pimd: Handling Null incoming interface of dummy upstream

When FRR receives IGMP/PIM (*, G) join and RP is not configured or not
reachable, then we are creating a dummy upstream with incoming interface
as NULL and upstream address as INADDR_ANY.

Added upstream address and incoming interface validation where it is necessary,
before doing any operation on the upstream.

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

8 files changed, 137 insertions, 21 deletions

diff --git a/pimd/pim_igmp_mtrace.c b/pimd/pim_igmp_mtrace.c
index 1fb624a6a0..f51e0c0d2f 100644
--- a/pimd/pim_igmp_mtrace.c
+++ b/pimd/pim_igmp_mtrace.c
@@ -133,6 +133,13 @@ static bool mtrace_fwd_info(struct pim_instance *pim,
 	if (!up)
 		return false;
 
+	if (!up->rpf.source_nexthop.interface) {
+		if (PIM_DEBUG_TRACE)
+			zlog_debug("%s: up %s RPF is not present",
+			__PRETTY_FUNCTION__, up->sg_str);
+		return false;
+	}
+
 	ifp_in = up->rpf.source_nexthop.interface;
 	nh_addr = up->rpf.source_nexthop.mrib_nexthop_addr.u.prefix4;
 	total = htonl(MTRACE_UNKNOWN_COUNT);
diff --git a/pimd/pim_join.c b/pimd/pim_join.c
index ae5032be73..cbacaf3ea8 100644
--- a/pimd/pim_join.c
+++ b/pimd/pim_join.c
@@ -439,9 +439,6 @@ int pim_joinprune_send(struct pim_rpf *rpf, struct list *groups)
 	size_t packet_size = 0;
 	size_t group_size = 0;
 
-	on_trace(__PRETTY_FUNCTION__, rpf->source_nexthop.interface,
-		 rpf->rpf_addr.u.prefix4);
-
 	if (rpf->source_nexthop.interface)
 		pim_ifp = rpf->source_nexthop.interface->info;
 	else {
@@ -450,6 +447,9 @@ int pim_joinprune_send(struct pim_rpf *rpf, struct list *groups)
 		return -1;
 	}
 
+	on_trace(__PRETTY_FUNCTION__, rpf->source_nexthop.interface,
+		rpf->rpf_addr.u.prefix4);
+
 	if (!pim_ifp) {
 		zlog_warn("%s: multicast not enabled on interface %s",
 			  __PRETTY_FUNCTION__,
diff --git a/pimd/pim_jp_agg.c b/pimd/pim_jp_agg.c
index 7726ffda57..06a9e6d0d6 100644
--- a/pimd/pim_jp_agg.c
+++ b/pimd/pim_jp_agg.c
@@ -213,8 +213,18 @@ void pim_jp_agg_upstream_verification(struct pim_upstream *up, bool ignore)
 {
 #ifdef PIM_JP_AGG_DEBUG
 	struct interface *ifp;
-	struct pim_interface *pim_ifp = up->rpf.source_nexthop.interface->info;
-	struct pim_instance *pim = pim_ifp->pim;
+	struct pim_interface *pim_ifp;
+	struct pim_instance *pim;
+
+	if (!up->rpf.source_nexthop.interface) {
+		if (PIM_DEBUG_TRACE)
+			zlog_debug("%s: up %s RPF is not present",
+				__PRETTY_FUNCTION__, up->sg_str);
+		return;
+	}
+
+	pim_ifp = up->rpf.source_nexthop.interface->info;
+	pim = pim_ifp->pim;
 
 	FOR_ALL_INTERFACES (pim->vrf, ifp) {
 		pim_ifp = ifp->info;
diff --git a/pimd/pim_mroute.c b/pimd/pim_mroute.c
index dd9e21cae8..67b1a95f74 100644
--- a/pimd/pim_mroute.c
+++ b/pimd/pim_mroute.c
@@ -234,7 +234,8 @@ static int pim_mroute_msg_nocache(int fd, struct interface *ifp,
 	up->channel_oil->cc.pktcnt++;
 	PIM_UPSTREAM_FLAG_SET_FHR(up->flags);
 	// resolve mfcc_parent prior to mroute_add in channel_add_oif
-	if (up->channel_oil->oil.mfcc_parent >= MAXVIFS) {
+	if (up->rpf.source_nexthop.interface &&
+	    up->channel_oil->oil.mfcc_parent >= MAXVIFS) {
 		int vif_index = 0;
 		vif_index = pim_if_find_vifindex_by_ifindex(
 			pim_ifp->pim,
@@ -301,6 +302,13 @@ static int pim_mroute_msg_wholepkt(int fd, struct interface *ifp,
 		return 0;
 	}
 
