| 1 | /* |
| 2 | * Serial back end (Unix-specific). |
| 3 | */ |
| 4 | |
| 5 | #include <stdio.h> |
| 6 | #include <stdlib.h> |
| 7 | #include <assert.h> |
| 8 | #include <limits.h> |
| 9 | |
| 10 | #include <errno.h> |
| 11 | #include <unistd.h> |
| 12 | #include <fcntl.h> |
| 13 | #include <termios.h> |
| 14 | |
| 15 | #include "putty.h" |
| 16 | #include "tree234.h" |
| 17 | |
| 18 | #define SERIAL_MAX_BACKLOG 4096 |
| 19 | |
| 20 | typedef struct serial_backend_data { |
| 21 | void *frontend; |
| 22 | int fd; |
| 23 | int finished; |
| 24 | int inbufsize; |
| 25 | bufchain output_data; |
| 26 | } *Serial; |
| 27 | |
| 28 | /* |
| 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. |
| 32 | */ |
| 33 | static int serial_compare_by_fd(void *av, void *bv) |
| 34 | { |
| 35 | Serial a = (Serial)av; |
| 36 | Serial b = (Serial)bv; |
| 37 | |
| 38 | if (a->fd < b->fd) |
| 39 | return -1; |
| 40 | else if (a->fd > b->fd) |
| 41 | return +1; |
| 42 | return 0; |
| 43 | } |
| 44 | |
| 45 | static int serial_find_by_fd(void *av, void *bv) |
| 46 | { |
| 47 | int a = *(int *)av; |
| 48 | Serial b = (Serial)bv; |
| 49 | |
| 50 | if (a < b->fd) |
| 51 | return -1; |
| 52 | else if (a > b->fd) |
| 53 | return +1; |
| 54 | return 0; |
| 55 | } |
| 56 | |
| 57 | static tree234 *serial_by_fd = NULL; |
| 58 | |
| 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); |
| 62 | |
| 63 | static const char *serial_configure(Serial serial, Config *cfg) |
| 64 | { |
| 65 | struct termios options; |
| 66 | int bflag, bval; |
| 67 | const char *str; |
| 68 | char *msg; |
| 69 | |
| 70 | if (serial->fd < 0) |
| 71 | return "Unable to reconfigure already-closed serial connection"; |
| 72 | |
| 73 | tcgetattr(serial->fd, &options); |
| 74 | |
| 75 | /* |
| 76 | * Find the appropriate baud rate flag. |
| 77 | */ |
| 78 | #define SETBAUD(x) (bflag = B ## x, bval = x) |
| 79 | #define CHECKBAUD(x) do { if (cfg->serspeed >= x) SETBAUD(x); } while (0) |
| 80 | SETBAUD(50); |
| 81 | #ifdef B75 |
| 82 | CHECKBAUD(75); |
| 83 | #endif |
| 84 | #ifdef B110 |
| 85 | CHECKBAUD(110); |
| 86 | #endif |
| 87 | #ifdef B134 |
| 88 | CHECKBAUD(134); |
| 89 | #endif |
| 90 | #ifdef B150 |
| 91 | CHECKBAUD(150); |
| 92 | #endif |
| 93 | #ifdef B200 |
| 94 | CHECKBAUD(200); |
| 95 | #endif |
| 96 | #ifdef B300 |
| 97 | CHECKBAUD(300); |
| 98 | #endif |
| 99 | #ifdef B600 |
| 100 | CHECKBAUD(600); |
| 101 | #endif |
| 102 | #ifdef B1200 |
| 103 | CHECKBAUD(1200); |
| 104 | #endif |
| 105 | #ifdef B1800 |
| 106 | CHECKBAUD(1800); |
| 107 | #endif |
| 108 | #ifdef B2400 |
| 109 | CHECKBAUD(2400); |
| 110 | #endif |
| 111 | #ifdef B4800 |
| 112 | CHECKBAUD(4800); |
| 113 | #endif |
| 114 | #ifdef B9600 |
| 115 | CHECKBAUD(9600); |
| 116 | #endif |
| 117 | #ifdef B19200 |
| 118 | CHECKBAUD(19200); |
| 119 | #endif |
| 120 | #ifdef B38400 |
| 121 | CHECKBAUD(38400); |
| 122 | #endif |
| 123 | #ifdef B57600 |
| 124 | CHECKBAUD(57600); |
