Remote Assistance on Chrome OS Part III - NativeMessageHost

chrome/browser/extensions/api/messaging/native_message_process_host.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/messaging/native_message_process_host.h"
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
-#include "base/prefs/pref_service.h"
 #include "base/process/kill.h"
 #include "base/threading/sequenced_worker_pool.h"
-#include "base/values.h"
 #include "chrome/browser/extensions/api/messaging/native_messaging_host_manifest.h"
 #include "chrome/browser/extensions/api/messaging/native_process_launcher.h"
 #include "chrome/common/chrome_version_info.h"
 #include "content/public/browser/browser_thread.h"
-#include "extensions/browser/pref_names.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/features/feature.h"
 #include "net/base/file_stream.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "net/base/net_util.h"
 #include "url/gurl.h"
 
 namespace {
 
 // Maximum message size in bytes for messages received from Native Messaging
 // hosts. Message size is limited mainly to prevent Chrome from crashing when
 // native application misbehaves (e.g. starts writing garbage to the pipe).
 const size_t kMaximumMessageSize = 1024 * 1024;
 
 // Message header contains 4-byte integer size of the message.
 const size_t kMessageHeaderSize = 4;
 
 // Size of the buffer to be allocated for each read.
 const size_t kReadBufferSize = 4096;
 
-const char kFailedToStartError[] = "Failed to start native messaging host.";
-const char kInvalidNameError[] =
-    "Invalid native messaging host name specified.";
-const char kNativeHostExited[] = "Native host has exited.";
-const char kNotFoundError[] = "Specified native messaging host not found.";
-const char kForbiddenError[] =
-    "Access to the specified native messaging host is forbidden.";
-const char kHostInputOuputError[] =
-    "Error when communicating with the native messaging host.";
-
 }  // namespace
 
 namespace extensions {
 
-// static
-NativeMessageProcessHost::PolicyPermission
-NativeMessageProcessHost::IsHostAllowed(const PrefService* pref_service,
-                                        const std::string& native_host_name) {
-  NativeMessageProcessHost::PolicyPermission allow_result = ALLOW_ALL;
-  if (pref_service->IsManagedPreference(
-          pref_names::kNativeMessagingUserLevelHosts)) {
-    if (!pref_service->GetBoolean(pref_names::kNativeMessagingUserLevelHosts))
-      allow_result = ALLOW_SYSTEM_ONLY;
-  }
-
-  // All native messaging hosts are allowed if there is no blacklist.
-  if (!pref_service->IsManagedPreference(pref_names::kNativeMessagingBlacklist))
-    return allow_result;
-  const base::ListValue* blacklist =
-      pref_service->GetList(pref_names::kNativeMessagingBlacklist);
-  if (!blacklist)
-    return allow_result;
-
-  // Check if the name or the wildcard is in the blacklist.
-  base::StringValue name_value(native_host_name);
-  base::StringValue wildcard_value("*");
-  if (blacklist->Find(name_value) == blacklist->end() &&
-      blacklist->Find(wildcard_value) == blacklist->end()) {
-    return allow_result;
-  }
-
-  // The native messaging host is blacklisted. Check the whitelist.
-  if (pref_service->IsManagedPreference(
-          pref_names::kNativeMessagingWhitelist)) {
-    const base::ListValue* whitelist =
-        pref_service->GetList(pref_names::kNativeMessagingWhitelist);
-    if (whitelist && whitelist->Find(name_value) != whitelist->end())
-      return allow_result;
-  }
-
-  return DISALLOW;
-}
-
 NativeMessageProcessHost::NativeMessageProcessHost(
-    base::WeakPtr<Client> weak_client_ui,
     const std::string& source_extension_id,
     const std::string& native_host_name,
-    int destination_port,
     scoped_ptr<NativeProcessLauncher> launcher)
-    : weak_client_ui_(weak_client_ui),
-      source_extension_id_(source_extension_id),
+    : source_extension_id_(source_extension_id),
       native_host_name_(native_host_name),
-      destination_port_(destination_port),
       launcher_(launcher.Pass()),
       closed_(false),
       process_handle_(base::kNullProcessHandle),
 #if defined(OS_POSIX)
       read_file_(-1),
 #endif
       read_pending_(false),
       write_pending_(false) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
+  task_runner_ = content::BrowserThread::GetMessageLoopProxyForThread(
+      content::BrowserThread::IO);
   // It's safe to use base::Unretained() here because NativeMessagePort always
   // deletes us on the IO thread.
-  content::BrowserThread::PostTask(content::BrowserThread::IO, FROM_HERE,
+  task_runner_->PostTask(
+      FROM_HERE,
       base::Bind(&NativeMessageProcessHost::LaunchHostProcess,
                  base::Unretained(this)));
 }
 
 NativeMessageProcessHost::~NativeMessageProcessHost() {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
-  Close(std::string());
+  DCHECK(task_runner_->BelongsToCurrentThread());
 }
 
