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b76f24f759
freebsd-skq/sys/kern/tty.c
Archie Cobbs b76f24f759 Fix a bug where SIGIO was not being delivered to a process requesting 
async I/O when a tty device became writable.

PR:		kern/8324
Submitted by:	Don Lewis <Don.Lewis@tsc.tdk.com>
2000-04-05 18:38:21 +00:00

2478 lines
57 KiB
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/*-
* Copyright (c) 1982, 1986, 1990, 1991, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* 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.c 8.8 (Berkeley) 1/21/94
* $FreeBSD$
*/
/*-
* TODO:
* o Fix races for sending the start char in ttyflush().
* o Handle inter-byte timeout for "MIN > 0, TIME > 0" in ttyselect().
* With luck, there will be MIN chars before select() returns().
* o Handle CLOCAL consistently for ptys. Perhaps disallow setting it.
* o Don't allow input in TS_ZOMBIE case. It would be visible through
* FIONREAD.
* o Do the new sio locking stuff here and use it to avoid special
* case for EXTPROC?
* o Lock PENDIN too?
* o Move EXTPROC and/or PENDIN to t_state?
* o Wrap most of ttioctl in spltty/splx.
* o Implement TIOCNOTTY or remove it from <sys/ioctl.h>.
* o Send STOP if IXOFF is toggled off while TS_TBLOCK is set.
* o Don't allow certain termios flags to affect disciplines other
* than TTYDISC. Cancel their effects before switch disciplines
* and ignore them if they are set while we are in another
* discipline.
* o Now that historical speed conversions are handled here, don't
* do them in drivers.
* o Check for TS_CARR_ON being set while everything is closed and not
* waiting for carrier. TS_CARR_ON isn't cleared if nothing is open,
* so it would live until the next open even if carrier drops.
* o Restore TS_WOPEN since it is useful in pstat. It must be cleared
* only when _all_ openers leave open().
*/
#include "snp.h"
#include "opt_compat.h"
#include "opt_uconsole.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/filio.h>
#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
#include <sys/ioctl_compat.h>
#endif
#include <sys/proc.h>
#define TTYDEFCHARS
#include <sys/tty.h>
#undef TTYDEFCHARS
#include <sys/fcntl.h>
#include <sys/conf.h>
#include <sys/dkstat.h>
#include <sys/poll.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/signalvar.h>
#include <sys/resourcevar.h>
#include <sys/malloc.h>
#include <sys/filedesc.h>
#if NSNP > 0
#include <sys/snoop.h>
#endif
#include <sys/sysctl.h>
#include <vm/vm.h>
#include <sys/lock.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
MALLOC_DEFINE(M_TTYS, "ttys", "tty data structures");
static int proc_compare __P((struct proc *p1, struct proc *p2));
static int ttnread __P((struct tty *tp));
static void ttyecho __P((int c, struct tty *tp));
static int ttyoutput __P((int c, register struct tty *tp));
static void ttypend __P((struct tty *tp));
static void ttyretype __P((struct tty *tp));
static void ttyrub __P((int c, struct tty *tp));
static void ttyrubo __P((struct tty *tp, int cnt));
static void ttyunblock __P((struct tty *tp));
static int ttywflush __P((struct tty *tp));
/*
* Table with character classes and parity. The 8th bit indicates parity,
* the 7th bit indicates the character is an alphameric or underscore (for
* ALTWERASE), and the low 6 bits indicate delay type. If the low 6 bits
* are 0 then the character needs no special processing on output; classes
* other than 0 might be translated or (not currently) require delays.
*/
#define E 0x00 /* Even parity. */
#define O 0x80 /* Odd parity. */
#define PARITY(c) (char_type[c] & O)
#define ALPHA 0x40 /* Alpha or underscore. */
#define ISALPHA(c) (char_type[(c) & TTY_CHARMASK] & ALPHA)
#define CCLASSMASK 0x3f
#define CCLASS(c) (char_type[c] & CCLASSMASK)
#define BS BACKSPACE
#define CC CONTROL
#define CR RETURN
#define NA ORDINARY | ALPHA
#define NL NEWLINE
#define NO ORDINARY
#define TB TAB
#define VT VTAB
static u_char const char_type[] = {
E|CC, O|CC, O|CC, E|CC, O|CC, E|CC, E|CC, O|CC, /* nul - bel */
O|BS, E|TB, E|NL, O|CC, E|VT, O|CR, O|CC, E|CC, /* bs - si */
O|CC, E|CC, E|CC, O|CC, E|CC, O|CC, O|CC, E|CC, /* dle - etb */
E|CC, O|CC, O|CC, E|CC, O|CC, E|CC, E|CC, O|CC, /* can - us */
O|NO, E|NO, E|NO, O|NO, E|NO, O|NO, O|NO, E|NO, /* sp - ' */
E|NO, O|NO, O|NO, E|NO, O|NO, E|NO, E|NO, O|NO, /* ( - / */
E|NA, O|NA, O|NA, E|NA, O|NA, E|NA, E|NA, O|NA, /* 0 - 7 */
O|NA, E|NA, E|NO, O|NO, E|NO, O|NO, O|NO, E|NO, /* 8 - ? */
O|NO, E|NA, E|NA, O|NA, E|NA, O|NA, O|NA, E|NA, /* @ - G */
E|NA, O|NA, O|NA, E|NA, O|NA, E|NA, E|NA, O|NA, /* H - O */
E|NA, O|NA, O|NA, E|NA, O|NA, E|NA, E|NA, O|NA, /* P - W */
O|NA, E|NA, E|NA, O|NO, E|NO, O|NO, O|NO, O|NA, /* X - _ */
E|NO, O|NA, O|NA, E|NA, O|NA, E|NA, E|NA, O|NA, /* ` - g */
O|NA, E|NA, E|NA, O|NA, E|NA, O|NA, O|NA, E|NA, /* h - o */
O|NA, E|NA, E|NA, O|NA, E|NA, O|NA, O|NA, E|NA, /* p - w */
E|NA, O|NA, O|NA, E|NO, O|NO, E|NO, E|NO, O|CC, /* x - del */
/*
* Meta chars; should be settable per character set;
* for now, treat them all as normal characters.
*/
NA, NA, NA, NA, NA, NA, NA, NA,
NA, NA, NA, NA, NA, NA, NA, NA,
NA, NA, NA, NA, NA, NA, NA, NA,
NA, NA, NA, NA, NA, NA, NA, NA,
NA, NA, NA, NA, NA, NA, NA, NA,
NA, NA, NA, NA, NA, NA, NA, NA,
NA, NA, NA, NA, NA, NA, NA, NA,
NA, NA, NA, NA, NA, NA, NA, NA,
NA, NA, NA, NA, NA, NA, NA, NA,
NA, NA, NA, NA, NA, NA, NA, NA,
NA, NA, NA, NA, NA, NA, NA, NA,
NA, NA, NA, NA, NA, NA, NA, NA,
NA, NA, NA, NA, NA, NA, NA, NA,
NA, NA, NA, NA, NA, NA, NA, NA,
NA, NA, NA, NA, NA, NA, NA, NA,
NA, NA, NA, NA, NA, NA, NA, NA,
};
#undef BS
#undef CC
#undef CR
#undef NA
#undef NL
#undef NO
#undef TB
#undef VT
/* Macros to clear/set/test flags. */
#define SET(t, f) (t) |= (f)
#define CLR(t, f) (t) &= ~(f)
#define ISSET(t, f) ((t) & (f))
#undef MAX_INPUT /* XXX wrong in <sys/syslimits.h> */
#define MAX_INPUT TTYHOG /* XXX limit is usually larger for !ICANON */
/*
* list of struct tty where pstat(8) can pick it up with sysctl
*/
static SLIST_HEAD(, tty) tty_list;
/*
* Initial open of tty, or (re)entry to standard tty line discipline.
*/
int
ttyopen(device, tp)
dev_t device;
register struct tty *tp;
{
int s;
s = spltty();
tp->t_dev = device;
if (!ISSET(tp->t_state, TS_ISOPEN)) {
SET(tp->t_state, TS_ISOPEN);
if (ISSET(tp->t_cflag, CLOCAL))
SET(tp->t_state, TS_CONNECTED);
bzero(&tp->t_winsize, sizeof(tp->t_winsize));
}
ttsetwater(tp);
splx(s);
return (0);
}
/*
* Handle close() on a tty line: flush and set to initial state,
* bumping generation number so that pending read/write calls
* can detect recycling of the tty.
* XXX our caller should have done `spltty(); l_close(); ttyclose();'
* and l_close() should have flushed, but we repeat the spltty() and
* the flush in case there are buggy callers.
