pimd: create dummy (*,G) upstream when RP not configured/reachable

In this commit, we are creating a dummy upstream & dummy channel_oil
for (*, G) when RP is not configured or not reachable.
Dummy upstream: <upstream_addr = INADDR_ANY, rpf = Unknown>
Dummy channel oil: <iif = MAXVIFS>

Signed-off-by: Sarita Patra <saritap@vmware.com>

pimd/pim_oil.c

@@ -168,13 +168,15 @@ struct channel_oil *pim_channel_oil_add(struct pim_instance *pim,
 		return c_oil;
 	}
 
-	ifp = pim_if_find_by_vif_index(pim, input_vif_index);
+	if (input_vif_index != MAXVIFS) {
-	if (!ifp) {
+		ifp = pim_if_find_by_vif_index(pim, input_vif_index);
-		/* warning only */
+		if (!ifp) {
-		zlog_warn(
+			/* warning only */
-			"%s: (S,G)=%s could not find input interface for input_vif_index=%d",
+			zlog_warn(
-			__PRETTY_FUNCTION__, pim_str_sg_dump(sg),
+				"%s: (S,G)=%s could not find input interface for input_vif_index=%d",
-			input_vif_index);
+				__PRETTY_FUNCTION__, pim_str_sg_dump(sg),
+				input_vif_index);
+		}
 	}
 
 	c_oil = XCALLOC(MTYPE_PIM_CHANNEL_OIL, sizeof(*c_oil));
@@ -188,6 +190,10 @@ struct channel_oil *pim_channel_oil_add(struct pim_instance *pim,
 	c_oil->installed = 0;
 	c_oil->up = pim_upstream_find(pim, sg);
 	c_oil->pim = pim;
+	if (input_vif_index != MAXVIFS)
+		c_oil->is_valid = 1;
+	else
+		c_oil->is_valid = 0;
 
 	listnode_add_sort(pim->channel_oil_list, c_oil);
 

pimd/pim_rp.c

@@ -870,7 +870,7 @@ struct pim_rpf *pim_rp_g(struct pim_instance *pim, struct in_addr group)
  * the rp configured and the source address
  *
  * If we have don't have a RP configured and the source address is *
- * then return failure.
+ * then set the upstream addr as INADDR_ANY and return failure.
  *
  */
 int pim_rp_set_upstream_addr(struct pim_instance *pim, struct in_addr *up,
@@ -891,6 +891,7 @@ int pim_rp_set_upstream_addr(struct pim_instance *pim, struct in_addr *up,
 		if (PIM_DEBUG_PIM_NHT_RP)
 			zlog_debug("%s: Received a (*,G) with no RP configured",
 				   __PRETTY_FUNCTION__);
+		up->s_addr = INADDR_ANY;
 		return 0;
 	}
 

pimd/pim_upstream.c

@@ -668,15 +668,14 @@ static struct pim_upstream *pim_upstream_new(struct pim_instance *pim,
 		ch->upstream = up;
 
 	up = hash_get(pim->upstream_hash, up, hash_alloc_intern);
+	/* Set up->upstream_addr as INADDR_ANY, if RP is not
+	 * configured and retain the upstream data structure
+	 */
 	if (!pim_rp_set_upstream_addr(pim, &up->upstream_addr, sg->src,
 				      sg->grp)) {
 		if (PIM_DEBUG_TRACE)
 			zlog_debug("%s: Received a (*,G) with no RP configured",
 				   __PRETTY_FUNCTION__);
-
-		hash_release(pim->upstream_hash, up);
-		XFREE(MTYPE_PIM_UPSTREAM, up);
-		return NULL;
 	}
 
 	up->parent = pim_upstream_find_parent(pim, up);
@@ -716,45 +715,34 @@ static struct pim_upstream *pim_upstream_new(struct pim_instance *pim,
 	if (up->sg.src.s_addr != INADDR_ANY)
 		wheel_add_item(pim->upstream_sg_wheel, up);
 
-	rpf_result = pim_rpf_update(pim, up, NULL, 1);
+	if (up->upstream_addr.s_addr == INADDR_ANY)
-	if (rpf_result == PIM_RPF_FAILURE) {
+		/* Create a dummmy channel oil with incoming ineterface MAXVIFS,
-		struct prefix nht_p;
+		 * since RP is not configured
+		 */
+		up->channel_oil = pim_channel_oil_add(pim, &up->sg, MAXVIFS);
 
