1 /* $NetBSD: kern_drvctl.c,v 1.41 2015/12/07 20:01:43 christos 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 1.41 2015/12/07 20:01:43 christos 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 #include <sys/module.h>
51
52 #include "ioconf.h"
53
54 struct drvctl_event {
55 TAILQ_ENTRY(drvctl_event) dce_link;
56 prop_dictionary_t dce_event;
57 };
58
59 TAILQ_HEAD(drvctl_queue, drvctl_event);
60
61 static struct drvctl_queue drvctl_eventq; /* FIFO */
62 static kcondvar_t drvctl_cond;
63 static kmutex_t drvctl_lock;
64 static int drvctl_nopen = 0, drvctl_eventcnt = 0;
65 static struct selinfo drvctl_rdsel;
66
67 #define DRVCTL_EVENTQ_DEPTH 64 /* arbitrary queue limit */
68
69 dev_type_open(drvctlopen);
70
71 const struct cdevsw drvctl_cdevsw = {
72 .d_open = drvctlopen,
73 .d_close = nullclose,
74 .d_read = nullread,
75 .d_write = nullwrite,
76 .d_ioctl = noioctl,
77 .d_stop = nostop,
78 .d_tty = notty,
79 .d_poll = nopoll,
80 .d_mmap = nommap,
81 .d_kqfilter = nokqfilter,
82 .d_discard = nodiscard,
83 .d_flag = D_OTHER
84 };
85
86 static int drvctl_read(struct file *, off_t *, struct uio *,
87 kauth_cred_t, int);
88 static int drvctl_write(struct file *, off_t *, struct uio *,
89 kauth_cred_t, int);
90 static int drvctl_ioctl(struct file *, u_long, void *);
91 static int drvctl_poll(struct file *, int);
92 static int drvctl_stat(struct file *, struct stat *);
93 static int drvctl_close(struct file *);
94
95 static const struct fileops drvctl_fileops = {
96 .fo_read = drvctl_read,
97 .fo_write = drvctl_write,
98 .fo_ioctl = drvctl_ioctl,
99 .fo_fcntl = fnullop_fcntl,
100 .fo_poll = drvctl_poll,
101 .fo_stat = drvctl_stat,
102 .fo_close = drvctl_close,
103 .fo_kqfilter = fnullop_kqfilter,
104 .fo_restart = fnullop_restart,
105 };
106
107 #define MAXLOCATORS 100
108
109 extern int (*devmon_insert_vec)(const char *, prop_dictionary_t);
110 static int (*saved_insert_vec)(const char *, prop_dictionary_t) = NULL;
111
112 static int drvctl_command(struct lwp *, struct plistref *, u_long, int);
113 static int drvctl_getevent(struct lwp *, struct plistref *, u_long, int);
114
115 void
drvctl_init(void)116 drvctl_init(void)
117 {
118 TAILQ_INIT(&drvctl_eventq);
119 mutex_init(&drvctl_lock, MUTEX_DEFAULT, IPL_NONE);
120 cv_init(&drvctl_cond, "devmon");
121 selinit(&drvctl_rdsel);
122 }
123
124 void
drvctl_fini(void)125 drvctl_fini(void)
126 {
127
128 seldestroy(&drvctl_rdsel);
129 cv_destroy(&drvctl_cond);
130 mutex_destroy(&drvctl_lock);
131 }
132
133 int
devmon_insert(const char * event,prop_dictionary_t ev)134 devmon_insert(const char *event, prop_dictionary_t ev)
135 {
136 struct drvctl_event *dce, *odce;
137
138 mutex_enter(&drvctl_lock);
139
140 if (drvctl_nopen == 0) {
141 prop_object_release(ev);
142 mutex_exit(&drvctl_lock);
143 return 0;
144 }
145
146 /* Fill in mandatory member */
147 if (!prop_dictionary_set_cstring_nocopy(ev, "event", event)) {
148 prop_object_release(ev);
149 mutex_exit(&drvctl_lock);
