Merge pull request #11594 from louis-6wind/lfa-netlink

isisd: apply fast-reroute as soon an interface or an adjacency falls down

11 files changed, 229 insertions, 31 deletions

diff --git a/isisd/isis_adjacency.c b/isisd/isis_adjacency.c
index 00763135e6..0957c897e6 100644
--- a/isisd/isis_adjacency.c
+++ b/isisd/isis_adjacency.c
@@ -212,6 +212,36 @@ static const char *adj_level2string(int level)
 	return NULL; /* not reached */
 }
 
+static void isis_adj_route_switchover(struct isis_adjacency *adj)
+{
+	union g_addr ip = {};
+	ifindex_t ifindex;
+	unsigned int i;
+
+	if (!adj->circuit || !adj->circuit->interface)
+		return;
+
+	ifindex = adj->circuit->interface->ifindex;
+
+	for (i = 0; i < adj->ipv4_address_count; i++) {
+		ip.ipv4 = adj->ipv4_addresses[i];
+		isis_circuit_switchover_routes(adj->circuit, AF_INET, &ip,
+					       ifindex);
+	}
+
+	for (i = 0; i < adj->ll_ipv6_count; i++) {
+		ip.ipv6 = adj->ll_ipv6_addrs[i];
+		isis_circuit_switchover_routes(adj->circuit, AF_INET6, &ip,
+					       ifindex);
+	}
+
+	for (i = 0; i < adj->global_ipv6_count; i++) {
+		ip.ipv6 = adj->global_ipv6_addrs[i];
+		isis_circuit_switchover_routes(adj->circuit, AF_INET6, &ip,
+					       ifindex);
+	}
+}
+
 void isis_adj_process_threeway(struct isis_adjacency *adj,
 			       struct isis_threeway_adj *tw_adj,
 			       enum isis_adj_usage adj_usage)
@@ -298,6 +328,16 @@ void isis_adj_state_change(struct isis_adjacency **padj,
 	if (new_state == old_state)
 		return;
 
+	if (old_state == ISIS_ADJ_UP &&
+	    !CHECK_FLAG(adj->circuit->flags, ISIS_CIRCUIT_IF_DOWN_FROM_Z)) {
+		if (IS_DEBUG_EVENTS)
+			zlog_debug(
+				"ISIS-Adj (%s): Starting fast-reroute on state change %d->%d: %s",
+				circuit->area->area_tag, old_state, new_state,
+				reason ? reason : "unspecified");
+		isis_adj_route_switchover(adj);
+	}
+
 	adj->adj_state = new_state;
 	send_hello_sched(circuit, adj->level, TRIGGERED_IIH_DELAY);
 
diff --git a/isisd/isis_adjacency.h b/isisd/isis_adjacency.h
index 7467a619cb..49adc89ae5 100644
--- a/isisd/isis_adjacency.h
+++ b/isisd/isis_adjacency.h
@@ -151,5 +151,4 @@ void isis_adj_build_up_list(struct list *adjdb, struct list *list);
 int isis_adj_usage2levels(enum isis_adj_usage usage);
 void isis_bfd_startup_timer(struct thread *thread);
 const char *isis_adj_name(const struct isis_adjacency *adj);
-
 #endif /* ISIS_ADJACENCY_H */
diff --git a/isisd/isis_circuit.c b/isisd/isis_circuit.c
index dcc4ed6e42..fa0f2c998f 100644
--- a/isisd/isis_circuit.c
+++ b/isisd/isis_circuit.c
@@ -598,6 +598,32 @@ size_t isis_circuit_pdu_size(struct isis_circuit *circuit)
 	return ISO_MTU(circuit);
 }
 
