// Copyright 2013 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef URL_URL_CANON_INTERNAL_H_ #define URL_URL_CANON_INTERNAL_H_ // This file is intended to be included in another C++ file where the character // types are defined. This allows us to write mostly generic code, but not have // templace bloat because everything is inlined when anybody calls any of our // functions. #include <stdlib.h> #include "base/logging.h" #include "url/url_canon.h" namespace url_canon { // Character type handling ----------------------------------------------------- // Bits that identify different character types. These types identify different // bits that are set for each 8-bit character in the kSharedCharTypeTable. enum SharedCharTypes { // Characters that do not require escaping in queries. Characters that do // not have this flag will be escaped; see url_canon_query.cc CHAR_QUERY = 1, // Valid in the username/password field. CHAR_USERINFO = 2, // Valid in a IPv4 address (digits plus dot and 'x' for hex). CHAR_IPV4 = 4, // Valid in an ASCII-representation of a hex digit (as in %-escaped). CHAR_HEX = 8, // Valid in an ASCII-representation of a decimal digit. CHAR_DEC = 16, // Valid in an ASCII-representation of an octal digit. CHAR_OCT = 32, // Characters that do not require escaping in encodeURIComponent. Characters // that do not have this flag will be escaped; see url_util.cc. CHAR_COMPONENT = 64, }; // This table contains the flags in SharedCharTypes for each 8-bit character. // Some canonicalization functions have their own specialized lookup table. // For those with simple requirements, we have collected the flags in one // place so there are fewer lookup tables to load into the CPU cache. // // Using an unsigned char type has a small but measurable performance benefit // over using a 32-bit number. extern const unsigned char kSharedCharTypeTable[0x100]; // More readable wrappers around the character type lookup table. inline bool IsCharOfType(unsigned char c, SharedCharTypes type) { return !!(kSharedCharTypeTable[c] & type); } inline bool IsQueryChar(unsigned char c) { return IsCharOfType(c, CHAR_QUERY); } inline bool IsIPv4Char(unsigned char c) { return IsCharOfType(c, CHAR_IPV4); } inline bool IsHexChar(unsigned char c) { return IsCharOfType(c, CHAR_HEX); } inline bool IsComponentChar(unsigned char c) { return IsCharOfType(c, CHAR_COMPONENT); } // Appends the given string to the output, escaping characters that do not // match the given |type| in SharedCharTypes. void AppendStringOfType(const char* source, int length, SharedCharTypes type, CanonOutput* output); void AppendStringOfType(const base::char16* source, int length, SharedCharTypes type, CanonOutput* output); // Maps the hex numerical values 0x0 to 0xf to the corresponding ASCII digit // that will be used to represent it. URL_EXPORT extern const char kHexCharLookup[0x10]; // This lookup table allows fast conversion between ASCII hex letters and their // corresponding numerical value. The 8-bit range is divided up into 8 // regions of 0x20 characters each. Each of the three character types (numbers, // uppercase, lowercase) falls into different regions of this range. The table // contains the amount to subtract from characters in that range to get at // the corresponding numerical value. // // See HexDigitToValue for the lookup. extern const char kCharToHexLookup[8]; // Assumes the input is a valid hex digit! Call IsHexChar before using this. inline unsigned char HexCharToValue(unsigned char c) { return c - kCharToHexLookup[c / 0x20]; } // Indicates if the given character is a dot or dot equivalent, returning the // number of characters taken by it. This will be one for a literal dot, 3 for // an escaped dot. If the character is not a dot, this will return 0. template<typename CHAR> inline int IsDot(const CHAR* spec, int offset, int end) { if (spec[offset] == '.') { return 1; } else if (spec[offset] == '%' && offset + 3 <= end && spec[offset + 1] == '2' && (spec[offset + 2] == 'e' || spec[offset + 2] == 'E')) { // Found "%2e" return 3; } return 0; } // Returns the canonicalized version of the input character according to scheme // rules. This is implemented alongside the scheme canonicalizer, and is // required for relative URL resolving to test for scheme equality. // // Returns 0 if the