ospf6d: add support for NSSA Type-7 address ranges

Implement NSSA address ranges as specified by RFC 3101:

   NSSA border routers may be configured with Type-7 address ranges.
   Each Type-7 address range is defined as an [address,mask] pair.  Many
   separate Type-7 networks may fall into a single Type-7 address range,
   just as a subnetted network is composed of many separate subnets.
   NSSA border routers may aggregate Type-7 routes by advertising a
   single Type-5 LSA for each Type-7 address range.  The Type-5 LSA
   resulting from a Type-7 address range match will be distributed to
   all Type-5 capable areas.

Syntax:
  area A.B.C.D nssa range X:X::X:X/M [<not-advertise|cost (0-16777215)>]

Example:
  router ospf6
   ospf6 router-id 1.1.1.1
   area 1 nssa
   area 1 nssa range 2001:db8:1000::/64
   area 1 nssa range 2001:db8:2000::/64
  !

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>

7 files changed, 250 insertions, 25 deletions

diff --git a/doc/user/ospf6d.rst b/doc/user/ospf6d.rst
index d823c5d5b5..4e23223596 100644
--- a/doc/user/ospf6d.rst
+++ b/doc/user/ospf6d.rst
@@ -204,6 +204,21 @@ OSPF6 area
    existence of a default route in the RIB that wasn't learned via the OSPF
    protocol.
 
+.. clicmd:: area A.B.C.D nssa range X:X::X:X/M [<not-advertise|cost (0-16777215)>]
+
+.. clicmd:: area (0-4294967295) nssa range X:X::X:X/M [<not-advertise|cost (0-16777215)>]
+
+    Summarize a group of external subnets into a single Type-7 LSA, which is
+    then translated to a Type-5 LSA and avertised to the backbone.
+    This command can only be used at the area boundary (NSSA ABR router).
+
+    By default, the metric of the summary route is calculated as the highest
+    metric among the summarized routes. The `cost` option, however, can be used
+    to set an explicit metric.
+
+    The `not-advertise` option, when present, prevents the summary route from
+    being advertised, effectively filtering the summarized routes.
+
 .. clicmd:: area A.B.C.D export-list NAME
 
 .. clicmd:: area (0-4294967295) export-list NAME
diff --git a/ospf6d/ospf6_abr.c b/ospf6d/ospf6_abr.c
index 690a0dd254..ddc71b3bbf 100644
--- a/ospf6d/ospf6_abr.c
+++ b/ospf6d/ospf6_abr.c
@@ -593,10 +593,14 @@ void ospf6_abr_range_reset_cost(struct ospf6 *ospf6)
 	struct ospf6_area *oa;
 	struct ospf6_route *range;
 
-	for (ALL_LIST_ELEMENTS(ospf6->area_list, node, nnode, oa))
+	for (ALL_LIST_ELEMENTS(ospf6->area_list, node, nnode, oa)) {
 		for (range = ospf6_route_head(oa->range_table); range;
 		     range = ospf6_route_next(range))
 			OSPF6_ABR_RANGE_CLEAR_COST(range);
+		for (range = ospf6_route_head(oa->nssa_range_table); range;
+		     range = ospf6_route_next(range))
+			OSPF6_ABR_RANGE_CLEAR_COST(range);
+	}
 }
 
 static inline uint32_t ospf6_abr_range_compute_cost(struct ospf6_route *range,
@@ -607,10 +611,19 @@ static inline uint32_t ospf6_abr_range_compute_cost(struct ospf6_route *range,
 
