1 /* $NetBSD: kern_drvctl.c,v 1.51 2022/03/28 12:33:22 riastradh 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 1.51 2022/03/28 12:33:22 riastradh 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_name = "drvctl",
97 .fo_read = drvctl_read,
98 .fo_write = drvctl_write,
99 .fo_ioctl = drvctl_ioctl,
100 .fo_fcntl = fnullop_fcntl,
101 .fo_poll = drvctl_poll,
102 .fo_stat = drvctl_stat,
103 .fo_close = drvctl_close,
104 .fo_kqfilter = fnullop_kqfilter,
105 .fo_restart = fnullop_restart,
106 };
107
108 #define MAXLOCATORS 100
109
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_string_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 dce->dce_event = ev;
155
156 if (drvctl_eventcnt == DRVCTL_EVENTQ_DEPTH) {
157 odce = TAILQ_FIRST(&drvctl_eventq);
158 TAILQ_REMOVE(&drvctl_eventq, odce, dce_link);
159 prop_object_release(odce->dce_event);
160 kmem_free(odce, sizeof(*odce));
161 --drvctl_eventcnt;
162 }
163
164 TAILQ_INSERT_TAIL(&drvctl_eventq, dce, dce_link);
165 ++drvctl_eventcnt;
166 cv_broadcast(&drvctl_cond);
167 selnotify(&drvctl_rdsel, 0, 0);
168
169 mutex_exit(&drvctl_lock);
170 return 0;
171 }
172
173 int
drvctlopen(dev_t dev,int flags,int mode,struct lwp * l)174 drvctlopen(dev_t dev, int flags, int mode, struct lwp *l)
175 {
176 struct file *fp;
177 int fd;
178 int ret;
179
180 ret = fd_allocfile(&fp, &fd);
181 if (ret)
182 return ret;
183
184 /* XXX setup context */
185 mutex_enter(&drvctl_lock);
186 ret = fd_clone(fp, fd, flags, &drvctl_fileops, /* context */NULL);
187 ++drvctl_nopen;
188 mutex_exit(&drvctl_lock);
189
190 return ret;
191 }
192
193 static int
pmdevbyname(u_long cmd,struct devpmargs * a)194 pmdevbyname(u_long cmd, struct devpmargs *a)
195 {
196 device_t d;
197
198 KASSERT(KERNEL_LOCKED_P());
199
200 if ((d = device_find_by_xname(a->devname)) == NULL)
201 return ENXIO;
202
203 switch (cmd) {
204 case DRVSUSPENDDEV:
205 return pmf_device_recursive_suspend(d, PMF_Q_DRVCTL) ? 0 : EBUSY;
206 case DRVRESUMEDEV:
207 if (a->flags & DEVPM_F_SUBTREE) {
208 return pmf_device_subtree_resume(d, PMF_Q_DRVCTL)
209 ? 0 : EBUSY;
210 } else {
211 return pmf_device_recursive_resume(d, PMF_Q_DRVCTL)
212 ? 0 : EBUSY;
213 }
214 default:
215 return EPASSTHROUGH;
216 }
217 }
218
219 static int
listdevbyname(struct devlistargs * l)220 listdevbyname(struct devlistargs *l)
221 {
222 device_t d, child;
223 deviter_t di;
224 int cnt = 0, idx, error = 0;
225
226 KASSERT(KERNEL_LOCKED_P());
227
228 if (*l->l_devname == '\0')
229 d = NULL;
230 else if (memchr(l->l_devname, 0, sizeof(l->l_devname)) == NULL)
231 return EINVAL;
232 else if ((d = device_find_by_xname(l->l_devname)) == NULL)
233 return ENXIO;
234
235 for (child = deviter_first(&di, 0); child != NULL;
236 child = deviter_next(&di)) {
237 if (device_parent(child) != d)
238 continue;
239 idx = cnt++;
240 if (l->l_childname == NULL || idx >= l->l_children)
241 continue;
242 error = copyoutstr(device_xname(child), l->l_childname[idx],
243 sizeof(l->l_childname[idx]), NULL);
244 if (error != 0)
245 break;
246 }
247 deviter_release(&di);
248
249 l->l_children = cnt;
250 return error;
251 }
252
253 static int
detachdevbyname(const char * devname)254 detachdevbyname(const char *devname)
255 {
256 device_t d;
257 deviter_t di;
258 int error;
259
260 KASSERT(KERNEL_LOCKED_P());
261
262 for (d = deviter_first(&di, DEVITER_F_RW);
263 d != NULL;
264 d = deviter_next(&di)) {
265 if (strcmp(device_xname(d), devname) == 0)
266 break;
267 }
268 if (d == NULL) {
269 error = ENXIO;
270 goto out;
271 }
272
273 #ifndef XXXFULLRISK
274 /*
275 * If the parent cannot be notified, it might keep
276 * pointers to the detached device.
