zebra: refactor netlink route message parsing

Separate core netlink route message parsing into a new api that
uses a dplane ctx to hold the parsed attribute data. Use the new
api in two paths: the normal netlink update message parsing path,
and in the FPM plugin, which also uses netlink encoding. The FPM
route-notificatin code runs in its own pthread, and only needs
a subset of the route info that zebra ordinarily develops. This
change stops that pthread from accessing zebra's internal
data, such as vrfs and ifps, that are not thread-safe.

Signed-off-by: Mark Stapp <mjs@cisco.com>

6 files changed, 397 insertions, 104 deletions

diff --git a/zebra/dplane_fpm_nl.c b/zebra/dplane_fpm_nl.c
index 3ec1c9d65..b8dbabb60 100644
--- a/zebra/dplane_fpm_nl.c
+++ b/zebra/dplane_fpm_nl.c
@@ -587,6 +587,7 @@ static void fpm_read(struct event *t)
 	struct zebra_dplane_ctx *ctx;
 	size_t available_bytes;
 	size_t hdr_available_bytes;
+	int ival;
 
 	/* Let's ignore the input at the moment. */
 	rv = stream_read_try(fnc->ibuf, fnc->socket,
@@ -715,17 +716,28 @@ static void fpm_read(struct event *t)
 				break;
 			}
 
+			/* Parse the route data into a dplane ctx, then
+			 * enqueue it to zebra for processing.
+			 */
 			ctx = dplane_ctx_alloc();
 			dplane_ctx_route_init(ctx, DPLANE_OP_ROUTE_NOTIFY, NULL,
 					      NULL);
-			if (netlink_route_change_read_unicast_internal(
-				    hdr, 0, false, ctx) != 1) {
-				dplane_ctx_fini(&ctx);
-				stream_pulldown(fnc->ibuf);
+
+			if (netlink_route_notify_read_ctx(hdr, 0, ctx) >= 0) {
+				/* In the FPM encoding, the vrfid is present */
+				ival = dplane_ctx_get_table(ctx);
+				dplane_ctx_set_vrf(ctx, ival);
+				dplane_ctx_set_table(ctx,
+						     ZEBRA_ROUTE_TABLE_UNKNOWN);
+
+				dplane_provider_enqueue_to_zebra(ctx);
+			} else {
 				/*
 				 * Let's continue to read other messages
 				 * Even if we ignore this one.
 				 */
+				dplane_ctx_fini(&ctx);
+				stream_pulldown(fnc->ibuf);
 			}
 			break;
 		default:
diff --git a/zebra/rt_netlink.c b/zebra/rt_netlink.c
index 492fe5288..f88c70cc5 100644
--- a/zebra/rt_netlink.c
+++ b/zebra/rt_netlink.c
@@ -723,44 +723,52 @@ static uint16_t parse_multipath_nexthops_unicast(ns_id_t ns_id, struct nexthop_g
 	return nhop_num;
 }
 
-/* Looking up routing table by netlink interface. */
-int netlink_route_change_read_unicast_internal(struct nlmsghdr *h,
-					       ns_id_t ns_id, int startup,
-					       struct zebra_dplane_ctx *ctx)
+/*
+ * Parse netlink route message and capture info into a dplane ctx.
+ * Returns <0 if the message is to be skipped (might be an error)
+ */
+static int netlink_route_read_unicast_ctx(struct nlmsghdr *h, ns_id_t ns_id,
+					  struct rtattr **tb_in,
+					  struct zebra_dplane_ctx *ctx)
 {
+	int ret = 0;
 	int len;
 	struct rtmsg *rtm;
-	struct rtattr *tb[RTA_MAX + 1];
+	struct rtattr **tb, *tb_array[RTA_MAX + 1];
 	uint32_t flags = 0;
 	struct prefix p;
-	struct prefix_ipv6 src_p = {};
-	vrf_id_t vrf_id;
+	struct prefix src_p = {};
 	bool selfroute;
-
-	char anyaddr[16] = {0};
-
+	char anyaddr[16] = {};
 	int proto = ZEBRA_ROUTE_KERNEL;
 	int index = 0;
-	int table;
+	int tableid;
 	int metric = 0;
 	uint32_t mtu = 0;
 	uint8_t distance = 0;
 	route_tag_t tag = 0;
-	uint32_t nhe_id = 0;
-
+	uint32_t nhg_id = 0;
 	void *dest = NULL;
 	void *gate = NULL;
+	int gate_len;
 	void *prefsrc = NULL; /* IPv4 preferred source host address */
+	int prefsrc_len;
 	void *src = NULL;     /* IPv6 srcdest   source prefix */
 	enum blackhole_type bh_type = BLACKHOLE_UNSPEC;
+	afi_t afi = AFI_IP;
+	struct ipaddr addr = {};
 
