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 1.18 2005/02/05 23:04:28 joerg 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/sysproto.h> 52 #include <sys/lock.h> 53 #include <vm/vm.h> 54 #include <vm/vm_extern.h> 55 56 static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic"); 57 static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids"); 58 59 static struct lock sysctl_lkp; 60 static struct lock sysctl_ctx_lkp; 61 62 static void sysctl_lock(int type); 63 static void sysctl_unlock(void); 64 static void sysctl_ctx_lock(int type); 65 static void sysctl_ctx_unlock(void); 66 67 static int sysctl_root(SYSCTL_HANDLER_ARGS); 68 static void sysctl_register_oid_int(struct sysctl_oid *oipd); 69 static void sysctl_unregister_oid_int(struct sysctl_oid *oipd); 70 static struct sysctl_ctx_entry* sysctl_ctx_entry_find_int 71 (struct sysctl_ctx_list *, struct sysctl_oid *oidp); 72 73 struct sysctl_oid_list sysctl__children; /* root list */ 74 75 static struct sysctl_oid * 76 sysctl_find_oidname(const char *name, struct sysctl_oid_list *list, int lock) 77 { 78 struct sysctl_oid *oidp; 79 80 SLIST_FOREACH(oidp, list, oid_link) { 81 if (strcmp(oidp->oid_name, name) == 0) { 82 break; 83 } 84 } 85 return (oidp); 86 } 87 88 /* 89 * Initialization of the MIB tree. 90 * 91 * Order by number in each list. 92 */ 93 94 void 95 sysctl_register_oid(struct sysctl_oid *oidp) 96 { 97 sysctl_lock(LK_EXCLUSIVE); 98 sysctl_register_oid_int(oidp); 99 sysctl_unlock(); 100 } 101 102 static void 103 sysctl_register_oid_int(struct sysctl_oid *oidp) 104 { 105 struct sysctl_oid_list *parent = oidp->oid_parent; 106 struct sysctl_oid *p; 107 struct sysctl_oid *q; 108 109 /* 110 * First check if another oid with the same name already 111 * exists in the parent's list. 112 */ 113 p = sysctl_find_oidname(oidp->oid_name, parent, 0); 114 if (p != NULL) { 115 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) 116 p->oid_refcnt++; 117 else 118 printf("can't re-use a leaf (%s)!\n", p->oid_name); 119 return; 120 } 121 122 /* 123 * If this oid has a number OID_AUTO, give it a number which 124 * is greater than any current oid. Make sure it is at least 125 * 256 to leave space for pre-assigned oid numbers. 126 */ 127 if (oidp->oid_number == OID_AUTO) { 128 int newoid = 0x100; /* minimum AUTO oid */ 129 130 /* 131 * Adjust based on highest oid in parent list 132 */ 133 SLIST_FOREACH(p, parent, oid_link) { 134 if (newoid <= p->oid_number) 135 newoid = p->oid_number + 1; 136 } 137 oidp->oid_number = newoid; 138 } 139 140 /* 141 * Insert the oid into the parent's list in order. 142 */ 143 q = NULL; 144 SLIST_FOREACH(p, parent, oid_link) { 145 if (oidp->oid_number < p->oid_number) 146 break; 147 q = p; 148 } 149 if (q) 150 SLIST_INSERT_AFTER(q, oidp, oid_link); 151 else 152 SLIST_INSERT_HEAD(parent, oidp, oid_link); 153 } 154 155 void 156 sysctl_unregister_oid(struct sysctl_oid *oidp) 157 { 158 sysctl_lock(LK_EXCLUSIVE); 159 sysctl_unregister_oid_int(oidp); 160 sysctl_unlock(); 161 } 162 163 static void 164 sysctl_unregister_oid_int(struct sysctl_oid *oidp) 165 { 166 struct sysctl_oid *p; 167 168 if (oidp->oid_number == OID_AUTO) 169 panic("Trying to unregister OID_AUTO entry: %p", oidp); 170 171 SLIST_FOREACH(p, oidp->oid_parent, oid_link) { 172 if (p != oidp) 173 continue; 174 SLIST_REMOVE(oidp->oid_parent, oidp, sysctl_oid, oid_link); 175 return; 176 } 177 178 /* 179 * This can happen when a module fails to register and is 180 * being unloaded afterwards. It should not be a panic() 181 * for normal use. 182 */ 183 printf("%s: failed to unregister sysctl\n", __func__); 184 } 185 186 /* Initialize a new context to keep track of dynamically added sysctls. */ 187 int 188 sysctl_ctx_init(struct sysctl_ctx_list *c) 189 { 190 if (c == NULL) 191 return(EINVAL); 