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 6b519b8..e333d98 100644 (file)
--- a/lib/dpif.c
+++ b/lib/dpif.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -1073,15 +1073,30 @@ dpif_execute_helper_execute__(void *aux_, struct ofpbuf *packet,
     struct dpif_execute execute;
     struct odputil_keybuf key_stub;
     struct ofpbuf key;
+    struct ofpbuf execute_actions;
+    uint64_t stub[256 / 8];
     int error;
 
     ofpbuf_use_stub(&key, &key_stub, sizeof key_stub);
     odp_flow_key_from_flow(&key, flow, flow->in_port.odp_port);
 
+    if (flow->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(&flow->tunnel, &execute_actions);
+        ofpbuf_put(&execute_actions, actions, actions_len);
+
+        execute.actions = execute_actions.data;
+        execute.actions_len = execute_actions.size;
+    } else {
+        execute.actions = actions;
+        execute.actions_len = actions_len;
+    }
+
     execute.key = key.data;
     execute.key_len = key.size;
-    execute.actions = actions;
-    execute.actions_len = actions_len;
     execute.packet = packet;
     execute.needs_help = false;
 
@@ -1089,6 +1104,10 @@ dpif_execute_helper_execute__(void *aux_, struct ofpbuf *packet,
     if (error) {
         aux->error = error;
     }
+
+    if (flow->tunnel.ip_dst) {
+        ofpbuf_uninit(&execute_actions);
+    }
 }
 
 static void