kern_sysctl.c revision 196176
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 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)kern_sysctl.c 8.4 (Berkeley) 4/14/94 36 */ 37 38#include <sys/cdefs.h> 39__FBSDID("$FreeBSD: head/sys/kern/kern_sysctl.c 196176 2009-08-13 10:26:34Z bz $"); 40 41#include "opt_compat.h" 42#include "opt_ktrace.h" 43 44#include <sys/param.h> 45#include <sys/systm.h> 46#include <sys/kernel.h> 47#include <sys/sysctl.h> 48#include <sys/malloc.h> 49#include <sys/priv.h> 50#include <sys/proc.h> 51#include <sys/jail.h> 52#include <sys/lock.h> 53#include <sys/mutex.h> 54#include <sys/sx.h> 55#include <sys/sysproto.h> 56#include <sys/uio.h> 57#ifdef KTRACE 58#include <sys/ktrace.h> 59#endif 60 61#include <net/vnet.h> 62 63#include <security/mac/mac_framework.h> 64 65#include <vm/vm.h> 66#include <vm/vm_extern.h> 67 68static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic"); 69static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids"); 70static MALLOC_DEFINE(M_SYSCTLTMP, "sysctltmp", "sysctl temp output buffer"); 71 72/* 73 * The sysctllock protects the MIB tree. It also protects sysctl 74 * contexts used with dynamic sysctls. The sysctl_register_oid() and 75 * sysctl_unregister_oid() routines require the sysctllock to already 76 * be held, so the sysctl_lock() and sysctl_unlock() routines are 77 * provided for the few places in the kernel which need to use that 78 * API rather than using the dynamic API. Use of the dynamic API is 79 * strongly encouraged for most code. 80 * 81 * The sysctlmemlock is used to limit the amount of user memory wired for 82 * sysctl requests. This is implemented by serializing any userland 83 * sysctl requests larger than a single page via an exclusive lock. 84 */ 85static struct sx sysctllock; 86static struct sx sysctlmemlock; 87 88#define SYSCTL_SLOCK() sx_slock(&sysctllock) 89#define SYSCTL_SUNLOCK() sx_sunlock(&sysctllock) 90#define SYSCTL_XLOCK() sx_xlock(&sysctllock) 91#define SYSCTL_XUNLOCK() sx_xunlock(&sysctllock) 92#define SYSCTL_ASSERT_XLOCKED() sx_assert(&sysctllock, SA_XLOCKED) 93#define SYSCTL_ASSERT_LOCKED() sx_assert(&sysctllock, SA_LOCKED) 94#define SYSCTL_INIT() sx_init(&sysctllock, "sysctl lock") 95 96static int sysctl_root(SYSCTL_HANDLER_ARGS); 97 98struct sysctl_oid_list sysctl__children; /* root list */ 99 100static int sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, 101 int recurse); 102 103static struct sysctl_oid * 104sysctl_find_oidname(const char *name, struct sysctl_oid_list *list) 105{ 106 struct sysctl_oid *oidp; 107 108 SYSCTL_ASSERT_LOCKED(); 109 SLIST_FOREACH(oidp, list, oid_link) { 110 if (strcmp(oidp->oid_name, name) == 0) { 111 return (oidp); 112 } 113 } 114 return (NULL); 115} 116 117/* 118 * Initialization of the MIB tree. 119 * 120 * Order by number in each list. 121 */ 122void 123sysctl_lock(void) 124{ 125 126 SYSCTL_XLOCK(); 127} 128 129void 130sysctl_unlock(void) 131{ 132 133 SYSCTL_XUNLOCK(); 134} 135 136void 137sysctl_register_oid(struct sysctl_oid *oidp) 138{ 139 struct sysctl_oid_list *parent = oidp->oid_parent; 140 struct sysctl_oid *p; 141 struct sysctl_oid *q; 142 143 /* 144 * First check if another oid with the same name already 145 * exists in the parent's list. 146 */ 147 SYSCTL_ASSERT_XLOCKED(); 148 p = sysctl_find_oidname(oidp->oid_name, parent); 149 if (p != NULL) { 150 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 151 p->oid_refcnt++; 152 return; 153 } else { 154 printf("can't re-use a leaf (%s)!