blob: f10958a1122402b5d862c23e7e37d85baa6aeae2 [file] [log] [blame]
// Copyright (c) 2012 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 "components/url_fixer/url_fixer.h"
#include <algorithm>
#include "base/files/file_path.h"
#include "base/files/file_util.h"
#include "base/logging.h"
#if defined(OS_POSIX)
#include "base/path_service.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "net/base/escape.h"
#include "net/base/filename_util.h"
#include "net/base/net_util.h"
#include "net/base/registry_controlled_domains/registry_controlled_domain.h"
#include "url/url_file.h"
#include "url/url_parse.h"
#include "url/url_util.h"
const char* url_fixer::home_directory_override = NULL;
namespace {
// Hardcode these constants to avoid dependences on //chrome and //content.
const char kChromeUIScheme[] = "chrome";
const char kChromeUIDefaultHost[] = "version";
const char kViewSourceScheme[] = "view-source";
// TODO(estade): Remove these ugly, ugly functions. They are only used in
// SegmentURL. A url::Parsed object keeps track of a bunch of indices into
// a url string, and these need to be updated when the URL is converted from
// UTF8 to UTF16. Instead of this after-the-fact adjustment, we should parse it
// in the correct string format to begin with.
url::Component UTF8ComponentToUTF16Component(
const std::string& text_utf8,
const url::Component& component_utf8) {
if (component_utf8.len == -1)
return url::Component();
std::string before_component_string =
text_utf8.substr(0, component_utf8.begin);
std::string component_string =
text_utf8.substr(component_utf8.begin, component_utf8.len);
base::string16 before_component_string_16 =
base::string16 component_string_16 = base::UTF8ToUTF16(component_string);
url::Component component_16(before_component_string_16.length(),
return component_16;
void UTF8PartsToUTF16Parts(const std::string& text_utf8,
const url::Parsed& parts_utf8,
url::Parsed* parts) {
if (base::IsStringASCII(text_utf8)) {
*parts = parts_utf8;
parts->scheme = UTF8ComponentToUTF16Component(text_utf8, parts_utf8.scheme);
parts->username =
UTF8ComponentToUTF16Component(text_utf8, parts_utf8.username);
parts->password =
UTF8ComponentToUTF16Component(text_utf8, parts_utf8.password);
parts->host = UTF8ComponentToUTF16Component(text_utf8,;
parts->port = UTF8ComponentToUTF16Component(text_utf8, parts_utf8.port);
parts->path = UTF8ComponentToUTF16Component(text_utf8, parts_utf8.path);
parts->query = UTF8ComponentToUTF16Component(text_utf8, parts_utf8.query);
parts->ref = UTF8ComponentToUTF16Component(text_utf8, parts_utf8.ref);
base::TrimPositions TrimWhitespaceUTF8(const std::string& input,
base::TrimPositions positions,
std::string* output) {
// This implementation is not so fast since it converts the text encoding
// twice. Please feel free to file a bug if this function hurts the
// performance of Chrome.
base::string16 input16 = base::UTF8ToUTF16(input);
base::string16 output16;
base::TrimPositions result =
base::TrimWhitespace(input16, positions, &output16);
*output = base::UTF16ToUTF8(output16);
return result;
// does some basic fixes for input that we want to test for file-ness
void PrepareStringForFileOps(const base::FilePath& text,
base::FilePath::StringType* output) {
#if defined(OS_WIN)
base::TrimWhitespace(text.value(), base::TRIM_ALL, output);
replace(output->begin(), output->end(), '/', '\\');
TrimWhitespaceUTF8(text.value(), base::TRIM_ALL, output);
// Tries to create a full path from |text|. If the result is valid and the
// file exists, returns true and sets |full_path| to the result. Otherwise,
// returns false and leaves |full_path| unchanged.
bool ValidPathForFile(const base::FilePath::StringType& text,
base::FilePath* full_path) {
base::FilePath file_path = base::MakeAbsoluteFilePath(base::FilePath(text));
if (file_path.empty())
return false;
if (!base::PathExists(file_path))
return false;
*full_path = file_path;
return true;
#if defined(OS_POSIX)
// Given a path that starts with ~, return a path that starts with an
// expanded-out /user/foobar directory.
