ttymodes.c

   1 /* $OpenBSD: ttymodes.c,v 1.23 2006/03/25 13:17:03 djm 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 <termios.h>
  49
  50 #include "packet.h"
  51 #include "log.h"
  52 #include "ssh1.h"
  53 #include "compat.h"
  54 #include "buffer.h"
  55 #include "bufaux.h"
  56
  57 #define TTY_OP_END              0
  58 /*
  59  * uint32 (u_int) follows speed in SSH1 and SSH2
  60  */
  61 #define TTY_OP_ISPEED_PROTO1    192
  62 #define TTY_OP_OSPEED_PROTO1    193
  63 #define TTY_OP_ISPEED_PROTO2    128
  64 #define TTY_OP_OSPEED_PROTO2    129
  65
  66 /*
  67  * Converts POSIX speed_t to a baud rate.  The values of the
  68  * constants for speed_t are not themselves portable.
  69  */
  70 static int
  71 speed_to_baud(speed_t speed)
  72 {
  73         switch (speed) {
  74         case B0:
  75                 return 0;
  76         case B50:
  77                 return 50;
  78         case B75:
  79                 return 75;
  80         case B110:
  81                 return 110;
  82         case B134:
  83                 return 134;
  84         case B150:
  85                 return 150;
  86         case B200:
  87                 return 200;
  88         case B300:
  89                 return 300;
  90         case B600:
  91                 return 600;
  92         case B1200:
  93                 return 1200;
  94         case B1800:
  95                 return 1800;
  96         case B2400:
  97                 return 2400;
  98         case B4800:
  99                 return 4800;
 100         case B9600:
 101                 return 9600;
 102
 103 #ifdef B19200
 104         case B19200:
 105                 return 19200;
 106 #else /* B19200 */
 107 #ifdef EXTA
 108         case EXTA:
 109                 return 19200;
 110 #endif /* EXTA */
 111 #endif /* B19200 */
 112
 113 #ifdef B38400
 114         case B38400:
 115                 return 38400;
 116 #else /* B38400 */
 117 #ifdef EXTB
 118         case EXTB:
 119                 return 38400;
 120 #endif /* EXTB */
 121 #endif /* B38400 */
 122
 123 #ifdef B7200
 124         case B7200:
 125                 return 7200;
 126 #endif /* B7200 */
 127 #ifdef B14400
 128         case B14400:
 129                 return 14400;
 130 #endif /* B14400 */
 131 #ifdef B28800
 132         case B28800:
 133                 return 28800;
 134 #endif /* B28800 */
 135 #ifdef B57600
 136         case B57600:
 137                 return 57600;
 138 #endif /* B57600 */
 139 #ifdef B76800
 140         case B76800:
 141                 return 76800;
 142 #endif /* B76800 */
 143 #ifdef B115200
 144         case B115200:
 145                 return 115200;
 146 #endif /* B115200 */
 147 #ifdef B230400
 148         case B230400:
 149                 return 230400;
 150 #endif /* B230400 */
 151         default:
 152                 return 9600;
 153         }
 154 }
 155
 156 /*
 157  * Converts a numeric baud rate to a POSIX speed_t.
 158  */
 159 static speed_t
 160 baud_to_speed(int baud)
 161 {
 162         switch (baud) {
 163         case 0:
 164                 return B0;
 165         case 50:
 166                 return B50;
 167         case 75:
 168                 return B75;
 169         case 110:
 170                 return B110;
 171         case 134:
 172                 return B134;
 173         case 150:
 174                 return B150;
 175         case 200:
 176                 return B200;
 177         case 300:
 178                 return B300;
 179         case 600:
 180                 return B600;
 181         case 1200:
 182                 return B1200;
 183         case 1800:
 184                 return B1800;
 185         case 2400:
 186                 return B2400;
 187         case 4800:
 188                 return B4800;
 189         case 9600:
 190                 return B9600;
 191
 192 #ifdef B19200
 193         case 19200:
 194                 return B19200;
 195 #else /* B19200 */
 196 #ifdef EXTA
 197         case 19200:
 198                 return EXTA;
 199 #endif /* EXTA */
 200 #endif /* B19200 */
 201
 202 #ifdef B38400
 203         case 38400:
 204                 return B38400;
 205 #else /* B38400 */
 206 #ifdef EXTB
 207         case 38400:
 208                 return EXTB;
 209 #endif /* EXTB */
 210 #endif /* B38400 */
 211
 212 #ifdef B7200
 213         case 7200:
 214                 return B7200;
 215 #endif /* B7200 */
 216 #ifdef B14400
 217         case 14400:
 218                 return B14400;
 219 #endif /* B14400 */
 220 #ifdef B28800
 221         case 28800:
 222                 return B28800;
 223 #endif /* B28800 */
 224 #ifdef B57600
 225         case 57600:
 226                 return B57600;
 227 #endif /* B57600 */
 228 #ifdef B76800
 229         case 76800:
 230                 return B76800;
 231 #endif /* B76800 */
 232 #ifdef B115200
 233         case 115200:
 234                 return B115200;
 235 #endif /* B115200 */
 236 #ifdef B230400
 237         case 230400:
 238                 return B230400;
 239 #endif /* B230400 */
 240         default:
 241                 return B9600;
 242         }
 243 }
 244
 245 /*
 246  * Encode a special character into SSH line format.
