Revert of Move file_handlers API from //chrome to //extensions

chrome/browser/extensions/api/file_handlers/app_file_handler_util.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 "chrome/browser/extensions/api/file_handlers/app_file_handler_util.h"
+
+#include "base/files/file.h"
+#include "base/files/file_path.h"
+#include "base/files/file_util.h"
+#include "build/build_config.h"
+#include "chrome/browser/profiles/profile.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/child_process_security_policy.h"
+#include "extensions/browser/api/extensions_api_client.h"
+#include "extensions/browser/entry_info.h"
+#include "extensions/browser/extension_prefs.h"
+#include "extensions/browser/granted_file_entry.h"
+#include "extensions/common/permissions/permissions_data.h"
+#include "net/base/mime_util.h"
+#include "storage/browser/fileapi/isolated_context.h"
+#include "storage/common/fileapi/file_system_mount_option.h"
+#include "storage/common/fileapi/file_system_types.h"
+
+#if defined(OS_CHROMEOS)
+#include "extensions/browser/api/file_handlers/non_native_file_system_delegate.h"
+#endif
+
+namespace extensions {
+
+namespace app_file_handler_util {
+
+const char kInvalidParameters[] = "Invalid parameters";
+const char kSecurityError[] = "Security error";
+
+namespace {
+
+bool FileHandlerCanHandleFileWithExtension(const FileHandlerInfo& handler,
+                                           const base::FilePath& path) {
+  for (std::set<std::string>::const_iterator extension =
+           handler.extensions.begin();
+       extension != handler.extensions.end(); ++extension) {
+    if (*extension == "*")
+      return true;
+
+    // Accept files whose extension or combined extension (e.g. ".tar.gz")
+    // match the supported extensions of file handler.
+    base::FilePath::StringType handler_extention(
+        base::FilePath::kExtensionSeparator +
+        base::FilePath::FromUTF8Unsafe(*extension).value());
+    if (base::FilePath::CompareEqualIgnoreCase(handler_extention,
+                                               path.Extension()) ||
+        base::FilePath::CompareEqualIgnoreCase(handler_extention,
+                                               path.FinalExtension())) {
+      return true;
+    }
+
+    // Also accept files with no extension for handlers that support an
+    // empty extension, i.e. both "foo" and "foo." match.
+    if (extension->empty() &&
+        path.MatchesExtension(base::FilePath::StringType())) {
+      return true;
+    }
+  }
+  return false;
+}
+
+bool FileHandlerCanHandleFileWithMimeType(const FileHandlerInfo& handler,
+                                          const std::string& mime_type) {
+  for (std::set<std::string>::const_iterator type = handler.types.begin();
+       type != handler.types.end(); ++type) {
+    if (net::MatchesMimeType(*type, mime_type))
+      return true;
+  }
+  return false;
+}
+
+bool PrepareNativeLocalFileForWritableApp(const base::FilePath& path,
+                                          bool is_directory) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::FILE);
+
+  // Don't allow links.
+  if (base::PathExists(path) && base::IsLink(path))
+    return false;
+
+  if (is_directory)
+    return base::DirectoryExists(path);
+
+  // Create the file if it doesn't already exist.
+  int creation_flags = base::File::FLAG_OPEN_ALWAYS | base::File::FLAG_READ;
+  base::File file(path, creation_flags);
+
+  return file.IsValid();
+}
+
+// Checks whether a list of paths are all OK for writing and calls a provided
+// on_success or on_failure callback when done. A path is OK for writing if it
+// is not a symlink, is not in a blacklisted path and can be opened for writing.
+// Creates files if they do not exist, but fails for non-existent directory
+// paths. On Chrome OS, also fails for non-local files that don't already exist.
+class WritableFileChecker
+    : public base::RefCountedThreadSafe<WritableFileChecker> {
+ public:
+  WritableFileChecker(
+      const std::vector<base::FilePath>& paths,
+      Profile* profile,
+      const std::set<base::FilePath>& directory_paths,
+      const base::Closure& on_success,
+      const base::Callback<void(const base::FilePath&)>& on_failure);
+
+  void Check();
+
+ private:
+  friend class base::RefCountedThreadSafe<WritableFileChecker>;
+  virtual ~WritableFileChecker();
+
+  // Called when a work item is completed. If all work items are done, this
+  // calls the success or failure callback.
+  void TaskDone();
+
+  // Reports an error in completing a work item. This may be called more than
+  // once, but only the last message will be retained.
