zebra: add support for maintaining local neigh entries

Currently specific local neighbors (attached to SVIs) are maintatined
in an EVPN specific database. There is a need to maintain L3 neighbors
for other purposes including MAC resolution for PBR nexthops.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>
   Cleanup compile and fix crash
Signed-off-by: Anuradha Karuppiah <anuradhak@nvidia.com>

zebra/debug.c

@@ -42,6 +42,7 @@ unsigned long zebra_debug_mlag;
 unsigned long zebra_debug_nexthop;
 unsigned long zebra_debug_evpn_mh;
 unsigned long zebra_debug_pbr;
+unsigned long zebra_debug_neigh;
 
 DEFINE_HOOK(zebra_debug_show_debugging, (struct vty *vty), (vty));
 
@@ -327,6 +328,22 @@ DEFUN (debug_zebra_pbr,
 	return CMD_SUCCESS;
 }
 
+DEFPY (debug_zebra_neigh,
+       debug_zebra_neigh_cmd,
+       "[no$no] debug zebra neigh",
+       NO_STR
+       DEBUG_STR
+       "Zebra configuration\n"
+       "Debug zebra neigh events\n")
+{
+	if (no)
+		UNSET_FLAG(zebra_debug_neigh, ZEBRA_DEBUG_NEIGH);
+	else
+		SET_FLAG(zebra_debug_neigh, ZEBRA_DEBUG_NEIGH);
+
+	return CMD_SUCCESS;
+}
+
 DEFPY (debug_zebra_mlag,
        debug_zebra_mlag_cmd,
        "[no$no] debug zebra mlag",
@@ -694,6 +711,11 @@ static int config_write_debug(struct vty *vty)
 		write++;
 	}
 
+	if (IS_ZEBRA_DEBUG_NEIGH) {
+		vty_out(vty, "debug zebra neigh\n");
+		write++;
+	}
+
 	return write;
 }
 
@@ -713,6 +735,7 @@ void zebra_debug_init(void)
 	zebra_debug_nht = 0;
 	zebra_debug_nexthop = 0;
 	zebra_debug_pbr = 0;
+	zebra_debug_neigh = 0;
 
 	install_node(&debug_node);
 
@@ -734,6 +757,7 @@ void zebra_debug_init(void)
 	install_element(ENABLE_NODE, &debug_zebra_mlag_cmd);
 	install_element(ENABLE_NODE, &debug_zebra_nexthop_cmd);
 	install_element(ENABLE_NODE, &debug_zebra_pbr_cmd);
+	install_element(ENABLE_NODE, &debug_zebra_neigh_cmd);
 	install_element(ENABLE_NODE, &no_debug_zebra_events_cmd);
 	install_element(ENABLE_NODE, &no_debug_zebra_nht_cmd);
 	install_element(ENABLE_NODE, &no_debug_zebra_mpls_cmd);
@@ -764,6 +788,7 @@ void zebra_debug_init(void)
 	install_element(CONFIG_NODE, &debug_zebra_dplane_cmd);
 	install_element(CONFIG_NODE, &debug_zebra_nexthop_cmd);
 	install_element(CONFIG_NODE, &debug_zebra_pbr_cmd);
+	install_element(CONFIG_NODE, &debug_zebra_neigh_cmd);
 
 	install_element(CONFIG_NODE, &no_debug_zebra_events_cmd);
 	install_element(CONFIG_NODE, &no_debug_zebra_nht_cmd);

zebra/debug.h

@@ -70,6 +70,8 @@ extern "C" {
 
 #define ZEBRA_DEBUG_PBR 0x01
 
+#define ZEBRA_DEBUG_NEIGH 0x01
+
 /* Debug related macro. */
 #define IS_ZEBRA_DEBUG_EVENT  (zebra_debug_event & ZEBRA_DEBUG_EVENT)
 
@@ -121,6 +123,8 @@ extern "C" {
 
 #define IS_ZEBRA_DEBUG_PBR (zebra_debug_pbr & ZEBRA_DEBUG_PBR)
 
