zebra: fix missing kernel routes (backport #17326)

tests/topotests/zebra_multiple_connected/r1/ip_route_kernel_blackhole.json

@@ -0,0 +1,24 @@
+{
+  "0.0.0.0/0":[
+    {
+      "prefix":"0.0.0.0/0",
+      "prefixLen":0,
+      "protocol":"kernel",
+      "vrfName":"default",
+      "selected":true,
+      "destSelected":true,
+      "distance":0,
+      "metric":0,
+      "installed":true,
+      "table":254,
+      "nexthops":[
+        {
+          "fib":true,
+          "unreachable":true,
+          "blackhole":true,
+          "active":true
+        }
+      ]
+    }
+  ]
+}

tests/topotests/zebra_multiple_connected/test_zebra_multiple_connected.py

@@ -161,6 +161,70 @@ def test_zebra_noprefix_connected():
     assert result, "Connected Route should not have been added"
 
 
+<<<<<<< HEAD
+=======
+def test_zebra_noprefix_connected_add():
+    "Test that a noprefixroute created with a manual route works as expected, this is for NetworkManager"
+
+    tgen = get_topogen()
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    router = tgen.gears["r1"]
+    router.run("ip route add 192.168.44.0/24 dev r1-eth1")
+
+    connected = "{}/{}/ip_route_connected.json".format(CWD, router.name)
+    expected = json.loads(open(connected).read())
+
+    test_func = partial(
+        topotest.router_json_cmp, router, "show ip route 192.168.44.0/24 json", expected
+    )
+    result, _ = topotest.run_and_expect(test_func, None, count=20, wait=1)
+    assert result, "Connected Route should have been added\n{}".format(_)
+
+
+def test_zebra_kernel_route_add():
+    "Test that a random kernel route is properly handled as expected"
+
+    tgen = get_topogen()
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    router = tgen.gears["r1"]
+    router.run("ip route add 4.5.6.7/32 dev r1-eth1")
+
+    kernel = "{}/{}/ip_route_kernel.json".format(CWD, router.name)
+    expected = json.loads(open(kernel).read())
+
+    test_func = partial(
+        topotest.router_json_cmp, router, "show ip route 4.5.6.7/32 json", expected
+    )
+    result, _ = topotest.run_and_expect(test_func, None, count=20, wait=1)
+    assert result, "Connected Route should have been added\n{}".format(_)
+
+
+def test_zebra_kernel_route_blackhole_add():
+    "Test that a blackhole route is not affected by interface's link change"
+
+    tgen = get_topogen()
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    router = tgen.gears["r1"]
+    router.run("ip route add blackhole default")
+    router.run("ip link set dev r1-eth1 down")
+
+    kernel = "{}/{}/ip_route_kernel_blackhole.json".format(CWD, router.name)
+    expected = json.loads(open(kernel).read())
+
+    test_func = partial(
+        topotest.router_json_cmp, router, "show ip route 0.0.0.0/0 json", expected
+    )
+    result, _ = topotest.run_and_expect(test_func, None, count=20, wait=1)
+    assert result, "Blackhole Route should have not been removed\n{}".format(_)
+
+
+>>>>>>> 0073a870d1 (test: add test case for kernel blackhole routes)
 if __name__ == "__main__":
     args = ["-s"] + sys.argv[1:]
     sys.exit(pytest.main(args))

zebra/zebra_rib.c

@@ -4464,6 +4464,46 @@ static const char *rib_update_event2str(enum rib_update_event event)
 	return ret;
 }
 
+<<<<<<< HEAD
+=======
+/*
+ * We now keep kernel routes, but we don't have any
+ * trigger events for them when they are implicitly
+ * deleted.  Since we are already walking the
+ * entire table on a down event let's look at
+ * the few kernel routes we may have
+ */
+static void
+rib_update_handle_kernel_route_down_possibility(struct route_node *rn,
+						struct route_entry *re)
+{
+	struct nexthop *nexthop = NULL;
+	bool alive = false;
+
+	for (ALL_NEXTHOPS(re->nhe->nhg, nexthop)) {
+		struct interface *ifp = if_lookup_by_index(nexthop->ifindex,
+							   nexthop->vrf_id);
+
+		if ((ifp && if_is_up(ifp)) || nexthop->type == NEXTHOP_TYPE_BLACKHOLE) {
+			alive = true;
+			break;
+		}
+	}
+
+	if (!alive) {
+		struct rib_table_info *rib_table = srcdest_rnode_table_info(rn);
+		const struct prefix *p;
+		const struct prefix_ipv6 *src_p;
+
+		srcdest_rnode_prefixes(rn, &p, (const struct prefix **)&src_p);
+
+		rib_delete(rib_table->afi, rib_table->safi, re->vrf_id,
+			   re->type, re->instance, re->flags, p, src_p, NULL, 0,
+			   re->table, re->metric, re->distance, true);
+	}
+}
+
+>>>>>>> 44a82da405 (zebra: fix missing kernel routes)
 
 /* Schedule route nodes to be processed if they match the type */
 static void rib_update_route_node(struct route_node *rn, int type)