dpif-netdev: preserve packet metadata fields across recirculation

If the actions executed during recirculation changed metadata fields,
then any actions after the recirculation returns would see those new
values. Now, all metadata are saved and restored across a recirculation.

Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>

diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index 423daba..9fc51db 100644 (file)
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -2140,33 +2140,31 @@ dp_execute_cb(void *aux_, struct ofpbuf *packet,
 
     case OVS_ACTION_ATTR_RECIRC:
         if (*depth < MAX_RECIRC_DEPTH) {
-            uint32_t old_recirc_id = md->recirc_id;
-            uint32_t old_dp_hash = md->dp_hash;
-            const struct ovs_action_recirc *act;
+            struct pkt_metadata recirc_md = *md;
             struct ofpbuf *recirc_packet;
+            const struct ovs_action_recirc *act;
 
             recirc_packet = may_steal ? packet : ofpbuf_clone(packet);
 
             act = nl_attr_get(a);
-            md->recirc_id = act->recirc_id;
-            md->dp_hash = 0;
+            recirc_md.recirc_id = act->recirc_id;
+            recirc_md.dp_hash = 0;
 
             if (act->hash_alg == OVS_RECIRC_HASH_ALG_L4) {
                 struct flow flow;
 
                 flow_extract(recirc_packet, md, &flow);
-                md->dp_hash = flow_hash_symmetric_l4(&flow, act->hash_bias);
-                if (!md->dp_hash) {
-                    md->dp_hash = 1;  /* 0 is not valid */
+                recirc_md.dp_hash = flow_hash_symmetric_l4(&flow,
+                                                           act->hash_bias);
+                if (!recirc_md.dp_hash) {
+                    recirc_md.dp_hash = 1;  /* 0 is not valid */
                 }
             }
 
             (*depth)++;
-            dp_netdev_input(aux->dp, recirc_packet, md);
+            dp_netdev_input(aux->dp, recirc_packet, &recirc_md);
             (*depth)--;
 
-            md->recirc_id = old_recirc_id;
-            md->recirc_id = old_dp_hash;
             break;
         } else {
             VLOG_WARN("Packet dropped. Max recirculation depth exceeded.");