1 /* $NetBSD: kern_drvctl.c,v 1.51 2022/03/28 12:33:22 riastradh 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 1.51 2022/03/28 12:33:22 riastradh 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_string_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 KASSERT(KERNEL_LOCKED_P()); 199 200 if ((d = device_find_by_xname(a->devname)) == NULL) 201 return ENXIO; 202 203 switch (cmd) { 204 case DRVSUSPENDDEV: 205 return pmf_device_recursive_suspend(d, PMF_Q_DRVCTL) ? 0 : EBUSY; 206 case DRVRESUMEDEV: 207 if (a->flags & DEVPM_F_SUBTREE) { 208 return pmf_device_subtree_resume(d, PMF_Q_DRVCTL) 209 ? 0 : EBUSY; 210 } else { 211 return pmf_device_recursive_resume(d, PMF_Q_DRVCTL) 212 ? 0 : EBUSY; 213 } 214 default: 215 return EPASSTHROUGH; 216 } 217 } 218 219 static int 220 listdevbyname(struct devlistargs *l) 221 { 222 device_t d, child; 223 deviter_t di; 224 int cnt = 0, idx, error = 0; 225 226 KASSERT(KERNEL_LOCKED_P()); 227 228 if (*l->l_devname == '\0') 229 d = NULL; 230 else if (memchr(l->l_devname, 0, sizeof(l->l_devname)) == NULL) 231 return EINVAL; 232 else if ((d = device_find_by_xname(l->l_devname)) == NULL) 233 return ENXIO; 234 235 for (child = deviter_first(&di, 0); child != NULL; 236 child = deviter_next(&di)) { 237 if (device_parent(child) != d) 238 continue; 239 idx = cnt++; 240 if (l->l_childname == NULL || idx >= l->l_children) 241 continue; 242 error = copyoutstr(device_xname(child), l->l_childname[idx], 243 sizeof(l->l_childname[idx]), NULL); 244 if (error != 0) 245 break; 246 } 247 deviter_release(&di); 248 249 l->l_children = cnt; 250 return error; 251 } 252 253 static int 254 detachdevbyname(const char *devname) 255 { 256 device_t d; 257 deviter_t di; 258 int error; 259 260 KASSERT(KERNEL_LOCKED_P()); 261 262 for (d = deviter_first(&di, DEVITER_F_RW); 263 d != NULL; 264 d = deviter_next(&di)) { 265 if (strcmp(device_xname(d), devname) == 0) 266 break; 267 } 268 if (d == NULL) { 269 error = ENXIO; 270 goto out; 271 } 272 273 #ifndef XXXFULLRISK 274 /* 275 * If the parent cannot be notified, it might keep 276 * pointers to the detached device. 277 * There might be a private notification mechanism, 278 * but better play it safe here. 279 */ 280 if (device_parent(d) && 281 !device_cfattach(device_parent(d))->ca_childdetached) { 282 error = ENOTSUP; 283 goto out; 284 } 285 #endif 286 287 error = config_detach(d, 0); 288 out: deviter_release(&di); 289 return error; 290 } 291 292 static int 293 rescanbus(const char *busname, const char *ifattr, 294 int numlocators, const int *locators) 295 { 296 int i, rc; 297 device_t d; 298 const struct cfiattrdata * const *ap; 299 300 KASSERT(KERNEL_LOCKED_P()); 301 302 /* XXX there should be a way to get limits and defaults (per device) 303 from config generated data */ 304 int locs[MAXLOCATORS]; 305 for (i = 0; i < MAXLOCATORS; i++) 306 locs[i] = -1; 307 308 for (i = 0; i < numlocators;i++) 309 locs[i] = locators[i]; 310 311 if ((d = device_find_by_xname(busname)) == NULL) 312 return ENXIO; 313 314 /* 315 * must support rescan, and must have something 316 * to attach to 317 */ 318 if (!device_cfattach(d)->ca_rescan || 319 !device_cfdriver(d)->cd_attrs) 320 return ENODEV; 321 322 /* rescan all ifattrs if none is specified */ 323 if (!ifattr) { 324 rc = 0; 325 for (ap = device_cfdriver(d)->cd_attrs; *ap; ap++) { 326 rc = (*device_cfattach(d)->ca_rescan)(d, 327 (*ap)->ci_name, locs); 328 if (rc) 329 break; 330 } 331 } else { 332 /* check for valid attribute passed */ 333 for (ap = device_cfdriver(d)->cd_attrs; *ap; ap++) 334 if (!strcmp((*ap)->ci_name, ifattr)) 335 break; 336 if (!