2 * Copyright (c) 1982, 1986, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
33 * @(#)tty_tty.c 8.2 (Berkeley) 9/23/93
34 * $FreeBSD: src/sys/kern/tty_tty.c,v 1.30 1999/09/25 18:24:24 phk Exp $
35 * $DragonFly: src/sys/kern/tty_tty.c,v 1.4 2003/06/25 03:55:57 dillon Exp $
39 * Indirect driver for controlling tty.
42 #include <sys/param.h>
43 #include <sys/systm.h>
47 #include <sys/ttycom.h>
48 #include <sys/vnode.h>
49 #include <sys/kernel.h>
51 static d_open_t cttyopen;
52 static d_read_t cttyread;
53 static d_write_t cttywrite;
54 static d_ioctl_t cttyioctl;
55 static d_poll_t cttypoll;
58 /* Don't make this static, since fdesc_vnops uses it. */
59 struct cdevsw ctty_cdevsw = {
61 /* close */ nullclose,
63 /* write */ cttywrite,
64 /* ioctl */ cttyioctl,
67 /* strategy */ nostrategy,
76 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL)
80 cttyopen(dev_t dev, int flag, int mode, struct thread *td)
82 struct proc *p = td->td_proc;
91 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, td);
94 * Since group is tty and mode is 620 on most terminal lines
95 * and since sessions protect terminals from processes outside
96 * your session, this check is probably no longer necessary.
97 * Since it inhibits setuid root programs that later switch
98 * to another user from accessing /dev/tty, we have decided
99 * to delete this test. (mckusick 5/93)
101 error = VOP_ACCESS(ttyvp,
102 (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, td);
104 #endif /* PARANOID */
105 error = VOP_OPEN(ttyvp, flag, NOCRED, td);
106 VOP_UNLOCK(ttyvp, 0, td);
112 cttyread(dev, uio, flag)
117 struct thread *td = uio->uio_td;
118 struct proc *p = td->td_proc;
126 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, td);
127 error = VOP_READ(ttyvp, uio, flag, NOCRED);
128 VOP_UNLOCK(ttyvp, 0, td);
134 cttywrite(dev, uio, flag)
139 struct thread *td = uio->uio_td;
140 struct proc *p = td->td_proc;
148 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, td);
149 error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
150 VOP_UNLOCK(ttyvp, 0, td);
156 cttyioctl(dev, cmd, addr, flag, td)
164 struct proc *p = td->td_proc;
170 if (cmd == TIOCSCTTY) /* don't allow controlling tty to be set */
171 return EINVAL; /* to controlling tty -- infinite recursion */
172 if (cmd == TIOCNOTTY) {
173 if (!SESS_LEADER(p)) {
174 p->p_flag &= ~P_CONTROLT;
179 return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, td));
184 cttypoll(dev_t dev, int events, struct thread *td)
187 struct proc *p = td->td_proc;
192 /* try operation to get EOF/failure */
193 return (seltrue(dev, events, td));
194 return (VOP_POLL(ttyvp, events, p->p_ucred, td));
197 static void ctty_drvinit __P((void *unused));
203 make_dev(&ctty_cdevsw, 0, 0, 0, 0666, "tty");
206 SYSINIT(cttydev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,ctty_drvinit,NULL)