\n", p->oid_name); 155 return; 156 } 157 } 158 /* 159 * If this oid has a number OID_AUTO, give it a number which 160 * is greater than any current oid. 161 * NOTE: DO NOT change the starting value here, change it in 162 * <sys/sysctl.h>, and make sure it is at least 256 to 163 * accomodate e.g. net.inet.raw as a static sysctl node. 164 */ 165 if (oidp->oid_number == OID_AUTO) { 166 static int newoid = CTL_AUTO_START; 167 168 oidp->oid_number = newoid++; 169 if (newoid == 0x7fffffff) 170 panic("out of oids"); 171 } 172#if 0 173 else if (oidp->oid_number >= CTL_AUTO_START) { 174 /* do not panic; this happens when unregistering sysctl sets */ 175 printf("static sysctl oid too high: %d", oidp->oid_number); 176 } 177#endif 178 179 /* 180 * Insert the oid into the parent's list in order. 181 */ 182 q = NULL; 183 SLIST_FOREACH(p, parent, oid_link) { 184 if (oidp->oid_number < p->oid_number) 185 break; 186 q = p; 187 } 188 if (q) 189 SLIST_INSERT_AFTER(q, oidp, oid_link); 190 else 191 SLIST_INSERT_HEAD(parent, oidp, oid_link); 192} 193 194void 195sysctl_unregister_oid(struct sysctl_oid *oidp) 196{ 197 struct sysctl_oid *p; 198 int error; 199 200 SYSCTL_ASSERT_XLOCKED(); 201 error = ENOENT; 202 if (oidp->oid_number == OID_AUTO) { 203 error = EINVAL; 204 } else { 205 SLIST_FOREACH(p, oidp->oid_parent, oid_link) { 206 if (p == oidp) { 207 SLIST_REMOVE(oidp->oid_parent, oidp, 208 sysctl_oid, oid_link); 209 error = 0; 210 break; 211 } 212 } 213 } 214 215 /* 216 * This can happen when a module fails to register and is 217 * being unloaded afterwards. It should not be a panic() 218 * for normal use. 219 */ 220 if (error) 221 printf("%s: failed to unregister sysctl\n", __func__); 222} 223 224/* Initialize a new context to keep track of dynamically added sysctls. */ 225int 226sysctl_ctx_init(struct sysctl_ctx_list *c) 227{ 228 229 if (c == NULL) { 230 return (EINVAL); 231 } 232 233 /* 234 * No locking here, the caller is responsible for not adding 235 * new nodes to a context until after this function has 236 * returned. 237 */ 238 TAILQ_INIT(c); 239 return (0); 240} 241 242/* Free the context, and destroy all dynamic oids registered in this context */ 243int 244sysctl_ctx_free(struct sysctl_ctx_list *clist) 245{ 246 struct sysctl_ctx_entry *e, *e1; 247 int error; 248 249 error = 0; 250 /* 251 * First perform a "dry run" to check if it's ok to remove oids. 252 * XXX FIXME 253 * XXX This algorithm is a hack. But I don't know any 254 * XXX better solution for now... 255 */ 256 SYSCTL_XLOCK(); 257 TAILQ_FOREACH(e, clist, link) { 258 error = sysctl_remove_oid_locked(e->entry, 0, 0); 259 if (error) 260 break; 261 } 262 /* 263 * Restore deregistered entries, either from the end, 264 * or from the place where error occured. 265 * e contains the entry that was not unregistered 266 */ 267 if (error) 268 e1 = TAILQ_PREV(e, sysctl_ctx_list, link); 269 else 270 e1 = TAILQ_LAST(clist, sysctl_ctx_list); 271 while (e1 != NULL) { 272 sysctl_register_oid(e1->entry); 273 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link); 274 } 275 if (error) { 276 SYSCTL_XUNLOCK(); 277 return(EBUSY); 278 } 279 /* Now really delete the entries */ 280 e = TAILQ_FIRST(clist); 281 while (e != NULL) { 282 e1 = TAILQ_NEXT(e, link); 283 error = sysctl_remove_oid_locked(e->entry, 1, 0); 284 if (error) 285 panic("sysctl_remove_oid: corrupt tree, entry: %s", 286 e->entry->oid_name); 287 free(e, M_SYSCTLOID); 288 e = e1; 289 } 290 SYSCTL_XUNLOCK(); 291 return (error); 292} 293 294/* Add an entry to the context */ 295struct