 247  */
 248 static u_int
 249 special_char_encode(cc_t c)
 250 {
 251 #ifdef _POSIX_VDISABLE
 252         if (c == _POSIX_VDISABLE)
 253                 return 255;
 254 #endif /* _POSIX_VDISABLE */
 255         return c;
 256 }
 257
 258 /*
 259  * Decode a special character from SSH line format.
 260  */
 261 static cc_t
 262 special_char_decode(u_int c)
 263 {
 264 #ifdef _POSIX_VDISABLE
 265         if (c == 255)
 266                 return _POSIX_VDISABLE;
 267 #endif /* _POSIX_VDISABLE */
 268         return c;
 269 }
 270
 271 /*
 272  * Encodes terminal modes for the terminal referenced by fd
 273  * or tiop in a portable manner, and appends the modes to a packet
 274  * being constructed.
 275  */
 276 void
 277 tty_make_modes(int fd, struct termios *tiop)
 278 {
 279         struct termios tio;
 280         int baud;
 281         Buffer buf;
 282         int tty_op_ospeed, tty_op_ispeed;
 283         void (*put_arg)(Buffer *, u_int);
 284
 285         buffer_init(&buf);
 286         if (compat20) {
 287                 tty_op_ospeed = TTY_OP_OSPEED_PROTO2;
 288                 tty_op_ispeed = TTY_OP_ISPEED_PROTO2;
 289                 put_arg = buffer_put_int;
 290         } else {
 291                 tty_op_ospeed = TTY_OP_OSPEED_PROTO1;
 292                 tty_op_ispeed = TTY_OP_ISPEED_PROTO1;
 293                 put_arg = (void (*)(Buffer *, u_int)) buffer_put_char;
 294         }
 295
 296         if (tiop == NULL) {
 297                 if (tcgetattr(fd, &tio) == -1) {
 298                         logit("tcgetattr: %.100s", strerror(errno));
 299                         goto end;
 300                 }
 301         } else
 302                 tio = *tiop;
 303
 304         /* Store input and output baud rates. */
 305         baud = speed_to_baud(cfgetospeed(&tio));
 306         debug3("tty_make_modes: ospeed %d", baud);
 307         buffer_put_char(&buf, tty_op_ospeed);
 308         buffer_put_int(&buf, baud);
 309         baud = speed_to_baud(cfgetispeed(&tio));
 310         debug3("tty_make_modes: ispeed %d", baud);
 311         buffer_put_char(&buf, tty_op_ispeed);
 312         buffer_put_int(&buf, baud);
 313
 314         /* Store values of mode flags. */
 315 #define TTYCHAR(NAME, OP) \
 316         debug3("tty_make_modes: %d %d", OP, tio.c_cc[NAME]); \
 317         buffer_put_char(&buf, OP); \
 318         put_arg(&buf, special_char_encode(tio.c_cc[NAME]));
 319
 320 #define TTYMODE(NAME, FIELD, OP) \
 321         debug3("tty_make_modes: %d %d", OP, ((tio.FIELD & NAME) != 0)); \
 322         buffer_put_char(&buf, OP); \
 323         put_arg(&buf, ((tio.FIELD & NAME) != 0));
 324
 325 #include "ttymodes.h"
 326
 327 #undef TTYCHAR
 328 #undef TTYMODE
 329
 330 end:
 331         /* Mark end of mode data. */
 332         buffer_put_char(&buf, TTY_OP_END);
 333         if (compat20)
 334                 packet_put_string(buffer_ptr(&buf), buffer_len(&buf));
 335         else
 336                 packet_put_raw(buffer_ptr(&buf), buffer_len(&buf));
 337         buffer_free(&buf);
 338 }
 339
 340 /*
 341  * Decodes terminal modes for the terminal referenced by fd in a portable
 342  * manner from a packet being read.
 343  */
 344 void
 345 tty_parse_modes(int fd, int *n_bytes_ptr)
 346 {
 347         struct termios tio;
 348         int opcode, baud;
 349         int n_bytes = 0;
 350         int failure = 0;
 351         u_int (*get_arg)(void);
 352         int arg, arg_size;
 353
 354         if (compat20) {
 355                 *n_bytes_ptr = packet_get_int();
 356                 debug3("tty_parse_modes: SSH2 n_bytes %d", *n_bytes_ptr);
 357                 if (*n_bytes_ptr == 0)
 358                         return;
 359                 get_arg = packet_get_int;
 360                 arg_size = 4;
 361         } else {
 362                 get_arg = packet_get_char;
 363                 arg_size = 1;
 364         }
 365
 366         /*
 367          * Get old attributes for the terminal.  We will modify these
 368          * flags. I am hoping that if there are any machine-specific
 369          * modes, they will initially have reasonable values.
