Merge pull request FRRouting#9585 from opensourcerouting/ospf6d-nssa-…

…dflt-originate

ospf6d: add a knob to generate Type-7 default routes

doc/user/ospf6d.rst

@@ -178,7 +178,7 @@ OSPF6 area
 
 .. clicmd:: area A.B.C.D nssa [no-summary]
 
-.. clicmd:: area (0-4294967295) nssa [no-summary]
+.. clicmd:: area (0-4294967295) nssa [no-summary] [default-information-originate [metric-type (1-2)] [metric (0-16777214)]]
 
    Configure the area to be a NSSA (Not-So-Stubby Area).
 
@@ -198,6 +198,12 @@ OSPF6 area
    advertisement of summaries into the area. In that case, a single Type-3 LSA
    containing a default route is originated into the NSSA.
 
+   NSSA ABRs and ASBRs can be configured with `default-information-originate`
+   option to originate a Type-7 default route into the NSSA area. In the case
+   of NSSA ASBRs, the origination of the default route is conditioned to the
+   existence of a default route in the RIB that wasn't learned via the OSPF
+   protocol.
+
 .. clicmd:: area A.B.C.D export-list NAME
 
 .. clicmd:: area (0-4294967295) export-list NAME

ospf6d/ospf6_area.c

@@ -43,6 +43,7 @@
 #include "ospf6_intra.h"
 #include "ospf6_abr.h"
 #include "ospf6_asbr.h"
+#include "ospf6_zebra.h"
 #include "ospf6d.h"
 #include "lib/json.h"
 #include "ospf6_nssa.h"
@@ -234,6 +235,36 @@ static void ospf6_area_no_summary_unset(struct ospf6 *ospf6,
 	}
 }
 
+static void ospf6_nssa_default_originate_set(struct ospf6 *ospf6,
+					     struct ospf6_area *area,
+					     int metric, int metric_type)
+{
+	if (!area->nssa_default_originate.enabled) {
+		area->nssa_default_originate.enabled = true;
+		if (++ospf6->nssa_default_import_check.refcnt == 1) {
+			ospf6->nssa_default_import_check.status = false;
+			ospf6_zebra_import_default_route(ospf6, false);
+		}
+	}
+
+	area->nssa_default_originate.metric_value = metric;
+	area->nssa_default_originate.metric_type = metric_type;
+}
+
+static void ospf6_nssa_default_originate_unset(struct ospf6 *ospf6,
+					       struct ospf6_area *area)
+{
+	if (area->nssa_default_originate.enabled) {
+		area->nssa_default_originate.enabled = false;
+		if (--ospf6->nssa_default_import_check.refcnt == 0) {
+			ospf6->nssa_default_import_check.status = false;
+			ospf6_zebra_import_default_route(ospf6, true);
+		}
+		area->nssa_default_originate.metric_value = -1;
+		area->nssa_default_originate.metric_type = -1;
+	}
+}
+
 /**
  * Make new area structure.
  *
@@ -648,6 +679,17 @@ void ospf6_area_config_write(struct vty *vty, struct ospf6 *ospf6)
 		}
 		if (IS_AREA_NSSA(oa)) {
 			vty_out(vty, " area %s nssa", oa->name);
+			if (oa->nssa_default_originate.enabled) {
+				vty_out(vty, " default-information-originate");
+				if (oa->nssa_default_originate.metric_value
+				    != -1)
+					vty_out(vty, " metric %d",
+						oa->nssa_default_originate
+							.metric_value);
+				if (oa->nssa_default_originate.metric_type
+				    != DEFAULT_METRIC_TYPE)
+					vty_out(vty, " metric-type 1");
+			}
 			if (oa->no_summary)
 				vty_out(vty, " no-summary");
 			vty_out(vty, "\n");
@@ -1278,11 +1320,20 @@ DEFUN (no_ospf6_area_stub_no_summary,
 }
 
 DEFPY(ospf6_area_nssa, ospf6_area_nssa_cmd,
-      "area <A.B.C.D|(0-4294967295)>$area_str nssa [no-summary$no_summary]",
+      "area <A.B.C.D|(0-4294967295)>$area_str nssa\
+        [{\
+	  default-information-originate$dflt_originate [{metric (0-16777214)$mval|metric-type (1-2)$mtype}]\
+	  |no-summary$no_summary\
+	 }]",
       "OSPF6 area parameters\n"
       "OSPF6 area ID in IP address format\n"
       "OSPF6 area ID as a decimal value\n"
       "Configure OSPF6 area as nssa\n"
+      "Originate Type 7 default into NSSA area\n"
+      "OSPFv3 default metric\n"
+      "OSPFv3 metric\n"
+      "OSPFv3 metric type for default routes\n"
+      "Set OSPFv3 External Type 1/2 metrics\n"
       "Do not inject inter-area routes into area\n")
 {
 	struct ospf6_area *area;
@@ -1296,23 +1347,44 @@ DEFPY(ospf6_area_nssa, ospf6_area_nssa_cmd,
 		return CMD_WARNING_CONFIG_FAILED;
 	}
 
