blob: 7347db0ad726fd8e35d1d0624b5093caccd15648 [file] [log] [blame]
// 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 "dbus/bus.h"
#include "base/bind.h"
#include "base/logging.h"
#include "base/message_loop/message_loop.h"
#include "base/metrics/histogram.h"
#include "base/strings/string_piece.h"
#include "base/strings/stringprintf.h"
#include "base/task_runner_util.h"
#include "base/threading/thread.h"
#include "base/threading/thread_restrictions.h"
#include "dbus/dbus_statistics.h"
#include "dbus/message.h"
#include "dbus/object_path.h"
#include "dbus/object_proxy.h"
#include "dbus/scoped_dbus_error.h"
#include "dbus/util.h"
namespace dbus {
namespace {
const char kErrorServiceUnknown[] = "org.freedesktop.DBus.Error.ServiceUnknown";
const char kErrorObjectUnknown[] = "org.freedesktop.DBus.Error.UnknownObject";
// Used for success ratio histograms. 1 for success, 0 for failure.
const int kSuccessRatioHistogramMaxValue = 2;
// The path of D-Bus Object sending NameOwnerChanged signal.
const char kDBusSystemObjectPath[] = "/org/freedesktop/DBus";
// The D-Bus Object interface.
const char kDBusSystemObjectInterface[] = "org.freedesktop.DBus";
// The D-Bus Object address.
const char kDBusSystemObjectAddress[] = "org.freedesktop.DBus";
// The NameOwnerChanged member in |kDBusSystemObjectInterface|.
const char kNameOwnerChangedMember[] = "NameOwnerChanged";
// An empty function used for ObjectProxy::EmptyResponseCallback().
void EmptyResponseCallbackBody(Response* /*response*/) {
}
} // namespace
ObjectProxy::ObjectProxy(Bus* bus,
const std::string& service_name,
const ObjectPath& object_path,
int options)
: bus_(bus),
service_name_(service_name),
object_path_(object_path),
ignore_service_unknown_errors_(
options & IGNORE_SERVICE_UNKNOWN_ERRORS) {
}
ObjectProxy::~ObjectProxy() {
}
// Originally we tried to make |method_call| a const reference, but we
// gave up as dbus_connection_send_with_reply_and_block() takes a
// non-const pointer of DBusMessage as the second parameter.
scoped_ptr<Response> ObjectProxy::CallMethodAndBlockWithErrorDetails(
MethodCall* method_call, int timeout_ms, ScopedDBusError* error) {
bus_->AssertOnDBusThread();
if (!bus_->Connect() ||
!method_call->SetDestination(service_name_) ||
!method_call->SetPath(object_path_))
return scoped_ptr<Response>();
DBusMessage* request_message = method_call->raw_message();
// Send the message synchronously.
const base::TimeTicks start_time = base::TimeTicks::Now();
DBusMessage* response_message =
bus_->SendWithReplyAndBlock(request_message, timeout_ms, error->get());
// Record if the method call is successful, or not. 1 if successful.
UMA_HISTOGRAM_ENUMERATION("DBus.SyncMethodCallSuccess",
response_message ? 1 : 0,
kSuccessRatioHistogramMaxValue);
statistics::AddBlockingSentMethodCall(service_name_,
method_call->GetInterface(),
method_call->GetMember());
if (!response_message) {
LogMethodCallFailure(method_call->GetInterface(),
method_call->GetMember(),
error->is_set() ? error->name() : "unknown error type",
error->is_set() ? error->message() : "");
return scoped_ptr<Response>();
}
// Record time spent for the method call. Don't include failures.
