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kern_drvctl.c revision 1.22 
      1 /* $NetBSD: kern_drvctl.c,v 1.22 2009/01/17 07:02:35 yamt 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 1.22 2009/01/17 07:02:35 yamt 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 	drvctl_read,
     82 	drvctl_write,
     83 	drvctl_ioctl,
     84 	fnullop_fcntl,
     85 	drvctl_poll,
     86 	fbadop_stat,
     87 	drvctl_close,
     88 	fnullop_kqfilter
     89 };
     90 
     91 #define MAXLOCATORS 100
     92 
     93 static int drvctl_command(struct lwp *, struct plistref *, u_long, int);
     94 static int drvctl_getevent(struct lwp *, struct plistref *, u_long, int);
     95 
     96 void
     97 drvctl_init(void)
     98 {
     99 	TAILQ_INIT(&drvctl_eventq);
    100 	mutex_init(&drvctl_lock, MUTEX_DEFAULT, IPL_NONE);
    101 	cv_init(&drvctl_cond, "devmon");
    102 	selinit(&drvctl_rdsel);
    103 }
    104 
    105 void
    106 devmon_insert(const char *event, prop_dictionary_t ev)
    107 {
    108 	struct drvctl_event *dce, *odce;
    109 
    110 	mutex_enter(&drvctl_lock);
    111 
    112 	if (drvctl_nopen == 0) {
    113 		mutex_exit(&drvctl_lock);
    114 		return;
    115 	}
    116 
    117 	/* Fill in mandatory member */
    118 	if (!prop_dictionary_set_cstring_nocopy(ev, "event", event)) {
    119 		prop_object_release(ev);
    120 		mutex_exit(&drvctl_lock);
    121 		return;
    122 	}
    123 
    124 	dce = kmem_alloc(sizeof(*dce), KM_SLEEP);
    125 	if (dce == NULL) {
    126 		mutex_exit(&drvctl_lock);
    127 		return;
    128 	}
    129 
    130 	dce->dce_event = ev;
    131 
    132 	if (drvctl_eventcnt == DRVCTL_EVENTQ_DEPTH) {
    133 		odce = TAILQ_FIRST(&drvctl_eventq);
    134 		TAILQ_REMOVE(&drvctl_eventq, odce, dce_link);
    135 		prop_object_release(odce->dce_event);
    136 		kmem_free(odce, sizeof(*odce));
    137 		--drvctl_eventcnt;
    138 	}
    139 
    140 	TAILQ_INSERT_TAIL(&drvctl_eventq, dce, dce_link);
    141 	++drvctl_eventcnt;
    142 	cv_broadcast(&drvctl_cond);
    143 	selnotify(&drvctl_rdsel, 0, 0);
    144 
    145 	mutex_exit(&drvctl_lock);
    146 }
    147 
    148 int
    149 drvctlopen(dev_t dev, int flags, int mode, struct lwp *l)
    150 {
    151 	struct file *fp;
    152 	int fd;
    153 	int ret;
    154 
    155 	ret = fd_allocfile(&fp, &fd);
    156 	if (ret)
    157 		return (ret);
    158 
    159 	/* XXX setup context */
    160 	mutex_enter(&drvctl_lock);
    161 	ret = fd_clone(fp, fd, flags, &drvctl_fileops, /* context */NULL);
    162 	++drvctl_nopen;
    163 	mutex_exit(&drvctl_lock);
    164 
    165 	return ret;
    166 }
    167 
    168 static int
    169 pmdevbyname(u_long cmd, struct devpmargs *a)
    170 {
    171 	struct device *d;
    172 
    173 	if ((d = device_find_by_xname(a->devname)) == NULL)
    174 		return ENXIO;
    175 
    176 	switch (cmd) {
    177 	case DRVSUSPENDDEV:
    178 		return pmf_device_recursive_suspend(d, PMF_F_NONE) ? 0 : EBUSY;
    179 	case DRVRESUMEDEV:
    180 		if (a->flags & DEVPM_F_SUBTREE) {
    181 			return pmf_device_resume_subtree(d, PMF_F_NONE)
    182 			    ? 0 : EBUSY;
    183 		} else {
    184 			return pmf_device_recursive_resume(d, PMF_F_NONE)
    185 			    ? 0 : EBUSY;
    186 		}
    187 	default:
    188 		return EPASSTHROUGH;
    189 	}
    190 }
    191 
    192 static int
    193 listdevbyname(struct devlistargs *l)
    194 {
    195 	device_t d, child;
    196 	deviter_t di;
    197 	int cnt = 0, idx, error = 0;
    198 
