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kern_drvctl.c revision 1.34 
      1 /* $NetBSD: kern_drvctl.c,v 1.34 2013/04/26 09:04:43 msaitoh 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 1.34 2013/04/26 09:04:43 msaitoh 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 		prop_object_release(ev);
    119 		mutex_exit(&drvctl_lock);
    120 		return;
    121 	}
    122 
    123 	/* Fill in mandatory member */
    124 	if (!prop_dictionary_set_cstring_nocopy(ev, "event", event)) {
    125 		prop_object_release(ev);
    126 		mutex_exit(&drvctl_lock);
    127 		return;
    128 	}
    129 
    130 	dce = kmem_alloc(sizeof(*dce), KM_SLEEP);
    131 	if (dce == NULL) {
    132 		prop_object_release(ev);
    133 		mutex_exit(&drvctl_lock);
    134 		return;
    135 	}
    136 
    137 	dce->dce_event = ev;
    138 
    139 	if (drvctl_eventcnt == DRVCTL_EVENTQ_DEPTH) {
    140 		odce = TAILQ_FIRST(&drvctl_eventq);
    141 		TAILQ_REMOVE(&drvctl_eventq, odce, dce_link);
    142 		prop_object_release(odce->dce_event);
    143 		kmem_free(odce, sizeof(*odce));
    144 		--drvctl_eventcnt;
    145 	}
    146 
    147 	TAILQ_INSERT_TAIL(&drvctl_eventq, dce, dce_link);
    148 	++drvctl_eventcnt;
    149 	cv_broadcast(&drvctl_cond);
    150 	selnotify(&drvctl_rdsel, 0, 0);
    151 
    152 	mutex_exit(&drvctl_lock);
    153 }
    154 
    155 int
    156 drvctlopen(dev_t dev, int flags, int mode, struct lwp *l)
    157 {
    158 	struct file *fp;
    159 	int fd;
    160 	int ret;
    161 
    162 	ret = fd_allocfile(&fp, &fd);
    163 	if (ret)
    164 		return ret;
    165 
    166 	/* XXX setup context */
    167 	mutex_enter(&drvctl_lock);
    168 	ret = fd_clone(fp, fd, flags, &drvctl_fileops, /* context */NULL);
    169 	++drvctl_nopen;
    170 	mutex_exit(&drvctl_lock);
    171 
    172 	return ret;
    173 }
    174 
    175 static int
    176 pmdevbyname(u_long cmd, struct devpmargs *a)
    177 {
    178 	device_t d;
    179 
    180 	if ((d = device_find_by_xname(a->devname)) == NULL)
    181 		return ENXIO;
    182 
    183 	switch (cmd) {
    184 	case DRVSUSPENDDEV:
    185 		return pmf_device_recursive_suspend(d, PMF_Q_DRVCTL) ? 0 : EBUSY;
    186 	case DRVRESUMEDEV:
    187 		if (a->flags & DEVPM_F_SUBTREE) {
    188 			return pmf_device_subtree_resume(d, PMF_Q_DRVCTL)
    189 			    ? 0 : EBUSY;
    190 		} else {
    191 			return pmf_device_recursive_resume(d, PMF_Q_DRVCTL)
    192 			    ? 0 : EBUSY;
    193 		}
    194 	default:
    195 		return EPASSTHROUGH;
    196 	}
    197 }
    198 
    199 static int
    200 listdevbyname(struct devlistargs *l)
    201 {
    202 	device_t d, child;
    203 	deviter_t di;
    204 	int cnt = 0, idx, error = 0;
    205 
    206 	if (*l->l_devname == '\0')
    207 		d = NULL;
    208 	else if (memchr(l->l_devname, 0, sizeof(l->l_devname)) == NULL)
    209 		return EINVAL;
    210 	else if ((d = device_find_by_xname(l->l_devname)) == NULL)
    211 		return ENXIO;
    212 
    213 	for (child = deviter_first(&di, 0); child != NULL;
    214 	     child = deviter_next(&di)) {
    215 		if (device_parent(child) != d)
    216 			continue;
    217 		idx = cnt++;
    218 		if (l->l_childname == NULL || idx >= l->l_children)
    219 			continue;
    220 		error = copyoutstr(device_xname(child), l->l_childname[idx],
    221 				sizeof(l->l_childname[idx]), NULL);
    222 		if (error != 0)
    223 			break;
    224 	}
    225 	deviter_release(&di);
    226 
    227 	l->l_children = cnt;
    228 	return error;
    229 }
    230 
    231 static int
    232 detachdevbyname(const char *devname)
    233 {
    234 	device_t d;
    235 
    236 	if ((d = device_find_by_xname(devname)) == NULL)
    237 		return ENXIO;
    238 
    239 #ifndef XXXFULLRISK
    240 	/*
    241 	 * If the parent cannot be notified, it might keep
    242 	 * pointers to the detached device.
