gems-kernel/source/THIRDPARTY/xnu/bsd/kern/tty_compat.c
2024-06-03 11:29:39 -05:00

821 lines
22 KiB
C

/*
* Copyright (c) 2019 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/* Copyright (c) 1997 Apple Computer, Inc. All Rights Reserved */
/*-
* Copyright (c) 1982, 1986, 1991, 1993
* The Regents of the University of California. 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
*
* @(#)tty_compat.c 8.1 (Berkeley) 6/10/93
*/
/*
* Compatibility routines for BSD 4.3 tty ioctl() commands
*
* The only function externalized from this file is ttcompat() and it is
* externalized as private extern to prevent exporting of the symbol when
* KEXTs link against the kernel.
*
* Locks: All functions in this file assume that the tty_lock()
* is held on the tty structure before these functions are
* called.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/proc_internal.h>
#include <sys/tty.h>
#include <sys/termios.h>
#include <sys/file_internal.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
static int ttcompatgetflags(struct tty *tp);
static void ttcompatsetflags(struct tty *tp, struct termios *t);
static void ttcompatsetlflags(struct tty *tp, struct termios *t);
static unsigned int ttcompatspeedtab(speed_t speed, struct speedtab *table);
/*
* These two tables encode baud rate to speed code and speed code to
* baud rate information. They are a mapping between the <sys/termios.h>
* baud rate constants and the <sys/ttydev.h> baud rate constants. We
* cannot use those constants directly here because they occupy the same
* name space.
*/
static struct speedtab compatspeeds[] = {
#define MAX_SPEED 17
{ .sp_speed = 115200, .sp_code = 17 },
{ .sp_speed = 57600, .sp_code = 16 },
{ .sp_speed = 38400, .sp_code = 15 },
{ .sp_speed = 19200, .sp_code = 14 },
{ .sp_speed = 9600, .sp_code = 13 },
{ .sp_speed = 4800, .sp_code = 12 },
{ .sp_speed = 2400, .sp_code = 11 },
{ .sp_speed = 1800, .sp_code = 10 },
{ .sp_speed = 1200, .sp_code = 9 },
{ .sp_speed = 600, .sp_code = 8 },
{ .sp_speed = 300, .sp_code = 7 },
{ .sp_speed = 200, .sp_code = 6 },
{ .sp_speed = 150, .sp_code = 5 },
{ .sp_speed = 134, .sp_code = 4 },
{ .sp_speed = 110, .sp_code = 3 },
{ .sp_speed = 75, .sp_code = 2 },
{ .sp_speed = 50, .sp_code = 1 },
{ .sp_speed = 0, .sp_code = 0 },
{ .sp_speed = -1, .sp_code = -1 },
};
static int compatspcodes[] = {
0, 50, 75, 110, 134, 150, 200, 300, 600, 1200,
1800, 2400, 4800, 9600, 19200, 38400, 57600, 115200,
};
/*
* ttcompatspeedtab
*
* Description: Given a baud rate value as a speed_t, and a speed table,
* convert the baud rate to a speed code integer, according to the
* contents of the table. This effectively changes termios.h
* baud rate values into ttydev.h baud rate codes.
*
* Parameters: speed_t speed Baud rate
* struct speedtab *table Baud rate table to speed code table
*
* Returns: 1 B50 speed code; returned if we can
* not find an answer in the table.
* 0 If a 0 was requested in order to
* trigger a hangup (250ms of line
* silence, per Bell 103C standard).
* [2, MAX_SPEED] A speed code matching the requested
* baud rate (potentially rounded down,
* if there is no exact match).
*
* Notes: This function is used for TIOCGETP, TIOCSETP, and TIOCSETN.