-		if (PIM_DEBUG_TRACE)
+	else {
-			zlog_debug(
+		rpf_result = pim_rpf_update(pim, up, NULL, 1);
-				"%s: Attempting to create upstream(%s), Unable to RPF for source",
+		if (rpf_result == PIM_RPF_FAILURE) {
-				__PRETTY_FUNCTION__, up->sg_str);
+			if (PIM_DEBUG_TRACE)
-
+				zlog_debug(
-		nht_p.family = AF_INET;
+					"%s: Attempting to create upstream(%s), Unable to RPF for source",
-		nht_p.prefixlen = IPV4_MAX_BITLEN;
+					__PRETTY_FUNCTION__, up->sg_str);
-		nht_p.u.prefix4 = up->upstream_addr;
+			/* Create a dummmy channel oil with incoming ineterface
-		pim_delete_tracked_nexthop(pim, &nht_p, up, NULL);
+			 * MAXVIFS, since RP is not reachable
-
+			 */
-		if (up->parent) {
+			up->channel_oil = pim_channel_oil_add(
-			listnode_delete(up->parent->sources, up);
+				pim, &up->sg, MAXVIFS);
-			up->parent = NULL;
 		}
 
-		if (up->sg.src.s_addr != INADDR_ANY)
+		if (up->rpf.source_nexthop.interface) {
-			wheel_remove_item(pim->upstream_sg_wheel, up);
+			pim_ifp = up->rpf.source_nexthop.interface->info;
-
+			if (pim_ifp)
-		pim_upstream_remove_children(pim, up);
+				up->channel_oil = pim_channel_oil_add(pim,
-		if (up->sources)
+					&up->sg, pim_ifp->mroute_vif_index);
-			list_delete(&up->sources);
+		}
-
-		list_delete(&up->ifchannels);
-
-		hash_release(pim->upstream_hash, up);
-		XFREE(MTYPE_PIM_UPSTREAM, up);
-		return NULL;
 	}
 
-	if (up->rpf.source_nexthop.interface) {
-		pim_ifp = up->rpf.source_nexthop.interface->info;
-		if (pim_ifp)
-			up->channel_oil = pim_channel_oil_add(
-				pim, &up->sg, pim_ifp->mroute_vif_index);
-	}
 	listnode_add_sort(pim->upstream_list, up);
 
 	if (PIM_DEBUG_TRACE) {

pimd/pim_zebra.c

@@ -569,10 +569,9 @@ void pim_scan_individual_oil(struct channel_oil *c_oil, int in_vif_index)
 	int input_iface_vif_index;
 	int old_vif_index;
 
-	if (!pim_rp_set_upstream_addr(c_oil->pim, &vif_source,
+	pim_rp_set_upstream_addr(c_oil->pim, &vif_source,
 				      c_oil->oil.mfcc_origin,
-				      c_oil->oil.mfcc_mcastgrp))
+				      c_oil->oil.mfcc_mcastgrp);
-		return;
 
 	if (in_vif_index)
 		input_iface_vif_index = in_vif_index;
@@ -958,112 +957,141 @@ void igmp_source_forward_start(struct pim_instance *pim,
 		struct pim_upstream *up = NULL;
 
 		if (!pim_rp_set_upstream_addr(pim, &vif_source,
-					      source->source_addr, sg.grp))
+					      source->source_addr, sg.grp)) {
-			return;
+			/*Create a dummy channel oil */
+			source->source_channel_oil =
+			    pim_channel_oil_add(pim, &sg, MAXVIFS);
 
