// 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 "base/logging.h"
#include "url/url_file.h"
#include "url/url_parse.h"
#include "url/url_parse_internal.h"
// Interesting IE file:isms...
//
// INPUT OUTPUT
// ========================= ==============================
// file:/foo/bar file:///foo/bar
// The result here seems totally invalid!?!? This isn't UNC.
//
// file:/
// file:// or any other number of slashes
// IE6 doesn't do anything at all if you click on this link. No error:
// nothing. IE6's history system seems to always color this link, so I'm
// guessing that it maps internally to the empty URL.
//
// C:\ file:///C:/
// When on a file: URL source page, this link will work. When over HTTP,
// the file: URL will appear in the status bar but the link will not work
// (security restriction for all file URLs).
//
// file:foo/ file:foo/ (invalid?!?!?)
// file:/foo/ file:///foo/ (invalid?!?!?)
// file://foo/ file://foo/ (UNC to server "foo")
// file:///foo/ file:///foo/ (invalid, seems to be a file)
// file:////foo/ file://foo/ (UNC to server "foo")
// Any more than four slashes is also treated as UNC.
//
// file:C:/ file://C:/
// file:/C:/ file://C:/
// The number of slashes after "file:" don't matter if the thing following
// it looks like an absolute drive path. Also, slashes and backslashes are
// equally valid here.
namespace url_parse {
namespace {
// A subcomponent of DoInitFileURL, the input of this function should be a UNC
// path name, with the index of the first character after the slashes following
// the scheme given in |after_slashes|. This will initialize the host, path,
// query, and ref, and leave the other output components untouched
// (DoInitFileURL handles these for us).
template<typename CHAR>
void DoParseUNC(const CHAR* spec,
int after_slashes,
int spec_len,
Parsed* parsed) {
int next_slash = FindNextSlash(spec, after_slashes, spec_len);
if (next_slash == spec_len) {
// No additional slash found, as in "file://foo", treat the text as the
// host with no path (this will end up being UNC to server "foo").
int host_len = spec_len - after_slashes;
if (host_len)
parsed->host = Component(after_slashes, host_len);
else
parsed->host.reset();
parsed->path.reset();
return;
}
#ifdef WIN32
// See if we have something that looks like a path following the first
// component. As in "file://localhost/c:/", we get "c:/" out. We want to
// treat this as a having no host but the path given. Works on Windows only.
if (DoesBeginWindowsDriveSpec(spec, next_slash + 1, spec_len)) {
parsed->host.reset();
ParsePathInternal(spec, MakeRange(next_slash, spec_len),
&parsed->path, &parsed->query, &parsed->ref);
return;
}
#endif
// Otherwise, everything up until that first slash we found is the host name,
// which will end up being the UNC host. For example "file://foo/bar.txt"
// will get a server name of "foo" and a path of "/bar". Later, on Windows,
// this should be treated as the filename "\\foo\bar.txt" in proper UNC
// notation.
int host_len = next_slash - after_slashes;
if (host_len)
parsed->host = MakeRange(after_slashes, next_slash);
else
parsed->host.reset();
if (next_slash < spec_len) {
ParsePathInternal(spec, MakeRange(next_slash, spec_len),
&parsed->path, &parsed->query, &parsed->ref);
} else {
parsed->path.reset();
}
}
// A subcomponent of DoParseFileURL, the input should be a local file, with the
// beginning of the path indicated by the index in |path_begin|. This will
// initialize the host, path, query, and ref, and leave the other output
// components untouched (DoInitFileURL handles these for us).
template<typename CHAR>
void DoParseLocalFile(const CHAR* spec,
int path_begin,
int spec_len,
Parsed* parsed) {
parsed->host.reset();
ParsePathInternal(spec, MakeRange(path_begin, spec_len),
&parsed->path, &parsed->query, &parsed->ref);
}
// Backend for the external functions that operates on either char type.
