bgpd: Implement set metric igp command

Set metric automatically from the path info (IGP protocol).

Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>

bgpd/bgp_routemap.c

@@ -125,6 +125,9 @@ o Local extensions
 #define RMAP_VALUE_ADD 1
 #define RMAP_VALUE_SUB 2
 
+#define RMAP_VALUE_TYPE_RTT  1
+#define RMAP_VALUE_TYPE_IGP  2
+
 struct rmap_value {
 	uint8_t action;
 	uint8_t variable;
@@ -140,14 +143,18 @@ static int route_value_match(struct rmap_value *rv, uint32_t value)
 }
 
 static uint32_t route_value_adjust(struct rmap_value *rv, uint32_t current,
-				   struct peer *peer)
+				   struct bgp_path_info *bpi)
 {
 	uint32_t value;
+	struct peer *peer = bpi->peer;
 
 	switch (rv->variable) {
-	case 1:
+	case RMAP_VALUE_TYPE_RTT:
 		value = peer->rtt;
 		break;
+	case RMAP_VALUE_TYPE_IGP:
+		value = bpi->extra ? bpi->extra->igpmetric : 0;
+		break;
 	default:
 		value = rv->value;
 		break;
@@ -187,10 +194,11 @@ static void *route_value_compile(const char *arg)
 		larg = strtoul(arg, &endptr, 10);
 		if (*arg == 0 || *endptr != 0 || errno || larg > UINT32_MAX)
 			return NULL;
+	} else if (strmatch(arg, "rtt")) {
+		var = RMAP_VALUE_TYPE_RTT;
+	} else if (strmatch(arg, "igp")) {
+		var = RMAP_VALUE_TYPE_IGP;
 	} else {
-		if (strcmp(arg, "rtt") == 0)
-			var = 1;
-		else
 		return NULL;
 	}
 
@@ -2145,7 +2153,7 @@ route_set_local_pref(void *rule, const struct prefix *prefix, void *object)
 		locpref = path->attr->local_pref;
 
 	path->attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_LOCAL_PREF);
-	path->attr->local_pref = route_value_adjust(rv, locpref, path->peer);
+	path->attr->local_pref = route_value_adjust(rv, locpref, path);
 
 	return RMAP_OKAY;
 }
@@ -2172,7 +2180,7 @@ route_set_weight(void *rule, const struct prefix *prefix, void *object)
 	path = object;
 
 	/* Set weight value. */
-	path->attr->weight = route_value_adjust(rv, 0, path->peer);
+	path->attr->weight = route_value_adjust(rv, 0, path);
 
 	return RMAP_OKAY;
 }
@@ -2222,7 +2230,7 @@ route_set_metric(void *rule, const struct prefix *prefix, void *object)
 	if (path->attr->flag & ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC))
 		med = path->attr->med;
 
-	bgp_attr_set_med(path->attr, route_value_adjust(rv, med, path->peer));
+	bgp_attr_set_med(path->attr, route_value_adjust(rv, med, path));
 
 	return RMAP_OKAY;
 }

doc/user/routemap.rst

@@ -305,13 +305,15 @@ Route Map Set Command
 
    Set the route's weight.
 
-.. clicmd:: set metric <[+|-](1-4294967295)|rtt|+rtt|-rtt>
+.. clicmd:: set metric <[+|-](1-4294967295)|rtt|+rtt|-rtt|igp>
 
    Set the route metric. When used with BGP, set the BGP attribute MED to a
    specific value. Use `+`/`-` to add or subtract the specified value to/from
    the existing/MED. Use `rtt` to set the MED to the round trip time or
    `+rtt`/`-rtt` to add/subtract the round trip time to/from the MED.
 
