xref: /openbsd/usr.bin/ssh/ttymodes.c (revision 5af055cd)
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 <sys/types.h>
47 
48 #include <errno.h>
49 #include <string.h>
50 #include <termios.h>
51 #include <stdarg.h>
52 
53 #include "packet.h"
54 #include "log.h"
55 #include "ssh1.h"
56 #include "compat.h"
57 #include "buffer.h"
58 
59 #define TTY_OP_END		0
60 /*
61  * uint32 (u_int) follows speed in SSH1 and SSH2
62  */
63 #define TTY_OP_ISPEED_PROTO1	192
64 #define TTY_OP_OSPEED_PROTO1	193
65 #define TTY_OP_ISPEED_PROTO2	128
66 #define TTY_OP_OSPEED_PROTO2	129
67 
68 /*
69  * Converts POSIX speed_t to a baud rate.  The values of the
70  * constants for speed_t are not themselves portable.
71  */
72 static int
73 speed_to_baud(speed_t speed)
74 {
75 	switch (speed) {
76 	case B0:
77 		return 0;
78 	case B50:
79 		return 50;
80 	case B75:
81 		return 75;
82 	case B110:
83 		return 110;
84 	case B134:
85 		return 134;
86 	case B150:
87 		return 150;
88 	case B200:
89 		return 200;
90 	case B300:
91 		return 300;
92 	case B600:
93 		return 600;
94 	case B1200:
95 		return 1200;
96 	case B1800:
97 		return 1800;
98 	case B2400:
99 		return 2400;
100 	case B4800:
101 		return 4800;
102 	case B9600:
103 		return 9600;
104 
105 #ifdef B19200
106 	case B19200:
107 		return 19200;
108 #else /* B19200 */
109 #ifdef EXTA
110 	case EXTA:
111 		return 19200;
112 #endif /* EXTA */
113 #endif /* B19200 */
114 
115 #ifdef B38400
116 	case B38400:
117 		return 38400;
118 #else /* B38400 */
119 #ifdef EXTB
120 	case EXTB:
121 		return 38400;
122 #endif /* EXTB */
123 #endif /* B38400 */
124 
125 #ifdef B7200
126 	case B7200:
127 		return 7200;
128 #endif /* B7200 */
129 #ifdef B14400
130 	case B14400:
131 		return 14400;
132 #endif /* B14400 */
133 #ifdef B28800
134 	case B28800:
135 		return 28800;
136 #endif /* B28800 */
137 #ifdef B57600
138 	case B57600:
139 		return 57600;
140 #endif /* B57600 */
141 #ifdef B76800
142 	case B76800:
143 		return 76800;
144 #endif /* B76800 */
145 #ifdef B115200
146 	case B115200:
147 		return 115200;
148 #endif /* B115200 */
149 #ifdef B230400
150 	case B230400:
151 		return 230400;
152 #endif /* B230400 */
153 	default:
154 		return 9600;
155 	}
156 }
157 
158 /*
159  * Converts a numeric baud rate to a POSIX speed_t.
160  */
161 static speed_t
162 baud_to_speed(int baud)
163 {
164 	switch (baud) {
165 	case 0:
166 		return B0;
167 	case 50:
168 		return B50;
169 	case 75:
170 		return B75;
171 	case 110:
172 		return B110;
173 	case 134:
174 		return B134;
175 	case 150:
176 		return B150;
177 	case 200:
178 		return B200;
179 	case 300:
180 		return B300;
181 	case 600:
182 		return B600;
183 	case 1200:
184 		return B1200;
185 	case 1800:
186 		return B1800;
187 	case 2400:
188 		return B2400;
189 	case 4800:
190 		return B4800;
191 	case 9600:
192 		return B9600;
193 
194 #ifdef B19200
195 	case 19200:
196 		return B19200;
197 #else /* B19200 */
198 #ifdef EXTA
199 	case 19200:
200 		return EXTA;
201 #endif /* EXTA */
202 #endif /* B19200 */
203 
204 #ifdef B38400
205 	case 38400:
206 		return B38400;
207 #else /* B38400 */
208 #ifdef EXTB
209 	case 38400:
210 		return EXTB;
211 #endif /* EXTB */
212 #endif /* B38400 */
213 
214 #ifdef B7200
215 	case 7200:
216 		return B7200;
217 #endif /* B7200 */
218 #ifdef B14400
219 	case 14400:
220 		return B14400;
221 #endif /* B14400 */
222 #ifdef B28800
223 	case 28800:
224 		return B28800;
225 #endif /* B28800 */
226 #ifdef B57600
227 	case 57600:
228 		return B57600;
229 #endif /* B57600 */
230 #ifdef B76800
231 	case 76800:
232 		return B76800;
233 #endif /* B76800 */
234 #ifdef B115200
235 	case 115200:
236 		return B115200;
237 #endif /* B115200 */
238 #ifdef B230400
239 	case 230400:
240 		return B230400;
241 #endif /* B230400 */
242 	default:
243 		return B9600;
244 	}
245 }
246 
247 /*
248  * Encodes terminal modes for the terminal referenced by fd
249  * or tiop in a portable manner, and appends the modes to a packet
250  * being constructed.
