[Patch 5 of 6] Split out the site_isolation_policy files

content/child/site_isolation_stats_gatherer.cc

Index: content/child/site_isolation_stats_gatherer.cc
diff --git a/content/child/site_isolation_policy.cc b/content/child/site_isolation_stats_gatherer.cc
similarity index 52%
copy from content/child/site_isolation_policy.cc
copy to content/child/site_isolation_stats_gatherer.cc
index 0f9fc61ff26f93dd0be8b1c4f1587218d6d0273c..c91847984db7f3e4a629f93de197f558416f63af 100644
--- a/content/child/site_isolation_policy.cc
+++ b/content/child/site_isolation_stats_gatherer.cc
@@ -1,22 +1,15 @@
-// Copyright 2013 The Chromium Authors. All rights reserved.
+// Copyright 2015 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/child/site_isolation_policy.h"
+#include "content/child/site_isolation_stats_gatherer.h"
 
-#include "base/basictypes.h"
-#include "base/command_line.h"
-#include "base/lazy_instance.h"
-#include "base/logging.h"
 #include "base/metrics/histogram.h"
+#include "base/strings/string_piece.h"
 #include "base/strings/string_util.h"
-#include "content/public/common/content_switches.h"
 #include "content/public/common/resource_response_info.h"
-#include "net/base/registry_controlled_domains/registry_controlled_domain.h"
 #include "net/http/http_response_headers.h"
 
-using base::StringPiece;
-
 namespace content {
 
 namespace {
@@ -25,18 +18,6 @@ namespace {
 // only activated in renderer processes.
 static bool g_stats_gathering_enabled = false;
 
-// MIME types
-const char kTextHtml[] = "text/html";
-const char kTextXml[] = "text/xml";
-const char xAppRssXml[] = "application/rss+xml";
-const char kAppXml[] = "application/xml";
-const char kAppJson[] = "application/json";
-const char kTextJson[] = "text/json";
-const char kTextXjson[] = "text/x-json";
-const char kTextPlain[] = "text/plain";
-
-// TODO(dsjang): this is only needed for collecting UMA stat. Will be deleted
-// when this class is used for actual blocking.
 bool IsRenderableStatusCode(int status_code) {
   // Chrome only uses the content of a response with one of these status codes
   // for CSS/JavaScript. For images, Chrome just ignores status code.
@@ -49,30 +30,6 @@ bool IsRenderableStatusCode(int status_code) {
   return false;
 }
 
-bool MatchesSignature(StringPiece data,
-                      const StringPiece signatures[],
-                      size_t arr_size) {
-  size_t offset = data.find_first_not_of(" \t\r\n");
-  // There is no not-whitespace character in this document.
-  if (offset == base::StringPiece::npos)
-    return false;
-
-  data.remove_prefix(offset);
-  size_t length = data.length();
-
-  for (size_t sig_index = 0; sig_index < arr_size; ++sig_index) {
-    const StringPiece& signature = signatures[sig_index];
-    size_t signature_length = signature.length();
-    if (length < signature_length)
-      continue;
-
-    if (LowerCaseEqualsASCII(data.begin(), data.begin() + signature_length,
-                             signature.data()))
-      return true;
-  }
-  return false;
-}
-
 void IncrementHistogramCount(const std::string& name) {
   // The default value of min, max, bucket_count are copied from histogram.h.
   base::HistogramBase* histogram_pointer = base::Histogram::FactoryGet(
@@ -210,7 +167,7 @@ bool SiteIsolationStatsGatherer::OnReceivedFirstChunk(
 
   DCHECK(resp_data.get());
 
-  StringPiece data(raw_data, raw_length);
+  base::StringPiece data(raw_data, raw_length);
 
   // Record the length of the first received chunk of data to see if it's enough
   // for sniffing.
@@ -290,200 +247,7 @@ bool SiteIsolationStatsGatherer::OnReceivedFirstChunk(
   return would_block;
 }
 