*/
int
ttyclose(tp)
register struct tty *tp;
{
int s;
funsetown(tp->t_sigio);
s = spltty();
if (constty == tp)
constty = NULL;
ttyflush(tp, FREAD | FWRITE);
clist_free_cblocks(&tp->t_canq);
clist_free_cblocks(&tp->t_outq);
clist_free_cblocks(&tp->t_rawq);
#if NSNP > 0
if (ISSET(tp->t_state, TS_SNOOP) && tp->t_sc != NULL)
snpdown((struct snoop *)tp->t_sc);
#endif
tp->t_gen++;
tp->t_line = TTYDISC;
tp->t_pgrp = NULL;
tp->t_session = NULL;
tp->t_state = 0;
splx(s);
return (0);
}
#define FLUSHQ(q) { \
if ((q)->c_cc) \
ndflush(q, (q)->c_cc); \
}
/* Is 'c' a line delimiter ("break" character)? */
#define TTBREAKC(c, lflag) \
((c) == '\n' || (((c) == cc[VEOF] || \
(c) == cc[VEOL] || ((c) == cc[VEOL2] && lflag & IEXTEN)) && \
(c) != _POSIX_VDISABLE))
/*
* Process input of a single character received on a tty.
*/
int
ttyinput(c, tp)
register int c;
register struct tty *tp;
{
register tcflag_t iflag, lflag;
register cc_t *cc;
int i, err;
/*
* If input is pending take it first.
*/
lflag = tp->t_lflag;
if (ISSET(lflag, PENDIN))
ttypend(tp);
/*
* Gather stats.
*/
if (ISSET(lflag, ICANON)) {
++tk_cancc;
++tp->t_cancc;
} else {
++tk_rawcc;
++tp->t_rawcc;
}
++tk_nin;
/*
* Block further input iff:
* current input > threshold AND input is available to user program
* AND input flow control is enabled and not yet invoked.
* The 3 is slop for PARMRK.
*/
iflag = tp->t_iflag;
if (tp->t_rawq.c_cc + tp->t_canq.c_cc > tp->t_ihiwat - 3 &&
(!ISSET(lflag, ICANON) || tp->t_canq.c_cc != 0) &&
(ISSET(tp->t_cflag, CRTS_IFLOW) || ISSET(iflag, IXOFF)) &&
!ISSET(tp->t_state, TS_TBLOCK))
ttyblock(tp);
/* Handle exceptional conditions (break, parity, framing). */
cc = tp->t_cc;
err = (ISSET(c, TTY_ERRORMASK));
if (err) {
CLR(c, TTY_ERRORMASK);
if (ISSET(err, TTY_BI)) {
if (ISSET(iflag, IGNBRK))
return (0);
if (ISSET(iflag, BRKINT)) {
ttyflush(tp, FREAD | FWRITE);
pgsignal(tp->t_pgrp, SIGINT, 1);
goto endcase;
}
if (ISSET(iflag, PARMRK))
goto parmrk;
} else if ((ISSET(err, TTY_PE) && ISSET(iflag, INPCK))
|| ISSET(err, TTY_FE)) {
if (ISSET(iflag, IGNPAR))
return (0);
else if (ISSET(iflag, PARMRK)) {
parmrk:
if (tp->t_rawq.c_cc + tp->t_canq.c_cc >
MAX_INPUT - 3)
goto input_overflow;
(void)putc(0377 | TTY_QUOTE, &tp->t_rawq);
(void)putc(0 | TTY_QUOTE, &tp->t_rawq);
(void)putc(c | TTY_QUOTE, &tp->t_rawq);
goto endcase;
} else
c = 0;
}
}
if (!ISSET(tp->t_state, TS_TYPEN) && ISSET(iflag, ISTRIP))
CLR(c, 0x80);
if (!ISSET(lflag, EXTPROC)) {
/*
* Check for literal nexting very first
*/
if (ISSET(tp->t_state, TS_LNCH)) {
SET(c, TTY_QUOTE);
CLR(tp->t_state, TS_LNCH);
}
/*
* Scan for special characters. This code
* is really just a big case statement with
* non-constant cases. The bottom of the
* case statement is labeled ``endcase'', so goto
* it after a case match, or similar.
*/
/*
* Control chars which aren't controlled
* by ICANON, ISIG, or IXON.
*/
if (ISSET(lflag, IEXTEN)) {
if (CCEQ(cc[VLNEXT], c)) {
if (ISSET(lflag, ECHO)) {
if (ISSET(lflag, ECHOE)) {
(void)ttyoutput('^', tp);
(void)ttyoutput('\b', tp);
} else
ttyecho(c, tp);
}
SET(tp->t_state, TS_LNCH);
goto endcase;
}
if (CCEQ(cc[VDISCARD], c)) {
if (ISSET(lflag, FLUSHO))
CLR(tp->t_lflag, FLUSHO);
else {
ttyflush(tp, FWRITE);
ttyecho(c, tp);
if (tp->t_rawq.c_cc + tp->t_canq.c_cc)
ttyretype(tp);
SET(tp->t_lflag, FLUSHO);
}
goto startoutput;
}
}
/*
* Signals.
*/
if (ISSET(lflag, ISIG)) {
if (CCEQ(cc[VINTR], c) || CCEQ(cc[VQUIT], c)) {
if (!ISSET(lflag, NOFLSH))
ttyflush(tp, FREAD | FWRITE);
ttyecho(c, tp);
pgsignal(tp->t_pgrp,
CCEQ(cc[VINTR], c) ? SIGINT : SIGQUIT, 1);
goto endcase;
}
if (CCEQ(cc[VSUSP], c)) {
if (!ISSET(lflag, NOFLSH))
ttyflush(tp, FREAD);
ttyecho(c, tp);
pgsignal(tp->t_pgrp, SIGTSTP, 1);
goto endcase;
}
}
/*
* Handle start/stop characters.
*/
if (ISSET(iflag, IXON)) {
if (CCEQ(cc[VSTOP], c)) {
if (!ISSET(tp->t_state, TS_TTSTOP)) {
SET(tp->t_state, TS_TTSTOP);
(*tp->t_stop)(tp, 0);
return (0);
}
if (!CCEQ(cc[VSTART], c))
return (0);
/*
* if VSTART == VSTOP then toggle
*/
goto endcase;
}
if (CCEQ(cc[VSTART], c))
goto restartoutput;
}
/*
* IGNCR, ICRNL, & INLCR
*/
if (c == '\r') {
if (ISSET(iflag, IGNCR))
return (0);
else if (ISSET(iflag, ICRNL))
c = '\n';
} else if (c == '\n' && ISSET(iflag, INLCR))
c = '\r';
}
if (!ISSET(tp->t_lflag, EXTPROC) && ISSET(lflag, ICANON)) {
/*
* From here on down canonical mode character
* processing takes place.
*/
/*
* erase (^H / ^?)
*/
if (CCEQ(cc[VERASE], c)) {
if (tp->t_rawq.c_cc)
ttyrub(unputc(&tp->t_rawq), tp);
goto endcase;
}
/*
* kill (^U)
*/
if (CCEQ(cc[VKILL], c)) {
if (ISSET(lflag, ECHOKE) &&
tp->t_rawq.c_cc == tp->t_rocount &&
!ISSET(lflag, ECHOPRT))
while (tp->t_rawq.c_cc)
ttyrub(unputc(&tp->t_rawq), tp);
else {
ttyecho(c, tp);
if (ISSET(lflag, ECHOK) ||
ISSET(lflag, ECHOKE))
ttyecho('\n', tp);
FLUSHQ(&tp->t_rawq);
tp->t_rocount = 0;
}
CLR(tp->t_state, TS_LOCAL);
goto endcase;
}
/*
* word erase (^W)
*/
if (CCEQ(cc[VWERASE], c) && ISSET(lflag, IEXTEN)) {
int ctype;
/*
* erase whitespace
*/
while ((c = unputc(&tp->t_rawq)) == ' ' || c == '\t')
ttyrub(c, tp);
if (c == -1)
goto endcase;
/*
* erase last char of word and remember the
* next chars type (for ALTWERASE)
*/
ttyrub(c, tp);
c = unputc(&tp->t_rawq);
if (c == -1)
goto endcase;
if (c == ' ' || c == '\t') {
(void)putc(c, &tp->t_rawq);
goto endcase;
}
ctype = ISALPHA(c);
/*
* erase rest of word
*/
do {
ttyrub(c, tp);
c = unputc(&tp->t_rawq);
if (c == -1)
goto endcase;
} while (c != ' ' && c != '\t' &&
(!ISSET(lflag, ALTWERASE) || ISALPHA(c) == ctype));
(void)putc(c, &tp->t_rawq);
goto endcase;
}
/*
* reprint line (^R)
*/
if (CCEQ(cc[VREPRINT], c) && ISSET(lflag, IEXTEN)) {
ttyretype(tp);
goto endcase;
}
/*
* ^T - kernel info and generate SIGINFO
*/
if (CCEQ(cc[VSTATUS], c) && ISSET(lflag, IEXTEN)) {
if (ISSET(lflag, ISIG))
pgsignal(tp->t_pgrp, SIGINFO, 1);
if (!ISSET(lflag, NOKERNINFO))
ttyinfo(tp);
goto endcase;
}
}
/*
* Check for input buffer overflow
*/
if (tp->t_rawq.c_cc + tp->t_canq.c_cc >= MAX_INPUT) {
input_overflow:
if (ISSET(iflag, IMAXBEL)) {
if (tp->t_outq.c_cc < tp->t_ohiwat)
(void)ttyoutput(CTRL('g'), tp);
}
goto endcase;
}
if ( c == 0377 && ISSET(iflag, PARMRK) && !ISSET(iflag, ISTRIP)
&& ISSET(iflag, IGNBRK|IGNPAR) != (IGNBRK|IGNPAR))
(void)putc(0377 | TTY_QUOTE, &tp->t_rawq);
/*
* Put data char in q for user and
* wakeup on seeing a line delimiter.