UMA_HISTOGRAM_TIMES("DBus.SyncMethodCallTime",
base::TimeTicks::Now() - start_time);
return Response::FromRawMessage(response_message);
}
scoped_ptr<Response> ObjectProxy::CallMethodAndBlock(MethodCall* method_call,
int timeout_ms) {
ScopedDBusError error;
return CallMethodAndBlockWithErrorDetails(method_call, timeout_ms, &error);
}
void ObjectProxy::CallMethod(MethodCall* method_call,
int timeout_ms,
ResponseCallback callback) {
CallMethodWithErrorCallback(method_call, timeout_ms, callback,
base::Bind(&ObjectProxy::OnCallMethodError,
this,
method_call->GetInterface(),
method_call->GetMember(),
callback));
}
void ObjectProxy::CallMethodWithErrorCallback(MethodCall* method_call,
int timeout_ms,
ResponseCallback callback,
ErrorCallback error_callback) {
bus_->AssertOnOriginThread();
const base::TimeTicks start_time = base::TimeTicks::Now();
if (!method_call->SetDestination(service_name_) ||
!method_call->SetPath(object_path_)) {
// In case of a failure, run the error callback with NULL.
DBusMessage* response_message = NULL;
base::Closure task = base::Bind(&ObjectProxy::RunResponseCallback,
this,
callback,
error_callback,
start_time,
response_message);
bus_->GetOriginTaskRunner()->PostTask(FROM_HERE, task);
return;
}
// Increment the reference count so we can safely reference the
// underlying request message until the method call is complete. This
// will be unref'ed in StartAsyncMethodCall().
DBusMessage* request_message = method_call->raw_message();
dbus_message_ref(request_message);
base::Closure task = base::Bind(&ObjectProxy::StartAsyncMethodCall,
this,
timeout_ms,
request_message,
callback,
error_callback,
start_time);
statistics::AddSentMethodCall(service_name_,
method_call->GetInterface(),
method_call->GetMember());
// Wait for the response in the D-Bus thread.
bus_->GetDBusTaskRunner()->PostTask(FROM_HERE, task);
}
void ObjectProxy::ConnectToSignal(const std::string& interface_name,
const std::string& signal_name,
SignalCallback signal_callback,
OnConnectedCallback on_connected_callback) {
bus_->AssertOnOriginThread();
if (bus_->HasDBusThread()) {
base::PostTaskAndReplyWithResult(
bus_->GetDBusTaskRunner(), FROM_HERE,
base::Bind(&ObjectProxy::ConnectToSignalInternal, this, interface_name,
signal_name, signal_callback),
base::Bind(on_connected_callback, interface_name, signal_name));
} else {
// If the bus doesn't have a dedicated dbus thread we need to call
// ConnectToSignalInternal directly otherwise we might miss a signal
// that is currently queued if we do a PostTask.
const bool success =
ConnectToSignalInternal(interface_name, signal_name, signal_callback);
on_connected_callback.Run(interface_name, signal_name, success);
}
}
void ObjectProxy::SetNameOwnerChangedCallback(
NameOwnerChangedCallback callback) {
bus_->AssertOnOriginThread();
name_owner_changed_callback_ = callback;
}
void ObjectProxy::WaitForServiceToBeAvailable(
WaitForServiceToBeAvailableCallback callback) {
bus_->AssertOnOriginThread();
wait_for_service_to_be_available_callbacks_.push_back(callback);
bus_->GetDBusTaskRunner()->PostTask(
FROM_HERE,
base::Bind(&ObjectProxy::WaitForServiceToBeAvailableInternal, this));
}
void ObjectProxy::Detach() {
bus_->AssertOnDBusThread();
if (bus_->is_connected())
bus_->RemoveFilterFunction(&ObjectProxy::HandleMessageThunk, this);
for (std::set<std::string>::iterator iter = match_rules_.begin();
iter != match_rules_.end(); ++iter) {
ScopedDBusError error;
bus_->RemoveMatch(*iter, error.get());
if (error.is_set()) {
// There is nothing we can do to recover, so just print the error.
LOG(ERROR) << "Failed to remove match rule: " << *iter;
}
}
match_rules_.clear();
}
// static
ObjectProxy::ResponseCallback ObjectProxy::EmptyResponseCallback() {
return base::Bind(&EmptyResponseCallbackBody);
}
ObjectProxy::OnPendingCallIsCompleteData::OnPendingCallIsCompleteData(
ObjectProxy* in_object_proxy,
ResponseCallback in_response_callback,
ErrorCallback in_error_callback,
base::TimeTicks in_start_time)
: object_proxy(in_object_proxy),
response_callback(in_response_callback),
error_callback(in_error_callback),
start_time(in_start_time) {
}
ObjectProxy::OnPendingCallIsCompleteData::~OnPendingCallIsCompleteData() {
}
void ObjectProxy::StartAsyncMethodCall(int timeout_ms,
DBusMessage* request_message,
ResponseCallback response_callback,
ErrorCallback error_callback,
base::TimeTicks start_time) {
bus_->AssertOnDBusThread();
if (!bus_->Connect() || !bus_->SetUpAsyncOperations()) {
// In case of a failure, run the error callback with NULL.
