/src/frr/pimd/pim_mlag.c

Source (jump to first uncovered line)
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * This is an implementation of PIM MLAG Functionality
 *
 * Module name: PIM MLAG
 *
 * Author: sathesh Kumar karra <sathk@cumulusnetworks.com>
 *
 * Copyright (C) 2019 Cumulus Networks http://www.cumulusnetworks.com
 */
#include <zebra.h>

#include "pimd.h"
#include "pim_mlag.h"
#include "pim_upstream.h"
#include "pim_vxlan.h"

extern struct zclient *zclient;

#define PIM_MLAG_METADATA_LEN 4

/*********************ACtual Data processing *****************************/
/* TBD: There can be duplicate updates to FIB***/
#define PIM_MLAG_ADD_OIF_TO_OIL(ch, ch_oil)                                    \
  do {                                                                   \
    if (PIM_DEBUG_MLAG)                                            \
      zlog_debug(                                            \
        "%s: add Dual-active Interface to %s "         \
        "to oil:%s",                                   \
        __func__, ch->interface->name, ch->sg_str);    \
    pim_channel_update_oif_mute(ch_oil, ch->interface->info);      \
  } while (0)

#define PIM_MLAG_DEL_OIF_TO_OIL(ch, ch_oil)                                    \
  do {                                                                   \
    if (PIM_DEBUG_MLAG)                                            \
      zlog_debug(                                            \
        "%s: del Dual-active Interface to %s "         \
        "to oil:%s",                                   \
        __func__, ch->interface->name, ch->sg_str);    \
    pim_channel_update_oif_mute(ch_oil, ch->interface->info);      \
  } while (0)


static void pim_mlag_calculate_df_for_ifchannels(struct pim_upstream *up,
             bool is_df)
{
  struct listnode *chnode;
  struct listnode *chnextnode;
  struct pim_ifchannel *ch;
  struct pim_interface *pim_ifp = NULL;
  struct channel_oil *ch_oil = NULL;

  ch_oil = (up) ? up->channel_oil : NULL;

  if (!ch_oil)
    return;

  if (PIM_DEBUG_MLAG)
    zlog_debug("%s: Calculating DF for Dual active if-channel%s",
         __func__, up->sg_str);

  for (ALL_LIST_ELEMENTS(up->ifchannels, chnode, chnextnode, ch)) {
    pim_ifp = (ch->interface) ? ch->interface->info : NULL;
    if (!pim_ifp || !PIM_I_am_DualActive(pim_ifp))
      continue;

    if (is_df)
      PIM_MLAG_ADD_OIF_TO_OIL(ch, ch_oil);
    else
      PIM_MLAG_DEL_OIF_TO_OIL(ch, ch_oil);
  }
}

static void pim_mlag_inherit_mlag_flags(struct pim_upstream *up, bool is_df)
{
  struct listnode *listnode;
  struct pim_upstream *child;
  struct listnode *chnode;
  struct listnode *chnextnode;
  struct pim_ifchannel *ch;
  struct pim_interface *pim_ifp = NULL;
  struct channel_oil *ch_oil = NULL;

  if (PIM_DEBUG_MLAG)
    zlog_debug("%s: Updating DF for uptream:%s children", __func__,
         up->sg_str);


  for (ALL_LIST_ELEMENTS(up->ifchannels, chnode, chnextnode, ch)) {
    pim_ifp = (ch->interface) ? ch->interface->info : NULL;
    if (!pim_ifp || !PIM_I_am_DualActive(pim_ifp))
      continue;

    for (ALL_LIST_ELEMENTS_RO(up->sources, listnode, child)) {
      if (PIM_DEBUG_MLAG)
        zlog_debug("%s: Updating DF for child:%s",
             __func__, child->sg_str);
      ch_oil = (child) ? child->channel_oil : NULL;

      if (!ch_oil)
        continue;

      if (is_df)
        PIM_MLAG_ADD_OIF_TO_OIL(ch, ch_oil);
      else
        PIM_MLAG_DEL_OIF_TO_OIL(ch, ch_oil);
    }
  }
}

/******************************* pim upstream sync **************************/
/* Update DF role for the upstream entry and return true on role change */
bool pim_mlag_up_df_role_update(struct pim_instance *pim,
    struct pim_upstream *up, bool is_df, const char *reason)
{
  struct channel_oil *c_oil = up->channel_oil;
  bool old_is_df = !PIM_UPSTREAM_FLAG_TEST_MLAG_NON_DF(up->flags);
  struct pim_interface *vxlan_ifp;

  if (is_df == old_is_df) {
    if (PIM_DEBUG_MLAG)
      zlog_debug(
        "%s: Ignoring Role update for %s, since no change",
        __func__, up->sg_str);
    return false;
  }

  if (PIM_DEBUG_MLAG)
    zlog_debug("local MLAG mroute %s role changed to %s based on %s",
        up->sg_str, is_df ? "df" : "non-df", reason);

  if (is_df)
    PIM_UPSTREAM_FLAG_UNSET_MLAG_NON_DF(up->flags);
  else
    PIM_UPSTREAM_FLAG_SET_MLAG_NON_DF(up->flags);


