tests: Check if addpath with disabled RX flag is working correctly in RS setup

Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>

tests/topotests/bgp_addpath_disable_rx/r1/frr.conf

@@ -0,0 +1,38 @@
+!
+int r1-eth0
+ ip address 192.168.137.1/24
+!
+router bgp 65000
+ bgp router-id 192.168.137.1
+ no bgp ebgp-requires-policy
+ no bgp enforce-first
+ neighbor AS65100-V4 peer-group
+ neighbor AS65100-V4 remote-as 65100
+ neighbor AS65100-V4 timers 1 3
+ neighbor AS65200-V4 peer-group
+ neighbor AS65200-V4 remote-as 65200
+ neighbor AS65200-V4 timers 1 3
+ neighbor AS65600-V4 peer-group
+ neighbor AS65600-V4 remote-as 65600
+ neighbor AS65600-V4 timers 1 3
+ neighbor 192.168.137.100 peer-group AS65100-V4
+ neighbor 192.168.137.201 peer-group AS65200-V4
+ neighbor 192.168.137.202 peer-group AS65200-V4
+ neighbor 192.168.137.60 peer-group AS65600-V4
+ !
+ address-family ipv4 unicast
+  neighbor AS65100-V4 addpath-tx-bestpath-per-AS
+  neighbor AS65100-V4 route-server-client
+  neighbor AS65200-V4 addpath-tx-bestpath-per-AS
+  neighbor AS65200-V4 disable-addpath-rx
+  neighbor AS65200-V4 route-server-client
+  neighbor AS65600-V4 addpath-tx-bestpath-per-AS
+  neighbor AS65600-V4 disable-addpath-rx
+  neighbor AS65600-V4 route-server-client
+  neighbor 192.168.137.201 disable-addpath-rx
+  neighbor 192.168.137.202 disable-addpath-rx
+  neighbor 192.168.137.60 disable-addpath-rx
+ exit-address-family
+!
+exit
+!

tests/topotests/bgp_addpath_disable_rx/r2/frr.conf

@@ -0,0 +1,19 @@
+!
+int r2-eth0
+ ip address 192.168.137.60/24
+!
+router bgp 65600
+ bgp router-id 192.168.137.60
+ no bgp ebgp-requires-policy
+ no bgp enforce-first-as
+ neighbor 192.168.137.1 remote-as 65000
+ !
+ address-family ipv4 unicast
+  neighbor 192.168.137.1 disable-addpath-rx
+  neighbor 192.168.137.1 prefix-list out out
+ exit-address-family
+!
+exit
+!
+ip prefix-list out seq 100 deny any
+!

tests/topotests/bgp_addpath_disable_rx/r3/frr.conf

@@ -0,0 +1,20 @@
+!
+int r3-eth0
+ ip address 192.168.137.100/24
+!
+int r3-eth1
+ ip address 192.168.44.1/24
+!
+router bgp 65100
+ bgp router-id 192.168.137.100
+ no bgp ebgp-requires-policy
+ no bgp enforce-first
+ neighbor 192.168.44.44 remote-as 65444
+ neighbor 192.168.137.1 remote-as 65000
+ !
+ address-family ipv4 unicast
+  neighbor 192.168.44.44 disable-addpath-rx
+ exit-address-family
+!
+exit
+!

tests/topotests/bgp_addpath_disable_rx/r4/frr.conf

@@ -0,0 +1,21 @@
+!
+int r4-eth0
+ ip address 192.168.137.201/24
+!
+int r4-eth1
+ ip address 192.168.54.21/24
+!
+router bgp 65200
+ bgp router-id 192.168.137.201
+ no bgp enforce-first
+ no bgp ebgp-requires-policy
+ neighbor 192.168.54.44 remote-as 65444
+ neighbor 192.168.137.1 remote-as 65000
+ !
+ address-family ipv4 unicast
+  neighbor 192.168.54.44 disable-addpath-rx
+  neighbor 192.168.137.1 disable-addpath-rx
+ exit-address-family
+!
+exit
+!

tests/topotests/bgp_addpath_disable_rx/r5/frr.conf

@@ -0,0 +1,20 @@
+int r5-eth0
+ ip address 192.168.137.202/24
+!
+int r5-eth1
+ ip address 192.168.54.22/24
+!
+router bgp 65200
+ bgp router-id 192.168.137.202
+ no bgp ebgp-requires-policy
+ no bgp enforce-first
+ neighbor 192.168.54.44 remote-as 65444
+ neighbor 192.168.137.1 remote-as 65000
+ !
+ address-family ipv4 unicast
+  neighbor 192.168.54.44 disable-addpath-rx
+  neighbor 192.168.137.1 disable-addpath-rx
+ exit-address-family
+!
+exit
+!

