xref: /netbsd-src/sys/dev/cons.c (revision 4472dbe5e3bd91ef2540bada7a7ca7384627ff9b)
1 /*	$NetBSD: cons.c,v 1.36 2000/05/08 16:30:57 itojun Exp $	*/
2 
3 /*
4  * Copyright (c) 1988 University of Utah.
5  * Copyright (c) 1990, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * the Systems Programming Group of the University of Utah Computer
10  * Science Department.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. All advertising materials mentioning features or use of this software
21  *    must display the following acknowledgement:
22  *	This product includes software developed by the University of
23  *	California, Berkeley and its contributors.
24  * 4. Neither the name of the University nor the names of its contributors
25  *    may be used to endorse or promote products derived from this software
26  *    without specific prior written permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38  * SUCH DAMAGE.
39  *
40  * from: Utah $Hdr: cons.c 1.7 92/01/21$
41  *
42  *	@(#)cons.c	8.2 (Berkeley) 1/12/94
43  */
44 
45 #include <sys/param.h>
46 #include <sys/proc.h>
47 #include <sys/user.h>
48 #include <sys/systm.h>
49 #include <sys/buf.h>
50 #include <sys/ioctl.h>
51 #include <sys/tty.h>
52 #include <sys/file.h>
53 #include <sys/conf.h>
54 #include <sys/vnode.h>
55 
56 #include <dev/cons.h>
57 
58 struct	tty *constty = NULL;	/* virtual console output device */
59 struct	consdev *cn_tab;	/* physical console device info */
60 struct	vnode *cn_devvp;	/* vnode for underlying device. */
61 
62 int
63 cnopen(dev, flag, mode, p)
64 	dev_t dev;
65 	int flag, mode;
66 	struct proc *p;
67 {
68 
69 	if (cn_tab == NULL)
70 		return (0);
71 
72 	/*
73 	 * always open the 'real' console device, so we don't get nailed
74 	 * later.  This follows normal device semantics; they always get
75 	 * open() calls.
76 	 */
77 	dev = cn_tab->cn_dev;
78 	if (dev == NODEV) {
79 		/*
80 		 * This is most likely an error in the console attach
81 		 * code. Panicing looks better than jumping into nowhere
82 		 * through cdevsw below....
83 		 */
84 		panic("cnopen: cn_tab->cn_dev == NODEV\n");
85 	}
86 
87 	if (cn_devvp == NULLVP) {
88 		/* try to get a reference on its vnode, but fail silently */
89 		cdevvp(dev, &cn_devvp);
90 	}
91 	return ((*cdevsw[major(dev)].d_open)(dev, flag, mode, p));
92 }
93 
94 int
95 cnclose(dev, flag, mode, p)
96 	dev_t dev;
97 	int flag, mode;
98 	struct proc *p;
99 {
100 	struct vnode *vp;
101 
102 	if (cn_tab == NULL)
103 		return (0);
104 
105 	/*
106 	 * If the real console isn't otherwise open, close it.
107 	 * If it's otherwise open, don't close it, because that'll
108 	 * screw up others who have it open.
109 	 */
110 	dev = cn_tab->cn_dev;
111 	if (cn_devvp != NULLVP) {
112 		/* release our reference to real dev's vnode */
113 		vrele(cn_devvp);
114 		cn_devvp = NULLVP;
115 	}
116 	if (vfinddev(dev, VCHR, &vp) && vcount(vp))
117 		return (0);
118 	return ((*cdevsw[major(dev)].d_close)(dev, flag, mode, p));
119 }
120 
121 int
122 cnread(dev, uio, flag)
123 	dev_t dev;
124 	struct uio *uio;
125 	int flag;
126 {
127 
128 	/*
129 	 * If we would redirect input, punt.  This will keep strange
130 	 * things from happening to people who are using the real
131 	 * console.  Nothing should be using /dev/console for
132 	 * input (except a shell in single-user mode, but then,
133 	 * one wouldn't TIOCCONS then).
134 	 */
135 	if (constty != NULL && (cn_tab == NULL || cn_tab->cn_pri != CN_REMOTE))
136 		return 0;
137 	else if (cn_tab == NULL)
138 		return ENXIO;
139 
140 	dev = cn_tab->cn_dev;
141 	return ((*cdevsw[major(dev)].d_read)(dev, uio, flag));
142 }
143 
144 int
145 cnwrite(dev, uio, flag)
146 	dev_t dev;
147 	struct uio *uio;
148 	int flag;
149 {
150 
151 	/*
152 	 * Redirect output, if that's appropriate.
153 	 * If there's no real console, return ENXIO.