    243 	 * There might be a private notification mechanism,
    244 	 * but better play it safe here.
    245 	 */
    246 	if (d->dv_parent && !d->dv_parent->dv_cfattach->ca_childdetached)
    247 		return ENOTSUP;
    248 #endif
    249 	return config_detach(d, 0);
    250 }
    251 
    252 static int
    253 rescanbus(const char *busname, const char *ifattr,
    254 	  int numlocators, const int *locators)
    255 {
    256 	int i, rc;
    257 	device_t d;
    258 	const struct cfiattrdata * const *ap;
    259 
    260 	/* XXX there should be a way to get limits and defaults (per device)
    261 	   from config generated data */
    262 	int locs[MAXLOCATORS];
    263 	for (i = 0; i < MAXLOCATORS; i++)
    264 		locs[i] = -1;
    265 
    266 	for (i = 0; i < numlocators;i++)
    267 		locs[i] = locators[i];
    268 
    269 	if ((d = device_find_by_xname(busname)) == NULL)
    270 		return ENXIO;
    271 
    272 	/*
    273 	 * must support rescan, and must have something
    274 	 * to attach to
    275 	 */
    276 	if (!d->dv_cfattach->ca_rescan ||
    277 	    !d->dv_cfdriver->cd_attrs)
    278 		return ENODEV;
    279 
    280 	/* allow to omit attribute if there is exactly one */
    281 	if (!ifattr) {
    282 		if (d->dv_cfdriver->cd_attrs[1])
    283 			return EINVAL;
    284 		ifattr = d->dv_cfdriver->cd_attrs[0]->ci_name;
    285 	} else {
    286 		/* check for valid attribute passed */
    287 		for (ap = d->dv_cfdriver->cd_attrs; *ap; ap++)
    288 			if (!strcmp((*ap)->ci_name, ifattr))
    289 				break;
    290 		if (!*ap)
    291 			return EINVAL;
    292 	}
    293 
    294 	rc = (*d->dv_cfattach->ca_rescan)(d, ifattr, locs);
    295 	config_deferred(NULL);
    296 	return rc;
    297 }
    298 
    299 static int
    300 drvctl_read(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred,
    301     int flags)
    302 {
    303 	return ENODEV;
    304 }
    305 
    306 static int
    307 drvctl_write(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred,
    308     int flags)
    309 {
    310 	return ENODEV;
    311 }
    312 
    313 static int
    314 drvctl_ioctl(struct file *fp, u_long cmd, void *data)
    315 {
    316 	int res;
    317 	char *ifattr;
    318 	int *locs;
    319 	size_t locs_sz = 0; /* XXXgcc */
    320 
    321 	switch (cmd) {
    322 	case DRVSUSPENDDEV:
    323 	case DRVRESUMEDEV:
    324 #define d ((struct devpmargs *)data)
    325 		res = pmdevbyname(cmd, d);
    326 #undef d
    327 		break;
    328 	case DRVLISTDEV:
    329 		res = listdevbyname((struct devlistargs *)data);
    330 		break;
    331 	case DRVDETACHDEV:
    332 #define d ((struct devdetachargs *)data)
    333 		res = detachdevbyname(d->devname);
    334 #undef d
    335 		break;
    336 	case DRVRESCANBUS:
    337 #define d ((struct devrescanargs *)data)
    338 		d->busname[sizeof(d->busname) - 1] = '\0';
    339 
    340 		/* XXX better copyin? */
    341 		if (d->ifattr[0]) {
    342 			d->ifattr[sizeof(d->ifattr) - 1] = '\0';
    343 			ifattr = d->ifattr;
    344 		} else
    345 			ifattr = 0;
    346 
    347 		if (d->numlocators) {
    348 			if (d->numlocators > MAXLOCATORS)
    349 				return EINVAL;
    350 			locs_sz = d->numlocators * sizeof(int);
    351 			locs = kmem_alloc(locs_sz, KM_SLEEP);
