[FRR]: Patch for kernel level graceful restart.

src/sonic-frr/patch/0008-zebra-kernel-level-graceful-restart.patch

@@ -0,0 +1,227 @@
+
+ zebra: Add kernel level graceful restart
+
+ <Initial Code from Praveen Chaudhary>
+
+ Add the a `--graceful_restart X` flag to zebra start that
+ now creates a timer that pops in X seconds and will go
+ through and remove all routes that are older than startup.
+
+ If graceful_restart is not specified then we will just pop
+ a timer that cleans everything up immediately.
+
+ Signed-off-by: Praveen Chaudhary <[email protected]>
+ Signed-off-by: Donald Sharp <[email protected]>
+
+diff --git a/doc/user/zebra.rst b/doc/user/zebra.rst
+index f38db9d24..40d894929 100644
+--- a/doc/user/zebra.rst
++++ b/doc/user/zebra.rst
+@@ -23,9 +23,12 @@ Besides the common invocation options (:ref:`common-invocation-options`), the
+    Runs in batch mode. *zebra* parses configuration file and terminates
+    immediately.
+
+-.. option:: -k, --keep_kernel
++.. option:: -K TIME, --graceful_restart TIME
+
+-   When zebra starts up, don't delete old self inserted routes.
++   If this option is specified, the graceful restart time is TIME seconds.
++   Zebra, when started, will read in routes.  Those routes that Zebra
++   identifies that it was the originator of will be swept in TIME seconds.
++   If no time is specified then we will sweep those routes immediately.
+
+ .. option:: -r, --retain
+
+diff --git a/zebra/main.c b/zebra/main.c
+index 184e798bd..3d1d156ad 100644
+--- a/zebra/main.c
++++ b/zebra/main.c
+@@ -74,8 +74,7 @@ int retain_mode = 0;
+ /* Allow non-quagga entities to delete quagga routes */
+ int allow_delete = 0;
+
+-/* Don't delete kernel route. */
+-int keep_kernel_mode = 0;
++int graceful_restart;
+
+ bool v6_rr_semantics = false;
+
+@@ -89,12 +88,12 @@ uint32_t nl_rcvbufsize = 4194304;
+ struct option longopts[] = {
+ 	{"batch", no_argument, NULL, 'b'},
+ 	{"allow_delete", no_argument, NULL, 'a'},
+-	{"keep_kernel", no_argument, NULL, 'k'},
+ 	{"socket", required_argument, NULL, 'z'},
+ 	{"ecmp", required_argument, NULL, 'e'},
+ 	{"label_socket", no_argument, NULL, 'l'},
+ 	{"retain", no_argument, NULL, 'r'},
+ 	{"vrfdefaultname", required_argument, NULL, 'o'},
++	{"graceful_restart", required_argument, NULL, 'K'},
+ #ifdef HAVE_NETLINK
+ 	{"vrfwnetns", no_argument, NULL, 'n'},
+ 	{"nl-bufsize", required_argument, NULL, 's'},
+@@ -264,13 +263,14 @@ int main(int argc, char **argv)
+ 	char *netlink_fuzzing = NULL;
+ #endif /* HANDLE_NETLINK_FUZZING */
+
++	graceful_restart = 0;
+ 	vrf_configure_backend(VRF_BACKEND_VRF_LITE);
+ 	logicalrouter_configure_backend(LOGICALROUTER_BACKEND_NETNS);
+
+ 	frr_preinit(&zebra_di, argc, argv);
+
+ 	frr_opt_add(
+-		"bakz:e:l:o:r"
++		"baz:e:l:o:rK:"
+ #ifdef HAVE_NETLINK
+ 		"s:n"
+ #endif
+@@ -282,24 +282,24 @@ int main(int argc, char **argv)
+ #endif /* HANDLE_NETLINK_FUZZING */
+ 		,
+ 		longopts,
+-		"  -b, --batch           Runs in batch mode\n"
+-		"  -a, --allow_delete    Allow other processes to delete zebra routes\n"
+-		"  -z, --socket          Set path of zebra socket\n"
+-		"  -e, --ecmp            Specify ECMP to use.\n"
+-		"  -l, --label_socket    Socket to external label manager\n"
+-		"  -k, --keep_kernel     Don't delete old routes which were installed by zebra.\n"
+-		"  -r, --retain          When program terminates, retain added route by zebra.\n"
+-		"  -o, --vrfdefaultname  Set default VRF name.\n"
++		"  -b, --batch              Runs in batch mode\n"
++		"  -a, --allow_delete       Allow other processes to delete zebra routes\n"
++		"  -z, --socket             Set path of zebra socket\n"
++		"  -e, --ecmp               Specify ECMP to use.\n"
++		"  -l, --label_socket       Socket to external label manager\n"
++		"  -r, --retain             When program terminates, retain added route by zebra.\n"
++		"  -o, --vrfdefaultname     Set default VRF name.\n"
++		"  -K, --graceful_restart   Graceful restart at the kernel level, timer in seconds for expiration\n"
+ #ifdef HAVE_NETLINK
+-		"  -n, --vrfwnetns       Use NetNS as VRF backend\n"
+-		"  -s, --nl-bufsize      Set netlink receive buffer size\n"
+-		"      --v6-rr-semantics Use v6 RR semantics\n"
