1 /* $NetBSD: kern_drvctl.c,v 1.44 2018/09/18 01:25:09 mrg 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 1.44 2018/09/18 01:25:09 mrg 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 #include <sys/module.h> 51 52 #include "ioconf.h" 53 54 struct drvctl_event { 55 TAILQ_ENTRY(drvctl_event) dce_link; 56 prop_dictionary_t dce_event; 57 }; 58 59 TAILQ_HEAD(drvctl_queue, drvctl_event); 60 61 static struct drvctl_queue drvctl_eventq; /* FIFO */ 62 static kcondvar_t drvctl_cond; 63 static kmutex_t drvctl_lock; 64 static int drvctl_nopen = 0, drvctl_eventcnt = 0; 65 static struct selinfo drvctl_rdsel; 66 67 #define DRVCTL_EVENTQ_DEPTH 64 /* arbitrary queue limit */ 68 69 dev_type_open(drvctlopen); 70 71 const struct cdevsw drvctl_cdevsw = { 72 .d_open = drvctlopen, 73 .d_close = nullclose, 74 .d_read = nullread, 75 .d_write = nullwrite, 76 .d_ioctl = noioctl, 77 .d_stop = nostop, 78 .d_tty = notty, 79 .d_poll = nopoll, 80 .d_mmap = nommap, 81 .d_kqfilter = nokqfilter, 82 .d_discard = nodiscard, 83 .d_flag = D_OTHER 84 }; 85 86 static int drvctl_read(struct file *, off_t *, struct uio *, 87 kauth_cred_t, int); 88 static int drvctl_write(struct file *, off_t *, struct uio *, 89 kauth_cred_t, int); 90 static int drvctl_ioctl(struct file *, u_long, void *); 91 static int drvctl_poll(struct file *, int); 92 static int drvctl_stat(struct file *, struct stat *); 93 static int drvctl_close(struct file *); 94 95 static const struct fileops drvctl_fileops = { 96 .fo_name = "drvctl", 97 .fo_read = drvctl_read, 98 .fo_write = drvctl_write, 99 .fo_ioctl = drvctl_ioctl, 100 .fo_fcntl = fnullop_fcntl, 101 .fo_poll = drvctl_poll, 102 .fo_stat = drvctl_stat, 103 .fo_close = drvctl_close, 104 .fo_kqfilter = fnullop_kqfilter, 105 .fo_restart = fnullop_restart, 106 }; 107 108 #define MAXLOCATORS 100 109 110 static int (*saved_insert_vec)(const char *, prop_dictionary_t) = NULL; 111 112 static int drvctl_command(struct lwp *, struct plistref *, u_long, int); 113 static int drvctl_getevent(struct lwp *, struct plistref *, u_long, int); 114 115 void 116 drvctl_init(void) 117 { 118 TAILQ_INIT(&drvctl_eventq); 119 mutex_init(&drvctl_lock, MUTEX_DEFAULT, IPL_NONE); 120 cv_init(&drvctl_cond, "devmon"); 121 selinit(&drvctl_rdsel); 122 } 123 124 void 125 drvctl_fini(void) 126 { 127 128 seldestroy(&drvctl_rdsel); 129 cv_destroy(&drvctl_cond); 130 mutex_destroy(&drvctl_lock); 131 } 132 133 int 134 devmon_insert(const char *event, prop_dictionary_t ev) 135 { 136 struct drvctl_event *dce, *odce; 137 138 mutex_enter(&drvctl_lock); 139 140 if (drvctl_nopen == 0) { 141 prop_object_release(ev); 142 mutex_exit(&drvctl_lock); 143 return 0; 144 } 145 146 /* Fill in mandatory member */ 147 if (!prop_dictionary_set_cstring_nocopy(ev, "event", event)) { 148 prop_object_release(ev); 149 mutex_exit(&drvctl_lock); 150 return 0; 151 } 152 153 dce = kmem_alloc(sizeof(*dce), KM_SLEEP); 154 dce->dce_event = ev; 155 156 if (drvctl_eventcnt == DRVCTL_EVENTQ_DEPTH) { 