From 176cc4ab2aa058597f1c3cb54d825d429dab45b9 Mon Sep 17 00:00:00 2001
From: Renuka Manavalan <47282725+renukamanavalan@users.noreply.github.com>
Date: Fri, 16 Apr 2021 07:40:27 -0700
Subject: [PATCH] 1) Loopback interfaces with valid nexthop IP are not
 ignored/treated as loopback. (#1565)

2) The vrf routes are *not* handled.
---
 scripts/route_check.py    | 22 ++++++++++++++++++----
 tests/route_check_test.py | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 4 deletions(-)

diff --git a/scripts/route_check.py b/scripts/route_check.py
index fe870ab076..1e03a9c6bd 100755
--- a/scripts/route_check.py
+++ b/scripts/route_check.py
@@ -264,6 +264,10 @@ def get_subscribe_updates(selector, subs):
     return (sorted(adds), sorted(deletes))
 
 
+def is_vrf(k):
+    return k.startswith("Vrf")
+
+
 def get_routes():
     """
     helper to read route table from APPL-DB.
@@ -276,7 +280,7 @@ def get_routes():
 
     valid_rt = []
     for k in keys:
-        if not is_local(k):
+        if not is_vrf(k) and not is_local(k):
             valid_rt.append(add_prefix_ifnot(k.lower()))
 
     print_message(syslog.LOG_DEBUG, json.dumps({"ROUTE_TABLE": sorted(valid_rt)}, indent=4))
@@ -341,15 +345,25 @@ def filter_out_local_interfaces(keys):
     :return keys filtered out of local
     """
     rt = []
-    local_if_re = [r'eth0', r'lo', r'docker0', r'tun0', r'Loopback\d+']
+    local_if_lst = {'eth0', 'docker0'}
+    local_if_lo = [r'tun0', r'lo', r'Loopback\d+']
 
     db = swsscommon.DBConnector(APPL_DB_NAME, 0)
     tbl = swsscommon.Table(db, 'ROUTE_TABLE')
 
     for k in keys:
         e = dict(tbl.get(k)[1])
-        if not e or all([not re.match(x, e['ifname']) for x in local_if_re]):
-            rt.append(k)
+
+        ifname = e.get('ifname', '')
+        if ifname in local_if_lst:
+            continue
+
+        if any([re.match(x, ifname) for x in local_if_lo]):
+            nh = e.get('nexthop')
+            if not nh or ipaddress.ip_address(nh).is_unspecified:
+                continue
+
+        rt.append(k)
 
     return rt
 
diff --git a/tests/route_check_test.py b/tests/route_check_test.py
index f981275314..a39015c07f 100644
--- a/tests/route_check_test.py
+++ b/tests/route_check_test.py
@@ -218,6 +218,40 @@
                 }
             }
         }
+    },
+    "5": {
+        DESCR: "local route with nexthop - fail",
+        ARGS: "route_check -m INFO -i 1000",
+        RET: -1,
+        PRE: {
+            APPL_DB: {
+                ROUTE_TABLE: {
+                    "0.0.0.0/0" : { "ifname": "portchannel0" },
+                    "10.10.196.12/31" : { "ifname": "portchannel0" },
+                    "10.10.196.20/31" : { "ifname": "portchannel0" },
+                    "10.10.196.30/31" : { "ifname": "lo", "nexthop": "100.0.0.2" }
+                },
+                INTF_TABLE: {
+                    "PortChannel1013:10.10.196.24/31": {},
+                    "PortChannel1023:2603:10b0:503:df4::5d/126": {},
+                    "PortChannel1024": {}
+                }
+            },
+            ASIC_DB: {
+                RT_ENTRY_TABLE: {
+                    RT_ENTRY_KEY_PREFIX + "10.10.196.12/31" + RT_ENTRY_KEY_SUFFIX: {},
+                    RT_ENTRY_KEY_PREFIX + "10.10.196.20/31" + RT_ENTRY_KEY_SUFFIX: {},
+                    RT_ENTRY_KEY_PREFIX + "10.10.196.24/32" + RT_ENTRY_KEY_SUFFIX: {},
+                    RT_ENTRY_KEY_PREFIX + "2603:10b0:503:df4::5d/128" + RT_ENTRY_KEY_SUFFIX: {},
+                    RT_ENTRY_KEY_PREFIX + "0.0.0.0/0" + RT_ENTRY_KEY_SUFFIX: {}
+                }
+            }
+        },
+        RESULT: {
+            "missed_ROUTE_TABLE_routes": [
+                "10.10.196.30/31"
+            ]
+        }
     }
 }