192 TAILQ_INIT(c); 193 return(0); 194 } 195 196 /* Free the context, and destroy all dynamic oids registered in this context */ 197 int 198 sysctl_ctx_free(struct sysctl_ctx_list *clist) 199 { 200 struct sysctl_ctx_entry *e, *e1; 201 int error; 202 203 error = 0; 204 sysctl_ctx_lock(LK_EXCLUSIVE); 205 /* 206 * First perform a "dry run" to check if it's ok to remove oids. 207 * XXX FIXME 208 * XXX This algorithm is a hack. But I don't know any 209 * XXX better solution for now... 210 */ 211 TAILQ_FOREACH(e, clist, link) { 212 error = sysctl_remove_oid(e->entry, 0, 0); 213 if (error) 214 break; 215 } 216 /* 217 * Restore deregistered entries, either from the end, 218 * or from the place where error occured. 219 * e contains the entry that was not unregistered 220 */ 221 if (error) 222 e1 = TAILQ_PREV(e, sysctl_ctx_list, link); 223 else 224 e1 = TAILQ_LAST(clist, sysctl_ctx_list); 225 while (e1 != NULL) { 226 sysctl_register_oid(e1->entry); 227 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link); 228 } 229 if (error) { 230 sysctl_ctx_unlock(); 231 return(EBUSY); 232 } 233 /* Now really delete the entries */ 234 e = TAILQ_FIRST(clist); 235 while (e != NULL) { 236 e1 = TAILQ_NEXT(e, link); 237 error = sysctl_remove_oid(e->entry, 1, 0); 238 if (error) 239 panic("sysctl_remove_oid: corrupt tree, entry: %s", 240 e->entry->oid_name); 241 free(e, M_SYSCTLOID); 242 e = e1; 243 } 244 sysctl_ctx_unlock(); 245 return (error); 246 } 247 248 /* Add an entry to the context */ 249 struct sysctl_ctx_entry * 250 sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 251 { 252 struct sysctl_ctx_entry *e; 253 254 if (clist == NULL || oidp == NULL) 255 return(NULL); 256 e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK); 257 e->entry = oidp; 258 sysctl_ctx_lock(LK_EXCLUSIVE); 259 TAILQ_INSERT_HEAD(clist, e, link); 260 sysctl_ctx_unlock(); 261 return (e); 262 } 263 264 /* Find an entry in the context */ 265 struct sysctl_ctx_entry * 266 sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 267 { 268 struct sysctl_ctx_entry *e; 269 270 if (clist == NULL || oidp == NULL) 271 return(NULL); 272 273 sysctl_ctx_lock(LK_SHARED); 274 e = sysctl_ctx_entry_find_int(clist, oidp); 275 sysctl_ctx_unlock(); 276 277 return(e); 278 } 279 280 struct sysctl_ctx_entry * 281 sysctl_ctx_entry_find_int(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 282 { 283 struct sysctl_ctx_entry *e; 284 285 KKASSERT(clist != NULL && oidp != NULL); 286 287 for (e = TAILQ_FIRST(clist); e != NULL; e = TAILQ_NEXT(e, link)) { 288 if(e->entry == oidp) 289 break; 290 } 291 292 return (e); 293 } 294 295 /* 296 * Delete an entry from the context. 297 * NOTE: this function doesn't free oidp! You have to remove it 298 * with sysctl_remove_oid(). 299 */ 300 int 301 sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 302 { 303 struct sysctl_ctx_entry *e; 304 305 if (clist == NULL || oidp == NULL) 306 return (EINVAL); 307 308 sysctl_ctx_lock(LK_EXCLUSIVE); 309 e = sysctl_ctx_entry_find_int(clist, oidp); 310 if (e == NULL) { 311 sysctl_ctx_unlock(); 312 return (ENOENT); 313 } 314 TAILQ_REMOVE(clist, e, link); 315 free(e, M_SYSCTLOID); 316 sysctl_ctx_unlock(); 317 318 return(0); 319 } 320 321 /* 322 * Remove dynamically created sysctl trees. 323 * oidp - top of the tree to be removed 324 * del - if 0 - just deregister, otherwise free up entries as well 325 * recurse - if != 0 traverse the subtree to be deleted 326 */ 327 int 328 sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse) 329 { 330 struct sysctl_oid *p; 331 int error; 332 333 if (oidp == NULL) 334 return(EINVAL); 335 if ((oidp->oid_kind & CTLFLAG_DYN) == 0) { 336 printf("can't remove non-dynamic nodes!