| 125 | #endif |
| 126 | #ifdef B76800 |
| 127 | CHECKBAUD(76800); |
| 128 | #endif |
| 129 | #ifdef B115200 |
| 130 | CHECKBAUD(115200); |
| 131 | #endif |
| 132 | #ifdef B230400 |
| 133 | CHECKBAUD(230400); |
| 134 | #endif |
| 135 | #undef CHECKBAUD |
| 136 | #undef SETBAUD |
| 137 | cfsetispeed(&options, bflag); |
| 138 | cfsetospeed(&options, bflag); |
| 139 | msg = dupprintf("Configuring baud rate %d", bval); |
| 140 | logevent(serial->frontend, msg); |
| 141 | sfree(msg); |
| 142 | |
| 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)"; |
| 150 | } |
| 151 | msg = dupprintf("Configuring %d data bits", cfg->serdatabits); |
| 152 | logevent(serial->frontend, msg); |
| 153 | sfree(msg); |
| 154 | |
| 155 | if (cfg->serstopbits >= 4) { |
| 156 | options.c_cflag |= CSTOPB; |
| 157 | } else { |
| 158 | options.c_cflag &= ~CSTOPB; |
| 159 | } |
| 160 | msg = dupprintf("Configuring %d stop bits", |
| 161 | (options.c_cflag & CSTOPB ? 2 : 1)); |
| 162 | logevent(serial->frontend, msg); |
| 163 | sfree(msg); |
| 164 | |
| 165 | options.c_iflag &= ~(IXON|IXOFF); |
| 166 | #ifdef CRTSCTS |
| 167 | options.c_cflag &= ~CRTSCTS; |
| 168 | #endif |
| 169 | #ifdef CNEW_RTSCTS |
| 170 | options.c_cflag &= ~CNEW_RTSCTS; |
| 171 | #endif |
| 172 | if (cfg->serflow == SER_FLOW_XONXOFF) { |
| 173 | options.c_iflag |= IXON | IXOFF; |
| 174 | str = "XON/XOFF"; |
| 175 | } else if (cfg->serflow == SER_FLOW_RTSCTS) { |
| 176 | #ifdef CRTSCTS |
| 177 | options.c_cflag |= CRTSCTS; |
| 178 | #endif |
| 179 | #ifdef CNEW_RTSCTS |
| 180 | options.c_cflag |= CNEW_RTSCTS; |
| 181 | #endif |
| 182 | str = "RTS/CTS"; |
| 183 | } else |
| 184 | str = "no"; |
| 185 | msg = dupprintf("Configuring %s flow control", str); |
| 186 | logevent(serial->frontend, msg); |
| 187 | sfree(msg); |
| 188 | |
| 189 | /* Parity */ |
| 190 | if (cfg->serparity == SER_PAR_ODD) { |
| 191 | options.c_cflag |= PARENB; |
| 192 | options.c_cflag |= PARODD; |
| 193 | str = "odd"; |
| 194 | } else if (cfg->serparity == SER_PAR_EVEN) { |
| 195 | options.c_cflag |= PARENB; |
| 196 | options.c_cflag &= ~PARODD; |
| 197 | str = "even"; |
| 198 | } else { |
| 199 | options.c_cflag &= ~PARENB; |
| 200 | str = "no"; |
| 201 | } |
| 202 | msg = dupprintf("Configuring %s parity", str); |
| 203 | logevent(serial->frontend, msg); |
| 204 | sfree(msg); |
| 205 | |
| 206 | options.c_cflag |= CLOCAL | CREAD; |
| 207 | options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); |
| 208 | options.c_iflag &= ~(ISTRIP | IGNCR | INLCR | ICRNL |
| 209 | #ifdef IUCLC |
| 210 | | IUCLC |
| 211 | #endif |
| 212 | ); |
| 213 | options.c_oflag &= ~(OPOST |
| 214 | #ifdef ONLCR |
| 215 | | ONLCR |
| 216 | #endif |
| 217 | #ifdef OCRNL |
| 218 | | OCRNL |
| 219 | #endif |
| 220 | #ifdef ONOCR |
| 221 | | ONOCR |
| 222 | #endif |
| 223 | #ifdef ONLRET |
| 224 | | ONLRET |
| 225 | #endif |
| 226 | ); |
| 227 | options.c_cc[VMIN] = 1; |
| 228 | options.c_cc[VTIME] = 0; |
| 229 | |
