url/url_canon_fileurl.cc - chromium/src - Git at Google

 // Copyright 2013 The Chromium Authors
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 // Functions for canonicalizing "file:" URLs.

 #include <string_view>

 #include "base/strings/string_util.h"
 #include "url/url_canon.h"
 #include "url/url_canon_internal.h"
 #include "url/url_file.h"
 #include "url/url_parse_internal.h"

 namespace url {

 namespace {

 bool IsLocalhost(std::optional<std::string_view> host) {
   return host.has_value() && *host == "localhost";
 }

 bool IsLocalhost(std::optional<std::u16string_view> host) {
   return host.has_value() && *host == u"localhost";
 }

 template <typename CHAR>
 size_t DoFindWindowsDriveLetter(
     std::optional<std::basic_string_view<CHAR>> path) {
   using string_view = std::basic_string_view<CHAR>;
   if (!path.has_value()) {
     return string_view::npos;
   }

   // First guess the beginning of the drive letter.
   // If there is something that looks like a drive letter in the spec between
   // begin and end, store its position in drive_letter_pos.
   size_t drive_letter_pos =
       DoesContainWindowsDriveSpecUntil(*path, 0, path->length());
   if (drive_letter_pos == string_view::npos) {
     return string_view::npos;
   }

   // Check if the path up to the drive letter candidate can be canonicalized as
   // "/".
   Component sub_path = MakeRange(0u, drive_letter_pos);
   RawCanonOutput<1024> output;
   Component output_path;
   bool success =
       CanonicalizePath(sub_path.MaybeAsViewOn(*path), &output, &output_path);
   if (!success || output_path.len != 1 || output.at(output_path.begin) != '/') {
     return string_view::npos;
   }

   return drive_letter_pos;
 }

 #ifdef WIN32

 // Given a path string, this copies and canonicalizes the drive letter and
 // colon to the `output`, if one is found. If there is not a drive spec, it
 // won't do anything. The index of the next character in the input string
 // is returned (after the colon when a drive spec is found, zero if one is
 // not).
 template <typename CHAR>
 size_t FileDoDriveSpec(std::basic_string_view<CHAR> path, CanonOutput* output) {
   size_t drive_letter_pos = FindWindowsDriveLetter(path);
   if (drive_letter_pos == std::basic_string_view<CHAR>::npos) {
     return 0;
   }

   // By now, a valid drive letter is confirmed at position drive_letter_pos,
   // followed by a valid drive letter separator (a colon or a pipe).

   output->push_back('/');

   // Normalize Windows drive letters to uppercase.
   output->push_back(
       static_cast<char>(base::ToUpperASCII(path[drive_letter_pos])));

   // Normalize the character following it to a colon rather than pipe.
   output->push_back(':');
   return drive_letter_pos + 2;
 }

 #endif  // WIN32

 template <typename CHAR, typename UCHAR>
 bool DoFileCanonicalizePath(std::optional<std::basic_string_view<CHAR>> path,
                             CanonOutput* output,
                             Component* out_path) {
   // Copies and normalizes the "c:" at the beginning, if present.
   out_path->begin = output->length();
   size_t after_drive = 0;
 #ifdef WIN32
   if (path) {
     after_drive = FileDoDriveSpec(*path, output);
   }
 #endif

   // Copies the rest of the path, starting from the slash following the
   // drive colon (if any, Windows only), or the first slash of the path.
   bool success = true;
   if (path && after_drive < path->length()) {
     // Use the regular path canonicalizer to canonicalize the rest of the path
     // after the drive.
     //
     // Give it a fake output component to write into, since we will be
     // calculating the out_path ourselves (consisting of both the drive and the
     // path we canonicalize here).
     Component fake_output_path;
     success = CanonicalizePath(
         path->substr(after_drive, path->length() - after_drive), output,
         &fake_output_path);
   } else if (after_drive == 0) {
     // No input path and no drive spec, canonicalize to a slash.
     output->push_back('/');
   }

   out_path->len = output->length() - out_path->begin;
   return success;
 }

 template <typename CHAR, typename UCHAR>
 bool DoCanonicalizeFileUrl(const Replacements<CHAR>& source,
                            CharsetConverter* query_converter,
                            CanonOutput* output,
                            Parsed* new_parsed) {
   DCHECK(!source.components().has_opaque_path);