  /*
   * This Upstream entry synced to peer Because of Dual-active
   * Interface configuration
   */
  if (PIM_UPSTREAM_FLAG_TEST_MLAG_INTERFACE(up->flags)) {
    pim_mlag_inherit_mlag_flags(up, is_df);
    pim_mlag_calculate_df_for_ifchannels(up, is_df);
  }

  /* If the DF role has changed check if ipmr-lo needs to be
   * muted/un-muted. Active-Active devices and vxlan termination
   * devices (ipmr-lo) are suppressed on the non-DF.
   * This may leave the mroute with the empty OIL in which case the
   * the forwarding entry's sole purpose is to just blackhole the flow
   * headed to the switch.
   */
  if (c_oil) {
    vxlan_ifp = pim_vxlan_get_term_ifp(pim);
    if (vxlan_ifp)
      pim_channel_update_oif_mute(c_oil, vxlan_ifp);
  }

  /* If DF role changed on a (*,G) termination mroute update the
   * associated DF role on the inherited (S,G) entries
   */
  if (pim_addr_is_any(up->sg.src) &&
      PIM_UPSTREAM_FLAG_TEST_MLAG_VXLAN(up->flags))
    pim_vxlan_inherit_mlag_flags(pim, up, true /* inherit */);

  return true;
}

/* Run per-upstream entry DF election and return true on role change */
static bool pim_mlag_up_df_role_elect(struct pim_instance *pim,
    struct pim_upstream *up)
{
  bool is_df;
  uint32_t peer_cost;
  uint32_t local_cost;
  bool rv;

  if (!pim_up_mlag_is_local(up))
    return false;

  /* We are yet to rx a status update from the local MLAG daemon so
   * we will assume DF status.
   */
  if (!(router->mlag_flags & PIM_MLAGF_STATUS_RXED))
    return pim_mlag_up_df_role_update(pim, up,
        true /*is_df*/, "mlagd-down");

  /* If not connected to peer assume DF role on the MLAG primary
   * switch (and non-DF on the secondary switch.
   */
  if (!(router->mlag_flags & PIM_MLAGF_PEER_CONN_UP)) {
    is_df = (router->mlag_role == MLAG_ROLE_PRIMARY) ? true : false;
    return pim_mlag_up_df_role_update(pim, up,
        is_df, "peer-down");
  }

  /* If MLAG peer session is up but zebra is down on the peer
   * assume DF role.
   */
  if (!(router->mlag_flags & PIM_MLAGF_PEER_ZEBRA_UP))
    return pim_mlag_up_df_role_update(pim, up,
        true /*is_df*/, "zebra-down");

  /* If we are connected to peer switch but don't have a mroute
   * from it we have to assume non-DF role to avoid duplicates.
   * Note: When the peer connection comes up we wait for initial
   * replay to complete before moving "strays" i.e. local-mlag-mroutes
   * without a peer reference to non-df role.
   */
  if (!PIM_UPSTREAM_FLAG_TEST_MLAG_PEER(up->flags))
    return pim_mlag_up_df_role_update(pim, up,
        false /*is_df*/, "no-peer-mroute");

  /* switch with the lowest RPF cost wins. if both switches have the same
   * cost MLAG role is used as a tie breaker (MLAG primary wins).
   */
  peer_cost = up->mlag.peer_mrib_metric;
  local_cost = pim_up_mlag_local_cost(up);
  if (local_cost == peer_cost) {
    is_df = (router->mlag_role == MLAG_ROLE_PRIMARY) ? true : false;
    rv = pim_mlag_up_df_role_update(pim, up, is_df, "equal-cost");
  } else {
    is_df = (local_cost < peer_cost) ? true : false;
    rv = pim_mlag_up_df_role_update(pim, up, is_df, "cost");
  }

  return rv;
}

/* Handle upstream entry add from the peer MLAG switch -
 * - if a local entry doesn't exist one is created with reference
 *   _MLAG_PEER
 * - if a local entry exists and has a MLAG OIF DF election is run.
 *   the non-DF switch stop forwarding traffic to MLAG devices.
 */
static void pim_mlag_up_peer_add(struct mlag_mroute_add *msg)
{
  struct pim_upstream *up;
  struct pim_instance *pim;
  int flags = 0;
  pim_sgaddr sg;
  struct vrf *vrf;

  memset(&sg, 0, sizeof(sg));
  sg.src.s_addr = htonl(msg->source_ip);
  sg.grp.s_addr = htonl(msg->group_ip);

  if (PIM_DEBUG_MLAG)
    zlog_debug("peer MLAG mroute add %s:%pSG cost %d",
         msg->vrf_name, &sg, msg->cost_to_rp);

