| blob | 2e3a9073ccf743f2005b651167197c5be01287d4 |
1 /*\r
2 * Serial back end (Windows-specific).\r
3 */\r
4 \r
5 #include <stdio.h>\r
6 #include <stdlib.h>\r
7 #include <limits.h>\r
8 \r
9 #include "putty.h"\r
10 \r
11 #define SERIAL_MAX_BACKLOG 4096\r
12 \r
13 typedef struct serial_backend_data {\r
14 HANDLE port;\r
15 struct handle *out, *in;\r
16 void *frontend;\r
17 int bufsize;\r
18 long clearbreak_time;\r
19 int break_in_progress;\r
20 } *Serial;\r
21 \r
22 static void serial_terminate(Serial serial)\r
23 {\r
24 if (serial->out) {\r
25 handle_free(serial->out);\r
26 serial->out = NULL;\r
27 }\r
28 if (serial->in) {\r
29 handle_free(serial->in);\r
30 serial->in = NULL;\r
31 }\r
32 if (serial->port != INVALID_HANDLE_VALUE) {\r
33 if (serial->break_in_progress)\r
34 ClearCommBreak(serial->port);\r
35 CloseHandle(serial->port);\r
36 serial->port = INVALID_HANDLE_VALUE;\r
37 }\r
38 }\r
39 \r
40 static int serial_gotdata(struct handle *h, void *data, int len)\r
41 {\r
42 Serial serial = (Serial)handle_get_privdata(h);\r
43 if (len <= 0) {\r
44 const char *error_msg;\r
45 \r
46 /*\r
47 * Currently, len==0 should never happen because we're\r
48 * ignoring EOFs. However, it seems not totally impossible\r
49 * that this same back end might be usable to talk to named\r
50 * pipes or some other non-serial device, in which case EOF\r
51 * may become meaningful here.\r
52 */\r
53 if (len == 0)\r
54 error_msg = "End of file reading from serial device";\r
55 else\r
56 error_msg = "Error reading from serial device";\r
57 \r
58 serial_terminate(serial);\r
59 \r
60 notify_remote_exit(serial->frontend);\r
61 \r
62 logevent(serial->frontend, error_msg);\r
63 \r
64 connection_fatal(serial->frontend, "%s", error_msg);\r
65 \r
66 return 0; /* placate optimiser */\r
67 } else {\r
68 return from_backend(serial->frontend, 0, data, len);\r
69 }\r
70 }\r
71 \r
72 static void serial_sentdata(struct handle *h, int new_backlog)\r
73 {\r
74 Serial serial = (Serial)handle_get_privdata(h);\r
75 if (new_backlog < 0) {\r
76 const char *error_msg = "Error writing to serial device";\r
77 \r
78 serial_terminate(serial);\r
79 \r
80 notify_remote_exit(serial->frontend);\r
81 \r
82 logevent(serial->frontend, error_msg);\r
83 \r
84 connection_fatal(serial->frontend, "%s", error_msg);\r
85 } else {\r
86 serial->bufsize = new_backlog;\r
87 }\r
88 }\r
89 \r
90 static const char *serial_configure(Serial serial, HANDLE serport, Conf *conf)\r
91 {\r
92 DCB dcb;\r
93 COMMTIMEOUTS timeouts;\r
94 \r
95 /*\r
96 * Set up the serial port parameters. If we can't even\r
97 * GetCommState, we ignore the problem on the grounds that the\r
98 * user might have pointed us at some other type of two-way\r
99 * device instead of a serial port.\r
100 */\r
101 if (GetCommState(serport, &dcb)) {\r
102 char *msg;\r
103 const char *str;\r
104 \r
105 /*\r
106 * Boilerplate.\r
107 */\r
108 dcb.fBinary = TRUE;\r
109 dcb.fDtrControl = DTR_CONTROL_ENABLE;\r
110 dcb.fDsrSensitivity = FALSE;\r
111 dcb.fTXContinueOnXoff = FALSE;\r
112 dcb.fOutX = FALSE;\r
113 dcb.fInX = FALSE;\r
114 dcb.fErrorChar = FALSE;\r
115 dcb.fNull = FALSE;\r
116 dcb.fRtsControl = RTS_CONTROL_ENABLE;\r
117 dcb.fAbortOnError = FALSE;\r
118 dcb.fOutxCtsFlow = FALSE;\r
119 dcb.fOutxDsrFlow = FALSE;\r
120 \r
121 /*\r
122 * Configurable parameters.\r
123 */\r
124 dcb.BaudRate = conf_get_int(conf, CONF_serspeed);\r
