/**

 * WinPR: Windows Portable Runtime

 * Serial Communication API

 *

 * Copyright 2011 O.S. Systems Software Ltda.

 * Copyright 2011 Eduardo Fiss Beloni <beloni@ossystems.com.br>

 * Copyright 2014 Marc-Andre Moreau <marcandre.moreau@gmail.com>

 * Copyright 2014 Hewlett-Packard Development Company, L.P.

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#include <winpr/config.h>

#include <winpr/assert.h>

#include <errno.h>

#include <winpr/wlog.h>

#include "comm.h"

#include "comm_ioctl.h"

#include "comm_serial_sys.h"

#include "comm_sercx_sys.h"

#include "comm_sercx2_sys.h"

static const char* comm_ioctl_modem_status_string(ULONG status, char* buffer, size_t size);

/* NB: MS-RDPESP's recommendation:

 *

 * <2> Section 3.2.5.1.6: Windows Implementations use IOCTL constants

 * for IoControlCode values.  The content and values of the IOCTLs are

 * opaque to the protocol. On the server side, the data contained in

 * an IOCTL is simply packaged and sent to the client side. For

 * maximum compatibility between the different versions of the Windows

 * operating system, the client implementation only singles out

 * critical IOCTLs and invokes the applicable Win32 port API. The

 * other IOCTLS are passed directly to the client-side driver, and the

 * processing of this value depends on the drivers installed on the

 * client side. The values and parameters for these IOCTLS can be

 * found in [MSFT-W2KDDK] Volume 2, Part 2—Serial and Parallel

 * Drivers, and in [MSDN-PORTS].

 */

static BOOL s_CommDeviceIoControl(HANDLE hDevice, DWORD dwIoControlCode, LPVOID lpInBuffer,

                                  DWORD nInBufferSize, LPVOID lpOutBuffer, DWORD nOutBufferSize,

                                  LPDWORD lpBytesReturned, LPOVERLAPPED lpOverlapped)

{

  char buffer[128] = WINPR_C_ARRAY_INIT;

  WINPR_COMM* pComm = (WINPR_COMM*)hDevice;

  const SERIAL_DRIVER* pServerSerialDriver = nullptr;

  if (!CommIsHandleValid(hDevice))

    return FALSE;

  if (lpOverlapped)

  {

    SetLastError(ERROR_NOT_SUPPORTED);

    return FALSE;

  }

  if (lpBytesReturned == nullptr)

  {

    SetLastError(

        ERROR_INVALID_PARAMETER); /* since we doesn't support lpOverlapped != nullptr */

    return FALSE;

  }

  /* clear any previous last error */

  SetLastError(ERROR_SUCCESS);

  *lpBytesReturned = 0; /* will be adjusted if required ... */

  CommLog_Print(WLOG_DEBUG, "CommDeviceIoControl: IoControlCode: %s [0x%08" PRIx32 "]",

                _comm_serial_ioctl_name(dwIoControlCode), dwIoControlCode);

  /* remoteSerialDriver to be use ...

   *

   * FIXME: might prefer to use an automatic rather than static structure

   */

  switch (pComm->serverSerialDriverId)

  {

    case SerialDriverSerialSys:

      pServerSerialDriver = SerialSys_s();

      break;

    case SerialDriverSerCxSys:

      pServerSerialDriver = SerCxSys_s();

      break;

    case SerialDriverSerCx2Sys:

      pServerSerialDriver = SerCx2Sys_s();

      break;

    case SerialDriverUnknown:

    default:

      CommLog_Print(WLOG_DEBUG, "Unknown remote serial driver (%u), using SerCx2.sys",

                    pComm->serverSerialDriverId);

      pServerSerialDriver = SerCx2Sys_s();

      break;

  }

  WINPR_ASSERT(pServerSerialDriver != nullptr);

  switch (dwIoControlCode)

  {

    case IOCTL_USBPRINT_GET_1284_ID:

    {

      /* FIXME:

       * http://msdn.microsoft.com/en-us/library/windows/hardware/ff551803(v=vs.85).aspx */

      *lpBytesReturned = nOutBufferSize; /* an empty OutputBuffer will be returned */

      SetLastError(ERROR_CALL_NOT_IMPLEMENTED);

      return FALSE;

    }

    case IOCTL_SERIAL_SET_BAUD_RATE:

    {

      if (pServerSerialDriver->set_baud_rate)

      {

        SERIAL_BAUD_RATE* pBaudRate = (SERIAL_BAUD_RATE*)lpInBuffer;

