FreeRDP/winpr/libwinpr/comm/comm_io.c
David Fort de7d7e43c9 serial redirection: implement event char
The signotec signature device requires the eventChar support to work properly in
serial redirection mode. This implementation is basic but does the job for this
device.

Sponsored by: Rangee GmbH (http://www.rangee.de)
2017-11-06 22:26:17 +01:00

573 lines
15 KiB
C

/**
* WinPR: Windows Portable Runtime
* Serial Communication API
*
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#if defined __linux__ && !defined ANDROID
#include <assert.h>
#include <errno.h>
#include <termios.h>
#include <unistd.h>
#include <winpr/io.h>
#include <winpr/wlog.h>
#include <winpr/wtypes.h>
#include "comm.h"
BOOL _comm_set_permissive(HANDLE hDevice, BOOL permissive)
{
WINPR_COMM* pComm = (WINPR_COMM*) hDevice;
if (hDevice == INVALID_HANDLE_VALUE)
{
SetLastError(ERROR_INVALID_HANDLE);
return FALSE;
}
if (!pComm || pComm->Type != HANDLE_TYPE_COMM)
{
SetLastError(ERROR_INVALID_HANDLE);
return FALSE;
}
pComm->permissive = permissive;
return TRUE;
}
/* Computes VTIME in deciseconds from Ti in milliseconds */
static UCHAR _vtime(ULONG Ti)
{
/* FIXME: look for an equivalent math function otherwise let
* do the compiler do the optimization */
if (Ti == 0)
return 0;
else if (Ti < 100)
return 1;
else if (Ti > 25500)
return 255; /* 0xFF */
else
return Ti / 100;
}
/**
* ERRORS:
* ERROR_INVALID_HANDLE
* ERROR_NOT_SUPPORTED
* ERROR_INVALID_PARAMETER
* ERROR_TIMEOUT
* ERROR_IO_DEVICE
* ERROR_BAD_DEVICE
*/
BOOL CommReadFile(HANDLE hDevice, LPVOID lpBuffer, DWORD nNumberOfBytesToRead,
LPDWORD lpNumberOfBytesRead, LPOVERLAPPED lpOverlapped)
{
WINPR_COMM* pComm = (WINPR_COMM*) hDevice;
int biggestFd = -1;
fd_set read_set;
int nbFds;
COMMTIMEOUTS* pTimeouts;
UCHAR vmin = 0;
UCHAR vtime = 0;
ULONGLONG Tmax = 0;
struct timeval tmaxTimeout, *pTmaxTimeout;
struct termios currentTermios;
EnterCriticalSection(&pComm->ReadLock); /* KISSer by the function's beginning */
if (hDevice == INVALID_HANDLE_VALUE)
{
SetLastError(ERROR_INVALID_HANDLE);
goto return_false;
}
if (!pComm || pComm->Type != HANDLE_TYPE_COMM)
{
SetLastError(ERROR_INVALID_HANDLE);
goto return_false;
}
if (lpOverlapped != NULL)
{
SetLastError(ERROR_NOT_SUPPORTED);
goto return_false;
}
if (lpNumberOfBytesRead == NULL)
{
SetLastError(
ERROR_INVALID_PARAMETER); /* since we doesn't suppport lpOverlapped != NULL */
goto return_false;
}
*lpNumberOfBytesRead = 0; /* will be ajusted if required ... */
if (nNumberOfBytesToRead <= 0) /* N */
{
goto return_true; /* FIXME: or FALSE? */
}
if (tcgetattr(pComm->fd, &currentTermios) < 0)
{
SetLastError(ERROR_IO_DEVICE);
goto return_false;
}
if (currentTermios.c_lflag & ICANON)
{
CommLog_Print(WLOG_WARN,
"Canonical mode not supported"); /* the timeout could not be set */
SetLastError(ERROR_NOT_SUPPORTED);
goto return_false;
}
/* http://msdn.microsoft.com/en-us/library/hh439614%28v=vs.85%29.aspx
* http://msdn.microsoft.com/en-us/library/windows/hardware/hh439614%28v=vs.85%29.aspx
*
* ReadIntervalTimeout | ReadTotalTimeoutMultiplier | ReadTotalTimeoutConstant | VMIN | VTIME | TMAX |
* 0 | 0 | 0 | N | 0 | INDEF | Blocks for N bytes available.
* 0< Ti <MAXULONG | 0 | 0 | N | Ti | INDEF | Blocks on first byte, then use Ti between bytes.