\n"); 337 return (EINVAL); 338 } 339 sysctl_lock(LK_EXCLUSIVE | LK_CANRECURSE); 340 /* 341 * WARNING: normal method to do this should be through 342 * sysctl_ctx_free(). Use recursing as the last resort 343 * method to purge your sysctl tree of leftovers... 344 * However, if some other code still references these nodes, 345 * it will panic. 346 */ 347 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 348 if (oidp->oid_refcnt == 1) { 349 SLIST_FOREACH(p, SYSCTL_CHILDREN(oidp), oid_link) { 350 if (!recurse) { 351 sysctl_unlock(); 352 return(ENOTEMPTY); 353 } 354 error = sysctl_remove_oid(p, del, recurse); 355 if (error) { 356 sysctl_unlock(); 357 return(error); 358 } 359 } 360 if (del) 361 free(SYSCTL_CHILDREN(oidp), M_SYSCTLOID); 362 } 363 } 364 if (oidp->oid_refcnt > 1 ) { 365 oidp->oid_refcnt--; 366 } else { 367 if (oidp->oid_refcnt == 0) { 368 printf("Warning: bad oid_refcnt=%u (%s)!\n", 369 oidp->oid_refcnt, oidp->oid_name); 370 sysctl_unlock(); 371 return(EINVAL); 372 } 373 sysctl_unregister_oid_int(oidp); 374 if (del) { 375 if (oidp->oid_descr) 376 free(__DECONST(char *,oidp->oid_descr), 377 M_SYSCTLOID); 378 free(__DECONST(char *, oidp->oid_name), M_SYSCTLOID); 379 free(oidp, M_SYSCTLOID); 380 } 381 } 382 sysctl_unlock(); 383 return(0); 384 } 385 386 /* 387 * Create new sysctls at run time. 388 * clist may point to a valid context initialized with sysctl_ctx_init(). 389 */ 390 struct sysctl_oid * 391 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent, 392 int number, const char *name, int kind, void *arg1, int arg2, 393 int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr) 394 { 395 struct sysctl_oid *oidp; 396 ssize_t len; 397 char *newname; 398 399 /* You have to hook up somewhere.. */ 400 if (parent == NULL) 401 return(NULL); 402 sysctl_lock(LK_EXCLUSIVE); 403 /* Check if the node already exists, otherwise create it */ 404 oidp = sysctl_find_oidname(name, parent, 0); 405 if (oidp != NULL) { 406 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 407 oidp->oid_refcnt++; 408 /* Update the context */ 409 if (clist != NULL) 410 sysctl_ctx_entry_add(clist, oidp); 411 sysctl_unlock(); 412 return (oidp); 413 } else { 414 printf("can't re-use a leaf (%s)!\n", name); 415 sysctl_unlock(); 416 return (NULL); 417 } 418 } 419 oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK | M_ZERO); 420 oidp->oid_parent = parent; 421 SLIST_NEXT(oidp, oid_link) = NULL; 422 oidp->oid_number = number; 423 oidp->oid_refcnt = 1; 424 len = strlen(name); 425 newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK); 426 bcopy(name, newname, len + 1); 427 newname[len] = '\0'; 428 oidp->oid_name = newname; 429 oidp->oid_handler = handler; 430 oidp->oid_kind = CTLFLAG_DYN | kind; 431 if ((kind & CTLTYPE) == CTLTYPE_NODE) { 432 struct sysctl_oid_list *children; 433 434 /* Allocate space for children */ 435 children = malloc(sizeof(*children), M_SYSCTLOID, M_WAITOK); 436 SYSCTL_SET_CHILDREN(oidp, children); 437 SLIST_INIT(children); 438 } else { 439 oidp->oid_arg1 = arg1; 440 oidp->oid_arg2 = arg2; 441 } 442 oidp->oid_fmt = fmt; 443 if (descr) { 444 int len = strlen(descr) + 1; 445 oidp->oid_descr = malloc(len, M_SYSCTLOID, M_WAITOK); 446 if (oidp->oid_descr) 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 sysctl_register_all(void *arg) 464 { 465 struct sysctl_oid **oidp; 466 467 lockinit(&sysctl_lkp, 0, "sysctl", 0, 0); 468 lockinit(&sysctl_ctx_lkp, 0, "sysctl ctx", 0, 0); 469 SET_FOREACH(oidp, sysctl_set) 470 sysctl_register_oid_int(*oidp); 471 } 472 473 SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_ANY, sysctl_register_all, 0); 474 475 /* 476 * "Staff-functions" 477 * 478 * These functions implement a presently undocumented interface 479 * used by the sysctl program to walk the tree, and get the type 480 * so it can print the value. 