

                        STREAM_GET(&src_p.u.prefix, s, src_p.prefixlen);
                        if (src_p.family == AF_INET) {
                                inet_ntop(AF_INET, &src_p.u.prefix4, buf,
                                          sizeof(buf));
                                ptm_lib_append_msg(ptm_hdl, out_ctxt,
                                                   ZEBRA_PTM_BFD_SRC_IP_FIELD,
                                                   buf);
                        } else {
                                inet_ntop(AF_INET6, &src_p.u.prefix6, buf,
                                          sizeof(buf));
                                ptm_lib_append_msg(ptm_hdl, out_ctxt,
                                                   ZEBRA_PTM_BFD_SRC_IP_FIELD,
                                                   buf);
                        }
                }

                STREAM_GETC(s, len);
                STREAM_GET(if_name, s, len);
                if_name[len] = '\0';

                ptm_lib_append_msg(ptm_hdl, out_ctxt,
                                   ZEBRA_PTM_BFD_IFNAME_FIELD, if_name);
        }

        ptm_lib_complete_msg(ptm_hdl, out_ctxt, ptm_cb.out_data, &data_len);
        if (IS_ZEBRA_DEBUG_SEND)
                zlog_debug("%s: Sent message (%d) %s", __func__, data_len,
                           ptm_cb.out_data);

        zebra_ptm_send_message(ptm_cb.out_data, data_len);

        return;

stream_failure:
        ptm_lib_cleanup_msg(ptm_hdl, out_ctxt);
}

/* BFD client register */
void zebra_ptm_bfd_client_register(ZAPI_HANDLER_ARGS)
{
        struct stream *s;
        unsigned int pid;
        void *out_ctxt = NULL;
        char tmp_buf[64];
        int data_len = ZEBRA_PTM_SEND_MAX_SOCKBUF;

        client->bfd_client_reg_cnt++;

        if (IS_ZEBRA_DEBUG_EVENT)
                zlog_debug("bfd_client_register msg from client %s: length=%d",
                           zebra_route_string(client->proto), hdr->length);

        s = msg;
        STREAM_GETL(s, pid);

        if (ptm_cb.ptm_sock == -1) {
                ptm_cb.t_timer = NULL;
                thread_add_timer(zrouter.master, zebra_ptm_connect, NULL,
                                 ptm_cb.reconnect_time, &ptm_cb.t_timer);
                return;
        }

        ptm_lib_init_msg(ptm_hdl, 0, PTMLIB_MSG_TYPE_CMD, NULL, &out_ctxt);

        snprintf(tmp_buf, sizeof(tmp_buf), "%s", ZEBRA_PTM_BFD_CLIENT_REG_CMD);
        ptm_lib_append_msg(ptm_hdl, out_ctxt, ZEBRA_PTM_CMD_STR, tmp_buf);

        snprintf(tmp_buf, sizeof(tmp_buf), "%s",
                 zebra_route_string(client->proto));
        ptm_lib_append_msg(ptm_hdl, out_ctxt, ZEBRA_PTM_BFD_CLIENT_FIELD,
                           tmp_buf);

        snprintf(tmp_buf, sizeof(tmp_buf), "%d", pid);
        ptm_lib_append_msg(ptm_hdl, out_ctxt, ZEBRA_PTM_BFD_SEQID_FIELD,
                           tmp_buf);

        ptm_lib_complete_msg(ptm_hdl, out_ctxt, ptm_cb.out_data, &data_len);

        if (IS_ZEBRA_DEBUG_SEND)
                zlog_debug("%s: Sent message (%d) %s", __func__, data_len,
                           ptm_cb.out_data);
        zebra_ptm_send_message(ptm_cb.out_data, data_len);

        SET_FLAG(ptm_cb.client_flags[client->proto],
                 ZEBRA_PTM_BFD_CLIENT_FLAG_REG);

        return;

stream_failure:
        /*
         * IF we ever add more STREAM_GETXXX functions after the out_ctxt
         * is allocated then we need to add this code back in
         *
         * if (out_ctxt)
         *      ptm_lib_cleanup_msg(ptm_hdl, out_ctxt);
         */
        return;
}