251  */
252 void
253 tty_make_modes(int fd, struct termios *tiop)
254 {
255 	struct termios tio;
256 	int baud;
257 	Buffer buf;
258 	int tty_op_ospeed, tty_op_ispeed;
259 	void (*put_arg)(Buffer *, u_int);
260 
261 	buffer_init(&buf);
262 	if (compat20) {
263 		tty_op_ospeed = TTY_OP_OSPEED_PROTO2;
264 		tty_op_ispeed = TTY_OP_ISPEED_PROTO2;
265 		put_arg = buffer_put_int;
266 	} else {
267 		tty_op_ospeed = TTY_OP_OSPEED_PROTO1;
268 		tty_op_ispeed = TTY_OP_ISPEED_PROTO1;
269 		put_arg = (void (*)(Buffer *, u_int)) buffer_put_char;
270 	}
271 
272 	if (tiop == NULL) {
273 		if (fd == -1) {
274 			debug("tty_make_modes: no fd or tio");
275 			goto end;
276 		}
277 		if (tcgetattr(fd, &tio) == -1) {
278 			logit("tcgetattr: %.100s", strerror(errno));
279 			goto end;
280 		}
281 	} else
282 		tio = *tiop;
283 
284 	/* Store input and output baud rates. */
285 	baud = speed_to_baud(cfgetospeed(&tio));
286 	buffer_put_char(&buf, tty_op_ospeed);
287 	buffer_put_int(&buf, baud);
288 	baud = speed_to_baud(cfgetispeed(&tio));
289 	buffer_put_char(&buf, tty_op_ispeed);
290 	buffer_put_int(&buf, baud);
291 
292 	/* Store values of mode flags. */
293 #define TTYCHAR(NAME, OP) \
294 	buffer_put_char(&buf, OP); \
295 	put_arg(&buf, tio.c_cc[NAME]);
296 
297 #define TTYMODE(NAME, FIELD, OP) \
298 	buffer_put_char(&buf, OP); \
299 	put_arg(&buf, ((tio.FIELD & NAME) != 0));
300 
301 #include "ttymodes.h"
302 
303 #undef TTYCHAR
304 #undef TTYMODE
305 
306 end:
307 	/* Mark end of mode data. */
308 	buffer_put_char(&buf, TTY_OP_END);
309 	if (compat20)
310 		packet_put_string(buffer_ptr(&buf), buffer_len(&buf));
311 	else
312 		packet_put_raw(buffer_ptr(&buf), buffer_len(&buf));
313 	buffer_free(&buf);
314 }
315 
316 /*
317  * Decodes terminal modes for the terminal referenced by fd in a portable
318  * manner from a packet being read.
319  */
320 void
321 tty_parse_modes(int fd, int *n_bytes_ptr)
322 {
323 	struct termios tio;
324 	int opcode, baud;
325 	int n_bytes = 0;
326 	int failure = 0;
327 	u_int (*get_arg)(void);
328 	int arg_size;
329 
330 	if (compat20) {
331 		*n_bytes_ptr = packet_get_int();
332 		if (*n_bytes_ptr == 0)
333 			return;
334 		get_arg = packet_get_int;
335 		arg_size = 4;
336 	} else {
337 		get_arg = packet_get_char;
338 		arg_size = 1;
339 	}
340 
341 	/*
342 	 * Get old attributes for the terminal.  We will modify these
343 	 * flags. I am hoping that if there are any machine-specific
344 	 * modes, they will initially have reasonable values.
