xref: /netbsd-src/external/bsd/ntp/dist/libntp/strl_obsd.c (revision cdfa2a7ef92791ba9db70a584a1d904730e6fb46)
1 /*	$NetBSD: strl_obsd.c,v 1.5 2020/05/25 20:47:24 christos Exp $	*/
2 
3 /*
4  * Why use strlcpy()/strlcat() instead of standard strncpy()/strncat()?
5  * To reduce likelihood of bugs and avoid wasteful zero fills.  See:
6  * http://www.gratisoft.us/todd/papers/strlcpy.html
7  */
8 
9 /*	$OpenBSD: strlcpy.c,v 1.11 2006/05/05 15:27:38 millert Exp $	*/
10 
11 /*
12  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
13  *
14  * Permission to use, copy, modify, and distribute this software for any
15  * purpose with or without fee is hereby granted, provided that the above
16  * copyright notice and this permission notice appear in all copies.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
19  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
20  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
21  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
22  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
23  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
24  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
25  */
26 
27 #include <config.h>		/* + marks local changes */
28 #ifdef HAVE_SYS_TYPES_H		/* + */
29 #include <sys/types.h>
30 #endif				/* + */
31 #include <string.h>
32 
33 #include "ntp_stdlib.h"		/* + strlcpy, strlcat prototypes */
34 
35 #ifndef HAVE_STRLCPY		/* + */
36 /*
37  * Copy src to string dst of size siz.  At most siz-1 characters
38  * will be copied.  Always NUL terminates (unless siz == 0).
39  * Returns strlen(src); if retval >= siz, truncation occurred.
40  */
41 size_t
strlcpy(char * dst,const char * src,size_t siz)42 strlcpy(char *dst, const char *src, size_t siz)
43 {
44 	char *d = dst;
45 	const char *s = src;
46 	size_t n = siz;
47 
48 	/* Copy as many bytes as will fit */
49 	if (n != 0) {
50 		while (--n != 0) {
51 			if ((*d++ = *s++) == '\0')
52 				break;
53 		}
54 	}
55 
56 	/* Not enough room in dst, add NUL and traverse rest of src */
57 	if (n == 0) {
58 		if (siz != 0)
59 			*d = '\0';		/* NUL-terminate dst */
60 		while (*s++)
61 			;
62 	}
63 
64 	return(s - src - 1);	/* count does not include NUL */
65 }
66 #endif				/* + */
67 
68 
69 /*	$OpenBSD: strlcat.c,v 1.13 2005/08/08 08:05:37 espie Exp $	*/
70 
71 /*
72  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
73  *
74  * Permission to use, copy, modify, and distribute this software for any
75  * purpose with or without fee is hereby granted, provided that the above
76  * copyright notice and this permission notice appear in all copies.
77  *
78  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
79  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
80  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
81  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
82  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
83  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
84  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
85  */
86 
87 /* #include <sys/types.h> */	/* + */
88 /* #include <string.h> */	/* + */
89 
90 #ifndef HAVE_STRLCAT		/* + */
91 /*
92  * Appends src to string dst of size siz (unlike strncat, siz is the
93  * full size of dst, not space left).  At most siz-1 characters
94  * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
95  * Returns strlen(src) + MIN(siz, strlen(initial dst)).
96  * If retval >= siz, truncation occurred.
97  */
98 size_t
strlcat(char * dst,const char * src,size_t siz)99 strlcat(char *dst, const char *src, size_t siz)
100 {
101 	char *d = dst;
102 	const char *s = src;
103 	size_t n = siz;
104 	size_t dlen;
105 
106 	/* Find the end of dst and adjust bytes left but don't go past end */
107 	while (n-- != 0 && *d != '\0')
108 		d++;
109 	dlen = d - dst;
110 	n = siz - dlen;
111 
112 	if (n == 0)
113 		return(dlen + strlen(s));
114 	while (*s != '\0') {
115 		if (n != 1) {
116 			*d++ = *s;
117 			n--;
118 		}
119 		s++;
120 	}
121 	*d = '\0';
122 
123 	return(dlen + (s - src));	/* count does not include NUL */
124 }
125 #endif				/* + */
126