xref: /freebsd/crypto/openssh/ttymodes.c (revision 6780ab54325a71e7e70112b11657973edde8655e)
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 1.18 2002/06/19 00:27:55 deraadt 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 	debug3("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 	debug3("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 	debug3("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 	debug3("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 }
311 
312 /*
313  * Decodes terminal modes for the terminal referenced by fd in a portable
314  * manner from a packet being read.
315  */
316 void
317 tty_parse_modes(int fd, int *n_bytes_ptr)
318 {
319 	struct termios tio;
320 	int opcode, baud;
321 	int n_bytes = 0;
322 	int failure = 0;
323 	u_int (*get_arg)(void);
324 	int arg, arg_size;
325 
326 	if (compat20) {
327 		*n_bytes_ptr = packet_get_int();
328 		debug3("tty_parse_modes: SSH2 n_bytes %d", *n_bytes_ptr);
329 		if (*n_bytes_ptr == 0)
330 			return;
331 		get_arg = packet_get_int;
332 		arg_size = 4;
333 	} else {
334 		get_arg = packet_get_char;
335 		arg_size = 1;
336 	}
337 
338 	/*
339 	 * Get old attributes for the terminal.  We will modify these
340 	 * flags. I am hoping that if there are any machine-specific
341 	 * modes, they will initially have reasonable values.
342 	 */
343 	if (tcgetattr(fd, &tio) == -1) {
344 		log("tcgetattr: %.100s", strerror(errno));
345 		failure = -1;
346 	}
347 
348 	for (;;) {
349 		n_bytes += 1;
350 		opcode = packet_get_char();
351 		switch (opcode) {
352 		case TTY_OP_END:
353 			goto set;
354 
355 		/* XXX: future conflict possible */
356 		case TTY_OP_ISPEED_PROTO1:
357 		case TTY_OP_ISPEED_PROTO2:
358 			n_bytes += 4;
359 			baud = packet_get_int();
360 			debug3("tty_parse_modes: ispeed %d", baud);
361 			if (failure != -1 && cfsetispeed(&tio, baud_to_speed(baud)) == -1)
362 				error("cfsetispeed failed for %d", baud);
363 			break;
364 
365 		/* XXX: future conflict possible */
366 		case TTY_OP_OSPEED_PROTO1:
367 		case TTY_OP_OSPEED_PROTO2:
368 			n_bytes += 4;
369 			baud = packet_get_int();
370 			debug3("tty_parse_modes: ospeed %d", baud);
371 			if (failure != -1 && cfsetospeed(&tio, baud_to_speed(baud)) == -1)
372 				error("cfsetospeed failed for %d", baud);
373 			break;
374 
375 #define TTYCHAR(NAME, OP) \
376 	case OP: \
377 	  n_bytes += arg_size; \
378 	  tio.c_cc[NAME] = get_arg(); \
379 	  debug3("tty_parse_modes: %d %d", OP, tio.c_cc[NAME]); \
380 	  break;
381 #define TTYMODE(NAME, FIELD, OP) \
382 	case OP: \
383 	  n_bytes += arg_size; \
384 	  if ((arg = get_arg())) \
385 	    tio.FIELD |= NAME; \
386 	  else \
387 	    tio.FIELD &= ~NAME;	\
388 	  debug3("tty_parse_modes: %d %d", OP, arg); \
389 	  break;
390 
391 #include "ttymodes.h"
392 
393 #undef TTYCHAR
394 #undef TTYMODE
395 
396 		default:
397 			debug("Ignoring unsupported tty mode opcode %d (0x%x)",
398 			    opcode, opcode);
399 			if (!compat20) {
400 				/*
401 				 * SSH1:
402 				 * Opcodes 1 to 127 are defined to have
403 				 * a one-byte argument.
404 				 * Opcodes 128 to 159 are defined to have
405 				 * an integer argument.
406 				 */
407 				if (opcode > 0 && opcode < 128) {
408 					n_bytes += 1;
409 					(void) packet_get_char();
410 					break;
411 				} else if (opcode >= 128 && opcode < 160) {
412 					n_bytes += 4;
413 					(void) packet_get_int();
414 					break;
415 				} else {
416 					/*
417 					 * It is a truly undefined opcode (160 to 255).
418 					 * We have no idea about its arguments.  So we
419 					 * must stop parsing.  Note that some data may be
420 					 * left in the packet; hopefully there is nothing
421 					 * more coming after the mode data.
422 					 */
423 					log("parse_tty_modes: unknown opcode %d", opcode);
424 					goto set;
425 				}
426 			} else {
427 				/*
428 				 * SSH2:
429 				 * Opcodes 1 to 159 are defined to have
430 				 * a uint32 argument.
431 				 * Opcodes 160 to 255 are undefined and
432 				 * cause parsing to stop.
433 				 */
434 				if (opcode > 0 && opcode < 160) {
435 					n_bytes += 4;
436 					(void) packet_get_int();
437 					break;
438 				} else {
439 					log("parse_tty_modes: unknown opcode %d", opcode);
440 					goto set;
441 				}
442 			}
443 		}
444 	}
445 
446 set:
447 	if (*n_bytes_ptr != n_bytes) {
448 		*n_bytes_ptr = n_bytes;
449 		log("parse_tty_modes: n_bytes_ptr != n_bytes: %d %d",
450 		    *n_bytes_ptr, n_bytes);
451 		return;		/* Don't process bytes passed */
452 	}
453 	if (failure == -1)
454 		return;		/* Packet parsed ok but tcgetattr() failed */
455 
456 	/* Set the new modes for the terminal. */
457 	if (tcsetattr(fd, TCSANOW, &tio) == -1)
458 		log("Setting tty modes failed: %.100s", strerror(errno));
459 }
460