+	if (!up->rpf.source_nexthop.interface) {
+		if (PIM_DEBUG_TRACE)
+			zlog_debug("%s: up %s RPF is not present",
+				__PRETTY_FUNCTION__, up->sg_str);
+		return 0;
+	}
+
 	pim_ifp = up->rpf.source_nexthop.interface->info;
 
 	rpg = pim_ifp ? RP(pim_ifp->pim, sg.grp) : NULL;
diff --git a/pimd/pim_nht.c b/pimd/pim_nht.c
index 2d808639b5..8c24bcdaed 100644
--- a/pimd/pim_nht.c
+++ b/pimd/pim_nht.c
@@ -283,7 +283,7 @@ static int pim_update_upstream_nh_helper(struct hash_backet *backet, void *arg)
 	}
 
 	/* update kernel multicast forwarding cache (MFC) */
-	if (up->channel_oil) {
+	if (up->rpf.source_nexthop.interface) {
 		ifindex_t ifindex = up->rpf.source_nexthop.interface->ifindex;
 
 		vif_index = pim_if_find_vifindex_by_ifindex(pim, ifindex);
@@ -306,9 +306,10 @@ static int pim_update_upstream_nh_helper(struct hash_backet *backet, void *arg)
 
 	if (PIM_DEBUG_PIM_NHT) {
 		zlog_debug("%s: NHT upstream %s(%s) old ifp %s new ifp %s",
-			   __PRETTY_FUNCTION__, up->sg_str, pim->vrf->name,
-			   old.source_nexthop.interface->name,
-			   up->rpf.source_nexthop.interface->name);
+			__PRETTY_FUNCTION__, up->sg_str, pim->vrf->name,
+			old.source_nexthop.interface
+			? old.source_nexthop.interface->name : "Unknwon",
+			up->rpf.source_nexthop.interface->name);
 	}
 
 	return HASHWALK_CONTINUE;
diff --git a/pimd/pim_rpf.c b/pimd/pim_rpf.c
index 814d2e076b..d689b276b7 100644
--- a/pimd/pim_rpf.c
+++ b/pimd/pim_rpf.c
@@ -205,6 +205,12 @@ enum pim_rpf_result pim_rpf_update(struct pim_instance *pim,
 	struct prefix src, grp;
 	bool neigh_needed = true;
 
+	if (up->upstream_addr.s_addr == INADDR_ANY) {
+		zlog_debug("%s: RP is not configured yet for %s",
+			__PRETTY_FUNCTION__, up->sg_str);
+		return PIM_RPF_OK;
+	}
+
 	saved.source_nexthop = rpf->source_nexthop;
 	saved.rpf_addr = rpf->rpf_addr;
 
diff --git a/pimd/pim_upstream.c b/pimd/pim_upstream.c
index c6ab8f5a2a..cd0610eb82 100644
--- a/pimd/pim_upstream.c
+++ b/pimd/pim_upstream.c
@@ -238,6 +238,13 @@ struct pim_upstream *pim_upstream_del(struct pim_instance *pim,
 
 void pim_upstream_send_join(struct pim_upstream *up)
 {
+	if (!up->rpf.source_nexthop.interface) {
+		if (PIM_DEBUG_TRACE)
+			zlog_debug("%s: up %s RPF is not present",
+				__PRETTY_FUNCTION__, up->sg_str);
+		return;
+	}
+
 	if (PIM_DEBUG_TRACE) {
 		char rpf_str[PREFIX_STRLEN];
 		pim_addr_dump("<rpf?>", &up->rpf.rpf_addr, rpf_str,
@@ -263,6 +270,13 @@ static int on_join_timer(struct thread *t)
 
 	up = THREAD_ARG(t);
 
+	if (!up->rpf.source_nexthop.interface) {
+		if (PIM_DEBUG_TRACE)
+			zlog_debug("%s: up %s RPF is not present",
+			__PRETTY_FUNCTION__, up->sg_str);
+		return 0;
+	}
+
 	/*
 	 * In the case of a HFR we will not ahve anyone to send this to.
 	 */
@@ -286,6 +300,13 @@ static void join_timer_stop(struct pim_upstream *up)
 {
 	struct pim_neighbor *nbr;
 
