url/url_canon_icu.cc - chromium/src.git - Git at Google

 // 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.

 // ICU integration functions.

 #include <stdlib.h>
 #include <string.h>

 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "third_party/icu/source/common/unicode/ucnv.h"
 #include "third_party/icu/source/common/unicode/ucnv_cb.h"
 #include "third_party/icu/source/common/unicode/uidna.h"
 #include "url/url_canon_icu.h"
 #include "url/url_canon_internal.h"  // for _itoa_s

 namespace url {

 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 "&#1234;" 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_;
 };

 // A wrapper to use LazyInstance<>::Leaky with ICU's UIDNA, a C pointer to
 // a UTS46/IDNA 2008 handling object opened with uidna_openUTS46().
 //
 // We use UTS46 with BiDiCheck to migrate from IDNA 2003 (with unassigned
 // code points allowed) to IDNA 2008 with
 // the backward compatibility in mind. What it does:
 //
 // 1. Use the up-to-date Unicode data.
 // 2. Define a case folding/mapping with the up-to-date Unicode data as
 //    in IDNA 2003.
 // 3. Use transitional mechanism for 4 deviation characters (sharp-s,
 //    final sigma, ZWJ and ZWNJ) for now.
 // 4. Continue to allow symbols and punctuations.
 // 5. Apply new BiDi check rules more permissive than the IDNA 2003 BiDI rules.
 // 6. Do not apply STD3 rules
 // 7. Do not allow unassigned code points.
 //
 // It also closely matches what IE 10 does except for the BiDi check (
 // http://goo.gl/3XBhqw ).
 // See http://http://unicode.org/reports/tr46/ and references therein
 // for more details.
 struct UIDNAWrapper {
   UIDNAWrapper() {
     UErrorCode err = U_ZERO_ERROR;
     // TODO(jungshik): Change options as different parties (browsers,
     // registrars, search engines) converge toward a consensus.
     value = uidna_openUTS46(UIDNA_CHECK_BIDI, &err);
     if (U_FAILURE(err))
       value = NULL;
   }

   UIDNA* value;
 };

 }  // namespace

 ICUCharsetConverter::ICUCharsetConverter(UConverter* converter)
     : converter_(converter) {
 }

 ICUCharsetConverter::~ICUCharsetConverter() {
 }

 void ICUCharsetConverter::ConvertFromUTF16(const base::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);
 }

 static base::LazyInstance<UIDNAWrapper>::Leaky
     g_uidna = LAZY_INSTANCE_INITIALIZER;

 // 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.
 // TODO(jungshik): use UTF-8/ASCII version of nameToASCII.
 // Change the function signature and callers accordingly to avoid unnecessary
 // conversions in our code. In addition, consider using icu::IDNA's UTF-8/ASCII
 // version with StringByteSink. That way, we can avoid C wrappers and additional
 // string conversion.
 bool IDNToASCII(const base::char16* src, int src_len, CanonOutputW* output) {
   DCHECK(output->length() == 0);  // Output buffer is assumed empty.

   UIDNA* uidna = g_uidna.Get().value;
   DCHECK(uidna != NULL);
   while (true) {
     UErrorCode err = U_ZERO_ERROR;
     UIDNAInfo info = UIDNA_INFO_INITIALIZER;
     int output_length = uidna_nameToASCII(uidna, src, src_len, output->data(),
                                           output->capacity(), &info, &err);
     if (U_SUCCESS(err) && info.errors == 0) {
       output->set_length(output_length);
       return true;
     }

     // TODO(jungshik): Look at info.errors to handle them case-by-case basis
     // if necessary.
     if (err != U_BUFFER_OVERFLOW_ERROR || info.errors != 0)
       return false;  // Unknown error, give up.

     // Not enough room in our buffer, expand.
     output->Resize(output_length);
   }
 }

 }  // namespace url
	// 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.

	// ICU integration functions.

	#include <stdlib.h>
	#include <string.h>

	#include "base/lazy_instance.h"
	#include "base/logging.h"
	#include "third_party/icu/source/common/unicode/ucnv.h"
	#include "third_party/icu/source/common/unicode/ucnv_cb.h"
	#include "third_party/icu/source/common/unicode/uidna.h"
	#include "url/url_canon_icu.h"
	#include "url/url_canon_internal.h" // for _itoa_s

	namespace url {

	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_;
	};

	// A wrapper to use LazyInstance<>::Leaky with ICU's UIDNA, a C pointer to
	// a UTS46/IDNA 2008 handling object opened with uidna_openUTS46().
	//
	// We use UTS46 with BiDiCheck to migrate from IDNA 2003 (with unassigned
	// code points allowed) to IDNA 2008 with
	// the backward compatibility in mind. What it does:
	//
	// 1. Use the up-to-date Unicode data.
	// 2. Define a case folding/mapping with the up-to-date Unicode data as
	// in IDNA 2003.
	// 3. Use transitional mechanism for 4 deviation characters (sharp-s,
	// final sigma, ZWJ and ZWNJ) for now.
	// 4. Continue to allow symbols and punctuations.
	// 5. Apply new BiDi check rules more permissive than the IDNA 2003 BiDI rules.
	// 6. Do not apply STD3 rules
	// 7. Do not allow unassigned code points.
	//
	// It also closely matches what IE 10 does except for the BiDi check (
	// http://goo.gl/3XBhqw ).
	// See http://http://unicode.org/reports/tr46/ and references therein
	// for more details.
	struct UIDNAWrapper {
	UIDNAWrapper() {
	UErrorCode err = U_ZERO_ERROR;
	// TODO(jungshik): Change options as different parties (browsers,
	// registrars, search engines) converge toward a consensus.
	value = uidna_openUTS46(UIDNA_CHECK_BIDI, &err);
	if (U_FAILURE(err))
	value = NULL;
	}

	UIDNA* value;
	};

	} // namespace

	ICUCharsetConverter::ICUCharsetConverter(UConverter* converter)
	: converter_(converter) {
	}

	ICUCharsetConverter::~ICUCharsetConverter() {
	}

	void ICUCharsetConverter::ConvertFromUTF16(const base::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);
	}

	static base::LazyInstance<UIDNAWrapper>::Leaky
	g_uidna = LAZY_INSTANCE_INITIALIZER;

	// 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.
	// TODO(jungshik): use UTF-8/ASCII version of nameToASCII.
	// Change the function signature and callers accordingly to avoid unnecessary
	// conversions in our code. In addition, consider using icu::IDNA's UTF-8/ASCII
	// version with StringByteSink. That way, we can avoid C wrappers and additional
	// string conversion.
	bool IDNToASCII(const base::char16* src, int src_len, CanonOutputW* output) {
	DCHECK(output->length() == 0); // Output buffer is assumed empty.

	UIDNA* uidna = g_uidna.Get().value;
	DCHECK(uidna != NULL);
	while (true) {
	UErrorCode err = U_ZERO_ERROR;
	UIDNAInfo info = UIDNA_INFO_INITIALIZER;
	int output_length = uidna_nameToASCII(uidna, src, src_len, output->data(),
	output->capacity(), &info, &err);
	if (U_SUCCESS(err) && info.errors == 0) {
	output->set_length(output_length);
	return true;
	}

	// TODO(jungshik): Look at info.errors to handle them case-by-case basis
	// if necessary.
	if (err != U_BUFFER_OVERFLOW_ERROR \|\| info.errors != 0)
	return false; // Unknown error, give up.

	// Not enough room in our buffer, expand.
	output->Resize(output_length);
	}
	}

	} // namespace url