125 msg = dupprintf("Configuring baud rate %d", dcb.BaudRate);\r
126 logevent(serial->frontend, msg);\r
127 sfree(msg);\r
128 \r
129 dcb.ByteSize = conf_get_int(conf, CONF_serdatabits);\r
130 msg = dupprintf("Configuring %d data bits", dcb.ByteSize);\r
131 logevent(serial->frontend, msg);\r
132 sfree(msg);\r
133 \r
134 switch (conf_get_int(conf, CONF_serstopbits)) {\r
135 case 2: dcb.StopBits = ONESTOPBIT; str = "1"; break;\r
136 case 3: dcb.StopBits = ONE5STOPBITS; str = "1.5"; break;\r
137 case 4: dcb.StopBits = TWOSTOPBITS; str = "2"; break;\r
138 default: return "Invalid number of stop bits (need 1, 1.5 or 2)";\r
139 }\r
140 msg = dupprintf("Configuring %s data bits", str);\r
141 logevent(serial->frontend, msg);\r
142 sfree(msg);\r
143 \r
144 switch (conf_get_int(conf, CONF_serparity)) {\r
145 case SER_PAR_NONE: dcb.Parity = NOPARITY; str = "no"; break;\r
146 case SER_PAR_ODD: dcb.Parity = ODDPARITY; str = "odd"; break;\r
147 case SER_PAR_EVEN: dcb.Parity = EVENPARITY; str = "even"; break;\r
148 case SER_PAR_MARK: dcb.Parity = MARKPARITY; str = "mark"; break;\r
149 case SER_PAR_SPACE: dcb.Parity = SPACEPARITY; str = "space"; break;\r
150 }\r
151 msg = dupprintf("Configuring %s parity", str);\r
152 logevent(serial->frontend, msg);\r
153 sfree(msg);\r
154 \r
155 switch (conf_get_int(conf, CONF_serflow)) {\r
156 case SER_FLOW_NONE:\r
157 str = "no";\r
158 break;\r
159 case SER_FLOW_XONXOFF:\r
160 dcb.fOutX = dcb.fInX = TRUE;\r
161 str = "XON/XOFF";\r
162 break;\r
163 case SER_FLOW_RTSCTS:\r
164 dcb.fRtsControl = RTS_CONTROL_HANDSHAKE;\r
165 dcb.fOutxCtsFlow = TRUE;\r
166 str = "RTS/CTS";\r
167 break;\r
168 case SER_FLOW_DSRDTR:\r
169 dcb.fDtrControl = DTR_CONTROL_HANDSHAKE;\r
170 dcb.fOutxDsrFlow = TRUE;\r
171 str = "DSR/DTR";\r
172 break;\r
173 }\r
174 msg = dupprintf("Configuring %s flow control", str);\r
175 logevent(serial->frontend, msg);\r
176 sfree(msg);\r
177 \r
178 if (!SetCommState(serport, &dcb))\r
179 return "Unable to configure serial port";\r
180 \r
181 timeouts.ReadIntervalTimeout = 1;\r
182 timeouts.ReadTotalTimeoutMultiplier = 0;\r
183 timeouts.ReadTotalTimeoutConstant = 0;\r
184 timeouts.WriteTotalTimeoutMultiplier = 0;\r
185 timeouts.WriteTotalTimeoutConstant = 0;\r
186 if (!SetCommTimeouts(serport, &timeouts))\r
187 return "Unable to configure serial timeouts";\r
188 }\r
189 \r
190 return NULL;\r
191 }\r
192 \r
193 /*\r
194 * Called to set up the serial connection.\r
195 * \r
196 * Returns an error message, or NULL on success.\r
197 *\r
198 * Also places the canonical host name into `realhost'. It must be\r
199 * freed by the caller.\r
200 */\r
201 static const char *serial_init(void *frontend_handle, void **backend_handle,\r
202 Conf *conf, char *host, int port,\r
203 char **realhost, int nodelay, int keepalive)\r
204 {\r
205 Serial serial;\r
206 HANDLE serport;\r
207 const char *err;\r
208 char *serline;\r
209 \r
210 serial = snew(struct serial_backend_data);\r
211 serial->port = INVALID_HANDLE_VALUE;\r
212 serial->out = serial->in = NULL;\r
213 serial->bufsize = 0;\r
214 serial->break_in_progress = FALSE;\r
215 *backend_handle = serial;\r
216 \r
217 serial->frontend = frontend_handle;\r
218 \r
219 serline = conf_get_str(conf, CONF_serline);\r
220 {\r
221 char *msg = dupprintf("Opening serial device %s", serline);\r
222 logevent(serial->frontend, msg);\r
223 }\r
224 \r
225 {\r
