ttymodes.c revision 323129
1/* $OpenBSD: ttymodes.c,v 1.30 2016/05/04 14:22:33 markus Exp $ */ 2/* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * 7 * As far as I am concerned, the code I have written for this software 8 * can be used freely for any purpose. Any derived versions of this 9 * software must be clearly marked as such, and if the derived work is 10 * incompatible with the protocol description in the RFC file, it must be 11 * called by a name other than "ssh" or "Secure Shell". 12 */ 13 14/* 15 * SSH2 tty modes support by Kevin Steves. 16 * Copyright (c) 2001 Kevin Steves. All rights reserved. 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions 20 * are met: 21 * 1. Redistributions of source code must retain the above copyright 22 * notice, this list of conditions and the following disclaimer. 23 * 2. Redistributions in binary form must reproduce the above copyright 24 * notice, this list of conditions and the following disclaimer in the 25 * documentation and/or other materials provided with the distribution. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 28 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 29 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 30 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 31 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 32 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 33 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 34 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 35 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 36 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39/* 40 * Encoding and decoding of terminal modes in a portable way. 41 * Much of the format is defined in ttymodes.h; it is included multiple times 42 * into this file with the appropriate macro definitions to generate the 43 * suitable code. 44 */ 45 46#include "includes.h" 47 48#include <sys/types.h> 49 50#include <errno.h> 51#include <string.h> 52#include <termios.h> 53#include <stdarg.h> 54 55#include "packet.h" 56#include "log.h" 57#include "compat.h" 58#include "buffer.h" 59 60#define TTY_OP_END 0 61/* 62 * uint32 (u_int) follows speed in SSH1 and SSH2 63 */ 64#define TTY_OP_ISPEED_PROTO1 192 65#define TTY_OP_OSPEED_PROTO1 193 66#define TTY_OP_ISPEED_PROTO2 128 67#define TTY_OP_OSPEED_PROTO2 129 68 69/* 70 * Converts POSIX speed_t to a baud rate. The values of the 71 * constants for speed_t are not themselves portable. 72 */ 73static int 74speed_to_baud(speed_t speed) 75{ 76 switch (speed) { 77 case B0: 78 return 0; 79 case B50: 80 return 50; 81 case B75: 82 return 75; 83 case B110: 84 return 110; 85 case B134: 86 return 134; 87 case B150: 88 return 150; 89 case B200: 90 return 200; 91 case B300: 92 return 300; 93 case B600: 94 return 600; 95 case B1200: 96 return 1200; 97 case B1800: 98 return 1800; 99 case B2400: 100 return 2400; 101 case B4800: 102 return 4800; 103 case B9600: 104 return 9600; 105 106#ifdef B19200 107 case B19200: 108 return 19200; 109#else /* B19200 */ 110#ifdef EXTA 111 case EXTA: 112 return 19200; 113#endif /* EXTA */ 114#endif /* B19200 */ 115 116#ifdef B38400 117 case B38400: 118 return 38400; 119#else /* B38400 */ 120#ifdef EXTB 121 case EXTB: 122 return 38400; 123#endif /* EXTB */ 124#endif /* B38400 */ 125 126#ifdef B7200 127 case B7200: 128 return 7200; 129#endif /* B7200 */ 130#ifdef B14400 131 case B14400: 132 return 14400; 133#endif /* B14400 */ 134#ifdef B28800 135 case B28800: 136 return 28800; 137#endif /* B28800 */ 138#ifdef B57600 139 case B57600: 140 return 57600; 141#endif /* B57600 */ 142#ifdef B76800 143 case B76800: 144 return 76800; 145#endif /* B76800 */ 146#ifdef B115200 147 case B115200: 148 return 115200; 149#endif /* B115200 */ 150#ifdef B230400 151 case