dpif: When executing actions needs help, use "set" action to set tunnel.

Open vSwitch userspace is able to implement some actions that the kernel
doesn't support, such as modifying ARP fields.  When it does this for a
tunneled packet, it needs to supply the tunnel information with a "set"
action, because the Linux kernel datapath throws away tunnel information
supplied in the OVS_PACKET_CMD_EXECUTE metadata argument.

VMware-BZ: #1270110
Reported-by: Srinivas Neginhal <sneginha@vmware.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>

diff --git a/lib/dpif.c b/lib/dpif.c
index 48b2d1e..8ec8200 100644 (file)
--- a/lib/dpif.c
+++ b/lib/dpif.c
@@ -1112,20 +1112,41 @@ dpif_execute_helper_cb(void *aux_, struct ofpbuf *packet,
                        const struct nlattr *action, bool may_steal OVS_UNUSED)
 {
     struct dpif_execute_helper_aux *aux = aux_;
-    struct dpif_execute execute;
     int type = nl_attr_type(action);
 
     switch ((enum ovs_action_attr)type) {
     case OVS_ACTION_ATTR_OUTPUT:
     case OVS_ACTION_ATTR_USERSPACE:
-    case OVS_ACTION_ATTR_RECIRC:
-        execute.actions = action;
-        execute.actions_len = NLA_ALIGN(action->nla_len);
+    case OVS_ACTION_ATTR_RECIRC: {
+        struct dpif_execute execute;
+        struct ofpbuf execute_actions;
+        uint64_t stub[256 / 8];
+
+        if (md->tunnel.ip_dst) {
+            /* The Linux kernel datapath throws away the tunnel information
+             * that we supply as metadata.  We have to use a "set" action to
+             * supply it. */
+            ofpbuf_use_stub(&execute_actions, stub, sizeof stub);
+            odp_put_tunnel_action(&md->tunnel, &execute_actions);
+            ofpbuf_put(&execute_actions, action, NLA_ALIGN(action->nla_len));
+
+            execute.actions = ofpbuf_data(&execute_actions);
+            execute.actions_len = ofpbuf_size(&execute_actions);
+        } else {
+            execute.actions = action;
+            execute.actions_len = NLA_ALIGN(action->nla_len);
+        }
+
         execute.packet = packet;
         execute.md = *md;
         execute.needs_help = false;
         aux->error = aux->dpif->dpif_class->execute(aux->dpif, &execute);
+
+        if (md->tunnel.ip_dst) {
+            ofpbuf_uninit(&execute_actions);
+        }
         break;
+    }
 
     case OVS_ACTION_ATTR_HASH:
     case OVS_ACTION_ATTR_PUSH_VLAN: