1 | /* $NetBSD: cons.c,v 1.75 2015/05/29 16:26:45 macallan 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. Neither the name of the University nor the names of its contributors |
21 | * may be used to endorse or promote products derived from this software |
22 | * without specific prior written permission. |
23 | * |
24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
34 | * SUCH DAMAGE. |
35 | * |
36 | * from: Utah $Hdr: cons.c 1.7 92/01/21$ |
37 | * |
38 | * @(#)cons.c 8.2 (Berkeley) 1/12/94 |
39 | */ |
40 | |
41 | #include <sys/cdefs.h> |
42 | __KERNEL_RCSID(0, "$NetBSD: cons.c,v 1.75 2015/05/29 16:26:45 macallan Exp $" ); |
43 | |
44 | #include <sys/param.h> |
45 | #include <sys/proc.h> |
46 | #include <sys/systm.h> |
47 | #include <sys/buf.h> |
48 | #include <sys/ioctl.h> |
49 | #include <sys/poll.h> |
50 | #include <sys/tty.h> |
51 | #include <sys/file.h> |
52 | #include <sys/conf.h> |
53 | #include <sys/vnode.h> |
54 | #include <sys/kauth.h> |
55 | #include <sys/mutex.h> |
56 | |
57 | #include <dev/cons.h> |
58 | |
59 | #include "nullcons.h" |
60 | |
61 | dev_type_open(cnopen); |
62 | dev_type_close(cnclose); |
63 | dev_type_read(cnread); |
64 | dev_type_write(cnwrite); |
65 | dev_type_ioctl(cnioctl); |
66 | dev_type_poll(cnpoll); |
67 | dev_type_kqfilter(cnkqfilter); |
68 | |
69 | static bool cn_redirect(dev_t *, int, int *); |
70 | |
71 | const struct cdevsw cons_cdevsw = { |
72 | .d_open = cnopen, |
73 | .d_close = cnclose, |
74 | .d_read = cnread, |
75 | .d_write = cnwrite, |
76 | .d_ioctl = cnioctl, |
77 | .d_stop = nostop, |
78 | .d_tty = notty, |
79 | .d_poll = cnpoll, |
80 | .d_mmap = nommap, |
81 | .d_kqfilter = cnkqfilter, |
82 | .d_discard = nodiscard, |
83 | .d_flag = D_TTY |
84 | }; |
85 | |
86 | struct tty *constty = NULL; /* virtual console output device */ |
87 | struct consdev *cn_tab; /* physical console device info */ |
88 | struct vnode *cn_devvp[2]; /* vnode for underlying device. */ |
89 | |
90 | int |
91 | cnopen(dev_t dev, int flag, int mode, struct lwp *l) |
92 | { |
93 | dev_t cndev; |
94 | int unit, error; |
95 | |
96 | unit = minor(dev); |
97 | if (unit > 1) |
98 | return ENODEV; |
99 | |
100 | if (cn_tab == NULL) |
101 | return (0); |
102 | |
103 | /* |
104 | * always open the 'real' console device, so we don't get nailed |
105 | * later. This follows normal device semantics; they always get |
106 | * open() calls. |
107 | */ |
108 | cndev = cn_tab->cn_dev; |
109 | #if NNULLCONS > 0 |
110 | if (cndev == NODEV) { |
111 | nullconsattach(0); |
112 | } |
113 | #else /* NNULLCONS > 0 */ |
114 | if (cndev == NODEV) { |
115 | /* |
116 | * This is most likely an error in the console attach |
117 | * code. Panicking looks better than jumping into nowhere |
118 | * through cdevsw below.... |
119 | */ |
120 | panic("cnopen: no console device" ); |
121 | } |
122 | #endif /* NNULLCONS > 0 */ |
123 | if (dev == cndev) { |
124 | /* |
125 | * This causes cnopen() to be called recursively, which |
126 | * is generally a bad thing. It is often caused when |
127 | * dev == 0 and cn_dev has not been set, but was probably |
128 | * initialised to 0. |
129 | */ |
130 | panic("cnopen: cn_tab->cn_dev == dev" ); |
131 | } |
132 | if (cn_devvp[unit] != NULLVP) |
133 | return 0; |
134 | if ((error = cdevvp(cndev, &cn_devvp[unit])) != 0) |
135 | printf("cnopen: unable to get vnode reference\n" ); |
136 | error = vn_lock(cn_devvp[unit], LK_EXCLUSIVE | LK_RETRY); |