B230400: 152 return 230400; 153#endif /* B230400 */ 154 default: 155 return 9600; 156 } 157} 158 159/* 160 * Converts a numeric baud rate to a POSIX speed_t. 161 */ 162static speed_t 163baud_to_speed(int baud) 164{ 165 switch (baud) { 166 case 0: 167 return B0; 168 case 50: 169 return B50; 170 case 75: 171 return B75; 172 case 110: 173 return B110; 174 case 134: 175 return B134; 176 case 150: 177 return B150; 178 case 200: 179 return B200; 180 case 300: 181 return B300; 182 case 600: 183 return B600; 184 case 1200: 185 return B1200; 186 case 1800: 187 return B1800; 188 case 2400: 189 return B2400; 190 case 4800: 191 return B4800; 192 case 9600: 193 return B9600; 194 195#ifdef B19200 196 case 19200: 197 return B19200; 198#else /* B19200 */ 199#ifdef EXTA 200 case 19200: 201 return EXTA; 202#endif /* EXTA */ 203#endif /* B19200 */ 204 205#ifdef B38400 206 case 38400: 207 return B38400; 208#else /* B38400 */ 209#ifdef EXTB 210 case 38400: 211 return EXTB; 212#endif /* EXTB */ 213#endif /* B38400 */ 214 215#ifdef B7200 216 case 7200: 217 return B7200; 218#endif /* B7200 */ 219#ifdef B14400 220 case 14400: 221 return B14400; 222#endif /* B14400 */ 223#ifdef B28800 224 case 28800: 225 return B28800; 226#endif /* B28800 */ 227#ifdef B57600 228 case 57600: 229 return B57600; 230#endif /* B57600 */ 231#ifdef B76800 232 case 76800: 233 return B76800; 234#endif /* B76800 */ 235#ifdef B115200 236 case 115200: 237 return B115200; 238#endif /* B115200 */ 239#ifdef B230400 240 case 230400: 241 return B230400; 242#endif /* B230400 */ 243 default: 244 return B9600; 245 } 246} 247 248/* 249 * Encode a special character into SSH line format. 250 */ 251static u_int 252special_char_encode(cc_t c) 253{ 254#ifdef _POSIX_VDISABLE 255 if (c == _POSIX_VDISABLE) 256 return 255; 257#endif /* _POSIX_VDISABLE */ 258 return c; 259} 260 261/* 262 * Decode a special character from SSH line format. 263 */ 264static cc_t 265special_char_decode(u_int c) 266{ 267#ifdef _POSIX_VDISABLE 268 if (c == 255) 269 return _POSIX_VDISABLE; 270#endif /* _POSIX_VDISABLE */ 271 return c; 272} 273 274/* 275 * Encodes terminal modes for the terminal referenced by fd 276 * or tiop in a portable manner, and appends the modes to a packet 277 * being constructed. 278 */ 279void 280tty_make_modes(int fd, struct termios *tiop) 281{ 282 struct termios tio; 283 int baud; 284 Buffer buf; 285 int tty_op_ospeed, tty_op_ispeed; 286 void (*put_arg)(Buffer *, u_int); 287 288 buffer_init(&buf); 289 if (compat20) { 290 tty_op_ospeed = TTY_OP_OSPEED_PROTO2; 291 tty_op_ispeed = TTY_OP_ISPEED_PROTO2; 292 put_arg = buffer_put_int; 293 } else { 294 tty_op_ospeed = TTY_OP_OSPEED_PROTO1; 295 tty_op_ispeed = TTY_OP_ISPEED_PROTO1; 296 put_arg = (void (*)(Buffer *, u_int)) buffer_put_char; 297 } 298 299 if (tiop == NULL) { 300 if (fd == -1) { 301 debug("tty_make_modes: no fd or tio"); 302 goto end; 303 } 304 if (tcgetattr(fd, &tio) == -1) { 305 logit("tcgetattr: %.100s", strerror(errno)); 306 goto end; 307 } 308 } else 309 tio = *tiop; 310 311 /* Store input and output baud rates. */ 312 baud = speed_to_baud(cfgetospeed(&tio)); 313 buffer_put_char(&buf, tty_op_ospeed); 314 buffer_put_int(&buf, baud); 315 baud = speed_to_baud(cfgetispeed(&tio)); 316 buffer_put_char(&buf, tty_op_ispeed); 317 buffer_put_int(&buf, baud); 318 319 /* Store values of mode flags. */ 320#define TTYCHAR(NAME, OP) \ 321 buffer_put_char(&buf, OP); \ 322 put_arg(&buf, special_char_encode(tio.c_cc[NAME])); 323 324#define TTYMODE(NAME, FIELD, OP) \ 325 buffer_put_char(&buf, OP); \ 326 put_arg(&buf, ((tio.FIELD & NAME) != 0)); 327 328#include "ttymodes.h" 329 330#undef TTYCHAR 331#undef TTYMODE 332 333end: 334 /* Mark end of mode data. */ 335 buffer_put_char(&buf, TTY_OP_END); 336 if (compat20) 337 