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// Copyright (c) 2010 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 "ipc/ipc_channel_win.h"
#include <windows.h>
#include <sddl.h>
#include <sstream>
#include "base/auto_reset.h"
#include "base/compiler_specific.h"
#include "base/logging.h"
#include "base/non_thread_safe.h"
#include "base/utf_string_conversions.h"
#include "base/win_util.h"
#include "ipc/ipc_logging.h"
#include "ipc/ipc_message_utils.h"
namespace IPC {
namespace {
// Creates a security descriptor with a DACL that has one ace giving full
// access to the current logon session.
// The security descriptor returned must be freed using LocalFree.
// The function returns true if it succeeds, false otherwise.
bool GetLogonSessionOnlyDACL(SECURITY_DESCRIPTOR** security_descriptor) {
// Get the current token.
HANDLE token = NULL;
if (!::OpenProcessToken(::GetCurrentProcess(), TOKEN_QUERY, &token))
return false;
ScopedHandle token_scoped(token);
// Get the size of the TokenGroups structure.
DWORD size = 0;
BOOL result = GetTokenInformation(token, TokenGroups, NULL, 0, &size);
if (result != FALSE && GetLastError() != ERROR_INSUFFICIENT_BUFFER)
return false;
// Get the data.
scoped_array<char> token_groups_chars(new char[size]);
TOKEN_GROUPS* token_groups =
reinterpret_cast<TOKEN_GROUPS*>(token_groups_chars.get());
if (!GetTokenInformation(token, TokenGroups, token_groups, size, &size))
return false;
// Look for the logon sid.
SID* logon_sid = NULL;
for (unsigned int i = 0; i < token_groups->GroupCount ; ++i) {
if ((token_groups->Groups[i].Attributes & SE_GROUP_LOGON_ID) != 0) {
logon_sid = static_cast<SID*>(token_groups->Groups[i].Sid);
break;
}
}
if (!logon_sid)
return false;
// Convert the data to a string.
wchar_t* sid_string;
if (!ConvertSidToStringSid(logon_sid, &sid_string))
return false;
static const wchar_t dacl_format[] = L"D:(A;OICI;GA;;;%ls)";
wchar_t dacl[SECURITY_MAX_SID_SIZE + arraysize(dacl_format) + 1] = {0};
wsprintf(dacl, dacl_format, sid_string);
LocalFree(sid_string);
// Convert the string to a security descriptor
if (!ConvertStringSecurityDescriptorToSecurityDescriptor(
dacl,
SDDL_REVISION_1,
reinterpret_cast<PSECURITY_DESCRIPTOR*>(security_descriptor),
NULL)) {
return false;
}
return true;
}
} // namespace
//------------------------------------------------------------------------------
Channel::ChannelImpl::State::State(ChannelImpl* channel) : is_pending(false) {
memset(&context.overlapped, 0, sizeof(context.overlapped));
context.handler = channel;
}
Channel::ChannelImpl::State::~State() {
COMPILE_ASSERT(!offsetof(Channel::ChannelImpl::State, context),
starts_with_io_context);
}
//------------------------------------------------------------------------------
Channel::ChannelImpl::ChannelImpl(const IPC::ChannelHandle &channel_handle,
Mode mode, Listener* listener)
: ALLOW_THIS_IN_INITIALIZER_LIST(input_state_(this)),
ALLOW_THIS_IN_INITIALIZER_LIST(output_state_(this)),
pipe_(INVALID_HANDLE_VALUE),
listener_(listener),
waiting_connect_(mode == MODE_SERVER),
processing_incoming_(false),
ALLOW_THIS_IN_INITIALIZER_LIST(factory_(this)) {
if (!CreatePipe(channel_handle, mode)) {
// The pipe may have been closed already.
LOG(WARNING) << "Unable to create pipe named \"" << channel_handle.name <<
"\" in " << (mode == 0 ? "server" : "client") << " mode.";
}
}
Channel::ChannelImpl::~ChannelImpl() {
Close();
}
void Channel::ChannelImpl::Close() {
if (thread_check_.get()) {
DCHECK(thread_check_->CalledOnValidThread());
}
if (input_state_.is_pending || output_state_.is_pending)
CancelIo(pipe_);
// Closing the handle at this point prevents us from issuing more requests
// form OnIOCompleted().
if (pipe_ != INVALID_HANDLE_VALUE) {
CloseHandle(pipe_);
pipe_ = INVALID_HANDLE_VALUE;
}
// Make sure all IO has completed.
