xref: /freebsd/contrib/ntp/libntp/strl_obsd.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
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  */
39 size_t
40 strlcpy(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  */
96 size_t
97 strlcat(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