 370          */
 371         if (tcgetattr(fd, &tio) == -1) {
 372                 logit("tcgetattr: %.100s", strerror(errno));
 373                 failure = -1;
 374         }
 375
 376         for (;;) {
 377                 n_bytes += 1;
 378                 opcode = packet_get_char();
 379                 switch (opcode) {
 380                 case TTY_OP_END:
 381                         goto set;
 382
 383                 /* XXX: future conflict possible */
 384                 case TTY_OP_ISPEED_PROTO1:
 385                 case TTY_OP_ISPEED_PROTO2:
 386                         n_bytes += 4;
 387                         baud = packet_get_int();
 388                         debug3("tty_parse_modes: ispeed %d", baud);
 389                         if (failure != -1 &&
 390                             cfsetispeed(&tio, baud_to_speed(baud)) == -1)
 391                                 error("cfsetispeed failed for %d", baud);
 392                         break;
 393
 394                 /* XXX: future conflict possible */
 395                 case TTY_OP_OSPEED_PROTO1:
 396                 case TTY_OP_OSPEED_PROTO2:
 397                         n_bytes += 4;
 398                         baud = packet_get_int();
 399                         debug3("tty_parse_modes: ospeed %d", baud);
 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           debug3("tty_parse_modes: %d %d", OP, tio.c_cc[NAME]); \
 410           break;
 411 #define TTYMODE(NAME, FIELD, OP) \
 412         case OP: \
 413           n_bytes += arg_size; \
 414           if ((arg = get_arg())) \
 415             tio.FIELD |= NAME; \
 416           else \
 417             tio.FIELD &= ~NAME; \
 418           debug3("tty_parse_modes: %d %d", OP, arg); \
 419           break;
 420
 421 #include "ttymodes.h"
 422
 423 #undef TTYCHAR
 424 #undef TTYMODE
 425
 426                 default:
 427                         debug("Ignoring unsupported tty mode opcode %d (0x%x)",
 428                             opcode, opcode);
 429                         if (!compat20) {
 430                                 /*
 431                                  * SSH1:
 432                                  * Opcodes 1 to 127 are defined to have
 433                                  * a one-byte argument.
 434                                  * Opcodes 128 to 159 are defined to have
 435                                  * an integer argument.
 436                                  */
 437                                 if (opcode > 0 && opcode < 128) {
 438                                         n_bytes += 1;
 439                                         (void) packet_get_char();
 440                                         break;
 441                                 } else if (opcode >= 128 && opcode < 160) {
 442                                         n_bytes += 4;
 443                                         (void) packet_get_int();
 444                                         break;
 445                                 } else {
 446                                         /*
 447                                          * It is a truly undefined opcode (160 to 255).
 448                                          * We have no idea about its arguments.  So we
 449                                          * must stop parsing.  Note that some data
 450                                          * may be left in the packet; hopefully there
 451                                          * is nothing more coming after the mode data.
 452                                          */
 453                                         logit("parse_tty_modes: unknown opcode %d",
 454                                             opcode);
 455                                         goto set;
 456                                 }
 457                         } else {
 458                                 /*
 459                                  * SSH2:
 460                                  * Opcodes 1 to 159 are defined to have
 461                                  * a uint32 argument.
 462                                  * Opcodes 160 to 255 are undefined and
 463                                  * cause parsing to stop.
 464                                  */
 465                                 if (opcode > 0 && opcode < 160) {
 466                                         n_bytes += 4;
 467                                         (void) packet_get_int();
 468                                         break;
 469                                 } else {
 470                                         logit("parse_tty_modes: unknown opcode %d",
 471                                             opcode);
 472                                         goto set;
 473                                 }
 474                         }
 475                 }
 476         }
 477
 478 set:
 479         if (*n_bytes_ptr != n_bytes) {
 480                 *n_bytes_ptr = n_bytes;
 481                 logit("parse_tty_modes: n_bytes_ptr != n_bytes: %d %d",
 482                     *n_bytes_ptr, n_bytes);
 483                 return;         /* Don't process bytes passed */
 484         }
 485         if (failure == -1)
 486                 return;         /* Packet parsed ok but tcgetattr() failed */
 487
 488         /* Set the new modes for the terminal. */
 489         if (tcsetattr(fd, TCSANOW, &tio) == -1)
 490                 logit("Setting tty modes failed: %.100s", strerror(errno));
 491 }