+	if (dflt_originate) {
+		if (mval_str == NULL)
+			mval = -1;
+		if (mtype_str == NULL)
+			mtype = DEFAULT_METRIC_TYPE;
+		ospf6_nssa_default_originate_set(ospf6, area, mval, mtype);
+	} else
+		ospf6_nssa_default_originate_unset(ospf6, area);
+
 	if (no_summary)
 		ospf6_area_no_summary_set(ospf6, area);
 	else
 		ospf6_area_no_summary_unset(ospf6, area);
-	if (ospf6_check_and_set_router_abr(ospf6))
+
+	if (ospf6_check_and_set_router_abr(ospf6)) {
 		ospf6_abr_defaults_to_stub(ospf6);
+		ospf6_abr_nssa_type_7_defaults(ospf6);
+	}
 
 	return CMD_SUCCESS;
 }
 
 DEFPY(no_ospf6_area_nssa, no_ospf6_area_nssa_cmd,
-      "no area <A.B.C.D|(0-4294967295)>$area_str nssa [no-summary$no_summary]",
+      "no area <A.B.C.D|(0-4294967295)>$area_str nssa\
+        [{\
+	  default-information-originate [{metric (0-16777214)|metric-type (1-2)}]\
+	  |no-summary\
+	 }]",
       NO_STR
       "OSPF6 area parameters\n"
       "OSPF6 area ID in IP address format\n"
       "OSPF6 area ID as a decimal value\n"
       "Configure OSPF6 area as nssa\n"
+      "Originate Type 7 default into NSSA area\n"
+      "OSPFv3 default metric\n"
+      "OSPFv3 metric\n"
+      "OSPFv3 metric type for default routes\n"
+      "Set OSPFv3 External Type 1/2 metrics\n"
       "Do not inject inter-area routes into area\n")
 {
 	struct ospf6_area *area;
@@ -1322,6 +1394,7 @@ DEFPY(no_ospf6_area_nssa, no_ospf6_area_nssa_cmd,
 
 	ospf6_area_nssa_unset(ospf6, area);
 	ospf6_area_no_summary_unset(ospf6, area);
+	ospf6_nssa_default_originate_unset(ospf6, area);
 
 	return CMD_SUCCESS;
 }

ospf6d/ospf6_area.h

@@ -52,6 +52,13 @@ struct ospf6_area {
 	/* Area type */
 	int no_summary;
 
+	/* NSSA default-information-originate */
+	struct {
+		bool enabled;
+		int metric_type;
+		int metric_value;
+	} nssa_default_originate;
+
 	/* Brouter traversal protection */
 	bool intra_brouter_calc;
 

ospf6d/ospf6_asbr.c

@@ -49,6 +49,7 @@
 #include "ospf6_abr.h"
 #include "ospf6_intra.h"
 #include "ospf6_flood.h"
+#include "ospf6_nssa.h"
 #include "ospf6d.h"
 #include "ospf6_spf.h"
 #include "ospf6_nssa.h"
@@ -85,7 +86,7 @@ static struct ospf6_lsa *ospf6_originate_type5_type7_lsas(
 
 	for (ALL_LIST_ELEMENTS_RO(ospf6->area_list, lnode, oa)) {
 		if (IS_AREA_NSSA(oa))
-			ospf6_nssa_lsa_originate(route, oa);
+			ospf6_nssa_lsa_originate(route, oa, true);
 	}
 
 	return lsa;
@@ -1433,7 +1434,10 @@ void ospf6_asbr_redistribute_add(int type, ifindex_t ifindex,
 	memset(&tinfo, 0, sizeof(tinfo));
 
 	if (IS_OSPF6_DEBUG_ASBR)
-		zlog_debug("Redistribute %pFX (%s)", prefix, ZROUTE_NAME(type));
+		zlog_debug("Redistribute %pFX (%s)", prefix,
+			   type == DEFAULT_ROUTE
+				   ? "default-information-originate"
+				   : ZROUTE_NAME(type));
 
