/src/frr/pimd/pim_rp.c

Source
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * PIM for Quagga
 * Copyright (C) 2015 Cumulus Networks, Inc.
 * Donald Sharp
 */
#include <zebra.h>

#include "lib/json.h"
#include "log.h"
#include "network.h"
#include "if.h"
#include "linklist.h"
#include "prefix.h"
#include "memory.h"
#include "vty.h"
#include "vrf.h"
#include "plist.h"
#include "nexthop.h"
#include "table.h"
#include "lib_errors.h"

#include "pimd.h"
#include "pim_instance.h"
#include "pim_vty.h"
#include "pim_str.h"
#include "pim_iface.h"
#include "pim_rp.h"
#include "pim_rpf.h"
#include "pim_sock.h"
#include "pim_memory.h"
#include "pim_neighbor.h"
#include "pim_msdp.h"
#include "pim_nht.h"
#include "pim_mroute.h"
#include "pim_oil.h"
#include "pim_zebra.h"
#include "pim_bsm.h"
#include "pim_util.h"
#include "pim_ssm.h"
#include "termtable.h"

/* Cleanup pim->rpf_hash each node data */
void pim_rp_list_hash_clean(void *data)
{
  struct pim_nexthop_cache *pnc = (struct pim_nexthop_cache *)data;

  list_delete(&pnc->rp_list);

  hash_clean_and_free(&pnc->upstream_hash, NULL);
  if (pnc->nexthop)
    nexthops_free(pnc->nexthop);

  XFREE(MTYPE_PIM_NEXTHOP_CACHE, pnc);
}

static void pim_rp_info_free(struct rp_info *rp_info)
{
  XFREE(MTYPE_PIM_FILTER_NAME, rp_info->plist);

  XFREE(MTYPE_PIM_RP, rp_info);
}

int pim_rp_list_cmp(void *v1, void *v2)
{
  struct rp_info *rp1 = (struct rp_info *)v1;
  struct rp_info *rp2 = (struct rp_info *)v2;
  int ret;

  /*
   * Sort by RP IP address
   */
  ret = pim_addr_cmp(rp1->rp.rpf_addr, rp2->rp.rpf_addr);
  if (ret)
    return ret;

  /*
   * Sort by group IP address
   */
  ret = prefix_cmp(&rp1->group, &rp2->group);
  if (ret)
    return ret;

  return 0;
}

void pim_rp_init(struct pim_instance *pim)
{
  struct rp_info *rp_info;
  struct route_node *rn;

  pim->rp_list = list_new();
  pim->rp_list->del = (void (*)(void *))pim_rp_info_free;
  pim->rp_list->cmp = pim_rp_list_cmp;

  pim->rp_table = route_table_init();

  rp_info = XCALLOC(MTYPE_PIM_RP, sizeof(*rp_info));

  if (!pim_get_all_mcast_group(&rp_info->group)) {
    flog_err(EC_LIB_DEVELOPMENT,
       "Unable to convert all-multicast prefix");
    list_delete(&pim->rp_list);
    route_table_finish(pim->rp_table);
    XFREE(MTYPE_PIM_RP, rp_info);
    return;
  }
  rp_info->rp.rpf_addr = PIMADDR_ANY;

  listnode_add(pim->rp_list, rp_info);

  rn = route_node_get(pim->rp_table, &rp_info->group);
  rn->info = rp_info;
  if (PIM_DEBUG_PIM_TRACE)
    zlog_debug("Allocated: %p for rp_info: %p(%pFX) Lock: %d", rn,
         rp_info, &rp_info->group,
         route_node_get_lock_count(rn));
}

void pim_rp_free(struct pim_instance *pim)
{
  if (pim->rp_table)
    route_table_finish(pim->rp_table);
  pim->rp_table = NULL;

  if (pim->rp_list)
    list_delete(&pim->rp_list);
}

/*
 * Given an RP's prefix-list, return the RP's rp_info for that prefix-list
 */
static struct rp_info *pim_rp_find_prefix_list(struct pim_instance *pim,
                 pim_addr rp, const char *plist)
{
  struct listnode *node;
  struct rp_info *rp_info;

  for (ALL_LIST_ELEMENTS_RO(pim->rp_list, node, rp_info)) {
    if ((!pim_addr_cmp(rp, rp_info->rp.rpf_addr)) &&
        rp_info->plist && strcmp(rp_info->plist, plist) == 0) {
      return rp_info;
    }
  }

  return NULL;
}

/*
 * Return true if plist is used by any rp_info
 */
static int pim_rp_prefix_list_used(struct pim_instance *pim, const char *plist)
{
  struct listnode *node;
  struct rp_info *rp_info;

  for (ALL_LIST_ELEMENTS_RO(pim->rp_list, node, rp_info)) {
    if (rp_info->plist && strcmp(rp_info->plist, plist) == 0) {
      return 1;
    }
  }

  return 0;
}

/*
 * Given an RP's address, return the RP's rp_info that is an exact match for
 * 'group'
 */
static struct rp_info *pim_rp_find_exact(struct pim_instance *pim, pim_addr rp,
           const struct prefix *group)
{
  struct listnode *node;
  struct rp_info *rp_info;

  for (ALL_LIST_ELEMENTS_RO(pim->rp_list, node, rp_info)) {
    if ((!pim_addr_cmp(rp, rp_info->rp.rpf_addr)) &&
        prefix_same(&rp_info->group, group))
      return rp_info;
  }

  return NULL;
}

/*
 * XXX: long-term issue:  we don't actually have a good "ip address-list"
 * implementation.  ("access-list XYZ" is the closest but honestly it's
 * kinda garbage.)
 *
 * So it's using a prefix-list to match an address here, which causes very
 * unexpected results for the user since prefix-lists by default only match
 * when the prefix length is an exact match too.  i.e. you'd have to add the
 * "le 32" and do "ip prefix-list foo permit 10.0.0.0/24 le 32"
 *
 * To avoid this pitfall, this code uses "address_mode = true" for the prefix
 * list match (this is the only user for that.)
 *
 * In the long run, we need to add a "ip address-list", but that's a wholly
 * separate bag of worms, and existing configs using ip prefix-list would
 * drop into the UX pitfall.
 */