* MAXULONG | 0 | 0 | 0 | 0 | 0 | Returns immediately with bytes available (don't block)
* MAXULONG | MAXULONG | 0< Tc <MAXULONG | N | 0 | Tc | Blocks on first byte during Tc or returns immediately whith bytes available
* MAXULONG | m | MAXULONG | | Invalid
* 0 | m | 0< Tc <MAXULONG | N | 0 | Tmax | Blocks on first byte during Tmax or returns immediately whith bytes available
* 0< Ti <MAXULONG | m | 0< Tc <MAXULONG | N | Ti | Tmax | Blocks on first byte, then use Ti between bytes. Tmax is used for the whole system call.
*/
/* NB: timeouts are in milliseconds, VTIME are in deciseconds and is an unsigned char */
/* FIXME: double check whether open(pComm->fd_read_event, O_NONBLOCK) doesn't conflict with above use cases */
pTimeouts = &(pComm->timeouts);
if ((pTimeouts->ReadIntervalTimeout == MAXULONG)
&& (pTimeouts->ReadTotalTimeoutConstant == MAXULONG))
{
CommLog_Print(WLOG_WARN,
"ReadIntervalTimeout and ReadTotalTimeoutConstant cannot be both set to MAXULONG");
SetLastError(ERROR_INVALID_PARAMETER);
goto return_false;
}
/* VMIN */
if ((pTimeouts->ReadIntervalTimeout == MAXULONG)
&& (pTimeouts->ReadTotalTimeoutMultiplier == 0)
&& (pTimeouts->ReadTotalTimeoutConstant == 0))
{
vmin = 0;
}
else
{
/* N */
/* vmin = nNumberOfBytesToRead < 256 ? nNumberOfBytesToRead : 255;*/ /* 0xFF */
/* NB: we might wait endlessly with vmin=N, prefer to
* force vmin=1 and return with bytes
* available. FIXME: is a feature disarded here? */
vmin = 1;
}
/* VTIME */
if ((pTimeouts->ReadIntervalTimeout > 0)
&& (pTimeouts->ReadIntervalTimeout < MAXULONG))
{
/* Ti */
vtime = _vtime(pTimeouts->ReadIntervalTimeout);
}
/* TMAX */
pTmaxTimeout = &tmaxTimeout;
if ((pTimeouts->ReadIntervalTimeout == MAXULONG)
&& (pTimeouts->ReadTotalTimeoutMultiplier == MAXULONG))
{
/* Tc */
Tmax = pTimeouts->ReadTotalTimeoutConstant;
}
else
{
/* Tmax */
Tmax = nNumberOfBytesToRead * pTimeouts->ReadTotalTimeoutMultiplier +
pTimeouts->ReadTotalTimeoutConstant;
/* INDEFinitely */
if ((Tmax == 0) && (pTimeouts->ReadIntervalTimeout < MAXULONG)
&& (pTimeouts->ReadTotalTimeoutMultiplier == 0))
pTmaxTimeout = NULL;
}
if ((currentTermios.c_cc[VMIN] != vmin)
|| (currentTermios.c_cc[VTIME] != vtime))
{
currentTermios.c_cc[VMIN] = vmin;
currentTermios.c_cc[VTIME] = vtime;
if (tcsetattr(pComm->fd, TCSANOW, &currentTermios) < 0)
{
CommLog_Print(WLOG_WARN,
"CommReadFile failure, could not apply new timeout values: VMIN=%"PRIu8", VTIME=%"PRIu8"",
vmin, vtime);
SetLastError(ERROR_IO_DEVICE);
goto return_false;
}
}
/* wait indefinitely if pTmaxTimeout is NULL */
if (pTmaxTimeout != NULL)
{
ZeroMemory(pTmaxTimeout, sizeof(struct timeval));
if (Tmax > 0) /* return immdiately if Tmax == 0 */
{
pTmaxTimeout->tv_sec = Tmax / 1000; /* s */
pTmaxTimeout->tv_usec = (Tmax % 1000) * 1000; /* us */
}
}
/* FIXME: had expected eventfd_write() to return EAGAIN when
* there is no eventfd_read() but this not the case. */
/* discard a possible and no more relevant event */
eventfd_read(pComm->fd_read_event, NULL);
biggestFd = pComm->fd_read;
if (pComm->fd_read_event > biggestFd)
biggestFd = pComm->fd_read_event;
FD_ZERO(&read_set);
assert(pComm->fd_read_event < FD_SETSIZE);
assert(pComm->fd_read < FD_SETSIZE);
FD_SET(pComm->fd_read_event, &read_set);
FD_SET(pComm->fd_read, &read_set);
nbFds = select(biggestFd + 1, &read_set, NULL, NULL, pTmaxTimeout);
if (nbFds < 0)
{
