1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Mike Karels at Berkeley Software Design, Inc. 7 * 8 * Quite extensively rewritten by Poul-Henning Kamp of the FreeBSD 9 * project, to make these variables more userfriendly. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * @(#)kern_sysctl.c 8.4 (Berkeley) 4/14/94 40 * $FreeBSD: src/sys/kern/kern_sysctl.c,v 1.92.2.9 2003/05/01 22:48:09 trhodes Exp $ 41 * $DragonFly: src/sys/kern/kern_sysctl.c,v 1.30 2008/08/03 11:00:32 sephe Exp $ 42 */ 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kernel.h> 47 #include <sys/buf.h> 48 #include <sys/sysctl.h> 49 #include <sys/malloc.h> 50 #include <sys/proc.h> 51 #include <sys/priv.h> 52 #include <sys/sysproto.h> 53 #include <sys/lock.h> 54 #include <vm/vm.h> 55 #include <vm/vm_extern.h> 56 57 static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic"); 58 static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids"); 59 60 static struct lock sysctl_lkp; 61 static struct lock sysctl_ctx_lkp; 62 63 static void sysctl_lock(int type); 64 static void sysctl_unlock(void); 65 static void sysctl_ctx_lock(int type); 66 static void sysctl_ctx_unlock(void); 67 68 static int sysctl_root(SYSCTL_HANDLER_ARGS); 69 static void sysctl_register_oid_int(struct sysctl_oid *oipd); 70 static void sysctl_unregister_oid_int(struct sysctl_oid *oipd); 71 static struct sysctl_ctx_entry* sysctl_ctx_entry_find_int 72 (struct sysctl_ctx_list *, struct sysctl_oid *oidp); 73 74 struct sysctl_oid_list sysctl__children; /* root list */ 75 76 static struct sysctl_oid * 77 sysctl_find_oidname(const char *name, struct sysctl_oid_list *list, int lock) 78 { 79 struct sysctl_oid *oidp; 80 81 SLIST_FOREACH(oidp, list, oid_link) { 82 if (strcmp(oidp->oid_name, name) == 0) { 83 break; 84 } 85 } 86 return (oidp); 87 } 88 89 /* 90 * Initialization of the MIB tree. 91 * 92 * Order by number in each list. 93 */ 94 95 void 96 sysctl_register_oid(struct sysctl_oid *oidp) 97 { 98 sysctl_lock(LK_EXCLUSIVE); 99 sysctl_register_oid_int(oidp); 100 sysctl_unlock(); 101 } 102 103 static void 104 sysctl_register_oid_int(struct sysctl_oid *oidp) 105 { 106 struct sysctl_oid_list *parent = oidp->oid_parent; 107 struct sysctl_oid *p; 108 struct sysctl_oid *q; 109 110 /* 111 * First check if another oid with the same name already 112 * exists in the parent's list. 113 */ 114 p = sysctl_find_oidname(oidp->oid_name, parent, 0); 115 if (p != NULL) { 116 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) 117 p->oid_refcnt++; 118 else 119 kprintf("can't re-use a leaf (%s)!\n", p->oid_name); 120 return; 121 } 122 123 /* 124 * If this oid has a number OID_AUTO, give it a number which 125 * is greater than any current oid. Make sure it is at least 126 * 256 to leave space for pre-assigned oid numbers. 127 */ 128 if (oidp->oid_number == OID_AUTO) { 129 int newoid = 0x100; /* minimum AUTO oid */ 130 131 /* 132 * Adjust based on highest oid in parent list 133 */ 134 SLIST_FOREACH(p, parent, oid_link) { 135 if (newoid <= p->oid_number) 136 newoid = p->oid_number + 1; 137 } 138 oidp->oid_number = newoid; 139 } 140 141 /* 142 * Insert the oid into the parent's list in order. 143 */ 144 q = NULL; 145 SLIST_FOREACH(p, parent, oid_link) { 146 if (oidp->oid_number < p->oid_number) 147 break; 148 q = p; 149 } 150 if (q) 151 SLIST_INSERT_AFTER(q, oidp, oid_link); 152 else 153 SLIST_INSERT_HEAD(parent, oidp, oid_link); 154 } 155 156 void 157 sysctl_unregister_oid(struct sysctl_oid *oidp) 158 { 159 sysctl_lock(LK_EXCLUSIVE); 160 sysctl_unregister_oid_int(oidp); 161 sysctl_unlock(); 162 } 163 164 static void 165 sysctl_unregister_oid_int(struct sysctl_oid *oidp) 166 { 167 struct sysctl_oid *p; 168 169 if (oidp->oid_number == OID_AUTO) 170 panic("Trying to unregister OID_AUTO entry: %p", oidp); 171 172 SLIST_FOREACH(p, oidp->oid_parent, oid_link) { 173 if (p != oidp) 174 continue; 175 SLIST_REMOVE(oidp->oid_parent, oidp, sysctl_oid, oid_link); 176 