 	/* if route-map was specified but not found, do not advertise */
 	if (ROUTEMAP_NAME(red)) {
@@ -1787,7 +1791,7 @@ int ospf6_redistribute_config_write(struct vty *vty, struct ospf6 *ospf6)
 		vty_out(vty, " redistribute %s", ZROUTE_NAME(type));
 		if (red->dmetric.value >= 0)
 			vty_out(vty, " metric %d", red->dmetric.value);
-		if (red->dmetric.type != DEFAULT_METRIC_TYPE)
+		if (red->dmetric.type == 1)
 			vty_out(vty, " metric-type 1");
 		if (ROUTEMAP_NAME(red))
 			vty_out(vty, " route-map %s", ROUTEMAP_NAME(red));

ospf6d/ospf6_nssa.c

@@ -368,6 +368,11 @@ static void ospf6_abr_task(struct ospf6 *ospf6)
 		if (IS_OSPF6_DEBUG_ABR)
 			zlog_debug("%s : announce stub defaults", __func__);
 		ospf6_abr_defaults_to_stub(ospf6);
+
+		if (IS_OSPF6_DEBUG_ABR)
+			zlog_debug("%s : announce NSSA Type-7 defaults",
+				   __func__);
+		ospf6_abr_nssa_type_7_defaults(ospf6);
 	}
 
 	if (IS_OSPF6_DEBUG_ABR)
@@ -872,6 +877,83 @@ static void ospf6_abr_remove_unapproved_translates(struct ospf6 *ospf6)
 		zlog_debug("ospf_abr_remove_unapproved_translates(): Stop");
 }
 
+static void ospf6_abr_nssa_type_7_default_create(struct ospf6 *ospf6,
+						 struct ospf6_area *oa)
+{
+	struct ospf6_route *def;
+	int metric;
+	int metric_type;
+
+	if (IS_OSPF6_DEBUG_NSSA)
+		zlog_debug("Announcing Type-7 default route into NSSA area %s",
+			   oa->name);
+
+	def = ospf6_route_create(ospf6);
+	def->type = OSPF6_DEST_TYPE_NETWORK;
+	def->prefix.family = AF_INET6;
+	def->prefix.prefixlen = 0;
+	memset(&def->prefix.u.prefix6, 0, sizeof(struct in6_addr));
+	def->type = OSPF6_DEST_TYPE_NETWORK;
+	def->path.subtype = OSPF6_PATH_SUBTYPE_DEFAULT_RT;
+	if (CHECK_FLAG(ospf6->flag, OSPF6_FLAG_ABR))
+		def->path.area_id = ospf6->backbone->area_id;
+	else
+		def->path.area_id = oa->area_id;
+
+	/* Compute default route type and metric. */
+	if (oa->nssa_default_originate.metric_value != -1)
+		metric = oa->nssa_default_originate.metric_value;
+	else
+		metric = DEFAULT_DEFAULT_ALWAYS_METRIC;
+	if (oa->nssa_default_originate.metric_type != -1)
+		metric_type = oa->nssa_default_originate.metric_type;
+	else
+		metric_type = DEFAULT_METRIC_TYPE;
+	def->path.metric_type = metric_type;
+	def->path.cost = metric;
+	if (metric_type == 1)
+		def->path.type = OSPF6_PATH_TYPE_EXTERNAL1;
+	else
+		def->path.type = OSPF6_PATH_TYPE_EXTERNAL2;
+
+	ospf6_nssa_lsa_originate(def, oa, false);
+	ospf6_route_delete(def);
+}
+
+static void ospf6_abr_nssa_type_7_default_delete(struct ospf6 *ospf6,
+						 struct ospf6_area *oa)
+{
+	struct ospf6_lsa *lsa;
+
+	lsa = ospf6_lsdb_lookup(htons(OSPF6_LSTYPE_TYPE_7), 0,
+				oa->ospf6->router_id, oa->lsdb);
+	if (lsa && !OSPF6_LSA_IS_MAXAGE(lsa)) {
+		if (IS_OSPF6_DEBUG_NSSA)
+			zlog_debug(
+				"Withdrawing Type-7 default route from area %s",
+				oa->name);
+
+		ospf6_lsa_purge(lsa);
+	}
+}
+
+/* NSSA Type-7 default route. */
+void ospf6_abr_nssa_type_7_defaults(struct ospf6 *ospf6)
+{
+	struct listnode *node;
+	struct ospf6_area *oa;
+
+	for (ALL_LIST_ELEMENTS_RO(ospf6->area_list, node, oa)) {
+		if (IS_AREA_NSSA(oa) && oa->nssa_default_originate.enabled
+		    && (IS_OSPF6_ABR(ospf6)
+			|| (IS_OSPF6_ASBR(ospf6)
+			    && ospf6->nssa_default_import_check.status)))
+			ospf6_abr_nssa_type_7_default_create(ospf6, oa);
+		else
+			ospf6_abr_nssa_type_7_default_delete(ospf6, oa);
+	}
+}
+
 static void ospf6_abr_nssa_task(struct ospf6 *ospf6)
 {
 	/* called only if any_nssa */
@@ -1169,10 +1251,11 @@ static void ospf6_check_and_originate_type7_lsa(struct ospf6_area *area)
 	for (route = ospf6_route_head(
 		     area->ospf6->external_table);
 	     route; route = ospf6_route_next(route)) {
-		/* This means the Type-5 LSA was originated for this route */
-		if (route->path.origin.id != 0)
-			ospf6_nssa_lsa_originate(route, area);
+		struct ospf6_external_info *info = route->route_option;
 
