[202211][EVPN]Fixing nexthop group delete when multiple routes point to the nexthop group (#2753)

* [EVPN]Fixing nexthop group delete when multiple routes point to the nexthop

Author: dgsudharsan

orchagent/routeorch.cpp

@@ -2164,15 +2164,22 @@ bool RouteOrch::addRoutePost(const RouteBulkContext& ctx, const NextHopGroupKey
         {
             decreaseNextHopRefCount(it_route->second.nhg_key);
             auto ol_nextHops = it_route->second.nhg_key;
-            if (ol_nextHops.getSize() > 1
-                && m_syncdNextHopGroups[ol_nextHops].ref_count == 0)
+            if (ol_nextHops.getSize() > 1)
             {
-                m_bulkNhgReducedRefCnt.emplace(ol_nextHops, 0);
+                if (m_syncdNextHopGroups[ol_nextHops].ref_count == 0)
+                {
+                    SWSS_LOG_NOTICE("Update Nexthop Group %s", ol_nextHops.to_string().c_str());
+                    m_bulkNhgReducedRefCnt.emplace(ol_nextHops, 0);
+                }
             }
             else if (ol_nextHops.is_overlay_nexthop())
             {
-                SWSS_LOG_NOTICE("Update overlay Nexthop %s", ol_nextHops.to_string().c_str());
-                m_bulkNhgReducedRefCnt.emplace(ol_nextHops, vrf_id);
+                const NextHopKey& nexthop = *it_route->second.nhg_key.getNextHops().begin();
+                if (m_neighOrch->getNextHopRefCount(nexthop) == 0)
+                {
+                    SWSS_LOG_NOTICE("Update overlay Nexthop %s", ol_nextHops.to_string().c_str());
+                    m_bulkNhgReducedRefCnt.emplace(ol_nextHops, vrf_id);
+                }
             }
             else if (ol_nextHops.is_srv6_nexthop())
             {
@@ -2403,15 +2410,22 @@ bool RouteOrch::removeRoutePost(const RouteBulkContext& ctx)
 
         auto ol_nextHops = it_route->second.nhg_key;
 
-        if (it_route->second.nhg_key.getSize() > 1
-            && m_syncdNextHopGroups[it_route->second.nhg_key].ref_count == 0)
+        if (it_route->second.nhg_key.getSize() > 1)
         {
-            m_bulkNhgReducedRefCnt.emplace(it_route->second.nhg_key, 0);
+            if (m_syncdNextHopGroups[it_route->second.nhg_key].ref_count == 0)
+            {
+                SWSS_LOG_NOTICE("Remove Nexthop Group %s", ol_nextHops.to_string().c_str());
+                m_bulkNhgReducedRefCnt.emplace(it_route->second.nhg_key, 0);
+            }
         }
         else if (ol_nextHops.is_overlay_nexthop())
         {
-            SWSS_LOG_NOTICE("Remove overlay Nexthop %s", ol_nextHops.to_string().c_str());
-            m_bulkNhgReducedRefCnt.emplace(ol_nextHops, vrf_id);
+            const NextHopKey& nexthop = *it_route->second.nhg_key.getNextHops().begin();
+            if (m_neighOrch->getNextHopRefCount(nexthop) == 0)
+            {
+                SWSS_LOG_NOTICE("Remove overlay Nexthop %s", ol_nextHops.to_string().c_str());
+                m_bulkNhgReducedRefCnt.emplace(ol_nextHops, vrf_id);
+            }
         }
         /*
          * Additionally check if the NH has label and its ref count == 0, then

tests/evpn_tunnel.py

@@ -1156,7 +1156,7 @@ def check_del_vrf_routes(self, dvs, prefix, vrf_name):
             assert found_route
 
         self.helper.check_deleted_object(asic_db, self.ASIC_ROUTE_ENTRY, self.route_id[vrf_name + ":" + prefix])
-        self.route_id.clear()
+        del self.route_id[vrf_name + ":" + prefix]
 
         return True
 

tests/test_evpn_l3_vxlan.py

@@ -309,6 +309,44 @@ def test_tunnel_ipv4_routes(self, dvs, testlog):
         vxlan_obj.check_vrf_routes_ecmp_nexthop_grp_del(dvs, 2)
         vxlan_obj.check_del_vrf_routes(dvs, "80.80.1.0/24", 'Vrf-RED')
 