*/
if (putc(c, &tp->t_rawq) >= 0) {
if (!ISSET(lflag, ICANON)) {
ttwakeup(tp);
ttyecho(c, tp);
goto endcase;
}
if (TTBREAKC(c, lflag)) {
tp->t_rocount = 0;
catq(&tp->t_rawq, &tp->t_canq);
ttwakeup(tp);
} else if (tp->t_rocount++ == 0)
tp->t_rocol = tp->t_column;
if (ISSET(tp->t_state, TS_ERASE)) {
/*
* end of prterase \.../
*/
CLR(tp->t_state, TS_ERASE);
(void)ttyoutput('/', tp);
}
i = tp->t_column;
ttyecho(c, tp);
if (CCEQ(cc[VEOF], c) && ISSET(lflag, ECHO)) {
/*
* Place the cursor over the '^' of the ^D.
*/
i = imin(2, tp->t_column - i);
while (i > 0) {
(void)ttyoutput('\b', tp);
i--;
}
}
}
endcase:
/*
* IXANY means allow any character to restart output.
*/
if (ISSET(tp->t_state, TS_TTSTOP) &&
!ISSET(iflag, IXANY) && cc[VSTART] != cc[VSTOP])
return (0);
restartoutput:
CLR(tp->t_lflag, FLUSHO);
CLR(tp->t_state, TS_TTSTOP);
startoutput:
return (ttstart(tp));
}
/*
* Output a single character on a tty, doing output processing
* as needed (expanding tabs, newline processing, etc.).
* Returns < 0 if succeeds, otherwise returns char to resend.
* Must be recursive.
*/
static int
ttyoutput(c, tp)
register int c;
register struct tty *tp;
{
register tcflag_t oflag;
register int col, s;
oflag = tp->t_oflag;
if (!ISSET(oflag, OPOST)) {
if (ISSET(tp->t_lflag, FLUSHO))
return (-1);
if (putc(c, &tp->t_outq))
return (c);
tk_nout++;
tp->t_outcc++;
return (-1);
}
/*
* Do tab expansion if OXTABS is set. Special case if we external
* processing, we don't do the tab expansion because we'll probably
* get it wrong. If tab expansion needs to be done, let it happen
* externally.
*/
CLR(c, ~TTY_CHARMASK);
if (c == '\t' &&
ISSET(oflag, OXTABS) && !ISSET(tp->t_lflag, EXTPROC)) {
c = 8 - (tp->t_column & 7);
if (!ISSET(tp->t_lflag, FLUSHO)) {
s = spltty(); /* Don't interrupt tabs. */
c -= b_to_q(" ", c, &tp->t_outq);
tk_nout += c;
tp->t_outcc += c;
splx(s);
}
tp->t_column += c;
return (c ? -1 : '\t');
}
if (c == CEOT && ISSET(oflag, ONOEOT))
return (-1);
/*
* Newline translation: if ONLCR is set,
* translate newline into "\r\n".
*/
if (c == '\n' && ISSET(tp->t_oflag, ONLCR)) {
tk_nout++;
tp->t_outcc++;
if (putc('\r', &tp->t_outq))
return (c);
}
tk_nout++;
tp->t_outcc++;
if (!ISSET(tp->t_lflag, FLUSHO) && putc(c, &tp->t_outq))
return (c);
col = tp->t_column;
switch (CCLASS(c)) {
case BACKSPACE:
if (col > 0)
--col;
break;
case CONTROL:
break;
case NEWLINE:
case RETURN:
col = 0;
break;
case ORDINARY:
++col;
break;
case TAB:
col = (col + 8) & ~7;
break;
}
tp->t_column = col;
return (-1);
}
/*
* Ioctls for all tty devices. Called after line-discipline specific ioctl
* has been called to do discipline-specific functions and/or reject any
* of these ioctl commands.
*/
/* ARGSUSED */
int
ttioctl(tp, cmd, data, flag)
register struct tty *tp;
u_long cmd;
int flag;
void *data;
{
register struct proc *p;
int s, error;
p = curproc; /* XXX */
/* If the ioctl involves modification, hang if in the background. */
switch (cmd) {
case TIOCCBRK:
case TIOCCONS:
case TIOCDRAIN:
case TIOCEXCL:
case TIOCFLUSH:
#ifdef TIOCHPCL
case TIOCHPCL:
#endif
case TIOCNXCL:
case TIOCSBRK:
case TIOCSCTTY:
case TIOCSDRAINWAIT:
case TIOCSETA:
case TIOCSETAF:
case TIOCSETAW:
case TIOCSETD:
case TIOCSPGRP:
case TIOCSTART:
case TIOCSTAT:
case TIOCSTI:
case TIOCSTOP:
case TIOCSWINSZ:
#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
case TIOCLBIC:
case TIOCLBIS:
case TIOCLSET:
case TIOCSETC:
case OTIOCSETD:
case TIOCSETN:
case TIOCSETP:
case TIOCSLTC:
#endif
while (isbackground(p, tp) && !(p->p_flag & P_PPWAIT) &&
!SIGISMEMBER(p->p_sigignore, SIGTTOU) &&
!SIGISMEMBER(p->p_sigmask, SIGTTOU)) {
if (p->p_pgrp->pg_jobc == 0)
return (EIO);
pgsignal(p->p_pgrp, SIGTTOU, 1);
error = ttysleep(tp, &lbolt, TTOPRI | PCATCH, "ttybg1",
0);
if (error)
return (error);
}
break;
}
switch (cmd) { /* Process the ioctl. */
case FIOASYNC: /* set/clear async i/o */
s = spltty();
if (*(int *)data)
SET(tp->t_state, TS_ASYNC);
else
CLR(tp->t_state, TS_ASYNC);
splx(s);
break;
case FIONBIO: /* set/clear non-blocking i/o */
break; /* XXX: delete. */
case FIONREAD: /* get # bytes to read */
s = spltty();
*(int *)data = ttnread(tp);
splx(s);
break;
case FIOSETOWN:
/*
* Policy -- Don't allow FIOSETOWN on someone else's
* controlling tty
*/
if (tp->t_session != NULL && !isctty(p, tp))
return (ENOTTY);
error = fsetown(*(int *)data, &tp->t_sigio);
if (error)
return (error);
break;
case FIOGETOWN:
if (tp->t_session != NULL && !isctty(p, tp))
return (ENOTTY);
*(int *)data = fgetown(tp->t_sigio);
break;
case TIOCEXCL: /* set exclusive use of tty */
s = spltty();
SET(tp->t_state, TS_XCLUDE);
splx(s);
break;
case TIOCFLUSH: { /* flush buffers */
register int flags = *(int *)data;
if (flags == 0)
flags = FREAD | FWRITE;
else
flags &= FREAD | FWRITE;
ttyflush(tp, flags);
break;
}
case TIOCCONS: /* become virtual console */
if (*(int *)data) {
if (constty && constty != tp &&
ISSET(constty->t_state, TS_CONNECTED))
return (EBUSY);
#ifndef UCONSOLE
if ((error = suser(p)) != 0)
return (error);
#endif
constty = tp;
} else if (tp == constty)
constty = NULL;
break;
case TIOCDRAIN: /* wait till output drained */
error = ttywait(tp);
if (error)
return (error);
break;
case TIOCGETA: { /* get termios struct */
struct termios *t = (struct termios *)data;
bcopy(&tp->t_termios, t, sizeof(struct termios));
break;
}
case TIOCGETD: /* get line discipline */
*(int *)data = tp->t_line;
break;
case TIOCGWINSZ: /* get window size */
*(struct winsize *)data = tp->t_winsize;
break;
case TIOCGPGRP: /* get pgrp of tty */
if (!isctty(p, tp))
return (ENOTTY);
*(int *)data = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PID;
break;
#ifdef TIOCHPCL
case TIOCHPCL: /* hang up on last close */
s = spltty();
SET(tp->t_cflag, HUPCL);
splx(s);
break;
#endif
case TIOCNXCL: /* reset exclusive use of tty */
s = spltty();
CLR(tp->t_state, TS_XCLUDE);
splx(s);
break;
case TIOCOUTQ: /* output queue size */
*(int *)data = tp->t_outq.c_cc;
break;
case TIOCSETA: /* set termios struct */
case TIOCSETAW: /* drain output, set */
case TIOCSETAF: { /* drn out, fls in, set */
register struct termios *t = (struct termios *)data;
if (t->c_ispeed == 0)
t->c_ispeed = t->c_ospeed;
if (t->c_ispeed == 0)
t->c_ispeed = tp->t_ospeed;
if (t->c_ispeed == 0)
return (EINVAL);
s = spltty();
if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
error = ttywait(tp);
if (error) {
splx(s);
return (error);
}
if (cmd == TIOCSETAF)
ttyflush(tp, FREAD);
}
if (!ISSET(t->c_cflag, CIGNORE)) {
/*
* Set device hardware.
