ttymodes.c

   1 /* $OpenBSD: ttymodes.c,v 1.29 2008/11/02 00:16:16 stevesk 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 "ssh1.h"
  58 #include "compat.h"
  59 #include "buffer.h"
  60
  61 #define TTY_OP_END              0
  62 /*
  63  * uint32 (u_int) follows speed in SSH1 and SSH2
  64  */
  65 #define TTY_OP_ISPEED_PROTO1    192
  66 #define TTY_OP_OSPEED_PROTO1    193
  67 #define TTY_OP_ISPEED_PROTO2    128
  68 #define TTY_OP_OSPEED_PROTO2    129
  69
  70 /*
  71  * Converts POSIX speed_t to a baud rate.  The values of the
  72  * constants for speed_t are not themselves portable.
  73  */
  74 static int
  75 speed_to_baud(speed_t speed)
  76 {
  77         switch (speed) {
  78         case B0:
  79                 return 0;
  80         case B50:
  81                 return 50;
  82         case B75:
  83                 return 75;
  84         case B110:
  85                 return 110;
  86         case B134:
  87                 return 134;
  88         case B150:
  89                 return 150;
  90         case B200:
  91                 return 200;
  92         case B300:
  93                 return 300;
  94         case B600:
  95                 return 600;
  96         case B1200:
  97                 return 1200;
  98         case B1800:
  99                 return 1800;
 100         case B2400:
 101                 return 2400;
 102         case B4800:
 103                 return 4800;
 104         case B9600:
 105                 return 9600;
 106
 107 #ifdef B19200
 108         case B19200:
 109                 return 19200;
 110 #else /* B19200 */
 111 #ifdef EXTA
 112         case EXTA:
 113                 return 19200;
 114 #endif /* EXTA */
 115 #endif /* B19200 */
 116
 117 #ifdef B38400
 118         case B38400:
 119                 return 38400;
 120 #else /* B38400 */
 121 #ifdef EXTB
 122         case EXTB:
 123                 return 38400;
 124 #endif /* EXTB */
 125 #endif /* B38400 */
 126
 127 #ifdef B7200
 128         case B7200:
 129                 return 7200;
 130 #endif /* B7200 */
 131 #ifdef B14400
 132         case B14400:
 133                 return 14400;
 134 #endif /* B14400 */
 135 #ifdef B28800
 136         case B28800:
 137                 return 28800;
 138 #endif /* B28800 */
 139 #ifdef B57600
 140         case B57600:
 141                 return 57600;
 142 #endif /* B57600 */
 143 #ifdef B76800
 144         case B76800:
 145                 return 76800;
 146 #endif /* B76800 */
 147 #ifdef B115200
 148         case B115200:
 149                 return 115200;
 150 #endif /* B115200 */
 151 #ifdef B230400
 152         case B230400:
 153                 return 230400;
 154 #endif /* B230400 */
 155         default:
 156                 return 9600;
 157         }
 158 }
 159
 160 /*
 161  * Converts a numeric baud rate to a POSIX speed_t.
 162  */
 163 static speed_t
 164 baud_to_speed(int baud)
 165 {
 166         switch (baud) {
 167         case 0:
 168                 return B0;
 169         case 50:
 170                 return B50;
 171         case 75:
 172                 return B75;
 173         case 110:
 174                 return B110;
 175         case 134:
 176                 return B134;
 177         case 150:
 178                 return B150;
 179         case 200:
 180                 return B200;
 181         case 300:
 182                 return B300;
 183         case 600:
 184                 return B600;
 185         case 1200:
 186                 return B1200;
 187         case 1800:
 188                 return B1800;
 189         case 2400:
 190                 return B2400;
 191         case 4800:
 192                 return B4800;
 193         case 9600:
 194                 return B9600;
 195
 196 #ifdef B19200
 197         case 19200:
 198                 return B19200;
 199 #else /* B19200 */
 200 #ifdef EXTA
 201         case 19200:
 202                 return EXTA;
 203 #endif /* EXTA */
 204 #endif /* B19200 */
 205
 206 #ifdef B38400
 207         case 38400:
 208                 return B38400;
 209 #else /* B38400 */
 210 #ifdef EXTB
 211         case 38400:
 212                 return EXTB;
 213 #endif /* EXTB */
 214 #endif /* B38400 */
 215
 216 #ifdef B7200
 217         case 7200:
 218                 return B7200;
 219 #endif /* B7200 */
 220 #ifdef B14400
 221         case 14400:
 222                 return B14400;
 223 #endif /* B14400 */
 224 #ifdef B28800
 225         case 28800:
 226                 return B28800;
 227 #endif /* B28800 */
 228 #ifdef B57600
 229         case 57600:
 230                 return B57600;
 231 #endif /* B57600 */
 232 #ifdef B76800
 233         case 76800:
 234                 return B76800;
 235 #endif /* B76800 */
 236 #ifdef B115200
 237         case 115200:
 238                 return B115200;
 239 #endif /* B115200 */
 240 #ifdef B230400
 241         case 230400:
 242                 return B230400;
 243 #endif /* B230400 */
 244         default:
 245                 return B9600;
 246         }
 247 }
 248
 249 /*
 250  * Encode a special character into SSH line format.
