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
speed_to_baud(speed_t speed)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
baud_to_speed(int baud)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
special_char_encode(cc_t c)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
special_char_decode(u_int c)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
tty_make_modes(int fd,struct termios * tiop)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
tty_parse_modes(int fd,int * n_bytes_ptr)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 }
491