// Copyright 2014 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.
//
// This is a port of ManifestParser.cc from WebKit/WebCore/loader/appcache.
/*
* Copyright (C) 2008 Apple Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "content/browser/appcache/appcache_manifest_parser.h"
#include "base/command_line.h"
#include "base/i18n/icu_string_conversions.h"
#include "base/logging.h"
#include "base/strings/utf_string_conversions.h"
#include "url/gurl.h"
namespace content {
namespace {
// Helper function used to identify 'isPattern' annotations.
bool HasPatternMatchingAnnotation(const wchar_t* line_p,
const wchar_t* line_end) {
// Skip whitespace separating the resource url from the annotation.
// Note: trailing whitespace has already been trimmed from the line.
while (line_p < line_end && (*line_p == '\t' || *line_p == ' '))
++line_p;
if (line_p == line_end)
return false;
std::wstring annotation(line_p, line_end - line_p);
return annotation == L"isPattern";
}
}
enum Mode {
EXPLICIT,
INTERCEPT,
FALLBACK,
ONLINE_WHITELIST,
UNKNOWN_MODE,
};
enum InterceptVerb {
RETURN,
EXECUTE,
UNKNOWN_VERB,
};
AppCacheManifest::AppCacheManifest()
: online_whitelist_all(false),
did_ignore_intercept_namespaces(false) {
}
AppCacheManifest::~AppCacheManifest() {}
bool ParseManifest(const GURL& manifest_url, const char* data, int length,
ParseMode parse_mode, AppCacheManifest& manifest) {
// This is an implementation of the parsing algorithm specified in
// the HTML5 offline web application docs:
// http://www.w3.org/TR/html5/offline.html
// Do not modify it without consulting those docs.
// Though you might be tempted to convert these wstrings to UTF-8 or
// base::string16, this implementation seems simpler given the constraints.
const wchar_t kSignature[] = L"CACHE MANIFEST";
const size_t kSignatureLength = arraysize(kSignature) - 1;
const wchar_t kChromiumSignature[] = L"CHROMIUM CACHE MANIFEST";
const size_t kChromiumSignatureLength = arraysize(kChromiumSignature) - 1;
DCHECK(manifest.explicit_urls.empty());
DCHECK(manifest.fallback_namespaces.empty());
DCHECK(manifest.online_whitelist_namespaces.empty());
DCHECK(!manifest.online_whitelist_all);
DCHECK(!manifest.did_ignore_intercept_namespaces);
Mode mode = EXPLICIT;
std::wstring data_string;
// TODO(jennb): cannot do UTF8ToWide(data, length, &data_string);
// until UTF8ToWide uses 0xFFFD Unicode replacement character.
base::CodepageToWide(std::string(data, length), base::kCodepageUTF8,
base::OnStringConversionError::SUBSTITUTE, &data_string);
const wchar_t* p = data_string.c_str();
const wchar_t* end = p + data_string.length();
// Look for the magic signature: "^\xFEFF?CACHE MANIFEST[ \t]?"
// Example: "CACHE MANIFEST #comment" is a valid signature.
// Example: "CACHE MANIFEST;V2" is not.
// When the input data starts with a UTF-8 Byte-Order-Mark
// (0xEF, 0xBB, 0xBF), the UTF8ToWide() function converts it to a
// Unicode BOM (U+FEFF). Skip a converted Unicode BOM if it exists.
int bom_offset = 0;
if (!data_string.empty() && data_string[0] == 0xFEFF) {
bom_offset = 1;
++p;
}
if (p >= end)
return false;
// Check for a supported signature and skip p past it.
if (0 == data_string.compare(bom_offset, kSignatureLength,
kSignature)) {
p += kSignatureLength;
} else if (0 == data_string.compare(bom_offset, kChromiumSignatureLength,
kChromiumSignature)) {
p += kChromiumSignatureLength;
} else {
return false;
}
// Character after "CACHE MANIFEST" must be whitespace.
if (p < end && *p != ' ' && *p != '\t' && *p != '\n' && *p != '\r')
return false;
// Skip to the end of the line.