        WINPR_ASSERT(nInBufferSize >= sizeof(SERIAL_BAUD_RATE));

        if (nInBufferSize < sizeof(SERIAL_BAUD_RATE))

        {

          SetLastError(ERROR_INVALID_PARAMETER);

          return FALSE;

        }

        return pServerSerialDriver->set_baud_rate(pComm, pBaudRate);

      }

      break;

    }

    case IOCTL_SERIAL_GET_BAUD_RATE:

    {

      if (pServerSerialDriver->get_baud_rate)

      {

        SERIAL_BAUD_RATE* pBaudRate = (SERIAL_BAUD_RATE*)lpOutBuffer;

        WINPR_ASSERT(nOutBufferSize >= sizeof(SERIAL_BAUD_RATE));

        if (nOutBufferSize < sizeof(SERIAL_BAUD_RATE))

        {

          SetLastError(ERROR_INSUFFICIENT_BUFFER);

          return FALSE;

        }

        if (!pServerSerialDriver->get_baud_rate(pComm, pBaudRate))

          return FALSE;

        *lpBytesReturned = sizeof(SERIAL_BAUD_RATE);

        return TRUE;

      }

      break;

    }

    case IOCTL_SERIAL_GET_PROPERTIES:

    {

      if (pServerSerialDriver->get_properties)

      {

        COMMPROP* pProperties = (COMMPROP*)lpOutBuffer;

        WINPR_ASSERT(nOutBufferSize >= sizeof(COMMPROP));

        if (nOutBufferSize < sizeof(COMMPROP))

        {

          SetLastError(ERROR_INSUFFICIENT_BUFFER);

          return FALSE;

        }

        if (!pServerSerialDriver->get_properties(pComm, pProperties))

          return FALSE;

        *lpBytesReturned = sizeof(COMMPROP);

        return TRUE;

      }

      break;

    }

    case IOCTL_SERIAL_SET_CHARS:

    {

      if (pServerSerialDriver->set_serial_chars)

      {

        SERIAL_CHARS* pSerialChars = (SERIAL_CHARS*)lpInBuffer;

        WINPR_ASSERT(nInBufferSize >= sizeof(SERIAL_CHARS));

        if (nInBufferSize < sizeof(SERIAL_CHARS))

        {

          SetLastError(ERROR_INVALID_PARAMETER);

          return FALSE;

        }

        return pServerSerialDriver->set_serial_chars(pComm, pSerialChars);

      }

      break;

    }

    case IOCTL_SERIAL_GET_CHARS:

    {

      if (pServerSerialDriver->get_serial_chars)

      {

        SERIAL_CHARS* pSerialChars = (SERIAL_CHARS*)lpOutBuffer;

        WINPR_ASSERT(nOutBufferSize >= sizeof(SERIAL_CHARS));

        if (nOutBufferSize < sizeof(SERIAL_CHARS))

        {

          SetLastError(ERROR_INSUFFICIENT_BUFFER);

          return FALSE;

        }

        if (!pServerSerialDriver->get_serial_chars(pComm, pSerialChars))

          return FALSE;

        *lpBytesReturned = sizeof(SERIAL_CHARS);

        return TRUE;

      }

      break;

    }

    case IOCTL_SERIAL_SET_LINE_CONTROL:

    {

      if (pServerSerialDriver->set_line_control)

      {

        SERIAL_LINE_CONTROL* pLineControl = (SERIAL_LINE_CONTROL*)lpInBuffer;

        WINPR_ASSERT(nInBufferSize >= sizeof(SERIAL_LINE_CONTROL));

        if (nInBufferSize < sizeof(SERIAL_LINE_CONTROL))

        {

          SetLastError(ERROR_INVALID_PARAMETER);

          return FALSE;

        }

        return pServerSerialDriver->set_line_control(pComm, pLineControl);

      }

      break;

    }

    case IOCTL_SERIAL_GET_LINE_CONTROL:

    {

      if (pServerSerialDriver->get_line_control)

      {

        SERIAL_LINE_CONTROL* pLineControl = (SERIAL_LINE_CONTROL*)lpOutBuffer;

        WINPR_ASSERT(nOutBufferSize >= sizeof(SERIAL_LINE_CONTROL));

        if (nOutBufferSize < sizeof(SERIAL_LINE_CONTROL))

        {

          SetLastError(ERROR_INSUFFICIENT_BUFFER);

          return FALSE;

        }

        if (!pServerSerialDriver->get_line_control(pComm, pLineControl))

          return FALSE;