input character is not a valid scheme character. char CanonicalSchemeChar(base::char16 ch); // Write a single character, escaped, to the output. This always escapes: it // does no checking that thee character requires escaping. // Escaping makes sense only 8 bit chars, so code works in all cases of // input parameters (8/16bit). template<typename UINCHAR, typename OUTCHAR> inline void AppendEscapedChar(UINCHAR ch, CanonOutputT<OUTCHAR>* output) { output->push_back('%'); output->push_back(kHexCharLookup[(ch >> 4) & 0xf]); output->push_back(kHexCharLookup[ch & 0xf]); } // The character we'll substitute for undecodable or invalid characters. extern const base::char16 kUnicodeReplacementCharacter; // UTF-8 functions ------------------------------------------------------------ // Reads one character in UTF-8 starting at |*begin| in |str| and places // the decoded value into |*code_point|. If the character is valid, we will // return true. If invalid, we'll return false and put the // kUnicodeReplacementCharacter into |*code_point|. // // |*begin| will be updated to point to the last character consumed so it // can be incremented in a loop and will be ready for the next character. // (for a single-byte ASCII character, it will not be changed). // // Implementation is in url_canon_icu.cc. URL_EXPORT bool ReadUTFChar(const char* str, int* begin, int length, unsigned* code_point_out); // Generic To-UTF-8 converter. This will call the given append method for each // character that should be appended, with the given output method. Wrappers // are provided below for escaped and non-escaped versions of this. // // The char_value must have already been checked that it's a valid Unicode // character. template<class Output, void Appender(unsigned char, Output*)> inline void DoAppendUTF8(unsigned char_value, Output* output) { if (char_value <= 0x7f) { Appender(static_cast<unsigned char>(char_value), output); } else if (char_value <= 0x7ff) { // 110xxxxx 10xxxxxx Appender(static_cast<unsigned char>(0xC0 | (char_value >> 6)), output); Appender(static_cast<unsigned char>(0x80 | (char_value & 0x3f)), output); } else if (char_value <= 0xffff) { // 1110xxxx 10xxxxxx 10xxxxxx Appender(static_cast<unsigned char>(0xe0 | (char_value >> 12)), output); Appender(static_cast<unsigned char>(0x80 | ((char_value >> 6) & 0x3f)), output); Appender(static_cast<unsigned char>(0x80 | (char_value & 0x3f)), output); } else if (char_value <= 0x10FFFF) { // Max unicode code point. // 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx Appender(static_cast<unsigned char>(0xf0 | (char_value >> 18)), output); Appender(static_cast<unsigned char>(0x80 | ((char_value >> 12) & 0x3f)), output); Appender(static_cast<unsigned char>(0x80 | ((char_value >> 6) & 0x3f)), output); Appender(static_cast<unsigned char>(0x80 | (char_value & 0x3f)), output); } else { // Invalid UTF-8 character (>20 bits). NOTREACHED(); } } // Helper used by AppendUTF8Value below. We use an unsigned parameter so there // are no funny sign problems with the input, but then have to convert it to // a regular char for appending. inline void AppendCharToOutput(unsigned char ch, CanonOutput* output) { output->push_back(static_cast<char>(ch)); } // Writes the given character to the output as UTF-8. This does NO checking // of the validity of the unicode characters; the caller should ensure that // the value it is appending is valid to append. inline void AppendUTF8Value(unsigned char_value, CanonOutput* output) { DoAppendUTF8<CanonOutput, AppendCharToOutput>(char_value, output); } // Writes the given character to the output as UTF-8, escaping ALL // characters (even when they are ASCII). This does NO checking of the // validity of the unicode characters; the caller should ensure that the value // it is appending is valid to append. inline void AppendUTF8EscapedValue(unsigned char_value, CanonOutput* output) { DoAppendUTF8<CanonOutput, AppendEscapedChar>(char_value, output); } // UTF-16 functions ----------------------------------------------------------- // Reads one character in UTF-16 starting at |*begin| in |str| and places // the decoded value into |*code_point|. If the character is valid, we will // return true. If invalid, we'll return false and put the // kUnicodeReplacementCharacter into |*code_point|. // // |*begin| will be