while (p < end && *p != '\r' && *p != '\n')
++p;
while (1) {
// Skip whitespace
while (p < end && (*p == '\n' || *p == '\r' || *p == ' ' || *p == '\t'))
++p;
if (p == end)
break;
const wchar_t* line_start = p;
// Find the end of the line
while (p < end && *p != '\r' && *p != '\n')
++p;
// Check if we have a comment
if (*line_start == '#')
continue;
// Get rid of trailing whitespace
const wchar_t* tmp = p - 1;
while (tmp > line_start && (*tmp == ' ' || *tmp == '\t'))
--tmp;
std::wstring line(line_start, tmp - line_start + 1);
if (line == L"CACHE:") {
mode = EXPLICIT;
} else if (line == L"FALLBACK:") {
mode = FALLBACK;
} else if (line == L"NETWORK:") {
mode = ONLINE_WHITELIST;
} else if (line == L"CHROMIUM-INTERCEPT:") {
mode = INTERCEPT;
} else if (*(line.end() - 1) == ':') {
mode = UNKNOWN_MODE;
} else if (mode == UNKNOWN_MODE) {
continue;
} else if (line == L"*" && mode == ONLINE_WHITELIST) {
manifest.online_whitelist_all = true;
continue;
} else if (mode == EXPLICIT || mode == ONLINE_WHITELIST) {
const wchar_t *line_p = line.c_str();
const wchar_t *line_end = line_p + line.length();
// Look for whitespace separating the URL from subsequent ignored tokens.
while (line_p < line_end && *line_p != '\t' && *line_p != ' ')
++line_p;
base::string16 url16;
base::WideToUTF16(line.c_str(), line_p - line.c_str(), &url16);
GURL url = manifest_url.Resolve(url16);
if (!url.is_valid())
continue;
if (url.has_ref()) {
GURL::Replacements replacements;
replacements.ClearRef();
url = url.ReplaceComponents(replacements);
}
// Scheme component must be the same as the manifest URL's.
if (url.scheme() != manifest_url.scheme()) {
continue;
}
// See http://code.google.com/p/chromium/issues/detail?id=69594
// We willfully violate the HTML5 spec at this point in order
// to support the appcaching of cross-origin HTTPS resources.
// Per the spec, EXPLICIT cross-origin HTTS resources should be
// ignored here. We've opted for a milder constraint and allow
// caching unless the resource has a "no-store" header. That
// condition is enforced in AppCacheUpdateJob.
if (mode == EXPLICIT) {
manifest.explicit_urls.insert(url.spec());
} else {
bool is_pattern = HasPatternMatchingAnnotation(line_p, line_end);
manifest.online_whitelist_namespaces.push_back(
AppCacheNamespace(APPCACHE_NETWORK_NAMESPACE, url, GURL(),
is_pattern));
}
} else if (mode == INTERCEPT) {
if (parse_mode != PARSE_MANIFEST_ALLOWING_INTERCEPTS) {
manifest.did_ignore_intercept_namespaces = true;
continue;
}
// Lines of the form,
// <urlnamespace> <intercept_type> <targeturl>
const wchar_t* line_p = line.c_str();
const wchar_t* line_end = line_p + line.length();
// Look for first whitespace separating the url namespace from
// the intercept type.
while (line_p < line_end && *line_p != '\t' && *line_p != ' ')
++line_p;
if (line_p == line_end)
continue; // There was no whitespace separating the URLs.
base::string16 namespace_url16;
base::WideToUTF16(line.c_str(), line_p - line.c_str(), &namespace_url16);
GURL namespace_url = manifest_url.Resolve(namespace_url16);
if (!namespace_url.is_valid())
continue;
if (namespace_url.has_ref()) {
GURL::Replacements replacements;
replacements.ClearRef();
namespace_url = namespace_url.ReplaceComponents(replacements);
}
// The namespace URL must have the same scheme, host and port
// as the manifest's URL.
if (manifest_url.GetOrigin() != namespace_url.GetOrigin())
continue;
// Skip whitespace separating namespace from the type.
while (line_p < line_end && (*line_p == '\t' || *line_p == ' '))
++line_p;
// Look for whitespace separating the type from the target url.
const wchar_t* type_start = line_p;
while (line_p < line_end && *line_p != '\t' && *line_p != ' ')
++line_p;
// Look for a type value we understand, otherwise skip the line.