157 odce = TAILQ_FIRST(&drvctl_eventq); 158 TAILQ_REMOVE(&drvctl_eventq, odce, dce_link); 159 prop_object_release(odce->dce_event); 160 kmem_free(odce, sizeof(*odce)); 161 --drvctl_eventcnt; 162 } 163 164 TAILQ_INSERT_TAIL(&drvctl_eventq, dce, dce_link); 165 ++drvctl_eventcnt; 166 cv_broadcast(&drvctl_cond); 167 selnotify(&drvctl_rdsel, 0, 0); 168 169 mutex_exit(&drvctl_lock); 170 return 0; 171 } 172 173 int 174 drvctlopen(dev_t dev, int flags, int mode, struct lwp *l) 175 { 176 struct file *fp; 177 int fd; 178 int ret; 179 180 ret = fd_allocfile(&fp, &fd); 181 if (ret) 182 return ret; 183 184 /* XXX setup context */ 185 mutex_enter(&drvctl_lock); 186 ret = fd_clone(fp, fd, flags, &drvctl_fileops, /* context */NULL); 187 ++drvctl_nopen; 188 mutex_exit(&drvctl_lock); 189 190 return ret; 191 } 192 193 static int 194 pmdevbyname(u_long cmd, struct devpmargs *a) 195 { 196 device_t d; 197 198 if ((d = device_find_by_xname(a->devname)) == NULL) 199 return ENXIO; 200 201 switch (cmd) { 202 case DRVSUSPENDDEV: 203 return pmf_device_recursive_suspend(d, PMF_Q_DRVCTL) ? 0 : EBUSY; 204 case DRVRESUMEDEV: 205 if (a->flags & DEVPM_F_SUBTREE) { 206 return pmf_device_subtree_resume(d, PMF_Q_DRVCTL) 207 ? 0 : EBUSY; 208 } else { 209 return pmf_device_recursive_resume(d, PMF_Q_DRVCTL) 210 ? 0 : EBUSY; 211 } 212 default: 213 return EPASSTHROUGH; 214 } 215 } 216 217 static int 218 listdevbyname(struct devlistargs *l) 219 { 220 device_t d, child; 221 deviter_t di; 222 int cnt = 0, idx, error = 0; 223 224 if (*l->l_devname == '\0') 225 d = NULL; 226 else if (memchr(l->l_devname, 0, sizeof(l->l_devname)) == NULL) 227 return EINVAL; 228 else if ((d = device_find_by_xname(l->l_devname)) == NULL) 229 return ENXIO; 230 231 for (child = deviter_first(&di, 0); child != NULL; 232 child = deviter_next(&di)) { 233 if (device_parent(child) != d) 234 continue; 235 idx = cnt++; 236 if (l->l_childname == NULL || idx >= l->l_children) 237 continue; 238 error = copyoutstr(device_xname(child), l->l_childname[idx], 239 sizeof(l->l_childname[idx]), NULL); 240 if (error != 0) 241 break; 242 } 243 deviter_release(&di); 244 245 l->l_children = cnt; 246 return error; 247 } 248 249 static int 250 detachdevbyname(const char *devname) 251 { 252 device_t d; 253 254 if ((d = device_find_by_xname(devname)) == NULL) 255 return ENXIO; 256 257 #ifndef XXXFULLRISK 258 /* 259 * If the parent cannot be notified, it might keep 260 * pointers to the detached device. 261 * There might be a private notification mechanism, 262 * but better play it safe here. 263 */ 264 if (d->dv_parent && !d->dv_parent->dv_cfattach->ca_childdetached) 265 return ENOTSUP; 266 #endif 267 return config_detach(d, 0); 268 } 269 270 static int 271 rescanbus(const char *busname, const char *ifattr, 272 int numlocators, const int *locators) 273 { 274 int i, rc; 275 device_t d; 276 const struct cfiattrdata * const *ap; 277 278 /* XXX there should be a way to get limits and defaults (per