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kern_drvctl.c revision 1.23 
      1 /* $NetBSD: kern_drvctl.c,v 1.23 2009/04/04 10:12:51 ad 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 1.23 2009/04/04 10:12:51 ad 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 
     48 struct drvctl_event {
     49 	TAILQ_ENTRY(drvctl_event) dce_link;
     50 	prop_dictionary_t	dce_event;
     51 };
     52 
     53 TAILQ_HEAD(drvctl_queue, drvctl_event);
     54 
     55 static struct drvctl_queue	drvctl_eventq;		/* FIFO */
     56 static kcondvar_t		drvctl_cond;
     57 static kmutex_t			drvctl_lock;
     58 static int			drvctl_nopen = 0, drvctl_eventcnt = 0;
     59 static struct selinfo		drvctl_rdsel;
     60 
     61 #define DRVCTL_EVENTQ_DEPTH	64	/* arbitrary queue limit */
     62 
     63 dev_type_open(drvctlopen);
     64 
     65 const struct cdevsw drvctl_cdevsw = {
     66 	drvctlopen, nullclose, nullread, nullwrite, noioctl,
     67 	nostop, notty, nopoll, nommap, nokqfilter, D_OTHER
     68 };
     69 
     70 void drvctlattach(int);
     71 
     72 static int	drvctl_read(struct file *, off_t *, struct uio *,
     73 			    kauth_cred_t, int);
     74 static int	drvctl_write(struct file *, off_t *, struct uio *,
     75 			     kauth_cred_t, int);
     76 static int	drvctl_ioctl(struct file *, u_long, void *);
     77 static int	drvctl_poll(struct file *, int);
     78 static int	drvctl_close(struct file *);
     79 
     80 static const struct fileops drvctl_fileops = {
     81 	.fo_read = drvctl_read,
     82 	.fo_write = drvctl_write,
     83 	.fo_ioctl = drvctl_ioctl,
     84 	.fo_fcntl = fnullop_fcntl,
     85 	.fo_poll = drvctl_poll,
     86 	.fo_stat = fbadop_stat,
     87 	.fo_close = drvctl_close,
     88 	.fo_kqfilter = fnullop_kqfilter,
     89 	.fo_drain = fnullop_drain,
     90 };
     91 
     92 #define MAXLOCATORS 100
     93 
     94 static int drvctl_command(struct lwp *, struct plistref *, u_long, int);
     95 static int drvctl_getevent(struct lwp *, struct plistref *, u_long, int);
     96 
     97 void
     98 drvctl_init(void)
     99 {
    100 	TAILQ_INIT(&drvctl_eventq);
    101 	mutex_init(&drvctl_lock, MUTEX_DEFAULT, IPL_NONE);
    102 	cv_init(&drvctl_cond, "devmon");
    103 	selinit(&drvctl_rdsel);
    104 }
    105 
    106 void
    107 devmon_insert(const char *event, prop_dictionary_t ev)
    108 {
    109 	struct drvctl_event *dce, *odce;
    110 
    111 	mutex_enter(&drvctl_lock);
    112 
    113 	if (drvctl_nopen == 0) {
    114 		mutex_exit(&drvctl_lock);
    115 		return;
    116 	}
    117 
    118 	/* Fill in mandatory member */
    119 	if (!prop_dictionary_set_cstring_nocopy(ev, "event", event)) {
    120 		prop_object_release(ev);
    121 		mutex_exit(&drvctl_lock);
    122 		return;
    123 	}
    124 
    125 	dce = kmem_alloc(sizeof(*dce), KM_SLEEP);
    126 	if (dce == NULL) {
    127 		mutex_exit(&drvctl_lock);
    128 		return;
    129 	}
    130 
    131 	dce->dce_event = ev;
    132 
    133 	if (drvctl_eventcnt == DRVCTL_EVENTQ_DEPTH) {
    134 		odce = TAILQ_FIRST(&drvctl_eventq);
    135 		TAILQ_REMOVE(&drvctl_eventq, odce, dce_link);
    136 		prop_object_release(odce->dce_event);
    137 		kmem_free(odce, sizeof(*odce));
    138 		--drvctl_eventcnt;
    139 	}
    140 
    141 	TAILQ_INSERT_TAIL(&drvctl_eventq, dce, dce_link);
    142 	++drvctl_eventcnt;
    143 	cv_broadcast(&drvctl_cond);
    144 	selnotify(&drvctl_rdsel, 0, 0);
    145 
    146 	mutex_exit(&drvctl_lock);
    147 }
    148 
    149 int
    150 drvctlopen(dev_t dev, int flags, int mode, struct lwp *l)
    151 {
    152 	struct file *fp;
    153 	int fd;
    154 	int ret;
    155 
    156 	ret = fd_allocfile(&fp, &fd);
    157 	if (ret)
    158 		return (ret);
    159 
    160 	/* XXX setup context */
    161 	mutex_enter(&drvctl_lock);
    162 	ret = fd_clone(fp, fd, flags, &drvctl_fileops, /* context */NULL);