*ap) 337 return EINVAL; 338 rc = (*device_cfattach(d)->ca_rescan)(d, ifattr, locs); 339 } 340 341 config_deferred(NULL); 342 return rc; 343 } 344 345 static int 346 drvctl_read(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred, 347 int flags) 348 { 349 return ENODEV; 350 } 351 352 static int 353 drvctl_write(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred, 354 int flags) 355 { 356 return ENODEV; 357 } 358 359 static int 360 drvctl_ioctl(struct file *fp, u_long cmd, void *data) 361 { 362 int res; 363 char *ifattr; 364 int *locs; 365 size_t locs_sz = 0; /* XXXgcc */ 366 367 KERNEL_LOCK(1, NULL); 368 switch (cmd) { 369 case DRVSUSPENDDEV: 370 case DRVRESUMEDEV: 371 #define d ((struct devpmargs *)data) 372 res = pmdevbyname(cmd, d); 373 #undef d 374 break; 375 case DRVLISTDEV: 376 res = listdevbyname((struct devlistargs *)data); 377 break; 378 case DRVDETACHDEV: 379 #define d ((struct devdetachargs *)data) 380 res = detachdevbyname(d->devname); 381 #undef d 382 break; 383 case DRVRESCANBUS: 384 #define d ((struct devrescanargs *)data) 385 d->busname[sizeof(d->busname) - 1] = '\0'; 386 387 /* XXX better copyin? */ 388 if (d->ifattr[0]) { 389 d->ifattr[sizeof(d->ifattr) - 1] = '\0'; 390 ifattr = d->ifattr; 391 } else 392 ifattr = 0; 393 394 if (d->numlocators) { 395 if (d->numlocators > MAXLOCATORS) { 396 res = EINVAL; 397 goto out; 398 } 399 locs_sz = d->numlocators * sizeof(int); 400 locs = kmem_alloc(locs_sz, KM_SLEEP); 401 res = copyin(d->locators, locs, locs_sz); 402 if (res) { 403 kmem_free(locs, locs_sz); 404 goto out; 405 } 406 } else 407 locs = NULL; 408 res = rescanbus(d->busname, ifattr, d->numlocators, locs); 409 if (locs) 410 kmem_free(locs, locs_sz); 411 #undef d 412 break; 413 case DRVCTLCOMMAND: 414 res = drvctl_command(curlwp, (struct plistref *)data, cmd, 415 fp->f_flag); 416 break; 417 case DRVGETEVENT: 418 res = drvctl_getevent(curlwp, (struct plistref *)data, cmd, 419 fp->f_flag); 420 break; 421 default: 422 res = EPASSTHROUGH; 423 break; 424 } 425 out: KERNEL_UNLOCK_ONE(NULL); 426 return res; 427 } 428 429 static int 430 drvctl_stat(struct file *fp, struct stat *st) 431 { 432 (void)memset(st, 0, sizeof(*st)); 433 st->st_uid = kauth_cred_geteuid(fp->f_cred); 434 st->st_gid = kauth_cred_getegid(fp->f_cred); 435 return 0; 436 } 437 438 static int 439 drvctl_poll(struct file *fp, int events) 440 { 441 int revents = 0; 442 443 if (!TAILQ_EMPTY(&drvctl_eventq)) 444 revents |= events & (POLLIN | POLLRDNORM); 445 else 446 selrecord(curlwp, &drvctl_rdsel); 447 448 return revents; 449 } 450 451 static int 452 drvctl_close(struct file *fp) 453 { 454 struct drvctl_event *dce; 455 456 /* XXX free context */ 457 mutex_enter(&drvctl_lock); 458 KASSERT(drvctl_nopen > 0); 459 --drvctl_nopen; 460 if (drvctl_nopen == 0) { 461 /* flush queue */ 462 while ((dce = TAILQ_FIRST(&drvctl_eventq)) != NULL) { 463 TAILQ_REMOVE(&drvctl_eventq, dce, dce_link); 464 KASSERT(drvctl_eventcnt > 0); 465 --drvctl_eventcnt; 466 prop_object_release(dce->dce_event); 467 kmem_free(dce, sizeof(*dce)); 468 } 469 } 470 mutex_exit(&drvctl_lock); 471 472 return 0; 473 } 474 475 void 476 drvctlattach(int arg __unused) 477 { 478 } 479 480 /***************************************************************************** 481 * Driver control command processing engine 482 *****************************************************************************/ 483 484 static int 485 drvctl_command_get_properties(struct lwp *l, 486 prop_dictionary_t command_dict, 487 prop_dictionary_t results_dict) 488 { 489 prop_dictionary_t args_dict; 490 prop_string_t devname_string; 491 device_t dev; 492 deviter_t di; 493 494 args_dict = prop_dictionary_get(command_dict, "drvctl-arguments"); 495 if (args_dict == NULL) 496 return EINVAL; 497 498 devname_string = prop_dictionary_get(args_dict, "device-name"); 499 if (devname_string == NULL) 500 return EINVAL; 501 502 for (dev = deviter_first(&di, 0); dev != NULL; 503 dev = deviter_next(&di)) { 504 if (prop_string_equals_string(devname_string, 505 device_xname(dev))) { 506 prop_dictionary_set(results_dict, "drvctl-result-data", 507 device_properties(dev)); 508 break; 509 } 510 } 511 512 deviter_release(&di); 513 