   // Things we don't set in file: URLs.
   new_parsed->username = Component();
   new_parsed->password = Component();
   new_parsed->port = Component();

   // Scheme (known, so we don't bother running it through the more
   // complicated scheme canonicalizer).
   new_parsed->scheme.begin = output->length();
   output->Append("file://");
   new_parsed->scheme.len = 4;

   // If the host is localhost, and the path starts with a Windows drive letter,
   // remove the host component. This does the following transformation:
   //     file://localhost/C:/hello.txt -> file:///C:/hello.txt
   //
   // Note: we do this on every platform per URL Standard, not just Windows.
   //
   // TODO(crbug.com/41299821): According to the latest URL spec, this
   // transformation should be done regardless of the path.
   Component host_range = source.components().host;
   using string_view = std::basic_string_view<CHAR>;
   if (IsLocalhost(source.MaybeHost()) &&
       FindWindowsDriveLetter(source.MaybePath()) != string_view::npos) {
     host_range.reset();
   }

   // Append the host. For many file URLs, this will be empty. For UNC, this
   // will be present.
   // TODO(brettw) This doesn't do any checking for host name validity. We
   // should probably handle validity checking of UNC hosts differently than
   // for regular IP hosts.
   bool success = CanonicalizeFileHost(source.SpecUntilHostOrEmpty(), host_range,
                                       *output, new_parsed->host);
   success &= DoFileCanonicalizePath<CHAR, UCHAR>(source.MaybePath(), output,
                                                  &new_parsed->path);

   CanonicalizeQuery(source.MaybeQuery(), query_converter, output,
                     &new_parsed->query);
   CanonicalizeRef(source.MaybeRef(), output, &new_parsed->ref);

   return success;
 }

 } // namespace

 size_t FindWindowsDriveLetter(std::optional<std::string_view> path) {
   return DoFindWindowsDriveLetter(path);
 }

 size_t FindWindowsDriveLetter(std::optional<std::u16string_view> path) {
   return DoFindWindowsDriveLetter(path);
 }

 bool CanonicalizeFileUrl(std::string_view spec,
                          const Parsed& parsed,
                          CharsetConverter* query_converter,
                          CanonOutput* output,
                          Parsed* new_parsed) {
   return DoCanonicalizeFileUrl<char, unsigned char>(
       Replacements<char>(spec, parsed), query_converter, output, new_parsed);
 }

 bool CanonicalizeFileUrl(std::u16string_view spec,
                          const Parsed& parsed,
                          CharsetConverter* query_converter,
                          CanonOutput* output,
                          Parsed* new_parsed) {
   return DoCanonicalizeFileUrl<char16_t, char16_t>(
       Replacements<char16_t>(spec, parsed), query_converter, output,
       new_parsed);
 }

 bool FileCanonicalizePath(std::optional<std::string_view> path,
                           CanonOutput* output,
                           Component* out_path) {
   return DoFileCanonicalizePath<char, unsigned char>(path, output, out_path);
 }

 bool FileCanonicalizePath(std::optional<std::u16string_view> path,
                           CanonOutput* output,
                           Component* out_path) {
   return DoFileCanonicalizePath<char16_t, char16_t>(path, output, out_path);
 }

 bool ReplaceFileUrl(std::string_view base,
                     const Parsed& base_parsed,
                     const Replacements<char>& replacements,
                     CharsetConverter* query_converter,
                     CanonOutput* output,
                     Parsed* new_parsed) {
   Replacements overridden(base, base_parsed);
   SetupOverrideComponents(replacements, overridden);
   return DoCanonicalizeFileUrl<char, unsigned char>(overridden, query_converter,
                                                     output, new_parsed);
 }

 bool ReplaceFileUrl(std::string_view base,
                     const Parsed& base_parsed,
                     const Replacements<char16_t>& replacements,
                     CharsetConverter* query_converter,
                     CanonOutput* output,
                     Parsed* new_parsed) {
   RawCanonOutput<1024> utf8;
   Replacements overridden(base, base_parsed);
   SetupUtf16OverrideComponents(replacements, utf8, overridden);
   return DoCanonicalizeFileUrl<char, unsigned char>(overridden, query_converter,
                                                     output, new_parsed);
 }

 }  // namespace url
	// Copyright 2013 The Chromium Authors
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	// Functions for canonicalizing "file:" URLs.