CommLog_Print(WLOG_WARN, "select() failure, errno=[%d] %s\n", errno,
strerror(errno));
SetLastError(ERROR_IO_DEVICE);
goto return_false;
}
if (nbFds == 0)
{
/* timeout */
SetLastError(ERROR_TIMEOUT);
goto return_false;
}
/* read_set */
if (FD_ISSET(pComm->fd_read_event, &read_set))
{
eventfd_t event = 0;
if (eventfd_read(pComm->fd_read_event, &event) < 0)
{
if (errno == EAGAIN)
{
assert(FALSE); /* not quite sure this should ever happen */
/* keep on */
}
else
{
CommLog_Print(WLOG_WARN,
"unexpected error on reading fd_read_event, errno=[%d] %s\n", errno,
strerror(errno));
/* FIXME: goto return_false ? */
}
assert(errno == EAGAIN);
}
if (event == FREERDP_PURGE_RXABORT)
{
SetLastError(ERROR_CANCELLED);
goto return_false;
}
assert(event == FREERDP_PURGE_RXABORT); /* no other expected event so far */
}
if (FD_ISSET(pComm->fd_read, &read_set))
{
ssize_t nbRead = 0;
nbRead = read(pComm->fd_read, lpBuffer, nNumberOfBytesToRead);
if (nbRead < 0)
{
CommLog_Print(WLOG_WARN,
"CommReadFile failed, ReadIntervalTimeout=%"PRIu32", ReadTotalTimeoutMultiplier=%"PRIu32", ReadTotalTimeoutConstant=%"PRIu32" VMIN=%u, VTIME=%u",
pTimeouts->ReadIntervalTimeout, pTimeouts->ReadTotalTimeoutMultiplier,
pTimeouts->ReadTotalTimeoutConstant,
currentTermios.c_cc[VMIN], currentTermios.c_cc[VTIME]);
CommLog_Print(WLOG_WARN,
"CommReadFile failed, nNumberOfBytesToRead=%"PRIu32", errno=[%d] %s",
nNumberOfBytesToRead, errno, strerror(errno));
if (errno == EAGAIN)
{
/* keep on */
goto return_true; /* expect a read-loop to be implemented on the server side */
}
else if (errno == EBADF)
{
SetLastError(ERROR_BAD_DEVICE); /* STATUS_INVALID_DEVICE_REQUEST */
goto return_false;
}
else
{
assert(FALSE);
SetLastError(ERROR_IO_DEVICE);
goto return_false;
}
}
if (nbRead == 0)
{
/* termios timeout */
SetLastError(ERROR_TIMEOUT);
goto return_false;
}
*lpNumberOfBytesRead = nbRead;
EnterCriticalSection(&pComm->EventsLock);
if (pComm->PendingEvents & SERIAL_EV_FREERDP_WAITING)
{
if (pComm->eventChar != '\0' && memchr(lpBuffer, pComm->eventChar, nbRead))
pComm->PendingEvents |= SERIAL_EV_RXCHAR;
}
LeaveCriticalSection(&pComm->EventsLock);
goto return_true;
}
assert(FALSE);
*lpNumberOfBytesRead = 0;
return_false:
LeaveCriticalSection(&pComm->ReadLock);
return FALSE;
return_true:
LeaveCriticalSection(&pComm->ReadLock);
return TRUE;
}
/**
* ERRORS:
* ERROR_INVALID_HANDLE
* ERROR_NOT_SUPPORTED
* ERROR_INVALID_PARAMETER
* ERROR_BAD_DEVICE
*/
BOOL CommWriteFile(HANDLE hDevice, LPCVOID lpBuffer,
DWORD nNumberOfBytesToWrite,
LPDWORD lpNumberOfBytesWritten, LPOVERLAPPED lpOverlapped)
{
WINPR_COMM* pComm = (WINPR_COMM*) hDevice;
struct timeval tmaxTimeout, *pTmaxTimeout;
EnterCriticalSection(
&pComm->WriteLock); /* KISSer by the function's beginning */
if (hDevice == INVALID_HANDLE_VALUE)
{
SetLastError(ERROR_INVALID_HANDLE);
goto return_false;
}
if (!pComm || pComm->Type != HANDLE_TYPE_COMM)
{
SetLastError(ERROR_INVALID_HANDLE);
goto return_false;
}
if (lpOverlapped != NULL)
{
SetLastError(ERROR_NOT_SUPPORTED);
goto return_false;
}
if (lpNumberOfBytesWritten == NULL)
{
SetLastError(
ERROR_INVALID_PARAMETER); /* since we doesn't suppport lpOverlapped != NULL */
goto return_false;
}
*lpNumberOfBytesWritten = 0; /* will be ajusted if required ... */
if (nNumberOfBytesToWrite <= 0)
{
goto return_true; /* FIXME: or FALSE? */
}
/* FIXME: had expected eventfd_write() to return EAGAIN when
