bgpd: Fix aggregate-address summary-only matching-MED-only

Before it worked only when configured initially via CLI. Later, when we
receive a new route, that should match a decent MED, we just skip it, because
MED mismatch is not recalculated.

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

bgpd/bgp_route.c

@@ -7423,31 +7423,21 @@ void bgp_aggregate_toggle_suppressed(struct bgp_aggregate *aggregate,
 static void bgp_aggregate_med_update(struct bgp_aggregate *aggregate,
 				     struct bgp *bgp, const struct prefix *p,
 				     afi_t afi, safi_t safi,
-				     struct bgp_path_info *pi, bool is_adding)
+				     struct bgp_path_info *pi)
 {
 	/* MED matching disabled. */
 	if (!aggregate->match_med)
 		return;
 
-	/* Aggregation with different MED, nothing to do. */
-	if (aggregate->med_mismatched)
-		return;
-
-	/*
-	 * Test the current entry:
-	 *
-	 * is_adding == true: if the new entry doesn't match then we must
-	 * install all suppressed routes.
-	 *
-	 * is_adding == false: if the entry being removed was the last
-	 * unmatching entry then we can suppress all routes.
+	/* Aggregation with different MED, recheck if we have got equal MEDs
+	 * now.
 	 */
-	if (!is_adding) {
-		if (bgp_aggregate_test_all_med(aggregate, bgp, p, afi, safi)
-		    && aggregate->summary_only)
-			bgp_aggregate_toggle_suppressed(aggregate, bgp, p, afi,
-							safi, true);
-	} else
+	if (aggregate->med_mismatched &&
+	    bgp_aggregate_test_all_med(aggregate, bgp, p, afi, safi) &&
+	    aggregate->summary_only)
+		bgp_aggregate_toggle_suppressed(aggregate, bgp, p, afi, safi,
+						true);
+	else
 		bgp_aggregate_med_match(aggregate, bgp, pi);
 
 	/* No mismatches, just quit. */
@@ -7813,7 +7803,7 @@ static void bgp_add_route_to_aggregate(struct bgp *bgp,
 	 */
 	if (aggregate->match_med)
 		bgp_aggregate_med_update(aggregate, bgp, aggr_p, afi, safi,
-					 pinew, true);
+					 pinew);
 
 	if (aggregate->summary_only && AGGREGATE_MED_VALID(aggregate))
 		aggr_suppress_path(aggregate, pinew);
@@ -7936,8 +7926,7 @@ static void bgp_remove_route_from_aggregate(struct bgp *bgp, afi_t afi,
 	 * "unsuppressing" twice.
 	 */
 	if (aggregate->match_med)
-		bgp_aggregate_med_update(aggregate, bgp, aggr_p, afi, safi, pi,
-					 true);
+		bgp_aggregate_med_update(aggregate, bgp, aggr_p, afi, safi, pi);
 
 	if (aggregate->count > 0)
 		aggregate->count--;

tests/topotests/bgp_aggregate_address_matching_med/r1/bgpd.conf

@@ -0,0 +1,21 @@
+!
+router bgp 65001
+ no bgp ebgp-requires-policy
+ neighbor 192.168.1.2 remote-as external
+ neighbor 192.168.1.2 timers 3 10
+ address-family ipv4 unicast
+  redistribute connected
+  neighbor 192.168.1.2 route-map r2 out
+ exit-address-family
+!
+ip prefix-list p1 seq 5 permit 172.16.255.1/32
+ip prefix-list p1 seq 10 permit 172.16.255.2/32
+ip prefix-list p2 seq 15 permit 172.16.255.3/32
+!
+route-map r2 permit 10
+ match ip address prefix-list p1
+ set metric 300
+route-map r2 permit 20
+ match ip address prefix-list p2
+ set metric 400
+!

tests/topotests/bgp_aggregate_address_matching_med/r1/zebra.conf

@@ -0,0 +1,11 @@
+!
+interface lo
+ ip address 172.16.255.1/32
+ ip address 172.16.255.2/32
+ ip address 172.16.255.3/32
+!
+interface r1-eth0
+ ip address 192.168.1.1/24
+!
+ip forwarding
+!

tests/topotests/bgp_aggregate_address_matching_med/r2/bgpd.conf

@@ -0,0 +1,11 @@
+!
+router bgp 65002
+ no bgp ebgp-requires-policy
+ neighbor 192.168.1.1 remote-as external
+ neighbor 192.168.1.1 timers 3 10
+ neighbor 192.168.2.1 remote-as external
+ neighbor 192.168.2.1 timers 3 10
+ address-family ipv4 unicast
+  aggregate-address 172.16.255.0/24 summary-only matching-MED-only
+ exit-address-family
+!

tests/topotests/bgp_aggregate_address_matching_med/r2/zebra.conf

@@ -0,0 +1,9 @@
+!
+interface r2-eth0
+ ip address 192.168.1.2/24
+!
+interface r2-eth1
+ ip address 192.168.2.2/24
+!
+ip forwarding
+!

