Merge pull request #12059 from achernavin22/fix-max-med-on-startup

bgpd: fix "bgp max-med on-startup"

bgpd/bgp_updgrp_adv.c

@@ -355,6 +355,11 @@ static int update_group_announce_walkcb(struct update_group *updgrp, void *arg)
 	struct update_subgroup *subgrp;
 
 	UPDGRP_FOREACH_SUBGRP (updgrp, subgrp) {
+		/* Avoid supressing duplicate routes later
+		 * when processing in subgroup_announce_table().
+		 */
+		SET_FLAG(subgrp->sflags, SUBGRP_STATUS_FORCE_UPDATES);
+
 		subgroup_announce_all(subgrp);
 	}
 

tests/topotests/bgp_max_med_on_startup/r1/bgpd.conf

@@ -0,0 +1,11 @@
+!
+router bgp 65001
+  bgp max-med on-startup 5 777
+  no bgp ebgp-requires-policy
+  neighbor 192.168.255.2 remote-as 65001
+  neighbor 192.168.255.2 timers 3 10
+  address-family ipv4 unicast
+    redistribute connected
+  exit-address-family
+  !
+!

tests/topotests/bgp_max_med_on_startup/r1/zebra.conf

@@ -0,0 +1,9 @@
+!
+interface lo
+ ip address 172.16.255.254/32
+!
+interface r1-eth0
+ ip address 192.168.255.1/30
+!
+ip forwarding
+!

tests/topotests/bgp_max_med_on_startup/r2/bgpd.conf

@@ -0,0 +1,7 @@
+!
+router bgp 65001
+  no bgp ebgp-requires-policy
+  neighbor 192.168.255.1 remote-as 65001
+  neighbor 192.168.255.1 timers 3 10
+  !
+!

tests/topotests/bgp_max_med_on_startup/r2/zebra.conf

@@ -0,0 +1,6 @@
+!
+interface r2-eth0
+ ip address 192.168.255.2/30
+!
+ip forwarding
+!

tests/topotests/bgp_max_med_on_startup/test_bgp_max_med_on_startup.py

@@ -0,0 +1,114 @@
+#!/usr/bin/env python
+
+#
+# test_bgp_max_med_on_startup.py
+#
+# Copyright (c) 2022 Rubicon Communications, LLC.
+#
+# 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 whether `bgp max-med on-startup (5-86400) [(0-4294967295)]` is working
+correctly.
+"""
+
+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, TopoRouter, get_topogen
+
+pytestmark = [pytest.mark.bgpd]
+
+
+def build_topo(tgen):
+    for routern in range(1, 3):
+        tgen.add_router("r{}".format(routern))
+
+    switch = tgen.add_switch("s1")
+    switch.add_link(tgen.gears["r1"])
+    switch.add_link(tgen.gears["r2"])
+
+
+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_bgp_max_med_on_startup():
+    tgen = get_topogen()
+
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    router1 = tgen.gears["r1"]
+    router2 = tgen.gears["r2"]
+
+    def _bgp_converge(router):
+        output = json.loads(router.vtysh_cmd("show ip bgp neighbor 192.168.255.1 json"))
+        expected = {"192.168.255.1": {"bgpState": "Established"}}
+        return topotest.json_cmp(output, expected)
+
+    def _bgp_has_routes(router, metric):
+        output = json.loads(
+            router.vtysh_cmd("show ip bgp neighbor 192.168.255.1 routes json")
+        )
+        expected = {"routes": {"172.16.255.254/32": [{"metric": metric}]}}
+        return topotest.json_cmp(output, expected)
+
+    # Check session is established
+    test_func = functools.partial(_bgp_converge, router2)
+    success, result = topotest.run_and_expect(test_func, None, count=30, wait=0.5)
+    assert result is None, "Failed bgp convergence on r2"
+
+    # Check metric has value of max-med
+    test_func = functools.partial(_bgp_has_routes, router2, 777)
+    success, result = topotest.run_and_expect(test_func, None, count=30, wait=0.5)
+    assert result is None, "r2 does not receive routes with metric 777"
+
+    # Check that when the max-med timer expires, metric is updated
+    test_func = functools.partial(_bgp_has_routes, router2, 0)
+    success, result = topotest.run_and_expect(test_func, None, count=16, wait=0.5)
+    assert result is None, "r2 does not receive routes with metric 0"
+
+
+if __name__ == "__main__":
+    args = ["-s"] + sys.argv[1:]
+    sys.exit(pytest.main(args))