 // static
-scoped_ptr<NativeMessageProcessHost> NativeMessageProcessHost::Create(
+scoped_ptr<NativeMessageHost> NativeMessageHost::Create(
     gfx::NativeView native_view,
-    base::WeakPtr<Client> weak_client_ui,
     const std::string& source_extension_id,
     const std::string& native_host_name,
-    int destination_port,
-    bool allow_user_level) {
-  return CreateWithLauncher(weak_client_ui, source_extension_id,
-                            native_host_name, destination_port,
-                            NativeProcessLauncher::CreateDefault(
-                                allow_user_level, native_view));
+    bool allow_user_level,
+    std::string* error_message) {
+  return NativeMessageProcessHost::CreateWithLauncher(
+      source_extension_id,
+      native_host_name,
+      NativeProcessLauncher::CreateDefault(allow_user_level, native_view));
 }
 
 // static
-scoped_ptr<NativeMessageProcessHost>
-NativeMessageProcessHost::CreateWithLauncher(
-    base::WeakPtr<Client> weak_client_ui,
+scoped_ptr<NativeMessageHost> NativeMessageProcessHost::CreateWithLauncher(
     const std::string& source_extension_id,
     const std::string& native_host_name,
-    int destination_port,
     scoped_ptr<NativeProcessLauncher> launcher) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
-  scoped_ptr<NativeMessageProcessHost> process(new NativeMessageProcessHost(
-      weak_client_ui, source_extension_id, native_host_name,
-      destination_port, launcher.Pass()));
+  scoped_ptr<NativeMessageHost> process(
+      new NativeMessageProcessHost(source_extension_id,
+                                   native_host_name,
+                                   launcher.Pass()));
 
   return process.Pass();
 }
 
 void NativeMessageProcessHost::LaunchHostProcess() {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  DCHECK(task_runner_->BelongsToCurrentThread());
 
   GURL origin(std::string(kExtensionScheme) + "://" + source_extension_id_);
   launcher_->Launch(origin, native_host_name_,
                     base::Bind(&NativeMessageProcessHost::OnHostProcessLaunched,
                                base::Unretained(this)));
 }
 
 void NativeMessageProcessHost::OnHostProcessLaunched(
     NativeProcessLauncher::LaunchResult result,
     base::ProcessHandle process_handle,
     base::File read_file,
     base::File write_file) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  DCHECK(task_runner_->BelongsToCurrentThread());
 
   switch (result) {
     case NativeProcessLauncher::RESULT_INVALID_NAME:
       Close(kInvalidNameError);
       return;
     case NativeProcessLauncher::RESULT_NOT_FOUND:
       Close(kNotFoundError);
       return;
     case NativeProcessLauncher::RESULT_FORBIDDEN:
       Close(kForbiddenError);
@@ skipping 16 matching lines @@
           GetTaskRunnerWithShutdownBehavior(
               base::SequencedWorkerPool::SKIP_ON_SHUTDOWN));
 
   read_stream_.reset(new net::FileStream(read_file.Pass(), task_runner));
   write_stream_.reset(new net::FileStream(write_file.Pass(), task_runner));
 
   WaitRead();
   DoWrite();
 }
 
-void NativeMessageProcessHost::Send(const std::string& json) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+void NativeMessageProcessHost::OnMessage(const std::string& json) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
 
   if (closed_)
     return;
 
   // Allocate new buffer for the message.
   scoped_refptr<net::IOBufferWithSize> buffer =
       new net::IOBufferWithSize(json.size() + kMessageHeaderSize);
 
   // Copy size and content of the message to the buffer.
   COMPILE_ASSERT(sizeof(uint32) == kMessageHeaderSize, incorrect_header_size);
   *reinterpret_cast<uint32*>(buffer->data()) = json.size();
   memcpy(buffer->data() + kMessageHeaderSize, json.data(), json.size());
 
   // Push new message to the write queue.
   write_queue_.push(buffer);
 
   // Send() may be called before the host process is started. In that case the
   // message will be written when OnHostProcessLaunched() is called. If it's
   // already started then write the message now.
   if (write_stream_)
     DoWrite();
 }
 
+void NativeMessageProcessHost::Start(Client* client) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+  client_ = client;
+}
+
+scoped_refptr<base::SingleThreadTaskRunner>
+NativeMessageProcessHost::task_runner() const {
+  return task_runner_;
+}
+
 #if defined(OS_POSIX)
 void NativeMessageProcessHost::OnFileCanReadWithoutBlocking(int fd) {
   DCHECK_EQ(fd, read_file_);
   DoRead();
 }
 
 void NativeMessageProcessHost::OnFileCanWriteWithoutBlocking(int fd) {
   NOTREACHED();
 }
 #endif  // !defined(OS_POSIX)
@@ skipping 15 matching lines @@
 #if defined(OS_POSIX)
   base::MessageLoopForIO::current()->WatchFileDescriptor(
     read_file_, false /* persistent */,
     base::MessageLoopForIO::WATCH_READ, &read_watcher_, this);
 #else  // defined(OS_POSIX)
   DoRead();
 #endif  // defined(!OS_POSIX)
 }
 
 void NativeMessageProcessHost::DoRead() {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  DCHECK(task_runner_->BelongsToCurrentThread());
 
   while (!closed_ && !read_pending_) {
     read_buffer_ = new net::IOBuffer(kReadBufferSize);
     int result = read_stream_->Read(
         read_buffer_.get(),
         kReadBufferSize,
         base::Bind(&NativeMessageProcessHost::OnRead, base::Unretained(this)));
     HandleReadResult(result);
   }
 }
 
 void NativeMessageProcessHost::OnRead(int result) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(read_pending_);
   read_pending_ = false;
 
