tests: Check if RIPd passive-interface works as expected

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

tests/topotests/rip_passive_interface/r1/frr.conf

@@ -0,0 +1,9 @@
+!
+int r1-eth0
+ ip address 192.168.1.1/24
+!
+router rip
+ allow-ecmp
+ network 192.168.1.0/24
+ timers basic 5 15 10
+exit

tests/topotests/rip_passive_interface/r2/frr.conf

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+!
+int lo
+ ip address 10.10.10.1/32
+!
+int r2-eth0
+ ip address 192.168.1.2/24
+!
+router rip
+ network 192.168.1.0/24
+ network 10.10.10.1/32
+ timers basic 5 15 10
+exit
+

tests/topotests/rip_passive_interface/r3/frr.conf

@@ -0,0 +1,13 @@
+!
+int lo
+ ip address 10.10.10.1/32
+!
+int r3-eth0
+ ip address 192.168.1.3/24
+!
+router rip
+ network 192.168.1.0/24
+ network 10.10.10.1/32
+ timers basic 5 15 10
+exit
+

tests/topotests/rip_passive_interface/test_rip_passive_interface.py

@@ -0,0 +1,102 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: ISC
+
+# Copyright (c) 2023 by
+# Donatas Abraitis <donatas@opensourcerouting.org>
+#
+
+"""
+Test if RIP `passive-interface default` and `no passive-interface IFNAME`
+combination works as expected.
+"""
+
+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 step
+
+pytestmark = [pytest.mark.ripd]
+
+
+def setup_module(mod):
+    topodef = {"s1": ("r1", "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_rip_passive_interface():
+    tgen = get_topogen()
+
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    r1 = tgen.gears["r1"]
+    r2 = tgen.gears["r2"]
+
+    def _show_routes(nh_num):
+        output = json.loads(r1.vtysh_cmd("show ip route 10.10.10.1/32 json"))
+        expected = {
+            "10.10.10.1/32": [
+                {
+                    "internalNextHopNum": nh_num,
+                    "internalNextHopActiveNum": nh_num,
+                }
+            ]
+        }
+        return topotest.json_cmp(output, expected)
+
+    test_func = functools.partial(_show_routes, 2)
+    _, result = topotest.run_and_expect(test_func, None, count=60, wait=1)
+    assert result is None, "Got 10.10.10.1/32, but the next-hop count is not 2"
+
+    step("Configure `passive-interface default` on r2")
+    r2.vtysh_cmd(
+        """
+    configure terminal
+        router rip
+            passive-interface default
+    """
+    )
+
+    test_func = functools.partial(_show_routes, 1)
+    _, result = topotest.run_and_expect(test_func, None, count=60, wait=1)
+    assert result is None, "Got 10.10.10.1/32, but the next-hop count is not 1"
+
+    step("Configure `no passive-interface r2-eth0` on r2 towards r1")
+    r2.vtysh_cmd(
+        """
+    configure terminal
+        router rip
+            no passive-interface r2-eth0
+    """
+    )
+
+    test_func = functools.partial(_show_routes, 2)
+    _, result = topotest.run_and_expect(test_func, None, count=60, wait=1)
+    assert result is None, "Got 10.10.10.1/32, but the next-hop count is not 2"
+
+
+if __name__ == "__main__":
+    args = ["-s"] + sys.argv[1:]
+    sys.exit(pytest.main(args))