/* BFD client deregister */
int zebra_ptm_bfd_client_deregister(struct zserv *client)
{
        uint8_t proto = client->proto;
        void *out_ctxt;
        char tmp_buf[64];
        int data_len = ZEBRA_PTM_SEND_MAX_SOCKBUF;

        if (!IS_BFD_ENABLED_PROTOCOL(proto))
                return 0;

        if (IS_ZEBRA_DEBUG_EVENT)
                zlog_debug("bfd_client_deregister msg for client %s",
                           zebra_route_string(proto));

        if (ptm_cb.ptm_sock == -1) {
                ptm_cb.t_timer = NULL;
                thread_add_timer(zrouter.master, zebra_ptm_connect, NULL,
                                 ptm_cb.reconnect_time, &ptm_cb.t_timer);
                return 0;
        }

        ptm_lib_init_msg(ptm_hdl, 0, PTMLIB_MSG_TYPE_CMD, NULL, &out_ctxt);

        snprintf(tmp_buf, sizeof(tmp_buf), "%s",
                 ZEBRA_PTM_BFD_CLIENT_DEREG_CMD);
        ptm_lib_append_msg(ptm_hdl, out_ctxt, ZEBRA_PTM_CMD_STR, tmp_buf);

        snprintf(tmp_buf, sizeof(tmp_buf), "%s", zebra_route_string(proto));
        ptm_lib_append_msg(ptm_hdl, out_ctxt, ZEBRA_PTM_BFD_CLIENT_FIELD,
                           tmp_buf);

        ptm_lib_complete_msg(ptm_hdl, out_ctxt, ptm_cb.out_data, &data_len);

        if (IS_ZEBRA_DEBUG_SEND)
                zlog_debug("%s: Sent message (%d) %s", __func__, data_len,
                           ptm_cb.out_data);

        zebra_ptm_send_message(ptm_cb.out_data, data_len);
        UNSET_FLAG(ptm_cb.client_flags[proto], ZEBRA_PTM_BFD_CLIENT_FLAG_REG);

        return 0;
}

int zebra_ptm_get_enable_state(void)
{
        return ptm_cb.ptm_enable;
}

/*
 * zebra_ptm_get_status_str - Convert status to a display string.
 */
static const char *zebra_ptm_get_status_str(int status)
{
        switch (status) {
        case ZEBRA_PTM_STATUS_DOWN:
                return "fail";
        case ZEBRA_PTM_STATUS_UP:
                return "pass";
        case ZEBRA_PTM_STATUS_UNKNOWN:
        default:
                return "n/a";
        }
}

void zebra_ptm_show_status(struct vty *vty, json_object *json,
                           struct interface *ifp)
{
        const char *status;

        if (ifp->ptm_enable)
                status = zebra_ptm_get_status_str(ifp->ptm_status);
        else
                status = "disabled";

        if (json)
                json_object_string_add(json, "ptmStatus", status);
        else
                vty_out(vty, "  PTM status: %s\n", status);
}

void zebra_ptm_send_status_req(void)
{
        void *out_ctxt;
        int len = ZEBRA_PTM_SEND_MAX_SOCKBUF;

        if (ptm_cb.ptm_enable) {
                ptm_lib_init_msg(ptm_hdl, 0, PTMLIB_MSG_TYPE_CMD, NULL,
                                 &out_ctxt);
                ptm_lib_append_msg(ptm_hdl, out_ctxt, ZEBRA_PTM_CMD_STR,
                                   ZEBRA_PTM_GET_STATUS_CMD);
                ptm_lib_complete_msg(ptm_hdl, out_ctxt, ptm_cb.out_data, &len);

                zebra_ptm_send_message(ptm_cb.out_data, len);
        }
}

void zebra_ptm_reset_status(int ptm_disable)
{
        struct vrf *vrf;
        struct interface *ifp;
        int send_linkup;

        RB_FOREACH (vrf, vrf_id_head, &vrfs_by_id)
                FOR_ALL_INTERFACES (vrf, ifp) {
                        send_linkup = 0;
                        if (ifp->ptm_enable) {
                                if (!if_is_operative(ifp))
                                        send_linkup = 1;

                                if (ptm_disable)
                                        ifp->ptm_enable =
                                                ZEBRA_IF_PTM_ENABLE_OFF;
                                ifp->ptm_status = ZEBRA_PTM_STATUS_UNKNOWN;

