zebra: Fix ships in the night issue

When using wait for install there exists situations where
zebra will issue several route change operations to the kernel
but end up in a state where we shouldn't be at the end
due to extra data being received.  Example:

a) zebra receives from bgp a route change, installs sends the
route to the kernel.
b) zebra receives a route deletion from bgp, removes the
struct route entry and then sends to the kernel a deletion.
c) zebra receives an asynchronous notification that (a) succeeded
but we treat this as a new route.

This is the ships in the night problem.  In this case if we receive
notification from the kernel about a route that we know nothing
about and we are not in startup and we are doing asic offload
then we can ignore this update.

Ticket: #2563300
Signed-off-by: Donald Sharp <sharpd@nvidia.com>

zebra/connected.c

@@ -290,10 +290,12 @@ void connected_up(struct interface *ifp, struct connected *ifc)
 	}
 
 	rib_add(afi, SAFI_UNICAST, zvrf->vrf->vrf_id, ZEBRA_ROUTE_CONNECT, 0,
-		flags, &p, NULL, &nh, 0, zvrf->table_id, metric, 0, 0, 0);
+		flags, &p, NULL, &nh, 0, zvrf->table_id, metric, 0, 0, 0,
+		false);
 
 	rib_add(afi, SAFI_MULTICAST, zvrf->vrf->vrf_id, ZEBRA_ROUTE_CONNECT, 0,
-		flags, &p, NULL, &nh, 0, zvrf->table_id, metric, 0, 0, 0);
+		flags, &p, NULL, &nh, 0, zvrf->table_id, metric, 0, 0, 0,
+		false);
 
 	/* Schedule LSP forwarding entries for processing, if appropriate. */
 	if (zvrf->vrf->vrf_id == VRF_DEFAULT) {

zebra/kernel_socket.c

@@ -1113,7 +1113,7 @@ void rtm_read(struct rt_msghdr *rtm)
 	    || rtm->rtm_type == RTM_CHANGE)
 		rib_add(afi, SAFI_UNICAST, VRF_DEFAULT, ZEBRA_ROUTE_KERNEL, 0,
 			zebra_flags, &p, NULL, &nh, 0, RT_TABLE_MAIN,
-			0, 0, 0, 0);
+			0, 0, 0, 0, false);
 	else
 		rib_delete(afi, SAFI_UNICAST, VRF_DEFAULT, ZEBRA_ROUTE_KERNEL,
 			   0, zebra_flags, &p, NULL, &nh, 0, RT_TABLE_MAIN, 0,

zebra/redistribute.c

@@ -698,7 +698,7 @@ int zebra_add_import_table_entry(struct zebra_vrf *zvrf, struct route_node *rn,
 	ng = nexthop_group_new();
 	copy_nexthops(&ng->nexthop, re->nhe->nhg.nexthop, NULL);
 
-	rib_add_multipath(afi, SAFI_UNICAST, &p, NULL, newre, ng);
+	rib_add_multipath(afi, SAFI_UNICAST, &p, NULL, newre, ng, false);
 
 	return 0;
 }

zebra/rib.h

@@ -394,13 +394,14 @@ extern int rib_add(afi_t afi, safi_t safi, vrf_id_t vrf_id, int type,
 		   unsigned short instance, uint32_t flags, struct prefix *p,
 		   struct prefix_ipv6 *src_p, const struct nexthop *nh,
 		   uint32_t nhe_id, uint32_t table_id, uint32_t metric,
-		   uint32_t mtu, uint8_t distance, route_tag_t tag);
+		   uint32_t mtu, uint8_t distance, route_tag_t tag,
+		   bool startup);
 /*
  * Multipath route apis.
  */
 extern int rib_add_multipath(afi_t afi, safi_t safi, struct prefix *p,
 			     struct prefix_ipv6 *src_p, struct route_entry *re,
-			     struct nexthop_group *ng);
+			     struct nexthop_group *ng, bool startup);
 /*
  * -1 -> some sort of error
  *  0 -> an add
@@ -409,7 +410,7 @@ extern int rib_add_multipath(afi_t afi, safi_t safi, struct prefix *p,
 extern int rib_add_multipath_nhe(afi_t afi, safi_t safi, struct prefix *p,
 				 struct prefix_ipv6 *src_p,
 				 struct route_entry *re,
-				 struct nhg_hash_entry *nhe);
+				 struct nhg_hash_entry *nhe, bool startup);
 
 extern void rib_delete(afi_t afi, safi_t safi, vrf_id_t vrf_id, int type,
 		       unsigned short instance, uint32_t flags,

zebra/rt_netlink.c

@@ -920,7 +920,7 @@ static int netlink_route_change_read_unicast(struct nlmsghdr *h, ns_id_t ns_id,
 			}
 			rib_add(afi, SAFI_UNICAST, vrf_id, proto, 0, flags, &p,
 				&src_p, &nh, nhe_id, table, metric, mtu,
-				distance, tag);
+				distance, tag, startup);
 		} else {
 			/* This is a multipath route */
 			struct route_entry *re;
@@ -964,7 +964,7 @@ static int netlink_route_change_read_unicast(struct nlmsghdr *h, ns_id_t ns_id,
 
