2 files changed, 69 insertions, 1 deletions

diff --git a/src/vlib/buffer.c b/src/vlib/buffer.c
index 4f5eb09da91..9f26bec7b56 100644
--- a/src/vlib/buffer.c
+++ b/src/vlib/buffer.c
@@ -360,7 +360,7 @@ vlib_buffer_create_free_list_helper (vlib_main_t * vm,
   memset (f, 0, sizeof (f[0]));
   f->index = f - bm->buffer_free_list_pool;
   f->n_data_bytes = vlib_buffer_round_size (n_data_bytes);
-  f->min_n_buffers_each_physmem_alloc = 16;
+  f->min_n_buffers_each_physmem_alloc = VLIB_FRAME_SIZE;
   f->name = clib_mem_is_heap_object (name) ? name : format (0, "%s", name);
 
   /* Setup free buffer template. */
diff --git a/src/vlib/buffer.h b/src/vlib/buffer.h
index 1f723f3b677..69c8c7ccb09 100644
--- a/src/vlib/buffer.h
+++ b/src/vlib/buffer.h
@@ -240,6 +240,74 @@ vlib_get_buffer_opaque2 (vlib_buffer_t * b)
   return (void *) b->opaque2;
 }
 
+/** \brief Get pointer to the end of buffer's data
+ * @param b     pointer to the buffer
+ * @return      pointer to tail of packet's data
+ */
+always_inline u8 *
+vlib_buffer_get_tail (vlib_buffer_t * b)
+{
+  return b->data + b->current_data + b->current_length;
+}
+
+/** \brief Append uninitialized data to buffer
+ * @param b     pointer to the buffer
+ * @param size  number of uninitialized bytes
+ * @return      pointer to beginning of uninitialized data
+ */
+always_inline void *
+vlib_buffer_put_uninit (vlib_buffer_t * b, u8 size)
+{
+  void *p = vlib_buffer_get_tail (b);
+  /* XXX make sure there's enough space */
+  b->current_length += size;
+  return p;
+}
+
+/** \brief Prepend uninitialized data to buffer
+ * @param b     pointer to the buffer
+ * @param size  number of uninitialized bytes
+ * @return      pointer to beginning of uninitialized data
+ */
+always_inline void *
+vlib_buffer_push_uninit (vlib_buffer_t * b, u8 size)
+{
+  ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
+  b->current_data -= size;
+  b->current_length += size;
+
+  return vlib_buffer_get_current (b);
+}
+
+/** \brief Make head room, typically for packet headers
+ * @param b     pointer to the buffer
+ * @param size  number of head room bytes
+ * @return      pointer to start of buffer (current data)
+ */
+always_inline void *
+vlib_buffer_make_headroom (vlib_buffer_t * b, u8 size)
+{
+  ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
+  b->current_data += size;
+  return vlib_buffer_get_current (b);
+}
+
+/** \brief Retrieve bytes from buffer head
+ * @param b     pointer to the buffer
+ * @param size  number of bytes to pull
+ * @return      pointer to start of buffer (current data)
+ */
+always_inline void *
+vlib_buffer_pull (vlib_buffer_t * b, u8 size)
+{
+  if (b->current_length + VLIB_BUFFER_PRE_DATA_SIZE < size)
+    return 0;
+
+  void *data = vlib_buffer_get_current (b);
+  vlib_buffer_advance (b, size);
+  return data;
+}
+
 /* Forward declaration. */
 struct vlib_main_t;