return; 177 } 178 179 /* 180 * This can happen when a module fails to register and is 181 * being unloaded afterwards. It should not be a panic() 182 * for normal use. 183 */ 184 kprintf("%s: failed to unregister sysctl\n", __func__); 185 } 186 187 /* Initialize a new context to keep track of dynamically added sysctls. */ 188 int 189 sysctl_ctx_init(struct sysctl_ctx_list *c) 190 { 191 if (c == NULL) 192 return(EINVAL); 193 TAILQ_INIT(c); 194 return(0); 195 } 196 197 /* Free the context, and destroy all dynamic oids registered in this context */ 198 int 199 sysctl_ctx_free(struct sysctl_ctx_list *clist) 200 { 201 struct sysctl_ctx_entry *e, *e1; 202 int error; 203 204 error = 0; 205 sysctl_ctx_lock(LK_EXCLUSIVE); 206 /* 207 * First perform a "dry run" to check if it's ok to remove oids. 208 * XXX FIXME 209 * XXX This algorithm is a hack. But I don't know any 210 * XXX better solution for now... 211 */ 212 TAILQ_FOREACH(e, clist, link) { 213 error = sysctl_remove_oid(e->entry, 0, 0); 214 if (error) 215 break; 216 } 217 /* 218 * Restore deregistered entries, either from the end, 219 * or from the place where error occured. 220 * e contains the entry that was not unregistered 221 */ 222 if (error) 223 e1 = TAILQ_PREV(e, sysctl_ctx_list, link); 224 else 225 e1 = TAILQ_LAST(clist, sysctl_ctx_list); 226 while (e1 != NULL) { 227 sysctl_register_oid(e1->entry); 228 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link); 229 } 230 if (error) { 231 sysctl_ctx_unlock(); 232 return(EBUSY); 233 } 234 /* Now really delete the entries */ 235 e = TAILQ_FIRST(clist); 236 while (e != NULL) { 237 e1 = TAILQ_NEXT(e, link); 238 error = sysctl_remove_oid(e->entry, 1, 0); 239 if (error) 240 panic("sysctl_remove_oid: corrupt tree, entry: %s", 241 e->entry->oid_name); 242 kfree(e, M_SYSCTLOID); 243 e = e1; 244 } 245 sysctl_ctx_unlock(); 246 return (error); 247 } 248 249 /* Add an entry to the context */ 250 struct sysctl_ctx_entry * 251 sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 252 { 253 struct sysctl_ctx_entry *e; 254 255 if (clist == NULL || oidp == NULL) 256 return(NULL); 257 e = kmalloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK); 258 e->entry = oidp; 259 sysctl_ctx_lock(LK_EXCLUSIVE); 260 TAILQ_INSERT_HEAD(clist, e, link); 261 sysctl_ctx_unlock(); 262 return (e); 263 } 264 265 /* Find an entry in the context */ 266 struct sysctl_ctx_entry * 267 sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 268 { 269 struct sysctl_ctx_entry *e; 270 271 if (clist == NULL || oidp == NULL) 272 return(NULL); 273 274 sysctl_ctx_lock(LK_SHARED); 275 e = sysctl_ctx_entry_find_int(clist, oidp); 276 sysctl_ctx_unlock(); 277 278 return(e); 279 } 280 281 struct sysctl_ctx_entry * 282 sysctl_ctx_entry_find_int(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 283 { 284 struct sysctl_ctx_entry *e; 285 286 KKASSERT(clist != NULL && oidp != NULL); 287 288 for (e = TAILQ_FIRST(clist); e != NULL; e = TAILQ_NEXT(e, link)) { 289 if(e->entry == oidp) 290 break; 291 } 292 293 return (e); 294 } 295 296 /* 297 * Delete an entry from the context. 298 * NOTE: this function doesn't free oidp! You have to remove it 299 * with sysctl_remove_oid(). 300 */ 301 int 302 sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 303 { 304 struct sysctl_ctx_entry *e; 305 306 if (clist == NULL || oidp == NULL) 307 return (EINVAL); 308 309 sysctl_ctx_lock(LK_EXCLUSIVE); 310 e = sysctl_ctx_entry_find_int(clist, oidp); 311 if (e == NULL) { 312 sysctl_ctx_unlock(); 313 return (ENOENT); 314 } 315 TAILQ_REMOVE(clist, e, link); 316 kfree(e, M_SYSCTLOID); 317 sysctl_ctx_unlock(); 318 319 return(0); 320 } 321 322 /* 323 * Remove dynamically created sysctl trees. 324 * oidp - top of the tree to be removed 325 * del - if 0 - just deregister, otherwise free up entries as well 326 * recurse - if != 0 traverse the subtree to be deleted 327 */ 328 int 329 sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse) 330 { 331 struct sysctl_oid *p; 332 int error; 333 334 if (oidp == NULL) 335 return(EINVAL); 336 if ((oidp->oid_kind & CTLFLAG_DYN) == 0) { 337 kprintf("can't remove non-dynamic nodes!