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kern_drvctl.c revision 1.5 
      1 /* $NetBSD: kern_drvctl.c,v 1.5 2006/09/22 04:37:37 thorpej 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 1.5 2006/09/22 04:37:37 thorpej 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/malloc.h>
     39 #include <sys/ioctl.h>
     40 #include <sys/fcntl.h>
     41 #include <sys/drvctlio.h>
     42 
     43 dev_type_ioctl(drvctlioctl);
     44 
     45 const struct cdevsw drvctl_cdevsw = {
     46 	nullopen, nullclose, nullread, nullwrite, drvctlioctl,
     47 	nostop, notty, nopoll, nommap, nokqfilter,
     48 };
     49 
     50 void drvctlattach(int);
     51 
     52 #define MAXLOCATORS 100
     53 
     54 static int drvctl_command(struct lwp *, struct plistref *, u_long, int flag);
     55 
     56 static int
     57 detachdevbyname(const char *devname)
     58 {
     59 	struct device *d;
     60 
     61 	TAILQ_FOREACH(d, &alldevs, dv_list) {
     62 		if (!strcmp(devname, d->dv_xname)) {
     63 #ifndef XXXFULLRISK
     64 			/*
     65 			 * If the parent cannot be notified, it might keep
     66 			 * pointers to the detached device.
     67 			 * There might be a private notification mechanism,
     68 			 * but better play save here.
     69 			 */
     70 			if (d->dv_parent &&
     71 			    !d->dv_parent->dv_cfattach->ca_childdetached)
     72 				return (ENOTSUP);
     73 #endif
     74 			return (config_detach(d, 0));
     75 		}
     76 	}
     77 
     78 	return (ENXIO);
     79 }
     80 
     81 static int
     82 rescanbus(const char *busname, const char *ifattr,
     83 	  int numlocators, const int *locators)
     84 {
     85 	int i;
     86 	struct device *d;
     87 	const struct cfiattrdata * const *ap;
     88 
     89 	/* XXX there should be a way to get limits and defaults (per device)
     90 	   from config generated data */
     91 	int locs[MAXLOCATORS];
     92 	for (i = 0; i < MAXLOCATORS; i++)
     93 		locs[i] = -1;
     94 
     95 	for (i = 0; i < numlocators;i++)
     96 		locs[i] = locators[i];
     97 
     98 	TAILQ_FOREACH(d, &alldevs, dv_list) {
     99 		if (!strcmp(busname, d->dv_xname)) {
    100 			/*
    101 			 * must support rescan, and must have something
    102 			 * to attach to
    103 			 */
    104 			if (!d->dv_cfattach->ca_rescan ||
    105 			    !d->dv_cfdriver->cd_attrs)
    106 				return (ENODEV);
    107 
    108 			/* allow to omit attribute if there is exactly one */
    109 			if (!ifattr) {
    110 				if (d->dv_cfdriver->cd_attrs[1])
    111 					return (EINVAL);
    112 				ifattr = d->dv_cfdriver->cd_attrs[0]->ci_name;
    113 			} else {
    114 				/* check for valid attribute passed */
    115 				for (ap = d->dv_cfdriver->cd_attrs; *ap; ap++)
    116 					if (!strcmp((*ap)->ci_name, ifattr))
    117 						break;
    118 				if (!*ap)
    119 					return (EINVAL);
    120 			}
    121 
    122 			return (*d->dv_cfattach->ca_rescan)(d, ifattr, locs);
    123 		}
    124 	}
    125 
    126 	return (ENXIO);
    127 }
    128 
    129 int
    130 drvctlioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct lwp *p)
    131 {
    132 	int res;
    133 	char *ifattr;
    134 	int *locs;
    135 
    136 	switch (cmd) {
    137 	case DRVDETACHDEV:
    138 #define d ((struct devdetachargs *)data)
    139 		res = detachdevbyname(d->devname);
    140 #undef d
    141 		break;
    142 	case DRVRESCANBUS:
    143 #define d ((struct devrescanargs *)data)
    144 		d->busname[sizeof(d->busname) - 1] = '\0';
    145 
    146 		/* XXX better copyin? */
    147 		if (d->ifattr[0]) {
    148 			d->ifattr[sizeof(d->ifattr) - 1] = '\0';
    149 			ifattr = d->ifattr;
    150 		} else
    151 			ifattr = 0;
    152 
    153 		if (d->numlocators) {
    154 			if (d->numlocators > MAXLOCATORS)
    155 				return (EINVAL);
    156 			locs = malloc(d->numlocators * sizeof(int), M_DEVBUF,
    157 				      M_WAITOK);
    158 			res = copyin(d->locators, locs,
    159 				     d->numlocators * sizeof(int));