*/
static unsigned int
ttcompatspeedtab(speed_t speed, struct speedtab *table)
{
if (speed == 0) {
return 0; /* hangup */
}
for (; table->sp_speed > 0; table++) {
if (table->sp_speed <= speed) { /* nearest one, rounded down */
return (unsigned int)table->sp_code;
}
}
return 1; /* 50, min and not hangup */
}
/*
* ttsetcompat
*
* Description: Convert backward compatability set command arguments as
* follows:
*
* TIOCSETP -> TIOSETAF
* TIOCSETN -> TIOCSETA
* TIOCSETC -> TIOCSETA
* TIOCSLTC -> TIOCSETA
* TIOCLBIS -> TIOCSETA
* TIOCLBIC -> TIOCSETA
* TIOCLSET -> TIOCSETA
*
* The converted command argument and potentially modified 'term'
* argument are returned to ttcompat(), which will then call
* ttioctl_locked(), if this function returns successfully.
*
* Parameters struct tty *tp The tty on which the operation is
* being performed.
* u_long *com A pointer to the terminal input/output
* command being requested; its contents
* will be modified per the table above,
* on a non-error return.
* caddr_t data Command specific parameter data; this
* data is read but not modified.
* struct termios *term A local stack termios structure from
* ttcompat(), whose contents are to be
* modified based on *com and *data.
*
* Returns: EINVAL An input speed or output speed is
* outside the allowable range for a
* TIOCSETP or TIOCSETN command.
* 0 All other cases return 0.
*
* Notes: This function may modify the contents of the tp->t_flags
* field in a successful call to TIOCSETP, TIOCSETN, TIOCLBIS,
* TIOCLBIC, or TIOCLSET.
*
* All other tp fields will remain unmodifed, since the struct
* termios is a local stack copy from ttcompat(), and not the
* real thing. A subsequent call to ttioctl_locked() in
* ttcompat(), however, may result in subsequent changes.
*
* WARNING: This compatibility code is not 64/32 clean; it will only
* work for 32 bit processes on 32 bit kernels or 64 bit
* processes on 64 bit kernels. We are not addressing this
* due to <rdar://6904053>.
*/
static int
ttsetcompat(struct tty *tp, u_long *com, caddr_t data, struct termios *term)
{
switch (*com) {
case TIOCSETP:
/*
* Wait for all characters queued for output to drain, then
* Discard all characters queued for input, and then set
* the input and output speeds and device flags, per the
* contents of the struct sgttyb that 'data' points to.
*/
case TIOCSETN:
/*
* Same as TIOCSETP, but the output is not drained, and any
* pending input is not discarded.
*/
{
__IGNORE_WCASTALIGN(struct sgttyb *sg = (struct sgttyb *)data);
if (sg->sg_ispeed < 0) {
return EINVAL;
}
unsigned int ispeed = (unsigned int)sg->sg_ispeed;
if (ispeed > MAX_SPEED) {
return EINVAL;
}
if (ispeed != ttcompatspeedtab(tp->t_ispeed, compatspeeds)) {
term->c_ispeed = compatspcodes[ispeed];
} else {
term->c_ispeed = tp->t_ispeed;
}
/*
* Can't error out at the beginning due to potential for
* backwards-incompatibility. For instance:
*
* struct sgttyb sg; // uninitialized
* sg.sg_ispeed = SOME_VALID_VALUE;
*
* Should still set the input speed.
*/
if (sg->sg_ospeed < 0) {
return EINVAL;
}
unsigned int ospeed = (unsigned int)sg->sg_ospeed;
if (ospeed > MAX_SPEED) {
return EINVAL;
}
if (ospeed != ttcompatspeedtab(tp->t_ospeed, compatspeeds)) {
term->c_ospeed = compatspcodes[ospeed];
} else {
term->c_ospeed = tp->t_ospeed;
}
term->c_cc[VERASE] = sg->sg_erase;
term->c_cc[VKILL] = sg->sg_kill;
tp->t_flags = (tp->t_flags & 0xffff0000) | (sg->sg_flags & 0xffff);
ttcompatsetflags(tp, term);
*com = (*com == TIOCSETP) ? TIOCSETAF : TIOCSETA;
break;
}
case TIOCSETC:
/*
* Set the terminal control characters per the contents of
* the struct tchars that 'data' points to.
