2 * Serial back end (Unix-specific).
18 #define SERIAL_MAX_BACKLOG 4096
20 typedef struct serial_backend_data {
29 * We store our serial backends in a tree sorted by fd, so that
30 * when we get an uxsel notification we know which backend instance
31 * is the owner of the serial port that caused it.
33 static int serial_compare_by_fd(void *av, void *bv)
35 Serial a = (Serial)av;
36 Serial b = (Serial)bv;
40 else if (a->fd > b->fd)
45 static int serial_find_by_fd(void *av, void *bv)
48 Serial b = (Serial)bv;
57 static tree234 *serial_by_fd = NULL;
59 static int serial_select_result(int fd, int event);
60 static void serial_uxsel_setup(Serial serial);
61 static void serial_try_write(Serial serial);
63 static const char *serial_configure(Serial serial, Config *cfg)
65 struct termios options;
71 return "Unable to reconfigure already-closed serial connection";
73 tcgetattr(serial->fd, &options);
76 * Find the appropriate baud rate flag.
78 #define SETBAUD(x) (bflag = B ## x, bval = x)
79 #define CHECKBAUD(x) do { if (cfg->serspeed >= x) SETBAUD(x); } while (0)
137 cfsetispeed(&options, bflag);
138 cfsetospeed(&options, bflag);
139 msg = dupprintf("Configuring baud rate %d", bval);
140 logevent(serial->frontend, msg);
143 options.c_cflag &= ~CSIZE;
144 switch (cfg->serdatabits) {
145 case 5: options.c_cflag |= CS5; break;
146 case 6: options.c_cflag |= CS6; break;
147 case 7: options.c_cflag |= CS7; break;
148 case 8: options.c_cflag |= CS8; break;
149 default: return "Invalid number of data bits (need 5, 6, 7 or 8)";
151 msg = dupprintf("Configuring %d data bits", cfg->serdatabits);
152 logevent(serial->frontend, msg);
155 if (cfg->serstopbits >= 4) {
156 options.c_cflag |= CSTOPB;
158 options.c_cflag &= ~CSTOPB;
160 msg = dupprintf("Configuring %d stop bits",
161 (options.c_cflag & CSTOPB ? 2 : 1));
162 logevent(serial->frontend, msg);
165 options.c_iflag &= ~(IXON|IXOFF);
167 options.c_cflag &= ~CRTSCTS;
170 options.c_cflag &= ~CNEW_RTSCTS;
172 if (cfg->serflow == SER_FLOW_XONXOFF) {
173 options.c_iflag |= IXON | IXOFF;
175 } else if (cfg->serflow == SER_FLOW_RTSCTS) {
177 options.c_cflag |= CRTSCTS;
180 options.c_cflag |= CNEW_RTSCTS;
185 msg = dupprintf("Configuring %s flow control", str);
186 logevent(serial->frontend, msg);
190 if (cfg->serparity == SER_PAR_ODD) {
191 options.c_cflag |= PARENB;
192 options.c_cflag |= PARODD;
194 } else if (cfg->serparity == SER_PAR_EVEN) {
195 options.c_cflag |= PARENB;
196 options.c_cflag &= ~PARODD;
199 options.c_cflag &= ~PARENB;
202 msg = dupprintf("Configuring %s parity", str);
203 logevent(serial->frontend, msg);
206 options.c_cflag |= CLOCAL | CREAD;
207 options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
208 options.c_iflag &= ~(ISTRIP | IGNCR | INLCR | ICRNL
213 options.c_oflag &= ~(OPOST
217 | OCRNL | ONOCR | ONLRET);
218 options.c_cc[VMIN] = 1;
219 options.c_cc[VTIME] = 0;
221 if (tcsetattr(serial->fd, TCSANOW, &options) < 0)
222 return "Unable to configure serial port";
228 * Called to set up the serial connection.
230 * Returns an error message, or NULL on success.
232 * Also places the canonical host name into `realhost'. It must be
233 * freed by the caller.
235 static const char *serial_init(void *frontend_handle, void **backend_handle,
237 char *host, int port, char **realhost, int nodelay,
243 serial = snew(struct serial_backend_data);
244 *backend_handle = serial;
246 serial->frontend = frontend_handle;
247 serial->finished = FALSE;
248 serial->inbufsize = 0;
249 bufchain_init(&serial->output_data);
252 char *msg = dupprintf("Opening serial device %s", cfg->serline);
253 logevent(serial->frontend, msg);
256 serial->fd = open(cfg->serline, O_RDWR | O_NOCTTY | O_NDELAY | O_NONBLOCK);
258 return "Unable to open serial port";
260 err = serial_configure(serial, cfg);
264 *realhost = dupstr(cfg->serline);
267 serial_by_fd = newtree234(serial_compare_by_fd);
268 add234(serial_by_fd, serial);
270 serial_uxsel_setup(serial);
273 * Specials are always available.
