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content / browser / file_system_access / file_system_access_observer_observation.cc [blame]
// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "content/browser/file_system_access/file_system_access_observer_observation.h"
#include <memory>
#include <string>
#include <vector>
#include "base/files/file_path.h"
#include "base/functional/bind.h"
#include "build/buildflag.h"
#include "content/browser/file_system_access/file_system_access_change_source.h"
#include "content/browser/file_system_access/file_system_access_directory_handle_impl.h"
#include "content/browser/file_system_access/file_system_access_file_handle_impl.h"
#include "content/browser/file_system_access/file_system_access_handle_base.h"
#include "content/browser/file_system_access/file_system_access_manager_impl.h"
#include "content/browser/file_system_access/file_system_access_observer_host.h"
#include "content/browser/file_system_access/file_system_access_watch_scope.h"
#include "content/browser/file_system_access/file_system_access_watcher_manager.h"
#include "content/browser/renderer_host/render_frame_host_impl.h"
#include "content/public/browser/file_system_access_permission_context.h"
#include "content/public/browser/global_routing_id.h"
#include "content/public/browser/web_contents.h"
#include "storage/browser/file_system/file_system_context.h"
#include "storage/browser/file_system/file_system_url.h"
#include "third_party/blink/public/mojom/file_system_access/file_system_access_directory_handle.mojom.h"
#include "third_party/blink/public/mojom/file_system_access/file_system_access_observer.mojom.h"
#include "third_party/blink/public/mojom/permissions/permission_status.mojom-shared.h"
#if BUILDFLAG(IS_WIN)
#include "base/strings/utf_string_conversions.h"
#endif // BUILDFLAG(IS_WIN)
namespace content {
namespace {
FileSystemAccessPermissionContext::HandleType GetHandleType(
const absl::variant<std::unique_ptr<FileSystemAccessDirectoryHandleImpl>,
std::unique_ptr<FileSystemAccessFileHandleImpl>>&
handle) {
return absl::get_if<std::unique_ptr<FileSystemAccessDirectoryHandleImpl>>(
&handle)
? FileSystemAccessPermissionContext::HandleType::kDirectory
: FileSystemAccessPermissionContext::HandleType::kFile;
}
FileSystemAccessHandleBase& AsHandleBase(
const absl::variant<std::unique_ptr<FileSystemAccessDirectoryHandleImpl>,
std::unique_ptr<FileSystemAccessFileHandleImpl>>&
handle) {
auto* dir_handle_ptr =
absl::get_if<std::unique_ptr<FileSystemAccessDirectoryHandleImpl>>(
&handle);
if (dir_handle_ptr) {
return *static_cast<FileSystemAccessHandleBase*>(dir_handle_ptr->get());
}
return *absl::get<std::unique_ptr<FileSystemAccessFileHandleImpl>>(handle);
}
// TODO(crbug.com/40105284): Move this to a helper shared with
// `FileSystemAccessDirectoryHandleImpl`.
std::vector<std::string> GetRelativePathAsVectorOfStrings(
const base::FilePath& relative_path) {
CHECK(!relative_path.IsAbsolute());
CHECK(!relative_path.ReferencesParent());
std::vector<base::FilePath::StringType> components =
relative_path.GetComponents();
#if BUILDFLAG(IS_WIN)
std::vector<std::string> result;
result.reserve(components.size());
for (const auto& component : components) {
result.push_back(base::WideToUTF8(component));
}
return result;
#else
return components;
#endif // BUILDFLAG(IS_WIN)
}
blink::mojom::FileSystemAccessEntryPtr CreateEntryForUrl(
FileSystemAccessManagerImpl& manager,
const FileSystemAccessManagerImpl::BindingContext& binding_context,
const FileSystemAccessManagerImpl::SharedHandleState& handle_state,
const storage::FileSystemURL& url,
FileSystemAccessPermissionContext::HandleType handle_type) {
switch (handle_type) {
case FileSystemAccessPermissionContext::HandleType::kFile:
return blink::mojom::FileSystemAccessEntry::New(
blink::mojom::FileSystemAccessHandle::NewFile(
manager.CreateFileHandle(binding_context, url, handle_state)),
url.virtual_path().BaseName().AsUTF8Unsafe());
case FileSystemAccessPermissionContext::HandleType::kDirectory:
return blink::mojom::FileSystemAccessEntry::New(
blink::mojom::FileSystemAccessHandle::NewDirectory(
manager.CreateDirectoryHandle(binding_context, url,
handle_state)),
url.virtual_path().BaseName().AsUTF8Unsafe());
}
}
std::optional<base::FilePath> GetRelativePath(const base::FilePath& root_path,
const base::FilePath& target) {
if (root_path.empty()) {
return base::FilePath(target);
}
if (root_path == target) {
return base::FilePath();
}
if (root_path.IsParent(target)) {
base::FilePath relative_path;
CHECK(root_path.AppendRelativePath(target, &relative_path));
return relative_path;
}
return std::nullopt;
}
bool RenderFrameHostIsActive(
const FileSystemAccessManagerImpl::BindingContext& binding_context) {
GlobalRenderFrameHostId render_frame_host_id = binding_context.frame_id;
RenderFrameHostImpl* rfh = RenderFrameHostImpl::FromID(render_frame_host_id);
// Frames without an associated render frame host (e.g. Service Workers,
// Shared Workers) are considered active.