std::string FixupHomedir(const std::string& text) {
DCHECK(text.length() > 0 && text[0] == '~');
if (text.length() == 1 || text[1] == '/') {
base::FilePath file_path;
if (url_fixer::home_directory_override)
file_path = base::FilePath(url_fixer::home_directory_override);
PathService::Get(base::DIR_HOME, &file_path);
// We'll probably break elsewhere if $HOME is undefined, but check here
// just in case.
if (file_path.value().empty())
return text;
// Append requires to be a relative path, so we have to cut all preceeding
// '/' characters.
size_t i = 1;
while (i < text.length() && text[i] == '/')
return file_path.Append(text.substr(i)).value();
// Otherwise, this is a path like ~foobar/baz, where we must expand to
// user foobar's home directory. Officially, we should use getpwent(),
// but that is a nasty blocking call.
#if defined(OS_MACOSX)
static const char kHome[] = "/Users/";
static const char kHome[] = "/home/";
return kHome + text.substr(1);
// Tries to create a file: URL from |text| if it looks like a filename, even if
// it doesn't resolve as a valid path or to an existing file. Returns a
// (possibly invalid) file: URL in |fixed_up_url| for input beginning
// with a drive specifier or "\\". Returns the unchanged input in other cases
// (including file: URLs: these don't look like filenames).
std::string FixupPath(const std::string& text) {
base::FilePath::StringType filename;
#if defined(OS_WIN)
base::FilePath input_path(base::UTF8ToWide(text));
PrepareStringForFileOps(input_path, &filename);
// Fixup Windows-style drive letters, where "C:" gets rewritten to "C|".
if (filename.length() > 1 && filename[1] == '|')
filename[1] = ':';
#elif defined(OS_POSIX)
base::FilePath input_path(text);
PrepareStringForFileOps(input_path, &filename);
if (filename.length() > 0 && filename[0] == '~')
filename = FixupHomedir(filename);
// Here, we know the input looks like a file.
GURL file_url = net::FilePathToFileURL(base::FilePath(filename));
if (file_url.is_valid()) {
return base::UTF16ToUTF8(net::FormatUrl(file_url,
// Invalid file URL, just return the input.
return text;
// Checks |domain| to see if a valid TLD is already present. If not, appends
// |desired_tld| to the domain, and prepends "www." unless it's already present.
void AddDesiredTLD(const std::string& desired_tld, std::string* domain) {
if (desired_tld.empty() || domain->empty())
// Check the TLD. If the return value is positive, we already have a TLD, so
// abort. If the return value is std::string::npos, there's no valid host,
// but we can try to append a TLD anyway, since the host may become valid once
// the TLD is attached -- for example, "999999999999" is detected as a broken
// IP address and marked invalid, but attaching ".com" makes it legal. When
// the return value is 0, there's a valid host with no known TLD, so we can
// definitely append the user's TLD. We disallow unknown registries here so
// users can input "" and hit ctrl-enter to get
// "".
const size_t registry_length =
if ((registry_length != 0) && (registry_length != std::string::npos))
// Add the suffix at the end of the domain.
const size_t domain_length(domain->length());
DCHECK_GT(domain_length, 0U);
DCHECK_NE(desired_tld[0], '.');
if ((*domain)[domain_length - 1] != '.')
// Now, if the domain begins with "www.", stop.
const std::string prefix("www.");
if (domain->compare(0, prefix.length(), prefix) != 0) {
// Otherwise, add www. to the beginning of the URL.
domain->insert(0, prefix);
inline void FixupUsername(const std::string& text,
const url::Component& part,
std::string* url) {
if (!part.is_valid())
// We don't fix up the username at the moment.
url->append(text, part.begin, part.len);
// Do not append the trailing '@' because we might need to include the user's
// password. FixupURL itself will append the '@' for us.
inline void FixupPassword(const std::string& text,
const url::Component& part,
std::string* url) {
if (!part.is_valid())
// We don't fix up the password at the moment.
url->append(text, part.begin, part.len);
void FixupHost(const std::string& text,
const url::Component& part,
bool has_scheme,
const std::string& desired_tld,
std::string* url) {
if (!part.is_valid())
// Make domain valid.