481 * This interface is under work and consideration, and should probably 482 * be killed with a big axe by the first person who can find the time. 483 * (be aware though, that the proper interface isn't as obvious as it 484 * may seem, there are various conflicting requirements. 485 * 486 * {0,0} printf the entire MIB-tree. 487 * {0,1,...} return the name of the "..." OID. 488 * {0,2,...} return the next OID. 489 * {0,3} return the OID of the name in "new" 490 * {0,4,...} return the kind & format info for the "..." OID. 491 */ 492 493 static void 494 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i) 495 { 496 int k; 497 struct sysctl_oid *oidp; 498 499 sysctl_lock(LK_SHARED); 500 SLIST_FOREACH(oidp, l, oid_link) { 501 502 for (k=0; k<i; k++) 503 printf(" "); 504 505 printf("%d %s ", oidp->oid_number, oidp->oid_name); 506 507 printf("%c%c", 508 oidp->oid_kind & CTLFLAG_RD ? 'R':' ', 509 oidp->oid_kind & CTLFLAG_WR ? 'W':' '); 510 511 if (oidp->oid_handler) 512 printf(" *Handler"); 513 514 switch (oidp->oid_kind & CTLTYPE) { 515 case CTLTYPE_NODE: 516 printf(" Node\n"); 517 if (!oidp->oid_handler) { 518 sysctl_sysctl_debug_dump_node( 519 oidp->oid_arg1, i+2); 520 } 521 break; 522 case CTLTYPE_INT: printf(" Int\n"); break; 523 case CTLTYPE_STRING: printf(" String\n"); break; 524 case CTLTYPE_QUAD: printf(" Quad\n"); break; 525 case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break; 526 default: printf("\n"); 527 } 528 529 } 530 sysctl_unlock(); 531 } 532 533 static int 534 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS) 535 { 536 int error; 537 538 error = suser(req->td); 539 if (error) 540 return error; 541 sysctl_sysctl_debug_dump_node(&sysctl__children, 0); 542 return ENOENT; 543 } 544 545 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD, 546 0, 0, sysctl_sysctl_debug, "-", ""); 547 548 static int 549 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS) 550 { 551 int *name = (int *) arg1; 552 u_int namelen = arg2; 553 int error = 0; 554 struct sysctl_oid *oid; 555 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2; 556 char buf[10]; 557 558 sysctl_lock(LK_SHARED); 559 while (namelen) { 560 if (!lsp) { 561 snprintf(buf,sizeof(buf),"%d",*name); 562 if (req->oldidx) 563 error = SYSCTL_OUT(req, ".", 1); 564 if (!error) 565 error = SYSCTL_OUT(req, buf, strlen(buf)); 566 if (error) { 567 sysctl_unlock(); 568 return (error); 569 } 570 namelen--; 571 name++; 572 continue; 573 } 574 lsp2 = 0; 575 SLIST_FOREACH(oid, lsp, oid_link) { 576 if (oid->oid_number != *name) 577 continue; 578 579 if (req->oldidx) 580 error = SYSCTL_OUT(req, ".", 1); 581 if (!error) 582 error = SYSCTL_OUT(req, oid->oid_name, 583 strlen(oid->oid_name)); 584 if (error) { 585 sysctl_unlock(); 586 return (error); 587 } 588 589 namelen--; 590 name++; 591 592 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) 593 break; 594 595 if (oid->oid_handler) 596 break; 597 598 lsp2 = (struct sysctl_oid_list *)oid->oid_arg1; 599 break; 600 } 601 lsp = lsp2; 602 } 603 sysctl_unlock(); 604 return (SYSCTL_OUT(req, "", 1)); 605 } 606 607 SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD, sysctl_sysctl_name, ""); 608 609 static int 610 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 611 int *next, int *len, int level, struct sysctl_oid **oidpp) 612 { 613 struct sysctl_oid *oidp; 614 615 *len = level; 616 sysctl_lock(LK_SHARED); 617 SLIST_FOREACH(oidp, lsp, oid_link) { 618 *next = oidp->oid_number; 619 *oidpp = oidp; 620 621 if (!namelen) { 622 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) { 623 sysctl_unlock(); 624 return 0; 625 } 626 if (oidp->oid_handler) { 627 /* We really should call the handler here...*/ 628 sysctl_unlock(); 629 return 0; 630 } 631 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 632 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, 633 len, level+1, oidpp)) { 634 sysctl_unlock(); 635 return 0; 636 } 637 goto emptynode; 638 } 639 640 if (oidp->oid_number < *name) 641 continue; 642 643 if (oidp->oid_number > *name) { 644 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) { 645 sysctl_unlock(); 646 return 0; 647 } 648 if (oidp->oid_handler) { 649 sysctl_unlock(); 650 return 0; 651 } 652 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 653 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, 654 next+1, len, level+1, oidpp)) { 655 sysctl_unlock(); 656 return (0); 657 } 658 goto next; 659 } 660 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 661 continue; 662 663 if (oidp->oid_handler) 664 continue; 665 666 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 667 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, 668 len, level+1, oidpp)) { 669 sysctl_unlock(); 670 return (0); 671 } 672 next: 673 namelen = 1; 674 *len = level; 675 emptynode: 676 *len = level; 677 } 678 sysctl_unlock(); 679 return 1; 680 } 681 682 static int 683 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS) 684 { 685 int *name = (int *) arg1; 686 u_int namelen = arg2; 687 int i, j, error; 688 struct sysctl_oid *oid; 689 struct sysctl_oid_list *lsp = &sysctl__children; 690 int newoid[CTL_MAXNAME]; 691 692 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid); 693 if (i) 694 return ENOENT; 695 error = SYSCTL_OUT(req, newoid, j * sizeof (int)); 696 return (error); 697 } 698 699 SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD, sysctl_sysctl_next, ""); 700 701 static int 702 name2oid (char *name, int *oid, int *len, struct sysctl_oid **oidpp) 703 { 704 int i; 705 struct sysctl_oid *oidp; 706 struct sysctl_oid_list *lsp = &sysctl__children; 707 char *p; 708 709 if (!*name) 710 return ENOENT; 711 712 p = name + strlen(name) - 1 ; 713 if (*p == '.') 714 *p = '\0'; 715 716 *len = 0; 717 718 for (p = name; *p && *p != '.'; p++) 719 ; 720 i = *p; 721 if (i == '.') 722 *p = '\0'; 723 724 sysctl_lock(LK_SHARED); 725 oidp = SLIST_FIRST(lsp); 726 727 while (oidp && *len < CTL_MAXNAME) { 728 if (strcmp(name, oidp->oid_name)) { 729 oidp = SLIST_NEXT(oidp, oid_link); 730 continue; 731 } 732 *oid++ = oidp->oid_number; 733 (*len)++; 734 735 if (!i) { 736 if (oidpp) 737 *oidpp = oidp; 738 sysctl_unlock(); 739 return (0); 740 } 741 742 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 743 break; 744 745 if (oidp->oid_handler) 746 break; 747 748 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 749 oidp = SLIST_FIRST(lsp); 750 name = p+1; 751 for (p = name; *p && *p != '.'; p++) 752 ; 753 i = *p; 754 if (i == '.') 755 *p = '\0'; 756 } 757 sysctl_unlock(); 758 return ENOENT; 759 } 760 761 static int 762 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS) 763 { 764 char *p; 765 int error, oid[CTL_MAXNAME], len; 766 struct sysctl_oid *op = 0; 767 768 if (!req->newlen) 769 return ENOENT; 770 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */ 771 return (ENAMETOOLONG); 772 773 p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK); 774 775 error = SYSCTL_IN(req, p, req->newlen); 776 if (error) { 777 free(p, M_SYSCTL); 778 return (error); 779 } 780 781 p [req->newlen] = '\0'; 782 783 error = name2oid(p, oid, &len, &op); 784 785 free(p, M_SYSCTL); 786 787 if (error) 788 return (error); 789 790 error = SYSCTL_OUT(req, oid, len * sizeof *oid); 791 return (error); 792 } 793 794 SYSCTL_PROC(_sysctl, 3, name2oid, CTLFLAG_RW|CTLFLAG_ANYBODY, 0, 0, 795 sysctl_sysctl_name2oid, "I", ""); 796 797 static int 798 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) 799 { 800 struct sysctl_oid *oid; 801 int error; 802 803 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 804 if (error) 805 return (error); 806 807 if (!oid->oid_fmt) 808 return (ENOENT); 809 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind)); 810 if (error) 811 return (error); 812 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1); 813 return (error); 814 } 815 816 817 SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD, sysctl_sysctl_oidfmt, ""); 818 819 static int 820 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) 821 { 822 struct sysctl_oid *oid; 823 int error; 824 825 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 826 if (error) 827 return (error); 828 829 if (!oid->oid_descr) 830 return (ENOENT); 831 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1); 832 return (error); 833 } 834 835 SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD, sysctl_sysctl_oiddescr, ""); 836 837 /* 838 * Default "handler" functions. 839 */ 840 841 /* 842 * Handle an int, signed or unsigned. 843 * Two cases: 844 * a variable: point arg1 at it. 845 * a constant: pass it in arg2. 846 */ 847 848 int 849 sysctl_handle_int(SYSCTL_HANDLER_ARGS) 850 { 851 int error = 0; 852 853 if (arg1) 854 error = SYSCTL_OUT(req, arg1, sizeof(int)); 855 else 856 error = SYSCTL_OUT(req, &arg2, sizeof(int)); 857 858 if (error || !req->newptr) 859 return (error); 860 861 if (!arg1) 862 error = EPERM; 863 else 864 error = SYSCTL_IN(req, arg1, sizeof(int)); 865 return (error); 866 } 867 868 /* 869 * Handle a long, signed or unsigned. arg1 points to it. 870 */ 871 872 int 873 sysctl_handle_long(SYSCTL_HANDLER_ARGS) 874 { 875 int error = 0; 876 877 if (!arg1) 878 return (EINVAL); 879 error = SYSCTL_OUT(req, arg1, sizeof(long)); 880 881 if (error || !req->newptr) 882 return (error); 883 884 error = SYSCTL_IN(req, arg1, sizeof(long)); 885 return (error); 886 } 887 888 /* 889 * Handle a quad, signed or unsigned. arg1 points to it. 890 */ 891 892 int 893 sysctl_handle_quad(SYSCTL_HANDLER_ARGS) 894 { 895 int error = 0; 896 897 if (!arg1) 898 return (EINVAL); 899 error = SYSCTL_OUT(req, arg1, sizeof(quad_t)); 900 901 if (error || !req->newptr) 902 return (error); 903 904 error = SYSCTL_IN(req, arg1, sizeof(quad_t)); 905 return (error); 906 } 907 908 /* 909 * Handle our generic '\0' terminated 'C' string. 910 * Two cases: 911 * a variable string: point arg1 at it, arg2 is max length. 912 * a constant string: point arg1 at it, arg2 is zero. 913 */ 914 915 int 916 sysctl_handle_string(SYSCTL_HANDLER_ARGS) 917 { 918 int error=0; 919 920 error = SYSCTL_OUT(req, arg1, strlen((char *)arg1)+1); 921 922 if (error || !req->newptr) 923 return (error); 924 925 if ((req->newlen - req->newidx) >= arg2) { 926 error = EINVAL; 927 } else { 928 arg2 = (req->newlen - req->newidx); 929 error = SYSCTL_IN(req, arg1, arg2); 930 ((char *)arg1)[arg2] = '\0'; 931 } 932 933 return (error); 934 } 935 936 /* 937 * Handle any kind of opaque data. 938 * arg1 points to it, arg2 is the size. 939 */ 940 941 int 942 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS) 943 { 944 int error; 945 946 error = SYSCTL_OUT(req, arg1, arg2); 947 948 if (error || !req->newptr) 949 return (error); 950 951 error = SYSCTL_IN(req, arg1, arg2); 952 953 return (error); 954 } 955 956 /* 957 * Transfer functions to/from kernel space. 958 * XXX: rather untested at this point 959 */ 960 static int 961 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l) 962 { 963 size_t i = 0; 964 965 if (req->oldptr) { 966 i = l; 967 if (i > req->oldlen - req->oldidx) 968 i = req->oldlen - req->oldidx; 969 if (i > 0) 970 bcopy(p, (char *)req->oldptr + req->oldidx, i); 971 } 972 req->oldidx += l; 973 if (req->oldptr && i != l) 974 return (ENOMEM); 975 return (0); 976 } 977 978 static int 979 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l) 980 { 981 982 if (!req->newptr) 983 return 0; 984 if (req->newlen - req->newidx < l) 985 return (EINVAL); 986 bcopy((char *)req->newptr + req->newidx, p, l); 987 req->newidx += l; 988 return (0); 989 } 990 991 int 992 kernel_sysctl(int *name, u_int namelen, void *old, size_t *oldlenp, void *new, size_t newlen, size_t *retval) 993 { 994 int error = 0; 995 struct sysctl_req req; 996 997 bzero(&req, sizeof req); 998 999 req.td = curthread; 1000 1001 if (oldlenp) { 1002 req.oldlen = *oldlenp; 1003 } 1004 1005 if (old) { 1006 req.oldptr = old; 1007 } 1008 1009 if (new != NULL) { 1010 req.newlen = newlen; 1011 req.newptr = new; 1012 } 1013 1014 req.oldfunc = sysctl_old_kernel; 1015 req.newfunc = sysctl_new_kernel; 1016 req.lock = 1; 1017 1018 sysctl_lock(LK_SHARED); 1019 1020 error = sysctl_root(0, name, namelen, &req); 1021 1022 if (req.lock == 2) 1023 vsunlock(req.oldptr, req.oldlen); 1024 1025 sysctl_unlock(); 1026 1027 if (error && error != ENOMEM) 1028 return (error); 1029 1030 if (retval) { 1031 if (req.oldptr && req.oldidx > req.oldlen) 1032 *retval = req.oldlen; 1033 else 1034 *retval = req.oldidx; 1035 } 1036 return (error); 1037 } 1038 1039 int 1040 kernel_sysctlbyname(char *name, void *old, size_t *oldlenp, 1041 void *new, size_t newlen, size_t *retval) 1042 { 1043 int oid[CTL_MAXNAME]; 1044 size_t oidlen, plen; 1045 int error; 1046 1047 oid[0] = 0; /* sysctl internal magic */ 1048 oid[1] = 3; /* name2oid */ 1049 oidlen = sizeof(oid); 1050 1051 error = kernel_sysctl(oid, 2, oid, &oidlen, (void *)name, 1052 strlen(name), &plen); 1053 if (error) 1054 return (error); 1055 1056 error = kernel_sysctl(oid, plen / sizeof(int), old, oldlenp, 1057 new, newlen, retval); 1058 return (error); 1059 } 1060 1061 /* 1062 * Transfer function to/from user space. 1063 */ 1064 static int 1065 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l) 1066 { 1067 int error = 0; 1068 size_t i = 0; 1069 1070 if (req->lock == 1 && req->oldptr) { 1071 vslock(req->oldptr, req->oldlen); 1072 req->lock = 2; 1073 } 1074 if (req->oldptr) { 1075 i = l; 1076 if (i > req->oldlen - req->oldidx) 1077 i = req->oldlen - req->oldidx; 1078 if (i > 0) 1079 error = copyout(p, (char *)req->oldptr + req->oldidx, 1080 i); 1081 } 1082 req->oldidx += l; 1083 if (error) 1084 return (error); 1085 if (req->oldptr && i < l) 1086 return (ENOMEM); 1087 return (0); 1088 } 1089 1090 static int 1091 sysctl_new_user(struct sysctl_req *req, void *p, size_t l) 1092 { 1093 int error; 1094 1095 if (!req->newptr) 1096 return 0; 1097 if (req->newlen - req->newidx < l) 1098 return (EINVAL); 1099 error = copyin((char *)req->newptr + req->newidx, p, l); 1100 req->newidx += l; 1101 return (error); 1102 } 1103 1104 int 1105 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid, 1106 int *nindx, struct sysctl_req *req) 1107 { 1108 struct sysctl_oid *oid; 1109 int indx; 1110 1111 sysctl_lock(LK_SHARED); 1112 oid = SLIST_FIRST(&sysctl__children); 1113 indx = 0; 1114 while (oid && indx < CTL_MAXNAME) { 1115 if (oid->oid_number == name[indx]) { 1116 indx++; 1117 if (oid->oid_kind & CTLFLAG_NOLOCK) 1118 req->lock = 0; 1119 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1120 if (oid->oid_handler != NULL || 1121 indx == namelen) { 1122 *noid = oid; 1123 if (nindx != NULL) 1124 *nindx = indx; 1125 sysctl_unlock(); 1126 return (0); 1127 } 1128 oid = SLIST_FIRST( 1129 (struct sysctl_oid_list *)oid->oid_arg1); 1130 } else if (indx == namelen) { 1131 *noid = oid; 1132 if (nindx != NULL) 1133 *nindx = indx; 1134 sysctl_unlock(); 1135 return (0); 1136 } else { 1137 sysctl_unlock(); 1138 return (ENOTDIR); 1139 } 1140 } else { 1141 oid = SLIST_NEXT(oid, oid_link); 1142 } 1143 } 1144 sysctl_unlock(); 1145 return (ENOENT); 1146 } 1147 1148 /* 1149 * Traverse our tree, and find the right node, execute whatever it points 1150 * to, and return the resulting error code. 1151 */ 1152 1153 int 1154 sysctl_root(SYSCTL_HANDLER_ARGS) 1155 { 1156 struct thread *td = req->td; 1157 struct proc *p = td ? td->td_proc : NULL; 1158 struct sysctl_oid *oid; 1159 int error, indx; 1160 1161 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req); 1162 if (error) 1163 return (error); 1164 1165 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1166 /* 1167 * You can't call a sysctl when it's a node, but has 1168 * no handler. Inform the user that it's a node. 1169 * The indx may or may not be the same as namelen. 