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Diffstat (limited to 'googleurl/src/url_canon_icu.cc')
| -rw-r--r-- | googleurl/src/url_canon_icu.cc | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/googleurl/src/url_canon_icu.cc b/googleurl/src/url_canon_icu.cc new file mode 100644 index 0000000..b06808c --- /dev/null +++ b/googleurl/src/url_canon_icu.cc @@ -0,0 +1,207 @@ +// Copyright 2007, Google Inc. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +// ICU integration functions. + +#include <stdlib.h> +#include <string.h> +#include <unicode/ucnv.h> +#include <unicode/ucnv_cb.h> +#include <unicode/uidna.h> + +#include "googleurl/src/url_canon_icu.h" +#include "googleurl/src/url_canon_internal.h" // for _itoa_s + +#include "base/logging.h" + +namespace url_canon { + +namespace { + +// Called when converting a character that can not be represented, this will +// append an escaped version of the numerical character reference for that code +// point. It is of the form "Ӓ" and we will escape the non-digits to +// "%26%231234%3B". Why? This is what Netscape did back in the olden days. +void appendURLEscapedChar(const void* context, + UConverterFromUnicodeArgs* from_args, + const UChar* code_units, + int32_t length, + UChar32 code_point, + UConverterCallbackReason reason, + UErrorCode* err) { + if (reason == UCNV_UNASSIGNED) { + *err = U_ZERO_ERROR; + + const static int prefix_len = 6; + const static char prefix[prefix_len + 1] = "%26%23"; // "&#" percent-escaped + ucnv_cbFromUWriteBytes(from_args, prefix, prefix_len, 0, err); + + DCHECK(code_point < 0x110000); + char number[8]; // Max Unicode code point is 7 digits. + _itoa_s(code_point, number, 10); + int number_len = static_cast<int>(strlen(number)); + ucnv_cbFromUWriteBytes(from_args, number, number_len, 0, err); + + const static int postfix_len = 3; + const static char postfix[postfix_len + 1] = "%3B"; // ";" percent-escaped + ucnv_cbFromUWriteBytes(from_args, postfix, postfix_len, 0, err); + } +} + +// A class for scoping the installation of the invalid character callback. +class AppendHandlerInstaller { + public: + // The owner of this object must ensure that the converter is alive for the + // duration of this object's lifetime. + AppendHandlerInstaller(UConverter* converter) : converter_(converter) { + UErrorCode err = U_ZERO_ERROR; + ucnv_setFromUCallBack(converter_, appendURLEscapedChar, 0, + &old_callback_, &old_context_, &err); + } + + ~AppendHandlerInstaller() { + UErrorCode err = U_ZERO_ERROR; + ucnv_setFromUCallBack(converter_, old_callback_, old_context_, 0, 0, &err); + } + + private: + UConverter* converter_; + + UConverterFromUCallback old_callback_; + const void* old_context_; +}; + +} // namespace + +ICUCharsetConverter::ICUCharsetConverter(UConverter* converter) + : converter_(converter) { +} + +void ICUCharsetConverter::ConvertFromUTF16(const char16* input, + int input_len, + CanonOutput* output) { + // Install our error handler. It will be called for character that can not + // be represented in the destination character set. + AppendHandlerInstaller handler(converter_); + + int begin_offset = output->length(); + int dest_capacity = output->capacity() - begin_offset; + output->set_length(output->length()); + + do { + UErrorCode err = U_ZERO_ERROR; + char* dest = &output->data()[begin_offset]; + int required_capacity = ucnv_fromUChars(converter_, dest, dest_capacity, + input, input_len, &err); + if (err != U_BUFFER_OVERFLOW_ERROR) { + output->set_length(begin_offset + required_capacity); + return; + } + + // Output didn't fit, expand + dest_capacity = required_capacity; + output->Resize(begin_offset + dest_capacity); + } while (true); +} + +// Converts the Unicode input representing a hostname to ASCII using IDN rules. +// The output must be ASCII, but is represented as wide characters. +// +// On success, the output will be filled with the ASCII host name and it will +// return true. Unlike most other canonicalization functions, this assumes that +// the output is empty. The beginning of the host will be at offset 0, and +// the length of the output will be set to the length of the new host name. +// +// On error, this will return false. The output in this case is undefined. +bool IDNToASCII(const char16* src, int src_len, CanonOutputW* output) { + DCHECK(output->length() == 0); // Output buffer is assumed empty. + while (true) { + // Use ALLOW_UNASSIGNED to be more tolerant of hostnames that violate + // the spec (which do exist). This does not present any risk and is a + // little more future proof. + UErrorCode err = U_ZERO_ERROR; + int num_converted = uidna_IDNToASCII(src, src_len, output->data(), + output->capacity(), + UIDNA_ALLOW_UNASSIGNED, NULL, &err); + if (err == U_ZERO_ERROR) { + output->set_length(num_converted); + return true; + } + if (err != U_BUFFER_OVERFLOW_ERROR) + return false; // Unknown error, give up. + + // Not enough room in our buffer, expand. + output->Resize(output->capacity() * 2); + } +} + +bool ReadUTFChar(const char* str, int* begin, int length, + unsigned* code_point_out) { + int code_point; // Avoids warning when U8_NEXT writes -1 to it. + U8_NEXT(str, *begin, length, code_point); + *code_point_out = static_cast<unsigned>(code_point); + + // The ICU macro above moves to the next char, we want to point to the last + // char consumed. + (*begin)--; + + // Validate the decoded value. + if (U_IS_UNICODE_CHAR(code_point)) + return true; + *code_point_out = kUnicodeReplacementCharacter; + return false; +} + +bool ReadUTFChar(const char16* str, int* begin, int length, + unsigned* code_point) { + if (U16_IS_SURROGATE(str[*begin])) { + if (!U16_IS_SURROGATE_LEAD(str[*begin]) || *begin + 1 >= length || + !U16_IS_TRAIL(str[*begin + 1])) { + // Invalid surrogate pair. + *code_point = kUnicodeReplacementCharacter; + return false; + } else { + // Valid surrogate pair. + *code_point = U16_GET_SUPPLEMENTARY(str[*begin], str[*begin + 1]); + (*begin)++; + } + } else { + // Not a surrogate, just one 16-bit word. + *code_point = str[*begin]; + } + + if (U_IS_UNICODE_CHAR(*code_point)) + return true; + + // Invalid code point. + *code_point = kUnicodeReplacementCharacter; + return false; +} + +} // namespace url_canon |