DBusMessage* response_message = NULL;
base::Closure task = base::Bind(&ObjectProxy::RunResponseCallback,
this,
response_callback,
error_callback,
start_time,
response_message);
bus_->GetOriginTaskRunner()->PostTask(FROM_HERE, task);
dbus_message_unref(request_message);
return;
}
DBusPendingCall* pending_call = NULL;
bus_->SendWithReply(request_message, &pending_call, timeout_ms);
// Prepare the data we'll be passing to OnPendingCallIsCompleteThunk().
// The data will be deleted in OnPendingCallIsCompleteThunk().
OnPendingCallIsCompleteData* data =
new OnPendingCallIsCompleteData(this, response_callback, error_callback,
start_time);
// This returns false only when unable to allocate memory.
const bool success = dbus_pending_call_set_notify(
pending_call,
&ObjectProxy::OnPendingCallIsCompleteThunk,
data,
NULL);
CHECK(success) << "Unable to allocate memory";
dbus_pending_call_unref(pending_call);
// It's now safe to unref the request message.
dbus_message_unref(request_message);
}
void ObjectProxy::OnPendingCallIsComplete(DBusPendingCall* pending_call,
ResponseCallback response_callback,
ErrorCallback error_callback,
base::TimeTicks start_time) {
bus_->AssertOnDBusThread();
DBusMessage* response_message = dbus_pending_call_steal_reply(pending_call);
base::Closure task = base::Bind(&ObjectProxy::RunResponseCallback,
this,
response_callback,
error_callback,
start_time,
response_message);
bus_->GetOriginTaskRunner()->PostTask(FROM_HERE, task);
}
void ObjectProxy::RunResponseCallback(ResponseCallback response_callback,
ErrorCallback error_callback,
base::TimeTicks start_time,
DBusMessage* response_message) {
bus_->AssertOnOriginThread();
bool method_call_successful = false;
if (!response_message) {
// The response is not received.
error_callback.Run(NULL);
} else if (dbus_message_get_type(response_message) ==
DBUS_MESSAGE_TYPE_ERROR) {
// This will take |response_message| and release (unref) it.
scoped_ptr<ErrorResponse> error_response(
ErrorResponse::FromRawMessage(response_message));
error_callback.Run(error_response.get());
// Delete the message on the D-Bus thread. See below for why.
bus_->GetDBusTaskRunner()->PostTask(
FROM_HERE,
base::Bind(&base::DeletePointer<ErrorResponse>,
error_response.release()));
} else {
// This will take |response_message| and release (unref) it.
scoped_ptr<Response> response(Response::FromRawMessage(response_message));
// The response is successfully received.
response_callback.Run(response.get());
// The message should be deleted on the D-Bus thread for a complicated
// reason:
//
// libdbus keeps track of the number of bytes in the incoming message
// queue to ensure that the data size in the queue is manageable. The
// bookkeeping is partly done via dbus_message_unref(), and immediately
// asks the client code (Chrome) to stop monitoring the underlying
// socket, if the number of bytes exceeds a certian number, which is set
// to 63MB, per dbus-transport.cc:
//
// /* Try to default to something that won't totally hose the system,
// * but doesn't impose too much of a limitation.
// */
// transport->max_live_messages_size = _DBUS_ONE_MEGABYTE * 63;
//
// The monitoring of the socket is done on the D-Bus thread (see Watch
// class in bus.cc), hence we should stop the monitoring from D-Bus
// thread, not from the current thread here, which is likely UI thread.
bus_->GetDBusTaskRunner()->PostTask(
FROM_HERE,
base::Bind(&base::DeletePointer<Response>, response.release()));
method_call_successful = true;
// Record time spent for the method call. Don't include failures.