+#define IS_ZEBRA_DEBUG_NEIGH (zebra_debug_neigh & ZEBRA_DEBUG_NEIGH)
+
 extern unsigned long zebra_debug_event;
 extern unsigned long zebra_debug_packet;
 extern unsigned long zebra_debug_kernel;
@@ -135,6 +139,7 @@ extern unsigned long zebra_debug_mlag;
 extern unsigned long zebra_debug_nexthop;
 extern unsigned long zebra_debug_evpn_mh;
 extern unsigned long zebra_debug_pbr;
+extern unsigned long zebra_debug_neigh;
 
 extern void zebra_debug_init(void);
 

zebra/rt_netlink.c

@@ -80,6 +80,7 @@
 #include "zebra/zebra_errors.h"
 #include "zebra/zebra_evpn_mh.h"
 #include "zebra/zebra_trace.h"
+#include "zebra/zebra_neigh.h"
 
 #ifndef AF_MPLS
 #define AF_MPLS 28
@@ -3882,10 +3883,10 @@ static int netlink_ipneigh_change(struct nlmsghdr *h, int len, ns_id_t ns_id)
 	} else if (IS_ZEBRA_IF_BRIDGE(ifp))
 		link_if = ifp;
 	else {
+		link_if = NULL;
 		if (IS_ZEBRA_DEBUG_KERNEL)
 			zlog_debug(
 				"    Neighbor Entry received is not on a VLAN or a BRIDGE, ignoring");
-		return 0;
 	}
 
 	memset(&mac, 0, sizeof(mac));
@@ -3949,12 +3950,25 @@ static int netlink_ipneigh_change(struct nlmsghdr *h, int len, ns_id_t ns_id)
 				 */
 				local_inactive = false;
 
-			return zebra_vxlan_handle_kernel_neigh_update(
-				ifp, link_if, &ip, &mac, ndm->ndm_state, is_ext,
-				is_router, local_inactive, dp_static);
+			/* Add local neighbors to the l3 interface database */
+			if (is_ext)
+				zebra_neigh_del(ifp, &ip);
+			else
+				zebra_neigh_add(ifp, &ip, &mac);
+
+			if (link_if)
+				zebra_vxlan_handle_kernel_neigh_update(
+					ifp, link_if, &ip, &mac, ndm->ndm_state,
+					is_ext, is_router, local_inactive,
+					dp_static);
+			return 0;
 		}
 
-		return zebra_vxlan_handle_kernel_neigh_del(ifp, link_if, &ip);
+
+		zebra_neigh_del(ifp, &ip);
+		if (link_if)
+			zebra_vxlan_handle_kernel_neigh_del(ifp, link_if, &ip);
+		return 0;
 	}
 
 	if (IS_ZEBRA_DEBUG_KERNEL)
@@ -3967,7 +3981,11 @@ static int netlink_ipneigh_change(struct nlmsghdr *h, int len, ns_id_t ns_id)
 	/* Process the delete - it may result in re-adding the neighbor if it is
 	 * a valid "remote" neighbor.
 	 */
-	return zebra_vxlan_handle_kernel_neigh_del(ifp, link_if, &ip);
+	zebra_neigh_del(ifp, &ip);
+	if (link_if)
+		zebra_vxlan_handle_kernel_neigh_del(ifp, link_if, &ip);
+
+	return 0;
 }
 
 static int netlink_neigh_table(struct nlmsghdr *h, ns_id_t ns_id, int startup)

zebra/subdir.am

@@ -125,6 +125,7 @@ zebra_zebra_SOURCES = \
 	zebra/zebra_vty.c \
 	zebra/zebra_vxlan.c \
 	zebra/zebra_evpn_mh.c \
+	zebra/zebra_neigh.c \
 	zebra/zserv.c \
 	# end
 
@@ -197,6 +198,7 @@ noinst_HEADERS += \
 	zebra/zebra_vxlan.h \
 	zebra/zebra_vxlan_private.h \
 	zebra/zebra_evpn_mh.h \
+	zebra/zebra_neigh.h \
 	zebra/zserv.h \
 	# end