        *lpBytesReturned = sizeof(SERIAL_LINE_CONTROL);

        return TRUE;

      }

      break;

    }

    case IOCTL_SERIAL_SET_HANDFLOW:

    {

      if (pServerSerialDriver->set_handflow)

      {

        SERIAL_HANDFLOW* pHandflow = (SERIAL_HANDFLOW*)lpInBuffer;

        WINPR_ASSERT(nInBufferSize >= sizeof(SERIAL_HANDFLOW));

        if (nInBufferSize < sizeof(SERIAL_HANDFLOW))

        {

          SetLastError(ERROR_INVALID_PARAMETER);

          return FALSE;

        }

        return pServerSerialDriver->set_handflow(pComm, pHandflow);

      }

      break;

    }

    case IOCTL_SERIAL_GET_HANDFLOW:

    {

      if (pServerSerialDriver->get_handflow)

      {

        SERIAL_HANDFLOW* pHandflow = (SERIAL_HANDFLOW*)lpOutBuffer;

        WINPR_ASSERT(nOutBufferSize >= sizeof(SERIAL_HANDFLOW));

        if (nOutBufferSize < sizeof(SERIAL_HANDFLOW))

        {

          SetLastError(ERROR_INSUFFICIENT_BUFFER);

          return FALSE;

        }

        if (!pServerSerialDriver->get_handflow(pComm, pHandflow))

          return FALSE;

        *lpBytesReturned = sizeof(SERIAL_HANDFLOW);

        return TRUE;

      }

      break;

    }

    case IOCTL_SERIAL_SET_TIMEOUTS:

    {

      if (pServerSerialDriver->set_timeouts)

      {

        SERIAL_TIMEOUTS* pHandflow = (SERIAL_TIMEOUTS*)lpInBuffer;

        WINPR_ASSERT(nInBufferSize >= sizeof(SERIAL_TIMEOUTS));

        if (nInBufferSize < sizeof(SERIAL_TIMEOUTS))

        {

          SetLastError(ERROR_INVALID_PARAMETER);

          return FALSE;

        }

        return pServerSerialDriver->set_timeouts(pComm, pHandflow);

      }

      break;

    }

    case IOCTL_SERIAL_GET_TIMEOUTS:

    {

      if (pServerSerialDriver->get_timeouts)

      {

        SERIAL_TIMEOUTS* pHandflow = (SERIAL_TIMEOUTS*)lpOutBuffer;

        WINPR_ASSERT(nOutBufferSize >= sizeof(SERIAL_TIMEOUTS));

        if (nOutBufferSize < sizeof(SERIAL_TIMEOUTS))

        {

          SetLastError(ERROR_INSUFFICIENT_BUFFER);

          return FALSE;

        }

        if (!pServerSerialDriver->get_timeouts(pComm, pHandflow))

          return FALSE;

        *lpBytesReturned = sizeof(SERIAL_TIMEOUTS);

        return TRUE;

      }

      break;

    }

    case IOCTL_SERIAL_SET_DTR:

    {

      if (pServerSerialDriver->set_dtr)

      {

        return pServerSerialDriver->set_dtr(pComm);

      }

      break;

    }

    case IOCTL_SERIAL_CLR_DTR:

    {

      if (pServerSerialDriver->clear_dtr)

      {

        return pServerSerialDriver->clear_dtr(pComm);

      }

      break;

    }

    case IOCTL_SERIAL_SET_RTS:

    {

      if (pServerSerialDriver->set_rts)

      {

        return pServerSerialDriver->set_rts(pComm);

      }

      break;

    }

    case IOCTL_SERIAL_CLR_RTS:

    {

      if (pServerSerialDriver->clear_rts)

      {

        return pServerSerialDriver->clear_rts(pComm);

      }

      break;

    }

    case IOCTL_SERIAL_GET_MODEMSTATUS:

    {

      if (pServerSerialDriver->get_modemstatus)

      {

        ULONG* pRegister = (ULONG*)lpOutBuffer;

        WINPR_ASSERT(nOutBufferSize >= sizeof(ULONG));

        if (nOutBufferSize < sizeof(ULONG))

        {

          SetLastError(ERROR_INSUFFICIENT_BUFFER);

          return FALSE;

        }

        if (!pServerSerialDriver->get_modemstatus(pComm, pRegister))

          return FALSE;

        CommLog_Print(WLOG_DEBUG, "modem status %s" PRIx32,

                      comm_ioctl_modem_status_string(*pRegister, buffer, sizeof(buffer)));