*/
if (tp->t_param && (error = (*tp->t_param)(tp, t))) {
splx(s);
return (error);
}
if (ISSET(t->c_cflag, CLOCAL) &&
!ISSET(tp->t_cflag, CLOCAL)) {
/*
* XXX disconnections would be too hard to
* get rid of without this kludge. The only
* way to get rid of controlling terminals
* is to exit from the session leader.
*/
CLR(tp->t_state, TS_ZOMBIE);
wakeup(TSA_CARR_ON(tp));
ttwakeup(tp);
ttwwakeup(tp);
}
if ((ISSET(tp->t_state, TS_CARR_ON) ||
ISSET(t->c_cflag, CLOCAL)) &&
!ISSET(tp->t_state, TS_ZOMBIE))
SET(tp->t_state, TS_CONNECTED);
else
CLR(tp->t_state, TS_CONNECTED);
tp->t_cflag = t->c_cflag;
tp->t_ispeed = t->c_ispeed;
if (t->c_ospeed != 0)
tp->t_ospeed = t->c_ospeed;
ttsetwater(tp);
}
if (ISSET(t->c_lflag, ICANON) != ISSET(tp->t_lflag, ICANON) &&
cmd != TIOCSETAF) {
if (ISSET(t->c_lflag, ICANON))
SET(tp->t_lflag, PENDIN);
else {
/*
* XXX we really shouldn't allow toggling
* ICANON while we're in a non-termios line
* discipline. Now we have to worry about
* panicing for a null queue.
*/
if (tp->t_canq.c_cbreserved > 0 &&
tp->t_rawq.c_cbreserved > 0) {
catq(&tp->t_rawq, &tp->t_canq);
/*
* XXX the queue limits may be
* different, so the old queue
* swapping method no longer works.
*/
catq(&tp->t_canq, &tp->t_rawq);
}
CLR(tp->t_lflag, PENDIN);
}
ttwakeup(tp);
}
tp->t_iflag = t->c_iflag;
tp->t_oflag = t->c_oflag;
/*
* Make the EXTPROC bit read only.
*/
if (ISSET(tp->t_lflag, EXTPROC))
SET(t->c_lflag, EXTPROC);
else
CLR(t->c_lflag, EXTPROC);
tp->t_lflag = t->c_lflag | ISSET(tp->t_lflag, PENDIN);
if (t->c_cc[VMIN] != tp->t_cc[VMIN] ||
t->c_cc[VTIME] != tp->t_cc[VTIME])
ttwakeup(tp);
bcopy(t->c_cc, tp->t_cc, sizeof(t->c_cc));
splx(s);
break;
}
case TIOCSETD: { /* set line discipline */
register int t = *(int *)data;
dev_t device = tp->t_dev;
if ((u_int)t >= nlinesw)
return (ENXIO);
if (t != tp->t_line) {
s = spltty();
(*linesw[tp->t_line].l_close)(tp, flag);
error = (*linesw[t].l_open)(device, tp);
if (error) {
(void)(*linesw[tp->t_line].l_open)(device, tp);
splx(s);
return (error);
}
tp->t_line = t;
splx(s);
}
break;
}
case TIOCSTART: /* start output, like ^Q */
s = spltty();
if (ISSET(tp->t_state, TS_TTSTOP) ||
ISSET(tp->t_lflag, FLUSHO)) {
CLR(tp->t_lflag, FLUSHO);
CLR(tp->t_state, TS_TTSTOP);
ttstart(tp);
}
splx(s);
break;
case TIOCSTI: /* simulate terminal input */
if ((flag & FREAD) == 0 && suser(p))
return (EPERM);
if (!isctty(p, tp) && suser(p))
return (EACCES);
s = spltty();
(*linesw[tp->t_line].l_rint)(*(u_char *)data, tp);
splx(s);
break;
case TIOCSTOP: /* stop output, like ^S */
s = spltty();
if (!ISSET(tp->t_state, TS_TTSTOP)) {
SET(tp->t_state, TS_TTSTOP);
(*tp->t_stop)(tp, 0);
}
splx(s);
break;
case TIOCSCTTY: /* become controlling tty */
/* Session ctty vnode pointer set in vnode layer. */
if (!SESS_LEADER(p) ||
((p->p_session->s_ttyvp || tp->t_session) &&
(tp->t_session != p->p_session)))
return (EPERM);
tp->t_session = p->p_session;
tp->t_pgrp = p->p_pgrp;
p->p_session->s_ttyp = tp;
p->p_flag |= P_CONTROLT;
break;
case TIOCSPGRP: { /* set pgrp of tty */
register struct pgrp *pgrp = pgfind(*(int *)data);
if (!isctty(p, tp))
return (ENOTTY);
else if (pgrp == NULL || pgrp->pg_session != p->p_session)
return (EPERM);
tp->t_pgrp = pgrp;
break;
}
case TIOCSTAT: /* simulate control-T */
s = spltty();
ttyinfo(tp);
splx(s);
break;
case TIOCSWINSZ: /* set window size */
if (bcmp((caddr_t)&tp->t_winsize, data,
sizeof (struct winsize))) {
tp->t_winsize = *(struct winsize *)data;
pgsignal(tp->t_pgrp, SIGWINCH, 1);
}
break;
case TIOCSDRAINWAIT:
error = suser(p);
if (error)
return (error);
tp->t_timeout = *(int *)data * hz;
wakeup(TSA_OCOMPLETE(tp));
wakeup(TSA_OLOWAT(tp));
break;
case TIOCGDRAINWAIT:
*(int *)data = tp->t_timeout / hz;
break;
default:
#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
return (ttcompat(tp, cmd, data, flag));
#else
return (ENOIOCTL);
#endif
}
return (0);
}
int
ttypoll(dev, events, p)
dev_t dev;
int events;
struct proc *p;
{
int s;
int revents = 0;
struct tty *tp;
tp = dev->si_tty;
if (tp == NULL) /* XXX used to return ENXIO, but that means true! */
return ((events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM))
| POLLHUP);
s = spltty();
if (events & (POLLIN | POLLRDNORM)) {
if (ttnread(tp) > 0 || ISSET(tp->t_state, TS_ZOMBIE))
revents |= events & (POLLIN | POLLRDNORM);
else
selrecord(p, &tp->t_rsel);
}
if (events & (POLLOUT | POLLWRNORM)) {
if ((tp->t_outq.c_cc <= tp->t_olowat &&
ISSET(tp->t_state, TS_CONNECTED))
|| ISSET(tp->t_state, TS_ZOMBIE))
revents |= events & (POLLOUT | POLLWRNORM);
else
selrecord(p, &tp->t_wsel);
}
splx(s);
return (revents);
}
/*
* Must be called at spltty().
*/
static int
ttnread(tp)
struct tty *tp;
{
int nread;
if (ISSET(tp->t_lflag, PENDIN))
ttypend(tp);
nread = tp->t_canq.c_cc;
if (!ISSET(tp->t_lflag, ICANON)) {
nread += tp->t_rawq.c_cc;
if (nread < tp->t_cc[VMIN] && tp->t_cc[VTIME] == 0)
nread = 0;
}
return (nread);
}
/*
* Wait for output to drain.
*/
int
ttywait(tp)
register struct tty *tp;
{
int error, s;
error = 0;
s = spltty();
while ((tp->t_outq.c_cc || ISSET(tp->t_state, TS_BUSY)) &&
ISSET(tp->t_state, TS_CONNECTED) && tp->t_oproc) {
(*tp->t_oproc)(tp);
if ((tp->t_outq.c_cc || ISSET(tp->t_state, TS_BUSY)) &&
ISSET(tp->t_state, TS_CONNECTED)) {
SET(tp->t_state, TS_SO_OCOMPLETE);
error = ttysleep(tp, TSA_OCOMPLETE(tp),
TTOPRI | PCATCH, "ttywai",
tp->t_timeout);
if (error) {
if (error == EWOULDBLOCK)
error = EIO;
break;
}
} else
break;
}
if (!error && (tp->t_outq.c_cc || ISSET(tp->t_state, TS_BUSY)))
error = EIO;
splx(s);
return (error);
}
/*
* Flush if successfully wait.
*/
static int
ttywflush(tp)
struct tty *tp;
{
int error;
if ((error = ttywait(tp)) == 0)
ttyflush(tp, FREAD);
return (error);
}
/*
* Flush tty read and/or write queues, notifying anyone waiting.
*/
void
ttyflush(tp, rw)
register struct tty *tp;
int rw;
{
register int s;
s = spltty();
#if 0
again:
#endif
if (rw & FWRITE) {
FLUSHQ(&tp->t_outq);
CLR(tp->t_state, TS_TTSTOP);
}
(*tp->t_stop)(tp, rw);
if (rw & FREAD) {
FLUSHQ(&tp->t_canq);
FLUSHQ(&tp->t_rawq);
CLR(tp->t_lflag, PENDIN);
tp->t_rocount = 0;
tp->t_rocol = 0;
CLR(tp->t_state, TS_LOCAL);
ttwakeup(tp);
if (ISSET(tp->t_state, TS_TBLOCK)) {
if (rw & FWRITE)
FLUSHQ(&tp->t_outq);
ttyunblock(tp);
/*
* Don't let leave any state that might clobber the
* next line discipline (although we should do more
* to send the START char). Not clearing the state
* may have caused the "putc to a clist with no
* reserved cblocks" panic/printf.
