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Cleanups for 4.4BSD-Lite
[unix-history] / usr / src / sys / kern / tty.c
/*-
* Copyright (c) 1982, 1986, 1990, 1991, 1993
* The Regents of the University of California. All rights reserved.
* All rights reserved.
*
* %sccs.include.redist.c%
*
* @(#)tty.c 8.2 (Berkeley) %G%
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/proc.h>
#define TTYDEFCHARS
#include <sys/tty.h>
#undef TTYDEFCHARS
#define TTYDEFCHARS
#include "ttydefaults.h"
#undef TTYDEFCHARS
#include "termios.h"
#include <sys/file.h>
#include <sys/conf.h>
#include <sys/dkstat.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/syslog.h>
#include <vm/vm.h>
#include "syslog.h"
static int proc_compare __P((struct proc *p1, struct proc *p2));
static int ttnread __P((struct tty *));
static void ttyblock __P((struct tty *tp));
static void ttyecho __P((int, struct tty *tp));
static void ttyrubo __P((struct tty *, int));
/* Symbolic sleep message strings. */
char ttclos[] = "ttycls";
char ttopen[] = "ttyopn";
char ttybg[] = "ttybg";
char ttybuf[] = "ttybuf";
char ttyin[] = "ttyin";
char ttyout[] = "ttyout";
/*
* 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
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))
/*
* 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);
bzero(&tp->t_winsize, sizeof(tp->t_winsize));
}
CLR(tp->t_state, TS_WOPEN);
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.
*/
int
ttyclose(tp)
register struct tty *tp;
{
extern struct tty *constty; /* Temporary virtual console. */
if (constty == tp)
constty = NULL;
ttyflush(tp, FREAD | FWRITE);
tp->t_gen++;
tp->t_pgrp = NULL;
tp->t_session = NULL;
tp->t_state = 0;
return (0);
}
#define FLUSHQ(q) { \
if ((q)->c_cc) \
ndflush(q, (q)->c_cc); \
}
/* Is 'c' a line delimiter ("break" character)? */
#define TTBREAKC(c) \
((c) == '\n' || ((c) == cc[VEOF] || \
(c) == cc[VEOL] || (c) == cc[VEOL2]) && (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 int iflag = tp->t_iflag;
register int lflag = tp->t_lflag;
register u_char *cc = tp->t_cc;
int i, err;
/*
* If input is pending take it first.
*/
if (lflag&PENDIN)
ttypend(tp);
/*
* Gather stats.
*/
if (ISSET(lflag, ICANON)) {
++tk_cancc;
++tp->t_cancc;
} else {
++tk_rawcc;
++tp->t_rawcc;
}
if (err = (c&TTY_ERRORMASK)) {
c &= TTY_CHARMASK;
if (err&TTY_FE && !c) { /* break */
if (iflag&IGNBRK)
goto endcase;
else if (iflag&BRKINT && lflag&ISIG &&
(cc[VINTR] != POSIX_V_DISABLE))
c = cc[VINTR];
else
c = 0;
} else if ((err&TTY_PE && iflag&INPCK) || err&TTY_FE) {
if (iflag&IGNPAR)
goto endcase;
else if (iflag&PARMRK) {
ttyinput(0377, tp);
ttyinput(0, tp);
} else
c = 0;
}
}
dprintf("<%o>\n", c);
/*
* In tandem mode, check high water mark.
*/
if (iflag&IXOFF)
ttyblock(tp);
/*
* In tandem mode, check high water mark.
*/
if ((tp->t_state&TS_TYPEN) == 0 && (iflag&ISTRIP))
c &= ~0x80;
/*
* Extensions to POSIX input modes which aren't controlled
* by ICANON, ISIG, or IXON.