base::Time start = base::Time::Now();
while (input_state_.is_pending || output_state_.is_pending) {
MessageLoopForIO::current()->WaitForIOCompletion(INFINITE, this);
}
while (!output_queue_.empty()) {
Message* m = output_queue_.front();
output_queue_.pop();
delete m;
}
}
bool Channel::ChannelImpl::Send(Message* message) {
DCHECK(thread_check_->CalledOnValidThread());
DVLOG(2) << "sending message @" << message << " on channel @" << this
<< " with type " << message->type()
<< " (" << output_queue_.size() << " in queue)";
#ifdef IPC_MESSAGE_LOG_ENABLED
Logging::GetInstance()->OnSendMessage(message, "");
#endif
output_queue_.push(message);
// ensure waiting to write
if (!waiting_connect_) {
if (!output_state_.is_pending) {
if (!ProcessOutgoingMessages(NULL, 0))
return false;
}
}
return true;
}
const std::wstring Channel::ChannelImpl::PipeName(
const std::string& channel_id) const {
std::wostringstream ss;
// XXX(darin): get application name from somewhere else
ss << L"\\\\.\\pipe\\chrome." << ASCIIToWide(channel_id);
return ss.str();
}
bool Channel::ChannelImpl::CreatePipe(const IPC::ChannelHandle &channel_handle,
Mode mode) {
DCHECK(pipe_ == INVALID_HANDLE_VALUE);
const std::wstring pipe_name = PipeName(channel_handle.name);
if (mode == MODE_SERVER) {
SECURITY_ATTRIBUTES security_attributes = {0};
security_attributes.bInheritHandle = FALSE;
security_attributes.nLength = sizeof(SECURITY_ATTRIBUTES);
if (!GetLogonSessionOnlyDACL(
reinterpret_cast<SECURITY_DESCRIPTOR**>(
&security_attributes.lpSecurityDescriptor))) {
NOTREACHED();
}
pipe_ = CreateNamedPipeW(pipe_name.c_str(),
PIPE_ACCESS_DUPLEX | FILE_FLAG_OVERLAPPED |
FILE_FLAG_FIRST_PIPE_INSTANCE,
PIPE_TYPE_BYTE | PIPE_READMODE_BYTE,
1, // number of pipe instances
// output buffer size (XXX tune)
Channel::kReadBufferSize,
// input buffer size (XXX tune)
Channel::kReadBufferSize,
5000, // timeout in milliseconds (XXX tune)
&security_attributes);
LocalFree(security_attributes.lpSecurityDescriptor);
} else {
pipe_ = CreateFileW(pipe_name.c_str(),
GENERIC_READ | GENERIC_WRITE,
0,
NULL,
OPEN_EXISTING,
SECURITY_SQOS_PRESENT | SECURITY_IDENTIFICATION |
FILE_FLAG_OVERLAPPED,
NULL);
}
if (pipe_ == INVALID_HANDLE_VALUE) {
// If this process is being closed, the pipe may be gone already.
LOG(WARNING) << "failed to create pipe: " << GetLastError();
return false;
}
// Create the Hello message to be sent when Connect is called
scoped_ptr<Message> m(new Message(MSG_ROUTING_NONE,
HELLO_MESSAGE_TYPE,
IPC::Message::PRIORITY_NORMAL));
if (!m->WriteInt(GetCurrentProcessId())) {
CloseHandle(pipe_);
pipe_ = INVALID_HANDLE_VALUE;
return false;
}
output_queue_.push(m.release());
return true;
}
bool Channel::ChannelImpl::Connect() {
DLOG_IF(WARNING, thread_check_.get()) << "Connect called more than once";
if (!thread_check_.get())
thread_check_.reset(new NonThreadSafe());
if (pipe_ == INVALID_HANDLE_VALUE)
return false;
MessageLoopForIO::current()->RegisterIOHandler(pipe_, this);
// Check to see if there is a client connected to our pipe...
if (waiting_connect_)
ProcessConnection();
if (!input_state_.is_pending) {
// Complete setup asynchronously. By not setting input_state_.is_pending
// to true, we indicate to OnIOCompleted that this is the special
// initialization signal.
MessageLoopForIO::current()->PostTask(FROM_HERE, factory_.NewRunnableMethod(
&Channel::ChannelImpl::OnIOCompleted, &input_state_.context, 0, 0));
}
if (!waiting_connect_)
ProcessOutgoingMessages(NULL, 0);
return true;
}
bool Channel::ChannelImpl::ProcessConnection() {
DCHECK(thread_check_->CalledOnValidThread());
if (input_state_.is_pending)
input_state_.is_pending = false;
// Do we have a client connected to our pipe?
if (INVALID_HANDLE_VALUE == pipe_)
return false;
BOOL ok = ConnectNamedPipe(pipe_, &input_state_.context.overlapped);
DWORD err = GetLastError();
if (ok) {
// Uhm, the API documentation says that this function should never
// return success when used in overlapped mode.
NOTREACHED();
return false;
}
switch (err) {
case ERROR_IO_PENDING:
input_state_.is_pending = true;
break;
case ERROR_PIPE_CONNECTED:
waiting_connect_ = false;
break;
case ERROR_NO_DATA:
// The pipe is being closed.
return false;
default:
NOTREACHED();
return false;
}
return true;
}
bool Channel::ChannelImpl::ProcessIncomingMessages(
MessageLoopForIO::IOContext* context,
DWORD bytes_read) {
DCHECK(thread_check_->CalledOnValidThread());
if (input_state_.is_pending) {
input_state_.is_pending = false;
DCHECK(context);
if (!context || !bytes_read)
return false;
} else {
// This happens at channel initialization.