*/
CLR(tp->t_state, TS_TBLOCK);
#if 0 /* forget it, sleeping isn't always safe and we don't know when it is */
if (ISSET(tp->t_iflag, IXOFF)) {
/*
* XXX wait a bit in the hope that the stop
* character (if any) will go out. Waiting
* isn't good since it allows races. This
* will be fixed when the stop character is
* put in a special queue. Don't bother with
* the checks in ttywait() since the timeout
* will save us.
*/
SET(tp->t_state, TS_SO_OCOMPLETE);
ttysleep(tp, TSA_OCOMPLETE(tp), TTOPRI,
"ttyfls", hz / 10);
/*
* Don't try sending the stop character again.
*/
CLR(tp->t_state, TS_TBLOCK);
goto again;
}
#endif
}
}
if (rw & FWRITE) {
FLUSHQ(&tp->t_outq);
ttwwakeup(tp);
}
splx(s);
}
/*
* Copy in the default termios characters.
*/
void
termioschars(t)
struct termios *t;
{
bcopy(ttydefchars, t->c_cc, sizeof t->c_cc);
}
/*
* Old interface.
*/
void
ttychars(tp)
struct tty *tp;
{
termioschars(&tp->t_termios);
}
/*
* Handle input high water. Send stop character for the IXOFF case. Turn
* on our input flow control bit and propagate the changes to the driver.
* XXX the stop character should be put in a special high priority queue.
*/
void
ttyblock(tp)
struct tty *tp;
{
SET(tp->t_state, TS_TBLOCK);
if (ISSET(tp->t_iflag, IXOFF) && tp->t_cc[VSTOP] != _POSIX_VDISABLE &&
putc(tp->t_cc[VSTOP], &tp->t_outq) != 0)
CLR(tp->t_state, TS_TBLOCK); /* try again later */
ttstart(tp);
}
/*
* Handle input low water. Send start character for the IXOFF case. Turn
* off our input flow control bit and propagate the changes to the driver.
* XXX the start character should be put in a special high priority queue.
*/
static void
ttyunblock(tp)
struct tty *tp;
{
CLR(tp->t_state, TS_TBLOCK);
if (ISSET(tp->t_iflag, IXOFF) && tp->t_cc[VSTART] != _POSIX_VDISABLE &&
putc(tp->t_cc[VSTART], &tp->t_outq) != 0)
SET(tp->t_state, TS_TBLOCK); /* try again later */
ttstart(tp);
}
#ifdef notyet
/* Not used by any current (i386) drivers. */
/*
* Restart after an inter-char delay.
*/
void
ttrstrt(tp_arg)
void *tp_arg;
{
struct tty *tp;
int s;
KASSERT(tp_arg != NULL, ("ttrstrt"));
tp = tp_arg;
s = spltty();
CLR(tp->t_state, TS_TIMEOUT);
ttstart(tp);
splx(s);
}
#endif
int
ttstart(tp)
struct tty *tp;
{
if (tp->t_oproc != NULL) /* XXX: Kludge for pty. */
(*tp->t_oproc)(tp);
return (0);
}
/*
* "close" a line discipline
*/
int
ttylclose(tp, flag)
struct tty *tp;
int flag;
{
if (flag & FNONBLOCK || ttywflush(tp))
ttyflush(tp, FREAD | FWRITE);
return (0);
}
/*
* Handle modem control transition on a tty.
* Flag indicates new state of carrier.
* Returns 0 if the line should be turned off, otherwise 1.
*/
int
ttymodem(tp, flag)
register struct tty *tp;
int flag;
{
if (ISSET(tp->t_state, TS_CARR_ON) && ISSET(tp->t_cflag, MDMBUF)) {
/*
* MDMBUF: do flow control according to carrier flag
* XXX TS_CAR_OFLOW doesn't do anything yet. TS_TTSTOP
* works if IXON and IXANY are clear.
*/
if (flag) {
CLR(tp->t_state, TS_CAR_OFLOW);
CLR(tp->t_state, TS_TTSTOP);
ttstart(tp);
} else if (!ISSET(tp->t_state, TS_CAR_OFLOW)) {
SET(tp->t_state, TS_CAR_OFLOW);
SET(tp->t_state, TS_TTSTOP);
(*tp->t_stop)(tp, 0);
}
} else if (flag == 0) {
/*
* Lost carrier.
*/
CLR(tp->t_state, TS_CARR_ON);
if (ISSET(tp->t_state, TS_ISOPEN) &&
!ISSET(tp->t_cflag, CLOCAL)) {
SET(tp->t_state, TS_ZOMBIE);
CLR(tp->t_state, TS_CONNECTED);
if (tp->t_session && tp->t_session->s_leader)
psignal(tp->t_session->s_leader, SIGHUP);
ttyflush(tp, FREAD | FWRITE);
return (0);
}
} else {
/*
* Carrier now on.
*/
SET(tp->t_state, TS_CARR_ON);
if (!ISSET(tp->t_state, TS_ZOMBIE))
SET(tp->t_state, TS_CONNECTED);
wakeup(TSA_CARR_ON(tp));
ttwakeup(tp);
ttwwakeup(tp);
}
return (1);
}
/*
* Reinput pending characters after state switch
* call at spltty().
*/
static void
ttypend(tp)
register struct tty *tp;
{
struct clist tq;
register int c;
CLR(tp->t_lflag, PENDIN);
SET(tp->t_state, TS_TYPEN);
/*
* XXX this assumes too much about clist internals. It may even
* fail if the cblock slush pool is empty. We can't allocate more
* cblocks here because we are called from an interrupt handler
* and clist_alloc_cblocks() can wait.
*/
tq = tp->t_rawq;
bzero(&tp->t_rawq, sizeof tp->t_rawq);
tp->t_rawq.c_cbmax = tq.c_cbmax;
tp->t_rawq.c_cbreserved = tq.c_cbreserved;
while ((c = getc(&tq)) >= 0)
ttyinput(c, tp);
CLR(tp->t_state, TS_TYPEN);
}
/*
* Process a read call on a tty device.
*/
int
ttread(tp, uio, flag)
register struct tty *tp;
struct uio *uio;
int flag;
{
register struct clist *qp;
register int c;
register tcflag_t lflag;
register cc_t *cc = tp->t_cc;
register struct proc *p = curproc;
int s, first, error = 0;
int has_stime = 0, last_cc = 0;
long slp = 0; /* XXX this should be renamed `timo'. */
struct timeval stime;
loop:
s = spltty();
lflag = tp->t_lflag;
/*
* take pending input first
*/
if (ISSET(lflag, PENDIN)) {
ttypend(tp);
splx(s); /* reduce latency */
s = spltty();
lflag = tp->t_lflag; /* XXX ttypend() clobbers it */
}
/*
* Hang process if it's in the background.
*/
if (isbackground(p, tp)) {
splx(s);
if (SIGISMEMBER(p->p_sigignore, SIGTTIN) ||
SIGISMEMBER(p->p_sigmask, SIGTTIN) ||
(p->p_flag & P_PPWAIT) || p->p_pgrp->pg_jobc == 0)
return (EIO);
pgsignal(p->p_pgrp, SIGTTIN, 1);
error = ttysleep(tp, &lbolt, TTIPRI | PCATCH, "ttybg2", 0);
if (error)
return (error);
goto loop;
}
if (ISSET(tp->t_state, TS_ZOMBIE)) {
splx(s);
return (0); /* EOF */
}
/*
* If canonical, use the canonical queue,
* else use the raw queue.
*
* (should get rid of clists...)
*/
qp = ISSET(lflag, ICANON) ? &tp->t_canq : &tp->t_rawq;
if (flag & IO_NDELAY) {
if (qp->c_cc > 0)
goto read;
if (!ISSET(lflag, ICANON) && cc[VMIN] == 0) {
splx(s);
return (0);
}
splx(s);
return (EWOULDBLOCK);
}
if (!ISSET(lflag, ICANON)) {
int m = cc[VMIN];
long t = cc[VTIME];
struct timeval timecopy;
/*
* Check each of the four combinations.
* (m > 0 && t == 0) is the normal read case.
* It should be fairly efficient, so we check that and its
* companion case (m == 0 && t == 0) first.
* For the other two cases, we compute the target sleep time
* into slp.