| 230 | if (tcsetattr(serial->fd, TCSANOW, &options) < 0) |
| 231 | return "Unable to configure serial port"; |
| 232 | |
| 233 | return NULL; |
| 234 | } |
| 235 | |
| 236 | /* |
| 237 | * Called to set up the serial connection. |
| 238 | * |
| 239 | * Returns an error message, or NULL on success. |
| 240 | * |
| 241 | * Also places the canonical host name into `realhost'. It must be |
| 242 | * freed by the caller. |
| 243 | */ |
| 244 | static const char *serial_init(void *frontend_handle, void **backend_handle, |
| 245 | Config *cfg, |
| 246 | char *host, int port, char **realhost, int nodelay, |
| 247 | int keepalive) |
| 248 | { |
| 249 | Serial serial; |
| 250 | const char *err; |
| 251 | |
| 252 | serial = snew(struct serial_backend_data); |
| 253 | *backend_handle = serial; |
| 254 | |
| 255 | serial->frontend = frontend_handle; |
| 256 | serial->finished = FALSE; |
| 257 | serial->inbufsize = 0; |
| 258 | bufchain_init(&serial->output_data); |
| 259 | |
| 260 | { |
| 261 | char *msg = dupprintf("Opening serial device %s", cfg->serline); |
| 262 | logevent(serial->frontend, msg); |
| 263 | } |
| 264 | |
| 265 | serial->fd = open(cfg->serline, O_RDWR | O_NOCTTY | O_NDELAY | O_NONBLOCK); |
| 266 | if (serial->fd < 0) |
| 267 | return "Unable to open serial port"; |
| 268 | |
| 269 | cloexec(serial->fd); |
| 270 | |
| 271 | err = serial_configure(serial, cfg); |
| 272 | if (err) |
| 273 | return err; |
| 274 | |
| 275 | *realhost = dupstr(cfg->serline); |
| 276 | |
| 277 | if (!serial_by_fd) |
| 278 | serial_by_fd = newtree234(serial_compare_by_fd); |
| 279 | add234(serial_by_fd, serial); |
| 280 | |
| 281 | serial_uxsel_setup(serial); |
| 282 | |
| 283 | /* |
| 284 | * Specials are always available. |
| 285 | */ |
| 286 | update_specials_menu(serial->frontend); |
| 287 | |
| 288 | return NULL; |
| 289 | } |
| 290 | |
| 291 | static void serial_close(Serial serial) |
| 292 | { |
| 293 | if (serial->fd >= 0) { |
| 294 | close(serial->fd); |
| 295 | serial->fd = -1; |
| 296 | } |
| 297 | } |
| 298 | |
| 299 | static void serial_free(void *handle) |
| 300 | { |
| 301 | Serial serial = (Serial) handle; |
| 302 | |
| 303 | serial_close(serial); |
| 304 | |
| 305 | bufchain_clear(&serial->output_data); |
| 306 | |
| 307 | sfree(serial); |
| 308 | } |
| 309 | |
| 310 | static void serial_reconfig(void *handle, Config *cfg) |
| 311 | { |
| 312 | Serial serial = (Serial) handle; |
| 313 | const char *err; |
| 314 | |
| 315 | err = serial_configure(serial, cfg); |
| 316 | |
| 317 | /* |
| 318 | * FIXME: what should we do if err returns something? |
| 319 | */ |
| 320 | } |
| 321 | |
| 322 | static int serial_select_result(int fd, int event) |
| 323 | { |
| 324 | Serial serial; |
| 325 | char buf[4096]; |
| 326 | int ret; |
| 327 | int finished = FALSE; |
| 328 | |
| 329 | serial = find234(serial_by_fd, &fd, serial_find_by_fd); |
| 330 | |
| 331 | if (!serial) |
| 332 | return 1; /* spurious event; keep going */ |
