| 1 | /* |
| 2 | * Serial back end (Windows-specific). |
| 3 | */ |
| 4 | |
| 5 | #include <stdio.h> |
| 6 | #include <stdlib.h> |
| 7 | #include <limits.h> |
| 8 | |
| 9 | #include "putty.h" |
| 10 | |
| 11 | #define SERIAL_MAX_BACKLOG 4096 |
| 12 | |
| 13 | typedef struct serial_backend_data { |
| 14 | HANDLE port; |
| 15 | struct handle *out, *in; |
| 16 | void *frontend; |
| 17 | int bufsize; |
| 18 | long clearbreak_time; |
| 19 | int break_in_progress; |
| 20 | } *Serial; |
| 21 | |
| 22 | static void serial_terminate(Serial serial) |
| 23 | { |
| 24 | if (serial->out) { |
| 25 | handle_free(serial->out); |
| 26 | serial->out = NULL; |
| 27 | } |
| 28 | if (serial->in) { |
| 29 | handle_free(serial->in); |
| 30 | serial->in = NULL; |
| 31 | } |
| 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; |
| 37 | } |
| 38 | } |
| 39 | |
| 40 | static int serial_gotdata(struct handle *h, void *data, int len) |
| 41 | { |
| 42 | Serial serial = (Serial)handle_get_privdata(h); |
| 43 | if (len <= 0) { |
| 44 | const char *error_msg; |
| 45 | |
| 46 | /* |
| 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. |
| 52 | */ |
| 53 | if (len == 0) |
| 54 | error_msg = "End of file reading from serial device"; |
| 55 | else |
| 56 | error_msg = "Error reading from serial device"; |
| 57 | |
| 58 | serial_terminate(serial); |
| 59 | |
| 60 | notify_remote_exit(serial->frontend); |
| 61 | |
| 62 | logevent(serial->frontend, error_msg); |
| 63 | |
| 64 | connection_fatal(serial->frontend, "%s", error_msg); |
| 65 | |
| 66 | return 0; /* placate optimiser */ |
| 67 | } else { |
| 68 | return from_backend(serial->frontend, 0, data, len); |
| 69 | } |
| 70 | } |
| 71 | |
| 72 | static void serial_sentdata(struct handle *h, int new_backlog) |
| 73 | { |
| 74 | Serial serial = (Serial)handle_get_privdata(h); |
| 75 | if (new_backlog < 0) { |
| 76 | const char *error_msg = "Error writing to serial device"; |
| 77 | |
| 78 | serial_terminate(serial); |
| 79 | |
| 80 | notify_remote_exit(serial->frontend); |
| 81 | |
| 82 | logevent(serial->frontend, error_msg); |
| 83 | |
| 84 | connection_fatal(serial->frontend, "%s", error_msg); |
| 85 | } else { |
| 86 | serial->bufsize = new_backlog; |
| 87 | } |
| 88 | } |
| 89 | |
| 90 | static const char *serial_configure(Serial serial, HANDLE serport, Config *cfg) |
| 91 | { |
| 92 | DCB dcb; |
| 93 | COMMTIMEOUTS timeouts; |
| 94 | |
| 95 | /* |
| 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. |
| 100 | */ |
| 101 | if (GetCommState(serport, &dcb)) { |
| 102 | char *msg; |
| 103 | const char *str; |
| 104 | |
| 105 | /* |
| 106 | * Boilerplate. |
| 107 | */ |
| 108 | dcb.fBinary = TRUE; |
| 109 | dcb.fDtrControl = DTR_CONTROL_ENABLE; |
| 110 | dcb.fDsrSensitivity = FALSE; |
| 111 | dcb.fTXContinueOnXoff = FALSE; |
| 112 | dcb.fOutX = FALSE; |
| 113 | dcb.fInX = FALSE; |
| 114 | dcb.fErrorChar = FALSE; |
| 115 | dcb.fNull = FALSE; |
| 116 | dcb.fRtsControl = RTS_CONTROL_ENABLE; |
| 117 | dcb.fAbortOnError = FALSE; |
| 118 | dcb.fOutxCtsFlow = FALSE; |
| 119 | dcb.fOutxDsrFlow = FALSE; |
| 120 | |
| 121 | /* |
| 122 | * Configurable parameters. |
| 123 | */ |
| 124 | dcb.BaudRate = cfg->serspeed; |
| 125 | msg = dupprintf("Configuring baud rate %d", cfg->serspeed); |
| 126 | logevent(serial->frontend, msg); |
| 127 | sfree(msg); |
| 128 | |
| 129 | dcb.ByteSize = cfg->serdatabits; |
| 130 | msg = dupprintf("Configuring %d data bits", cfg->serdatabits); |
| 131 | logevent(serial->frontend, msg); |
| 132 | sfree(msg); |
| 133 | |
| 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)"; |
| 139 | } |
| 140 | msg = dupprintf("Configuring %s data bits", str); |
| 141 | logevent(serial->frontend, msg); |
| 142 | sfree(msg); |
| 143 | |
| 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; |
| 150 | } |
| 151 | msg = dupprintf("Configuring %s parity", str); |
| 152 | logevent(serial->frontend, msg); |
| 153 | sfree(msg); |
| 154 | |