// Strip all leading dots and all but one trailing dot, unless the user only
// typed dots, in which case their input is totally invalid and we should just
// leave it unchanged.
std::string domain(text, part.begin, part.len);
const size_t first_nondot(domain.find_first_not_of('.'));
if (first_nondot != std::string::npos) {
domain.erase(0, first_nondot);
size_t last_nondot(domain.find_last_not_of('.'));
DCHECK(last_nondot != std::string::npos);
last_nondot += 2; // Point at second period in ending string
if (last_nondot < domain.length())
// Add any user-specified TLD, if applicable.
AddDesiredTLD(desired_tld, &domain);
void FixupPort(const std::string& text,
const url::Component& part,
std::string* url) {
if (!part.is_valid())
// We don't fix up the port at the moment.
url->append(text, part.begin, part.len);
inline void FixupPath(const std::string& text,
const url::Component& part,
std::string* url) {
if (!part.is_valid() || part.len == 0) {
// We should always have a path.
// Append the path as is.
url->append(text, part.begin, part.len);
inline void FixupQuery(const std::string& text,
const url::Component& part,
std::string* url) {
if (!part.is_valid())
// We don't fix up the query at the moment.
url->append(text, part.begin, part.len);
inline void FixupRef(const std::string& text,
const url::Component& part,
std::string* url) {
if (!part.is_valid())
// We don't fix up the ref at the moment.
url->append(text, part.begin, part.len);
bool HasPort(const std::string& original_text,
const url::Component& scheme_component) {
// Find the range between the ":" and the "/".
size_t port_start = scheme_component.end() + 1;
size_t port_end = port_start;
while ((port_end < original_text.length()) &&
if (port_end == port_start)
return false;
// Scan the range to see if it is entirely digits.
for (size_t i = port_start; i < port_end; ++i) {
if (!IsAsciiDigit(original_text[i]))
return false;
return true;
// Try to extract a valid scheme from the beginning of |text|.
// If successful, set |scheme_component| to the text range where the scheme
// was located, and fill |canon_scheme| with its canonicalized form.
// Otherwise, return false and leave the outputs in an indeterminate state.
bool GetValidScheme(const std::string& text,
url::Component* scheme_component,
std::string* canon_scheme) {
// Locate everything up to (but not including) the first ':'
if (!url::ExtractScheme(, static_cast<int>(text.length()), scheme_component)) {
return false;
// Make sure the scheme contains only valid characters, and convert
// to lowercase. This also catches IPv6 literals like [::1], because
// brackets are not in the whitelist.
url::StdStringCanonOutput canon_scheme_output(canon_scheme);
url::Component canon_scheme_component;
if (!url::CanonicalizeScheme(,
&canon_scheme_component)) {
return false;
// Strip the ':', and any trailing buffer space.
DCHECK_EQ(0, canon_scheme_component.begin);
// We need to fix up the segmentation for "". For this
// case, we guess that schemes with a "." are not actually schemes.
if (canon_scheme->find('.') != std::string::npos)
return false;
// We need to fix up the segmentation for "www:123/". For this case, we
// will add an HTTP scheme later and make the URL parser happy.
// TODO(pkasting): Maybe we should try to use GURL's parser for this?
if (HasPort(text, *scheme_component))
return false;
// Everything checks out.
return true;
// Performs the work for url_fixer::SegmentURL. |text| may be modified on
// output on success: a semicolon following a valid scheme is replaced with a
// colon.
std::string SegmentURLInternal(std::string* text, url::Parsed* parts) {
// Initialize the result.
*parts = url::Parsed();
std::string trimmed;
TrimWhitespaceUTF8(*text, base::TRIM_ALL, &trimmed);
if (trimmed.empty())
return std::string(); // Nothing to segment.
