xref: /freebsd/crypto/openssh/ttymodes.c (revision 6990ffd8a95caaba6858ad44ff1b3157d1efba8f)
1 /*
2  * Author: Tatu Ylonen <ylo@cs.hut.fi>
3  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4  *                    All rights reserved
5  *
6  * As far as I am concerned, the code I have written for this software
7  * can be used freely for any purpose.  Any derived versions of this
8  * software must be clearly marked as such, and if the derived work is
9  * incompatible with the protocol description in the RFC file, it must be
10  * called by a name other than "ssh" or "Secure Shell".
11  */
12 
13 /*
14  * SSH2 tty modes support by Kevin Steves.
15  * Copyright (c) 2001 Kevin Steves.  All rights reserved.
16  *
17  * Redistribution and use in source and binary forms, with or without
18  * modification, are permitted provided that the following conditions
19  * are met:
20  * 1. Redistributions of source code must retain the above copyright
21  *    notice, this list of conditions and the following disclaimer.
22  * 2. Redistributions in binary form must reproduce the above copyright
23  *    notice, this list of conditions and the following disclaimer in the
24  *    documentation and/or other materials provided with the distribution.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 /*
39  * Encoding and decoding of terminal modes in a portable way.
40  * Much of the format is defined in ttymodes.h; it is included multiple times
41  * into this file with the appropriate macro definitions to generate the
42  * suitable code.
43  */
44 
45 #include "includes.h"
46 RCSID("$OpenBSD: ttymodes.c,v 1.13 2001/04/15 01:35:22 stevesk Exp $");
47 
48 #include "packet.h"
49 #include "log.h"
50 #include "ssh1.h"
51 #include "compat.h"
52 #include "buffer.h"
53 #include "bufaux.h"
54 
55 #define TTY_OP_END		0
56 /*
57  * uint32 (u_int) follows speed in SSH1 and SSH2
58  */
59 #define TTY_OP_ISPEED_PROTO1	192
60 #define TTY_OP_OSPEED_PROTO1	193
61 #define TTY_OP_ISPEED_PROTO2	128
62 #define TTY_OP_OSPEED_PROTO2	129
63 
64 /*
65  * Converts POSIX speed_t to a baud rate.  The values of the
66  * constants for speed_t are not themselves portable.
67  */
68 static int
69 speed_to_baud(speed_t speed)
70 {
71 	switch (speed) {
72 	case B0:
73 		return 0;
74 	case B50:
75 		return 50;
76 	case B75:
77 		return 75;
78 	case B110:
79 		return 110;
80 	case B134:
81 		return 134;
82 	case B150:
83 		return 150;
84 	case B200:
85 		return 200;
86 	case B300:
87 		return 300;
88 	case B600:
89 		return 600;
90 	case B1200:
91 		return 1200;
92 	case B1800:
93 		return 1800;
94 	case B2400:
95 		return 2400;
96 	case B4800:
97 		return 4800;
98 	case B9600:
99 		return 9600;
100 
101 #ifdef B19200
102 	case B19200:
103 		return 19200;
104 #else /* B19200 */
105 #ifdef EXTA
106 	case EXTA:
107 		return 19200;
108 #endif /* EXTA */
109 #endif /* B19200 */
110 
111 #ifdef B38400
112 	case B38400:
113 		return 38400;
114 #else /* B38400 */
115 #ifdef EXTB
116 	case EXTB:
117 		return 38400;
118 #endif /* EXTB */
119 #endif /* B38400 */
120 
121 #ifdef B7200
122 	case B7200:
123 		return 7200;
124 #endif /* B7200 */
125 #ifdef B14400
126 	case B14400:
127 		return 14400;
128 #endif /* B14400 */
129 #ifdef B28800
130 	case B28800:
131 		return 28800;
132 #endif /* B28800 */
133 #ifdef B57600
134 	case B57600:
135 		return 57600;
136 #endif /* B57600 */
137 #ifdef B76800
138 	case B76800:
139 		return 76800;
140 #endif /* B76800 */
141 #ifdef B115200
142 	case B115200:
143 		return 115200;
144 #endif /* B115200 */
145 #ifdef B230400
146 	case B230400:
147 		return 230400;
148 #endif /* B230400 */
149 	default:
150 		return 9600;
151 	}
152 }
153 
154 /*
155  * Converts a numeric baud rate to a POSIX speed_t.
