+/* duplicate first buffer in chain */
+always_inline vlib_buffer_t *
+vlib_buffer_copy_no_chain (vlib_main_t * vm, vlib_buffer_t * b, u32 * di)
+{
+ vlib_buffer_t *d;
+
+ if ((vlib_buffer_alloc (vm, di, 1)) != 1)
+ return 0;
+
+ d = vlib_get_buffer (vm, *di);
+ /* 1st segment */
+ d->current_data = b->current_data;
+ d->current_length = b->current_length;
+ clib_memcpy_fast (d->opaque, b->opaque, sizeof (b->opaque));
+ clib_memcpy_fast (d->opaque2, b->opaque2, sizeof (b->opaque2));
+ clib_memcpy_fast (vlib_buffer_get_current (d),
+ vlib_buffer_get_current (b), b->current_length);
+
+ return d;
+}
+
+/* \brief Move packet from current position to offset position in buffer.
+ Only work for small packet using one buffer with room to fit the move
+ @param vm - (vlib_main_t *) vlib main data structure pointer
+ @param b - (vlib_buffer_t *) pointer to buffer
+ @param offset - (i16) position to move the packet in buffer
+ */
+always_inline void
+vlib_buffer_move (vlib_main_t * vm, vlib_buffer_t * b, i16 offset)
+{
+ ASSERT ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0);
+ ASSERT (offset + VLIB_BUFFER_PRE_DATA_SIZE >= 0);
+ ASSERT (offset + b->current_length <
+ vlib_buffer_get_default_data_size (vm));
+
+ u8 *source = vlib_buffer_get_current (b);
+ b->current_data = offset;
+ u8 *destination = vlib_buffer_get_current (b);
+ u16 length = b->current_length;
+
+ if (source + length <= destination) /* no overlap */
+ clib_memcpy_fast (destination, source, length);
+ else
+ memmove (destination, source, length);
+}
+