Merge pull request #10385 from iqras23/nh

zebra: Nexthop tracking, route resolution recursive lookup

5 files changed, 184 insertions, 12 deletions

diff --git a/tests/topotests/lib/common_config.py b/tests/topotests/lib/common_config.py
index f538b5a52b..c0572fca4c 100644
--- a/tests/topotests/lib/common_config.py
+++ b/tests/topotests/lib/common_config.py
@@ -1195,7 +1195,7 @@ def add_interfaces_to_vlan(tgen, input_dict):
 
                         # Assigning IP address
                         ifaddr = ipaddress.ip_interface(
-                            u"{}/{}".format(
+                            "{}/{}".format(
                                 frr_unicode(data["ip"]), frr_unicode(data["subnet"])
                             )
                         )
@@ -1626,7 +1626,7 @@ def create_interface_in_kernel(
         ifaddr = ipaddress.ip_interface(frr_unicode(ip_addr))
     else:
         ifaddr = ipaddress.ip_interface(
-            u"{}/{}".format(frr_unicode(ip_addr), frr_unicode(netmask))
+            "{}/{}".format(frr_unicode(ip_addr), frr_unicode(netmask))
         )
     cmd = "ip -{0} a flush {1} scope global && ip a add {2} dev {1} && ip l set {1} up".format(
         ifaddr.version, name, ifaddr
@@ -4921,8 +4921,13 @@ def verify_ip_nht(tgen, input_dict):
 