| 155 | switch (cfg->serflow) { |
| 156 | case SER_FLOW_NONE: |
| 157 | str = "no"; |
| 158 | break; |
| 159 | case SER_FLOW_XONXOFF: |
| 160 | dcb.fOutX = dcb.fInX = TRUE; |
| 161 | str = "XON/XOFF"; |
| 162 | break; |
| 163 | case SER_FLOW_RTSCTS: |
| 164 | dcb.fRtsControl = RTS_CONTROL_HANDSHAKE; |
| 165 | dcb.fOutxCtsFlow = TRUE; |
| 166 | str = "RTS/CTS"; |
| 167 | break; |
| 168 | case SER_FLOW_DSRDTR: |
| 169 | dcb.fDtrControl = DTR_CONTROL_HANDSHAKE; |
| 170 | dcb.fOutxDsrFlow = TRUE; |
| 171 | str = "DSR/DTR"; |
| 172 | break; |
| 173 | } |
| 174 | msg = dupprintf("Configuring %s flow control", str); |
| 175 | logevent(serial->frontend, msg); |
| 176 | sfree(msg); |
| 177 | |
| 178 | if (!SetCommState(serport, &dcb)) |
| 179 | return "Unable to configure serial port"; |
| 180 | |
| 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"; |
| 188 | } |
| 189 | |
| 190 | return NULL; |
| 191 | } |
| 192 | |
| 193 | /* |
| 194 | * Called to set up the serial connection. |
| 195 | * |
| 196 | * Returns an error message, or NULL on success. |
| 197 | * |
| 198 | * Also places the canonical host name into `realhost'. It must be |
| 199 | * freed by the caller. |
| 200 | */ |
| 201 | static const char *serial_init(void *frontend_handle, void **backend_handle, |
| 202 | Config *cfg, |
| 203 | char *host, int port, char **realhost, int nodelay, |
| 204 | int keepalive) |
| 205 | { |
| 206 | Serial serial; |
| 207 | HANDLE serport; |
| 208 | const char *err; |
| 209 | |
| 210 | serial = snew(struct serial_backend_data); |
| 211 | serial->port = INVALID_HANDLE_VALUE; |
| 212 | serial->out = serial->in = NULL; |
| 213 | serial->bufsize = 0; |
| 214 | serial->break_in_progress = FALSE; |
| 215 | *backend_handle = serial; |
| 216 | |
| 217 | serial->frontend = frontend_handle; |
| 218 | |
| 219 | { |
| 220 | char *msg = dupprintf("Opening serial device %s", cfg->serline); |
| 221 | logevent(serial->frontend, msg); |
| 222 | } |
| 223 | |
| 224 | { |
| 225 | /* |
| 226 | * Munge the string supplied by the user into a Windows filename. |
| 227 | * |
| 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.) |
| 233 | * |
| 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). |
| 241 | * |
| 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.) |
| 247 | */ |
| 248 | char *serfilename = |
| 249 | dupprintf("%s%s", |
| 250 | strchr(cfg->serline, '\\') ? "" : "\\\\.\\", |
| 251 | cfg->serline); |
| 252 | serport = CreateFile(serfilename, GENERIC_READ | GENERIC_WRITE, 0, NULL, |
| 253 | OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL); |
| 254 | sfree(serfilename); |
| 255 | } |
| 256 | |
| 257 | if (serport == INVALID_HANDLE_VALUE) |
| 258 | return "Unable to open serial port"; |
| 259 | |
| 260 | err = serial_configure(serial, serport, cfg); |
| 261 | if (err) |
| 262 | return err; |
| 263 | |
| 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); |
| 271 | |
| 272 | *realhost = dupstr(cfg->serline); |
| 273 | |
| 274 | /* |
| 275 | * Specials are always available. |
| 276 | */ |
| 277 | update_specials_menu(serial->frontend); |
| 278 | |
| 279 | return NULL; |
| 280 | } |
| 281 | |
| 282 | static void serial_free(void *handle) |
| 283 | { |
| 284 | Serial serial = (Serial) handle; |
| 285 | |
| 286 | serial_terminate(serial); |
| 287 | expire_timer_context(serial); |
| 288 | sfree(serial); |
| 289 | } |
| 290 | |
| 291 | static void serial_reconfig(void *handle, Config *cfg) |
| 292 | { |
| 293 | Serial serial = (Serial) handle; |
| 294 | const char *err; |
| 295 | |
| 296 | err = serial_configure(serial, serial->port, cfg); |
| 297 | |
| 298 | /* |
| 299 | * FIXME: what should we do if err returns something? |
| 300 | */ |
| 301 | } |
| 302 | |
| 303 | /* |
| 304 | * Called to send data down the serial connection. |
| 305 | */ |
| 306 | static int serial_send(void *handle, char *buf, int len) |
| 307 | { |
| 308 | Serial serial = (Serial) handle; |
| 309 | |
| 310 | if (serial->out == NULL) |