#include "lib/plist_int.h"

/*
 * Given a group, return the rp_info for that group
 */
struct rp_info *pim_rp_find_match_group(struct pim_instance *pim,
                 const struct prefix *group)
{
  struct listnode *node;
  struct rp_info *best = NULL;
  struct rp_info *rp_info;
  struct prefix_list *plist;
  const struct prefix *bp;
  const struct prefix_list_entry *entry;
  struct route_node *rn;

  bp = NULL;
  for (ALL_LIST_ELEMENTS_RO(pim->rp_list, node, rp_info)) {
    if (rp_info->plist) {
      plist = prefix_list_lookup(PIM_AFI, rp_info->plist);

      if (prefix_list_apply_ext(plist, &entry, group, true)
          == PREFIX_DENY || !entry)
        continue;

      if (!best) {
        best = rp_info;
        bp = &entry->prefix;
        continue;
      }

      if (bp && bp->prefixlen < entry->prefix.prefixlen) {
        best = rp_info;
        bp = &entry->prefix;
      }
    }
  }

  rn = route_node_match(pim->rp_table, group);
  if (!rn) {
    flog_err(
      EC_LIB_DEVELOPMENT,
      "%s: BUG We should have found default group information",
      __func__);
    return best;
  }

  rp_info = rn->info;
  if (PIM_DEBUG_PIM_TRACE) {
    if (best)
      zlog_debug(
        "Lookedup(%pFX): prefix_list match %s, rn %p found: %pFX",
        group, best->plist, rn, &rp_info->group);
    else
      zlog_debug("Lookedup(%pFX): rn %p found:%pFX", group,
           rn, &rp_info->group);
  }

  route_unlock_node(rn);

  /*
   * rp's with prefix lists have the group as 224.0.0.0/4 which will
   * match anything.  So if we have a rp_info that should match a prefix
   * list then if we do match then best should be the answer( even
   * if it is NULL )
   */
  if (!rp_info || (rp_info && rp_info->plist))
    return best;

  /*
   * So we have a non plist rp_info found in the lookup and no plists
   * at all to be choosen, return it!
   */
  if (!best)
    return rp_info;

  /*
   * If we have a matching non prefix list and a matching prefix
   * list we should return the actual rp_info that has the LPM
   * If they are equal, use the prefix-list( but let's hope
   * the end-operator doesn't do this )
   */
  if (rp_info->group.prefixlen > bp->prefixlen)
    best = rp_info;

  return best;
}

/*
 * When the user makes "ip pim rp" configuration changes or if they change the
 * prefix-list(s) used by these statements we must tickle the upstream state
 * for each group to make them re-lookup who their RP should be.
 *
 * This is a placeholder function for now.
 */
void pim_rp_refresh_group_to_rp_mapping(struct pim_instance *pim)
{
  pim_msdp_i_am_rp_changed(pim);
  pim_upstream_reeval_use_rpt(pim);
}

void pim_rp_prefix_list_update(struct pim_instance *pim,
             struct prefix_list *plist)
{
  struct listnode *node;
  struct rp_info *rp_info;
  int refresh_needed = 0;

  for (ALL_LIST_ELEMENTS_RO(pim->rp_list, node, rp_info)) {
    if (rp_info->plist
        && strcmp(rp_info->plist, prefix_list_name(plist)) == 0) {
      refresh_needed = 1;
      break;
    }
  }

  if (refresh_needed)
    pim_rp_refresh_group_to_rp_mapping(pim);
}

static int pim_rp_check_interface_addrs(struct rp_info *rp_info,
          struct pim_interface *pim_ifp)
{
  struct listnode *node;
  struct pim_secondary_addr *sec_addr;
  pim_addr sec_paddr;

  if (!pim_addr_cmp(pim_ifp->primary_address, rp_info->rp.rpf_addr))
    return 1;

  if (!pim_ifp->sec_addr_list) {
    return 0;
  }

  for (ALL_LIST_ELEMENTS_RO(pim_ifp->sec_addr_list, node, sec_addr)) {
    sec_paddr = pim_addr_from_prefix(&sec_addr->addr);
    /* If an RP-address is self, It should be enough to say
     * I am RP the prefix-length should not matter here */
    if (!pim_addr_cmp(sec_paddr, rp_info->rp.rpf_addr))
      return 1;
  }

  return 0;
}

static void pim_rp_check_interfaces(struct pim_instance *pim,
            struct rp_info *rp_info)
{
  struct interface *ifp;

  rp_info->i_am_rp = 0;
  FOR_ALL_INTERFACES (pim->vrf, ifp) {
    struct pim_interface *pim_ifp = ifp->info;

    if (!pim_ifp)
      continue;

    if (pim_rp_check_interface_addrs(rp_info, pim_ifp)) {
      rp_info->i_am_rp = 1;
    }
  }
}

void pim_upstream_update(struct pim_instance *pim, struct pim_upstream *up)
{
  struct pim_rpf old_rpf;
  enum pim_rpf_result rpf_result;
  pim_addr old_upstream_addr;
  pim_addr new_upstream_addr;

  old_upstream_addr = up->upstream_addr;
  pim_rp_set_upstream_addr(pim, &new_upstream_addr, up->sg.src,
         up->sg.grp);

  if (PIM_DEBUG_PIM_TRACE)
    zlog_debug("%s: pim upstream update for old upstream %pPA",
         __func__, &old_upstream_addr);

  if (!pim_addr_cmp(old_upstream_addr, new_upstream_addr))
    return;