150 return 0;
151 }
152
153 dce = kmem_alloc(sizeof(*dce), KM_SLEEP);
154 if (dce == NULL) {
155 prop_object_release(ev);
156 mutex_exit(&drvctl_lock);
157 return 0;
158 }
159
160 dce->dce_event = ev;
161
162 if (drvctl_eventcnt == DRVCTL_EVENTQ_DEPTH) {
163 odce = TAILQ_FIRST(&drvctl_eventq);
164 TAILQ_REMOVE(&drvctl_eventq, odce, dce_link);
165 prop_object_release(odce->dce_event);
166 kmem_free(odce, sizeof(*odce));
167 --drvctl_eventcnt;
168 }
169
170 TAILQ_INSERT_TAIL(&drvctl_eventq, dce, dce_link);
171 ++drvctl_eventcnt;
172 cv_broadcast(&drvctl_cond);
173 selnotify(&drvctl_rdsel, 0, 0);
174
175 mutex_exit(&drvctl_lock);
176 return 0;
177 }
178
179 int
drvctlopen(dev_t dev,int flags,int mode,struct lwp * l)180 drvctlopen(dev_t dev, int flags, int mode, struct lwp *l)
181 {
182 struct file *fp;
183 int fd;
184 int ret;
185
186 ret = fd_allocfile(&fp, &fd);
187 if (ret)
188 return ret;
189
190 /* XXX setup context */
191 mutex_enter(&drvctl_lock);
192 ret = fd_clone(fp, fd, flags, &drvctl_fileops, /* context */NULL);
193 ++drvctl_nopen;
194 mutex_exit(&drvctl_lock);
195
196 return ret;
197 }
198
199 static int
pmdevbyname(u_long cmd,struct devpmargs * a)200 pmdevbyname(u_long cmd, struct devpmargs *a)
201 {
202 device_t d;
203
204 if ((d = device_find_by_xname(a->devname)) == NULL)
205 return ENXIO;
206
207 switch (cmd) {
208 case DRVSUSPENDDEV:
209 return pmf_device_recursive_suspend(d, PMF_Q_DRVCTL) ? 0 : EBUSY;
210 case DRVRESUMEDEV:
211 if (a->flags & DEVPM_F_SUBTREE) {
212 return pmf_device_subtree_resume(d, PMF_Q_DRVCTL)
213 ? 0 : EBUSY;
214 } else {
215 return pmf_device_recursive_resume(d, PMF_Q_DRVCTL)
216 ? 0 : EBUSY;
217 }
218 default:
219 return EPASSTHROUGH;
220 }
221 }
222
223 static int
listdevbyname(struct devlistargs * l)224 listdevbyname(struct devlistargs *l)
225 {
226 device_t d, child;
227 deviter_t di;
228 int cnt = 0, idx, error = 0;
229
230 if (*l->l_devname == '\0')
231 d = NULL;
232 else if (memchr(l->l_devname, 0, sizeof(l->l_devname)) == NULL)
233 return EINVAL;
234 else if ((d = device_find_by_xname(l->l_devname)) == NULL)
235 return ENXIO;
236
237 for (child = deviter_first(&di, 0); child != NULL;
238 child = deviter_next(&di)) {
239 if (device_parent(child) != d)
240 continue;
241 idx = cnt++;
242 if (l->l_childname == NULL || idx >= l->l_children)
243 continue;
244 error = copyoutstr(device_xname(child), l->l_childname[idx],
245 sizeof(l->l_childname[idx]), NULL);
246 if (error != 0)
247 break;
248 }
249 deviter_release(&di);
250
251 l->l_children = cnt;
252 return error;
253 }
254
255 static int
detachdevbyname(const char * devname)256 detachdevbyname(const char *devname)
257 {
258 device_t d;
259
260 if ((d = device_find_by_xname(devname)) == NULL)
261 return ENXIO;
262
263 #ifndef XXXFULLRISK
264 /*
265 * If the parent cannot be notified, it might keep
266 * pointers to the detached device.
267 * There might be a private notification mechanism,
268 * but better play it safe here.
