Implement a loopback instance allocation scheme.

To support creating loopback interfaces with a specific
instance number, a new CREATE_LOOPBACK_INSTANCE API call
with flag is_specified and value user_instance is introduced.
Presumably the existing CREATE_LOOPBACK API message will be
obsoleted and revmoved.

The VAT cli commands can now mention and format
the new field as 'instance %d' data.  If no instance
number is named, the old call CREATE_LOOPBACK is used
to maintain backward compatibility.  However, if the
instance is named, the new CREATE_LOOPBACK_INSTANCE
message will be used.

Both the dynamically allocated and user-requested instance
number are tracked in a bitvector.  If is_specified is 0,
the next free instance will be used..  A request for a specific
instance number will be granted if it is available.  On error,
the value ~0 is returned.

Change-Id: I849815563a5da736dcd6bccd262ef49b963f6643
Signed-off-by: Jon Loeliger <jdl@netgate.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/src/vpp/api/vpe.api b/src/vpp/api/vpe.api
index 7f9c2038..a4ba180d 100644
--- a/src/vpp/api/vpe.api
+++ b/src/vpp/api/vpe.api
@@ -425,6 +425,34 @@ define create_loopback_reply
   u32 sw_if_index;
 };
 
+/** \brief Create loopback interface instance request
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param mac_address - mac addr to assign to the interface if none-zero
+    @param is_specified - if non-0, a specific user_instance is being requested
+    @param user_instance - requested instance, ~0 => dynamically allocate
+*/
+define create_loopback_instance
+{
+  u32 client_index;
+  u32 context;
+  u8 mac_address[6];
+  u8 is_specified;
+  u32 user_instance;
+};
+
+/** \brief Create loopback interface instance response
+    @param context - sender context, to match reply w/ request
+    @param sw_if_index - sw index of the interface that was created
+    @param retval - return code for the request
+*/
+define create_loopback_instance_reply
+{
+  u32 context;
+  i32 retval;
+  u32 sw_if_index;
+};
+
 /** \brief Delete loopback interface request
     @param client_index - opaque cookie to identify the sender
     @param context - sender context, to match reply w/ request