*/
if (iflag&IEXTEN) {
if (CCEQ(cc[VLNEXT],c) && (iflag&ISTRIP)) {
if (lflag&ECHO)
ttyout("^\b", tp); /*XXX - presumes too much */
}
/*
* 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);
tp->t_lflag |= FLUSHO;
}
if (CCEQ(cc[VSUSP], c)) {
if (!ISSET(lflag, NOFLSH))
ttyflush(tp, FREAD);
ttyecho(c, tp);
pgsignal(tp->t_pgrp, SIGTSTP, 1);
goto endcase;
}
}
if (iflag&IXON) {
if (CCEQ(cc[VSTOP],c)) {
if ((tp->t_state&TS_TTSTOP) == 0) {
tp->t_state |= TS_TTSTOP;
(*cdevsw[major(tp->t_dev)].d_stop)(tp, 0);
return;
}
if (!CCEQ(cc[VSTART], c))
return;
/*
* if VSTART == VSTOP we toggle
*/
goto endcase;
}
if (CCEQ(cc[VSTART], c))
goto restartoutput;
}
c = unputc(&tp->t_rawq);
} while (c != ' ' && c != '\t');
(void) putc(c, &tp->t_rawq);
goto endcase;
}
/*
* reprint line (^R)
*/
if (CCEQ(cc[VREPRINT], c)) {
ttyretype(tp);
goto endcase;
}
/*
* Check for input buffer overflow
*/
if (tp->t_rawq.c_cc + tp->t_canq.c_cc >= TTYHOG) {
if (iflag&IMAXBEL) {
if (tp->t_outq.c_cc < TTHIWAT(tp))
(void) ttyoutput(CTRL('g'), tp);
} else
ttyflush(tp, FREAD | FWRITE);
goto endcase;
}
/*
* 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)) {
tp->t_rocount = 0;
catq(&tp->t_rawq, &tp->t_canq);
ttwakeup(tp);
} else if (tp->t_rocount++ == 0)
tp->t_rocol = tp->t_col;
if (CCEQ(cc[VQUOTE], c) && (iflag&ISTRIP))
tp->t_state |= TS_QUOT; /* '\' escape */
if (ISSET(tp->t_state, TS_ERASE)) {
/*
* end of prterase \.../
*/
/*
* end of prterase \.../
*/
CLR(tp->t_state, TS_ERASE);
(void)ttyoutput('/', tp);
}
i = tp->t_col;
ttyecho(c, tp);
if (CCEQ(cc[VEOF], c) && lflag&ECHO) {
/*
* Place the cursor over the '^' of the ^D.
*/
i = min(2, tp->t_col - 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:
tp->t_lflag &= ~FLUSHO;
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.
*/
int
ttyoutput(c, tp)
register int c;
register struct tty *tp;
{
if (!(tp->t_oflag&OPOST)) {
if (tp->t_lflag&FLUSHO)
return (-1);
if (putc(c, &tp->t_outq))
return (c);
tk_nout++;
tp->t_outcc++;
return (-1);
}
c &= 0377;
/*
* 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.
*/
c &= TTY_CHARMASK;
if (c == '\t' &&
ISSET(oflag, OXTABS) && !ISSET(tp->t_lflag, EXTPROC)) {
c = 8 - (tp->t_col & 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_col += c;
return (c ? -1 : '\t');
}
if (c == CEOT && ISSET(oflag, ONOEOT))
return (-1);
tk_nout++;
tp->t_outcc++;
#ifdef notdef
/*
* Newline translation: if ONLCR is set,
* translate newline into "\r\n".
*/
#endif
if ((tp->t_lflag&FLUSHO) == 0 && putc(c, &tp->t_outq))
return (c);
if (!ISSET(tp->t_lflag, FLUSHO) && putc(c, &tp->t_outq))
return (c);
col = tp->t_col;
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_col = col;
return (-1);
}
/*
* Common code for ioctls on 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, com, data, flag)
register struct tty *tp;
int com, flag;
void *data;
{
extern struct tty *constty; /* Temporary virtual console. */
extern int nldisp;
register struct proc *p;
int s, error;
p = curproc; /* XXX */
/* If the ioctl involves modification, hang if in the background. */
switch (com) {
case TIOCFLUSH:
case TIOCSETA:
case TIOCSETD:
case TIOCSETAF:
case TIOCSETAW:
#ifdef notdef
case TIOCSPGRP:
#endif
case TIOCSTI:
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(curproc, tp) &&
p->p_pgrp->pg_jobc && (p->p_flag & SPPWAIT) == 0 &&
(p->p_sigignore & sigmask(SIGTTOU)) == 0 &&
(p->p_sigmask & sigmask(SIGTTOU)) == 0) {
pgsignal(p->p_pgrp, SIGTTOU, 1);
if (error = ttysleep(tp,
&lbolt, TTOPRI | PCATCH, ttybg, 0))
return (error);
}
break;
}
switch (com) { /* 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 */
*(int *)data = ttnread(tp);
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_CARR_ON | TS_ISOPEN) ==
(TS_CARR_ON | TS_ISOPEN))
return (EBUSY);