++		"  -n, --vrfwnetns          Use NetNS as VRF backend\n"
++		"  -s, --nl-bufsize         Set netlink receive buffer size\n"
++		"      --v6-rr-semantics    Use v6 RR semantics\n"
+ #endif /* HAVE_NETLINK */
+ #if defined(HANDLE_ZAPI_FUZZING)
+-		"  -c <file>             Bypass normal startup and use this file for testing of zapi\n"
++		"  -c <file>                Bypass normal startup and use this file for testing of zapi\n"
+ #endif /* HANDLE_ZAPI_FUZZING */
+ #if defined(HANDLE_NETLINK_FUZZING)
+-		"  -w <file>             Bypass normal startup and use this file for testing of netlink input\n"
++		"  -w <file>                Bypass normal startup and use this file for testing of netlink input\n"
+ #endif /* HANDLE_NETLINK_FUZZING */
+ 	);
+
+@@ -318,9 +318,6 @@ int main(int argc, char **argv)
+ 		case 'a':
+ 			allow_delete = 1;
+ 			break;
+-		case 'k':
+-			keep_kernel_mode = 1;
+-			break;
+ 		case 'e':
+ 			multipath_num = atoi(optarg);
+ 			if (multipath_num > MULTIPATH_NUM
+@@ -350,6 +347,9 @@ int main(int argc, char **argv)
+ 		case 'r':
+ 			retain_mode = 1;
+ 			break;
++		case 'K':
++			graceful_restart = atoi(optarg);
++			break;
+ #ifdef HAVE_NETLINK
+ 		case 's':
+ 			nl_rcvbufsize = atoi(optarg);
+@@ -437,9 +437,9 @@ int main(int argc, char **argv)
+ 	*  will be equal to the current getpid(). To know about such routes,
+ 	* we have to have route_read() called before.
+ 	*/
+-	if (!keep_kernel_mode)
+-		rib_sweep_route();
+-
++	zrouter.startup_time = monotime(NULL);
++	thread_add_timer(zrouter.master, rib_sweep_route,
++			NULL, graceful_restart, NULL);
+ 	/* Needed for BSD routing socket. */
+ 	pid = getpid();
+
+diff --git a/zebra/rib.h b/zebra/rib.h
+index 9fe42aef3..69850f3a0 100644
+--- a/zebra/rib.h
++++ b/zebra/rib.h
+@@ -351,7 +351,7 @@ extern struct route_entry *rib_lookup_ipv4(struct prefix_ipv4 *p,
+ extern void rib_update(vrf_id_t vrf_id, rib_update_event_t event);
+ extern void rib_update_table(struct route_table *table,
+ 			     rib_update_event_t event);
+-extern void rib_sweep_route(void);
++extern int  rib_sweep_route(struct thread *t);
+ extern void rib_sweep_table(struct route_table *table);
+ extern void rib_close_table(struct route_table *table);
+ extern void rib_init(void);
+diff --git a/zebra/zebra_rib.c b/zebra/zebra_rib.c
+index 555127b09..b6afcdc8c 100644
+--- a/zebra/zebra_rib.c
++++ b/zebra/zebra_rib.c
+@@ -3145,6 +3145,7 @@ void rib_sweep_table(struct route_table *table)
+
+ 	for (rn = route_top(table); rn; rn = srcdest_route_next(rn)) {
+ 		RNODE_FOREACH_RE_SAFE (rn, re, next) {
++
+ 			if (IS_ZEBRA_DEBUG_RIB)
+ 				route_entry_dump(&rn->p, NULL, re);
+
+@@ -3154,6 +3155,14 @@ void rib_sweep_table(struct route_table *table)
+ 			if (!CHECK_FLAG(re->flags, ZEBRA_FLAG_SELFROUTE))
+ 				continue;
+
++			/*
++			 * If routes are older than startup_time then
++			 * we know we read them in from the kernel.
++			 * As such we can safely remove them.
++			 */
++			if (zrouter.startup_time < re->uptime)
++				continue;
++
+ 			/*
+ 			 * So we are starting up and have received
+ 			 * routes from the kernel that we have installed
+@@ -3183,7 +3192,7 @@ void rib_sweep_table(struct route_table *table)
+ }
+
+ /* Sweep all RIB tables.  */
+-void rib_sweep_route(void)
++int rib_sweep_route(struct thread *t)
+ {
+ 	struct vrf *vrf;
+ 	struct zebra_vrf *zvrf;
+@@ -3197,6 +3206,8 @@ void rib_sweep_route(void)
+ 	}
+
+ 	zebra_router_sweep_route();
++
++	return 0;
+ }
+
+ /* Remove specific by protocol routes from 'table'. */
+diff --git a/zebra/zebra_router.h b/zebra/zebra_router.h
+index b316b91d0..b2e92bad0 100644
+--- a/zebra/zebra_router.h
++++ b/zebra/zebra_router.h
+@@ -110,8 +110,15 @@ struct zebra_router {
+ 	 * The EVPN instance, if any
+ 	 */
+ 	struct zebra_vrf *evpn_vrf;
++
++	/*
++	 * Time for when we sweep the rib from old routes
++	 */
++	time_t startup_time;
+ };
+
++#define GRACEFUL_RESTART_TIME 60
++
+ extern struct zebra_router zrouter;
+
+ extern void zebra_router_init(void);

src/sonic-frr/patch/series

@@ -4,3 +4,4 @@
 0005-Support-VRF.patch
 0006-changes-for-making-snmp-socket-non-blocking.patch
 0007-prevent-dead-fd-poll-data-port-fix-from-frr.patch
+0008-zebra-kernel-level-graceful-restart.patch