Merge pull request #11001 from donaldsharp/system_route_recursion

zebra: Allow system routes to recurse through themselves

tests/topotests/zebra_multiple_connected/r1/ip_route2.json

@@ -0,0 +1,102 @@
+{
+  "10.0.1.0/24":[
+    {
+      "prefix":"10.0.1.0/24",
+      "prefixLen":24,
+      "protocol":"connected",
+      "vrfName":"default",
+      "distance":0,
+      "metric":0,
+      "installed":true,
+      "table":254,
+      "nexthops":[
+        {
+          "fib":true,
+          "directlyConnected":true,
+          "interfaceName":"r1-eth1",
+          "active":true
+        }
+      ]
+    },
+    {
+      "prefix":"10.0.1.0/24",
+      "prefixLen":24,
+      "protocol":"connected",
+      "vrfName":"default",
+      "distance":0,
+      "metric":0,
+      "installed":true,
+      "table":254,
+      "nexthops":[
+        {
+          "fib":true,
+          "directlyConnected":true,
+          "interfaceName":"r1-eth0",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "10.0.1.30/32":[
+    {
+      "prefix":"10.0.1.30/32",
+      "prefixLen":32,
+      "protocol":"kernel",
+      "vrfName":"default",
+      "distance":0,
+      "metric":0,
+      "installed":true,
+      "table":254,
+      "nexthops":[
+        {
+          "fib":true,
+          "directlyConnected":true,
+          "interfaceName":"r1-eth1",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "10.9.9.0/24":[
+    {
+      "prefix":"10.9.9.0/24",
+      "prefixLen":24,
+      "protocol":"kernel",
+      "vrfName":"default",
+      "distance":0,
+      "metric":0,
+      "installed":true,
+      "table":254,
+      "nexthops":[
+        {
+          "fib":true,
+          "ip":"10.0.1.30",
+          "afi":"ipv4",
+          "interfaceName":"r1-eth1",
+          "active":true
+        }
+      ]
+    }
+  ],
+  "192.168.1.1/32":[
+    {
+      "prefix":"192.168.1.1/32",
+      "prefixLen":32,
+      "protocol":"kernel",
+      "vrfName":"default",
+      "distance":0,
+      "metric":0,
+      "installed":true,
+      "table":254,
+      "nexthops":[
+        {
+          "fib":true,
+          "ip":"10.0.1.99",
+          "afi":"ipv4",
+          "interfaceName":"r1-eth1",
+          "active":true
+        }
+      ]
+    }
+  ]
+}

tests/topotests/zebra_multiple_connected/test_zebra_multiple_connected.py

@@ -133,6 +133,30 @@ def test_zebra_connected_multiple():
     assert result is None, "Kernel route is missing from zebra"
 
 
+def test_zebra_system_recursion():
+    "Test a system route recursing through another system route"
+
+    tgen = get_topogen()
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    router = tgen.gears["r1"]
+    router.run("ip route add 10.0.1.30/32 dev r1-eth1")
+    router.run("ip route add 10.9.9.0/24 via 10.0.1.30 dev r1-eth1")
+    router.run("ip link add dummy2 type dummy")
+    router.run("ip link set dummy2 up")
+    router.run("ip link set dummy2 down")
+
+    routes = "{}/{}/ip_route2.json".format(CWD, router.name)
+    expected = json.loads(open(routes).read())
+    test_func = partial(
+        topotest.router_json_cmp, router, "show ip route json", expected
+    )
+
+    _, result = topotest.run_and_expect(test_func, None, count=20, wait=1)
+    assert result is None, "Kernel route is missing from zebra"
+
+
 if __name__ == "__main__":
     args = ["-s"] + sys.argv[1:]
     sys.exit(pytest.main(args))

zebra/zebra_nhg.c

@@ -2265,7 +2265,8 @@ static int nexthop_active(struct nexthop *nexthop, struct nhg_hash_entry *nhe,
 			continue;
 		}
 
-		if (match->type == ZEBRA_ROUTE_CONNECT) {
+		if ((match->type == ZEBRA_ROUTE_CONNECT) ||
+		    (RIB_SYSTEM_ROUTE(match) && RSYSTEM_ROUTE(type))) {
 			match = zebra_nhg_connected_ifindex(rn, match,
 							    nexthop->ifindex);