1 /* $OpenBSD: cons.c,v 1.18 2007/06/17 18:50:58 jasper Exp $ */
2 /* $NetBSD: cons.c,v 1.30 1996/04/08 19:57:30 jonathan Exp $ */
3
4 /*
5 * Copyright (c) 1988 University of Utah.
6 * Copyright (c) 1990, 1993
7 * The Regents of the University of California. All rights reserved.
8 *
9 * This code is derived from software contributed to Berkeley by
10 * the Systems Programming Group of the University of Utah Computer
11 * Science Department.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 * from: Utah $Hdr: cons.c 1.7 92/01/21$
38 *
39 * @(#)cons.c 8.2 (Berkeley) 1/12/94
40 */
41
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/proc.h>
45 #include <sys/user.h>
46 #include <sys/buf.h>
47 #include <sys/ioctl.h>
48 #include <sys/tty.h>
49 #include <sys/file.h>
50 #include <sys/conf.h>
51 #include <sys/vnode.h>
52 #include <sys/poll.h>
53
54 #include <dev/cons.h>
55
56 struct tty *constty = NULL; /* virtual console output device */
57 struct consdev *cn_tab; /* physical console device info */
58 struct vnode *cn_devvp; /* vnode for underlying device. */
59
60 int
61 cnopen(dev_t dev, int flag, int mode, struct proc *p)
62 {
63 dev_t cndev;
64
65 if (cn_tab == NULL)
66 return (0);
67
68 /*
69 * always open the 'real' console device, so we don't get nailed
70 * later. This follows normal device semantics; they always get
71 * open() calls.
72 */
73 cndev = cn_tab->cn_dev;
74 if (cndev == NODEV)
75 return (ENXIO);
76 #ifdef DIAGNOSTIC
77 if (cndev == dev)
78 panic("cnopen: recursive");
79 #endif
80 if (cn_devvp == NULLVP) {
81 /* try to get a reference on its vnode, but fail silently */
82 cdevvp(cndev, &cn_devvp);
83 }
84 return ((*cdevsw[major(cndev)].d_open)(cndev, flag, mode, p));
85 }
86
87 int
88 cnclose(dev_t dev, int flag, int mode, struct proc *p)
89 {
90 struct vnode *vp;
91
92 if (cn_tab == NULL)
93 return (0);
94
95 /*
96 * If the real console isn't otherwise open, close it.
97 * If it's otherwise open, don't close it, because that'll
98 * screw up others who have it open.
99 */
100 dev = cn_tab->cn_dev;
101 if (cn_devvp != NULLVP) {
102 /* release our reference to real dev's vnode */
103 vrele(cn_devvp);
104 cn_devvp = NULLVP;
105 }
106 if (vfinddev(dev, VCHR, &vp) && vcount(vp))
107 return (0);
108 return ((*cdevsw[major(dev)].d_close)(dev, flag, mode, p));
109 }
110
111 int
112 cnread(dev_t dev, struct uio *uio, int flag)
113 {
114
115 /*
116 * If we would redirect input, punt. This will keep strange
117 * things from happening to people who are using the real
118 * console. Nothing should be using /dev/console for
119 * input (except a shell in single-user mode, but then,
120 * one wouldn't TIOCCONS then).
121 */
122 if (constty != NULL)
123 return 0;
124 else if (cn_tab == NULL)
125 return ENXIO;
126
127 dev = cn_tab->cn_dev;
128 return ((*cdevsw[major(dev)].d_read)(dev, uio, flag));
129 }
130
131 int
132 cnwrite(dev_t dev, struct uio *uio, int flag)
133 {
134
135 /*
136 * Redirect output, if that's appropriate.
137 * If there's no real console, return ENXIO.
138 */
139 if (constty != NULL)
140 dev = constty->t_dev;
141 else if (cn_tab == NULL)
142 return ENXIO;
143 else
144 dev = cn_tab->cn_dev;
145 return ((*cdevsw[major(dev)].d_write)(dev, uio, flag));
146 }
147
148 int
149 cnstop(struct tty *tp, int flag)
150 {
151 return (0);
152 }
153
154 int
155 cnioctl(dev_t dev, u_long cmd, caddr_t data, int flag,
156 struct proc *p)
157 {
158 int error;
159
160 /*
161 * Superuser can always use this to wrest control of console
162 * output from the "virtual" console.
163 */
164 if (cmd == TIOCCONS && constty != NULL) {
165 error = suser(p, SUSER_NOACCT);
166 if (error)
167 return (error);
168 constty = NULL;
169 return (0);
170 }
171
172 /*
173 * Redirect the ioctl, if that's appropriate.
174 * Note that strange things can happen, if a program does
175 * ioctls on /dev/console, then the console is redirected
176 * out from under it.
177 */
178 if (constty != NULL)
179 dev = constty->t_dev;
180 else if (cn_tab == NULL)
181 return ENXIO;
182 else
183 dev = cn_tab->cn_dev;
184 return ((*cdevsw[major(dev)].d_ioctl)(dev, cmd, data, flag, p));
185 }
186
187 /*ARGSUSED*/
188 int
189 cnpoll(dev_t dev, int rw, struct proc *p)
190 {
191
192 /*
193 * Redirect the poll, if that's appropriate.
194 * I don't want to think of the possible side effects
195 * of console redirection here.
196 */
197 if (constty != NULL)
198 dev = constty->t_dev;
199 else if (cn_tab == NULL)
200 return POLLERR;
201 else
202 dev = cn_tab->cn_dev;
203 return (ttpoll(cn_tab->cn_dev, rw, p));
204 }
205
206
207 int
208 cnkqfilter(dev_t dev, struct knote *kn)
209 {
210
211 /*
212 * Redirect output, if that's appropriate.
213 * If there's no real console, return 1.
214 */
215 if (constty != NULL)
216 dev = constty->t_dev;
217 else if (cn_tab == NULL)
218 return (1);
219 else
220 dev = cn_tab->cn_dev;
221 if (cdevsw[major(dev)].d_flags & D_KQFILTER)
222 return ((*cdevsw[major(dev)].d_kqfilter)(dev, kn));
223 return (1);
224 }
225
226 int
227 cngetc(void)
228 {
229
230 if (cn_tab == NULL)
231 return (0);
232 return ((*cn_tab->cn_getc)(cn_tab->cn_dev));
233 }
234
235 void
236 cnputc(int c)
237 {
238
239 if (cn_tab == NULL)
240 return;
241
242 if (c) {
243 (*cn_tab->cn_putc)(cn_tab->cn_dev, c);
244 if (c == '\n')
245 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r');
246 }
247 }
248
249 void
250 cnpollc(int on)
251 {
252 static int refcount = 0;
253
254 if (cn_tab == NULL)
255 return;
256 if (!on)
257 --refcount;
258 if (refcount == 0)
259 (*cn_tab->cn_pollc)(cn_tab->cn_dev, on);
260 if (on)
261 ++refcount;
262 }
263
264 void
265 nullcnpollc(dev_t dev, int on)
266 {
267
268 }
269
270 void
271 cnbell(u_int pitch, u_int period, u_int volume)
272 {
273 if (cn_tab == NULL || cn_tab->cn_bell == NULL)
274 return;
275
276 (*cn_tab->cn_bell)(cn_tab->cn_dev, pitch, period, volume);
277 }