sysctl_ctx_entry * 296sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 297{ 298 struct sysctl_ctx_entry *e; 299 300 SYSCTL_ASSERT_XLOCKED(); 301 if (clist == NULL || oidp == NULL) 302 return(NULL); 303 e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK); 304 e->entry = oidp; 305 TAILQ_INSERT_HEAD(clist, e, link); 306 return (e); 307} 308 309/* Find an entry in the context */ 310struct sysctl_ctx_entry * 311sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 312{ 313 struct sysctl_ctx_entry *e; 314 315 SYSCTL_ASSERT_LOCKED(); 316 if (clist == NULL || oidp == NULL) 317 return(NULL); 318 TAILQ_FOREACH(e, clist, link) { 319 if(e->entry == oidp) 320 return(e); 321 } 322 return (e); 323} 324 325/* 326 * Delete an entry from the context. 327 * NOTE: this function doesn't free oidp! You have to remove it 328 * with sysctl_remove_oid(). 329 */ 330int 331sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 332{ 333 struct sysctl_ctx_entry *e; 334 335 if (clist == NULL || oidp == NULL) 336 return (EINVAL); 337 SYSCTL_XLOCK(); 338 e = sysctl_ctx_entry_find(clist, oidp); 339 if (e != NULL) { 340 TAILQ_REMOVE(clist, e, link); 341 SYSCTL_XUNLOCK(); 342 free(e, M_SYSCTLOID); 343 return (0); 344 } else { 345 SYSCTL_XUNLOCK(); 346 return (ENOENT); 347 } 348} 349 350/* 351 * Remove dynamically created sysctl trees. 352 * oidp - top of the tree to be removed 353 * del - if 0 - just deregister, otherwise free up entries as well 354 * recurse - if != 0 traverse the subtree to be deleted 355 */ 356int 357sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse) 358{ 359 int error; 360 361 SYSCTL_XLOCK(); 362 error = sysctl_remove_oid_locked(oidp, del, recurse); 363 SYSCTL_XUNLOCK(); 364 return (error); 365} 366 367static int 368sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse) 369{ 370 struct sysctl_oid *p; 371 int error; 372 373 SYSCTL_ASSERT_XLOCKED(); 374 if (oidp == NULL) 375 return(EINVAL); 376 if ((oidp->oid_kind & CTLFLAG_DYN) == 0) { 377 printf("can't remove non-dynamic nodes!\n"); 378 return (EINVAL); 379 } 380 /* 381 * WARNING: normal method to do this should be through 382 * sysctl_ctx_free(). Use recursing as the last resort 383 * method to purge your sysctl tree of leftovers... 384 * However, if some other code still references these nodes, 385 * it will panic. 386 */ 387 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 388 if (oidp->oid_refcnt == 1) { 389 SLIST_FOREACH(p, SYSCTL_CHILDREN(oidp), oid_link) { 390 if (!recurse) 391 return (ENOTEMPTY); 392 error = sysctl_remove_oid_locked(p, del, 393 recurse); 394 if (error) 395 return (error); 396 } 397 if (del) 398 free(SYSCTL_CHILDREN(oidp), M_SYSCTLOID); 399 } 400 } 401 if (oidp->oid_refcnt > 1 ) { 402 oidp->oid_refcnt--; 403 } else { 404 if (oidp->oid_refcnt == 0) { 405 printf("Warning: bad oid_refcnt=%u (%s)!\n", 406 oidp->oid_refcnt, oidp->oid_name); 407 return (EINVAL); 408 } 409 sysctl_unregister_oid(oidp); 410 if (del) { 411 if (oidp->oid_descr) 412 free((void *)(uintptr_t)(const void *)oidp->oid_descr, M_SYSCTLOID); 413 free((void *)(uintptr_t)(const void *)oidp->oid_name, 414 M_SYSCTLOID); 415 free(oidp, M_SYSCTLOID); 416 } 417 } 418 return (0); 419} 420 421/* 422 * Create new sysctls at run time. 423 * clist may point to a valid context initialized with sysctl_ctx_init(). 