/src/frr/pimd/pim_vxlan.c

Source
// SPDX-License-Identifier: GPL-2.0-or-later
/* PIM support for VxLAN BUM flooding
 *
 * Copyright (C) 2019 Cumulus Networks, Inc.
 */

#include <zebra.h>

#include <hash.h>
#include <jhash.h>
#include <log.h>
#include <prefix.h>
#include <vrf.h>

#include "pimd.h"
#include "pim_iface.h"
#include "pim_memory.h"
#include "pim_oil.h"
#include "pim_register.h"
#include "pim_str.h"
#include "pim_upstream.h"
#include "pim_ifchannel.h"
#include "pim_nht.h"
#include "pim_zebra.h"
#include "pim_vxlan.h"
#include "pim_mlag.h"

/* pim-vxlan global info */
struct pim_vxlan vxlan_info, *pim_vxlan_p = &vxlan_info;

static void pim_vxlan_work_timer_setup(bool start);
static void pim_vxlan_set_peerlink_rif(struct pim_instance *pim,
      struct interface *ifp);

/*************************** vxlan work list **********************************
 * A work list is maintained for staggered generation of pim null register
 * messages for vxlan SG entries that are in a reg_join state.
 *
 * A max of 500 NULL registers are generated at one shot. If paused reg
 * generation continues on the next second and so on till all register
 * messages have been sent out. And the process is restarted every 60s.
 *
 * purpose of this null register generation is to setup the SPT and maintain
 * independent of the presence of overlay BUM traffic.
 ****************************************************************************/
static void pim_vxlan_do_reg_work(void)
{
  struct listnode *listnode;
  int work_cnt = 0;
  struct pim_vxlan_sg *vxlan_sg;
  static int sec_count;

  ++sec_count;

  if (sec_count > PIM_VXLAN_NULL_REG_INTERVAL) {
    sec_count = 0;
    listnode = vxlan_info.next_work ?
          vxlan_info.next_work :
          vxlan_info.work_list->head;
    if (PIM_DEBUG_VXLAN && listnode)
      zlog_debug("vxlan SG work %s",
        vxlan_info.next_work ? "continues" : "starts");
  } else {
    listnode = vxlan_info.next_work;
  }

  for (; listnode; listnode = listnode->next) {
    vxlan_sg = (struct pim_vxlan_sg *)listnode->data;
    if (vxlan_sg->up && (vxlan_sg->up->reg_state == PIM_REG_JOIN)) {
      if (PIM_DEBUG_VXLAN)
        zlog_debug("vxlan SG %s periodic NULL register",
            vxlan_sg->sg_str);

      /*
       * If we are on the work queue *and* the rpf
       * has been lost on the vxlan_sg->up let's
       * make sure that we don't send it.
       */
      if (vxlan_sg->up->rpf.source_nexthop.interface) {
        pim_null_register_send(vxlan_sg->up);
        ++work_cnt;
      }
    }

    if (work_cnt > vxlan_info.max_work_cnt) {
      vxlan_info.next_work = listnode->next;
      if (PIM_DEBUG_VXLAN)
        zlog_debug("vxlan SG %d work items proc and pause",
          work_cnt);
      return;
    }
  }

  if (work_cnt) {
    if (PIM_DEBUG_VXLAN)
      zlog_debug("vxlan SG %d work items proc", work_cnt);
  }
  vxlan_info.next_work = NULL;
}

/* Staggered work related info is initialized when the first work comes
 * along
 */
static void pim_vxlan_init_work(void)
{
  if (vxlan_info.flags & PIM_VXLANF_WORK_INITED)
    return;

  vxlan_info.max_work_cnt = PIM_VXLAN_WORK_MAX;
  vxlan_info.flags |= PIM_VXLANF_WORK_INITED;
  vxlan_info.work_list = list_new();
  pim_vxlan_work_timer_setup(true/* start */);
}

static void pim_vxlan_add_work(struct pim_vxlan_sg *vxlan_sg)
{
  if (vxlan_sg->flags & PIM_VXLAN_SGF_DEL_IN_PROG) {
    if (PIM_DEBUG_VXLAN)
      zlog_debug("vxlan SG %s skip work list; del-in-prog",
          vxlan_sg->sg_str);
    return;
  }

  pim_vxlan_init_work();

  /* already a part of the work list */
  if (vxlan_sg->work_node)
    return;

  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan SG %s work list add",
        vxlan_sg->sg_str);
  vxlan_sg->work_node = listnode_add(vxlan_info.work_list, vxlan_sg);
  /* XXX: adjust max_work_cnt if needed */
}

static void pim_vxlan_del_work(struct pim_vxlan_sg *vxlan_sg)
{
  if (!vxlan_sg->work_node)
    return;

  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan SG %s work list del",
        vxlan_sg->sg_str);

  if (vxlan_sg->work_node == vxlan_info.next_work)
    vxlan_info.next_work = vxlan_sg->work_node->next;

  list_delete_node(vxlan_info.work_list, vxlan_sg->work_node);
  vxlan_sg->work_node = NULL;
}

void pim_vxlan_update_sg_reg_state(struct pim_instance *pim,
    struct pim_upstream *up, bool reg_join)
{
  struct pim_vxlan_sg *vxlan_sg;

  vxlan_sg = pim_vxlan_sg_find(pim, &up->sg);
  if (!vxlan_sg)
    return;