+static bool isis_circuit_lfa_enabled(struct isis_circuit *circuit, int level)
+{
+	return (circuit->lfa_protection[level - 1] ||
+		circuit->rlfa_protection[level - 1] ||
+		circuit->tilfa_protection[level - 1]);
+}
+
+void isis_circuit_switchover_routes(struct isis_circuit *circuit, int family,
+				    union g_addr *nexthop_ip, ifindex_t ifindex)
+{
+	char is_type;
+
+	if (!circuit->area)
+		return;
+
+	is_type = circuit->area->is_type;
+	if ((is_type == IS_LEVEL_1 || is_type == IS_LEVEL_1_AND_2) &&
+	    isis_circuit_lfa_enabled(circuit, IS_LEVEL_1))
+		isis_area_switchover_routes(circuit->area, family, nexthop_ip,
+					    ifindex, IS_LEVEL_1);
+	if ((is_type == IS_LEVEL_2 || is_type == IS_LEVEL_1_AND_2) &&
+	    isis_circuit_lfa_enabled(circuit, IS_LEVEL_2))
+		isis_area_switchover_routes(circuit->area, family, nexthop_ip,
+					    ifindex, IS_LEVEL_2);
+}
+
 void isis_circuit_stream(struct isis_circuit *circuit, struct stream **stream)
 {
 	size_t stream_size = isis_circuit_pdu_size(circuit);
@@ -1602,17 +1628,26 @@ static int isis_ifp_up(struct interface *ifp)
 {
 	struct isis_circuit *circuit = ifp->info;
 
-	if (circuit)
+	if (circuit) {
+		UNSET_FLAG(circuit->flags, ISIS_CIRCUIT_IF_DOWN_FROM_Z);
 		isis_csm_state_change(IF_UP_FROM_Z, circuit, ifp);
+	}
 
 	return 0;
 }
 
 static int isis_ifp_down(struct interface *ifp)
 {
+	afi_t afi;
 	struct isis_circuit *circuit = ifp->info;
 
-	if (circuit) {
+	if (circuit &&
+	    !CHECK_FLAG(circuit->flags, ISIS_CIRCUIT_IF_DOWN_FROM_Z)) {
+		SET_FLAG(circuit->flags, ISIS_CIRCUIT_IF_DOWN_FROM_Z);
+		for (afi = AFI_IP; afi <= AFI_IP6; afi++)
+			isis_circuit_switchover_routes(
+				circuit, afi == AFI_IP ? AF_INET : AF_INET6,
+				NULL, ifp->ifindex);
 		isis_csm_state_change(IF_DOWN_FROM_Z, circuit, ifp);
 
 		SET_FLAG(circuit->flags, ISIS_CIRCUIT_FLAPPED_AFTER_SPF);
diff --git a/isisd/isis_circuit.h b/isisd/isis_circuit.h
index 5ff0390c26..b3ad3f7ffe 100644
--- a/isisd/isis_circuit.h
+++ b/isisd/isis_circuit.h
@@ -28,6 +28,7 @@
 #include "qobj.h"
 #include "prefix.h"
 #include "ferr.h"
+#include "nexthop.h"
 
 #include "isis_constants.h"
 #include "isis_common.h"
@@ -141,6 +142,7 @@ struct isis_circuit {
 	struct list *ipv6_non_link; /* our non-link local IPv6 addresses */
 	uint16_t upadjcount[ISIS_LEVELS];
 #define ISIS_CIRCUIT_FLAPPED_AFTER_SPF 0x01
+#define ISIS_CIRCUIT_IF_DOWN_FROM_Z 0x02
 	uint8_t flags;
 	bool disable_threeway_adj;
 	struct {
@@ -209,6 +211,9 @@ void isis_circuit_print_vty(struct isis_circuit *circuit, struct vty *vty,
 void isis_circuit_print_json(struct isis_circuit *circuit,
 			     struct json_object *json, char detail);
 size_t isis_circuit_pdu_size(struct isis_circuit *circuit);
+void isis_circuit_switchover_routes(struct isis_circuit *circuit, int family,
+				    union g_addr *nexthop_ip,
+				    ifindex_t ifindex);
 void isis_circuit_stream(struct isis_circuit *circuit, struct stream **stream);
 