226 /*\r
227 * Munge the string supplied by the user into a Windows filename.\r
228 *\r
229 * Windows supports opening a few "legacy" devices (including\r
230 * COM1-9) by specifying their names verbatim as a filename to\r
231 * open. (Thus, no files can ever have these names. See\r
232 * <http://msdn2.microsoft.com/en-us/library/aa365247.aspx>\r
233 * ("Naming a File") for the complete list of reserved names.)\r
234 *\r
235 * However, this doesn't let you get at devices COM10 and above.\r
236 * For that, you need to specify a filename like "\\.\COM10".\r
237 * This is also necessary for special serial and serial-like\r
238 * devices such as \\.\WCEUSBSH001. It also works for the "legacy"\r
239 * names, so you can do \\.\COM1 (verified as far back as Win95).\r
240 * See <http://msdn2.microsoft.com/en-us/library/aa363858.aspx>\r
241 * (CreateFile() docs).\r
242 *\r
243 * So, we believe that prepending "\\.\" should always be the\r
244 * Right Thing. However, just in case someone finds something to\r
245 * talk to that doesn't exist under there, if the serial line\r
246 * contains a backslash, we use it verbatim. (This also lets\r
247 * existing configurations using \\.\ continue working.)\r
248 */\r
249 char *serfilename =\r
250 dupprintf("%s%s", strchr(serline, '\\') ? "" : "\\\\.\\", serline);\r
251 serport = CreateFile(serfilename, GENERIC_READ | GENERIC_WRITE, 0, NULL,\r
252 OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);\r
253 sfree(serfilename);\r
254 }\r
255 \r
256 if (serport == INVALID_HANDLE_VALUE)\r
257 return "Unable to open serial port";\r
258 \r
259 err = serial_configure(serial, serport, conf);\r
260 if (err)\r
261 return err;\r
262 \r
263 serial->port = serport;\r
264 serial->out = handle_output_new(serport, serial_sentdata, serial,\r
265 HANDLE_FLAG_OVERLAPPED);\r
266 serial->in = handle_input_new(serport, serial_gotdata, serial,\r
267 HANDLE_FLAG_OVERLAPPED |\r
268 HANDLE_FLAG_IGNOREEOF |\r
269 HANDLE_FLAG_UNITBUFFER);\r
270 \r
271 *realhost = dupstr(serline);\r
272 \r
273 /*\r
274 * Specials are always available.\r
275 */\r
276 update_specials_menu(serial->frontend);\r
277 \r
278 return NULL;\r
279 }\r
280 \r
281 static void serial_free(void *handle)\r
282 {\r
283 Serial serial = (Serial) handle;\r
284 \r
285 serial_terminate(serial);\r
286 expire_timer_context(serial);\r
287 sfree(serial);\r
288 }\r
289 \r
290 static void serial_reconfig(void *handle, Conf *conf)\r
291 {\r
292 Serial serial = (Serial) handle;\r
293 const char *err;\r
294 \r
295 err = serial_configure(serial, serial->port, conf);\r
296 \r
297 /*\r
298 * FIXME: what should we do if err returns something?\r
299 */\r
300 }\r
301 \r
302 /*\r
303 * Called to send data down the serial connection.\r
304 */\r
305 static int serial_send(void *handle, char *buf, int len)\r
306 {\r
307 Serial serial = (Serial) handle;\r
308 \r
309 if (serial->out == NULL)\r
310 return 0;\r
311 \r
312 serial->bufsize = handle_write(serial->out, buf, len);\r
313 return serial->bufsize;\r
314 }\r
315 \r
316 /*\r
317 * Called to query the current sendability status.\r
318 */\r
319 static int serial_sendbuffer(void *handle)\r
320 {\r
321 Serial serial = (Serial) handle;\r
322 return serial->bufsize;\r
323 }\r
324 \r
325 /*\r
326 * Called to set the size of the window\r
327 */\r
328 static void serial_size(void *handle, int width, int height)\r