\n"); 338 return (EINVAL); 339 } 340 sysctl_lock(LK_EXCLUSIVE | LK_CANRECURSE); 341 /* 342 * WARNING: normal method to do this should be through 343 * sysctl_ctx_free(). Use recursing as the last resort 344 * method to purge your sysctl tree of leftovers... 345 * However, if some other code still references these nodes, 346 * it will panic. 347 */ 348 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 349 if (oidp->oid_refcnt == 1) { 350 SLIST_FOREACH(p, SYSCTL_CHILDREN(oidp), oid_link) { 351 if (!recurse) { 352 sysctl_unlock(); 353 return(ENOTEMPTY); 354 } 355 error = sysctl_remove_oid(p, del, recurse); 356 if (error) { 357 sysctl_unlock(); 358 return(error); 359 } 360 } 361 if (del) 362 kfree(SYSCTL_CHILDREN(oidp), M_SYSCTLOID); 363 } 364 } 365 if (oidp->oid_refcnt > 1 ) { 366 oidp->oid_refcnt--; 367 } else { 368 if (oidp->oid_refcnt == 0) { 369 kprintf("Warning: bad oid_refcnt=%u (%s)!\n", 370 oidp->oid_refcnt, oidp->oid_name); 371 sysctl_unlock(); 372 return(EINVAL); 373 } 374 sysctl_unregister_oid_int(oidp); 375 if (del) { 376 if (oidp->oid_descr) 377 kfree(__DECONST(char *,oidp->oid_descr), 378 M_SYSCTLOID); 379 kfree(__DECONST(char *, oidp->oid_name), M_SYSCTLOID); 380 kfree(oidp, M_SYSCTLOID); 381 } 382 } 383 sysctl_unlock(); 384 return(0); 385 } 386 387 /* 388 * Create new sysctls at run time. 389 * clist may point to a valid context initialized with sysctl_ctx_init(). 390 */ 391 struct sysctl_oid * 392 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent, 393 int number, const char *name, int kind, void *arg1, int arg2, 394 int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr) 395 { 396 struct sysctl_oid *oidp; 397 ssize_t len; 398 char *newname; 399 400 /* You have to hook up somewhere.. */ 401 if (parent == NULL) 402 return(NULL); 403 sysctl_lock(LK_EXCLUSIVE); 404 /* Check if the node already exists, otherwise create it */ 405 oidp = sysctl_find_oidname(name, parent, 0); 406 if (oidp != NULL) { 407 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 408 oidp->oid_refcnt++; 409 /* Update the context */ 410 if (clist != NULL) 411 sysctl_ctx_entry_add(clist, oidp); 412 sysctl_unlock(); 413 return (oidp); 414 } else { 415 kprintf("can't re-use a leaf (%s)!\n", name); 416 sysctl_unlock(); 417 return (NULL); 418 } 419 } 420 oidp = kmalloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK | M_ZERO); 421 oidp->oid_parent = parent; 422 SLIST_NEXT(oidp, oid_link) = NULL; 423 oidp->oid_number = number; 424 oidp->oid_refcnt = 1; 425 len = strlen(name); 426 newname = kmalloc(len + 1, M_SYSCTLOID, M_WAITOK); 427 bcopy(name, newname, len + 1); 428 newname[len] = '\0'; 429 oidp->oid_name = newname; 430 oidp->oid_handler = handler; 431 oidp->oid_kind = CTLFLAG_DYN | kind; 432 if ((kind & CTLTYPE) == CTLTYPE_NODE) { 433 struct sysctl_oid_list *children; 434 435 /* Allocate space for children */ 436 children = kmalloc(sizeof(*children), M_SYSCTLOID, M_WAITOK); 437 SYSCTL_SET_CHILDREN(oidp, children); 438 SLIST_INIT(children); 439 } else { 440 oidp->oid_arg1 = arg1; 441 oidp->oid_arg2 = arg2; 442 } 443 oidp->oid_fmt = fmt; 444 if (descr) { 445 int len = strlen(descr) + 1; 446 oidp->oid_descr = kmalloc(len, M_SYSCTLOID, M_WAITOK); 447 strcpy((char *)(uintptr_t)(const void *)oidp->oid_descr, descr); 448 }; 449 /* Update the context, if used */ 450 if (clist != NULL) 451 sysctl_ctx_entry_add(clist, oidp); 452 /* Register this oid */ 453 sysctl_register_oid_int(oidp); 454 sysctl_unlock(); 455 return (oidp); 456 } 457 458 /* 459 * Register the kernel's oids on startup. 