Optimize GRE Tunnel and add support for ERSPAN encap

Change GRE tunnel to use the interface type where the same encap
node is used as output node for all GRE tunnels, instead of having
dedicated output and tx node for each tunnel. This allows for more
efficient tunnel creation and deletion at scale tested at 1000's
of GRE tunnels.

Add support for ERSPAN encap as another tunnel type, in addition
to the existing L3 and TEB types. The GRE ERSPAN encap supported
is type 2 thus GRE encap need to include sequence number and GRE-
ERSPAN tunnel can be created with user secified ERSPAN session ID.
The GRE tunnel lookup hash key is updated to inclue tunnel type
and session ID, in addition to SIP/DIP and FIB index.
Thus, GRE-ERSPAN tunnel can be created, with the appropriate
session ID, to be used as output interface for SPAN config to
send mirrored packets.

Change interface naming so that all GRE tunnels, irrespective of
tunnel type, uses "greN" where N is the instance number. Removed
interface reuse on tunnel creation and deletion to enable unfied
tunnel interface name.

Add support of user specified instance on GRE tunnel creation.
Thus, N in the "greN" interface name can optionally be specified
by user via CLI/API.

Optimize GRE tunnel encap DPO stacking to bypass load-balance DPO
node since packet output on GRE tunnel always belong to the same
flow after 5-tupple hash.

Change-Id: Ifa83915744a1a88045c998604777cc3583f4da52
Signed-off-by: John Lo <loj@cisco.com>

1 files changed, 19 insertions, 3 deletions

diff --git a/src/vnet/gre/gre.api b/src/vnet/gre/gre.api
index b410ac9d49a..28c970154ae 100644
--- a/src/vnet/gre/gre.api
+++ b/src/vnet/gre/gre.api
@@ -13,18 +13,32 @@
  * limitations under the License.
  */
 
-option version = "1.0.0";
+option version = "1.0.1";
 
+/** \brief Create or delete a GRE tunnel
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_add - Use 1 to create the tunnel, 0 to remove it
+    @param is_ipv6 - Use 0 for IPv4, 1 for IPv6
+    @param tunnel_type - 0: L3, 1: TEB, 2: ERSPAN
+    @param instance - optional unique custom device instance, else ~0.
+    @param src_address - Source IP address
+    @param dst_address - Destination IP address, can be multicast
+    @param outer_fib_id - Encap FIB table ID
+    @param session_id - session for ERSPAN tunnel, range 0-1023
+*/
 define gre_add_del_tunnel
 {
   u32 client_index;
   u32 context;
   u8 is_add;
   u8 is_ipv6;
-  u8 teb;
+  u8 tunnel_type;
+  u32 instance;		/* If non-~0, specifies a custom dev instance */
   u8 src_address[16];
   u8 dst_address[16];
   u32 outer_fib_id;
+  u16 session_id;
 };
 
 define gre_add_del_tunnel_reply
@@ -45,11 +59,13 @@ define gre_tunnel_details
 {
   u32 context;
   u32 sw_if_index;
+  u32 instance;
   u8 is_ipv6;
-  u8 teb;
+  u8 tunnel_type;
   u8 src_address[16];
   u8 dst_address[16];
   u32 outer_fib_id;
+  u16 session_id;
 };
 
 /*