	#include <string_view>

	#include "base/strings/string_util.h"
	#include "url/url_canon.h"
	#include "url/url_canon_internal.h"
	#include "url/url_file.h"
	#include "url/url_parse_internal.h"

	namespace url {

	namespace {

	bool IsLocalhost(std::optional<std::string_view> host) {
	return host.has_value() && *host == "localhost";
	}

	bool IsLocalhost(std::optional<std::u16string_view> host) {
	return host.has_value() && *host == u"localhost";
	}

	template <typename CHAR>
	size_t DoFindWindowsDriveLetter(
	std::optional<std::basic_string_view<CHAR>> path) {
	using string_view = std::basic_string_view<CHAR>;
	if (!path.has_value()) {
	return string_view::npos;
	}

	// First guess the beginning of the drive letter.
	// If there is something that looks like a drive letter in the spec between
	// begin and end, store its position in drive_letter_pos.
	size_t drive_letter_pos =
	DoesContainWindowsDriveSpecUntil(*path, 0, path->length());
	if (drive_letter_pos == string_view::npos) {
	return string_view::npos;
	}

	// Check if the path up to the drive letter candidate can be canonicalized as
	// "/".
	Component sub_path = MakeRange(0u, drive_letter_pos);
	RawCanonOutput<1024> output;
	Component output_path;
	bool success =
	CanonicalizePath(sub_path.MaybeAsViewOn(*path), &output, &output_path);
	if (!success \|\| output_path.len != 1 \|\| output.at(output_path.begin) != '/') {
	return string_view::npos;
	}

	return drive_letter_pos;
	}

	#ifdef WIN32

	// Given a path string, this copies and canonicalizes the drive letter and
	// colon to the `output`, if one is found. If there is not a drive spec, it
	// won't do anything. The index of the next character in the input string
	// is returned (after the colon when a drive spec is found, zero if one is
	// not).
	template <typename CHAR>
	size_t FileDoDriveSpec(std::basic_string_view<CHAR> path, CanonOutput* output) {
	size_t drive_letter_pos = FindWindowsDriveLetter(path);
	if (drive_letter_pos == std::basic_string_view<CHAR>::npos) {
	return 0;
	}

	// By now, a valid drive letter is confirmed at position drive_letter_pos,
	// followed by a valid drive letter separator (a colon or a pipe).

	output->push_back('/');

	// Normalize Windows drive letters to uppercase.
	output->push_back(
	static_cast<char>(base::ToUpperASCII(path[drive_letter_pos])));

	// Normalize the character following it to a colon rather than pipe.
	output->push_back(':');
	return drive_letter_pos + 2;
	}

	#endif // WIN32

	template <typename CHAR, typename UCHAR>
	bool DoFileCanonicalizePath(std::optional<std::basic_string_view<CHAR>> path,
	CanonOutput* output,
	Component* out_path) {
	// Copies and normalizes the "c:" at the beginning, if present.
	out_path->begin = output->length();
	size_t after_drive = 0;
	#ifdef WIN32
	if (path) {
	after_drive = FileDoDriveSpec(*path, output);
	}
	#endif

	// Copies the rest of the path, starting from the slash following the
	// drive colon (if any, Windows only), or the first slash of the path.
	bool success = true;
	if (path && after_drive < path->length()) {
	// Use the regular path canonicalizer to canonicalize the rest of the path
	// after the drive.
	//
	// Give it a fake output component to write into, since we will be
	// calculating the out_path ourselves (consisting of both the drive and the
	// path we canonicalize here).
	Component fake_output_path;
	success = CanonicalizePath(
	path->substr(after_drive, path->length() - after_drive), output,
	&fake_output_path);
	} else if (after_drive == 0) {
	// No input path and no drive spec, canonicalize to a slash.
	output->push_back('/');
	}

	out_path->len = output->length() - out_path->begin;
	return success;
	}

	template <typename CHAR, typename UCHAR>
	bool DoCanonicalizeFileUrl(const Replacements<CHAR>& source,
	CharsetConverter* query_converter,
	CanonOutput* output,
	Parsed* new_parsed) {
	DCHECK(!source.components().has_opaque_path);