  /* add the vxlan sg entry to a work list for periodic reg joins.
   * the entry will stay in the list as long as the register state is
   * PIM_REG_JOIN
   */
  if (reg_join)
    pim_vxlan_add_work(vxlan_sg);
  else
    pim_vxlan_del_work(vxlan_sg);
}

static void pim_vxlan_work_timer_cb(struct event *t)
{
  pim_vxlan_do_reg_work();
  pim_vxlan_work_timer_setup(true /* start */);
}

/* global 1second timer used for periodic processing */
static void pim_vxlan_work_timer_setup(bool start)
{
  EVENT_OFF(vxlan_info.work_timer);
  if (start)
    event_add_timer(router->master, pim_vxlan_work_timer_cb, NULL,
        PIM_VXLAN_WORK_TIME, &vxlan_info.work_timer);
}

/**************************** vxlan origination mroutes ***********************
 * For every (local-vtep-ip, bum-mcast-grp) registered by evpn an origination
 * mroute is setup by pimd. The purpose of this mroute is to forward vxlan
 * encapsulated BUM (broadcast, unknown-unicast and unknown-multicast packets
 * over the underlay.)
 *
 * Sample mroute (single VTEP):
 * (27.0.0.7, 239.1.1.100)     Iif: lo      Oifs: uplink-1
 *
 * Sample mroute (anycast VTEP):
 * (36.0.0.9, 239.1.1.100)          Iif: peerlink-3.4094\
 *                                       Oifs: peerlink-3.4094 uplink-1
 ***************************************************************************/
static void pim_vxlan_orig_mr_up_del(struct pim_vxlan_sg *vxlan_sg)
{
  struct pim_upstream *up = vxlan_sg->up;

  if (!up)
    return;

  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan SG %s orig mroute-up del",
      vxlan_sg->sg_str);

  vxlan_sg->up = NULL;

  if (up->flags & PIM_UPSTREAM_FLAG_MASK_SRC_VXLAN_ORIG) {
    /* clear out all the vxlan properties */
    up->flags &= ~(PIM_UPSTREAM_FLAG_MASK_SRC_VXLAN_ORIG |
      PIM_UPSTREAM_FLAG_MASK_STATIC_IIF |
      PIM_UPSTREAM_FLAG_MASK_DISABLE_KAT_EXPIRY |
      PIM_UPSTREAM_FLAG_MASK_FORCE_PIMREG |
      PIM_UPSTREAM_FLAG_MASK_NO_PIMREG_DATA |
      PIM_UPSTREAM_FLAG_MASK_ALLOW_IIF_IN_OIL);

    /* We bring things to a grinding halt by force expirying
     * the kat. Doing this will also remove the reference we
     * created as a "vxlan" source and delete the upstream entry
     * if there are no other references.
     */
    if (PIM_UPSTREAM_FLAG_TEST_SRC_STREAM(up->flags)) {
      EVENT_OFF(up->t_ka_timer);
      up = pim_upstream_keep_alive_timer_proc(up);
    } else {
      /* this is really unexpected as we force vxlan
       * origination mroutes active sources but just in
       * case
       */
      up = pim_upstream_del(vxlan_sg->pim, up, __func__);
    }
    /* if there are other references register the source
     * for nht
     */
    if (up) {
      enum pim_rpf_result r;

      r = pim_rpf_update(vxlan_sg->pim, up, NULL, __func__);
      if (r == PIM_RPF_FAILURE) {
        if (PIM_DEBUG_VXLAN)
          zlog_debug(
            "vxlan SG %s rpf_update failure",
            vxlan_sg->sg_str);
      }
    }
  }
}

static void pim_vxlan_orig_mr_up_iif_update(struct pim_vxlan_sg *vxlan_sg)
{
  /* update MFC with the new IIF */
  pim_upstream_fill_static_iif(vxlan_sg->up, vxlan_sg->iif);
  pim_upstream_mroute_iif_update(vxlan_sg->up->channel_oil, __func__);

  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan SG %s orig mroute-up updated with iif %s",
      vxlan_sg->sg_str,
      vxlan_sg->iif?vxlan_sg->iif->name:"-");

}

/* For every VxLAN BUM multicast group we setup a SG-up that has the following
 * "forced properties" -
 * 1. Directly connected on a DR interface i.e. we must act as an FHR
 * 2. We prime the pump i.e. no multicast data is needed to register this
 *    source with the FHR. To do that we send periodic null registers if
 *    the SG entry is in a register-join state. We also prevent expiry of
 *    KAT.
 * 3. As this SG is setup without data there is no need to register encapsulate
 *    data traffic. This encapsulation is explicitly skipped for the following
 *    reasons -
 *    a) Many levels of encapsulation are needed creating MTU disc challenges.
 *       Overlay BUM is encapsulated in a vxlan/UDP/IP header and then
 *       encapsulated again in a pim-register header.
 *    b) On a vxlan-aa setup both switches rx a copy of each BUM packet. if
 *       they both reg encapsulated traffic the RP will accept the duplicates
 *       as there are no RPF checks for this encapsulated data.
 *    a), b) can be workarounded if needed, but there is really no need because
 *    of (2) i.e. the pump is primed without data.
 */
static void pim_vxlan_orig_mr_up_add(struct pim_vxlan_sg *vxlan_sg)
{
  struct pim_upstream *up;
  struct pim_interface *term_ifp;
  int flags = 0;
  struct pim_instance *pim = vxlan_sg->pim;

  if (vxlan_sg->up) {
    /* nothing to do */
    return;
  }

  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan SG %s orig mroute-up add with iif %s",
      vxlan_sg->sg_str,
      vxlan_sg->iif?vxlan_sg->iif->name:"-");

  PIM_UPSTREAM_FLAG_SET_SRC_VXLAN_ORIG(flags);
  /* pin the IIF to lo or peerlink-subinterface and disable NHT */
  PIM_UPSTREAM_FLAG_SET_STATIC_IIF(flags);
  /* Fake traffic by setting SRC_STREAM and starting KAT */
  /* We intentionally skip updating ref count for SRC_STREAM/FHR.
   * Setting SRC_VXLAN should have already created a reference
   * preventing the entry from being deleted
   */
  PIM_UPSTREAM_FLAG_SET_FHR(flags);
  PIM_UPSTREAM_FLAG_SET_SRC_STREAM(flags);
  /* Force pimreg even if non-DR. This is needed on a MLAG setup for
   * VxLAN AA
   */
  PIM_UPSTREAM_FLAG_SET_FORCE_PIMREG(flags);
  /* prevent KAT expiry. we want the MDT setup even if there is no BUM
   * traffic
   */
  PIM_UPSTREAM_FLAG_SET_DISABLE_KAT_EXPIRY(flags);
  /* SPT for vxlan BUM groups is primed and maintained via NULL
   * registers so there is no need to reg-encapsulate
   * vxlan-encapsulated overlay data traffic
   */
  PIM_UPSTREAM_FLAG_SET_NO_PIMREG_DATA(flags);
  /* On a MLAG setup we force a copy to the MLAG peer while also
   * accepting traffic from the peer. To do this we set peerlink-rif as
   * the IIF and also add it to the OIL
   */
  PIM_UPSTREAM_FLAG_SET_ALLOW_IIF_IN_OIL(flags);

  /* XXX: todo: defer pim_upstream add if pim is not enabled on the iif */
  up = pim_upstream_find(vxlan_sg->pim, &vxlan_sg->sg);
  if (up) {
    /* if the iif is set to something other than the vxlan_sg->iif
     * we must dereg the old nexthop and force to new "static"
     * iif
     */
    if (!PIM_UPSTREAM_FLAG_TEST_STATIC_IIF(up->flags)) {
      pim_delete_tracked_nexthop(vxlan_sg->pim,
               up->upstream_addr, up, NULL);
    }
    /* We are acting FHR; clear out use_rpt setting if any */
    pim_upstream_update_use_rpt(up, false /*update_mroute*/);
    pim_upstream_ref(up, flags, __func__);
    vxlan_sg->up = up;
    term_ifp = pim_vxlan_get_term_ifp(pim);
    /* mute termination device on origination mroutes */
    if (term_ifp)
      pim_channel_update_oif_mute(up->channel_oil,
          term_ifp);
    pim_vxlan_orig_mr_up_iif_update(vxlan_sg);
    /* mute pimreg on origination mroutes */
    if (pim->regiface)
      pim_channel_update_oif_mute(up->channel_oil,
          pim->regiface->info);
  } else {
    up = pim_upstream_add(vxlan_sg->pim, &vxlan_sg->sg,
              vxlan_sg->iif, flags, __func__, NULL);
    vxlan_sg->up = up;
  }

  if (!up) {
    if (PIM_DEBUG_VXLAN)
      zlog_debug("vxlan SG %s orig mroute-up add failed",
          vxlan_sg->sg_str);
    return;
  }

  pim_upstream_keep_alive_timer_start(up, vxlan_sg->pim->keep_alive_time);

  /* register the source with the RP */
  switch (up->reg_state) {

  case PIM_REG_NOINFO:
    pim_register_join(up);
    pim_null_register_send(up);
    break;

  case PIM_REG_JOIN:
    /* if the pim upstream entry is already in reg-join state
     * send null_register right away and add to the register
     * worklist
     */
    pim_null_register_send(up);
    pim_vxlan_update_sg_reg_state(pim, up, true);
    break;

  case PIM_REG_JOIN_PENDING:
  case PIM_REG_PRUNE:
    break;
  }

  /* update the inherited OIL */
  pim_upstream_inherited_olist(vxlan_sg->pim, up);
  if (!up->channel_oil->installed)
    pim_upstream_mroute_add(up->channel_oil, __func__);
}

static void pim_vxlan_orig_mr_oif_add(struct pim_vxlan_sg *vxlan_sg)
{
  if (!vxlan_sg->up || !vxlan_sg->orig_oif)
    return;

  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan SG %s oif %s add",
      vxlan_sg->sg_str, vxlan_sg->orig_oif->name);

  vxlan_sg->flags |= PIM_VXLAN_SGF_OIF_INSTALLED;
  pim_channel_add_oif(vxlan_sg->up->channel_oil,
    vxlan_sg->orig_oif, PIM_OIF_FLAG_PROTO_VXLAN,
    __func__);
}

static void pim_vxlan_orig_mr_oif_del(struct pim_vxlan_sg *vxlan_sg)
{
  struct interface *orig_oif;

  orig_oif = vxlan_sg->orig_oif;
  vxlan_sg->orig_oif = NULL;

  if (!(vxlan_sg->flags & PIM_VXLAN_SGF_OIF_INSTALLED))
    return;

  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan SG %s oif %s del",
      vxlan_sg->sg_str, orig_oif->name);

  vxlan_sg->flags &= ~PIM_VXLAN_SGF_OIF_INSTALLED;
  pim_channel_del_oif(vxlan_sg->up->channel_oil,
      orig_oif, PIM_OIF_FLAG_PROTO_VXLAN, __func__);
}

static inline struct interface *pim_vxlan_orig_mr_oif_get(
    struct pim_instance *pim)
{
  return (vxlan_mlag.flags & PIM_VXLAN_MLAGF_ENABLED) ?
    pim->vxlan.peerlink_rif : NULL;
}

/* Single VTEPs: IIF for the vxlan-origination-mroutes is lo or vrf-dev (if
 * the mroute is in a non-default vrf).
 * Anycast VTEPs: IIF is the MLAG ISL/peerlink.
 */
static inline struct interface *pim_vxlan_orig_mr_iif_get(
    struct pim_instance *pim)
{
  return ((vxlan_mlag.flags & PIM_VXLAN_MLAGF_ENABLED) &&
      pim->vxlan.peerlink_rif) ?
    pim->vxlan.peerlink_rif : pim->vxlan.default_iif;
}

static bool pim_vxlan_orig_mr_add_is_ok(struct pim_vxlan_sg *vxlan_sg)
{
  struct pim_interface *pim_ifp;

  vxlan_sg->iif = pim_vxlan_orig_mr_iif_get(vxlan_sg->pim);
  if (!vxlan_sg->iif)
    return false;

  pim_ifp = (struct pim_interface *)vxlan_sg->iif->info;
  if (!pim_ifp || (pim_ifp->mroute_vif_index < 0))
    return false;

  return true;
}

static void pim_vxlan_orig_mr_install(struct pim_vxlan_sg *vxlan_sg)
{
  pim_vxlan_orig_mr_up_add(vxlan_sg);

  vxlan_sg->orig_oif = pim_vxlan_orig_mr_oif_get(vxlan_sg->pim);
  pim_vxlan_orig_mr_oif_add(vxlan_sg);
}

static void pim_vxlan_orig_mr_add(struct pim_vxlan_sg *vxlan_sg)
{
  if (!pim_vxlan_orig_mr_add_is_ok(vxlan_sg))
    return;

  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan SG %s orig-mr add", vxlan_sg->sg_str);

  pim_vxlan_orig_mr_install(vxlan_sg);
}

static void pim_vxlan_orig_mr_del(struct pim_vxlan_sg *vxlan_sg)
{
  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan SG %s orig-mr del", vxlan_sg->sg_str);

  pim_vxlan_orig_mr_oif_del(vxlan_sg);
  pim_vxlan_orig_mr_up_del(vxlan_sg);
}

static void pim_vxlan_orig_mr_iif_update(struct hash_bucket *bucket, void *arg)
{
  struct interface *ifp;
  struct pim_vxlan_sg *vxlan_sg = (struct pim_vxlan_sg *)bucket->data;
  struct interface *old_iif = vxlan_sg->iif;

  if (!pim_vxlan_is_orig_mroute(vxlan_sg))
    return;

  ifp = pim_vxlan_orig_mr_iif_get(vxlan_sg->pim);
  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan SG %s iif changed from %s to %s",
        vxlan_sg->sg_str,
        old_iif ? old_iif->name : "-",
        ifp ? ifp->name : "-");

  if (pim_vxlan_orig_mr_add_is_ok(vxlan_sg)) {
    if (vxlan_sg->up) {
      /* upstream exists but iif changed */
      pim_vxlan_orig_mr_up_iif_update(vxlan_sg);
    } else {
      /* install mroute */
      pim_vxlan_orig_mr_install(vxlan_sg);
    }
  } else {
    pim_vxlan_orig_mr_del(vxlan_sg);
  }
}

/**************************** vxlan termination mroutes ***********************
 * For every bum-mcast-grp registered by evpn a *G termination
 * mroute is setup by pimd. The purpose of this mroute is to pull down vxlan
 * packets with the bum-mcast-grp dip from the underlay and terminate the
 * tunnel. This is done by including the vxlan termination device (ipmr-lo) in
 * its OIL. The vxlan de-capsulated packets are subject to subsequent overlay
 * bridging.
 *
 * Sample mroute:
 * (0.0.0.0, 239.1.1.100)     Iif: uplink-1      Oifs: ipmr-lo, uplink-1
 *****************************************************************************/
struct pim_interface *pim_vxlan_get_term_ifp(struct pim_instance *pim)
{
  return pim->vxlan.term_if ?
    (struct pim_interface *)pim->vxlan.term_if->info : NULL;
}

static void pim_vxlan_term_mr_oif_add(struct pim_vxlan_sg *vxlan_sg)
{
  if (vxlan_sg->flags & PIM_VXLAN_SGF_OIF_INSTALLED)
    return;

  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan SG %s term-oif %s add",
      vxlan_sg->sg_str, vxlan_sg->term_oif->name);

  if (pim_ifchannel_local_membership_add(vxlan_sg->term_oif,
        &vxlan_sg->sg, true /*is_vxlan */)) {
    vxlan_sg->flags |= PIM_VXLAN_SGF_OIF_INSTALLED;
    /* update the inherited OIL */
    /* XXX - I don't see the inherited OIL updated when a local
     * member is added. And that probably needs to be fixed. Till
     * that happens we do a force update on the inherited OIL
     * here.
     */
    pim_upstream_inherited_olist(vxlan_sg->pim, vxlan_sg->up);
  } else {
    zlog_warn("vxlan SG %s term-oif %s add failed",
      vxlan_sg->sg_str, vxlan_sg->term_oif->name);
  }
}

static void pim_vxlan_term_mr_oif_del(struct pim_vxlan_sg *vxlan_sg)
{
  if (!(vxlan_sg->flags & PIM_VXLAN_SGF_OIF_INSTALLED))
    return;

  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan SG %s oif %s del",
      vxlan_sg->sg_str, vxlan_sg->term_oif->name);

  vxlan_sg->flags &= ~PIM_VXLAN_SGF_OIF_INSTALLED;
  pim_ifchannel_local_membership_del(vxlan_sg->term_oif, &vxlan_sg->sg);
  /* update the inherited OIL */
  /* XXX - I don't see the inherited OIL updated when a local member
   * is deleted. And that probably needs to be fixed. Till that happens
   * we do a force update on the inherited OIL here.
   */
  pim_upstream_inherited_olist(vxlan_sg->pim, vxlan_sg->up);
}

static void pim_vxlan_update_sg_entry_mlag(struct pim_instance *pim,
    struct pim_upstream *up, bool inherit)
{
  bool is_df = true;

  if (inherit && up->parent &&
      PIM_UPSTREAM_FLAG_TEST_MLAG_VXLAN(up->parent->flags) &&
      PIM_UPSTREAM_FLAG_TEST_MLAG_NON_DF(up->parent->flags))
    is_df = false;

  pim_mlag_up_df_role_update(pim, up, is_df, "inherit_xg_df");
}

/* We run MLAG DF election only on mroutes that have the termination
 * device ipmr-lo in the immediate OIL. This is only (*, G) entries at the
 * moment. For (S, G) entries that (with ipmr-lo in the inherited OIL) we
 * inherit the DF role from the (*, G) entry.
 */
void pim_vxlan_inherit_mlag_flags(struct pim_instance *pim,
    struct pim_upstream *up, bool inherit)
{
  struct listnode *listnode;
  struct pim_upstream *child;

  for (ALL_LIST_ELEMENTS_RO(up->sources, listnode,
        child)) {
    pim_vxlan_update_sg_entry_mlag(pim,
        child, true /* inherit */);
  }
}

static void pim_vxlan_term_mr_up_add(struct pim_vxlan_sg *vxlan_sg)
{
  struct pim_upstream *up;
  int flags = 0;

  if (vxlan_sg->up) {
    /* nothing to do */
    return;
  }

  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan SG %s term mroute-up add",
      vxlan_sg->sg_str);

  PIM_UPSTREAM_FLAG_SET_SRC_VXLAN_TERM(flags);
  /* enable MLAG designated-forwarder election on termination mroutes */
  PIM_UPSTREAM_FLAG_SET_MLAG_VXLAN(flags);

  up = pim_upstream_add(vxlan_sg->pim, &vxlan_sg->sg, NULL /* iif */,
            flags, __func__, NULL);
  vxlan_sg->up = up;

  if (!up) {
    zlog_warn("vxlan SG %s term mroute-up add failed",
      vxlan_sg->sg_str);
    return;
  }

  /* update existing SG entries with the parent's MLAG flag */
  pim_vxlan_inherit_mlag_flags(vxlan_sg->pim, up, true /*enable*/);
}

static void pim_vxlan_term_mr_up_del(struct pim_vxlan_sg *vxlan_sg)
{
  struct pim_upstream *up = vxlan_sg->up;

  if (!up)
    return;

  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan SG %s term mroute-up del",
      vxlan_sg->sg_str);
  vxlan_sg->up = NULL;
  if (up->flags & PIM_UPSTREAM_FLAG_MASK_SRC_VXLAN_TERM) {
    /* update SG entries that are inheriting from this XG entry */
    pim_vxlan_inherit_mlag_flags(vxlan_sg->pim, up,
        false /*enable*/);
    /* clear out all the vxlan related flags */
    up->flags &= ~(PIM_UPSTREAM_FLAG_MASK_SRC_VXLAN_TERM |
      PIM_UPSTREAM_FLAG_MASK_MLAG_VXLAN);
    pim_mlag_up_local_del(vxlan_sg->pim, up);
    pim_upstream_del(vxlan_sg->pim, up, __func__);
  }
}

static void pim_vxlan_term_mr_add(struct pim_vxlan_sg *vxlan_sg)
{
  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan SG %s term mroute add", vxlan_sg->sg_str);

  vxlan_sg->term_oif = vxlan_sg->pim->vxlan.term_if;
  if (!vxlan_sg->term_oif)
    /* defer termination mroute till we have a termination device */
    return;

  pim_vxlan_term_mr_up_add(vxlan_sg);
  /* set up local membership for the term-oif */
  pim_vxlan_term_mr_oif_add(vxlan_sg);
}

static void pim_vxlan_term_mr_del(struct pim_vxlan_sg *vxlan_sg)
{
  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan SG %s term mroute del", vxlan_sg->sg_str);

  /* remove local membership associated with the term oif */
  pim_vxlan_term_mr_oif_del(vxlan_sg);
  /* remove references to the upstream entry */
  pim_vxlan_term_mr_up_del(vxlan_sg);
}

/************************** vxlan SG cache management ************************/
static unsigned int pim_vxlan_sg_hash_key_make(const void *p)
{
  const struct pim_vxlan_sg *vxlan_sg = p;

  return pim_sgaddr_hash(vxlan_sg->sg, 0);
}

static bool pim_vxlan_sg_hash_eq(const void *p1, const void *p2)
{
  const struct pim_vxlan_sg *sg1 = p1;
  const struct pim_vxlan_sg *sg2 = p2;

  return !pim_sgaddr_cmp(sg1->sg, sg2->sg);
}

static struct pim_vxlan_sg *pim_vxlan_sg_new(struct pim_instance *pim,
               pim_sgaddr *sg)
{
  struct pim_vxlan_sg *vxlan_sg;

  vxlan_sg = XCALLOC(MTYPE_PIM_VXLAN_SG, sizeof(*vxlan_sg));

  vxlan_sg->pim = pim;
  vxlan_sg->sg = *sg;
  snprintfrr(vxlan_sg->sg_str, sizeof(vxlan_sg->sg_str), "%pSG", sg);

