pimd: PIM nexthop tracking changes for tracking nexthop path of BSR.

Signed-off-by: Saravanan K <saravanank@vmware.com>

6 files changed, 33 insertions, 14 deletions

diff --git a/pimd/pim_nht.c b/pimd/pim_nht.c
index 8a459fe86e..3a3a74b155 100644
--- a/pimd/pim_nht.c
+++ b/pimd/pim_nht.c
@@ -121,6 +121,7 @@ static struct pim_nexthop_cache *pim_nexthop_cache_add(struct pim_instance *pim,
  */
 int pim_find_or_track_nexthop(struct pim_instance *pim, struct prefix *addr,
 			      struct pim_upstream *up, struct rp_info *rp,
+			      bool bsr_track_needed,
 			      struct pim_nexthop_cache *out_pnc)
 {
 	struct pim_nexthop_cache *pnc = NULL;
@@ -157,6 +158,9 @@ int pim_find_or_track_nexthop(struct pim_instance *pim, struct prefix *addr,
 	if (up != NULL)
 		hash_get(pnc->upstream_hash, up, hash_alloc_intern);
 
+	if (bsr_track_needed)
+		pnc->bsr_tracking = true;
+
 	if (CHECK_FLAG(pnc->flags, PIM_NEXTHOP_VALID)) {
 		if (out_pnc)
 			memcpy(out_pnc, pnc, sizeof(struct pim_nexthop_cache));
@@ -167,7 +171,8 @@ int pim_find_or_track_nexthop(struct pim_instance *pim, struct prefix *addr,
 }
 
 void pim_delete_tracked_nexthop(struct pim_instance *pim, struct prefix *addr,
-				struct pim_upstream *up, struct rp_info *rp)
+				struct pim_upstream *up, struct rp_info *rp,
+				bool del_bsr_tracking)
 {
 	struct pim_nexthop_cache *pnc = NULL;
 	struct pim_nexthop_cache lookup;
@@ -208,6 +213,9 @@ void pim_delete_tracked_nexthop(struct pim_instance *pim, struct prefix *addr,
 		if (up)
 			hash_release(pnc->upstream_hash, up);
 
+		if (del_bsr_tracking)
+			pnc->bsr_tracking = false;
+
 		if (PIM_DEBUG_PIM_NHT) {
 			char buf[PREFIX_STRLEN];
 			prefix2str(addr, buf, sizeof buf);
@@ -218,7 +226,8 @@ void pim_delete_tracked_nexthop(struct pim_instance *pim, struct prefix *addr,
 		}
 
 		if (pnc->rp_list->count == 0
-		    && pnc->upstream_hash->count == 0) {
+		    && pnc->upstream_hash->count == 0
+		    && pnc->bsr_tracking == false) {
 			pim_sendmsg_zebra_rnh(pim, zclient, pnc,
 					      ZEBRA_NEXTHOP_UNREGISTER);
 
diff --git a/pimd/pim_nht.h b/pimd/pim_nht.h
index 13bb0fcb55..5324aba445 100644
--- a/pimd/pim_nht.h
+++ b/pimd/pim_nht.h
@@ -45,15 +45,23 @@ struct pim_nexthop_cache {
 
 	struct list *rp_list;
 	struct hash *upstream_hash;
+	/* Ideally this has to be list of scope zone. But for now we can just
+	 * have as a bool variable to say bsr_tracking.
+	 * Later this variable can be changed as a list of scope zones for
+	 * tracking same bsr for multiple scope zones.
+	 */
+	bool bsr_tracking;
 };
 
 int pim_parse_nexthop_update(int command, struct zclient *zclient,
 			     zebra_size_t length, vrf_id_t vrf_id);
 int pim_find_or_track_nexthop(struct pim_instance *pim, struct prefix *addr,
 			      struct pim_upstream *up, struct rp_info *rp,
+			      bool bsr_track_needed,
 			      struct pim_nexthop_cache *out_pnc);
 void pim_delete_tracked_nexthop(struct pim_instance *pim, struct prefix *addr,
-				struct pim_upstream *up, struct rp_info *rp);
+				struct pim_upstream *up, struct rp_info *rp,
+				bool del_bsr_tracking);
 struct pim_nexthop_cache *pim_nexthop_cache_find(struct pim_instance *pim,
 						 struct pim_rpf *rpf);
 uint32_t pim_compute_ecmp_hash(struct prefix *src, struct prefix *grp);
diff --git a/pimd/pim_rp.c b/pimd/pim_rp.c
index 14643743ad..f01af07537 100644
--- a/pimd/pim_rp.c
+++ b/pimd/pim_rp.c
@@ -372,7 +372,7 @@ void pim_upstream_update(struct pim_instance *pim, struct pim_upstream *up)
 			zlog_debug("%s: Deregister upstream %s addr %s with Zebra NHT",
 				   __PRETTY_FUNCTION__, up->sg_str, buf);
 		}
-		pim_delete_tracked_nexthop(pim, &nht_p, up, NULL);
+		pim_delete_tracked_nexthop(pim, &nht_p, up, NULL, false);
 	}
 
 	/* Update the upstream address */
@@ -567,7 +567,8 @@ int pim_rp_new(struct pim_instance *pim, const char *rp,
 			pim_rp_refresh_group_to_rp_mapping(pim);
 
 			pim_find_or_track_nexthop(pim, &nht_p, NULL, rp_all,
-						  NULL);
+						  false, NULL);
+
 			if (!pim_ecmp_nexthop_lookup(pim,
 						     &rp_all->rp.source_nexthop,
 						     &nht_p, &rp_all->group, 1))
@@ -655,7 +656,7 @@ int pim_rp_new(struct pim_instance *pim, const char *rp,
 			   __PRETTY_FUNCTION__, buf, buf1);
 	}
 