  /* Lets consider a case, where a PIM upstream has a better RP as a
   * result of a new RP configuration with more precise group range.
   * This upstream has to be added to the upstream hash of new RP's
   * NHT(pnc) and has to be removed from old RP's NHT upstream hash
   */
  if (!pim_addr_is_any(old_upstream_addr)) {
    /* Deregister addr with Zebra NHT */
    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug(
        "%s: Deregister upstream %s addr %pPA with Zebra NHT",
        __func__, up->sg_str, &old_upstream_addr);
    pim_delete_tracked_nexthop(pim, old_upstream_addr, up, NULL);
  }

  /* Update the upstream address */
  up->upstream_addr = new_upstream_addr;

  old_rpf.source_nexthop.interface = up->rpf.source_nexthop.interface;

  rpf_result = pim_rpf_update(pim, up, &old_rpf, __func__);
  if (rpf_result == PIM_RPF_FAILURE)
    pim_mroute_del(up->channel_oil, __func__);

  /* update kernel multicast forwarding cache (MFC) */
  if (up->rpf.source_nexthop.interface && up->channel_oil)
    pim_upstream_mroute_iif_update(up->channel_oil, __func__);

  if (rpf_result == PIM_RPF_CHANGED ||
      (rpf_result == PIM_RPF_FAILURE &&
       old_rpf.source_nexthop.interface))
    pim_zebra_upstream_rpf_changed(pim, up, &old_rpf);

}

int pim_rp_new(struct pim_instance *pim, pim_addr rp_addr, struct prefix group,
         const char *plist, enum rp_source rp_src_flag)
{
  int result = 0;
  struct rp_info *rp_info;
  struct rp_info *rp_all;
  struct prefix group_all;
  struct listnode *node, *nnode;
  struct rp_info *tmp_rp_info;
  char buffer[BUFSIZ];
  pim_addr nht_p;
  struct route_node *rn = NULL;
  struct pim_upstream *up;
  bool upstream_updated = false;

  if (pim_addr_is_any(rp_addr))
    return PIM_RP_BAD_ADDRESS;

  rp_info = XCALLOC(MTYPE_PIM_RP, sizeof(*rp_info));

  rp_info->rp.rpf_addr = rp_addr;
  prefix_copy(&rp_info->group, &group);
  rp_info->rp_src = rp_src_flag;

  if (plist) {
    /*
     * Return if the prefix-list is already configured for this RP
     */
    if (pim_rp_find_prefix_list(pim, rp_addr, plist)) {
      XFREE(MTYPE_PIM_RP, rp_info);
      return PIM_SUCCESS;
    }

    /*
     * Barf if the prefix-list is already configured for an RP
     */
    if (pim_rp_prefix_list_used(pim, plist)) {
      XFREE(MTYPE_PIM_RP, rp_info);
      return PIM_RP_PFXLIST_IN_USE;
    }

    /*
     * Free any existing rp_info entries for this RP
     */
    for (ALL_LIST_ELEMENTS(pim->rp_list, node, nnode,
               tmp_rp_info)) {
      if (!pim_addr_cmp(rp_info->rp.rpf_addr,
            tmp_rp_info->rp.rpf_addr)) {
        if (tmp_rp_info->plist)
          pim_rp_del_config(pim, rp_addr, NULL,
                tmp_rp_info->plist);
        else
          pim_rp_del_config(
            pim, rp_addr,
            prefix2str(&tmp_rp_info->group,
                 buffer, BUFSIZ),
            NULL);
      }
    }

    rp_info->plist = XSTRDUP(MTYPE_PIM_FILTER_NAME, plist);
  } else {

    if (!pim_get_all_mcast_group(&group_all)) {
      XFREE(MTYPE_PIM_RP, rp_info);
      return PIM_GROUP_BAD_ADDRESS;
    }
    rp_all = pim_rp_find_match_group(pim, &group_all);

    /*
     * Barf if group is a non-multicast subnet
     */
    if (!prefix_match(&rp_all->group, &rp_info->group)) {
      XFREE(MTYPE_PIM_RP, rp_info);
      return PIM_GROUP_BAD_ADDRESS;
    }

    /*
     * Remove any prefix-list rp_info entries for this RP
     */
    for (ALL_LIST_ELEMENTS(pim->rp_list, node, nnode,
               tmp_rp_info)) {
      if (tmp_rp_info->plist &&
          (!pim_addr_cmp(rp_info->rp.rpf_addr,
             tmp_rp_info->rp.rpf_addr))) {
        pim_rp_del_config(pim, rp_addr, NULL,
              tmp_rp_info->plist);
      }
    }

    /*
     * Take over the 224.0.0.0/4 group if the rp is INADDR_ANY
     */
    if (prefix_same(&rp_all->group, &rp_info->group) &&
        pim_rpf_addr_is_inaddr_any(&rp_all->rp)) {
      rp_all->rp.rpf_addr = rp_info->rp.rpf_addr;
      rp_all->rp_src = rp_src_flag;
      XFREE(MTYPE_PIM_RP, rp_info);