-CrossSiteDocumentMimeType CrossSiteDocumentClassifier::GetCanonicalMimeType(
-    const std::string& mime_type) {
-  if (LowerCaseEqualsASCII(mime_type, kTextHtml)) {
-    return CROSS_SITE_DOCUMENT_MIME_TYPE_HTML;
-  }
-
-  if (LowerCaseEqualsASCII(mime_type, kTextPlain)) {
-    return CROSS_SITE_DOCUMENT_MIME_TYPE_PLAIN;
-  }
-
-  if (LowerCaseEqualsASCII(mime_type, kAppJson) ||
-      LowerCaseEqualsASCII(mime_type, kTextJson) ||
-      LowerCaseEqualsASCII(mime_type, kTextXjson)) {
-    return CROSS_SITE_DOCUMENT_MIME_TYPE_JSON;
-  }
-
-  if (LowerCaseEqualsASCII(mime_type, kTextXml) ||
-      LowerCaseEqualsASCII(mime_type, xAppRssXml) ||
-      LowerCaseEqualsASCII(mime_type, kAppXml)) {
-    return CROSS_SITE_DOCUMENT_MIME_TYPE_XML;
-  }
-
-  return CROSS_SITE_DOCUMENT_MIME_TYPE_OTHERS;
-}
-
-bool CrossSiteDocumentClassifier::IsBlockableScheme(const GURL& url) {
-  // We exclude ftp:// from here. FTP doesn't provide a Content-Type
-  // header which our policy depends on, so we cannot protect any
-  // document from FTP servers.
-  return url.SchemeIs(url::kHttpScheme) || url.SchemeIs(url::kHttpsScheme);
-}
-
-bool CrossSiteDocumentClassifier::IsSameSite(const GURL& frame_origin,
-                                             const GURL& response_url) {
-  if (!frame_origin.is_valid() || !response_url.is_valid())
-    return false;
-
-  if (frame_origin.scheme() != response_url.scheme())
-    return false;
-
-  // SameDomainOrHost() extracts the effective domains (public suffix plus one)
-  // from the two URLs and compare them.
-  return net::registry_controlled_domains::SameDomainOrHost(
-      frame_origin, response_url,
-      net::registry_controlled_domains::INCLUDE_PRIVATE_REGISTRIES);
-}
-
-// We don't use Webkit's existing CORS policy implementation since
-// their policy works in terms of origins, not sites. For example,
-// when frame is sub.a.com and it is not allowed to access a document
-// with sub1.a.com. But under Site Isolation, it's allowed.
-bool CrossSiteDocumentClassifier::IsValidCorsHeaderSet(
-    const GURL& frame_origin,
-    const GURL& website_origin,
-    const std::string& access_control_origin) {
-  // Many websites are sending back "\"*\"" instead of "*". This is
-  // non-standard practice, and not supported by Chrome. Refer to
-  // CrossOriginAccessControl::passesAccessControlCheck().
-
-  // TODO(dsjang): * is not allowed for the response from a request
-  // with cookies. This allows for more than what the renderer will
-  // eventually be able to receive, so we won't see illegal cross-site
-  // documents allowed by this. We have to find a way to see if this
-  // response is from a cookie-tagged request or not in the future.
-  if (access_control_origin == "*")
-    return true;
-
-  // TODO(dsjang): The CORS spec only treats a fully specified URL, except for
-  // "*", but many websites are using just a domain for access_control_origin,
-  // and this is blocked by Webkit's CORS logic here :
-  // CrossOriginAccessControl::passesAccessControlCheck(). GURL is set
-  // is_valid() to false when it is created from a URL containing * in the
-  // domain part.
-
-  GURL cors_origin(access_control_origin);
-  return IsSameSite(frame_origin, cors_origin);
-}
-
-// This function is a slight modification of |net::SniffForHTML|.
-bool CrossSiteDocumentClassifier::SniffForHTML(StringPiece data) {
-  // The content sniffer used by Chrome and Firefox are using "<!--"
-  // as one of the HTML signatures, but it also appears in valid
-  // JavaScript, considered as well-formed JS by the browser.  Since
-  // we do not want to block any JS, we exclude it from our HTML
-  // signatures. This can weaken our document block policy, but we can
-  // break less websites.
-  // TODO(dsjang): parameterize |net::SniffForHTML| with an option
-  // that decides whether to include <!-- or not, so that we can
-  // remove this function.
-  // TODO(dsjang): Once CrossSiteDocumentClassifier is moved into the browser
-  // process, we should do single-thread checking here for the static
-  // initializer.
