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content / browser / file_system / browser_file_system_helper.cc [blame]
// Copyright 2012 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/browser_file_system_helper.h"
#include <stddef.h>
#include <memory>
#include <string>
#include <utility>
#include <vector>
#include "base/command_line.h"
#include "base/files/file_path.h"
#include "base/functional/bind.h"
#include "base/strings/utf_string_conversions.h"
#include "base/task/lazy_thread_pool_task_runner.h"
#include "base/task/sequenced_task_runner.h"
#include "base/task/thread_pool.h"
#include "build/chromeos_buildflags.h"
#include "content/browser/child_process_security_policy_impl.h"
#include "content/public/browser/browser_context.h"
#include "content/public/browser/browser_task_traits.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/child_process_security_policy.h"
#include "content/public/browser/content_browser_client.h"
#include "content/public/common/content_client.h"
#include "content/public/common/content_switches.h"
#include "content/public/common/drop_data.h"
#include "content/public/common/url_constants.h"
#include "net/base/filename_util.h"
#include "storage/browser/file_system/external_mount_points.h"
#include "storage/browser/file_system/file_permission_policy.h"
#include "storage/browser/file_system/file_system_backend.h"
#include "storage/browser/file_system/file_system_context.h"
#include "storage/browser/file_system/file_system_operation_runner.h"
#include "storage/browser/file_system/file_system_options.h"
#include "storage/browser/file_system/file_system_url.h"
#include "storage/browser/file_system/isolated_context.h"
#include "storage/browser/quota/quota_manager.h"
#include "storage/browser/quota/quota_manager_proxy.h"
#include "third_party/blink/public/common/storage_key/storage_key.h"
#include "third_party/leveldatabase/leveldb_chrome.h"
#include "url/gurl.h"
#include "url/url_constants.h"
using storage::FileSystemOptions;
namespace content {
namespace {
FileSystemOptions CreateBrowserFileSystemOptions(bool is_incognito) {
FileSystemOptions::ProfileMode profile_mode =
is_incognito ? FileSystemOptions::PROFILE_MODE_INCOGNITO
: FileSystemOptions::PROFILE_MODE_NORMAL;
std::vector<std::string> additional_allowed_schemes;
GetContentClient()->browser()->GetAdditionalAllowedSchemesForFileSystem(
&additional_allowed_schemes);
if (base::CommandLine::ForCurrentProcess()->HasSwitch(
switches::kAllowFileAccessFromFiles)) {
additional_allowed_schemes.push_back(url::kFileScheme);
}
return FileSystemOptions(profile_mode, is_incognito,
additional_allowed_schemes);
}
bool CheckCanReadFileSystemFileOnUIThread(int process_id,
const storage::FileSystemURL& url) {
DCHECK_CURRENTLY_ON(BrowserThread::UI);
ChildProcessSecurityPolicyImpl* policy =
ChildProcessSecurityPolicyImpl::GetInstance();
return policy->CanReadFileSystemFile(process_id, url);
}
void GrantReadAccessOnUIThread(int process_id,
const base::FilePath& platform_path) {
DCHECK_CURRENTLY_ON(BrowserThread::UI);
ChildProcessSecurityPolicyImpl* policy =
ChildProcessSecurityPolicyImpl::GetInstance();
if (!policy->CanReadFile(process_id, platform_path)) {
policy->GrantReadFile(process_id, platform_path);
}
}
// Helper function that used by GetPlatformPath() to get the platform
// path, grant read access, and send return the path via a callback.
void GetPlatformPathOnFileThread(
scoped_refptr<storage::FileSystemContext> context,
int process_id,
const storage::FileSystemURL& url,
DoGetPlatformPathCB callback,
bool can_read_filesystem_file) {
DCHECK(context->default_file_task_runner()->RunsTasksInCurrentSequence());
if (!can_read_filesystem_file) {
std::move(callback).Run(base::FilePath());
return;
}
base::FilePath platform_path;
context->operation_runner()->SyncGetPlatformPath(url, &platform_path);
GetUIThreadTaskRunner({})->PostTaskAndReply(
FROM_HERE,
base::BindOnce(&GrantReadAccessOnUIThread, process_id, platform_path),
base::BindOnce(std::move(callback), platform_path));
}
} // namespace
scoped_refptr<storage::FileSystemContext> CreateFileSystemContext(
BrowserContext* browser_context,
const base::FilePath& profile_path,
bool is_incognito,
scoped_refptr<storage::QuotaManagerProxy> quota_manager_proxy) {
// Setting up additional filesystem backends.
std::vector<std::unique_ptr<storage::FileSystemBackend>> additional_backends;
GetContentClient()->browser()->GetAdditionalFileSystemBackends(
browser_context, profile_path, &additional_backends);
// Set up the auto mount handlers for url requests.
std::vector<storage::URLRequestAutoMountHandler>
url_request_auto_mount_handlers;
GetContentClient()->browser()->GetURLRequestAutoMountHandlers(
&url_request_auto_mount_handlers);
auto options = CreateBrowserFileSystemOptions(
browser_context->CanUseDiskWhenOffTheRecord() ? false : is_incognito);
auto file_system_context = storage::FileSystemContext::Create(
GetIOThreadTaskRunner({}),
base::ThreadPool::CreateSequencedTaskRunner(
{base::MayBlock(), base::TaskPriority::USER_VISIBLE,
base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN}),
browser_context->GetMountPoints(),
browser_context->GetSpecialStoragePolicy(),
std::move(quota_manager_proxy), std::move(additional_backends),
url_request_auto_mount_handlers, profile_path, options);
for (const storage::FileSystemType& type :
file_system_context->GetFileSystemTypes()) {
ChildProcessSecurityPolicyImpl::GetInstance()
->RegisterFileSystemPermissionPolicy(
type, storage::FileSystemContext::GetPermissionPolicy(type));
}
return file_system_context;
}
bool FileSystemURLIsValid(storage::FileSystemContext* context,
const storage::FileSystemURL& url) {
if (!url.is_valid())
return false;
return context->GetFileSystemBackend(url.type()) != nullptr;
}
void DoGetPlatformPath(scoped_refptr<storage::FileSystemContext> context,
int process_id,
const GURL& path,
const blink::StorageKey& storage_key,
DoGetPlatformPathCB callback) {
DCHECK(context->default_file_task_runner()->RunsTasksInCurrentSequence());
DCHECK(callback);
storage::FileSystemURL url(context->CrackURL(path, storage_key));
if (!FileSystemURLIsValid(context.get(), url)) {
// Note: Posting a task here so this function always returns
// before the callback is called no matter which path is taken.
