Support the Clear-Site-Data header on resource requests

content/browser/browsing_data/clear_site_data_throttle.cc

 // Copyright 2016 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 "content/browser/browsing_data/clear_site_data_throttle.h"
 
 #include "base/command_line.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_string_value_serializer.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/values.h"
-#include "content/browser/frame_host/navigation_handle_impl.h"
+#include "content/browser/service_worker/service_worker_response_info.h"
 #include "content/public/browser/browser_context.h"
+#include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
-#include "content/public/browser/navigation_handle.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/resource_controller.h"
+#include "content/public/browser/storage_partition.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/content_client.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/origin_util.h"
+#include "net/base/load_flags.h"
 #include "net/http/http_response_headers.h"
+#include "net/url_request/redirect_info.h"
 #include "url/gurl.h"
 #include "url/origin.h"
 
 namespace content {
 
 namespace {
 
+static const char* kNameForLogging = "ClearSiteDataThrottle";
+
 static const char* kClearSiteDataHeader = "Clear-Site-Data";
 
 static const char* kTypesKey = "types";
 
 // Pretty-printed log output.
 static const char* kConsoleMessagePrefix = "Clear-Site-Data header on '%s': %s";
 static const char* kClearingOneType = "Clearing %s.";
 static const char* kClearingTwoTypes = "Clearing %s and %s.";
 static const char* kClearingThreeTypes = "Clearing %s, %s, and %s.";
 
@@ skipping 10 matching lines @@
       switches::kEnableExperimentalWebPlatformFeatures);
 }
 
 // Represents the parameters as a single number to be recorded in a histogram.
 int ParametersMask(bool clear_cookies, bool clear_storage, bool clear_cache) {
   return static_cast<int>(clear_cookies) * (1 << 0) +
          static_cast<int>(clear_storage) * (1 << 1) +
          static_cast<int>(clear_cache) * (1 << 2);
 }
 
-}  // namespace
-
-// static
-std::unique_ptr<NavigationThrottle>
-ClearSiteDataThrottle::CreateThrottleForNavigation(NavigationHandle* handle) {
-  if (AreExperimentalFeaturesEnabled())
-    return base::WrapUnique(new ClearSiteDataThrottle(handle));
-
-  return std::unique_ptr<NavigationThrottle>();
+// A helper function to pass an IO thread callback to a method called on
+// the UI thread.
+void JumpFromUIToIOThread(const base::Closure& callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, callback);
 }
 
-ClearSiteDataThrottle::ClearSiteDataThrottle(
-    NavigationHandle* navigation_handle)
-    : NavigationThrottle(navigation_handle),
-      clearing_in_progress_(false),
-      weak_ptr_factory_(this) {}
+// Finds the BrowserContext associated with the request and requests
+// the actual clearing of data for |origin|. The datatypes to be deleted
+// are determined by |clear_cookies|, |clear_storage|, and |clear_cache|.
+// |web_contents_getter| identifies the WebContents from which the request
+// originated. Must be run on the UI thread. The |callback| will be executed
+// on the IO thread.
+void ClearSiteDataOnUIThread(
+    const ResourceRequestInfo::WebContentsGetter& web_contents_getter,
+    url::Origin origin,
+    bool clear_cookies,
+    bool clear_storage,
+    bool clear_cache,
+    const base::Closure& callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
-ClearSiteDataThrottle::~ClearSiteDataThrottle() {
-  // At the end of the navigation we finally have access to the correct
-  // RenderFrameHost. Output the cached console messages. Prefix each sequence
-  // of messages belonging to the same URL with |kConsoleMessagePrefix|.
+  WebContents* web_contents = web_contents_getter.Run();
+  if (!web_contents)
+    return;
+
+  BrowserContext* browser_context = web_contents->GetBrowserContext();
+
+  GetContentClient()->browser()->ClearSiteData(
+      browser_context, origin, clear_cookies, clear_storage, clear_cache,
+      base::Bind(&JumpFromUIToIOThread, callback));
+}
+
+// Outputs |messages| to the console of WebContents retrieved from
+// |web_contents_getter|. Must be run on the UI thread.
+void OutputConsoleMessagesOnUIThread(
+    const ResourceRequestInfo::WebContentsGetter& web_contents_getter,
+    const std::vector<ClearSiteDataThrottle::ConsoleMessage>& messages) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  WebContents* web_contents = web_contents_getter.Run();
+  if (!web_contents)
+    return;
+
   GURL last_seen_url;
-  for (const ConsoleMessage& message : messages_) {
+  for (const ClearSiteDataThrottle::ConsoleMessage& message : messages) {
     if (message.url == last_seen_url) {
-      navigation_handle()->GetRenderFrameHost()->AddMessageToConsole(
-          message.level, message.text);
+      web_contents->GetMainFrame()->AddMessageToConsole(message.level,
+                                                        message.text);
     } else {
-      navigation_handle()->GetRenderFrameHost()->AddMessageToConsole(
+      web_contents->GetMainFrame()->AddMessageToConsole(
           message.level,
           base::StringPrintf(kConsoleMessagePrefix, message.url.spec().c_str(),
                              message.text.c_str()));
     }
 
