isisd: learn and advertise IPv6 dst-src routes

Receive IPv6 dst-src routes from zebra and advertise them in our LSPs
if so configured.

Signed-off-by: Christian Franke <chris@opensourcerouting.org>

8 files changed, 120 insertions, 70 deletions

diff --git a/isisd/isis_lsp.c b/isisd/isis_lsp.c
index c8ef82906..37651163f 100644
--- a/isisd/isis_lsp.c
+++ b/isisd/isis_lsp.c
@@ -37,6 +37,7 @@
 #include "checksum.h"
 #include "md5.h"
 #include "table.h"
+#include "srcdest_table.h"
 
 #include "isisd/dict.h"
 #include "isisd/isis_constants.h"
@@ -765,18 +766,28 @@ static void lsp_build_ext_reach_ipv6(struct isis_lsp *lsp,
 		return;
 
 	for (struct route_node *rn = route_top(er_table); rn;
-	     rn = route_next(rn)) {
+	     rn = srcdest_route_next(rn)) {
 		if (!rn->info)
 			continue;
-
-		struct prefix_ipv6 *ipv6 = (struct prefix_ipv6 *)&rn->p;
 		struct isis_ext_info *info = rn->info;
 
+		struct prefix_ipv6 *p, *src_p;
+		srcdest_rnode_prefixes(rn, (const struct prefix **)&p,
+				       (const struct prefix **)&src_p);
+
 		uint32_t metric = info->metric;
 		if (info->metric > MAX_WIDE_PATH_METRIC)
 			metric = MAX_WIDE_PATH_METRIC;
-		isis_tlvs_add_ipv6_reach(
-			lsp->tlvs, isis_area_ipv6_topology(area), ipv6, metric);
+
+		if (!src_p || !src_p->prefixlen) {
+			isis_tlvs_add_ipv6_reach(lsp->tlvs,
+						 isis_area_ipv6_topology(area),
+						 p, metric);
+		} else if (isis_area_ipv6_dstsrc_enabled(area)) {
+			isis_tlvs_add_ipv6_dstsrc_reach(lsp->tlvs,
+							ISIS_MT_IPV6_DSTSRC,
+							p, src_p, metric);
+		}
 	}
 }
 
diff --git a/isisd/isis_mt.c b/isisd/isis_mt.c
index d13f2a13f..2155bf584 100644
--- a/isisd/isis_mt.c
+++ b/isisd/isis_mt.c
@@ -33,6 +33,14 @@ DEFINE_MTYPE_STATIC(ISISD, MT_AREA_SETTING, "ISIS MT Area Setting")
 DEFINE_MTYPE_STATIC(ISISD, MT_CIRCUIT_SETTING, "ISIS MT Circuit Setting")
 DEFINE_MTYPE_STATIC(ISISD, MT_ADJ_INFO, "ISIS MT Adjacency Info")
 
+bool isis_area_ipv6_dstsrc_enabled(struct isis_area *area)
+{
+	struct isis_area_mt_setting *area_mt_setting;
+	area_mt_setting = area_lookup_mt_setting(area, ISIS_MT_IPV6_DSTSRC);
+
+	return (area_mt_setting && area_mt_setting->enabled);
+}
+
 uint16_t isis_area_ipv6_topology(struct isis_area *area)
 {
 	struct isis_area_mt_setting *area_mt_setting;
@@ -61,6 +69,8 @@ const char *isis_mtid2str(uint16_t mtid)
 		return "ipv6-multicast";
 	case ISIS_MT_IPV6_MGMT:
 		return "ipv6-mgmt";
+	case ISIS_MT_IPV6_DSTSRC:
+		return "ipv6-dstsrc";
 	default:
 		snprintf(buf, sizeof(buf), "%" PRIu16, mtid);
 		return buf;
@@ -81,6 +91,8 @@ uint16_t isis_str2mtid(const char *name)
 		return ISIS_MT_IPV6_MULTICAST;
 	if (!strcmp(name, "ipv6-mgmt"))
 		return ISIS_MT_IPV6_MGMT;
+	if (!strcmp(name, "ipv6-dstsrc"))
+		return ISIS_MT_IPV6_DSTSRC;
 	return -1;
 }
 
diff --git a/isisd/isis_mt.h b/isisd/isis_mt.h
index 95aa99dba..8c57d24af 100644
--- a/isisd/isis_mt.h
+++ b/isisd/isis_mt.h
@@ -32,6 +32,7 @@
 #define ISIS_MT_IPV4_MULTICAST 3
 #define ISIS_MT_IPV6_MULTICAST 4
 #define ISIS_MT_IPV6_MGMT      5
+#define ISIS_MT_IPV6_DSTSRC    3996 /* FIXME: IANA */
 