424 */ 425struct sysctl_oid * 426sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent, 427 int number, const char *name, int kind, void *arg1, int arg2, 428 int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr) 429{ 430 struct sysctl_oid *oidp; 431 ssize_t len; 432 char *newname; 433 434 /* You have to hook up somewhere.. */ 435 if (parent == NULL) 436 return(NULL); 437 /* Check if the node already exists, otherwise create it */ 438 SYSCTL_XLOCK(); 439 oidp = sysctl_find_oidname(name, parent); 440 if (oidp != NULL) { 441 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 442 oidp->oid_refcnt++; 443 /* Update the context */ 444 if (clist != NULL) 445 sysctl_ctx_entry_add(clist, oidp); 446 SYSCTL_XUNLOCK(); 447 return (oidp); 448 } else { 449 SYSCTL_XUNLOCK(); 450 printf("can't re-use a leaf (%s)!\n", name); 451 return (NULL); 452 } 453 } 454 oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO); 455 oidp->oid_parent = parent; 456 SLIST_NEXT(oidp, oid_link) = NULL; 457 oidp->oid_number = number; 458 oidp->oid_refcnt = 1; 459 len = strlen(name); 460 newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK); 461 bcopy(name, newname, len + 1); 462 newname[len] = '\0'; 463 oidp->oid_name = newname; 464 oidp->oid_handler = handler; 465 oidp->oid_kind = CTLFLAG_DYN | kind; 466 if ((kind & CTLTYPE) == CTLTYPE_NODE) { 467 /* Allocate space for children */ 468 SYSCTL_CHILDREN_SET(oidp, malloc(sizeof(struct sysctl_oid_list), 469 M_SYSCTLOID, M_WAITOK)); 470 SLIST_INIT(SYSCTL_CHILDREN(oidp)); 471 } else { 472 oidp->oid_arg1 = arg1; 473 oidp->oid_arg2 = arg2; 474 } 475 oidp->oid_fmt = fmt; 476 if (descr) { 477 int len = strlen(descr) + 1; 478 oidp->oid_descr = malloc(len, M_SYSCTLOID, M_WAITOK); 479 if (oidp->oid_descr) 480 strcpy((char *)(uintptr_t)(const void *)oidp->oid_descr, descr); 481 } 482 /* Update the context, if used */ 483 if (clist != NULL) 484 sysctl_ctx_entry_add(clist, oidp); 485 /* Register this oid */ 486 sysctl_register_oid(oidp); 487 SYSCTL_XUNLOCK(); 488 return (oidp); 489} 490 491/* 492 * Rename an existing oid. 493 */ 494void 495sysctl_rename_oid(struct sysctl_oid *oidp, const char *name) 496{ 497 ssize_t len; 498 char *newname; 499 void *oldname; 500 501 len = strlen(name); 502 newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK); 503 bcopy(name, newname, len + 1); 504 newname[len] = '\0'; 505 SYSCTL_XLOCK(); 506 oldname = (void *)(uintptr_t)(const void *)oidp->oid_name; 507 oidp->oid_name = newname; 508 SYSCTL_XUNLOCK(); 509 free(oldname, M_SYSCTLOID); 510} 511 512/* 513 * Reparent an existing oid. 514 */ 515int 516sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent) 517{ 518 struct sysctl_oid *oidp; 519 520 SYSCTL_XLOCK(); 521 if (oid->oid_parent == parent) { 522 SYSCTL_XUNLOCK(); 523 return (0); 524 } 525 oidp = sysctl_find_oidname(oid->oid_name, parent); 526 if (oidp != NULL) { 527 SYSCTL_XUNLOCK(); 528 return (EEXIST); 529 } 530 sysctl_unregister_oid(oid); 531 oid->oid_parent = parent; 532 oid->oid_number = OID_AUTO; 533 sysctl_register_oid(oid); 534 SYSCTL_XUNLOCK(); 535 return (0); 536} 537 538/* 539 * Register the kernel's oids on startup. 540 */ 541SET_DECLARE(sysctl_set, struct sysctl_oid); 542 543static void 544sysctl_register_all(void *arg) 545{ 546 struct sysctl_oid **oidp; 547 548 sx_init(&sysctlmemlock, "sysctl mem"); 549 SYSCTL_INIT(); 550 SYSCTL_XLOCK(); 551 SET_FOREACH(oidp, sysctl_set) 552 sysctl_register_oid(*oidp); 553 SYSCTL_XUNLOCK(); 554} 555SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_ANY, sysctl_register_all, 0); 556 557/* 558 * "Staff-functions" 559 * 560 * These functions implement a presently undocumented interface 561 * used by the sysctl program to walk the tree, and get the type 562 * so it can print the value. 