                                if (if_is_operative(ifp) && send_linkup) {
                                        if (IS_ZEBRA_DEBUG_EVENT)
                                                zlog_debug(
                                                        "%s: Bringing up interface %s",
                                                        __func__, ifp->name);
                                        if_up(ifp);
                                }
                        }
                }
}

void zebra_ptm_if_init(struct zebra_if *zebra_ifp)
{
        zebra_ifp->ptm_enable = ZEBRA_IF_PTM_ENABLE_UNSPEC;
}

void zebra_ptm_if_set_ptm_state(struct interface *ifp,
                                struct zebra_if *zebra_ifp)
{
        if (zebra_ifp && zebra_ifp->ptm_enable != ZEBRA_IF_PTM_ENABLE_UNSPEC)
                ifp->ptm_enable = zebra_ifp->ptm_enable;
}

void zebra_ptm_if_write(struct vty *vty, struct zebra_if *zebra_ifp)
{
        if (zebra_ifp->ptm_enable == ZEBRA_IF_PTM_ENABLE_OFF)
                vty_out(vty, " no ptm-enable\n");
}

#else /* HAVE_BFDD */

/*
 * Data structures.
 */
struct ptm_process {
        struct zserv *pp_zs;
        pid_t pp_pid;

        TAILQ_ENTRY(ptm_process) pp_entry;
};
TAILQ_HEAD(ppqueue, ptm_process) ppqueue;

DEFINE_MTYPE_STATIC(ZEBRA, ZEBRA_PTM_BFD_PROCESS,
                    "PTM BFD process registration table.");

/*
 * Prototypes.
 */
static struct ptm_process *pp_new(pid_t pid, struct zserv *zs);
static struct ptm_process *pp_lookup_byzs(struct zserv *zs);
static void pp_free(struct ptm_process *pp);
static void pp_free_all(void);

static void zebra_ptm_send_bfdd(struct stream *msg);
static void zebra_ptm_send_clients(struct stream *msg);
static int _zebra_ptm_bfd_client_deregister(struct zserv *zs);
static void _zebra_ptm_reroute(struct zserv *zs, struct zebra_vrf *zvrf,
                               struct stream *msg, uint32_t command);


/*
 * Process PID registration.
 */
static struct ptm_process *pp_new(pid_t pid, struct zserv *zs)
{
        struct ptm_process *pp;

#ifdef PTM_DEBUG
        /* Sanity check: more than one client can't have the same PID. */
        TAILQ_FOREACH(pp, &ppqueue, pp_entry) {
                if (pp->pp_pid == pid && pp->pp_zs != zs)
                        zlog_err("%s:%d pid and client pointer doesn't match",
                                 __FILE__, __LINE__);
        }
#endif /* PTM_DEBUG */

        /* Lookup for duplicates. */
        pp = pp_lookup_byzs(zs);
        if (pp != NULL)
                return pp;

        /* Allocate and register new process. */
        pp = XCALLOC(MTYPE_ZEBRA_PTM_BFD_PROCESS, sizeof(*pp));

        pp->pp_pid = pid;
        pp->pp_zs = zs;
        TAILQ_INSERT_HEAD(&ppqueue, pp, pp_entry);

        return pp;
}

static struct ptm_process *pp_lookup_byzs(struct zserv *zs)
{
        struct ptm_process *pp;

        TAILQ_FOREACH(pp, &ppqueue, pp_entry) {
                if (pp->pp_zs != zs)
                        continue;

                break;
        }

        return pp;
}

static void pp_free(struct ptm_process *pp)
{
        if (pp == NULL)
                return;

        TAILQ_REMOVE(&ppqueue, pp, pp_entry);
        XFREE(MTYPE_ZEBRA_PTM_BFD_PROCESS, pp);
}

static void pp_free_all(void)
{
        struct ptm_process *pp;

        while (!TAILQ_EMPTY(&ppqueue)) {
                pp = TAILQ_FIRST(&ppqueue);
                pp_free(pp);
        }
}


/*
 * Use the FRR's internal daemon implementation.
 */
static void zebra_ptm_send_bfdd(struct stream *msg)
{
        struct listnode *node;
        struct zserv *client;
        struct stream *msgc;

        /* Create copy for replication. */
        msgc = stream_dup(msg);
        if (msgc == NULL) {
                zlog_debug("%s: not enough memory", __func__);
                return;
        }

        /* Send message to all running BFDd daemons. */
        for (ALL_LIST_ELEMENTS_RO(zrouter.client_list, node, client)) {
                if (client->proto != ZEBRA_ROUTE_BFD)
                        continue;

                zserv_send_message(client, msg);