        *lpBytesReturned = sizeof(ULONG);

        return TRUE;

      }

      break;

    }

    case IOCTL_SERIAL_SET_WAIT_MASK:

    {

      if (pServerSerialDriver->set_wait_mask)

      {

        ULONG* pWaitMask = (ULONG*)lpInBuffer;

        WINPR_ASSERT(nInBufferSize >= sizeof(ULONG));

        if (nInBufferSize < sizeof(ULONG))

        {

          SetLastError(ERROR_INVALID_PARAMETER);

          return FALSE;

        }

        const BOOL rc = pServerSerialDriver->set_wait_mask(pComm, pWaitMask);

        CommLog_Print(WLOG_DEBUG, "set_wait_mask %s -> %d",

                      CommSerialEvString(*pWaitMask, buffer, sizeof(buffer)), rc);

        return rc;

      }

      break;

    }

    case IOCTL_SERIAL_GET_WAIT_MASK:

    {

      if (pServerSerialDriver->get_wait_mask)

      {

        ULONG* pWaitMask = (ULONG*)lpOutBuffer;

        WINPR_ASSERT(nOutBufferSize >= sizeof(ULONG));

        if (nOutBufferSize < sizeof(ULONG))

        {

          SetLastError(ERROR_INSUFFICIENT_BUFFER);

          return FALSE;

        }

        if (!pServerSerialDriver->get_wait_mask(pComm, pWaitMask))

          return FALSE;

        CommLog_Print(WLOG_DEBUG, "get_wait_mask %s",

                      CommSerialEvString(*pWaitMask, buffer, sizeof(buffer)));

        *lpBytesReturned = sizeof(ULONG);

        return TRUE;

      }

      break;

    }

    case IOCTL_SERIAL_WAIT_ON_MASK:

    {

      if (pServerSerialDriver->wait_on_mask)

      {

        ULONG* pOutputMask = (ULONG*)lpOutBuffer;

        WINPR_ASSERT(nOutBufferSize >= sizeof(ULONG));

        if (nOutBufferSize < sizeof(ULONG))

        {

          SetLastError(ERROR_INSUFFICIENT_BUFFER);

          return FALSE;

        }

        const BOOL rc = pServerSerialDriver->wait_on_mask(pComm, pOutputMask);

        *lpBytesReturned = sizeof(ULONG);

        CommLog_Print(WLOG_DEBUG, "wait_on_mask %s -> %d",

                      CommSerialEvString(*pOutputMask, buffer, sizeof(buffer)), rc);

        return rc;

      }

      break;

    }

    case IOCTL_SERIAL_SET_QUEUE_SIZE:

    {

      if (pServerSerialDriver->set_queue_size)

      {

        SERIAL_QUEUE_SIZE* pQueueSize = (SERIAL_QUEUE_SIZE*)lpInBuffer;

        WINPR_ASSERT(nInBufferSize >= sizeof(SERIAL_QUEUE_SIZE));

        if (nInBufferSize < sizeof(SERIAL_QUEUE_SIZE))

        {

          SetLastError(ERROR_INVALID_PARAMETER);

          return FALSE;

        }

        return pServerSerialDriver->set_queue_size(pComm, pQueueSize);

      }

      break;

    }

    case IOCTL_SERIAL_PURGE:

    {

      if (pServerSerialDriver->purge)

      {

        ULONG* pPurgeMask = (ULONG*)lpInBuffer;

        WINPR_ASSERT(nInBufferSize >= sizeof(ULONG));

        if (nInBufferSize < sizeof(ULONG))

        {

          SetLastError(ERROR_INVALID_PARAMETER);

          return FALSE;

        }

        return pServerSerialDriver->purge(pComm, pPurgeMask);

      }

      break;

    }

    case IOCTL_SERIAL_GET_COMMSTATUS:

    {

      if (pServerSerialDriver->get_commstatus)

      {

        SERIAL_STATUS* pCommstatus = (SERIAL_STATUS*)lpOutBuffer;

        WINPR_ASSERT(nOutBufferSize >= sizeof(SERIAL_STATUS));

        if (nOutBufferSize < sizeof(SERIAL_STATUS))

        {

          SetLastError(ERROR_INSUFFICIENT_BUFFER);

          return FALSE;

        }

        if (!pServerSerialDriver->get_commstatus(pComm, pCommstatus))

          return FALSE;

        *lpBytesReturned = sizeof(SERIAL_STATUS);

        return TRUE;

      }

      break;