137 | if (error == 0) { |
138 | error = VOP_OPEN(cn_devvp[unit], flag, kauth_cred_get()); |
139 | VOP_UNLOCK(cn_devvp[unit]); |
140 | } |
141 | return error; |
142 | } |
143 | |
144 | int |
145 | cnclose(dev_t dev, int flag, int mode, struct lwp *l) |
146 | { |
147 | struct vnode *vp; |
148 | int unit, error; |
149 | |
150 | unit = minor(dev); |
151 | |
152 | if (cn_tab == NULL) |
153 | return (0); |
154 | |
155 | vp = cn_devvp[unit]; |
156 | cn_devvp[unit] = NULL; |
157 | error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); |
158 | if (error == 0) { |
159 | error = VOP_CLOSE(vp, flag, kauth_cred_get()); |
160 | VOP_UNLOCK(vp); |
161 | } |
162 | return error; |
163 | } |
164 | |
165 | int |
166 | cnread(dev_t dev, struct uio *uio, int flag) |
167 | { |
168 | int error; |
169 | |
170 | /* |
171 | * If we would redirect input, punt. This will keep strange |
172 | * things from happening to people who are using the real |
173 | * console. Nothing should be using /dev/console for |
174 | * input (except a shell in single-user mode, but then, |
175 | * one wouldn't TIOCCONS then). |
176 | */ |
177 | if (!cn_redirect(&dev, 1, &error)) |
178 | return error; |
179 | return cdev_read(dev, uio, flag); |
180 | } |
181 | |
182 | int |
183 | cnwrite(dev_t dev, struct uio *uio, int flag) |
184 | { |
185 | int error; |
186 | |
187 | /* Redirect output, if that's appropriate. */ |
188 | if (!cn_redirect(&dev, 0, &error)) |
189 | return error; |
190 | return cdev_write(dev, uio, flag); |
191 | } |
192 | |
193 | int |
194 | cnioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) |
195 | { |
196 | int error; |
197 | |
198 | error = 0; |
199 | |
200 | /* |
201 | * Superuser can always use this to wrest control of console |
202 | * output from the "virtual" console. |
203 | */ |
204 | if (cmd == TIOCCONS && constty != NULL) { |
205 | error = kauth_authorize_device_tty(l->l_cred, |
206 | KAUTH_DEVICE_TTY_VIRTUAL, constty); |
207 | if (!error) |
208 | constty = NULL; |
209 | return (error); |
210 | } |
211 | |
212 | /* |
213 | * Redirect the ioctl, if that's appropriate. |
214 | * Note that strange things can happen, if a program does |
215 | * ioctls on /dev/console, then the console is redirected |
216 | * out from under it. |
217 | */ |
218 | if (!cn_redirect(&dev, 0, &error)) |
219 | return error; |
220 | return cdev_ioctl(dev, cmd, data, flag, l); |
221 | } |
222 | |
223 | /*ARGSUSED*/ |
224 | int |
225 | cnpoll(dev_t dev, int events, struct lwp *l) |
226 | { |
227 | int error; |
228 | |
229 | /* |
230 | * Redirect the poll, if that's appropriate. |
231 | * I don't want to think of the possible side effects |
232 | * of console redirection here. |
233 | */ |
234 | if (!cn_redirect(&dev, 0, &error)) |
235 | return POLLHUP; |
236 | return cdev_poll(dev, events, l); |
237 | } |
238 | |
239 | /*ARGSUSED*/ |
240 | int |
241 | cnkqfilter(dev_t dev, struct knote *kn) |
242 | { |
243 | int error; |
244 | |
245 | /* |
246 | * Redirect the kqfilter, if that's appropriate. |
247 | * I don't want to think of the possible side effects |
248 | * of console redirection here. |
249 | */ |
250 | if (!cn_redirect(&dev, 0, &error)) |
251 | return error; |
252 | return cdev_kqfilter(dev, kn); |
253 | } |
254 | |
255 | int |
256 | cngetc(void) |
257 | { |
258 | if (cn_tab == NULL) |
259 | return (0); |
260 | int s = splhigh(); |
261 | for (;;) { |
262 | const int rv = (*cn_tab->cn_getc)(cn_tab->cn_dev); |
263 | if (rv >= 0) { |