*/
if (t == 0) {
if (qp->c_cc < m)
goto sleep;
if (qp->c_cc > 0)
goto read;
/* m, t and qp->c_cc are all 0. 0 is enough input. */
splx(s);
return (0);
}
t *= 100000; /* time in us */
#define diff(t1, t2) (((t1).tv_sec - (t2).tv_sec) * 1000000 + \
((t1).tv_usec - (t2).tv_usec))
if (m > 0) {
if (qp->c_cc <= 0)
goto sleep;
if (qp->c_cc >= m)
goto read;
getmicrotime(&timecopy);
if (!has_stime) {
/* first character, start timer */
has_stime = 1;
stime = timecopy;
slp = t;
} else if (qp->c_cc > last_cc) {
/* got a character, restart timer */
stime = timecopy;
slp = t;
} else {
/* nothing, check expiration */
slp = t - diff(timecopy, stime);
if (slp <= 0)
goto read;
}
last_cc = qp->c_cc;
} else { /* m == 0 */
if (qp->c_cc > 0)
goto read;
getmicrotime(&timecopy);
if (!has_stime) {
has_stime = 1;
stime = timecopy;
slp = t;
} else {
slp = t - diff(timecopy, stime);
if (slp <= 0) {
/* Timed out, but 0 is enough input. */
splx(s);
return (0);
}
}
}
#undef diff
/*
* Rounding down may make us wake up just short
* of the target, so we round up.
* The formula is ceiling(slp * hz/1000000).
* 32-bit arithmetic is enough for hz < 169.
* XXX see tvtohz() for how to avoid overflow if hz
* is large (divide by `tick' and/or arrange to
* use tvtohz() if hz is large).
*/
slp = (long) (((u_long)slp * hz) + 999999) / 1000000;
goto sleep;
}
if (qp->c_cc <= 0) {
sleep:
/*
* There is no input, or not enough input and we can block.
*/
error = ttysleep(tp, TSA_HUP_OR_INPUT(tp), TTIPRI | PCATCH,
ISSET(tp->t_state, TS_CONNECTED) ?
"ttyin" : "ttyhup", (int)slp);
splx(s);
if (error == EWOULDBLOCK)
error = 0;
else if (error)
return (error);
/*
* XXX what happens if another process eats some input
* while we are asleep (not just here)? It would be
* safest to detect changes and reset our state variables
* (has_stime and last_cc).
*/
slp = 0;
goto loop;
}
read:
splx(s);
/*
* Input present, check for input mapping and processing.
*/
first = 1;
if (ISSET(lflag, ICANON | ISIG))
goto slowcase;
for (;;) {
char ibuf[IBUFSIZ];
int icc;
icc = imin(uio->uio_resid, IBUFSIZ);
icc = q_to_b(qp, ibuf, icc);
if (icc <= 0) {
if (first)
goto loop;
break;
}
error = uiomove(ibuf, icc, uio);
/*
* XXX if there was an error then we should ungetc() the
* unmoved chars and reduce icc here.
*/
#if NSNP > 0
if (ISSET(tp->t_lflag, ECHO) &&
ISSET(tp->t_state, TS_SNOOP) && tp->t_sc != NULL)
snpin((struct snoop *)tp->t_sc, ibuf, icc);
#endif
if (error)
break;
if (uio->uio_resid == 0)
break;
first = 0;
}
goto out;
slowcase:
for (;;) {
c = getc(qp);
if (c < 0) {
if (first)
goto loop;
break;
}
/*
* delayed suspend (^Y)
*/
if (CCEQ(cc[VDSUSP], c) &&
ISSET(lflag, IEXTEN | ISIG) == (IEXTEN | ISIG)) {
pgsignal(tp->t_pgrp, SIGTSTP, 1);
if (first) {
error = ttysleep(tp, &lbolt, TTIPRI | PCATCH,
"ttybg3", 0);
if (error)
break;
goto loop;
}
break;
}
/*
* Interpret EOF only in canonical mode.
*/
if (CCEQ(cc[VEOF], c) && ISSET(lflag, ICANON))
break;
/*
* Give user character.
*/
error = ureadc(c, uio);
if (error)
/* XXX should ungetc(c, qp). */
break;
#if NSNP > 0
/*
* Only snoop directly on input in echo mode. Non-echoed
* input will be snooped later iff the application echoes it.
*/
if (ISSET(tp->t_lflag, ECHO) &&
ISSET(tp->t_state, TS_SNOOP) && tp->t_sc != NULL)
snpinc((struct snoop *)tp->t_sc, (char)c);
#endif
if (uio->uio_resid == 0)
break;
/*
* In canonical mode check for a "break character"
* marking the end of a "line of input".
*/
if (ISSET(lflag, ICANON) && TTBREAKC(c, lflag))
break;
first = 0;
}
out:
/*
* Look to unblock input now that (presumably)
* the input queue has gone down.
*/
s = spltty();
if (ISSET(tp->t_state, TS_TBLOCK) &&
tp->t_rawq.c_cc + tp->t_canq.c_cc <= tp->t_ilowat)
ttyunblock(tp);
splx(s);
return (error);
}
/*
* Check the output queue on tp for space for a kernel message (from uprintf
* or tprintf). Allow some space over the normal hiwater mark so we don't
* lose messages due to normal flow control, but don't let the tty run amok.
* Sleeps here are not interruptible, but we return prematurely if new signals
* arrive.
*/
int
ttycheckoutq(tp, wait)
register struct tty *tp;
int wait;
{
int hiwat, s;
sigset_t oldmask;
hiwat = tp->t_ohiwat;
SIGEMPTYSET(oldmask);
s = spltty();
if (wait)
oldmask = curproc->p_siglist;
if (tp->t_outq.c_cc > hiwat + OBUFSIZ + 100)
while (tp->t_outq.c_cc > hiwat) {
ttstart(tp);
if (tp->t_outq.c_cc <= hiwat)
break;
if (!(wait && SIGSETEQ(curproc->p_siglist, oldmask))) {
splx(s);
return (0);
}
SET(tp->t_state, TS_SO_OLOWAT);
tsleep(TSA_OLOWAT(tp), PZERO - 1, "ttoutq", hz);
}
splx(s);
return (1);
}
/*
* Process a write call on a tty device.
*/
int
ttwrite(tp, uio, flag)
register struct tty *tp;
register struct uio *uio;
int flag;
{
register char *cp = NULL;
register int cc, ce;
register struct proc *p;
int i, hiwat, cnt, error, s;
char obuf[OBUFSIZ];
hiwat = tp->t_ohiwat;
cnt = uio->uio_resid;
error = 0;
cc = 0;
loop:
s = spltty();
if (ISSET(tp->t_state, TS_ZOMBIE)) {
splx(s);
if (uio->uio_resid == cnt)
error = EIO;
goto out;
}
if (!ISSET(tp->t_state, TS_CONNECTED)) {
if (flag & IO_NDELAY) {
splx(s);
error = EWOULDBLOCK;
goto out;
}
error = ttysleep(tp, TSA_CARR_ON(tp), TTIPRI | PCATCH,
"ttydcd", 0);
splx(s);
if (error)
goto out;
goto loop;
}
splx(s);
/*
* Hang the process if it's in the background.
*/
p = curproc;
if (isbackground(p, tp) &&
ISSET(tp->t_lflag, TOSTOP) && !(p->p_flag & P_PPWAIT) &&
!SIGISMEMBER(p->p_sigignore, SIGTTOU) &&
!SIGISMEMBER(p->p_sigmask, SIGTTOU)) {
if (p->p_pgrp->pg_jobc == 0) {
error = EIO;
goto out;
}
pgsignal(p->p_pgrp, SIGTTOU, 1);
error = ttysleep(tp, &lbolt, TTIPRI | PCATCH, "ttybg4", 0);
if (error)
goto out;
goto loop;
}
/*
* Process the user's data in at most OBUFSIZ chunks. Perform any
* output translation. Keep track of high water mark, sleep on
* overflow awaiting device aid in acquiring new space.
*/
while (uio->uio_resid > 0 || cc > 0) {
if (ISSET(tp->t_lflag, FLUSHO)) {
uio->uio_resid = 0;
return (0);
}
if (tp->t_outq.c_cc > hiwat)
goto ovhiwat;
/*
* Grab a hunk of data from the user, unless we have some
* leftover from last time.
*/
if (cc == 0) {
cc = imin(uio->uio_resid, OBUFSIZ);
cp = obuf;
error = uiomove(cp, cc, uio);
if (error) {
cc = 0;
break;
}
#if NSNP > 0
if (ISSET(tp->t_state, TS_SNOOP) && tp->t_sc != NULL)
snpin((struct snoop *)tp->t_sc, cp, cc);
#endif
}
/*
* If nothing fancy need be done, grab those characters we
* can handle without any of ttyoutput's processing and
* just transfer them to the output q. For those chars
* which require special processing (as indicated by the
* bits in char_type), call ttyoutput. After processing
* a hunk of data, look for FLUSHO so ^O's will take effect
* immediately.
*/
while (cc > 0) {
if (!ISSET(tp->t_oflag, OPOST))
ce = cc;
else {
ce = cc - scanc((u_int)cc, (u_char *)cp,
char_type, CCLASSMASK);
/*
* If ce is zero, then we're processing
* a special character through ttyoutput.
*/
if (ce == 0) {
tp->t_rocount = 0;
if (ttyoutput(*cp, tp) >= 0) {
/* No Clists, wait a bit. */
ttstart(tp);
if (flag & IO_NDELAY) {
error = EWOULDBLOCK;
goto out;
}
error = ttysleep(tp, &lbolt,
TTOPRI|PCATCH,
"ttybf1", 0);
if (error)
goto out;
goto loop;
}
cp++;
cc--;
if (ISSET(tp->t_lflag, FLUSHO) ||
tp->t_outq.c_cc > hiwat)
goto ovhiwat;
continue;
}
}
/*
* A bunch of normal characters have been found.