-  static const StringPiece kHtmlSignatures[] = {
-      StringPiece("<!DOCTYPE html"),  // HTML5 spec
-      StringPiece("<script"),         // HTML5 spec, Mozilla
-      StringPiece("<html"),           // HTML5 spec, Mozilla
-      StringPiece("<head"),           // HTML5 spec, Mozilla
-      StringPiece("<iframe"),         // Mozilla
-      StringPiece("<h1"),             // Mozilla
-      StringPiece("<div"),            // Mozilla
-      StringPiece("<font"),           // Mozilla
-      StringPiece("<table"),          // Mozilla
-      StringPiece("<a"),              // Mozilla
-      StringPiece("<style"),          // Mozilla
-      StringPiece("<title"),          // Mozilla
-      StringPiece("<b"),              // Mozilla
-      StringPiece("<body"),           // Mozilla
-      StringPiece("<br"),             // Mozilla
-      StringPiece("<p"),              // Mozilla
-      StringPiece("<?xml")            // Mozilla
-  };
-
-  while (data.length() > 0) {
-    if (MatchesSignature(data, kHtmlSignatures, arraysize(kHtmlSignatures)))
-      return true;
-
-    // If we cannot find "<!--", we fail sniffing this as HTML.
-    static const StringPiece kCommentBegins[] = {StringPiece("<!--")};
-    if (!MatchesSignature(data, kCommentBegins, arraysize(kCommentBegins)))
-      break;
-
-    // Search for --> and do SniffForHTML after that. If we can find the
-    // comment's end, we start HTML sniffing from there again.
-    static const char kEndComment[] = "-->";
-    size_t offset = data.find(kEndComment);
-    if (offset == base::StringPiece::npos)
-      break;
-
-    // Proceed to the index next to the ending comment (-->).
-    data.remove_prefix(offset + strlen(kEndComment));
-  }
-
-  return false;
-}
-
-bool CrossSiteDocumentClassifier::SniffForXML(base::StringPiece data) {
-  // TODO(dsjang): Chrome's mime_sniffer is using strncasecmp() for
-  // this signature. However, XML is case-sensitive. Don't we have to
-  // be more lenient only to block documents starting with the exact
-  // string <?xml rather than <?XML ?
-  // TODO(dsjang): Once CrossSiteDocumentClassifier is moved into the browser
-  // process, we should do single-thread checking here for the static
-  // initializer.
-  static const StringPiece kXmlSignatures[] = {StringPiece("<?xml")};
-  return MatchesSignature(data, kXmlSignatures, arraysize(kXmlSignatures));
-}
-
-bool CrossSiteDocumentClassifier::SniffForJSON(base::StringPiece data) {
-  // TODO(dsjang): We have to come up with a better way to sniff
-  // JSON. However, even RE cannot help us that much due to the fact
-  // that we don't do full parsing.  This DFA starts with state 0, and
-  // finds {, "/' and : in that order. We're avoiding adding a
-  // dependency on a regular expression library.
-  enum {
-    kStartState,
-    kLeftBraceState,
-    kLeftQuoteState,
-    kColonState,
-    kTerminalState,
-  } state = kStartState;
-
-  size_t length = data.length();
-  for (size_t i = 0; i < length && state < kColonState; ++i) {
-    const char c = data[i];
-    if (c == ' ' || c == '\t' || c == '\r' || c == '\n')
-      continue;
-
-    switch (state) {
-      case kStartState:
-        if (c == '{')
-          state = kLeftBraceState;
-        else
-          state = kTerminalState;
-        break;
-      case kLeftBraceState:
-        if (c == '\"' || c == '\'')
-          state = kLeftQuoteState;
-        else
-          state = kTerminalState;
-        break;
-      case kLeftQuoteState:
-        if (c == ':')
-          state = kColonState;
-        break;
-      case kColonState:
-      case kTerminalState:
-        NOTREACHED();
-        break;
-    }
-  }
-  return state == kColonState;
-}
-
-bool SiteIsolationStatsGatherer::SniffForJS(StringPiece data) {
+bool SiteIsolationStatsGatherer::SniffForJS(base::StringPiece data) {
   // The purpose of this function is to try to see if there's any possibility
   // that this data can be JavaScript (superset of JS). Search for "var " for JS
   // detection. This is a real hack and should only be used for stats gathering.