The Tcpdump Group git mirrors - libpcap/blob - missing/strlcpy.c

   1 /*      $OpenBSD: pcap_strlcpy.c,v 1.12 2015/01/15 03:54:12 millert Exp $       */
   2
   3 /*
   4  * Copyright (c) 1998, 2015 Todd C. Miller <Todd.Miller@courtesan.com>
   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
  19 #ifdef HAVE_CONFIG_H
  20 #include <config.h>
  21 #endif
  22
  23 #include <stddef.h>
  24 #include <string.h>
  25
  26 #include "portability.h"
  27
  28 /*
  29  * Copy string src to buffer dst of size dsize.  At most dsize-1
  30  * chars will be copied.  Always NUL terminates (unless dsize == 0).
  31  * Returns strlen(src); if retval >= dsize, truncation occurred.
  32  */
  33 size_t
  34 pcap_strlcpy(char * restrict dst, const char * restrict src, size_t dsize)
  35 {
  36         const char *osrc = src;
  37         size_t nleft = dsize;
  38
  39         /* Copy as many bytes as will fit. */
  40         if (nleft != 0) {
  41                 while (--nleft != 0) {
  42                         if ((*dst++ = *src++) == '\0')
  43                                 break;
  44                 }
  45         }
  46
  47         /* Not enough room in dst, add NUL and traverse rest of src. */
  48         if (nleft == 0) {
  49                 if (dsize != 0)
  50                         *dst = '\0';            /* NUL-terminate dst */
  51                 while (*src++)
  52                         ;
  53         }
  54
  55         return(src - osrc - 1); /* count does not include NUL */
  56 }