Merge pull request #17855 from opensourcerouting/fix/bgp_enhe_capability_via_dynamic_capability

bgpd: Handle ENHE capability via dynamic capability

3 files changed, 236 insertions, 0 deletions

diff --git a/tests/topotests/bgp_dynamic_capability/r1/frr.conf b/tests/topotests/bgp_dynamic_capability/r1/frr.conf
index c9594626f5..d91913e15e 100644
--- a/tests/topotests/bgp_dynamic_capability/r1/frr.conf
+++ b/tests/topotests/bgp_dynamic_capability/r1/frr.conf
@@ -3,6 +3,7 @@
 !
 int r1-eth0
  ip address 192.168.1.1/24
+ ipv6 address 2001:db8::1/64
 !
 router bgp 65001
  no bgp ebgp-requires-policy
@@ -12,11 +13,19 @@ router bgp 65001
  neighbor 192.168.1.2 timers 1 3
  neighbor 192.168.1.2 timers connect 1
  neighbor 192.168.1.2 capability dynamic
+ neighbor 2001:db8::2 remote-as external
+ neighbor 2001:db8::2 timers 1 3
+ neighbor 2001:db8::2 timers connect 1
+ neighbor 2001:db8::2 capability dynamic
  !
  address-family ipv4 unicast
   neighbor 192.168.1.2 addpath-tx-all-paths
   neighbor 192.168.1.2 addpath-rx-paths-limit 10
  exit-address-family
+ !
+ address-family ipv6 unicast
+  neighbor 2001:db8::2 activate
+ exit-address-family
 !
 ip prefix-list r2 seq 5 permit 10.10.10.10/32
 !
diff --git a/tests/topotests/bgp_dynamic_capability/r2/frr.conf b/tests/topotests/bgp_dynamic_capability/r2/frr.conf
index 3cc1f1fc39..621e9381e3 100644
--- a/tests/topotests/bgp_dynamic_capability/r2/frr.conf
+++ b/tests/topotests/bgp_dynamic_capability/r2/frr.conf
@@ -7,6 +7,7 @@ int lo
 !
 int r2-eth0
  ip address 192.168.1.2/24
+ ipv6 address 2001:db8::2/64
 !
 router bgp 65002
  bgp graceful-restart
@@ -16,9 +17,20 @@ router bgp 65002
  neighbor 192.168.1.1 timers 1 3
  neighbor 192.168.1.1 timers connect 1
  neighbor 192.168.1.1 capability dynamic
+ neighbor 192.168.1.1 capability extended-nexthop
  neighbor 192.168.1.1 addpath-rx-paths-limit 20
+ neighbor 2001:db8::1 remote-as external
+ neighbor 2001:db8::1 timers 1 3
+ neighbor 2001:db8::1 timers connect 1
+ neighbor 2001:db8::1 capability dynamic
+ neighbor 2001:db8::1 capability extended-nexthop
  !
  address-family ipv4 unicast
   redistribute connected
  exit-address-family
+ !
+ address-family ipv6 unicast
+  redistribute connected
+  neighbor 2001:db8::1 activate
+ exit-address-family
 !
diff --git a/tests/topotests/bgp_dynamic_capability/test_bgp_dynamic_capability_enhe.py b/tests/topotests/bgp_dynamic_capability/test_bgp_dynamic_capability_enhe.py
new file mode 100644
index 0000000000..aa0508e88f
--- /dev/null
+++ b/tests/topotests/bgp_dynamic_capability/test_bgp_dynamic_capability_enhe.py
@@ -0,0 +1,215 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: ISC
+
+# Copyright (c) 2024 by
+# Donatas Abraitis <donatas@opensourcerouting.org>
+#
+
+"""
+Test if extended nexthop capability is exchanged dynamically.
+"""
+
+import os
+import sys
+import json
+import pytest
+import functools
+import time
+
+pytestmark = [pytest.mark.bgpd]
+
+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 step
+
+
+def setup_module(mod):
+    topodef = {"s1": ("r1", "r2")}
+    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_dynamic_capability_enhe():
+    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(r1.vtysh_cmd("show bgp neighbor 2001:db8::2 json"))
+        expected = {
+            "2001:db8::2": {
+                "bgpState": "Established",
+                "localRole": "undefined",
+                "remoteRole": "undefined",
+                "neighborCapabilities": {
+                    "dynamic": "advertisedAndReceived",
+                    "extendedNexthop": "received",
+                },
+            }
+        }
+        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, "Can't converge"
+
+    def _bgp_check_nexthop():
+        output = json.loads(r1.vtysh_cmd("show ip route 10.10.10.10/32 json"))
+        expected = {
+            "10.10.10.10/32": [
+                {
+                    "protocol": "bgp",
+                    "selected": True,
+                    "installed": True,
+                    "nexthops": [
+                        {
+                            "fib": True,
+                            "ip": "192.168.1.2",
+                            "afi": "ipv4",
+                            "interfaceName": "r1-eth0",
+                            "active": True,
+                        },