 #define ISIS_MT_NAMES                                                          \
 	"<ipv4-unicast"                                                        \
@@ -40,6 +41,7 @@
 	"|ipv4-multicast"                                                      \
 	"|ipv6-multicast"                                                      \
 	"|ipv6-mgmt"                                                           \
+	"|ipv6-dstsrc"                                                         \
 	">"
 
 #define ISIS_MT_DESCRIPTIONS                                                   \
@@ -48,7 +50,9 @@
 	"IPv6 unicast topology\n"                                              \
 	"IPv4 multicast topology\n"                                            \
 	"IPv6 multicast topology\n"                                            \
-	"IPv6 management topology\n"
+	"IPv6 management topology\n"                                           \
+	"IPv6 dst-src topology\n"                                              \
+	""
 
 #define ISIS_MT_INFO_FIELDS uint16_t mtid;
 
@@ -75,6 +79,8 @@ struct tlvs;
 struct te_is_neigh;
 struct isis_tlvs;
 
+bool isis_area_ipv6_dstsrc_enabled(struct isis_area *area);
+
 uint16_t isis_area_ipv6_topology(struct isis_area *area);
 
 struct isis_area_mt_setting *area_lookup_mt_setting(struct isis_area *area,
diff --git a/isisd/isis_redist.c b/isisd/isis_redist.c
index e903dc8c7..1c061fe1c 100644
--- a/isisd/isis_redist.c
+++ b/isisd/isis_redist.c
@@ -30,6 +30,7 @@
 #include "stream.h"
 #include "table.h"
 #include "vty.h"
+#include "srcdest_table.h"
 
 #include "isisd/dict.h"
 #include "isisd/isis_constants.h"
@@ -86,33 +87,13 @@ struct route_table *get_ext_reach(struct isis_area *area, int family, int level)
 	return area->ext_reach[protocol][level - 1];
 }
 
-static struct route_node *
-isis_redist_route_node_create(route_table_delegate_t *delegate,
-			      struct route_table *table)
-{
-	struct route_node *node;
-	node = XCALLOC(MTYPE_ISIS_EXT_ROUTE, sizeof(*node));
-	return node;
-}
-
-static void isis_redist_route_node_destroy(route_table_delegate_t *delegate,
-					   struct route_table *table,
-					   struct route_node *node)
-{
-	if (node->info)
-		XFREE(MTYPE_ISIS_EXT_INFO, node->info);
-	XFREE(MTYPE_ISIS_EXT_ROUTE, node);
-}
-
-static route_table_delegate_t isis_redist_rt_delegate = {
-	.create_node = isis_redist_route_node_create,
-	.destroy_node = isis_redist_route_node_destroy};
-
 /* Install external reachability information into a
  * specific area for a specific level.
  * Schedule an lsp regenerate if necessary */
 static void isis_redist_install(struct isis_area *area, int level,
-				struct prefix *p, struct isis_ext_info *info)
+				const struct prefix *p,
+				const struct prefix_ipv6 *src_p,
+				struct isis_ext_info *info)
 {
 	int family = p->family;
 	struct route_table *er_table = get_ext_reach(area, family, level);
@@ -126,7 +107,7 @@ static void isis_redist_install(struct isis_area *area, int level,
 		return;
 	}
 
-	er_node = route_node_get(er_table, p);
+	er_node = srcdest_rnode_get(er_table, p, src_p);
 	if (er_node->info) {
 		route_unlock_node(er_node);
 
@@ -145,7 +126,8 @@ static void isis_redist_install(struct isis_area *area, int level,
  * specific area for a specific level.
  * Schedule an lsp regenerate if necessary. */
 static void isis_redist_uninstall(struct isis_area *area, int level,
-				  struct prefix *p)
+				  const struct prefix *p,
+				  const struct prefix_ipv6 *src_p)
 {
 	int family = p->family;
 	struct route_table *er_table = get_ext_reach(area, family, level);
@@ -159,7 +141,7 @@ static void isis_redist_uninstall(struct isis_area *area, int level,
 		return;
 	}
 
