tty.c

早期freebsd实现

/*-
 * 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
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/proc.h>
#define	TTYDEFCHARS
#include <sys/tty.h>
#undef	TTYDEFCHARS
#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>

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, lflag;
	register u_char *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;

	/* Handle exceptional conditions (break, parity, framing). */
	cc = tp->t_cc;
	iflag = tp->t_iflag;
	if (err = (ISSET(c, TTY_ERRORMASK))) {
		CLR(c, TTY_ERRORMASK);
		if (ISSET(err, TTY_FE) && !c) {	/* Break. */
			if (ISSET(iflag, IGNBRK))
				goto endcase;
			else if (ISSET(iflag, BRKINT) &&
			    ISSET(lflag, ISIG) &&
			    (cc[VINTR] != _POSIX_VDISABLE))
				c = cc[VINTR];
			else if (ISSET(iflag, PARMRK))
				goto parmrk;
		} else if (ISSET(err, TTY_PE) &&
		    ISSET(iflag, INPCK) || ISSET(err, TTY_FE)) {
			if (ISSET(iflag, IGNPAR))
				goto endcase;
			else if (ISSET(iflag, PARMRK)) {
parmrk:				(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;
		}
	}
	/*
	 * In tandem mode, check high water mark.
	 */
	if (ISSET(iflag, IXOFF))
		ttyblock(tp);
	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);
#ifdef sun4c						/* XXX */
					(*tp->t_stop)(tp, 0);
#else
					(*cdevsw[major(tp->t_dev)].d_stop)(tp,
					   0);
#endif
					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))
				goto endcase;
			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)) {
			int alt = ISSET(lflag, ALTWERASE);
			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' &&
			    (alt == 0 || ISALPHA(c) == ctype));
			(void)putc(c, &tp->t_rawq);
			goto endcase;
		}
		/*
		 * reprint line (^R)
		 */
		if (CCEQ(cc[VREPRINT], c)) {
			ttyretype(tp);
			goto endcase;
		}
		/*
		 * ^T - kernel info and generate SIGINFO
		 */
		if (CCEQ(cc[VSTATUS], c)) {
			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 >= TTYHOG) {
		if (ISSET(iflag, IMAXBEL)) {
			if (tp->t_outq.c_cc < tp->t_hiwat)
				(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_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 = min(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.
 */
int
ttyoutput(c, tp)
	register int c;
	register struct tty *tp;
{
	register long 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;
	int cmd, flag;
	void *data;
{
	extern struct tty *constty;	/* Temporary virtual console. */
	extern int nlinesw;
	register struct proc *p;
	int s, error;

	p = curproc;			/* XXX */

	/* If the ioctl involves modification, hang if in the background. */
	switch (cmd) {
	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: