]> The Tcpdump Group git mirrors - tcpdump/blob - missing/strlcat.c
need strl{cat,cpy} badly for buffer overflow
[tcpdump] / missing / strlcat.c
1 /* $NetBSD: strlcat.c,v 1.5 1999/09/20 04:39:47 lukem Exp $ */
2 /* from OpenBSD: strlcat.c,v 1.2 1999/06/17 16:28:58 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 #ifndef lint
32 static const char rcsid[] =
33 "@(#) $Header: /tcpdump/master/tcpdump/missing/strlcat.c,v 1.1 2000-01-19 05:34:19 itojun Exp $ (LBL)";
34 #endif
35
36 #include <config.h>
37
38 #include <sys/types.h>
39 #include <string.h>
40
41 #include "interface.h"
42
43 /*
44 * Appends src to string dst of size siz (unlike strncat, siz is the
45 * full size of dst, not space left). At most siz-1 characters
46 * will be copied. Always NUL terminates (unless siz == 0).
47 * Returns strlen(src); if retval >= siz, truncation occurred.
48 */
49 size_t
50 strlcat(dst, src, siz)
51 char *dst;
52 const char *src;
53 size_t siz;
54 {
55 register char *d = dst;
56 register const char *s = src;
57 register size_t n = siz;
58 size_t dlen;
59
60 /* Find the end of dst and adjust bytes left but don't go past end */
61 while (*d != '\0' && n-- != 0)
62 d++;
63 dlen = d - dst;
64 n = siz - dlen;
65
66 if (n == 0)
67 return(dlen + strlen(s));
68 while (*s != '\0') {
69 if (n != 1) {
70 *d++ = *s;
71 n--;
72 }
73 s++;
74 }
75 *d = '\0';
76
77 return(dlen + (s - src)); /* count does not include NUL */
78 }