if (!rfh) {
return true;
}
return rfh->IsActive();
}
} // namespace
FileSystemAccessObserverObservation::FileSystemAccessObserverObservation(
FileSystemAccessObserverHost* host,
std::unique_ptr<FileSystemAccessWatcherManager::Observation> observation,
mojo::PendingRemote<blink::mojom::FileSystemAccessObserver> remote,
absl::variant<std::unique_ptr<FileSystemAccessDirectoryHandleImpl>,
std::unique_ptr<FileSystemAccessFileHandleImpl>> handle)
: WebContentsObserver(
WebContents::FromRenderFrameHost(RenderFrameHostImpl::FromID(
AsHandleBase(handle).context().frame_id))),
host_(host),
handle_(std::move(handle)),
observation_(std::move(observation)),
remote_(std::move(remote)) {
CHECK(host);
CHECK(observation_);
CHECK(observation_->scope().Contains(AsHandleBase(handle_).url()));
// Observe `read_grant` changes in case we lose read permission.
const FileSystemAccessManagerImpl::SharedHandleState& handle_state =
AsHandleBase(handle_).handle_state();
handle_state.read_grant->AddObserver(this);
observation_->SetCallback(
base::BindRepeating(&FileSystemAccessObserverObservation::OnChanges,
weak_factory_.GetWeakPtr()));
// `base::Unretained` is safe here because this instance owns
// `remote_`.
remote_.set_disconnect_handler(
base::BindOnce(&FileSystemAccessObserverObservation::OnReceiverDisconnect,
base::Unretained(this)));
}
FileSystemAccessObserverObservation::~FileSystemAccessObserverObservation() {
const FileSystemAccessManagerImpl::SharedHandleState& handle_state =
AsHandleBase(handle_).handle_state();
handle_state.read_grant->RemoveObserver(this);
}
const storage::FileSystemURL& FileSystemAccessObserverObservation::handle_url()
const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
return AsHandleBase(handle_).url();
}
void FileSystemAccessObserverObservation::OnChanges(
const std::optional<
std::list<FileSystemAccessWatcherManager::Observation::Change>>&
changes_or_error) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (received_error_while_in_bf_cache_) {
return;
}
if (!changes_or_error.has_value()) {
HandleError();
return;
}
FileSystemAccessHandleBase& handle_base = AsHandleBase(handle_);
const FileSystemAccessManagerImpl::BindingContext& binding_context =
handle_base.context();
// Make sure the RenderFrameHost is Active before sending changes to the
// renderer.
if (!RenderFrameHostIsActive(binding_context)) {
received_changes_while_in_bf_cache_ = true;
return;
}
const FileSystemAccessManagerImpl::SharedHandleState& handle_state =
handle_base.handle_state();
// Do not relay changes if the site has lost read permission to the handle.
// TODO(crbug.com/321980366): Add tests for this.
if (handle_state.read_grant->GetStatus() !=
blink::mojom::PermissionStatus::GRANTED) {
return;
}
FileSystemAccessManagerImpl* manager = handle_base.manager();
const storage::FileSystemURL& handle_url = handle_base.url();
std::vector<blink::mojom::FileSystemAccessChangePtr> mojo_changes;
bool observation_root_disappeared = false;
for (const auto& change : changes_or_error.value()) {
// TODO(crbug.com/40105284): Consider refactoring to keep the "scope"
// concept within the WatcherManager and its associated classes. This method
// just needs the root url.
//
// It is illegal to receive a change outside of the observed scope.