329 {\r
330 /* Do nothing! */\r
331 return;\r
332 }\r
333 \r
334 static void serbreak_timer(void *ctx, unsigned long now)\r
335 {\r
336 Serial serial = (Serial)ctx;\r
337 \r
338 if (now == serial->clearbreak_time && serial->port) {\r
339 ClearCommBreak(serial->port);\r
340 serial->break_in_progress = FALSE;\r
341 logevent(serial->frontend, "Finished serial break");\r
342 }\r
343 }\r
344 \r
345 /*\r
346 * Send serial special codes.\r
347 */\r
348 static void serial_special(void *handle, Telnet_Special code)\r
349 {\r
350 Serial serial = (Serial) handle;\r
351 \r
352 if (serial->port && code == TS_BRK) {\r
353 logevent(serial->frontend, "Starting serial break at user request");\r
354 SetCommBreak(serial->port);\r
355 /*\r
356 * To send a serial break on Windows, we call SetCommBreak\r
357 * to begin the break, then wait a bit, and then call\r
358 * ClearCommBreak to finish it. Hence, I must use timing.c\r
359 * to arrange a callback when it's time to do the latter.\r
360 * \r
361 * SUS says that a default break length must be between 1/4\r
362 * and 1/2 second. FreeBSD apparently goes with 2/5 second,\r
363 * and so will I. \r
364 */\r
365 serial->clearbreak_time =\r
366 schedule_timer(TICKSPERSEC * 2 / 5, serbreak_timer, serial);\r
367 serial->break_in_progress = TRUE;\r
368 }\r
369 \r
370 return;\r
371 }\r
372 \r
373 /*\r
374 * Return a list of the special codes that make sense in this\r
375 * protocol.\r
376 */\r
377 static const struct telnet_special *serial_get_specials(void *handle)\r
378 {\r
379 static const struct telnet_special specials[] = {\r
380 {"Break", TS_BRK},\r
381 {NULL, TS_EXITMENU}\r
382 };\r
383 return specials;\r
384 }\r
385 \r
386 static int serial_connected(void *handle)\r
387 {\r
388 return 1; /* always connected */\r
389 }\r
390 \r
391 static int serial_sendok(void *handle)\r
392 {\r
393 return 1;\r
394 }\r
395 \r
396 static void serial_unthrottle(void *handle, int backlog)\r
397 {\r
398 Serial serial = (Serial) handle;\r
399 if (serial->in)\r
400 handle_unthrottle(serial->in, backlog);\r
401 }\r
402 \r
403 static int serial_ldisc(void *handle, int option)\r
404 {\r
405 /*\r
406 * Local editing and local echo are off by default.\r
407 */\r
408 return 0;\r
409 }\r
410 \r
411 static void serial_provide_ldisc(void *handle, void *ldisc)\r
412 {\r
413 /* This is a stub. */\r
414 }\r
415 \r
416 static void serial_provide_logctx(void *handle, void *logctx)\r
417 {\r
418 /* This is a stub. */\r
419 }\r
420 \r
421 static int serial_exitcode(void *handle)\r
422 {\r
423 Serial serial = (Serial) handle;\r
424 if (serial->port != INVALID_HANDLE_VALUE)\r
425 return -1; /* still connected */\r
426 else\r
427 /* Exit codes are a meaningless concept with serial ports */\r
428 return INT_MAX;\r
429 }\r
430 \r
431 /*\r
432 * cfg_info for Serial does nothing at all.\r
433 */\r
434 static int serial_cfg_info(void *handle)\r
435 {\r
436 return 0;\r
437 }\r
438 \r
439 Backend serial_backend = {\r
440 serial_init,\r
441 serial_free,\r
442 serial_reconfig,\r
443 serial_send,\r
444 serial_sendbuffer,\r
445 serial_size,\r
446 serial_special,\r
447 serial_get_specials,\r
448 serial_connected,\r
449 serial_exitcode,\r
450 serial_sendok,\r
451 serial_ldisc,\r
452 serial_provide_ldisc,\r
453 serial_provide_logctx,\r
454 serial_unthrottle,\r
455 serial_cfg_info,\r
456 "serial",\r
457 PROT_SERIAL,\r
458 0\r
459 };\r