tests/topotests/bgp_aggregate_address_matching_med/r3/bgpd.conf

@@ -0,0 +1,6 @@
+!
+router bgp 65003
+ no bgp ebgp-requires-policy
+ neighbor 192.168.2.2 remote-as external
+ neighbor 192.168.2.2 timers 3 10
+!

tests/topotests/bgp_aggregate_address_matching_med/r3/zebra.conf

@@ -0,0 +1,6 @@
+!
+interface r3-eth0
+ ip address 192.168.2.1/24
+!
+ip forwarding
+!

tests/topotests/bgp_aggregate_address_matching_med/test_bgp_aggregate_address_matching_med.py

@@ -0,0 +1,148 @@
+#!/usr/bin/env python
+
+#
+# Copyright (c) 2022 by
+# Donatas Abraitis <donatas@opensourcerouting.org>
+#
+# Permission to use, copy, modify, and/or distribute this software
+# for any purpose with or without fee is hereby granted, provided
+# that the above copyright notice and this permission notice appear
+# in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NETDEF DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NETDEF BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY
+# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+# OF THIS SOFTWARE.
+#
+
+"""
+Test if aggregate-address command works fine when suppressing summary-only
+and using matching-MED-only together.
+"""
+
+import os
+import sys
+import json
+import pytest
+import functools
+from lib.common_config import (
+    step,
+)
+
+# pylint: disable=C0413
+from lib import topotest
+from lib.topogen import Topogen, TopoRouter, get_topogen
+
+pytestmark = [pytest.mark.bgpd]
+
+CWD = os.path.dirname(os.path.realpath(__file__))
+sys.path.append(os.path.join(CWD, "../"))
+
+
+def build_topo(tgen):
+    for routern in range(1, 5):
+        tgen.add_router("r{}".format(routern))
+
+    switch = tgen.add_switch("s1")
+    switch.add_link(tgen.gears["r1"])
+    switch.add_link(tgen.gears["r2"])
+
+    switch = tgen.add_switch("s2")
+    switch.add_link(tgen.gears["r2"])
+    switch.add_link(tgen.gears["r3"])
+
+
+def setup_module(mod):
+    tgen = Topogen(build_topo, mod.__name__)
+    tgen.start_topology()
+
+    router_list = tgen.routers()
+
+    for i, (rname, router) in enumerate(router_list.items(), 1):
+        router.load_config(
+            TopoRouter.RD_ZEBRA, os.path.join(CWD, "{}/zebra.conf".format(rname))
+        )
+        router.load_config(
+            TopoRouter.RD_BGP, os.path.join(CWD, "{}/bgpd.conf".format(rname))
+        )
+
+    tgen.start_router()
+
+
+def teardown_module(mod):
+    tgen = get_topogen()
+    tgen.stop_topology()
+
+
+def test_aggregate_address_matching_med():
+    tgen = get_topogen()
+
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    r1 = tgen.gears["r1"]
+    r3 = tgen.gears["r3"]
+
+    def _bgp_converge():
+        output = json.loads(r3.vtysh_cmd("show bgp ipv4 unicast json"))
+        expected = {
+            "routes": {
+                "172.16.255.0/24": None,
+                "172.16.255.1/32": [{"path": "65002 65001"}],
+                "172.16.255.2/32": [{"path": "65002 65001"}],
+                "172.16.255.3/32": [{"path": "65002 65001"}],
+            }
+        }
+        return topotest.json_cmp(output, expected)
+
+    test_func = functools.partial(_bgp_converge)
+    _, result = topotest.run_and_expect(test_func, None, count=30, wait=0.5)
+    assert result is None, "Failed to see unsuppressed routes from R2"
+
+    step("Change MED for 172.16.255.3/32 from 400 to 300")
+    r1.vtysh_cmd(
+        """
+    configure terminal
+        route-map r2 permit 20
+            set metric 300
+    """
+    )
+
+    step("Check if 172.16.255.0/24 aggregated route was created and others suppressed")
+
+    def _bgp_aggregated_summary_only_med_match():
+        output = json.loads(r3.vtysh_cmd("show bgp ipv4 unicast json"))
+        expected = {
+            "routes": {
+                "172.16.255.0/24": [{"path": "65002"}],
+                "172.16.255.1/32": None,
+                "172.16.255.2/32": None,
+                "172.16.255.3/32": None,
+            }
+        }
+        return topotest.json_cmp(output, expected)
+
+    test_func = functools.partial(_bgp_aggregated_summary_only_med_match)
+    _, result = topotest.run_and_expect(test_func, None, count=30, wait=0.5)
+    assert result is None, "Failed to see unsuppressed routes from R2"
+
+    step("Change MED for 172.16.255.3/32 back to 400 from 300")
+    r1.vtysh_cmd(
+        """
+    configure terminal
+        route-map r2 permit 20
+            set metric 400
+    """
+    )
+    test_func = functools.partial(_bgp_converge)
+    _, result = topotest.run_and_expect(test_func, None, count=30, wait=0.5)
+    assert result is None, "Failed to see unsuppressed routes from R2"
+
+
+if __name__ == "__main__":
+    args = ["-s"] + sys.argv[1:]
+    sys.exit(pytest.main(args))