563 * This interface is under work and consideration, and should probably 564 * be killed with a big axe by the first person who can find the time. 565 * (be aware though, that the proper interface isn't as obvious as it 566 * may seem, there are various conflicting requirements. 567 * 568 * {0,0} printf the entire MIB-tree. 569 * {0,1,...} return the name of the "..." OID. 570 * {0,2,...} return the next OID. 571 * {0,3} return the OID of the name in "new" 572 * {0,4,...} return the kind & format info for the "..." OID. 573 * {0,5,...} return the description the "..." OID. 574 */ 575 576#ifdef SYSCTL_DEBUG 577static void 578sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i) 579{ 580 int k; 581 struct sysctl_oid *oidp; 582 583 SYSCTL_ASSERT_LOCKED(); 584 SLIST_FOREACH(oidp, l, oid_link) { 585 586 for (k=0; k<i; k++) 587 printf(" "); 588 589 printf("%d %s ", oidp->oid_number, oidp->oid_name); 590 591 printf("%c%c", 592 oidp->oid_kind & CTLFLAG_RD ? 'R':' ', 593 oidp->oid_kind & CTLFLAG_WR ? 'W':' '); 594 595 if (oidp->oid_handler) 596 printf(" *Handler"); 597 598 switch (oidp->oid_kind & CTLTYPE) { 599 case CTLTYPE_NODE: 600 printf(" Node\n"); 601 if (!oidp->oid_handler) { 602 sysctl_sysctl_debug_dump_node( 603 oidp->oid_arg1, i+2); 604 } 605 break; 606 case CTLTYPE_INT: printf(" Int\n"); break; 607 case CTLTYPE_STRING: printf(" String\n"); break; 608 case CTLTYPE_QUAD: printf(" Quad\n"); break; 609 case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break; 610 default: printf("\n"); 611 } 612 613 } 614} 615 616static int 617sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS) 618{ 619 int error; 620 621 error = priv_check(req->td, PRIV_SYSCTL_DEBUG); 622 if (error) 623 return (error); 624 sysctl_sysctl_debug_dump_node(&sysctl__children, 0); 625 return (ENOENT); 626} 627 628SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD, 629 0, 0, sysctl_sysctl_debug, "-", ""); 630#endif 631 632static int 633sysctl_sysctl_name(SYSCTL_HANDLER_ARGS) 634{ 635 int *name = (int *) arg1; 636 u_int namelen = arg2; 637 int error = 0; 638 struct sysctl_oid *oid; 639 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2; 640 char buf[10]; 641 642 SYSCTL_ASSERT_LOCKED(); 643 while (namelen) { 644 if (!lsp) { 645 snprintf(buf,sizeof(buf),"%d",*name); 646 if (req->oldidx) 647 error = SYSCTL_OUT(req, ".", 1); 648 if (!error) 649 error = SYSCTL_OUT(req, buf, strlen(buf)); 650 if (error) 651 return (error); 652 namelen--; 653 name++; 654 continue; 655 } 656 lsp2 = 0; 657 SLIST_FOREACH(oid, lsp, oid_link) { 658 if (oid->oid_number != *name) 659 continue; 660 661 if (req->oldidx) 662 error = SYSCTL_OUT(req, ".", 1); 663 if (!error) 664 error = SYSCTL_OUT(req, oid->oid_name, 665 strlen(oid->oid_name)); 666 if (error) 667 return (error); 668 669 namelen--; 670 name++; 671 672 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) 673 break; 674 675 if (oid->oid_handler) 676 break; 677 678 lsp2 = (struct sysctl_oid_list *)oid->oid_arg1; 679 break; 680 } 681 lsp = lsp2; 682 } 683 return (SYSCTL_OUT(req, "", 1)); 684} 685 686static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD, sysctl_sysctl_name, ""); 687 688static int 689sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 690 int *next, int *len, int level, struct sysctl_oid **oidpp) 691{ 692 struct sysctl_oid *oidp; 693 694 SYSCTL_ASSERT_LOCKED(); 695 *len = level; 696 SLIST_FOREACH(oidp, lsp, oid_link) { 697 *next = oidp->oid_number; 698 *oidpp = oidp; 699 700 if (oidp->oid_kind & CTLFLAG_SKIP) 701 continue; 702 703 if (!namelen) { 704 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 705 return (0); 706 if (oidp->oid_handler) 707 /* We really should call the handler here...