-	er_node = route_node_lookup(er_table, p);
+	er_node = srcdest_rnode_lookup(er_table, p, src_p);
 	if (!er_node)
 		return;
 	else
@@ -177,7 +159,8 @@ static void isis_redist_uninstall(struct isis_area *area, int level,
  * and prefix, using the given redistribution settings. */
 static void isis_redist_update_ext_reach(struct isis_area *area, int level,
 					 struct isis_redist *redist,
-					 struct prefix *p,
+					 const struct prefix *p,
+					 const struct prefix_ipv6 *src_p,
 					 struct isis_ext_info *info)
 {
 	struct isis_ext_info area_info;
@@ -188,7 +171,8 @@ static void isis_redist_update_ext_reach(struct isis_area *area, int level,
 
 	if (redist->map_name) {
 		map_ret =
-			route_map_apply(redist->map, p, RMAP_ISIS, &area_info);
+			route_map_apply(redist->map, (struct prefix *)p,
+					RMAP_ISIS, &area_info);
 		if (map_ret == RMAP_DENYMATCH)
 			area_info.distance = 255;
 	}
@@ -199,9 +183,9 @@ static void isis_redist_update_ext_reach(struct isis_area *area, int level,
 		area_info.distance = 255;
 
 	if (area_info.distance < 255)
-		isis_redist_install(area, level, p, &area_info);
+		isis_redist_install(area, level, p, src_p, &area_info);
 	else
-		isis_redist_uninstall(area, level, p);
+		isis_redist_uninstall(area, level, p, src_p);
 }
 
 static void isis_redist_ensure_default(struct isis *isis, int family)
@@ -222,7 +206,7 @@ static void isis_redist_ensure_default(struct isis *isis, int family)
 	} else
 		assert(!"Unknown family!");
 
-	ei_node = route_node_get(ei_table, &p);
+	ei_node = srcdest_rnode_get(ei_table, &p, NULL);
 	if (ei_node->info) {
 		route_unlock_node(ei_node);
 		return;
@@ -238,8 +222,8 @@ static void isis_redist_ensure_default(struct isis *isis, int family)
 }
 
 /* Handle notification about route being added */
-void isis_redist_add(int type, struct prefix *p, uint8_t distance,
-		     uint32_t metric)
+void isis_redist_add(int type, struct prefix *p, struct prefix_ipv6 *src_p,
+		     uint8_t distance, uint32_t metric)
 {
 	int family = p->family;
 	struct route_table *ei_table = get_ext_info(isis, family);
@@ -262,7 +246,7 @@ void isis_redist_add(int type, struct prefix *p, uint8_t distance,
 		return;
 	}
 
-	ei_node = route_node_get(ei_table, p);
+	ei_node = srcdest_rnode_get(ei_table, p, src_p);
 	if (ei_node->info)
 		route_unlock_node(ei_node);
 	else
@@ -274,8 +258,10 @@ void isis_redist_add(int type, struct prefix *p, uint8_t distance,
 	info->distance = distance;
 	info->metric = metric;
 
-	if (is_default_prefix(p))
+	if (is_default_prefix(p)
+	    && (!src_p || !src_p->prefixlen)) {
 		type = DEFAULT_ROUTE;
+	}
 
 	for (ALL_LIST_ELEMENTS_RO(isis->area_list, node, area))
 		for (level = 1; level <= ISIS_LEVELS; level++) {
@@ -284,11 +270,11 @@ void isis_redist_add(int type, struct prefix *p, uint8_t distance,
 				continue;
 
 			isis_redist_update_ext_reach(area, level, redist, p,
-						     info);
+						     src_p, info);
 		}
 }
 
-void isis_redist_delete(int type, struct prefix *p)
+void isis_redist_delete(int type, struct prefix *p, struct prefix_ipv6 *src_p)
 {
 	int family = p->family;
 	struct route_table *ei_table = get_ext_info(isis, family);
@@ -304,12 +290,14 @@ void isis_redist_delete(int type, struct prefix *p)
 	zlog_debug("%s: Removing route %s from %s.", __func__, debug_buf,
 		   zebra_route_string(type));
 
-	if (is_default_prefix(p)) {
+	if (is_default_prefix(p)
+	    && (!src_p || !src_p->prefixlen)) {
 		/* Don't remove default route but add synthetic route for use
 		 * by "default-information originate always". Areas without the
 		 * "always" setting will ignore routes with origin
 		 * DEFAULT_ROUTE. */
-		isis_redist_add(DEFAULT_ROUTE, p, 254, MAX_WIDE_PATH_METRIC);
+		isis_redist_add(DEFAULT_ROUTE, p, NULL,
+				254, MAX_WIDE_PATH_METRIC);
 		return;
 	}
 
@@ -319,7 +307,7 @@ void isis_redist_delete(int type, struct prefix *p)
 		return;
 	}
 