+   If ``igp`` is specified, then the actual value from the IGP protocol is used.
+
 .. clicmd:: set min-metric <(0-4294967295)>
 
    Set the minimum metric for the route.

lib/routemap_cli.c

@@ -922,13 +922,14 @@ DEFPY_YANG(
 
 DEFPY_YANG(
 	set_metric, set_metric_cmd,
-	"set metric <(-4294967295-4294967295)$metric|rtt$rtt|+rtt$artt|-rtt$srtt>",
+	"set metric <(-4294967295-4294967295)$metric|rtt$rtt|+rtt$artt|-rtt$srtt|igp$igp>",
 	SET_STR
 	"Metric value for destination routing protocol\n"
 	"Metric value (use +/- for additions or subtractions)\n"
 	"Assign round trip time\n"
 	"Add round trip time\n"
-	"Subtract round trip time\n")
+	"Subtract round trip time\n"
+	"Metric value from IGP protocol\n")
 {
 	const char *xpath = "./set-action[action='frr-route-map:set-metric']";
 	char xpath_value[XPATH_MAXLEN];
@@ -939,6 +940,9 @@ DEFPY_YANG(
 		snprintf(xpath_value, sizeof(xpath_value),
 			 "%s/rmap-set-action/use-round-trip-time", xpath);
 		snprintf(value, sizeof(value), "true");
+	} else if (igp) {
+		snprintf(xpath_value, sizeof(xpath_value), "%s/rmap-set-action/use-igp", xpath);
+		snprintf(value, sizeof(value), "true");
 	} else if (artt) {
 		snprintf(xpath_value, sizeof(xpath_value),
 			 "%s/rmap-set-action/add-round-trip-time", xpath);
@@ -1148,6 +1152,8 @@ void route_map_action_show(struct vty *vty, const struct lyd_node *dnode,
 		if (yang_dnode_get(dnode,
 				   "./rmap-set-action/use-round-trip-time")) {
 			vty_out(vty, " set metric rtt\n");
+		} else if (yang_dnode_get(dnode, "./rmap-set-action/use-igp")) {
+			vty_out(vty, " set metric igp\n");
 		} else if (yang_dnode_get(
 				   dnode,
 				   "./rmap-set-action/add-round-trip-time")) {

lib/routemap_northbound.c

@@ -1213,6 +1213,20 @@ static int lib_route_map_entry_set_action_use_round_trip_time_destroy(
 	return lib_route_map_entry_set_action_value_destroy(args);
 }
 
+/*
+ * XPath: /frr-route-map:lib/route-map/entry/set-action/use-igp
+ */
+static int lib_route_map_entry_set_action_use_igp_modify(struct nb_cb_modify_args *args)
+{
+	return set_action_modify(args->event, args->dnode, args->resource, "igp", args->errmsg,
+				 args->errmsg_len);
+}
+
+static int lib_route_map_entry_set_action_use_igp_destroy(struct nb_cb_destroy_args *args)
+{
+	return lib_route_map_entry_set_action_value_destroy(args);
+}
+
 /*
  * XPath: /frr-route-map:lib/route-map/entry/set-action/add-round-trip-time
  */
@@ -1516,6 +1530,13 @@ const struct frr_yang_module_info frr_route_map_info = {
 				.destroy = lib_route_map_entry_set_action_use_round_trip_time_destroy,
 			}
 		},
+		{
+			.xpath = "/frr-route-map:lib/route-map/entry/set-action/rmap-set-action/use-igp",
+			.cbs = {
+				.modify = lib_route_map_entry_set_action_use_igp_modify,
+				.destroy = lib_route_map_entry_set_action_use_igp_destroy,
+			}
+		},
 		{
 			.xpath = "/frr-route-map:lib/route-map/entry/set-action/rmap-set-action/add-round-trip-time",
 			.cbs = {

yang/frr-route-map.yang

@@ -355,6 +355,14 @@ module frr-route-map {
                   "Subtract round trip time to metric";
               }
             }
+
+            case use-igp {
+              leaf use-igp {
+                type boolean;
+                description
+                  "Use metric from IGP procotol";
+              }
+            }
           }
         }