// 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.
#include "url/url_util.h"
#include <string.h>
#include <vector>
#include "base/debug/leak_annotations.h"
#include "base/logging.h"
#include "url/url_canon_internal.h"
#include "url/url_file.h"
#include "url/url_util_internal.h"
namespace url {
namespace {
// ASCII-specific tolower. The standard library's tolower is locale sensitive,
// so we don't want to use it here.
template<class Char>
inline Char ToLowerASCII(Char c) {
return (c >= 'A' && c <= 'Z') ? (c + ('a' - 'A')) : c;
}
// Backend for LowerCaseEqualsASCII.
template<typename Iter>
inline bool DoLowerCaseEqualsASCII(Iter a_begin, Iter a_end, const char* b) {
for (Iter it = a_begin; it != a_end; ++it, ++b) {
if (!*b || ToLowerASCII(*it) != *b)
return false;
}
return *b == 0;
}
const int kNumStandardURLSchemes = 8;
const char* kStandardURLSchemes[kNumStandardURLSchemes] = {
kHttpScheme,
kHttpsScheme,
kFileScheme, // Yes, file urls can have a hostname!
kFtpScheme,
kGopherScheme,
kWsScheme, // WebSocket.
kWssScheme, // WebSocket secure.
kFileSystemScheme,
};
// List of the currently installed standard schemes. This list is lazily
// initialized by InitStandardSchemes and is leaked on shutdown to prevent
// any destructors from being called that will slow us down or cause problems.
std::vector<const char*>* standard_schemes = NULL;
// See the LockStandardSchemes declaration in the header.
bool standard_schemes_locked = false;
// Ensures that the standard_schemes list is initialized, does nothing if it
// already has values.
void InitStandardSchemes() {
if (standard_schemes)
return;
standard_schemes = new std::vector<const char*>;
for (int i = 0; i < kNumStandardURLSchemes; i++)
standard_schemes->push_back(kStandardURLSchemes[i]);
}
// Given a string and a range inside the string, compares it to the given
// lower-case |compare_to| buffer.
template<typename CHAR>
inline bool DoCompareSchemeComponent(const CHAR* spec,
const Component& component,
const char* compare_to) {
if (!component.is_nonempty())
return compare_to[0] == 0; // When component is empty, match empty scheme.
return LowerCaseEqualsASCII(&spec[component.begin],
&spec[component.end()],
compare_to);
}
// Returns true if the given scheme identified by |scheme| within |spec| is one
// of the registered "standard" schemes.
template<typename CHAR>
bool DoIsStandard(const CHAR* spec, const Component& scheme) {
if (!scheme.is_nonempty())
return false; // Empty or invalid schemes are non-standard.
InitStandardSchemes();
for (size_t i = 0; i < standard_schemes->size(); i++) {
if (LowerCaseEqualsASCII(&spec[scheme.begin], &spec[scheme.end()],
standard_schemes->at(i)))
return true;
}
return false;
}
template<typename CHAR>
bool DoFindAndCompareScheme(const CHAR* str,
int str_len,
const char* compare,
Component* found_scheme) {
// Before extracting scheme, canonicalize the URL to remove any whitespace.
// This matches the canonicalization done in DoCanonicalize function.
RawCanonOutputT<CHAR> whitespace_buffer;
int spec_len;
const CHAR* spec = RemoveURLWhitespace(str, str_len,
&whitespace_buffer, &spec_len);
Component our_scheme;
if (!ExtractScheme(spec, spec_len, &our_scheme)) {
// No scheme.
if (found_scheme)
*found_scheme = Component();
return false;
}
if (found_scheme)
*found_scheme = our_scheme;
return DoCompareSchemeComponent(spec, our_scheme, compare);
}
template<typename CHAR>
bool DoCanonicalize(const CHAR* in_spec,
int in_spec_len,
bool trim_path_end,
CharsetConverter* charset_converter,
CanonOutput* output,
Parsed* output_parsed) {
// Remove any whitespace from the middle of the relative URL, possibly
// copying to the new buffer.
