Introducing the OffDomainInclusionDetector to analyze resource requests for suspicious activity.

chrome/browser/safe_browsing/incident_reporting/off_domain_inclusion_detector.cc

Index: chrome/browser/safe_browsing/incident_reporting/off_domain_inclusion_detector.cc
diff --git a/chrome/browser/safe_browsing/incident_reporting/off_domain_inclusion_detector.cc b/chrome/browser/safe_browsing/incident_reporting/off_domain_inclusion_detector.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e40d6a5ad9c25ad21c5aab5d12a14d4cf2a406ef
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+++ b/chrome/browser/safe_browsing/incident_reporting/off_domain_inclusion_detector.cc
@@ -0,0 +1,122 @@
+// 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.
+
+#include "chrome/browser/safe_browsing/incident_reporting/off_domain_inclusion_detector.h"
+
+#include <string>
+
+#include "base/metrics/histogram.h"
+#include "content/public/browser/resource_request_info.h"
+#include "net/base/registry_controlled_domains/registry_controlled_domain.h"
+#include "net/url_request/url_request.h"
+#include "url/gurl.h"
+
+namespace safe_browsing {
+
+OffDomainInclusionDetector::OffDomainInclusionDetector() {
+}
+
+OffDomainInclusionDetector::OffDomainInclusionDetector(
+    const ReportAnalysisEventCallback& report_analysis_event_callback)
+    : report_analysis_event_callback_(report_analysis_event_callback) {
+}
+
+OffDomainInclusionDetector::~OffDomainInclusionDetector() {
+}
+
+void OffDomainInclusionDetector::OnResourceRequest(
+    const net::URLRequest* request) {
+  // Only look at actual net requests (e.g., not chrome-extensions://id/foo.js).
+  if (!request->url().SchemeIsHTTPOrHTTPS())
+    return;
+
+  const content::ResourceRequestInfo* request_info =
+      content::ResourceRequestInfo::ForRequest(request);
+
+  const content::ResourceType resource_type = request_info->GetResourceType();
+
+  // Explicitly filter every resource type.
+  switch (resource_type) {
+    case content::RESOURCE_TYPE_MAIN_FRAME:
+      // Analyze inclusions in the main frame, not the main frame itself.
+      return;
+    case content::RESOURCE_TYPE_SUB_FRAME:
+      DCHECK(!request_info->IsMainFrame());
+      // Only analyze top-level frames within the main frame.
+      if (!request_info->ParentIsMainFrame())
+        return;
+      break;
+    case content::RESOURCE_TYPE_STYLESHEET:
+    case content::RESOURCE_TYPE_SCRIPT:
+    case content::RESOURCE_TYPE_IMAGE:
+    case content::RESOURCE_TYPE_FONT_RESOURCE:
+    case content::RESOURCE_TYPE_SUB_RESOURCE:
+    case content::RESOURCE_TYPE_OBJECT:
+    case content::RESOURCE_TYPE_MEDIA:
+    case content::RESOURCE_TYPE_XHR:
+      // Types above are to be analyzed for off-domain inclusion if they are
+      // loaded as part of the main frame.
+      if (!request_info->IsMainFrame())
+        return;
+      break;
+    case content::RESOURCE_TYPE_WORKER:
+    case content::RESOURCE_TYPE_SHARED_WORKER:
+    case content::RESOURCE_TYPE_PREFETCH:
+    case content::RESOURCE_TYPE_FAVICON:
+    case content::RESOURCE_TYPE_PING:
+    case content::RESOURCE_TYPE_SERVICE_WORKER:
+      // Types above are not to be analyzed for off-domain inclusion.
+      return;
+    case content::RESOURCE_TYPE_LAST_TYPE:
+      NOTREACHED();
+      return;
+  }
+
+  // Record the type of request analyzed to be able to do ratio analysis w.r.t
+  // other histograms below.
+  UMA_HISTOGRAM_ENUMERATION("SBOffDomainInclusion.RequestAnalyzed",
+                            resource_type,
+                            content::RESOURCE_TYPE_LAST_TYPE);
+
+  AnalysisEvent analysis_event = AnalysisEvent::NO_EVENT;
+
+  const GURL main_frame_url(request->referrer());
+  if (!main_frame_url.is_valid()) {
+    if (main_frame_url.is_empty()) {
+      // This can happen in a few scenarios where the referer is dropped (e.g.,
+      // HTTPS => HTTP requests). Consider adding the original referer to
+      // ResourceRequestInfo if that's an issue.
+      UMA_HISTOGRAM_ENUMERATION("SBOffDomainInclusion.EmptyMainFrameURL",
+                                resource_type,
+                                content::RESOURCE_TYPE_LAST_TYPE);
+      analysis_event = AnalysisEvent::EMPTY_MAIN_FRAME_URL;
+    } else {
+      // There is no reason for the main frame to start loading resources if its
+      // own URL is invalid but measure this in the wild to make sure.
+      UMA_HISTOGRAM_ENUMERATION("SBOffDomainInclusion.InvalidMainFrameURL",
+                                resource_type,
+                                content::RESOURCE_TYPE_LAST_TYPE);
+      analysis_event = AnalysisEvent::INVALID_MAIN_FRAME_URL;
+    }
+  } else {
+    const std::string main_frame_domain =
+        net::registry_controlled_domains::GetDomainAndRegistry(
+            main_frame_url,
+            net::registry_controlled_domains::INCLUDE_PRIVATE_REGISTRIES);
+
+    if (!request->url().DomainIs(main_frame_domain.c_str())) {
+      UMA_HISTOGRAM_ENUMERATION("SBOffDomainInclusion.Detected",
+                                resource_type,
+                                content::RESOURCE_TYPE_LAST_TYPE);
+      analysis_event = AnalysisEvent::OFF_DOMAIN_INCLUSION_DETECTED;
+    }
+  }
+
+  if (!report_analysis_event_callback_.is_null() &&
+      analysis_event != AnalysisEvent::NO_EVENT) {
+    report_analysis_event_callback_.Run(analysis_event);
+  }
+}
+
+}  // namespace safe_browsing