Merge pull request #17038 from opensourcerouting/feature/bgp_set_metric_internal

bgpd: Derive and set MED from IGP or AIGP

bgpd/bgp_attr.c

@@ -1177,8 +1177,7 @@ struct attr *bgp_attr_aggregate_intern(
 	SET_FLAG(attr.flag, ATTR_FLAG_BIT(BGP_ATTR_ORIGIN));
 
 	/* MED */
-	attr.med = 0;
+	bgp_attr_set_med(&attr, 0);
-	SET_FLAG(attr.flag, ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC));
 
 	/* AS path attribute. */
 	if (aspath)
@@ -1933,9 +1932,7 @@ static enum bgp_attr_parse_ret bgp_attr_med(struct bgp_attr_parser_args *args)
 					  args->total);
 	}
 
-	attr->med = stream_getl(peer->curr);
+	bgp_attr_set_med(attr, stream_getl(peer->curr));
-
-	SET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC));
 
 	return BGP_ATTR_PARSE_PROCEED;
 }

bgpd/bgp_attr.h

@@ -608,6 +608,12 @@ static inline uint64_t bgp_aigp_metric_total(struct bgp_path_info *bpi)
 		return aigp;
 }
 
+static inline void bgp_attr_set_med(struct attr *attr, uint32_t med)
+{
+	attr->med = med;
+	SET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC));
+}
+
 static inline struct cluster_list *bgp_attr_get_cluster(const struct attr *attr)
 {
 	return attr->cluster1;

bgpd/bgp_route.c

@@ -3726,11 +3726,10 @@ static void bgp_process_main_one(struct bgp *bgp, struct bgp_dest *dest,
 
 		/* If there is a change of interest to peers, reannounce the
 		 * route. */
-		if (CHECK_FLAG(old_select->flags, BGP_PATH_ATTR_CHANGED)
+		if (CHECK_FLAG(old_select->flags, BGP_PATH_ATTR_CHANGED) ||
-		    || CHECK_FLAG(old_select->flags, BGP_PATH_LINK_BW_CHG)
+		    CHECK_FLAG(dest->flags, BGP_NODE_LABEL_CHANGED) ||
-		    || CHECK_FLAG(dest->flags, BGP_NODE_LABEL_CHANGED)) {
+		    bgp_zebra_has_route_changed(old_select)) {
 			group_announce_route(bgp, afi, safi, dest, new_select);
-
 			/* unicast routes must also be annouced to
 			 * labeled-unicast update-groups */
 			if (safi == SAFI_UNICAST)
@@ -6746,8 +6745,8 @@ void bgp_static_update(struct bgp *bgp, const struct prefix *p,
 	bgp_attr_default_set(&attr, bgp, BGP_ORIGIN_IGP);
 
 	attr.nexthop = bgp_static->igpnexthop;
-	attr.med = bgp_static->igpmetric;
+
-	attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC);
+	bgp_attr_set_med(&attr, bgp_static->igpmetric);
 
 	if (afi == AFI_IP)
 		attr.mp_nexthop_len = BGP_ATTR_NHLEN_IPV4;
@@ -9014,9 +9013,8 @@ void bgp_redistribute_add(struct bgp *bgp, struct prefix *p,
 	else
 		UNSET_FLAG(attr.nh_flags, BGP_ATTR_NH_IF_OPERSTATE);
 
-	attr.med = metric;
+	bgp_attr_set_med(&attr, metric);
 	attr.distance = distance;
-	attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC);
 	attr.tag = tag;
 
 	if (metric)

bgpd/bgp_routemap.c

@@ -125,6 +125,10 @@ 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
+#define RMAP_VALUE_TYPE_AIGP 3
+
 struct rmap_value {
 	uint8_t action;
 	uint8_t variable;
@@ -140,14 +144,21 @@ 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;
+	case RMAP_VALUE_TYPE_AIGP:
+		value = MIN(bpi->attr->aigp_metric, UINT32_MAX);
+		break;
 	default:
 		value = rv->value;
 		break;
@@ -187,11 +198,14 @@ 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 (strmatch(arg, "aigp")) {
+		var = RMAP_VALUE_TYPE_AIGP;
 	} else {
-		if (strcmp(arg, "rtt") == 0)
+		return NULL;
-			var = 1;
-		else
-			return NULL;
 	}
 
 	rv = XMALLOC(MTYPE_ROUTE_MAP_COMPILED, sizeof(struct rmap_value));
@@ -2145,7 +2159,7 @@ 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 +2186,7 @@ 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;
 }
@@ -2222,8 +2236,7 @@ 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;
 