RawCanonOutputT<CHAR> whitespace_buffer;
int spec_len;
const CHAR* spec = RemoveURLWhitespace(in_spec, in_spec_len,
&whitespace_buffer, &spec_len);
Parsed parsed_input;
#ifdef WIN32
// For Windows, we allow things that look like absolute Windows paths to be
// fixed up magically to file URLs. This is done for IE compatability. For
// example, this will change "c:/foo" into a file URL rather than treating
// it as a URL with the protocol "c". It also works for UNC ("\\foo\bar.txt").
// There is similar logic in url_canon_relative.cc for
//
// For Max & Unix, we don't do this (the equivalent would be "/foo/bar" which
// has no meaning as an absolute path name. This is because browsers on Mac
// & Unix don't generally do this, so there is no compatibility reason for
// doing so.
if (DoesBeginUNCPath(spec, 0, spec_len, false) ||
DoesBeginWindowsDriveSpec(spec, 0, spec_len)) {
ParseFileURL(spec, spec_len, &parsed_input);
return CanonicalizeFileURL(spec, spec_len, parsed_input, charset_converter,
output, output_parsed);
}
#endif
Component scheme;
if (!ExtractScheme(spec, spec_len, &scheme))
return false;
// This is the parsed version of the input URL, we have to canonicalize it
// before storing it in our object.
bool success;
if (DoCompareSchemeComponent(spec, scheme, url::kFileScheme)) {
// File URLs are special.
ParseFileURL(spec, spec_len, &parsed_input);
success = CanonicalizeFileURL(spec, spec_len, parsed_input,
charset_converter, output, output_parsed);
} else if (DoCompareSchemeComponent(spec, scheme, url::kFileSystemScheme)) {
// Filesystem URLs are special.
ParseFileSystemURL(spec, spec_len, &parsed_input);
success = CanonicalizeFileSystemURL(spec, spec_len, parsed_input,
charset_converter, output,
output_parsed);
} else if (DoIsStandard(spec, scheme)) {
// All "normal" URLs.
ParseStandardURL(spec, spec_len, &parsed_input);
success = CanonicalizeStandardURL(spec, spec_len, parsed_input,
charset_converter, output, output_parsed);
} else if (DoCompareSchemeComponent(spec, scheme, url::kMailToScheme)) {
// Mailto are treated like a standard url with only a scheme, path, query
ParseMailtoURL(spec, spec_len, &parsed_input);
success = CanonicalizeMailtoURL(spec, spec_len, parsed_input, output,
output_parsed);
} else {
// "Weird" URLs like data: and javascript:
ParsePathURL(spec, spec_len, trim_path_end, &parsed_input);
success = CanonicalizePathURL(spec, spec_len, parsed_input, output,
output_parsed);
}
return success;
}
template<typename CHAR>
bool DoResolveRelative(const char* base_spec,
int base_spec_len,
const Parsed& base_parsed,
const CHAR* in_relative,
int in_relative_length,
CharsetConverter* charset_converter,
CanonOutput* output,
Parsed* output_parsed) {
// Remove any whitespace from the middle of the relative URL, possibly
// copying to the new buffer.
RawCanonOutputT<CHAR> whitespace_buffer;
int relative_length;
const CHAR* relative = RemoveURLWhitespace(in_relative, in_relative_length,
&whitespace_buffer,
&relative_length);
bool base_is_authority_based = false;
bool base_is_hierarchical = false;
if (base_spec &&
base_parsed.scheme.is_nonempty()) {
int after_scheme = base_parsed.scheme.end() + 1; // Skip past the colon.
int num_slashes = CountConsecutiveSlashes(base_spec, after_scheme,
base_spec_len);
base_is_authority_based = num_slashes > 1;
base_is_hierarchical = num_slashes > 0;
}
bool standard_base_scheme =
base_parsed.scheme.is_nonempty() &&
DoIsStandard(base_spec, base_parsed.scheme);
bool is_relative;
Component relative_component;
if (!IsRelativeURL(base_spec, base_parsed, relative, relative_length,
(base_is_hierarchical || standard_base_scheme),
&is_relative, &relative_component)) {
// Error resolving.