  /* XXX - this is not correct. we MUST cache updates to avoid losing
   * an entry because of race conditions with the peer switch.
   */
  vrf = vrf_lookup_by_name(msg->vrf_name);
  if  (!vrf) {
    if (PIM_DEBUG_MLAG)
      zlog_debug(
        "peer MLAG mroute add failed %s:%pSG; no vrf",
        msg->vrf_name, &sg);
    return;
  }
  pim = vrf->info;

  up = pim_upstream_find(pim, &sg);
  if (up) {
    /* upstream already exists; create peer reference if it
     * doesn't already exist.
     */
    if (!PIM_UPSTREAM_FLAG_TEST_MLAG_PEER(up->flags))
      pim_upstream_ref(up, PIM_UPSTREAM_FLAG_MASK_MLAG_PEER,
           __func__);
  } else {
    PIM_UPSTREAM_FLAG_SET_MLAG_PEER(flags);
    up = pim_upstream_add(pim, &sg, NULL /*iif*/, flags, __func__,
              NULL /*if_ch*/);

    if (!up) {
      if (PIM_DEBUG_MLAG)
        zlog_debug(
          "peer MLAG mroute add failed %s:%pSG",
          vrf->name, &sg);
      return;
    }
  }
  up->mlag.peer_mrib_metric = msg->cost_to_rp;
  pim_mlag_up_df_role_elect(pim, up);
}

/* Handle upstream entry del from the peer MLAG switch -
 * - peer reference is removed. this can result in the upstream
 *   being deleted altogether.
 * - if a local entry continues to exisy and has a MLAG OIF DF election
 *   is re-run (at the end of which the local entry will be the DF).
 */
static struct pim_upstream *pim_mlag_up_peer_deref(struct pim_instance *pim,
               struct pim_upstream *up)
{
  if (!PIM_UPSTREAM_FLAG_TEST_MLAG_PEER(up->flags))
    return up;

  PIM_UPSTREAM_FLAG_UNSET_MLAG_PEER(up->flags);
  up = pim_upstream_del(pim, up, __func__);
  if (up)
    pim_mlag_up_df_role_elect(pim, up);

  return up;
}

static void pim_mlag_up_peer_del(struct mlag_mroute_del *msg)
{
  struct pim_upstream *up;
  struct pim_instance *pim;
  pim_sgaddr sg;
  struct vrf *vrf;

  memset(&sg, 0, sizeof(sg));
  sg.src.s_addr = htonl(msg->source_ip);
  sg.grp.s_addr = htonl(msg->group_ip);

  if (PIM_DEBUG_MLAG)
    zlog_debug("peer MLAG mroute del %s:%pSG", msg->vrf_name, &sg);

  vrf = vrf_lookup_by_name(msg->vrf_name);
  if  (!vrf) {
    if (PIM_DEBUG_MLAG)
      zlog_debug(
        "peer MLAG mroute del skipped %s:%pSG; no vrf",
        msg->vrf_name, &sg);
    return;
  }
  pim = vrf->info;

  up = pim_upstream_find(pim, &sg);
  if  (!up) {
    if (PIM_DEBUG_MLAG)
      zlog_debug(
        "peer MLAG mroute del skipped %s:%pSG; no up",
        vrf->name, &sg);
    return;
  }

  (void)pim_mlag_up_peer_deref(pim, up);
}

/* When we lose connection to the local MLAG daemon we can drop all peer
 * references.
 */
static void pim_mlag_up_peer_del_all(void)
{
  struct list *temp = list_new();
  struct pim_upstream *up;
  struct vrf *vrf;
  struct pim_instance *pim;

  /*
   * So why these gyrations?
   * pim->upstream_head has the list of *,G and S,G
   * that are in the system.  The problem of course
   * is that it is an ordered list:
   * (*,G1) -> (S1,G1) -> (S2,G2) -> (S3, G2) -> (*,G2) -> (S1,G2)
   * And the *,G1 has pointers to S1,G1 and S2,G1
   * if we delete *,G1 then we have a situation where
   * S1,G1 and S2,G2 can be deleted as well.  Then a
   * simple ALL_LIST_ELEMENTS will have the next listnode
   * pointer become invalid and we crash.
   * So let's grab the list of MLAG_PEER upstreams
   * add a refcount put on another list and delete safely
   */
  RB_FOREACH(vrf, vrf_name_head, &vrfs_by_name) {
    pim = vrf->info;
    frr_each (rb_pim_upstream, &pim->upstream_head, up) {
      if (!PIM_UPSTREAM_FLAG_TEST_MLAG_PEER(up->flags))
        continue;
      listnode_add(temp, up);
      /*
       * Add a reference since we are adding to this
       * list for deletion
       */
      up->ref_count++;
    }

    while (temp->count) {
      up = listnode_head(temp);
      listnode_delete(temp, up);

      up = pim_mlag_up_peer_deref(pim, up);
      /*
       * This is the deletion of the reference added
       * above
       */
      if (up)
        pim_upstream_del(pim, up, __func__);
    }
  }

  list_delete(&temp);
}

/* Send upstream entry to the local MLAG daemon (which will subsequently
 * send it to the peer MLAG switch).
 */
static void pim_mlag_up_local_add_send(struct pim_instance *pim,
    struct pim_upstream *up)
{
  struct stream *s = NULL;
  struct vrf *vrf = pim->vrf;

  if (!(router->mlag_flags & PIM_MLAGF_LOCAL_CONN_UP))
    return;

  s = stream_new(sizeof(struct mlag_mroute_add) + PIM_MLAG_METADATA_LEN);
  if (!s)
    return;

  if (PIM_DEBUG_MLAG)
    zlog_debug("local MLAG mroute add %s:%s",
        vrf->name, up->sg_str);

