mandoline: Fork the files service from the mojo repository.

components/filesystem/directory_impl.cc

+// 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 "components/filesystem/directory_impl.h"
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "base/files/scoped_temp_dir.h"
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/posix/eintr_wrapper.h"
+#include "build/build_config.h"
+#include "components/filesystem/file_impl.h"
+#include "components/filesystem/shared_impl.h"
+#include "components/filesystem/util.h"
+
+namespace mojo {
+namespace files {
+
+namespace {
+
+// Calls |closedir()| on a |DIR*|.
+struct DIRDeleter {
+  void operator()(DIR* dir) const { PCHECK(closedir(dir) == 0); }
+};
+using ScopedDIR = scoped_ptr<DIR, DIRDeleter>;
+
+Error ValidateOpenFlags(uint32_t open_flags, bool is_directory) {
+  // Treat unknown flags as "unimplemented".
+  if ((open_flags &
+       ~(kOpenFlagRead | kOpenFlagWrite | kOpenFlagCreate | kOpenFlagExclusive |
+         kOpenFlagAppend | kOpenFlagTruncate)))
+    return ERROR_UNIMPLEMENTED;
+
+  // At least one of |kOpenFlagRead| or |kOpenFlagWrite| must be set.
+  if (!(open_flags & (kOpenFlagRead | kOpenFlagWrite)))
+    return ERROR_INVALID_ARGUMENT;
+
+  // |kOpenFlagCreate| requires |kOpenFlagWrite|.
+  if ((open_flags & kOpenFlagCreate) && !(open_flags & kOpenFlagWrite))
+    return ERROR_INVALID_ARGUMENT;
+
+  // |kOpenFlagExclusive| requires |kOpenFlagCreate|.
+  if ((open_flags & kOpenFlagExclusive) && !(open_flags & kOpenFlagCreate))
+    return ERROR_INVALID_ARGUMENT;
+
+  if (is_directory) {
+    // Check that file-only flags aren't set.
+    if ((open_flags & (kOpenFlagAppend | kOpenFlagTruncate)))
+      return ERROR_INVALID_ARGUMENT;
+    return ERROR_OK;
+  }
+
+  // File-only flags:
+
+  // |kOpenFlagAppend| requires |kOpenFlagWrite|.
+  if ((open_flags & kOpenFlagAppend) && !(open_flags & kOpenFlagWrite))
+    return ERROR_INVALID_ARGUMENT;
+
+  // |kOpenFlagTruncate| requires |kOpenFlagWrite|.
+  if ((open_flags & kOpenFlagTruncate) && !(open_flags & kOpenFlagWrite))
+    return ERROR_INVALID_ARGUMENT;
+
+  return ERROR_OK;
+}
+
+Error ValidateDeleteFlags(uint32_t delete_flags) {
+  // Treat unknown flags as "unimplemented".
+  if ((delete_flags &
+       ~(kDeleteFlagFileOnly | kDeleteFlagDirectoryOnly |
+         kDeleteFlagRecursive)))
+    return ERROR_UNIMPLEMENTED;
+
+  // Only one of the three currently-defined flags may be set.
+  if ((delete_flags & kDeleteFlagFileOnly) &&
+      (delete_flags & (kDeleteFlagDirectoryOnly | kDeleteFlagRecursive)))
+    return ERROR_INVALID_ARGUMENT;
+  if ((delete_flags & kDeleteFlagDirectoryOnly) &&
+      (delete_flags & (kDeleteFlagFileOnly | kDeleteFlagRecursive)))
+    return ERROR_INVALID_ARGUMENT;
+  if ((delete_flags & kDeleteFlagRecursive) &&
+      (delete_flags & (kDeleteFlagFileOnly | kDeleteFlagDirectoryOnly)))
+    return ERROR_INVALID_ARGUMENT;
+
+  return ERROR_OK;
+}
+
+}  // namespace
+
+DirectoryImpl::DirectoryImpl(InterfaceRequest<Directory> request,
+                             base::ScopedFD dir_fd,
+                             scoped_ptr<base::ScopedTempDir> temp_dir)
+    : binding_(this, request.Pass()),
+      dir_fd_(dir_fd.Pass()),
+      temp_dir_(temp_dir.Pass()) {
+  DCHECK(dir_fd_.is_valid());
+}
+
+DirectoryImpl::~DirectoryImpl() {
+}
+
+void DirectoryImpl::Read(const ReadCallback& callback) {
+  static const size_t kMaxReadCount = 1000;
+
+  DCHECK(dir_fd_.is_valid());
+
+  // |fdopendir()| takes ownership of the FD (giving it to the |DIR| --
+  // |closedir()| will close the FD)), so we need to |dup()| ours.
