ospf6d: Redistribute metric for AS-external route

When ospf6d originates an AS-external route that has been read from a kernel
routing table, then the metric of that route was ignored until now.
If a routemap is configured, then this metric will be redistributed from
now on.

Using metric increment and decrement in routemaps is supported by ospf6d now.

Signed-off-by: Alexander Rose <alexander.rose@secunet.com>

5 files changed, 85 insertions, 21 deletions

diff --git a/ospf6d/ospf6_abr.h b/ospf6d/ospf6_abr.h
index 7bb161913..52686ed49 100644
--- a/ospf6d/ospf6_abr.h
+++ b/ospf6d/ospf6_abr.h
@@ -33,11 +33,12 @@ struct ospf6_inter_router_lsa {
 	uint32_t router_id;
 };
 
-#define OSPF6_ABR_SUMMARY_METRIC(E) (ntohl ((E)->metric & htonl (0x00ffffff)))
+#define OSPF6_ABR_SUMMARY_METRIC(E)                                            \
+	(ntohl((E)->metric & htonl(OSPF6_EXT_PATH_METRIC_MAX)))
 #define OSPF6_ABR_SUMMARY_METRIC_SET(E, C)                                     \
 	{                                                                      \
 		(E)->metric &= htonl(0x00000000);                              \
-		(E)->metric |= htonl(0x00ffffff) & htonl(C);                   \
+		(E)->metric |= htonl(OSPF6_EXT_PATH_METRIC_MAX) & htonl(C);    \
 	}
 
 #define OSPF6_ABR_RANGE_CLEAR_COST(range) (range->path.cost = OSPF_AREA_RANGE_COST_UNSPEC)
diff --git a/ospf6d/ospf6_asbr.c b/ospf6d/ospf6_asbr.c
index d1c2b8bfc..701704cdc 100644
--- a/ospf6d/ospf6_asbr.c
+++ b/ospf6d/ospf6_asbr.c
@@ -14,6 +14,7 @@
 #include "table.h"
 #include "plist.h"
 #include "frrevent.h"
+#include "frrstr.h"
 #include "linklist.h"
 #include "lib/northbound_cli.h"
 
@@ -1426,10 +1427,9 @@ static void ospf6_external_lsa_fwd_addr_set(struct ospf6 *ospf6,
 }
 
 void ospf6_asbr_redistribute_add(int type, ifindex_t ifindex,
-				 struct prefix *prefix,
-				 unsigned int nexthop_num,
-				 const struct in6_addr *nexthop,
-				 route_tag_t tag, struct ospf6 *ospf6)
+				 struct prefix *prefix, unsigned int nexthop_num,
+				 const struct in6_addr *nexthop, route_tag_t tag,
+				 struct ospf6 *ospf6, uint32_t metric)
 {
 	route_map_result_t ret;
 	struct ospf6_route troute;
@@ -1472,6 +1472,7 @@ void ospf6_asbr_redistribute_add(int type, ifindex_t ifindex,
 	if (ROUTEMAP(red)) {
 		troute.route_option = &tinfo;
 		troute.ospf6 = ospf6;
+		troute.path.redistribute_cost = metric;
 		tinfo.ifindex = ifindex;
 		tinfo.tag = tag;
 
@@ -1924,7 +1925,7 @@ static void ospf6_redistribute_default_set(struct ospf6 *ospf6, int originate)
 	case DEFAULT_ORIGINATE_ALWAYS:
 		ospf6_asbr_redistribute_add(DEFAULT_ROUTE, 0,
 					    (struct prefix *)&p, 0, &nexthop, 0,
-					    ospf6);
+					    ospf6, 0);
 		break;
 	}
 }
@@ -2153,25 +2154,81 @@ static const struct route_map_rule_cmd
 	ospf6_routemap_rule_set_metric_type_free,
 };
 
+struct ospf6_metric {
+	enum { metric_increment, metric_decrement, metric_absolute } type;
+	bool used;
+	uint32_t metric;
+};
+
 static enum route_map_cmd_result_t
 ospf6_routemap_rule_set_metric(void *rule, const struct prefix *prefix,
 			       void *object)
 {
-	char *metric = rule;
-	struct ospf6_route *route = object;
+	struct ospf6_metric *metric;
+	struct ospf6_route *route;
+
+	/* Fetch routemap's rule information. */
+	metric = rule;
+	route = object;
+
+	/* Set metric out value. */
+	if (!metric->used)
+		return RMAP_OKAY;
+
+	if (route->path.redistribute_cost > OSPF6_EXT_PATH_METRIC_MAX)
+		route->path.redistribute_cost = OSPF6_EXT_PATH_METRIC_MAX;
+
+	if (metric->type == metric_increment) {
+		route->path.cost = route->path.redistribute_cost +
+				   metric->metric;
+
+		/* Check overflow */
+		if (route->path.cost > OSPF6_EXT_PATH_METRIC_MAX ||
+		    route->path.cost < metric->metric)
+			route->path.cost = OSPF6_EXT_PATH_METRIC_MAX;
+	} else if (metric->type == metric_decrement) {
+		route->path.cost = route->path.redistribute_cost -
+				   metric->metric;
+
+		/* Check overflow */
+		if (route->path.cost == 0 ||
+		    route->path.cost > route->path.redistribute_cost)
+			route->path.cost = 1;
+	} else if (metric->type == metric_absolute)
+		route->path.cost = metric->metric;
 
