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tty_tty.c revision 1.6 
      1 /*-
      2  * Copyright (c) 1982, 1986, 1991 The Regents of the University of California.
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. All advertising materials mentioning features or use of this software
     14  *    must display the following acknowledgement:
     15  *	This product includes software developed by the University of
     16  *	California, Berkeley and its contributors.
     17  * 4. Neither the name of the University nor the names of its contributors
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  * SUCH DAMAGE.
     32  *
     33  *	from: @(#)tty_tty.c	7.15 (Berkeley) 5/28/91
     34  *	$Id: tty_tty.c,v 1.6 1993/11/24 03:40:10 deraadt Exp $
     35  */
     36 
     37 /*
     38  * Indirect driver for controlling tty.
     39  */
     40 #include "param.h"
     41 #include "systm.h"
     42 #include "conf.h"
     43 #include "ioctl.h"
     44 #include "tty.h"
     45 #include "proc.h"
     46 #include "vnode.h"
     47 #include "file.h"
     48 
     49 #define cttyvp(p) ((p)->p_flag&SCTTY ? (p)->p_session->s_ttyvp : NULL)
     50 
     51 /*ARGSUSED*/
     52 int
     53 cttyopen(dev, flag, mode, p)
     54 	dev_t dev;
     55 	int flag, mode;
     56 	struct proc *p;
     57 {
     58 	struct vnode *ttyvp = cttyvp(p);
     59 	int error;
     60 
     61 	if (ttyvp == NULL)
     62 		return (ENXIO);
     63 	VOP_LOCK(ttyvp);
     64 	error = VOP_ACCESS(ttyvp,
     65 	  (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p);
     66 	if (!error)
     67 		error = VOP_OPEN(ttyvp, flag, NOCRED, p);
     68 	VOP_UNLOCK(ttyvp);
     69 	return (error);
     70 }
     71 
     72 /*ARGSUSED*/
     73 int
     74 cttyread(dev, uio, flag)
     75 	dev_t dev;
     76 	struct uio *uio;
     77 	int flag;
     78 {
     79 	register struct vnode *ttyvp = cttyvp(uio->uio_procp);
     80 	int error;
     81 
     82 	if (ttyvp == NULL)
     83 		return (EIO);
     84 	VOP_LOCK(ttyvp);
     85 	error = VOP_READ(ttyvp, uio, flag, NOCRED);
     86 	VOP_UNLOCK(ttyvp);
     87 	return (error);
     88 }
     89 
     90 /*ARGSUSED*/
     91 int
     92 cttywrite(dev, uio, flag)
     93 	dev_t dev;
     94 	struct uio *uio;
     95 	int flag;
     96 {
     97 	register struct vnode *ttyvp = cttyvp(uio->uio_procp);
     98 	int error;
     99 
    100 	if (ttyvp == NULL)
    101 		return (EIO);
    102 	VOP_LOCK(ttyvp);
    103 	error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
    104 	VOP_UNLOCK(ttyvp);
    105 	return (error);
    106 }
    107 
    108 /*ARGSUSED*/
    109 int
    110 cttyioctl(dev, cmd, addr, flag, p)
    111 	dev_t dev;
    112 	int cmd;
    113 	caddr_t addr;
    114 	int flag;
    115 	struct proc *p;
    116 {
    117 	struct vnode *ttyvp = cttyvp(p);
    118 
    119 	if (ttyvp == NULL)
    120 		return (EIO);
    121 	if (cmd == TIOCSCTTY)
    122 		return (EINVAL);
    123 	if (cmd == TIOCNOTTY) {
    124 		if (!SESS_LEADER(p)) {
    125 			p->p_flag &= ~SCTTY;
    126 			return (0);
    127 		} else
    128 			return (EINVAL);
    129 	}
    130 	return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p));
    131 }
    132 
    133 /*ARGSUSED*/
    134 int
    135 cttyselect(dev, flag, p)
    136 	dev_t dev;
    137 	int flag;
    138 	struct proc *p;
    139 {
    140 	struct vnode *ttyvp = cttyvp(p);
    141 
    142 	if (ttyvp == NULL)
    143 		return (1);	/* try operation to get EOF/failure */
    144 	return (VOP_SELECT(ttyvp, flag, FREAD|FWRITE, NOCRED, p));
    145 }
    146