  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan SG %s alloc", vxlan_sg->sg_str);

  vxlan_sg = hash_get(pim->vxlan.sg_hash, vxlan_sg, hash_alloc_intern);

  /* we register with the MLAG daemon in the first VxLAN SG and never
   * de-register during that life of the pimd
   */
  if (pim->vxlan.sg_hash->count == 1) {
    vxlan_mlag.flags |= PIM_VXLAN_MLAGF_DO_REG;
    pim_mlag_register();
  }

  return vxlan_sg;
}

struct pim_vxlan_sg *pim_vxlan_sg_find(struct pim_instance *pim, pim_sgaddr *sg)
{
  struct pim_vxlan_sg lookup;

  lookup.sg = *sg;
  return hash_lookup(pim->vxlan.sg_hash, &lookup);
}

struct pim_vxlan_sg *pim_vxlan_sg_add(struct pim_instance *pim, pim_sgaddr *sg)
{
  struct pim_vxlan_sg *vxlan_sg;

  vxlan_sg = pim_vxlan_sg_find(pim, sg);
  if (vxlan_sg)
    return vxlan_sg;

  vxlan_sg = pim_vxlan_sg_new(pim, sg);

  if (pim_vxlan_is_orig_mroute(vxlan_sg))
    pim_vxlan_orig_mr_add(vxlan_sg);
  else
    pim_vxlan_term_mr_add(vxlan_sg);

  return vxlan_sg;
}

static void pim_vxlan_sg_del_item(struct pim_vxlan_sg *vxlan_sg)
{
  vxlan_sg->flags |= PIM_VXLAN_SGF_DEL_IN_PROG;

  pim_vxlan_del_work(vxlan_sg);

  if (pim_vxlan_is_orig_mroute(vxlan_sg))
    pim_vxlan_orig_mr_del(vxlan_sg);
  else
    pim_vxlan_term_mr_del(vxlan_sg);

  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan SG %s free", vxlan_sg->sg_str);

  XFREE(MTYPE_PIM_VXLAN_SG, vxlan_sg);
}

void pim_vxlan_sg_del(struct pim_instance *pim, pim_sgaddr *sg)
{
  struct pim_vxlan_sg *vxlan_sg;

  vxlan_sg = pim_vxlan_sg_find(pim, sg);
  if (!vxlan_sg)
    return;

  hash_release(pim->vxlan.sg_hash, vxlan_sg);
  pim_vxlan_sg_del_item(vxlan_sg);
}

/******************************* MLAG handling *******************************/
bool pim_vxlan_do_mlag_reg(void)
{
  return (vxlan_mlag.flags & PIM_VXLAN_MLAGF_DO_REG);
}

/* The peerlink sub-interface is added as an OIF to the origination-mroute.
 * This is done to send a copy of the multicast-vxlan encapsulated traffic
 * to the MLAG peer which may mroute it over the underlay if there are any
 * interested receivers.
 */
static void pim_vxlan_sg_peerlink_oif_update(struct hash_bucket *bucket,
               void *arg)
{
  struct interface *new_oif = (struct interface *)arg;
  struct pim_vxlan_sg *vxlan_sg = (struct pim_vxlan_sg *)bucket->data;

  if (!pim_vxlan_is_orig_mroute(vxlan_sg))
    return;

  if (vxlan_sg->orig_oif == new_oif)
    return;

  pim_vxlan_orig_mr_oif_del(vxlan_sg);

  vxlan_sg->orig_oif = new_oif;
  pim_vxlan_orig_mr_oif_add(vxlan_sg);
}

/* In the case of anycast VTEPs the VTEP-PIP must be used as the
 * register source.
 */
bool pim_vxlan_get_register_src(struct pim_instance *pim,
    struct pim_upstream *up, struct in_addr *src_p)
{
  if (!(vxlan_mlag.flags & PIM_VXLAN_MLAGF_ENABLED))
    return true;

  /* if address is not available suppress the pim-register */
  if (vxlan_mlag.reg_addr.s_addr == INADDR_ANY)
    return false;

  *src_p = vxlan_mlag.reg_addr;
  return true;
}

void pim_vxlan_mlag_update(bool enable, bool peer_state, uint32_t role,
        struct interface *peerlink_rif,
        struct in_addr *reg_addr)
{
  struct pim_instance *pim;
  char addr_buf[INET_ADDRSTRLEN];
  struct pim_interface *pim_ifp = NULL;

  if (PIM_DEBUG_VXLAN) {
    inet_ntop(AF_INET, reg_addr,
        addr_buf, INET_ADDRSTRLEN);
    zlog_debug("vxlan MLAG update %s state %s role %d rif %s addr %s",
        enable ? "enable" : "disable",
        peer_state ? "up" : "down",
        role,
        peerlink_rif ? peerlink_rif->name : "-",
        addr_buf);
  }

  /* XXX: for now vxlan termination is only possible in the default VRF
   * when that changes this will need to change to iterate all VRFs
   */
  pim = pim_get_pim_instance(VRF_DEFAULT);

  if (!pim) {
    if (PIM_DEBUG_VXLAN)
      zlog_debug("%s: Unable to find pim instance", __func__);
    return;
  }

  if (enable)
    vxlan_mlag.flags |= PIM_VXLAN_MLAGF_ENABLED;
  else
    vxlan_mlag.flags &= ~PIM_VXLAN_MLAGF_ENABLED;

  if (vxlan_mlag.peerlink_rif != peerlink_rif)
    vxlan_mlag.peerlink_rif = peerlink_rif;

  vxlan_mlag.reg_addr = *reg_addr;
  vxlan_mlag.peer_state = peer_state;
  vxlan_mlag.role = role;