+                        {
+                            "duplicate": True,
+                            "ip": "192.168.1.2",
+                            "afi": "ipv4",
+                            "interfaceName": "r1-eth0",
+                            "active": True,
+                        },
+                    ],
+                }
+            ]
+        }
+        return topotest.json_cmp(output, expected)
+
+    test_func = functools.partial(
+        _bgp_check_nexthop,
+    )
+    _, result = topotest.run_and_expect(test_func, None, count=30, wait=1)
+    assert result is None, "Can't see 10.10.10.10/32 with IPv4 only nexthops"
+
+    step("Enable ENHE capability")
+
+    # Clear message stats to check if we receive a notification or not after we
+    # change the role.
+    r1.vtysh_cmd("clear bgp 2001:db8::2 message-stats")
+    r1.vtysh_cmd(
+        """
+    configure terminal
+    router bgp
+      neighbor 2001:db8::2 capability extended-nexthop
+    """
+    )
+
+    def _bgp_check_if_session_not_reset():
+        output = json.loads(r2.vtysh_cmd("show bgp neighbor 2001:db8::1 json"))
+        expected = {
+            "2001:db8::1": {
+                "bgpState": "Established",
+                "neighborCapabilities": {
+                    "dynamic": "advertisedAndReceived",
+                    "extendedNexthop": "advertisedAndReceived",
+                    "extendedNexthopFamililesByPeer": {
+                        "ipv4Unicast": "recieved",
+                    },
+                },
+                "messageStats": {
+                    "notificationsRecv": 0,
+                    "capabilityRecv": 1,
+                },
+            }
+        }
+        return topotest.json_cmp(output, expected)
+
+    test_func = functools.partial(
+        _bgp_check_if_session_not_reset,
+    )
+    _, result = topotest.run_and_expect(test_func, None, count=30, wait=1)
+    assert result is None, "Session was reset after setting ENHE capability"
+
+    def _bgp_check_if_session_not_reset():
+        output = json.loads(r2.vtysh_cmd("show bgp neighbor 2001:db8::1 json"))
+        expected = {
+            "2001:db8::1": {
+                "bgpState": "Established",
+                "neighborCapabilities": {
+                    "dynamic": "advertisedAndReceived",
+                    "extendedNexthop": "advertisedAndReceived",
+                    "extendedNexthopFamililesByPeer": {
+                        "ipv4Unicast": "recieved",
+                    },
+                },
+                "messageStats": {
+                    "notificationsRecv": 0,
+                    "capabilityRecv": 1,
+                },
+            }
+        }
+        return topotest.json_cmp(output, expected)
+
+    test_func = functools.partial(
+        _bgp_check_if_session_not_reset,
+    )
+    _, result = topotest.run_and_expect(test_func, None, count=30, wait=1)
+    assert result is None, "Session was reset after setting ENHE capability"
+
+    def _bgp_check_nexthop_enhe():
+        output = json.loads(r1.vtysh_cmd("show ip route 10.10.10.10/32 json"))
+        expected = {
+            "10.10.10.10/32": [
+                {
+                    "protocol": "bgp",
+                    "selected": True,
+                    "installed": True,
+                    "nexthops": [
+                        {
+                            "fib": True,
+                            "ip": "192.168.1.2",
+                            "afi": "ipv4",
+                            "interfaceName": "r1-eth0",
+                            "active": True,
+                        },
+                        {
+                            "fib": True,
+                            "afi": "ipv6",
+                            "interfaceName": "r1-eth0",
+                            "active": True,
+                        },
+                    ],
+                }
+            ]
+        }
+        return topotest.json_cmp(output, expected)
+
+    test_func = functools.partial(
+        _bgp_check_nexthop_enhe,
+    )
+    _, result = topotest.run_and_expect(test_func, None, count=30, wait=1)
+    assert result is None, "Can't see 10.10.10.10/32 with IPv4 only nexthops"
+
+
+if __name__ == "__main__":
+    args = ["-s"] + sys.argv[1:]
+    sys.exit(pytest.main(args))