1 /*	$OpenBSD: pcap_strlcpy.c,v 1.12 2015/01/15 03:54:12 millert Exp $	*/
2 
3 /*
4  * Copyright (c) 1998, 2015 Todd C. Miller <Todd.Miller@courtesan.com>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #ifdef HAVE_CONFIG_H
20 #include <config.h>
21 #endif
22 
23 #include <stddef.h>
24 #include <string.h>
25 
26 #include "portability.h"
27 
28 /*
29  * Copy string src to buffer dst of size dsize.  At most dsize-1
30  * chars will be copied.  Always NUL terminates (unless dsize == 0).
31  * Returns strlen(src); if retval >= dsize, truncation occurred.
32  */
33 size_t
pcap_strlcpy(char * restrict dst,const char * restrict src,size_t dsize)34 pcap_strlcpy(char * restrict dst, const char * restrict src, size_t dsize)
35 {
36 	const char *osrc = src;
37 	size_t nleft = dsize;
38 
39 	/* Copy as many bytes as will fit. */
40 	if (nleft != 0) {
41 		while (--nleft != 0) {
42 			if ((*dst++ = *src++) == '\0')
43 				break;
44 		}
45 	}
46 
47 	/* Not enough room in dst, add NUL and traverse rest of src. */
48 	if (nleft == 0) {
49 		if (dsize != 0)
50 			*dst = '\0';		/* NUL-terminate dst */
51 		while (*src++)
52 			;
53 	}
54 
55 	return(src - osrc - 1);	/* count does not include NUL */
56 }
57