 void isis_circuit_af_set(struct isis_circuit *circuit, bool ip_router,
diff --git a/isisd/isis_lfa.c b/isisd/isis_lfa.c
index c4fadcba03..2ec6dafd3f 100644
--- a/isisd/isis_lfa.c
+++ b/isisd/isis_lfa.c
@@ -1836,7 +1836,7 @@ static bool clfa_loop_free_check(struct isis_spftree *spftree,
 				 struct isis_vertex *vertex_S_D,
 				 struct isis_spf_adj *sadj_primary,
 				 struct isis_spf_adj *sadj_N,
-				 uint32_t *lfa_metric)
+				 uint32_t *path_metric)
 {
 	struct isis_spf_node *node_N;
 	uint32_t dist_N_D;
@@ -1882,7 +1882,7 @@ static bool clfa_loop_free_check(struct isis_spftree *spftree,
 			   dist_N_S, dist_S_D);
 
 	if (dist_N_D < (dist_N_S + dist_S_D)) {
-		*lfa_metric = sadj_N->metric + dist_N_D;
+		*path_metric = sadj_N->metric + dist_N_D;
 		return true;
 	}
 
@@ -2082,7 +2082,7 @@ void isis_lfa_compute(struct isis_area *area, struct isis_circuit *circuit,
 		      struct isis_spftree *spftree,
 		      struct lfa_protected_resource *resource)
 {
-	struct isis_vertex *vertex;
+	struct isis_vertex *vertex, *parent_vertex;
 	struct listnode *vnode, *snode;
 	int level = spftree->level;
 
@@ -2099,7 +2099,7 @@ void isis_lfa_compute(struct isis_area *area, struct isis_circuit *circuit,
 		struct isis_vertex_adj *vadj_primary;
 		struct isis_spf_adj *sadj_primary;
 		bool allow_ecmp;
-		uint32_t best_metric = UINT32_MAX;
+		uint32_t prefix_metric, best_metric = UINT32_MAX;
 		char buf[VID2STR_BUFFER];
 
 		if (!VTYPE_IP(vertex->type))
@@ -2133,6 +2133,9 @@ void isis_lfa_compute(struct isis_area *area, struct isis_circuit *circuit,
 		vadj_primary = listnode_head(vertex->Adj_N);
 		sadj_primary = vadj_primary->sadj;
 
+		parent_vertex = listnode_head(vertex->parents);
+		prefix_metric = vertex->d_N - parent_vertex->d_N;
+
 		/*
 		 * Loop over list of SPF adjacencies and compute a list of
 		 * preliminary LFAs.
@@ -2140,7 +2143,7 @@ void isis_lfa_compute(struct isis_area *area, struct isis_circuit *circuit,
 		lfa_list = list_new();
 		lfa_list->del = isis_vertex_adj_free;
 		for (ALL_LIST_ELEMENTS_RO(spftree->sadj_list, snode, sadj_N)) {
-			uint32_t lfa_metric;
+			uint32_t lfa_metric, path_metric;
 			struct isis_vertex_adj *lfa;
 			struct isis_prefix_sid *psid = NULL;
 			bool last_hop = false;
@@ -2190,7 +2193,7 @@ void isis_lfa_compute(struct isis_area *area, struct isis_circuit *circuit,
 
 			/* Check loop-free criterion. */
 			if (!clfa_loop_free_check(spftree, vertex, sadj_primary,
-						  sadj_N, &lfa_metric)) {
+						  sadj_N, &path_metric)) {
 				if (IS_DEBUG_LFA)
 					zlog_debug(
 						"ISIS-LFA: LFA condition not met for %s",
@@ -2198,6 +2201,7 @@ void isis_lfa_compute(struct isis_area *area, struct isis_circuit *circuit,
 				continue;
 			}
 
+			lfa_metric = path_metric + prefix_metric;
 			if (lfa_metric < best_metric)
 				best_metric = lfa_metric;
 
