ttymodes.c revision 92555
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"
46RCSID("$OpenBSD: ttymodes.c,v 1.16 2001/12/27 20:39:58 markus 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 */
68static int
69speed_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 */
157static speed_t
158baud_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 */
248void
249tty_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
302end:
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 */
317void
318tty_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		debug3("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			debug3("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			debug3("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	  debug3("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	  debug3("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					goto set;
426  				}
427			} else {
428				/*
429				 * SSH2:
430				 * Opcodes 1 to 159 are defined to have
431				 * a uint32 argument.
432				 * Opcodes 160 to 255 are undefined and
433				 * cause parsing to stop.
434				 */
435				if (opcode > 0 && opcode < 160) {
436					n_bytes += 4;
437					(void) packet_get_int();
438					break;
439				} else {
440					log("parse_tty_modes: unknown opcode %d", opcode);
441					goto set;
442				}
443  			}
444		}
445	}
446
447set:
448	if (*n_bytes_ptr != n_bytes) {
449		*n_bytes_ptr = n_bytes;
450		log("parse_tty_modes: n_bytes_ptr != n_bytes: %d %d",
451		    *n_bytes_ptr, n_bytes);
452		return;		/* Don't process bytes passed */
453	}
454	if (failure == -1)
455		return;		/* Packet parsed ok but tcgetattr() failed */
456
457	/* Set the new modes for the terminal. */
458	if (tcsetattr(fd, TCSANOW, &tio) == -1)
459		log("Setting tty modes failed: %.100s", strerror(errno));
460	return;
461}
462