    199 	if ((d = device_find_by_xname(l->l_devname)) == NULL)
    200 		return ENXIO;
    201 
    202 	for (child = deviter_first(&di, 0); child != NULL;
    203 	     child = deviter_next(&di)) {
    204 		if (device_parent(child) != d)
    205 			continue;
    206 		idx = cnt++;
    207 		if (l->l_childname == NULL || idx >= l->l_children)
    208 			continue;
    209 		error = copyoutstr(device_xname(child), l->l_childname[idx],
    210 				sizeof(l->l_childname[idx]), NULL);
    211 		if (error != 0)
    212 			break;
    213 	}
    214 	deviter_release(&di);
    215 
    216 	l->l_children = cnt;
    217 	return error;
    218 }
    219 
    220 static int
    221 detachdevbyname(const char *devname)
    222 {
    223 	struct device *d;
    224 
    225 	if ((d = device_find_by_xname(devname)) == NULL)
    226 		return ENXIO;
    227 
    228 #ifndef XXXFULLRISK
    229 	/*
    230 	 * If the parent cannot be notified, it might keep
    231 	 * pointers to the detached device.
    232 	 * There might be a private notification mechanism,
    233 	 * but better play save here.
    234 	 */
    235 	if (d->dv_parent && !d->dv_parent->dv_cfattach->ca_childdetached)
    236 		return (ENOTSUP);
    237 #endif
    238 	return (config_detach(d, 0));
    239 }
    240 
    241 static int
    242 rescanbus(const char *busname, const char *ifattr,
    243 	  int numlocators, const int *locators)
    244 {
    245 	int i, rc;
    246 	struct device *d;
    247 	const struct cfiattrdata * const *ap;
    248 
    249 	/* XXX there should be a way to get limits and defaults (per device)
    250 	   from config generated data */
    251 	int locs[MAXLOCATORS];
    252 	for (i = 0; i < MAXLOCATORS; i++)
    253 		locs[i] = -1;
    254 
    255 	for (i = 0; i < numlocators;i++)
    256 		locs[i] = locators[i];
    257 
    258 	if ((d = device_find_by_xname(busname)) == NULL)
    259 		return ENXIO;
    260 
    261 	/*
    262 	 * must support rescan, and must have something
    263 	 * to attach to
    264 	 */
    265 	if (!d->dv_cfattach->ca_rescan ||
    266 	    !d->dv_cfdriver->cd_attrs)
    267 		return (ENODEV);
    268 
    269 	/* allow to omit attribute if there is exactly one */
    270 	if (!ifattr) {
    271 		if (d->dv_cfdriver->cd_attrs[1])
    272 			return (EINVAL);
    273 		ifattr = d->dv_cfdriver->cd_attrs[0]->ci_name;
    274 	} else {
    275 		/* check for valid attribute passed */
    276 		for (ap = d->dv_cfdriver->cd_attrs; *ap; ap++)
    277 			if (!strcmp((*ap)->ci_name, ifattr))
    278 				break;
    279 		if (!*ap)
    280 			return (EINVAL);
    281 	}
    282 
    283 	rc = (*d->dv_cfattach->ca_rescan)(d, ifattr, locs);
    284 	config_deferred(NULL);
    285 	return rc;
    286 }
    287 
    288 static int
    289 drvctl_read(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred,
    290     int flags)
    291 {
    292 	return (ENODEV);
    293 }
    294 
    295 static int
    296 drvctl_write(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred,
    297     int flags)
    298 {
    299 	return (ENODEV);
    300 }
    301 
    302 static int
    303 drvctl_ioctl(struct file *fp, u_long cmd, void *data)
    304 {
    305 	int res;
    306 	char *ifattr;
    307 	int *locs;
    308 	size_t locs_sz = 0; /* XXXgcc */
    309 
    310 	switch (cmd) {
    311 	case DRVSUSPENDDEV:
    312 	case DRVRESUMEDEV:
    313 #define d ((struct devpmargs *)data)
    314 		res = pmdevbyname(cmd, d);
    315 #undef d
    316 		break;
    317 	case DRVLISTDEV:
    318 		res = listdevbyname((struct devlistargs *)data);
