// SPDX-License-Identifier: GPL-2.0-or-later

/*

 * pim_bfd.c: PIM BFD handling routines

 *

 * Copyright (C) 2017 Cumulus Networks, Inc.

 * Chirag Shah

 */

#include <zebra.h>

#include "lib/json.h"

#include "command.h"

#include "vty.h"

#include "zclient.h"

#include "pim_instance.h"

#include "pim_neighbor.h"

#include "pim_vty.h"

#include "pim_iface.h"

#include "pim_bfd.h"

#include "bfd.h"

#include "pimd.h"

#include "pim_zebra.h"

/*

 * pim_bfd_write_config - Write the interface BFD configuration.

 */

void pim_bfd_write_config(struct vty *vty, struct interface *ifp)

{

  struct pim_interface *pim_ifp = ifp->info;

  if (!pim_ifp || !pim_ifp->bfd_config.enabled)

    return;

#if HAVE_BFDD == 0

  if (pim_ifp->bfd_config.detection_multiplier != BFD_DEF_DETECT_MULT

      || pim_ifp->bfd_config.min_rx != BFD_DEF_MIN_RX

      || pim_ifp->bfd_config.min_tx != BFD_DEF_MIN_TX)

    vty_out(vty, " " PIM_AF_NAME " pim bfd %d %d %d\n",

      pim_ifp->bfd_config.detection_multiplier,

      pim_ifp->bfd_config.min_rx, pim_ifp->bfd_config.min_tx);

  else

#endif /* ! HAVE_BFDD */

    vty_out(vty, " " PIM_AF_NAME " pim bfd\n");

  if (pim_ifp->bfd_config.profile)

    vty_out(vty, " " PIM_AF_NAME " pim bfd profile %s\n",

      pim_ifp->bfd_config.profile);

}

static void pim_neighbor_bfd_cb(struct bfd_session_params *bsp,

        const struct bfd_session_status *bss, void *arg)

{

  struct pim_neighbor *nbr = arg;

  if (PIM_DEBUG_PIM_TRACE) {

    zlog_debug("%s: status %s old_status %s", __func__,

         bfd_get_status_str(bss->state),

         bfd_get_status_str(bss->previous_state));

  }

  if (bss->state == BFD_STATUS_DOWN

      && bss->previous_state == BFD_STATUS_UP)

    pim_neighbor_delete(nbr->interface, nbr, "BFD Session Expired");

}

/*

 * pim_bfd_info_nbr_create - Create/update BFD information for a neighbor.

 */

void pim_bfd_info_nbr_create(struct pim_interface *pim_ifp,

           struct pim_neighbor *neigh)

{

  /* Check if Pim Interface BFD is enabled */

  if (!pim_ifp || !pim_ifp->bfd_config.enabled)

    return;

  if (neigh->bfd_session == NULL)

    neigh->bfd_session = bfd_sess_new(pim_neighbor_bfd_cb, neigh);

  bfd_sess_set_timers(

    neigh->bfd_session, pim_ifp->bfd_config.detection_multiplier,

    pim_ifp->bfd_config.min_rx, pim_ifp->bfd_config.min_tx);

#if PIM_IPV == 4

  bfd_sess_set_ipv4_addrs(neigh->bfd_session, NULL, &neigh->source_addr);

#else

  bfd_sess_set_ipv6_addrs(neigh->bfd_session, NULL, &neigh->source_addr);

#endif

  bfd_sess_set_interface(neigh->bfd_session, neigh->interface->name);

  bfd_sess_set_vrf(neigh->bfd_session, neigh->interface->vrf->vrf_id);

  bfd_sess_set_profile(neigh->bfd_session, pim_ifp->bfd_config.profile);

  bfd_sess_install(neigh->bfd_session);

}

/*

 * pim_bfd_reg_dereg_all_nbr - Register/Deregister all neighbors associated

 *                              with a interface with BFD through

 *                              zebra for starting/stopping the monitoring of

 *                              the neighbor rechahability.

 */

void pim_bfd_reg_dereg_all_nbr(struct interface *ifp)

{

  struct pim_interface *pim_ifp = NULL;

  struct listnode *node = NULL;

  struct pim_neighbor *neigh = NULL;

  pim_ifp = ifp->info;

  if (!pim_ifp)

    return;

  for (ALL_LIST_ELEMENTS_RO(pim_ifp->pim_neighbor_list, node, neigh)) {

    if (pim_ifp->bfd_config.enabled)

      pim_bfd_info_nbr_create(pim_ifp, neigh);

    else

      bfd_sess_free(&neigh->bfd_session);

  }

}

void pim_bfd_init(void)

{

  bfd_protocol_integration_init(pim_zebra_zclient_get(), router->master);

}