DCHECK(!bytes_read && context == &input_state_.context);
}
for (;;) {
if (bytes_read == 0) {
if (INVALID_HANDLE_VALUE == pipe_)
return false;
// Read from pipe...
BOOL ok = ReadFile(pipe_,
input_buf_,
Channel::kReadBufferSize,
&bytes_read,
&input_state_.context.overlapped);
if (!ok) {
DWORD err = GetLastError();
if (err == ERROR_IO_PENDING) {
input_state_.is_pending = true;
return true;
}
LOG(ERROR) << "pipe error: " << err;
return false;
}
input_state_.is_pending = true;
return true;
}
DCHECK(bytes_read);
// Process messages from input buffer.
const char* p, *end;
if (input_overflow_buf_.empty()) {
p = input_buf_;
end = p + bytes_read;
} else {
if (input_overflow_buf_.size() > (kMaximumMessageSize - bytes_read)) {
input_overflow_buf_.clear();
LOG(ERROR) << "IPC message is too big";
return false;
}
input_overflow_buf_.append(input_buf_, bytes_read);
p = input_overflow_buf_.data();
end = p + input_overflow_buf_.size();
}
while (p < end) {
const char* message_tail = Message::FindNext(p, end);
if (message_tail) {
int len = static_cast<int>(message_tail - p);
const Message m(p, len);
DVLOG(2) << "received message on channel @" << this
<< " with type " << m.type();
if (m.routing_id() == MSG_ROUTING_NONE &&
m.type() == HELLO_MESSAGE_TYPE) {
// The Hello message contains only the process id.
listener_->OnChannelConnected(MessageIterator(m).NextInt());
} else {
listener_->OnMessageReceived(m);
}
p = message_tail;
} else {
// Last message is partial.
break;
}
}
input_overflow_buf_.assign(p, end - p);
bytes_read = 0; // Get more data.
}
return true;
}
bool Channel::ChannelImpl::ProcessOutgoingMessages(
MessageLoopForIO::IOContext* context,
DWORD bytes_written) {
DCHECK(!waiting_connect_); // Why are we trying to send messages if there's
// no connection?
DCHECK(thread_check_->CalledOnValidThread());
if (output_state_.is_pending) {
DCHECK(context);
output_state_.is_pending = false;
if (!context || bytes_written == 0) {
DWORD err = GetLastError();
LOG(ERROR) << "pipe error: " << err;
return false;
}
// Message was sent.
DCHECK(!output_queue_.empty());
Message* m = output_queue_.front();
output_queue_.pop();
delete m;
}
if (output_queue_.empty())
return true;
if (INVALID_HANDLE_VALUE == pipe_)
return false;
// Write to pipe...
Message* m = output_queue_.front();
BOOL ok = WriteFile(pipe_,
m->data(),
m->size(),
&bytes_written,
&output_state_.context.overlapped);
if (!ok) {
DWORD err = GetLastError();
if (err == ERROR_IO_PENDING) {
output_state_.is_pending = true;
DVLOG(2) << "sent pending message @" << m << " on channel @" << this
<< " with type " << m->type();
return true;
}
LOG(ERROR) << "pipe error: " << err;
return false;
}
DVLOG(2) << "sent message @" << m << " on channel @" << this
<< " with type " << m->type();
output_state_.is_pending = true;
return true;
}
void Channel::ChannelImpl::OnIOCompleted(MessageLoopForIO::IOContext* context,
DWORD bytes_transfered, DWORD error) {
bool ok;
DCHECK(thread_check_->CalledOnValidThread());
if (context == &input_state_.context) {
if (waiting_connect_) {
if (!ProcessConnection())
return;
// We may have some messages queued up to send...
if (!output_queue_.empty() && !output_state_.is_pending)
ProcessOutgoingMessages(NULL, 0);
if (input_state_.is_pending)
return;
// else, fall-through and look for incoming messages...
}
// we don't support recursion through OnMessageReceived yet!
DCHECK(!processing_incoming_);
AutoReset<bool> auto_reset_processing_incoming(&processing_incoming_, true);
ok = ProcessIncomingMessages(context, bytes_transfered);
} else {
DCHECK(context == &output_state_.context);
ok = ProcessOutgoingMessages(context, bytes_transfered);
}
if (!ok && INVALID_HANDLE_VALUE != pipe_) {
// We don't want to re-enter Close().
Close();
listener_->OnChannelError();
}
}
//------------------------------------------------------------------------------
// Channel's methods simply call through to ChannelImpl.
Channel::Channel(const IPC::ChannelHandle &channel_handle, Mode mode,
Listener* listener)
: channel_impl_(new ChannelImpl(channel_handle, mode, listener)) {
}
Channel::~Channel() {
delete channel_impl_;
}
bool Channel::Connect() {
return channel_impl_->Connect();
}
void Channel::Close() {
channel_impl_->Close();
}
void Channel::set_listener(Listener* listener) {
channel_impl_->set_listener(listener);
}
bool Channel::Send(Message* message) {
return channel_impl_->Send(message);
}
} // namespace IPC
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