 251  */
 252 static u_int
 253 special_char_encode(cc_t c)
 254 {
 255 #ifdef _POSIX_VDISABLE
 256         if (c == _POSIX_VDISABLE)
 257                 return 255;
 258 #endif /* _POSIX_VDISABLE */
 259         return c;
 260 }
 261
 262 /*
 263  * Decode a special character from SSH line format.
 264  */
 265 static cc_t
 266 special_char_decode(u_int c)
 267 {
 268 #ifdef _POSIX_VDISABLE
 269         if (c == 255)
 270                 return _POSIX_VDISABLE;
 271 #endif /* _POSIX_VDISABLE */
 272         return c;
 273 }
 274
 275 /*
 276  * Encodes terminal modes for the terminal referenced by fd
 277  * or tiop in a portable manner, and appends the modes to a packet
 278  * being constructed.
 279  */
 280 void
 281 tty_make_modes(int fd, struct termios *tiop)
 282 {
 283         struct termios tio;
 284         int baud;
 285         Buffer buf;
 286         int tty_op_ospeed, tty_op_ispeed;
 287         void (*put_arg)(Buffer *, u_int);
 288
 289         buffer_init(&buf);
 290         if (compat20) {
 291                 tty_op_ospeed = TTY_OP_OSPEED_PROTO2;
 292                 tty_op_ispeed = TTY_OP_ISPEED_PROTO2;
 293                 put_arg = buffer_put_int;
 294         } else {
 295                 tty_op_ospeed = TTY_OP_OSPEED_PROTO1;
 296                 tty_op_ispeed = TTY_OP_ISPEED_PROTO1;
 297                 put_arg = (void (*)(Buffer *, u_int)) buffer_put_char;
 298         }
 299
 300         if (tiop == NULL) {
 301                 if (fd == -1) {
 302                         debug("tty_make_modes: no fd or tio");
 303                         goto end;
 304                 }
 305                 if (tcgetattr(fd, &tio) == -1) {
 306                         logit("tcgetattr: %.100s", strerror(errno));
 307                         goto end;
 308                 }
 309         } else
 310                 tio = *tiop;
 311
 312         /* Store input and output baud rates. */
 313         baud = speed_to_baud(cfgetospeed(&tio));
 314         buffer_put_char(&buf, tty_op_ospeed);
 315         buffer_put_int(&buf, baud);
 316         baud = speed_to_baud(cfgetispeed(&tio));
 317         buffer_put_char(&buf, tty_op_ispeed);
 318         buffer_put_int(&buf, baud);
 319
 320         /* Store values of mode flags. */
 321 #define TTYCHAR(NAME, OP) \
 322         buffer_put_char(&buf, OP); \
 323         put_arg(&buf, special_char_encode(tio.c_cc[NAME]));
 324
 325 #define TTYMODE(NAME, FIELD, OP) \
 326         buffer_put_char(&buf, OP); \
 327         put_arg(&buf, ((tio.FIELD & NAME) != 0));
 328
 329 #include "ttymodes.h"
 330
 331 #undef TTYCHAR
 332 #undef TTYMODE
 333
 334 end:
 335         /* Mark end of mode data. */
 336         buffer_put_char(&buf, TTY_OP_END);
 337         if (compat20)
 338                 packet_put_string(buffer_ptr(&buf), buffer_len(&buf));
 339         else
 340                 packet_put_raw(buffer_ptr(&buf), buffer_len(&buf));
 341         buffer_free(&buf);
 342 }
 343
 344 /*
 345  * Decodes terminal modes for the terminal referenced by fd in a portable
 346  * manner from a packet being read.
 347  */
 348 void
 349 tty_parse_modes(int fd, int *n_bytes_ptr)
 350 {
 351         struct termios tio;
 352         int opcode, baud;
 353         int n_bytes = 0;
 354         int failure = 0;
 355         u_int (*get_arg)(void);
 356         int arg_size;
 357
 358         if (compat20) {
 359                 *n_bytes_ptr = packet_get_int();
 360                 if (*n_bytes_ptr == 0)
 361                         return;
 362                 get_arg = packet_get_int;
 363                 arg_size = 4;
 364         } else {
 365                 get_arg = packet_get_char;
 366                 arg_size = 1;
 367         }
 368
 369         /*
 370          * Get old attributes for the terminal.  We will modify these
 371          * flags. I am hoping that if there are any machine-specific
 372          * modes, they will initially have reasonable values.
