2 * Serial back end (Windows-specific).
11 #define SERIAL_MAX_BACKLOG 4096
13 typedef struct serial_backend_data {
15 struct handle *out, *in;
19 int break_in_progress;
22 static void serial_terminate(Serial serial)
25 handle_free(serial->out);
29 handle_free(serial->in);
32 if (serial->port != INVALID_HANDLE_VALUE) {
33 if (serial->break_in_progress)
34 ClearCommBreak(serial->port);
35 CloseHandle(serial->port);
36 serial->port = INVALID_HANDLE_VALUE;
40 static int serial_gotdata(struct handle *h, void *data, int len)
42 Serial serial = (Serial)handle_get_privdata(h);
44 const char *error_msg;
47 * Currently, len==0 should never happen because we're
48 * ignoring EOFs. However, it seems not totally impossible
49 * that this same back end might be usable to talk to named
50 * pipes or some other non-serial device, in which case EOF
51 * may become meaningful here.
54 error_msg = "End of file reading from serial device";
56 error_msg = "Error reading from serial device";
58 serial_terminate(serial);
60 notify_remote_exit(serial->frontend);
62 logevent(serial->frontend, error_msg);
64 connection_fatal(serial->frontend, "%s", error_msg);
66 return 0; /* placate optimiser */
68 return from_backend(serial->frontend, 0, data, len);
72 static void serial_sentdata(struct handle *h, int new_backlog)
74 Serial serial = (Serial)handle_get_privdata(h);
75 if (new_backlog < 0) {
76 const char *error_msg = "Error writing to serial device";
78 serial_terminate(serial);
80 notify_remote_exit(serial->frontend);
82 logevent(serial->frontend, error_msg);
84 connection_fatal(serial->frontend, "%s", error_msg);
86 serial->bufsize = new_backlog;
90 static const char *serial_configure(Serial serial, HANDLE serport, Config *cfg)
93 COMMTIMEOUTS timeouts;
96 * Set up the serial port parameters. If we can't even
97 * GetCommState, we ignore the problem on the grounds that the
98 * user might have pointed us at some other type of two-way
99 * device instead of a serial port.
101 if (GetCommState(serport, &dcb)) {
109 dcb.fDtrControl = DTR_CONTROL_ENABLE;
110 dcb.fDsrSensitivity = FALSE;
111 dcb.fTXContinueOnXoff = FALSE;
114 dcb.fErrorChar = FALSE;
116 dcb.fRtsControl = RTS_CONTROL_ENABLE;
117 dcb.fAbortOnError = FALSE;
118 dcb.fOutxCtsFlow = FALSE;
119 dcb.fOutxDsrFlow = FALSE;
122 * Configurable parameters.
124 dcb.BaudRate = cfg->serspeed;
125 msg = dupprintf("Configuring baud rate %d", cfg->serspeed);
126 logevent(serial->frontend, msg);
129 dcb.ByteSize = cfg->serdatabits;
130 msg = dupprintf("Configuring %d data bits", cfg->serdatabits);
131 logevent(serial->frontend, msg);
134 switch (cfg->serstopbits) {
135 case 2: dcb.StopBits = ONESTOPBIT; str = "1"; break;
136 case 3: dcb.StopBits = ONE5STOPBITS; str = "1.5"; break;
137 case 4: dcb.StopBits = TWOSTOPBITS; str = "2"; break;
138 default: return "Invalid number of stop bits (need 1, 1.5 or 2)";
140 msg = dupprintf("Configuring %s data bits", str);
141 logevent(serial->frontend, msg);
144 switch (cfg->serparity) {
145 case SER_PAR_NONE: dcb.Parity = NOPARITY; str = "no"; break;
146 case SER_PAR_ODD: dcb.Parity = ODDPARITY; str = "odd"; break;
147 case SER_PAR_EVEN: dcb.Parity = EVENPARITY; str = "even"; break;
148 case SER_PAR_MARK: dcb.Parity = MARKPARITY; str = "mark"; break;
149 case SER_PAR_SPACE: dcb.Parity = SPACEPARITY; str = "space"; break;
151 msg = dupprintf("Configuring %s parity", str);
152 logevent(serial->frontend, msg);
155 switch (cfg->serflow) {
159 case SER_FLOW_XONXOFF:
160 dcb.fOutX = dcb.fInX = TRUE;
163 case SER_FLOW_RTSCTS:
164 dcb.fRtsControl = RTS_CONTROL_HANDSHAKE;
165 dcb.fOutxCtsFlow = TRUE;
168 case SER_FLOW_DSRDTR:
169 dcb.fDtrControl = DTR_CONTROL_HANDSHAKE;
170 dcb.fOutxDsrFlow = TRUE;
174 msg = dupprintf("Configuring %s flow control", str);
175 logevent(serial->frontend, msg);
178 if (!SetCommState(serport, &dcb))
179 return "Unable to configure serial port";
181 timeouts.ReadIntervalTimeout = 1;
182 timeouts.ReadTotalTimeoutMultiplier = 0;
183 timeouts.ReadTotalTimeoutConstant = 0;
184 timeouts.WriteTotalTimeoutMultiplier = 0;
185 timeouts.WriteTotalTimeoutConstant = 0;
186 if (!SetCommTimeouts(serport, &timeouts))
187 return "Unable to configure serial timeouts";
194 * Called to set up the serial connection.
196 * Returns an error message, or NULL on success.
198 * Also places the canonical host name into `realhost'. It must be
199 * freed by the caller.