*/
{
__IGNORE_WCASTALIGN(struct tchars *tc = (struct tchars *)data);
cc_t *cc;
cc = term->c_cc;
cc[VINTR] = tc->t_intrc;
cc[VQUIT] = tc->t_quitc;
cc[VSTART] = tc->t_startc;
cc[VSTOP] = tc->t_stopc;
cc[VEOF] = tc->t_eofc;
cc[VEOL] = tc->t_brkc;
if (tc->t_brkc == -1) {
cc[VEOL2] = _POSIX_VDISABLE;
}
*com = TIOCSETA;
break;
}
case TIOCSLTC:
/*
* Set the terminal control characters per the contents of
* the struct ltchars that 'data' points to.
*/
{
__IGNORE_WCASTALIGN(struct ltchars *ltc = (struct ltchars *)data);
cc_t *cc;
cc = term->c_cc;
cc[VSUSP] = ltc->t_suspc;
cc[VDSUSP] = ltc->t_dsuspc;
cc[VREPRINT] = ltc->t_rprntc;
cc[VDISCARD] = ltc->t_flushc;
cc[VWERASE] = ltc->t_werasc;
cc[VLNEXT] = ltc->t_lnextc;
*com = TIOCSETA;
break;
}
case TIOCLBIS:
/*
* Set the bits in the terminal state local flags word
* (16 bits) for the terminal to the current bits OR
* those in the 16 bit value pointed to by 'data'.
*/
case TIOCLBIC:
/*
* Clear the bits in the terminal state local flags word
* for the terminal to the current bits AND those bits NOT
* in the 16 bit value pointed to by 'data'.
*/
case TIOCLSET:
/*
* Set the terminal state local flags word to exactly those
* bits that correspond to the 16 bit value pointed to by
* 'data'.
*/
{
__IGNORE_WCASTALIGN(int set = *(int *)data);
if (*com == TIOCLSET) {
tp->t_flags = (tp->t_flags & 0xffff) | set << 16;
} else {
tp->t_flags =
(ttcompatgetflags(tp) & 0xffff0000) | (tp->t_flags & 0xffff);
if (*com == TIOCLBIS) {
tp->t_flags |= set << 16;
} else {
tp->t_flags &= ~(set << 16);
}
}
ttcompatsetlflags(tp, term);
*com = TIOCSETA;
break;
}
}
return 0;
}
/*
* ttcompat
*
* Description: For 'set' commands, convert the command and arguments as
* necessary, and call ttioctl_locked(), returning the result
* as our result; for 'get' commands, obtain the requested data
* from the appropriate source, and return it in the expected
* format. If the command is not recognized, return EINVAL.
*
* Parameters struct tty *tp The tty on which the operation is
* being performed.
* u_long com The terminal input/output command
* being requested.
* caddr_t data The pointer to the user data argument
* provided with the command.
* int flag The file open flags (e.g. FREAD).
* struct proc *p The current process pointer for the
* operation.
*
* Returns: 0 Most 'get' operations can't fail, and
* therefore return this.
* ENOTTY TIOCGSID may return this when you
* attempt to get the session ID for a
* terminal with no associated session,
* or for which there is a session, but
* no session leader.
* ENOTTY If the command cannot be handled at
* this layer, this will be returned.
* * Any value returned by ttioctl_locked(),
* if a set command is requested.
*
* Notes: The process pointer may be a proxy on whose behalf we are
* operating, so it is not safe to simply use current_process()
* instead.
*/
/*ARGSUSED*/
__private_extern__ int
ttcompat(struct tty *tp, u_long com, caddr_t data, int flag, struct proc *p)
{
switch (com) {
case TIOCSETP:
case TIOCSETN:
case TIOCSETC:
case TIOCSLTC:
case TIOCLBIS:
case TIOCLBIC:
case TIOCLSET:
/*
* See ttsetcompat() for a full description of these command
* values and their meanings.
