VRF deletetimeout

Problem:
Fix for bug#1666139 broke code where mpls label change handling for fmg.
Old fabric label can not be reliably picked from fmg path. It can be only picked
from multicast master path. Solution should take care of this point along with
not breaking 1666139.

Solution:
Pick up old fmg label as done prior to fix of 1666139, but check for reserved
fmg label to identify if multicast path is having evpn or fmg label.

Change-Id: I056b61867498f6ec83c11babc2b6aaabcc09a3e9
Closes-bug: #1681083

src/vnsw/agent/oper/bridge_route.cc

@@ -442,8 +442,8 @@ void BridgeRouteEntry::DeletePathUsingKeyData(const AgentRouteKey *key,
                 if (force_delete && (path->peer()->GetType() ==
                                      Peer::BGP_PEER)) {
                     delete_path = true;
-                } else if (is_multicast()) {
-                    assert(path->peer()->GetType() == Peer::BGP_PEER); 
+                } else if (is_multicast() &&
+                           (path->peer()->GetType() == Peer::BGP_PEER)) {
                     //BGP peer path uses channel peer unicast sequence number.
                     //If it is stale, then delete same.
                     if (data->CanDeletePath(agent, path, this) == false) {
@@ -644,7 +644,6 @@ bool BridgeRouteEntry::ReComputeMulticastPaths(AgentPath *path, bool del) {
     AgentPath *tor_peer_path = NULL;
     AgentPath *local_peer_path = NULL;
     bool tor_path = false;
-    uint32_t old_fabric_mpls_label = 0;
 
     const CompositeNH *cnh =
          static_cast<const CompositeNH *>(path->nexthop());
@@ -696,7 +695,6 @@ bool BridgeRouteEntry::ReComputeMulticastPaths(AgentPath *path, bool del) {
         } else if (it_path->peer()->GetType() ==
                    Peer::MULTICAST_FABRIC_TREE_BUILDER) {
             fabric_peer_path = it_path;
-            old_fabric_mpls_label = fabric_peer_path->label();
         } else if (it_path->peer() == agent->multicast_peer()) {
             multicast_peer_path = it_path;
         } else if (it_path->peer() == agent->local_peer()) {
@@ -735,9 +733,18 @@ bool BridgeRouteEntry::ReComputeMulticastPaths(AgentPath *path, bool del) {
 
     bool learning_enabled = false;
     bool pbb_nh = false;
+    uint32_t old_fabric_mpls_label = 0;
     if (multicast_peer_path == NULL) {
         multicast_peer_path = new AgentPath(agent->multicast_peer(), NULL);
         InsertPath(multicast_peer_path);
+    } else {
+        //Multicast peer path can have evpn or fabric label.
+        //Identify using isfabricmulticastlabel.
+        if (agent->mpls_table()->
+             IsFabricMulticastLabel(multicast_peer_path->label()))
+        {
+            old_fabric_mpls_label = multicast_peer_path->label();
+        }
     }
 
     ComponentNHKeyList component_nh_list;

src/vnsw/agent/resource_manager/test/test_mpls_label.cc

@@ -150,6 +150,43 @@ TEST_F(AgentDbEntry, bug_1680720) {
     delete nh_state;
 }
 
+//Bug# 1681083
+TEST_F(AgentDbEntry, fmg_label_freed_on_no_use_1681083) {
+   struct PortInfo input[] = {
+        {"vnet1", 1, "1.1.1.10", "00:00:01:01:01:10", 1, 1},
+    };
+
+    client->Reset();
+    //Alloc label
+    CreateVmportEnv(input, 1);
+    client->WaitForIdle();
+    agent_->mpls_table()->ReserveMulticastLabel(4000, 5000, 0);
+
+    //Test
+    //Add fabric group multicast route
+    TunnelOlist olist;
+    Ip4Address sip(0);
+    Ip4Address broadcast(0xFFFFFFFF);
+    MulticastHandler *mc_handler = static_cast<MulticastHandler *>(agent_->
+                                       oper_db()->multicast());
+    olist.push_back(OlistTunnelEntry(nil_uuid(), 10,
+                                     IpAddress::from_string("8.8.8.8").to_v4(),
+                                     TunnelType::MplsType()));
+    mc_handler->ModifyFabricMembers(agent_->multicast_tree_builder_peer(),
+                                    "vrf1", broadcast, sip, 4100, olist, 1);
+    client->WaitForIdle();
+    EXPECT_TRUE(agent_->mpls_table()->FindMplsLabel(4100) != NULL);
+    mc_handler->ModifyFabricMembers(agent_->multicast_tree_builder_peer(),
+                                    "vrf1", broadcast, sip, 4101, olist, 1);
+    client->WaitForIdle();
+    EXPECT_TRUE(agent_->mpls_table()->FindMplsLabel(4100) == NULL);
+    EXPECT_TRUE(agent_->mpls_table()->FindMplsLabel(4101) != NULL);
+
+    //Delete label
+    DeleteVmportEnv(input, 1, true);
+    client->WaitForIdle();
+}
+
 int main(int argc, char *argv[]) {
     GETUSERARGS();
     client = TestInit(init_file, ksync_init, true, true, false);