return false;
}
// Pretend for a moment that |base_spec| is a standard URL. Normally
// non-standard URLs are treated as PathURLs, but if the base has an
// authority we would like to preserve it.
if (is_relative && base_is_authority_based && !standard_base_scheme) {
Parsed base_parsed_authority;
ParseStandardURL(base_spec, base_spec_len, &base_parsed_authority);
if (base_parsed_authority.host.is_nonempty()) {
bool did_resolve_succeed =
ResolveRelativeURL(base_spec, base_parsed_authority, false, relative,
relative_component, charset_converter, output,
output_parsed);
// The output_parsed is incorrect at this point (because it was built
// based on base_parsed_authority instead of base_parsed) and needs to be
// re-created.
ParsePathURL(output->data(), output->length(), true,
output_parsed);
return did_resolve_succeed;
}
} else if (is_relative) {
// Relative, resolve and canonicalize.
bool file_base_scheme = base_parsed.scheme.is_nonempty() &&
DoCompareSchemeComponent(base_spec, base_parsed.scheme, kFileScheme);
return ResolveRelativeURL(base_spec, base_parsed, file_base_scheme, relative,
relative_component, charset_converter, output,
output_parsed);
}
// Not relative, canonicalize the input.
return DoCanonicalize(relative, relative_length, true, charset_converter,
output, output_parsed);
}
template<typename CHAR>
bool DoReplaceComponents(const char* spec,
int spec_len,
const Parsed& parsed,
const Replacements<CHAR>& replacements,
CharsetConverter* charset_converter,
CanonOutput* output,
Parsed* out_parsed) {
// If the scheme is overridden, just do a simple string substitution and
// reparse the whole thing. There are lots of edge cases that we really don't
// want to deal with. Like what happens if I replace "http://e:8080/foo"
// with a file. Does it become "file:///E:/8080/foo" where the port number
// becomes part of the path? Parsing that string as a file URL says "yes"
// but almost no sane rule for dealing with the components individually would
// come up with that.
//
// Why allow these crazy cases at all? Programatically, there is almost no
// case for replacing the scheme. The most common case for hitting this is
// in JS when building up a URL using the location object. In this case, the
// JS code expects the string substitution behavior:
// http://www.w3.org/TR/2008/WD-html5-20080610/structured.html#common3
if (replacements.IsSchemeOverridden()) {
// Canonicalize the new scheme so it is 8-bit and can be concatenated with
// the existing spec.
RawCanonOutput<128> scheme_replaced;
Component scheme_replaced_parsed;
CanonicalizeScheme(replacements.sources().scheme,
replacements.components().scheme,
&scheme_replaced, &scheme_replaced_parsed);
// We can assume that the input is canonicalized, which means it always has
// a colon after the scheme (or where the scheme would be).
int spec_after_colon = parsed.scheme.is_valid() ? parsed.scheme.end() + 1
: 1;
if (spec_len - spec_after_colon > 0) {
scheme_replaced.Append(&spec[spec_after_colon],
spec_len - spec_after_colon);
}
// We now need to completely re-parse the resulting string since its meaning
// may have changed with the different scheme.
RawCanonOutput<128> recanonicalized;
Parsed recanonicalized_parsed;
DoCanonicalize(scheme_replaced.data(), scheme_replaced.length(), true,
charset_converter,
&recanonicalized, &recanonicalized_parsed);
// Recurse using the version with the scheme already replaced. This will now
// use the replacement rules for the new scheme.
//
// Warning: this code assumes that ReplaceComponents will re-check all
// components for validity. This is because we can't fail if DoCanonicalize
// failed above since theoretically the thing making it fail could be
// getting replaced here. If ReplaceComponents didn't re-check everything,
// we wouldn't know if something *not* getting replaced is a problem.
// If the scheme-specific replacers are made more intelligent so they don't
// re-check everything, we should instead recanonicalize the whole thing
// after this call to check validity (this assumes replacing the scheme is
// much much less common than other types of replacements, like clearing the
// ref).