UMA_HISTOGRAM_TIMES("DBus.AsyncMethodCallTime",
base::TimeTicks::Now() - start_time);
}
// Record if the method call is successful, or not. 1 if successful.
UMA_HISTOGRAM_ENUMERATION("DBus.AsyncMethodCallSuccess",
method_call_successful,
kSuccessRatioHistogramMaxValue);
}
void ObjectProxy::OnPendingCallIsCompleteThunk(DBusPendingCall* pending_call,
void* user_data) {
OnPendingCallIsCompleteData* data =
reinterpret_cast<OnPendingCallIsCompleteData*>(user_data);
ObjectProxy* self = data->object_proxy;
self->OnPendingCallIsComplete(pending_call,
data->response_callback,
data->error_callback,
data->start_time);
delete data;
}
bool ObjectProxy::ConnectToNameOwnerChangedSignal() {
bus_->AssertOnDBusThread();
if (!bus_->Connect() || !bus_->SetUpAsyncOperations())
return false;
bus_->AddFilterFunction(&ObjectProxy::HandleMessageThunk, this);
// Add a match_rule listening NameOwnerChanged for the well-known name
// |service_name_|.
const std::string name_owner_changed_match_rule =
base::StringPrintf(
"type='signal',interface='org.freedesktop.DBus',"
"member='NameOwnerChanged',path='/org/freedesktop/DBus',"
"sender='org.freedesktop.DBus',arg0='%s'",
service_name_.c_str());
const bool success =
AddMatchRuleWithoutCallback(name_owner_changed_match_rule,
"org.freedesktop.DBus.NameOwnerChanged");
// Try getting the current name owner. It's not guaranteed that we can get
// the name owner at this moment, as the service may not yet be started. If
// that's the case, we'll get the name owner via NameOwnerChanged signal,
// as soon as the service is started.
UpdateNameOwnerAndBlock();
return success;
}
bool ObjectProxy::ConnectToSignalInternal(const std::string& interface_name,
const std::string& signal_name,
SignalCallback signal_callback) {
bus_->AssertOnDBusThread();
if (!ConnectToNameOwnerChangedSignal())
return false;
const std::string absolute_signal_name =
GetAbsoluteMemberName(interface_name, signal_name);
// Add a match rule so the signal goes through HandleMessage().
const std::string match_rule =
base::StringPrintf("type='signal', interface='%s', path='%s'",
interface_name.c_str(),
object_path_.value().c_str());
return AddMatchRuleWithCallback(match_rule,
absolute_signal_name,
signal_callback);
}
void ObjectProxy::WaitForServiceToBeAvailableInternal() {
bus_->AssertOnDBusThread();
if (!ConnectToNameOwnerChangedSignal()) { // Failed to connect to the signal.
const bool service_is_ready = false;
bus_->GetOriginTaskRunner()->PostTask(
FROM_HERE,
base::Bind(&ObjectProxy::RunWaitForServiceToBeAvailableCallbacks,
this, service_is_ready));
return;
}
const bool service_is_available = !service_name_owner_.empty();
if (service_is_available) { // Service is already available.
bus_->GetOriginTaskRunner()->PostTask(
FROM_HERE,
base::Bind(&ObjectProxy::RunWaitForServiceToBeAvailableCallbacks,
this, service_is_available));
return;
}
}
DBusHandlerResult ObjectProxy::HandleMessage(
DBusConnection* connection,
DBusMessage* raw_message) {
bus_->AssertOnDBusThread();
if (dbus_message_get_type(raw_message) != DBUS_MESSAGE_TYPE_SIGNAL)
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
// raw_message will be unrefed on exit of the function. Increment the
// reference so we can use it in Signal.
dbus_message_ref(raw_message);
scoped_ptr<Signal> signal(
Signal::FromRawMessage(raw_message));
// Verify the signal comes from the object we're proxying for, this is
// our last chance to return DBUS_HANDLER_RESULT_NOT_YET_HANDLED and
// allow other object proxies to handle instead.
const ObjectPath path = signal->GetPath();
if (path != object_path_) {
if (path.value() == kDBusSystemObjectPath &&
signal->GetMember() == kNameOwnerChangedMember) {
// Handle NameOwnerChanged separately
return HandleNameOwnerChanged(signal.Pass());
}
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
const std::string interface = signal->GetInterface();
const std::string member = signal->GetMember();
statistics::AddReceivedSignal(service_name_, interface, member);
// Check if we know about the signal.
const std::string absolute_signal_name = GetAbsoluteMemberName(
interface, member);
MethodTable::const_iterator iter = method_table_.find(absolute_signal_name);
if (iter == method_table_.end()) {
// Don't know about the signal.