tests/topotests/bgp_addpath_disable_rx/r6/frr.conf

@@ -0,0 +1,40 @@
+!
+int r6-eth0
+ ip address 192.168.44.44/24
+!
+int r6-eth1
+ ip address 192.168.54.44/24
+!
+router bgp 65444
+ bgp router-id 192.168.54.44
+ no bgp network import-check
+ no bgp ebgp-requires-policy
+ neighbor 192.168.44.1 remote-as 65100
+ neighbor 192.168.54.21 remote-as 65200
+ neighbor 192.168.54.22 remote-as 65200
+ !
+ address-family ipv4 unicast
+  network 10.0.0.0/24
+  neighbor 192.168.44.1 disable-addpath-rx
+  neighbor 192.168.44.1 route-map AS65100-OUT out
+  neighbor 192.168.54.21 disable-addpath-rx
+  neighbor 192.168.54.21 route-map AS65200-OUT out
+  neighbor 192.168.54.22 disable-addpath-rx
+  neighbor 192.168.54.22 route-map AS65200-OUT out
+ exit-address-family
+!
+exit
+!
+ip prefix-list out seq 2 permit 10.0.0.0/24
+ip prefix-list out seq 100 deny any
+ip prefix-list v4_our_to65200 seq 100 deny any
+!
+route-map AS65200-OUT permit 10
+ match ip address prefix-list v4_our_to65200
+exit
+!
+route-map AS65100-OUT permit 10
+ match ip address prefix-list out
+ set as-path prepend 65444
+exit
+!

tests/topotests/bgp_addpath_disable_rx/test_bgp_addpath_disable_rx.py

@@ -0,0 +1,131 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: ISC
+
+#
+# Copyright (c) 2025 by
+# Donatas Abraitis <donatas@opensourcerouting.org>
+#
+
+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
+
+pytestmark = [pytest.mark.bgpd]
+
+
+def build_topo(tgen):
+    r1 = tgen.add_router("r1")
+    r2 = tgen.add_router("r2")
+    r3 = tgen.add_router("r3")
+    r4 = tgen.add_router("r4")
+    r5 = tgen.add_router("r5")
+    r6 = tgen.add_router("r6")
+
+    switch = tgen.add_switch("s1")
+    switch.add_link(r1)
+    switch.add_link(r2)
+    switch.add_link(r3)
+    switch.add_link(r4)
+    switch.add_link(r5)
+
+    switch = tgen.add_switch("s2")
+    switch.add_link(r3)
+    switch.add_link(r6)
+
+    switch = tgen.add_switch("s3")
+    switch.add_link(r4)
+    switch.add_link(r5)
+    switch.add_link(r6)
+
+
+def setup_module(mod):
+    tgen = Topogen(build_topo, mod.__name__)
+    tgen.start_topology()
+
+    for _, (rname, router) in enumerate(tgen.routers().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_disable_rx():
+    tgen = get_topogen()
+
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    r1 = tgen.gears["r1"]
+    r2 = tgen.gears["r2"]
+    r6 = tgen.gears["r6"]
+
+    def _bgp_check_aspath(aspath):
+        output = json.loads(r2.vtysh_cmd("show bgp ipv4 10.0.0.0/24 json"))
+        expected = {
+            "paths": [
+                {
+                    "aspath": {
+                        "string": aspath,
+                    },
+                }
+            ]
+        }
+        return topotest.json_cmp(output, expected)
+
+    test_func = functools.partial(_bgp_check_aspath, "65100 65444 65444")
+    _, result = topotest.run_and_expect(test_func, None, count=30, wait=1)
+    assert result is None, "10.0.0.0/24 should have aspath (65100 65444 65444)"
+
+    # Send 10.0.0.0/24 from r6 towards r2.
+    # This should be the best path for r2 without any prepends.
+    r6.vtysh_cmd(
+        """
+    configure terminal
+    ip prefix-list v4_our_to65200 seq 2 permit 10.0.0.0/24
+    """
+    )
+
+    test_func = functools.partial(_bgp_check_aspath, "65200 65444")
+    _, result = topotest.run_and_expect(test_func, None, count=30, wait=1)
+    assert result is None, "10.0.0.0/24 should have aspath (65200 65444)"
+
+    # Drop 10.0.0.0/24 from r6 towards r2.
+    # This should be removed from r2 and the old path (65100 65444 65444)
+    # should be used.
+    r6.vtysh_cmd(
+        """
+    configure terminal
+    no ip prefix-list v4_our_to65200 seq 2 permit 10.0.0.0/24
+    """
+    )
+
+    test_func = functools.partial(_bgp_check_aspath, "65100 65444 65444")
+    _, result = topotest.run_and_expect(test_func, None, count=30, wait=1)
+    assert result is None, "10.0.0.0/24 should have aspath (65100 65444 65444)"
+
+
+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))