1*d83a80eeSchristos /*
2*d83a80eeSchristos * memmove.c: memmove compat implementation.
3*d83a80eeSchristos *
4*d83a80eeSchristos * Copyright (c) 2001-2006, NLnet Labs. All rights reserved.
5*d83a80eeSchristos *
6*d83a80eeSchristos * See LICENSE for the license.
7*d83a80eeSchristos */
8*d83a80eeSchristos
9*d83a80eeSchristos #include <config.h>
10*d83a80eeSchristos #include <stdlib.h>
11*d83a80eeSchristos
12*d83a80eeSchristos void *memmove(void *dest, const void *src, size_t n);
13*d83a80eeSchristos
memmove(void * dest,const void * src,size_t n)14*d83a80eeSchristos void *memmove(void *dest, const void *src, size_t n)
15*d83a80eeSchristos {
16*d83a80eeSchristos uint8_t* from = (uint8_t*) src;
17*d83a80eeSchristos uint8_t* to = (uint8_t*) dest;
18*d83a80eeSchristos
19*d83a80eeSchristos if (from == to || n == 0)
20*d83a80eeSchristos return dest;
21*d83a80eeSchristos if (to > from && to-from < (int)n) {
22*d83a80eeSchristos /* to overlaps with from */
23*d83a80eeSchristos /* <from......> */
24*d83a80eeSchristos /* <to........> */
25*d83a80eeSchristos /* copy in reverse, to avoid overwriting from */
26*d83a80eeSchristos int i;
27*d83a80eeSchristos for(i=n-1; i>=0; i--)
28*d83a80eeSchristos to[i] = from[i];
29*d83a80eeSchristos return dest;
30*d83a80eeSchristos }
31*d83a80eeSchristos if (from > to && from-to < (int)n) {
32*d83a80eeSchristos /* to overlaps with from */
33*d83a80eeSchristos /* <from......> */
34*d83a80eeSchristos /* <to........> */
35*d83a80eeSchristos /* copy forwards, to avoid overwriting from */
36*d83a80eeSchristos size_t i;
37*d83a80eeSchristos for(i=0; i<n; i++)
38*d83a80eeSchristos to[i] = from[i];
39*d83a80eeSchristos return dest;
40*d83a80eeSchristos }
41*d83a80eeSchristos memcpy(dest, src, n);
42*d83a80eeSchristos return dest;
43*d83a80eeSchristos }
44