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
VLOG(1) << "Signal received: " << signal->ToString();
std::string sender = signal->GetSender();
if (service_name_owner_ != sender) {
LOG(ERROR) << "Rejecting a message from a wrong sender.";
UMA_HISTOGRAM_COUNTS("DBus.RejectedSignalCount", 1);
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
const base::TimeTicks start_time = base::TimeTicks::Now();
if (bus_->HasDBusThread()) {
// Post a task to run the method in the origin thread.
// Transfer the ownership of |signal| to RunMethod().
// |released_signal| will be deleted in RunMethod().
Signal* released_signal = signal.release();
bus_->GetOriginTaskRunner()->PostTask(FROM_HERE,
base::Bind(&ObjectProxy::RunMethod,
this,
start_time,
iter->second,
released_signal));
} else {
const base::TimeTicks start_time = base::TimeTicks::Now();
// If the D-Bus thread is not used, just call the callback on the
// current thread. Transfer the ownership of |signal| to RunMethod().
Signal* released_signal = signal.release();
RunMethod(start_time, iter->second, released_signal);
}
// We don't return DBUS_HANDLER_RESULT_HANDLED for signals because other
// objects may be interested in them. (e.g. Signals from org.freedesktop.DBus)
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
void ObjectProxy::RunMethod(base::TimeTicks start_time,
std::vector<SignalCallback> signal_callbacks,
Signal* signal) {
bus_->AssertOnOriginThread();
for (std::vector<SignalCallback>::iterator iter = signal_callbacks.begin();
iter != signal_callbacks.end(); ++iter)
iter->Run(signal);
// Delete the message on the D-Bus thread. See comments in
// RunResponseCallback().
bus_->GetDBusTaskRunner()->PostTask(
FROM_HERE,
base::Bind(&base::DeletePointer<Signal>, signal));
// Record time spent for handling the signal.
UMA_HISTOGRAM_TIMES("DBus.SignalHandleTime",
base::TimeTicks::Now() - start_time);
}
DBusHandlerResult ObjectProxy::HandleMessageThunk(
DBusConnection* connection,
DBusMessage* raw_message,
void* user_data) {
ObjectProxy* self = reinterpret_cast<ObjectProxy*>(user_data);
return self->HandleMessage(connection, raw_message);
}
void ObjectProxy::LogMethodCallFailure(
const base::StringPiece& interface_name,
const base::StringPiece& method_name,
const base::StringPiece& error_name,
const base::StringPiece& error_message) const {
if (ignore_service_unknown_errors_ &&
(error_name == kErrorServiceUnknown || error_name == kErrorObjectUnknown))
return;
logging::LogSeverity severity = logging::LOG_ERROR;
// "UnknownObject" indicates that an object or service is no longer available,
// e.g. a Shill network service has gone out of range. Treat these as warnings
// not errors.
if (error_name == kErrorObjectUnknown)
severity = logging::LOG_WARNING;
std::ostringstream msg;
msg << "Failed to call method: " << interface_name << "." << method_name
<< ": object_path= " << object_path_.value()
<< ": " << error_name << ": " << error_message;
logging::LogAtLevel(severity, msg.str());
}
void ObjectProxy::OnCallMethodError(const std::string& interface_name,
const std::string& method_name,
ResponseCallback response_callback,
ErrorResponse* error_response) {
if (error_response) {
// Error message may contain the error message as string.
