release/src/router/pcre/pcre32_valid_utf32.c

   1 /*************************************************
   2 *      Perl-Compatible Regular Expressions       *
   3 *************************************************/
   4
   5 /* PCRE is a library of functions to support regular expressions whose syntax
   6 and semantics are as close as possible to those of the Perl 5 language.
   7
   8                        Written by Philip Hazel
   9            Copyright (c) 1997-2012 University of Cambridge
  10
  11 -----------------------------------------------------------------------------
  12 Redistribution and use in source and binary forms, with or without
  13 modification, are permitted provided that the following conditions are met:
  14
  15     * Redistributions of source code must retain the above copyright notice,
  16       this list of conditions and the following disclaimer.
  17
  18     * Redistributions in binary form must reproduce the above copyright
  19       notice, this list of conditions and the following disclaimer in the
  20       documentation and/or other materials provided with the distribution.
  21
  22     * Neither the name of the University of Cambridge nor the names of its
  23       contributors may be used to endorse or promote products derived from
  24       this software without specific prior written permission.
  25
  26 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  27 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  30 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  31 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  32 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  33 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  34 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  35 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  36 POSSIBILITY OF SUCH DAMAGE.
  37 -----------------------------------------------------------------------------
  38 */
  39
  40
  41 /* This module contains an internal function for validating UTF-32 character
  42 strings. */
  43
  44
  45 #ifdef HAVE_CONFIG_H
  46 #include "config.h"
  47 #endif
  48
  49 /* Generate code with 32 bit character support. */
  50 #define COMPILE_PCRE32
  51
  52 #include "pcre_internal.h"
  53
  54 /*************************************************
  55 *         Validate a UTF-32 string                *
  56 *************************************************/
  57
  58 /* This function is called (optionally) at the start of compile or match, to
  59 check that a supposed UTF-32 string is actually valid. The early check means
  60 that subsequent code can assume it is dealing with a valid string. The check
  61 can be turned off for maximum performance, but the consequences of supplying an
  62 invalid string are then undefined.
  63
  64 More information about the details of the error are passed
  65 back in the returned value:
  66
  67 PCRE_UTF32_ERR0  No error
  68 PCRE_UTF32_ERR1  Surrogate character
  69 PCRE_UTF32_ERR2  Non-character
  70 PCRE_UTF32_ERR3  Character > 0x10ffff
  71
  72 Arguments:
  73   string       points to the string
  74   length       length of string, or -1 if the string is zero-terminated
  75   errp         pointer to an error position offset variable
  76
  77 Returns:       = 0    if the string is a valid UTF-32 string
  78                > 0    otherwise, setting the offset of the bad character
  79 */
  80
  81 int
  82 PRIV(valid_utf)(PCRE_PUCHAR string, int length, int *erroroffset)
  83 {
  84 #ifdef SUPPORT_UTF
  85 register PCRE_PUCHAR p;
  86 register pcre_uchar c;
  87
  88 if (length < 0)
  89   {
  90   for (p = string; *p != 0; p++);
  91   length = p - string;
  92   }
  93
  94 for (p = string; length-- > 0; p++)
  95   {
  96   c = *p;
  97
  98   if ((c & 0xfffff800u) != 0xd800u)
  99     {
 100     /* Normal UTF-32 code point. Neither high nor low surrogate. */
 101
 102     /* Check for non-characters */
 103     if ((c & 0xfffeu) == 0xfffeu || (c >= 0xfdd0u && c <= 0xfdefu))
 104       {
 105       *erroroffset = p - string;
 106       return PCRE_UTF32_ERR2;
 107       }
 108     else if (c > 0x10ffffu)
 109       {
 110       *erroroffset = p - string;
 111       return PCRE_UTF32_ERR3;
 112       }
 113     }
 114   else
 115     {
 116     /* A surrogate */
 117     *erroroffset = p - string;
 118     return PCRE_UTF32_ERR1;
 119     }
 120   }
 121
 122 #else  /* SUPPORT_UTF */
 123 (void)(string);  /* Keep picky compilers happy */
 124 (void)(length);
 125 (void)(erroroffset);
 126 #endif /* SUPPORT_UTF */
 127
 128 return PCRE_UTF32_ERR0;   /* This indicates success */
 129 }
 130
 131 /* End of pcre32_valid_utf32.c */