1 /* $OpenBSD: cons.c,v 1.30 2022/07/02 08:50:41 visa 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/ioctl.h>
45 #include <sys/tty.h>
46 #include <sys/conf.h>
47 #include <sys/vnode.h>
48
49 #include <dev/cons.h>
50
51 struct tty *constty = NULL; /* virtual console output device */
52 struct vnode *cn_devvp = NULLVP; /* vnode for underlying device. */
53
54 int
cnopen(dev_t dev,int flag,int mode,struct proc * p)55 cnopen(dev_t dev, int flag, int mode, struct proc *p)
56 {
57 dev_t cndev;
58
59 if (cn_tab == NULL)
60 return (0);
61
62 /*
63 * always open the 'real' console device, so we don't get nailed
64 * later. This follows normal device semantics; they always get
65 * open() calls.
66 */
67 cndev = cn_tab->cn_dev;
68 if (cndev == NODEV)
69 return (ENXIO);
70 #ifdef DIAGNOSTIC
71 if (cndev == dev)
72 panic("cnopen: recursive");
73 #endif
74 if (cn_devvp == NULLVP) {
75 /* try to get a reference on its vnode, but fail silently */
76 cdevvp(cndev, &cn_devvp);
77 }
78 return ((*cdevsw[major(cndev)].d_open)(cndev, flag, mode, p));
79 }
80
81 int
cnclose(dev_t dev,int flag,int mode,struct proc * p)82 cnclose(dev_t dev, int flag, int mode, struct proc *p)
83 {
84 struct vnode *vp;
85
86 if (cn_tab == NULL)
87 return (0);
88
89 /*
90 * If the real console isn't otherwise open, close it.
91 * If it's otherwise open, don't close it, because that'll
92 * screw up others who have it open.
93 */
94 dev = cn_tab->cn_dev;
95 if (cn_devvp != NULLVP) {
96 /* release our reference to real dev's vnode */
97 vrele(cn_devvp);
98 cn_devvp = NULLVP;
99 }
100 if (vfinddev(dev, VCHR, &vp) && vcount(vp))
101 return (0);
102 return ((*cdevsw[major(dev)].d_close)(dev, flag, mode, p));
103 }
104
105 int
cnread(dev_t dev,struct uio * uio,int flag)106 cnread(dev_t dev, struct uio *uio, int flag)
107 {
108
109 /*
110 * If we would redirect input, punt. This will keep strange
111 * things from happening to people who are using the real
112 * console. Nothing should be using /dev/console for
113 * input (except a shell in single-user mode, but then,
114 * one wouldn't TIOCCONS then).
115 */
116 if (constty != NULL)
117 return 0;
118 else if (cn_tab == NULL)
119 return ENXIO;
120
121 dev = cn_tab->cn_dev;
122 return ((*cdevsw[major(dev)].d_read)(dev, uio, flag));
123 }
124
125 int
cnwrite(dev_t dev,struct uio * uio,int flag)126 cnwrite(dev_t dev, struct uio *uio, int flag)
127 {
128
129 /*
130 * Redirect output, if that's appropriate.
131 * If there's no real console, return ENXIO.
132 */
133 if (constty != NULL)
134 dev = constty->t_dev;
135 else if (cn_tab == NULL)
136 return ENXIO;
137 else
138 dev = cn_tab->cn_dev;
139 return ((*cdevsw[major(dev)].d_write)(dev, uio, flag));
140 }
141
142 int
cnstop(struct tty * tp,int flag)143 cnstop(struct tty *tp, int flag)
144 {
145 return (0);
146 }
147
148 int
cnioctl(dev_t dev,u_long cmd,caddr_t data,int flag,struct proc * p)149 cnioctl(dev_t dev, u_long cmd, caddr_t data, int flag,
150 struct proc *p)
151 {
152 int error;
153
154 /*
155 * Superuser can always use this to wrest control of console
156 * output from the "virtual" console.
157 */
158 if (cmd == TIOCCONS && constty != NULL) {
159 error = suser(p);
160 if (error)
161 return (error);
162 constty = NULL;
163 return (0);
164 }
165
166 /*
167 * Redirect the ioctl, if that's appropriate.
168 * Note that strange things can happen, if a program does
169 * ioctls on /dev/console, then the console is redirected
170 * out from under it.
171 */
172 if (constty != NULL)
173 dev = constty->t_dev;
174 else if (cn_tab == NULL)
175 return ENXIO;
176 else
177 dev = cn_tab->cn_dev;
178 return ((*cdevsw[major(dev)].d_ioctl)(dev, cmd, data, flag, p));
179 }
180
181 int
cnkqfilter(dev_t dev,struct knote * kn)182 cnkqfilter(dev_t dev, struct knote *kn)
183 {
184
185 /*
186 * Redirect output, if that's appropriate.
187 * If there's no real console, return 1.
188 */
189 if (constty != NULL)
190 dev = constty->t_dev;
191 else if (cn_tab == NULL)
192 return (ENXIO);
193 else
194 dev = cn_tab->cn_dev;
195 if (cdevsw[major(dev)].d_kqfilter)
196 return ((*cdevsw[major(dev)].d_kqfilter)(dev, kn));
197 return (EOPNOTSUPP);
198 }
199
200 int
cngetc(void)201 cngetc(void)
202 {
203
204 if (cn_tab == NULL)
205 return (0);
206 return ((*cn_tab->cn_getc)(cn_tab->cn_dev));
207 }
208
209 void
cnputc(int c)210 cnputc(int c)
211 {
212
213 if (cn_tab == NULL)
214 return;
215
216 if (c) {
217 (*cn_tab->cn_putc)(cn_tab->cn_dev, c);
218 if (c == '\n')
219 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r');
220 }
221 }
222
223 void
cnpollc(int on)224 cnpollc(int on)
225 {
226 static int refcount = 0;
227
228 if (cn_tab == NULL)
229 return;
230 if (!on)
231 --refcount;
232 if (refcount == 0)
233 (*cn_tab->cn_pollc)(cn_tab->cn_dev, on);
234 if (on)
235 ++refcount;
236 }
237
238 void
nullcnpollc(dev_t dev,int on)239 nullcnpollc(dev_t dev, int on)
240 {
241
242 }
243
244 void
cnbell(u_int pitch,u_int period,u_int volume)245 cnbell(u_int pitch, u_int period, u_int volume)
246 {
247 if (cn_tab == NULL || cn_tab->cn_bell == NULL)
248 return;
249
250 (*cn_tab->cn_bell)(cn_tab->cn_dev, pitch, period, volume);
251 }
252