-	ei_node = route_node_lookup(ei_table, p);
+	ei_node = srcdest_rnode_lookup(ei_table, p, src_p);
 	if (!ei_node || !ei_node->info) {
 		char buf[BUFSIZ];
 		prefix2str(p, buf, sizeof(buf));
@@ -339,7 +327,7 @@ void isis_redist_delete(int type, struct prefix *p)
 			if (!redist->redist)
 				continue;
 
-			isis_redist_uninstall(area, level, p);
+			isis_redist_uninstall(area, level, p, src_p);
 		}
 
 	XFREE(MTYPE_ISIS_EXT_INFO, ei_node->info);
@@ -418,17 +406,14 @@ static void isis_redist_set(struct isis_area *area, int level, int family,
 	isis_redist_routemap_set(redist, routemap);
 
 	if (!area->ext_reach[protocol][level - 1]) {
-		area->ext_reach[protocol][level - 1] =
-			route_table_init_with_delegate(
-				&isis_redist_rt_delegate);
+		area->ext_reach[protocol][level - 1] = srcdest_table_init();
 	}
 
-	for (i = 0; i < REDIST_PROTOCOL_COUNT; i++)
+	for (i = 0; i < REDIST_PROTOCOL_COUNT; i++) {
 		if (!area->isis->ext_info[i]) {
-			area->isis->ext_info[i] =
-				route_table_init_with_delegate(
-					&isis_redist_rt_delegate);
+			area->isis->ext_info[i] = srcdest_table_init();
 		}
+	}
 
 	isis_redist_update_zebra_subscriptions(area->isis);
 
@@ -436,20 +421,27 @@ static void isis_redist_set(struct isis_area *area, int level, int family,
 		isis_redist_ensure_default(area->isis, family);
 
 	ei_table = get_ext_info(area->isis, family);
-	for (rn = route_top(ei_table); rn; rn = route_next(rn)) {
+	for (rn = route_top(ei_table); rn; rn = srcdest_route_next(rn)) {
 		if (!rn->info)
 			continue;
 		info = rn->info;
 
+		const struct prefix *p, *src_p;
+
+		srcdest_rnode_prefixes(rn, &p, &src_p);
+
 		if (type == DEFAULT_ROUTE) {
-			if (!is_default_prefix(&rn->p))
+			if (!is_default_prefix(p)
+			    || (src_p && src_p->prefixlen)) {
 				continue;
+			}
 		} else {
 			if (info->origin != type)
 				continue;
 		}
 
-		isis_redist_update_ext_reach(area, level, redist, &rn->p, info);
+		isis_redist_update_ext_reach(area, level, redist, p,
+					     (struct prefix_ipv6 *)src_p, info);
 	}
 }
 
@@ -472,14 +464,19 @@ static void isis_redist_unset(struct isis_area *area, int level, int family,
 		return;
 	}
 
-	for (rn = route_top(er_table); rn; rn = route_next(rn)) {
+	for (rn = route_top(er_table); rn; rn = srcdest_route_next(rn)) {
 		if (!rn->info)
 			continue;
 		info = rn->info;
 
+		const struct prefix *p, *src_p;
+		srcdest_rnode_prefixes(rn, &p, &src_p);
+
 		if (type == DEFAULT_ROUTE) {
-			if (!is_default_prefix(&rn->p))
+			if (!is_default_prefix(p)
+			    || (src_p && src_p->prefixlen)) {
 				continue;
+			}
 		} else {
 			if (info->origin != type)
 				continue;
diff --git a/isisd/isis_redist.h b/isisd/isis_redist.h
index c12363d50..95f06f71e 100644
--- a/isisd/isis_redist.h
+++ b/isisd/isis_redist.h
@@ -42,13 +42,14 @@ struct isis_redist {
 
 struct isis_area;
 struct prefix;
+struct prefix_ipv6;
 struct vty;
 
 struct route_table *get_ext_reach(struct isis_area *area, int family,
 				  int level);
-void isis_redist_add(int type, struct prefix *p, uint8_t distance,
-		     uint32_t metric);
-void isis_redist_delete(int type, struct prefix *p);
+void isis_redist_add(int type, struct prefix *p, struct prefix_ipv6 *src_p,
+		     uint8_t distance, uint32_t metric);
+void isis_redist_delete(int type, struct prefix *p, struct prefix_ipv6 *src_p);
 int isis_redist_config_write(struct vty *vty, struct isis_area *area,
 			     int family);
 void isis_redist_init(void);
diff --git a/isisd/isis_tlvs.c b/isisd/isis_tlvs.c
index 9b2aa7470..a433fcdb4 100644
--- a/isisd/isis_tlvs.c
+++ b/isisd/isis_tlvs.c
@@ -1912,6 +1912,11 @@ static void append_item(struct isis_item_list *dest, struct isis_item *item)
 	dest->count++;
 }
 