+  void Error(const base::FilePath& error_path);
+
+  void CheckLocalWritableFiles();
+
+  // Called when processing a file is completed with either a success or an
+  // error.
+  void OnPrepareFileDone(const base::FilePath& path, bool success);
+
+  const std::vector<base::FilePath> paths_;
+  Profile* profile_;
+  const std::set<base::FilePath> directory_paths_;
+  int outstanding_tasks_;
+  base::FilePath error_path_;
+  base::Closure on_success_;
+  base::Callback<void(const base::FilePath&)> on_failure_;
+};
+
+WritableFileChecker::WritableFileChecker(
+    const std::vector<base::FilePath>& paths,
+    Profile* profile,
+    const std::set<base::FilePath>& directory_paths,
+    const base::Closure& on_success,
+    const base::Callback<void(const base::FilePath&)>& on_failure)
+    : paths_(paths),
+      profile_(profile),
+      directory_paths_(directory_paths),
+      outstanding_tasks_(1),
+      on_success_(on_success),
+      on_failure_(on_failure) {}
+
+void WritableFileChecker::Check() {
+  outstanding_tasks_ = paths_.size();
+  for (const auto& path : paths_) {
+    bool is_directory = directory_paths_.find(path) != directory_paths_.end();
+#if defined(OS_CHROMEOS)
+    NonNativeFileSystemDelegate* delegate =
+        ExtensionsAPIClient::Get()->GetNonNativeFileSystemDelegate();
+    if (delegate && delegate->IsUnderNonNativeLocalPath(profile_, path)) {
+      if (is_directory) {
+        delegate->IsNonNativeLocalPathDirectory(
+            profile_,
+            path,
+            base::Bind(&WritableFileChecker::OnPrepareFileDone, this, path));
+      } else {
+        delegate->PrepareNonNativeLocalFileForWritableApp(
+            profile_,
+            path,
+            base::Bind(&WritableFileChecker::OnPrepareFileDone, this, path));
+      }
+      continue;
+    }
+#endif
+    content::BrowserThread::PostTaskAndReplyWithResult(
+        content::BrowserThread::FILE, FROM_HERE,
+        base::Bind(&PrepareNativeLocalFileForWritableApp, path, is_directory),
+        base::Bind(&WritableFileChecker::OnPrepareFileDone, this, path));
+  }
+}
+
+WritableFileChecker::~WritableFileChecker() {}
+
+void WritableFileChecker::TaskDone() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  if (--outstanding_tasks_ == 0) {
+    if (error_path_.empty())
+      on_success_.Run();
+    else
+      on_failure_.Run(error_path_);
+  }
+}
+
+// Reports an error in completing a work item. This may be called more than
+// once, but only the last message will be retained.
+void WritableFileChecker::Error(const base::FilePath& error_path) {
+  DCHECK(!error_path.empty());
+  error_path_ = error_path;
+  TaskDone();
+}
+
+void WritableFileChecker::OnPrepareFileDone(const base::FilePath& path,
+                                            bool success) {
+  if (success)
+    TaskDone();
+  else
+    Error(path);
+}
+
+}  // namespace
+
+const FileHandlerInfo* FileHandlerForId(const Extension& app,
+                                        const std::string& handler_id) {
+  const FileHandlersInfo* file_handlers = FileHandlers::GetFileHandlers(&app);
+  if (!file_handlers)
+    return NULL;
+
+  for (FileHandlersInfo::const_iterator i = file_handlers->begin();
+       i != file_handlers->end(); i++) {
+    if (i->id == handler_id)
+      return &*i;
+  }
+  return NULL;
+}
+
+std::vector<const FileHandlerInfo*> FindFileHandlersForEntries(
+    const Extension& app,
+    const std::vector<EntryInfo> entries) {
+  std::vector<const FileHandlerInfo*> handlers;
+  if (entries.empty())
+    return handlers;
+
+  // Look for file handlers which can handle all the MIME types specified.