      /* Register addr with Zebra NHT */
      nht_p = rp_all->rp.rpf_addr;
      if (PIM_DEBUG_PIM_NHT_RP)
        zlog_debug(
          "%s: NHT Register rp_all addr %pPA grp %pFX ",
          __func__, &nht_p, &rp_all->group);

      frr_each (rb_pim_upstream, &pim->upstream_head, up) {
        /* Find (*, G) upstream whose RP is not
         * configured yet
         */
        if (pim_addr_is_any(up->upstream_addr) &&
            pim_addr_is_any(up->sg.src)) {
          struct prefix grp;
          struct rp_info *trp_info;

          pim_addr_to_prefix(&grp, up->sg.grp);
          trp_info = pim_rp_find_match_group(
            pim, &grp);
          if (trp_info == rp_all) {
            pim_upstream_update(pim, up);
            upstream_updated = true;
          }
        }
      }
      if (upstream_updated)
        pim_zebra_update_all_interfaces(pim);

      pim_rp_check_interfaces(pim, rp_all);
      pim_rp_refresh_group_to_rp_mapping(pim);
      pim_find_or_track_nexthop(pim, nht_p, NULL, rp_all,
              NULL);

      if (!pim_ecmp_nexthop_lookup(pim,
                 &rp_all->rp.source_nexthop,
                 nht_p, &rp_all->group, 1))
        return PIM_RP_NO_PATH;
      return PIM_SUCCESS;
    }

    /*
     * Return if the group is already configured for this RP
     */
    tmp_rp_info = pim_rp_find_exact(pim, rp_addr, &rp_info->group);
    if (tmp_rp_info) {
      if ((tmp_rp_info->rp_src != rp_src_flag)
          && (rp_src_flag == RP_SRC_STATIC))
        tmp_rp_info->rp_src = rp_src_flag;
      XFREE(MTYPE_PIM_RP, rp_info);
      return result;
    }

    /*
     * Barf if this group is already covered by some other RP
     */
    tmp_rp_info = pim_rp_find_match_group(pim, &rp_info->group);

    if (tmp_rp_info) {
      if (tmp_rp_info->plist) {
        XFREE(MTYPE_PIM_RP, rp_info);
        return PIM_GROUP_PFXLIST_OVERLAP;
      } else {
        /*
         * If the only RP that covers this group is an
         * RP configured for
         * 224.0.0.0/4 that is fine, ignore that one.
         * For all others
         * though we must return PIM_GROUP_OVERLAP
         */
        if (prefix_same(&rp_info->group,
            &tmp_rp_info->group)) {
          if ((rp_src_flag == RP_SRC_STATIC)
              && (tmp_rp_info->rp_src
            == RP_SRC_STATIC)) {
            XFREE(MTYPE_PIM_RP, rp_info);
            return PIM_GROUP_OVERLAP;
          }

          result = pim_rp_change(
            pim, rp_addr,
            tmp_rp_info->group,
            rp_src_flag);
          XFREE(MTYPE_PIM_RP, rp_info);
          return result;
        }
      }
    }
  }

  listnode_add_sort(pim->rp_list, rp_info);

  if (!rp_info->plist) {
    rn = route_node_get(pim->rp_table, &rp_info->group);
    rn->info = rp_info;
  }

  if (PIM_DEBUG_PIM_TRACE)
    zlog_debug("Allocated: %p for rp_info: %p(%pFX) Lock: %d", rn,
         rp_info, &rp_info->group,
         rn ? route_node_get_lock_count(rn) : 0);

  frr_each (rb_pim_upstream, &pim->upstream_head, up) {
    if (pim_addr_is_any(up->sg.src)) {
      struct prefix grp;
      struct rp_info *trp_info;

      pim_addr_to_prefix(&grp, up->sg.grp);
      trp_info = pim_rp_find_match_group(pim, &grp);

      if (trp_info == rp_info) {
        pim_upstream_update(pim, up);
        upstream_updated = true;
      }
    }
  }

  if (upstream_updated)
    pim_zebra_update_all_interfaces(pim);

  pim_rp_check_interfaces(pim, rp_info);
  pim_rp_refresh_group_to_rp_mapping(pim);

  /* Register addr with Zebra NHT */
  nht_p = rp_info->rp.rpf_addr;
  if (PIM_DEBUG_PIM_NHT_RP)
    zlog_debug("%s: NHT Register RP addr %pPA grp %pFX with Zebra ",
         __func__, &nht_p, &rp_info->group);
  pim_find_or_track_nexthop(pim, nht_p, NULL, rp_info, NULL);
  if (!pim_ecmp_nexthop_lookup(pim, &rp_info->rp.source_nexthop, nht_p,
             &rp_info->group, 1))
    return PIM_RP_NO_PATH;

  return PIM_SUCCESS;
}

void pim_rp_del_config(struct pim_instance *pim, pim_addr rp_addr,
           const char *group_range, const char *plist)
{
  struct prefix group;
  int result;

  if (group_range == NULL)
    result = pim_get_all_mcast_group(&group);
  else
    result = str2prefix(group_range, &group);

  if (!result) {
    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug(
        "%s: String to prefix failed for %pPAs group",
        __func__, &rp_addr);
    return;
  }

