xref: /netbsd-src/crypto/external/bsd/openssh/dist/ttymodes.c (revision 796c32c94f6e154afc9de0f63da35c91bb739b45)
1 /*	$NetBSD: ttymodes.c,v 1.8 2017/10/07 19:39:19 christos Exp $	*/
2 /* $OpenBSD: ttymodes.c,v 1.32 2017/04/30 23:26:54 djm Exp $ */
3 /*
4  * Author: Tatu Ylonen <ylo@cs.hut.fi>
5  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6  *                    All rights reserved
7  *
8  * As far as I am concerned, the code I have written for this software
9  * can be used freely for any purpose.  Any derived versions of this
10  * software must be clearly marked as such, and if the derived work is
11  * incompatible with the protocol description in the RFC file, it must be
12  * called by a name other than "ssh" or "Secure Shell".
13  */
14 
15 /*
16  * SSH2 tty modes support by Kevin Steves.
17  * Copyright (c) 2001 Kevin Steves.  All rights reserved.
18  *
19  * Redistribution and use in source and binary forms, with or without
20  * modification, are permitted provided that the following conditions
21  * are met:
22  * 1. Redistributions of source code must retain the above copyright
23  *    notice, this list of conditions and the following disclaimer.
24  * 2. Redistributions in binary form must reproduce the above copyright
25  *    notice, this list of conditions and the following disclaimer in the
26  *    documentation and/or other materials provided with the distribution.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38  */
39 
40 /*
41  * Encoding and decoding of terminal modes in a portable way.
42  * Much of the format is defined in ttymodes.h; it is included multiple times
43  * into this file with the appropriate macro definitions to generate the
44  * suitable code.
45  */
46 
47 #include "includes.h"
48 __RCSID("$NetBSD: ttymodes.c,v 1.8 2017/10/07 19:39:19 christos Exp $");
49 #include <sys/types.h>
50 
51 #include <errno.h>
52 #include <string.h>
53 #include <termios.h>
54 #include <stdarg.h>
55 
56 #include "packet.h"
57 #include "log.h"
58 #include "compat.h"
59 #include "buffer.h"
60 
61 #define TTY_OP_END		0
62 /*
63  * uint32 (u_int) follows speed.
64  */
65 #define TTY_OP_ISPEED	128
66 #define TTY_OP_OSPEED	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 
259 	buffer_init(&buf);
260 
261 	if (tiop == NULL) {
262 		if (fd == -1) {
263 			debug("tty_make_modes: no fd or tio");
264 			goto end;
265 		}
266 		if (tcgetattr(fd, &tio) == -1) {
267 			logit("tcgetattr: %.100s", strerror(errno));
268 			goto end;
269 		}
270 	} else
271 		tio = *tiop;
272 
273 	/* Store input and output baud rates. */
274 	baud = speed_to_baud(cfgetospeed(&tio));
275 	buffer_put_char(&buf, TTY_OP_OSPEED);
276 	buffer_put_int(&buf, baud);
277 	baud = speed_to_baud(cfgetispeed(&tio));
278 	buffer_put_char(&buf, TTY_OP_ISPEED);
279 	buffer_put_int(&buf, baud);
280 
281 	/* Store values of mode flags. */
282 #define TTYCHAR(NAME, OP) \
283 	buffer_put_char(&buf, OP); \
284 	buffer_put_int(&buf, tio.c_cc[NAME]);
285 
286 #define TTYMODE(NAME, FIELD, OP) \
287 	buffer_put_char(&buf, OP); \
288 	buffer_put_int(&buf, ((tio.FIELD & NAME) != 0));
289 
290 #include "ttymodes.h"
291 
292 #undef TTYCHAR
293 #undef TTYMODE
294 
295 end:
296 	/* Mark end of mode data. */
297 	buffer_put_char(&buf, TTY_OP_END);
298 	packet_put_string(buffer_ptr(&buf), buffer_len(&buf));
299 	buffer_free(&buf);
300 }
301 
302 /*
303  * Decodes terminal modes for the terminal referenced by fd in a portable
304  * manner from a packet being read.
305  */
306 void
307 tty_parse_modes(int fd, int *n_bytes_ptr)
308 {
309 	struct termios tio;
310 	int opcode, baud;
311 	int n_bytes = 0;
312 	int failure = 0;
313 
314 	*n_bytes_ptr = packet_get_int();
315 	if (*n_bytes_ptr == 0)
316 		return;
317 
318 	/*
319 	 * Get old attributes for the terminal.  We will modify these
320 	 * flags. I am hoping that if there are any machine-specific
321 	 * modes, they will initially have reasonable values.
322 	 */
323 	if (tcgetattr(fd, &tio) == -1) {
324 		logit("tcgetattr: %.100s", strerror(errno));
325 		failure = -1;
326 	}
327 
328 	for (;;) {
329 		n_bytes += 1;
330 		opcode = packet_get_char();
331 		switch (opcode) {
332 		case TTY_OP_END:
333 			goto set;
334 
335 		case TTY_OP_ISPEED:
336 			n_bytes += 4;
337 			baud = packet_get_int();
338 			if (failure != -1 &&
339 			    cfsetispeed(&tio, baud_to_speed(baud)) == -1)
340 				error("cfsetispeed failed for %d", baud);
341 			break;
342 
343 		case TTY_OP_OSPEED:
344 			n_bytes += 4;
345 			baud = packet_get_int();
346 			if (failure != -1 &&
347 			    cfsetospeed(&tio, baud_to_speed(baud)) == -1)
348 				error("cfsetospeed failed for %d", baud);
349 			break;
350 
351 #define TTYCHAR(NAME, OP) \
352 	case OP: \
353 	  n_bytes += 4; \
354 	  tio.c_cc[NAME] = packet_get_int(); \
355 	  break;
356 #define TTYMODE(NAME, FIELD, OP) \
357 	case OP: \
358 	  n_bytes += 4; \
359 	  if (packet_get_int()) \
360 	    tio.FIELD |= NAME; \
361 	  else \
362 	    tio.FIELD &= ~NAME;	\
363 	  break;
364 
365 #include "ttymodes.h"
366 
367 #undef TTYCHAR
368 #undef TTYMODE
369 
370 		default:
371 			debug("Ignoring unsupported tty mode opcode %d (0x%x)",
372 			    opcode, opcode);
373 			/*
374 			 * SSH2:
375 			 * Opcodes 1 to 159 are defined to have a uint32
376 			 * argument.
377 			 * Opcodes 160 to 255 are undefined and cause parsing
378 			 * to stop.
379 			 */
380 			if (opcode > 0 && opcode < 160) {
381 				n_bytes += 4;
382 				(void) packet_get_int();
383 				break;
384 			} else {
385 				logit("parse_tty_modes: unknown opcode %d",
386 				    opcode);
387 				goto set;
388 			}
389 		}
390 	}
391 
392 set:
393 	if (*n_bytes_ptr != n_bytes) {
394 		*n_bytes_ptr = n_bytes;
395 		logit("parse_tty_modes: n_bytes_ptr != n_bytes: %d %d",
396 		    *n_bytes_ptr, n_bytes);
397 		return;		/* Don't process bytes passed */
398 	}
399 	if (failure == -1)
400 		return;		/* Packet parsed ok but tcgetattr() failed */
401 
402 	/* Set the new modes for the terminal. */
403 	if (tcsetattr(fd, TCSANOW, &tio) == -1)
404 		logit("Setting tty modes failed: %.100s", strerror(errno));
405 }
406