-		/* Register addr with Zebra NHT */
+			if (!source->source_channel_oil) {
-		nht_p.family = AF_INET;
+				if (PIM_DEBUG_IGMP_TRACE) {
-		nht_p.prefixlen = IPV4_MAX_BITLEN;
-		nht_p.u.prefix4 = vif_source;
-		memset(&out_pnc, 0, sizeof(struct pim_nexthop_cache));
-
-		src.family = AF_INET;
-		src.prefixlen = IPV4_MAX_BITLEN;
-		src.u.prefix4 = vif_source; // RP or Src address
-		grp.family = AF_INET;
-		grp.prefixlen = IPV4_MAX_BITLEN;
-		grp.u.prefix4 = sg.grp;
-
-		if (pim_find_or_track_nexthop(pim, &nht_p, NULL, NULL,
-					      &out_pnc)) {
-			if (out_pnc.nexthop_num) {
-				up = pim_upstream_find(pim, &sg);
-				memset(&nexthop, 0, sizeof(nexthop));
-				if (up)
-					memcpy(&nexthop,
-					       &up->rpf.source_nexthop,
-					       sizeof(struct pim_nexthop));
-				pim_ecmp_nexthop_search(pim, &out_pnc, &nexthop,
-							&src, &grp, 0);
-				if (nexthop.interface)
-					input_iface_vif_index =
-						pim_if_find_vifindex_by_ifindex(
-							pim,
-							nexthop.interface->ifindex);
-			} else {
-				if (PIM_DEBUG_ZEBRA) {
-					char buf1[INET_ADDRSTRLEN];
-					char buf2[INET_ADDRSTRLEN];
-					pim_inet4_dump("<source?>",
-						       nht_p.u.prefix4, buf1,
-						       sizeof(buf1));
-					pim_inet4_dump("<source?>",
-						       grp.u.prefix4, buf2,
-						       sizeof(buf2));
 					zlog_debug(
-						"%s: NHT Nexthop not found for addr %s grp %s",
-						__PRETTY_FUNCTION__, buf1,
-						buf2);
-				}
-			}
-		} else
-			input_iface_vif_index =
-				pim_ecmp_fib_lookup_if_vif_index(pim, &src,
-								 &grp);
-
-		if (PIM_DEBUG_ZEBRA) {
-			char buf2[INET_ADDRSTRLEN];
-			pim_inet4_dump("<source?>", vif_source, buf2,
-				       sizeof(buf2));
-			zlog_debug("%s: NHT %s vif_source %s vif_index:%d ",
-				   __PRETTY_FUNCTION__, pim_str_sg_dump(&sg),
-				   buf2, input_iface_vif_index);
-		}
-
-		if (input_iface_vif_index < 1) {
-			if (PIM_DEBUG_IGMP_TRACE) {
-				char source_str[INET_ADDRSTRLEN];
-				pim_inet4_dump("<source?>", source->source_addr,
-					       source_str, sizeof(source_str));
-				zlog_debug(
-					"%s %s: could not find input interface for source %s",
-					__FILE__, __PRETTY_FUNCTION__,
-					source_str);
-			}
-			return;
-		}
-
-		/*
-		  Protect IGMP against adding looped MFC entries created by both
-		  source and receiver attached to the same interface. See TODO
-		  T22.
-		*/
-		if (input_iface_vif_index == pim_oif->mroute_vif_index) {
-			/* ignore request for looped MFC entry */
-			if (PIM_DEBUG_IGMP_TRACE) {
-				zlog_debug(
-					"%s: ignoring request for looped MFC entry (S,G)=%s: igmp_sock=%d oif=%s vif_index=%d",
-					__PRETTY_FUNCTION__,
-					pim_str_sg_dump(&sg),
-					source->source_group->group_igmp_sock
-						->fd,
-					source->source_group->group_igmp_sock
-						->interface->name,
-					input_iface_vif_index);
-			}
-			return;
-		}
-
-		source->source_channel_oil =
-			pim_channel_oil_add(pim, &sg, input_iface_vif_index);
-		if (!source->source_channel_oil) {
-			if (PIM_DEBUG_IGMP_TRACE) {
-				zlog_debug(
 					"%s %s: could not create OIL for channel (S,G)=%s",
 					__FILE__, __PRETTY_FUNCTION__,
 					pim_str_sg_dump(&sg));
+				}
+				return;
+			}
+		}
+
+		else {
+			/* Register addr with Zebra NHT */
+			nht_p.family = AF_INET;
+			nht_p.prefixlen = IPV4_MAX_BITLEN;
+			nht_p.u.prefix4 = vif_source;
+			memset(&out_pnc, 0, sizeof(struct pim_nexthop_cache));
+
+			src.family = AF_INET;
+			src.prefixlen = IPV4_MAX_BITLEN;
+			src.u.prefix4 = vif_source; // RP or Src address
+			grp.family = AF_INET;
+			grp.prefixlen = IPV4_MAX_BITLEN;
+			grp.u.prefix4 = sg.grp;
+
+			if (pim_find_or_track_nexthop(pim, &nht_p, NULL, NULL,
+					      &out_pnc)) {
+				if (out_pnc.nexthop_num) {
+					up = pim_upstream_find(pim, &sg);
+					memset(&nexthop, 0, sizeof(nexthop));
+					if (up)
+						memcpy(&nexthop,
+						    &up->rpf.source_nexthop,
+						    sizeof(struct pim_nexthop));
+					pim_ecmp_nexthop_search(pim, &out_pnc,
+								&nexthop,
+								&src, &grp, 0);
+					if (nexthop.interface)
+						input_iface_vif_index =
+						pim_if_find_vifindex_by_ifindex(
+						    pim,
+						    nexthop.interface->ifindex);
+				} else {
+					if (PIM_DEBUG_ZEBRA) {
+						char buf1[INET_ADDRSTRLEN];
+						char buf2[INET_ADDRSTRLEN];
+
+						pim_inet4_dump("<source?>",
+						       nht_p.u.prefix4, buf1,
+						       sizeof(buf1));
+						pim_inet4_dump("<source?>",
+						       grp.u.prefix4, buf2,
+						       sizeof(buf2));
+						zlog_debug(
+						"%s: NHT Nexthop not found for addr %s grp %s",
+						__PRETTY_FUNCTION__, buf1,
+						buf2);
+					}
+				}
+			} else
+				input_iface_vif_index =
+				    pim_ecmp_fib_lookup_if_vif_index(pim, &src,
+								 &grp);
+
+			if (PIM_DEBUG_ZEBRA) {
+				char buf2[INET_ADDRSTRLEN];
+
+				pim_inet4_dump("<source?>", vif_source, buf2,
+					       sizeof(buf2));
+				zlog_debug("%s: NHT %s vif_source %s vif_index:%d ",
+					__PRETTY_FUNCTION__,
+					pim_str_sg_dump(&sg),
+					buf2, input_iface_vif_index);
+			}
+
+			if (input_iface_vif_index < 1) {
+				if (PIM_DEBUG_IGMP_TRACE) {
+					char source_str[INET_ADDRSTRLEN];
+					pim_inet4_dump("<source?>",
+						source->source_addr,
+						source_str, sizeof(source_str));
+					zlog_debug(
+					    "%s %s: could not find input interface for source %s",
+					    __FILE__, __PRETTY_FUNCTION__,
+					    source_str);
+				}
+				source->source_channel_oil =
+				    pim_channel_oil_add(pim, &sg, MAXVIFS);
+			}
+
+			else {
+				/*
+				 * Protect IGMP against adding looped MFC
+				 * entries created by both source and receiver
+				 * attached to the same interface. See TODO
+				 * T22.
+				 */
+				if (input_iface_vif_index ==
+				    pim_oif->mroute_vif_index) {
+					/* ignore request for looped MFC entry
+					 */
+					if (PIM_DEBUG_IGMP_TRACE) {
+						zlog_debug(
+						    "%s: ignoring request for looped MFC entry (S,G)=%s: igmp_sock=%d oif=%s vif_index=%d",
+						    __PRETTY_FUNCTION__,
+						    pim_str_sg_dump(&sg),
+						    source->source_group
+						    ->group_igmp_sock->fd,
+						    source->source_group
+						    ->group_igmp_sock
+						    ->interface->name,
+						    input_iface_vif_index);
+					}
+					return;
+				}
+
+				source->source_channel_oil =
+				    pim_channel_oil_add(pim, &sg,
+					input_iface_vif_index);
+				if (!source->source_channel_oil) {
+					if (PIM_DEBUG_IGMP_TRACE) {
+						zlog_debug(
+						    "%s %s: could not create OIL for channel (S,G)=%s",
+						    __FILE__,
+						    __PRETTY_FUNCTION__,
+						    pim_str_sg_dump(&sg));
+					}
+					return;
+				}
 			}
-			return;
 		}
 	}
 