+static struct isis_item *last_item(struct isis_item_list *list)
+{
+	return container_of(list->tail, struct isis_item, next);
+}
+
 static int unpack_item(uint16_t mtid, enum isis_tlv_context context,
 		       uint8_t tlv_type, uint8_t len, struct stream *s,
 		       struct sbuf *log, void *dest, int indent)
@@ -3168,6 +3173,21 @@ void isis_tlvs_add_ipv6_reach(struct isis_tlvs *tlvs, uint16_t mtid,
 	append_item(l, (struct isis_item *)r);
 }
 
+void isis_tlvs_add_ipv6_dstsrc_reach(struct isis_tlvs *tlvs, uint16_t mtid,
+				     struct prefix_ipv6 *dest,
+				     struct prefix_ipv6 *src,
+				     uint32_t metric)
+{
+	isis_tlvs_add_ipv6_reach(tlvs, mtid, dest, metric);
+	struct isis_item_list *l = isis_get_mt_items(&tlvs->mt_ipv6_reach,
+						     mtid);
+
+	struct isis_ipv6_reach *r = (struct isis_ipv6_reach*)last_item(l);
+	r->subtlvs = isis_alloc_subtlvs();
+	r->subtlvs->source_prefix = XCALLOC(MTYPE_ISIS_SUBTLV, sizeof(*src));
+	memcpy(r->subtlvs->source_prefix, src, sizeof(*src));
+}
+
 void isis_tlvs_add_oldstyle_reach(struct isis_tlvs *tlvs, uint8_t *id,
 				  uint8_t metric)
 {
diff --git a/isisd/isis_tlvs.h b/isisd/isis_tlvs.h
index 98edbf14e..bd1fa3e67 100644
--- a/isisd/isis_tlvs.h
+++ b/isisd/isis_tlvs.h
@@ -313,6 +313,10 @@ void isis_tlvs_add_extended_ip_reach(struct isis_tlvs *tlvs,
 				     struct prefix_ipv4 *dest, uint32_t metric);
 void isis_tlvs_add_ipv6_reach(struct isis_tlvs *tlvs, uint16_t mtid,
 			      struct prefix_ipv6 *dest, uint32_t metric);
+void isis_tlvs_add_ipv6_dstsrc_reach(struct isis_tlvs *tlvs, uint16_t mtid,
+				     struct prefix_ipv6 *dest,
+				     struct prefix_ipv6 *src,
+				     uint32_t metric);
 void isis_tlvs_add_oldstyle_reach(struct isis_tlvs *tlvs, uint8_t *id,
 				  uint8_t metric);
 void isis_tlvs_add_extended_reach(struct isis_tlvs *tlvs, uint16_t mtid,
diff --git a/isisd/isis_zebra.c b/isisd/isis_zebra.c
index ac640c5e4..b225af106 100644
--- a/isisd/isis_zebra.c
+++ b/isisd/isis_zebra.c
@@ -359,24 +359,23 @@ static int isis_zebra_read(int command, struct zclient *zclient,
 	if (zapi_route_decode(zclient->ibuf, &api) < 0)
 		return -1;
 
-	/* we completely ignore srcdest routes for now. */
-	if (CHECK_FLAG(api.message, ZAPI_MESSAGE_SRCPFX))
-		return 0;
-
 	/*
 	 * Avoid advertising a false default reachability. (A default
 	 * route installed by IS-IS gets redistributed from zebra back
 	 * into IS-IS causing us to start advertising default reachabity
 	 * without this check)
 	 */
-	if (api.prefix.prefixlen == 0 && api.type == ZEBRA_ROUTE_ISIS)
+	if (api.prefix.prefixlen == 0
+	    && api.src_prefix.prefixlen == 0
+	    && api.type == ZEBRA_ROUTE_ISIS) {
 		command = ZEBRA_REDISTRIBUTE_ROUTE_DEL;
+	}
 
 	if (command == ZEBRA_REDISTRIBUTE_ROUTE_ADD)
-		isis_redist_add(api.type, &api.prefix, api.distance,
-				api.metric);
+		isis_redist_add(api.type, &api.prefix, &api.src_prefix,
+				api.distance, api.metric);
 	else
-		isis_redist_delete(api.type, &api.prefix);
+		isis_redist_delete(api.type, &api.prefix, &api.src_prefix);
 
 	return 0;
 }