Merge pull request #18236 from donaldsharp/zebra_multipath_num_operat…

…ional_data

zebra: Add operational retrieval of Multipath Number

tests/topotests/zebra_operational_data/r1/frr.conf

@@ -0,0 +1,41 @@
+log timestamp precision 6
+log file frr.log
+
+no debug memstats-at-exit
+
+debug northbound notifications
+debug northbound libyang
+debug northbound events
+debug northbound callbacks
+
+debug mgmt backend datastore frontend transaction
+debug mgmt client frontend
+debug mgmt client backend
+
+interface r1-eth0
+  ip address 1.1.1.1/24
+  ipv6 address 2001:1111::1/64
+exit
+
+interface r1-eth1
+  ip address 2.2.2.1/24
+  ipv6 address 2002:2222::1/64
+exit
+
+interface r1-eth2 vrf red
+  ip address 3.3.3.1/24
+  ipv6 address 2003:333::1/64
+exit
+
+interface r1-eth3 vrf red
+  ip address 4.4.4.1/24
+  ipv6 address 2004:4444::1/64
+exit
+
+ip route 11.0.0.0/8 Null0
+ip route 11.11.11.11/32 1.1.1.2
+ip route 12.12.12.12/32 2.2.2.2
+
+ip route 13.0.0.0/8 Null0 vrf red
+ip route 13.13.13.13/32 3.3.3.2 vrf red
+ip route 14.14.14.14/32 4.4.4.2 vrf red

tests/topotests/zebra_operational_data/test_zebra_operational.py

@@ -0,0 +1,64 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 eval: (blacken-mode 1) -*-
+# SPDX-License-Identifier: ISC
+#
+# Copyright (c) 2025 Nvidia Inc.
+# Donald Sharp
+#
+"""
+Test zebra operational values
+"""
+
+import pytest
+import json
+from lib.topogen import Topogen
+from lib.topolog import logger
+
+
+pytestmark = [pytest.mark.mgmtd]
+
+
+@pytest.fixture(scope="module")
+def tgen(request):
+    "Setup/Teardown the environment and provide tgen argument to tests"
+
+    topodef = {"s1": ("r1",), "s2": ("r1",), "s3": ("r1",), "s4": ("r1",)}
+
+    tgen = Topogen(topodef, request.module.__name__)
+    tgen.start_topology()
+
+    router_list = tgen.routers()
+    for rname, router in router_list.items():
+        # Setup VRF red
+        router.net.add_l3vrf("red", 10)
+        router.net.add_loop("lo-red")
+        router.net.attach_iface_to_l3vrf("lo-red", "red")
+        router.net.attach_iface_to_l3vrf(rname + "-eth2", "red")
+        router.net.attach_iface_to_l3vrf(rname + "-eth3", "red")
+        router.load_frr_config("frr.conf")
+
+    tgen.start_router()
+    yield tgen
+    tgen.stop_topology()
+
+
+def test_zebra_operationalr(tgen):
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    r1 = tgen.gears["r1"]
+
+    output = json.loads(r1.vtysh_cmd("show mgmt get-data /frr-zebra:zebra"))
+
+    logger.info("Output")
+    logger.info(output)
+
+    logger.info("Ensuring that the max-multipath value is returned")
+    assert "max-multipath" in output["frr-zebra:zebra"].keys()
+
+
+if __name__ == "__main__":
+    # To suppress tracebacks, either use the following pytest call or add "--tb=no" to cli
+    # retval = pytest.main(["-s", "--tb=no"])
+    retval = pytest.main(["-s"])
+    sys.exit(retval)

yang/frr-zebra.yang

@@ -2842,6 +2842,17 @@ module frr-zebra {
   container zebra {
     description
       "Data model for the Zebra daemon.";
+    leaf max-multipath {
+      config false;
+      type uint16 {
+        range "1..65535";
+      }
+      description
+        "The maximum number of nexthops for a route.  At this point it
+         is unlikely that a multipath number will ever get larger then
+         1024 but to allow for future expansions, the yang returns a
+         16 bit number";
+    }
     leaf ip-forwarding {
       type boolean;
       description

zebra/zebra_nb.c

@@ -25,6 +25,12 @@ const struct frr_yang_module_info frr_zebra_info = {
 	.name = "frr-zebra",
 	.features = features,
 	.nodes = {
+		{
+			.xpath = "/frr-zebra:zebra/max-multipath",
+			.cbs = {
+				.get_elem = zebra_max_multipath_get_elem,
+			}
+		},
 		{
 			.xpath = "/frr-zebra:zebra/ip-forwarding",
 			.cbs = {

zebra/zebra_nb.h

@@ -14,6 +14,7 @@ extern "C" {
 extern const struct frr_yang_module_info frr_zebra_info;
 
 /* prototypes */
+struct yang_data *zebra_max_multipath_get_elem(struct nb_cb_get_elem_args *args);
 int get_route_information_rpc(struct nb_cb_rpc_args *args);
 int get_v6_mroute_info_rpc(struct nb_cb_rpc_args *args);
 int get_vrf_info_rpc(struct nb_cb_rpc_args *args);

zebra/zebra_nb_state.c

@@ -1157,3 +1157,12 @@ lib_vrf_zebra_ribs_rib_route_route_entry_nexthop_group_nexthop_weight_get_elem(
 
 	return NULL;
 }
+
+/*
+ * XPath:
+ * /frr-zebra:zebra/max-multipath
+ */
+struct yang_data *zebra_max_multipath_get_elem(struct nb_cb_get_elem_args *args)
+{
+	return yang_data_new_uint16(args->xpath, zrouter.multipath_num);
+}