| 333 | |
| 334 | if (event == 1) { |
| 335 | ret = read(serial->fd, buf, sizeof(buf)); |
| 336 | |
| 337 | if (ret == 0) { |
| 338 | /* |
| 339 | * Shouldn't happen on a real serial port, but I'm open |
| 340 | * to the idea that there might be two-way devices we |
| 341 | * can treat _like_ serial ports which can return EOF. |
| 342 | */ |
| 343 | finished = TRUE; |
| 344 | } else if (ret < 0) { |
| 345 | perror("read serial port"); |
| 346 | exit(1); |
| 347 | } else if (ret > 0) { |
| 348 | serial->inbufsize = from_backend(serial->frontend, 0, buf, ret); |
| 349 | serial_uxsel_setup(serial); /* might acquire backlog and freeze */ |
| 350 | } |
| 351 | } else if (event == 2) { |
| 352 | /* |
| 353 | * Attempt to send data down the pty. |
| 354 | */ |
| 355 | serial_try_write(serial); |
| 356 | } |
| 357 | |
| 358 | if (finished) { |
| 359 | serial_close(serial); |
| 360 | |
| 361 | serial->finished = TRUE; |
| 362 | |
| 363 | notify_remote_exit(serial->frontend); |
| 364 | } |
| 365 | |
| 366 | return !finished; |
| 367 | } |
| 368 | |
| 369 | static void serial_uxsel_setup(Serial serial) |
| 370 | { |
| 371 | int rwx = 0; |
| 372 | |
| 373 | if (serial->inbufsize <= SERIAL_MAX_BACKLOG) |
| 374 | rwx |= 1; |
| 375 | if (bufchain_size(&serial->output_data)) |
| 376 | rwx |= 2; /* might also want to write to it */ |
| 377 | uxsel_set(serial->fd, rwx, serial_select_result); |
| 378 | } |
| 379 | |
| 380 | static void serial_try_write(Serial serial) |
| 381 | { |
| 382 | void *data; |
| 383 | int len, ret; |
| 384 | |
| 385 | assert(serial->fd >= 0); |
| 386 | |
| 387 | while (bufchain_size(&serial->output_data) > 0) { |
| 388 | bufchain_prefix(&serial->output_data, &data, &len); |
| 389 | ret = write(serial->fd, data, len); |
| 390 | |
| 391 | if (ret < 0 && (errno == EWOULDBLOCK)) { |
| 392 | /* |
| 393 | * We've sent all we can for the moment. |
| 394 | */ |
| 395 | break; |
| 396 | } |
| 397 | if (ret < 0) { |
| 398 | perror("write serial port"); |
| 399 | exit(1); |
| 400 | } |
| 401 | bufchain_consume(&serial->output_data, ret); |
| 402 | } |
| 403 | |
| 404 | serial_uxsel_setup(serial); |
| 405 | } |
| 406 | |
| 407 | /* |
| 408 | * Called to send data down the serial connection. |
| 409 | */ |
| 410 | static int serial_send(void *handle, char *buf, int len) |
| 411 | { |
| 412 | Serial serial = (Serial) handle; |
| 413 | |
| 414 | if (serial->fd < 0) |
| 415 | return 0; |
| 416 | |
| 417 | bufchain_add(&serial->output_data, buf, len); |
| 418 | serial_try_write(serial); |
| 419 | |
| 420 | return bufchain_size(&serial->output_data); |
| 421 | } |
| 422 | |
| 423 | /* |
| 424 | * Called to query the current sendability status. |
| 425 | */ |
| 426 | static int serial_sendbuffer(void *handle) |
| 427 | { |
| 428 | Serial serial = (Serial) handle; |
| 429 | return bufchain_size(&serial->output_data); |
| 430 | } |
| 431 | |
| 432 | /* |
| 433 | * Called to set the size of the window |