         for nh in nh_list:
             if nh in show_ip_nht:
-                logger.info("Nexthop %s is resolved on %s", nh, router)
-                return True
+                nht = run_frr_cmd(rnode, f"show ip nht {nh}")
+                if "unresolved" in nht:
+                    errormsg = "Nexthop {} became unresolved on {}".format(nh, router)
+                    return errormsg
+                else:
+                    logger.info("Nexthop %s is resolved on %s", nh, router)
+                    return True
             else:
                 errormsg = "Nexthop {} is resolved on {}".format(nh, router)
                 return errormsg
diff --git a/tests/topotests/zebra_nht_resolution/r1/sharpd.conf b/tests/topotests/zebra_nht_resolution/r1/sharpd.conf
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/tests/topotests/zebra_nht_resolution/r1/sharpd.conf
diff --git a/tests/topotests/zebra_nht_resolution/r1/zebra.conf b/tests/topotests/zebra_nht_resolution/r1/zebra.conf
new file mode 100644
index 0000000000..6c35c5c4b1
--- /dev/null
+++ b/tests/topotests/zebra_nht_resolution/r1/zebra.conf
@@ -0,0 +1,5 @@
+hostname r1
+!
+interface r1-eth0
+  ip address 192.168.120.1/24
+!
diff --git a/tests/topotests/zebra_nht_resolution/test_verify_nh_resolution.py b/tests/topotests/zebra_nht_resolution/test_verify_nh_resolution.py
new file mode 100644
index 0000000000..9a8f7cc1f7
--- /dev/null
+++ b/tests/topotests/zebra_nht_resolution/test_verify_nh_resolution.py
@@ -0,0 +1,166 @@
+#!/usr/bin/env python
+
+#
+# Copyright (c) 2022 by VMware, Inc. ("VMware")
+# Used Copyright (c) 2018 by Network Device Education Foundation,
+# Inc. ("NetDEF") in this file.
+#
+# Permission to use, copy, modify, and/or distribute this software
+# for any purpose with or without fee is hereby granted, provided
+# that the above copyright notice and this permission notice appear
+# in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND VMWARE DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL VMWARE BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY
+# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+# OF THIS SOFTWARE.
+#
+
+"""
+Test is indended for validating zebra NH resolution logic
+"""
+
+import os
+import sys
+import pytest
+
+from lib.common_config import (
+    start_topology,
+    verify_rib,
+    verify_ip_nht,
+    step,
+    create_static_routes,
+)
+
+# pylint: disable=C0413
+from lib import topotest
+from lib.topogen import Topogen, TopoRouter, get_topogen
+from lib.topolog import logger
+
+CWD = os.path.dirname(os.path.realpath(__file__))
+sys.path.append(os.path.join(CWD, "../"))
+
+pytestmark = [pytest.mark.sharpd]
+
+#GLOBAL VARIABLES
+NH1 = "2.2.2.32"
+
+def build_topo(tgen):
+    tgen.add_router("r1")
+
+    switch = tgen.add_switch("sw1")
+    switch.add_link(tgen.gears["r1"])
+
+def setup_module(mod):
+    tgen = Topogen(build_topo, mod.__name__)
+    tgen.start_topology()
+    router_list = tgen.routers()
+    for rname, router in tgen.routers().items():
+        router.load_config(TopoRouter.RD_ZEBRA, os.path.join(CWD, "{}/zebra.conf".format(rname)))
+        router.load_config(
+            TopoRouter.RD_SHARP, os.path.join(CWD, "{}/sharpd.conf".format(rname))
+        )
+    tgen.start_router()
+
+def teardown_module(_mod):
+    tgen = get_topogen()
+    tgen.stop_topology()
+
+def test_verify_zebra_nh_resolution(request):
+    tgen = get_topogen()
+    tc_name = request.node.name
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+    logger.info("Starting Zebra NH resolution testcase")
+    r1 = tgen.gears["r1"]
+
+    step("Configure static route")
+    input_dict_1 = {
+            "r1": {
+                "static_routes": [
+                    {"network": "2.2.2.0/24", "next_hop": "r1-eth0"}
+                ]
+            }
+        }
+
+    result = create_static_routes(tgen, input_dict_1)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(
+        tc_name, result
+    )
+
+    step("Verify static routes in RIB of R1")
+    input_dict_2 = {
+            "r1": {
+                "static_routes": [
+                    {"network": "2.2.2.0/24"}
+                ]
+            }
+    }
+
+    dut = "r1"
+    result = verify_rib(tgen, "ipv4", dut, input_dict_2)
+    assert result is True, "Testcase {} :Failed \n Error: {}".format(
+            tc_name, result)
+
+    step("Set the connected flag on the NH tracking entry")
+    r1.vtysh_cmd("sharp watch nexthop 2.2.2.32 connected")
+
+    step("Verify that NH 2.2.2.32 gets resolved over static route")
+    input_dict_nh = {
+        "r1": {
+            NH1: {
+                "Address": "2.2.2.0/24",
+                "resolvedVia": "static",
+                "nexthops": {"nexthop1": {"Interfcae": "r1-eth0"}},
+            }
+        }
+    }
+    result = verify_ip_nht(tgen, input_dict_nh)
+    assert result is True, "Testcase {} : Failed \n"
+    "Error: Nexthop is missing in RIB".format(
+        tc_name, result)
+
+    step("Add a .32/32 route with the NH as itself")
+    r1.vtysh_cmd("sharp install routes 2.2.2.32 nexthop 2.2.2.32 1")
+
+    step("Verify that the installation of .32/32 has no effect on the NHT")
+    input_dict_nh = {
+        "r1": {
+            NH1: {
+                "Address": "2.2.2.0/24",
+                "resolvedVia": "static",
+                "nexthops": {"nexthop1": {"Interface": "r1-eth0"}},
+            }
+        }
+    }
+    result = verify_ip_nht(tgen, input_dict_nh)
+    assert result is True, "Testcase {} : Failed \n"
+    "Error: Nexthop became unresolved".format(
+        tc_name, result)
+
+    step("Add a .31/32 route with the NH as 2.2.2.32"
+         "to verify the NH Resolution behaviour")
+    r1.vtysh_cmd("sharp install routes 2.2.2.31 nexthop 2.2.2.32 1")
+
+    step("Verify that NH 2.2.2.2/32 doesn't become unresolved")
+    input_dict_nh = {
+        "r1": {
+            NH1: {
+                "Address": "2.2.2.0/24",
+                "resolvedVia": "static",
+                "nexthops": {"nexthop1": {"Interface": "r1-eth0"}},
+            }
+        }
+    }
+    result = verify_ip_nht(tgen, input_dict_nh)
+    assert result is True, "Testcase {} : Failed \n"
+    "Error: Nexthop became unresolved".format(
+        tc_name, result)
+
+if __name__ == "__main__":
+    args = ["-s"] + sys.argv[1:]
+    sys.exit(pytest.main(args))
diff --git a/zebra/zebra_rnh.c b/zebra/zebra_rnh.c
index f5faaab71b..8ca25359be 100644
--- a/zebra/zebra_rnh.c
+++ b/zebra/zebra_rnh.c
@@ -637,15 +637,11 @@ zebra_rnh_resolve_nexthop_entry(struct zebra_vrf *zvrf, afi_t afi,
 		if (re) {
 			*prn = rn;
 			return re;
-		}
-
-		if (!CHECK_FLAG(rnh->flags, ZEBRA_NHT_CONNECTED))
+		} else {
+			/* Resolve the nexthop recursively by finding matching
+			 * route with lower prefix length
+			 */
 			rn = rn->parent;
-		else {
-			if (IS_ZEBRA_DEBUG_NHT_DETAILED)
-				zlog_debug(
-					"        Nexthop must be connected, cannot recurse up");
-			return NULL;
 		}
 	}