-	frrtrace(3, frr_zebra, netlink_route_change_read_unicast, h, ns_id,
-		 startup);
+	len = h->nlmsg_len - NLMSG_LENGTH(sizeof(struct rtmsg));
+	if (len < 0) {
+		zlog_err(
+			"%s: Netlink route message received with invalid size %d %zu",
+			__func__, h->nlmsg_len,
+			(size_t)NLMSG_LENGTH(sizeof(struct rtmsg)));
+		return -1;
+	}
 
 	rtm = NLMSG_DATA(h);
 
-	if (startup && h->nlmsg_type != RTM_NEWROUTE)
-		return 0;
 	switch (rtm->rtm_type) {
 	case RTN_UNICAST:
 		break;
@@ -778,54 +786,42 @@ int netlink_route_change_read_unicast_internal(struct nlmsghdr *h,
 			zlog_debug("Route rtm_type: %s(%d) intentionally ignoring",
 				   nl_rttype_to_str(rtm->rtm_type),
 				   rtm->rtm_type);
-		return 0;
+		ret = -1;
+		goto done;
 	}
 
-	len = h->nlmsg_len - NLMSG_LENGTH(sizeof(struct rtmsg));
-	if (len < 0) {
-		zlog_err(
-			"%s: Message received from netlink is of a broken size %d %zu",
-			__func__, h->nlmsg_len,
-			(size_t)NLMSG_LENGTH(sizeof(struct rtmsg)));
-		return -1;
+	if ((rtm->rtm_flags & RTM_F_CLONED) ||
+	    (rtm->rtm_protocol == RTPROT_REDIRECT)) {
+		ret = -1;
+		goto done;
 	}
 
-	netlink_parse_rtattr(tb, RTA_MAX, RTM_RTA(rtm), len);
-
-	if (rtm->rtm_flags & RTM_F_CLONED)
-		return 0;
-	if (rtm->rtm_protocol == RTPROT_REDIRECT)
-		return 0;
+	/* We don't care about change notifications for the MPLS table. */
+	/* TODO: Revisit this. */
+	if (rtm->rtm_family == AF_MPLS) {
+		ret = -1;
+		goto done;
+	}
 
-	selfroute = is_selfroute(rtm->rtm_protocol);
+	dplane_ctx_set_ns_id(ctx, ns_id);
 
-	if (!startup && selfroute && h->nlmsg_type == RTM_NEWROUTE &&
-	    !zrouter.asic_offloaded && !ctx) {
-		if (IS_ZEBRA_DEBUG_KERNEL)
-			zlog_debug("Route type: %d Received that we think we have originated, ignoring",
-				   rtm->rtm_protocol);
-		return 0;
+	/* Parse attrs if necessary */
+	if (tb_in != NULL) {
+		tb = tb_in;
+	} else {
+		netlink_parse_rtattr(tb_array, RTA_MAX, RTM_RTA(rtm), len);
+		tb = tb_array;
 	}
 
-	/* We don't care about change notifications for the MPLS table. */
-	/* TODO: Revisit this. */
-	if (rtm->rtm_family == AF_MPLS)
-		return 0;
+	selfroute = is_selfroute(rtm->rtm_protocol);
 
 	/* Table corresponding to route. */
 	if (tb[RTA_TABLE])
-		table = *(int *)RTA_DATA(tb[RTA_TABLE]);
+		tableid = *(int *)RTA_DATA(tb[RTA_TABLE]);
 	else
-		table = rtm->rtm_table;
-
-	/* Map to VRF */
-	vrf_id = zebra_vrf_lookup_by_table(table, ns_id);
-	if (vrf_id == VRF_DEFAULT) {
-		if (!is_zebra_valid_kernel_table(table)
-		    && !is_zebra_main_routing_table(table))
-			return 0;
-	}
+		tableid = rtm->rtm_table;
 
+	/* Map flags values */
 	if (rtm->rtm_flags & RTM_F_TRAP)
 		flags |= ZEBRA_FLAG_TRAPPED;
 	if (rtm->rtm_flags & RTM_F_OFFLOAD)
@@ -836,7 +832,7 @@ int netlink_route_change_read_unicast_internal(struct nlmsghdr *h,
 	if (h->nlmsg_flags & NLM_F_APPEND)
 		flags |= ZEBRA_FLAG_OUTOFSYNC;
 