 	for (ro = ospf6_route_match_head(&range->prefix, o->route_table); ro;
 	     ro = ospf6_route_match_next(&range->prefix, ro)) {
-		if (ro->path.area_id == range->path.area_id
-		    && (ro->path.type == OSPF6_PATH_TYPE_INTRA)
-		    && !CHECK_FLAG(ro->flag, OSPF6_ROUTE_REMOVE))
-			cost = MAX(cost, ro->path.cost);
+		if (CHECK_FLAG(ro->flag, OSPF6_ROUTE_REMOVE))
+			continue;
+		if (ro->path.area_id != range->path.area_id)
+			continue;
+		if (CHECK_FLAG(range->flag, OSPF6_ROUTE_NSSA_RANGE)
+		    && ro->path.type != OSPF6_PATH_TYPE_EXTERNAL1
+		    && ro->path.type != OSPF6_PATH_TYPE_EXTERNAL2)
+			continue;
+		if (!CHECK_FLAG(range->flag, OSPF6_ROUTE_NSSA_RANGE)
+		    && ro->path.type != OSPF6_PATH_TYPE_INTRA)
+			continue;
+
+		cost = MAX(cost, ro->path.cost);
 	}
 
 	return cost;
@@ -659,6 +672,8 @@ void ospf6_abr_range_update(struct ospf6_route *range, struct ospf6 *ospf6)
 	int summary_orig = 0;
 
 	assert(range->type == OSPF6_DEST_TYPE_RANGE);
+	oa = ospf6_area_lookup(range->path.area_id, ospf6);
+	assert(oa);
 
 	/* update range's cost and active flag */
 	cost = ospf6_abr_range_compute_cost(range, ospf6);
@@ -687,8 +702,26 @@ void ospf6_abr_range_update(struct ospf6_route *range, struct ospf6 *ospf6)
 	if (IS_OSPF6_DEBUG_ABR)
 		zlog_debug("%s: range %pFX update", __func__, &range->prefix);
 
-	for (ALL_LIST_ELEMENTS(ospf6->area_list, node, nnode, oa))
-		summary_orig += ospf6_abr_originate_summary_to_area(range, oa);
+	if (CHECK_FLAG(range->flag, OSPF6_ROUTE_NSSA_RANGE)) {
+		if (CHECK_FLAG(range->flag, OSPF6_ROUTE_ACTIVE_SUMMARY)
+		    && !CHECK_FLAG(range->flag, OSPF6_ROUTE_DO_NOT_ADVERTISE)) {
+			ospf6_nssa_lsa_originate(range, oa, true);
+			summary_orig = 1;
+		} else {
+			struct ospf6_lsa *lsa;
+
+			lsa = ospf6_lsdb_lookup(range->path.origin.type,
+						range->path.origin.id,
+						ospf6->router_id, oa->lsdb);
+			if (lsa)
+				ospf6_lsa_premature_aging(lsa);
+		}
+	} else {
+		for (ALL_LIST_ELEMENTS(ospf6->area_list, node, nnode, oa)) {
+			summary_orig +=
+				ospf6_abr_originate_summary_to_area(range, oa);
+		}
+	}
 
 	if (CHECK_FLAG(range->flag, OSPF6_ROUTE_ACTIVE_SUMMARY)
 	    && summary_orig) {
diff --git a/ospf6d/ospf6_area.c b/ospf6d/ospf6_area.c
index 2e04e0ee09..996892c49c 100644
--- a/ospf6d/ospf6_area.c
+++ b/ospf6d/ospf6_area.c
@@ -306,6 +306,8 @@ struct ospf6_area *ospf6_area_create(uint32_t area_id, struct ospf6 *o, int df)
 
 	oa->range_table = OSPF6_ROUTE_TABLE_CREATE(AREA, PREFIX_RANGES);
 	oa->range_table->scope = oa;
+	oa->nssa_range_table = OSPF6_ROUTE_TABLE_CREATE(AREA, PREFIX_RANGES);
+	oa->nssa_range_table->scope = oa;
 	oa->summary_prefix = OSPF6_ROUTE_TABLE_CREATE(AREA, SUMMARY_PREFIXES);
 	oa->summary_prefix->scope = oa;
 	oa->summary_router = OSPF6_ROUTE_TABLE_CREATE(AREA, SUMMARY_ROUTERS);
@@ -360,6 +362,7 @@ void ospf6_area_delete(struct ospf6_area *oa)
 	ospf6_route_table_delete(oa->route_table);
 
 	ospf6_route_table_delete(oa->range_table);
+	ospf6_route_table_delete(oa->nssa_range_table);
 	ospf6_route_table_delete(oa->summary_prefix);
 	ospf6_route_table_delete(oa->summary_router);
 