// Handles cases where there is a scheme, but also when handed the first
// character following the "file:" at the beginning of the spec. If so,
// this is usually a slash, but needn't be; we allow paths like "file:c:\foo".
template<typename CHAR>
void DoParseFileURL(const CHAR* spec, int spec_len, Parsed* parsed) {
DCHECK(spec_len >= 0);
// Get the parts we never use for file URLs out of the way.
parsed->username.reset();
parsed->password.reset();
parsed->port.reset();
// Many of the code paths don't set these, so it's convenient to just clear
// them. We'll write them in those cases we need them.
parsed->query.reset();
parsed->ref.reset();
// Strip leading & trailing spaces and control characters.
int begin = 0;
TrimURL(spec, &begin, &spec_len);
// Find the scheme, if any.
int num_slashes = CountConsecutiveSlashes(spec, begin, spec_len);
int after_scheme;
int after_slashes;
#ifdef WIN32
// See how many slashes there are. We want to handle cases like UNC but also
// "/c:/foo". This is when there is no scheme, so we can allow pages to do
// links like "c:/foo/bar" or "//foo/bar". This is also called by the
// relative URL resolver when it determines there is an absolute URL, which
// may give us input like "/c:/foo".
after_slashes = begin + num_slashes;
if (DoesBeginWindowsDriveSpec(spec, after_slashes, spec_len)) {
// Windows path, don't try to extract the scheme (for example, "c:\foo").
parsed->scheme.reset();
after_scheme = after_slashes;
} else if (DoesBeginUNCPath(spec, begin, spec_len, false)) {
// Windows UNC path: don't try to extract the scheme, but keep the slashes.
parsed->scheme.reset();
after_scheme = begin;
} else
#endif
{
// ExtractScheme doesn't understand the possibility of filenames with
// colons in them, in which case it returns the entire spec up to the
// colon as the scheme. So handle /foo.c:5 as a file but foo.c:5 as
// the foo.c: scheme.
if (!num_slashes &&
ExtractScheme(&spec[begin], spec_len - begin, &parsed->scheme)) {
// Offset the results since we gave ExtractScheme a substring.
parsed->scheme.begin += begin;
after_scheme = parsed->scheme.end() + 1;
} else {
// No scheme found, remember that.
parsed->scheme.reset();
after_scheme = begin;
}
}
// Handle empty specs ones that contain only whitespace or control chars,
// or that are just the scheme (for example "file:").
if (after_scheme == spec_len) {
parsed->host.reset();
parsed->path.reset();
return;
}
num_slashes = CountConsecutiveSlashes(spec, after_scheme, spec_len);
after_slashes = after_scheme + num_slashes;
#ifdef WIN32
// Check whether the input is a drive again. We checked above for windows
// drive specs, but that's only at the very beginning to see if we have a
// scheme at all. This test will be duplicated in that case, but will
// additionally handle all cases with a real scheme such as "file:///C:/".
if (!DoesBeginWindowsDriveSpec(spec, after_slashes, spec_len) &&
num_slashes != 3) {
// Anything not beginning with a drive spec ("c:\") on Windows is treated
// as UNC, with the exception of three slashes which always means a file.
// Even IE7 treats file:///foo/bar as "/foo/bar", which then fails.
DoParseUNC(spec, after_slashes, spec_len, parsed);
return;
}
#else
// file: URL with exactly 2 slashes is considered to have a host component.
if (num_slashes == 2) {
DoParseUNC(spec, after_slashes, spec_len, parsed);
return;
}
#endif // WIN32
// Easy and common case, the full path immediately follows the scheme
// (modulo slashes), as in "file://c:/foo". Just treat everything from
// there to the end as the path. Empty hosts have 0 length instead of -1.
// We include the last slash as part of the path if there is one.
DoParseLocalFile(spec,
num_slashes > 0 ? after_scheme + num_slashes - 1 : after_scheme,
spec_len, parsed);
}
} // namespace
void ParseFileURL(const char* url, int url_len, Parsed* parsed) {
DoParseFileURL(url, url_len, parsed);
}
void ParseFileURL(const base::char16* url, int url_len, Parsed* parsed) {
DoParseFileURL(url, url_len, parsed);
}
} // namespace url_parse