string/bits/string_fortified.h

   1 /* Copyright (C) 2004-2024 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 __attribute_overloadable__ char *
  77 __NTH (strcpy (__fortify_clang_overload_arg (char *, __restrict, __dest),
  78                const char *__restrict __src))
  79      __fortify_clang_warn_if_src_too_large (__dest, __src)
  80 {
  81   return __builtin___strcpy_chk (__dest, __src, __glibc_objsize (__dest));
  82 }
  83
  84 #ifdef __USE_XOPEN2K8
  85 __fortify_function __attribute_overloadable__ char *
  86 __NTH (stpcpy (__fortify_clang_overload_arg (char *, __restrict, __dest),
  87                const char *__restrict __src))
  88      __fortify_clang_warn_if_src_too_large (__dest, __src)
  89 {
  90   return __builtin___stpcpy_chk (__dest, __src, __glibc_objsize (__dest));
  91 }
  92 #endif
  93
  94
  95 __fortify_function __attribute_overloadable__ char *
  96 __NTH (strncpy (__fortify_clang_overload_arg (char *, __restrict, __dest),
  97                 const char *__restrict __src, size_t __len))
  98      __fortify_clang_warn_if_dest_too_small (__dest, __len)
  99 {
 100   return __builtin___strncpy_chk (__dest, __src, __len,
 101                                   __glibc_objsize (__dest));
 102 }
 103
 104 #ifdef __USE_XOPEN2K8
 105 # if __GNUC_PREREQ (4, 7) || __glibc_clang_prereq (2, 6)
 106 __fortify_function __attribute_overloadable__ char *
 107 __NTH (stpncpy (__fortify_clang_overload_arg (char *, ,__dest),
 108                 const char *__src, size_t __n))
 109      __fortify_clang_warn_if_dest_too_small (__dest, __n)
 110 {
 111   return __builtin___stpncpy_chk (__dest, __src, __n,
 112                                   __glibc_objsize (__dest));
 113 }
 114 # else
 115 extern char *__stpncpy_chk (char *__dest, const char *__src, size_t __n,
 116                             size_t __destlen) __THROW
 117   __fortified_attr_access (__write_only__, 1, 3)
 118   __attr_access ((__read_only__, 2));
 119 extern char *__REDIRECT_NTH (__stpncpy_alias, (char *__dest, const char *__src,
 120                                                size_t __n), stpncpy);
 121
 122 __fortify_function __attribute_overloadable__ char *
 123 __NTH (stpncpy (__fortify_clang_overload_arg (char *, ,__dest),
 124                 const char *__src, size_t __n))
 125 {
 126   if (__bos (__dest) != (size_t) -1
 127       && (!__builtin_constant_p (__n) || __n > __bos (__dest)))
 128     return __stpncpy_chk (__dest, __src, __n, __bos (__dest));
 129   return __stpncpy_alias (__dest, __src, __n);
 130 }
 131 # endif
 132 #endif
 133
 134
 135 __fortify_function __attribute_overloadable__ char *
 136 __NTH (strcat (__fortify_clang_overload_arg (char *, __restrict, __dest),
 137                const char *__restrict __src))
 138      __fortify_clang_warn_if_src_too_large (__dest, __src)
 139 {
 140   return __builtin___strcat_chk (__dest, __src, __glibc_objsize (__dest));
 141 }
 142
 143
 144 __fortify_function __attribute_overloadable__ char *
 145 __NTH (strncat (__fortify_clang_overload_arg (char *, __restrict, __dest),
 146                 const char *__restrict __src, size_t __len))
 147      __fortify_clang_warn_if_src_too_large (__dest, __src)
 148 {
 149   return __builtin___strncat_chk (__dest, __src, __len,
 150                                   __glibc_objsize (__dest));
 151 }
 152
 153 #ifdef __USE_MISC
 154 extern size_t __strlcpy_chk (char *__dest, const char *__src, size_t __n,
 155                              size_t __destlen) __THROW;
 156 extern size_t __REDIRECT_NTH (__strlcpy_alias,
 157                               (char *__dest, const char *__src, size_t __n),
 158                               strlcpy);
 159
 160 __fortify_function __attribute_overloadable__ size_t
 161 __NTH (strlcpy (__fortify_clang_overload_arg (char *, __restrict, __dest),
 162                 const char *__restrict __src, size_t __n))
 163      __fortify_clang_warn_if_dest_too_small (__dest, __n)
 164 {
 165   if (__glibc_objsize (__dest) != (size_t) -1
 166       && (!__builtin_constant_p (__n > __glibc_objsize (__dest))
 167           || __n > __glibc_objsize (__dest)))
 168     return __strlcpy_chk (__dest, __src, __n, __glibc_objsize (__dest));
 169   return __strlcpy_alias (__dest, __src, __n);
 170 }
 171
 172 extern size_t __strlcat_chk (char *__dest, const char *__src, size_t __n,
 173                              size_t __destlen) __THROW;
 174 extern size_t __REDIRECT_NTH (__strlcat_alias,
 175                               (char *__dest, const char *__src, size_t __n),
 176                               strlcat);
 177
 178 __fortify_function __attribute_overloadable__ size_t
 179 __NTH (strlcat (__fortify_clang_overload_arg (char *, __restrict, __dest),
 180                 const char *__restrict __src, size_t __n))
 181 {
 182   if (__glibc_objsize (__dest) != (size_t) -1
 183       && (!__builtin_constant_p (__n > __glibc_objsize (__dest))
 184           || __n > __glibc_objsize (__dest)))
 185     return __strlcat_chk (__dest, __src, __n, __glibc_objsize (__dest));
 186   return __strlcat_alias (__dest, __src, __n);
 187 }
 188 #endif /* __USE_MISC */
 189
 190 #endif /* bits/string_fortified.h */