    163 	++drvctl_nopen;
    164 	mutex_exit(&drvctl_lock);
    165 
    166 	return ret;
    167 }
    168 
    169 static int
    170 pmdevbyname(u_long cmd, struct devpmargs *a)
    171 {
    172 	struct device *d;
    173 
    174 	if ((d = device_find_by_xname(a->devname)) == NULL)
    175 		return ENXIO;
    176 
    177 	switch (cmd) {
    178 	case DRVSUSPENDDEV:
    179 		return pmf_device_recursive_suspend(d, PMF_F_NONE) ? 0 : EBUSY;
    180 	case DRVRESUMEDEV:
    181 		if (a->flags & DEVPM_F_SUBTREE) {
    182 			return pmf_device_resume_subtree(d, PMF_F_NONE)
    183 			    ? 0 : EBUSY;
    184 		} else {
    185 			return pmf_device_recursive_resume(d, PMF_F_NONE)
    186 			    ? 0 : EBUSY;
    187 		}
    188 	default:
    189 		return EPASSTHROUGH;
    190 	}
    191 }
    192 
    193 static int
    194 listdevbyname(struct devlistargs *l)
    195 {
    196 	device_t d, child;
    197 	deviter_t di;
    198 	int cnt = 0, idx, error = 0;
    199 
    200 	if ((d = device_find_by_xname(l->l_devname)) == NULL)
    201 		return ENXIO;
    202 
    203 	for (child = deviter_first(&di, 0); child != NULL;
    204 	     child = deviter_next(&di)) {
    205 		if (device_parent(child) != d)
    206 			continue;
    207 		idx = cnt++;
    208 		if (l->l_childname == NULL || idx >= l->l_children)
    209 			continue;
    210 		error = copyoutstr(device_xname(child), l->l_childname[idx],
    211 				sizeof(l->l_childname[idx]), NULL);
    212 		if (error != 0)
    213 			break;
    214 	}
    215 	deviter_release(&di);
    216 
    217 	l->l_children = cnt;
    218 	return error;
    219 }
    220 
    221 static int
    222 detachdevbyname(const char *devname)
    223 {
    224 	struct device *d;
    225 
    226 	if ((d = device_find_by_xname(devname)) == NULL)
    227 		return ENXIO;
    228 
    229 #ifndef XXXFULLRISK
    230 	/*
    231 	 * If the parent cannot be notified, it might keep
    232 	 * pointers to the detached device.
    233 	 * There might be a private notification mechanism,
    234 	 * but better play save here.
    235 	 */
    236 	if (d->dv_parent && !d->dv_parent->dv_cfattach->ca_childdetached)
    237 		return (ENOTSUP);
    238 #endif
    239 	return (config_detach(d, 0));
    240 }
    241 
    242 static int
    243 rescanbus(const char *busname, const char *ifattr,
    244 	  int numlocators, const int *locators)
    245 {
    246 	int i, rc;
    247 	struct device *d;
    248 	const struct cfiattrdata * const *ap;
    249 
    250 	/* XXX there should be a way to get limits and defaults (per device)
    251 	   from config generated data */
    252 	int locs[MAXLOCATORS];
    253 	for (i = 0; i < MAXLOCATORS; i++)
    254 		locs[i] = -1;
    255 
    256 	for (i = 0; i < numlocators;i++)
    257 		locs[i] = locators[i];
    258 
    259 	if ((d = device_find_by_xname(busname)) == NULL)
    260 		return ENXIO;
    261 
    262 	/*
    263 	 * must support rescan, and must have something
    264 	 * to attach to
    265 	 */
    266 	if (!d->dv_cfattach->ca_rescan ||
    267 	    !d->dv_cfdriver->cd_attrs)
    268 		return (ENODEV);
    269 
    270 	/* allow to omit attribute if there is exactly one */
    271 	if (!ifattr) {
    272 		if (d->dv_cfdriver->cd_attrs[1])
    273 			return (EINVAL);
    274 		ifattr = d->dv_cfdriver->cd_attrs[0]->ci_name;
    275 	} else {
    276 		/* check for valid attribute passed */
    277 		for (ap = d->dv_cfdriver->cd_attrs; *ap; ap++)
    278 			if (!strcmp((*ap)->ci_name, ifattr))
    279 				break;
    280 		if (!*ap)
    281 			return (EINVAL);
    282 	}
    283 
    284 	rc = (*d->dv_cfattach->ca_rescan)(d, ifattr, locs);
    285 	config_deferred(NULL);
    286 	return rc;
    287 }
    288 
    289 static int
    290 drvctl_read(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred,
    291     int flags)
    292 {
