1//
2// detail/impl/win_iocp_serial_port_service.ipp
3// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4//
5// Copyright (c) 2003-2021 Christopher M. Kohlhoff (chris at kohlhoff dot com)
6// Copyright (c) 2008 Rep Invariant Systems, Inc. ([email protected])
7//
8// Distributed under the Boost Software License, Version 1.0. (See accompanying
9// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
10//
11
12#ifndef BOOST_ASIO_DETAIL_IMPL_WIN_IOCP_SERIAL_PORT_SERVICE_IPP
13#define BOOST_ASIO_DETAIL_IMPL_WIN_IOCP_SERIAL_PORT_SERVICE_IPP
14
15#if defined(_MSC_VER) && (_MSC_VER >= 1200)
16# pragma once
17#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
18
19#include <boost/asio/detail/config.hpp>
20
21#if defined(BOOST_ASIO_HAS_IOCP) && defined(BOOST_ASIO_HAS_SERIAL_PORT)
22
23#include <cstring>
24#include <boost/asio/detail/win_iocp_serial_port_service.hpp>
25
26#include <boost/asio/detail/push_options.hpp>
27
28namespace boost {
29namespace asio {
30namespace detail {
31
32win_iocp_serial_port_service::win_iocp_serial_port_service(
33    execution_context& context)
34  : execution_context_service_base<win_iocp_serial_port_service>(context),
35    handle_service_(context)
36{
37}
38
39void win_iocp_serial_port_service::shutdown()
40{
41}
42
43boost::system::error_code win_iocp_serial_port_service::open(
44    win_iocp_serial_port_service::implementation_type& impl,
45    const std::string& device, boost::system::error_code& ec)
46{
47  if (is_open(impl))
48  {
49    ec = boost::asio::error::already_open;
50    return ec;
51  }
52
53  // For convenience, add a leading \\.\ sequence if not already present.
54  std::string name = (device[0] == '\\') ? device : "\\\\.\\" + device;
55
56  // Open a handle to the serial port.
57  ::HANDLE handle = ::CreateFileA(name.c_str(),
58      GENERIC_READ | GENERIC_WRITE, 0, 0,
59      OPEN_EXISTING, FILE_FLAG_OVERLAPPED, 0);
60  if (handle == INVALID_HANDLE_VALUE)
61  {
62    DWORD last_error = ::GetLastError();
63    ec = boost::system::error_code(last_error,
64        boost::asio::error::get_system_category());
65    return ec;
66  }
67
68  // Determine the initial serial port parameters.
69  using namespace std; // For memset.
70  ::DCB dcb;
71  memset(&dcb, 0, sizeof(DCB));
72  dcb.DCBlength = sizeof(DCB);
73  if (!::GetCommState(handle, &dcb))
74  {
75    DWORD last_error = ::GetLastError();
76    ::CloseHandle(handle);
77    ec = boost::system::error_code(last_error,
78        boost::asio::error::get_system_category());
79    return ec;
80  }
81
82  // Set some default serial port parameters. This implementation does not
83  // support changing all of these, so they might as well be in a known state.
84  dcb.fBinary = TRUE; // Win32 only supports binary mode.
85  dcb.fNull = FALSE; // Do not ignore NULL characters.
86  dcb.fAbortOnError = FALSE; // Ignore serial framing errors.
87  dcb.BaudRate = CBR_9600; // 9600 baud by default
88  dcb.ByteSize = 8; // 8 bit bytes
89  dcb.fOutxCtsFlow = FALSE; // No flow control
90  dcb.fOutxDsrFlow = FALSE;
91  dcb.fDtrControl = DTR_CONTROL_DISABLE;
92  dcb.fDsrSensitivity = FALSE;
93  dcb.fOutX = FALSE;
94  dcb.fInX = FALSE;
95  dcb.fRtsControl = RTS_CONTROL_DISABLE;
96  dcb.fParity = FALSE; // No parity
97  dcb.Parity = NOPARITY;
98  dcb.StopBits = ONESTOPBIT; // One stop bit
99  if (!::SetCommState(handle, &dcb))
100  {
101    DWORD last_error = ::GetLastError();
102    ::CloseHandle(handle);
103    ec = boost::system::error_code(last_error,
104        boost::asio::error::get_system_category());
105    return ec;
106  }
107
108  // Set up timeouts so that the serial port will behave similarly to a
109  // network socket. Reads wait for at least one byte, then return with
110  // whatever they have. Writes return once everything is out the door.
111  ::COMMTIMEOUTS timeouts;
112  timeouts.ReadIntervalTimeout = 1;
113  timeouts.ReadTotalTimeoutMultiplier = 0;
114  timeouts.ReadTotalTimeoutConstant = 0;
115  timeouts.WriteTotalTimeoutMultiplier = 0;
116  timeouts.WriteTotalTimeoutConstant = 0;
117  if (!::SetCommTimeouts(handle, &timeouts))
118  {
119    DWORD last_error = ::GetLastError();
120    ::CloseHandle(handle);
121    ec = boost::system::error_code(last_error,
122        boost::asio::error::get_system_category());
123    return ec;
124  }
125
126  // We're done. Take ownership of the serial port handle.
127  if (handle_service_.assign(impl, handle, ec))
128    ::CloseHandle(handle);
129  return ec;
130}
131
132boost::system::error_code win_iocp_serial_port_service::do_set_option(
133    win_iocp_serial_port_service::implementation_type& impl,
134    win_iocp_serial_port_service::store_function_type store,
135    const void* option, boost::system::error_code& ec)
136{
137  using namespace std; // For memcpy.
138
139  ::DCB dcb;
140  memset(&dcb, 0, sizeof(DCB));
141  dcb.DCBlength = sizeof(DCB);
142  if (!::GetCommState(handle_service_.native_handle(impl), &dcb))
143  {
144    DWORD last_error = ::GetLastError();
145    ec = boost::system::error_code(last_error,
146        boost::asio::error::get_system_category());
147    return ec;
148  }
149
150  if (store(option, dcb, ec))
151    return ec;
152
153  if (!::SetCommState(handle_service_.native_handle(impl), &dcb))
154  {
155    DWORD last_error = ::GetLastError();
156    ec = boost::system::error_code(last_error,
157        boost::asio::error::get_system_category());
158    return ec;
159  }
160
161  ec = boost::system::error_code();
162  return ec;
163}
164
165boost::system::error_code win_iocp_serial_port_service::do_get_option(
166    const win_iocp_serial_port_service::implementation_type& impl,
167    win_iocp_serial_port_service::load_function_type load,
168    void* option, boost::system::error_code& ec) const
169{
170  using namespace std; // For memset.
171
172  ::DCB dcb;
173  memset(&dcb, 0, sizeof(DCB));
174  dcb.DCBlength = sizeof(DCB);
175  if (!::GetCommState(handle_service_.native_handle(impl), &dcb))
176  {
177    DWORD last_error = ::GetLastError();
178    ec = boost::system::error_code(last_error,
179        boost::asio::error::get_system_category());
180    return ec;
181  }
182
183  return load(option, dcb, ec);
184}
185
186} // namespace detail
187} // namespace asio
188} // namespace boost
189
190#include <boost/asio/detail/pop_options.hpp>
191
192#endif // defined(BOOST_ASIO_HAS_IOCP) && defined(BOOST_ASIO_HAS_SERIAL_PORT)
193
194#endif // BOOST_ASIO_DETAIL_IMPL_WIN_IOCP_SERIAL_PORT_SERVICE_IPP
195