269 */
270 if (d->dv_parent && !d->dv_parent->dv_cfattach->ca_childdetached)
271 return ENOTSUP;
272 #endif
273 return config_detach(d, 0);
274 }
275
276 static int
rescanbus(const char * busname,const char * ifattr,int numlocators,const int * locators)277 rescanbus(const char *busname, const char *ifattr,
278 int numlocators, const int *locators)
279 {
280 int i, rc;
281 device_t d;
282 const struct cfiattrdata * const *ap;
283
284 /* XXX there should be a way to get limits and defaults (per device)
285 from config generated data */
286 int locs[MAXLOCATORS];
287 for (i = 0; i < MAXLOCATORS; i++)
288 locs[i] = -1;
289
290 for (i = 0; i < numlocators;i++)
291 locs[i] = locators[i];
292
293 if ((d = device_find_by_xname(busname)) == NULL)
294 return ENXIO;
295
296 /*
297 * must support rescan, and must have something
298 * to attach to
299 */
300 if (!d->dv_cfattach->ca_rescan ||
301 !d->dv_cfdriver->cd_attrs)
302 return ENODEV;
303
304 /* allow to omit attribute if there is exactly one */
305 if (!ifattr) {
306 if (d->dv_cfdriver->cd_attrs[1])
307 return EINVAL;
308 ifattr = d->dv_cfdriver->cd_attrs[0]->ci_name;
309 } else {
310 /* check for valid attribute passed */
311 for (ap = d->dv_cfdriver->cd_attrs; *ap; ap++)
312 if (!strcmp((*ap)->ci_name, ifattr))
313 break;
314 if (!*ap)
315 return EINVAL;
316 }
317
318 rc = (*d->dv_cfattach->ca_rescan)(d, ifattr, locs);
319 config_deferred(NULL);
320 return rc;
321 }
322
323 static int
drvctl_read(struct file * fp,off_t * offp,struct uio * uio,kauth_cred_t cred,int flags)324 drvctl_read(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred,
325 int flags)
326 {
327 return ENODEV;
328 }
329
330 static int
drvctl_write(struct file * fp,off_t * offp,struct uio * uio,kauth_cred_t cred,int flags)331 drvctl_write(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred,
332 int flags)
333 {
334 return ENODEV;
335 }
336
337 static int
drvctl_ioctl(struct file * fp,u_long cmd,void * data)338 drvctl_ioctl(struct file *fp, u_long cmd, void *data)
339 {
340 int res;
341 char *ifattr;
342 int *locs;
343 size_t locs_sz = 0; /* XXXgcc */
344
345 switch (cmd) {
346 case DRVSUSPENDDEV:
347 case DRVRESUMEDEV:
348 #define d ((struct devpmargs *)data)
349 res = pmdevbyname(cmd, d);
350 #undef d
351 break;
352 case DRVLISTDEV:
353 res = listdevbyname((struct devlistargs *)data);
354 break;
355 case DRVDETACHDEV:
356 #define d ((struct devdetachargs *)data)
357 res = detachdevbyname(d->devname);
358 #undef d
359 break;
360 case DRVRESCANBUS:
361 #define d ((struct devrescanargs *)data)
362 d->busname[sizeof(d->busname) - 1] = '\0';
363
364 /* XXX better copyin? */
365 if (d->ifattr[0]) {
366 d->ifattr[sizeof(d->ifattr) - 1] = '\0';
367 ifattr = d->ifattr;
368 } else
369 ifattr = 0;
370
371 if (d->numlocators) {
372 if (d->numlocators > MAXLOCATORS)
373 return EINVAL;
374 locs_sz = d->numlocators * sizeof(int);
375 locs = kmem_alloc(locs_sz, KM_SLEEP);
376 res = copyin(d->locators, locs, locs_sz);
377 if (res) {
378 kmem_free(locs, locs_sz);
379 return res;
380 }
381 } else
382 locs = NULL;
383 res = rescanbus(d->busname, ifattr, d->numlocators, locs);
384 if (locs)
385 kmem_free(locs, locs_sz);
386 #undef d
387 break;
388 case DRVCTLCOMMAND:
389 res = drvctl_command(curlwp, (struct plistref *)data, cmd,
390 fp->f_flag);
391 break;
392 case DRVGETEVENT:
393 res = drvctl_getevent(curlwp, (struct plistref *)data, cmd,
394 fp->f_flag);
395 break;
396 default:
397 return EPASSTHROUGH;
398 }
399 return res;
400 }
401
402 static int
drvctl_stat(struct file * fp,struct stat * st)403 drvctl_stat(struct file *fp, struct stat *st)
404 {
405 (void)memset(st, 0, sizeof(*st));
406 st->st_uid = kauth_cred_geteuid(fp->f_cred);
407 st->st_gid = kauth_cred_getegid(fp->f_cred);
408 return 0;
409 }
410
411 static int
drvctl_poll(struct file * fp,int events)412 drvctl_poll(struct file *fp, int events)
413 {
414 int revents = 0;
415
416 if (!TAILQ_EMPTY(&drvctl_eventq))
417 revents |= events & (POLLIN | POLLRDNORM);
418 else
419 selrecord(curlwp, &drvctl_rdsel);
420
421 return revents;
422 }
423
424 static int
drvctl_close(struct file * fp)425 drvctl_close(struct file *fp)
426 {
427 struct drvctl_event *dce;
428
429 /* XXX free context */
430 mutex_enter(&drvctl_lock);
431 KASSERT(drvctl_nopen > 0);
432 --drvctl_nopen;
433 if (drvctl_nopen == 0) {
434 /* flush queue */
435 while ((dce = TAILQ_FIRST(&drvctl_eventq)) != NULL) {
436 TAILQ_REMOVE(&drvctl_eventq, dce, dce_link);
437 KASSERT(drvctl_eventcnt > 0);
438 --drvctl_eventcnt;
439 prop_object_release(dce->dce_event);
440 kmem_free(dce, sizeof(*dce));
441 }
442 }
443 mutex_exit(&drvctl_lock);
444
445 return 0;
446 }
447
448 void
drvctlattach(int arg __unused)449 drvctlattach(int arg __unused)
450 {
451 }
452
453 /*****************************************************************************
454 * Driver control command processing engine
455 *****************************************************************************/
456
457 static int
drvctl_command_get_properties(struct lwp * l,prop_dictionary_t command_dict,prop_dictionary_t results_dict)458 drvctl_command_get_properties(struct lwp *l,
459 prop_dictionary_t command_dict,
460 prop_dictionary_t results_dict)
461 {
462 prop_dictionary_t args_dict;
463 prop_string_t devname_string;
464 device_t dev;
465 deviter_t di;
466
467 args_dict = prop_dictionary_get(command_dict, "drvctl-arguments");
468 if (args_dict == NULL)
469 return EINVAL;
470
471 devname_string = prop_dictionary_get(args_dict, "device-name");
472 if (devname_string == NULL)
473 return EINVAL;
474
475 for (dev = deviter_first(&di, 0); dev != NULL;
476 dev = deviter_next(&di)) {
477 if (prop_string_equals_cstring(devname_string,
478 device_xname(dev))) {
479 prop_dictionary_set(results_dict, "drvctl-result-data",
480 device_properties(dev));
481 break;
482 }
483 }
484
485 deviter_release(&di);
486
487 if (dev == NULL)
488 return ESRCH;
489
490 return 0;
491 }
492
493 struct drvctl_command_desc {
494 const char *dcd_name; /* command name */
495 int (*dcd_func)(struct lwp *, /* handler function */
496 prop_dictionary_t,
497 prop_dictionary_t);
498 int dcd_rw; /* read or write required */
499 };
500
501 static const struct drvctl_command_desc drvctl_command_table[] = {
502 { .dcd_name = "get-properties",
503 .dcd_func = drvctl_command_get_properties,
504 .dcd_rw = FREAD,
505 },
506
507 { .dcd_name = NULL }
508 };
509
510 static int
drvctl_command(struct lwp * l,struct plistref * pref,u_long ioctl_cmd,int fflag)511 drvctl_command(struct lwp *l, struct plistref *pref, u_long ioctl_cmd,
512 int fflag)
513 {
514 prop_dictionary_t command_dict, results_dict;
515 prop_string_t command_string;
516 const struct drvctl_command_desc *dcd;