@@ -1196,15 +1224,13 @@ void pim_forward_start(struct pim_ifchannel *ch)
 			       sizeof(upstream_str));
 		zlog_debug("%s: (S,G)=(%s,%s) oif=%s (%s)", __PRETTY_FUNCTION__,
 			   source_str, group_str, ch->interface->name,
-			   upstream_str);
+			   inet_ntoa(up->upstream_addr));
 	}
 
 	/* Resolve IIF for upstream as mroute_del sets mfcc_parent to MAXVIFS,
 	   as part of mroute_del called by pim_forward_stop.
 	*/
-	if (!up->channel_oil
+	if ((up->upstream_addr.s_addr != INADDR_ANY) && (!up->channel_oil)) {
-	    || (up->channel_oil
-		&& up->channel_oil->oil.mfcc_parent >= MAXVIFS)) {
 		struct prefix nht_p, src, grp;
 		struct pim_nexthop_cache out_pnc;
 
@@ -1275,17 +1301,33 @@ void pim_forward_start(struct pim_ifchannel *ch)
 					__FILE__, __PRETTY_FUNCTION__,
 					source_str);
 			}
-			return;
+			up->channel_oil = pim_channel_oil_add(pim, &up->sg,
+								MAXVIFS);
 		}
+
+		else {
+			up->channel_oil = pim_channel_oil_add(pim, &up->sg,
+							input_iface_vif_index);
+			if (!up->channel_oil) {
+				if (PIM_DEBUG_PIM_TRACE)
+					zlog_debug(
+					    "%s %s: could not create OIL for channel (S,G)=%s",
+					    __FILE__, __PRETTY_FUNCTION__,
+					    up->sg_str);
+				return;
+			}
+		}
+
 		if (PIM_DEBUG_TRACE) {
 			struct interface *in_intf = pim_if_find_by_vif_index(
 				pim, input_iface_vif_index);
 			zlog_debug(
 				"%s: Update channel_oil IIF %s VIFI %d entry %s ",
 				__PRETTY_FUNCTION__,
-				in_intf ? in_intf->name : "NIL",
+				in_intf ? in_intf->name : "Unknown",
 				input_iface_vif_index, up->sg_str);
 		}
+
 		up->channel_oil = pim_channel_oil_add(pim, &up->sg,
 						      input_iface_vif_index);
 		if (!up->channel_oil) {