Fill the NH of the packet in fragment assembler

When fragments are recieved out of order, assembler code caches them
till head fragment is received. While holding the packet, packet's nh is
not cached to avoid taking a reference to NH. Once the head fragment is
received, these out of order fragments are released for flow processing.
While doing this, packet's nh is not filled if the encap is Vxlan packet
as this requires a mac address lookup. For Mpls packets, label is looked
up to extract the NH. Not filling the NH, is resulting in Flow lookup
failure as NH id is also a key for the flow table. Failure to look up
the original flow entry (of head fragment) results in either creating
the new flow entry (with wrong key nh id) in Hold state, or dropping the
packet without flow processing.

To avoid this, bridge look up is done in the given VRF, to extract the
NH.

closes-bug: #1698986

Conflicts:
	dp-core/vr_bridge.c
	dp-core/vr_flow.c
	include/vr_bridge.h

Change-Id: Idf50ba23c1b04c828080cf258d1af35205bb1b4a

dp-core/vr_bridge.c

@@ -252,6 +252,25 @@ bridge_table_lookup(unsigned int vrf_id, struct vr_route_req *rt)
     return rt->rtr_nh;
 }
 
+struct vr_nexthop *
+__vrouter_bridge_lookup(unsigned int vrf_id, unsigned char *mac)
+{
+    struct vr_route_req rt;
+
+    if (!mac)
+        return NULL;
+
+    rt.rtr_req.rtr_label_flags = 0;
+    rt.rtr_req.rtr_index = VR_BE_INVALID_INDEX;
+    rt.rtr_req.rtr_mac_size = VR_ETHER_ALEN;
+    rt.rtr_req.rtr_mac = mac;
+    /* If multicast L2 packet, use broadcast composite nexthop */
+    if (IS_MAC_BMCAST(rt.rtr_req.rtr_mac))
+        rt.rtr_req.rtr_mac = (int8_t *)vr_bcast_mac;
+   rt.rtr_req.rtr_vrf_id = vrf_id;
+
+    return vr_bridge_lookup(vrf_id,  &rt);
+}
 
 unsigned short
 vr_bridge_route_flags(unsigned int vrf_id, unsigned char *mac)

dp-core/vr_flow.c

@@ -18,6 +18,7 @@
 #include "vr_datapath.h"
 #include "vr_hash.h"
 #include "vr_ip_mtrie.h"
+#include "vr_bridge.h"
 
 #define VR_NUM_FLOW_TABLES          1
 
@@ -1436,8 +1437,12 @@ vr_flow_flush_pnode(struct vrouter *router, struct vr_packet_node *pnode,
     if (!pkt->vp_nh) {
         if (vif_is_fabric(pkt->vp_if) && fmd &&
                 (fmd->fmd_label >= 0)) {
-            if (!vr_forwarding_md_label_is_vxlan_id(fmd))
+            if (!vr_forwarding_md_label_is_vxlan_id(fmd)) {
                 pkt->vp_nh = __vrouter_get_label(router, fmd->fmd_label);
+            }  else {
+                pkt->vp_nh = __vrouter_bridge_lookup(fmd->fmd_dvrf,
+                                                        pkt_data(pkt));
+            }
         }
     }
 

include/vr_bridge.h

@@ -45,5 +45,6 @@ extern char vr_bcast_mac[];
 
 unsigned int vr_bridge_table_used_oflow_entries(struct vrouter *);
 unsigned int vr_bridge_table_used_total_entries(struct vrouter *);
+struct vr_nexthop * __vrouter_bridge_lookup(unsigned int, unsigned char *);
 
 #endif