1 /* $NetBSD: kern_drvctl.c,v 1.49 2021/06/16 00:19:46 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 1.49 2021/06/16 00:19:46 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 (d->dv_parent && !d->dv_parent->dv_cfattach->ca_childdetached) { 281 error = ENOTSUP; 282 goto out; 283 } 284 #endif 285 286 error = config_detach(d, 0); 287 out: deviter_release(&di); 288 return error; 289 } 290 291 static int 292 rescanbus(const char *busname, const char *ifattr, 293 int numlocators, const int *locators) 294 { 295 int i, rc; 296 device_t d; 297 const struct cfiattrdata * const *ap; 298 299 KASSERT(KERNEL_LOCKED_P()); 300 301 /* XXX there should be a way to get limits and defaults (per device) 302 from config generated data */ 303 int locs[MAXLOCATORS]; 304 for (i = 0; i < MAXLOCATORS; i++) 305 locs[i] = -1; 306 307 for (i = 0; i < numlocators;i++) 308 locs[i] = locators[i]; 309 310 if ((d = device_find_by_xname(busname)) == NULL) 311 return ENXIO; 312 313 /* 314 * must support rescan, and must have something 315 * to attach to 316 */ 317 if (!d->dv_cfattach->ca_rescan || 318 !d->dv_cfdriver->cd_attrs) 319 return ENODEV; 320 321 /* rescan all ifattrs if none is specified */ 322 if (!ifattr) { 323 rc = 0; 324 for (ap = d->dv_cfdriver->cd_attrs; *ap; ap++) { 325 rc = (*d->dv_cfattach->ca_rescan)(d, (*ap)->ci_name, 326 locs); 327 if (rc) 328 break; 329 } 330 } else { 331 /* check for valid attribute passed */ 332 for (ap = d->dv_cfdriver->cd_attrs; *ap; ap++) 333 if (!strcmp((*ap)->ci_name, ifattr)) 334 break; 335 if (!*ap) 336 return EINVAL; 337 rc = (*d->dv_cfattach->ca_rescan)(d, ifattr, locs); 338 } 339 340 config_deferred(NULL); 341 return rc; 342 } 343 344 static int 345 drvctl_read(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred, 346 int flags) 347 { 348 return ENODEV; 349 } 350 351 static int 352 drvctl_write(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred, 353 int flags) 354 { 355 return ENODEV; 356 } 357 358 static int 359 drvctl_ioctl(struct file *fp, u_long cmd, void *data) 360 { 361 int res; 362 char *ifattr; 363 int *locs; 364 size_t locs_sz = 0; /* XXXgcc */ 365 366 KERNEL_LOCK(1, NULL); 367 switch (cmd) { 368 case DRVSUSPENDDEV: 369 case DRVRESUMEDEV: 370 #define d ((struct devpmargs *)data) 371 res = pmdevbyname(cmd, d); 372 #undef d 373 break; 374 case DRVLISTDEV: 375 res = listdevbyname((struct devlistargs *)data); 376 break; 377 case DRVDETACHDEV: 378 #define d ((struct devdetachargs *)data) 379 res = detachdevbyname(d->devname); 380 #undef d 381 break; 382 case DRVRESCANBUS: 383 #define d ((struct devrescanargs *)data) 384 d->busname[sizeof(d->busname) - 1] = '\0'; 385 386 /* XXX better copyin? */ 387 if (d->ifattr[0]) { 388 d->ifattr[sizeof(d->ifattr) - 1] = '\0'; 389 ifattr = d->ifattr; 390 } else 391 ifattr = 0; 392 393 if (d->numlocators) { 394 if (d->numlocators > MAXLOCATORS) { 395 res = EINVAL; 396 goto out; 397 } 398 locs_sz = d->numlocators * sizeof(int); 399 locs = kmem_alloc(locs_sz, KM_SLEEP); 400 res = copyin(d->locators, locs, locs_sz); 401 if (res) { 402 kmem_free(locs, locs_sz); 403 goto out; 404 } 405 } else 406 locs = NULL; 407 res = rescanbus(d->busname, ifattr, d->numlocators, locs); 408 if (locs) 409 kmem_free(locs, locs_sz); 