  ++router->mlag_stats.msg.mroute_add_tx;

  stream_putl(s, MLAG_MROUTE_ADD);
  stream_put(s, vrf->name, VRF_NAMSIZ);
  stream_putl(s, ntohl(up->sg.src.s_addr));
  stream_putl(s, ntohl(up->sg.grp.s_addr));

  stream_putl(s, pim_up_mlag_local_cost(up));
  /* XXX - who is addding*/
  stream_putl(s, MLAG_OWNER_VXLAN);
  /* XXX - am_i_DR field should be removed */
  stream_putc(s, false);
  stream_putc(s, !(PIM_UPSTREAM_FLAG_TEST_MLAG_NON_DF(up->flags)));
  stream_putl(s, vrf->vrf_id);
  /* XXX - this field is a No-op for VXLAN*/
  stream_put(s, NULL, INTERFACE_NAMSIZ);

  stream_fifo_push_safe(router->mlag_fifo, s);
  pim_mlag_signal_zpthread();
}

static void pim_mlag_up_local_del_send(struct pim_instance *pim,
    struct pim_upstream *up)
{
  struct stream *s = NULL;
  struct vrf *vrf = pim->vrf;

  if (!(router->mlag_flags & PIM_MLAGF_LOCAL_CONN_UP))
    return;

  s = stream_new(sizeof(struct mlag_mroute_del) + PIM_MLAG_METADATA_LEN);
  if (!s)
    return;

  if (PIM_DEBUG_MLAG)
    zlog_debug("local MLAG mroute del %s:%s",
        vrf->name, up->sg_str);

  ++router->mlag_stats.msg.mroute_del_tx;

  stream_putl(s, MLAG_MROUTE_DEL);
  stream_put(s, vrf->name, VRF_NAMSIZ);
  stream_putl(s, ntohl(up->sg.src.s_addr));
  stream_putl(s, ntohl(up->sg.grp.s_addr));
  /* XXX - who is adding */
  stream_putl(s, MLAG_OWNER_VXLAN);
  stream_putl(s, vrf->vrf_id);
  /* XXX - this field is a No-op for VXLAN */
  stream_put(s, NULL, INTERFACE_NAMSIZ);

  /* XXX - is this the the most optimal way to do things */
  stream_fifo_push_safe(router->mlag_fifo, s);
  pim_mlag_signal_zpthread();
}


/* Called when a local upstream entry is created or if it's cost changes */
void pim_mlag_up_local_add(struct pim_instance *pim,
    struct pim_upstream *up)
{
  pim_mlag_up_df_role_elect(pim, up);
  /* XXX - need to add some dup checks here */
  pim_mlag_up_local_add_send(pim, up);
}

/* Called when local MLAG reference is removed from an upstream entry */
void pim_mlag_up_local_del(struct pim_instance *pim,
    struct pim_upstream *up)
{
  pim_mlag_up_df_role_elect(pim, up);
  pim_mlag_up_local_del_send(pim, up);
}

/* When connection to local MLAG daemon is established all the local
 * MLAG upstream entries are replayed to it.
 */
static void pim_mlag_up_local_replay(void)
{
  struct pim_upstream *up;
  struct vrf *vrf;
  struct pim_instance *pim;

  RB_FOREACH(vrf, vrf_name_head, &vrfs_by_name) {
    pim = vrf->info;
    frr_each (rb_pim_upstream, &pim->upstream_head, up) {
      if (pim_up_mlag_is_local(up))
        pim_mlag_up_local_add_send(pim, up);
    }
  }
}

/* on local/peer mlag connection and role changes the DF status needs
 * to be re-evaluated
 */
static void pim_mlag_up_local_reeval(bool mlagd_send, const char *reason_code)
{
  struct pim_upstream *up;
  struct vrf *vrf;
  struct pim_instance *pim;

  if (PIM_DEBUG_MLAG)
    zlog_debug("%s re-run DF election because of %s",
        __func__, reason_code);
  RB_FOREACH(vrf, vrf_name_head, &vrfs_by_name) {
    pim = vrf->info;
    frr_each (rb_pim_upstream, &pim->upstream_head, up) {
      if (!pim_up_mlag_is_local(up))
        continue;
      /* if role changes re-send to peer */
      if (pim_mlag_up_df_role_elect(pim, up) &&
          mlagd_send)
        pim_mlag_up_local_add_send(pim, up);
    }
  }
}