156  */
157 static speed_t
158 baud_to_speed(int baud)
159 {
160 	switch (baud) {
161 	case 0:
162 		return B0;
163 	case 50:
164 		return B50;
165 	case 75:
166 		return B75;
167 	case 110:
168 		return B110;
169 	case 134:
170 		return B134;
171 	case 150:
172 		return B150;
173 	case 200:
174 		return B200;
175 	case 300:
176 		return B300;
177 	case 600:
178 		return B600;
179 	case 1200:
180 		return B1200;
181 	case 1800:
182 		return B1800;
183 	case 2400:
184 		return B2400;
185 	case 4800:
186 		return B4800;
187 	case 9600:
188 		return B9600;
189 
190 #ifdef B19200
191 	case 19200:
192 		return B19200;
193 #else /* B19200 */
194 #ifdef EXTA
195 	case 19200:
196 		return EXTA;
197 #endif /* EXTA */
198 #endif /* B19200 */
199 
200 #ifdef B38400
201 	case 38400:
202 		return B38400;
203 #else /* B38400 */
204 #ifdef EXTB
205 	case 38400:
206 		return EXTB;
207 #endif /* EXTB */
208 #endif /* B38400 */
209 
210 #ifdef B7200
211 	case 7200:
212 		return B7200;
213 #endif /* B7200 */
214 #ifdef B14400
215 	case 14400:
216 		return B14400;
217 #endif /* B14400 */
218 #ifdef B28800
219 	case 28800:
220 		return B28800;
221 #endif /* B28800 */
222 #ifdef B57600
223 	case 57600:
224 		return B57600;
225 #endif /* B57600 */
226 #ifdef B76800
227 	case 76800:
228 		return B76800;
229 #endif /* B76800 */
230 #ifdef B115200
231 	case 115200:
232 		return B115200;
233 #endif /* B115200 */
234 #ifdef B230400
235 	case 230400:
236 		return B230400;
237 #endif /* B230400 */
238 	default:
239 		return B9600;
240 	}
241 }
242 
243 /*
244  * Encodes terminal modes for the terminal referenced by fd
245  * or tiop in a portable manner, and appends the modes to a packet
246  * being constructed.
247  */
248 void
249 tty_make_modes(int fd, struct termios *tiop)
250 {
251 	struct termios tio;
252 	int baud;
253 	Buffer buf;
254 	int tty_op_ospeed, tty_op_ispeed;
255 	void (*put_arg)(Buffer *, u_int);
256 
257 	buffer_init(&buf);
258 	if (compat20) {
259 		tty_op_ospeed = TTY_OP_OSPEED_PROTO2;
260 		tty_op_ispeed = TTY_OP_ISPEED_PROTO2;
261 		put_arg = buffer_put_int;
262 	} else {
263 		tty_op_ospeed = TTY_OP_OSPEED_PROTO1;
264 		tty_op_ispeed = TTY_OP_ISPEED_PROTO1;
265 		put_arg = (void (*)(Buffer *, u_int)) buffer_put_char;
266 	}
267 
268 	if (tiop == NULL) {
269 		if (tcgetattr(fd, &tio) == -1) {
270 			log("tcgetattr: %.100s", strerror(errno));
271 			goto end;
272 		}
273 	} else
274 		tio = *tiop;
275 
276 	/* Store input and output baud rates. */
277 	baud = speed_to_baud(cfgetospeed(&tio));
278 	debug2("tty_make_modes: ospeed %d", baud);
279 	buffer_put_char(&buf, tty_op_ospeed);
280 	buffer_put_int(&buf, baud);
281 	baud = speed_to_baud(cfgetispeed(&tio));
282 	debug2("tty_make_modes: ispeed %d", baud);
283 	buffer_put_char(&buf, tty_op_ispeed);
284 	buffer_put_int(&buf, baud);
285 
286 	/* Store values of mode flags. */
287 #define TTYCHAR(NAME, OP) \
288 	debug2("tty_make_modes: %d %d", OP, tio.c_cc[NAME]); \
289 	buffer_put_char(&buf, OP); \
290 	put_arg(&buf, tio.c_cc[NAME]);
291 
292 #define TTYMODE(NAME, FIELD, OP) \
293 	debug2("tty_make_modes: %d %d", OP, ((tio.FIELD & NAME) != 0)); \
294 	buffer_put_char(&buf, OP); \
295 	put_arg(&buf, ((tio.FIELD & NAME) != 0));
296 
297 #include "ttymodes.h"
298 
299 #undef TTYCHAR
300 #undef TTYMODE
301 
302 end:
303 	/* Mark end of mode data. */
304 	buffer_put_char(&buf, TTY_OP_END);
305 	if (compat20)
306 		packet_put_string(buffer_ptr(&buf), buffer_len(&buf));
307 	else
308 		packet_put_raw(buffer_ptr(&buf), buffer_len(&buf));
309 	buffer_free(&buf);
310 	return;
311 }
312 
313 /*
314  * Decodes terminal modes for the terminal referenced by fd in a portable
315  * manner from a packet being read.