275 update_specials_menu(serial->frontend);
280 static void serial_close(Serial serial)
282 if (serial->fd >= 0) {
288 static void serial_free(void *handle)
290 Serial serial = (Serial) handle;
292 serial_close(serial);
294 bufchain_clear(&serial->output_data);
299 static void serial_reconfig(void *handle, Config *cfg)
301 Serial serial = (Serial) handle;
304 err = serial_configure(serial, cfg);
307 * FIXME: what should we do if err returns something?
311 static int serial_select_result(int fd, int event)
316 int finished = FALSE;
318 serial = find234(serial_by_fd, &fd, serial_find_by_fd);
321 return 1; /* spurious event; keep going */
324 ret = read(serial->fd, buf, sizeof(buf));
328 * Shouldn't happen on a real serial port, but I'm open
329 * to the idea that there might be two-way devices we
330 * can treat _like_ serial ports which can return EOF.
333 } else if (ret < 0) {
334 perror("read serial port");
336 } else if (ret > 0) {
337 serial->inbufsize = from_backend(serial->frontend, 0, buf, ret);
338 serial_uxsel_setup(serial); /* might acquire backlog and freeze */
340 } else if (event == 2) {
342 * Attempt to send data down the pty.
344 serial_try_write(serial);
348 serial_close(serial);
350 serial->finished = TRUE;
352 notify_remote_exit(serial->frontend);
358 static void serial_uxsel_setup(Serial serial)
362 if (serial->inbufsize <= SERIAL_MAX_BACKLOG)
364 if (bufchain_size(&serial->output_data))
365 rwx |= 2; /* might also want to write to it */
366 uxsel_set(serial->fd, rwx, serial_select_result);
369 static void serial_try_write(Serial serial)
374 assert(serial->fd >= 0);
376 while (bufchain_size(&serial->output_data) > 0) {
377 bufchain_prefix(&serial->output_data, &data, &len);
378 ret = write(serial->fd, data, len);
380 if (ret < 0 && (errno == EWOULDBLOCK)) {
382 * We've sent all we can for the moment.
387 perror("write serial port");
390 bufchain_consume(&serial->output_data, ret);
393 serial_uxsel_setup(serial);
397 * Called to send data down the serial connection.
399 static int serial_send(void *handle, char *buf, int len)
401 Serial serial = (Serial) handle;
406 bufchain_add(&serial->output_data, buf, len);
407 serial_try_write(serial);
409 return bufchain_size(&serial->output_data);
413 * Called to query the current sendability status.
415 static int serial_sendbuffer(void *handle)
417 Serial serial = (Serial) handle;
418 return bufchain_size(&serial->output_data);
422 * Called to set the size of the window
424 static void serial_size(void *handle, int width, int height)
431 * Send serial special codes.
433 static void serial_special(void *handle, Telnet_Special code)
435 Serial serial = (Serial) handle;
437 if (serial->fd >= 0 && code == TS_BRK) {
438 tcsendbreak(serial->fd, 0);
439 logevent(serial->frontend, "Sending serial break at user request");
446 * Return a list of the special codes that make sense in this
449 static const struct telnet_special *serial_get_specials(void *handle)
451 static const struct telnet_special specials[] = {
458 static int serial_connected(void *handle)
460 return 1; /* always connected */
463 static int serial_sendok(void *handle)
468 static void serial_unthrottle(void *handle, int backlog)
470 Serial serial = (Serial) handle;
471 serial->inbufsize = backlog;
472 serial_uxsel_setup(serial);
475 static int serial_ldisc(void *handle, int option)
478 * Local editing and local echo are off by default.
483 static void serial_provide_ldisc(void *handle, void *ldisc)
485 /* This is a stub. */
488 static void serial_provide_logctx(void *handle, void *logctx)
490 /* This is a stub. */
493 static int serial_exitcode(void *handle)
495 Serial serial = (Serial) handle;
497 return -1; /* still connected */
499 /* Exit codes are a meaningless concept with serial ports */
504 * cfg_info for Serial does nothing at all.
506 static int serial_cfg_info(void *handle)
511 Backend serial_backend = {
524 serial_provide_ldisc,
525 serial_provide_logctx,