#if defined(OS_WIN)
int trimmed_length = static_cast<int>(trimmed.length());
if (url::DoesBeginWindowsDriveSpec(, 0, trimmed_length) ||
url::DoesBeginUNCPath(, 0, trimmed_length, true))
return "file";
#elif defined(OS_POSIX)
if (base::FilePath::IsSeparator([0]) ||[0] == '~')
return "file";
// Otherwise, we need to look at things carefully.
std::string scheme;
if (!GetValidScheme(*text, &parts->scheme, &scheme)) {
// Try again if there is a ';' in the text. If changing it to a ':' results
// in a scheme being found, continue processing with the modified text.
bool found_scheme = false;
size_t semicolon = text->find(';');
if (semicolon != 0 && semicolon != std::string::npos) {
(*text)[semicolon] = ':';
if (GetValidScheme(*text, &parts->scheme, &scheme))
found_scheme = true;
(*text)[semicolon] = ';';
if (!found_scheme) {
// Couldn't determine the scheme, so just pick one.
scheme = StartsWithASCII(*text, "ftp.", false) ? url::kFtpScheme
: url::kHttpScheme;
// Proceed with about and chrome schemes, but not file or nonstandard schemes.
if ((scheme != url::kAboutScheme) && (scheme != kChromeUIScheme) &&
((scheme == url::kFileScheme) ||
url::Component(0, static_cast<int>(scheme.length()))))) {
return scheme;
if (scheme == url::kFileSystemScheme) {
// Have the GURL parser do the heavy lifting for us.
text->data(), static_cast<int>(text->length()), parts);
return scheme;
if (parts->scheme.is_valid()) {
// Have the GURL parser do the heavy lifting for us.
text->data(), static_cast<int>(text->length()), parts);
return scheme;
// We need to add a scheme in order for ParseStandardURL to be happy.
// Find the first non-whitespace character.
std::string::iterator first_nonwhite = text->begin();
while ((first_nonwhite != text->end()) && IsWhitespace(*first_nonwhite))
// Construct the text to parse by inserting the scheme.
std::string inserted_text(scheme);
std::string text_to_parse(text->begin(), first_nonwhite);
text_to_parse.append(first_nonwhite, text->end());
// Have the GURL parser do the heavy lifting for us.
url::ParseStandardURL(, static_cast<int>(text_to_parse.length()), parts);
// Offset the results of the parse to match the original text.
const int offset = -static_cast<int>(inserted_text.length());
url_fixer::OffsetComponent(offset, &parts->scheme);
url_fixer::OffsetComponent(offset, &parts->username);
url_fixer::OffsetComponent(offset, &parts->password);
url_fixer::OffsetComponent(offset, &parts->host);
url_fixer::OffsetComponent(offset, &parts->port);
url_fixer::OffsetComponent(offset, &parts->path);
url_fixer::OffsetComponent(offset, &parts->query);
url_fixer::OffsetComponent(offset, &parts->ref);
return scheme;
} // namespace
std::string url_fixer::SegmentURL(const std::string& text, url::Parsed* parts) {
std::string mutable_text(text);
return SegmentURLInternal(&mutable_text, parts);
base::string16 url_fixer::SegmentURL(const base::string16& text,
url::Parsed* parts) {
std::string text_utf8 = base::UTF16ToUTF8(text);
url::Parsed parts_utf8;
std::string scheme_utf8 = SegmentURL(text_utf8, &parts_utf8);
UTF8PartsToUTF16Parts(text_utf8, parts_utf8, parts);
return base::UTF8ToUTF16(scheme_utf8);
GURL url_fixer::FixupURL(const std::string& text,
const std::string& desired_tld) {
std::string trimmed;
TrimWhitespaceUTF8(text, base::TRIM_ALL, &trimmed);
if (trimmed.empty())
return GURL(); // Nothing here.
// Segment the URL.
url::Parsed parts;
std::string scheme(SegmentURLInternal(&trimmed, &parts));
// For view-source: URLs, we strip "view-source:", do fixup, and stick it back
// on. This allows us to handle things like "".
if (scheme == kViewSourceScheme) {
// Reject "view-source:view-source:..." to avoid deep recursion.
std::string view_source(kViewSourceScheme + std::string(":"));
if (!StartsWithASCII(text, view_source + view_source, false)) {
return GURL(kViewSourceScheme + std::string(":") +
FixupURL(trimmed.substr(scheme.length() + 1), desired_tld)
// We handle the file scheme separately.
if (scheme == url::kFileScheme)
return GURL(parts.scheme.is_valid() ? text : FixupPath(text));
// We handle the filesystem scheme separately.