410 #undef d 411 break; 412 case DRVCTLCOMMAND: 413 res = drvctl_command(curlwp, (struct plistref *)data, cmd, 414 fp->f_flag); 415 break; 416 case DRVGETEVENT: 417 res = drvctl_getevent(curlwp, (struct plistref *)data, cmd, 418 fp->f_flag); 419 break; 420 default: 421 res = EPASSTHROUGH; 422 break; 423 } 424 out: KERNEL_UNLOCK_ONE(NULL); 425 return res; 426 } 427 428 static int 429 drvctl_stat(struct file *fp, struct stat *st) 430 { 431 (void)memset(st, 0, sizeof(*st)); 432 st->st_uid = kauth_cred_geteuid(fp->f_cred); 433 st->st_gid = kauth_cred_getegid(fp->f_cred); 434 return 0; 435 } 436 437 static int 438 drvctl_poll(struct file *fp, int events) 439 { 440 int revents = 0; 441 442 if (!TAILQ_EMPTY(&drvctl_eventq)) 443 revents |= events & (POLLIN | POLLRDNORM); 444 else 445 selrecord(curlwp, &drvctl_rdsel); 446 447 return revents; 448 } 449 450 static int 451 drvctl_close(struct file *fp) 452 { 453 struct drvctl_event *dce; 454 455 /* XXX free context */ 456 mutex_enter(&drvctl_lock); 457 KASSERT(drvctl_nopen > 0); 458 --drvctl_nopen; 459 if (drvctl_nopen == 0) { 460 /* flush queue */ 461 while ((dce = TAILQ_FIRST(&drvctl_eventq)) != NULL) { 462 TAILQ_REMOVE(&drvctl_eventq, dce, dce_link); 463 KASSERT(drvctl_eventcnt > 0); 464 --drvctl_eventcnt; 465 prop_object_release(dce->dce_event); 466 kmem_free(dce, sizeof(*dce)); 467 } 468 } 469 mutex_exit(&drvctl_lock); 470 471 return 0; 472 } 473 474 void 475 drvctlattach(int arg __unused) 476 { 477 } 478 479 /***************************************************************************** 480 * Driver control command processing engine 481 *****************************************************************************/ 482 483 static int 484 drvctl_command_get_properties(struct lwp *l, 485 prop_dictionary_t command_dict, 486 prop_dictionary_t results_dict) 487 { 488 prop_dictionary_t args_dict; 489 prop_string_t devname_string; 490 device_t dev; 491 deviter_t di; 492 493 args_dict = prop_dictionary_get(command_dict, "drvctl-arguments"); 494 if (args_dict == NULL) 495 return EINVAL; 496 497 devname_string = prop_dictionary_get(args_dict, "device-name"); 498 if (devname_string == NULL) 499 return EINVAL; 500 501 for (dev = deviter_first(&di, 0); dev != NULL; 502 dev = deviter_next(&di)) { 503 if (prop_string_equals_string(devname_string, 504 device_xname(dev))) { 505 prop_dictionary_set(results_dict, "drvctl-result-data", 506 device_properties(dev)); 507 break; 508 } 509 } 510 511 deviter_release(&di); 512 513 if (dev == NULL) 514 return ESRCH; 515 516 return 0; 517 } 518 519 struct drvctl_command_desc { 520 const char *dcd_name; /* command name */ 521 int (*dcd_func)(struct lwp *, /* handler function */ 522 prop_dictionary_t, 523 prop_dictionary_t); 524 int dcd_rw; /* read or write required */ 525 }; 526 527 static const struct drvctl_command_desc drvctl_command_table[] = { 528 { .dcd_name = "get-properties", 529 .dcd_func = drvctl_command_get_properties, 530 .dcd_rw = FREAD, 531 }, 532 533 { .dcd_name = NULL } 534 }; 535 536 static int 537 drvctl_command(struct lwp *l, struct plistref *pref, u_long ioctl_cmd, 538 int fflag) 539 { 540 prop_dictionary_t command_dict, results_dict; 541 prop_string_t command_string; 542 const struct drvctl_command_desc *dcd; 543 int error; 544 545 error = prop_dictionary_copyin_ioctl(pref, ioctl_cmd, &command_dict); 546 if (error) 547 return error; 548 549 results_dict = prop_dictionary_create(); 550 if (results_dict == NULL) { 551 prop_object_release(command_dict); 552 return ENOMEM; 553 } 554 555 command_string = prop_dictionary_get(command_dict, "drvctl-command"); 556 if (command_string == NULL) { 557 error = EINVAL; 558 goto out; 559 } 560 561 for (dcd = drvctl_command_table; dcd->dcd_name != NULL; dcd++) { 562 if (prop_string_equals_string(command_string, 563 dcd->dcd_name)) 564 break; 565 } 566 567 if (dcd->dcd_name == NULL) { 568 error = EINVAL; 569 goto out; 570 } 571 572 if ((fflag & dcd->dcd_rw) == 0) { 573 error = EPERM; 574 goto out; 575 } 576 577 error = (*dcd->dcd_func)(l, command_dict, results_dict); 578 579 prop_dictionary_set_int32(results_dict, "drvctl-error", error); 580 581 error = prop_dictionary_copyout_ioctl(pref, ioctl_cmd, results_dict); 582 out: 583 prop_object_release(command_dict); 584 prop_object_release(results_dict); 585 return error; 586 } 587 588 static int 589 drvctl_getevent(struct lwp *l, struct plistref *pref, u_long ioctl_cmd, 590 int fflag) 591 { 592 struct drvctl_event *dce; 593 int ret; 594 595 if ((fflag & (FREAD|FWRITE)) != (FREAD|FWRITE)) 596 return EPERM; 597 598 mutex_enter(&drvctl_lock); 599 while ((dce = TAILQ_FIRST(&drvctl_eventq)) == NULL) { 600 if (fflag & O_NONBLOCK) { 601 mutex_exit(&drvctl_lock); 602 return EWOULDBLOCK; 603 } 604 605 ret = cv_wait_sig(&drvctl_cond, &drvctl_lock); 606 if (ret) { 607 mutex_exit(&drvctl_lock); 608 return ret; 609 } 610 } 611 TAILQ_REMOVE(&drvctl_eventq, dce, dce_link); 612 KASSERT(drvctl_eventcnt > 0); 613 --drvctl_eventcnt; 614 mutex_exit(&drvctl_lock); 615 616 ret = prop_dictionary_copyout_ioctl(pref, ioctl_cmd, dce->dce_event); 617 618 prop_object_release(dce->dce_event); 619 kmem_free(dce, sizeof(*dce)); 620 621 return ret; 622 } 623 624 /* 625 * Module glue 626 */ 627 628 MODULE(MODULE_CLASS_DRIVER, drvctl, NULL); 629 630 int 631 drvctl_modcmd(modcmd_t cmd, void *arg) 632 { 633 int error; 634 #ifdef _MODULE 635 int bmajor, cmajor; 636 #endif 637 638 error = 0; 639 switch (cmd) { 640 case MODULE_CMD_INIT: 641 drvctl_init(); 642 643 mutex_enter(&drvctl_lock); 644 #ifdef _MODULE 645 bmajor = cmajor = -1; 646 error = devsw_attach("drvctl", NULL, &bmajor, 647 &drvctl_cdevsw, &cmajor); 648 #endif 649 if (error == 0) { 650 KASSERT(saved_insert_vec == NULL); 651 saved_insert_vec = devmon_insert_vec; 652 devmon_insert_vec = devmon_insert; 653 } 654 655 mutex_exit(&drvctl_lock); 656 break; 657 658 case MODULE_CMD_FINI: 659 mutex_enter(&drvctl_lock); 660 if (drvctl_nopen != 0 || drvctl_eventcnt != 0 ) { 661 mutex_exit(&drvctl_lock); 662 return EBUSY; 663 } 664 KASSERT(saved_insert_vec != NULL); 665 devmon_insert_vec = saved_insert_vec; 666 saved_insert_vec = NULL; 667 #ifdef _MODULE 668 error = devsw_detach(NULL, &drvctl_cdevsw); 669 if (error != 0) { 670 saved_insert_vec = devmon_insert_vec; 671 devmon_insert_vec = devmon_insert; 672 } 673 #endif 674 mutex_exit(&drvctl_lock); 675 if (error == 0) 676 drvctl_fini(); 677 678 break; 679 default: 680 error = ENOTTY; 681 break; 682 } 683 684 return error; 685 } 686