201 static const char *serial_init(void *frontend_handle, void **backend_handle,
203 char *host, int port, char **realhost, int nodelay,
210 serial = snew(struct serial_backend_data);
211 serial->port = INVALID_HANDLE_VALUE;
212 serial->out = serial->in = NULL;
214 serial->break_in_progress = FALSE;
215 *backend_handle = serial;
217 serial->frontend = frontend_handle;
220 char *msg = dupprintf("Opening serial device %s", cfg->serline);
221 logevent(serial->frontend, msg);
226 * Munge the string supplied by the user into a Windows filename.
228 * Windows supports opening a few "legacy" devices (including
229 * COM1-9) by specifying their names verbatim as a filename to
230 * open. (Thus, no files can ever have these names. See
231 * <http://msdn2.microsoft.com/en-us/library/aa365247.aspx>
232 * ("Naming a File") for the complete list of reserved names.)
234 * However, this doesn't let you get at devices COM10 and above.
235 * For that, you need to specify a filename like "\\.\COM10".
236 * This is also necessary for special serial and serial-like
237 * devices such as \\.\WCEUSBSH001. It also works for the "legacy"
238 * names, so you can do \\.\COM1 (verified as far back as Win95).
239 * See <http://msdn2.microsoft.com/en-us/library/aa363858.aspx>
240 * (CreateFile() docs).
242 * So, we believe that prepending "\\.\" should always be the
243 * Right Thing. However, just in case someone finds something to
244 * talk to that doesn't exist under there, if the serial line
245 * contains a backslash, we use it verbatim. (This also lets
246 * existing configurations using \\.\ continue working.)
250 strchr(cfg->serline, '\\') ? "" : "\\\\.\\",
252 serport = CreateFile(serfilename, GENERIC_READ | GENERIC_WRITE, 0, NULL,
253 OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
257 if (serport == INVALID_HANDLE_VALUE)
258 return "Unable to open serial port";
260 err = serial_configure(serial, serport, cfg);
264 serial->port = serport;
265 serial->out = handle_output_new(serport, serial_sentdata, serial,
266 HANDLE_FLAG_OVERLAPPED);
267 serial->in = handle_input_new(serport, serial_gotdata, serial,
268 HANDLE_FLAG_OVERLAPPED |
269 HANDLE_FLAG_IGNOREEOF |
270 HANDLE_FLAG_UNITBUFFER);
272 *realhost = dupstr(cfg->serline);
275 * Specials are always available.
277 update_specials_menu(serial->frontend);
282 static void serial_free(void *handle)
284 Serial serial = (Serial) handle;
286 serial_terminate(serial);
287 expire_timer_context(serial);
291 static void serial_reconfig(void *handle, Config *cfg)
293 Serial serial = (Serial) handle;
296 err = serial_configure(serial, serial->port, cfg);
299 * FIXME: what should we do if err returns something?
304 * Called to send data down the serial connection.
306 static int serial_send(void *handle, char *buf, int len)
308 Serial serial = (Serial) handle;
310 if (serial->out == NULL)
313 serial->bufsize = handle_write(serial->out, buf, len);
314 return serial->bufsize;
318 * Called to query the current sendability status.
320 static int serial_sendbuffer(void *handle)
322 Serial serial = (Serial) handle;
323 return serial->bufsize;
327 * Called to set the size of the window
329 static void serial_size(void *handle, int width, int height)
335 static void serbreak_timer(void *ctx, long now)
337 Serial serial = (Serial)ctx;
339 if (now >= serial->clearbreak_time && serial->port) {
340 ClearCommBreak(serial->port);
341 serial->break_in_progress = FALSE;
342 logevent(serial->frontend, "Finished serial break");
347 * Send serial special codes.
349 static void serial_special(void *handle, Telnet_Special code)
351 Serial serial = (Serial) handle;
353 if (serial->port && code == TS_BRK) {
354 logevent(serial->frontend, "Starting serial break at user request");
355 SetCommBreak(serial->port);
357 * To send a serial break on Windows, we call SetCommBreak
358 * to begin the break, then wait a bit, and then call
359 * ClearCommBreak to finish it. Hence, I must use timing.c
360 * to arrange a callback when it's time to do the latter.
362 * SUS says that a default break length must be between 1/4
363 * and 1/2 second. FreeBSD apparently goes with 2/5 second,
366 serial->clearbreak_time =
367 schedule_timer(TICKSPERSEC * 2 / 5, serbreak_timer, serial);
368 serial->break_in_progress = TRUE;
375 * Return a list of the special codes that make sense in this
378 static const struct telnet_special *serial_get_specials(void *handle)
380 static const struct telnet_special specials[] = {
387 static int serial_connected(void *handle)
389 return 1; /* always connected */
392 static int serial_sendok(void *handle)
397 static void serial_unthrottle(void *handle, int backlog)
399 Serial serial = (Serial) handle;
401 handle_unthrottle(serial->in, backlog);
404 static int serial_ldisc(void *handle, int option)
407 * Local editing and local echo are off by default.
412 static void serial_provide_ldisc(void *handle, void *ldisc)
414 /* This is a stub. */
417 static void serial_provide_logctx(void *handle, void *logctx)
419 /* This is a stub. */
422 static int serial_exitcode(void *handle)
424 Serial serial = (Serial) handle;
425 if (serial->port != INVALID_HANDLE_VALUE)
426 return -1; /* still connected */
428 /* Exit codes are a meaningless concept with serial ports */
433 * cfg_info for Serial does nothing at all.
435 static int serial_cfg_info(void *handle)
440 Backend serial_backend = {
453 serial_provide_ldisc,
454 serial_provide_logctx,