 373          */
 374         if (tcgetattr(fd, &tio) == -1) {
 375                 logit("tcgetattr: %.100s", strerror(errno));
 376                 failure = -1;
 377         }
 378
 379         for (;;) {
 380                 n_bytes += 1;
 381                 opcode = packet_get_char();
 382                 switch (opcode) {
 383                 case TTY_OP_END:
 384                         goto set;
 385
 386                 /* XXX: future conflict possible */
 387                 case TTY_OP_ISPEED_PROTO1:
 388                 case TTY_OP_ISPEED_PROTO2:
 389                         n_bytes += 4;
 390                         baud = packet_get_int();
 391                         if (failure != -1 &&
 392                             cfsetispeed(&tio, baud_to_speed(baud)) == -1)
 393                                 error("cfsetispeed failed for %d", baud);
 394                         break;
 395
 396                 /* XXX: future conflict possible */
 397                 case TTY_OP_OSPEED_PROTO1:
 398                 case TTY_OP_OSPEED_PROTO2:
 399                         n_bytes += 4;
 400                         baud = packet_get_int();
 401                         if (failure != -1 &&
 402                             cfsetospeed(&tio, baud_to_speed(baud)) == -1)
 403                                 error("cfsetospeed failed for %d", baud);
 404                         break;
 405
 406 #define TTYCHAR(NAME, OP) \
 407         case OP: \
 408           n_bytes += arg_size; \
 409           tio.c_cc[NAME] = special_char_decode(get_arg()); \
 410           break;
 411 #define TTYMODE(NAME, FIELD, OP) \
 412         case OP: \
 413           n_bytes += arg_size; \
 414           if (get_arg()) \
 415             tio.FIELD |= NAME; \
 416           else \
 417             tio.FIELD &= ~NAME; \
 418           break;
 419
 420 #include "ttymodes.h"
 421
 422 #undef TTYCHAR
 423 #undef TTYMODE
 424
 425                 default:
 426                         debug("Ignoring unsupported tty mode opcode %d (0x%x)",
 427                             opcode, opcode);
 428                         if (!compat20) {
 429                                 /*
 430                                  * SSH1:
 431                                  * Opcodes 1 to 127 are defined to have
 432                                  * a one-byte argument.
 433                                  * Opcodes 128 to 159 are defined to have
 434                                  * an integer argument.
 435                                  */
 436                                 if (opcode > 0 && opcode < 128) {
 437                                         n_bytes += 1;
 438                                         (void) packet_get_char();
 439                                         break;
 440                                 } else if (opcode >= 128 && opcode < 160) {
 441                                         n_bytes += 4;
 442                                         (void) packet_get_int();
 443                                         break;
 444                                 } else {
 445                                         /*
 446                                          * It is a truly undefined opcode (160 to 255).
 447                                          * We have no idea about its arguments.  So we
 448                                          * must stop parsing.  Note that some data
 449                                          * may be left in the packet; hopefully there
 450                                          * is nothing more coming after the mode data.
 451                                          */
 452                                         logit("parse_tty_modes: unknown opcode %d",
 453                                             opcode);
 454                                         goto set;
 455                                 }
 456                         } else {
 457                                 /*
 458                                  * SSH2:
 459                                  * Opcodes 1 to 159 are defined to have
 460                                  * a uint32 argument.
 461                                  * Opcodes 160 to 255 are undefined and
 462                                  * cause parsing to stop.
 463                                  */
 464                                 if (opcode > 0 && opcode < 160) {
 465                                         n_bytes += 4;
 466                                         (void) packet_get_int();
 467                                         break;
 468                                 } else {
 469                                         logit("parse_tty_modes: unknown opcode %d",
 470                                             opcode);
 471                                         goto set;
 472                                 }
 473                         }
 474                 }
 475         }
 476
 477 set:
 478         if (*n_bytes_ptr != n_bytes) {
 479                 *n_bytes_ptr = n_bytes;
 480                 logit("parse_tty_modes: n_bytes_ptr != n_bytes: %d %d",
 481                     *n_bytes_ptr, n_bytes);
 482                 return;         /* Don't process bytes passed */
 483         }
 484         if (failure == -1)
 485                 return;         /* Packet parsed ok but tcgetattr() failed */
 486
 487         /* Set the new modes for the terminal. */
 488         if (tcsetattr(fd, TCSANOW, &tio) == -1)
 489                 logit("Setting tty modes failed: %.100s", strerror(errno));
 490 }