/*****************PIM Actions for MLAG state changes**********************/

/* notify the anycast VTEP component about state changes */
static inline void pim_mlag_vxlan_state_update(void)
{
  bool enable = !!(router->mlag_flags & PIM_MLAGF_STATUS_RXED);
  bool peer_state = !!(router->mlag_flags & PIM_MLAGF_PEER_CONN_UP);

  pim_vxlan_mlag_update(enable, peer_state, router->mlag_role,
      router->peerlink_rif_p, &router->local_vtep_ip);

}

/**************End of PIM Actions for MLAG State changes******************/


/********************API to process PIM MLAG Data ************************/

static void pim_mlag_process_mlagd_state_change(struct mlag_status msg)
{
  bool role_chg = false;
  bool state_chg = false;
  bool notify_vxlan = false;
  struct interface *peerlink_rif_p;
  char buf[MLAG_ROLE_STRSIZE];

  if (PIM_DEBUG_MLAG)
    zlog_debug("%s: msg dump: my_role: %s, peer_state: %s",
         __func__,
         mlag_role2str(msg.my_role, buf, sizeof(buf)),
         (msg.peer_state == MLAG_STATE_RUNNING ? "RUNNING"
                 : "DOWN"));

  if (!(router->mlag_flags & PIM_MLAGF_LOCAL_CONN_UP)) {
    if (PIM_DEBUG_MLAG)
      zlog_debug("%s: msg ignored mlagd process state down",
          __func__);
    return;
  }
  ++router->mlag_stats.msg.mlag_status_updates;

  /* evaluate the changes first */
  if (router->mlag_role != msg.my_role) {
    role_chg = true;
    notify_vxlan = true;
    router->mlag_role = msg.my_role;
  }

  strlcpy(router->peerlink_rif, msg.peerlink_rif,
    sizeof(router->peerlink_rif));

  /* XXX - handle the case where we may rx the interface name from the
   * MLAG daemon before we get the interface from zebra.
   */
  peerlink_rif_p = if_lookup_by_name(router->peerlink_rif, VRF_DEFAULT);
  if (router->peerlink_rif_p != peerlink_rif_p) {
    router->peerlink_rif_p = peerlink_rif_p;
    notify_vxlan = true;
  }

  if (msg.peer_state == MLAG_STATE_RUNNING) {
    if (!(router->mlag_flags & PIM_MLAGF_PEER_CONN_UP)) {
      state_chg = true;
      notify_vxlan = true;
      router->mlag_flags |= PIM_MLAGF_PEER_CONN_UP;
    }
    router->connected_to_mlag = true;
  } else {
    if (router->mlag_flags & PIM_MLAGF_PEER_CONN_UP) {
      ++router->mlag_stats.peer_session_downs;
      state_chg = true;
      notify_vxlan = true;
      router->mlag_flags &= ~PIM_MLAGF_PEER_CONN_UP;
    }
    router->connected_to_mlag = false;
  }

  /* apply the changes */
  /* when connection to mlagd comes up we hold send mroutes till we have
   * rxed the status and had a chance to re-valuate DF state
   */
  if (!(router->mlag_flags & PIM_MLAGF_STATUS_RXED)) {
    router->mlag_flags |= PIM_MLAGF_STATUS_RXED;
    pim_mlag_vxlan_state_update();
    /* on session up re-eval DF status */
    pim_mlag_up_local_reeval(false /*mlagd_send*/, "mlagd_up");
    /* replay all the upstream entries to the local MLAG daemon */
    pim_mlag_up_local_replay();
    return;
  }

  if (notify_vxlan)
    pim_mlag_vxlan_state_update();

  if (state_chg) {
    if (!(router->mlag_flags & PIM_MLAGF_PEER_CONN_UP))
      /* when a connection goes down the primary takes over
       * DF role for all entries
       */
      pim_mlag_up_local_reeval(true /*mlagd_send*/,
          "peer_down");
    else
      /* XXX - when session comes up we need to wait for
       * PEER_REPLAY_DONE before running re-election on
       * local-mlag entries that are missing peer reference
       */
      pim_mlag_up_local_reeval(true /*mlagd_send*/,
          "peer_up");
  } else if (role_chg) {
    /* MLAG role changed without a state change */
    pim_mlag_up_local_reeval(true /*mlagd_send*/, "role_chg");
  }
}

static void pim_mlag_process_peer_frr_state_change(struct mlag_frr_status msg)
{
  if (PIM_DEBUG_MLAG)
    zlog_debug(
      "%s: msg dump: peer_frr_state: %s", __func__,
      (msg.frr_state == MLAG_FRR_STATE_UP ? "UP" : "DOWN"));

  if (!(router->mlag_flags & PIM_MLAGF_LOCAL_CONN_UP)) {
    if (PIM_DEBUG_MLAG)
      zlog_debug("%s: msg ignored mlagd process state down",
          __func__);
    return;
  }
  ++router->mlag_stats.msg.peer_zebra_status_updates;

