bgpd: Do not start BGP session if BFD profile is in shutdown state

bgpd/bgp_packet.c

@@ -982,6 +982,7 @@ static void bgp_notify_send_internal(struct peer_connection *connection,
 		peer->notify.code = bgp_notify.code;
 		peer->notify.subcode = bgp_notify.subcode;
 		peer->notify.length = bgp_notify.length;
+		peer->notify.hard_reset = hard_reset;
 
 		if (bgp_notify.length && data) {
 			bgp_notify.data = XMALLOC(MTYPE_BGP_NOTIFICATION,

bgpd/bgpd.c

@@ -4507,6 +4507,12 @@ bool peer_active(struct peer *peer)
 {
 	if (BGP_CONNECTION_SU_UNSPEC(peer->connection))
 		return false;
+
+	if (peer->bfd_config) {
+		if (bfd_session_is_down(peer->bfd_config->session))
+			return false;
+	}
+
 	if (peer->afc[AFI_IP][SAFI_UNICAST] || peer->afc[AFI_IP][SAFI_MULTICAST]
 	    || peer->afc[AFI_IP][SAFI_LABELED_UNICAST]
 	    || peer->afc[AFI_IP][SAFI_MPLS_VPN] || peer->afc[AFI_IP][SAFI_ENCAP]

lib/bfd.c

@@ -1334,3 +1334,9 @@ int bfd_nht_update(const struct prefix *match, const struct zapi_route *route)
 
 	return 0;
 }
+
+bool bfd_session_is_down(const struct bfd_session_params *session)
+{
+	return session->bss.state == BSS_DOWN ||
+	       session->bss.state == BSS_ADMIN_DOWN;
+}

lib/bfd.h

@@ -464,6 +464,8 @@ extern bool bfd_protocol_integration_shutting_down(void);
 extern int bfd_nht_update(const struct prefix *match,
 			  const struct zapi_route *route);
 
+extern bool bfd_session_is_down(const struct bfd_session_params *session);
+
 #ifdef __cplusplus
 }
 #endif

tests/topotests/bgp_bfd_down_cease_notification/r1/bfdd.conf

@@ -1,5 +1,9 @@
 bfd
+ profile r1
+ exit
+ !
  peer 192.168.255.2 interface r1-eth0
+ profile r1
  exit
  !
 exit

tests/topotests/bgp_bfd_down_cease_notification/r1/bgpd.conf

@@ -3,7 +3,7 @@ router bgp 65001
  neighbor 192.168.255.2 remote-as external
  neighbor 192.168.255.2 timers 3 10
  neighbor 192.168.255.2 timers connect 1
- neighbor 192.168.255.2 bfd
+ neighbor 192.168.255.2 bfd profile r1
  neighbor 192.168.255.2 passive
  address-family ipv4
   redistribute connected

tests/topotests/bgp_bfd_down_cease_notification/test_bgp_bfd_down_cease_notification.py

@@ -89,6 +89,9 @@ def _bgp_bfd_down_notification():
             "192.168.255.1": {
                 "lastNotificationReason": "Cease/BFD Down",
                 "lastNotificationHardReset": True,
+                "peerBfdInfo": {
+                    "status": "Up",
+                },
             }
         }
         return topotest.json_cmp(output, expected)

tests/topotests/bgp_bfd_down_cease_notification/test_bgp_bfd_down_cease_notification_shutdown.py

@@ -0,0 +1,122 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: ISC
+
+#
+# bgp_bfd_down_cease_notification_shutdown.py
+#
+# Copyright (c) 2024 by
+# Donatas Abraitis <[email protected]>
+#
+
+"""
+Check if Cease/BFD Down notification message is sent/received
+when the BFD is down (administratively).
+"""
+
+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
+from lib.common_config import kill_router_daemons, step
+
+pytestmark = [pytest.mark.bfdd, 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))
+        )
+        router.load_config(
+            TopoRouter.RD_BFD, os.path.join(CWD, "{}/bfdd.conf".format(rname))
+        )
+
+    tgen.start_router()
+
+
+def teardown_module(mod):
+    tgen = get_topogen()
+    tgen.stop_topology()
+
+
+def test_bgp_bfd_down_notification_shutdown():
+    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(r2.vtysh_cmd("show ip bgp neighbor 192.168.255.1 json"))
+        expected = {
+            "192.168.255.1": {
+                "bgpState": "Established",
+                "addressFamilyInfo": {"ipv4Unicast": {"acceptedPrefixCounter": 2}},
+                "peerBfdInfo": {"status": "Up"},
+            }
+        }
+        return topotest.json_cmp(output, expected)
+
+    def _bgp_bfd_down_notification():
+        output = json.loads(r2.vtysh_cmd("show ip bgp neighbor 192.168.255.1 json"))
+        expected = {
+            "192.168.255.1": {
+                "lastNotificationReason": "Cease/BFD Down",
+                "lastNotificationHardReset": True,
+                "peerBfdInfo": {
+                    "status": "Down",
+                },
+            }
+        }
+        return topotest.json_cmp(output, expected)
+
+    step("Initial BGP converge")
+    test_func = functools.partial(_bgp_converge)
+    _, result = topotest.run_and_expect(test_func, None, count=30, wait=1)
+    assert result is None, "Failed to see BGP convergence on R2"
+
+    r1.vtysh_cmd(
+        """
+    configure
+     bfd
+      profile r1
+       shutdown
+    """
+    )
+
+    step("Check if we received Cease/BFD Down notification message")
+    test_func = functools.partial(_bgp_bfd_down_notification)
+    _, result = topotest.run_and_expect(test_func, None, count=30, wait=1)
+    assert result is None, "Failed to see BGP Cease/BFD Down notification message on R2"
+
+
+if __name__ == "__main__":
+    args = ["-s"] + sys.argv[1:]
+    sys.exit(pytest.main(args))