device) 279 from config generated data */ 280 int locs[MAXLOCATORS]; 281 for (i = 0; i < MAXLOCATORS; i++) 282 locs[i] = -1; 283 284 for (i = 0; i < numlocators;i++) 285 locs[i] = locators[i]; 286 287 if ((d = device_find_by_xname(busname)) == NULL) 288 return ENXIO; 289 290 /* 291 * must support rescan, and must have something 292 * to attach to 293 */ 294 if (!d->dv_cfattach->ca_rescan || 295 !d->dv_cfdriver->cd_attrs) 296 return ENODEV; 297 298 /* allow to omit attribute if there is exactly one */ 299 if (!ifattr) { 300 if (d->dv_cfdriver->cd_attrs[1]) 301 return EINVAL; 302 ifattr = d->dv_cfdriver->cd_attrs[0]->ci_name; 303 } else { 304 /* check for valid attribute passed */ 305 for (ap = d->dv_cfdriver->cd_attrs; *ap; ap++) 306 if (!strcmp((*ap)->ci_name, ifattr)) 307 break; 308 if (!*ap) 309 return EINVAL; 310 } 311 312 rc = (*d->dv_cfattach->ca_rescan)(d, ifattr, locs); 313 config_deferred(NULL); 314 return rc; 315 } 316 317 static int 318 drvctl_read(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred, 319 int flags) 320 { 321 return ENODEV; 322 } 323 324 static int 325 drvctl_write(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred, 326 int flags) 327 { 328 return ENODEV; 329 } 330 331 static int 332 drvctl_ioctl(struct file *fp, u_long cmd, void *data) 333 { 334 int res; 335 char *ifattr; 336 int *locs; 337 size_t locs_sz = 0; /* XXXgcc */ 338 339 switch (cmd) { 340 case DRVSUSPENDDEV: 341 case DRVRESUMEDEV: 342 #define d ((struct devpmargs *)data) 343 res = pmdevbyname(cmd, d); 344 #undef d 345 break; 346 case DRVLISTDEV: 347 res = listdevbyname((struct devlistargs *)data); 348 break; 349 case DRVDETACHDEV: 350 #define d ((struct devdetachargs *)data) 351 res = detachdevbyname(d->devname); 352 #undef d 353 break; 354 case DRVRESCANBUS: 355 #define d ((struct devrescanargs *)data) 356 d->busname[sizeof(d->busname) - 1] = '\0'; 357 358 /* XXX better copyin? */ 359 if (d->ifattr[0]) { 360 d->ifattr[sizeof(d->ifattr) - 1] = '\0'; 361 ifattr = d->ifattr; 362 } else 363 ifattr = 0; 364 365 if (d->numlocators) { 366 if (d->numlocators > MAXLOCATORS) 367 return EINVAL; 368 locs_sz = d->numlocators * sizeof(int); 369 locs = kmem_alloc(locs_sz, KM_SLEEP); 370 res = copyin(d->locators, locs, locs_sz); 371 if (res) { 372 kmem_free(locs, locs_sz); 373 return res; 374 } 375 } else 376 locs = NULL; 377 res = rescanbus(d->busname, ifattr, d->numlocators, locs); 378 if (locs) 379 kmem_free(locs, locs_sz); 380 #undef d 381 break; 382 case DRVCTLCOMMAND: 383 res = drvctl_command(curlwp, (struct plistref *)data, cmd, 384 fp->f_flag); 385 break; 386 case DRVGETEVENT: 387 res = drvctl_getevent(curlwp, (struct plistref *)data, cmd, 388 fp->f_flag); 389 break; 390 default: 391 return EPASSTHROUGH; 392 } 393 return res; 394 } 395 396 static int 397 drvctl_stat(struct file *fp, struct stat *st) 398 { 399 (void)memset(st, 0, sizeof(*st)); 400 st->st_uid = kauth_cred_geteuid(fp->f_cred); 401 st->st_gid = kauth_cred_getegid(fp->f_cred); 402 return 0; 403 } 404 405 static int 406 drvctl_poll(struct file *fp, int events) 407 { 408 int revents = 0; 409 410 if (!TAILQ_EMPTY(&drvctl_eventq)) 411 revents |= events & (POLLIN | POLLRDNORM); 412 else 413 selrecord(curlwp, &drvctl_rdsel); 414 415 return revents; 416 } 417 418 static int 419 drvctl_close(struct file *fp) 420 { 421 struct drvctl_event *dce; 422 423 /* XXX free context */ 424 mutex_enter(&drvctl_lock); 425 KASSERT(drvctl_nopen > 0); 426 --drvctl_nopen; 427 if (drvctl_nopen == 0) { 428 /* flush queue */ 429 while ((dce = TAILQ_FIRST(&drvctl_eventq)) != NULL) { 430 TAILQ_REMOVE(&drvctl_eventq, dce, dce_link); 431 KASSERT(drvctl_eventcnt > 0); 432 --drvctl_eventcnt; 433 prop_object_release(dce->dce_event); 434 kmem_free(dce, sizeof(*dce)); 435 } 436 } 437 mutex_exit(&drvctl_lock); 438 439 return 0; 440 } 441 442 void 443 drvctlattach(int arg __unused) 444 { 445 } 446 447 /***************************************************************************** 448 * Driver control command processing engine 449 *****************************************************************************/ 450 451 static int 452 drvctl_command_get_properties(struct lwp *l, 453 prop_dictionary_t command_dict, 454 prop_dictionary_t results_dict) 455 { 456 prop_dictionary_t args_dict; 457 prop_string_t devname_string; 458 device_t dev; 459 deviter_t di; 460 461 args_dict = prop_dictionary_get(command_dict, "drvctl-arguments"); 462 if (args_dict == NULL) 463 return EINVAL; 464 465 devname_string = prop_dictionary_get(args_dict, "device-name"); 466 if (devname_string == NULL) 467 return EINVAL; 468 469 for (dev = deviter_first(&di, 0); dev != NULL; 470 dev = deviter_next(&di)) { 471 if (prop_string_equals_cstring(devname_string, 472 device_xname(dev))) { 473 prop_dictionary_set(results_dict, "drvctl-result-data", 474 device_properties(dev)); 475 break; 476 } 477 } 478 479 deviter_release(&di); 480 481 if (dev == NULL) 482 return ESRCH; 483 484 return 0; 485 } 486 487 struct drvctl_command_desc { 488 const char *dcd_name; /* command name */ 489 int (*dcd_func)(struct lwp *, /* handler function */ 490 prop_dictionary_t, 491 prop_dictionary_t); 492 int dcd_rw; /* read or write required */ 493 }; 494 495 static const struct drvctl_command_desc drvctl_command_table[] = { 496 { .dcd_name = "get-properties", 497 .dcd_func = drvctl_command_get_properties, 498 .dcd_rw = FREAD, 499 }, 500 501 { .dcd_name = NULL } 502 }; 503 504 static int 505 drvctl_command(struct lwp *l, struct plistref *pref, u_long ioctl_cmd, 506 int fflag) 507 { 508 prop_dictionary_t command_dict, results_dict; 509 prop_string_t command_string; 510 const struct drvctl_command_desc *dcd; 511 int error; 512 513 error = prop_dictionary_copyin_ioctl(pref, ioctl_cmd, &command_dict); 514 if (error) 515 return error; 516 517 results_dict = prop_dictionary_create(); 518 if (results_dict == NULL) { 519 prop_object_release(command_dict); 520 return ENOMEM; 