  /* evaluate the changes first */
  if (msg.frr_state == MLAG_FRR_STATE_UP) {
    if (!(router->mlag_flags & PIM_MLAGF_PEER_ZEBRA_UP)) {
      router->mlag_flags |= PIM_MLAGF_PEER_ZEBRA_UP;
      /* XXX - when peer zebra comes up we need to wait for
       * for some time to let the peer setup MDTs before
       * before relinquishing DF status
       */
      pim_mlag_up_local_reeval(true /*mlagd_send*/,
          "zebra_up");
    }
  } else {
    if (router->mlag_flags & PIM_MLAGF_PEER_ZEBRA_UP) {
      ++router->mlag_stats.peer_zebra_downs;
      router->mlag_flags &= ~PIM_MLAGF_PEER_ZEBRA_UP;
      /* when a peer zebra goes down we assume DF role */
      pim_mlag_up_local_reeval(true /*mlagd_send*/,
          "zebra_down");
    }
  }
}

static void pim_mlag_process_vxlan_update(struct mlag_vxlan *msg)
{
  char addr_buf1[INET_ADDRSTRLEN];
  char addr_buf2[INET_ADDRSTRLEN];
  uint32_t local_ip;

  if (!(router->mlag_flags & PIM_MLAGF_LOCAL_CONN_UP)) {
    if (PIM_DEBUG_MLAG)
      zlog_debug("%s: msg ignored mlagd process state down",
          __func__);
    return;
  }

  ++router->mlag_stats.msg.vxlan_updates;
  router->anycast_vtep_ip.s_addr = htonl(msg->anycast_ip);
  local_ip = htonl(msg->local_ip);
  if (router->local_vtep_ip.s_addr != local_ip) {
    router->local_vtep_ip.s_addr = local_ip;
    pim_mlag_vxlan_state_update();
  }

  if (PIM_DEBUG_MLAG) {
    inet_ntop(AF_INET, &router->local_vtep_ip,
        addr_buf1, INET_ADDRSTRLEN);
    inet_ntop(AF_INET, &router->anycast_vtep_ip,
        addr_buf2, INET_ADDRSTRLEN);

    zlog_debug("%s: msg dump: local-ip:%s, anycast-ip:%s",
        __func__, addr_buf1, addr_buf2);
  }
}

static void pim_mlag_process_mroute_add(struct mlag_mroute_add msg)
{
  if (PIM_DEBUG_MLAG) {
    pim_sgaddr sg;

    sg.grp.s_addr = ntohl(msg.group_ip);
    sg.src.s_addr = ntohl(msg.source_ip);

    zlog_debug(
      "%s: msg dump: vrf_name: %s, s.ip: 0x%x, g.ip: 0x%x (%pSG) cost: %u",
      __func__, msg.vrf_name, msg.source_ip, msg.group_ip,
      &sg, msg.cost_to_rp);
    zlog_debug(
      "(%pSG)owner_id: %d, DR: %d, Dual active: %d, vrf_id: 0x%x intf_name: %s",
      &sg, msg.owner_id, msg.am_i_dr, msg.am_i_dual_active,
      msg.vrf_id, msg.intf_name);
  }

  if (!(router->mlag_flags & PIM_MLAGF_LOCAL_CONN_UP)) {
    if (PIM_DEBUG_MLAG)
      zlog_debug("%s: msg ignored mlagd process state down",
          __func__);
    return;
  }

  ++router->mlag_stats.msg.mroute_add_rx;

  pim_mlag_up_peer_add(&msg);
}

static void pim_mlag_process_mroute_del(struct mlag_mroute_del msg)
{
  if (PIM_DEBUG_MLAG) {
    pim_sgaddr sg;

    sg.grp.s_addr = ntohl(msg.group_ip);
    sg.src.s_addr = ntohl(msg.source_ip);
    zlog_debug(
      "%s: msg dump: vrf_name: %s, s.ip: 0x%x, g.ip: 0x%x(%pSG)",
      __func__, msg.vrf_name, msg.source_ip, msg.group_ip,
      &sg);
    zlog_debug("(%pSG)owner_id: %d, vrf_id: 0x%x intf_name: %s",
         &sg, msg.owner_id, msg.vrf_id, msg.intf_name);
  }

  if (!(router->mlag_flags & PIM_MLAGF_LOCAL_CONN_UP)) {
    if (PIM_DEBUG_MLAG)
      zlog_debug("%s: msg ignored mlagd process state down",
          __func__);
    return;
  }

  ++router->mlag_stats.msg.mroute_del_rx;

  pim_mlag_up_peer_del(&msg);
}

int pim_zebra_mlag_handle_msg(int cmd, struct zclient *zclient,
            uint16_t zapi_length, vrf_id_t vrf_id)
{
  struct stream *s = zclient->ibuf;
  struct mlag_msg mlag_msg;
  char buf[80];
  int rc = 0;
  size_t length;

  rc = mlag_lib_decode_mlag_hdr(s, &mlag_msg, &length);
  if (rc)
    return (rc);

  if (PIM_DEBUG_MLAG)
    zlog_debug("%s: Received msg type: %s length: %d, bulk_cnt: %d",
         __func__,
         mlag_lib_msgid_to_str(mlag_msg.msg_type, buf,
             sizeof(buf)),
         mlag_msg.data_len, mlag_msg.msg_cnt);