514 if (dev == NULL) 515 return ESRCH; 516 517 return 0; 518 } 519 520 struct drvctl_command_desc { 521 const char *dcd_name; /* command name */ 522 int (*dcd_func)(struct lwp *, /* handler function */ 523 prop_dictionary_t, 524 prop_dictionary_t); 525 int dcd_rw; /* read or write required */ 526 }; 527 528 static const struct drvctl_command_desc drvctl_command_table[] = { 529 { .dcd_name = "get-properties", 530 .dcd_func = drvctl_command_get_properties, 531 .dcd_rw = FREAD, 532 }, 533 534 { .dcd_name = NULL } 535 }; 536 537 static int 538 drvctl_command(struct lwp *l, struct plistref *pref, u_long ioctl_cmd, 539 int fflag) 540 { 541 prop_dictionary_t command_dict, results_dict; 542 prop_string_t command_string; 543 const struct drvctl_command_desc *dcd; 544 int error; 545 546 error = prop_dictionary_copyin_ioctl(pref, ioctl_cmd, &command_dict); 547 if (error) 548 return error; 549 550 results_dict = prop_dictionary_create(); 551 if (results_dict == NULL) { 552 prop_object_release(command_dict); 553 return ENOMEM; 554 } 555 556 command_string = prop_dictionary_get(command_dict, "drvctl-command"); 557 if (command_string == NULL) { 558 error = EINVAL; 559 goto out; 560 } 561 562 for (dcd = drvctl_command_table; dcd->dcd_name != NULL; dcd++) { 563 if (prop_string_equals_string(command_string, 564 dcd->dcd_name)) 565 break; 566 } 567 568 if (dcd->dcd_name == NULL) { 569 error = EINVAL; 570 goto out; 571 } 572 573 if ((fflag & dcd->dcd_rw) == 0) { 574 error = EPERM; 575 goto out; 576 } 577 578 error = (*dcd->dcd_func)(l, command_dict, results_dict); 579 580 prop_dictionary_set_int32(results_dict, "drvctl-error", error); 581 582 error = prop_dictionary_copyout_ioctl(pref, ioctl_cmd, results_dict); 583 out: 584 prop_object_release(command_dict); 585 prop_object_release(results_dict); 586 return error; 587 } 588 589 static int 590 drvctl_getevent(struct lwp *l, struct plistref *pref, u_long ioctl_cmd, 591 int fflag) 592 { 593 struct drvctl_event *dce; 594 int ret; 595 596 if ((fflag & (FREAD|FWRITE)) != (FREAD|FWRITE)) 597 return EPERM; 598 599 mutex_enter(&drvctl_lock); 600 while ((dce = TAILQ_FIRST(&drvctl_eventq)) == NULL) { 601 if (fflag & O_NONBLOCK) { 602 mutex_exit(&drvctl_lock); 603 return EWOULDBLOCK; 604 } 605 606 ret = cv_wait_sig(&drvctl_cond, &drvctl_lock); 607 if (ret) { 608 mutex_exit(&drvctl_lock); 609 return ret; 610 } 611 } 612 TAILQ_REMOVE(&drvctl_eventq, dce, dce_link); 613 KASSERT(drvctl_eventcnt > 0); 614 --drvctl_eventcnt; 615 mutex_exit(&drvctl_lock); 616 617 ret = prop_dictionary_copyout_ioctl(pref, ioctl_cmd, dce->dce_event); 618 619 prop_object_release(dce->dce_event); 620 kmem_free(dce, sizeof(*dce)); 621 622 return ret; 623 } 624 625 /* 626 * Module glue 627 */ 628 629 MODULE(MODULE_CLASS_DRIVER, drvctl, NULL); 630 631 int 632 drvctl_modcmd(modcmd_t cmd, void *arg) 633 { 634 int error; 635 #ifdef _MODULE 636 int bmajor, cmajor; 637 #endif 638 639 error = 0; 640 switch (cmd) { 641 case MODULE_CMD_INIT: 642 drvctl_init(); 643 644 mutex_enter(&drvctl_lock); 645 #ifdef _MODULE 646 bmajor = cmajor = -1; 647 error = devsw_attach("drvctl", NULL, &bmajor, 648 &drvctl_cdevsw, &cmajor); 649 #endif 650 if (error == 0) { 651 KASSERT(saved_insert_vec == NULL); 652 saved_insert_vec = devmon_insert_vec; 653 devmon_insert_vec = devmon_insert; 654 } 655 656 mutex_exit(&drvctl_lock); 657 break; 658 659 case MODULE_CMD_FINI: 660 mutex_enter(&drvctl_lock); 661 if (drvctl_nopen != 0 || drvctl_eventcnt != 0 ) { 662 mutex_exit(&drvctl_lock); 663 return EBUSY; 664 } 665 KASSERT(saved_insert_vec != NULL); 666 devmon_insert_vec = saved_insert_vec; 667 saved_insert_vec = NULL; 668 #ifdef _MODULE 669 devsw_detach(NULL, &drvctl_cdevsw); 670 #endif 671 mutex_exit(&drvctl_lock); 672 drvctl_fini(); 673 674 break; 675 default: 676 error = ENOTTY; 677 break; 678 } 679 680 return error; 681 } 682
Indexes created Sun Sep 21 15:09:59 GMT 2025