-	/* Route which inserted by Zebra. */
+	/* Route which was inserted by Zebra. */
 	if (selfroute) {
 		flags |= ZEBRA_FLAG_SELFROUTE;
 		proto = proto2zebra(rtm->rtm_protocol, rtm->rtm_family, false);
@@ -854,14 +850,18 @@ int netlink_route_change_read_unicast_internal(struct nlmsghdr *h,
 	else
 		src = anyaddr;
 
-	if (tb[RTA_PREFSRC])
+	if (tb[RTA_PREFSRC]) {
 		prefsrc = RTA_DATA(tb[RTA_PREFSRC]);
+		prefsrc_len = RTA_PAYLOAD(tb[RTA_PREFSRC]);
+	}
 
-	if (tb[RTA_GATEWAY])
+	if (tb[RTA_GATEWAY]) {
 		gate = RTA_DATA(tb[RTA_GATEWAY]);
+		gate_len = RTA_PAYLOAD(tb[RTA_GATEWAY]);
+	}
 
 	if (tb[RTA_NH_ID])
-		nhe_id = *(uint32_t *)RTA_DATA(tb[RTA_NH_ID]);
+		nhg_id = *(uint32_t *)RTA_DATA(tb[RTA_NH_ID]);
 
 	if (tb[RTA_PRIORITY])
 		metric = *(int *)RTA_DATA(tb[RTA_PRIORITY]);
@@ -887,7 +887,8 @@ int netlink_route_change_read_unicast_internal(struct nlmsghdr *h,
 			zlog_err(
 				"Invalid destination prefix length: %u received from kernel route change",
 				rtm->rtm_dst_len);
-			return -1;
+			ret = -1;
+			goto done;
 		}
 		memcpy(&p.u.prefix4, dest, 4);
 		p.prefixlen = rtm->rtm_dst_len;
@@ -895,14 +896,16 @@ int netlink_route_change_read_unicast_internal(struct nlmsghdr *h,
 		if (rtm->rtm_src_len != 0) {
 			flog_warn(
 				EC_ZEBRA_UNSUPPORTED_V4_SRCDEST,
-				"unsupported IPv4 sourcedest route (dest %pFX vrf %u)",
-				&p, vrf_id);
-			return 0;
+				"unsupported IPv4 sourcedest route (dest %pFX table %u)",
+				&p, tableid);
+			ret = -1;
+			goto done;
 		}
 
 		/* Force debug below to not display anything for source */
 		src_p.prefixlen = 0;
 	} else if (rtm->rtm_family == AF_INET6) {
+		afi = AFI_IP6;
 		p.family = AF_INET6;
 		if (rtm->rtm_dst_len > IPV6_MAX_BITLEN) {
 			zlog_err(
@@ -920,14 +923,15 @@ int netlink_route_change_read_unicast_internal(struct nlmsghdr *h,
 				rtm->rtm_src_len);
 			return -1;
 		}
-		memcpy(&src_p.prefix, src, 16);
+		memcpy(&src_p.u.prefix6, src, 16);
 		src_p.prefixlen = rtm->rtm_src_len;
 	} else {
 		/* We only handle the AFs we handle... */
 		if (IS_ZEBRA_DEBUG_KERNEL)
 			zlog_debug("%s: unknown address-family %u", __func__,
 				   rtm->rtm_family);
-		return 0;
+		ret = -1;
+		goto done;
 	}
 
 	/*
@@ -956,6 +960,249 @@ int netlink_route_change_read_unicast_internal(struct nlmsghdr *h,
 		char buf2[PREFIX_STRLEN];
 