+  base::ScopedFD fd(dup(dir_fd_.get()));
+  if (!fd.is_valid()) {
+    callback.Run(ErrnoToError(errno), Array<DirectoryEntryPtr>());
+    return;
+  }
+
+  ScopedDIR dir(fdopendir(fd.release()));
+  if (!dir) {
+    callback.Run(ErrnoToError(errno), Array<DirectoryEntryPtr>());
+    return;
+  }
+
+  Array<DirectoryEntryPtr> result(0);
+
+// Warning: This is not portable (per POSIX.1 -- |buffer| may not be large
+// enough), but it's fine for Linux.
+#if !defined(OS_ANDROID) && !defined(OS_LINUX)
+#error "Use of struct dirent for readdir_r() buffer not portable; please check."
+#endif
+  struct dirent buffer;
+  for (size_t n = 0;;) {
+    struct dirent* entry = nullptr;
+    if (int error = readdir_r(dir.get(), &buffer, &entry)) {
+      // |error| is effectively an errno (for |readdir_r()|), AFAICT.
+      callback.Run(ErrnoToError(error), Array<DirectoryEntryPtr>());
+      return;
+    }
+
+    if (!entry)
+      break;
+
+    n++;
+    if (n > kMaxReadCount) {
+      LOG(WARNING) << "Directory contents truncated";
+      callback.Run(ERROR_OUT_OF_RANGE, result.Pass());
+      return;
+    }
+
+    DirectoryEntryPtr e = DirectoryEntry::New();
+    switch (entry->d_type) {
+      case DT_DIR:
+        e->type = FILE_TYPE_DIRECTORY;
+        break;
+      case DT_REG:
+        e->type = FILE_TYPE_REGULAR_FILE;
+        break;
+      default:
+        e->type = FILE_TYPE_UNKNOWN;
+        break;
+    }
+    e->name = String(entry->d_name);
+    result.push_back(e.Pass());
+  }
+
+  callback.Run(ERROR_OK, result.Pass());
+}
+
+void DirectoryImpl::Stat(const StatCallback& callback) {
+  DCHECK(dir_fd_.is_valid());
+  StatFD(dir_fd_.get(), FILE_TYPE_DIRECTORY, callback);
+}
+
+void DirectoryImpl::Touch(TimespecOrNowPtr atime,
+                          TimespecOrNowPtr mtime,
+                          const TouchCallback& callback) {
+  DCHECK(dir_fd_.is_valid());
+  TouchFD(dir_fd_.get(), atime.Pass(), mtime.Pass(), callback);
+}
+
+// TODO(vtl): Move the implementation to a thread pool.
+void DirectoryImpl::OpenFile(const String& path,
+                             InterfaceRequest<File> file,
+                             uint32_t open_flags,
+                             const OpenFileCallback& callback) {
+  DCHECK(!path.is_null());
+  DCHECK(dir_fd_.is_valid());
+
+  if (Error error = IsPathValid(path)) {
+    callback.Run(error);
+    return;
+  }
+  // TODO(vtl): Make sure the path doesn't exit this directory (if appropriate).
+  // TODO(vtl): Maybe allow absolute paths?
+
+  if (Error error = ValidateOpenFlags(open_flags, false)) {
+    callback.Run(error);
+    return;
+  }
+
+  int flags = 0;
+  if ((open_flags & kOpenFlagRead))
+    flags |= (open_flags & kOpenFlagWrite) ? O_RDWR : O_RDONLY;
+  else
+    flags |= O_WRONLY;
+  if ((open_flags & kOpenFlagCreate))
+    flags |= O_CREAT;
+  if ((open_flags & kOpenFlagExclusive))
+    flags |= O_EXCL;
+  if ((open_flags & kOpenFlagAppend))
+    flags |= O_APPEND;
+  if ((open_flags & kOpenFlagTruncate))
+    flags |= O_TRUNC;
+
+  base::ScopedFD file_fd(
+      HANDLE_EINTR(openat(dir_fd_.get(), path.get().c_str(), flags, 0600)));
+  if (!file_fd.is_valid()) {
+    callback.Run(ErrnoToError(errno));
+    return;
+  }
+
+  if (file.is_pending())
+    new FileImpl(file.Pass(), file_fd.Pass());
+  callback.Run(ERROR_OK);
+}
+
+void DirectoryImpl::OpenDirectory(const String& path,
+                                  InterfaceRequest<Directory> directory,
+                                  uint32_t open_flags,
+                                  const OpenDirectoryCallback& callback) {
+  DCHECK(!path.is_null());
+  DCHECK(dir_fd_.is_valid());
+
+  if (Error error = IsPathValid(path)) {
+    callback.Run(error);
+    return;
+  }
+  // TODO(vtl): Make sure the path doesn't exit this directory (if appropriate).
