1 /*
2  * SPDX-License-Identifier: ISC
3  * SPDX-FileCopyrightText: Copyright Todd C. Miller <Todd.Miller@courtesan.com>
4  * SPDX-FileCopyrightText: Copyright TF-RMM Contributors.
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  * OpenBSD: strlcpy.c,v 1.12 2015/01/15 03:54:12 millert Exp $
19  */
20 
21 #include <stdint.h>
22 #include <string.h>
23 
24 /*
25  * Copy string src to buffer dst of size dsize.  At most dsize-1
26  * chars will be copied.  Always NUL terminates (unless dsize == 0).
27  * Returns strlen(src); if retval >= dsize, truncation occurred.
28  */
strlcpy(char * dst,const char * src,size_t dsize)29 size_t strlcpy(char *dst, const char *src, size_t dsize)
30 {
31 	const char *osrc = src;
32 	size_t nleft = dsize;
33 
34 	/* Copy as many bytes as will fit. */
35 	if (nleft != 0UL) {
36 		while (--nleft != 0UL) {
37 			*dst++ = *src++;
38 			if (*(dst - 1) == '\0') {
39 				break;
40 			}
41 		}
42 	}
43 
44 	/* Not enough room in dst, add NUL and traverse rest of src. */
45 	if (nleft == 0UL) {
46 		if (dsize != 0UL) {
47 			*dst = '\0'; /* NUL-terminate dst */
48 		}
49 		while (*src++) {
50 			;
51 		}
52 	}
53 
54 	return (src - osrc - 1); /* count does not include NUL */
55 }
56