UMA data collector for cross-site documents(XSD)

content/child/site_isolation_policy.h

Index: content/child/site_isolation_policy.h
diff --git a/content/child/site_isolation_policy.h b/content/child/site_isolation_policy.h
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+// Copyright (c) 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.
+
+#ifndef CONTENT_CHILD_SITE_ISOLATION_POLICY_H_
+#define CONTENT_CHILD_SITE_ISOLATION_POLICY_H_
+
+#include <map>
+#include <utility>
+
+#include "base/gtest_prod_util.h"
+#include "content/common/content_export.h"
+#include "third_party/WebKit/public/platform/WebURLRequest.h"
+#include "third_party/WebKit/public/platform/WebURLResponse.h"
+#include "third_party/WebKit/public/web/WebFrame.h"
+#include "webkit/common/resource_response_info.h"
+#include "webkit/common/resource_type.h"
+
+namespace content {
+
+// SiteIsolationPolicy implements the cross-site document blocking policy (XSDP)
+// for Site Isolation. XSDP will monitor network responses to a renderer and
+// block illegal responses so that a compromised renderer cannot steal private
+// information from other sites. For now SiteIsolationPolicy monitors responses
+// to gather various UMA stats to see the compatibility impact of actual
+// deployment of the policy. The UMA stat categories SiteIsolationPolicy gathers
+// are as follows:
+//
+// SiteIsolation.AllResponses : # of all network responses.
+// SiteIsolation.XSD.DataLength : the length of the first packet of a response.
+// SiteIsolation.XSD.MimeType (enum):
+//   # of responses from other sites, tagged with a document mime type.
+//   0:HTML, 1:XML, 2:JSON, 3:Plain, 4:Others
+// SiteIsolation.XSD.[%MIMETYPE].Blocked :
+//   blocked # of cross-site document responses grouped by sniffed MIME type.
+// SiteIsolation.XSD.[%MIMETYPE].Blocked.RenderableStatusCode :
+//   # of responses with renderable status code,
+//   out of SiteIsolation.XSD.[%MIMETYPE].Blocked.
+// SiteIsolation.XSD.[%MIMETYPE].Blocked.NonRenderableStatusCode :
+//   # of responses with non-renderable status code,
+//   out of SiteIsolation.XSD.[%MIMETYPE].Blocked.
+// SiteIsolation.XSD.[%MIMETYPE].NoSniffBlocked.RenderableStatusCode :
+//   # of responses failed to be sniffed for its MIME type, but blocked by
+//   "X-Content-Type-Options: nosniff" header, and with renderable status code
+//   out of SiteIsolation.XSD.[%MIMETYPE].Blocked.
+// SiteIsolation.XSD.[%MIMETYPE].NoSniffBlocked.NonRenderableStatusCode :
+//   # of responses failed to be sniffed for its MIME type, but blocked by
+//   "X-Content-Type-Options: nosniff" header, and with non-renderable status
+//   code out of SiteIsolation.XSD.[%MIMETYPE].Blocked.
+// SiteIsolation.XSD.[%MIMETYPE].NotBlocked :
+//   # of responses, but not blocked due to failure of mime sniffing.
+// SiteIsolation.XSD.[%MIMETYPE].NotBlocked.MaybeJS :
+//   # of responses that are plausibly sniffed to be JavaScript.
+
+class CONTENT_EXPORT SiteIsolationPolicy {
+ public:
+
+  // Records the bookkeeping data about the HTTP header information for the
+  // request identified by |request_id|. The bookkeeping data is used by
+  // ShouldBlockResponse. We have to make sure to call OnRequestComplete to free
+  // the bookkeeping data.
+  static void OnReceivedResponse(int request_id,
+                                 GURL& frame_origin,
+                                 GURL& response_url,
+                                 ResourceType::Type resource_type,
+                                 const webkit_glue::ResourceResponseInfo& info);
+
+  // Examines the first network packet in case response_url is registered as a
+  // cross-site document by DidReceiveResponse().  In case that this response is
+  // blocked, it returns an alternative data to be sent to the renderer in
+  // |alternative_data|. This records various kinds of UMA data stats. This
+  // function is called only if the length of received data is non-zero.
+  static bool ShouldBlockResponse(int request_id,
+                                  const char* payload,
+                                  int length,
+                                  std::string* alternative_data);
+
+  // Clean up booking data registered by OnReceiveResponse and OnReceivedData.
+  static void OnRequestComplete(int request_id);
+
+  struct ResponseMetaData {

[awong, 2013/08/26 20:31:41]

Is there a reason for these types to be public?