460 */ 461 SET_DECLARE(sysctl_set, struct sysctl_oid); 462 463 static void 464 sysctl_register_all(void *arg) 465 { 466 struct sysctl_oid **oidp; 467 468 lockinit(&sysctl_lkp, "sysctl", 0, 0); 469 lockinit(&sysctl_ctx_lkp, "sysctl ctx", 0, 0); 470 SET_FOREACH(oidp, sysctl_set) 471 sysctl_register_oid_int(*oidp); 472 } 473 474 SYSINIT(sysctl, SI_BOOT1_POST, SI_ORDER_ANY, sysctl_register_all, 0); 475 476 /* 477 * "Staff-functions" 478 * 479 * These functions implement a presently undocumented interface 480 * used by the sysctl program to walk the tree, and get the type 481 * so it can print the value. 482 * This interface is under work and consideration, and should probably 483 * be killed with a big axe by the first person who can find the time. 484 * (be aware though, that the proper interface isn't as obvious as it 485 * may seem, there are various conflicting requirements. 486 * 487 * {0,0} kprintf the entire MIB-tree. 488 * {0,1,...} return the name of the "..." OID. 489 * {0,2,...} return the next OID. 490 * {0,3} return the OID of the name in "new" 491 * {0,4,...} return the kind & format info for the "..." OID. 492 */ 493 494 static void 495 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i) 496 { 497 int k; 498 struct sysctl_oid *oidp; 499 500 sysctl_lock(LK_SHARED); 501 SLIST_FOREACH(oidp, l, oid_link) { 502 503 for (k=0; k<i; k++) 504 kprintf(" "); 505 506 kprintf("%d %s ", oidp->oid_number, oidp->oid_name); 507 508 kprintf("%c%c", 509 oidp->oid_kind & CTLFLAG_RD ? 'R':' ', 510 oidp->oid_kind & CTLFLAG_WR ? 'W':' '); 511 512 if (oidp->oid_handler) 513 kprintf(" *Handler"); 514 515 switch (oidp->oid_kind & CTLTYPE) { 516 case CTLTYPE_NODE: 517 kprintf(" Node\n"); 518 if (!oidp->oid_handler) { 519 sysctl_sysctl_debug_dump_node( 520 oidp->oid_arg1, i+2); 521 } 522 break; 523 case CTLTYPE_INT: kprintf(" Int\n"); break; 524 case CTLTYPE_STRING: kprintf(" String\n"); break; 525 case CTLTYPE_QUAD: kprintf(" Quad\n"); break; 526 case CTLTYPE_OPAQUE: kprintf(" Opaque/struct\n"); break; 527 default: kprintf("\n"); 528 } 529 530 } 531 sysctl_unlock(); 532 } 533 534 static int 535 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS) 536 { 537 int error; 538 539 error = priv_check(req->td, PRIV_SYSCTL_DEBUG); 540 if (error) 541 return error; 542 sysctl_sysctl_debug_dump_node(&sysctl__children, 0); 543 return ENOENT; 544 } 545 546 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD, 547 0, 0, sysctl_sysctl_debug, "-", ""); 548 549 static int 550 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS) 551 { 552 int *name = (int *) arg1; 553 u_int namelen = arg2; 554 int error = 0; 555 struct sysctl_oid *oid; 556 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2; 557 char buf[10]; 558 559 sysctl_lock(LK_SHARED); 560 while (namelen) { 561 if (!lsp) { 562 ksnprintf(buf,sizeof(buf),"%d",*name); 563 if (req->oldidx) 564 error = SYSCTL_OUT(req, ".", 1); 565 if (!error) 566 error = SYSCTL_OUT(req, buf, strlen(buf)); 567 if (error) { 568 sysctl_unlock(); 569 return (error); 570 } 571 namelen--; 572 name++; 573 continue; 574 } 575 lsp2 = 0; 576 SLIST_FOREACH(oid, lsp, oid_link) { 577 if (oid->oid_number != *name) 578 continue; 579 580 if (req->oldidx) 581 error = SYSCTL_OUT(req, ".", 1); 582 if (!error) 583 error = SYSCTL_OUT(req, oid->oid_name, 584 strlen(oid->oid_name)); 585 if (error) { 586 sysctl_unlock(); 587 return (error); 588 } 589 590 namelen--; 591 name++; 592 593 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) 594 break; 595 596 if (oid->oid_handler) 597 break; 598 599 lsp2 = (struct sysctl_oid_list *)oid->oid_arg1; 600 break; 601 } 602 lsp = lsp2; 603 } 604 sysctl_unlock(); 605 return (SYSCTL_OUT(req, "", 1)); 606 } 607 608 SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD, sysctl_sysctl_name, ""); 609 610 static int 611 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 612 int *next, int *len, int level, struct sysctl_oid **oidpp) 613 { 614 struct sysctl_oid *oidp; 615 616 *len = level; 617 sysctl_lock(LK_SHARED); 618 SLIST_FOREACH(oidp, lsp, oid_link) { 619 *next = oidp->oid_number; 620 *oidpp = oidp; 621 622 if (!namelen) { 623 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) { 624 sysctl_unlock(); 625 return 0; 626 } 627 if (oidp->oid_handler) { 628 /* We really should call the handler here...