 			if (nhe_id || ng)
 				rib_add_multipath(afi, SAFI_UNICAST, &p,
-						  &src_p, re, ng);
+						  &src_p, re, ng, startup);
 			else
 				XFREE(MTYPE_RE, re);
 		}

zebra/zapi_msg.c

@@ -2127,7 +2127,7 @@ static void zread_route_add(ZAPI_HANDLER_ARGS)
 		nhe.backup_info = bnhg;
 	}
 	ret = rib_add_multipath_nhe(afi, api.safi, &api.prefix, src_p,
-				    re, &nhe);
+				    re, &nhe, false);
 
 	/*
 	 * rib_add_multipath_nhe only fails in a couple spots

zebra/zebra_rib.c

@@ -3346,7 +3346,7 @@ void _route_entry_dump(const char *func, union prefixconstptr pp,
  */
 int rib_add_multipath_nhe(afi_t afi, safi_t safi, struct prefix *p,
 			  struct prefix_ipv6 *src_p, struct route_entry *re,
-			  struct nhg_hash_entry *re_nhe)
+			  struct nhg_hash_entry *re_nhe, bool startup)
 {
 	struct nhg_hash_entry *nhe = NULL;
 	struct route_table *table;
@@ -3438,6 +3438,32 @@ int rib_add_multipath_nhe(afi_t afi, safi_t safi, struct prefix *p,
 
 	same = first_same;
 
+	if (!startup &&
+	    (re->flags & ZEBRA_FLAG_SELFROUTE) && zrouter.asic_offloaded) {
+		if (!same) {
+			if (IS_ZEBRA_DEBUG_RIB)
+				zlog_debug("prefix: %pRN is a self route where we do not have an entry for it.  Dropping this update, it's useless", rn);
+			/*
+			 * We are not on startup, this is a self route
+			 * and we have asic offload.  Which means
+			 * we are getting a callback for a entry
+			 * that was already deleted to the kernel
+			 * but an earlier response was just handed
+			 * back.  Drop it on the floor
+			 */
+			if (re->nhe && re->nhe_id) {
+				assert(re->nhe->id == re->nhe_id);
+				route_entry_update_nhe(re, NULL);
+			} else if (re->nhe && re->nhe->nhg.nexthop)
+				nexthops_free(re->nhe->nhg.nexthop);
+
+			nexthops_free(re->fib_ng.nexthop);
+
+			XFREE(MTYPE_RE, re);
+			return ret;
+		}
+	}
+
 	/* If this route is kernel/connected route, notify the dataplane. */
 	if (RIB_SYSTEM_ROUTE(re)) {
 		/* Notify dataplane */
@@ -3491,7 +3517,7 @@ int rib_add_multipath_nhe(afi_t afi, safi_t safi, struct prefix *p,
  */
 int rib_add_multipath(afi_t afi, safi_t safi, struct prefix *p,
 		      struct prefix_ipv6 *src_p, struct route_entry *re,
-		      struct nexthop_group *ng)
+		      struct nexthop_group *ng, bool startup)
 {
 	int ret;
 	struct nhg_hash_entry nhe;
@@ -3512,7 +3538,7 @@ int rib_add_multipath(afi_t afi, safi_t safi, struct prefix *p,
 	else if (re->nhe_id > 0)
 		nhe.id = re->nhe_id;
 
-	ret = rib_add_multipath_nhe(afi, safi, p, src_p, re, &nhe);
+	ret = rib_add_multipath_nhe(afi, safi, p, src_p, re, &nhe, startup);
 
 	/* In this path, the callers expect memory to be freed. */
 	nexthop_group_delete(&ng);
@@ -3743,7 +3769,7 @@ int rib_add(afi_t afi, safi_t safi, vrf_id_t vrf_id, int type,
 	    unsigned short instance, uint32_t flags, struct prefix *p,
 	    struct prefix_ipv6 *src_p, const struct nexthop *nh,
 	    uint32_t nhe_id, uint32_t table_id, uint32_t metric, uint32_t mtu,
-	    uint8_t distance, route_tag_t tag)
+	    uint8_t distance, route_tag_t tag, bool startup)
 {
 	struct route_entry *re = NULL;
 	struct nexthop *nexthop = NULL;
@@ -3775,7 +3801,7 @@ int rib_add(afi_t afi, safi_t safi, vrf_id_t vrf_id, int type,
 		nexthop_group_add_sorted(ng, nexthop);
 	}
 
-	return rib_add_multipath(afi, safi, p, src_p, re, ng);
+	return rib_add_multipath(afi, safi, p, src_p, re, ng, startup);
 }
 
 static const char *rib_update_event2str(enum rib_update_event event)