xref: /netbsd/sys/kern/kern_drvctl.c (revision 6550d01e) 
1 /* $NetBSD: kern_drvctl.c,v 1.31 2009/12/20 09:36:05 dsl Exp $ */
2 
3 /*
4  * Copyright (c) 2004
5  * 	Matthias Drochner.  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  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: kern_drvctl.c,v 1.31 2009/12/20 09:36:05 dsl Exp $");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/conf.h>
36 #include <sys/device.h>
37 #include <sys/event.h>
38 #include <sys/kmem.h>
39 #include <sys/ioctl.h>
40 #include <sys/fcntl.h>
41 #include <sys/file.h>
42 #include <sys/filedesc.h>
43 #include <sys/select.h>
44 #include <sys/poll.h>
45 #include <sys/drvctlio.h>
46 #include <sys/devmon.h>
47 #include <sys/stat.h>
48 #include <sys/kauth.h>
49 #include <sys/lwp.h>
50 
51 struct drvctl_event {
52 	TAILQ_ENTRY(drvctl_event) dce_link;
53 	prop_dictionary_t	dce_event;
54 };
55 
56 TAILQ_HEAD(drvctl_queue, drvctl_event);
57 
58 static struct drvctl_queue	drvctl_eventq;		/* FIFO */
59 static kcondvar_t		drvctl_cond;
60 static kmutex_t			drvctl_lock;
61 static int			drvctl_nopen = 0, drvctl_eventcnt = 0;
62 static struct selinfo		drvctl_rdsel;
63 
64 #define DRVCTL_EVENTQ_DEPTH	64	/* arbitrary queue limit */
65 
66 dev_type_open(drvctlopen);
67 
68 const struct cdevsw drvctl_cdevsw = {
69 	drvctlopen, nullclose, nullread, nullwrite, noioctl,
70 	nostop, notty, nopoll, nommap, nokqfilter, D_OTHER
71 };
72 
73 void drvctlattach(int);
74 
75 static int	drvctl_read(struct file *, off_t *, struct uio *,
76 			    kauth_cred_t, int);
77 static int	drvctl_write(struct file *, off_t *, struct uio *,
78 			     kauth_cred_t, int);
79 static int	drvctl_ioctl(struct file *, u_long, void *);
80 static int	drvctl_poll(struct file *, int);
81 static int	drvctl_stat(struct file *, struct stat *);
82 static int	drvctl_close(struct file *);
83 
84 static const struct fileops drvctl_fileops = {
85 	.fo_read = drvctl_read,
86 	.fo_write = drvctl_write,
87 	.fo_ioctl = drvctl_ioctl,
88 	.fo_fcntl = fnullop_fcntl,
89 	.fo_poll = drvctl_poll,
90 	.fo_stat = drvctl_stat,
91 	.fo_close = drvctl_close,
92 	.fo_kqfilter = fnullop_kqfilter,
93 	.fo_restart = fnullop_restart,
94 };
95 
96 #define MAXLOCATORS 100
97 
98 static int drvctl_command(struct lwp *, struct plistref *, u_long, int);
99 static int drvctl_getevent(struct lwp *, struct plistref *, u_long, int);
100 
101 void
102 drvctl_init(void)
103 {
104 	TAILQ_INIT(&drvctl_eventq);
105 	mutex_init(&drvctl_lock, MUTEX_DEFAULT, IPL_NONE);
106 	cv_init(&drvctl_cond, "devmon");
107 	selinit(&drvctl_rdsel);
108 }
109 
110 void
111 devmon_insert(const char *event, prop_dictionary_t ev)
112 {
113 	struct drvctl_event *dce, *odce;
114 
115 	mutex_enter(&drvctl_lock);
116 
117 	if (drvctl_nopen == 0) {
118 		mutex_exit(&drvctl_lock);
119 		return;
120 	}
121 
122 	/* Fill in mandatory member */
123 	if (!prop_dictionary_set_cstring_nocopy(ev, "event", event)) {
124 		prop_object_release(ev);
125 		mutex_exit(&drvctl_lock);
126 		return;
127 	}
128 
129 	dce = kmem_alloc(sizeof(*dce), KM_SLEEP);
130 	if (dce == NULL) {
131 		mutex_exit(&drvctl_lock);
132 		return;
133 	}
134 
135 	dce->dce_event = ev;
136 
137 	if (drvctl_eventcnt == DRVCTL_EVENTQ_DEPTH) {
138 		odce = TAILQ_FIRST(&drvctl_eventq);
139 		TAILQ_REMOVE(&drvctl_eventq, odce, dce_link);
140 		prop_object_release(odce->dce_event);
141 		kmem_free(odce, sizeof(*odce));
142 		--drvctl_eventcnt;
143 	}
144 
145 	TAILQ_INSERT_TAIL(&drvctl_eventq, dce, dce_link);
146 	++drvctl_eventcnt;
147 	cv_broadcast(&drvctl_cond);
148 	selnotify(&drvctl_rdsel, 0, 0);
149 