     last_seen_url = message.url;
   }
 }
 
-ClearSiteDataThrottle::ThrottleCheckResult
-ClearSiteDataThrottle::WillStartRequest() {
-  current_url_ = navigation_handle()->GetURL();
-  return PROCEED;
+}  // namespace
+
+// static
+std::unique_ptr<ResourceThrottle>
+ClearSiteDataThrottle::CreateThrottleForRequest(net::URLRequest* request) {
+  // This is an experimental feature.
+  if (!AreExperimentalFeaturesEnabled())
+    return std::unique_ptr<ResourceThrottle>();
+
+  // The LOAD_DO_NOT_SAVE_COOKIES flag prohibits the request from doing any
+  // modification to cookies.
+  std::unique_ptr<base::Value> value = request->GetStateAsValue();
+  const base::DictionaryValue* state;
+  DCHECK(value->GetAsDictionary(&state));
+  int load_flags = 0;
+  bool success =
+      state->GetIntegerWithoutPathExpansion("load_flags", &load_flags);
+  DCHECK(success);
+  if (load_flags & net::LOAD_DO_NOT_SAVE_COOKIES)
+    return std::unique_ptr<ResourceThrottle>();
+
+  // The throttle has no purpose if the request has no ResourceRequestInfo,
+  // because we won't be able to determine whose data should be deleted.
+  if (!ResourceRequestInfo::ForRequest(request))
+    return std::unique_ptr<ResourceThrottle>();
+
+  return base::WrapUnique(new ClearSiteDataThrottle(request));
 }
 
-ClearSiteDataThrottle::ThrottleCheckResult
-ClearSiteDataThrottle::WillRedirectRequest() {
+ClearSiteDataThrottle::ClearSiteDataThrottle(net::URLRequest* request)
+    : request_(request),
+      clearing_in_progress_(false),
+      weak_ptr_factory_(this) {}
+
+ClearSiteDataThrottle::~ClearSiteDataThrottle() {
+  // Output the cached console messages. Prefix each sequence of messages
+  // belonging to the same URL with |kConsoleMessagePrefix|. We output console
+  // messages when the request is finished rather than in real time, since in
+  // case of navigations swapping RenderFrameHost would cause the outputs to
+  // disappear.
+  if (messages_.empty())
+    return;
+
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(&OutputConsoleMessagesOnUIThread,
+                 ResourceRequestInfo::ForRequest(request_)
+                     ->GetWebContentsGetterForRequest(),
+                 std::move(messages_)));
+}
+
+void ClearSiteDataThrottle::WillStartRequest(bool* defer) {
+  current_url_ = request_->original_url();
+  *defer = false;
+}
+
+void ClearSiteDataThrottle::WillRedirectRequest(
+    const net::RedirectInfo& redirect_info,
+    bool* defer) {
   // We are processing a redirect from url1 to url2. GetResponseHeaders()
   // contains headers from url1, but GetURL() is already equal to url2. Handle
   // the headers before updating the URL, so that |current_url_| corresponds
   // to the URL that sent the headers.
   HandleHeader();
-  current_url_ = navigation_handle()->GetURL();
-
-  return clearing_in_progress_ ? DEFER : PROCEED;
+  current_url_ = redirect_info.new_url;
+  *defer = clearing_in_progress_;
 }
 
