string/bits/string_fortified.h

   1 /* Copyright (C) 2004-2023 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, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _BITS_STRING_FORTIFIED_H
  19 #define _BITS_STRING_FORTIFIED_H 1
  20
  21 #ifndef _STRING_H
  22 # error "Never use <bits/string_fortified.h> directly; include <string.h> instead."
  23 #endif
  24
  25 __fortify_function void *
  26 __NTH (memcpy (void *__restrict __dest, const void *__restrict __src,
  27                size_t __len))
  28 {
  29   return __builtin___memcpy_chk (__dest, __src, __len,
  30                                  __glibc_objsize0 (__dest));
  31 }
  32
  33 __fortify_function void *
  34 __NTH (memmove (void *__dest, const void *__src, size_t __len))
  35 {
  36   return __builtin___memmove_chk (__dest, __src, __len,
  37                                   __glibc_objsize0 (__dest));
  38 }
  39
  40 #ifdef __USE_GNU
  41 __fortify_function void *
  42 __NTH (mempcpy (void *__restrict __dest, const void *__restrict __src,
  43                 size_t __len))
  44 {
  45   return __builtin___mempcpy_chk (__dest, __src, __len,
  46                                   __glibc_objsize0 (__dest));
  47 }
  48 #endif
  49
  50
  51 /* The first two tests here help to catch a somewhat common problem
  52    where the second and third parameter are transposed.  This is
  53    especially problematic if the intended fill value is zero.  In this
  54    case no work is done at all.  We detect these problems by referring
  55    non-existing functions.  */
  56 __fortify_function void *
  57 __NTH (memset (void *__dest, int __ch, size_t __len))
  58 {
  59   return __builtin___memset_chk (__dest, __ch, __len,
  60                                  __glibc_objsize0 (__dest));
  61 }
  62
  63 #ifdef __USE_MISC
  64 # include <bits/strings_fortified.h>
  65
  66 void __explicit_bzero_chk (void *__dest, size_t __len, size_t __destlen)
  67   __THROW __nonnull ((1)) __fortified_attr_access (__write_only__, 1, 2);
  68
  69 __fortify_function void
  70 __NTH (explicit_bzero (void *__dest, size_t __len))
  71 {
  72   __explicit_bzero_chk (__dest, __len, __glibc_objsize0 (__dest));
  73 }
  74 #endif
  75
  76 __fortify_function char *
  77 __NTH (strcpy (char *__restrict __dest, const char *__restrict __src))
  78 {
  79   return __builtin___strcpy_chk (__dest, __src, __glibc_objsize (__dest));
  80 }
  81
  82 #ifdef __USE_XOPEN2K8
  83 __fortify_function char *
  84 __NTH (stpcpy (char *__restrict __dest, const char *__restrict __src))
  85 {
  86   return __builtin___stpcpy_chk (__dest, __src, __glibc_objsize (__dest));
  87 }
  88 #endif
  89
  90
  91 __fortify_function char *
  92 __NTH (strncpy (char *__restrict __dest, const char *__restrict __src,
  93                 size_t __len))
  94 {
  95   return __builtin___strncpy_chk (__dest, __src, __len,
  96                                   __glibc_objsize (__dest));
  97 }
  98
  99 #ifdef __USE_XOPEN2K8
 100 # if __GNUC_PREREQ (4, 7) || __glibc_clang_prereq (2, 6)
 101 __fortify_function char *
 102 __NTH (stpncpy (char *__dest, const char *__src, size_t __n))
 103 {
 104   return __builtin___stpncpy_chk (__dest, __src, __n,
 105                                   __glibc_objsize (__dest));
 106 }
 107 # else
 108 extern char *__stpncpy_chk (char *__dest, const char *__src, size_t __n,
 109                             size_t __destlen) __THROW
 110   __fortified_attr_access (__write_only__, 1, 3)
 111   __attr_access ((__read_only__, 2));
 112 extern char *__REDIRECT_NTH (__stpncpy_alias, (char *__dest, const char *__src,
 113                                                size_t __n), stpncpy);
 114
 115 __fortify_function char *
 116 __NTH (stpncpy (char *__dest, const char *__src, size_t __n))
 117 {
 118   if (__bos (__dest) != (size_t) -1
 119       && (!__builtin_constant_p (__n) || __n > __bos (__dest)))
 120     return __stpncpy_chk (__dest, __src, __n, __bos (__dest));
 121   return __stpncpy_alias (__dest, __src, __n);
 122 }
 123 # endif
 124 #endif
 125
 126
 127 __fortify_function char *
 128 __NTH (strcat (char *__restrict __dest, const char *__restrict __src))
 129 {
 130   return __builtin___strcat_chk (__dest, __src, __glibc_objsize (__dest));
 131 }
 132
 133
 134 __fortify_function char *
 135 __NTH (strncat (char *__restrict __dest, const char *__restrict __src,
 136                 size_t __len))
 137 {
 138   return __builtin___strncat_chk (__dest, __src, __len,
 139                                   __glibc_objsize (__dest));
 140 }
 141
 142 #endif /* bits/string_fortified.h */