#ifndef UCONSOLE
if (error = suser(p->p_ucred, &p->p_acflag))
return (error);
#endif
constty = tp;
} else if (tp == constty)
constty = NULL;
break;
case TIOCDRAIN: /* wait till output drained */
if (error = ttywait(tp))
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();
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;
s = spltty();
if (com == TIOCSETAW || com == TIOCSETAF) {
if (error = ttywait(tp)) {
splx(s);
return (error);
}
if (com == 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);
} else {
if (!ISSET(tp->t_state, TS_CARR_ON) &&
ISSET(tp->t_cflag, CLOCAL) &&
!ISSET(t->c_cflag, CLOCAL)) {
CLR(tp->t_state, TS_ISOPEN);
SET(tp->t_state, TS_WOPEN);
ttwakeup(tp);
}
tp->t_cflag = t->c_cflag;
tp->t_ispeed = t->c_ispeed;
tp->t_ospeed = t->c_ospeed;
}
ttsetwater(tp);
}
if (com != TIOCSETAF) {
if (ISSET(t->c_lflag, ICANON) !=
ISSET(tp->t_lflag, ICANON))
if (ISSET(t->c_lflag, ICANON)) {
tp->t_lflag |= PENDIN;
ttwakeup(tp);
} else {
struct clist tq;
catq(&tp->t_rawq, &tp->t_canq);
tq = tp->t_rawq;
tp->t_rawq = tp->t_canq;
tp->t_canq = tq;
}
}
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;
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 >= nldisp)
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 (p->p_ucred->cr_uid && (flag & FREAD) == 0)
return (EPERM);
if (p->p_ucred->cr_uid && !isctty(p, tp))
return (EACCES);
(*linesw[tp->t_line].l_rint)(*(u_char *)data, tp);
break;
case TIOCSTOP: /* stop output, like ^S */
s = spltty();
if (!ISSET(tp->t_state, TS_TTSTOP)) {
SET(tp->t_state, TS_TTSTOP);
#ifdef sun4c /* XXX */
(*tp->t_stop)(tp, 0);
#else
(*cdevsw[major(tp->t_dev)].d_stop)(tp, 0);
#endif
}
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 |= SCTTY;
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 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;
default:
#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
return (ttcompat(tp, com, data, flag));
#else
return (-1);
#endif
}
return (0);
}
int
ttselect(device, rw, p)
dev_t device;
int rw;
struct proc *p;
{
register struct tty *tp;
int nread, s;
tp = &cdevsw[major(device)].d_ttys[minor(device)];
s = spltty();
switch (rw) {
case FREAD:
nread = ttnread(tp);
if (nread > 0 || !ISSET(tp->t_cflag, CLOCAL) &&
!ISSET(tp->t_state, TS_CARR_ON))
goto win;
selrecord(p, &tp->t_rsel);
break;
case FWRITE:
if (tp->t_outq.c_cc <= tp->t_lowat) {
win: splx(s);
return (1);
}
selrecord(p, &tp->t_wsel);
break;
}
splx(s);
return (0);
}
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;
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_CARR_ON) || ISSET(tp->t_cflag, CLOCAL))
&& tp->t_oproc) {
(*tp->t_oproc)(tp);
SET(tp->t_state, TS_ASLEEP);
if (error = ttysleep(tp,
&tp->t_outq, TTOPRI | PCATCH, ttyout, 0))
break;
}
splx(s);
return (error);
}
/*
* Flush if successfully wait.
*/
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 (rw & FREAD) {
FLUSHQ(&tp->t_canq);
FLUSHQ(&tp->t_rawq);
tp->t_rocount = 0;
tp->t_rocol = 0;
CLR(tp->t_state, TS_LOCAL);
ttwakeup(tp);
}
if (rw & FWRITE) {
CLR(tp->t_state, TS_TTSTOP);
#ifdef sun4c /* XXX */
(*tp->t_stop)(tp, rw);
#else
(*cdevsw[major(tp->t_dev)].d_stop)(tp, rw);
#endif
FLUSHQ(&tp->t_outq);
wakeup((caddr_t)&tp->t_outq);
selwakeup(&tp->t_wsel);
}
splx(s);
}
/*
* Copy in the default termios characters.
*/
void
ttychars(tp)
struct tty *tp;
{
bcopy(ttydefchars, tp->t_cc, sizeof(ttydefchars));
}
/*
* Send stop character on input overflow.
*/
static void
ttyblock(tp)
register struct tty *tp;
{
register int total;
total = tp->t_rawq.c_cc + tp->t_canq.c_cc;
if (tp->t_rawq.c_cc > TTYHOG) {
ttyflush(tp, FREAD | FWRITE);
CLR(tp->t_state, TS_TBLOCK);
}
/*
* Block further input iff: current input > threshold
* AND input is available to user program.