Replacements<CHAR> replacements_no_scheme = replacements;
replacements_no_scheme.SetScheme(NULL, Component());
return DoReplaceComponents(recanonicalized.data(), recanonicalized.length(),
recanonicalized_parsed, replacements_no_scheme,
charset_converter, output, out_parsed);
}
// If we get here, then we know the scheme doesn't need to be replaced, so can
// just key off the scheme in the spec to know how to do the replacements.
if (DoCompareSchemeComponent(spec, parsed.scheme, url::kFileScheme)) {
return ReplaceFileURL(spec, parsed, replacements, charset_converter, output,
out_parsed);
}
if (DoCompareSchemeComponent(spec, parsed.scheme, url::kFileSystemScheme)) {
return ReplaceFileSystemURL(spec, parsed, replacements, charset_converter,
output, out_parsed);
}
if (DoIsStandard(spec, parsed.scheme)) {
return ReplaceStandardURL(spec, parsed, replacements, charset_converter,
output, out_parsed);
}
if (DoCompareSchemeComponent(spec, parsed.scheme, url::kMailToScheme)) {
return ReplaceMailtoURL(spec, parsed, replacements, output, out_parsed);
}
// Default is a path URL.
return ReplacePathURL(spec, parsed, replacements, output, out_parsed);
}
} // namespace
void Initialize() {
InitStandardSchemes();
}
void Shutdown() {
if (standard_schemes) {
delete standard_schemes;
standard_schemes = NULL;
}
}
void AddStandardScheme(const char* new_scheme) {
// If this assert triggers, it means you've called AddStandardScheme after
// LockStandardSchemes have been called (see the header file for
// LockStandardSchemes for more).
//
// This normally means you're trying to set up a new standard scheme too late
// in your application's init process. Locate where your app does this
// initialization and calls LockStandardScheme, and add your new standard
// scheme there.
DCHECK(!standard_schemes_locked) <<
"Trying to add a standard scheme after the list has been locked.";
size_t scheme_len = strlen(new_scheme);
if (scheme_len == 0)
return;
// Dulicate the scheme into a new buffer and add it to the list of standard
// schemes. This pointer will be leaked on shutdown.
char* dup_scheme = new char[scheme_len + 1];
ANNOTATE_LEAKING_OBJECT_PTR(dup_scheme);
memcpy(dup_scheme, new_scheme, scheme_len + 1);
InitStandardSchemes();
standard_schemes->push_back(dup_scheme);
}
void LockStandardSchemes() {
standard_schemes_locked = true;
}
bool IsStandard(const char* spec, const Component& scheme) {
return DoIsStandard(spec, scheme);
}
bool IsStandard(const base::char16* spec, const Component& scheme) {
return DoIsStandard(spec, scheme);
}
bool FindAndCompareScheme(const char* str,
int str_len,
const char* compare,
Component* found_scheme) {
return DoFindAndCompareScheme(str, str_len, compare, found_scheme);
}
bool FindAndCompareScheme(const base::char16* str,
int str_len,
const char* compare,
Component* found_scheme) {
return DoFindAndCompareScheme(str, str_len, compare, found_scheme);
}
bool Canonicalize(const char* spec,
int spec_len,
bool trim_path_end,
CharsetConverter* charset_converter,
CanonOutput* output,
Parsed* output_parsed) {
return DoCanonicalize(spec, spec_len, trim_path_end, charset_converter,
output, output_parsed);
}
bool Canonicalize(const base::char16* spec,
int spec_len,
bool trim_path_end,
CharsetConverter* charset_converter,
CanonOutput* output,
Parsed* output_parsed) {
return DoCanonicalize(spec, spec_len, trim_path_end, charset_converter,
output, output_parsed);
}
bool ResolveRelative(const char* base_spec,
int base_spec_len,
const Parsed& base_parsed,
const char* relative,
int relative_length,
CharsetConverter* charset_converter,
CanonOutput* output,
Parsed* output_parsed) {
return DoResolveRelative(base_spec, base_spec_len, base_parsed,
relative, relative_length,
charset_converter, output, output_parsed);
}
bool ResolveRelative(const char* base_spec,
int base_spec_len,
const Parsed& base_parsed,
const base::char16* relative,
int relative_length,
CharsetConverter* charset_converter,
CanonOutput* output,
Parsed* output_parsed) {
return DoResolveRelative(base_spec, base_spec_len, base_parsed,
relative, relative_length,
charset_converter, output, output_parsed);
}
bool ReplaceComponents(const char* spec,
int spec_len,
const Parsed& parsed,
const Replacements<char>& replacements,
CharsetConverter* charset_converter,
CanonOutput* output,
Parsed* out_parsed) {
return DoReplaceComponents(spec, spec_len, parsed, replacements,
charset_converter, output, out_parsed);
}
bool ReplaceComponents(const char* spec,
int spec_len,
const Parsed& parsed,
const Replacements<base::char16>& replacements,
CharsetConverter* charset_converter,
CanonOutput* output,
Parsed* out_parsed) {
return DoReplaceComponents(spec, spec_len, parsed, replacements,
charset_converter, output, out_parsed);
}
// Front-ends for LowerCaseEqualsASCII.