*/ 629 sysctl_unlock(); 630 return 0; 631 } 632 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 633 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, 634 len, level+1, oidpp)) { 635 sysctl_unlock(); 636 return 0; 637 } 638 goto emptynode; 639 } 640 641 if (oidp->oid_number < *name) 642 continue; 643 644 if (oidp->oid_number > *name) { 645 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) { 646 sysctl_unlock(); 647 return 0; 648 } 649 if (oidp->oid_handler) { 650 sysctl_unlock(); 651 return 0; 652 } 653 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 654 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, 655 next+1, len, level+1, oidpp)) { 656 sysctl_unlock(); 657 return (0); 658 } 659 goto next; 660 } 661 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 662 continue; 663 664 if (oidp->oid_handler) 665 continue; 666 667 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 668 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, 669 len, level+1, oidpp)) { 670 sysctl_unlock(); 671 return (0); 672 } 673 next: 674 namelen = 1; 675 *len = level; 676 emptynode: 677 *len = level; 678 } 679 sysctl_unlock(); 680 return 1; 681 } 682 683 static int 684 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS) 685 { 686 int *name = (int *) arg1; 687 u_int namelen = arg2; 688 int i, j, error; 689 struct sysctl_oid *oid; 690 struct sysctl_oid_list *lsp = &sysctl__children; 691 int newoid[CTL_MAXNAME]; 692 693 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid); 694 if (i) 695 return ENOENT; 696 error = SYSCTL_OUT(req, newoid, j * sizeof (int)); 697 return (error); 698 } 699 700 SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD, sysctl_sysctl_next, ""); 701 702 static int 703 name2oid (char *name, int *oid, int *len, struct sysctl_oid **oidpp) 704 { 705 int i; 706 struct sysctl_oid *oidp; 707 struct sysctl_oid_list *lsp = &sysctl__children; 708 char *p; 709 710 if (!*name) 711 return ENOENT; 712 713 p = name + strlen(name) - 1 ; 714 if (*p == '.') 715 *p = '\0'; 716 717 *len = 0; 718 719 for (p = name; *p && *p != '.'; p++) 720 ; 721 i = *p; 722 if (i == '.') 723 *p = '\0'; 724 725 sysctl_lock(LK_SHARED); 726 oidp = SLIST_FIRST(lsp); 727 728 while (oidp && *len < CTL_MAXNAME) { 729 if (strcmp(name, oidp->oid_name)) { 730 oidp = SLIST_NEXT(oidp, oid_link); 731 continue; 732 } 733 *oid++ = oidp->oid_number; 734 (*len)++; 735 736 if (!i) { 737 if (oidpp) 738 *oidpp = oidp; 739 sysctl_unlock(); 740 return (0); 741 } 742 743 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 744 break; 745 746 if (oidp->oid_handler) 747 break; 748 749 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 750 oidp = SLIST_FIRST(lsp); 751 name = p+1; 752 for (p = name; *p && *p != '.'; p++) 753 ; 754 i = *p; 755 if (i == '.') 756 *p = '\0'; 757 } 758 sysctl_unlock(); 759 return ENOENT; 760 } 761 762 static int 763 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS) 764 { 765 char *p; 766 int error, oid[CTL_MAXNAME], len; 767 struct sysctl_oid *op = 0; 768 769 if (!req->newlen) 770 return ENOENT; 771 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */ 772 return (ENAMETOOLONG); 773 774 p = kmalloc(req->newlen+1, M_SYSCTL, M_WAITOK); 775 776 error = SYSCTL_IN(req, p, req->newlen); 777 if (error) { 778 kfree(p, M_SYSCTL); 779 return (error); 780 } 781 782 p [req->newlen] = '\0'; 783 784 error = name2oid(p, oid, &len, &op); 785 786 kfree(p, M_SYSCTL); 787 788 if (error) 789 return (error); 790 791 error = SYSCTL_OUT(req, oid, len * sizeof *oid); 792 return (error); 793 } 794 795 SYSCTL_PROC(_sysctl, 3, name2oid, CTLFLAG_RW|CTLFLAG_ANYBODY, 0, 0, 796 sysctl_sysctl_name2oid, "I", ""); 797 798 static int 799 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) 800 { 801 struct sysctl_oid *oid; 802 int error; 803 804 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 