	// Things we don't set in file: URLs.
	new_parsed->username = Component();
	new_parsed->password = Component();
	new_parsed->port = Component();

	// Scheme (known, so we don't bother running it through the more
	// complicated scheme canonicalizer).
	new_parsed->scheme.begin = output->length();
	output->Append("file://");
	new_parsed->scheme.len = 4;

	// If the host is localhost, and the path starts with a Windows drive letter,
	// remove the host component. This does the following transformation:
	// file://localhost/C:/hello.txt -> file:///C:/hello.txt
	//
	// Note: we do this on every platform per URL Standard, not just Windows.
	//
	// TODO(crbug.com/41299821): According to the latest URL spec, this
	// transformation should be done regardless of the path.
	Component host_range = source.components().host;
	using string_view = std::basic_string_view<CHAR>;
	if (IsLocalhost(source.MaybeHost()) &&
	FindWindowsDriveLetter(source.MaybePath()) != string_view::npos) {
	host_range.reset();
	}

	// Append the host. For many file URLs, this will be empty. For UNC, this
	// will be present.
	// TODO(brettw) This doesn't do any checking for host name validity. We
	// should probably handle validity checking of UNC hosts differently than
	// for regular IP hosts.
	bool success = CanonicalizeFileHost(source.SpecUntilHostOrEmpty(), host_range,
	*output, new_parsed->host);
	success &= DoFileCanonicalizePath<CHAR, UCHAR>(source.MaybePath(), output,
	&new_parsed->path);

	CanonicalizeQuery(source.MaybeQuery(), query_converter, output,
	&new_parsed->query);
	CanonicalizeRef(source.MaybeRef(), output, &new_parsed->ref);

	return success;
	}

	} // namespace

	size_t FindWindowsDriveLetter(std::optional<std::string_view> path) {
	return DoFindWindowsDriveLetter(path);
	}

	size_t FindWindowsDriveLetter(std::optional<std::u16string_view> path) {
	return DoFindWindowsDriveLetter(path);
	}

	bool CanonicalizeFileUrl(std::string_view spec,
	const Parsed& parsed,
	CharsetConverter* query_converter,
	CanonOutput* output,
	Parsed* new_parsed) {
	return DoCanonicalizeFileUrl<char, unsigned char>(
	Replacements<char>(spec, parsed), query_converter, output, new_parsed);
	}

	bool CanonicalizeFileUrl(std::u16string_view spec,
	const Parsed& parsed,
	CharsetConverter* query_converter,
	CanonOutput* output,
	Parsed* new_parsed) {
	return DoCanonicalizeFileUrl<char16_t, char16_t>(
	Replacements<char16_t>(spec, parsed), query_converter, output,
	new_parsed);
	}

	bool FileCanonicalizePath(std::optional<std::string_view> path,
	CanonOutput* output,
	Component* out_path) {
	return DoFileCanonicalizePath<char, unsigned char>(path, output, out_path);
	}

	bool FileCanonicalizePath(std::optional<std::u16string_view> path,
	CanonOutput* output,
	Component* out_path) {
	return DoFileCanonicalizePath<char16_t, char16_t>(path, output, out_path);
	}

	bool ReplaceFileUrl(std::string_view base,
	const Parsed& base_parsed,
	const Replacements<char>& replacements,
	CharsetConverter* query_converter,
	CanonOutput* output,
	Parsed* new_parsed) {
	Replacements overridden(base, base_parsed);
	SetupOverrideComponents(replacements, overridden);
	return DoCanonicalizeFileUrl<char, unsigned char>(overridden, query_converter,
	output, new_parsed);
	}

	bool ReplaceFileUrl(std::string_view base,
	const Parsed& base_parsed,
	const Replacements<char16_t>& replacements,
	CharsetConverter* query_converter,
	CanonOutput* output,
	Parsed* new_parsed) {
	RawCanonOutput<1024> utf8;
	Replacements overridden(base, base_parsed);
	SetupUtf16OverrideComponents(replacements, utf8, overridden);
	return DoCanonicalizeFileUrl<char, unsigned char>(overridden, query_converter,
	output, new_parsed);
	}

	} // namespace url