| 434 | */ |
| 435 | static void serial_size(void *handle, int width, int height) |
| 436 | { |
| 437 | /* Do nothing! */ |
| 438 | return; |
| 439 | } |
| 440 | |
| 441 | /* |
| 442 | * Send serial special codes. |
| 443 | */ |
| 444 | static void serial_special(void *handle, Telnet_Special code) |
| 445 | { |
| 446 | Serial serial = (Serial) handle; |
| 447 | |
| 448 | if (serial->fd >= 0 && code == TS_BRK) { |
| 449 | tcsendbreak(serial->fd, 0); |
| 450 | logevent(serial->frontend, "Sending serial break at user request"); |
| 451 | } |
| 452 | |
| 453 | return; |
| 454 | } |
| 455 | |
| 456 | /* |
| 457 | * Return a list of the special codes that make sense in this |
| 458 | * protocol. |
| 459 | */ |
| 460 | static const struct telnet_special *serial_get_specials(void *handle) |
| 461 | { |
| 462 | static const struct telnet_special specials[] = { |
| 463 | {"Break", TS_BRK}, |
| 464 | {NULL, TS_EXITMENU} |
| 465 | }; |
| 466 | return specials; |
| 467 | } |
| 468 | |
| 469 | static int serial_connected(void *handle) |
| 470 | { |
| 471 | return 1; /* always connected */ |
| 472 | } |
| 473 | |
| 474 | static int serial_sendok(void *handle) |
| 475 | { |
| 476 | return 1; |
| 477 | } |
| 478 | |
| 479 | static void serial_unthrottle(void *handle, int backlog) |
| 480 | { |
| 481 | Serial serial = (Serial) handle; |
| 482 | serial->inbufsize = backlog; |
| 483 | serial_uxsel_setup(serial); |
| 484 | } |
| 485 | |
| 486 | static int serial_ldisc(void *handle, int option) |
| 487 | { |
| 488 | /* |
| 489 | * Local editing and local echo are off by default. |
| 490 | */ |
| 491 | return 0; |
| 492 | } |
| 493 | |
| 494 | static void serial_provide_ldisc(void *handle, void *ldisc) |
| 495 | { |
| 496 | /* This is a stub. */ |
| 497 | } |
| 498 | |
| 499 | static void serial_provide_logctx(void *handle, void *logctx) |
| 500 | { |
| 501 | /* This is a stub. */ |
| 502 | } |
| 503 | |
| 504 | static int serial_exitcode(void *handle) |
| 505 | { |
| 506 | Serial serial = (Serial) handle; |
| 507 | if (serial->fd >= 0) |
| 508 | return -1; /* still connected */ |
| 509 | else |
| 510 | /* Exit codes are a meaningless concept with serial ports */ |
| 511 | return INT_MAX; |
| 512 | } |
| 513 | |
| 514 | /* |
| 515 | * cfg_info for Serial does nothing at all. |
| 516 | */ |
| 517 | static int serial_cfg_info(void *handle) |
| 518 | { |
| 519 | return 0; |
| 520 | } |
| 521 | |
| 522 | Backend serial_backend = { |
| 523 | serial_init, |
| 524 | serial_free, |
| 525 | serial_reconfig, |
| 526 | serial_send, |
| 527 | serial_sendbuffer, |
| 528 | serial_size, |
| 529 | serial_special, |
| 530 | serial_get_specials, |
| 531 | serial_connected, |
| 532 | serial_exitcode, |
| 533 | serial_sendok, |
| 534 | serial_ldisc, |
| 535 | serial_provide_ldisc, |
| 536 | serial_provide_logctx, |
| 537 | serial_unthrottle, |
| 538 | serial_cfg_info, |
| 539 | "serial", |
| 540 | PROT_SERIAL, |
| 541 | 0 |
| 542 | }; |