* there is no eventfd_read() but this not the case. */
/* discard a possible and no more relevant event */
eventfd_read(pComm->fd_write_event, NULL);
/* ms */
ULONGLONG Tmax = nNumberOfBytesToWrite *
pComm->timeouts.WriteTotalTimeoutMultiplier +
pComm->timeouts.WriteTotalTimeoutConstant;
/* NB: select() may update the timeout argument to indicate
* how much time was left. Keep the timeout variable out of
* the while() */
pTmaxTimeout = &tmaxTimeout;
ZeroMemory(pTmaxTimeout, sizeof(struct timeval));
if (Tmax > 0)
{
pTmaxTimeout->tv_sec = Tmax / 1000; /* s */
pTmaxTimeout->tv_usec = (Tmax % 1000) * 1000; /* us */
}
else if ((pComm->timeouts.WriteTotalTimeoutMultiplier == 0)
&& (pComm->timeouts.WriteTotalTimeoutConstant == 0))
{
pTmaxTimeout = NULL;
}
/* else return immdiately */
while (*lpNumberOfBytesWritten < nNumberOfBytesToWrite)
{
int biggestFd = -1;
fd_set event_set, write_set;
int nbFds;
biggestFd = pComm->fd_write;
if (pComm->fd_write_event > biggestFd)
biggestFd = pComm->fd_write_event;
FD_ZERO(&event_set);
FD_ZERO(&write_set);
assert(pComm->fd_write_event < FD_SETSIZE);
assert(pComm->fd_write < FD_SETSIZE);
FD_SET(pComm->fd_write_event, &event_set);
FD_SET(pComm->fd_write, &write_set);
nbFds = select(biggestFd + 1, &event_set, &write_set, NULL, pTmaxTimeout);
if (nbFds < 0)
{
CommLog_Print(WLOG_WARN, "select() failure, errno=[%d] %s\n", errno,
strerror(errno));
SetLastError(ERROR_IO_DEVICE);
goto return_false;
}
if (nbFds == 0)
{
/* timeout */
SetLastError(ERROR_TIMEOUT);
goto return_false;
}
/* event_set */
if (FD_ISSET(pComm->fd_write_event, &event_set))
{
eventfd_t event = 0;
if (eventfd_read(pComm->fd_write_event, &event) < 0)
{
if (errno == EAGAIN)
{
assert(FALSE); /* not quite sure this should ever happen */
/* keep on */
}
else
{
CommLog_Print(WLOG_WARN,
"unexpected error on reading fd_write_event, errno=[%d] %s\n", errno,
strerror(errno));
/* FIXME: goto return_false ? */
}
assert(errno == EAGAIN);
}
if (event == FREERDP_PURGE_TXABORT)
{
SetLastError(ERROR_CANCELLED);
goto return_false;
}
assert(event == FREERDP_PURGE_TXABORT); /* no other expected event so far */
}
/* write_set */
if (FD_ISSET(pComm->fd_write, &write_set))
{
ssize_t nbWritten;
nbWritten = write(pComm->fd_write,
((BYTE*)lpBuffer) + (*lpNumberOfBytesWritten),
nNumberOfBytesToWrite - (*lpNumberOfBytesWritten));
if (nbWritten < 0)
{
CommLog_Print(WLOG_WARN,
"CommWriteFile failed after %"PRIu32" bytes written, errno=[%d] %s\n",
*lpNumberOfBytesWritten, errno, strerror(errno));
if (errno == EAGAIN)
{
/* keep on */
continue;
}
else if (errno == EBADF)
{
SetLastError(ERROR_BAD_DEVICE); /* STATUS_INVALID_DEVICE_REQUEST */
goto return_false;
}
else
{
assert(FALSE);
SetLastError(ERROR_IO_DEVICE);
goto return_false;
}
}
*lpNumberOfBytesWritten += nbWritten;
}
} /* while */
/* FIXME: this call to tcdrain() doesn't look correct and
* might hide a bug but was required while testing a serial
* printer. Its driver was expecting the modem line status
* SERIAL_MSR_DSR true after the sending which was never
* happenning otherwise. A purge was also done before each
* Write operation. The serial port was opened with:
* DesiredAccess=0x0012019F. The printer worked fine with
* mstsc. */
tcdrain(pComm->fd_write);
return_true:
LeaveCriticalSection(&pComm->WriteLock);
return TRUE;
return_false:
LeaveCriticalSection(&pComm->WriteLock);
return FALSE;
}
#endif /* __linux__ */