*/
{
struct termios term;
int error;
term = tp->t_termios;
if ((error = ttsetcompat(tp, &com, data, &term)) != 0) {
return error;
}
return ttioctl_locked(tp, com, (caddr_t) &term, flag, p);
}
case TIOCGETP:
/*
* Get the current input and output speeds, and device
* flags, into the structure pointed to by 'data'.
*/
{
__IGNORE_WCASTALIGN(struct sgttyb *sg = (struct sgttyb *)data);
cc_t *cc = tp->t_cc;
static_assert(MAX_SPEED <= CHAR_MAX, "maximum speed fits in a char");
sg->sg_ospeed = (char)ttcompatspeedtab(tp->t_ospeed, compatspeeds);
if (tp->t_ispeed == 0) {
sg->sg_ispeed = sg->sg_ospeed;
} else {
sg->sg_ispeed = (char)ttcompatspeedtab(tp->t_ispeed, compatspeeds);
}
sg->sg_erase = cc[VERASE];
sg->sg_kill = cc[VKILL];
tp->t_flags = ttcompatgetflags(tp);
sg->sg_flags = (short)tp->t_flags;
break;
}
case TIOCGETC:
/*
* Get the terminal control characters into the struct
* tchars that 'data' points to.
*/
{
struct tchars *tc = (struct tchars *)data;
cc_t *cc = tp->t_cc;
tc->t_intrc = cc[VINTR];
tc->t_quitc = cc[VQUIT];
tc->t_startc = cc[VSTART];
tc->t_stopc = cc[VSTOP];
tc->t_eofc = cc[VEOF];
tc->t_brkc = cc[VEOL];
break;
}
case TIOCGLTC:
/*
* Get the terminal control characters into the struct
* ltchars that 'data' points to.
*/
{
struct ltchars *ltc = (struct ltchars *)data;
cc_t *cc = tp->t_cc;
ltc->t_suspc = cc[VSUSP];
ltc->t_dsuspc = cc[VDSUSP];
ltc->t_rprntc = cc[VREPRINT];
ltc->t_flushc = cc[VDISCARD];
ltc->t_werasc = cc[VWERASE];
ltc->t_lnextc = cc[VLNEXT];
break;
}
case TIOCLGET:
/*
* Get the terminal state local flags word into the 16 bit
* value pointed to by 'data'.
*/
tp->t_flags =
(ttcompatgetflags(tp) & 0xffff0000UL)
| (tp->t_flags & 0xffff);
*(int *)data = tp->t_flags >> 16;
break;
case OTIOCGETD:
/*
* Get the current line discipline into the int pointed to
* by 'data'.
*/
*(int *)data = tp->t_line ? tp->t_line : 2;
break;
case OTIOCSETD:
/*
* Set the current line discipline based on the value of the
* int pointed to by 'data'.
*/
{
int ldisczero = 0;
return ttioctl_locked(tp, TIOCSETD,
*(int *)data == 2 ? (caddr_t)&ldisczero : data, flag, p);
}
case OTIOCCONS:
/*
* Become the console device.
*/
*(int *)data = 1;
return ttioctl_locked(tp, TIOCCONS, data, flag, p);
case TIOCGSID:
/*
* Get the current session ID (controlling process' PID).
*/
if (tp->t_session == NULL) {
return ENOTTY;
}
if (tp->t_session->s_leader == NULL) {
return ENOTTY;
}
*(int *) data = proc_getpid(tp->t_session->s_leader);
break;
default:
/*
* This ioctl is not handled at this layer.
*/
return ENOTTY;
}
/*
* Successful 'get' operation.
*/
return 0;
}
/*
* ttcompatgetflags
*
* Description: Get the terminal state local flags, device flags, and current
* speed code for the device (all 32 bits are returned).
*
* Parameters struct tty *tp The tty on which the operation is
* being performed.
*
* Returns: * Integer value corresponding to the
* current terminal state local flags
* word.
*
* Notes: Caller is responsible for breaking these bits back out into
* separate 16 bit filelds, if that's what was actually desired.