    160 			if (res)
    161 				return (res);
    162 		} else
    163 			locs = 0;
    164 		res = rescanbus(d->busname, ifattr, d->numlocators, locs);
    165 		if (locs)
    166 			free(locs, M_DEVBUF);
    167 #undef d
    168 		break;
    169 	case DRVCTLCOMMAND:
    170 	    	res = drvctl_command(p, (struct plistref *)data, cmd, flag);
    171 	    	break;
    172 	default:
    173 		return (EPASSTHROUGH);
    174 	}
    175 	return (res);
    176 }
    177 
    178 void
    179 drvctlattach(int arg)
    180 {
    181 }
    182 
    183 /*****************************************************************************
    184  * Driver control command processing engine
    185  *****************************************************************************/
    186 
    187 static int
    188 drvctl_command_get_properties(struct lwp *l,
    189 			      prop_dictionary_t command_dict,
    190 			      prop_dictionary_t results_dict)
    191 {
    192 	prop_dictionary_t args_dict;
    193 	prop_string_t devname_string;
    194 	device_t dev;
    195 
    196 	args_dict = prop_dictionary_get(command_dict, "drvctl-arguments");
    197 	if (args_dict == NULL)
    198 		return (EINVAL);
    199 
    200 	devname_string = prop_dictionary_get(args_dict, "device-name");
    201 	if (devname_string == NULL)
    202 		return (EINVAL);
    203 
    204 	TAILQ_FOREACH(dev, &alldevs, dv_list) {
    205 		if (prop_string_equals_cstring(devname_string,
    206 					       device_xname(dev)))
    207 			break;
    208 	}
    209 
    210 	if (dev == NULL)
    211 		return (ESRCH);
    212 
    213 	prop_dictionary_set(results_dict, "drvctl-result-data",
    214 			    device_properties(dev));
    215 
    216 	return (0);
    217 }
    218 
    219 struct drvctl_command_desc {
    220 	const char *dcd_name;		/* command name */
    221 	int (*dcd_func)(struct lwp *,	/* handler function */
    222 			prop_dictionary_t,
    223 			prop_dictionary_t);
    224 	int dcd_rw;			/* read or write required */
    225 };
    226 
    227 static const struct drvctl_command_desc drvctl_command_table[] = {
    228 	{ .dcd_name = "get-properties",
    229 	  .dcd_func = drvctl_command_get_properties,
    230 	  .dcd_rw   = FREAD,
    231 	},
    232 
    233 	{ .dcd_name = NULL }
    234 };
    235 
    236 static int
    237 drvctl_command(struct lwp *l, struct plistref *pref, u_long ioctl_cmd,
    238 	       int fflag)
    239 {
    240 	prop_dictionary_t command_dict, results_dict;
    241 	prop_string_t command_string;
    242 	prop_number_t error_number;
    243 	const struct drvctl_command_desc *dcd;
    244 	int error;
    245 
    246 	error = prop_dictionary_copyin_ioctl(pref, ioctl_cmd, &command_dict);
    247 	if (error)
    248 		return (error);
    249 
    250 	results_dict = prop_dictionary_create();
    251 	if (results_dict == NULL) {
    252 		prop_object_release(command_dict);
    253 		return (ENOMEM);
    254 	}
    255 
    256 	command_string = prop_dictionary_get(command_dict, "drvctl-command");
    257 	if (command_string == NULL) {
    258 		error = EINVAL;
    259 		goto out;
    260 	}
    261 
    262 	for (dcd = drvctl_command_table; dcd->dcd_name != NULL; dcd++) {
    263 		if (prop_string_equals_cstring(command_string,
    264 					       dcd->dcd_name))
    265 			break;
    266 	}
    267 
    268 	if (dcd->dcd_name == NULL) {
    269 		error = EINVAL;
    270 		goto out;
    271 	}
    272 
    273 	if ((fflag & dcd->dcd_rw) == 0) {
    274 		error = EPERM;
    275 		goto out;
    276 	}
    277 
    278 	error = (*dcd->dcd_func)(l, command_dict, results_dict);
    279 
    280 	error_number = prop_number_create_integer(error);
    281 	prop_dictionary_set(results_dict, "drvctl-error", error_number);
    282 	prop_object_release(error_number);
    283 
    284 	error = prop_dictionary_copyout_ioctl(pref, ioctl_cmd, results_dict);
    285  out:
    286 	prop_object_release(command_dict);
    287 	prop_object_release(results_dict);
    288 	return (error);
    289 }
    290