xref: /freebsd/contrib/tcpdump/missing/strlcpy.c (revision 87b759f0fa1f7554d50ce640c40138512bbded44)
1 /*	$NetBSD: strlcpy.c,v 1.5 1999/09/20 04:39:47 lukem Exp $	*/
2 /*	from OpenBSD: strlcpy.c,v 1.4 1999/05/01 18:56:41 millert Exp	*/
3 
4 /*
5  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
20  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
21  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
22  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
23  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
24  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
25  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
26  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
27  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
28  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include <config.h>
32 
33 #include <netdissect-stdinc.h>
34 
35 #include <string.h>
36 
37 #include "netdissect.h"
38 
39 /*
40  * Copy src to string dst of size siz.  At most siz-1 characters
41  * will be copied.  Always NUL terminates (unless siz == 0).
42  * Returns strlen(src); if retval >= siz, truncation occurred.
43  */
44 size_t
45 strlcpy(char *dst, const char *src, size_t siz)
46 {
47 	char *d = dst;
48 	const char *s = src;
49 	size_t n = siz;
50 
51 	/* Copy as many bytes as will fit */
52 	if (n != 0 && --n != 0) {
53 		do {
54 			if ((*d++ = *s++) == 0)
55 				break;
56 		} while (--n != 0);
57 	}
58 
59 	/* Not enough room in dst, add NUL and traverse rest of src */
60 	if (n == 0) {
61 		if (siz != 0)
62 			*d = '\0';		/* NUL-terminate dst */
63 		while (*s++)
64 			;
65 	}
66 
67 	return(s - src - 1);	/* count does not include NUL */
68 }
69