+  // TODO(vtl): Maybe allow absolute paths?
+
+  if (Error error = ValidateOpenFlags(open_flags, false)) {
+    callback.Run(error);
+    return;
+  }
+
+  // TODO(vtl): Implement read-only (whatever that means).
+  if (!(open_flags & kOpenFlagWrite)) {
+    callback.Run(ERROR_UNIMPLEMENTED);
+    return;
+  }
+
+  if ((open_flags & kOpenFlagCreate)) {
+    if (mkdirat(dir_fd_.get(), path.get().c_str(), 0700) != 0) {
+      // Allow |EEXIST| if |kOpenFlagExclusive| is not set. Note, however, that
+      // it does not guarantee that |path| is a directory.
+      // TODO(vtl): Hrm, ponder if we should check that |path| is a directory.
+      if (errno != EEXIST || !(open_flags & kOpenFlagExclusive)) {
+        callback.Run(ErrnoToError(errno));
+        return;
+      }
+    }
+  }
+
+  base::ScopedFD new_dir_fd(
+      HANDLE_EINTR(openat(dir_fd_.get(), path.get().c_str(), O_DIRECTORY, 0)));
+  if (!new_dir_fd.is_valid()) {
+    callback.Run(ErrnoToError(errno));
+    return;
+  }
+
+  if (directory.is_pending())
+    new DirectoryImpl(directory.Pass(), new_dir_fd.Pass(), nullptr);
+  callback.Run(ERROR_OK);
+}
+
+void DirectoryImpl::Rename(const String& path,
+                           const String& new_path,
+                           const RenameCallback& callback) {
+  DCHECK(!path.is_null());
+  DCHECK(!new_path.is_null());
+  DCHECK(dir_fd_.is_valid());
+
+  if (Error error = IsPathValid(path)) {
+    callback.Run(error);
+    return;
+  }
+  if (Error error = IsPathValid(new_path)) {
+    callback.Run(error);
+    return;
+  }
+  // TODO(vtl): See TODOs about |path| in OpenFile().
+
+  if (renameat(dir_fd_.get(), path.get().c_str(), dir_fd_.get(),
+               new_path.get().c_str())) {
+    callback.Run(ErrnoToError(errno));
+    return;
+  }
+
+  callback.Run(ERROR_OK);
+}
+
+void DirectoryImpl::Delete(const String& path,
+                           uint32_t delete_flags,
+                           const DeleteCallback& callback) {
+  DCHECK(!path.is_null());
+  DCHECK(dir_fd_.is_valid());
+
+  if (Error error = IsPathValid(path)) {
+    callback.Run(error);
+    return;
+  }
+  // TODO(vtl): See TODOs about |path| in OpenFile().
+
+  if (Error error = ValidateDeleteFlags(delete_flags)) {
+    callback.Run(error);
+    return;
+  }
+
+  // TODO(vtl): Recursive not yet supported.
+  if ((delete_flags & kDeleteFlagRecursive)) {
+    callback.Run(ERROR_UNIMPLEMENTED);
+    return;
+  }
+
+  // First try deleting it as a file, unless we're told to do directory-only.
+  if (!(delete_flags & kDeleteFlagDirectoryOnly)) {
+    if (unlinkat(dir_fd_.get(), path.get().c_str(), 0) == 0) {
+      callback.Run(ERROR_OK);
+      return;
+    }
+
+    // If file-only, don't continue.
+    if ((delete_flags & kDeleteFlagFileOnly)) {
+      callback.Run(ErrnoToError(errno));
+      return;
+    }
+  }
+
+  // Try deleting it as a directory.
+  if (unlinkat(dir_fd_.get(), path.get().c_str(), AT_REMOVEDIR) == 0) {
+    callback.Run(ERROR_OK);
+    return;
+  }
+
+  callback.Run(ErrnoToError(errno));
+}
+
+}  // namespace files
+}  // namespace mojo