*/
static int
ttcompatgetflags(struct tty *tp)
{
tcflag_t iflag = tp->t_iflag;
tcflag_t lflag = tp->t_lflag;
tcflag_t oflag = tp->t_oflag;
tcflag_t cflag = tp->t_cflag;
int flags = 0;
if (iflag & IXOFF) {
flags |= TANDEM;
}
if (iflag & ICRNL || oflag & ONLCR) {
flags |= CRMOD;
}
if ((cflag & CSIZE) == CS8) {
flags |= PASS8;
if (iflag & ISTRIP) {
flags |= ANYP;
}
} else if (cflag & PARENB) {
if (iflag & INPCK) {
if (cflag & PARODD) {
flags |= ODDP;
} else {
flags |= EVENP;
}
} else {
flags |= EVENP | ODDP;
}
}
if ((lflag & ICANON) == 0) {
/* fudge */
if (iflag & (INPCK | ISTRIP | IXON) || lflag & (IEXTEN | ISIG)
|| (cflag & (CSIZE | PARENB)) != CS8) {
flags |= CBREAK;
} else {
flags |= RAW;
}
}
if (!(flags & RAW) && !(oflag & OPOST) && (cflag & (CSIZE | PARENB)) == CS8) {
flags |= LITOUT;
}
if (cflag & MDMBUF) {
flags |= MDMBUF;
}
if ((cflag & HUPCL) == 0) {
flags |= NOHANG;
}
if (oflag & OXTABS) {
flags |= XTABS;
}
if (lflag & ECHOE) {
flags |= CRTERA | CRTBS;
}
if (lflag & ECHOKE) {
flags |= CRTKIL | CRTBS;
}
if (lflag & ECHOPRT) {
flags |= PRTERA;
}
if (lflag & ECHOCTL) {
flags |= CTLECH;
}
if ((iflag & IXANY) == 0) {
flags |= DECCTQ;
}
flags |= lflag & (ECHO | TOSTOP | FLUSHO | PENDIN | NOFLSH);
return flags;
}
/*
* ttcompatsetflags
*
* Description: Given a set of compatability flags, convert the compatability
* flags in the terminal flags fields into canonical flags in the
* provided termios struct.
*
* Parameters: struct tty *tp The tty on which the operation is
* being performed.
* struct termios *t The termios structure into which to
* return the converted flags.
*
* Returns: void (implicit: *t, modified)
*/
static void
ttcompatsetflags(struct tty *tp, struct termios *t)
{
int flags = tp->t_flags;
tcflag_t iflag = t->c_iflag;
tcflag_t oflag = t->c_oflag;
tcflag_t lflag = t->c_lflag;
tcflag_t cflag = t->c_cflag;
if (flags & RAW) {
iflag = IGNBRK;
lflag &= ~(ECHOCTL | ISIG | ICANON | IEXTEN);
} else {
iflag &= ~(PARMRK | IGNPAR | IGNCR | INLCR);
iflag |= BRKINT | IXON | IMAXBEL;
lflag |= ISIG | IEXTEN | ECHOCTL; /* XXX was echoctl on ? */
if (flags & XTABS) {
oflag |= OXTABS;
} else {
oflag &= ~OXTABS;
}
if (flags & CBREAK) {
lflag &= ~ICANON;
} else {
lflag |= ICANON;
}
if (flags & CRMOD) {
iflag |= ICRNL;
oflag |= ONLCR;
} else {
iflag &= ~ICRNL;
oflag &= ~ONLCR;
}
}
if (flags & ECHO) {
lflag |= ECHO;
} else {
lflag &= ~ECHO;
}
cflag &= ~(CSIZE | PARENB);
if (flags & (RAW | LITOUT | PASS8)) {
cflag |= CS8;
if (!(flags & (RAW | PASS8))
|| (flags & (RAW | PASS8 | ANYP)) == (PASS8 | ANYP)) {
iflag |= ISTRIP;
} else {
iflag &= ~ISTRIP;
}
if (flags & (RAW | LITOUT)) {
oflag &= ~OPOST;
} else {
oflag |= OPOST;