    319 		break;
    320 	case DRVDETACHDEV:
    321 #define d ((struct devdetachargs *)data)
    322 		res = detachdevbyname(d->devname);
    323 #undef d
    324 		break;
    325 	case DRVRESCANBUS:
    326 #define d ((struct devrescanargs *)data)
    327 		d->busname[sizeof(d->busname) - 1] = '\0';
    328 
    329 		/* XXX better copyin? */
    330 		if (d->ifattr[0]) {
    331 			d->ifattr[sizeof(d->ifattr) - 1] = '\0';
    332 			ifattr = d->ifattr;
    333 		} else
    334 			ifattr = 0;
    335 
    336 		if (d->numlocators) {
    337 			if (d->numlocators > MAXLOCATORS)
    338 				return (EINVAL);
    339 			locs_sz = d->numlocators * sizeof(int);
    340 			locs = kmem_alloc(locs_sz, KM_SLEEP);
    341 			res = copyin(d->locators, locs, locs_sz);
    342 			if (res) {
    343 				kmem_free(locs, locs_sz);
    344 				return (res);
    345 			}
    346 		} else
    347 			locs = NULL;
    348 		res = rescanbus(d->busname, ifattr, d->numlocators, locs);
    349 		if (locs)
    350 			kmem_free(locs, locs_sz);
    351 #undef d
    352 		break;
    353 	case DRVCTLCOMMAND:
    354 	    	res = drvctl_command(curlwp, (struct plistref *)data, cmd,
    355 		    fp->f_flag);
    356 	    	break;
    357 	case DRVGETEVENT:
    358 		res = drvctl_getevent(curlwp, (struct plistref *)data, cmd,
    359 		    fp->f_flag);
    360 		break;
    361 	default:
    362 		return (EPASSTHROUGH);
    363 	}
    364 	return (res);
    365 }
    366 
    367 static int
    368 drvctl_poll(struct file *fp, int events)
    369 {
    370 	int revents = 0;
    371 
    372 	if (!TAILQ_EMPTY(&drvctl_eventq))
    373 		revents |= events & (POLLIN | POLLRDNORM);
    374 	else
    375 		selrecord(curlwp, &drvctl_rdsel);
    376 
    377 	return revents;
    378 }
    379 
    380 static int
    381 drvctl_close(struct file *fp)
    382 {
    383 	struct drvctl_event *dce;
    384 
    385 	/* XXX free context */
    386 	mutex_enter(&drvctl_lock);
    387 	KASSERT(drvctl_nopen > 0);
    388 	--drvctl_nopen;
    389 	if (drvctl_nopen == 0) {
    390 		/* flush queue */
    391 		while ((dce = TAILQ_FIRST(&drvctl_eventq)) != NULL) {
    392 			TAILQ_REMOVE(&drvctl_eventq, dce, dce_link);
    393 			KASSERT(drvctl_eventcnt > 0);
    394 			--drvctl_eventcnt;
    395 			prop_object_release(dce->dce_event);
    396 			kmem_free(dce, sizeof(*dce));
    397 		}
    398 	}
    399 	mutex_exit(&drvctl_lock);
    400 
    401 	return (0);
    402 }
    403 
    404 void
    405 drvctlattach(int arg)
    406 {
    407 }
    408 
    409 /*****************************************************************************
    410  * Driver control command processing engine
    411  *****************************************************************************/
    412 
    413 static int
    414 drvctl_command_get_properties(struct lwp *l,
    415 			      prop_dictionary_t command_dict,
    416 			      prop_dictionary_t results_dict)
    417 {
    418 	prop_dictionary_t args_dict;
    419 	prop_string_t devname_string;
    420 	device_t dev;
    421 	deviter_t di;
    422 
    423 	args_dict = prop_dictionary_get(command_dict, "drvctl-arguments");
    424 	if (args_dict == NULL)
    425 		return (EINVAL);
    426 
    427 	devname_string = prop_dictionary_get(args_dict, "device-name");
    428 	if (devname_string == NULL)
    429 		return (EINVAL);
    430 
    431 	for (dev = deviter_first(&di, 0); dev != NULL;
    432 	     dev = deviter_next(&di)) {
    433 		if (prop_string_equals_cstring(devname_string,
