commit 6855f6cdfee8c479f1e0ae440ce87a91ff41a708
author Ole Troan <ot@cisco.com> Sat Apr 09 03:16:30 2016 +0200
committer Dave Wallace <dwallacelf@gmail.com> Wed Apr 20 16:50:29 2016 +0000
tree e438e21c8107a675dc3a3141c6af6ba0ab458992
parent 633951c3d8dc1640813b4778f3e35463d08f3795

Python-API: Inital commit of Python bindings for the VPP API.
See: https://wiki.fd.io/view/VPP/Python_API

Change-Id: If135fc32208c7031787e1935b399d930e0e1ea1f
Signed-off-by: Ole Troan <ot@cisco.com>

vlib-api/vlibmemory/api.h

diff --git a/vlib-api/vlibmemory/api.h b/vlib-api/vlibmemory/api.h
index 117bf43..516d321 100644
--- a/vlib-api/vlibmemory/api.h
+++ b/vlib-api/vlibmemory/api.h
@@ -86,6 +86,13 @@
 
 } vl_shmem_hdr_t;
 
+/* Note that the size of the structure is 16 bytes, with 4 bytes of padding after data[0]. */
+typedef struct msgbuf_ {
+    unix_shared_memory_queue_t *q;
+    u32 data_len;
+    u8 data[0];
+} msgbuf_t;
+
 #define VL_SHM_VERSION 2
 
 #define VL_API_EPOCH_MASK 0xFF

vlib-api/vlibmemory/memory_shared.c

diff --git a/vlib-api/vlibmemory/memory_shared.c b/vlib-api/vlibmemory/memory_shared.c
index ecd5cff..a321943 100644
--- a/vlib-api/vlibmemory/memory_shared.c
+++ b/vlib-api/vlibmemory/memory_shared.c
@@ -21,6 +21,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <stddef.h>
 #include <string.h>
 #include <unistd.h>
 #include <signal.h>
@@ -38,11 +39,6 @@
 #include <vlibmemory/vl_memory_api_h.h>
 #undef vl_typedefs
 
-typedef struct msgbuf_ {
-    unix_shared_memory_queue_t *q;
-    u8 data[0];
-} msgbuf_t;
-
 static inline void *vl_msg_api_alloc_internal(int nbytes, int pool)
 {
     int i;
@@ -119,12 +115,13 @@
 
     pthread_mutex_lock (&am->vlib_rp->mutex);
     oldheap = svm_push_data_heap (am->vlib_rp);
-    rv = clib_mem_alloc(nbytes + sizeof(msgbuf_t));
+    rv = clib_mem_alloc(nbytes);
     rv->q = 0;
     svm_pop_heap (oldheap);
     pthread_mutex_unlock (&am->vlib_rp->mutex);
 
  out:
+    rv->data_len = htonl(nbytes - sizeof(msgbuf_t));
     return(rv->data);
 }
 
@@ -152,7 +149,8 @@
     void *oldheap;
     api_main_t *am = &api_main;
     
-    rv = (msgbuf_t *)(((u8 *)a) - sizeof(*rv));
+    rv = (msgbuf_t *)(((u8 *)a) - offsetof(msgbuf_t, data));
+
     /*
      * Here's the beauty of the scheme.  Only one proc/thread has
      * control of a given message buffer. To free a buffer, we just clear the 
@@ -176,7 +174,7 @@
     void *oldheap;
     api_main_t *am = &api_main;
     
-    rv = (msgbuf_t *)(((u8 *)a) - sizeof(*rv));
+    rv = (msgbuf_t *)(((u8 *)a) - offsetof(msgbuf_t, data));
     /*
      * Here's the beauty of the scheme.  Only one proc/thread has
      * control of a given message buffer. To free a buffer, we just clear the