    352 			res = copyin(d->locators, locs, locs_sz);
    353 			if (res) {
    354 				kmem_free(locs, locs_sz);
    355 				return res;
    356 			}
    357 		} else
    358 			locs = NULL;
    359 		res = rescanbus(d->busname, ifattr, d->numlocators, locs);
    360 		if (locs)
    361 			kmem_free(locs, locs_sz);
    362 #undef d
    363 		break;
    364 	case DRVCTLCOMMAND:
    365 	    	res = drvctl_command(curlwp, (struct plistref *)data, cmd,
    366 		    fp->f_flag);
    367 	    	break;
    368 	case DRVGETEVENT:
    369 		res = drvctl_getevent(curlwp, (struct plistref *)data, cmd,
    370 		    fp->f_flag);
    371 		break;
    372 	default:
    373 		return EPASSTHROUGH;
    374 	}
    375 	return res;
    376 }
    377 
    378 static int
    379 drvctl_stat(struct file *fp, struct stat *st)
    380 {
    381 	(void)memset(st, 0, sizeof(*st));
    382 	st->st_uid = kauth_cred_geteuid(fp->f_cred);
    383 	st->st_gid = kauth_cred_getegid(fp->f_cred);
    384 	return 0;
    385 }
    386 
    387 static int
    388 drvctl_poll(struct file *fp, int events)
    389 {
    390 	int revents = 0;
    391 
    392 	if (!TAILQ_EMPTY(&drvctl_eventq))
    393 		revents |= events & (POLLIN | POLLRDNORM);
    394 	else
    395 		selrecord(curlwp, &drvctl_rdsel);
    396 
    397 	return revents;
    398 }
    399 
    400 static int
    401 drvctl_close(struct file *fp)
    402 {
    403 	struct drvctl_event *dce;
    404 
    405 	/* XXX free context */
    406 	mutex_enter(&drvctl_lock);
    407 	KASSERT(drvctl_nopen > 0);
    408 	--drvctl_nopen;
    409 	if (drvctl_nopen == 0) {
    410 		/* flush queue */
    411 		while ((dce = TAILQ_FIRST(&drvctl_eventq)) != NULL) {
    412 			TAILQ_REMOVE(&drvctl_eventq, dce, dce_link);
    413 			KASSERT(drvctl_eventcnt > 0);
    414 			--drvctl_eventcnt;
    415 			prop_object_release(dce->dce_event);
    416 			kmem_free(dce, sizeof(*dce));
    417 		}
    418 	}
    419 	mutex_exit(&drvctl_lock);
    420 
    421 	return 0;
    422 }
    423 
    424 void
    425 drvctlattach(int arg)
    426 {
    427 }
    428 
    429 /*****************************************************************************
    430  * Driver control command processing engine
    431  *****************************************************************************/
    432 
    433 static int
    434 drvctl_command_get_properties(struct lwp *l,
    435 			      prop_dictionary_t command_dict,
    436 			      prop_dictionary_t results_dict)
    437 {
    438 	prop_dictionary_t args_dict;
    439 	prop_string_t devname_string;
    440 	device_t dev;
    441 	deviter_t di;
    442 
    443 	args_dict = prop_dictionary_get(command_dict, "drvctl-arguments");
    444 	if (args_dict == NULL)
    445 		return EINVAL;
    446 
    447 	devname_string = prop_dictionary_get(args_dict, "device-name");
    448 	if (devname_string == NULL)
    449 		return EINVAL;
    450 
    451 	for (dev = deviter_first(&di, 0); dev != NULL;
    452 	     dev = deviter_next(&di)) {
    453 		if (prop_string_equals_cstring(devname_string,
    454 					       device_xname(dev))) {
    455 			prop_dictionary_set(results_dict, "drvctl-result-data",
    456 			    device_properties(dev));
    457 			break;
    458 		}
    459 	}
    460 
    461 	deviter_release(&di);
    462 
