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>
(cherry picked from commit e5ff5a36dd126ee57dca4e0b03da2f7704e0a4f5)
Signed-off-by: Ole Troan <ot@cisco.com>

1 files changed, 8 insertions, 39 deletions

diff --git a/src/vat/api_format.c b/src/vat/api_format.c
index 19a7b29d01c..86457dc9218 100644
--- a/src/vat/api_format.c
+++ b/src/vat/api_format.c
@@ -1333,30 +1333,10 @@ static void vl_api_show_version_reply_t_handler
 
   if (retval >= 0)
     {
-      u8 *s = 0;
-      char *p = (char *) &mp->program;
-
-      s = vl_api_from_api_to_vec ((vl_api_string_t *) p);
-      errmsg ("        program: %v\n", s);
-      vec_free (s);
-
-      p +=
-	vl_api_string_len ((vl_api_string_t *) p) + sizeof (vl_api_string_t);
-      s = vl_api_from_api_to_vec ((vl_api_string_t *) p);
-      errmsg ("        version: %v\n", s);
-      vec_free (s);
-
-      p +=
-	vl_api_string_len ((vl_api_string_t *) p) + sizeof (vl_api_string_t);
-      s = vl_api_from_api_to_vec ((vl_api_string_t *) p);
-      errmsg ("     build date: %v\n", s);
-      vec_free (s);
-
-      p +=
-	vl_api_string_len ((vl_api_string_t *) p) + sizeof (vl_api_string_t);
-      s = vl_api_from_api_to_vec ((vl_api_string_t *) p);
-      errmsg ("build directory: %v\n", s);
-      vec_free (s);
+      errmsg ("        program: %s", mp->program);
+      errmsg ("        version: %s", mp->version);
+      errmsg ("     build date: %s", mp->build_date);
+      errmsg ("build directory: %s", mp->build_directory);
     }
   vam->retval = retval;
   vam->result_ready = 1;
@@ -1370,22 +1350,11 @@ static void vl_api_show_version_reply_t_handler_json
 
   vat_json_init_object (&node);
   vat_json_object_add_int (&node, "retval", ntohl (mp->retval));
-  char *p = (char *) &mp->program;
-  vat_json_object_add_string_copy (&node, "program",
-				   vl_api_from_api_string ((vl_api_string_t *)
-							   p));
-  p += vl_api_string_len ((vl_api_string_t *) p) + sizeof (u32);
-  vat_json_object_add_string_copy (&node, "version",
-				   vl_api_from_api_string ((vl_api_string_t *)
-							   p));
-  p += vl_api_string_len ((vl_api_string_t *) p) + sizeof (u32);
-  vat_json_object_add_string_copy (&node, "build_date",
-				   vl_api_from_api_string ((vl_api_string_t *)
-							   p));
-  p += vl_api_string_len ((vl_api_string_t *) p) + sizeof (u32);
+  vat_json_object_add_string_copy (&node, "program", mp->program);
+  vat_json_object_add_string_copy (&node, "version", mp->version);
+  vat_json_object_add_string_copy (&node, "build_date", mp->build_date);
   vat_json_object_add_string_copy (&node, "build_directory",
-				   vl_api_from_api_string ((vl_api_string_t *)
-							   p));
+				   mp->build_directory);
 
   vat_json_print (vam->ofp, &node);
   vat_json_free (&node);