+	if (!up->rpf.source_nexthop.interface) {
+		if (PIM_DEBUG_TRACE)
+			zlog_debug("%s: up %s RPF is not present",
+				__PRETTY_FUNCTION__, up->sg_str);
+		return;
+	}
+
 	THREAD_OFF(up->t_join_timer);
 
 	nbr = pim_neighbor_find(up->rpf.source_nexthop.interface,
@@ -301,6 +322,13 @@ void join_timer_start(struct pim_upstream *up)
 {
 	struct pim_neighbor *nbr = NULL;
 
+	if (!up->rpf.source_nexthop.interface) {
+		if (PIM_DEBUG_TRACE)
+			zlog_debug("%s: up %s RPF is not present",
+				__PRETTY_FUNCTION__, up->sg_str);
+		return;
+	}
+
 	if (up->rpf.source_nexthop.interface) {
 		nbr = pim_neighbor_find(up->rpf.source_nexthop.interface,
 					up->rpf.rpf_addr.u.prefix4);
@@ -356,6 +384,13 @@ void pim_upstream_join_suppress(struct pim_upstream *up,
 	long t_joinsuppress_msec;
 	long join_timer_remain_msec;
 
+	if (!up->rpf.source_nexthop.interface) {
+		if (PIM_DEBUG_TRACE)
+			zlog_debug("%s: up %s RPF is not present",
+				__PRETTY_FUNCTION__, up->sg_str);
+		return;
+	}
+
 	t_joinsuppress_msec =
 		MIN(pim_if_t_suppressed_msec(up->rpf.source_nexthop.interface),
 		    1000 * holdtime);
@@ -389,6 +424,13 @@ void pim_upstream_join_timer_decrease_to_t_override(const char *debug_label,
 	long join_timer_remain_msec;
 	int t_override_msec;
 
+	if (!up->rpf.source_nexthop.interface) {
+		if (PIM_DEBUG_TRACE)
+			zlog_debug("%s: up %s RPF is not present",
+				__PRETTY_FUNCTION__, up->sg_str);
+		return;
+	}
+
 	join_timer_remain_msec = pim_time_timer_remain_msec(up->t_join_timer);
 	t_override_msec =
 		pim_if_t_override_msec(up->rpf.source_nexthop.interface);
@@ -511,6 +553,18 @@ void pim_upstream_switch(struct pim_instance *pim, struct pim_upstream *up,
 {
 	enum pim_upstream_state old_state = up->join_state;
 