   HandleReadResult(result);
   WaitRead();
 }
 
 void NativeMessageProcessHost::HandleReadResult(int result) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  DCHECK(task_runner_->BelongsToCurrentThread());
 
   if (closed_)
     return;
 
   if (result > 0) {
     ProcessIncomingData(read_buffer_->data(), result);
   } else if (result == net::ERR_IO_PENDING) {
     read_pending_ = true;
   } else if (result == 0 || result == net::ERR_CONNECTION_RESET) {
     // On Windows we get net::ERR_CONNECTION_RESET for a broken pipe, while on
     // Posix read() returns 0 in that case.
     Close(kNativeHostExited);
   } else {
     LOG(ERROR) << "Error when reading from Native Messaging host: " << result;
     Close(kHostInputOuputError);
   }
 }
 
 void NativeMessageProcessHost::ProcessIncomingData(
     const char* data, int data_size) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  DCHECK(task_runner_->BelongsToCurrentThread());
 
   incoming_data_.append(data, data_size);
 
   while (true) {
     if (incoming_data_.size() < kMessageHeaderSize)
       return;
 
     size_t message_size =
         *reinterpret_cast<const uint32*>(incoming_data_.data());
 
     if (message_size > kMaximumMessageSize) {
       LOG(ERROR) << "Native Messaging host tried sending a message that is "
                  << message_size << " bytes long.";
       Close(kHostInputOuputError);
       return;
     }
 
     if (incoming_data_.size() < message_size + kMessageHeaderSize)
       return;
 
-    content::BrowserThread::PostTask(content::BrowserThread::UI, FROM_HERE,
-        base::Bind(&Client::PostMessageFromNativeProcess, weak_client_ui_,
-            destination_port_,
-            incoming_data_.substr(kMessageHeaderSize, message_size)));
+    client_->PostMessageFromNativeHost(
+        incoming_data_.substr(kMessageHeaderSize, message_size));
 
     incoming_data_.erase(0, kMessageHeaderSize + message_size);
   }
 }
 
 void NativeMessageProcessHost::DoWrite() {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  DCHECK(task_runner_->BelongsToCurrentThread());
 
   while (!write_pending_ && !closed_) {
     if (!current_write_buffer_.get() ||
         !current_write_buffer_->BytesRemaining()) {
       if (write_queue_.empty())
         return;
       current_write_buffer_ = new net::DrainableIOBuffer(
           write_queue_.front().get(), write_queue_.front()->size());
       write_queue_.pop();
     }
 
     int result =
         write_stream_->Write(current_write_buffer_.get(),
                              current_write_buffer_->BytesRemaining(),
                              base::Bind(&NativeMessageProcessHost::OnWritten,
                                         base::Unretained(this)));
     HandleWriteResult(result);
   }
 }
 
 void NativeMessageProcessHost::HandleWriteResult(int result) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  DCHECK(task_runner_->BelongsToCurrentThread());
 
   if (result <= 0) {
     if (result == net::ERR_IO_PENDING) {
       write_pending_ = true;
     } else {
       LOG(ERROR) << "Error when writing to Native Messaging host: " << result;
       Close(kHostInputOuputError);
     }
     return;
   }
 
   current_write_buffer_->DidConsume(result);
 }
 
 void NativeMessageProcessHost::OnWritten(int result) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  DCHECK(task_runner_->BelongsToCurrentThread());
 
   DCHECK(write_pending_);
   write_pending_ = false;
 
   HandleWriteResult(result);
   DoWrite();
 }
 
 void NativeMessageProcessHost::Close(const std::string& error_message) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  DCHECK(task_runner_->BelongsToCurrentThread());
 
   if (!closed_) {
     closed_ = true;
     read_stream_.reset();
     write_stream_.reset();
-    content::BrowserThread::PostTask(content::BrowserThread::UI, FROM_HERE,
-        base::Bind(&Client::CloseChannel, weak_client_ui_,
-                   destination_port_, error_message));
+    client_->CloseChannel(error_message);
   }
 
   if (process_handle_ != base::kNullProcessHandle) {
     // Kill the host process if necessary to make sure we don't leave zombies.
     // On OSX base::EnsureProcessTerminated() may block, so we have to post a
     // task on the blocking pool.
 #if defined(OS_MACOSX)
     content::BrowserThread::PostBlockingPoolTask(
         FROM_HERE, base::Bind(&base::EnsureProcessTerminated, process_handle_));
 #else
     base::EnsureProcessTerminated(process_handle_);
 #endif
     process_handle_ = base::kNullProcessHandle;
   }
 }
 
 }  // namespace extensions