316  */
317 void
318 tty_parse_modes(int fd, int *n_bytes_ptr)
319 {
320 	struct termios tio;
321 	int opcode, baud;
322 	int n_bytes = 0;
323 	int failure = 0;
324 	u_int (*get_arg)(void);
325 	int arg, arg_size;
326 
327 	if (compat20) {
328 		*n_bytes_ptr = packet_get_int();
329 		debug2("tty_parse_modes: SSH2 n_bytes %d", *n_bytes_ptr);
330 		if (*n_bytes_ptr == 0)
331 			return;
332 		get_arg = packet_get_int;
333 		arg_size = 4;
334 	} else {
335 		get_arg = packet_get_char;
336 		arg_size = 1;
337 	}
338 
339 	/*
340 	 * Get old attributes for the terminal.  We will modify these
341 	 * flags. I am hoping that if there are any machine-specific
342 	 * modes, they will initially have reasonable values.
343 	 */
344 	if (tcgetattr(fd, &tio) == -1) {
345 		log("tcgetattr: %.100s", strerror(errno));
346 		failure = -1;
347 	}
348 
349 	for (;;) {
350 		n_bytes += 1;
351 		opcode = packet_get_char();
352 		switch (opcode) {
353 		case TTY_OP_END:
354 			goto set;
355 
356 		/* XXX: future conflict possible */
357 		case TTY_OP_ISPEED_PROTO1:
358 		case TTY_OP_ISPEED_PROTO2:
359 			n_bytes += 4;
360 			baud = packet_get_int();
361 			debug2("tty_parse_modes: ispeed %d", baud);
362 			if (failure != -1 && cfsetispeed(&tio, baud_to_speed(baud)) == -1)
363 				error("cfsetispeed failed for %d", baud);
364 			break;
365 
366 		/* XXX: future conflict possible */
367 		case TTY_OP_OSPEED_PROTO1:
368 		case TTY_OP_OSPEED_PROTO2:
369 			n_bytes += 4;
370 			baud = packet_get_int();
371 			debug2("tty_parse_modes: ospeed %d", baud);
372 			if (failure != -1 && cfsetospeed(&tio, baud_to_speed(baud)) == -1)
373 				error("cfsetospeed failed for %d", baud);
374 			break;
375 
376 #define TTYCHAR(NAME, OP) \
377 	case OP: \
378 	  n_bytes += arg_size; \
379 	  tio.c_cc[NAME] = get_arg(); \
380 	  debug2("tty_parse_modes: %d %d", OP, tio.c_cc[NAME]); \
381 	  break;
382 #define TTYMODE(NAME, FIELD, OP) \
383 	case OP: \
384 	  n_bytes += arg_size; \
385 	  if ((arg = get_arg())) \
386 	    tio.FIELD |= NAME; \
387 	  else \
388 	    tio.FIELD &= ~NAME;	\
389 	  debug2("tty_parse_modes: %d %d", OP, arg); \
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 may be
421 					 * left in the packet; hopefully there is nothing
422 					 * more coming after the mode data.
423 					 */
424 					log("parse_tty_modes: unknown opcode %d", opcode);
425 					packet_integrity_check(0, 1, SSH_CMSG_REQUEST_PTY);
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 					log("parse_tty_modes: unknown opcode %d", opcode);
442 					goto set;
443 				}
444   			}
445 		}
446 	}
447 
448 set:
449 	if (*n_bytes_ptr != n_bytes) {
450 		*n_bytes_ptr = n_bytes;
451 		log("parse_tty_modes: n_bytes_ptr != n_bytes: %d %d",
452 		    *n_bytes_ptr, n_bytes);
453 		return;		/* Don't process bytes passed */
454 	}
455 	if (failure == -1)
456 		return;		/* Packet parsed ok but tcgetattr() failed */
457 
458 	/* Set the new modes for the terminal. */
459 	if (tcsetattr(fd, TCSANOW, &tio) == -1)
460 		log("Setting tty modes failed: %.100s", strerror(errno));
461 	return;
462 }
463