150 	mutex_exit(&drvctl_lock);
151 }
152 
153 int
154 drvctlopen(dev_t dev, int flags, int mode, struct lwp *l)
155 {
156 	struct file *fp;
157 	int fd;
158 	int ret;
159 
160 	ret = fd_allocfile(&fp, &fd);
161 	if (ret)
162 		return ret;
163 
164 	/* XXX setup context */
165 	mutex_enter(&drvctl_lock);
166 	ret = fd_clone(fp, fd, flags, &drvctl_fileops, /* context */NULL);
167 	++drvctl_nopen;
168 	mutex_exit(&drvctl_lock);
169 
170 	return ret;
171 }
172 
173 static int
174 pmdevbyname(u_long cmd, struct devpmargs *a)
175 {
176 	struct device *d;
177 
178 	if ((d = device_find_by_xname(a->devname)) == NULL)
179 		return ENXIO;
180 
181 	switch (cmd) {
182 	case DRVSUSPENDDEV:
183 		return pmf_device_recursive_suspend(d, PMF_Q_DRVCTL) ? 0 : EBUSY;
184 	case DRVRESUMEDEV:
185 		if (a->flags & DEVPM_F_SUBTREE) {
186 			return pmf_device_subtree_resume(d, PMF_Q_DRVCTL)
187 			    ? 0 : EBUSY;
188 		} else {
189 			return pmf_device_recursive_resume(d, PMF_Q_DRVCTL)
190 			    ? 0 : EBUSY;
191 		}
192 	default:
193 		return EPASSTHROUGH;
194 	}
195 }
196 
197 static int
198 listdevbyname(struct devlistargs *l)
199 {
200 	device_t d, child;
201 	deviter_t di;
202 	int cnt = 0, idx, error = 0;
203 
204 	if (*l->l_devname == '\0')
205 		d = (device_t)NULL;
206 	else if (memchr(l->l_devname, 0, sizeof(l->l_devname)) == NULL)
207 		return EINVAL;
208 	else if ((d = device_find_by_xname(l->l_devname)) == NULL)
209 		return ENXIO;
210 
211 	for (child = deviter_first(&di, 0); child != NULL;
212 	     child = deviter_next(&di)) {
213 		if (device_parent(child) != d)
214 			continue;
215 		idx = cnt++;
216 		if (l->l_childname == NULL || idx >= l->l_children)
217 			continue;
218 		error = copyoutstr(device_xname(child), l->l_childname[idx],
219 				sizeof(l->l_childname[idx]), NULL);
220 		if (error != 0)
221 			break;
222 	}
223 	deviter_release(&di);
224 
225 	l->l_children = cnt;
226 	return error;
227 }
228 
229 static int
230 detachdevbyname(const char *devname)
231 {
232 	struct device *d;
233 
234 	if ((d = device_find_by_xname(devname)) == NULL)
235 		return ENXIO;
236 
237 #ifndef XXXFULLRISK
238 	/*
239 	 * If the parent cannot be notified, it might keep
240 	 * pointers to the detached device.
241 	 * There might be a private notification mechanism,
242 	 * but better play it safe here.
243 	 */
244 	if (d->dv_parent && !d->dv_parent->dv_cfattach->ca_childdetached)
245 		return ENOTSUP;
246 #endif
247 	return config_detach(d, 0);
248 }
249 
250 static int
251 rescanbus(const char *busname, const char *ifattr,
252 	  int numlocators, const int *locators)
253 {
254 	int i, rc;
255 	struct device *d;
256 	const struct cfiattrdata * const *ap;
257 
258 	/* XXX there should be a way to get limits and defaults (per device)
259 	   from config generated data */
260 	int locs[MAXLOCATORS];
261 	for (i = 0; i < MAXLOCATORS; i++)
262 		locs[i] = -1;
263 
264 	for (i = 0; i < numlocators;i++)
265 		locs[i] = locators[i];
266 
267 	if ((d = device_find_by_xname(busname)) == NULL)
268 		return ENXIO;
269 
270 	/*
271 	 * must support rescan, and must have something
272 	 * to attach to
273 	 */
274 	if (!d->dv_cfattach->ca_rescan ||
275 	    !d->dv_cfdriver->cd_attrs)
276 		return ENODEV;
277 
278 	/* allow to omit attribute if there is exactly one */
279 	if (!ifattr) {
280 		if (d->dv_cfdriver->cd_attrs[1])
281 			return EINVAL;
282 		ifattr = d->dv_cfdriver->cd_attrs[0]->ci_name;
283 	} else {
284 		/* check for valid attribute passed */
285 		for (ap = d->dv_cfdriver->cd_attrs; *ap; ap++)
286 			if (!strcmp((*ap)->ci_name, ifattr))
287 				break;
288 		if (!*ap)