805 if (error) 806 return (error); 807 808 if (!oid->oid_fmt) 809 return (ENOENT); 810 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind)); 811 if (error) 812 return (error); 813 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1); 814 return (error); 815 } 816 817 818 SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD, sysctl_sysctl_oidfmt, ""); 819 820 static int 821 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) 822 { 823 struct sysctl_oid *oid; 824 int error; 825 826 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 827 if (error) 828 return (error); 829 830 if (!oid->oid_descr) 831 return (ENOENT); 832 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1); 833 return (error); 834 } 835 836 SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD, sysctl_sysctl_oiddescr, ""); 837 838 /* 839 * Default "handler" functions. 840 */ 841 842 /* 843 * Handle an int, signed or unsigned. 844 * Two cases: 845 * a variable: point arg1 at it. 846 * a constant: pass it in arg2. 847 */ 848 849 int 850 sysctl_handle_int(SYSCTL_HANDLER_ARGS) 851 { 852 int error = 0; 853 854 if (arg1) 855 error = SYSCTL_OUT(req, arg1, sizeof(int)); 856 else 857 error = SYSCTL_OUT(req, &arg2, sizeof(int)); 858 859 if (error || !req->newptr) 860 return (error); 861 862 if (!arg1) 863 error = EPERM; 864 else 865 error = SYSCTL_IN(req, arg1, sizeof(int)); 866 return (error); 867 } 868 869 /* 870 * Handle a long, signed or unsigned. arg1 points to it. 871 */ 872 873 int 874 sysctl_handle_long(SYSCTL_HANDLER_ARGS) 875 { 876 int error = 0; 877 878 if (!arg1) 879 return (EINVAL); 880 error = SYSCTL_OUT(req, arg1, sizeof(long)); 881 882 if (error || !req->newptr) 883 return (error); 884 885 error = SYSCTL_IN(req, arg1, sizeof(long)); 886 return (error); 887 } 888 889 /* 890 * Handle a quad, signed or unsigned. arg1 points to it. 891 */ 892 893 int 894 sysctl_handle_quad(SYSCTL_HANDLER_ARGS) 895 { 896 int error = 0; 897 898 if (!arg1) 899 return (EINVAL); 900 error = SYSCTL_OUT(req, arg1, sizeof(quad_t)); 901 902 if (error || !req->newptr) 903 return (error); 904 905 error = SYSCTL_IN(req, arg1, sizeof(quad_t)); 906 return (error); 907 } 908 909 /* 910 * Handle our generic '\0' terminated 'C' string. 911 * Two cases: 912 * a variable string: point arg1 at it, arg2 is max length. 913 * a constant string: point arg1 at it, arg2 is zero. 914 */ 915 916 int 917 sysctl_handle_string(SYSCTL_HANDLER_ARGS) 918 { 919 int error=0; 920 921 error = SYSCTL_OUT(req, arg1, strlen((char *)arg1)+1); 922 923 if (error || !req->newptr) 924 return (error); 925 926 if ((req->newlen - req->newidx) >= arg2) { 927 error = EINVAL; 928 } else { 929 arg2 = (req->newlen - req->newidx); 930 error = SYSCTL_IN(req, arg1, arg2); 931 ((char *)arg1)[arg2] = '\0'; 932 } 933 934 return (error); 935 } 936 937 /* 938 * Handle any kind of opaque data. 939 * arg1 points to it, arg2 is the size. 940 */ 941 942 int 943 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS) 944 { 945 int error; 946 947 error = SYSCTL_OUT(req, arg1, arg2); 948 949 if (error || !req->newptr) 950 return (error); 951 952 error = SYSCTL_IN(req, arg1, arg2); 953 954 return (error); 955 } 956 957 /* 958 * Transfer functions to/from kernel space. 959 * XXX: rather untested at this point 960 */ 961 static int 962 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l) 963 { 964 size_t i = 0; 965 966 if (req->oldptr) { 967 i = l; 968 if (i > req->oldlen - req->oldidx) 969 i = req->oldlen - req->oldidx; 970 if (i > 0) 971 bcopy(p, (char *)req->oldptr + req->oldidx, i); 972 } 973 req->oldidx += l; 974 if (req->oldptr && i != l) 975 return (ENOMEM); 976 return (0); 977 } 978 979 static int 980 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l) 981 { 982 983 if (!req->newptr) 984 return 0; 985 if (req->newlen - req->newidx < l) 986 return (EINVAL); 987 bcopy((char *)req->newptr + req->newidx, p, l); 988 req->newidx += l; 989 return (0); 990 } 991 992 int 993 kernel_sysctl(int *name, u_int namelen, void *old, size_t *oldlenp, void *new, size_t newlen, size_t *retval) 994 { 995 int error = 0; 996 struct sysctl_req req; 997 998 bzero(&req, sizeof req); 999 1000 req.td = curthread; 1001 1002 if (oldlenp) { 1003 req.oldlen = *oldlenp; 1004 } 1005 1006 if (old) { 1007 req.oldptr = old; 1008 } 1009 1010 if (new != NULL) { 1011 req.newlen = newlen; 1012 req.newptr = new; 1013 } 1014 1015 req.oldfunc = sysctl_old_kernel; 1016 req.newfunc = sysctl_new_kernel; 1017 req.lock = 1; 1018 1019 sysctl_lock(LK_SHARED); 1020 1021 error = sysctl_root(0, name, namelen, &req); 1022 1023 if (req.lock == 2) 1024 vsunlock(req.oldptr, req.oldlen); 1025 1026 sysctl_unlock(); 1027 1028 if (error && error != ENOMEM) 1029 return (error); 1030 1031 if (retval) { 1032 if (req.oldptr && req.oldidx > req.oldlen) 1033 *retval = req.oldlen; 1034 else 1035 *retval = req.oldidx; 1036 } 1037 return (error); 1038 } 1039 1040 int 1041 kernel_sysctlbyname(char *name, void *old, size_t *oldlenp, 1042 void *new, size_t newlen, size_t *retval) 1043 { 1044 int oid[CTL_MAXNAME]; 1045 size_t oidlen, plen; 1046 int error; 1047 1048 oid[0] = 0; /* sysctl internal magic */ 1049 oid[1] = 3; /* name2oid */ 1050 oidlen = sizeof(oid); 1051 1052 error = kernel_sysctl(oid, 2, oid, &oidlen, (void *)name, 1053 strlen(name), &plen); 1054 if (error) 1055 return (error); 1056 1057 error = kernel_sysctl(oid, plen / sizeof(int), old, oldlenp, 1058 new, newlen, retval); 1059 return (error); 1060 } 1061 1062 /* 1063 * Transfer function to/from user space. 1064 */ 1065 static int 1066 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l) 1067 { 1068 int error = 0; 1069 size_t i = 0; 1070 1071 if (req->lock == 1 && req->oldptr) { 1072 vslock(req->oldptr, req->oldlen); 1073 req->lock = 2; 1074 } 1075 if (req->oldptr) { 1076 i = l; 1077 if (i > req->oldlen - req->oldidx) 1078 i = req->oldlen - req->oldidx; 1079 if (i > 0) 1080 error = copyout(p, (char *)req->oldptr + req->oldidx, 1081 i); 1082 } 1083 req->oldidx += l; 1084 if (error) 1085 return (error); 1086 if (req->oldptr && i < l) 1087 return (ENOMEM); 1088 return (0); 1089 } 1090 1091 static int 1092 sysctl_new_user(struct sysctl_req *req, void *p, size_t l) 1093 { 1094 int error; 1095 1096 if (!req->newptr) 1097 return 0; 1098 if (req->newlen - req->newidx < l) 1099 return (EINVAL); 1100 error = copyin((char *)req->newptr + req->newidx, p, l); 1101 req->newidx += l; 1102 return (error); 1103 } 1104 1105 int 1106 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid, 1107 int *nindx, struct sysctl_req *req) 1108 { 1109 struct sysctl_oid *oid; 1110 int indx; 1111 1112 sysctl_lock(LK_SHARED); 1113 oid = SLIST_FIRST(&sysctl__children); 1114 indx = 0; 1115 while (oid && indx < CTL_MAXNAME) { 1116 if (oid->oid_number == name[indx]) { 1117 indx++; 1118 if (oid->oid_kind & CTLFLAG_NOLOCK) 1119 req->lock = 0; 1120 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1121 if (oid->oid_handler != NULL || 1122 indx == namelen) { 1123 *noid = oid; 1124 if (nindx != NULL) 1125 *nindx = indx; 1126 sysctl_unlock(); 1127 return (0); 1128 } 1129 oid = SLIST_FIRST( 1130 (struct sysctl_oid_list *)oid->oid_arg1); 1131 } else if (indx == namelen) { 1132 *noid = oid; 1133 if (nindx != NULL) 1134 *nindx = indx; 1135 sysctl_unlock(); 1136 return (0); 1137 } else { 1138 sysctl_unlock(); 1139 return (ENOTDIR); 1140 } 1141 } else { 1142 oid = SLIST_NEXT(oid, oid_link); 1143 } 1144 } 1145 sysctl_unlock(); 1146 return (ENOENT); 1147 } 1148 1149 /* 1150 * Traverse our tree, and find the right node, execute whatever it points 1151 * to, and return the resulting error code. 1152 */ 1153 1154 int 1155 sysctl_root(SYSCTL_HANDLER_ARGS) 1156 { 1157 struct thread *td = req->td; 1158 struct proc *p = td ? td->td_proc : NULL; 1159 struct sysctl_oid *oid; 1160 int error, indx; 1161 1162 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req); 1163 if (error) 1164 return (error); 1165 1166 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1167 /* 1168 * You can't call a sysctl when it's a node, but has 1169 * no handler. Inform the user that it's a node. 1170 * The indx may or may not be the same as namelen. 1171 */ 1172 if (oid->oid_handler == NULL) 1173 return (EISDIR); 1174 } 1175 1176 /* If writing isn't allowed */ 1177 if (req->newptr && (!(oid->oid_kind & CTLFLAG_WR) || 1178 ((oid->oid_kind & CTLFLAG_SECURE) && securelevel > 0))) 1179 return (EPERM); 1180 1181 /* Most likely only root can write */ 1182 if (!(oid->oid_kind & CTLFLAG_ANYBODY) && req->newptr && p && 1183 (error = priv_check_cred(p->p_ucred, 1184 (oid->oid_kind & CTLFLAG_PRISON) ? PRIV_SYSCTL_WRITEJAIL : 1185 PRIV_SYSCTL_WRITE, 0))) 1186 return (error); 1187 1188 if (!oid->oid_handler) 1189 return EINVAL; 1190 1191 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) 1192 error = oid->oid_handler(oid, (int *)arg1 + indx, arg2 - indx, 1193 req); 1194 else 1195 error = oid->oid_handler(oid, oid->oid_arg1, oid->oid_arg2, 1196 req); 1197 return (error); 1198 } 1199 1200 int 1201 sys___sysctl(struct sysctl_args *uap) 1202 { 1203 int error, i, name[CTL_MAXNAME]; 1204 size_t j; 1205 1206 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2) 1207 return (EINVAL); 1208 1209 error = copyin(uap->name, &name, uap->namelen * sizeof(int)); 1210 if (error) 1211 return (error); 1212 1213 error = userland_sysctl(name, uap->namelen, 1214 uap->old, uap->oldlenp, 0, 1215 uap->new, uap->newlen, &j); 1216 if (error && error != ENOMEM) 1217 return (error); 1218 if (uap->oldlenp) { 1219 i = copyout(&j, uap->oldlenp, sizeof(j)); 1220 if (i) 1221 return (i); 1222 } 1223 return (error); 1224 } 1225 1226 /* 1227 * This is used from various compatibility syscalls too. That's why name 1228 * must be in kernel space. 1229 */ 1230 int 1231 userland_sysctl(int *name, u_int namelen, void *old, size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval) 1232 { 1233 int error = 0; 1234 struct sysctl_req req, req2; 1235 1236 bzero(&req, sizeof req); 1237 1238 if (oldlenp) { 1239 if (inkernel) { 1240 req.oldlen = *oldlenp; 1241 } else { 1242 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp)); 1243 if (error) 1244 return (error); 1245 } 1246 } 1247 1248 if (old) { 1249 if (!useracc(old, req.oldlen, VM_PROT_WRITE)) 1250 return (EFAULT); 1251 req.oldptr= old; 1252 } 1253 1254 if (new != NULL) { 1255 if (!useracc(new, newlen, VM_PROT_READ)) 1256 return (EFAULT); 1257 req.newlen = newlen; 1258 req.newptr = new; 1259 } 1260 1261 req.oldfunc = sysctl_old_user; 1262 req.newfunc = sysctl_new_user; 1263 req.lock = 1; 1264 req.td = curthread; 1265 1266 sysctl_lock(LK_SHARED); 1267 1268 do { 1269 req2 = req; 1270 error = sysctl_root(0, name, namelen, &req2); 1271 } while (error == EAGAIN); 1272 1273 req = req2; 1274 if (req.lock == 2) 1275 vsunlock(req.oldptr, req.oldlen); 1276 1277 sysctl_unlock(); 1278 1279 if (error && error != ENOMEM) 1280 return (error); 1281 1282 if (retval) { 1283 if (req.oldptr && req.oldidx > req.oldlen) 1284 *retval = req.oldlen; 1285 else 1286 *retval = req.oldidx; 1287 } 1288 return (error); 1289 } 1290 1291 static void 1292 sysctl_lock(int flag) 1293 { 1294 lockmgr(&sysctl_lkp, flag); 1295 } 1296 1297 static void 1298 sysctl_unlock(void) 1299 { 1300 lockmgr(&sysctl_lkp, LK_RELEASE); 1301 } 1302 1303 static void 1304 sysctl_ctx_lock(int flag) 1305 { 1306 lockmgr(&sysctl_ctx_lkp, flag); 1307 } 1308 1309 static void 1310 sysctl_ctx_unlock(void) 1311 { 1312 lockmgr(&sysctl_ctx_lkp, LK_RELEASE); 1313 } 1314 1315 int 1316 sysctl_int_range(SYSCTL_HANDLER_ARGS, int low, int high) 1317 { 1318 int error, value; 1319 1320 value = *(int *)arg1; 1321 error = sysctl_handle_int(oidp, &value, 0, req); 1322 if (error || !req->newptr) 1323 return (error); 1324 if (value < low || value > high) 1325 return (EINVAL); 1326 *(int *)arg1 = value; 1327 return (0); 1328 } 1329