*/ 708 return (0); 709 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 710 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, 711 len, level+1, oidpp)) 712 return (0); 713 goto emptynode; 714 } 715 716 if (oidp->oid_number < *name) 717 continue; 718 719 if (oidp->oid_number > *name) { 720 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 721 return (0); 722 if (oidp->oid_handler) 723 return (0); 724 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 725 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, 726 next+1, len, level+1, oidpp)) 727 return (0); 728 goto next; 729 } 730 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 731 continue; 732 733 if (oidp->oid_handler) 734 continue; 735 736 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 737 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, 738 len, level+1, oidpp)) 739 return (0); 740 next: 741 namelen = 1; 742 emptynode: 743 *len = level; 744 } 745 return (1); 746} 747 748static int 749sysctl_sysctl_next(SYSCTL_HANDLER_ARGS) 750{ 751 int *name = (int *) arg1; 752 u_int namelen = arg2; 753 int i, j, error; 754 struct sysctl_oid *oid; 755 struct sysctl_oid_list *lsp = &sysctl__children; 756 int newoid[CTL_MAXNAME]; 757 758 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid); 759 if (i) 760 return (ENOENT); 761 error = SYSCTL_OUT(req, newoid, j * sizeof (int)); 762 return (error); 763} 764 765static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD, sysctl_sysctl_next, ""); 766 767static int 768name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp) 769{ 770 int i; 771 struct sysctl_oid *oidp; 772 struct sysctl_oid_list *lsp = &sysctl__children; 773 char *p; 774 775 SYSCTL_ASSERT_LOCKED(); 776 777 if (!*name) 778 return (ENOENT); 779 780 p = name + strlen(name) - 1 ; 781 if (*p == '.') 782 *p = '\0'; 783 784 *len = 0; 785 786 for (p = name; *p && *p != '.'; p++) 787 ; 788 i = *p; 789 if (i == '.') 790 *p = '\0'; 791 792 oidp = SLIST_FIRST(lsp); 793 794 while (oidp && *len < CTL_MAXNAME) { 795 if (strcmp(name, oidp->oid_name)) { 796 oidp = SLIST_NEXT(oidp, oid_link); 797 continue; 798 } 799 *oid++ = oidp->oid_number; 800 (*len)++; 801 802 if (!i) { 803 if (oidpp) 804 *oidpp = oidp; 805 return (0); 806 } 807 808 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 809 break; 810 811 if (oidp->oid_handler) 812 break; 813 814 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 815 oidp = SLIST_FIRST(lsp); 816 name = p+1; 817 for (p = name; *p && *p != '.'; p++) 818 ; 819 i = *p; 820 if (i == '.') 821 *p = '\0'; 822 } 823 return (ENOENT); 824} 825 826static int 827sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS) 828{ 829 char *p; 830 int error, oid[CTL_MAXNAME], len; 831 struct sysctl_oid *op = 0; 832 833 SYSCTL_ASSERT_LOCKED(); 834 835 if (!req->newlen) 836 return (ENOENT); 837 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */ 838 return (ENAMETOOLONG); 839 840 p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK); 841 842 error = SYSCTL_IN(req, p, req->newlen); 843 if (error) { 844 free(p, M_SYSCTL); 845 return (error); 846 } 847 848 p [req->newlen] = '\0'; 849 850 error = name2oid(p, oid, &len, &op); 851 852 free(p, M_SYSCTL); 853 854 if (error) 855 return (error); 856 857 error = SYSCTL_OUT(req, oid, len * sizeof *oid); 858 return (error); 859} 860 861SYSCTL_PROC(_sysctl, 3, name2oid, CTLFLAG_RW|CTLFLAG_ANYBODY|CTLFLAG_MPSAFE, 862 0, 0, sysctl_sysctl_name2oid, "I", ""); 863 864static int 865sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) 866{ 867 struct sysctl_oid *oid; 868 int error; 869 870 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 871 if (error) 872 return (error); 873 874 if (!oid->oid_fmt) 875 return (ENOENT); 876 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind)); 877 if (error) 878 return (error); 879 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1); 880 return (error); 881} 882 883 884static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE, 885 sysctl_sysctl_oidfmt, ""); 886 887static int 888sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) 889{ 890 struct sysctl_oid *oid; 891 int error; 892 893 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 894 if (error) 895 return (error); 896 897 if (!oid->oid_descr) 898 return (ENOENT); 899 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1); 900 return (error); 901} 902 903static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD, sysctl_sysctl_oiddescr, ""); 904 905/* 906 * Default "handler" functions. 907 */ 908 909/* 910 * Handle an int, signed or unsigned. 911 * Two cases: 912 * a variable: point arg1 at it. 913 * a constant: pass it in arg2. 914 */ 915 916int 917sysctl_handle_int(SYSCTL_HANDLER_ARGS) 918{ 919 int tmpout, error = 0; 920 921 /* 922 * Attempt to get a coherent snapshot by making a copy of the data. 923 */ 924 if (arg1) 925 tmpout = *(int *)arg1; 926 else 927 tmpout = arg2; 928 error = SYSCTL_OUT(req, &tmpout, sizeof(int)); 929 930 if (error || !req->newptr) 931 return (error); 932 933 if (!arg1) 934 error = EPERM; 935 else 936 error = SYSCTL_IN(req, arg1, sizeof(int)); 937 return (error); 938} 939 940/* 941 * Based on on sysctl_handle_int() convert milliseconds into ticks. 942 * Note: this is used by TCP. 943 */ 944 945int 946sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS) 947{ 948 int error, s, tt; 949 950 tt = *(int *)arg1; 951 s = (int)((int64_t)tt * 1000 / hz); 952 953 error = sysctl_handle_int(oidp, &s, 0, req); 954 if (error || !req->newptr) 955 return (error); 956 957 tt = (int)((int64_t)s * hz / 1000); 958 if (tt < 1) 959 return (EINVAL); 960 961 *(int *)arg1 = tt; 962 return (0); 963} 964 965 966/* 967 * Handle a long, signed or unsigned. arg1 points to it. 968 */ 969 970int 971sysctl_handle_long(SYSCTL_HANDLER_ARGS) 972{ 973 int error = 0; 974 long tmplong; 975#ifdef SCTL_MASK32 976 int tmpint; 977#endif 978 979 /* 980 * Attempt to get a coherent snapshot by making a copy of the data. 981 */ 982 if (!arg1) 983 return (EINVAL); 984 tmplong = *(long *)arg1; 985#ifdef SCTL_MASK32 986 if (req->flags & SCTL_MASK32) { 987 tmpint = tmplong; 988 error = SYSCTL_OUT(req, &tmpint, sizeof(int)); 989 } else 990#endif 991 error = SYSCTL_OUT(req, &tmplong, sizeof(long)); 992 993 if (error || !req->newptr) 994 return (error); 995 996#ifdef SCTL_MASK32 997 if (req->flags & SCTL_MASK32) { 998 error = SYSCTL_IN(req, &tmpint, sizeof(int)); 999 *(long *)arg1 = (long)tmpint; 1000 } else 1001#endif 1002 error = SYSCTL_IN(req, arg1, sizeof(long)); 1003 return (error); 1004} 1005 1006/* 1007 * Handle a 64 bit int, signed or unsigned. arg1 points to it. 1008 */ 1009 1010int 1011sysctl_handle_quad(SYSCTL_HANDLER_ARGS) 1012{ 1013 int error = 0; 1014 uint64_t tmpout; 1015 1016 /* 1017 * Attempt to get a coherent snapshot by making a copy of the data. 1018 */ 1019 if (!arg1) 1020 return (EINVAL); 1021 tmpout = *(uint64_t *)arg1; 1022 error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t)); 1023 1024 if (error || !req->newptr) 1025 return (error); 1026 1027 error = SYSCTL_IN(req, arg1, sizeof(uint64_t)); 1028 return (error); 1029} 1030 1031/* 1032 * Handle our generic '\0' terminated 'C' string. 