-	pim_find_or_track_nexthop(pim, &nht_p, NULL, rp_info, NULL);
+	pim_find_or_track_nexthop(pim, &nht_p, NULL, rp_info, false, NULL);
 	if (!pim_ecmp_nexthop_lookup(pim, &rp_info->rp.source_nexthop, &nht_p,
 				     &rp_info->group, 1))
 		return PIM_RP_NO_PATH;
@@ -714,7 +715,7 @@ int pim_rp_del(struct pim_instance *pim, const char *rp,
 		zlog_debug("%s: Deregister RP addr %s with Zebra ",
 			   __PRETTY_FUNCTION__, buf);
 	}
-	pim_delete_tracked_nexthop(pim, &nht_p, NULL, rp_info);
+	pim_delete_tracked_nexthop(pim, &nht_p, NULL, rp_info, false);
 
 	if (!str2prefix("224.0.0.0/4", &g_all))
 		return PIM_RP_BAD_ADDRESS;
@@ -819,7 +820,8 @@ void pim_rp_setup(struct pim_instance *pim)
 		nht_p.prefixlen = IPV4_MAX_BITLEN;
 		nht_p.u.prefix4 = rp_info->rp.rpf_addr.u.prefix4;
 
-		pim_find_or_track_nexthop(pim, &nht_p, NULL, rp_info, NULL);
+		pim_find_or_track_nexthop(pim, &nht_p, NULL, rp_info, false,
+					  NULL);
 		if (!pim_ecmp_nexthop_lookup(pim, &rp_info->rp.source_nexthop,
 					     &nht_p, &rp_info->group, 1))
 			if (PIM_DEBUG_PIM_NHT_RP)
@@ -969,8 +971,8 @@ struct pim_rpf *pim_rp_g(struct pim_instance *pim, struct in_addr group)
 				"%s: NHT Register RP addr %s grp %s with Zebra",
 				__PRETTY_FUNCTION__, buf, buf1);
 		}
-
-		pim_find_or_track_nexthop(pim, &nht_p, NULL, rp_info, NULL);
+		pim_find_or_track_nexthop(pim, &nht_p, NULL, rp_info, false,
+					  NULL);
 		pim_rpf_set_refresh_time(pim);
 		(void)pim_ecmp_nexthop_lookup(pim, &rp_info->rp.source_nexthop,
 					      &nht_p, &rp_info->group, 1);
@@ -1180,7 +1182,7 @@ void pim_resolve_rp_nh(struct pim_instance *pim, struct pim_neighbor *nbr)
 		nht_p.u.prefix4 = rp_info->rp.rpf_addr.u.prefix4;
 		memset(&pnc, 0, sizeof(struct pim_nexthop_cache));
 		if (!pim_find_or_track_nexthop(pim, &nht_p, NULL, rp_info,
-					       &pnc))
+					       false, &pnc))
 			continue;
 
 		for (nh_node = pnc.nexthop; nh_node; nh_node = nh_node->next) {
diff --git a/pimd/pim_rpf.c b/pimd/pim_rpf.c
index afe3886aa5..9b923086ef 100644
--- a/pimd/pim_rpf.c
+++ b/pimd/pim_rpf.c
@@ -238,7 +238,7 @@ enum pim_rpf_result pim_rpf_update(struct pim_instance *pim,
 	if ((up->sg.src.s_addr == INADDR_ANY && I_am_RP(pim, up->sg.grp)) ||
 	    PIM_UPSTREAM_FLAG_TEST_FHR(up->flags))
 		neigh_needed = FALSE;
-	pim_find_or_track_nexthop(pim, &nht_p, up, NULL, NULL);
+	pim_find_or_track_nexthop(pim, &nht_p, up, NULL, false, NULL);
 	if (!pim_ecmp_nexthop_lookup(pim, &rpf->source_nexthop, &src, &grp,
 				     neigh_needed))
 		return PIM_RPF_FAILURE;
diff --git a/pimd/pim_upstream.c b/pimd/pim_upstream.c
index b708e86a20..33506342e4 100644
--- a/pimd/pim_upstream.c
+++ b/pimd/pim_upstream.c
@@ -237,7 +237,7 @@ struct pim_upstream *pim_upstream_del(struct pim_instance *pim,
 			zlog_debug("%s: Deregister upstream %s addr %s with Zebra NHT",
 				   __PRETTY_FUNCTION__, up->sg_str, buf);
 		}
-		pim_delete_tracked_nexthop(pim, &nht_p, up, NULL);
+		pim_delete_tracked_nexthop(pim, &nht_p, up, NULL, false);
 	}
 
 	XFREE(MTYPE_PIM_UPSTREAM, up);
diff --git a/pimd/pim_vxlan.c b/pimd/pim_vxlan.c
index af76c6d732..c893fbe7e3 100644
--- a/pimd/pim_vxlan.c
+++ b/pimd/pim_vxlan.c
@@ -344,7 +344,7 @@ static void pim_vxlan_orig_mr_up_add(struct pim_vxlan_sg *vxlan_sg)
 			nht_p.prefixlen = IPV4_MAX_BITLEN;
 			nht_p.u.prefix4 = up->upstream_addr;
 			pim_delete_tracked_nexthop(vxlan_sg->pim,
-				&nht_p, up, NULL);
+				&nht_p, up, NULL, false);
 		}
 		pim_upstream_ref(up, flags, __PRETTY_FUNCTION__);
 		vxlan_sg->up = up;