tty.c

早期freebsd实现

	case OTIOCSETD:
	case  TIOCSETN:
	case  TIOCSETP:
	case  TIOCSLTC:
#endif
		while (isbackground(curproc, tp) &&
		    p->p_pgrp->pg_jobc && (p->p_flag & P_PPWAIT) == 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 (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 */
		*(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();
		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;

		s = spltty();
		if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
			if (error = ttywait(tp)) {
				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);
			} 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 (cmd != TIOCSETAF) {
			if (ISSET(t->c_lflag, ICANON) !=
			    ISSET(tp->t_lflag, ICANON))
				if (ISSET(t->c_lflag, ICANON)) {
					SET(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;
					CLR(tp->t_lflag, PENDIN);
				}
		}
		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);
		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 (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 |= 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 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, cmd, 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;
	register long lflag;
	register u_char *cc = tp->t_cc;
	register struct proc *p = curproc;
	int s, first, error = 0;

loop:	lflag = tp->t_lflag;
	s = spltty();
	/*
	 * take pending input first
	 */
	if (ISSET(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 & P_PPWAIT || 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.
	 *
	 * (should get rid of clists...)
	 */
	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) && ISSET(lflag, ICANON))
			break;
		/*