InterceptVerb verb = UNKNOWN_VERB;
std::wstring type(type_start, line_p - type_start);
if (type == L"return") {
verb = RETURN;
} else if (type == L"execute" &&
base::CommandLine::ForCurrentProcess()->HasSwitch(
kEnableExecutableHandlers)) {
verb = EXECUTE;
}
if (verb == UNKNOWN_VERB)
continue;
// Skip whitespace separating type from the target_url.
while (line_p < line_end && (*line_p == '\t' || *line_p == ' '))
++line_p;
// Look for whitespace separating the URL from subsequent ignored tokens.
const wchar_t* target_url_start = line_p;
while (line_p < line_end && *line_p != '\t' && *line_p != ' ')
++line_p;
base::string16 target_url16;
base::WideToUTF16(target_url_start, line_p - target_url_start,
&target_url16);
GURL target_url = manifest_url.Resolve(target_url16);
if (!target_url.is_valid())
continue;
if (target_url.has_ref()) {
GURL::Replacements replacements;
replacements.ClearRef();
target_url = target_url.ReplaceComponents(replacements);
}
if (manifest_url.GetOrigin() != target_url.GetOrigin())
continue;
bool is_pattern = HasPatternMatchingAnnotation(line_p, line_end);
manifest.intercept_namespaces.push_back(
AppCacheNamespace(APPCACHE_INTERCEPT_NAMESPACE, namespace_url,
target_url, is_pattern, verb == EXECUTE));
} else if (mode == FALLBACK) {
const wchar_t* line_p = line.c_str();
const wchar_t* line_end = line_p + line.length();
// Look for whitespace separating the two URLs
while (line_p < line_end && *line_p != '\t' && *line_p != ' ')
++line_p;
if (line_p == line_end) {
// There was no whitespace separating the URLs.
continue;
}
base::string16 namespace_url16;
base::WideToUTF16(line.c_str(), line_p - line.c_str(), &namespace_url16);
GURL namespace_url = manifest_url.Resolve(namespace_url16);
if (!namespace_url.is_valid())
continue;
if (namespace_url.has_ref()) {
GURL::Replacements replacements;
replacements.ClearRef();
namespace_url = namespace_url.ReplaceComponents(replacements);
}
// Fallback namespace URL must have the same scheme, host and port
// as the manifest's URL.
if (manifest_url.GetOrigin() != namespace_url.GetOrigin()) {
continue;
}
// Skip whitespace separating fallback namespace from URL.
while (line_p < line_end && (*line_p == '\t' || *line_p == ' '))
++line_p;
// Look for whitespace separating the URL from subsequent ignored tokens.
const wchar_t* fallback_start = line_p;
while (line_p < line_end && *line_p != '\t' && *line_p != ' ')
++line_p;
base::string16 fallback_url16;
base::WideToUTF16(fallback_start, line_p - fallback_start,
&fallback_url16);
GURL fallback_url = manifest_url.Resolve(fallback_url16);
if (!fallback_url.is_valid())
continue;
if (fallback_url.has_ref()) {
GURL::Replacements replacements;
replacements.ClearRef();
fallback_url = fallback_url.ReplaceComponents(replacements);
}
// Fallback entry URL must have the same scheme, host and port
// as the manifest's URL.
if (manifest_url.GetOrigin() != fallback_url.GetOrigin()) {
continue;
}
bool is_pattern = HasPatternMatchingAnnotation(line_p, line_end);
// Store regardless of duplicate namespace URL. Only first match
// will ever be used.
manifest.fallback_namespaces.push_back(
AppCacheNamespace(APPCACHE_FALLBACK_NAMESPACE, namespace_url,
fallback_url, is_pattern));
} else {
NOTREACHED();
}
}
return true;
}
} // namespace content