154 	 */
155 	if (constty != NULL && (cn_tab == NULL || cn_tab->cn_pri != CN_REMOTE))
156 		dev = constty->t_dev;
157 	else if (cn_tab == NULL)
158 		return ENXIO;
159 	else
160 		dev = cn_tab->cn_dev;
161 	return ((*cdevsw[major(dev)].d_write)(dev, uio, flag));
162 }
163 
164 void
165 cnstop(tp, flag)
166 	struct tty *tp;
167 	int flag;
168 {
169 
170 }
171 
172 int
173 cnioctl(dev, cmd, data, flag, p)
174 	dev_t dev;
175 	u_long cmd;
176 	caddr_t data;
177 	int flag;
178 	struct proc *p;
179 {
180 	int error;
181 
182 	/*
183 	 * Superuser can always use this to wrest control of console
184 	 * output from the "virtual" console.
185 	 */
186 	if (cmd == TIOCCONS && constty != NULL) {
187 		error = suser(p->p_ucred, (u_short *) NULL);
188 		if (error)
189 			return (error);
190 		constty = NULL;
191 		return (0);
192 	}
193 
194 	/*
195 	 * Redirect the ioctl, if that's appropriate.
196 	 * Note that strange things can happen, if a program does
197 	 * ioctls on /dev/console, then the console is redirected
198 	 * out from under it.
199 	 */
200 	if (constty != NULL && (cn_tab == NULL || cn_tab->cn_pri != CN_REMOTE))
201 		dev = constty->t_dev;
202 	else if (cn_tab == NULL)
203 		return ENXIO;
204 	else
205 		dev = cn_tab->cn_dev;
206 	return ((*cdevsw[major(dev)].d_ioctl)(dev, cmd, data, flag, p));
207 }
208 
209 /*ARGSUSED*/
210 int
211 cnpoll(dev, events, p)
212 	dev_t dev;
213 	int events;
214 	struct proc *p;
215 {
216 
217 	/*
218 	 * Redirect the ioctl, if that's appropriate.
219 	 * I don't want to think of the possible side effects
220 	 * of console redirection here.
221 	 */
222 	if (constty != NULL && (cn_tab == NULL || cn_tab->cn_pri != CN_REMOTE))
223 		dev = constty->t_dev;
224 	else if (cn_tab == NULL)
225 		return ENXIO;
226 	else
227 		dev = cn_tab->cn_dev;
228 	return ((*cdevsw[major(dev)].d_poll)(dev, events, p));
229 }
230 
231 int
232 cngetc()
233 {
234 
235 	if (cn_tab == NULL)
236 		return (0);
237 	return ((*cn_tab->cn_getc)(cn_tab->cn_dev));
238 }
239 
240 int
241 cngetsn(cp, size)
242 	char *cp;
243 	int size;
244 {
245 	char *lp;
246 	int c, len;
247 
248 	cnpollc(1);
249 
250 	lp = cp;
251 	len = 0;
252 	for (;;) {
253 		c = cngetc();
254 		switch (c) {
255 		case '\n':
256 		case '\r':
257 			printf("\n");
258 			*lp++ = '\0';
259 			cnpollc(0);
260 			return (len);
261 		case '\b':
262 		case '\177':
263 		case '#':
264 			if (len) {
265 				--len;
266 				--lp;
267 				printf("\b \b");
268 			}
269 			continue;
270 		case '@':
271 		case 'u'&037:
272 			len = 0;
273 			lp = cp;
274 			printf("\n");
275 			continue;
276 		default:
277 			if (len + 1 >= size || c < ' ') {
278 				printf("\007");
279 				continue;
280 			}
281 			printf("%c", c);
282 			++len;
283 			*lp++ = c;
284 		}
285 	}
286 }
287 
288 void
289 cnputc(c)
290 	int c;
291 {
292 
293 	if (cn_tab == NULL)
294 		return;
295 
296 	if (c) {
297 		(*cn_tab->cn_putc)(cn_tab->cn_dev, c);
298 		if (c == '\n')
299 			(*cn_tab->cn_putc)(cn_tab->cn_dev, '\r');
300 	}
301 }
302 
303 void
304 cnpollc(on)
305 	int on;
306 {
307 	static int refcount = 0;
308 
309 	if (cn_tab == NULL)
310 		return;
311 	if (!on)
312 		--refcount;
313 	if (refcount == 0)
314 		(*cn_tab->cn_pollc)(cn_tab->cn_dev, on);
315 	if (on)
316 		++refcount;
317 }
318 
319 void
320 nullcnpollc(dev, on)
321 	dev_t dev;
322 	int on;
323 {
324 
325 }
326 
327 void
328 cnbell(pitch, period, volume)
329 	u_int pitch, period, volume;
330 {
331 
332 	if (cn_tab == NULL || cn_tab->cn_bell == NULL)
333 		return;
334 	(*cn_tab->cn_bell)(cn_tab->cn_dev, pitch, period, volume);
335 }
336