517 int error;
518
519 error = prop_dictionary_copyin_ioctl(pref, ioctl_cmd, &command_dict);
520 if (error)
521 return error;
522
523 results_dict = prop_dictionary_create();
524 if (results_dict == NULL) {
525 prop_object_release(command_dict);
526 return ENOMEM;
527 }
528
529 command_string = prop_dictionary_get(command_dict, "drvctl-command");
530 if (command_string == NULL) {
531 error = EINVAL;
532 goto out;
533 }
534
535 for (dcd = drvctl_command_table; dcd->dcd_name != NULL; dcd++) {
536 if (prop_string_equals_cstring(command_string,
537 dcd->dcd_name))
538 break;
539 }
540
541 if (dcd->dcd_name == NULL) {
542 error = EINVAL;
543 goto out;
544 }
545
546 if ((fflag & dcd->dcd_rw) == 0) {
547 error = EPERM;
548 goto out;
549 }
550
551 error = (*dcd->dcd_func)(l, command_dict, results_dict);
552
553 prop_dictionary_set_int32(results_dict, "drvctl-error", error);
554
555 error = prop_dictionary_copyout_ioctl(pref, ioctl_cmd, results_dict);
556 out:
557 prop_object_release(command_dict);
558 prop_object_release(results_dict);
559 return error;
560 }
561
562 static int
drvctl_getevent(struct lwp * l,struct plistref * pref,u_long ioctl_cmd,int fflag)563 drvctl_getevent(struct lwp *l, struct plistref *pref, u_long ioctl_cmd,
564 int fflag)
565 {
566 struct drvctl_event *dce;
567 int ret;
568
569 if ((fflag & (FREAD|FWRITE)) != (FREAD|FWRITE))
570 return EPERM;
571
572 mutex_enter(&drvctl_lock);
573 while ((dce = TAILQ_FIRST(&drvctl_eventq)) == NULL) {
574 if (fflag & O_NONBLOCK) {
575 mutex_exit(&drvctl_lock);
576 return EWOULDBLOCK;
577 }
578
579 ret = cv_wait_sig(&drvctl_cond, &drvctl_lock);
580 if (ret) {
581 mutex_exit(&drvctl_lock);
582 return ret;
583 }
584 }
585 TAILQ_REMOVE(&drvctl_eventq, dce, dce_link);
586 KASSERT(drvctl_eventcnt > 0);
587 --drvctl_eventcnt;
588 mutex_exit(&drvctl_lock);
589
590 ret = prop_dictionary_copyout_ioctl(pref, ioctl_cmd, dce->dce_event);
591
592 prop_object_release(dce->dce_event);
593 kmem_free(dce, sizeof(*dce));
594
595 return ret;
596 }
597
598 /*
599 * Module glue
600 */
601
602 MODULE(MODULE_CLASS_DRIVER, drvctl, NULL);
603
604 int
drvctl_modcmd(modcmd_t cmd,void * arg)605 drvctl_modcmd(modcmd_t cmd, void *arg)
606 {
607 int error;
608 #ifdef _MODULE
609 int bmajor, cmajor;
610 #endif
611
612 error = 0;
613 switch (cmd) {
614 case MODULE_CMD_INIT:
615 drvctl_init();
616
617 mutex_enter(&drvctl_lock);
618 #ifdef _MODULE
619 bmajor = cmajor = -1;
620 error = devsw_attach("drvctl", NULL, &bmajor,
621 &drvctl_cdevsw, &cmajor);
622 #endif
623 if (error == 0) {
624 KASSERT(saved_insert_vec == NULL);
625 saved_insert_vec = devmon_insert_vec;
626 devmon_insert_vec = devmon_insert;
627 }
628
629 mutex_exit(&drvctl_lock);
630 break;
631
632 case MODULE_CMD_FINI:
633 mutex_enter(&drvctl_lock);
634 if (drvctl_nopen != 0 || drvctl_eventcnt != 0 ) {
635 mutex_exit(&drvctl_lock);
636 return EBUSY;
637 }
638 KASSERT(saved_insert_vec != NULL);
639 devmon_insert_vec = saved_insert_vec;
640 saved_insert_vec = NULL;
641 #ifdef _MODULE
642 error = devsw_detach(NULL, &drvctl_cdevsw);
643 if (error != 0) {
644 saved_insert_vec = devmon_insert_vec;
645 devmon_insert_vec = devmon_insert;
646 }
647 #endif
648 mutex_exit(&drvctl_lock);
649 if (error == 0)
650 drvctl_fini();
651
652 break;
653 default:
654 error = ENOTTY;
655 break;
656 }
657
658 return error;
659 }
660