Encap & Decap actions for MPLS packet type.

The encap & decap actions are extended to support MPLS packet type.
Encap & decap actions adds and removes MPLS header at start of the
packet.

The existing PUSH MPLS & POP MPLS actions inserts & removes MPLS
header between ethernet header and the IP header. Though this behaviour
is fine for L3 VPN where an IP packet is encapsulated inside a MPLS
tunnel, it does not suffice the L2 VPN requirements. In L2 VPN the
ethernet packets must be encapsulated inside MPLS tunnel.

In this change the encap & decap actions are extended to support MPLS
packet type. The encap & decap adds and removes MPLS header at the
start of packet as depicted below.

Encapsulation:

Actions - encap(mpls),encap(ethernet)

Incoming packet -> | ETH | IP | Payload |

1 Actions -  encap(mpls) [Datapath action - ADD_MPLS:0x8847]

        Outgoing packet -> | MPLS | ETH | Payload|

2 Actions - encap(ethernet) [ Datapath action - push_eth ]

        Outgoing packet -> | ETH | MPLS | ETH | Payload|

Decapsulation:

Incoming packet -> | ETH | MPLS | ETH | IP | Payload |

Actions - decap(),decap(packet_type(ns=0,type=0))

1 Actions -  decap() [Datapath action - pop_eth)

        Outgoing packet -> | MPLS | ETH | IP | Payload|

2 Actions - decap(packet_type(ns=0,type=0)) [Datapath action - POP_MPLS:0x6558]

        Outgoing packet -> | ETH  | IP | Payload|

Signed-off-by: Martin Varghese <martin.varghese@nokia.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>

1 files changed, 31 insertions, 0 deletions

diff --git a/datapath/linux/compat/include/linux/openvswitch.h b/datapath/linux/compat/include/linux/openvswitch.h
index 936644192..8d9300091 100644
--- a/datapath/linux/compat/include/linux/openvswitch.h
+++ b/datapath/linux/compat/include/linux/openvswitch.h
@@ -755,6 +755,32 @@ struct ovs_action_push_mpls {
 };
 
 /**
+ * struct ovs_action_add_mpls - %OVS_ACTION_ATTR_ADD_MPLS action
+ * argument.
+ * @mpls_lse: MPLS label stack entry to push.
+ * @mpls_ethertype: Ethertype to set in the encapsulating ethernet frame.
+ * @tun_flags: MPLS tunnel attributes.
+ *
+ * The only values @mpls_ethertype should ever be given are %ETH_P_MPLS_UC and
+ * %ETH_P_MPLS_MC, indicating MPLS unicast or multicast. Other are rejected.
+ */
+struct ovs_action_add_mpls {
+	__be32 mpls_lse;
+	__be16 mpls_ethertype; /* Either %ETH_P_MPLS_UC or %ETH_P_MPLS_MC */
+	__u16 tun_flags;
+};
+
+#define OVS_MPLS_L3_TUNNEL_FLAG_MASK  (1 << 0) /* Flag to specify the place of
+						* insertion of MPLS header.
+						* When false, the MPLS header
+						* will be inserted at the start
+						* of the packet.
+						* When true, the MPLS header
+						* will be inserted at the start
+						* of the l3 header.
+						*/
+
+/**
  * struct ovs_action_push_vlan - %OVS_ACTION_ATTR_PUSH_VLAN action argument.
  * @vlan_tpid: Tag protocol identifier (TPID) to push.
  * @vlan_tci: Tag control identifier (TCI) to push.  The CFI bit must be set
@@ -1008,6 +1034,10 @@ struct check_pkt_len_arg {
  * @OVS_ACTION_ATTR_CHECK_PKT_LEN: Check the packet length and execute a set
  * of actions if greater than the specified packet length, else execute
  * another set of actions.
+ * @OVS_ACTION_ATTR_ADD_MPLS: Push a new MPLS label stack entry at the
+ * start of the packet or at the start of the l3 header depending on the value
+ * of l3 tunnel flag in the tun_flags field of OVS_ACTION_ATTR_ADD_MPLS
+ * argument.
  * @OVS_ACTION_ATTR_DROP: Explicit drop action.
  */
 
@@ -1037,6 +1067,7 @@ enum ovs_action_attr {
 	OVS_ACTION_ATTR_METER,        /* u32 meter number. */
 	OVS_ACTION_ATTR_CLONE,        /* Nested OVS_CLONE_ATTR_*.  */
 	OVS_ACTION_ATTR_CHECK_PKT_LEN, /* Nested OVS_CHECK_PKT_LEN_ATTR_*. */
+	OVS_ACTION_ATTR_ADD_MPLS,     /* struct ovs_action_add_mpls. */
 
 #ifndef __KERNEL__
 	OVS_ACTION_ATTR_TUNNEL_PUSH,   /* struct ovs_action_push_tnl*/