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tty_tty.c revision 1.4 
      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 1.4 1993/05/22 11:41:52 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 "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 cttyopen(dev, flag, mode, p)
     53 	dev_t dev;
     54 	int flag, mode;
     55 	struct proc *p;
     56 {
     57 	struct vnode *ttyvp = cttyvp(p);
     58 	int error;
     59 
     60 	if (ttyvp == NULL)
     61 		return (ENXIO);
     62 	VOP_LOCK(ttyvp);
     63 	error = VOP_ACCESS(ttyvp,
     64 	  (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p);
     65 	if (!error)
     66 		error = VOP_OPEN(ttyvp, flag, NOCRED, p);
     67 	VOP_UNLOCK(ttyvp);
     68 	return (error);
     69 }
     70 
     71 /*ARGSUSED*/
     72 cttyread(dev, uio, flag)
     73 	dev_t dev;
     74 	struct uio *uio;
     75 {
     76 	register struct vnode *ttyvp = cttyvp(uio->uio_procp);
     77 	int error;
     78 
     79 	if (ttyvp == NULL)
     80 		return (EIO);
     81 	VOP_LOCK(ttyvp);
     82 	error = VOP_READ(ttyvp, uio, flag, NOCRED);
     83 	VOP_UNLOCK(ttyvp);
     84 	return (error);
     85 }
     86 
     87 /*ARGSUSED*/
     88 cttywrite(dev, uio, flag)
     89 	dev_t dev;
     90 	struct uio *uio;
     91 {
     92 	register struct vnode *ttyvp = cttyvp(uio->uio_procp);
     93 	int error;
     94 
     95 	if (ttyvp == NULL)
     96 		return (EIO);
     97 	VOP_LOCK(ttyvp);
     98 	error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
     99 	VOP_UNLOCK(ttyvp);
    100 	return (error);
    101 }
    102 
    103 /*ARGSUSED*/
    104 cttyioctl(dev, cmd, addr, flag, p)
    105 	dev_t dev;
    106 	int cmd;
    107 	caddr_t addr;
    108 	int flag;
    109 	struct proc *p;
    110 {
    111 	struct vnode *ttyvp = cttyvp(p);
    112 
    113 	if (ttyvp == NULL)
    114 		return (EIO);
    115 	if (cmd == TIOCNOTTY) {
    116 		if (!SESS_LEADER(p)) {
    117 			p->p_flag &= ~SCTTY;
    118 			return (0);
    119 		} else
    120 			return (EINVAL);
    121 	}
    122 	return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p));
    123 }
    124 
    125 /*ARGSUSED*/
    126 cttyselect(dev, flag, p)
    127 	dev_t dev;
    128 	int flag;
    129 	struct proc *p;
    130 {
    131 	struct vnode *ttyvp = cttyvp(p);
    132 
    133 	if (ttyvp == NULL)
    134 		return (1);	/* try operation to get EOF/failure */
    135 	return (VOP_SELECT(ttyvp, flag, FREAD|FWRITE, NOCRED, p));
    136 }
    137