  switch (mlag_msg.msg_type) {
  case MLAG_STATUS_UPDATE: {
    struct mlag_status msg;

    rc = mlag_lib_decode_mlag_status(s, &msg);
    if (rc)
      return (rc);
    pim_mlag_process_mlagd_state_change(msg);
  } break;
  case MLAG_PEER_FRR_STATUS: {
    struct mlag_frr_status msg;

    rc = mlag_lib_decode_frr_status(s, &msg);
    if (rc)
      return (rc);
    pim_mlag_process_peer_frr_state_change(msg);
  } break;
  case MLAG_VXLAN_UPDATE: {
    struct mlag_vxlan msg;

    rc = mlag_lib_decode_vxlan_update(s, &msg);
    if (rc)
      return rc;
    pim_mlag_process_vxlan_update(&msg);
  } break;
  case MLAG_MROUTE_ADD: {
    struct mlag_mroute_add msg;

    rc = mlag_lib_decode_mroute_add(s, &msg, &length);
    if (rc)
      return (rc);
    pim_mlag_process_mroute_add(msg);
  } break;
  case MLAG_MROUTE_DEL: {
    struct mlag_mroute_del msg;

    rc = mlag_lib_decode_mroute_del(s, &msg, &length);
    if (rc)
      return (rc);
    pim_mlag_process_mroute_del(msg);
  } break;
  case MLAG_MROUTE_ADD_BULK: {
    struct mlag_mroute_add msg;
    int i;

    for (i = 0; i < mlag_msg.msg_cnt; i++) {
      rc = mlag_lib_decode_mroute_add(s, &msg, &length);
      if (rc)
        return (rc);
      pim_mlag_process_mroute_add(msg);
    }
  } break;
  case MLAG_MROUTE_DEL_BULK: {
    struct mlag_mroute_del msg;
    int i;

    for (i = 0; i < mlag_msg.msg_cnt; i++) {
      rc = mlag_lib_decode_mroute_del(s, &msg, &length);
      if (rc)
        return (rc);
      pim_mlag_process_mroute_del(msg);
    }
  } break;
  case MLAG_MSG_NONE:
  case MLAG_REGISTER:
  case MLAG_DEREGISTER:
  case MLAG_DUMP:
  case MLAG_PIM_CFG_DUMP:
    break;
  }
  return 0;
}

/****************End of PIM Mesasge processing handler********************/

int pim_zebra_mlag_process_up(ZAPI_CALLBACK_ARGS)
{
  if (PIM_DEBUG_MLAG)
    zlog_debug("%s: Received Process-Up from Mlag", __func__);

  /*
   * Incase of local MLAG restart, PIM needs to replay all the data
   * since MLAG is empty.
   */
  router->connected_to_mlag = true;
  router->mlag_flags |= PIM_MLAGF_LOCAL_CONN_UP;
  return 0;
}

static void pim_mlag_param_reset(void)
{
  /* reset the cached params and stats */
  router->mlag_flags &=
    (uint8_t) ~(PIM_MLAGF_STATUS_RXED | PIM_MLAGF_LOCAL_CONN_UP
          | PIM_MLAGF_PEER_CONN_UP | PIM_MLAGF_PEER_ZEBRA_UP);
  router->local_vtep_ip.s_addr = INADDR_ANY;
  router->anycast_vtep_ip.s_addr = INADDR_ANY;
  router->mlag_role = MLAG_ROLE_NONE;
  memset(&router->mlag_stats.msg, 0, sizeof(router->mlag_stats.msg));
  router->peerlink_rif[0] = '\0';
}

int pim_zebra_mlag_process_down(ZAPI_CALLBACK_ARGS)
{
  if (PIM_DEBUG_MLAG)
    zlog_debug("%s: Received Process-Down from Mlag", __func__);

  /* Local CLAG is down, reset peer data and forward the traffic if
   * we are DR
   */
  if (router->mlag_flags & PIM_MLAGF_PEER_CONN_UP)
    ++router->mlag_stats.peer_session_downs;
  if (router->mlag_flags & PIM_MLAGF_PEER_ZEBRA_UP)
    ++router->mlag_stats.peer_zebra_downs;
  router->connected_to_mlag = false;
  pim_mlag_param_reset();
  /* on mlagd session down re-eval DF status */
  pim_mlag_up_local_reeval(false /*mlagd_send*/, "mlagd_down");
  /* flush all peer references */
  pim_mlag_up_peer_del_all();
  /* notify the vxlan component */
  pim_mlag_vxlan_state_update();
  return 0;
}

static void pim_mlag_register_handler(struct event *thread)
{
  uint32_t bit_mask = 0;

  if (!zclient)
    return;