  pim_rp_del(pim, rp_addr, group, plist, RP_SRC_STATIC);
}

int pim_rp_del(struct pim_instance *pim, pim_addr rp_addr, struct prefix group,
         const char *plist, enum rp_source rp_src_flag)
{
  struct prefix g_all;
  struct rp_info *rp_info;
  struct rp_info *rp_all;
  pim_addr nht_p;
  struct route_node *rn;
  bool was_plist = false;
  struct rp_info *trp_info;
  struct pim_upstream *up;
  struct bsgrp_node *bsgrp = NULL;
  struct bsm_rpinfo *bsrp = NULL;
  bool upstream_updated = false;

  if (plist)
    rp_info = pim_rp_find_prefix_list(pim, rp_addr, plist);
  else
    rp_info = pim_rp_find_exact(pim, rp_addr, &group);

  if (!rp_info)
    return PIM_RP_NOT_FOUND;

  if (rp_info->plist) {
    XFREE(MTYPE_PIM_FILTER_NAME, rp_info->plist);
    was_plist = true;
  }

  if (PIM_DEBUG_PIM_TRACE)
    zlog_debug("%s: Delete RP %pPA for the group %pFX", __func__,
         &rp_addr, &group);

  /* While static RP is getting deleted, we need to check if dynamic RP
   * present for the same group in BSM RP table, then install the dynamic
   * RP for the group node into the main rp table
   */
  if (rp_src_flag == RP_SRC_STATIC) {
    bsgrp = pim_bsm_get_bsgrp_node(&pim->global_scope, &group);

    if (bsgrp) {
      bsrp = bsm_rpinfos_first(bsgrp->bsrp_list);
      if (bsrp) {
        if (PIM_DEBUG_PIM_TRACE)
          zlog_debug(
            "%s: BSM RP %pPA found for the group %pFX",
            __func__, &bsrp->rp_address,
            &group);
        return pim_rp_change(pim, bsrp->rp_address,
                 group, RP_SRC_BSR);
      }
    } else {
      if (PIM_DEBUG_PIM_TRACE)
        zlog_debug(
          "%s: BSM RP not found for the group %pFX",
          __func__, &group);
    }
  }

  /* Deregister addr with Zebra NHT */
  nht_p = rp_info->rp.rpf_addr;
  if (PIM_DEBUG_PIM_NHT_RP)
    zlog_debug("%s: Deregister RP addr %pPA with Zebra ", __func__,
         &nht_p);
  pim_delete_tracked_nexthop(pim, nht_p, NULL, rp_info);

  if (!pim_get_all_mcast_group(&g_all))
    return PIM_RP_BAD_ADDRESS;

  rp_all = pim_rp_find_match_group(pim, &g_all);

  if (rp_all == rp_info) {
    frr_each (rb_pim_upstream, &pim->upstream_head, up) {
      /* Find the upstream (*, G) whose upstream address is
       * same as the deleted RP
       */
      pim_addr rpf_addr;

      rpf_addr = rp_info->rp.rpf_addr;
      if (!pim_addr_cmp(up->upstream_addr, rpf_addr) &&
          pim_addr_is_any(up->sg.src)) {
        struct prefix grp;

        pim_addr_to_prefix(&grp, up->sg.grp);
        trp_info = pim_rp_find_match_group(pim, &grp);
        if (trp_info == rp_all) {
          pim_upstream_rpf_clear(pim, up);
          up->upstream_addr = PIMADDR_ANY;
        }
      }
    }
    rp_all->rp.rpf_addr = PIMADDR_ANY;
    rp_all->i_am_rp = 0;
    return PIM_SUCCESS;
  }

  listnode_delete(pim->rp_list, rp_info);

  if (!was_plist) {
    rn = route_node_get(pim->rp_table, &rp_info->group);
    if (rn) {
      if (rn->info != rp_info)
        flog_err(
          EC_LIB_DEVELOPMENT,
          "Expected rn->info to be equal to rp_info");

      if (PIM_DEBUG_PIM_TRACE)
        zlog_debug(
          "%s:Found for Freeing: %p for rp_info: %p(%pFX) Lock: %d",
          __func__, rn, rp_info, &rp_info->group,
          route_node_get_lock_count(rn));

      rn->info = NULL;
      route_unlock_node(rn);
      route_unlock_node(rn);
    }
  }

  pim_rp_refresh_group_to_rp_mapping(pim);

  frr_each (rb_pim_upstream, &pim->upstream_head, up) {
    /* Find the upstream (*, G) whose upstream address is same as
     * the deleted RP
     */
    pim_addr rpf_addr;

    rpf_addr = rp_info->rp.rpf_addr;
    if (!pim_addr_cmp(up->upstream_addr, rpf_addr) &&
        pim_addr_is_any(up->sg.src)) {
      struct prefix grp;

      pim_addr_to_prefix(&grp, up->sg.grp);
      trp_info = pim_rp_find_match_group(pim, &grp);

      if (!trp_info)
        continue;

      /* RP not found for the group grp */
      if (pim_rpf_addr_is_inaddr_any(&trp_info->rp)) {
        pim_upstream_rpf_clear(pim, up);
        pim_rp_set_upstream_addr(
          pim, &up->upstream_addr, up->sg.src,
          up->sg.grp);
      }

      /* RP found for the group grp */
      else {
        pim_upstream_update(pim, up);
        upstream_updated = true;
      }
    }
  }

  if (upstream_updated)
    pim_zebra_update_all_interfaces(pim);