-	path->attr->med = route_value_adjust(rv, med, path->peer);
+	bgp_attr_set_med(path->attr, route_value_adjust(rv, med, path));
-	path->attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC);
 
 	return RMAP_OKAY;
 }

bgpd/bgp_updgrp_adv.c

@@ -906,8 +906,8 @@ void subgroup_default_originate(struct update_subgroup *subgrp, bool withdraw)
 	assert(attr.aspath);
 
 	aspath = attr.aspath;
-	attr.med = 0;
+
-	attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC);
+	bgp_attr_set_med(&attr, 0);
 
 	if ((afi == AFI_IP6) || peer_cap_enhe(peer, afi, safi)) {
 		/* IPv6 global nexthop must be included. */

bgpd/rfapi/rfapi.c

@@ -667,10 +667,8 @@ void add_vnc_route(struct rfapi_descriptor *rfd, /* cookie, VPN UN addr, peer */
 		attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_LOCAL_PREF);
 	}
 
-	if (med) {
+	if (med)
-		attr.med = *med;
+		bgp_attr_set_med(&attr, *med);
-		attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC);
-	}
 
 	/* override default weight assigned by bgp_attr_default_set() */
 	attr.weight = rfd->peer ? rfd->peer->weight[afi][safi] : 0;
@@ -863,10 +861,8 @@ void add_vnc_route(struct rfapi_descriptor *rfd, /* cookie, VPN UN addr, peer */
 
 	red = bgp_redist_lookup(bgp, afi, type, 0);
 
-	if (red && red->redist_metric_flag) {
+	if (red && red->redist_metric_flag)
-		attr.med = red->redist_metric;
+		bgp_attr_set_med(&attr, red->redist_metric);
-		attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC);
-	}
 
 	bn = bgp_afi_node_get(bgp->rib[afi][safi], afi, safi, p, prd);
 

bgpd/rfapi/vnc_export_bgp.c

@@ -96,15 +96,16 @@ static void encap_attr_export_ce(struct attr *new, struct attr *orig,
 	 *          neighbor NEIGHBOR attribute-unchanged med
 	 */
 	if (!CHECK_FLAG(new->flag, BGP_ATTR_MULTI_EXIT_DISC)) {
+		uint32_t med = 255;
+
 		if (CHECK_FLAG(new->flag, BGP_ATTR_LOCAL_PREF)) {
 			if (new->local_pref > 255)
-				new->med = 0;
+				med = 0;
 			else
-				new->med = 255 - new->local_pref;
+				med = 255 - new->local_pref;
-		} else {
-			new->med = 255; /* shouldn't happen */
 		}
-		new->flag |= ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC);
+
+		bgp_attr_set_med(new, med);
 	}
 
 	/*
@@ -642,15 +643,16 @@ encap_attr_export(struct attr *new, struct attr *orig,
 	 *          neighbor NEIGHBOR attribute-unchanged med
 	 */
 	if (!CHECK_FLAG(new->flag, BGP_ATTR_MULTI_EXIT_DISC)) {
+		uint32_t med = 255;
+
 		if (CHECK_FLAG(new->flag, BGP_ATTR_LOCAL_PREF)) {
 			if (new->local_pref > 255)
-				new->med = 0;
+				med = 0;
 			else
-				new->med = 255 - new->local_pref;
+				med = 255 - new->local_pref;
-		} else {
-			new->med = 255; /* shouldn't happen */
 		}
-		new->flag |= ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC);
+
+		bgp_attr_set_med(new, med);
 	}
 
 	/*

doc/user/routemap.rst

@@ -305,13 +305,18 @@ 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|aigp>
 
    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.
+
+   If ``aigp`` is specified, then the actual value from the AIGP metric is used
+   (encoded as MED instead of AIGP attribute).
+
 .. clicmd:: set min-metric <(0-4294967295)>
 
    Set the minimum metric for the route.

