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 "includes.h"
47
48#include <sys/types.h>
49
50#include <errno.h>
51#include <string.h>
52#include <termios.h>
53#include <stdarg.h>
54
55#include "packet.h"
56#include "log.h"
57#include "ssh1.h"
58#include "compat.h"
59#include "buffer.h"
60
61#define TTY_OP_END		0
62/*
63 * uint32 (u_int) follows speed in SSH1 and SSH2
64 */
65#define TTY_OP_ISPEED_PROTO1	192
66#define TTY_OP_OSPEED_PROTO1	193
67#define TTY_OP_ISPEED_PROTO2	128
68#define TTY_OP_OSPEED_PROTO2	129
69
70/*
71 * Converts POSIX speed_t to a baud rate.  The values of the
72 * constants for speed_t are not themselves portable.
73 */
74static int
75speed_to_baud(speed_t speed)
76{
77	switch (speed) {
78	case B0:
79		return 0;
80	case B50:
81		return 50;
82	case B75:
83		return 75;
84	case B110:
85		return 110;
86	case B134:
87		return 134;
88	case B150:
89		return 150;
90	case B200:
91		return 200;
92	case B300:
93		return 300;
94	case B600:
95		return 600;
96	case B1200:
97		return 1200;
98	case B1800:
99		return 1800;
100	case B2400:
101		return 2400;
102	case B4800:
103		return 4800;
104	case B9600:
105		return 9600;
106
107#ifdef B19200
108	case B19200:
109		return 19200;
110#else /* B19200 */
111#ifdef EXTA
112	case EXTA:
113		return 19200;
114#endif /* EXTA */
115#endif /* B19200 */
116
117#ifdef B38400
118	case B38400:
119		return 38400;
120#else /* B38400 */
121#ifdef EXTB
122	case EXTB:
123		return 38400;
124#endif /* EXTB */
125#endif /* B38400 */
126
127#ifdef B7200
128	case B7200:
129		return 7200;
130#endif /* B7200 */
131#ifdef B14400
132	case B14400:
133		return 14400;
134#endif /* B14400 */
135#ifdef B28800
136	case B28800:
137		return 28800;
138#endif /* B28800 */
139#ifdef B57600
140	case B57600:
141		return 57600;
142#endif /* B57600 */
143#ifdef B76800
144	case B76800:
145		return 76800;
146#endif /* B76800 */
147#ifdef B115200
148	case B115200:
149		return 115200;
150#endif /* B115200 */
151#ifdef B230400
152	case B230400:
153		return 230400;
154#endif /* B230400 */
155	default:
156		return 9600;
157	}
158}
159
160/*
161 * Converts a numeric baud rate to a POSIX speed_t.
162 */
163static speed_t
164baud_to_speed(int baud)
165{
166	switch (baud) {
167	case 0:
168		return B0;
169	case 50:
170		return B50;
171	case 75:
172		return B75;
173	case 110:
174		return B110;
175	case 134:
176		return B134;
177	case 150:
178		return B150;
179	case 200:
180		return B200;
181	case 300:
182		return B300;
183	case 600:
184		return B600;
185	case 1200:
186		return B1200;
187	case 1800:
188		return B1800;
189	case 2400:
190		return B2400;
191	case 4800:
192		return B4800;
193	case 9600:
194		return B9600;
195
196#ifdef B19200
197	case 19200:
198		return B19200;
199#else /* B19200 */
200#ifdef EXTA
201	case 19200:
202		return EXTA;
203#endif /* EXTA */
204#endif /* B19200 */
205
206#ifdef B38400
207	case 38400:
208		return B38400;
209#else /* B38400 */
210#ifdef EXTB
211	case 38400:
212		return EXTB;
213#endif /* EXTB */
214#endif /* B38400 */
215
216#ifdef B7200
217	case 7200:
218		return B7200;
219#endif /* B7200 */
220#ifdef B14400
221	case 14400:
222		return B14400;
223#endif /* B14400 */
224#ifdef B28800
225	case 28800:
226		return B28800;
227#endif /* B28800 */
228#ifdef B57600
229	case 57600:
230		return B57600;
231#endif /* B57600 */
232#ifdef B76800
233	case 76800:
234		return B76800;
235#endif /* B76800 */
236#ifdef B115200
237	case 115200:
238		return B115200;
239#endif /* B115200 */
240#ifdef B230400
241	case 230400:
242		return B230400;
243#endif /* B230400 */
244	default:
245		return B9600;
246	}
247}
248
249/*
250 * Encode a special character into SSH line format.
251 */
252static u_int
253special_char_encode(cc_t c)
254{
255#ifdef _POSIX_VDISABLE
256	if (c == _POSIX_VDISABLE)
257		return 255;
258#endif /* _POSIX_VDISABLE */
259	return c;
260}
261
262/*
263 * Decode a special character from SSH line format.
264 */
265static cc_t
266special_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 */
280void
281tty_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
334end:
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 */
348void
349tty_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
477set:
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