    }

    case IOCTL_SERIAL_SET_BREAK_ON:

    {

      if (pServerSerialDriver->set_break_on)

      {

        return pServerSerialDriver->set_break_on(pComm);

      }

      break;

    }

    case IOCTL_SERIAL_SET_BREAK_OFF:

    {

      if (pServerSerialDriver->set_break_off)

      {

        return pServerSerialDriver->set_break_off(pComm);

      }

      break;

    }

    case IOCTL_SERIAL_SET_XOFF:

    {

      if (pServerSerialDriver->set_xoff)

      {

        return pServerSerialDriver->set_xoff(pComm);

      }

      break;

    }

    case IOCTL_SERIAL_SET_XON:

    {

      if (pServerSerialDriver->set_xon)

      {

        return pServerSerialDriver->set_xon(pComm);

      }

      break;

    }

    case IOCTL_SERIAL_GET_DTRRTS:

    {

      if (pServerSerialDriver->get_dtrrts)

      {

        ULONG* pMask = (ULONG*)lpOutBuffer;

        WINPR_ASSERT(nOutBufferSize >= sizeof(ULONG));

        if (nOutBufferSize < sizeof(ULONG))

        {

          SetLastError(ERROR_INSUFFICIENT_BUFFER);

          return FALSE;

        }

        if (!pServerSerialDriver->get_dtrrts(pComm, pMask))

          return FALSE;

        *lpBytesReturned = sizeof(ULONG);

        return TRUE;

      }

      break;

    }

    case IOCTL_SERIAL_CONFIG_SIZE:

    {

      if (pServerSerialDriver->config_size)

      {

        ULONG* pSize = (ULONG*)lpOutBuffer;

        WINPR_ASSERT(nOutBufferSize >= sizeof(ULONG));

        if (nOutBufferSize < sizeof(ULONG))

        {

          SetLastError(ERROR_INSUFFICIENT_BUFFER);

          return FALSE;

        }

        if (!pServerSerialDriver->config_size(pComm, pSize))

          return FALSE;

        *lpBytesReturned = sizeof(ULONG);

        return TRUE;

      }

      break;

    }

    case IOCTL_SERIAL_IMMEDIATE_CHAR:

    {

      if (pServerSerialDriver->immediate_char)

      {

        UCHAR* pChar = (UCHAR*)lpInBuffer;

        WINPR_ASSERT(nInBufferSize >= sizeof(UCHAR));

        if (nInBufferSize < sizeof(UCHAR))

        {

          SetLastError(ERROR_INVALID_PARAMETER);

          return FALSE;

        }

        return pServerSerialDriver->immediate_char(pComm, pChar);

      }

      break;

    }

    case IOCTL_SERIAL_RESET_DEVICE:

    {

      if (pServerSerialDriver->reset_device)

      {

        return pServerSerialDriver->reset_device(pComm);

      }

      break;

    }

    default:

      break;

  }

  CommLog_Print(

      WLOG_WARN, _T("unsupported IoControlCode=[0x%08" PRIX32 "] %s (remote serial driver: %s)"),

      dwIoControlCode, _comm_serial_ioctl_name(dwIoControlCode), pServerSerialDriver->name);

  SetLastError(ERROR_CALL_NOT_IMPLEMENTED); /* => STATUS_NOT_IMPLEMENTED */

  return FALSE;

}

/**

 * FIXME: to be used through winpr-io's DeviceIoControl

 *

 * Any previous error as returned by GetLastError is cleared.

 *

 * ERRORS:

 *   ERROR_INVALID_HANDLE

 *   ERROR_INVALID_PARAMETER

 *   ERROR_NOT_SUPPORTED lpOverlapped is not supported

 *   ERROR_INSUFFICIENT_BUFFER

 *   ERROR_CALL_NOT_IMPLEMENTED unimplemented ioctl

 */

BOOL CommDeviceIoControl(HANDLE hDevice, DWORD dwIoControlCode, LPVOID lpInBuffer,

                         DWORD nInBufferSize, LPVOID lpOutBuffer, DWORD nOutBufferSize,

                         LPDWORD lpBytesReturned, LPOVERLAPPED lpOverlapped)

{

  WINPR_COMM* pComm = (WINPR_COMM*)hDevice;

  BOOL result = 0;

  if (hDevice == INVALID_HANDLE_VALUE)

  {

    SetLastError(ERROR_INVALID_HANDLE);

    return FALSE;

  }

  if (!CommIsHandled(hDevice))

    return FALSE;

  if (!pComm->fd)