 		zlog_debug(
+			"%s %pFX%s%s nsid: %u table_id: %u metric: %d Admin Distance: %d",
+			nl_msg_type_to_str(h->nlmsg_type), &p,
+			src_p.prefixlen ? " from " : "",
+			src_p.prefixlen ? prefix2str(&src_p, buf2, sizeof(buf2))
+					: "",
+			ns_id, tableid, metric, distance);
+	}
+
+	/* Set values in ctx. Note that vrf is not set, because we can only
+	 * resolve the FRR vrf info in the main pthread.
+	 */
+	dplane_ctx_set_afi(ctx, afi);
+	dplane_ctx_set_safi(ctx, SAFI_UNICAST);
+	dplane_ctx_set_table(ctx, tableid);
+	dplane_ctx_set_vrf(ctx, VRF_UNKNOWN);
+	dplane_ctx_set_ns_id(ctx, ns_id);
+	dplane_ctx_set_dest(ctx, &p);
+	if (src_p.prefixlen > 0)
+		dplane_ctx_set_src(ctx, &src_p);
+	else
+		dplane_ctx_set_src(ctx, NULL);
+	dplane_ctx_set_type(ctx, proto);
+	dplane_ctx_set_flags(ctx, flags);
+	dplane_ctx_set_route_metric(ctx, metric);
+	dplane_ctx_set_route_mtu(ctx, mtu);
+	dplane_ctx_set_distance(ctx, distance);
+	dplane_ctx_set_tag(ctx, tag);
+
+	dplane_ctx_set_ifindex(ctx, index);
+	dplane_ctx_set_route_bhtype(ctx, bh_type);
+	if (prefsrc) {
+		/* Convert to ipaddr */
+		memset(&addr, 0, sizeof(addr));
+
+		if (afi == AFI_IP) {
+			SET_IPADDR_V4(&addr);
+			memcpy(&addr.ipaddr_v4, prefsrc, prefsrc_len);
+		} else {
+			SET_IPADDR_V6(&addr);
+			memcpy(&addr.ipaddr_v6, prefsrc, prefsrc_len);
+		}
+
+		dplane_ctx_set_route_prefsrc(ctx, &addr);
+	} else {
+		dplane_ctx_set_route_prefsrc(ctx, NULL);
+	}
+
+	if (gate) {
+		/* Convert to ipaddr */
+		memset(&addr, 0, sizeof(addr));
+
+		if (afi == AFI_IP) {
+			SET_IPADDR_V4(&addr);
+			memcpy(&addr.ipaddr_v4, gate, gate_len);
+		} else {
+			SET_IPADDR_V6(&addr);
+			memcpy(&addr.ipaddr_v6, gate, gate_len);
+		}
+
+		dplane_ctx_set_route_gw(ctx, &addr);
+	}
+
+	if (nhg_id > 0)
+		dplane_ctx_set_nhg_id(ctx, nhg_id);
+
+done:
+
+	return ret;
+}
+
+/*
+ * Public api for use parsing a route notification message: this notification
+ * only parses the top-level route attributes, and doesn't include nexthops.
+ */
+int netlink_route_notify_read_ctx(struct nlmsghdr *h, ns_id_t ns_id,
+				  struct zebra_dplane_ctx *ctx)
+{
+	/* Use the common parser for route-level netlink message info;
+	 * we expect the caller to have set the context up with the correct
+	 * dplane opcode, and we expect the caller to submit the resulting ctx
+	 * for processing in zebra.
+	 */
+	return netlink_route_read_unicast_ctx(h, ns_id, NULL, ctx);
+}
+
+/*
+ * Parse a route update netlink message, extract and validate its data,
+ * call into zebra with an update.
+ */
+static int netlink_route_change_read_unicast_internal(struct nlmsghdr *h,
+						      ns_id_t ns_id, int startup)
+{
+	int len;
+	struct rtmsg *rtm;
+	struct rtattr *tb[RTA_MAX + 1];
+	uint32_t flags = 0;
+	struct prefix p;
+	struct prefix src_p = {};
+	vrf_id_t vrf_id;
+	bool selfroute;
+
+	int proto = ZEBRA_ROUTE_KERNEL;
+	int index = 0;
+	int table;
+	int metric = 0;
+	uint32_t mtu = 0;
+	uint8_t distance = 0;
+	route_tag_t tag = 0;
+	uint32_t nhe_id = 0;
+	void *gate = NULL;
+	const struct ipaddr *gate_addr;
+	void *prefsrc = NULL; /* IPv4 preferred source host address */
+	const struct ipaddr *prefsrc_addr;
+	enum blackhole_type bh_type = BLACKHOLE_UNSPEC;
+	afi_t afi;
+	struct zebra_dplane_ctx *ctx = NULL;
+	int ret;
+
+	frrtrace(3, frr_zebra, netlink_route_change_read_unicast, h, ns_id,
+		 startup);
+