@@ -2208,7 +2212,7 @@ void isis_lfa_compute(struct isis_area *area, struct isis_circuit *circuit,
 
 			if (vertex->N.ip.sr.present) {
 				psid = &vertex->N.ip.sr.sid;
-				if (lfa_metric == sadj_N->metric)
+				if (path_metric == sadj_N->metric)
 					last_hop = true;
 			}
 			lfa = isis_vertex_adj_add(spftree, vertex, lfa_list,
diff --git a/isisd/isis_route.c b/isisd/isis_route.c
index 9f8f639e5d..4fdb11b211 100644
--- a/isisd/isis_route.c
+++ b/isisd/isis_route.c
@@ -91,11 +91,18 @@ static struct isis_nexthop *nexthoplookup(struct list *nexthops, int family,
 	struct isis_nexthop *nh;
 
 	for (ALL_LIST_ELEMENTS_RO(nexthops, node, nh)) {
-		if (nh->family != family)
-			continue;
 		if (nh->ifindex != ifindex)
 			continue;
 
+		/* if the IP is unspecified, return the first nexthop found on
+		 * the interface
+		 */
+		if (!ip)
+			return nh;
+
+		if (nh->family != family)
+			continue;
+
 		switch (family) {
 		case AF_INET:
 			if (IPV4_ADDR_CMP(&nh->ip.ipv4, &ip->ipv4))
@@ -459,6 +466,21 @@ void isis_route_delete(struct isis_area *area, struct route_node *rode,
 	route_unlock_node(rode);
 }
 
+static void isis_route_remove_previous_sid(struct isis_area *area,
+					   struct prefix *prefix,
+					   struct isis_route_info *route_info)
+{
+	/*
+	 * Explicitly uninstall previous Prefix-SID label if it has
+	 * changed or was removed.
+	 */
+	if (route_info->sr_previous.present &&
+	    (!route_info->sr.present ||
+	     route_info->sr_previous.label != route_info->sr.label))
+		isis_zebra_prefix_sid_uninstall(area, prefix, route_info,
+						&route_info->sr_previous);
+}
+
 static void isis_route_update(struct isis_area *area, struct prefix *prefix,
 			      struct prefix_ipv6 *src_p,
 			      struct isis_route_info *route_info)
@@ -467,21 +489,12 @@ static void isis_route_update(struct isis_area *area, struct prefix *prefix,
 		if (CHECK_FLAG(route_info->flag, ISIS_ROUTE_FLAG_ZEBRA_SYNCED))
 			return;
 
-		/*
-		 * Explicitly uninstall previous Prefix-SID label if it has
-		 * changed or was removed.
-		 */
-		if (route_info->sr_previous.present
-		    && (!route_info->sr.present
-			|| route_info->sr_previous.label
-				   != route_info->sr.label))
-			isis_zebra_prefix_sid_uninstall(
-				area, prefix, route_info,
-				&route_info->sr_previous);
+		isis_route_remove_previous_sid(area, prefix, route_info);
 
 		/* Install route. */
-		isis_zebra_route_add_route(area->isis, prefix, src_p,
-					   route_info);
+		if (area)
+			isis_zebra_route_add_route(area->isis, prefix, src_p,
+						   route_info);
 		/* Install/reinstall Prefix-SID label. */
 		if (route_info->sr.present)
 			isis_zebra_prefix_sid_install(area, prefix, route_info,
@@ -496,8 +509,9 @@ static void isis_route_update(struct isis_area *area, struct prefix *prefix,
 			isis_zebra_prefix_sid_uninstall(
 				area, prefix, route_info, &route_info->sr);
 		/* Uninstall route. */
-		isis_zebra_route_del_route(area->isis, prefix, src_p,
-					   route_info);
+		if (area)
+			isis_zebra_route_del_route(area->isis, prefix, src_p,
+						   route_info);
 		hook_call(isis_route_update_hook, area, prefix, route_info);
 