lib/routemap_cli.c

@@ -922,13 +922,15 @@ 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$igp|aigp$aigp>",
 	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"
+	"Metric value from AIGP (Accumulated IGP)\n")
 {
 	const char *xpath = "./set-action[action='frr-route-map:set-metric']";
 	char xpath_value[XPATH_MAXLEN];
@@ -939,6 +941,12 @@ 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 (aigp) {
+		snprintf(xpath_value, sizeof(xpath_value), "%s/rmap-set-action/use-aigp", xpath);
+		snprintf(value, sizeof(value), "true");
 	} else if (artt) {
 		snprintf(xpath_value, sizeof(xpath_value),
 			 "%s/rmap-set-action/add-round-trip-time", xpath);
@@ -1148,23 +1156,19 @@ 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(
+		} else if (yang_dnode_get(dnode, "./rmap-set-action/use-igp")) {
-				   dnode,
+			vty_out(vty, " set metric igp\n");
-				   "./rmap-set-action/add-round-trip-time")) {
+		} else if (yang_dnode_get(dnode, "./rmap-set-action/use-aigp")) {
+			vty_out(vty, " set metric aigp\n");
+		} else if (yang_dnode_get(dnode, "./rmap-set-action/add-round-trip-time")) {
 			vty_out(vty, " set metric +rtt\n");
-		} else if (
+		} else if (yang_dnode_get(dnode, "./rmap-set-action/subtract-round-trip-time")) {
-			yang_dnode_get(
-				dnode,
-				"./rmap-set-action/subtract-round-trip-time")) {
 			vty_out(vty, " set metric -rtt\n");
-		} else if (yang_dnode_get(dnode,
+		} else if (yang_dnode_get(dnode, "./rmap-set-action/add-metric")) {
-					  "./rmap-set-action/add-metric")) {
 			vty_out(vty, " set metric +%s\n",
 				yang_dnode_get_string(
 					dnode, "./rmap-set-action/add-metric"));
-		} else if (yang_dnode_get(
+		} else if (yang_dnode_get(dnode, "./rmap-set-action/subtract-metric")) {
-				   dnode,
-				   "./rmap-set-action/subtract-metric")) {
 			vty_out(vty, " set metric -%s\n",
 				yang_dnode_get_string(
 					dnode,

lib/routemap_northbound.c

@@ -1213,6 +1213,34 @@ 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/use-aigp
+ */
+static int lib_route_map_entry_set_action_use_aigp_modify(struct nb_cb_modify_args *args)
+{
+	return set_action_modify(args->event, args->dnode, args->resource, "aigp", args->errmsg,
+				 args->errmsg_len);
+}
+
+static int lib_route_map_entry_set_action_use_aigp_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 +1544,20 @@ 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/use-aigp",
+			.cbs = {
+				.modify = lib_route_map_entry_set_action_use_aigp_modify,
+				.destroy = lib_route_map_entry_set_action_use_aigp_destroy,
+			}
+		},
 		{
 			.xpath = "/frr-route-map:lib/route-map/entry/set-action/rmap-set-action/add-round-trip-time",
 			.cbs = {

tests/topotests/bgp_aigp/r1/bgpd.conf

@@ -9,4 +9,20 @@ router bgp 65001
  neighbor 10.0.0.3 timers 1 3
  neighbor 10.0.0.3 timers connect 1
  neighbor 10.0.0.3 update-source lo
+ neighbor 192.168.18.8 remote-as external
+ neighbor 192.168.18.8 timers 1 3
+ neighbor 192.168.18.8 timers connect 1
+ address-family ipv4
+  neighbor 192.168.18.8 route-map r8 out
+ exit-address-family
 !
+ip prefix-list p71 seq 5 permit 10.0.0.71/32
+ip prefix-list p72 seq 5 permit 10.0.0.72/32
+!
+route-map r8 permit 10
+ match ip address prefix-list p71
+ set metric igp
+route-map r8 permit 20
+ match ip address prefix-list p72
+ set metric aigp
+exit

tests/topotests/bgp_aigp/r1/zebra.conf

@@ -8,3 +8,6 @@ interface r1-eth0
 interface r1-eth1
  ip address 192.168.13.1/24
 !
+interface r1-eth2
+ ip address 192.168.18.1/24
+!