+	rtm = NLMSG_DATA(h);
+
+	if (startup && h->nlmsg_type != RTM_NEWROUTE)
+		return 0;
+
+	switch (rtm->rtm_type) {
+	case RTN_UNICAST:
+	case RTN_BLACKHOLE:
+	case RTN_UNREACHABLE:
+	case RTN_PROHIBIT:
+		break;
+	default:
+		if (IS_ZEBRA_DEBUG_KERNEL)
+			zlog_debug("Route rtm_type: %s(%d) intentionally ignoring",
+				   nl_rttype_to_str(rtm->rtm_type),
+				   rtm->rtm_type);
+		return 0;
+	}
+
+	len = h->nlmsg_len - NLMSG_LENGTH(sizeof(struct rtmsg));
+	if (len < 0) {
+		zlog_err(
+			"%s: Message received from netlink is of a broken size %d %zu",
+			__func__, h->nlmsg_len,
+			(size_t)NLMSG_LENGTH(sizeof(struct rtmsg)));
+		return -1;
+	}
+
+	if (rtm->rtm_flags & RTM_F_CLONED)
+		return 0;
+	if (rtm->rtm_protocol == RTPROT_REDIRECT)
+		return 0;
+
+	/* We don't care about change notifications for the MPLS table. */
+	/* TODO: Revisit this. */
+	if (rtm->rtm_family == AF_MPLS)
+		return 0;
+
+	netlink_parse_rtattr(tb, RTA_MAX, RTM_RTA(rtm), len);
+
+	/*
+	 * Allocate a context object and parse the core parts of the route
+	 * message.
+	 * After this point, note that we need to 'goto done' to exit,
+	 * so that the ctx gets cleaned-up.
+	 */
+	ctx = dplane_ctx_alloc();
+
+	dplane_ctx_route_init(ctx,
+			      h->nlmsg_type == RTM_NEWROUTE ?
+			      DPLANE_OP_ROUTE_INSTALL :
+			      DPLANE_OP_ROUTE_DELETE, NULL, NULL);
+
+	/* Finish parsing the core route info */
+	ret = netlink_route_read_unicast_ctx(h, ns_id, tb, ctx);
+	if (ret < 0) {
+		ret = 0;
+		goto done;
+	}
+
+	flags = dplane_ctx_get_flags(ctx);
+
+	selfroute = CHECK_FLAG(flags, ZEBRA_FLAG_SELFROUTE);
+
+	if (!startup && selfroute && h->nlmsg_type == RTM_NEWROUTE &&
+	    !zrouter.asic_offloaded) {
+		if (IS_ZEBRA_DEBUG_KERNEL)
+			zlog_debug("Route type: %d Received that we think we have originated, ignoring",
+				   rtm->rtm_protocol);
+		ret = 0;
+		goto done;
+	}
+
+	/* Table corresponding to route. */
+	table = dplane_ctx_get_table(ctx);
+
+	/* Map to VRF: note that this can _only_ be done in the main pthread */
+	vrf_id = zebra_vrf_lookup_by_table(table, ns_id);
+	if (vrf_id == VRF_DEFAULT) {
+		if (!is_zebra_valid_kernel_table(table)
+		    && !is_zebra_main_routing_table(table)) {
+			ret = 0;
+			goto done;
+		}
+	}
+
+	/* Route which inserted by Zebra. */
+	if (selfroute)
+		proto = dplane_ctx_get_type(ctx);
+
+	index = dplane_ctx_get_ifindex(ctx);
+
+	p = *(dplane_ctx_get_dest(ctx));
+
+	if (dplane_ctx_get_src(ctx) == NULL)
+		src_p.prefixlen = 0;
+	else
+		src_p = *(dplane_ctx_get_src(ctx));
+
+	prefsrc_addr = dplane_ctx_get_route_prefsrc(ctx);
+	if (prefsrc_addr)
+		prefsrc = (void *)&(prefsrc_addr->ip.addr);
+
+	gate_addr = dplane_ctx_get_route_gw(ctx);
+	if (!IS_IPADDR_NONE(gate_addr))
+		gate = (void *)&(gate_addr->ip.addr);
+
+	nhe_id = dplane_ctx_get_nhe_id(ctx);
+
+	metric = dplane_ctx_get_metric(ctx);
+	distance = dplane_ctx_get_distance(ctx);
+	tag = dplane_ctx_get_tag(ctx);
+	mtu = dplane_ctx_get_mtu(ctx);
+
+	afi = dplane_ctx_get_afi(ctx);
+
+	bh_type = dplane_ctx_get_route_bhtype(ctx);
+
+	if (IS_ZEBRA_DEBUG_KERNEL) {
+		char buf2[PREFIX_STRLEN];
+
+		zlog_debug(
 			"%s %pFX%s%s vrf %s(%u) table_id: %u metric: %d Admin Distance: %d",
 			nl_msg_type_to_str(h->nlmsg_type), &p,
 			src_p.prefixlen ? " from " : "",
@@ -965,10 +1212,6 @@ int netlink_route_change_read_unicast_internal(struct nlmsghdr *h,
 			distance);
 	}
 