277 * There might be a private notification mechanism,
278 * but better play it safe here.
279 */
280 if (device_parent(d) &&
281 !device_cfattach(device_parent(d))->ca_childdetached) {
282 error = ENOTSUP;
283 goto out;
284 }
285 #endif
286
287 error = config_detach(d, 0);
288 out: deviter_release(&di);
289 return error;
290 }
291
292 static int
rescanbus(const char * busname,const char * ifattr,int numlocators,const int * locators)293 rescanbus(const char *busname, const char *ifattr,
294 int numlocators, const int *locators)
295 {
296 int i, rc;
297 device_t d;
298 const struct cfiattrdata * const *ap;
299
300 KASSERT(KERNEL_LOCKED_P());
301
302 /* XXX there should be a way to get limits and defaults (per device)
303 from config generated data */
304 int locs[MAXLOCATORS];
305 for (i = 0; i < MAXLOCATORS; i++)
306 locs[i] = -1;
307
308 for (i = 0; i < numlocators;i++)
309 locs[i] = locators[i];
310
311 if ((d = device_find_by_xname(busname)) == NULL)
312 return ENXIO;
313
314 /*
315 * must support rescan, and must have something
316 * to attach to
317 */
318 if (!device_cfattach(d)->ca_rescan ||
319 !device_cfdriver(d)->cd_attrs)
320 return ENODEV;
321
322 /* rescan all ifattrs if none is specified */
323 if (!ifattr) {
324 rc = 0;
325 for (ap = device_cfdriver(d)->cd_attrs; *ap; ap++) {
326 rc = (*device_cfattach(d)->ca_rescan)(d,
327 (*ap)->ci_name, locs);
328 if (rc)
329 break;
330 }
331 } else {
332 /* check for valid attribute passed */
333 for (ap = device_cfdriver(d)->cd_attrs; *ap; ap++)
334 if (!strcmp((*ap)->ci_name, ifattr))
335 break;
336 if (!*ap)
337 return EINVAL;
338 rc = (*device_cfattach(d)->ca_rescan)(d, ifattr, locs);
339 }
340
341 config_deferred(NULL);
342 return rc;
343 }
344
345 static int
drvctl_read(struct file * fp,off_t * offp,struct uio * uio,kauth_cred_t cred,int flags)346 drvctl_read(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred,
347 int flags)
348 {
349 return ENODEV;
350 }
351
352 static int
drvctl_write(struct file * fp,off_t * offp,struct uio * uio,kauth_cred_t cred,int flags)353 drvctl_write(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred,
354 int flags)
355 {
356 return ENODEV;
357 }
358
359 static int
drvctl_ioctl(struct file * fp,u_long cmd,void * data)360 drvctl_ioctl(struct file *fp, u_long cmd, void *data)
361 {
362 int res;
363 char *ifattr;
364 int *locs;
365 size_t locs_sz = 0; /* XXXgcc */
366
367 KERNEL_LOCK(1, NULL);
368 switch (cmd) {
369 case DRVSUSPENDDEV:
370 case DRVRESUMEDEV:
371 #define d ((struct devpmargs *)data)
372 res = pmdevbyname(cmd, d);
373 #undef d
374 break;
375 case DRVLISTDEV:
376 res = listdevbyname((struct devlistargs *)data);
377 break;
378 case DRVDETACHDEV:
379 #define d ((struct devdetachargs *)data)
380 res = detachdevbyname(d->devname);
381 #undef d
382 break;
383 case DRVRESCANBUS:
384 #define d ((struct devrescanargs *)data)
385 d->busname[sizeof(d->busname) - 1] = '\0';
386
387 /* XXX better copyin? */
388 if (d->ifattr[0]) {
389 d->ifattr[sizeof(d->ifattr) - 1] = '\0';
390 ifattr = d->ifattr;
391 } else
392 ifattr = 0;
393
394 if (d->numlocators) {
395 if (d->numlocators > MAXLOCATORS) {
396 res = EINVAL;
397 goto out;
398 }
399 locs_sz = d->numlocators * sizeof(int);
400 locs = kmem_alloc(locs_sz, KM_SLEEP);
401 res = copyin(d->locators, locs, locs_sz);
402 if (res) {
403 kmem_free(locs, locs_sz);
404 goto out;
405 }
406 } else
407 locs = NULL;