    293 	return (ENODEV);
    294 }
    295 
    296 static int
    297 drvctl_write(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred,
    298     int flags)
    299 {
    300 	return (ENODEV);
    301 }
    302 
    303 static int
    304 drvctl_ioctl(struct file *fp, u_long cmd, void *data)
    305 {
    306 	int res;
    307 	char *ifattr;
    308 	int *locs;
    309 	size_t locs_sz = 0; /* XXXgcc */
    310 
    311 	switch (cmd) {
    312 	case DRVSUSPENDDEV:
    313 	case DRVRESUMEDEV:
    314 #define d ((struct devpmargs *)data)
    315 		res = pmdevbyname(cmd, d);
    316 #undef d
    317 		break;
    318 	case DRVLISTDEV:
    319 		res = listdevbyname((struct devlistargs *)data);
    320 		break;
    321 	case DRVDETACHDEV:
    322 #define d ((struct devdetachargs *)data)
    323 		res = detachdevbyname(d->devname);
    324 #undef d
    325 		break;
    326 	case DRVRESCANBUS:
    327 #define d ((struct devrescanargs *)data)
    328 		d->busname[sizeof(d->busname) - 1] = '\0';
    329 
    330 		/* XXX better copyin? */
    331 		if (d->ifattr[0]) {
    332 			d->ifattr[sizeof(d->ifattr) - 1] = '\0';
    333 			ifattr = d->ifattr;
    334 		} else
    335 			ifattr = 0;
    336 
    337 		if (d->numlocators) {
    338 			if (d->numlocators > MAXLOCATORS)
    339 				return (EINVAL);
    340 			locs_sz = d->numlocators * sizeof(int);
    341 			locs = kmem_alloc(locs_sz, KM_SLEEP);
    342 			res = copyin(d->locators, locs, locs_sz);
    343 			if (res) {
    344 				kmem_free(locs, locs_sz);
    345 				return (res);
    346 			}
    347 		} else
    348 			locs = NULL;
    349 		res = rescanbus(d->busname, ifattr, d->numlocators, locs);
    350 		if (locs)
    351 			kmem_free(locs, locs_sz);
    352 #undef d
    353 		break;
    354 	case DRVCTLCOMMAND:
    355 	    	res = drvctl_command(curlwp, (struct plistref *)data, cmd,
    356 		    fp->f_flag);
    357 	    	break;
    358 	case DRVGETEVENT:
    359 		res = drvctl_getevent(curlwp, (struct plistref *)data, cmd,
    360 		    fp->f_flag);
    361 		break;
    362 	default:
    363 		return (EPASSTHROUGH);
    364 	}
    365 	return (res);
    366 }
    367 
    368 static int
    369 drvctl_poll(struct file *fp, int events)
    370 {
    371 	int revents = 0;
    372 
    373 	if (!TAILQ_EMPTY(&drvctl_eventq))
    374 		revents |= events & (POLLIN | POLLRDNORM);
    375 	else
    376 		selrecord(curlwp, &drvctl_rdsel);
    377 
    378 	return revents;
    379 }
    380 
    381 static int
    382 drvctl_close(struct file *fp)
    383 {
    384 	struct drvctl_event *dce;
    385 
    386 	/* XXX free context */
    387 	mutex_enter(&drvctl_lock);
    388 	KASSERT(drvctl_nopen > 0);
    389 	--drvctl_nopen;
    390 	if (drvctl_nopen == 0) {
    391 		/* flush queue */
    392 		while ((dce = TAILQ_FIRST(&drvctl_eventq)) != NULL) {
    393 			TAILQ_REMOVE(&drvctl_eventq, dce, dce_link);
    394 			KASSERT(drvctl_eventcnt > 0);
    395 			--drvctl_eventcnt;
    396 			prop_object_release(dce->dce_event);
    397 			kmem_free(dce, sizeof(*dce));
    398 		}
    399 	}
    400 	mutex_exit(&drvctl_lock);
    401 
    402 	return (0);
    403 }
    404 
    405 void
    406 drvctlattach(int arg)
    407 {
    408 }
    409 
    410 /*****************************************************************************
    411  * Driver control command processing engine
    412  *****************************************************************************/
    413 
    414 static int
    415 drvctl_command_get_properties(struct lwp *l,
    416 			      prop_dictionary_t command_dict,
    417 			      prop_dictionary_t results_dict)
    418 {
    419 	prop_dictionary_t args_dict;
    420 	prop_string_t devname_string;
    421 	device_t dev;
    422 	deviter_t di;
    423 
    424 	args_dict = prop_dictionary_get(command_dict, "drvctl-arguments");
    425 	if (args_dict == NULL)