tests/topotests/bgp_aigp/r8/bgpd.conf

@@ -0,0 +1,4 @@
+router bgp 65008
+ no bgp ebgp-requires-policy
+ neighbor 192.168.18.1 remote-as external
+!

tests/topotests/bgp_aigp/r8/zebra.conf

@@ -0,0 +1,4 @@
+!
+interface r8-eth0
+ ip address 192.168.18.8/24
+!

tests/topotests/bgp_aigp/test_bgp_aigp.py

@@ -15,6 +15,10 @@ r2 and r3 receives those routes with aigp-metric TLV increased by 20,
 and 10 appropriately.
 
 r1 receives routes with aigp-metric TLV 81, 91 and 82, 92 respectively.
+
+r1 advertises MED from IGP protocol (set metric igp) to r8.
+
+r1 advertises MED from AIGP (set metric aigp) to r8.
 """
 
 import os
@@ -34,7 +38,7 @@ pytestmark = [pytest.mark.bgpd]
 
 
 def build_topo(tgen):
-    for routern in range(1, 8):
+    for routern in range(1, 9):
         tgen.add_router("r{}".format(routern))
 
     switch = tgen.add_switch("s1")
@@ -65,6 +69,10 @@ def build_topo(tgen):
     switch.add_link(tgen.gears["r6"])
     switch.add_link(tgen.gears["r7"])
 
+    switch = tgen.add_switch("s8")
+    switch.add_link(tgen.gears["r1"])
+    switch.add_link(tgen.gears["r8"])
+
 
 def setup_module(mod):
     tgen = Topogen(build_topo, mod.__name__)
@@ -102,6 +110,7 @@ def test_bgp_aigp():
     r3 = tgen.gears["r3"]
     r4 = tgen.gears["r4"]
     r5 = tgen.gears["r5"]
+    r8 = tgen.gears["r8"]
 
     def _bgp_converge():
         output = json.loads(r1.vtysh_cmd("show bgp ipv4 unicast 10.0.0.71/32 json"))
@@ -143,6 +152,18 @@ def test_bgp_aigp():
         expected = {"paths": [{"aigpMetric": aigp, "valid": True}]}
         return topotest.json_cmp(output, expected)
 
+    def _bgp_check_received_med():
+        output = json.loads(
+            r8.vtysh_cmd("show bgp ipv4 unicast 10.0.0.64/28 longer-prefixes json")
+        )
+        expected = {
+            "routes": {
+                "10.0.0.71/32": [{"valid": True, "metric": 10}],
+                "10.0.0.72/32": [{"valid": True, "metric": 92}],
+            }
+        }
+        return topotest.json_cmp(output, expected)
+
     def _bgp_check_aigp_metric_bestpath():
         output = json.loads(
             r1.vtysh_cmd(
@@ -252,6 +273,13 @@ def test_bgp_aigp():
     _, result = topotest.run_and_expect(test_func, None, count=60, wait=1)
     assert result is None, "AIGP attribute is not considered in best-path selection"
 
+    # r8, check if MED is set derived from `set metric igp`, and `set metric aigp`
+    test_func = functools.partial(_bgp_check_received_med)
+    _, result = topotest.run_and_expect(test_func, None, count=30, wait=1)
+    assert (
+        result is None
+    ), "MED attribute values are not derived from `set metric [a]igp`"
+
 
 if __name__ == "__main__":
     args = ["-s"] + sys.argv[1:]

tests/topotests/bgp_set_metric_igp/r1/frr.conf

@@ -0,0 +1,13 @@
+!
+int r1-eth0
+ ip address 10.0.0.1/24
+!
+int r1-eth1
+ ip address 10.0.1.1/24
+!
+router bgp 65001
+ no bgp ebgp-requires-policy
+ no bgp network import-check
+ neighbor 10.0.0.2 remote-as external
+ neighbor 10.0.1.2 remote-as external
+!