408 res = rescanbus(d->busname, ifattr, d->numlocators, locs);
409 if (locs)
410 kmem_free(locs, locs_sz);
411 #undef d
412 break;
413 case DRVCTLCOMMAND:
414 res = drvctl_command(curlwp, (struct plistref *)data, cmd,
415 fp->f_flag);
416 break;
417 case DRVGETEVENT:
418 res = drvctl_getevent(curlwp, (struct plistref *)data, cmd,
419 fp->f_flag);
420 break;
421 default:
422 res = EPASSTHROUGH;
423 break;
424 }
425 out: KERNEL_UNLOCK_ONE(NULL);
426 return res;
427 }
428
429 static int
drvctl_stat(struct file * fp,struct stat * st)430 drvctl_stat(struct file *fp, struct stat *st)
431 {
432 (void)memset(st, 0, sizeof(*st));
433 st->st_uid = kauth_cred_geteuid(fp->f_cred);
434 st->st_gid = kauth_cred_getegid(fp->f_cred);
435 return 0;
436 }
437
438 static int
drvctl_poll(struct file * fp,int events)439 drvctl_poll(struct file *fp, int events)
440 {
441 int revents = 0;
442
443 if (!TAILQ_EMPTY(&drvctl_eventq))
444 revents |= events & (POLLIN | POLLRDNORM);
445 else
446 selrecord(curlwp, &drvctl_rdsel);
447
448 return revents;
449 }
450
451 static int
drvctl_close(struct file * fp)452 drvctl_close(struct file *fp)
453 {
454 struct drvctl_event *dce;
455
456 /* XXX free context */
457 mutex_enter(&drvctl_lock);
458 KASSERT(drvctl_nopen > 0);
459 --drvctl_nopen;
460 if (drvctl_nopen == 0) {
461 /* flush queue */
462 while ((dce = TAILQ_FIRST(&drvctl_eventq)) != NULL) {
463 TAILQ_REMOVE(&drvctl_eventq, dce, dce_link);
464 KASSERT(drvctl_eventcnt > 0);
465 --drvctl_eventcnt;
466 prop_object_release(dce->dce_event);
467 kmem_free(dce, sizeof(*dce));
468 }
469 }
470 mutex_exit(&drvctl_lock);
471
472 return 0;
473 }
474
475 void
drvctlattach(int arg __unused)476 drvctlattach(int arg __unused)
477 {
478 }
479
480 /*****************************************************************************
481 * Driver control command processing engine
482 *****************************************************************************/
483
484 static int
drvctl_command_get_properties(struct lwp * l,prop_dictionary_t command_dict,prop_dictionary_t results_dict)485 drvctl_command_get_properties(struct lwp *l,
486 prop_dictionary_t command_dict,
487 prop_dictionary_t results_dict)
488 {
489 prop_dictionary_t args_dict;
490 prop_string_t devname_string;
491 device_t dev;
492 deviter_t di;
493
494 args_dict = prop_dictionary_get(command_dict, "drvctl-arguments");
495 if (args_dict == NULL)
496 return EINVAL;
497
498 devname_string = prop_dictionary_get(args_dict, "device-name");
499 if (devname_string == NULL)
500 return EINVAL;
501
502 for (dev = deviter_first(&di, 0); dev != NULL;
503 dev = deviter_next(&di)) {
504 if (prop_string_equals_string(devname_string,
505 device_xname(dev))) {
506 prop_dictionary_set(results_dict, "drvctl-result-data",
507 device_properties(dev));
508 break;
509 }
510 }
511
512 deviter_release(&di);
513
514 if (dev == NULL)
515 return ESRCH;
516
517 return 0;
518 }
519
520 struct drvctl_command_desc {
521 const char *dcd_name; /* command name */
522 int (*dcd_func)(struct lwp *, /* handler function */
523 prop_dictionary_t,
524 prop_dictionary_t);
525 int dcd_rw; /* read or write required */
526 };
527
528 static const struct drvctl_command_desc drvctl_command_table[] = {
529 { .dcd_name = "get-properties",
530 .dcd_func = drvctl_command_get_properties,
531 .dcd_rw = FREAD,
532 },
533
534 { .dcd_name = NULL }
535 };
536
537 static int