+		/* This means the Type-5 LSA was originated for this route */
+		if (route->path.origin.id != 0 && info->type != DEFAULT_ROUTE)
+			ospf6_nssa_lsa_originate(route, area, true);
 	}
 
 	/* Loop through the aggregation table to originate type-7 LSAs
@@ -1192,7 +1275,7 @@ static void ospf6_check_and_originate_type7_lsa(struct ospf6_area *area)
 					"Originating Type-7 LSAs for area %s",
 					area->name);
 
-			ospf6_nssa_lsa_originate(aggr->route, area);
+			ospf6_nssa_lsa_originate(aggr->route, area, true);
 		}
 	}
 
@@ -1286,7 +1369,7 @@ static struct in6_addr *ospf6_get_nssa_fwd_addr(struct ospf6_area *oa)
 }
 
 void ospf6_nssa_lsa_originate(struct ospf6_route *route,
-			      struct ospf6_area *area)
+			      struct ospf6_area *area, bool p_bit)
 {
 	char buffer[OSPF6_MAX_LSASIZE];
 	struct ospf6_lsa_header *lsa_header;
@@ -1311,13 +1394,13 @@ void ospf6_nssa_lsa_originate(struct ospf6_route *route,
 
 	/* Fill AS-External-LSA */
 	/* Metric type */
-	if (route->path.metric_type == OSPF6_PATH_TYPE_EXTERNAL2)
+	if (route->path.metric_type == 2)
 		SET_FLAG(as_external_lsa->bits_metric, OSPF6_ASBR_BIT_E);
 	else
 		UNSET_FLAG(as_external_lsa->bits_metric, OSPF6_ASBR_BIT_E);
 
 	/* external route tag */
-	if (info->tag)
+	if (info && info->tag)
 		SET_FLAG(as_external_lsa->bits_metric, OSPF6_ASBR_BIT_T);
 	else
 		UNSET_FLAG(as_external_lsa->bits_metric, OSPF6_ASBR_BIT_T);
@@ -1332,7 +1415,8 @@ void ospf6_nssa_lsa_originate(struct ospf6_route *route,
 	as_external_lsa->prefix.prefix_options = route->prefix_options;
 
 	/* Set the P bit */
-	as_external_lsa->prefix.prefix_options |= OSPF6_PREFIX_OPTION_P;
+	if (p_bit)
+		as_external_lsa->prefix.prefix_options |= OSPF6_PREFIX_OPTION_P;
 
 	/* don't use refer LS-type */
 	as_external_lsa->prefix.prefix_refer_lstype = htons(0);
@@ -1353,7 +1437,8 @@ void ospf6_nssa_lsa_originate(struct ospf6_route *route,
 		UNSET_FLAG(as_external_lsa->bits_metric, OSPF6_ASBR_BIT_F);
 
 	/* External Route Tag */
-	if (CHECK_FLAG(as_external_lsa->bits_metric, OSPF6_ASBR_BIT_T)) {
+	if (info
+	    && CHECK_FLAG(as_external_lsa->bits_metric, OSPF6_ASBR_BIT_T)) {
 		route_tag_t network_order = htonl(info->tag);
 
 		memcpy(p, &network_order, sizeof(network_order));

ospf6d/ospf6_nssa.h

@@ -64,8 +64,9 @@ extern void ospf6_schedule_abr_task(struct ospf6 *ospf6);
 extern void ospf6_area_nssa_update(struct ospf6_area *area);
 void ospf6_asbr_prefix_readvertise(struct ospf6 *ospf6);
 extern void ospf6_nssa_lsa_originate(struct ospf6_route *route,
-				     struct ospf6_area *area);
+				     struct ospf6_area *area, bool p_bit);
 extern void install_element_ospf6_debug_nssa(void);
+extern void ospf6_abr_nssa_type_7_defaults(struct ospf6 *osof6);
 int ospf6_redistribute_check(struct ospf6 *ospf6, struct ospf6_route *route,
 			     int type);
 extern int ospf6_abr_translate_nssa(struct ospf6_area *area,