  XFREE(MTYPE_PIM_RP, rp_info);
  return PIM_SUCCESS;
}

int pim_rp_change(struct pim_instance *pim, pim_addr new_rp_addr,
      struct prefix group, enum rp_source rp_src_flag)
{
  pim_addr nht_p;
  struct route_node *rn;
  int result = 0;
  struct rp_info *rp_info = NULL;
  struct pim_upstream *up;
  bool upstream_updated = false;
  pim_addr old_rp_addr;

  rn = route_node_lookup(pim->rp_table, &group);
  if (!rn) {
    result = pim_rp_new(pim, new_rp_addr, group, NULL, rp_src_flag);
    return result;
  }

  rp_info = rn->info;

  if (!rp_info) {
    route_unlock_node(rn);
    result = pim_rp_new(pim, new_rp_addr, group, NULL, rp_src_flag);
    return result;
  }

  old_rp_addr = rp_info->rp.rpf_addr;
  if (!pim_addr_cmp(new_rp_addr, old_rp_addr)) {
    if (rp_info->rp_src != rp_src_flag) {
      rp_info->rp_src = rp_src_flag;
      route_unlock_node(rn);
      return PIM_SUCCESS;
    }
  }

  /* Deregister old RP addr with Zebra NHT */

  if (!pim_addr_is_any(old_rp_addr)) {
    nht_p = rp_info->rp.rpf_addr;
    if (PIM_DEBUG_PIM_NHT_RP)
      zlog_debug("%s: Deregister RP addr %pPA with Zebra ",
           __func__, &nht_p);
    pim_delete_tracked_nexthop(pim, nht_p, NULL, rp_info);
  }

  pim_rp_nexthop_del(rp_info);
  listnode_delete(pim->rp_list, rp_info);
  /* Update the new RP address*/

  rp_info->rp.rpf_addr = new_rp_addr;
  rp_info->rp_src = rp_src_flag;
  rp_info->i_am_rp = 0;

  listnode_add_sort(pim->rp_list, rp_info);

  frr_each (rb_pim_upstream, &pim->upstream_head, up) {
    if (pim_addr_is_any(up->sg.src)) {
      struct prefix grp;
      struct rp_info *trp_info;

      pim_addr_to_prefix(&grp, up->sg.grp);
      trp_info = pim_rp_find_match_group(pim, &grp);

      if (trp_info == rp_info) {
        pim_upstream_update(pim, up);
        upstream_updated = true;
      }
    }
  }

  if (upstream_updated)
    pim_zebra_update_all_interfaces(pim);

  /* Register new RP addr with Zebra NHT */
  nht_p = rp_info->rp.rpf_addr;
  if (PIM_DEBUG_PIM_NHT_RP)
    zlog_debug("%s: NHT Register RP addr %pPA grp %pFX with Zebra ",
         __func__, &nht_p, &rp_info->group);

  pim_find_or_track_nexthop(pim, nht_p, NULL, rp_info, NULL);
  if (!pim_ecmp_nexthop_lookup(pim, &rp_info->rp.source_nexthop, nht_p,
             &rp_info->group, 1)) {
    route_unlock_node(rn);
    return PIM_RP_NO_PATH;
  }

  pim_rp_check_interfaces(pim, rp_info);

  route_unlock_node(rn);

  pim_rp_refresh_group_to_rp_mapping(pim);

  return result;
}

void pim_rp_setup(struct pim_instance *pim)
{
  struct listnode *node;
  struct rp_info *rp_info;
  pim_addr nht_p;

  for (ALL_LIST_ELEMENTS_RO(pim->rp_list, node, rp_info)) {
    if (pim_rpf_addr_is_inaddr_any(&rp_info->rp))
      continue;

    nht_p = rp_info->rp.rpf_addr;

    pim_find_or_track_nexthop(pim, nht_p, NULL, rp_info, NULL);
    if (!pim_ecmp_nexthop_lookup(pim, &rp_info->rp.source_nexthop,
               nht_p, &rp_info->group, 1)) {
      if (PIM_DEBUG_PIM_NHT_RP)
        zlog_debug(
          "Unable to lookup nexthop for rp specified");
      pim_rp_nexthop_del(rp_info);
    }
  }
}

/*
 * Checks to see if we should elect ourself the actual RP when new if
 * addresses are added against an interface.
 */
void pim_rp_check_on_if_add(struct pim_interface *pim_ifp)
{
  struct listnode *node;
  struct rp_info *rp_info;
  bool i_am_rp_changed = false;
  struct pim_instance *pim = pim_ifp->pim;

  if (pim->rp_list == NULL)
    return;

  for (ALL_LIST_ELEMENTS_RO(pim->rp_list, node, rp_info)) {
    if (pim_rpf_addr_is_inaddr_any(&rp_info->rp))
      continue;

    /* if i_am_rp is already set nothing to be done (adding new
     * addresses
     * is not going to make a difference). */
    if (rp_info->i_am_rp) {
      continue;
    }

    if (pim_rp_check_interface_addrs(rp_info, pim_ifp)) {
      i_am_rp_changed = true;
      rp_info->i_am_rp = 1;
      if (PIM_DEBUG_PIM_NHT_RP)
        zlog_debug("%s: %pPA: i am rp", __func__,
             &rp_info->rp.rpf_addr);
    }
  }

  if (i_am_rp_changed) {
    pim_msdp_i_am_rp_changed(pim);
    pim_upstream_reeval_use_rpt(pim);
  }
}

