freebsd-dev/crypto/openssh/ttymodes.c
Dag-Erling Smørgrav 190cef3d52 Upgrade to OpenSSH 7.8p1.
Approved by:	re (kib@)
2018-09-10 16:20:12 +00:00

457 lines
10 KiB
C

/* $OpenBSD: ttymodes.c,v 1.34 2018/07/09 21:20:26 markus Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*/
/*
* SSH2 tty modes support by Kevin Steves.
* Copyright (c) 2001 Kevin Steves. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Encoding and decoding of terminal modes in a portable way.
* Much of the format is defined in ttymodes.h; it is included multiple times
* into this file with the appropriate macro definitions to generate the
* suitable code.
*/
#include "includes.h"
#include <sys/types.h>
#include <errno.h>
#include <string.h>
#include <termios.h>
#include <stdarg.h>
#include "packet.h"
#include "log.h"
#include "compat.h"
#include "sshbuf.h"
#include "ssherr.h"
#define TTY_OP_END 0
/*
* uint32 (u_int) follows speed.
*/
#define TTY_OP_ISPEED 128
#define TTY_OP_OSPEED 129
/*
* Converts POSIX speed_t to a baud rate. The values of the
* constants for speed_t are not themselves portable.
*/
static int
speed_to_baud(speed_t speed)
{
switch (speed) {
case B0:
return 0;
case B50:
return 50;
case B75:
return 75;
case B110:
return 110;
case B134:
return 134;
case B150:
return 150;
case B200:
return 200;
case B300:
return 300;
case B600:
return 600;
case B1200:
return 1200;
case B1800:
return 1800;
case B2400:
return 2400;
case B4800:
return 4800;
case B9600:
return 9600;
#ifdef B19200
case B19200:
return 19200;
#else /* B19200 */
#ifdef EXTA
case EXTA:
return 19200;
#endif /* EXTA */
#endif /* B19200 */
#ifdef B38400
case B38400:
return 38400;
#else /* B38400 */
#ifdef EXTB
case EXTB:
return 38400;
#endif /* EXTB */
#endif /* B38400 */
#ifdef B7200
case B7200:
return 7200;
#endif /* B7200 */
#ifdef B14400
case B14400:
return 14400;
#endif /* B14400 */
#ifdef B28800
case B28800:
return 28800;
#endif /* B28800 */
#ifdef B57600
case B57600:
return 57600;
#endif /* B57600 */
#ifdef B76800
case B76800:
return 76800;
#endif /* B76800 */
#ifdef B115200
case B115200:
return 115200;
#endif /* B115200 */
#ifdef B230400
case B230400:
return 230400;
#endif /* B230400 */
default:
return 9600;
}
}
/*
* Converts a numeric baud rate to a POSIX speed_t.
*/
static speed_t
baud_to_speed(int baud)
{
switch (baud) {
case 0:
return B0;
case 50:
return B50;
case 75:
return B75;
case 110:
return B110;
case 134:
return B134;
case 150:
return B150;
case 200:
return B200;
case 300:
return B300;
case 600:
return B600;
case 1200:
return B1200;
case 1800:
return B1800;
case 2400:
return B2400;
case 4800:
return B4800;
case 9600:
return B9600;
#ifdef B19200
case 19200:
return B19200;
#else /* B19200 */
#ifdef EXTA
case 19200:
return EXTA;
#endif /* EXTA */
#endif /* B19200 */
#ifdef B38400
case 38400:
return B38400;
#else /* B38400 */
#ifdef EXTB
case 38400:
return EXTB;
#endif /* EXTB */
#endif /* B38400 */
#ifdef B7200
case 7200:
return B7200;
#endif /* B7200 */
#ifdef B14400
case 14400:
return B14400;
#endif /* B14400 */
#ifdef B28800
case 28800:
return B28800;
#endif /* B28800 */
#ifdef B57600
case 57600:
return B57600;
#endif /* B57600 */
#ifdef B76800
case 76800:
return B76800;
#endif /* B76800 */
#ifdef B115200
case 115200:
return B115200;
#endif /* B115200 */
#ifdef B230400
case 230400:
return B230400;
#endif /* B230400 */
default:
return B9600;
}
}
/*
* Encode a special character into SSH line format.
*/
static u_int
special_char_encode(cc_t c)
{
#ifdef _POSIX_VDISABLE
if (c == _POSIX_VDISABLE)
return 255;
#endif /* _POSIX_VDISABLE */
return c;
}
/*
* Decode a special character from SSH line format.
*/
static cc_t
special_char_decode(u_int c)
{
#ifdef _POSIX_VDISABLE
if (c == 255)
return _POSIX_VDISABLE;
#endif /* _POSIX_VDISABLE */
return c;
}
/*
* Encodes terminal modes for the terminal referenced by fd
* or tiop in a portable manner, and appends the modes to a packet
* being constructed.
*/
void
ssh_tty_make_modes(struct ssh *ssh, int fd, struct termios *tiop)
{
struct termios tio;
struct sshbuf *buf;
int r, ibaud, obaud;
if ((buf = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
if (tiop == NULL) {
if (fd == -1) {
debug("%s: no fd or tio", __func__);
goto end;
}
if (tcgetattr(fd, &tio) == -1) {
logit("tcgetattr: %.100s", strerror(errno));
goto end;
}
} else
tio = *tiop;
/* Store input and output baud rates. */
obaud = speed_to_baud(cfgetospeed(&tio));
ibaud = speed_to_baud(cfgetispeed(&tio));
if ((r = sshbuf_put_u8(buf, TTY_OP_OSPEED)) != 0 ||
(r = sshbuf_put_u32(buf, obaud)) != 0 ||
(r = sshbuf_put_u8(buf, TTY_OP_ISPEED)) != 0 ||
(r = sshbuf_put_u32(buf, ibaud)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
/* Store values of mode flags. */
#define TTYCHAR(NAME, OP) \
if ((r = sshbuf_put_u8(buf, OP)) != 0 || \
(r = sshbuf_put_u32(buf, \
special_char_encode(tio.c_cc[NAME]))) != 0) \
fatal("%s: buffer error: %s", __func__, ssh_err(r)); \
#define SSH_TTYMODE_IUTF8 42 /* for SSH_BUG_UTF8TTYMODE */
#define TTYMODE(NAME, FIELD, OP) \
if (OP == SSH_TTYMODE_IUTF8 && (datafellows & SSH_BUG_UTF8TTYMODE)) { \
debug3("%s: SSH_BUG_UTF8TTYMODE", __func__); \
} else if ((r = sshbuf_put_u8(buf, OP)) != 0 || \
(r = sshbuf_put_u32(buf, ((tio.FIELD & NAME) != 0))) != 0) \
fatal("%s: buffer error: %s", __func__, ssh_err(r)); \
#include "ttymodes.h"
#undef TTYCHAR
#undef TTYMODE
end:
/* Mark end of mode data. */
if ((r = sshbuf_put_u8(buf, TTY_OP_END)) != 0 ||
(r = sshpkt_put_stringb(ssh, buf)) != 0)
fatal("%s: packet error: %s", __func__, ssh_err(r));
sshbuf_free(buf);
}
/*
* Decodes terminal modes for the terminal referenced by fd in a portable
* manner from a packet being read.
*/
void
ssh_tty_parse_modes(struct ssh *ssh, int fd)
{
struct termios tio;
struct sshbuf *buf;
const u_char *data;
u_char opcode;
u_int baud, u;
int r, failure = 0;
size_t len;
if ((r = sshpkt_get_string_direct(ssh, &data, &len)) != 0)
fatal("%s: packet error: %s", __func__, ssh_err(r));
if (len == 0)
return;
if ((buf = sshbuf_from(data, len)) == NULL) {
error("%s: sshbuf_from failed", __func__);
return;
}
/*
* Get old attributes for the terminal. We will modify these
* flags. I am hoping that if there are any machine-specific
* modes, they will initially have reasonable values.
*/
if (tcgetattr(fd, &tio) == -1) {
logit("tcgetattr: %.100s", strerror(errno));
failure = -1;
}
while (sshbuf_len(buf) > 0) {
if ((r = sshbuf_get_u8(buf, &opcode)) != 0)
fatal("%s: packet error: %s", __func__, ssh_err(r));
switch (opcode) {
case TTY_OP_END:
goto set;
case TTY_OP_ISPEED:
if ((r = sshbuf_get_u32(buf, &baud)) != 0)
fatal("%s: packet error: %s",
__func__, ssh_err(r));
if (failure != -1 &&
cfsetispeed(&tio, baud_to_speed(baud)) == -1)
error("cfsetispeed failed for %d", baud);
break;
case TTY_OP_OSPEED:
if ((r = sshbuf_get_u32(buf, &baud)) != 0)
fatal("%s: packet error: %s",
__func__, ssh_err(r));
if (failure != -1 &&
cfsetospeed(&tio, baud_to_speed(baud)) == -1)
error("cfsetospeed failed for %d", baud);
break;
#define TTYCHAR(NAME, OP) \
case OP: \
if ((r = sshbuf_get_u32(buf, &u)) != 0) \
fatal("%s: packet error: %s", __func__, \
ssh_err(r)); \
tio.c_cc[NAME] = special_char_decode(u); \
break;
#define TTYMODE(NAME, FIELD, OP) \
case OP: \
if ((r = sshbuf_get_u32(buf, &u)) != 0) \
fatal("%s: packet error: %s", __func__, \
ssh_err(r)); \
if (u) \
tio.FIELD |= NAME; \
else \
tio.FIELD &= ~NAME; \
break;
#include "ttymodes.h"
#undef TTYCHAR
#undef TTYMODE
default:
debug("Ignoring unsupported tty mode opcode %d (0x%x)",
opcode, opcode);
/*
* SSH2:
* Opcodes 1 to 159 are defined to have a uint32
* argument.
* Opcodes 160 to 255 are undefined and cause parsing
* to stop.
*/
if (opcode > 0 && opcode < 160) {
if ((r = sshbuf_get_u32(buf, NULL)) != 0)
fatal("%s: packet error: %s", __func__,
ssh_err(r));
break;
} else {
logit("%s: unknown opcode %d", __func__,
opcode);
goto set;
}
}
}
set:
len = sshbuf_len(buf);
sshbuf_free(buf);
if (len > 0) {
logit("%s: %zu bytes left", __func__, len);
return; /* Don't process bytes passed */
}
if (failure == -1)
return; /* Packet parsed ok but tcgetattr() failed */
/* Set the new modes for the terminal. */
if (tcsetattr(fd, TCSANOW, &tio) == -1)
logit("Setting tty modes failed: %.100s", strerror(errno));
}