packet_put_string(buffer_ptr(&buf), buffer_len(&buf)); 338 else 339 packet_put_raw(buffer_ptr(&buf), buffer_len(&buf)); 340 buffer_free(&buf); 341} 342 343/* 344 * Decodes terminal modes for the terminal referenced by fd in a portable 345 * manner from a packet being read. 346 */ 347void 348tty_parse_modes(int fd, int *n_bytes_ptr) 349{ 350 struct termios tio; 351 int opcode, baud; 352 int n_bytes = 0; 353 int failure = 0; 354 u_int (*get_arg)(void); 355 int arg_size; 356 357 if (compat20) { 358 *n_bytes_ptr = packet_get_int(); 359 if (*n_bytes_ptr == 0) 360 return; 361 get_arg = packet_get_int; 362 arg_size = 4; 363 } else { 364 get_arg = packet_get_char; 365 arg_size = 1; 366 } 367 368 /* 369 * Get old attributes for the terminal. We will modify these 370 * flags. I am hoping that if there are any machine-specific 371 * modes, they will initially have reasonable values. 372 */ 373 if (tcgetattr(fd, &tio) == -1) { 374 logit("tcgetattr: %.100s", strerror(errno)); 375 failure = -1; 376 } 377 378 for (;;) { 379 n_bytes += 1; 380 opcode = packet_get_char(); 381 switch (opcode) { 382 case TTY_OP_END: 383 goto set; 384 385 /* XXX: future conflict possible */ 386 case TTY_OP_ISPEED_PROTO1: 387 case TTY_OP_ISPEED_PROTO2: 388 n_bytes += 4; 389 baud = packet_get_int(); 390 if (failure != -1 && 391 cfsetispeed(&tio, baud_to_speed(baud)) == -1) 392 error("cfsetispeed failed for %d", baud); 393 break; 394 395 /* XXX: future conflict possible */ 396 case TTY_OP_OSPEED_PROTO1: 397 case TTY_OP_OSPEED_PROTO2: 398 n_bytes += 4; 399 baud = packet_get_int(); 400 if (failure != -1 && 401 cfsetospeed(&tio, baud_to_speed(baud)) == -1) 402 error("cfsetospeed failed for %d", baud); 403 break; 404 405#define TTYCHAR(NAME, OP) \ 406 case OP: \ 407 n_bytes += arg_size; \ 408 tio.c_cc[NAME] = special_char_decode(get_arg()); \ 409 break; 410#define TTYMODE(NAME, FIELD, OP) \ 411 case OP: \ 412 n_bytes += arg_size; \ 413 if (get_arg()) \ 414 tio.FIELD |= NAME; \ 415 else \ 416 tio.FIELD &= ~NAME; \ 417 break; 418 419#include "ttymodes.h" 420 421#undef TTYCHAR 422#undef TTYMODE 423 424 default: 425 debug("Ignoring unsupported tty mode opcode %d (0x%x)", 426 opcode, opcode); 427 if (!compat20) { 428 /* 429 * SSH1: 430 * Opcodes 1 to 127 are defined to have 431 * a one-byte argument. 432 * Opcodes 128 to 159 are defined to have 433 * an integer argument. 434 */ 435 if (opcode > 0 && opcode < 128) { 436 n_bytes += 1; 437 (void) packet_get_char(); 438 break; 439 } else if (opcode >= 128 && opcode < 160) { 440 n_bytes += 4; 441 (void) packet_get_int(); 442 break; 443 } else { 444 /* 445 * It is a truly undefined opcode (160 to 255). 446 * We have no idea about its arguments. So we 447 * must stop parsing. Note that some data 448 * may be left in the packet; hopefully there 449 * is nothing more coming after the mode data. 450 */ 451 logit("parse_tty_modes: unknown opcode %d", 452 opcode); 453 goto set; 454 } 455 } else { 456 /* 457 * SSH2: 458 * Opcodes 1 to 159 are defined to have 459 * a uint32 argument. 460 * Opcodes 160 to 255 are undefined and 461 * cause parsing to stop. 462 */ 463 if (opcode > 0 && opcode < 160) { 464 n_bytes += 4; 465 (void) packet_get_int(); 466 break; 467 } else { 468 logit("parse_tty_modes: unknown opcode %d", 469 opcode); 470 goto set; 471 } 472 } 473 } 474 } 475 476set: 477 if (*n_bytes_ptr != n_bytes) { 478 *n_bytes_ptr = n_bytes; 479 logit("parse_tty_modes: n_bytes_ptr != n_bytes: %d %d", 480 *n_bytes_ptr, n_bytes); 481 return; /* Don't process bytes passed */ 482 } 483 if (failure == -1) 484 return; /* Packet parsed ok but tcgetattr() failed */ 485 486 /* Set the new modes for the terminal. */ 487 if (tcsetattr(fd, TCSANOW, &tio) == -1) 488 logit("Setting tty modes failed: %.100s", strerror(errno)); 489} 490