Merge pull request FRRouting#17376 from opensourcerouting/fix/stale_r…

…outes_with_addpath

bgpd: Clear stale routes with multiple paths

bgpd/bgp_fsm.c

@@ -689,6 +689,11 @@ static void bgp_set_llgr_stale(struct peer *peer, afi_t afi, safi_t safi)
 						    COMMUNITY_NO_LLGR))
 						continue;
 
+					if (bgp_attr_get_community(pi->attr) &&
+					    community_include(bgp_attr_get_community(pi->attr),
+							      COMMUNITY_LLGR_STALE))
+						continue;
+
 					if (bgp_debug_neighbor_events(peer))
 						zlog_debug(
 							"%pBP Long-lived set stale community (LLGR_STALE) for: %pFX",
@@ -699,7 +704,6 @@ static void bgp_set_llgr_stale(struct peer *peer, afi_t afi, safi_t safi)
 					pi->attr = bgp_attr_intern(&attr);
 					bgp_process(peer->bgp, rm, pi, afi,
 						    safi);
-					break;
 				}
 		}
 	} else {
@@ -716,6 +720,11 @@ static void bgp_set_llgr_stale(struct peer *peer, afi_t afi, safi_t safi)
 					    COMMUNITY_NO_LLGR))
 					continue;
 
+				if (bgp_attr_get_community(pi->attr) &&
+				    community_include(bgp_attr_get_community(pi->attr),
+						      COMMUNITY_LLGR_STALE))
+					continue;
+
 				if (bgp_debug_neighbor_events(peer))
 					zlog_debug(
 						"%pBP Long-lived set stale community (LLGR_STALE) for: %pFX",
@@ -725,7 +734,6 @@ static void bgp_set_llgr_stale(struct peer *peer, afi_t afi, safi_t safi)
 				bgp_attr_add_llgr_community(&attr);
 				pi->attr = bgp_attr_intern(&attr);
 				bgp_process(peer->bgp, dest, pi, afi, safi);
-				break;
 			}
 	}
 }

bgpd/bgp_route.c

@@ -6292,7 +6292,6 @@ void bgp_clear_stale_route(struct peer *peer, afi_t afi, safi_t safi)
 						vpn_leak_to_vrf_withdraw(pi);
 
 					bgp_rib_remove(rm, pi, peer, afi, safi);
-					break;
 				}
 		}
 	} else {
@@ -6321,7 +6320,6 @@ void bgp_clear_stale_route(struct peer *peer, afi_t afi, safi_t safi)
 						pi);
 
 				bgp_rib_remove(dest, pi, peer, afi, safi);
-				break;
 			}
 	}
 }

tests/topotests/bgp_addpath_graceful_restart/r1/frr.conf

@@ -0,0 +1,23 @@
+!
+int r1-eth0
+ ip address 192.168.1.1/24
+!
+int r1-eth1
+ ip address 192.168.2.1/24
+!
+router bgp 65001
+ no bgp ebgp-requires-policy
+ no bgp network import-check
+ neighbor 192.168.1.2 remote-as auto
+ neighbor 192.168.1.2 timers 1 3
+ neighbor 192.168.1.2 timers connect 1
+ neighbor 192.168.2.2 remote-as auto
+ neighbor 192.168.2.2 timers 1 3
+ neighbor 192.168.2.2 timers connect 1
+ neighbor r1-eth1 interface remote-as auto
+ neighbor r1-eth1 timers 1 3
+ neighbor r1-eth1 timers connect 1
+ address-family ipv4 unicast
+  network 10.0.0.1/32
+ exit-address-family
+!

tests/topotests/bgp_addpath_graceful_restart/r2/frr.conf

@@ -0,0 +1,28 @@
+!
+int r2-eth0
+ ip address 192.168.1.2/24
+!
+int r2-eth1
+ ip address 192.168.2.2/24
+!
+int r2-eth2
+ ip address 192.168.3.2/24
+!
+router bgp 65002
+ bgp graceful-restart
+ bgp graceful-restart preserve-fw-state
+ bgp graceful-restart restart-time 10
+ no bgp ebgp-requires-policy
+ neighbor 192.168.1.1 remote-as auto
+ neighbor 192.168.1.1 timers 1 3
+ neighbor 192.168.1.1 timers connect 1
+ neighbor 192.168.2.1 remote-as auto
+ neighbor 192.168.2.1 timers 1 3
+ neighbor 192.168.2.1 timers connect 1
+ neighbor 192.168.3.3 remote-as auto
+ neighbor 192.168.3.3 timers 1 3
+ neighbor 192.168.3.3 timers connect 1
+ address-family ipv4 unicast
+  neighbor 192.168.3.3 addpath-tx-all-paths
+ exit-address-family
+!

tests/topotests/bgp_addpath_graceful_restart/r3/frr.conf

@@ -0,0 +1,13 @@
+!
+int r3-eth0
+ ip address 192.168.3.3/24
+!
+router bgp 65003
+ bgp graceful-restart
+ bgp graceful-restart preserve-fw-state
+ bgp graceful-restart restart-time 10
+ no bgp ebgp-requires-policy
+ neighbor 192.168.3.2 remote-as auto
+ neighbor 192.168.3.2 timers 1 3
+ neighbor 192.168.3.2 timers connect 1
+!

tests/topotests/bgp_addpath_graceful_restart/test_bgp_addpath_graceful_restart.py