                /* Allocate more messages. */
                msg = stream_dup(msgc);
                if (msg == NULL) {
                        zlog_debug("%s: not enough memory", __func__);
                        return;
                }
        }

        stream_free(msgc);
        stream_free(msg);
}

static void zebra_ptm_send_clients(struct stream *msg)
{
        struct listnode *node;
        struct zserv *client;
        struct stream *msgc;

        /* Create copy for replication. */
        msgc = stream_dup(msg);
        if (msgc == NULL) {
                zlog_debug("%s: not enough memory", __func__);
                return;
        }

        /* Send message to all running client daemons. */
        for (ALL_LIST_ELEMENTS_RO(zrouter.client_list, node, client)) {
                if (!IS_BFD_ENABLED_PROTOCOL(client->proto))
                        continue;

                zserv_send_message(client, msg);

                /* Allocate more messages. */
                msg = stream_dup(msgc);
                if (msg == NULL) {
                        zlog_debug("%s: not enough memory", __func__);
                        return;
                }
        }

        stream_free(msgc);
        stream_free(msg);
}

static int _zebra_ptm_bfd_client_deregister(struct zserv *zs)
{
        struct stream *msg;
        struct ptm_process *pp;

        if (!IS_BFD_ENABLED_PROTOCOL(zs->proto))
                return 0;

        /* Find daemon pid by zebra connection pointer. */
        pp = pp_lookup_byzs(zs);
        if (pp == NULL) {
                zlog_err("%s:%d failed to find process pid registration",
                         __FILE__, __LINE__);
                return -1;
        }

        /* Generate, send message and free() daemon related data. */
        msg = stream_new(ZEBRA_MAX_PACKET_SIZ);
        if (msg == NULL) {
                zlog_debug("%s: not enough memory", __func__);
                return 0;
        }

        /*
         * The message type will be BFD_DEST_REPLY so we can use only
         * one callback at the `bfdd` side, however the real command
         * number will be included right after the zebra header.
         */
        zclient_create_header(msg, ZEBRA_BFD_DEST_REPLAY, 0);
        stream_putl(msg, ZEBRA_BFD_CLIENT_DEREGISTER);

        /* Put process PID. */
        stream_putl(msg, pp->pp_pid);

        /* Update the data pointers. */
        stream_putw_at(msg, 0, stream_get_endp(msg));

        zebra_ptm_send_bfdd(msg);

        pp_free(pp);

        return 0;
}

void zebra_ptm_init(void)
{
        /* Initialize the ptm process information list. */
        TAILQ_INIT(&ppqueue);

        /*
         * Send deregistration messages to BFD daemon when some other
         * daemon closes. This will help avoid sending daemons
         * unnecessary notification messages.
         */
        hook_register(zserv_client_close, _zebra_ptm_bfd_client_deregister);
}

void zebra_ptm_finish(void)
{
        /* Remove the client disconnect hook and free all memory. */
        hook_unregister(zserv_client_close, _zebra_ptm_bfd_client_deregister);
        pp_free_all();
}


/*
 * Message handling.
 */
static void _zebra_ptm_reroute(struct zserv *zs, struct zebra_vrf *zvrf,
                               struct stream *msg, uint32_t command)
{
        struct stream *msgc;
        char buf[ZEBRA_MAX_PACKET_SIZ];
        pid_t ppid;

        /* Create BFD header */
        msgc = stream_new(ZEBRA_MAX_PACKET_SIZ);
        zclient_create_header(msgc, ZEBRA_BFD_DEST_REPLAY, zvrf->vrf->vrf_id);
        stream_putl(msgc, command);

        if (STREAM_READABLE(msg) > STREAM_WRITEABLE(msgc)) {
                zlog_warn("Cannot fit extended BFD header plus original message contents into ZAPI packet; dropping message");
                goto stream_failure;
        }

        /* Copy original message, excluding header, into new message */
        stream_get_from(buf, msg, stream_get_getp(msg), STREAM_READABLE(msg));
        stream_put(msgc, buf, STREAM_READABLE(msg));

        /* Update length field */
        stream_putw_at(msgc, 0, STREAM_READABLE(msgc));

        zebra_ptm_send_bfdd(msgc);
        msgc = NULL;

        /* Registrate process PID for shutdown hook. */
        STREAM_GETL(msg, ppid);
        pp_new(ppid, zs);

        return;

stream_failure:
        if (msgc)
                stream_free(msgc);
        zlog_err("%s:%d failed to registrate client pid", __FILE__, __LINE__);
}

void zebra_ptm_bfd_dst_register(ZAPI_HANDLER_ARGS)
{
        if (IS_ZEBRA_DEBUG_EVENT)
                zlog_debug("bfd_dst_register msg from client %s: length=%d",
                           zebra_route_string(client->proto), hdr->length);