bool LowerCaseEqualsASCII(const char* a_begin,
const char* a_end,
const char* b) {
return DoLowerCaseEqualsASCII(a_begin, a_end, b);
}
bool LowerCaseEqualsASCII(const char* a_begin,
const char* a_end,
const char* b_begin,
const char* b_end) {
while (a_begin != a_end && b_begin != b_end &&
ToLowerASCII(*a_begin) == *b_begin) {
a_begin++;
b_begin++;
}
return a_begin == a_end && b_begin == b_end;
}
bool LowerCaseEqualsASCII(const base::char16* a_begin,
const base::char16* a_end,
const char* b) {
return DoLowerCaseEqualsASCII(a_begin, a_end, b);
}
void DecodeURLEscapeSequences(const char* input,
int length,
CanonOutputW* output) {
RawCanonOutputT<char> unescaped_chars;
for (int i = 0; i < length; i++) {
if (input[i] == '%') {
unsigned char ch;
if (DecodeEscaped(input, &i, length, &ch)) {
unescaped_chars.push_back(ch);
} else {
// Invalid escape sequence, copy the percent literal.
unescaped_chars.push_back('%');
}
} else {
// Regular non-escaped 8-bit character.
unescaped_chars.push_back(input[i]);
}
}
// Convert that 8-bit to UTF-16. It's not clear IE does this at all to
// JavaScript URLs, but Firefox and Safari do.
for (int i = 0; i < unescaped_chars.length(); i++) {
unsigned char uch = static_cast<unsigned char>(unescaped_chars.at(i));
if (uch < 0x80) {
// Non-UTF-8, just append directly
output->push_back(uch);
} else {
// next_ch will point to the last character of the decoded
// character.
int next_character = i;
unsigned code_point;
if (ReadUTFChar(unescaped_chars.data(), &next_character,
unescaped_chars.length(), &code_point)) {
// Valid UTF-8 character, convert to UTF-16.
AppendUTF16Value(code_point, output);
i = next_character;
} else {
// If there are any sequences that are not valid UTF-8, we keep
// invalid code points and promote to UTF-16. We copy all characters
// from the current position to the end of the identified sequence.
while (i < next_character) {
output->push_back(static_cast<unsigned char>(unescaped_chars.at(i)));
i++;
}
output->push_back(static_cast<unsigned char>(unescaped_chars.at(i)));
}
}
}
}
void EncodeURIComponent(const char* input, int length, CanonOutput* output) {
for (int i = 0; i < length; ++i) {
unsigned char c = static_cast<unsigned char>(input[i]);
if (IsComponentChar(c))
output->push_back(c);
else
AppendEscapedChar(c, output);
}
}
bool CompareSchemeComponent(const char* spec,
const Component& component,
const char* compare_to) {
return DoCompareSchemeComponent(spec, component, compare_to);
}
bool CompareSchemeComponent(const base::char16* spec,
const Component& component,
const char* compare_to) {
return DoCompareSchemeComponent(spec, component, compare_to);
}
} // namespace url