521 } 522 523 command_string = prop_dictionary_get(command_dict, "drvctl-command"); 524 if (command_string == NULL) { 525 error = EINVAL; 526 goto out; 527 } 528 529 for (dcd = drvctl_command_table; dcd->dcd_name != NULL; dcd++) { 530 if (prop_string_equals_cstring(command_string, 531 dcd->dcd_name)) 532 break; 533 } 534 535 if (dcd->dcd_name == NULL) { 536 error = EINVAL; 537 goto out; 538 } 539 540 if ((fflag & dcd->dcd_rw) == 0) { 541 error = EPERM; 542 goto out; 543 } 544 545 error = (*dcd->dcd_func)(l, command_dict, results_dict); 546 547 prop_dictionary_set_int32(results_dict, "drvctl-error", error); 548 549 error = prop_dictionary_copyout_ioctl(pref, ioctl_cmd, results_dict); 550 out: 551 prop_object_release(command_dict); 552 prop_object_release(results_dict); 553 return error; 554 } 555 556 static int 557 drvctl_getevent(struct lwp *l, struct plistref *pref, u_long ioctl_cmd, 558 int fflag) 559 { 560 struct drvctl_event *dce; 561 int ret; 562 563 if ((fflag & (FREAD|FWRITE)) != (FREAD|FWRITE)) 564 return EPERM; 565 566 mutex_enter(&drvctl_lock); 567 while ((dce = TAILQ_FIRST(&drvctl_eventq)) == NULL) { 568 if (fflag & O_NONBLOCK) { 569 mutex_exit(&drvctl_lock); 570 return EWOULDBLOCK; 571 } 572 573 ret = cv_wait_sig(&drvctl_cond, &drvctl_lock); 574 if (ret) { 575 mutex_exit(&drvctl_lock); 576 return ret; 577 } 578 } 579 TAILQ_REMOVE(&drvctl_eventq, dce, dce_link); 580 KASSERT(drvctl_eventcnt > 0); 581 --drvctl_eventcnt; 582 mutex_exit(&drvctl_lock); 583 584 ret = prop_dictionary_copyout_ioctl(pref, ioctl_cmd, dce->dce_event); 585 586 prop_object_release(dce->dce_event); 587 kmem_free(dce, sizeof(*dce)); 588 589 return ret; 590 } 591 592 /* 593 * Module glue 594 */ 595 596 MODULE(MODULE_CLASS_DRIVER, drvctl, NULL); 597 598 int 599 drvctl_modcmd(modcmd_t cmd, void *arg) 600 { 601 int error; 602 #ifdef _MODULE 603 int bmajor, cmajor; 604 #endif 605 606 error = 0; 607 switch (cmd) { 608 case MODULE_CMD_INIT: 609 drvctl_init(); 610 611 mutex_enter(&drvctl_lock); 612 #ifdef _MODULE 613 bmajor = cmajor = -1; 614 error = devsw_attach("drvctl", NULL, &bmajor, 615 &drvctl_cdevsw, &cmajor); 616 #endif 617 if (error == 0) { 618 KASSERT(saved_insert_vec == NULL); 619 saved_insert_vec = devmon_insert_vec; 620 devmon_insert_vec = devmon_insert; 621 } 622 623 mutex_exit(&drvctl_lock); 624 break; 625 626 case MODULE_CMD_FINI: 627 mutex_enter(&drvctl_lock); 628 if (drvctl_nopen != 0 || drvctl_eventcnt != 0 ) { 629 mutex_exit(&drvctl_lock); 630 return EBUSY; 631 } 632 KASSERT(saved_insert_vec != NULL); 633 devmon_insert_vec = saved_insert_vec; 634 saved_insert_vec = NULL; 635 #ifdef _MODULE 636 error = devsw_detach(NULL, &drvctl_cdevsw); 637 if (error != 0) { 638 saved_insert_vec = devmon_insert_vec; 639 devmon_insert_vec = devmon_insert; 640 } 641 #endif 642 mutex_exit(&drvctl_lock); 643 if (error == 0) 644 drvctl_fini(); 645 646 break; 647 default: 648 error = ENOTTY; 649 break; 650 } 651 652 return error; 653 } 654