base::ThreadPool::PostTask(
FROM_HERE, base::BindOnce(std::move(callback), base::FilePath()));
return;
}
// Make sure if this file is ok to be read (in the current architecture
// which means roughly same as the renderer is allowed to get the platform
// path to the file).
GetUIThreadTaskRunner({})->PostTaskAndReplyWithResult(
FROM_HERE,
base::BindOnce(&CheckCanReadFileSystemFileOnUIThread, process_id, url),
base::BindOnce(&GetPlatformPathOnFileThread, std::move(context),
process_id, url, std::move(callback)));
}
void PrepareDropDataForChildProcess(
DropData* drop_data,
ChildProcessSecurityPolicyImpl* security_policy,
int child_id,
const storage::FileSystemContext* file_system_context) {
#if BUILDFLAG(IS_CHROMEOS_ASH)
// The externalfile:// scheme is used in Chrome OS to open external files in a
// browser tab.
// TODO(https://crbug.com/858972): This seems like it could be forged by the
// renderer. This probably needs to check that this didn't originate from the
// renderer... Also, this probably can just be GrantRequestURL (which doesn't
// yet exist) instead of GrantCommitURL.
if (drop_data->url.SchemeIs(content::kExternalFileScheme))
security_policy->GrantCommitURL(child_id, drop_data->url);
#endif
std::string filesystem_id = PrepareDataTransferFilenamesForChildProcess(
drop_data->filenames, security_policy, child_id, file_system_context);
drop_data->filesystem_id = base::UTF8ToUTF16(filesystem_id);
storage::IsolatedContext* isolated_context =
storage::IsolatedContext::GetInstance();
DCHECK(isolated_context);
for (auto& file_system_file : drop_data->file_system_files) {
storage::FileSystemURL file_system_url =
file_system_context->CrackURLInFirstPartyContext(file_system_file.url);
// Sandboxed filesystem files should never be handled via this path, so
// assert that none are sent from the renderer (wrapping these won't work
// anyway).
DCHECK(file_system_url.type() != storage::kFileSystemTypePersistent);
DCHECK(file_system_url.type() != storage::kFileSystemTypeTemporary);
std::string register_name;
storage::IsolatedContext::ScopedFSHandle filesystem =
isolated_context->RegisterFileSystemForPath(
file_system_url.type(), file_system_url.filesystem_id(),
file_system_url.path(), ®ister_name);
if (filesystem.is_valid()) {
// Grant the permission iff the ID is valid. This will also keep the FS
// alive after |filesystem| goes out of scope.
security_policy->GrantReadFileSystem(child_id, filesystem.id());
}
// Note: We are using the origin URL provided by the sender here. It may be
// different from the receiver's.
file_system_file.url = GURL(
storage::GetIsolatedFileSystemRootURIString(
file_system_url.origin().GetURL(), filesystem.id(), std::string())
.append(register_name));
file_system_file.filesystem_id = filesystem.id();
}
}
std::string PrepareDataTransferFilenamesForChildProcess(
std::vector<ui::FileInfo>& filenames,
ChildProcessSecurityPolicyImpl* security_policy,
int child_id,
const storage::FileSystemContext* file_system_context) {
// The filenames vector represents a capability to access the given files.
storage::IsolatedContext::FileInfoSet files;
for (auto& filename : filenames) {
// Make sure we have the same display_name as the one we register.
if (filename.display_name.empty()) {
std::string name;
files.AddPath(filename.path, &name);
filename.display_name = base::FilePath::FromUTF8Unsafe(name);
} else {
files.AddPathWithName(filename.path,
filename.display_name.AsUTF8Unsafe());
}
// A dragged file may wind up as the value of an input element, or it
// may be used as the target of a navigation instead. We don't know
// which will happen at this point, so generously grant both access
// and request permissions to the specific file to cover both cases.
// We do not give it the permission to request all file:// URLs.
security_policy->GrantRequestOfSpecificFile(child_id, filename.path);
// If the renderer already has permission to read these paths, we don't need
// to re-grant them. This prevents problems with DnD for files in the CrOS
// file manager--the file manager already had read/write access to those
// directories, but dragging a file would cause the read/write access to be
// overwritten with read-only access, making them impossible to delete or
// rename until the renderer was killed.
if (!security_policy->CanReadFile(child_id, filename.path))
security_policy->GrantReadFile(child_id, filename.path);
}
storage::IsolatedContext* isolated_context =
storage::IsolatedContext::GetInstance();
DCHECK(isolated_context);
std::string filesystem_id;
if (!files.fileset().empty()) {
filesystem_id = isolated_context->RegisterDraggedFileSystem(files);
if (!filesystem_id.empty()) {
// Grant the permission iff the ID is valid.
security_policy->GrantReadFileSystem(child_id, filesystem_id);
}
}
return filesystem_id;
}
} // namespace content