*/
if (total >= TTYHOG / 2 &&
!ISSET(tp->t_state, TS_TBLOCK) &&
!ISSET(tp->t_lflag, ICANON) || tp->t_canq.c_cc > 0 &&
tp->t_cc[VSTOP] != _POSIX_VDISABLE) {
if (putc(tp->t_cc[VSTOP], &tp->t_outq) == 0) {
SET(tp->t_state, TS_TBLOCK);
ttstart(tp);
}
}
}
void
ttrstrt(tp_arg)
void *tp_arg;
{
struct tty *tp;
int s;
#ifdef DIAGNOSTIC
if (tp_arg == NULL)
panic("ttrstrt");
#endif
tp = tp_arg;
s = spltty();
CLR(tp->t_state, TS_TIMEOUT);
ttstart(tp);
splx(s);
}
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 & IO_NDELAY)
ttyflush(tp, FREAD | FWRITE);
else
ttywflush(tp);
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_WOPEN) && ISSET(tp->t_cflag, MDMBUF)) {
/*
* MDMBUF: do flow control according to carrier flag
*/
if (flag) {
CLR(tp->t_state, TS_TTSTOP);
ttstart(tp);
} else if (!ISSET(tp->t_state, TS_TTSTOP)) {
SET(tp->t_state, TS_TTSTOP);
#ifdef sun4c /* XXX */
(*tp->t_stop)(tp, 0);
#else
(*cdevsw[major(tp->t_dev)].d_stop)(tp, 0);
#endif
}
} 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)) {
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);
ttwakeup(tp);
}
return (1);
}
/*
* Default modem control routine (for other line disciplines).
* Return argument flag, to turn off device on carrier drop.
*/
int
nullmodem(tp, flag)
register struct tty *tp;
int flag;
{
if (flag)
SET(tp->t_state, TS_CARR_ON);
else {
CLR(tp->t_state, TS_CARR_ON);
if (!ISSET(tp->t_cflag, CLOCAL)) {
if (tp->t_session && tp->t_session->s_leader)
psignal(tp->t_session->s_leader, SIGHUP);
return (0);
}
}
return (1);
}
/*
* Reinput pending characters after state switch
* call at spltty().
*/
void
ttypend(tp)
register struct tty *tp;
{
struct clist tq;
register c;
CLR(tp->t_lflag, PENDIN);
SET(tp->t_state, TS_TYPEN);
tq = tp->t_rawq;
tp->t_rawq.c_cc = 0;
tp->t_rawq.c_cf = tp->t_rawq.c_cl = 0;
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, t_flags;
register long lflag = tp->t_lflag;
register long iflag = tp->t_iflag;
register u_char *cc = tp->t_cc;
int s, first, error = 0;
loop: lflag = tp->t_lflag;
s = spltty();
/*
* take pending input first
*/
if (tp->t_lflag&PENDIN)
ttypend(tp);
splx(s);
/*
* Hang process if it's in the background.
*/
if (isbackground(p, tp)) {
if ((p->p_sigignore & sigmask(SIGTTIN)) ||
(p->p_sigmask & sigmask(SIGTTIN)) ||
p->p_flag & SPPWAIT || p->p_pgrp->pg_jobc == 0)
return (EIO);
pgsignal(p->p_pgrp, SIGTTIN, 1);
if (error = ttysleep(tp, &lbolt, TTIPRI | PCATCH, ttybg, 0))
return (error);
goto loop;
}
/*
* If canonical, use the canonical queue,
* else use the raw queue.
*/
qp = ISSET(lflag, ICANON) ? &tp->t_canq : &tp->t_rawq;
/*
* If there is no input, sleep on rawq
* awaiting hardware receipt and notification.
* If we have data, we don't need to check for carrier.
*/
s = spltty();
if (qp->c_cc <= 0) {
int carrier;
carrier = ISSET(tp->t_state, TS_CARR_ON) ||
ISSET(tp->t_cflag, CLOCAL);
if (!carrier && ISSET(tp->t_state, TS_ISOPEN)) {
splx(s);
return (0); /* EOF */
}
if (flag & IO_NDELAY) {
splx(s);
return (EWOULDBLOCK);
}
error = ttysleep(tp, &tp->t_rawq, TTIPRI | PCATCH,
carrier ? ttyin : ttopen, 0);
splx(s);
if (error)
return (error);
goto loop;
}
splx(s);
/*
* Input present, check for input mapping and processing.