  /* process changes */
  if (vxlan_mlag.peerlink_rif)
    pim_ifp = (struct pim_interface *)vxlan_mlag.peerlink_rif->info;
  if ((vxlan_mlag.flags & PIM_VXLAN_MLAGF_ENABLED) &&
      pim_ifp && (pim_ifp->mroute_vif_index > 0))
    pim_vxlan_set_peerlink_rif(pim, peerlink_rif);
  else
    pim_vxlan_set_peerlink_rif(pim, NULL);
}

/****************************** misc callbacks *******************************/
static void pim_vxlan_set_default_iif(struct pim_instance *pim,
        struct interface *ifp)
{
  struct interface *old_iif;

  if (pim->vxlan.default_iif == ifp)
    return;

  old_iif = pim->vxlan.default_iif;
  if (PIM_DEBUG_VXLAN)
    zlog_debug("%s: vxlan default iif changed from %s to %s",
         __func__, old_iif ? old_iif->name : "-",
         ifp ? ifp->name : "-");

  old_iif = pim_vxlan_orig_mr_iif_get(pim);
  pim->vxlan.default_iif = ifp;
  ifp = pim_vxlan_orig_mr_iif_get(pim);
  if (old_iif == ifp)
    return;

  if (PIM_DEBUG_VXLAN)
    zlog_debug("%s: vxlan orig iif changed from %s to %s", __func__,
         old_iif ? old_iif->name : "-",
         ifp ? ifp->name : "-");

  /* add/del upstream entries for the existing vxlan SG when the
   * interface becomes available
   */
  if (pim->vxlan.sg_hash)
    hash_iterate(pim->vxlan.sg_hash,
        pim_vxlan_orig_mr_iif_update, NULL);
}

static void pim_vxlan_up_cost_update(struct pim_instance *pim,
    struct pim_upstream *up,
    struct interface *old_peerlink_rif)
{
  if (!PIM_UPSTREAM_FLAG_TEST_MLAG_VXLAN(up->flags))
    return;

  if (up->rpf.source_nexthop.interface &&
      ((up->rpf.source_nexthop.interface ==
        pim->vxlan.peerlink_rif) ||
       (up->rpf.source_nexthop.interface ==
        old_peerlink_rif))) {
    if (PIM_DEBUG_VXLAN)
      zlog_debug("RPF cost adjust for %s on peerlink-rif (old: %s, new: %s) change",
          up->sg_str,
          old_peerlink_rif ?
          old_peerlink_rif->name : "-",
          pim->vxlan.peerlink_rif ?
          pim->vxlan.peerlink_rif->name : "-");
    pim_mlag_up_local_add(pim, up);
  }
}

static void pim_vxlan_term_mr_cost_update(struct hash_bucket *bucket, void *arg)
{
  struct interface *old_peerlink_rif = (struct interface *)arg;
  struct pim_vxlan_sg *vxlan_sg = (struct pim_vxlan_sg *)bucket->data;
  struct pim_upstream *up;
  struct listnode *listnode;
  struct pim_upstream *child;

  if (pim_vxlan_is_orig_mroute(vxlan_sg))
    return;

  /* Lookup all XG and SG entries with RPF-interface peerlink_rif */
  up = vxlan_sg->up;
  if (!up)
    return;

  pim_vxlan_up_cost_update(vxlan_sg->pim, up,
      old_peerlink_rif);

  for (ALL_LIST_ELEMENTS_RO(up->sources, listnode,
        child))
    pim_vxlan_up_cost_update(vxlan_sg->pim, child,
        old_peerlink_rif);
}

static void pim_vxlan_sg_peerlink_rif_update(struct hash_bucket *bucket,
               void *arg)
{
  pim_vxlan_orig_mr_iif_update(bucket, NULL);
  pim_vxlan_term_mr_cost_update(bucket, arg);
}

static void pim_vxlan_set_peerlink_rif(struct pim_instance *pim,
      struct interface *ifp)
{
  struct interface *old_iif;
  struct interface *new_iif;
  struct interface *old_oif;
  struct interface *new_oif;

  if (pim->vxlan.peerlink_rif == ifp)
    return;

  old_iif = pim->vxlan.peerlink_rif;
  if (PIM_DEBUG_VXLAN)
    zlog_debug("%s: vxlan peerlink_rif changed from %s to %s",
         __func__, old_iif ? old_iif->name : "-",
         ifp ? ifp->name : "-");

  old_iif = pim_vxlan_orig_mr_iif_get(pim);
  old_oif = pim_vxlan_orig_mr_oif_get(pim);
  pim->vxlan.peerlink_rif = ifp;

  new_iif = pim_vxlan_orig_mr_iif_get(pim);
  if (old_iif != new_iif) {
    if (PIM_DEBUG_VXLAN)
      zlog_debug("%s: vxlan orig iif changed from %s to %s",
           __func__, old_iif ? old_iif->name : "-",
           new_iif ? new_iif->name : "-");

