bgpd: fix, do not access peer->notify.data when it is null

bgpd/bgp_snmp_bgp4v2.c

@@ -340,7 +340,8 @@ static uint8_t *bgpv2PeerErrorsTable(struct variable *v, oid name[],
  }
  return SNMP_STRING("");
  case BGP4V2_PEER_LAST_ERROR_RECEIVED_DATA:
- if (peer->last_reset == PEER_DOWN_NOTIFY_RECEIVED)
+ if (peer->last_reset == PEER_DOWN_NOTIFY_RECEIVED &&
+ peer->notify.data)
  return SNMP_STRING(peer->notify.data);
  else
  return SNMP_STRING("");

tests/topotests/bgp_snmp_bgp4v2_notification/r2/bgpd.conf

@@ -0,0 +1,18 @@
+!
+!debug bgp updates
+!
+router bgp 65002
+ no bgp ebgp-requires-policy
+ no bgp network import-check
+ no bgp default ipv4-unicast
+ neighbor 192.168.12.4 remote-as external
+ neighbor 192.168.12.4 timers 1 3
+ neighbor 192.168.12.4 timers connect 1
+ !
+ address-family ipv4 unicast
+ neighbor 192.168.12.4 activate
+ neighbor 192.168.12.4 addpath-tx-all-paths
+ exit-address-family
+!
+agentx
+!

tests/topotests/bgp_snmp_bgp4v2_notification/r2/snmpd.conf

@@ -0,0 +1,17 @@
+agentAddress 127.0.0.1,[::1]
+
+group public_group v1 public
+group public_group v2c public
+access public_group "" any noauth prefix all all none
+
+rocommunity public default
+
+view all included .1
+
+iquerySecName frr
+rouser frr
+
+master agentx
+
+agentXSocket /etc/frr/agentx
+agentXPerms 777 755 root frr

tests/topotests/bgp_snmp_bgp4v2_notification/r2/zebra.conf

@@ -0,0 +1,4 @@
+!
+interface r2-eth0
+ ip address 192.168.12.2/24
+!

tests/topotests/bgp_snmp_bgp4v2_notification/rr/bgpd.conf

@@ -0,0 +1,19 @@
+!
+!debug bgp updates
+!
+router bgp 65004
+ no bgp ebgp-requires-policy
+ no bgp network import-check
+ no bgp default ipv4-unicast
+ neighbor 192.168.12.2 remote-as external
+ neighbor 192.168.12.2 timers 1 3
+ neighbor 192.168.12.2 timers connect 1
+ !
+ address-family ipv4 unicast
+ neighbor 192.168.12.2 activate
+ neighbor 192.168.12.2 addpath-tx-all-paths
+ neighbor 192.168.12.2 route-server-client
+ exit-address-family
+!
+agentx
+!

tests/topotests/bgp_snmp_bgp4v2_notification/rr/zebra.conf

@@ -0,0 +1,4 @@
+!
+interface rr-eth0
+ ip address 192.168.12.4/24
+!

tests/topotests/bgp_snmp_bgp4v2_notification/test_bgp_snmp_bgp4v2_notification.py

@@ -0,0 +1,118 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Copyright 2024 6WIND S.A.
+#
+
+
+"""
+Test BGP OPEN NOTIFY (Configuration mismatch) followed by snmpwalk.
+"""
+
+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
+# Import topogen and topotest helpers
+from lib.topogen import Topogen, TopoRouter, get_topogen
+from lib import topotest
+
+pytestmark = [pytest.mark.bgpd, pytest.mark.snmp]
+
+
+def build_topo(tgen):
+ """Build function"""
+
+ tgen.add_router("r2")
+ tgen.add_router("rr")
+
+ switch = tgen.add_switch("s1")
+ switch.add_link(tgen.gears["r2"])
+ switch.add_link(tgen.gears["rr"])
+
+
+def setup_module(mod):
+ snmpd = os.system("which snmpd")
+ if snmpd:
+ error_msg = "SNMP not installed - skipping"
+ pytest.skip(error_msg)
+
+ tgen = Topogen(build_topo, mod.__name__)
+ tgen.start_topology()
+
+ for rname, router in tgen.routers().items():
+ 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)),
+ "-M snmp",
+ )
+ router.load_config(
+ TopoRouter.RD_SNMP,
+ os.path.join(CWD, "{}/snmpd.conf".format(rname)),
+ "-Le -Ivacm_conf,usmConf,iquery -V -DAgentX",
+ )
+
+ tgen.start_router()
+
+
+def teardown_module(mod):
+ tgen = get_topogen()
+ tgen.stop_topology()
+
+
+def test_bgp_open_notification_change_configuration():
+ tgen = get_topogen()
+
+ tgen.gears["rr"].vtysh_multicmd(
+ """
+configure terminal
+router bgp 65004
+neighbor 192.168.12.2 password 8888"
+"""
+ )
+ tgen.net["r2"].cmd("snmpwalk -v 2c -c public 127.0.0.1 .1.3.6.1.4.1.7336.4.2.1")
+ tgen.gears["rr"].vtysh_multicmd(
+ """
+configure terminal
+router bgp 65004
+no neighbor 192.168.12.2 password 8888"
+"""
+ )
+
+ def _check_bgp_session():
+ r2 = tgen.gears["r2"]
+
+ output = json.loads(r2.vtysh_cmd("show bgp summary json"))
+ expected = {
+ "ipv4Unicast": {"peers": {"192.168.12.4": {"state": "Established"}}}
+ }
+
+ return topotest.json_cmp(output, expected)
+
+ test_func1 = functools.partial(_check_bgp_session)
+ _, result1 = topotest.run_and_expect(test_func1, None, count=120, wait=0.5)
+
+ assert result1 is None, "Failed to verify the bgp session"
+
+
+def test_memory_leak():
+ "Run the memory leak test and report results."
+ tgen = get_topogen()
+ if not tgen.is_memleak_enabled():
+ pytest.skip("Memory leak test/report is disabled")
+
+ tgen.report_memory_leaks()
+
+
+if __name__ == "__main__":
+ args = ["-s"] + sys.argv[1:]
+ sys.exit(pytest.main(args))