/* up-optimized re-evaluation of "i_am_rp". this is used when ifaddresses
 * are removed. Removing numbers is an uncommon event in an active network
 * so I have made no attempt to optimize it. */
void pim_i_am_rp_re_evaluate(struct pim_instance *pim)
{
  struct listnode *node;
  struct rp_info *rp_info;
  bool i_am_rp_changed = false;
  int old_i_am_rp;

  if (pim->rp_list == NULL)
    return;

  for (ALL_LIST_ELEMENTS_RO(pim->rp_list, node, rp_info)) {
    if (pim_rpf_addr_is_inaddr_any(&rp_info->rp))
      continue;

    old_i_am_rp = rp_info->i_am_rp;
    pim_rp_check_interfaces(pim, rp_info);

    if (old_i_am_rp != rp_info->i_am_rp) {
      i_am_rp_changed = true;
      if (PIM_DEBUG_PIM_NHT_RP) {
        if (rp_info->i_am_rp)
          zlog_debug("%s: %pPA: i am rp",
               __func__,
               &rp_info->rp.rpf_addr);
        else
          zlog_debug(
            "%s: %pPA: i am no longer rp",
            __func__,
            &rp_info->rp.rpf_addr);
      }
    }
  }

  if (i_am_rp_changed) {
    pim_msdp_i_am_rp_changed(pim);
    pim_upstream_reeval_use_rpt(pim);
  }
}

/*
 * I_am_RP(G) is true if the group-to-RP mapping indicates that
 * this router is the RP for the group.
 *
 * Since we only have static RP, all groups are part of this RP
 */
int pim_rp_i_am_rp(struct pim_instance *pim, pim_addr group)
{
  struct prefix g;
  struct rp_info *rp_info;

  memset(&g, 0, sizeof(g));
  pim_addr_to_prefix(&g, group);
  rp_info = pim_rp_find_match_group(pim, &g);

  if (rp_info)
    return rp_info->i_am_rp;
  return 0;
}

/*
 * RP(G)
 *
 * Return the RP that the Group belongs too.
 */
struct pim_rpf *pim_rp_g(struct pim_instance *pim, pim_addr group)
{
  struct prefix g;
  struct rp_info *rp_info;

  memset(&g, 0, sizeof(g));
  pim_addr_to_prefix(&g, group);

  rp_info = pim_rp_find_match_group(pim, &g);

  if (rp_info) {
    pim_addr nht_p;

    if (pim_addr_is_any(rp_info->rp.rpf_addr)) {
      if (PIM_DEBUG_PIM_NHT_RP)
        zlog_debug(
          "%s: Skipping NHT Register since RP is not configured for the group %pPA",
          __func__, &group);
      return &rp_info->rp;
    }

    /* Register addr with Zebra NHT */
    nht_p = rp_info->rp.rpf_addr;
    if (PIM_DEBUG_PIM_NHT_RP)
      zlog_debug(
        "%s: NHT Register RP addr %pPA grp %pFX with Zebra",
        __func__, &nht_p, &rp_info->group);
    pim_find_or_track_nexthop(pim, nht_p, NULL, rp_info, NULL);
    pim_rpf_set_refresh_time(pim);
    (void)pim_ecmp_nexthop_lookup(pim, &rp_info->rp.source_nexthop,
                nht_p, &rp_info->group, 1);
    return (&rp_info->rp);
  }

  // About to Go Down
  return NULL;
}

/*
 * Set the upstream IP address we want to talk to based upon
 * the rp configured and the source address
 *
 * If we have don't have a RP configured and the source address is *
 * then set the upstream addr as INADDR_ANY and return failure.
 *
 */
int pim_rp_set_upstream_addr(struct pim_instance *pim, pim_addr *up,
           pim_addr source, pim_addr group)
{
  struct rp_info *rp_info;
  struct prefix g;

  memset(&g, 0, sizeof(g));

  pim_addr_to_prefix(&g, group);

  rp_info = pim_rp_find_match_group(pim, &g);

  if (!rp_info || ((pim_rpf_addr_is_inaddr_any(&rp_info->rp)) &&
       (pim_addr_is_any(source)))) {
    if (PIM_DEBUG_PIM_NHT_RP)
      zlog_debug("%s: Received a (*,G) with no RP configured",
           __func__);
    *up = PIMADDR_ANY;
    return 0;
  }

  if (pim_addr_is_any(source))
    *up = rp_info->rp.rpf_addr;
  else
    *up = source;

  return 1;
}

int pim_rp_config_write(struct pim_instance *pim, struct vty *vty,
      const char *spaces)
{
  struct listnode *node;
  struct rp_info *rp_info;
  int count = 0;
  pim_addr rp_addr;

  for (ALL_LIST_ELEMENTS_RO(pim->rp_list, node, rp_info)) {
    if (pim_rpf_addr_is_inaddr_any(&rp_info->rp))
      continue;

    if (rp_info->rp_src == RP_SRC_BSR)
      continue;

    rp_addr = rp_info->rp.rpf_addr;
    if (rp_info->plist)
      vty_out(vty,
        "%s" PIM_AF_NAME
        " pim rp %pPA prefix-list %s\n",
        spaces, &rp_addr, rp_info->plist);
    else
      vty_out(vty, "%s" PIM_AF_NAME " pim rp %pPA %pFX\n",
        spaces, &rp_addr, &rp_info->group);
    count++;
  }

  return count;
}

void pim_rp_show_information(struct pim_instance *pim, struct prefix *range,
           struct vty *vty, json_object *json)
{
  struct rp_info *rp_info;
  struct rp_info *prev_rp_info = NULL;
  struct listnode *node;
  struct ttable *tt = NULL;
  char *table = NULL;
  char source[7];
  char grp[INET6_ADDRSTRLEN];

  json_object *json_rp_rows = NULL;
  json_object *json_row = NULL;

  if (!json) {
    /* Prepare table. */
    tt = ttable_new(&ttable_styles[TTSTYLE_BLANK]);
    ttable_add_row(
      tt,
      "RP address|group/prefix-list|OIF|I am RP|Source|Group-Type");
    tt->style.cell.rpad = 2;
    tt->style.corner = '+';
    ttable_restyle(tt);
  }

  for (ALL_LIST_ELEMENTS_RO(pim->rp_list, node, rp_info)) {
    if (pim_rpf_addr_is_inaddr_any(&rp_info->rp))
      continue;

