zebra: Cleanup ctx leak on shutdown and turn off event

two things:

On shutdown cleanup any events associated with the update walker.
Also do not allow new events to be created.

Fixes this mem-leak:

./msdp_topo1.test_msdp_topo1/r2.zebra.asan.1117790:Direct leak of 8 byte(s) in 1 object(s) allocated from:
./msdp_topo1.test_msdp_topo1/r2.zebra.asan.1117790-    #0 0x7f0dd0b08037 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154
./msdp_topo1.test_msdp_topo1/r2.zebra.asan.1117790-    sonic-net#1 0x7f0dd06c19f9 in qcalloc lib/memory.c:105
./msdp_topo1.test_msdp_topo1/r2.zebra.asan.1117790-    sonic-net#2 0x55b42fb605bc in rib_update_ctx_init zebra/zebra_rib.c:4383
./msdp_topo1.test_msdp_topo1/r2.zebra.asan.1117790-    sonic-net#3 0x55b42fb6088f in rib_update zebra/zebra_rib.c:4421
./msdp_topo1.test_msdp_topo1/r2.zebra.asan.1117790-    sonic-net#4 0x55b42fa00344 in netlink_link_change zebra/if_netlink.c:2221
./msdp_topo1.test_msdp_topo1/r2.zebra.asan.1117790-    sonic-net#5 0x55b42fa24622 in netlink_information_fetch zebra/kernel_netlink.c:399
./msdp_topo1.test_msdp_topo1/r2.zebra.asan.1117790-    sonic-net#6 0x55b42fa28c02 in netlink_parse_info zebra/kernel_netlink.c:1183
./msdp_topo1.test_msdp_topo1/r2.zebra.asan.1117790-    sonic-net#7 0x55b42fa24951 in kernel_read zebra/kernel_netlink.c:493
./msdp_topo1.test_msdp_topo1/r2.zebra.asan.1117790-    sonic-net#8 0x7f0dd0797f0c in event_call lib/event.c:1995
./msdp_topo1.test_msdp_topo1/r2.zebra.asan.1117790-    sonic-net#9 0x7f0dd0684fd9 in frr_run lib/libfrr.c:1185
./msdp_topo1.test_msdp_topo1/r2.zebra.asan.1117790-    sonic-net#10 0x55b42fa30caa in main zebra/main.c:465
./msdp_topo1.test_msdp_topo1/r2.zebra.asan.1117790-    sonic-net#11 0x7f0dd01b5d09 in __libc_start_main ../csu/libc-start.c:308
./msdp_topo1.test_msdp_topo1/r2.zebra.asan.1117790-
./msdp_topo1.test_msdp_topo1/r2.zebra.asan.1117790-SUMMARY: AddressSanitizer: 8 byte(s) leaked in 1 allocation(s).

Signed-off-by: Donald Sharp <[email protected]>
(cherry picked from commit 3cd0acc)
Signed-off-by: Donatas Abraitis <[email protected]>

Author: donaldsharp

zebra/main.c

@@ -204,6 +204,8 @@ static void sigint(void)
 	 */
 	zebra_routemap_finish();
 
+	rib_update_finish();
+
 	list_delete(&zrouter.client_list);
 
 	/* Indicate that all new dplane work has been enqueued. When that

zebra/rib.h

@@ -338,6 +338,7 @@ enum rib_update_event {
 	RIB_UPDATE_OTHER,
 	RIB_UPDATE_MAX
 };
+void rib_update_finish(void);
 
 int route_entry_update_nhe(struct route_entry *re,
 			   struct nhg_hash_entry *new_nhghe);

zebra/zebra_rib.c

@@ -4393,6 +4393,22 @@ static void rib_update_handler(struct thread *thread)
  */
 static struct thread *t_rib_update_threads[RIB_UPDATE_MAX];
 
+void rib_update_finish(void)
+{
+	int i;
+
+	for (i = RIB_UPDATE_KERNEL; i < RIB_UPDATE_MAX; i++) {
+		if (thread_is_scheduled(t_rib_update_threads[i])) {
+			struct rib_update_ctx *ctx;
+
+			ctx = THREAD_ARG(t_rib_update_threads[i]);
+
+			rib_update_ctx_fini(&ctx);
+			THREAD_OFF(t_rib_update_threads[i]);
+		}
+	}
+}
+
 /* Schedule a RIB update event for all vrfs */
 void rib_update(enum rib_update_event event)
 {
@@ -4401,6 +4417,9 @@ void rib_update(enum rib_update_event event)
 	if (thread_is_scheduled(t_rib_update_threads[event]))
 		return;
 
+	if (zebra_router_in_shutdown())
+		return;
+
 	ctx = rib_update_ctx_init(0, event);
 
 	thread_add_event(zrouter.master, rib_update_handler, ctx, 0,