1: /* Copyright (C) 1991, 1997, 2000, 2003, 2004 Free Software Foundation, Inc.
    2:    This file is part of the GNU C Library.
    3: 
    4:    The GNU C Library is free software; you can redistribute it and/or
    5:    modify it under the terms of the GNU Lesser General Public
    6:    License as published by the Free Software Foundation; either
    7:    version 2.1 of the License, or (at your option) any later version.
    8: 
    9:    The GNU C Library is distributed in the hope that it will be useful,
   10:    but WITHOUT ANY WARRANTY; without even the implied warranty of
   11:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   12:    Lesser General Public License for more details.
   13: 
   14:    You should have received a copy of the GNU Lesser General Public
   15:    License along with the GNU C Library; if not, write to the Free
   16:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   17:    02111-1307 USA.  */
   18: 
   19: #include <stddef.h>
   20: #include <string.h>
   21: #include <memcopy.h>
   22: 
   23: #undef strcpy
   24: 
   25: /* Copy SRC to DEST with checking of destination buffer overflow.  */
   26: char *
   27: __strcpy_chk (dest, src, destlen)
   28:      char *dest;
   29:      const char *src;
   30:      size_t destlen;
   31: {
   32:   reg_char c;
   33:   char *s = (char *) src;
   34:   const ptrdiff_t off = dest - s;
   35: 
   36:   while (__builtin_expect (destlen >= 4, 0))
   37:     {
   38:       c = s[0];
   39:       s[off] = c;
   40:       if (c == '\0')
   41:         return dest;
   42:       c = s[1];
   43:       s[off + 1] = c;
   44:       if (c == '\0')
   45:         return dest;
   46:       c = s[2];
   47:       s[off + 2] = c;
   48:       if (c == '\0')
   49:         return dest;
   50:       c = s[3];
   51:       s[off + 3] = c;
   52:       if (c == '\0')
   53:         return dest;
   54:       destlen -= 4;
   55:       s += 4;
   56:     }
   57: 
   58:   do
   59:     {
   60:       if (__builtin_expect (destlen-- == 0, 0))
   61:         __chk_fail ();
   62:       c = *s;
   63:       *(s++ + off) = c;
   64:     }
   65:   while (c != '\0');
   66: 
   67:   return dest;
   68: }