+        print ("\n\nTest VRF IPv4 Multiple Route with ECMP Tunnel Nexthop Add and Delete")
+        vxlan_obj.fetch_exist_entries(dvs)
+
+        ecmp_nexthop_attr = [
+            ("nexthop", "7.7.7.7,8.8.8.8"),
+            ("ifname", "Vlan100,Vlan100"),
+            ("vni_label", "1000,1000"),
+            ("router_mac", "00:11:11:11:11:11,00:22:22:22:22:22"),
+        ]
+
+        print ("\tTest VRF IPv4 Multiple Route with ECMP Tunnel Nexthop [7.7.7.7 , 8.8.8.8] Add")
+        vxlan_obj.create_vrf_route_ecmp(dvs, "80.80.1.0/24", 'Vrf-RED', ecmp_nexthop_attr)
+
+        nh_count = 2
+        ecmp_nhid_list = vxlan_obj.check_vrf_routes_ecmp(dvs, "80.80.1.0/24", 'Vrf-RED', tunnel_name, nh_count)
+        assert nh_count == len(ecmp_nhid_list)
+        vxlan_obj.check_add_tunnel_nexthop(dvs, ecmp_nhid_list[0], '7.7.7.7', tunnel_name, '00:11:11:11:11:11', '1000')
+        vxlan_obj.check_add_tunnel_nexthop(dvs, ecmp_nhid_list[1], '8.8.8.8', tunnel_name, '00:22:22:22:22:22', '1000')
+
+        nh_count = 2
+        vxlan_obj.create_vrf_route_ecmp(dvs, "90.90.1.0/24", 'Vrf-RED', ecmp_nexthop_attr)
+        ecmp_nhid_list = vxlan_obj.check_vrf_routes_ecmp(dvs, "90.90.1.0/24", 'Vrf-RED', tunnel_name, nh_count)
+        assert nh_count == len(ecmp_nhid_list)
+        vxlan_obj.check_add_tunnel_nexthop(dvs, ecmp_nhid_list[0], '7.7.7.7', tunnel_name, '00:11:11:11:11:11', '1000')
+        vxlan_obj.check_add_tunnel_nexthop(dvs, ecmp_nhid_list[1], '8.8.8.8', tunnel_name, '00:22:22:22:22:22', '1000')
+
+        print ("\tTest VRF IPv4 Multiple Route with ECMP Tunnel Nexthop [7.7.7.7 , 8.8.8.8] Delete")
+        vxlan_obj.fetch_exist_entries(dvs)
+        vxlan_obj.delete_vrf_route(dvs, "80.80.1.0/24", 'Vrf-RED')
+        vxlan_obj.check_del_vrf_routes(dvs, "80.80.1.0/24", 'Vrf-RED')
+        vxlan_obj.fetch_exist_entries(dvs)
+        vxlan_obj.delete_vrf_route(dvs, "90.90.1.0/24", 'Vrf-RED')
+        vxlan_obj.check_del_vrf_routes(dvs, "90.90.1.0/24", 'Vrf-RED')
+        helper.check_deleted_object(self.adb, vxlan_obj.ASIC_NEXT_HOP, ecmp_nhid_list[0])
+        helper.check_deleted_object(self.adb, vxlan_obj.ASIC_NEXT_HOP, ecmp_nhid_list[1])
+
+        vxlan_obj.check_vrf_routes_ecmp_nexthop_grp_del(dvs, 2)
+
         print ("\n\nTest VRF IPv4 Route with Tunnel Nexthop update from non-ECMP to ECMP")
         print ("\tTest VRF IPv4 Route with Tunnel Nexthop 7.7.7.7 Add")
         vxlan_obj.fetch_exist_entries(dvs)