@@ -0,0 +1,132 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: ISC
+
+# Copyright (c) 2024 by
+# Donatas Abraitis <[email protected]>
+#
+
+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
+from lib.common_config import kill_router_daemons
+
+pytestmark = [pytest.mark.bgpd]
+
+
+def setup_module(mod):
+    topodef = {"s1": ("r1", "r2"), "s2": ("r1", "r2"), "s3": ("r2", "r3")}
+    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_addpath_graceful_restart():
+    tgen = get_topogen()
+
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    r2 = tgen.gears["r2"]
+    r3 = tgen.gears["r3"]
+
+    def _bgp_converge():
+        output = json.loads(r2.vtysh_cmd("show bgp ipv4 unicast summary json"))
+        expected = {
+            "peers": {
+                "192.168.1.1": {
+                    "hostname": "r1",
+                    "remoteAs": 65001,
+                    "localAs": 65002,
+                    "pfxRcd": 1,
+                    "state": "Established",
+                },
+                "192.168.2.1": {
+                    "hostname": "r1",
+                    "remoteAs": 65001,
+                    "localAs": 65002,
+                    "pfxRcd": 1,
+                    "state": "Established",
+                },
+                "192.168.3.3": {
+                    "hostname": "r3",
+                    "remoteAs": 65003,
+                    "localAs": 65002,
+                    "pfxSnt": 2,
+                    "state": "Established",
+                },
+            }
+        }
+        return topotest.json_cmp(output, expected)
+
+    test_func = functools.partial(
+        _bgp_converge,
+    )
+    _, result = topotest.run_and_expect(test_func, None, count=30, wait=1)
+    assert result is None, "Initial peering failed"
+
+    kill_router_daemons(tgen, "r2", ["bgpd"])
+
+    def _bgp_check_stale_routes():
+        output = json.loads(r3.vtysh_cmd("show bgp ipv4 unicast json"))
+        expected = {
+            "routes": {
+                "10.0.0.1/32": [
+                    {
+                        "stale": True,
+                        "valid": True,
+                    },
+                    {
+                        "stale": True,
+                        "valid": True,
+                        "multipath": True,
+                    },
+                ]
+            }
+        }
+        return topotest.json_cmp(output, expected)
+
+    test_func = functools.partial(
+        _bgp_check_stale_routes,
+    )
+    _, result = topotest.run_and_expect(test_func, None, count=30, wait=1)
+    assert result is None, "Can't see stale routes"
+
+    def _bgp_check_stale_routes_cleared():
+        output = json.loads(r3.vtysh_cmd("show bgp ipv4 unicast json"))
+        expected = {
+            "routes": {
+                "10.0.0.1/32": None,
+            }
+        }
+        return topotest.json_cmp(output, expected)
+
+    test_func = functools.partial(
+        _bgp_check_stale_routes_cleared,
+    )
+    _, result = topotest.run_and_expect(test_func, None, count=30, wait=1)
+    assert result is None, "Can't see stale routes"
+
+
+if __name__ == "__main__":
+    args = ["-s"] + sys.argv[1:]
+    sys.exit(pytest.main(args))

tests/topotests/bgp_addpath_llgr/r1/frr.conf

@@ -0,0 +1,23 @@
+!
+int r1-eth0
+ ip address 192.168.1.1/24
+!
+int r1-eth1
+ ip address 192.168.2.1/24
+!
+router bgp 65001
+ no bgp ebgp-requires-policy
+ no bgp network import-check
+ neighbor 192.168.1.2 remote-as auto
+ neighbor 192.168.1.2 timers 1 3
+ neighbor 192.168.1.2 timers connect 1
+ neighbor 192.168.2.2 remote-as auto
+ neighbor 192.168.2.2 timers 1 3
+ neighbor 192.168.2.2 timers connect 1
+ neighbor r1-eth1 interface remote-as auto
+ neighbor r1-eth1 timers 1 3
+ neighbor r1-eth1 timers connect 1
+ address-family ipv4 unicast
+  network 10.0.0.1/32
+ exit-address-family
+!

tests/topotests/bgp_addpath_llgr/r2/frr.conf

@@ -0,0 +1,29 @@
+!
+int r2-eth0
+ ip address 192.168.1.2/24
+!
+int r2-eth1
+ ip address 192.168.2.2/24
+!
+int r2-eth2
+ ip address 192.168.3.2/24
+!
+router bgp 65002
+ bgp graceful-restart
+ bgp graceful-restart preserve-fw-state
+ bgp graceful-restart restart-time 0
+ bgp long-lived-graceful-restart stale-time 10
+ no bgp ebgp-requires-policy
+ neighbor 192.168.1.1 remote-as auto
+ neighbor 192.168.1.1 timers 1 3
+ neighbor 192.168.1.1 timers connect 1
+ neighbor 192.168.2.1 remote-as auto
+ neighbor 192.168.2.1 timers 1 3
+ neighbor 192.168.2.1 timers connect 1
+ neighbor 192.168.3.3 remote-as auto
+ neighbor 192.168.3.3 timers 1 3
+ neighbor 192.168.3.3 timers connect 1
+ address-family ipv4 unicast
+  neighbor 192.168.3.3 addpath-tx-all-paths
+ exit-address-family
+!

tests/topotests/bgp_addpath_llgr/r3/frr.conf

@@ -0,0 +1,14 @@
+!
+int r3-eth0
+ ip address 192.168.3.3/24
+!
+router bgp 65003
+ bgp graceful-restart
+ bgp graceful-restart preserve-fw-state
+ bgp graceful-restart restart-time 0
+ bgp long-lived-graceful-restart stale-time 10
+ no bgp ebgp-requires-policy
+ neighbor 192.168.3.2 remote-as auto
+ neighbor 192.168.3.2 timers 1 3
+ neighbor 192.168.3.2 timers connect 1
+!