    434 					       device_xname(dev))) {
    435 			prop_dictionary_set(results_dict, "drvctl-result-data",
    436 			    device_properties(dev));
    437 			break;
    438 		}
    439 	}
    440 
    441 	deviter_release(&di);
    442 
    443 	if (dev == NULL)
    444 		return (ESRCH);
    445 
    446 	return (0);
    447 }
    448 
    449 struct drvctl_command_desc {
    450 	const char *dcd_name;		/* command name */
    451 	int (*dcd_func)(struct lwp *,	/* handler function */
    452 			prop_dictionary_t,
    453 			prop_dictionary_t);
    454 	int dcd_rw;			/* read or write required */
    455 };
    456 
    457 static const struct drvctl_command_desc drvctl_command_table[] = {
    458 	{ .dcd_name = "get-properties",
    459 	  .dcd_func = drvctl_command_get_properties,
    460 	  .dcd_rw   = FREAD,
    461 	},
    462 
    463 	{ .dcd_name = NULL }
    464 };
    465 
    466 static int
    467 drvctl_command(struct lwp *l, struct plistref *pref, u_long ioctl_cmd,
    468 	       int fflag)
    469 {
    470 	prop_dictionary_t command_dict, results_dict;
    471 	prop_string_t command_string;
    472 	const struct drvctl_command_desc *dcd;
    473 	int error;
    474 
    475 	error = prop_dictionary_copyin_ioctl(pref, ioctl_cmd, &command_dict);
    476 	if (error)
    477 		return (error);
    478 
    479 	results_dict = prop_dictionary_create();
    480 	if (results_dict == NULL) {
    481 		prop_object_release(command_dict);
    482 		return (ENOMEM);
    483 	}
    484 
    485 	command_string = prop_dictionary_get(command_dict, "drvctl-command");
    486 	if (command_string == NULL) {
    487 		error = EINVAL;
    488 		goto out;
    489 	}
    490 
    491 	for (dcd = drvctl_command_table; dcd->dcd_name != NULL; dcd++) {
    492 		if (prop_string_equals_cstring(command_string,
    493 					       dcd->dcd_name))
    494 			break;
    495 	}
    496 
    497 	if (dcd->dcd_name == NULL) {
    498 		error = EINVAL;
    499 		goto out;
    500 	}
    501 
    502 	if ((fflag & dcd->dcd_rw) == 0) {
    503 		error = EPERM;
    504 		goto out;
    505 	}
    506 
    507 	error = (*dcd->dcd_func)(l, command_dict, results_dict);
    508 
    509 	prop_dictionary_set_int32(results_dict, "drvctl-error", error);
    510 
    511 	error = prop_dictionary_copyout_ioctl(pref, ioctl_cmd, results_dict);
    512  out:
    513 	prop_object_release(command_dict);
    514 	prop_object_release(results_dict);
    515 	return (error);
    516 }
    517 
    518 static int
    519 drvctl_getevent(struct lwp *l, struct plistref *pref, u_long ioctl_cmd,
    520 	        int fflag)
    521 {
    522 	struct drvctl_event *dce;
    523 	int ret;
    524 
    525 	if ((fflag & (FREAD|FWRITE)) != (FREAD|FWRITE))
    526 		return (EPERM);
    527 
    528 	mutex_enter(&drvctl_lock);
    529 	while ((dce = TAILQ_FIRST(&drvctl_eventq)) == NULL) {
    530 		if (fflag & O_NONBLOCK) {
    531 			mutex_exit(&drvctl_lock);
    532 			return (EWOULDBLOCK);
    533 		}
    534 
    535 		ret = cv_wait_sig(&drvctl_cond, &drvctl_lock);
    536 		if (ret) {
    537 			mutex_exit(&drvctl_lock);
    538 			return (ret);
    539 		}
    540 	}
    541 	TAILQ_REMOVE(&drvctl_eventq, dce, dce_link);
    542 	KASSERT(drvctl_eventcnt > 0);
    543 	--drvctl_eventcnt;
    544 	mutex_exit(&drvctl_lock);
    545 
    546 	ret = prop_dictionary_copyout_ioctl(pref, ioctl_cmd, dce->dce_event);
    547 
    548 	prop_object_release(dce->dce_event);
    549 	kmem_free(dce, sizeof(*dce));
    550 
    551 	return (ret);
    552 }
    553