345 	 */
346 	if (tcgetattr(fd, &tio) == -1) {
347 		logit("tcgetattr: %.100s", strerror(errno));
348 		failure = -1;
349 	}
350 
351 	for (;;) {
352 		n_bytes += 1;
353 		opcode = packet_get_char();
354 		switch (opcode) {
355 		case TTY_OP_END:
356 			goto set;
357 
358 		/* XXX: future conflict possible */
359 		case TTY_OP_ISPEED_PROTO1:
360 		case TTY_OP_ISPEED_PROTO2:
361 			n_bytes += 4;
362 			baud = packet_get_int();
363 			if (failure != -1 &&
364 			    cfsetispeed(&tio, baud_to_speed(baud)) == -1)
365 				error("cfsetispeed failed for %d", baud);
366 			break;
367 
368 		/* XXX: future conflict possible */
369 		case TTY_OP_OSPEED_PROTO1:
370 		case TTY_OP_OSPEED_PROTO2:
371 			n_bytes += 4;
372 			baud = packet_get_int();
373 			if (failure != -1 &&
374 			    cfsetospeed(&tio, baud_to_speed(baud)) == -1)
375 				error("cfsetospeed failed for %d", baud);
376 			break;
377 
378 #define TTYCHAR(NAME, OP) \
379 	case OP: \
380 	  n_bytes += arg_size; \
381 	  tio.c_cc[NAME] = get_arg(); \
382 	  break;
383 #define TTYMODE(NAME, FIELD, OP) \
384 	case OP: \
385 	  n_bytes += arg_size; \
386 	  if (get_arg()) \
387 	    tio.FIELD |= NAME; \
388 	  else \
389 	    tio.FIELD &= ~NAME;	\
390 	  break;
391 
392 #include "ttymodes.h"
393 
394 #undef TTYCHAR
395 #undef TTYMODE
396 
397 		default:
398 			debug("Ignoring unsupported tty mode opcode %d (0x%x)",
399 			    opcode, opcode);
400 			if (!compat20) {
401 				/*
402 				 * SSH1:
403 				 * Opcodes 1 to 127 are defined to have
404 				 * a one-byte argument.
405 				 * Opcodes 128 to 159 are defined to have
406 				 * an integer argument.
407 				 */
408 				if (opcode > 0 && opcode < 128) {
409 					n_bytes += 1;
410 					(void) packet_get_char();
411 					break;
412 				} else if (opcode >= 128 && opcode < 160) {
413 					n_bytes += 4;
414 					(void) packet_get_int();
415 					break;
416 				} else {
417 					/*
418 					 * It is a truly undefined opcode (160 to 255).
419 					 * We have no idea about its arguments.  So we
420 					 * must stop parsing.  Note that some data
421 					 * may be left in the packet; hopefully there
422 					 * is nothing more coming after the mode data.
423 					 */
424 					logit("parse_tty_modes: unknown opcode %d",
425 					    opcode);
426 					goto set;
427 				}
428 			} else {
429 				/*
430 				 * SSH2:
431 				 * Opcodes 1 to 159 are defined to have
432 				 * a uint32 argument.
433 				 * Opcodes 160 to 255 are undefined and
434 				 * cause parsing to stop.
435 				 */
436 				if (opcode > 0 && opcode < 160) {
437 					n_bytes += 4;
438 					(void) packet_get_int();
439 					break;
440 				} else {
441 					logit("parse_tty_modes: unknown opcode %d",
442 					    opcode);
443 					goto set;
444 				}
445 			}
446 		}
447 	}
448 
449 set:
450 	if (*n_bytes_ptr != n_bytes) {
451 		*n_bytes_ptr = n_bytes;
452 		logit("parse_tty_modes: n_bytes_ptr != n_bytes: %d %d",
453 		    *n_bytes_ptr, n_bytes);
454 		return;		/* Don't process bytes passed */
455 	}
456 	if (failure == -1)
457 		return;		/* Packet parsed ok but tcgetattr() failed */
458 
459 	/* Set the new modes for the terminal. */
460 	if (tcsetattr(fd, TCSANOW, &tio) == -1)
461 		logit("Setting tty modes failed: %.100s", strerror(errno));
462 }
463