    /* add/del upstream entries for the existing vxlan SG when the
     * interface becomes available
     */
    if (pim->vxlan.sg_hash)
      hash_iterate(pim->vxlan.sg_hash,
          pim_vxlan_sg_peerlink_rif_update,
          old_iif);
  }

  new_oif = pim_vxlan_orig_mr_oif_get(pim);
  if (old_oif != new_oif) {
    if (PIM_DEBUG_VXLAN)
      zlog_debug("%s: vxlan orig oif changed from %s to %s",
           __func__, old_oif ? old_oif->name : "-",
           new_oif ? new_oif->name : "-");
    if (pim->vxlan.sg_hash)
      hash_iterate(pim->vxlan.sg_hash,
          pim_vxlan_sg_peerlink_oif_update,
          new_oif);
  }
}

static void pim_vxlan_term_mr_oif_update(struct hash_bucket *bucket, void *arg)
{
  struct interface *ifp = (struct interface *)arg;
  struct pim_vxlan_sg *vxlan_sg = (struct pim_vxlan_sg *)bucket->data;

  if (pim_vxlan_is_orig_mroute(vxlan_sg))
    return;

  if (vxlan_sg->term_oif == ifp)
    return;

  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan SG %s term oif changed from %s to %s",
      vxlan_sg->sg_str,
      vxlan_sg->term_oif ? vxlan_sg->term_oif->name : "-",
      ifp ? ifp->name : "-");

  pim_vxlan_term_mr_del(vxlan_sg);
  vxlan_sg->term_oif = ifp;
  pim_vxlan_term_mr_add(vxlan_sg);
}

static void pim_vxlan_term_oif_update(struct pim_instance *pim,
    struct interface *ifp)
{
  if (pim->vxlan.term_if == ifp)
    return;

  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan term oif changed from %s to %s",
      pim->vxlan.term_if ? pim->vxlan.term_if->name : "-",
      ifp ? ifp->name : "-");

  pim->vxlan.term_if = ifp;
  if (pim->vxlan.sg_hash)
    hash_iterate(pim->vxlan.sg_hash,
        pim_vxlan_term_mr_oif_update, ifp);
}

void pim_vxlan_add_vif(struct interface *ifp)
{
  struct pim_interface *pim_ifp = ifp->info;
  struct pim_instance *pim = pim_ifp->pim;

  if (pim->vrf->vrf_id != VRF_DEFAULT)
    return;

  if (if_is_loopback(ifp))
    pim_vxlan_set_default_iif(pim, ifp);

  if (vxlan_mlag.flags & PIM_VXLAN_MLAGF_ENABLED &&
      (ifp == vxlan_mlag.peerlink_rif))
    pim_vxlan_set_peerlink_rif(pim, ifp);

  if (pim->vxlan.term_if_cfg == ifp)
    pim_vxlan_term_oif_update(pim, ifp);
}

void pim_vxlan_del_vif(struct interface *ifp)
{
  struct pim_interface *pim_ifp = ifp->info;
  struct pim_instance *pim = pim_ifp->pim;

  if (pim->vrf->vrf_id != VRF_DEFAULT)
    return;

  if (pim->vxlan.default_iif == ifp)
    pim_vxlan_set_default_iif(pim, NULL);

  if (pim->vxlan.peerlink_rif == ifp)
    pim_vxlan_set_peerlink_rif(pim, NULL);

  if (pim->vxlan.term_if == ifp)
    pim_vxlan_term_oif_update(pim, NULL);
}

/* enable pim implicitly on the termination device add */
void pim_vxlan_add_term_dev(struct pim_instance *pim,
    struct interface *ifp)
{
  struct pim_interface *pim_ifp;

  if (pim->vxlan.term_if_cfg == ifp)
    return;

  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan term oif cfg changed from %s to %s",
         pim->vxlan.term_if_cfg ?
         pim->vxlan.term_if_cfg->name : "-",
         ifp->name);

  pim->vxlan.term_if_cfg = ifp;

  /* enable pim on the term ifp */
  pim_ifp = (struct pim_interface *)ifp->info;
  if (pim_ifp) {
    pim_ifp->pim_enable = true;
    /* ifp is already oper up; activate it as a term dev */
    if (pim_ifp->mroute_vif_index >= 0)
      pim_vxlan_term_oif_update(pim, ifp);
  } else {
    /* ensure that pimreg exists before using the newly created
     * vxlan termination device
     */
    pim_if_create_pimreg(pim);
    (void)pim_if_new(ifp, false /*igmp*/, true /*pim*/,
         false /*pimreg*/, true /*vxlan_term*/);
  }
}

/* disable pim implicitly, if needed, on the termination device deletion */
void pim_vxlan_del_term_dev(struct pim_instance *pim)
{
  struct interface *ifp = pim->vxlan.term_if_cfg;
  struct pim_interface *pim_ifp;

  if (PIM_DEBUG_VXLAN)
    zlog_debug("vxlan term oif cfg changed from %s to -",
        ifp->name);

  pim->vxlan.term_if_cfg = NULL;

  pim_ifp = (struct pim_interface *)ifp->info;
  if (pim_ifp) {
    pim_ifp->pim_enable = false;
    if (!pim_ifp->gm_enable)
      pim_if_delete(ifp);
  }
}

void pim_vxlan_init(struct pim_instance *pim)
{
  char hash_name[64];

  snprintf(hash_name, sizeof(hash_name),
    "PIM %s vxlan SG hash", pim->vrf->name);
  pim->vxlan.sg_hash = hash_create(pim_vxlan_sg_hash_key_make,
      pim_vxlan_sg_hash_eq, hash_name);
}

void pim_vxlan_exit(struct pim_instance *pim)
{
  hash_clean_and_free(&pim->vxlan.sg_hash,
          (void (*)(void *))pim_vxlan_sg_del_item);
}

void pim_vxlan_terminate(void)
{
  pim_vxlan_work_timer_setup(false);
}

Coverage Report

Created: 2025-11-11 06:17