-	afi_t afi = AFI_IP;
-	if (rtm->rtm_family == AF_INET6)
-		afi = AFI_IP6;
-
 	if (h->nlmsg_type == RTM_NEWROUTE) {
 		struct route_entry *re;
 		struct nexthop_group *ng = NULL;
@@ -1018,12 +1261,11 @@ int netlink_route_change_read_unicast_internal(struct nlmsghdr *h,
 			}
 		}
 		if (nhe_id || ng) {
-			dplane_rib_add_multipath(afi, SAFI_UNICAST, &p, &src_p,
-						 re, ng, startup, ctx);
+			rib_add_multipath(afi, SAFI_UNICAST, &p,
+					  (struct prefix_ipv6 *)&src_p,
+					  re, ng, startup);
 			if (ng)
 				nexthop_group_delete(&ng);
-			if (ctx)
-				zebra_rib_route_entry_free(re);
 		} else {
 			/*
 			 * I really don't see how this is possible
@@ -1038,17 +1280,10 @@ int netlink_route_change_read_unicast_internal(struct nlmsghdr *h,
 			zebra_rib_route_entry_free(re);
 		}
 	} else {
-		if (ctx) {
-			zlog_err(
-				"%s: %pFX RTM_DELROUTE received but received a context as well",
-				__func__, &p);
-			return 0;
-		}
-
 		if (nhe_id) {
 			rib_delete(afi, SAFI_UNICAST, vrf_id, proto, 0, flags,
-				   &p, &src_p, NULL, nhe_id, table, metric,
-				   distance, true);
+				   &p, (struct prefix_ipv6 *)&src_p, NULL,
+				   nhe_id, table, metric, distance, true);
 		} else {
 			if (!tb[RTA_MULTIPATH]) {
 				struct nexthop nh;
@@ -1057,26 +1292,33 @@ int netlink_route_change_read_unicast_internal(struct nlmsghdr *h,
 					ns_id, rtm, tb, bh_type, index, prefsrc,
 					gate, afi, vrf_id);
 				rib_delete(afi, SAFI_UNICAST, vrf_id, proto, 0,
-					   flags, &p, &src_p, &nh, 0, table,
-					   metric, distance, true);
+					   flags, &p,
+					   (struct prefix_ipv6 *)&src_p, &nh, 0,
+					   table, metric, distance, true);
 			} else {
 				/* XXX: need to compare the entire list of
 				 * nexthops here for NLM_F_APPEND stupidity */
 				rib_delete(afi, SAFI_UNICAST, vrf_id, proto, 0,
-					   flags, &p, &src_p, NULL, 0, table,
-					   metric, distance, true);
+					   flags, &p,
+					   (struct prefix_ipv6 *)&src_p, NULL, 0,
+					   table, metric, distance, true);
 			}
 		}
 	}
 