+	if (up->upstream_addr.s_addr == INADDR_ANY) {
+		zlog_debug("%s: RPF not configured for %s",
+			__PRETTY_FUNCTION__, up->sg_str);
+		return;
+	}
+
+	if (!up->rpf.source_nexthop.interface)  {
+		zlog_debug("%s: RP not reachable for %s",
+			__PRETTY_FUNCTION__, up->sg_str);
+		return;
+	}
+
 	if (PIM_DEBUG_PIM_EVENTS) {
 		zlog_debug("%s: PIM_UPSTREAM_%s: (S,G) old: %s new: %s",
 			   __PRETTY_FUNCTION__, up->sg_str,
@@ -558,11 +612,14 @@ void pim_upstream_switch(struct pim_instance *pim, struct pim_upstream *up,
 		    && !I_am_RP(pim, up->sg.grp)) {
 			if (PIM_DEBUG_PIM_TRACE_DETAIL)
 				zlog_debug(
-					"%s: *,G IIF %s S,G IIF %s ",
-					__PRETTY_FUNCTION__,
-					up->parent->rpf.source_nexthop
-						.interface->name,
-					up->rpf.source_nexthop.interface->name);
+				  "%s: *,G IIF %s S,G IIF %s ",
+				  __PRETTY_FUNCTION__,
+				  up->parent->rpf.source_nexthop.interface ?
+				  up->parent->rpf.source_nexthop.interface->name
+				  : "Unknown",
+				  up->rpf.source_nexthop.interface ?
+				  up->rpf.source_nexthop.interface->name :
+				  "Unknown");
 			pim_jp_agg_single_upstream_send(&up->parent->rpf,
 							up->parent,
 							1 /* (W,G) Join */);
@@ -783,7 +840,7 @@ struct pim_upstream *pim_upstream_add(struct pim_instance *pim,
 			zlog_debug("%s(%s): %s, iif %s (%s) found: %d: ref_count: %d",
 		   __PRETTY_FUNCTION__, name,
 		   up->sg_str, buf, up->rpf.source_nexthop.interface ?
-                   up->rpf.source_nexthop.interface->name : "NIL" ,
+                   up->rpf.source_nexthop.interface->name : "Unknown" ,
 		   found, up->ref_count);
 		} else
 			zlog_debug("%s(%s): (%s) failure to create",
@@ -973,7 +1030,9 @@ void pim_upstream_rpf_interface_changed(struct pim_upstream *up,
 				(old_rpf_ifp == ch->interface) &&
 				/* RPF_interface(S) stopped being I */
 				(ch->upstream->rpf.source_nexthop
-					 .interface != ch->interface)) {
+					.interface) &&
+				(ch->upstream->rpf.source_nexthop
+					.interface != ch->interface)) {
 				assert_action_a5(ch);
 			}
 		} /* PIM_IFASSERT_I_AM_LOSER */
@@ -1339,6 +1398,13 @@ static int pim_upstream_register_stop_timer(struct thread *t)
 	case PIM_REG_JOIN:
 		break;
 	case PIM_REG_PRUNE:
+		if (!up->rpf.source_nexthop.interface) {
+			if (PIM_DEBUG_TRACE)
+				zlog_debug("%s: up %s RPF is not present",
+					__PRETTY_FUNCTION__, up->sg_str);
+			return 0;
+		}
+
 		pim_ifp = up->rpf.source_nexthop.interface->info;
 		if (!pim_ifp) {
 			if (PIM_DEBUG_TRACE)
@@ -1515,11 +1581,19 @@ void pim_upstream_find_new_rpf(struct pim_instance *pim)
 	 * Scan all (S,G) upstreams searching for RPF'(S,G)=neigh_addr
 	 */
 	for (ALL_LIST_ELEMENTS(pim->upstream_list, up_node, up_nextnode, up)) {
+		if (up->upstream_addr.s_addr == INADDR_ANY) {
+			if (PIM_DEBUG_TRACE)
+				zlog_debug(
+				    "%s: RP not configured for Upstream %s",
+				    __PRETTY_FUNCTION__, up->sg_str);
+			continue;
+		}
+
 		if (pim_rpf_addr_is_inaddr_any(&up->rpf)) {
 			if (PIM_DEBUG_TRACE)
 				zlog_debug(
-					"Upstream %s without a path to send join, checking",
-					up->sg_str);
+					"%s: Upstream %s without a path to send join, checking",
+					__PRETTY_FUNCTION__, up->sg_str);
 			pim_rpf_update(pim, up, NULL, 1);
 		}
 	}
@@ -1586,7 +1660,8 @@ static bool pim_upstream_kat_start_ok(struct pim_upstream *up)
 
 	/* "iif == RPF_interface(S)" check has to be done by the kernel or hw
 	 * so we will skip that here */
-	if (pim_if_connected_to_source(up->rpf.source_nexthop.interface,
+	if (up->rpf.source_nexthop.interface &&
+		pim_if_connected_to_source(up->rpf.source_nexthop.interface,
 				       up->sg.src)) {
 		return true;
 	}
@@ -1679,7 +1754,8 @@ static void pim_upstream_sg_running(void *arg)
 	} else if (PIM_UPSTREAM_FLAG_TEST_SRC_LHR(up->flags))
 		pim_upstream_keep_alive_timer_start(up, pim->keep_alive_time);
 
-	if (up->sptbit != PIM_UPSTREAM_SPTBIT_TRUE) {
+	if ((up->sptbit != PIM_UPSTREAM_SPTBIT_TRUE) &&
+	    (up->rpf.source_nexthop.interface)) {
 		pim_upstream_set_sptbit(up, up->rpf.source_nexthop.interface);
 	}
 	return;
diff --git a/pimd/pim_zebra.c b/pimd/pim_zebra.c
index 11ca6e8a10..2c5c7f6174 100644
--- a/pimd/pim_zebra.c
+++ b/pimd/pim_zebra.c
@@ -535,6 +535,14 @@ static void scan_upstream_rpf_cache(struct pim_instance *pim)
 		struct pim_rpf old;
 		struct prefix nht_p;
 
+		if (up->upstream_addr.s_addr == INADDR_ANY) {
+			if (PIM_DEBUG_TRACE)
+				zlog_debug(
+				    "%s: RP not configured for Upstream %s",
+				    __PRETTY_FUNCTION__, up->sg_str);
+			continue;
+		}
+
 		nht_p.family = AF_INET;
 		nht_p.prefixlen = IPV4_MAX_BITLEN;
 		nht_p.u.prefix4.s_addr = up->upstream_addr.s_addr;