xref: /netbsd-src/crypto/external/bsd/openssh/dist/ttymodes.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: ttymodes.c,v 1.2 2009/06/07 22:38:48 christos Exp $	*/
2 /* $OpenBSD: ttymodes.c,v 1.29 2008/11/02 00:16:16 stevesk Exp $ */
3 /*
4  * Author: Tatu Ylonen <ylo@cs.hut.fi>
5  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6  *                    All rights reserved
7  *
8  * As far as I am concerned, the code I have written for this software
9  * can be used freely for any purpose.  Any derived versions of this
10  * software must be clearly marked as such, and if the derived work is
11  * incompatible with the protocol description in the RFC file, it must be
12  * called by a name other than "ssh" or "Secure Shell".
13  */
14 
15 /*
16  * SSH2 tty modes support by Kevin Steves.
17  * Copyright (c) 2001 Kevin Steves.  All rights reserved.
18  *
19  * Redistribution and use in source and binary forms, with or without
20  * modification, are permitted provided that the following conditions
21  * are met:
22  * 1. Redistributions of source code must retain the above copyright
23  *    notice, this list of conditions and the following disclaimer.
24  * 2. Redistributions in binary form must reproduce the above copyright
25  *    notice, this list of conditions and the following disclaimer in the
26  *    documentation and/or other materials provided with the distribution.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38  */
39 
40 /*
41  * Encoding and decoding of terminal modes in a portable way.
42  * Much of the format is defined in ttymodes.h; it is included multiple times
43  * into this file with the appropriate macro definitions to generate the
44  * suitable code.
45  */
46 
47 #include "includes.h"
48 __RCSID("$NetBSD: ttymodes.c,v 1.2 2009/06/07 22:38:48 christos Exp $");
49 #include <sys/types.h>
50 
51 #include <errno.h>
52 #include <string.h>
53 #include <termios.h>
54 #include <stdarg.h>
55 
56 #include "packet.h"
57 #include "log.h"
58 #include "ssh1.h"
59 #include "compat.h"
60 #include "buffer.h"
61 
62 #define TTY_OP_END		0
63 /*
64  * uint32 (u_int) follows speed in SSH1 and SSH2
65  */
66 #define TTY_OP_ISPEED_PROTO1	192
67 #define TTY_OP_OSPEED_PROTO1	193
68 #define TTY_OP_ISPEED_PROTO2	128
69 #define TTY_OP_OSPEED_PROTO2	129
70 
71 /*
72  * Converts POSIX speed_t to a baud rate.  The values of the
73  * constants for speed_t are not themselves portable.
74  */
75 static int
76 speed_to_baud(speed_t speed)
77 {
78 	switch (speed) {
79 	case B0:
80 		return 0;
81 	case B50:
82 		return 50;
83 	case B75:
84 		return 75;
85 	case B110:
86 		return 110;
87 	case B134:
88 		return 134;
89 	case B150:
90 		return 150;
91 	case B200:
92 		return 200;
93 	case B300:
94 		return 300;
95 	case B600:
96 		return 600;
97 	case B1200:
98 		return 1200;
99 	case B1800:
100 		return 1800;
101 	case B2400:
102 		return 2400;
103 	case B4800:
104 		return 4800;
105 	case B9600:
106 		return 9600;
107 
108 #ifdef B19200
109 	case B19200:
110 		return 19200;
111 #else /* B19200 */
112 #ifdef EXTA
113 	case EXTA:
114 		return 19200;
115 #endif /* EXTA */
116 #endif /* B19200 */
117 
118 #ifdef B38400
119 	case B38400:
120 		return 38400;
121 #else /* B38400 */
122 #ifdef EXTB
123 	case EXTB:
124 		return 38400;
125 #endif /* EXTB */
126 #endif /* B38400 */
127 
128 #ifdef B7200
129 	case B7200:
130 		return 7200;
131 #endif /* B7200 */
132 #ifdef B14400
133 	case B14400:
134 		return 14400;
135 #endif /* B14400 */
136 #ifdef B28800
137 	case B28800:
138 		return 28800;
139 #endif /* B28800 */
140 #ifdef B57600
141 	case B57600:
142 		return 57600;
143 #endif /* B57600 */
144 #ifdef B76800
145 	case B76800:
146 		return 76800;
147 #endif /* B76800 */
148 #ifdef B115200
149 	case B115200:
150 		return 115200;
151 #endif /* B115200 */
152 #ifdef B230400
153 	case B230400:
154 		return 230400;
155 #endif /* B230400 */
156 	default:
157 		return 9600;
158 	}
159 }
160 
161 /*
162  * Converts a numeric baud rate to a POSIX speed_t.
163  */
164 static speed_t
165 baud_to_speed(int baud)
166 {
167 	switch (baud) {
168 	case 0:
169 		return B0;
170 	case 50:
171 		return B50;
172 	case 75:
173 		return B75;
174 	case 110:
175 		return B110;
176 	case 134:
177 		return B134;
178 	case 150:
179 		return B150;
180 	case 200:
181 		return B200;
182 	case 300:
183 		return B300;
184 	case 600:
185 		return B600;
186 	case 1200:
187 		return B1200;
188 	case 1800:
189 		return B1800;
190 	case 2400:
191 		return B2400;
192 	case 4800:
193 		return B4800;
194 	case 9600:
195 		return B9600;
196 
197 #ifdef B19200
198 	case 19200:
199 		return B19200;
200 #else /* B19200 */
201 #ifdef EXTA
202 	case 19200:
203 		return EXTA;
204 #endif /* EXTA */
205 #endif /* B19200 */
206 
207 #ifdef B38400
208 	case 38400:
209 		return B38400;
210 #else /* B38400 */
211 #ifdef EXTB
212 	case 38400:
213 		return EXTB;
214 #endif /* EXTB */
215 #endif /* B38400 */
216 
217 #ifdef B7200
218 	case 7200:
219 		return B7200;
220 #endif /* B7200 */
221 #ifdef B14400
222 	case 14400:
223 		return B14400;
224 #endif /* B14400 */
225 #ifdef B28800
226 	case 28800:
227 		return B28800;
228 #endif /* B28800 */
229 #ifdef B57600
230 	case 57600:
231 		return B57600;
232 #endif /* B57600 */
233 #ifdef B76800
234 	case 76800:
235 		return B76800;
236 #endif /* B76800 */
237 #ifdef B115200
238 	case 115200:
239 		return B115200;
240 #endif /* B115200 */
241 #ifdef B230400
242 	case 230400:
243 		return B230400;
244 #endif /* B230400 */
245 	default:
246 		return B9600;
247 	}
248 }
249 
250 /*
251  * Encode a special character into SSH line format.
252  */
253 static u_int
254 special_char_encode(cc_t c)
255 {
256 #ifdef _POSIX_VDISABLE
257 	if (c == _POSIX_VDISABLE)
258 		return 255;
259 #endif /* _POSIX_VDISABLE */
260 	return c;
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 }
491