*/
first = 1;
while ((c = getc(qp)) >= 0) {
/*
* delayed suspend (^Y)
*/
if (CCEQ(cc[VDSUSP], c) && ISSET(lflag, ISIG)) {
pgsignal(tp->t_pgrp, SIGTSTP, 1);
if (first) {
if (error = ttysleep(tp,
&lbolt, TTIPRI | PCATCH, ttybg, 0))
break;
goto loop;
}
break;
}
/*
* Interpret EOF only in canonical mode.
*/
if (CCEQ(cc[VEOF], c) && lflag&ICANON)
break;
/*
* Give user character.
*/
error = ureadc(iflag&ISTRIP ? c & 0177 : c , uio);
if (error)
break;
if (uio->uio_resid == 0)
break;
/*
* In canonical mode check for a "break character"
* marking the end of a "line of input".
*/
if (lflag&ICANON && ttbreakc(c)) {
break;
}
first = 0;
}
/*
* Look to unblock output now that (presumably)
* the input queue has gone down.
*/
s = spltty();
if (tp->t_state&TS_TBLOCK && tp->t_rawq.c_cc < TTYHOG/5) {
if (cc[VSTART] != POSIX_V_DISABLE
&& putc(cc[VSTART], &tp->t_outq) == 0) {
CLR(tp->t_state, TS_TBLOCK);
ttstart(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, oldsig;
hiwat = tp->t_hiwat;
s = spltty();
oldsig = wait ? curproc->p_sig : 0;
if (tp->t_outq.c_cc > hiwat + 200)
while (tp->t_outq.c_cc > hiwat) {
ttstart(tp);
if (wait == 0 || curproc->p_sig != oldsig) {
splx(s);
return (0);
}
timeout((void (*)__P((void *)))wakeup,
(void *)&tp->t_outq, hz);
SET(tp->t_state, TS_ASLEEP);
sleep((caddr_t)&tp->t_outq, PZERO - 1);
}
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;
register int cc, ce;
register struct proc *p;
int i, hiwat, cnt, error, s;
char obuf[OBUFSIZ];
hiwat = tp->t_hiwat;
cnt = uio->uio_resid;
error = 0;
loop:
s = spltty();
if (!ISSET(tp->t_state, TS_CARR_ON) &&
!ISSET(tp->t_cflag, CLOCAL)) {
if (ISSET(tp->t_state, TS_ISOPEN)) {
splx(s);
return (EIO);
} else if (flag & IO_NDELAY) {
splx(s);
error = EWOULDBLOCK;
goto out;
} else {
/* Sleep awaiting carrier. */
error = ttysleep(tp,
&tp->t_rawq, TTIPRI | PCATCH,ttopen, 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 & SPPWAIT) == 0 &&
(p->p_sigignore & sigmask(SIGTTOU)) == 0 &&
(p->p_sigmask & sigmask(SIGTTOU)) == 0 &&
p->p_pgrp->pg_jobc) {
pgsignal(p->p_pgrp, SIGTTOU, 1);
if (error = ttysleep(tp, &lbolt, TTIPRI | PCATCH, ttybg, 0))
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.
*/
for (cc = 0; 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 = min(uio->uio_resid, OBUFSIZ);
cp = obuf;
error = uiomove(cp, cc, uio);
if (error) {
cc = 0;
break;
}
}
#ifdef notdef
/*
* 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 (!(tp->t_oflag&OPOST))
ce = cc;
else {
ce = cc - scanc((u_int)cc, (u_char *)cp,
(u_char *)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 (error = ttysleep(tp, &lbolt,
TTOPRI | PCATCH, ttybuf, 0))
break;
goto loop;
}
if (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_col += ce;
cp += ce, cc -= ce, tk_nout += ce;
tp->t_outcc += ce;
if (i > 0) {
/* No Clists, wait a bit. */
ttstart(tp);
if (error = ttysleep(tp,
&lbolt, TTOPRI | PCATCH, ttybuf, 0))
break;
goto loop;
}
if (tp->t_lflag&FLUSHO || tp->t_outq.c_cc > hiwat)
break;
}
ttstart(tp);
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_ASLEEP);
error = ttysleep(tp, &tp->t_outq, TTOPRI | PCATCH, ttyout, 0);
splx(s);
if (error)
goto out;
goto loop;
}
/*
* Rubout one character from the rawq of tp
* as cleanly as possible.