264 | splx(s); |
265 | return rv; |
266 | } |
267 | docritpollhooks(); |
268 | } |
269 | } |
270 | |
271 | int |
272 | cngetsn(char *cp, int size) |
273 | { |
274 | char *lp; |
275 | int c, len; |
276 | |
277 | cnpollc(1); |
278 | |
279 | lp = cp; |
280 | len = 0; |
281 | for (;;) { |
282 | c = cngetc(); |
283 | switch (c) { |
284 | case '\n': |
285 | case '\r': |
286 | printf("\n" ); |
287 | *lp++ = '\0'; |
288 | cnpollc(0); |
289 | return (len); |
290 | case '\b': |
291 | case '\177': |
292 | case '#': |
293 | if (len) { |
294 | --len; |
295 | --lp; |
296 | printf("\b \b" ); |
297 | } |
298 | continue; |
299 | case '@': |
300 | case 'u'&037: /* CTRL-u */ |
301 | len = 0; |
302 | lp = cp; |
303 | printf("\n" ); |
304 | continue; |
305 | default: |
306 | if (len + 1 >= size || c < ' ') { |
307 | printf("\007" ); |
308 | continue; |
309 | } |
310 | printf("%c" , c); |
311 | ++len; |
312 | *lp++ = c; |
313 | } |
314 | } |
315 | } |
316 | |
317 | void |
318 | cnputc(int c) |
319 | { |
320 | |
321 | if (cn_tab == NULL) |
322 | return; |
323 | |
324 | /* |
325 | * XXX |
326 | * for some reason this causes ARCS firmware to output an endless stream of |
327 | * whitespaces with n32 kernels, so use the pre-1.74 code for now until I can |
328 | * figure out why this happens |
329 | */ |
330 | #ifndef sgimips |
331 | if (c) { |
332 | if (c == '\n') { |
333 | (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); |
334 | docritpollhooks(); |
335 | } |
336 | (*cn_tab->cn_putc)(cn_tab->cn_dev, c); |
337 | } |
338 | #else |
339 | if (c) { |
340 | (*cn_tab->cn_putc)(cn_tab->cn_dev, c); |
341 | if (c == '\n') { |
342 | docritpollhooks(); |
343 | (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); |
344 | } |
345 | } |
346 | #endif |
347 | } |
348 | |
349 | void |
350 | cnpollc(int on) |
351 | { |
352 | static int refcount = 0; |
353 | |
354 | if (cn_tab == NULL) |
355 | return; |
356 | if (!on) |
357 | --refcount; |
358 | if (refcount == 0) |
359 | (*cn_tab->cn_pollc)(cn_tab->cn_dev, on); |
360 | if (on) |
361 | ++refcount; |
362 | } |
363 | |
364 | void |
365 | nullcnpollc(dev_t dev, int on) |
366 | { |
367 | |
368 | } |
369 | |
370 | void |
371 | cnbell(u_int pitch, u_int period, u_int volume) |
372 | { |
373 | |
374 | if (cn_tab == NULL || cn_tab->cn_bell == NULL) |
375 | return; |
376 | (*cn_tab->cn_bell)(cn_tab->cn_dev, pitch, period, volume); |
377 | } |
378 | |
379 | void |
380 | cnflush(void) |
381 | { |
382 | if (cn_tab == NULL || cn_tab->cn_flush == NULL) |
383 | return; |
384 | (*cn_tab->cn_flush)(cn_tab->cn_dev); |
385 | } |
386 | |
387 | void |
388 | cnhalt(void) |
389 | { |
390 | if (cn_tab == NULL || cn_tab->cn_halt == NULL) |
391 | return; |
392 | (*cn_tab->cn_halt)(cn_tab->cn_dev); |
393 | } |
394 | |
395 | /* |
396 | * Redirect output, if that's appropriate. If there's no real console, |
397 | * return ENXIO. |
398 | * |
399 | * Call with tty_mutex held. |
400 | */ |
401 | static bool |
402 | cn_redirect(dev_t *devp, int is_read, int *error) |
403 | { |
404 | dev_t dev = *devp; |
405 | |
406 | *error = ENXIO; |
407 | if (constty != NULL && minor(dev) == 0 && |
408 | (cn_tab == NULL || (cn_tab->cn_pri != CN_REMOTE))) { |
409 | if (is_read) { |
410 | *error = 0; |
411 | return false; |
412 | } |
413 | dev = constty->t_dev; |
414 | } else if (cn_tab == NULL) |
415 | return false; |
416 | else |
417 | dev = cn_tab->cn_dev; |
418 | *devp = dev; |
419 | return true; |
420 | } |
421 | |