drvctl_command(struct lwp * l,struct plistref * pref,u_long ioctl_cmd,int fflag)538 drvctl_command(struct lwp *l, struct plistref *pref, u_long ioctl_cmd,
539 int fflag)
540 {
541 prop_dictionary_t command_dict, results_dict;
542 prop_string_t command_string;
543 const struct drvctl_command_desc *dcd;
544 int error;
545
546 error = prop_dictionary_copyin_ioctl(pref, ioctl_cmd, &command_dict);
547 if (error)
548 return error;
549
550 results_dict = prop_dictionary_create();
551 if (results_dict == NULL) {
552 prop_object_release(command_dict);
553 return ENOMEM;
554 }
555
556 command_string = prop_dictionary_get(command_dict, "drvctl-command");
557 if (command_string == NULL) {
558 error = EINVAL;
559 goto out;
560 }
561
562 for (dcd = drvctl_command_table; dcd->dcd_name != NULL; dcd++) {
563 if (prop_string_equals_string(command_string,
564 dcd->dcd_name))
565 break;
566 }
567
568 if (dcd->dcd_name == NULL) {
569 error = EINVAL;
570 goto out;
571 }
572
573 if ((fflag & dcd->dcd_rw) == 0) {
574 error = EPERM;
575 goto out;
576 }
577
578 error = (*dcd->dcd_func)(l, command_dict, results_dict);
579
580 prop_dictionary_set_int32(results_dict, "drvctl-error", error);
581
582 error = prop_dictionary_copyout_ioctl(pref, ioctl_cmd, results_dict);
583 out:
584 prop_object_release(command_dict);
585 prop_object_release(results_dict);
586 return error;
587 }
588
589 static int
drvctl_getevent(struct lwp * l,struct plistref * pref,u_long ioctl_cmd,int fflag)590 drvctl_getevent(struct lwp *l, struct plistref *pref, u_long ioctl_cmd,
591 int fflag)
592 {
593 struct drvctl_event *dce;
594 int ret;
595
596 if ((fflag & (FREAD|FWRITE)) != (FREAD|FWRITE))
597 return EPERM;
598
599 mutex_enter(&drvctl_lock);
600 while ((dce = TAILQ_FIRST(&drvctl_eventq)) == NULL) {
601 if (fflag & O_NONBLOCK) {
602 mutex_exit(&drvctl_lock);
603 return EWOULDBLOCK;
604 }
605
606 ret = cv_wait_sig(&drvctl_cond, &drvctl_lock);
607 if (ret) {
608 mutex_exit(&drvctl_lock);
609 return ret;
610 }
611 }
612 TAILQ_REMOVE(&drvctl_eventq, dce, dce_link);
613 KASSERT(drvctl_eventcnt > 0);
614 --drvctl_eventcnt;
615 mutex_exit(&drvctl_lock);
616
617 ret = prop_dictionary_copyout_ioctl(pref, ioctl_cmd, dce->dce_event);
618
619 prop_object_release(dce->dce_event);
620 kmem_free(dce, sizeof(*dce));
621
622 return ret;
623 }
624
625 /*
626 * Module glue
627 */
628
629 MODULE(MODULE_CLASS_DRIVER, drvctl, NULL);
630
631 int
drvctl_modcmd(modcmd_t cmd,void * arg)632 drvctl_modcmd(modcmd_t cmd, void *arg)
633 {
634 int error;
635 #ifdef _MODULE
636 int bmajor, cmajor;
637 #endif
638
639 error = 0;
640 switch (cmd) {
641 case MODULE_CMD_INIT:
642 drvctl_init();
643
644 mutex_enter(&drvctl_lock);
645 #ifdef _MODULE
646 bmajor = cmajor = -1;
647 error = devsw_attach("drvctl", NULL, &bmajor,
648 &drvctl_cdevsw, &cmajor);
649 #endif
650 if (error == 0) {
651 KASSERT(saved_insert_vec == NULL);
652 saved_insert_vec = devmon_insert_vec;
653 devmon_insert_vec = devmon_insert;
654 }
655
656 mutex_exit(&drvctl_lock);
657 break;
658
659 case MODULE_CMD_FINI:
660 mutex_enter(&drvctl_lock);
661 if (drvctl_nopen != 0 || drvctl_eventcnt != 0 ) {
662 mutex_exit(&drvctl_lock);
663 return EBUSY;
664 }
665 KASSERT(saved_insert_vec != NULL);
666 devmon_insert_vec = saved_insert_vec;
667 saved_insert_vec = NULL;
668 #ifdef _MODULE
669 devsw_detach(NULL, &drvctl_cdevsw);
670 #endif
671 mutex_exit(&drvctl_lock);
672 drvctl_fini();
673
674 break;
675 default:
676 error = ENOTTY;
677 break;
678 }
679
680 return error;
681 }
682