User-Space MPLS actions and matches

This patch implements use-space datapath and non-datapath code
to match and use the datapath API set out in Leo Alterman's patch
"user-space datapath: Add basic MPLS support to kernel".

The resulting MPLS implementation supports:
* Pushing a single MPLS label
* Poping a single MPLS label
* Modifying an MPLS lable using set-field or load actions
  that act on the label value, tc and bos bit.
* There is no support for manipulating the TTL
  this is considered future work.

The single-level push pop limitation is implemented by processing
push, pop and set-field/load actions in order and discarding information
that would require multiple levels of push/pop to be supported.

e.g.
   push,push -> the first push is discarded
   pop,pop -> the first pop is discarded

This patch is based heavily on work by Ravi K.

Cc: Ravi K <rkerur@gmail.com>
Reviewed-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Ben Pfaff <blp@nicira.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index 038dfdc9..d315b594 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -1233,6 +1233,10 @@ execute_set_action(struct ofpbuf *packet, const struct nlattr *a)
         packet_set_udp_port(packet, udp_key->udp_src, udp_key->udp_dst);
         break;
 
+     case OVS_KEY_ATTR_MPLS:
+         set_mpls_lse(packet, nl_attr_get_be32(a));
+         break;
+
      case OVS_KEY_ATTR_UNSPEC:
      case OVS_KEY_ATTR_ENCAP:
      case OVS_KEY_ATTR_ETHERTYPE:
@@ -1279,6 +1283,16 @@ dp_netdev_execute_actions(struct dp_netdev *dp,
             eth_pop_vlan(packet);
             break;
 
+        case OVS_ACTION_ATTR_PUSH_MPLS: {
+            const struct ovs_action_push_mpls *mpls = nl_attr_get(a);
+            push_mpls(packet, mpls->mpls_ethertype, mpls->mpls_lse);
+            break;
+         }
+
+        case OVS_ACTION_ATTR_POP_MPLS:
+            pop_mpls(packet, nl_attr_get_be16(a));
+            break;
+
         case OVS_ACTION_ATTR_SET:
             execute_set_action(packet, nl_attr_get(a));
             break;