sys/kern/kern_drvctl.c

   1 /* $NetBSD: kern_drvctl.c,v 1.30 2009/12/09 21:32:59 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 1.30 2009/12/09 21:32:59 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 }