api: enforce vla is last and fixed string type

Enforce that variable length fields are the last element of API messages.

Add a 'fixed' version of string type, since dealing with
multiple variable length strings turned out too painful
for the C language bindings.

The string type is now:
{
  string name[64]; // NUL terminated C-string. Essentially decays to u8 name[64]
  string name[];   // Variable length string with embedded len field (vl_api_string_t)
};

The latter notation could be made available to other types as well.
e.g.
{
  vl_api_address_t addresses[];
}
instead of

{
  u32 n_addr;
  vl_api_address_t addresses[n_addr];
};

Type: fix
Change-Id: I18fa17ef47227633752ab50453e8d20a652a9f9b
Signed-off-by: Ole Troan <ot@cisco.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/vnet/session/session.api b/src/vnet/session/session.api
index 52e050d3978..6f208ff5b0e 100644
--- a/src/vnet/session/session.api
+++ b/src/vnet/session/session.api
@@ -320,9 +320,9 @@ autoreply define connect_sock {
   u8 ip[16];
   u16 port;
   u8 proto;
+  u64 parent_handle;
   u8 hostname_len;
   u8 hostname[hostname_len];
-  u64 parent_handle;
 };
 
 /** \brief ask app to add a new cut-through registration