For that matter...for each of the private functions, unless you need to expose
it for testing, can they made to be file-local to the implementation?

+
+    enum CanonicalMimeType {
+      HTML = 0,
+      XML = 1,
+      JSON = 2,
+      Plain = 3,
+      Others = 4,
+      MaxCanonicalMimeType,
+    };
+
+    ResponseMetaData();
+
+    std::string frame_origin;
+    GURL response_url;
+    ResourceType::Type resource_type;
+    CanonicalMimeType canonical_mime_type;
+    int http_status_code;
+    bool no_sniff;
+  };
+
+  typedef std::map<int, ResponseMetaData> RequestIdToMetaDataMap;
+  typedef std::map<int, bool> RequestIdToResultMap;
+
+private:
+  FRIEND_TEST_ALL_PREFIXES(SiteIsolationPolicyTest, IsBlockableScheme);
+  FRIEND_TEST_ALL_PREFIXES(SiteIsolationPolicyTest, IsSameSite);
+  FRIEND_TEST_ALL_PREFIXES(SiteIsolationPolicyTest, IsValidCorsHeaderSet);
+  FRIEND_TEST_ALL_PREFIXES(SiteIsolationPolicyTest, SniffForHTML);
+  FRIEND_TEST_ALL_PREFIXES(SiteIsolationPolicyTest, SniffForXML);
+  FRIEND_TEST_ALL_PREFIXES(SiteIsolationPolicyTest, SniffForJSON);
+  FRIEND_TEST_ALL_PREFIXES(SiteIsolationPolicyTest, SniffForJS);
+
+  // Returns the representative mime type enum value of the mime type of
+  // response. For example, this returns the same value for all text/xml mime
+  // type families such as application/xml, application/rss+xml.
+  static ResponseMetaData::CanonicalMimeType GetCanonicalMimeType(
+      const std::string& mime_type);
+
+  // Returns whether this scheme is a target of cross-site document
+  // policy(XSDP). This returns true only for http://* and https://* urls.
+  static bool IsBlockableScheme(const GURL& frame_origin);
+
+  // Returns whether the two urls belong to the same sites.
+  static bool IsSameSite(const GURL& frame_origin, const GURL& response_url);
+
+  // Returns whether there's a valid CORS header for frame_origin.  This is
+  // simliar to CrossOriginAccessControl::passesAccessControlCheck(), but we use
+  // sites as our security domain, not origins.
+  // TODO(dsjang): this must be improved to be more accurate to the actual CORS
+  // specification. For now, this works conservatively, allowing XSDs that are
+  // not allowed by actual CORS rules by ignoring 1) credentials and 2)
+  // methods. Preflight requests don't matter here since they are not used to
+  // decide whether to block a document or not on the client side.
+  static bool IsValidCorsHeaderSet(GURL& frame_origin,
+                                   GURL& website_origin,
+                                   std::string access_control_origin);
+
+  // Returns whether the given frame is navigating. When this is true, the frame
+  // is requesting is a web page to be loaded.
+  static bool IsFrameNavigating(WebKit::WebFrame* frame);
+
+  static bool SniffForHTML(const char* data, size_t length);
+  static bool SniffForXML(const char* data, size_t length);
+  static bool SniffForJSON(const char* data, size_t length);
+
+  static bool MatchesSignature(const char* data,
+                               size_t length,
+                               const char* signatures[],
+                               size_t arr_size);
+
+  // TODO(dsjang): this is only needed for collecting UMA stat. Will be deleted
+  // when this class is used for actual blocking.
+  static bool SniffForJS(const char* data, size_t length);
+
+  // TODO(dsjang): this is only needed for collecting UMA stat. Will be deleted
+  // when this class is used for actual blocking.
+  static bool IsRenderableStatusCodeForDocument(int status_code);
+
+  // Maintain the bookkeeping data between OnReceivedResponse and
+  // OnReceivedData. The key is a request id maintained by ResourceDispatcher.
+  static RequestIdToMetaDataMap* GetRequestIdToMetaDataMap();
+
+  // Maintain the bookkeeping data for OnReceivedData. Blocking decision is made
+  // when OnReceivedData is called for the first time for a request, and the
+  // decision will remain the same for following data. This map maintains the
+  // decision. The key is a request id maintained by ResourceDispatcher.
+  static RequestIdToResultMap* GetRequestIdToResultMap();
+
+  // Never needs to be constructed/destructed.
+  SiteIsolationPolicy() {}
+  ~SiteIsolationPolicy() {}
+
+  DISALLOW_COPY_AND_ASSIGN(SiteIsolationPolicy);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_CHILD_SITE_ISOLATION_POLICY_H_