289 			return EINVAL;
290 	}
291 
292 	rc = (*d->dv_cfattach->ca_rescan)(d, ifattr, locs);
293 	config_deferred(NULL);
294 	return rc;
295 }
296 
297 static int
298 drvctl_read(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred,
299     int flags)
300 {
301 	return ENODEV;
302 }
303 
304 static int
305 drvctl_write(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred,
306     int flags)
307 {
308 	return ENODEV;
309 }
310 
311 static int
312 drvctl_ioctl(struct file *fp, u_long cmd, void *data)
313 {
314 	int res;
315 	char *ifattr;
316 	int *locs;
317 	size_t locs_sz = 0; /* XXXgcc */
318 
319 	switch (cmd) {
320 	case DRVSUSPENDDEV:
321 	case DRVRESUMEDEV:
322 #define d ((struct devpmargs *)data)
323 		res = pmdevbyname(cmd, d);
324 #undef d
325 		break;
326 	case DRVLISTDEV:
327 		res = listdevbyname((struct devlistargs *)data);
328 		break;
329 	case DRVDETACHDEV:
330 #define d ((struct devdetachargs *)data)
331 		res = detachdevbyname(d->devname);
332 #undef d
333 		break;
334 	case DRVRESCANBUS:
335 #define d ((struct devrescanargs *)data)
336 		d->busname[sizeof(d->busname) - 1] = '\0';
337 
338 		/* XXX better copyin? */
339 		if (d->ifattr[0]) {
340 			d->ifattr[sizeof(d->ifattr) - 1] = '\0';
341 			ifattr = d->ifattr;
342 		} else
343 			ifattr = 0;
344 
345 		if (d->numlocators) {
346 			if (d->numlocators > MAXLOCATORS)
347 				return EINVAL;
348 			locs_sz = d->numlocators * sizeof(int);
349 			locs = kmem_alloc(locs_sz, KM_SLEEP);
350 			res = copyin(d->locators, locs, locs_sz);
351 			if (res) {
352 				kmem_free(locs, locs_sz);
353 				return res;
354 			}
355 		} else
356 			locs = NULL;
357 		res = rescanbus(d->busname, ifattr, d->numlocators, locs);
358 		if (locs)
359 			kmem_free(locs, locs_sz);
360 #undef d
361 		break;
362 	case DRVCTLCOMMAND:
363 	    	res = drvctl_command(curlwp, (struct plistref *)data, cmd,
364 		    fp->f_flag);
365 	    	break;
366 	case DRVGETEVENT:
367 		res = drvctl_getevent(curlwp, (struct plistref *)data, cmd,
368 		    fp->f_flag);
369 		break;
370 	default:
371 		return EPASSTHROUGH;
372 	}
373 	return res;
374 }
375 
376 static int
377 drvctl_stat(struct file *fp, struct stat *st)
378 {
379 	(void)memset(st, 0, sizeof(*st));
380 	st->st_uid = kauth_cred_geteuid(fp->f_cred);
381 	st->st_gid = kauth_cred_getegid(fp->f_cred);
382 	return 0;
383 }
384 
385 static int
386 drvctl_poll(struct file *fp, int events)
387 {
388 	int revents = 0;
389 
390 	if (!TAILQ_EMPTY(&drvctl_eventq))
391 		revents |= events & (POLLIN | POLLRDNORM);
392 	else
393 		selrecord(curlwp, &drvctl_rdsel);
394 
395 	return revents;
396 }
397 
398 static int
399 drvctl_close(struct file *fp)
400 {
401 	struct drvctl_event *dce;
402 
403 	/* XXX free context */
404 	mutex_enter(&drvctl_lock);
405 	KASSERT(drvctl_nopen > 0);
406 	--drvctl_nopen;
407 	if (drvctl_nopen == 0) {
408 		/* flush queue */
409 		while ((dce = TAILQ_FIRST(&drvctl_eventq)) != NULL) {
410 			TAILQ_REMOVE(&drvctl_eventq, dce, dce_link);
411 			KASSERT(drvctl_eventcnt > 0);
412 			--drvctl_eventcnt;
413 			prop_object_release(dce->dce_event);
414 			kmem_free(dce, sizeof(*dce));
415 		}
416 	}
417 	mutex_exit(&drvctl_lock);
418 
419 	return 0;
420 }
421 
422 void
423 drvctlattach(int arg)
424 {
425 }
426 
427 /*****************************************************************************
428  * Driver control command processing engine
429  *****************************************************************************/
430 
431 static int
432 drvctl_command_get_properties(struct lwp *l,
433 			      prop_dictionary_t command_dict,