    463 	if (dev == NULL)
    464 		return ESRCH;
    465 
    466 	return 0;
    467 }
    468 
    469 struct drvctl_command_desc {
    470 	const char *dcd_name;		/* command name */
    471 	int (*dcd_func)(struct lwp *,	/* handler function */
    472 			prop_dictionary_t,
    473 			prop_dictionary_t);
    474 	int dcd_rw;			/* read or write required */
    475 };
    476 
    477 static const struct drvctl_command_desc drvctl_command_table[] = {
    478 	{ .dcd_name = "get-properties",
    479 	  .dcd_func = drvctl_command_get_properties,
    480 	  .dcd_rw   = FREAD,
    481 	},
    482 
    483 	{ .dcd_name = NULL }
    484 };
    485 
    486 static int
    487 drvctl_command(struct lwp *l, struct plistref *pref, u_long ioctl_cmd,
    488 	       int fflag)
    489 {
    490 	prop_dictionary_t command_dict, results_dict;
    491 	prop_string_t command_string;
    492 	const struct drvctl_command_desc *dcd;
    493 	int error;
    494 
    495 	error = prop_dictionary_copyin_ioctl(pref, ioctl_cmd, &command_dict);
    496 	if (error)
    497 		return error;
    498 
    499 	results_dict = prop_dictionary_create();
    500 	if (results_dict == NULL) {
    501 		prop_object_release(command_dict);
    502 		return ENOMEM;
    503 	}
    504 
    505 	command_string = prop_dictionary_get(command_dict, "drvctl-command");
    506 	if (command_string == NULL) {
    507 		error = EINVAL;
    508 		goto out;
    509 	}
    510 
    511 	for (dcd = drvctl_command_table; dcd->dcd_name != NULL; dcd++) {
    512 		if (prop_string_equals_cstring(command_string,
    513 					       dcd->dcd_name))
    514 			break;
    515 	}
    516 
    517 	if (dcd->dcd_name == NULL) {
    518 		error = EINVAL;
    519 		goto out;
    520 	}
    521 
    522 	if ((fflag & dcd->dcd_rw) == 0) {
    523 		error = EPERM;
    524 		goto out;
    525 	}
    526 
    527 	error = (*dcd->dcd_func)(l, command_dict, results_dict);
    528 
    529 	prop_dictionary_set_int32(results_dict, "drvctl-error", error);
    530 
    531 	error = prop_dictionary_copyout_ioctl(pref, ioctl_cmd, results_dict);
    532  out:
    533 	prop_object_release(command_dict);
    534 	prop_object_release(results_dict);
    535 	return error;
    536 }
    537 
    538 static int
    539 drvctl_getevent(struct lwp *l, struct plistref *pref, u_long ioctl_cmd,
    540 	        int fflag)
    541 {
    542 	struct drvctl_event *dce;
    543 	int ret;
    544 
    545 	if ((fflag & (FREAD|FWRITE)) != (FREAD|FWRITE))
    546 		return EPERM;
    547 
    548 	mutex_enter(&drvctl_lock);
    549 	while ((dce = TAILQ_FIRST(&drvctl_eventq)) == NULL) {
    550 		if (fflag & O_NONBLOCK) {
    551 			mutex_exit(&drvctl_lock);
    552 			return EWOULDBLOCK;
    553 		}
    554 
    555 		ret = cv_wait_sig(&drvctl_cond, &drvctl_lock);
    556 		if (ret) {
    557 			mutex_exit(&drvctl_lock);
    558 			return ret;
    559 		}
    560 	}
    561 	TAILQ_REMOVE(&drvctl_eventq, dce, dce_link);
    562 	KASSERT(drvctl_eventcnt > 0);
    563 	--drvctl_eventcnt;
    564 	mutex_exit(&drvctl_lock);
    565 
    566 	ret = prop_dictionary_copyout_ioctl(pref, ioctl_cmd, dce->dce_event);
    567 
    568 	prop_object_release(dce->dce_event);
    569 	kmem_free(dce, sizeof(*dce));
    570 
    571 	return ret;
    572 }
    573