#if PIM_IPV == 4
    pim_addr group = rp_info->group.u.prefix4;
#else
    pim_addr group = rp_info->group.u.prefix6;
#endif
    const char *group_type =
      pim_is_grp_ssm(pim, group) ? "SSM" : "ASM";

    if (range && !prefix_match(&rp_info->group, range))
      continue;

    if (rp_info->rp_src == RP_SRC_STATIC)
      strlcpy(source, "Static", sizeof(source));
    else if (rp_info->rp_src == RP_SRC_BSR)
      strlcpy(source, "BSR", sizeof(source));
    else
      strlcpy(source, "None", sizeof(source));
    if (json) {
      /*
       * If we have moved on to a new RP then add the
       * entry for the previous RP
       */
      if (prev_rp_info &&
          (pim_addr_cmp(prev_rp_info->rp.rpf_addr,
            rp_info->rp.rpf_addr))) {
        json_object_object_addf(
          json, json_rp_rows, "%pPA",
          &prev_rp_info->rp.rpf_addr);
        json_rp_rows = NULL;
      }

      if (!json_rp_rows)
        json_rp_rows = json_object_new_array();

      json_row = json_object_new_object();
      json_object_string_addf(json_row, "rpAddress", "%pPA",
            &rp_info->rp.rpf_addr);
      if (rp_info->rp.source_nexthop.interface)
        json_object_string_add(
          json_row, "outboundInterface",
          rp_info->rp.source_nexthop
            .interface->name);
      else
        json_object_string_add(json_row,
                   "outboundInterface",
                   "Unknown");
      if (rp_info->i_am_rp)
        json_object_boolean_true_add(json_row, "iAmRP");
      else
        json_object_boolean_false_add(json_row,
                    "iAmRP");

      if (rp_info->plist)
        json_object_string_add(json_row, "prefixList",
                   rp_info->plist);
      else
        json_object_string_addf(json_row, "group",
              "%pFX",
              &rp_info->group);
      json_object_string_add(json_row, "source", source);
      json_object_string_add(json_row, "groupType",
                 group_type);

      json_object_array_add(json_rp_rows, json_row);
    } else {
      prefix2str(&rp_info->group, grp, sizeof(grp));
      ttable_add_row(tt, "%pPA|%s|%s|%s|%s|%s",
            &rp_info->rp.rpf_addr,
            rp_info->plist
            ? rp_info->plist
            : grp,
            rp_info->rp.source_nexthop.interface
            ? rp_info->rp.source_nexthop
            .interface->name
            : "Unknown",
            rp_info->i_am_rp
            ? "yes"
            : "no",
            source, group_type);
    }
    prev_rp_info = rp_info;
  }

  /* Dump the generated table. */
  if (!json) {
    table = ttable_dump(tt, "\n");
    vty_out(vty, "%s\n", table);
    XFREE(MTYPE_TMP, table);
    ttable_del(tt);
  } else {
    if (prev_rp_info && json_rp_rows)
      json_object_object_addf(json, json_rp_rows, "%pPA",
            &prev_rp_info->rp.rpf_addr);
  }
}

void pim_resolve_rp_nh(struct pim_instance *pim, struct pim_neighbor *nbr)
{
  struct listnode *node = NULL;
  struct rp_info *rp_info = NULL;
  struct nexthop *nh_node = NULL;
  pim_addr nht_p;
  struct pim_nexthop_cache pnc;

  for (ALL_LIST_ELEMENTS_RO(pim->rp_list, node, rp_info)) {
    if (pim_rpf_addr_is_inaddr_any(&rp_info->rp))
      continue;

    nht_p = rp_info->rp.rpf_addr;
    memset(&pnc, 0, sizeof(struct pim_nexthop_cache));
    if (!pim_find_or_track_nexthop(pim, nht_p, NULL, rp_info, &pnc))
      continue;

    for (nh_node = pnc.nexthop; nh_node; nh_node = nh_node->next) {
#if PIM_IPV == 4
      if (!pim_addr_is_any(nh_node->gate.ipv4))
        continue;
#else
      if (!pim_addr_is_any(nh_node->gate.ipv6))
        continue;
#endif

      struct interface *ifp1 = if_lookup_by_index(
        nh_node->ifindex, pim->vrf->vrf_id);

      if (nbr->interface != ifp1)
        continue;

#if PIM_IPV == 4
      nh_node->gate.ipv4 = nbr->source_addr;
#else
      nh_node->gate.ipv6 = nbr->source_addr;
#endif
      if (PIM_DEBUG_PIM_NHT_RP)
        zlog_debug(
          "%s: addr %pPA new nexthop addr %pPAs interface %s",
          __func__, &nht_p, &nbr->source_addr,
          ifp1->name);
    }
  }
}

Coverage Report

Created: 2026-05-11 06:50