434 			      prop_dictionary_t results_dict)
435 {
436 	prop_dictionary_t args_dict;
437 	prop_string_t devname_string;
438 	device_t dev;
439 	deviter_t di;
440 
441 	args_dict = prop_dictionary_get(command_dict, "drvctl-arguments");
442 	if (args_dict == NULL)
443 		return EINVAL;
444 
445 	devname_string = prop_dictionary_get(args_dict, "device-name");
446 	if (devname_string == NULL)
447 		return EINVAL;
448 
449 	for (dev = deviter_first(&di, 0); dev != NULL;
450 	     dev = deviter_next(&di)) {
451 		if (prop_string_equals_cstring(devname_string,
452 					       device_xname(dev))) {
453 			prop_dictionary_set(results_dict, "drvctl-result-data",
454 			    device_properties(dev));
455 			break;
456 		}
457 	}
458 
459 	deviter_release(&di);
460 
461 	if (dev == NULL)
462 		return ESRCH;
463 
464 	return 0;
465 }
466 
467 struct drvctl_command_desc {
468 	const char *dcd_name;		/* command name */
469 	int (*dcd_func)(struct lwp *,	/* handler function */
470 			prop_dictionary_t,
471 			prop_dictionary_t);
472 	int dcd_rw;			/* read or write required */
473 };
474 
475 static const struct drvctl_command_desc drvctl_command_table[] = {
476 	{ .dcd_name = "get-properties",
477 	  .dcd_func = drvctl_command_get_properties,
478 	  .dcd_rw   = FREAD,
479 	},
480 
481 	{ .dcd_name = NULL }
482 };
483 
484 static int
485 drvctl_command(struct lwp *l, struct plistref *pref, u_long ioctl_cmd,
486 	       int fflag)
487 {
488 	prop_dictionary_t command_dict, results_dict;
489 	prop_string_t command_string;
490 	const struct drvctl_command_desc *dcd;
491 	int error;
492 
493 	error = prop_dictionary_copyin_ioctl(pref, ioctl_cmd, &command_dict);
494 	if (error)
495 		return error;
496 
497 	results_dict = prop_dictionary_create();
498 	if (results_dict == NULL) {
499 		prop_object_release(command_dict);
500 		return ENOMEM;
501 	}
502 
503 	command_string = prop_dictionary_get(command_dict, "drvctl-command");
504 	if (command_string == NULL) {
505 		error = EINVAL;
506 		goto out;
507 	}
508 
509 	for (dcd = drvctl_command_table; dcd->dcd_name != NULL; dcd++) {
510 		if (prop_string_equals_cstring(command_string,
511 					       dcd->dcd_name))
512 			break;
513 	}
514 
515 	if (dcd->dcd_name == NULL) {
516 		error = EINVAL;
517 		goto out;
518 	}
519 
520 	if ((fflag & dcd->dcd_rw) == 0) {
521 		error = EPERM;
522 		goto out;
523 	}
524 
525 	error = (*dcd->dcd_func)(l, command_dict, results_dict);
526 
527 	prop_dictionary_set_int32(results_dict, "drvctl-error", error);
528 
529 	error = prop_dictionary_copyout_ioctl(pref, ioctl_cmd, results_dict);
530  out:
531 	prop_object_release(command_dict);
532 	prop_object_release(results_dict);
533 	return error;
534 }
535 
536 static int
537 drvctl_getevent(struct lwp *l, struct plistref *pref, u_long ioctl_cmd,
538 	        int fflag)
539 {
540 	struct drvctl_event *dce;
541 	int ret;
542 
543 	if ((fflag & (FREAD|FWRITE)) != (FREAD|FWRITE))
544 		return EPERM;
545 
546 	mutex_enter(&drvctl_lock);
547 	while ((dce = TAILQ_FIRST(&drvctl_eventq)) == NULL) {
548 		if (fflag & O_NONBLOCK) {
549 			mutex_exit(&drvctl_lock);
550 			return EWOULDBLOCK;
551 		}
552 
553 		ret = cv_wait_sig(&drvctl_cond, &drvctl_lock);
554 		if (ret) {
555 			mutex_exit(&drvctl_lock);
556 			return ret;
557 		}
558 	}
559 	TAILQ_REMOVE(&drvctl_eventq, dce, dce_link);
560 	KASSERT(drvctl_eventcnt > 0);
561 	--drvctl_eventcnt;
562 	mutex_exit(&drvctl_lock);
563 
564 	ret = prop_dictionary_copyout_ioctl(pref, ioctl_cmd, dce->dce_event);
565 
566 	prop_object_release(dce->dce_event);
567 	kmem_free(dce, sizeof(*dce));
568 
569 	return ret;
570 }
571