 		UNSET_FLAG(route_info->flag, ISIS_ROUTE_FLAG_ZEBRA_SYNCED);
@@ -724,3 +738,54 @@ void isis_route_invalidate_table(struct isis_area *area,
 		UNSET_FLAG(rinfo->flag, ISIS_ROUTE_FLAG_ACTIVE);
 	}
 }
+
+void isis_route_switchover_nexthop(struct isis_area *area,
+				   struct route_table *table, int family,
+				   union g_addr *nexthop_addr,
+				   ifindex_t ifindex)
+{
+	const char *ifname = NULL, *vrfname = NULL;
+	struct isis_route_info *rinfo;
+	struct prefix_ipv6 *src_p;
+	struct route_node *rnode;
+	vrf_id_t vrf_id;
+	struct prefix *prefix;
+
+	if (IS_DEBUG_EVENTS) {
+		if (area && area->isis) {
+			vrf_id = area->isis->vrf_id;
+			vrfname = vrf_id_to_name(vrf_id);
+			ifname = ifindex2ifname(ifindex, vrf_id);
+		}
+		zlog_debug("%s: initiating fast-reroute %s on VRF %s iface %s",
+			   __func__, family2str(family), vrfname ? vrfname : "",
+			   ifname ? ifname : "");
+	}
+
+	for (rnode = route_top(table); rnode;
+	     rnode = srcdest_route_next(rnode)) {
+		if (!rnode->info)
+			continue;
+		rinfo = rnode->info;
+
+		if (!rinfo->backup)
+			continue;
+
+		if (!nexthoplookup(rinfo->nexthops, family, nexthop_addr,
+				   ifindex))
+			continue;
+
+		srcdest_rnode_prefixes(rnode, (const struct prefix **)&prefix,
+				       (const struct prefix **)&src_p);
+
+		/* Switchover route. */
+		isis_route_remove_previous_sid(area, prefix, rinfo);
+		UNSET_FLAG(rinfo->flag, ISIS_ROUTE_FLAG_ZEBRA_SYNCED);
+		isis_route_update(area, prefix, src_p, rinfo->backup);
+
+		isis_route_info_delete(rinfo);
+
+		rnode->info = NULL;
+		route_unlock_node(rnode);
+	}
+}
diff --git a/isisd/isis_route.h b/isisd/isis_route.h
index 0e206d08f4..a0e0500aec 100644
--- a/isisd/isis_route.h
+++ b/isisd/isis_route.h
@@ -86,4 +86,9 @@ void isis_route_invalidate_table(struct isis_area *area,
 void isis_route_node_cleanup(struct route_table *table,
 			     struct route_node *node);
 
+void isis_route_switchover_nexthop(struct isis_area *area,
+				   struct route_table *table, int family,
+				   union g_addr *nexthop_addr,
+				   ifindex_t ifindex);
+
 #endif /* _ZEBRA_ISIS_ROUTE_H */
diff --git a/isisd/isis_spf.c b/isisd/isis_spf.c
index bdd323e1a7..0d1a5db0d6 100644
--- a/isisd/isis_spf.c
+++ b/isisd/isis_spf.c
@@ -1851,6 +1851,15 @@ void isis_spf_invalidate_routes(struct isis_spftree *tree)
 	tree->route_table_backup->cleanup = isis_route_node_cleanup;
 }
 
+void isis_spf_switchover_routes(struct isis_area *area,
+				struct isis_spftree **trees, int family,
+				union g_addr *nexthop_ip, ifindex_t ifindex,
+				int level)
+{
+	isis_route_switchover_nexthop(area, trees[level - 1]->route_table,
+				      family, nexthop_ip, ifindex);
+}
+
 static void isis_run_spf_cb(struct thread *thread)
 {
 	struct isis_spf_run *run = THREAD_ARG(thread);
@@ -1922,9 +1931,19 @@ void isis_spf_timer_free(void *run)
 int _isis_spf_schedule(struct isis_area *area, int level,
 		       const char *func, const char *file, int line)
 {
-	struct isis_spftree *spftree = area->spftree[SPFTREE_IPV4][level - 1];
-	time_t now = monotime(NULL);
-	int diff = now - spftree->last_run_monotime;
+	struct isis_spftree *spftree;
+	time_t now;
+	long tree_diff, diff;
+	int tree;
+
+	now = monotime(NULL);
+	diff = 0;
+	for (tree = SPFTREE_IPV4; tree < SPFTREE_COUNT; tree++) {
+		spftree = area->spftree[tree][level - 1];
+		tree_diff = difftime(now - spftree->last_run_monotime, 0);
+		if (tree_diff != now && (diff == 0 || tree_diff < diff))
+			diff = tree_diff;
+	}
 