+  const FileHandlersInfo* file_handlers = FileHandlers::GetFileHandlers(&app);
+  if (!file_handlers)
+    return handlers;
+
+  for (FileHandlersInfo::const_iterator data = file_handlers->begin();
+       data != file_handlers->end(); ++data) {
+    bool handles_all_types = true;
+    for (std::vector<EntryInfo>::const_iterator it = entries.begin();
+         it != entries.end(); ++it) {
+      if (!FileHandlerCanHandleEntry(*data, *it)) {
+        handles_all_types = false;
+        break;
+      }
+    }
+    if (handles_all_types)
+      handlers.push_back(&*data);
+  }
+  return handlers;
+}
+
+bool FileHandlerCanHandleEntry(const FileHandlerInfo& handler,
+                               const EntryInfo& entry) {
+  if (entry.is_directory)
+    return handler.include_directories;
+
+  return FileHandlerCanHandleFileWithMimeType(handler, entry.mime_type) ||
+         FileHandlerCanHandleFileWithExtension(handler, entry.path);
+}
+
+GrantedFileEntry CreateFileEntry(Profile* profile,
+                                 const Extension* extension,
+                                 int renderer_id,
+                                 const base::FilePath& path,
+                                 bool is_directory) {
+  GrantedFileEntry result;
+  storage::IsolatedContext* isolated_context =
+      storage::IsolatedContext::GetInstance();
+  DCHECK(isolated_context);
+
+  result.filesystem_id = isolated_context->RegisterFileSystemForPath(
+      storage::kFileSystemTypeNativeForPlatformApp, std::string(), path,
+      &result.registered_name);
+
+  content::ChildProcessSecurityPolicy* policy =
+      content::ChildProcessSecurityPolicy::GetInstance();
+  policy->GrantReadFileSystem(renderer_id, result.filesystem_id);
+  if (HasFileSystemWritePermission(extension)) {
+    if (is_directory) {
+      policy->GrantCreateReadWriteFileSystem(renderer_id, result.filesystem_id);
+    } else {
+      policy->GrantWriteFileSystem(renderer_id, result.filesystem_id);
+      policy->GrantDeleteFromFileSystem(renderer_id, result.filesystem_id);
+    }
+  }
+
+  result.id = result.filesystem_id + ":" + result.registered_name;
+  return result;
+}
+
+void PrepareFilesForWritableApp(
+    const std::vector<base::FilePath>& paths,
+    Profile* profile,
+    const std::set<base::FilePath>& directory_paths,
+    const base::Closure& on_success,
+    const base::Callback<void(const base::FilePath&)>& on_failure) {
+  scoped_refptr<WritableFileChecker> checker(new WritableFileChecker(
+      paths, profile, directory_paths, on_success, on_failure));
+  checker->Check();
+}
+
+bool HasFileSystemWritePermission(const Extension* extension) {
+  return extension->permissions_data()->HasAPIPermission(
+      APIPermission::kFileSystemWrite);
+}
+
+bool ValidateFileEntryAndGetPath(const std::string& filesystem_name,
+                                 const std::string& filesystem_path,
+                                 int render_process_id,
+                                 base::FilePath* file_path,
+                                 std::string* error) {
+  if (filesystem_path.empty()) {
+    *error = kInvalidParameters;
+    return false;
+  }
+
+  std::string filesystem_id;
+  if (!storage::CrackIsolatedFileSystemName(filesystem_name, &filesystem_id)) {
+    *error = kInvalidParameters;
+    return false;
+  }
+
+  // Only return the display path if the process has read access to the
+  // filesystem.
+  content::ChildProcessSecurityPolicy* policy =
+      content::ChildProcessSecurityPolicy::GetInstance();
+  if (!policy->CanReadFileSystem(render_process_id, filesystem_id)) {
+    *error = kSecurityError;
+    return false;
+  }
+
+  storage::IsolatedContext* context = storage::IsolatedContext::GetInstance();
+  base::FilePath relative_path =
+      base::FilePath::FromUTF8Unsafe(filesystem_path);
+  base::FilePath virtual_path =
+      context->CreateVirtualRootPath(filesystem_id).Append(relative_path);
+  storage::FileSystemType type;
+  storage::FileSystemMountOption mount_option;
+  std::string cracked_id;
+  if (!context->CrackVirtualPath(virtual_path, &filesystem_id, &type,
+                                 &cracked_id, file_path, &mount_option)) {
+    *error = kInvalidParameters;
+    return false;
+  }
+
+  // The file system API is only intended to operate on file entries that
+  // correspond to a native file, selected by the user so only allow file
+  // systems returned by the file system API or from a drag and drop operation.
+  if (type != storage::kFileSystemTypeNativeForPlatformApp &&
+      type != storage::kFileSystemTypeDragged) {
+    *error = kInvalidParameters;
+    return false;
+  }
+
+  return true;
+}
+
+}  // namespace app_file_handler_util
+
+}  // namespace extensions