Home | History | Annotate | Line # | Download | only in kern
tty_tty.c revision 1.17 
      1 /*	$NetBSD: tty_tty.c,v 1.17 2001/11/12 15:25:30 lukem Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1982, 1986, 1991, 1993, 1995
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  *
     35  *	@(#)tty_tty.c	8.2 (Berkeley) 9/23/93
     36  */
     37 
     38 /*
     39  * Indirect driver for controlling tty.
     40  */
     41 
     42 #include <sys/cdefs.h>
     43 __KERNEL_RCSID(0, "$NetBSD: tty_tty.c,v 1.17 2001/11/12 15:25:30 lukem Exp $");
     44 
     45 #include <sys/param.h>
     46 #include <sys/systm.h>
     47 #include <sys/ioctl.h>
     48 #include <sys/proc.h>
     49 #include <sys/tty.h>
     50 #include <sys/vnode.h>
     51 #include <sys/file.h>
     52 #include <sys/conf.h>
     53 
     54 
     55 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL)
     56 
     57 /*ARGSUSED*/
     58 int
     59 cttyopen(dev, flag, mode, p)
     60 	dev_t dev;
     61 	int flag, mode;
     62 	struct proc *p;
     63 {
     64 	struct vnode *ttyvp = cttyvp(p);
     65 	int error;
     66 
     67 	if (ttyvp == NULL)
     68 		return (ENXIO);
     69 	vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY);
     70 #ifdef PARANOID
     71 	/*
     72 	 * Since group is tty and mode is 620 on most terminal lines
     73 	 * and since sessions protect terminals from processes outside
     74 	 * your session, this check is probably no longer necessary.
     75 	 * Since it inhibits setuid root programs that later switch
     76 	 * to another user from accessing /dev/tty, we have decided
     77 	 * to delete this test. (mckusick 5/93)
     78 	 */
     79 	error = VOP_ACCESS(ttyvp,
     80 	  (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p);
     81 	if (!error)
     82 #endif /* PARANOID */
     83 		error = VOP_OPEN(ttyvp, flag, NOCRED, p);
     84 	VOP_UNLOCK(ttyvp, 0);
     85 	return (error);
     86 }
     87 
     88 /*ARGSUSED*/
     89 int
     90 cttyread(dev, uio, flag)
     91 	dev_t dev;
     92 	struct uio *uio;
     93 	int flag;
     94 {
     95 	struct vnode *ttyvp = cttyvp(uio->uio_procp);
     96 	int error;
     97 
     98 	if (ttyvp == NULL)
     99 		return (EIO);
    100 	vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY);
    101 	error = VOP_READ(ttyvp, uio, flag, NOCRED);
    102 	VOP_UNLOCK(ttyvp, 0);
    103 	return (error);
    104 }
    105 
    106 /*ARGSUSED*/
    107 int
    108 cttywrite(dev, uio, flag)
    109 	dev_t dev;
    110 	struct uio *uio;
    111 	int flag;
    112 {
    113 	struct vnode *ttyvp = cttyvp(uio->uio_procp);
    114 	int error;
    115 
    116 	if (ttyvp == NULL)
    117 		return (EIO);
    118 	vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY);
    119 	error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
    120 	VOP_UNLOCK(ttyvp, 0);
    121 	return (error);
    122 }
    123 
    124 /*ARGSUSED*/
    125 int
    126 cttyioctl(dev, cmd, addr, flag, p)
    127 	dev_t dev;
    128 	u_long cmd;
    129 	caddr_t addr;
    130 	int flag;
    131 	struct proc *p;
    132 {
    133 	struct vnode *ttyvp = cttyvp(p);
    134 
    135 	if (ttyvp == NULL)
    136 		return (EIO);
    137 	if (cmd == TIOCSCTTY)		/* XXX */
    138 		return (EINVAL);
    139 	if (cmd == TIOCNOTTY) {
    140 		if (!SESS_LEADER(p)) {
    141 			p->p_flag &= ~P_CONTROLT;
    142 			return (0);
    143 		} else
    144 			return (EINVAL);
    145 	}
    146 	return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p));
    147 }
    148 
    149 /*ARGSUSED*/
    150 int
    151 cttypoll(dev, events, p)
    152 	dev_t dev;
    153 	int events;
    154 	struct proc *p;
    155 {
    156 	struct vnode *ttyvp = cttyvp(p);
    157 
    158 	if (ttyvp == NULL)
    159 		return (seltrue(dev, events, p));
    160 	return (VOP_POLL(ttyvp, events, p));
    161 }
    162