}
} else {
cflag |= CS7 | PARENB;
iflag |= ISTRIP;
oflag |= OPOST;
}
/* XXX don't set INPCK if RAW or PASS8? */
if ((flags & (EVENP | ODDP)) == EVENP) {
iflag |= INPCK;
cflag &= ~PARODD;
} else if ((flags & (EVENP | ODDP)) == ODDP) {
iflag |= INPCK;
cflag |= PARODD;
} else {
iflag &= ~INPCK;
}
if (flags & TANDEM) {
iflag |= IXOFF;
} else {
iflag &= ~IXOFF;
}
if ((flags & DECCTQ) == 0) {
iflag |= IXANY;
} else {
iflag &= ~IXANY;
}
t->c_iflag = iflag;
t->c_oflag = oflag;
t->c_lflag = lflag;
t->c_cflag = cflag;
}
/*
* ttcompatsetlflags
*
* Description: Given a set of compatability terminal state local flags,
* convert the compatability flags in the terminal flags
* fields into canonical flags in the provided termios struct.
*
* Parameters: struct tty *tp The tty on which the operation is
* being performed.
* struct termios *t The termios structure into which to
* return the converted local flags.
*
* Returns: void (implicit: *t, modified)
*/
static void
ttcompatsetlflags(struct tty *tp, struct termios *t)
{
int flags = tp->t_flags;
tcflag_t iflag = t->c_iflag;
tcflag_t oflag = t->c_oflag;
tcflag_t lflag = t->c_lflag;
tcflag_t cflag = t->c_cflag;
iflag &= ~(PARMRK | IGNPAR | IGNCR | INLCR);
if (flags & CRTERA) {
lflag |= ECHOE;
} else {
lflag &= ~ECHOE;
}
if (flags & CRTKIL) {
lflag |= ECHOKE;
} else {
lflag &= ~ECHOKE;
}
if (flags & PRTERA) {
lflag |= ECHOPRT;
} else {
lflag &= ~ECHOPRT;
}
if (flags & CTLECH) {
lflag |= ECHOCTL;
} else {
lflag &= ~ECHOCTL;
}
if (flags & TANDEM) {
iflag |= IXOFF;
} else {
iflag &= ~IXOFF;
}
if ((flags & DECCTQ) == 0) {
iflag |= IXANY;
} else {
iflag &= ~IXANY;
}
if (flags & MDMBUF) {
cflag |= MDMBUF;
} else {
cflag &= ~MDMBUF;
}
if (flags & NOHANG) {
cflag &= ~HUPCL;
} else {
cflag |= HUPCL;
}
lflag &= ~(TOSTOP | FLUSHO | PENDIN | NOFLSH);
lflag |= flags & (TOSTOP | FLUSHO | PENDIN | NOFLSH);
/*
* The next if-else statement is copied from above so don't bother
* checking it separately. We could avoid fiddlling with the
* character size if the mode is already RAW or if neither the
* LITOUT bit or the PASS8 bit is being changed, but the delta of
* the change is not available here and skipping the RAW case would
* make the code different from above.
*/
cflag &= ~(CSIZE | PARENB);
if (flags & (RAW | LITOUT | PASS8)) {
cflag |= CS8;
if (!(flags & (RAW | PASS8))
|| (flags & (RAW | PASS8 | ANYP)) == (PASS8 | ANYP)) {
iflag |= ISTRIP;
} else {
iflag &= ~ISTRIP;
}
if (flags & (RAW | LITOUT)) {
oflag &= ~OPOST;
} else {
oflag |= OPOST;
}
} else {
cflag |= CS7 | PARENB;
iflag |= ISTRIP;
oflag |= OPOST;
}
t->c_iflag = iflag;
t->c_oflag = oflag;
t->c_lflag = lflag;
t->c_cflag = cflag;
}