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)
179 cfsetispeed(&options, bflag);
180 cfsetospeed(&options, bflag);
181 msg = dupprintf("Configuring baud rate %d", bval);
182 logevent(serial->frontend, msg);
185 options.c_cflag &= ~CSIZE;
186 switch (cfg->serdatabits) {
187 case 5: options.c_cflag |= CS5; break;
188 case 6: options.c_cflag |= CS6; break;
189 case 7: options.c_cflag |= CS7; break;
190 case 8: options.c_cflag |= CS8; break;
191 default: return "Invalid number of data bits (need 5, 6, 7 or 8)";
193 msg = dupprintf("Configuring %d data bits", cfg->serdatabits);
194 logevent(serial->frontend, msg);
197 if (cfg->serstopbits >= 4) {
198 options.c_cflag |= CSTOPB;
200 options.c_cflag &= ~CSTOPB;
202 msg = dupprintf("Configuring %d stop bits",
203 (options.c_cflag & CSTOPB ? 2 : 1));
204 logevent(serial->frontend, msg);
207 options.c_iflag &= ~(IXON|IXOFF);
209 options.c_cflag &= ~CRTSCTS;
212 options.c_cflag &= ~CNEW_RTSCTS;
214 if (cfg->serflow == SER_FLOW_XONXOFF) {
215 options.c_iflag |= IXON | IXOFF;
217 } else if (cfg->serflow == SER_FLOW_RTSCTS) {
219 options.c_cflag |= CRTSCTS;
222 options.c_cflag |= CNEW_RTSCTS;
227 msg = dupprintf("Configuring %s flow control", str);
228 logevent(serial->frontend, msg);
232 if (cfg->serparity == SER_PAR_ODD) {
233 options.c_cflag |= PARENB;
234 options.c_cflag |= PARODD;
236 } else if (cfg->serparity == SER_PAR_EVEN) {
237 options.c_cflag |= PARENB;
238 options.c_cflag &= ~PARODD;
241 options.c_cflag &= ~PARENB;
244 msg = dupprintf("Configuring %s parity", str);
245 logevent(serial->frontend, msg);
248 options.c_cflag |= CLOCAL | CREAD;
249 options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
250 options.c_iflag &= ~(ISTRIP | IGNCR | INLCR | ICRNL
255 options.c_oflag &= ~(OPOST
269 options.c_cc[VMIN] = 1;
270 options.c_cc[VTIME] = 0;
272 if (tcsetattr(serial->fd, TCSANOW, &options) < 0)
273 return "Unable to configure serial port";
279 * Called to set up the serial connection.
281 * Returns an error message, or NULL on success.
283 * Also places the canonical host name into `realhost'. It must be
284 * freed by the caller.
286 static const char *serial_init(void *frontend_handle, void **backend_handle,
288 char *host, int port, char **realhost, int nodelay,
294 serial = snew(struct serial_backend_data);
295 *backend_handle = serial;
297 serial->frontend = frontend_handle;
298 serial->finished = FALSE;
299 serial->inbufsize = 0;
300 bufchain_init(&serial->output_data);
303 char *msg = dupprintf("Opening serial device %s", cfg->serline);
304 logevent(serial->frontend, msg);
307 serial->fd = open(cfg->serline, O_RDWR | O_NOCTTY | O_NDELAY | O_NONBLOCK);
309 return "Unable to open serial port";
313 err = serial_configure(serial, cfg);
317 *realhost = dupstr(cfg->serline);
320 serial_by_fd = newtree234(serial_compare_by_fd);
321 add234(serial_by_fd, serial);
323 serial_uxsel_setup(serial);
326 * Specials are always available.
328 update_specials_menu(serial->frontend);
333 static void serial_close(Serial serial)
335 if (serial->fd >= 0) {
341 static void serial_free(void *handle)
343 Serial serial = (Serial) handle;
345 serial_close(serial);
347 bufchain_clear(&serial->output_data);
352 static void serial_reconfig(void *handle, Config *cfg)
354 Serial serial = (Serial) handle;
357 * FIXME: what should we do if this returns an error?