-	return 1;
+	ret = 1;
+
+done:
+	if (ctx)
+		dplane_ctx_fini(&ctx);
+
+	return ret;
 }
 
 static int netlink_route_change_read_unicast(struct nlmsghdr *h, ns_id_t ns_id,
 					     int startup)
 {
-	return netlink_route_change_read_unicast_internal(h, ns_id, startup,
-							  NULL);
+	return netlink_route_change_read_unicast_internal(h, ns_id, startup);
 }
 
 static struct mcast_route_data *mroute = NULL;
diff --git a/zebra/rt_netlink.h b/zebra/rt_netlink.h
index d51944f1a..1c113baee 100644
--- a/zebra/rt_netlink.h
+++ b/zebra/rt_netlink.h
@@ -64,6 +64,15 @@ extern ssize_t netlink_macfdb_update_ctx(struct zebra_dplane_ctx *ctx,
 extern int netlink_route_change(struct nlmsghdr *h, ns_id_t ns_id, int startup);
 extern int netlink_route_read(struct zebra_ns *zns);
 
+/*
+ * Public api for parsing a route notification message: this notification
+ * only parses the top-level route attributes, and doesn't include nexthops.
+ * FPM, for example, is a user.
+ * Returns <0 if the message should be ignored/skipped.
+ */
+int netlink_route_notify_read_ctx(struct nlmsghdr *h, ns_id_t ns_id,
+				  struct zebra_dplane_ctx *ctx);
+
 extern int netlink_nexthop_change(struct nlmsghdr *h, ns_id_t ns_id,
 				  int startup);
 extern int netlink_nexthop_read(struct zebra_ns *zns);
@@ -109,10 +118,6 @@ netlink_put_lsp_update_msg(struct nl_batch *bth, struct zebra_dplane_ctx *ctx);
 extern enum netlink_msg_status
 netlink_put_pw_update_msg(struct nl_batch *bth, struct zebra_dplane_ctx *ctx);
 
-int netlink_route_change_read_unicast_internal(struct nlmsghdr *h,
-					       ns_id_t ns_id, int startup,
-					       struct zebra_dplane_ctx *ctx);
-
 #ifdef NETLINK_DEBUG
 const char *nlmsg_type2str(uint16_t type);
 const char *af_type2str(int type);
diff --git a/zebra/zebra_rib.c b/zebra/zebra_rib.c
index b2543ca0e..8e4550846 100644
--- a/zebra/zebra_rib.c
+++ b/zebra/zebra_rib.c
@@ -2279,8 +2279,20 @@ static void rib_process_dplane_notify(struct zebra_dplane_ctx *ctx)
 	bool fib_changed = false;
 	bool debug_p = IS_ZEBRA_DEBUG_DPLANE | IS_ZEBRA_DEBUG_RIB;
 	int start_count, end_count;
+	vrf_id_t vrf_id;
+	int tableid;
+
+	/* Locate vrf and route table - we must have one or the other */
+	tableid = dplane_ctx_get_table(ctx);
+	vrf_id = dplane_ctx_get_vrf(ctx);
+	if (vrf_id == VRF_UNKNOWN)
+		vrf_id = zebra_vrf_lookup_by_table(tableid,
+						   dplane_ctx_get_ns_id(ctx));
+	else if (tableid == ZEBRA_ROUTE_TABLE_UNKNOWN)
+		tableid = zebra_vrf_lookup_tableid(vrf_id,
+						   dplane_ctx_get_ns_id(ctx));
 
-	vrf = vrf_lookup_by_id(dplane_ctx_get_vrf(ctx));
+	vrf = vrf_lookup_by_id(vrf_id);
 
 	/* Locate rn and re(s) from ctx */
 	rn = rib_find_rn_from_ctx(ctx);
@@ -2289,7 +2301,7 @@ static void rib_process_dplane_notify(struct zebra_dplane_ctx *ctx)
 			zlog_debug(
 				"Failed to process dplane notification: no routes for %s(%u:%u):%pRN",
 				VRF_LOGNAME(vrf), dplane_ctx_get_vrf(ctx),
-				dplane_ctx_get_table(ctx), rn);
+				tableid, rn);
 		}
 		goto done;
 	}
@@ -2299,7 +2311,7 @@ static void rib_process_dplane_notify(struct zebra_dplane_ctx *ctx)
 	if (debug_p)
 		zlog_debug("%s(%u:%u):%pRN Processing dplane notif ctx %p",
 			   VRF_LOGNAME(vrf), dplane_ctx_get_vrf(ctx),
-			   dplane_ctx_get_table(ctx), rn, ctx);
+			   tableid, rn, ctx);
 
 	/*
 	 * Take a pass through the routes, look for matches with the context
@@ -2316,7 +2328,7 @@ static void rib_process_dplane_notify(struct zebra_dplane_ctx *ctx)
 			zlog_debug(
 				"%s(%u:%u):%pRN Unable to process dplane notification: no entry for type %s",
 				VRF_LOGNAME(vrf), dplane_ctx_get_vrf(ctx),
-				dplane_ctx_get_table(ctx), rn,
+				tableid, rn,
 				zebra_route_string(dplane_ctx_get_type(ctx)));
 
 		goto done;
@@ -2352,7 +2364,7 @@ static void rib_process_dplane_notify(struct zebra_dplane_ctx *ctx)
 					"%s(%u:%u):%pRN dplane notif, uninstalled type %s route",
 					VRF_LOGNAME(vrf),
 					dplane_ctx_get_vrf(ctx),
-					dplane_ctx_get_table(ctx), rn,
+					tableid, rn,
 					zebra_route_string(
 						dplane_ctx_get_type(ctx)));
 		} else {
@@ -2362,7 +2374,7 @@ static void rib_process_dplane_notify(struct zebra_dplane_ctx *ctx)
 					"%s(%u:%u):%pRN dplane notif, but type %s not selected_fib",
 					VRF_LOGNAME(vrf),
 					dplane_ctx_get_vrf(ctx),
-					dplane_ctx_get_table(ctx), rn,
+					tableid, rn,
 					zebra_route_string(
 						dplane_ctx_get_type(ctx)));
 		}
@@ -2401,7 +2413,7 @@ static void rib_process_dplane_notify(struct zebra_dplane_ctx *ctx)
 			zlog_debug(
 				"%s(%u:%u):%pRN dplane notification: rib_update returns FALSE",
 				VRF_LOGNAME(vrf), dplane_ctx_get_vrf(ctx),
-				dplane_ctx_get_table(ctx), rn);
+				tableid, rn);
 	}
 
