* In a scenario where there are 2 vgw exporting same subnet route,

  and traffic session gets initiated from external domain to
  VM, then for setting reverse flow agent was trying to get policy
  enabled interface nexthop for vgw, and for vgw we would only
  create policy disabled nh. Fixing the same to pick
  policy disabled nexthop for vgw destination
Closes-bug:#1425856

Change-Id: I23462aec80cc7fc351c376705f2fb2dc062acf16

src/vnsw/agent/pkt/pkt_flow_info.cc

@@ -206,7 +206,20 @@ static bool NhDecode(const NextHop *nh, const PktInfo *pkt, PktFlowInfo *info,
             const InetUnicastRouteEntry *rt =
                 static_cast<const InetUnicastRouteEntry *>(in->rt_);
             if (rt != NULL && rt->GetLocalNextHop()) {
-                out->nh_ = GetPolicyEnabledNH(rt->GetLocalNextHop())->id();
+                const NextHop *local_nh = rt->GetLocalNextHop();
+                out->nh_ = local_nh->id();
+                if (local_nh->GetType() == NextHop::INTERFACE) {
+                    const Interface *local_intf =
+                        static_cast<const InterfaceNH*>(local_nh)->GetInterface();
+                    //Get policy enabled nexthop only for
+                    //vm interface, in case of vgw or service interface in
+                    //transparent mode we should still
+                    //use policy disabled interface
+                    if (local_intf &&
+                            local_intf->type() == Interface::VM_INTERFACE) {
+                        out->nh_ = GetPolicyEnabledNH(local_nh)->id();
+                    }
+                }
             } else {
                 out->nh_ = in->nh_;
             }

src/vnsw/agent/pkt/test/test_ecmp.cc

@@ -2257,6 +2257,67 @@ TEST_F(EcmpTest, TrapFlag) {
     client->WaitForIdle();
 }
 
+//Send a packet from vgw to ecmp destination
+TEST_F(EcmpTest, VgwFlag) {
+    Agent *agent = Agent::GetInstance();
+    InetInterface::CreateReq(agent->interface_table(), "vgw1",
+                            InetInterface::SIMPLE_GATEWAY, "vrf2",
+                            Ip4Address(0), 0, Ip4Address(0), Agent::NullString(),
+                            "");
+    client->WaitForIdle();
+
+    InetInterfaceKey *intf_key = new InetInterfaceKey("vgw1");
+    std::auto_ptr<const NextHopKey> nh_key(new InterfaceNHKey(intf_key, false,
+                                                              InterfaceNHFlags::INET4));
+
+    Ip4Address remote_server_ip1 = Ip4Address::from_string("10.10.10.100");
+    ComponentNHKeyPtr nh_data1(new ComponentNHKey(16, nh_key));
+    ComponentNHKeyPtr nh_data2(new ComponentNHKey(20, agent->fabric_vrf_name(),
+                                                  agent->router_id(),
+                                                  remote_server_ip1,
+                                                  false,
+                                                  TunnelType::DefaultType()));
+    Ip4Address ip = Ip4Address::from_string("0.0.0.0");
+    ComponentNHKeyList comp_nh_list;
+    comp_nh_list.push_back(nh_data1);
+    comp_nh_list.push_back(nh_data2);
+    EcmpTunnelRouteAdd(bgp_peer, "vrf2", ip, 0,
+                       comp_nh_list, false, "vn2",
+                       SecurityGroupList(), PathPreference());
+    client->WaitForIdle();
+
+    InetInterfaceKey tmp_key("vgw1");
+    Interface *intf =
+       static_cast<Interface *>(agent->interface_table()->
+           FindActiveEntry(&tmp_key));
+
+    //Send packet on vgw interface
+    TxIpPacket(intf->id(), "100.1.1.1", "2.2.2.2", 1);
+    client->WaitForIdle();
+
+    FlowEntry *entry;
+    FlowEntry *rev_entry;
+    entry = FlowGet(VrfGet("vrf2")->vrf_id(),
+                    "2.2.2.2", "100.1.1.1", 1, 0, 0, intf->flow_key_nh()->id());
+    EXPECT_TRUE(entry != NULL);
+    EXPECT_TRUE(entry->data().component_nh_idx  ==
+                CompositeNH::kInvalidComponentNHIdx);
+
+    rev_entry = FlowGet(VrfGet("vrf2")->vrf_id(),
+                       "100.1.1.1", "2.2.2.2", 1, 0, 0, intf->flow_key_nh()->id());
+    EXPECT_TRUE(rev_entry != NULL);
+    EXPECT_TRUE(rev_entry->data().component_nh_idx ==
+                CompositeNH::kInvalidComponentNHIdx);
+
+    client->WaitForIdle();
+    agent->fabric_inet4_unicast_table()->DeleteReq(bgp_peer, "vrf2",
+                                                   ip, 0, NULL);
+    InetInterface::DeleteReq(agent->interface_table(), "vgw1");
+    client->WaitForIdle();
+    WAIT_FOR(1000, 1000, (Agent::GetInstance()->pkt()->
+                flow_table()->Size() == 0));
+}
+
 int main(int argc, char *argv[]) {
     GETUSERARGS();
     client = TestInit(init_file, ksync_init, true, true, true, 100*1000);