1170 */ 1171 if (oid->oid_handler == NULL) 1172 return (EISDIR); 1173 } 1174 1175 /* If writing isn't allowed */ 1176 if (req->newptr && (!(oid->oid_kind & CTLFLAG_WR) || 1177 ((oid->oid_kind & CTLFLAG_SECURE) && securelevel > 0))) 1178 return (EPERM); 1179 1180 /* Most likely only root can write */ 1181 if (!(oid->oid_kind & CTLFLAG_ANYBODY) && req->newptr && p && 1182 (error = suser_cred(p->p_ucred, 1183 (oid->oid_kind & CTLFLAG_PRISON) ? PRISON_ROOT : 0))) 1184 return (error); 1185 1186 if (!oid->oid_handler) 1187 return EINVAL; 1188 1189 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) 1190 error = oid->oid_handler(oid, (int *)arg1 + indx, arg2 - indx, 1191 req); 1192 else 1193 error = oid->oid_handler(oid, oid->oid_arg1, oid->oid_arg2, 1194 req); 1195 return (error); 1196 } 1197 1198 int 1199 __sysctl(struct sysctl_args *uap) 1200 { 1201 int error, i, name[CTL_MAXNAME]; 1202 size_t j; 1203 1204 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2) 1205 return (EINVAL); 1206 1207 error = copyin(uap->name, &name, uap->namelen * sizeof(int)); 1208 if (error) 1209 return (error); 1210 1211 error = userland_sysctl(name, uap->namelen, 1212 uap->old, uap->oldlenp, 0, 1213 uap->new, uap->newlen, &j); 1214 if (error && error != ENOMEM) 1215 return (error); 1216 if (uap->oldlenp) { 1217 i = copyout(&j, uap->oldlenp, sizeof(j)); 1218 if (i) 1219 return (i); 1220 } 1221 return (error); 1222 } 1223 1224 /* 1225 * This is used from various compatibility syscalls too. That's why name 1226 * must be in kernel space. 1227 */ 1228 int 1229 userland_sysctl(int *name, u_int namelen, void *old, size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval) 1230 { 1231 int error = 0; 1232 struct sysctl_req req, req2; 1233 1234 bzero(&req, sizeof req); 1235 1236 if (oldlenp) { 1237 if (inkernel) { 1238 req.oldlen = *oldlenp; 1239 } else { 1240 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp)); 1241 if (error) 1242 return (error); 1243 } 1244 } 1245 1246 if (old) { 1247 if (!useracc(old, req.oldlen, VM_PROT_WRITE)) 1248 return (EFAULT); 1249 req.oldptr= old; 1250 } 1251 1252 if (new != NULL) { 1253 if (!useracc(new, req.newlen, VM_PROT_READ)) 1254 return (EFAULT); 1255 req.newlen = newlen; 1256 req.newptr = new; 1257 } 1258 1259 req.oldfunc = sysctl_old_user; 1260 req.newfunc = sysctl_new_user; 1261 req.lock = 1; 1262 req.td = curthread; 1263 1264 sysctl_lock(LK_SHARED); 1265 1266 do { 1267 req2 = req; 1268 error = sysctl_root(0, name, namelen, &req2); 1269 } while (error == EAGAIN); 1270 1271 req = req2; 1272 if (req.lock == 2) 1273 vsunlock(req.oldptr, req.oldlen); 1274 1275 sysctl_unlock(); 1276 1277 if (error && error != ENOMEM) 1278 return (error); 1279 1280 if (retval) { 1281 if (req.oldptr && req.oldidx > req.oldlen) 1282 *retval = req.oldlen; 1283 else 1284 *retval = req.oldidx; 1285 } 1286 return (error); 1287 } 1288 1289 static void 1290 sysctl_lock(int flag) 1291 { 1292 lockmgr(&sysctl_lkp, flag, NULL, curthread); 1293 } 1294 1295 static void 1296 sysctl_unlock(void) 1297 { 1298 lockmgr(&sysctl_lkp, LK_RELEASE, NULL, curthread); 1299 } 1300 1301 static void 1302 sysctl_ctx_lock(int flag) 1303 { 1304 lockmgr(&sysctl_ctx_lkp, flag, NULL, curthread); 1305 } 1306 1307 static void 1308 sysctl_ctx_unlock(void) 1309 { 1310 lockmgr(&sysctl_ctx_lkp, LK_RELEASE, NULL, curthread); 1311 } 1312