topotests: test SSM matching

Simple topology test with a single router just to call the group
matching functionality.

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

tests/topotests/multicast_ssm_topo1/r1/frr.conf

@@ -0,0 +1,14 @@
+log commands
+!
+ip prefix-list pim-ssm permit 230.0.0.0/8
+!
+ipv6 prefix-list pim6-ssm permit ff35::/32
+!
+router pim
+ ssm prefix-list pim-ssm
+exit
+!
+router pim6
+ ssm prefix-list pim6-ssm
+exit
+!

tests/topotests/multicast_ssm_topo1/test_multicast_ssm_topo1.py

@@ -0,0 +1,94 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: ISC
+
+#
+# test_multicast_ssm_topo1.py
+# Part of NetDEF Topology Tests
+#
+# Copyright (c) 2025 by
+# Network Device Education Foundation, Inc. ("NetDEF")
+#
+
+"""
+test_multicast_ssm_topo1.py: Test PIM SSM configuration.
+"""
+
+import os
+import sys
+import json
+from functools import partial
+import re
+import pytest
+
+# Save the Current Working Directory to find configuration files.
+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 import topotest
+
+# Required to instantiate the topology builder class.
+from lib.topogen import Topogen, TopoRouter, get_topogen
+from lib.topolog import logger
+
+pytestmark = [pytest.mark.pimd]
+
+
+def build_topo(tgen):
+    tgen.add_router(f"r1")
+
+
+def setup_module(mod):
+    "Sets up the pytest environment"
+    tgen = Topogen(build_topo, mod.__name__)
+    tgen.start_topology()
+
+    tgen.gears["r1"].load_frr_config(os.path.join(CWD, f"r1/frr.conf"))
+    tgen.start_router()
+
+
+def teardown_module():
+    "Teardown the pytest environment"
+    tgen = get_topogen()
+    tgen.stop_topology()
+
+
+def test_multicast_ssm():
+    "Test SSM group"
+    pim_test = [
+        {"address": "229.0.0.100", "type": "ASM"},
+        {"address": "230.0.0.100", "type": "SSM"}
+    ]
+    pim6_test = [
+        {"address": "FF32::100", "type": "ASM"},
+        {"address": "FF35::100", "type": "SSM"}
+    ]
+
+    tgen = get_topogen()
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    router = tgen.gears["r1"]
+
+    for test in pim_test:
+        output = router.vtysh_cmd(f"show ip pim group-type {test['address']} json", isjson=True)
+        assert test["type"] == output["groupType"], "Wrong group type"
+
+    for test in pim6_test:
+        output = router.vtysh_cmd(f"show ipv6 pim group-type {test['address']} json", isjson=True)
+        assert test["type"] == output["groupType"], "Wrong group type"
+
+
+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))