  SET_FLAG(bit_mask, (1 << MLAG_STATUS_UPDATE));
  SET_FLAG(bit_mask, (1 << MLAG_MROUTE_ADD));
  SET_FLAG(bit_mask, (1 << MLAG_MROUTE_DEL));
  SET_FLAG(bit_mask, (1 << MLAG_DUMP));
  SET_FLAG(bit_mask, (1 << MLAG_MROUTE_ADD_BULK));
  SET_FLAG(bit_mask, (1 << MLAG_MROUTE_DEL_BULK));
  SET_FLAG(bit_mask, (1 << MLAG_PIM_CFG_DUMP));
  SET_FLAG(bit_mask, (1 << MLAG_VXLAN_UPDATE));
  SET_FLAG(bit_mask, (1 << MLAG_PEER_FRR_STATUS));

  if (PIM_DEBUG_MLAG)
    zlog_debug("%s: Posting Client Register to MLAG mask: 0x%x",
         __func__, bit_mask);

  zclient_send_mlag_register(zclient, bit_mask);
}

void pim_mlag_register(void)
{
  if (router->mlag_process_register)
    return;

  router->mlag_process_register = true;

  event_add_event(router->master, pim_mlag_register_handler, NULL, 0,
      NULL);
}

static void pim_mlag_deregister_handler(struct event *thread)
{
  if (!zclient)
    return;

  if (PIM_DEBUG_MLAG)
    zlog_debug("%s: Posting Client De-Register to MLAG from PIM",
         __func__);
  router->connected_to_mlag = false;
  zclient_send_mlag_deregister(zclient);
}

void pim_mlag_deregister(void)
{
  /* if somebody still interested in the MLAG channel skip de-reg */
  if (router->pim_mlag_intf_cnt || pim_vxlan_do_mlag_reg())
    return;

  /* not registered; nothing do */
  if (!router->mlag_process_register)
    return;

  router->mlag_process_register = false;

  event_add_event(router->master, pim_mlag_deregister_handler, NULL, 0,
      NULL);
}

void pim_if_configure_mlag_dualactive(struct pim_interface *pim_ifp)
{
  if (!pim_ifp || !pim_ifp->pim || pim_ifp->activeactive == true)
    return;

  if (PIM_DEBUG_MLAG)
    zlog_debug("%s: Configuring active-active on Interface: %s",
         __func__, "NULL");

  pim_ifp->activeactive = true;
  if (pim_ifp->pim)
    pim_ifp->pim->inst_mlag_intf_cnt++;

  router->pim_mlag_intf_cnt++;
  if (PIM_DEBUG_MLAG)
    zlog_debug(
      "%s: Total MLAG configured Interfaces on router: %d, Inst: %d",
      __func__, router->pim_mlag_intf_cnt,
      pim_ifp->pim->inst_mlag_intf_cnt);

  if (router->pim_mlag_intf_cnt == 1) {
    /*
     * at least one Interface is configured for MLAG, send register
     * to Zebra for receiving MLAG Updates
     */
    pim_mlag_register();
  }
}

void pim_if_unconfigure_mlag_dualactive(struct pim_interface *pim_ifp)
{
  if (!pim_ifp || !pim_ifp->pim || pim_ifp->activeactive == false)
    return;

  if (PIM_DEBUG_MLAG)
    zlog_debug("%s: UnConfiguring active-active on Interface: %s",
         __func__, "NULL");

  pim_ifp->activeactive = false;
  pim_ifp->pim->inst_mlag_intf_cnt--;

  router->pim_mlag_intf_cnt--;
  if (PIM_DEBUG_MLAG)
    zlog_debug(
      "%s: Total MLAG configured Interfaces on router: %d, Inst: %d",
      __func__, router->pim_mlag_intf_cnt,
      pim_ifp->pim->inst_mlag_intf_cnt);

  if (router->pim_mlag_intf_cnt == 0) {
    /*
     * all the Interfaces are MLAG un-configured, post MLAG
     * De-register to Zebra
     */
    pim_mlag_deregister();
    pim_mlag_param_reset();
  }
}


void pim_instance_mlag_init(struct pim_instance *pim)
{
  if (!pim)
    return;

  pim->inst_mlag_intf_cnt = 0;
}


void pim_instance_mlag_terminate(struct pim_instance *pim)
{
  struct interface *ifp;

  if (!pim)
    return;

  FOR_ALL_INTERFACES (pim->vrf, ifp) {
    struct pim_interface *pim_ifp = ifp->info;

    if (!pim_ifp || pim_ifp->activeactive == false)
      continue;

    pim_if_unconfigure_mlag_dualactive(pim_ifp);
  }
  pim->inst_mlag_intf_cnt = 0;
}

void pim_mlag_terminate(void)
{
  stream_free(router->mlag_stream);
  router->mlag_stream = NULL;
  stream_fifo_free(router->mlag_fifo);
  router->mlag_fifo = NULL;
}

void pim_mlag_init(void)
{
  pim_mlag_param_reset();
  router->pim_mlag_intf_cnt = 0;
  router->connected_to_mlag = false;
  router->mlag_fifo = stream_fifo_new();
  router->zpthread_mlag_write = NULL;
  router->mlag_stream = stream_new(MLAG_BUF_LIMIT);
}

Coverage Report

Created: 2025-08-28 06:29