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tty_tty.c revision 1.3 
      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 1.3 1993/05/20 02:55:18 cgd 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 "select.h"
     45 #include "tty.h"
     46 #include "proc.h"
     47 #include "vnode.h"
     48 #include "file.h"
     49 
     50 #define cttyvp(p) ((p)->p_flag&SCTTY ? (p)->p_session->s_ttyvp : NULL)
     51 
     52 /*ARGSUSED*/
     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 cttyread(dev, uio, flag)
     74 	dev_t dev;
     75 	struct uio *uio;
     76 {
     77 	register struct vnode *ttyvp = cttyvp(uio->uio_procp);
     78 	int error;
     79 
     80 	if (ttyvp == NULL)
     81 		return (EIO);
     82 	VOP_LOCK(ttyvp);
     83 	error = VOP_READ(ttyvp, uio, flag, NOCRED);
     84 	VOP_UNLOCK(ttyvp);
     85 	return (error);
     86 }
     87 
     88 /*ARGSUSED*/
     89 cttywrite(dev, uio, flag)
     90 	dev_t dev;
     91 	struct uio *uio;
     92 {
     93 	register struct vnode *ttyvp = cttyvp(uio->uio_procp);
     94 	int error;
     95 
     96 	if (ttyvp == NULL)
     97 		return (EIO);
     98 	VOP_LOCK(ttyvp);
     99 	error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
    100 	VOP_UNLOCK(ttyvp);
    101 	return (error);
    102 }
    103 
    104 /*ARGSUSED*/
    105 cttyioctl(dev, cmd, addr, flag, p)
    106 	dev_t dev;
    107 	int cmd;
    108 	caddr_t addr;
    109 	int flag;
    110 	struct proc *p;
    111 {
    112 	struct vnode *ttyvp = cttyvp(p);
    113 
    114 	if (ttyvp == NULL)
    115 		return (EIO);
    116 	if (cmd == TIOCNOTTY) {
    117 		if (!SESS_LEADER(p)) {
    118 			p->p_flag &= ~SCTTY;
    119 			return (0);
    120 		} else
    121 			return (EINVAL);
    122 	}
    123 	return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p));
    124 }
    125 
    126 /*ARGSUSED*/
    127 cttyselect(dev, flag, p)
    128 	dev_t dev;
    129 	int flag;
    130 	struct proc *p;
    131 {
    132 	struct vnode *ttyvp = cttyvp(p);
    133 
    134 	if (ttyvp == NULL)
    135 		return (1);	/* try operation to get EOF/failure */
    136 	return (VOP_SELECT(ttyvp, flag, FREAD|FWRITE, NOCRED, p));
    137 }
    138