@@ -691,6 +694,22 @@ void ospf6_area_config_write(struct vty *vty, struct ospf6 *ospf6)
 				vty_out(vty, " no-summary");
 			vty_out(vty, "\n");
 		}
+		for (range = ospf6_route_head(oa->nssa_range_table); range;
+		     range = ospf6_route_next(range)) {
+			vty_out(vty, " area %s nssa range %pFX", oa->name,
+				&range->prefix);
+
+			if (CHECK_FLAG(range->flag,
+				       OSPF6_ROUTE_DO_NOT_ADVERTISE)) {
+				vty_out(vty, " not-advertise");
+			} else {
+				if (range->path.u.cost_config
+				    != OSPF_AREA_RANGE_COST_UNSPEC)
+					vty_out(vty, " cost %u",
+						range->path.u.cost_config);
+			}
+			vty_out(vty, "\n");
+		}
 		if (PREFIX_NAME_IN(oa))
 			vty_out(vty, " area %s filter-list prefix %s in\n",
 				oa->name, PREFIX_NAME_IN(oa));
diff --git a/ospf6d/ospf6_area.h b/ospf6d/ospf6_area.h
index 77cbad8b9e..905fbac949 100644
--- a/ospf6d/ospf6_area.h
+++ b/ospf6d/ospf6_area.h
@@ -46,6 +46,7 @@ struct ospf6_area {
 	/* Summary routes to be originated (includes Configured Address Ranges)
 	 */
 	struct ospf6_route_table *range_table;
+	struct ospf6_route_table *nssa_range_table;
 	struct ospf6_route_table *summary_prefix;
 	struct ospf6_route_table *summary_router;
 
diff --git a/ospf6d/ospf6_nssa.c b/ospf6d/ospf6_nssa.c
index 3f555577e5..43bf1b06b3 100644
--- a/ospf6d/ospf6_nssa.c
+++ b/ospf6d/ospf6_nssa.c
@@ -49,6 +49,9 @@
 #include "ospf6_asbr.h"
 #include "ospf6d.h"
 #include "ospf6_nssa.h"
+#ifndef VTYSH_EXTRACT_PL
+#include "ospf6d/ospf6_nssa_clippy.c"
+#endif
 
 DEFINE_MTYPE_STATIC(OSPF6D, OSPF6_LSA,         "OSPF6 LSA");
 unsigned char config_debug_ospf6_nssa = 0;
@@ -412,6 +415,7 @@ static struct ospf6_lsa *ospf6_lsa_translated_nssa_new(struct ospf6_area *area,
 	struct ospf6 *ospf6 = area->ospf6;
 	ptrdiff_t tag_offset = 0;
 	route_tag_t network_order;
+	struct ospf6_route *range;
 
 	if (IS_OSPF6_DEBUG_NSSA)
 		zlog_debug("%s : Start", __func__);
@@ -423,6 +427,25 @@ static struct ospf6_lsa *ospf6_lsa_translated_nssa_new(struct ospf6_area *area,
 		return NULL;
 	}
 