updated to point to the last character consumed so it // can be incremented in a loop and will be ready for the next character. // (for a single-16-bit-word character, it will not be changed). // // Implementation is in url_canon_icu.cc. URL_EXPORT bool ReadUTFChar(const base::char16* str, int* begin, int length, unsigned* code_point); // Equivalent to U16_APPEND_UNSAFE in ICU but uses our output method. inline void AppendUTF16Value(unsigned code_point, CanonOutputT<base::char16>* output) { if (code_point > 0xffff) { output->push_back(static_cast<base::char16>((code_point >> 10) + 0xd7c0)); output->push_back(static_cast<base::char16>((code_point & 0x3ff) | 0xdc00)); } else { output->push_back(static_cast<base::char16>(code_point)); } } // Escaping functions --------------------------------------------------------- // Writes the given character to the output as UTF-8, escaped. Call this // function only when the input is wide. Returns true on success. Failure // means there was some problem with the encoding, we'll still try to // update the |*begin| pointer and add a placeholder character to the // output so processing can continue. // // We will append the character starting at ch[begin] with the buffer ch // being |length|. |*begin| will be updated to point to the last character // consumed (we may consume more than one for UTF-16) so that if called in // a loop, incrementing the pointer will move to the next character. // // Every single output character will be escaped. This means that if you // give it an ASCII character as input, it will be escaped. Some code uses // this when it knows that a character is invalid according to its rules // for validity. If you don't want escaping for ASCII characters, you will // have to filter them out prior to calling this function. // // Assumes that ch[begin] is within range in the array, but does not assume // that any following characters are. inline bool AppendUTF8EscapedChar(const base::char16* str, int* begin, int length, CanonOutput* output) { // UTF-16 input. Readchar16 will handle invalid characters for us and give // us the kUnicodeReplacementCharacter, so we don't have to do special // checking after failure, just pass through the failure to the caller. unsigned char_value; bool success = ReadUTFChar(str, begin, length, &char_value); AppendUTF8EscapedValue(char_value, output); return success; } // Handles UTF-8 input. See the wide version above for usage. inline bool AppendUTF8EscapedChar(const char* str, int* begin, int length, CanonOutput* output) { // ReadUTF8Char will handle invalid characters for us and give us the // kUnicodeReplacementCharacter, so we don't have to do special checking // after failure, just pass through the failure to the caller. unsigned ch; bool success = ReadUTFChar(str, begin, length, &ch); AppendUTF8EscapedValue(ch, output); return success; } // Given a '%' character at |*begin| in the string |spec|, this will decode // the escaped value and put it into |*unescaped_value| on success (returns // true). On failure, this will return false, and will not write into // |*unescaped_value|. // // |*begin| will be updated to point to the last character of the escape // sequence so that when called with the index of a for loop, the next time // through it will point to the next character to be considered. On failure, // |*begin| will be unchanged. inline bool Is8BitChar(char c) { return true; // this case is specialized to avoid a warning } inline bool Is8BitChar(base::char16 c) { return c <= 255; } template<typename CHAR> inline bool DecodeEscaped(const CHAR* spec, int* begin, int end, unsigned char* unescaped_value) { if (*begin + 3 > end || !Is8BitChar(spec[*begin + 1]) || !Is8BitChar(spec[*begin + 2])) { // Invalid escape sequence because there's not enough room, or the // digits are not ASCII. return false; } unsigned char first = static_cast<unsigned char>(spec[*begin + 1]); unsigned char second = static_cast<unsigned char>(spec[*begin + 2]); if (!IsHexChar(first) || !IsHexChar(second)) { // Invalid hex digits, fail. return false; } // Valid escape sequence. *unescaped_value = (HexCharToValue(first) << 4) + HexCharToValue(second); *begin += 2; return true; } // Appends the given substring to the output, escaping "some" characters that // it feels may not be safe. It assumes