1/*
2 * Why use strlcpy()/strlcat() instead of standard strncpy()/strncat()?
3 * To reduce likelihood of bugs and avoid wasteful zero fills.  See:
4 * http://www.gratisoft.us/todd/papers/strlcpy.html
5 */
6
7/*	$OpenBSD: strlcpy.c,v 1.11 2006/05/05 15:27:38 millert Exp $	*/
8
9/*
10 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
11 *
12 * Permission to use, copy, modify, and distribute this software for any
13 * purpose with or without fee is hereby granted, provided that the above
14 * copyright notice and this permission notice appear in all copies.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
17 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
18 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
19 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
20 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
21 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
22 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
23 */
24
25#include <config.h>		/* + marks local changes */
26#ifdef HAVE_SYS_TYPES_H		/* + */
27#include <sys/types.h>
28#endif				/* + */
29#include <string.h>
30
31#include "ntp_stdlib.h"		/* + strlcpy, strlcat prototypes */
32
33#ifndef HAVE_STRLCPY		/* + */
34/*
35 * Copy src to string dst of size siz.  At most siz-1 characters
36 * will be copied.  Always NUL terminates (unless siz == 0).
37 * Returns strlen(src); if retval >= siz, truncation occurred.
38 */
39size_t
40strlcpy(char *dst, const char *src, size_t siz)
41{
42	char *d = dst;
43	const char *s = src;
44	size_t n = siz;
45
46	/* Copy as many bytes as will fit */
47	if (n != 0) {
48		while (--n != 0) {
49			if ((*d++ = *s++) == '\0')
50				break;
51		}
52	}
53
54	/* Not enough room in dst, add NUL and traverse rest of src */
55	if (n == 0) {
56		if (siz != 0)
57			*d = '\0';		/* NUL-terminate dst */
58		while (*s++)
59			;
60	}
61
62	return(s - src - 1);	/* count does not include NUL */
63}
64#endif				/* + */
65
66
67/*	$OpenBSD: strlcat.c,v 1.13 2005/08/08 08:05:37 espie Exp $	*/
68
69/*
70 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
71 *
72 * Permission to use, copy, modify, and distribute this software for any
73 * purpose with or without fee is hereby granted, provided that the above
74 * copyright notice and this permission notice appear in all copies.
75 *
76 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
77 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
78 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
79 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
80 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
81 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
82 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
83 */
84
85/* #include <sys/types.h> */	/* + */
86/* #include <string.h> */	/* + */
87
88#ifndef HAVE_STRLCAT		/* + */
89/*
90 * Appends src to string dst of size siz (unlike strncat, siz is the
91 * full size of dst, not space left).  At most siz-1 characters
92 * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
93 * Returns strlen(src) + MIN(siz, strlen(initial dst)).
94 * If retval >= siz, truncation occurred.
95 */
96size_t
97strlcat(char *dst, const char *src, size_t siz)
98{
99	char *d = dst;
100	const char *s = src;
101	size_t n = siz;
102	size_t dlen;
103
104	/* Find the end of dst and adjust bytes left but don't go past end */
105	while (n-- != 0 && *d != '\0')
106		d++;
107	dlen = d - dst;
108	n = siz - dlen;
109
110	if (n == 0)
111		return(dlen + strlen(s));
112	while (*s != '\0') {
113		if (n != 1) {
114			*d++ = *s;
115			n--;
116		}
117		s++;
118	}
119	*d = '\0';
120
121	return(dlen + (s - src));	/* count does not include NUL */
122}
123#endif				/* + */
124