MessageReader reader(error_response);
std::string error_message;
reader.PopString(&error_message);
LogMethodCallFailure(interface_name,
method_name,
error_response->GetErrorName(),
error_message);
}
response_callback.Run(NULL);
}
bool ObjectProxy::AddMatchRuleWithCallback(
const std::string& match_rule,
const std::string& absolute_signal_name,
SignalCallback signal_callback) {
DCHECK(!match_rule.empty());
DCHECK(!absolute_signal_name.empty());
bus_->AssertOnDBusThread();
if (match_rules_.find(match_rule) == match_rules_.end()) {
ScopedDBusError error;
bus_->AddMatch(match_rule, error.get());
if (error.is_set()) {
LOG(ERROR) << "Failed to add match rule \"" << match_rule << "\". Got "
<< error.name() << ": " << error.message();
return false;
} else {
// Store the match rule, so that we can remove this in Detach().
match_rules_.insert(match_rule);
// Add the signal callback to the method table.
method_table_[absolute_signal_name].push_back(signal_callback);
return true;
}
} else {
// We already have the match rule.
method_table_[absolute_signal_name].push_back(signal_callback);
return true;
}
}
bool ObjectProxy::AddMatchRuleWithoutCallback(
const std::string& match_rule,
const std::string& absolute_signal_name) {
DCHECK(!match_rule.empty());
DCHECK(!absolute_signal_name.empty());
bus_->AssertOnDBusThread();
if (match_rules_.find(match_rule) != match_rules_.end())
return true;
ScopedDBusError error;
bus_->AddMatch(match_rule, error.get());
if (error.is_set()) {
LOG(ERROR) << "Failed to add match rule \"" << match_rule << "\". Got "
<< error.name() << ": " << error.message();
return false;
}
// Store the match rule, so that we can remove this in Detach().
match_rules_.insert(match_rule);
return true;
}
void ObjectProxy::UpdateNameOwnerAndBlock() {
bus_->AssertOnDBusThread();
// Errors should be suppressed here, as the service may not be yet running
// when connecting to signals of the service, which is just fine.
// The ObjectProxy will be notified when the service is launched via
// NameOwnerChanged signal. See also comments in ConnectToSignalInternal().
service_name_owner_ =
bus_->GetServiceOwnerAndBlock(service_name_, Bus::SUPPRESS_ERRORS);
}
DBusHandlerResult ObjectProxy::HandleNameOwnerChanged(
scoped_ptr<Signal> signal) {
DCHECK(signal);
bus_->AssertOnDBusThread();
// Confirm the validity of the NameOwnerChanged signal.
if (signal->GetMember() == kNameOwnerChangedMember &&
signal->GetInterface() == kDBusSystemObjectInterface &&
signal->GetSender() == kDBusSystemObjectAddress) {
MessageReader reader(signal.get());
std::string name, old_owner, new_owner;
if (reader.PopString(&name) &&
reader.PopString(&old_owner) &&
reader.PopString(&new_owner) &&
name == service_name_) {
service_name_owner_ = new_owner;
bus_->GetOriginTaskRunner()->PostTask(
FROM_HERE,
base::Bind(&ObjectProxy::RunNameOwnerChangedCallback,
this, old_owner, new_owner));
const bool service_is_available = !service_name_owner_.empty();
if (service_is_available) {
bus_->GetOriginTaskRunner()->PostTask(
FROM_HERE,
base::Bind(&ObjectProxy::RunWaitForServiceToBeAvailableCallbacks,
this, service_is_available));
}
}
}
// Always return unhandled to let other object proxies handle the same
// signal.
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
void ObjectProxy::RunNameOwnerChangedCallback(const std::string& old_owner,
const std::string& new_owner) {
bus_->AssertOnOriginThread();
if (!name_owner_changed_callback_.is_null())
name_owner_changed_callback_.Run(old_owner, new_owner);
}
void ObjectProxy::RunWaitForServiceToBeAvailableCallbacks(
bool service_is_available) {
bus_->AssertOnOriginThread();
std::vector<WaitForServiceToBeAvailableCallback> callbacks;
callbacks.swap(wait_for_service_to_be_available_callbacks_);
for (size_t i = 0; i < callbacks.size(); ++i)
callbacks[i].Run(service_is_available);
}
} // namespace dbus