359 serial_configure(serial, cfg);
362 static int serial_select_result(int fd, int event)
367 int finished = FALSE;
369 serial = find234(serial_by_fd, &fd, serial_find_by_fd);
372 return 1; /* spurious event; keep going */
375 ret = read(serial->fd, buf, sizeof(buf));
379 * Shouldn't happen on a real serial port, but I'm open
380 * to the idea that there might be two-way devices we
381 * can treat _like_ serial ports which can return EOF.
384 } else if (ret < 0) {
387 return 1; /* spurious */
390 if (errno == EWOULDBLOCK)
391 return 1; /* spurious */
393 perror("read serial port");
395 } else if (ret > 0) {
396 serial->inbufsize = from_backend(serial->frontend, 0, buf, ret);
397 serial_uxsel_setup(serial); /* might acquire backlog and freeze */
399 } else if (event == 2) {
401 * Attempt to send data down the pty.
403 serial_try_write(serial);
407 serial_close(serial);
409 serial->finished = TRUE;
411 notify_remote_exit(serial->frontend);
417 static void serial_uxsel_setup(Serial serial)
421 if (serial->inbufsize <= SERIAL_MAX_BACKLOG)
423 if (bufchain_size(&serial->output_data))
424 rwx |= 2; /* might also want to write to it */
425 uxsel_set(serial->fd, rwx, serial_select_result);
428 static void serial_try_write(Serial serial)
433 assert(serial->fd >= 0);
435 while (bufchain_size(&serial->output_data) > 0) {
436 bufchain_prefix(&serial->output_data, &data, &len);
437 ret = write(serial->fd, data, len);
439 if (ret < 0 && (errno == EWOULDBLOCK)) {
441 * We've sent all we can for the moment.
446 perror("write serial port");
449 bufchain_consume(&serial->output_data, ret);
452 serial_uxsel_setup(serial);
456 * Called to send data down the serial connection.
458 static int serial_send(void *handle, char *buf, int len)
460 Serial serial = (Serial) handle;
465 bufchain_add(&serial->output_data, buf, len);
466 serial_try_write(serial);
468 return bufchain_size(&serial->output_data);
472 * Called to query the current sendability status.
474 static int serial_sendbuffer(void *handle)
476 Serial serial = (Serial) handle;
477 return bufchain_size(&serial->output_data);
481 * Called to set the size of the window
483 static void serial_size(void *handle, int width, int height)
490 * Send serial special codes.
492 static void serial_special(void *handle, Telnet_Special code)
494 Serial serial = (Serial) handle;
496 if (serial->fd >= 0 && code == TS_BRK) {
497 tcsendbreak(serial->fd, 0);
498 logevent(serial->frontend, "Sending serial break at user request");
505 * Return a list of the special codes that make sense in this
508 static const struct telnet_special *serial_get_specials(void *handle)
510 static const struct telnet_special specials[] = {
517 static int serial_connected(void *handle)
519 return 1; /* always connected */
522 static int serial_sendok(void *handle)
527 static void serial_unthrottle(void *handle, int backlog)
529 Serial serial = (Serial) handle;
530 serial->inbufsize = backlog;
531 serial_uxsel_setup(serial);
534 static int serial_ldisc(void *handle, int option)
537 * Local editing and local echo are off by default.
542 static void serial_provide_ldisc(void *handle, void *ldisc)
544 /* This is a stub. */
547 static void serial_provide_logctx(void *handle, void *logctx)
549 /* This is a stub. */
552 static int serial_exitcode(void *handle)
554 Serial serial = (Serial) handle;
556 return -1; /* still connected */
558 /* Exit codes are a meaningless concept with serial ports */
563 * cfg_info for Serial does nothing at all.
565 static int serial_cfg_info(void *handle)
570 Backend serial_backend = {
583 serial_provide_ldisc,
584 serial_provide_logctx,