  {

    SetLastError(ERROR_INVALID_HANDLE);

    return FALSE;

  }

  result = s_CommDeviceIoControl(hDevice, dwIoControlCode, lpInBuffer, nInBufferSize, lpOutBuffer,

                                 nOutBufferSize, lpBytesReturned, lpOverlapped);

  if (lpBytesReturned && *lpBytesReturned != nOutBufferSize)

  {

    /* This might be a hint for a bug, especially when result==TRUE */

    CommLog_Print(WLOG_WARN,

                  "IoControlCode=[0x%08" PRIX32 "] %s: lpBytesReturned=%" PRIu32

                  " and nOutBufferSize=%" PRIu32 " are different!",

                  dwIoControlCode, _comm_serial_ioctl_name(dwIoControlCode), *lpBytesReturned,

                  nOutBufferSize);

  }

  if (pComm->permissive)

  {

    if (!result)

    {

      CommLog_Print(WLOG_WARN,

                    "[permissive]: IoControlCode=[0x%08" PRIX32 "] %s failed, ignoring",

                    dwIoControlCode, _comm_serial_ioctl_name(dwIoControlCode));

    }

    return TRUE; /* always! */

  }

  return result;

}

int comm_ioctl_tcsetattr(int fd, int optional_actions, const struct termios* termios_p)

{

  struct termios currentState = WINPR_C_ARRAY_INIT;

  size_t count = 0;

  do

  {

    const int src = tcsetattr(fd, optional_actions, termios_p);

    if (src < 0)

    {

      char buffer[64] = WINPR_C_ARRAY_INIT;

      CommLog_Print(WLOG_WARN, "[%" PRIuz "] tcsetattr failure, errno: %s [%d]", count,

                    winpr_strerror(errno, buffer, sizeof(buffer)), errno);

      return src;

    }

    /* NB: tcsetattr() can succeed even if not all changes have been applied. */

    const int rrc = tcgetattr(fd, &currentState);

    if (rrc < 0)

    {

      char buffer[64] = WINPR_C_ARRAY_INIT;

      CommLog_Print(WLOG_WARN, "[%" PRIuz "] tcgetattr failure, errno: %s [%d]", count,

                    winpr_strerror(errno, buffer, sizeof(buffer)), errno);

      return rrc;

    }

    // NOLINTNEXTLINE(bugprone-suspicious-memory-comparison,cert-exp42-c,cert-flp37-c)

  } while ((memcmp(&currentState, termios_p, sizeof(struct termios)) != 0) && (count++ < 2));

  return 0;

}

static const char* comm_ioctl_modem_flag_str(ULONG flag)

{

  switch (flag)

  {

    case SERIAL_MSR_DCTS:

      return "SERIAL_MSR_DCTS";

    case SERIAL_MSR_DDSR:

      return "SERIAL_MSR_DDSR";

    case SERIAL_MSR_TERI:

      return "SERIAL_MSR_TERI";

    case SERIAL_MSR_DDCD:

      return "SERIAL_MSR_DDCD";

    case SERIAL_MSR_CTS:

      return "SERIAL_MSR_CTS";

    case SERIAL_MSR_DSR:

      return "SERIAL_MSR_DSR";

    case SERIAL_MSR_RI:

      return "SERIAL_MSR_RI";

    case SERIAL_MSR_DCD:

      return "SERIAL_MSR_DCD";

    default:

      return "SERIAL_MSR_UNKNOWN";

  }

}

const char* comm_ioctl_modem_status_string(ULONG status, char* buffer, size_t size)

{

  const ULONG flags[] = { SERIAL_MSR_DCTS, SERIAL_MSR_DDSR, SERIAL_MSR_TERI, SERIAL_MSR_DDCD,

                        SERIAL_MSR_CTS,  SERIAL_MSR_DSR,  SERIAL_MSR_RI,   SERIAL_MSR_DCD

  };

  winpr_str_append("{", buffer, size, "");

  const char* sep = "";

  for (size_t x = 0; x < ARRAYSIZE(flags); x++)

  {

    const ULONG flag = flags[x];

    if (status & flag)

    {

      winpr_str_append(comm_ioctl_modem_flag_str(flag), buffer, size, sep);

      sep = "|";

    }

  }

  char number[32] = WINPR_C_ARRAY_INIT;

  (void)_snprintf(number, sizeof(number), "}[0x%08" PRIx32 "]", status);

  winpr_str_append(number, buffer, size, "");

  return buffer;

}