    426 		return (EINVAL);
    427 
    428 	devname_string = prop_dictionary_get(args_dict, "device-name");
    429 	if (devname_string == NULL)
    430 		return (EINVAL);
    431 
    432 	for (dev = deviter_first(&di, 0); dev != NULL;
    433 	     dev = deviter_next(&di)) {
    434 		if (prop_string_equals_cstring(devname_string,
    435 					       device_xname(dev))) {
    436 			prop_dictionary_set(results_dict, "drvctl-result-data",
    437 			    device_properties(dev));
    438 			break;
    439 		}
    440 	}
    441 
    442 	deviter_release(&di);
    443 
    444 	if (dev == NULL)
    445 		return (ESRCH);
    446 
    447 	return (0);
    448 }
    449 
    450 struct drvctl_command_desc {
    451 	const char *dcd_name;		/* command name */
    452 	int (*dcd_func)(struct lwp *,	/* handler function */
    453 			prop_dictionary_t,
    454 			prop_dictionary_t);
    455 	int dcd_rw;			/* read or write required */
    456 };
    457 
    458 static const struct drvctl_command_desc drvctl_command_table[] = {
    459 	{ .dcd_name = "get-properties",
    460 	  .dcd_func = drvctl_command_get_properties,
    461 	  .dcd_rw   = FREAD,
    462 	},
    463 
    464 	{ .dcd_name = NULL }
    465 };
    466 
    467 static int
    468 drvctl_command(struct lwp *l, struct plistref *pref, u_long ioctl_cmd,
    469 	       int fflag)
    470 {
    471 	prop_dictionary_t command_dict, results_dict;
    472 	prop_string_t command_string;
    473 	const struct drvctl_command_desc *dcd;
    474 	int error;
    475 
    476 	error = prop_dictionary_copyin_ioctl(pref, ioctl_cmd, &command_dict);
    477 	if (error)
    478 		return (error);
    479 
    480 	results_dict = prop_dictionary_create();
    481 	if (results_dict == NULL) {
    482 		prop_object_release(command_dict);
    483 		return (ENOMEM);
    484 	}
    485 
    486 	command_string = prop_dictionary_get(command_dict, "drvctl-command");
    487 	if (command_string == NULL) {
    488 		error = EINVAL;
    489 		goto out;
    490 	}
    491 
    492 	for (dcd = drvctl_command_table; dcd->dcd_name != NULL; dcd++) {
    493 		if (prop_string_equals_cstring(command_string,
    494 					       dcd->dcd_name))
    495 			break;
    496 	}
    497 
    498 	if (dcd->dcd_name == NULL) {
    499 		error = EINVAL;
    500 		goto out;
    501 	}
    502 
    503 	if ((fflag & dcd->dcd_rw) == 0) {
    504 		error = EPERM;
    505 		goto out;
    506 	}
    507 
    508 	error = (*dcd->dcd_func)(l, command_dict, results_dict);
    509 
    510 	prop_dictionary_set_int32(results_dict, "drvctl-error", error);
    511 
    512 	error = prop_dictionary_copyout_ioctl(pref, ioctl_cmd, results_dict);
    513  out:
    514 	prop_object_release(command_dict);
    515 	prop_object_release(results_dict);
    516 	return (error);
    517 }
    518 
    519 static int
    520 drvctl_getevent(struct lwp *l, struct plistref *pref, u_long ioctl_cmd,
    521 	        int fflag)
    522 {
    523 	struct drvctl_event *dce;
    524 	int ret;
    525 
    526 	if ((fflag & (FREAD|FWRITE)) != (FREAD|FWRITE))
    527 		return (EPERM);
    528 
    529 	mutex_enter(&drvctl_lock);
    530 	while ((dce = TAILQ_FIRST(&drvctl_eventq)) == NULL) {
    531 		if (fflag & O_NONBLOCK) {
    532 			mutex_exit(&drvctl_lock);
    533 			return (EWOULDBLOCK);
    534 		}
    535 
    536 		ret = cv_wait_sig(&drvctl_cond, &drvctl_lock);
    537 		if (ret) {
    538 			mutex_exit(&drvctl_lock);
    539 			return (ret);
    540 		}
    541 	}
    542 	TAILQ_REMOVE(&drvctl_eventq, dce, dce_link);
    543 	KASSERT(drvctl_eventcnt > 0);
    544 	--drvctl_eventcnt;
    545 	mutex_exit(&drvctl_lock);
    546 
    547 	ret = prop_dictionary_copyout_ioctl(pref, ioctl_cmd, dce->dce_event);
    548 
    549 	prop_object_release(dce->dce_event);
    550 	kmem_free(dce, sizeof(*dce));
    551 
    552 	return (ret);
    553 }
    554