 	/*
@@ -2420,7 +2432,7 @@ static void rib_process_dplane_notify(struct zebra_dplane_ctx *ctx)
 					"%s(%u:%u):%pRN applied nexthop changes from dplane notification",
 					VRF_LOGNAME(vrf),
 					dplane_ctx_get_vrf(ctx),
-					dplane_ctx_get_table(ctx), rn);
+					tableid, rn);
 
 			/* Changed nexthops - update kernel/others */
 			dplane_route_notif_update(rn, re,
@@ -2432,7 +2444,7 @@ static void rib_process_dplane_notify(struct zebra_dplane_ctx *ctx)
 					"%s(%u:%u):%pRN installed transition from dplane notification",
 					VRF_LOGNAME(vrf),
 					dplane_ctx_get_vrf(ctx),
-					dplane_ctx_get_table(ctx), rn);
+					tableid, rn);
 
 			/* We expect this to be the selected route, so we want
 			 * to tell others about this transition.
@@ -2452,7 +2464,7 @@ static void rib_process_dplane_notify(struct zebra_dplane_ctx *ctx)
 					"%s(%u:%u):%pRN un-installed transition from dplane notification",
 					VRF_LOGNAME(vrf),
 					dplane_ctx_get_vrf(ctx),
-					dplane_ctx_get_table(ctx), rn);
+					tableid, rn);
 
 			/* Transition from _something_ installed to _nothing_
 			 * installed.
diff --git a/zebra/zebra_vrf.c b/zebra/zebra_vrf.c
index 2b3cfc876..c7781e86d 100644
--- a/zebra/zebra_vrf.c
+++ b/zebra/zebra_vrf.c
@@ -417,6 +417,25 @@ vrf_id_t zebra_vrf_lookup_by_table(uint32_t table_id, ns_id_t ns_id)
 	return VRF_DEFAULT;
 }
 
+/*
+ * Lookup tableid by vrfid; handle vrf-lite and vrf-netns cases
+ */
+int zebra_vrf_lookup_tableid(vrf_id_t vrf_id, ns_id_t ns_id)
+{
+	struct zebra_vrf *zvrf;
+
+	/* Handle vrf-lite and vrf-netns */
+	if (vrf_is_backend_netns())
+		zvrf = vrf_info_lookup(ns_id);
+	else
+		zvrf = vrf_info_lookup(vrf_id);
+
+	if (zvrf)
+		return zvrf->table_id;
+	else
+		return ZEBRA_ROUTE_TABLE_UNKNOWN;
+}
+
 /* Lookup VRF by identifier.  */
 struct zebra_vrf *zebra_vrf_lookup_by_id(vrf_id_t vrf_id)
 {
diff --git a/zebra/zebra_vrf.h b/zebra/zebra_vrf.h
index f97138c81..334bb9368 100644
--- a/zebra/zebra_vrf.h
+++ b/zebra/zebra_vrf.h
@@ -24,6 +24,8 @@ FRR_CFG_DEFAULT_BOOL(ZEBRA_IP_NHT_RESOLVE_VIA_DEFAULT,
 	{ .val_bool = false },
 );
 
+#define ZEBRA_ROUTE_TABLE_UNKNOWN 0
+
 /* MPLS (Segment Routing) global block */
 struct mpls_srgb {
 	uint32_t start_label;
@@ -247,6 +249,7 @@ extern struct zebra_vrf *zebra_vrf_lookup_by_name(const char *);
 extern vrf_id_t zebra_vrf_lookup_by_table(uint32_t table_id, ns_id_t ns_id);
 extern struct zebra_vrf *zebra_vrf_alloc(struct vrf *vrf);
 extern struct route_table *zebra_vrf_table(afi_t, safi_t, vrf_id_t);
+int zebra_vrf_lookup_tableid(vrf_id_t vrf_id, ns_id_t ns_id);
 
 /*
  * API to associate a VRF with a NETNS.