| 311 | return 0; |
| 312 | |
| 313 | serial->bufsize = handle_write(serial->out, buf, len); |
| 314 | return serial->bufsize; |
| 315 | } |
| 316 | |
| 317 | /* |
| 318 | * Called to query the current sendability status. |
| 319 | */ |
| 320 | static int serial_sendbuffer(void *handle) |
| 321 | { |
| 322 | Serial serial = (Serial) handle; |
| 323 | return serial->bufsize; |
| 324 | } |
| 325 | |
| 326 | /* |
| 327 | * Called to set the size of the window |
| 328 | */ |
| 329 | static void serial_size(void *handle, int width, int height) |
| 330 | { |
| 331 | /* Do nothing! */ |
| 332 | return; |
| 333 | } |
| 334 | |
| 335 | static void serbreak_timer(void *ctx, long now) |
| 336 | { |
| 337 | Serial serial = (Serial)ctx; |
| 338 | |
| 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"); |
| 343 | } |
| 344 | } |
| 345 | |
| 346 | /* |
| 347 | * Send serial special codes. |
| 348 | */ |
| 349 | static void serial_special(void *handle, Telnet_Special code) |
| 350 | { |
| 351 | Serial serial = (Serial) handle; |
| 352 | |
| 353 | if (serial->port && code == TS_BRK) { |
| 354 | logevent(serial->frontend, "Starting serial break at user request"); |
| 355 | SetCommBreak(serial->port); |
| 356 | /* |
| 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. |
| 361 | * |
| 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, |
| 364 | * and so will I. |
| 365 | */ |
| 366 | serial->clearbreak_time = |
| 367 | schedule_timer(TICKSPERSEC * 2 / 5, serbreak_timer, serial); |
| 368 | serial->break_in_progress = TRUE; |
| 369 | } |
| 370 | |
| 371 | return; |
| 372 | } |
| 373 | |
| 374 | /* |
| 375 | * Return a list of the special codes that make sense in this |
| 376 | * protocol. |
| 377 | */ |
| 378 | static const struct telnet_special *serial_get_specials(void *handle) |
| 379 | { |
| 380 | static const struct telnet_special specials[] = { |
| 381 | {"Break", TS_BRK}, |
| 382 | {NULL, TS_EXITMENU} |
| 383 | }; |
| 384 | return specials; |
| 385 | } |
| 386 | |
| 387 | static int serial_connected(void *handle) |
| 388 | { |
| 389 | return 1; /* always connected */ |
| 390 | } |
| 391 | |
| 392 | static int serial_sendok(void *handle) |
| 393 | { |
| 394 | return 1; |
| 395 | } |
| 396 | |
| 397 | static void serial_unthrottle(void *handle, int backlog) |
| 398 | { |
| 399 | Serial serial = (Serial) handle; |
| 400 | if (serial->in) |
| 401 | handle_unthrottle(serial->in, backlog); |
| 402 | } |
| 403 | |
| 404 | static int serial_ldisc(void *handle, int option) |
| 405 | { |
| 406 | /* |
| 407 | * Local editing and local echo are off by default. |
| 408 | */ |
| 409 | return 0; |
| 410 | } |
| 411 | |
| 412 | static void serial_provide_ldisc(void *handle, void *ldisc) |
| 413 | { |
| 414 | /* This is a stub. */ |
| 415 | } |
| 416 | |
| 417 | static void serial_provide_logctx(void *handle, void *logctx) |
| 418 | { |
| 419 | /* This is a stub. */ |
| 420 | } |
| 421 | |
| 422 | static int serial_exitcode(void *handle) |
| 423 | { |
| 424 | Serial serial = (Serial) handle; |
| 425 | if (serial->port != INVALID_HANDLE_VALUE) |
| 426 | return -1; /* still connected */ |
| 427 | else |
| 428 | /* Exit codes are a meaningless concept with serial ports */ |
| 429 | return INT_MAX; |
| 430 | } |
| 431 | |
| 432 | /* |
| 433 | * cfg_info for Serial does nothing at all. |
| 434 | */ |
| 435 | static int serial_cfg_info(void *handle) |
| 436 | { |
| 437 | return 0; |
| 438 | } |
| 439 | |
| 440 | Backend serial_backend = { |
| 441 | serial_init, |
| 442 | serial_free, |
| 443 | serial_reconfig, |
| 444 | serial_send, |
| 445 | serial_sendbuffer, |
| 446 | serial_size, |
| 447 | serial_special, |
| 448 | serial_get_specials, |
| 449 | serial_connected, |
| 450 | serial_exitcode, |
| 451 | serial_sendok, |
| 452 | serial_ldisc, |
| 453 | serial_provide_ldisc, |
| 454 | serial_provide_logctx, |
| 455 | serial_unthrottle, |
| 456 | serial_cfg_info, |
| 457 | 1 |
| 458 | }; |