if (scheme == url::kFileSystemScheme) {
if (parts.inner_parsed() && parts.inner_parsed()->scheme.is_valid())
return GURL(text);
return GURL();
// Parse and rebuild about: and chrome: URLs, except about:blank.
bool chrome_url =
!LowerCaseEqualsASCII(trimmed, url::kAboutBlankURL) &&
((scheme == url::kAboutScheme) || (scheme == kChromeUIScheme));
// For some schemes whose layouts we understand, we rebuild it.
if (chrome_url ||
url::Component(0, static_cast<int>(scheme.length())))) {
// Replace the about: scheme with the chrome: scheme.
std::string url(chrome_url ? kChromeUIScheme : scheme);
// We need to check whether the |username| is valid because it is our
// responsibility to append the '@' to delineate the user information from
// the host portion of the URL.
if (parts.username.is_valid()) {
FixupUsername(trimmed, parts.username, &url);
FixupPassword(trimmed, parts.password, &url);
FixupHost(trimmed,, parts.scheme.is_valid(), desired_tld, &url);
if (chrome_url && !
FixupPort(trimmed, parts.port, &url);
FixupPath(trimmed, parts.path, &url);
FixupQuery(trimmed, parts.query, &url);
FixupRef(trimmed, parts.ref, &url);
return GURL(url);
// In the worst-case, we insert a scheme if the URL lacks one.
if (!parts.scheme.is_valid()) {
std::string fixed_scheme(scheme);
trimmed.insert(0, fixed_scheme);
return GURL(trimmed);
// The rules are different here than for regular fixup, since we need to handle
// input like "hello.html" and know to look in the current directory. Regular
// fixup will look for cues that it is actually a file path before trying to
// figure out what file it is. If our logic doesn't work, we will fall back on
// regular fixup.
GURL url_fixer::FixupRelativeFile(const base::FilePath& base_dir,
const base::FilePath& text) {
base::FilePath old_cur_directory;
if (!base_dir.empty()) {
// Save the old current directory before we move to the new one.
// Allow funny input with extra whitespace and the wrong kind of slashes.
base::FilePath::StringType trimmed;
PrepareStringForFileOps(text, &trimmed);
bool is_file = true;
// Avoid recognizing definite non-file URLs as file paths.
GURL gurl(trimmed);
if (gurl.is_valid() && gurl.IsStandard())
is_file = false;
base::FilePath full_path;
if (is_file && !ValidPathForFile(trimmed, &full_path)) {
// Not a path as entered, try unescaping it in case the user has
// escaped things. We need to go through 8-bit since the escaped values
// only represent 8-bit values.
#if defined(OS_WIN)
std::wstring unescaped = base::UTF8ToWide(net::UnescapeURLComponent(
net::UnescapeRule::SPACES | net::UnescapeRule::URL_SPECIAL_CHARS));
#elif defined(OS_POSIX)
std::string unescaped = net::UnescapeURLComponent(
net::UnescapeRule::SPACES | net::UnescapeRule::URL_SPECIAL_CHARS);
if (!ValidPathForFile(unescaped, &full_path))
is_file = false;
// Put back the current directory if we saved it.
if (!base_dir.empty())
if (is_file) {
GURL file_url = net::FilePathToFileURL(full_path);
if (file_url.is_valid())
return GURL(
// Invalid files fall through to regular processing.
// Fall back on regular fixup for this input.
#if defined(OS_WIN)
std::string text_utf8 = base::WideToUTF8(text.value());
#elif defined(OS_POSIX)
std::string text_utf8 = text.value();
return FixupURL(text_utf8, std::string());
void url_fixer::OffsetComponent(int offset, url::Component* part) {
if (part->is_valid()) {
// Offset the location of this component.
part->begin += offset;
// This part might not have existed in the original text.
if (part->begin < 0)
bool url_fixer::IsEquivalentScheme(const std::string& scheme1,
const std::string& scheme2) {
return scheme1 == scheme2 ||
(scheme1 == url::kAboutScheme && scheme2 == kChromeUIScheme) ||
(scheme1 == kChromeUIScheme && scheme2 == url::kAboutScheme);