tests/topotests/bgp_set_metric_igp/r2/frr.conf

@@ -0,0 +1,36 @@
+!
+int r2-eth0
+ ip address 10.0.0.2/24
+ ip router isis n2
+ isis circuit-type level-2-only
+ isis fast-reroute lfa level-2
+ isis network point-to-point
+ isis hello-interval 1
+ isis hello-multiplier 10
+!
+int r2-eth1
+ ip address 10.0.2.1/24
+ ip router isis n2
+ isis circuit-type level-2-only
+ isis fast-reroute lfa level-2
+ isis network point-to-point
+ isis hello-interval 1
+ isis hello-multiplier 10
+!
+router bgp 65002
+ no bgp ebgp-requires-policy
+ neighbor 10.0.0.1 remote-as external
+ neighbor 10.0.2.2 remote-as internal
+ address-family ipv4 unicast
+  neighbor 10.0.0.1 route-map igp out
+ exit-address-family
+!
+router isis n2
+ is-type level-2-only
+ net 49.0001.0000.0000.0002.00
+ lsp-mtu 1440
+exit
+!
+route-map igp permit 10
+ set metric igp
+exit

tests/topotests/bgp_set_metric_igp/r3/frr.conf

@@ -0,0 +1,38 @@
+!
+int r3-eth0
+ ip address 10.0.1.2/24
+ ip router isis n3
+ isis circuit-type level-2-only
+ isis fast-reroute lfa level-2
+ isis network point-to-point
+ isis hello-interval 1
+ isis hello-multiplier 10
+!
+int r3-eth1
+ ip address 10.0.3.1/24
+ ip router isis n3
+ isis circuit-type level-2-only
+ isis fast-reroute lfa level-2
+ isis metric level-1 10
+ isis metric level-2 100
+ isis network point-to-point
+ isis hello-interval 1
+ isis hello-multiplier 10
+!
+router bgp 65002
+ no bgp ebgp-requires-policy
+ neighbor 10.0.1.1 remote-as external
+ neighbor 10.0.3.2 remote-as internal
+ address-family ipv4 unicast
+  neighbor 10.0.1.1 route-map igp out
+ exit-address-family
+!
+router isis n3
+ is-type level-2-only
+ net 49.0001.0000.0000.0003.00
+ lsp-mtu 1440
+exit
+!
+route-map igp permit 10
+ set metric igp
+exit

tests/topotests/bgp_set_metric_igp/r4/frr.conf

@@ -0,0 +1,41 @@
+!
+int r4-eth0
+ ip address 10.0.2.2/24
+ ip router isis n4
+ isis circuit-type level-2-only
+ isis fast-reroute lfa level-2
+ isis network point-to-point
+ isis hello-interval 1
+ isis hello-multiplier 10
+!
+int r4-eth1
+ ip address 10.0.3.2/24
+ ip router isis n4
+ isis circuit-type level-2-only
+ isis fast-reroute lfa level-2
+ isis metric level-1 10
+ isis metric level-2 100
+ isis network point-to-point
+ isis hello-interval 1
+ isis hello-multiplier 10
+!
+int r4-eth2
+ ip address 10.0.4.1/24
+ ip router isis n4
+ isis circuit-type level-2-only
+ isis fast-reroute lfa level-2
+ isis network point-to-point
+ isis hello-interval 1
+ isis hello-multiplier 10
+!
+router bgp 65002
+ no bgp ebgp-requires-policy
+ neighbor 10.0.2.1 remote-as internal
+ neighbor 10.0.3.1 remote-as internal
+ neighbor 10.0.4.2 remote-as external
+!
+router isis n4
+ is-type level-2-only
+ net 49.0001.0000.0000.0004.00
+ lsp-mtu 1440
+exit

tests/topotests/bgp_set_metric_igp/r5/frr.conf

@@ -0,0 +1,14 @@
+!
+int r5-eth0
+ ip address 10.0.4.2/24
+!
+router bgp 65005
+ no bgp ebgp-requires-policy
+ no bgp network import-check
+ neighbor 10.0.4.1 remote-as external
+ neighbor 10.0.4.1 timers 1 3
+ neighbor 10.0.4.1 timers connect 1
+ address-family ipv4 unicast
+  network 10.5.5.5/32
+ exit-address-family
+!