*/
void
ttyrub(c, tp)
register int c;
register struct tty *tp;
{
register char *cp;
register int savecol;
int tabc, s;
if ((tp->t_lflag&ECHO) == 0)
return;
if (tp->t_lflag&ECHOE) {
if (tp->t_rocount == 0) {
/*
* Screwed by ttwrite; retype
*/
ttyretype(tp);
return;
}
/* if tab or newline was escaped - XXX - not 8bit */
if (c == ('\t' | TTY_QUOTE) || c == ('\n' | TTY_QUOTE))
ttyrubo(tp, 2);
else switch (CCLASS(c &= TTY_CHARMASK)) {
case ORDINARY:
#ifdef notdef
ttyrubo(tp, 1);
break;
case BACKSPACE:
case CONTROL:
case NEWLINE:
if (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_col;
tp->t_lflag |= FLUSHO;
tp->t_col = tp->t_rocol;
cp = tp->t_rawq.c_cf;
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_col;
tp->t_col += 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;
{
register char *rubostring = tp->t_lflag&ECHOE ? "\b \b" : "\b";
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.
*/
void
ttyretype(tp)
register struct tty *tp;
{
register char *cp;
int s, c;
/* Echo the reprint character. */
if (tp->t_cc[VREPRINT] != POSIX_V_DISABLE)
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;
{
c &= 0377;
tp->t_lflag &= ~FLUSHO;
if ((tp->t_lflag&ECHO) == 0 && !(tp->t_lflag&ECHONL && c == '\n'))
return;
if (ISSET(tp->t_lflag, ECHOCTL) &&
((c & TTY_CHARMASK) <= 037 && c != '\t' && c != '\n' ||
(c & TTY_CHARMASK) == 0177)) {
(void)ttyoutput('^', tp);
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;
{
selwakeup(&tp->t_rsel);
if (ISSET(tp->t_state, TS_ASYNC))
pgsignal(tp->t_pgrp, SIGIO, 1);
wakeup((caddr_t)&tp->t_rawq);
}
/*
* 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 tty hi and low water marks.
*
* Try to arrange the dynamics so there's about one second
* from hi to low water.
*
*/
void
ttsetwater(tp)
struct tty *tp;
{
register int cps, x;
#define CLAMP(x, h, l) ((x) > h ? h : ((x) < l) ? l : (x))
cps = tp->t_ospeed / 10;
tp->t_lowat = x = CLAMP(cps / 2, TTMAXLOWAT, TTMINLOWAT);
x += cps;
x = CLAMP(x, TTMAXHIWAT, TTMINHIWAT);
tp->t_hiwat = roundup(x, CBSIZE);
#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 = tp->t_pgrp->pg_mem) == NULL)
ttyprintf(tp, "empty foreground process group\n");
else {
/* Pick interesting process. */
for (pick = NULL; p != NULL; p = p->p_pgrpnxt)
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");
calcru(pick, &utime, &stime, NULL);
/* Print user time. */
ttyprintf(tp, "%d.%02du ",
utime.tv_sec, (utime.tv_usec + 5000) / 10000);
/* Print system time. */
ttyprintf(tp, "%d.%02ds ",
stime.tv_sec, (stime.tv_usec + 5000) / 10000);
#define pgtok(a) (((a) * NBPG) / 1024)
/* Print percentage cpu, resident set size. */
tmp = pick->p_pctcpu * 10000 + FSCALE / 2 >> FSHIFT;
ttyprintf(tp, "%d%% %dk\n",
tmp / 100,
pick->p_stat == SIDL || pick->p_stat == SZOMB ? 0 :
pgtok(pick->p_vmspace->vm_rssize));
}
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 eligable - implied)
* 2) Runnable processes are favored over anything
* else. The runner with the highest cpu
* utilization is picked (p_cpu). Ties are
* broken by picking the highest pid.
* 3 Next, the sleeper with the shortest sleep
* time is favored. With ties, we pick out
* just "short-term" sleepers (SSINTR == 0).
* 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_cpu > p1->p_cpu)
return (1);
if (p1->p_cpu > p2->p_cpu)
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 & SSINTR && (p2->p_flag & SSINTR) == 0)
return (1);
if (p2->p_flag & SSINTR && (p1->p_flag & SSINTR) == 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_CARR_ON | TS_ISOPEN) != (TS_CARR_ON | TS_ISOPEN)) {
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/ETIMEDOUT) 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;
short gen;
gen = tp->t_gen;
if (error = tsleep(chan, pri, wmesg, timo))
return (error);
return (tp->t_gen == gen ? 0 : ERESTART);
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.