-	route->path.cost = atoi(metric);
 	return RMAP_OKAY;
 }
 
 static void *ospf6_routemap_rule_set_metric_compile(const char *arg)
 {
-	uint32_t metric;
-	char *endp;
-	metric = strtoul(arg, &endp, 0);
-	if (metric > OSPF_LS_INFINITY || *endp != '\0')
-		return NULL;
-	return XSTRDUP(MTYPE_ROUTE_MAP_COMPILED, arg);
+	struct ospf6_metric *metric;
+
+	metric = XCALLOC(MTYPE_ROUTE_MAP_COMPILED, sizeof(*metric));
+	metric->used = false;
+
+	if (all_digit(arg))
+		metric->type = metric_absolute;
+
+	if ((arg[0] == '+') && all_digit(arg + 1)) {
+		metric->type = metric_increment;
+		arg++;
+	}
+
+	if ((arg[0] == '-') && all_digit(arg + 1)) {
+		metric->type = metric_decrement;
+		arg++;
+	}
+
+	metric->metric = strtoul(arg, NULL, 10);
+
+	if (metric->metric > OSPF6_EXT_PATH_METRIC_MAX)
+		metric->metric = OSPF6_EXT_PATH_METRIC_MAX;
+
+	if (metric->metric)
+		metric->used = true;
+
+	return metric;
 }
 
 static void ospf6_routemap_rule_set_metric_free(void *rule)
diff --git a/ospf6d/ospf6_asbr.h b/ospf6d/ospf6_asbr.h
index d63e46727..21e6d898e 100644
--- a/ospf6d/ospf6_asbr.h
+++ b/ospf6d/ospf6_asbr.h
@@ -94,11 +94,13 @@ struct ospf6_as_external_lsa {
 #define OSPF6_ASBR_BIT_F  ntohl (0x02000000)
 #define OSPF6_ASBR_BIT_E  ntohl (0x04000000)
 
-#define OSPF6_ASBR_METRIC(E) (ntohl ((E)->bits_metric & htonl (0x00ffffff)))
+#define OSPF6_ASBR_METRIC(E)                                                   \
+	(ntohl((E)->bits_metric & htonl(OSPF6_EXT_PATH_METRIC_MAX)))
 #define OSPF6_ASBR_METRIC_SET(E, C)                                            \
 	{                                                                      \
-		(E)->bits_metric &= htonl(0xff000000);                         \
-		(E)->bits_metric |= htonl(0x00ffffff) & htonl(C);              \
+		(E)->bits_metric &= htonl(~OSPF6_EXT_PATH_METRIC_MAX);         \
+		(E)->bits_metric |= htonl(OSPF6_EXT_PATH_METRIC_MAX) &         \
+				    htonl(C);                                  \
 	}
 
 extern void ospf6_asbr_lsa_add(struct ospf6_lsa *lsa);
@@ -115,7 +117,8 @@ extern void ospf6_asbr_redistribute_add(int type, ifindex_t ifindex,
 					struct prefix *prefix,
 					unsigned int nexthop_num,
 					const struct in6_addr *nexthop,
-					route_tag_t tag, struct ospf6 *ospf6);
+					route_tag_t tag, struct ospf6 *ospf6,
+					uint32_t metric);
 extern void ospf6_asbr_redistribute_remove(int type, ifindex_t ifindex,
 					   struct prefix *prefix,
 					   struct ospf6 *ospf6);
diff --git a/ospf6d/ospf6_route.h b/ospf6d/ospf6_route.h
index 2c1d17efc..d3c180465 100644
--- a/ospf6d/ospf6_route.h
+++ b/ospf6d/ospf6_route.h
@@ -115,6 +115,7 @@ struct ospf6_path {
 	/* Cost */
 	uint8_t metric_type;
 	uint32_t cost;
+	uint32_t redistribute_cost;
 
 	struct prefix ls_prefix;
 
@@ -139,6 +140,8 @@ struct ospf6_path {
 
 #define OSPF6_PATH_COST_IS_CONFIGURED(path) (path.u.cost_config != OSPF_AREA_RANGE_COST_UNSPEC)
 
+#define OSPF6_EXT_PATH_METRIC_MAX 0x00ffffff
+
 #include "prefix.h"
 #include "table.h"
 #include "bitfield.h"
diff --git a/ospf6d/ospf6_zebra.c b/ospf6d/ospf6_zebra.c
index 3245578b0..911f3567d 100644
--- a/ospf6d/ospf6_zebra.c
+++ b/ospf6d/ospf6_zebra.c
@@ -289,7 +289,7 @@ static int ospf6_zebra_read_route(ZAPI_CALLBACK_ARGS)
 	if (cmd == ZEBRA_REDISTRIBUTE_ROUTE_ADD)
 		ospf6_asbr_redistribute_add(api.type, ifindex, &api.prefix,
 					    api.nexthop_num, nexthop, api.tag,
-					    ospf6);
+					    ospf6, api.metric);
 	else
 		ospf6_asbr_redistribute_remove(api.type, ifindex, &api.prefix,
 					       ospf6);