1 | /* $NetBSD: tty_tty.c,v 1.40 2014/07/25 08:10:40 dholland 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. Neither the name of the University nor the names of its contributors |
16 | * may be used to endorse or promote products derived from this software |
17 | * without specific prior written permission. |
18 | * |
19 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
20 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
21 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
22 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
23 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
24 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
25 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
26 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
27 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
28 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
29 | * SUCH DAMAGE. |
30 | * |
31 | * @(#)tty_tty.c 8.2 (Berkeley) 9/23/93 |
32 | */ |
33 | |
34 | /* |
35 | * Indirect driver for controlling tty. |
36 | */ |
37 | |
38 | #include <sys/cdefs.h> |
39 | __KERNEL_RCSID(0, "$NetBSD: tty_tty.c,v 1.40 2014/07/25 08:10:40 dholland Exp $" ); |
40 | |
41 | #include <sys/param.h> |
42 | #include <sys/systm.h> |
43 | #include <sys/ioctl.h> |
44 | #include <sys/proc.h> |
45 | #include <sys/tty.h> |
46 | #include <sys/vnode.h> |
47 | #include <sys/file.h> |
48 | #include <sys/conf.h> |
49 | #include <sys/kauth.h> |
50 | |
51 | /* XXXSMP */ |
52 | #define cttyvp(p) ((p)->p_lflag & PL_CONTROLT ? (p)->p_session->s_ttyvp : NULL) |
53 | |
54 | /*ARGSUSED*/ |
55 | static int |
56 | cttyopen(dev_t dev, int flag, int mode, struct lwp *l) |
57 | { |
58 | struct vnode *ttyvp = cttyvp(l->l_proc); |
59 | int error; |
60 | |
61 | if (ttyvp == NULL) |
62 | return (ENXIO); |
63 | vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY); |
64 | #ifdef PARANOID |
65 | /* |
66 | * Since group is tty and mode is 620 on most terminal lines |
67 | * and since sessions protect terminals from processes outside |
68 | * your session, this check is probably no longer necessary. |
69 | * Since it inhibits setuid root programs that later switch |
70 | * to another user from accessing /dev/tty, we have decided |
71 | * to delete this test. (mckusick 5/93) |
72 | */ |
73 | error = VOP_ACCESS(ttyvp, |
74 | (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), l->l_cred, l); |
75 | if (!error) |
76 | #endif /* PARANOID */ |
77 | error = VOP_OPEN(ttyvp, flag, NOCRED); |
78 | VOP_UNLOCK(ttyvp); |
79 | return (error); |
80 | } |
81 | |
82 | /*ARGSUSED*/ |
83 | static int |
84 | cttyread(dev_t dev, struct uio *uio, int flag) |
85 | { |
86 | struct vnode *ttyvp = cttyvp(curproc); |
87 | int error; |
88 | |
89 | if (ttyvp == NULL) |
90 | return (EIO); |
91 | vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY); |
92 | error = VOP_READ(ttyvp, uio, flag, NOCRED); |
93 | VOP_UNLOCK(ttyvp); |
94 | return (error); |
95 | } |
96 | |
97 | /*ARGSUSED*/ |
98 | static int |
99 | cttywrite(dev_t dev, struct uio *uio, int flag) |
100 | { |
101 | struct vnode *ttyvp = cttyvp(curproc); |
102 | int error; |
103 | |
104 | if (ttyvp == NULL) |
105 | return (EIO); |
106 | vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY); |
107 | error = VOP_WRITE(ttyvp, uio, flag, NOCRED); |
108 | VOP_UNLOCK(ttyvp); |
109 | return (error); |
110 | } |
111 | |
112 | /*ARGSUSED*/ |
113 | static int |
114 | cttyioctl(dev_t dev, u_long cmd, void *addr, int flag, struct lwp *l) |
115 | { |
116 | struct vnode *ttyvp = cttyvp(l->l_proc); |
117 | int rv; |
118 | |
119 | if (ttyvp == NULL) |
120 | return (EIO); |
121 | if (cmd == TIOCSCTTY) /* XXX */ |
122 | return (EINVAL); |
123 | if (cmd == TIOCNOTTY) { |
124 | mutex_enter(proc_lock); |
125 | if (!SESS_LEADER(l->l_proc)) { |
126 | l->l_proc->p_lflag &= ~PL_CONTROLT; |
127 | rv = 0; |
128 | } else |
129 | rv = EINVAL; |
130 | mutex_exit(proc_lock); |
131 | return (rv); |
132 | } |
133 | return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED)); |
134 | } |
135 | |
136 | /*ARGSUSED*/ |
137 | static int |
138 | cttypoll(dev_t dev, int events, struct lwp *l) |
139 | { |
140 | struct vnode *ttyvp = cttyvp(l->l_proc); |
141 | |
142 | if (ttyvp == NULL) |
143 | return (seltrue(dev, events, l)); |
144 | return (VOP_POLL(ttyvp, events)); |
145 | } |
146 | |
147 | static int |
148 | cttykqfilter(dev_t dev, struct knote *kn) |
149 | { |
150 | /* This is called from filt_fileattach() by the attaching process. */ |
151 | struct proc *p = curproc; |
152 | struct vnode *ttyvp = cttyvp(p); |
153 | |
154 | if (ttyvp == NULL) |
155 | return (1); |
156 | return (VOP_KQFILTER(ttyvp, kn)); |
157 | } |
158 | |
159 | const struct cdevsw ctty_cdevsw = { |
160 | .d_open = cttyopen, |
161 | .d_close = nullclose, |
162 | .d_read = cttyread, |
163 | .d_write = cttywrite, |
164 | .d_ioctl = cttyioctl, |
165 | .d_stop = nullstop, |
166 | .d_tty = notty, |
167 | .d_poll = cttypoll, |
168 | .d_mmap = nommap, |
169 | .d_kqfilter = cttykqfilter, |
170 | .d_discard = nodiscard, |
171 | .d_flag = D_TTY |
172 | }; |
173 | |