-ClearSiteDataThrottle::ThrottleCheckResult
-ClearSiteDataThrottle::WillProcessResponse() {
+void ClearSiteDataThrottle::WillProcessResponse(bool* defer) {
   HandleHeader();
-  return clearing_in_progress_ ? DEFER : PROCEED;
+  *defer = clearing_in_progress_;
+}
+
+const char* ClearSiteDataThrottle::GetNameForLogging() const {
+  return kNameForLogging;
 }
 
 void ClearSiteDataThrottle::HandleHeader() {
-  NavigationHandleImpl* handle =
-      static_cast<NavigationHandleImpl*>(navigation_handle());
-  const net::HttpResponseHeaders* headers = handle->GetResponseHeaders();
+  const net::HttpResponseHeaders* headers = request_->response_headers();
 
   if (!headers || !headers->HasHeader(kClearSiteDataHeader))
     return;
 
   // Only accept the header on secure origins.
   if (!IsOriginSecure(current_url_)) {
     ConsoleLog(&messages_, current_url_, "Not supported for insecure origins.",
                CONSOLE_MESSAGE_LEVEL_ERROR);
     return;
   }
 
+  // Service workers can handle fetches of third-party resources and inject
+  // arbitrary headers. Supporting Clear-Site-Data would give them the power
+  // to delete data from any website.
+  if (ServiceWorkerResponseInfo::ForRequest(request_)) {
+    ConsoleLog(&messages_, current_url_,
+               "Ignoring, as the response came from a service worker.",
+               CONSOLE_MESSAGE_LEVEL_ERROR);
+    return;
+  }
+
   std::string header_value;
   headers->GetNormalizedHeader(kClearSiteDataHeader, &header_value);
 
   bool clear_cookies;
   bool clear_storage;
   bool clear_cache;
 
   if (!ParseHeader(header_value, &clear_cookies, &clear_storage, &clear_cache,
                    &messages_)) {
     return;
   }
 
   // Record the call parameters.
   UMA_HISTOGRAM_ENUMERATION(
       "Navigation.ClearSiteData.Parameters",
       ParametersMask(clear_cookies, clear_storage, clear_cache), (1 << 3));
 
   // If the header is valid, clear the data for this browser context and origin.
-  BrowserContext* browser_context =
-      navigation_handle()->GetWebContents()->GetBrowserContext();
   url::Origin origin(current_url_);
-
   if (origin.unique()) {
     ConsoleLog(&messages_, current_url_, "Not supported for unique origins.",
                CONSOLE_MESSAGE_LEVEL_ERROR);
     return;
   }
 
   clearing_in_progress_ = true;
   clearing_started_ = base::TimeTicks::Now();
-  GetContentClient()->browser()->ClearSiteData(
-      browser_context, origin, clear_cookies, clear_storage, clear_cache,
-      base::Bind(&ClearSiteDataThrottle::TaskFinished,
-                 weak_ptr_factory_.GetWeakPtr()));
+
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(&ClearSiteDataOnUIThread,
+                 ResourceRequestInfo::ForRequest(request_)
+                     ->GetWebContentsGetterForRequest(),
+                 origin, clear_cookies, clear_storage, clear_cache,
+                 base::Bind(&ClearSiteDataThrottle::TaskFinished,
+                            weak_ptr_factory_.GetWeakPtr())));
 }
 
 bool ClearSiteDataThrottle::ParseHeader(const std::string& header,
                                         bool* clear_cookies,
                                         bool* clear_storage,
                                         bool* clear_cache,
                                         std::vector<ConsoleMessage>* messages) {
   if (!base::IsStringASCII(header)) {
     ConsoleLog(messages, current_url_, "Must only contain ASCII characters.",
                CONSOLE_MESSAGE_LEVEL_ERROR);
@@ skipping 80 matching lines @@
       break;
     default:
       NOTREACHED();
   }
   ConsoleLog(messages, current_url_, output, CONSOLE_MESSAGE_LEVEL_LOG);
 
   return true;
 }
 
 void ClearSiteDataThrottle::TaskFinished() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(clearing_in_progress_);
   clearing_in_progress_ = false;
 
   UMA_HISTOGRAM_CUSTOM_TIMES("Navigation.ClearSiteData.Duration",
                              base::TimeTicks::Now() - clearing_started_,
                              base::TimeDelta::FromMilliseconds(1),
                              base::TimeDelta::FromSeconds(1), 50);
 
-  navigation_handle()->Resume();
+  controller()->Resume();
 }
 
 }  // namespace content