        _zebra_ptm_reroute(client, zvrf, msg, ZEBRA_BFD_DEST_REGISTER);
}

void zebra_ptm_bfd_dst_deregister(ZAPI_HANDLER_ARGS)
{
        if (IS_ZEBRA_DEBUG_EVENT)
                zlog_debug("bfd_dst_deregister msg from client %s: length=%d",
                           zebra_route_string(client->proto), hdr->length);

        _zebra_ptm_reroute(client, zvrf, msg, ZEBRA_BFD_DEST_DEREGISTER);
}

void zebra_ptm_bfd_client_register(ZAPI_HANDLER_ARGS)
{
        if (IS_ZEBRA_DEBUG_EVENT)
                zlog_debug("bfd_client_register msg from client %s: length=%d",
                           zebra_route_string(client->proto), hdr->length);

        _zebra_ptm_reroute(client, zvrf, msg, ZEBRA_BFD_CLIENT_REGISTER);
}

void zebra_ptm_bfd_dst_replay(ZAPI_HANDLER_ARGS)
{
        struct stream *msgc;
        size_t zmsglen, zhdrlen;
        uint32_t cmd;

        /*
         * NOTE:
         * Replay messages with HAVE_BFDD are meant to be replayed to
         * the client daemons. These messages are composed and
         * originated from the `bfdd` daemon.
         */
        if (IS_ZEBRA_DEBUG_EVENT)
                zlog_debug("bfd_dst_update msg from client %s: length=%d",
                           zebra_route_string(client->proto), hdr->length);

        /*
         * Client messages must be re-routed, otherwise do the `bfdd`
         * special treatment.
         */
        if (client->proto != ZEBRA_ROUTE_BFD) {
                _zebra_ptm_reroute(client, zvrf, msg, ZEBRA_BFD_DEST_REPLAY);
                return;
        }

        /* Figure out if this is an DEST_UPDATE or DEST_REPLAY. */
        if (stream_getl2(msg, &cmd) == false) {
                zlog_err("%s: expected at least 4 bytes (command)", __func__);
                return;
        }

        /*
         * Don't modify message in the zebra API. In order to do that we
         * need to allocate a new message stream and copy the message
         * provided by zebra.
         */
        msgc = stream_new(ZEBRA_MAX_PACKET_SIZ);
        if (msgc == NULL) {
                zlog_debug("%s: not enough memory", __func__);
                return;
        }

        /* Calculate our header size plus the message contents. */
        if (cmd != ZEBRA_BFD_DEST_REPLAY) {
                zhdrlen = ZEBRA_HEADER_SIZE;
                zmsglen = msg->endp - msg->getp;
                memcpy(msgc->data + zhdrlen, msg->data + msg->getp, zmsglen);

                zclient_create_header(msgc, cmd, zvrf_id(zvrf));

                msgc->getp = 0;
                msgc->endp = zhdrlen + zmsglen;
        } else
                zclient_create_header(msgc, cmd, zvrf_id(zvrf));

        /* Update the data pointers. */
        stream_putw_at(msgc, 0, stream_get_endp(msgc));

        zebra_ptm_send_clients(msgc);
}

/*
 * Unused functions.
 */
void zebra_ptm_if_init(struct zebra_if *zifp __attribute__((__unused__)))
{
        /* NOTHING */
}

int zebra_ptm_get_enable_state(void)
{
        return 0;
}

void zebra_ptm_show_status(struct vty *vty __attribute__((__unused__)),
                           json_object *json __attribute__((__unused__)),
                           struct interface *ifp __attribute__((__unused__)))
{
        /* NOTHING */
}

void zebra_ptm_write(struct vty *vty __attribute__((__unused__)))
{
        /* NOTHING */
}

void zebra_ptm_if_write(struct vty *vty __attribute__((__unused__)),
                        struct zebra_if *zifp __attribute__((__unused__)))
{
        /* NOTHING */
}
void zebra_ptm_if_set_ptm_state(struct interface *i __attribute__((__unused__)),
                                struct zebra_if *zi __attribute__((__unused__)))
{
        /* NOTHING */
}

#endif /* HAVE_BFDD */