tests/topotests/bgp_set_metric_igp/test_bgp_set_metric_igp.py

@@ -0,0 +1,146 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: ISC
+
+# Copyright (c) 2024 by
+# Donatas Abraitis <donatas@opensourcerouting.org>
+#
+
+import os
+import sys
+import json
+import pytest
+import functools
+
+CWD = os.path.dirname(os.path.realpath(__file__))
+sys.path.append(os.path.join(CWD, "../"))
+
+# pylint: disable=C0413
+from lib import topotest
+from lib.topogen import Topogen, get_topogen
+
+pytestmark = [pytest.mark.bgpd]
+
+
+def setup_module(mod):
+    topodef = {
+        "s1": ("r1", "r2"),
+        "s2": ("r1", "r3"),
+        "s3": ("r2", "r4"),
+        "s4": ("r3", "r4"),
+        "s5": ("r4", "r5"),
+    }
+    tgen = Topogen(topodef, mod.__name__)
+    tgen.start_topology()
+
+    router_list = tgen.routers()
+
+    for _, (rname, router) in enumerate(router_list.items(), 1):
+        router.load_frr_config(os.path.join(CWD, "{}/frr.conf".format(rname)))
+
+    tgen.start_router()
+
+
+def teardown_module(mod):
+    tgen = get_topogen()
+    tgen.stop_topology()
+
+
+def test_bgp_set_metric_igp():
+    tgen = get_topogen()
+
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    r1 = tgen.gears["r1"]
+    r2 = tgen.gears["r2"]
+
+    def _bgp_converge():
+        output = json.loads(r1.vtysh_cmd("show bgp ipv4 unicast json"))
+        expected = {
+            "routes": {
+                "10.5.5.5/32": [
+                    {
+                        "valid": True,
+                        "bestpath": True,
+                        "selectionReason": "MED",
+                        "metric": 20,
+                        "nexthops": [
+                            {
+                                "ip": "10.0.0.2",
+                                "hostname": "r2",
+                            }
+                        ],
+                    },
+                    {
+                        "valid": True,
+                        "bestpath": None,
+                        "metric": 110,
+                        "nexthops": [
+                            {
+                                "ip": "10.0.1.2",
+                                "hostname": "r3",
+                            }
+                        ],
+                    },
+                ]
+            }
+        }
+        return topotest.json_cmp(output, expected)
+
+    test_func = functools.partial(
+        _bgp_converge,
+    )
+    _, result = topotest.run_and_expect(test_func, None, count=120, wait=5)
+    assert result is None, "10.5.5.5/32 best path is not via r2 (MED == 20)"
+
+    r2.vtysh_cmd(
+        """
+configure terminal
+interface r2-eth1
+ isis metric level-2 6000
+"""
+    )
+
+    def _bgp_converge_after_isis_metric_changes():
+        output = json.loads(r1.vtysh_cmd("show bgp ipv4 unicast json"))
+        expected = {
+            "routes": {
+                "10.5.5.5/32": [
+                    {
+                        "valid": True,
+                        "bestpath": None,
+                        "metric": 6010,
+                        "nexthops": [
+                            {
+                                "ip": "10.0.0.2",
+                                "hostname": "r2",
+                            }
+                        ],
+                    },
+                    {
+                        "valid": True,
+                        "bestpath": True,
+                        "selectionReason": "MED",
+                        "metric": 110,
+                        "nexthops": [
+                            {
+                                "ip": "10.0.1.2",
+                                "hostname": "r3",
+                            }
+                        ],
+                    },
+                ]
+            }
+        }
+        return topotest.json_cmp(output, expected)
+
+    test_func = functools.partial(
+        _bgp_converge_after_isis_metric_changes,
+    )
+    _, result = topotest.run_and_expect(test_func, None, count=120, wait=5)
+    assert result is None, "10.5.5.5/32 best path is not via r3 (MED == 110)"
+
+
+if __name__ == "__main__":
+    args = ["-s"] + sys.argv[1:]
+    sys.exit(pytest.main(args))

yang/frr-route-map.yang

@@ -355,6 +355,22 @@ module frr-route-map {
                   "Subtract round trip time to metric";
               }
             }
+
+            case use-igp {
+              leaf use-igp {
+                type boolean;
+                description
+                  "Use metric from IGP procotol";
+              }
+            }
+
+            case use-aigp {
+              leaf use-aigp {
+                type boolean;
+                description
+                  "Use metric from AIGP (Accumulated IGP)";
+              }
+            }
           }
         }