* Transfer them en masse to the output queue and
* continue processing at the top of the loop.
* If there are any further characters in this
* <= OBUFSIZ chunk, the first should be a character
* requiring special handling by ttyoutput.
*/
tp->t_rocount = 0;
i = b_to_q(cp, ce, &tp->t_outq);
ce -= i;
tp->t_column += ce;
cp += ce, cc -= ce, tk_nout += ce;
tp->t_outcc += ce;
if (i > 0) {
/* No Clists, wait a bit. */
ttstart(tp);
if (flag & IO_NDELAY) {
error = EWOULDBLOCK;
goto out;
}
error = ttysleep(tp, &lbolt, TTOPRI | PCATCH,
"ttybf2", 0);
if (error)
goto out;
goto loop;
}
if (ISSET(tp->t_lflag, FLUSHO) ||
tp->t_outq.c_cc > hiwat)
break;
}
ttstart(tp);
}
out:
/*
* If cc is nonzero, we leave the uio structure inconsistent, as the
* offset and iov pointers have moved forward, but it doesn't matter
* (the call will either return short or restart with a new uio).
*/
uio->uio_resid += cc;
return (error);
ovhiwat:
ttstart(tp);
s = spltty();
/*
* This can only occur if FLUSHO is set in t_lflag,
* or if ttstart/oproc is synchronous (or very fast).
*/
if (tp->t_outq.c_cc <= hiwat) {
splx(s);
goto loop;
}
if (flag & IO_NDELAY) {
splx(s);
uio->uio_resid += cc;
return (uio->uio_resid == cnt ? EWOULDBLOCK : 0);
}
SET(tp->t_state, TS_SO_OLOWAT);
error = ttysleep(tp, TSA_OLOWAT(tp), TTOPRI | PCATCH, "ttywri",
tp->t_timeout);
splx(s);
if (error == EWOULDBLOCK)
error = EIO;
if (error)
goto out;
goto loop;
}
/*
* Rubout one character from the rawq of tp
* as cleanly as possible.
*/
static void
ttyrub(c, tp)
register int c;
register struct tty *tp;
{
register char *cp;
register int savecol;
int tabc, s;
if (!ISSET(tp->t_lflag, ECHO) || ISSET(tp->t_lflag, EXTPROC))
return;
CLR(tp->t_lflag, FLUSHO);
if (ISSET(tp->t_lflag, ECHOE)) {
if (tp->t_rocount == 0) {
/*
* Screwed by ttwrite; retype
*/
ttyretype(tp);
return;
}
if (c == ('\t' | TTY_QUOTE) || c == ('\n' | TTY_QUOTE))
ttyrubo(tp, 2);
else {
CLR(c, ~TTY_CHARMASK);
switch (CCLASS(c)) {
case ORDINARY:
ttyrubo(tp, 1);
break;
case BACKSPACE:
case CONTROL:
case NEWLINE:
case RETURN:
case VTAB:
if (ISSET(tp->t_lflag, ECHOCTL))
ttyrubo(tp, 2);
break;
case TAB:
if (tp->t_rocount < tp->t_rawq.c_cc) {
ttyretype(tp);
return;
}
s = spltty();
savecol = tp->t_column;
SET(tp->t_state, TS_CNTTB);
SET(tp->t_lflag, FLUSHO);
tp->t_column = tp->t_rocol;
cp = tp->t_rawq.c_cf;
if (cp)
tabc = *cp; /* XXX FIX NEXTC */
for (; cp; cp = nextc(&tp->t_rawq, cp, &tabc))
ttyecho(tabc, tp);
CLR(tp->t_lflag, FLUSHO);
CLR(tp->t_state, TS_CNTTB);
splx(s);
/* savecol will now be length of the tab. */
savecol -= tp->t_column;
tp->t_column += savecol;
if (savecol > 8)
savecol = 8; /* overflow screw */
while (--savecol >= 0)
(void)ttyoutput('\b', tp);
break;
default: /* XXX */
#define PANICSTR "ttyrub: would panic c = %d, val = %d\n"
(void)printf(PANICSTR, c, CCLASS(c));
#ifdef notdef
panic(PANICSTR, c, CCLASS(c));
#endif
}
}
} else if (ISSET(tp->t_lflag, ECHOPRT)) {
if (!ISSET(tp->t_state, TS_ERASE)) {
SET(tp->t_state, TS_ERASE);
(void)ttyoutput('\\', tp);
}
ttyecho(c, tp);
} else
ttyecho(tp->t_cc[VERASE], tp);
--tp->t_rocount;
}
/*
* Back over cnt characters, erasing them.
*/
static void
ttyrubo(tp, cnt)
register struct tty *tp;
int cnt;
{
while (cnt-- > 0) {
(void)ttyoutput('\b', tp);
(void)ttyoutput(' ', tp);
(void)ttyoutput('\b', tp);
}
}
/*
* ttyretype --
* Reprint the rawq line. Note, it is assumed that c_cc has already
* been checked.
*/
static void
ttyretype(tp)
register struct tty *tp;
{
register char *cp;
int s, c;
/* Echo the reprint character. */
if (tp->t_cc[VREPRINT] != _POSIX_VDISABLE)
ttyecho(tp->t_cc[VREPRINT], tp);
(void)ttyoutput('\n', tp);
/*
* XXX
* FIX: NEXTC IS BROKEN - DOESN'T CHECK QUOTE
* BIT OF FIRST CHAR.
*/
s = spltty();
for (cp = tp->t_canq.c_cf, c = (cp != NULL ? *cp : 0);
cp != NULL; cp = nextc(&tp->t_canq, cp, &c))
ttyecho(c, tp);
for (cp = tp->t_rawq.c_cf, c = (cp != NULL ? *cp : 0);
cp != NULL; cp = nextc(&tp->t_rawq, cp, &c))
ttyecho(c, tp);
CLR(tp->t_state, TS_ERASE);
splx(s);
tp->t_rocount = tp->t_rawq.c_cc;
tp->t_rocol = 0;
}
/*
* Echo a typed character to the terminal.
*/
static void
ttyecho(c, tp)
register int c;
register struct tty *tp;
{
if (!ISSET(tp->t_state, TS_CNTTB))
CLR(tp->t_lflag, FLUSHO);
if ((!ISSET(tp->t_lflag, ECHO) &&
(c != '\n' || !ISSET(tp->t_lflag, ECHONL))) ||
ISSET(tp->t_lflag, EXTPROC))
return;
if (ISSET(tp->t_lflag, ECHOCTL) &&
((ISSET(c, TTY_CHARMASK) <= 037 && c != '\t' && c != '\n') ||
ISSET(c, TTY_CHARMASK) == 0177)) {
(void)ttyoutput('^', tp);
CLR(c, ~TTY_CHARMASK);
if (c == 0177)
c = '?';
else
c += 'A' - 1;
}
(void)ttyoutput(c, tp);
}
/*
* Wake up any readers on a tty.
*/
void
ttwakeup(tp)
register struct tty *tp;
{
if (tp->t_rsel.si_pid != 0)
selwakeup(&tp->t_rsel);
if (ISSET(tp->t_state, TS_ASYNC) && tp->t_sigio != NULL)
pgsigio(tp->t_sigio, SIGIO, (tp->t_session != NULL));
wakeup(TSA_HUP_OR_INPUT(tp));
}
/*
* Wake up any writers on a tty.
*/
void
ttwwakeup(tp)
register struct tty *tp;
{
if (tp->t_wsel.si_pid != 0 && tp->t_outq.c_cc <= tp->t_olowat)
selwakeup(&tp->t_wsel);
if (ISSET(tp->t_state, TS_ASYNC) && tp->t_sigio != NULL)
pgsigio(tp->t_sigio, SIGIO, (tp->t_session != NULL));
if (ISSET(tp->t_state, TS_BUSY | TS_SO_OCOMPLETE) ==
TS_SO_OCOMPLETE && tp->t_outq.c_cc == 0) {
CLR(tp->t_state, TS_SO_OCOMPLETE);
wakeup(TSA_OCOMPLETE(tp));
}
if (ISSET(tp->t_state, TS_SO_OLOWAT) &&
tp->t_outq.c_cc <= tp->t_olowat) {
CLR(tp->t_state, TS_SO_OLOWAT);
wakeup(TSA_OLOWAT(tp));
}
}
/*
* Look up a code for a specified speed in a conversion table;
* used by drivers to map software speed values to hardware parameters.
*/
int
ttspeedtab(speed, table)
int speed;
register struct speedtab *table;
{
for ( ; table->sp_speed != -1; table++)
if (table->sp_speed == speed)
return (table->sp_code);
return (-1);
}
/*
* Set input and output watermarks and buffer sizes. For input, the
* high watermark is about one second's worth of input above empty, the
* low watermark is slightly below high water, and the buffer size is a
* driver-dependent amount above high water. For output, the watermarks
* are near the ends of the buffer, with about 1 second's worth of input
* between them. All this only applies to the standard line discipline.