CHECK(observation_->scope().Contains(change.url));
blink::mojom::FileSystemAccessEntryPtr root_entry =
CreateEntryForUrl(*manager, binding_context, handle_state, handle_url,
GetHandleType(handle_));
const auto& change_info = change.change_info;
FileSystemAccessPermissionContext::HandleType changed_entry_handle_type;
switch (change_info.file_path_type) {
case FileSystemAccessChangeSource::FilePathType::kUnknown:
// Fall back to using the same handle type as the root handle.
changed_entry_handle_type = GetHandleType(handle_);
break;
case FileSystemAccessChangeSource::FilePathType::kDirectory:
changed_entry_handle_type =
FileSystemAccessPermissionContext::HandleType::kDirectory;
break;
case FileSystemAccessChangeSource::FilePathType::kFile:
changed_entry_handle_type =
FileSystemAccessPermissionContext::HandleType::kFile;
break;
}
blink::mojom::FileSystemAccessEntryPtr changed_entry =
CreateEntryForUrl(*manager, binding_context, handle_state, change.url,
changed_entry_handle_type);
// Some platforms do not support ChangeInfo for Local FS changes, in which
// case a default, empty ChangeInfo is passed. In this case, report an event
// without metadata. Remove this section once ChangeInfo is supported in all
// platforms.
if (change_info == FileSystemAccessChangeSource::ChangeInfo()) {
mojo_changes.emplace_back(blink::mojom::FileSystemAccessChange::New(
blink::mojom::FileSystemAccessChangeMetadata::New(
std::move(root_entry), std::move(changed_entry),
std::vector<std::string>()),
blink::mojom::FileSystemAccessChangeType::NewUnknown(
blink::mojom::FileSystemAccessChangeTypeUnknown::New())));
continue;
}
// TODO(crbug.com/340583257): It is expected that `ChangeInfo.modified_path`
// match the path of `Observation::Change.url`. Consider refactoring
// Observation::Change so that we do not need to do this check.
CHECK_EQ(change.url.virtual_path(), change_info.modified_path);
const base::FilePath& root_path = handle_url.path();
std::optional<base::FilePath> relative_modified_path =
GetRelativePath(root_path, change_info.modified_path);
// It is expected that modified_path is a descendent of the root,
// or the same as the root.
CHECK(relative_modified_path.has_value());
std::optional<base::FilePath> relative_moved_from_path =
change_info.moved_from_path.has_value()
? GetRelativePath(root_path, change_info.moved_from_path.value())
: std::nullopt;
blink::mojom::FileSystemAccessChangeTypePtr mojo_change_type;
switch (change_info.change_type) {
case FileSystemAccessChangeSource::ChangeType::kUnknown:
mojo_change_type = blink::mojom::FileSystemAccessChangeType::NewUnknown(
blink::mojom::FileSystemAccessChangeTypeUnknown::New());
break;
case FileSystemAccessChangeSource::ChangeType::kCreated:
mojo_change_type =
blink::mojom::FileSystemAccessChangeType::NewAppeared(
blink::mojom::FileSystemAccessChangeTypeAppeared::New());
break;
case FileSystemAccessChangeSource::ChangeType::kDeleted:
mojo_change_type =
blink::mojom::FileSystemAccessChangeType::NewDisappeared(
blink::mojom::FileSystemAccessChangeTypeDisappeared::New());
break;
case FileSystemAccessChangeSource::ChangeType::kModified:
mojo_change_type =
blink::mojom::FileSystemAccessChangeType::NewModified(
blink::mojom::FileSystemAccessChangeTypeModified::New());
break;
case FileSystemAccessChangeSource::ChangeType::kMoved:
if (relative_moved_from_path.has_value()) {
mojo_change_type = blink::mojom::FileSystemAccessChangeType::NewMoved(
blink::mojom::FileSystemAccessChangeTypeMoved::New(
GetRelativePathAsVectorOfStrings(
relative_moved_from_path.value())));
} else {
mojo_change_type = blink::mojom::FileSystemAccessChangeType::NewMoved(
blink::mojom::FileSystemAccessChangeTypeMoved::New());
}
break;
}
observation_root_disappeared =
(observation_->scope().GetWatchType() ==
FileSystemAccessWatchScope::WatchType::kDirectoryRecursive ||
observation_->scope().GetWatchType() ==
FileSystemAccessWatchScope::WatchType::kDirectoryNonRecursive) &&
mojo_change_type->is_disappeared() &&
observation_->scope().root_url() == change.url;
mojo_changes.emplace_back(blink::mojom::FileSystemAccessChange::New(
blink::mojom::FileSystemAccessChangeMetadata::New(
std::move(root_entry), std::move(changed_entry),
GetRelativePathAsVectorOfStrings(relative_modified_path.value())),
std::move(mojo_change_type)));
if (observation_root_disappeared) {
break;
}
}
// Report the number of events in a 1s time window.
if (callback_count_ == 0) {
base::SingleThreadTaskRunner::GetCurrentDefault()->PostDelayedTask(
FROM_HERE,
base::BindOnce(
&FileSystemAccessObserverObservation::RecordCallbackCountUMA,
weak_factory_.GetWeakPtr()),
base::Seconds(1));
}
callback_count_++;
remote_->OnFileChanges(std::move(mojo_changes));
// Send an "errored" event and destruct if the root of the observation
// disappeared.
