1*3b6c3722Schristos /*
2*3b6c3722Schristos * memmove.c: memmove compat implementation.
3*3b6c3722Schristos *
4*3b6c3722Schristos * Copyright (c) 2001-2006, NLnet Labs. All rights reserved.
5*3b6c3722Schristos *
6*3b6c3722Schristos * See LICENSE for the license.
7*3b6c3722Schristos */
8*3b6c3722Schristos
9*3b6c3722Schristos #include <config.h>
10*3b6c3722Schristos #include <stdlib.h>
11*3b6c3722Schristos
12*3b6c3722Schristos void *memmove(void *dest, const void *src, size_t n);
13*3b6c3722Schristos
memmove(void * dest,const void * src,size_t n)14*3b6c3722Schristos void *memmove(void *dest, const void *src, size_t n)
15*3b6c3722Schristos {
16*3b6c3722Schristos uint8_t* from = (uint8_t*) src;
17*3b6c3722Schristos uint8_t* to = (uint8_t*) dest;
18*3b6c3722Schristos
19*3b6c3722Schristos if (from == to || n == 0)
20*3b6c3722Schristos return dest;
21*3b6c3722Schristos if (to > from && to-from < (int)n) {
22*3b6c3722Schristos /* to overlaps with from */
23*3b6c3722Schristos /* <from......> */
24*3b6c3722Schristos /* <to........> */
25*3b6c3722Schristos /* copy in reverse, to avoid overwriting from */
26*3b6c3722Schristos int i;
27*3b6c3722Schristos for(i=n-1; i>=0; i--)
28*3b6c3722Schristos to[i] = from[i];
29*3b6c3722Schristos return dest;
30*3b6c3722Schristos }
31*3b6c3722Schristos if (from > to && from-to < (int)n) {
32*3b6c3722Schristos /* to overlaps with from */
33*3b6c3722Schristos /* <from......> */
34*3b6c3722Schristos /* <to........> */
35*3b6c3722Schristos /* copy forwards, to avoid overwriting from */
36*3b6c3722Schristos size_t i;
37*3b6c3722Schristos for(i=0; i<n; i++)
38*3b6c3722Schristos to[i] = from[i];
39*3b6c3722Schristos return dest;
40*3b6c3722Schristos }
41*3b6c3722Schristos memcpy(dest, src, n);
42*3b6c3722Schristos return dest;
43*3b6c3722Schristos }
44