Annotation of sys/kern/tty_tty.c, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: tty_tty.c,v 1.10 2007/03/15 10:22:30 art Exp $ */
2: /* $NetBSD: tty_tty.c,v 1.13 1996/03/30 22:24:46 christos Exp $ */
3:
4: /*-
5: * Copyright (c) 1982, 1986, 1991, 1993
6: * The Regents of the University of California. All rights reserved.
7: *
8: * Redistribution and use in source and binary forms, with or without
9: * modification, are permitted provided that the following conditions
10: * are met:
11: * 1. Redistributions of source code must retain the above copyright
12: * notice, this list of conditions and the following disclaimer.
13: * 2. Redistributions in binary form must reproduce the above copyright
14: * notice, this list of conditions and the following disclaimer in the
15: * documentation and/or other materials provided with the distribution.
16: * 3. Neither the name of the University nor the names of its contributors
17: * may be used to endorse or promote products derived from this software
18: * without specific prior written permission.
19: *
20: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30: * SUCH DAMAGE.
31: *
32: * @(#)tty_tty.c 8.2 (Berkeley) 9/23/93
33: */
34:
35: /*
36: * Indirect driver for controlling tty.
37: */
38: #include <sys/param.h>
39: #include <sys/systm.h>
40: #include <sys/ioctl.h>
41: #include <sys/proc.h>
42: #include <sys/tty.h>
43: #include <sys/vnode.h>
44: #include <sys/file.h>
45: #include <sys/conf.h>
46:
47:
48: #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL)
49:
50: /*ARGSUSED*/
51: int
52: cttyopen(dev_t dev, int flag, int mode, struct proc *p)
53: {
54: struct vnode *ttyvp = cttyvp(p);
55: int error;
56:
57: if (ttyvp == NULL)
58: return (ENXIO);
59: vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
60: #ifdef PARANOID
61: /*
62: * Since group is tty and mode is 620 on most terminal lines
63: * and since sessions protect terminals from processes outside
64: * your session, this check is probably no longer necessary.
65: * Since it inhibits setuid root programs that later switch
66: * to another user from accessing /dev/tty, we have decided
67: * to delete this test. (mckusick 5/93)
68: */
69: error = VOP_ACCESS(ttyvp,
70: (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p);
71: if (!error)
72: #endif /* PARANOID */
73: error = VOP_OPEN(ttyvp, flag, NOCRED, p);
74: VOP_UNLOCK(ttyvp, 0, p);
75: return (error);
76: }
77:
78: /*ARGSUSED*/
79: int
80: cttyread(dev_t dev, struct uio *uio, int flag)
81: {
82: struct proc *p = uio->uio_procp;
83: struct vnode *ttyvp = cttyvp(uio->uio_procp);
84: int error;
85:
86: if (ttyvp == NULL)
87: return (EIO);
88: vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
89: error = VOP_READ(ttyvp, uio, flag, NOCRED);
90: VOP_UNLOCK(ttyvp, 0, p);
91: return (error);
92: }
93:
94: /*ARGSUSED*/
95: int
96: cttywrite(dev_t dev, struct uio *uio, int flag)
97: {
98: struct proc *p = uio->uio_procp;
99: struct vnode *ttyvp = cttyvp(uio->uio_procp);
100: int error;
101:
102: if (ttyvp == NULL)
103: return (EIO);
104: vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
105: error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
106: VOP_UNLOCK(ttyvp, 0, p);
107: return (error);
108: }
109:
110: /*ARGSUSED*/
111: int
112: cttyioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
113: {
114: struct vnode *ttyvp = cttyvp(p);
115:
116: if (ttyvp == NULL)
117: return (EIO);
118: if (cmd == TIOCSCTTY) /* XXX */
119: return (EINVAL);
120: if (cmd == TIOCNOTTY) {
121: if (!SESS_LEADER(p)) {
122: atomic_clearbits_int(&p->p_flag, P_CONTROLT);
123: return (0);
124: } else
125: return (EINVAL);
126: }
127: return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p));
128: }
129:
130: /*ARGSUSED*/
131: int
132: cttypoll(dev_t dev, int events, struct proc *p)
133: {
134: struct vnode *ttyvp = cttyvp(p);
135:
136: if (ttyvp == NULL) /* try operation to get EOF/failure */
137: return (seltrue(dev, events, p));
138: return (VOP_POLL(ttyvp, events, p));
139: }
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