+	/* find the translated Type-5 for this Type-7 */
+	nssa = (struct ospf6_as_external_lsa *)OSPF6_LSA_HEADER_END(
+		type7->header);
+	prefix.family = AF_INET6;
+	prefix.prefixlen = nssa->prefix.prefix_length;
+	ospf6_prefix_in6_addr(&prefix.u.prefix6, nssa, &nssa->prefix);
+
+	/* Check if the Type-7 LSA should be suppressed by aggregation. */
+	range = ospf6_route_lookup_bestmatch(&prefix, area->nssa_range_table);
+	if (range && !prefix_same(&prefix, &range->prefix)
+	    && !CHECK_FLAG(range->flag, OSPF6_ROUTE_REMOVE)) {
+		if (IS_OSPF6_DEBUG_NSSA)
+			zlog_debug(
+				"%s: LSA %s suppressed by range %pFX of area %s",
+				__func__, type7->name, &range->prefix,
+				area->name);
+		return NULL;
+	}
+
 	/* prepare buffer */
 	memset(buffer, 0, sizeof(buffer));
 	lsa_header = (struct ospf6_lsa_header *)buffer;
@@ -439,14 +462,6 @@ static struct ospf6_lsa *ospf6_lsa_translated_nssa_new(struct ospf6_area *area,
 
 	memcpy(extnew, ext, sizeof(struct ospf6_as_external_lsa));
 
-	/* find the translated Type-5 for this Type-7 */
-	nssa = (struct ospf6_as_external_lsa *)OSPF6_LSA_HEADER_END(
-		type7->header);
-
-	prefix.family = AF_INET6;
-	prefix.prefixlen = nssa->prefix.prefix_length;
-	ospf6_prefix_in6_addr(&prefix.u.prefix6, nssa, &nssa->prefix);
-
 	/* set Prefix */
 	memcpy(new_ptr, old_ptr, OSPF6_PREFIX_SPACE(ext->prefix.prefix_length));
 	ospf6_prefix_apply_mask(&extnew->prefix);
@@ -600,7 +615,6 @@ static void ospf6_abr_translate_nssa(struct ospf6_area *area, struct ospf6_lsa *
 	/* Incoming Type-7 or later aggregated Type-7
 	 *
 	 * LSA is skipped if P-bit is off.
-	 * LSA is aggregated if within range.
 	 *
 	 * The Type-7 is translated, Installed/Approved as a Type-5 into
 	 * global LSDB, then Flooded through AS
@@ -732,6 +746,32 @@ static void ospf6_abr_process_nssa_translates(struct ospf6 *ospf6)
 		zlog_debug("%s : Stop", __func__);
 }
 
+static void ospf6_abr_send_nssa_aggregates(struct ospf6 *ospf6)
+{
+	struct listnode *node;
+	struct ospf6_area *area;
+	struct ospf6_route *range;
+
+	if (IS_OSPF6_DEBUG_NSSA)
+		zlog_debug("%s: Start", __func__);
+
+	for (ALL_LIST_ELEMENTS_RO(ospf6->area_list, node, area)) {
+		if (area->NSSATranslatorState == OSPF6_NSSA_TRANSLATE_DISABLED)
+			continue;
+
+		if (IS_OSPF6_DEBUG_NSSA)
+			zlog_debug("%s: looking at area %pI4", __func__,
+				   &area->area_id);
+
+		for (range = ospf6_route_head(area->nssa_range_table); range;
+		     range = ospf6_route_next(range))
+			ospf6_abr_range_update(range, ospf6);
+	}
+
+	if (IS_OSPF6_DEBUG_NSSA)
+		zlog_debug("%s: Stop", __func__);
+}
+
 static void ospf6_abr_remove_unapproved_translates(struct ospf6 *ospf6)
 {
 	struct ospf6_lsa *lsa;
@@ -862,6 +902,11 @@ static void ospf6_abr_nssa_task(struct ospf6 *ospf6)
 
 	ospf6_abr_unapprove_translates(ospf6);
 
+	/* Originate Type-7 aggregates */
+	if (IS_OSPF6_DEBUG_NSSA)
+		zlog_debug("ospf6_abr_nssa_task(): send NSSA aggregates");
+	ospf6_abr_send_nssa_aggregates(ospf6);
+
 	/* For all NSSAs, Type-7s, translate to 5's, INSTALL/FLOOD, or
 	 *  Aggregate as Type-7
 	 * Install or Approve in Type-5 Global LSDB
@@ -1097,6 +1142,13 @@ int ospf6_area_nssa_unset(struct ospf6 *ospf6, struct ospf6_area *area)
 		UNSET_FLAG(area->flag, OSPF6_AREA_NSSA);
 		if (IS_OSPF6_DEBUG_NSSA)
 			zlog_debug("area %s nssa reset", area->name);
+
+		/* Clear the table of NSSA ranges. */
+		ospf6_route_table_delete(area->nssa_range_table);
+		area->nssa_range_table =
+			OSPF6_ROUTE_TABLE_CREATE(AREA, PREFIX_RANGES);
+		area->nssa_range_table->scope = area;
+
 		ospf6_area_nssa_update(area);
 	}
 
@@ -1240,6 +1292,106 @@ void ospf6_abr_check_translate_nssa(struct ospf6_area *area,
 	}
 }
 
+DEFPY (area_nssa_range,
+       area_nssa_range_cmd,
+       "area <A.B.C.D|(0-4294967295)>$area nssa range X:X::X:X/M$prefix [<not-advertise$not_adv|cost (0-16777215)$cost>]",
+       "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"
+       "Configured address range\n"
+       "Specify IPv6 prefix\n"
+       "Do not advertise\n"
+       "User specified metric for this range\n"
+       "Advertised metric for this range\n")
+{
+	struct ospf6_area *oa;
+	struct ospf6_route *range;
+
+	VTY_DECLVAR_CONTEXT(ospf6, ospf6);
+
+	OSPF6_CMD_AREA_GET(area, oa, ospf6);
+
+	if (!IS_AREA_NSSA(oa)) {
+		vty_out(vty, "%% First configure %s as an NSSA area\n", area);
+		return CMD_WARNING;
+	}
+
+	range = ospf6_route_lookup((struct prefix *)prefix,
+				   oa->nssa_range_table);
+	if (range == NULL) {
+		range = ospf6_route_create(ospf6);
+		range->type = OSPF6_DEST_TYPE_RANGE;
+		SET_FLAG(range->flag, OSPF6_ROUTE_NSSA_RANGE);
+		prefix_copy(&range->prefix, prefix);
+		range->path.area_id = oa->area_id;
+		range->path.metric_type = 2;
+		range->path.cost = OSPF_AREA_RANGE_COST_UNSPEC;
+		range->path.origin.type = htons(OSPF6_LSTYPE_TYPE_7);
+		range->path.origin.id = htonl(ospf6->external_id++);
+		range->path.origin.adv_router = ospf6->router_id;
+		ospf6_route_add(range, oa->nssa_range_table);
+	}
+
+	/* process "not-advertise" */
+	if (not_adv)
+		SET_FLAG(range->flag, OSPF6_ROUTE_DO_NOT_ADVERTISE);
+	else
+		UNSET_FLAG(range->flag, OSPF6_ROUTE_DO_NOT_ADVERTISE);
+
+	/* process "cost" */
+	if (!cost_str)
+		cost = OSPF_AREA_RANGE_COST_UNSPEC;
+	range->path.u.cost_config = cost;
+
+	/* Redo summaries if required */
+	if (ospf6_check_and_set_router_abr(ospf6))
+		ospf6_schedule_abr_task(ospf6);
+
+	return CMD_SUCCESS;
+}
+
+DEFPY (no_area_nssa_range,
+       no_area_nssa_range_cmd,
+       "no area <A.B.C.D|(0-4294967295)>$area nssa range X:X::X:X/M$prefix [<not-advertise|cost (0-16777215)>]",
+       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"
+       "Configured address range\n"
+       "Specify IPv6 prefix\n"
+       "Do not advertise\n"
+       "User specified metric for this range\n"
+       "Advertised metric for this range\n")
+{
+	struct ospf6_area *oa;
+	struct ospf6_route *range;
+
+	VTY_DECLVAR_CONTEXT(ospf6, ospf6);
+
+	OSPF6_CMD_AREA_GET(area, oa, ospf6);
+
+	range = ospf6_route_lookup((struct prefix *)prefix,
+				   oa->nssa_range_table);
+	if (range == NULL) {
+		vty_out(vty, "%% range %s does not exists.\n", prefix_str);
+		return CMD_SUCCESS;
+	}
+
+	if (ospf6_check_and_set_router_abr(oa->ospf6)) {
+		/* Blow away the aggregated LSA and route */
+		SET_FLAG(range->flag, OSPF6_ROUTE_REMOVE);
+
+		/* Redo summaries if required */
+		thread_execute(master, ospf6_abr_task_timer, ospf6, 0);
+	}
+
+	ospf6_route_remove(range, oa->nssa_range_table);
+
+	return CMD_SUCCESS;
+}
+
 DEFUN(debug_ospf6_nssa, debug_ospf6_nssa_cmd,
       "debug ospf6 nssa",
       DEBUG_STR
@@ -1269,6 +1421,9 @@ void config_write_ospf6_debug_nssa(struct vty *vty)
 