*/
void
ttsetwater(tp)
struct tty *tp;
{
register int cps, ttmaxhiwat, x;
/* Input. */
clist_alloc_cblocks(&tp->t_canq, TTYHOG, 512);
switch (tp->t_ispeedwat) {
case (speed_t)-1:
cps = tp->t_ispeed / 10;
break;
case 0:
/*
* This case is for old drivers that don't know about
* t_ispeedwat. Arrange for them to get the old buffer
* sizes and watermarks.
*/
cps = TTYHOG - 2 * 256;
tp->t_ififosize = 2 * 256;
break;
default:
cps = tp->t_ispeedwat / 10;
break;
}
tp->t_ihiwat = cps;
tp->t_ilowat = 7 * cps / 8;
x = cps + tp->t_ififosize;
clist_alloc_cblocks(&tp->t_rawq, x, x);
/* Output. */
switch (tp->t_ospeedwat) {
case (speed_t)-1:
cps = tp->t_ospeed / 10;
ttmaxhiwat = 2 * TTMAXHIWAT;
break;
case 0:
cps = tp->t_ospeed / 10;
ttmaxhiwat = TTMAXHIWAT;
break;
default:
cps = tp->t_ospeedwat / 10;
ttmaxhiwat = 8 * TTMAXHIWAT;
break;
}
#define CLAMP(x, h, l) ((x) > h ? h : ((x) < l) ? l : (x))
tp->t_olowat = x = CLAMP(cps / 2, TTMAXLOWAT, TTMINLOWAT);
x += cps;
x = CLAMP(x, ttmaxhiwat, TTMINHIWAT); /* XXX clamps are too magic */
tp->t_ohiwat = roundup(x, CBSIZE); /* XXX for compat */
x = imax(tp->t_ohiwat, TTMAXHIWAT); /* XXX for compat/safety */
x += OBUFSIZ + 100;
clist_alloc_cblocks(&tp->t_outq, x, x);
#undef CLAMP
}
/*
* Report on state of foreground process group.
*/
void
ttyinfo(tp)
register struct tty *tp;
{
register struct proc *p, *pick;
struct timeval utime, stime;
int tmp;
if (ttycheckoutq(tp,0) == 0)
return;
/* Print load average. */
tmp = (averunnable.ldavg[0] * 100 + FSCALE / 2) >> FSHIFT;
ttyprintf(tp, "load: %d.%02d ", tmp / 100, tmp % 100);
if (tp->t_session == NULL)
ttyprintf(tp, "not a controlling terminal\n");
else if (tp->t_pgrp == NULL)
ttyprintf(tp, "no foreground process group\n");
else if ((p = LIST_FIRST(&tp->t_pgrp->pg_members)) == 0)
ttyprintf(tp, "empty foreground process group\n");
else {
/* Pick interesting process. */
for (pick = NULL; p != 0; p = LIST_NEXT(p, p_pglist))
if (proc_compare(pick, p))
pick = p;
ttyprintf(tp, " cmd: %s %d [%s] ", pick->p_comm, pick->p_pid,
pick->p_stat == SRUN ? "running" :
pick->p_wmesg ? pick->p_wmesg : "iowait");
if (pick->p_flag & P_INMEM) {
calcru(pick, &utime, &stime, NULL);
/* Print user time. */
ttyprintf(tp, "%ld.%02ldu ",
utime.tv_sec, utime.tv_usec / 10000);
/* Print system time. */
ttyprintf(tp, "%ld.%02lds ",
stime.tv_sec, stime.tv_usec / 10000);
} else
ttyprintf(tp, "?.??u ?.??s ");
/* Print percentage cpu, resident set size. */
tmp = (pick->p_pctcpu * 10000 + FSCALE / 2) >> FSHIFT;
ttyprintf(tp, "%d%% %ldk\n",
tmp / 100,
pick->p_stat == SIDL || pick->p_stat == SZOMB ? 0 :
(long)pgtok(vmspace_resident_count(pick->p_vmspace)));
}
tp->t_rocount = 0; /* so pending input will be retyped if BS */
}
/*
* Returns 1 if p2 is "better" than p1
*
* The algorithm for picking the "interesting" process is thus:
*
* 1) Only foreground processes are eligible - implied.
* 2) Runnable processes are favored over anything else. The runner
* with the highest cpu utilization is picked (p_estcpu). Ties are
* broken by picking the highest pid.
* 3) The sleeper with the shortest sleep time is next. With ties,
* we pick out just "short-term" sleepers (P_SINTR == 0).
* 4) Further ties are broken by picking the highest pid.
*/
#define ISRUN(p) (((p)->p_stat == SRUN) || ((p)->p_stat == SIDL))
#define TESTAB(a, b) ((a)<<1 | (b))
#define ONLYA 2
#define ONLYB 1
#define BOTH 3
static int
proc_compare(p1, p2)
register struct proc *p1, *p2;
{
if (p1 == NULL)
return (1);
/*
* see if at least one of them is runnable
*/
switch (TESTAB(ISRUN(p1), ISRUN(p2))) {
case ONLYA:
return (0);
case ONLYB:
return (1);
case BOTH:
/*
* tie - favor one with highest recent cpu utilization
*/
if (p2->p_estcpu > p1->p_estcpu)
return (1);
if (p1->p_estcpu > p2->p_estcpu)
return (0);
return (p2->p_pid > p1->p_pid); /* tie - return highest pid */
}
/*
* weed out zombies
*/
switch (TESTAB(p1->p_stat == SZOMB, p2->p_stat == SZOMB)) {
case ONLYA:
return (1);
case ONLYB:
return (0);
case BOTH:
return (p2->p_pid > p1->p_pid); /* tie - return highest pid */
}
/*
* pick the one with the smallest sleep time
*/
if (p2->p_slptime > p1->p_slptime)
return (0);
if (p1->p_slptime > p2->p_slptime)
return (1);
/*
* favor one sleeping in a non-interruptible sleep
*/
if (p1->p_flag & P_SINTR && (p2->p_flag & P_SINTR) == 0)
return (1);
if (p2->p_flag & P_SINTR && (p1->p_flag & P_SINTR) == 0)
return (0);
return (p2->p_pid > p1->p_pid); /* tie - return highest pid */
}
/*
* Output char to tty; console putchar style.
*/
int
tputchar(c, tp)
int c;
struct tty *tp;
{
register int s;
s = spltty();
if (!ISSET(tp->t_state, TS_CONNECTED)) {
splx(s);
return (-1);
}
if (c == '\n')
(void)ttyoutput('\r', tp);
(void)ttyoutput(c, tp);
ttstart(tp);
splx(s);
return (0);
}
/*
* Sleep on chan, returning ERESTART if tty changed while we napped and
* returning any errors (e.g. EINTR/EWOULDBLOCK) reported by tsleep. If
* the tty is revoked, restarting a pending call will redo validation done
* at the start of the call.
*/
int
ttysleep(tp, chan, pri, wmesg, timo)
struct tty *tp;
void *chan;
int pri, timo;
char *wmesg;
{
int error;
int gen;
gen = tp->t_gen;
error = tsleep(chan, pri, wmesg, timo);
if (error)
return (error);
return (tp->t_gen == gen ? 0 : ERESTART);
}
/*
* Allocate a tty struct. Clists in the struct will be allocated by
* ttyopen().
*/
struct tty *
ttymalloc(tp)
struct tty *tp;
{
if (tp)
return(tp);
tp = malloc(sizeof *tp, M_TTYS, M_WAITOK);
bzero(tp, sizeof *tp);
ttyregister(tp);
return (tp);
}
#if 0 /* XXX not yet usable: session leader holds a ref (see kern_exit.c). */
/*
* Free a tty struct. Clists in the struct should have been freed by
* ttyclose().
*/
void
ttyfree(tp)
struct tty *tp;
{
free(tp, M_TTYS);
}
#endif /* 0 */
void
ttyregister(tp)
struct tty *tp;
{
SLIST_INSERT_HEAD(&tty_list, tp, t_list);
}
static int
sysctl_kern_ttys SYSCTL_HANDLER_ARGS
{
int error;
struct tty *tp, t;
SLIST_FOREACH(tp, &tty_list, t_list) {
t = *tp;
if (t.t_dev)
t.t_dev = (dev_t)dev2udev(t.t_dev);
error = SYSCTL_OUT(req, (caddr_t)&t, sizeof(t));
if (error)
return (error);
}
return (0);
}
SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD,
0, 0, sysctl_kern_ttys, "S,tty", "All struct ttys");
void
nottystop(tp, rw)
struct tty *tp;
int rw;
{
return;
}
int
ttyread(dev, uio, flag)
dev_t dev;
struct uio *uio;
int flag;
{
struct tty *tp;
tp = dev->si_tty;
if (tp == NULL)
return (ENODEV);
return ((*linesw[tp->t_line].l_read)(tp, uio, flag));
}
int
ttywrite(dev, uio, flag)
dev_t dev;
struct uio *uio;
int flag;
{
struct tty *tp;
tp = dev->si_tty;
if (tp == NULL)
return (ENODEV);
return ((*linesw[tp->t_line].l_write)(tp, uio, flag));
}
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