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kern_drvctl.c revision 1.31 
      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