 void install_element_ospf6_debug_nssa(void)
 {
+	install_element(OSPF6_NODE, &area_nssa_range_cmd);
+	install_element(OSPF6_NODE, &no_area_nssa_range_cmd);
+
 	install_element(ENABLE_NODE, &debug_ospf6_nssa_cmd);
 	install_element(ENABLE_NODE, &no_debug_ospf6_nssa_cmd);
 	install_element(CONFIG_NODE, &debug_ospf6_nssa_cmd);
diff --git a/ospf6d/ospf6_route.h b/ospf6d/ospf6_route.h
index 397860515b..fd8b6a9c1d 100644
--- a/ospf6d/ospf6_route.h
+++ b/ospf6d/ospf6_route.h
@@ -186,7 +186,7 @@ struct ospf6_route {
 	struct timeval changed;
 
 	/* flag */
-	uint8_t flag;
+	uint16_t flag;
 
 	/* Prefix Options */
 	uint8_t prefix_options;
@@ -221,14 +221,15 @@ struct ospf6_route {
 #define OSPF6_DEST_TYPE_RANGE      5
 #define OSPF6_DEST_TYPE_MAX        6
 
-#define OSPF6_ROUTE_CHANGE           0x01
-#define OSPF6_ROUTE_ADD              0x02
-#define OSPF6_ROUTE_REMOVE           0x04
-#define OSPF6_ROUTE_BEST             0x08
-#define OSPF6_ROUTE_ACTIVE_SUMMARY   0x10
-#define OSPF6_ROUTE_DO_NOT_ADVERTISE 0x20
-#define OSPF6_ROUTE_WAS_REMOVED      0x40
-#define OSPF6_ROUTE_BLACKHOLE_ADDED  0x80
+#define OSPF6_ROUTE_CHANGE           0x0001
+#define OSPF6_ROUTE_ADD              0x0002
+#define OSPF6_ROUTE_REMOVE           0x0004
+#define OSPF6_ROUTE_BEST             0x0008
+#define OSPF6_ROUTE_ACTIVE_SUMMARY   0x0010
+#define OSPF6_ROUTE_DO_NOT_ADVERTISE 0x0020
+#define OSPF6_ROUTE_WAS_REMOVED      0x0040
+#define OSPF6_ROUTE_BLACKHOLE_ADDED  0x0080
+#define OSPF6_ROUTE_NSSA_RANGE       0x0100
 struct ospf6;
 
 struct ospf6_route_table {
diff --git a/ospf6d/subdir.am b/ospf6d/subdir.am
index be626646a0..34aabc205b 100644
--- a/ospf6d/subdir.am
+++ b/ospf6d/subdir.am
@@ -99,6 +99,7 @@ clippy_scan += \
 	ospf6d/ospf6_lsa.c \
 	ospf6d/ospf6_gr_helper.c \
 	ospf6d/ospf6_gr.c \
+	ospf6d/ospf6_nssa.c \
 	ospf6d/ospf6_route.c \
 	# end