 	if (CHECK_FLAG(im->options, F_ISIS_UNIT_TEST))
 		return 0;
@@ -1934,7 +1953,7 @@ int _isis_spf_schedule(struct isis_area *area, int level,
 
 	if (IS_DEBUG_SPF_EVENTS) {
 		zlog_debug(
-			"ISIS-SPF (%s) L%d SPF schedule called, lastrun %d sec ago Caller: %s %s:%d",
+			"ISIS-SPF (%s) L%d SPF schedule called, lastrun %ld sec ago Caller: %s %s:%d",
 			area->area_tag, level, diff, func, file, line);
 	}
 
diff --git a/isisd/isis_spf.h b/isisd/isis_spf.h
index 815db7b226..3fa5182baf 100644
--- a/isisd/isis_spf.h
+++ b/isisd/isis_spf.h
@@ -60,6 +60,10 @@ struct isis_vertex *isis_spf_prefix_sid_lookup(struct isis_spftree *spftree,
 void isis_spf_invalidate_routes(struct isis_spftree *tree);
 void isis_spf_verify_routes(struct isis_area *area,
 			    struct isis_spftree **trees);
+void isis_spf_switchover_routes(struct isis_area *area,
+				struct isis_spftree **trees, int family,
+				union g_addr *nexthop_ip, ifindex_t ifindex,
+				int level);
 void isis_spftree_del(struct isis_spftree *spftree);
 void spftree_area_init(struct isis_area *area);
 void spftree_area_del(struct isis_area *area);
diff --git a/isisd/isisd.c b/isisd/isisd.c
index 17f4b20737..cd08525471 100644
--- a/isisd/isisd.c
+++ b/isisd/isisd.c
@@ -3090,6 +3090,25 @@ void isis_area_verify_routes(struct isis_area *area)
 		isis_spf_verify_routes(area, area->spftree[tree]);
 }
 
+void isis_area_switchover_routes(struct isis_area *area, int family,
+				 union g_addr *nexthop_ip, ifindex_t ifindex,
+				 int level)
+{
+	int tree;
+
+	/* TODO SPFTREE_DSTSRC */
+	if (family == AF_INET)
+		tree = SPFTREE_IPV4;
+	else if (family == AF_INET6)
+		tree = SPFTREE_IPV6;
+	else
+		return;
+
+	isis_spf_switchover_routes(area, area->spftree[tree], family,
+				   nexthop_ip, ifindex, level);
+}
+
+
 static void area_resign_level(struct isis_area *area, int level)
 {
 	isis_area_invalidate_routes(area, level);
diff --git a/isisd/isisd.h b/isisd/isisd.h
index a9c1d60439..38f20b2113 100644
--- a/isisd/isisd.h
+++ b/isisd/isisd.h
@@ -291,6 +291,9 @@ struct isis_lsp *lsp_for_sysid(struct lspdb_head *head, const char *sysid_str,
 
 void isis_area_invalidate_routes(struct isis_area *area, int levels);
 void isis_area_verify_routes(struct isis_area *area);
+void isis_area_switchover_routes(struct isis_area *area, int family,
+				 union g_addr *nexthop_ip, ifindex_t ifindex,
+				 int level);
 
 void isis_area_overload_bit_set(struct isis_area *area, bool overload_bit);
 void isis_area_overload_on_startup_set(struct isis_area *area,