[Downloads] Consolidate MOTW annotation APIs into a single API.

content/browser/download/base_file.cc

 // Copyright (c) 2012 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/download/base_file.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/files/file.h"
 #include "base/files/file_util.h"
 #include "base/format_macros.h"
 #include "base/logging.h"
 #include "base/pickle.h"
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread_restrictions.h"
 #include "build/build_config.h"
 #include "content/browser/download/download_interrupt_reasons_impl.h"
 #include "content/browser/download/download_net_log_parameters.h"
 #include "content/browser/download/download_stats.h"
+#include "content/browser/download/quarantine.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
 #include "crypto/secure_hash.h"
 #include "net/base/net_errors.h"
 #include "net/log/net_log.h"
 #include "net/log/net_log_event_type.h"
 
 namespace content {
 
 BaseFile::BaseFile(const net::BoundNetLog& bound_net_log)
@@ skipping 155 matching lines @@
 
   Detach();
 }
 
 std::unique_ptr<crypto::SecureHash> BaseFile::Finish() {
   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
   Close();
   return std::move(secure_hash_);
 }
 
-// OS_WIN, OS_MACOSX and OS_LINUX have specialized implementations.
-#if !defined(OS_WIN) && !defined(OS_MACOSX) && !defined(OS_LINUX)
-DownloadInterruptReason BaseFile::AnnotateWithSourceInformation(
-    const std::string& client_guid,
-    const GURL& source_url,
-    const GURL& referrer_url) {
-  return DOWNLOAD_INTERRUPT_REASON_NONE;
-}
-#endif
-
 std::string BaseFile::DebugString() const {
   return base::StringPrintf(
       "{ "
       " full_path_ = \"%" PRFilePath
       "\""
       " bytes_so_far_ = %" PRId64 " detached_ = %c }",
       full_path_.value().c_str(),
       bytes_so_far_,
       detached_ ? 'T' : 'F');
 }
@@ skipping 161 matching lines @@
     DownloadInterruptReason reason) {
   DVLOG(1) << __func__ << "() operation:" << operation
            << " os_error:" << os_error
            << " reason:" << DownloadInterruptReasonToString(reason);
   bound_net_log_.AddEvent(
       net::NetLogEventType::DOWNLOAD_FILE_ERROR,
       base::Bind(&FileInterruptedNetLogCallback, operation, os_error, reason));
   return reason;
 }
 
+#if defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX)
+DownloadInterruptReason BaseFile::AnnotateWithSourceInformation(
+    const std::string& client_guid,
+    const GURL& source_url,
+    const GURL& referrer_url) {
+  DCHECK_CURRENTLY_ON(BrowserThread::FILE);
+  DCHECK(!detached_);
+  DCHECK(!full_path_.empty());
+
+  bound_net_log_.BeginEvent(net::NetLogEventType::DOWNLOAD_FILE_ANNOTATED);
+  QuarantineFileResult result =
+      QuarantineFile(full_path_, source_url, referrer_url, client_guid);
+  bound_net_log_.EndEvent(net::NetLogEventType::DOWNLOAD_FILE_ANNOTATED);
+  switch (result) {
+    case QuarantineFileResult::OK:
+      return DOWNLOAD_INTERRUPT_REASON_NONE;
+    case QuarantineFileResult::VIRUS_INFECTED:
+      return DOWNLOAD_INTERRUPT_REASON_FILE_VIRUS_INFECTED;
+    case QuarantineFileResult::SECURITY_CHECK_FAILED:
+      return DOWNLOAD_INTERRUPT_REASON_FILE_SECURITY_CHECK_FAILED;
+    case QuarantineFileResult::BLOCKED_BY_POLICY:
+      return DOWNLOAD_INTERRUPT_REASON_FILE_BLOCKED;
+    case QuarantineFileResult::ACCESS_DENIED:
+      return DOWNLOAD_INTERRUPT_REASON_FILE_ACCESS_DENIED;
+
+    case QuarantineFileResult::FILE_MISSING:
+      // Don't have a good interrupt reason here. This return code means that
+      // the file at |full_path_| went missing before QuarantineFile got to look
+      // at it. Not expected to happen, but we've seen instances where a file
+      // goes missing immediately after BaseFile closes the handle.
+      //

[cpu_(ooo_6.6-7.5), 2016/09/20 15:52:33]

On windows the attachment service can delete the file directly. I forgot in what
cases.

[asanka, 2016/09/21 14:57:00]

Got it. This status specifically addresses the case where the file was missing
before the Attachment Services check. The cases where the file is missing after
the Attachment Services check is covered under the VIRUS_INFECTED,
SECURITY_CHECK_FAILED, BLOCKED_BY_POLICY and ACCESS_DENIED cases above.

+      // Intentonally using a different error message than SECURITY_CHECK_FAILED
+      // in order to distinguish the two.
+      return DOWNLOAD_INTERRUPT_REASON_FILE_FAILED;
+
+    case QuarantineFileResult::ANNOTATION_FAILED:
+      // This means that the mark-of-the-web couldn't be applied. The file is
+      // already on the file system under its final target name.
+      //
+      // Causes of failed annotations typically aren't transient. E.g. the
+      // target file system may not support extended attributes or alternate
+      // streams. We are going to allow these downloads to progress on the
+      // assumption that failures to apply MOTW can't reliably be introduced
+      // remotely.
+      return DOWNLOAD_INTERRUPT_REASON_NONE;
+  }
+  return DOWNLOAD_INTERRUPT_REASON_FILE_FAILED;
+}
+#else  // !OS_WIN && !OS_MACOSX && !OS_LINUX
+DownloadInterruptReason BaseFile::AnnotateWithSourceInformation(
+    const std::string& client_guid,
+    const GURL& source_url,
+    const GURL& referrer_url) {
+  return DOWNLOAD_INTERRUPT_REASON_NONE;
+}
+#endif
+
 }  // namespace content