if (observation_root_disappeared) {
HandleError();
}
}
void FileSystemAccessObserverObservation::HandleError() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
FileSystemAccessHandleBase& handle_base = AsHandleBase(handle_);
const FileSystemAccessManagerImpl::BindingContext& binding_context =
handle_base.context();
// Skip sending changes to the renderer if RenderFrameHost is not valid.
if (!RenderFrameHostIsActive(binding_context)) {
received_error_while_in_bf_cache_ = true;
return;
}
std::vector<blink::mojom::FileSystemAccessChangePtr> mojo_changes;
const FileSystemAccessManagerImpl::SharedHandleState& handle_state =
handle_base.handle_state();
FileSystemAccessManagerImpl* manager = handle_base.manager();
const storage::FileSystemURL& handle_url = handle_base.url();
mojo_changes.emplace_back(blink::mojom::FileSystemAccessChange::New(
blink::mojom::FileSystemAccessChangeMetadata::New(
CreateEntryForUrl(*manager, binding_context, handle_state, handle_url,
GetHandleType(handle_)),
CreateEntryForUrl(*manager, binding_context, handle_state, handle_url,
GetHandleType(handle_)),
std::vector<std::string>()),
blink::mojom::FileSystemAccessChangeType::NewErrored(
blink::mojom::FileSystemAccessChangeTypeErrored::New())));
remote_->OnFileChanges(std::move(mojo_changes));
// Destroys `this`. It not only removes this observation but also its
// corresponding watch set up by FileSystemAccessWatcherManager if this
// observation is the only one using the watch.
host_->RemoveObservation(this);
}
void FileSystemAccessObserverObservation::RenderFrameHostStateChanged(
RenderFrameHost* render_frame_host,
RenderFrameHost::LifecycleState old_state,
RenderFrameHost::LifecycleState new_state) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
bool transitioned_from_bf_cache_to_active =
new_state == RenderFrameHost::LifecycleState::kActive &&
old_state == RenderFrameHost::LifecycleState::kInBackForwardCache;
if (render_frame_host !=
RenderFrameHost::FromID(AsHandleBase(handle_).context().frame_id) ||
!transitioned_from_bf_cache_to_active) {
return;
}
if (received_error_while_in_bf_cache_) {
HandleError();
return;
}
if (!received_changes_while_in_bf_cache_) {
return;
}
// RFH's state changed to kActive from kInBackForwardCache. File System
// changes are not sent while the page is in BFCache. So, we use
// ChangeType::kUnknown to signal to the renderer that some changes could be
// missing.
std::vector<blink::mojom::FileSystemAccessChangePtr> mojo_changes;
FileSystemAccessManagerImpl* manager = AsHandleBase(handle_).manager();
const FileSystemAccessManagerImpl::BindingContext& binding_context =
AsHandleBase(handle_).context();
const FileSystemAccessManagerImpl::SharedHandleState& handle_state =
AsHandleBase(handle_).handle_state();
const storage::FileSystemURL& handle_url = AsHandleBase(handle_).url();
mojo_changes.emplace_back(blink::mojom::FileSystemAccessChange::New(
blink::mojom::FileSystemAccessChangeMetadata::New(
CreateEntryForUrl(*manager, binding_context, handle_state, handle_url,
GetHandleType(handle_)),
CreateEntryForUrl(*manager, binding_context, handle_state, handle_url,
GetHandleType(handle_)),
std::vector<std::string>()),
blink::mojom::FileSystemAccessChangeType::NewUnknown(
blink::mojom::FileSystemAccessChangeTypeUnknown::New())));
remote_->OnFileChanges(std::move(mojo_changes));
received_changes_while_in_bf_cache_ = false;
}
void FileSystemAccessObserverObservation::OnReceiverDisconnect() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
// Destroys `this`.
host_->RemoveObservation(this);
}
void FileSystemAccessObserverObservation::OnPermissionStatusChanged() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (received_error_while_in_bf_cache_) {
return;
}
const FileSystemAccessManagerImpl::SharedHandleState& handle_state =
AsHandleBase(handle_).handle_state();
if (handle_state.read_grant->GetStatus() ==
blink::mojom::PermissionStatus::GRANTED) {
return;
}
// The read permission has been revoked. Send an "errored" event and destroy
// this observation.
HandleError();
}
void FileSystemAccessObserverObservation::RecordCallbackCountUMA() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
base::UmaHistogramCounts1000(
"Storage.FileSystemAccess.ObservationCallbackRate", callback_count_);
callback_count_ = 0;
}
} // namespace content