the input values are all contained in // 8-bit although it allows any type. // // This is used in error cases to append invalid output so that it looks // approximately correct. Non-error cases should not call this function since // the escaping rules are not guaranteed! void AppendInvalidNarrowString(const char* spec, int begin, int end, CanonOutput* output); void AppendInvalidNarrowString(const base::char16* spec, int begin, int end, CanonOutput* output); // Misc canonicalization helpers ---------------------------------------------- // Converts between UTF-8 and UTF-16, returning true on successful conversion. // The output will be appended to the given canonicalizer output (so make sure // it's empty if you want to replace). // // On invalid input, this will still write as much output as possible, // replacing the invalid characters with the "invalid character". It will // return false in the failure case, and the caller should not continue as // normal. URL_EXPORT bool ConvertUTF16ToUTF8(const base::char16* input, int input_len, CanonOutput* output); URL_EXPORT bool ConvertUTF8ToUTF16(const char* input, int input_len, CanonOutputT<base::char16>* output); // Converts from UTF-16 to 8-bit using the character set converter. If the // converter is NULL, this will use UTF-8. void ConvertUTF16ToQueryEncoding(const base::char16* input, const url_parse::Component& query, CharsetConverter* converter, CanonOutput* output); // Applies the replacements to the given component source. The component source // should be pre-initialized to the "old" base. That is, all pointers will // point to the spec of the old URL, and all of the Parsed components will // be indices into that string. // // The pointers and components in the |source| for all non-NULL strings in the // |repl| (replacements) will be updated to reference those strings. // Canonicalizing with the new |source| and |parsed| can then combine URL // components from many different strings. void SetupOverrideComponents(const char* base, const Replacements<char>& repl, URLComponentSource<char>* source, url_parse::Parsed* parsed); // Like the above 8-bit version, except that it additionally converts the // UTF-16 input to UTF-8 before doing the overrides. // // The given utf8_buffer is used to store the converted components. They will // be appended one after another, with the parsed structure identifying the // appropriate substrings. This buffer is a parameter because the source has // no storage, so the buffer must have the same lifetime as the source // parameter owned by the caller. // // THE CALLER MUST NOT ADD TO THE |utf8_buffer| AFTER THIS CALL. Members of // |source| will point into this buffer, which could be invalidated if // additional data is added and the CanonOutput resizes its buffer. // // Returns true on success. False means that the input was not valid UTF-16, // although we will have still done the override with "invalid characters" in // place of errors. bool SetupUTF16OverrideComponents(const char* base, const Replacements<base::char16>& repl, CanonOutput* utf8_buffer, URLComponentSource<char>* source, url_parse::Parsed* parsed); // Implemented in url_canon_path.cc, these are required by the relative URL // resolver as well, so we declare them here. bool CanonicalizePartialPath(const char* spec, const url_parse::Component& path, int path_begin_in_output, CanonOutput* output); bool CanonicalizePartialPath(const base::char16* spec, const url_parse::Component& path, int path_begin_in_output, CanonOutput* output); #ifndef WIN32 // Implementations of Windows' int-to-string conversions URL_EXPORT int _itoa_s(int value, char* buffer, size_t size_in_chars, int radix); URL_EXPORT int _itow_s(int value, base::char16* buffer, size_t size_in_chars, int radix); // Secure template overloads for these functions template<size_t N> inline int _itoa_s(int value, char (&buffer)[N], int radix) { return _itoa_s(value, buffer, N, radix); } template<size_t N> inline int _itow_s(int value, base::char16 (&buffer)[N], int radix) { return _itow_s(value, buffer, N, radix); } // _strtoui64 and strtoull behave the same inline unsigned long long _strtoui64(const char* nptr, char** endptr, int base) { return strtoull(nptr, endptr, base); } #endif // WIN32 } // namespace url_canon #endif // URL_URL_CANON_INTERNAL_H_