1033 * Two cases: 1034 * a variable string: point arg1 at it, arg2 is max length. 1035 * a constant string: point arg1 at it, arg2 is zero. 1036 */ 1037 1038int 1039sysctl_handle_string(SYSCTL_HANDLER_ARGS) 1040{ 1041 int error=0; 1042 char *tmparg; 1043 size_t outlen; 1044 1045 /* 1046 * Attempt to get a coherent snapshot by copying to a 1047 * temporary kernel buffer. 1048 */ 1049retry: 1050 outlen = strlen((char *)arg1)+1; 1051 tmparg = malloc(outlen, M_SYSCTLTMP, M_WAITOK); 1052 1053 if (strlcpy(tmparg, (char *)arg1, outlen) >= outlen) { 1054 free(tmparg, M_SYSCTLTMP); 1055 goto retry; 1056 } 1057 1058 error = SYSCTL_OUT(req, tmparg, outlen); 1059 free(tmparg, M_SYSCTLTMP); 1060 1061 if (error || !req->newptr) 1062 return (error); 1063 1064 if ((req->newlen - req->newidx) >= arg2) { 1065 error = EINVAL; 1066 } else { 1067 arg2 = (req->newlen - req->newidx); 1068 error = SYSCTL_IN(req, arg1, arg2); 1069 ((char *)arg1)[arg2] = '\0'; 1070 } 1071 1072 return (error); 1073} 1074 1075/* 1076 * Handle any kind of opaque data. 1077 * arg1 points to it, arg2 is the size. 1078 */ 1079 1080int 1081sysctl_handle_opaque(SYSCTL_HANDLER_ARGS) 1082{ 1083 int error, tries; 1084 u_int generation; 1085 struct sysctl_req req2; 1086 1087 /* 1088 * Attempt to get a coherent snapshot, by using the thread 1089 * pre-emption counter updated from within mi_switch() to 1090 * determine if we were pre-empted during a bcopy() or 1091 * copyout(). Make 3 attempts at doing this before giving up. 1092 * If we encounter an error, stop immediately. 1093 */ 1094 tries = 0; 1095 req2 = *req; 1096retry: 1097 generation = curthread->td_generation; 1098 error = SYSCTL_OUT(req, arg1, arg2); 1099 if (error) 1100 return (error); 1101 tries++; 1102 if (generation != curthread->td_generation && tries < 3) { 1103 *req = req2; 1104 goto retry; 1105 } 1106 1107 error = SYSCTL_IN(req, arg1, arg2); 1108 1109 return (error); 1110} 1111 1112/* 1113 * Transfer functions to/from kernel space. 1114 * XXX: rather untested at this point 1115 */ 1116static int 1117sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l) 1118{ 1119 size_t i = 0; 1120 1121 if (req->oldptr) { 1122 i = l; 1123 if (req->oldlen <= req->oldidx) 1124 i = 0; 1125 else 1126 if (i > req->oldlen - req->oldidx) 1127 i = req->oldlen - req->oldidx; 1128 if (i > 0) 1129 bcopy(p, (char *)req->oldptr + req->oldidx, i); 1130 } 1131 req->oldidx += l; 1132 if (req->oldptr && i != l) 1133 return (ENOMEM); 1134 return (0); 1135} 1136 1137static int 1138sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l) 1139{ 1140 if (!req->newptr) 1141 return (0); 1142 if (req->newlen - req->newidx < l) 1143 return (EINVAL); 1144 bcopy((char *)req->newptr + req->newidx, p, l); 1145 req->newidx += l; 1146 return (0); 1147} 1148 1149int 1150kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1151 size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags) 1152{ 1153 int error = 0; 1154 struct sysctl_req req; 1155 1156 bzero(&req, sizeof req); 1157 1158 req.td = td; 1159 req.flags = flags; 1160 1161 if (oldlenp) { 1162 req.oldlen = *oldlenp; 1163 } 1164 req.validlen = req.oldlen; 1165 1166 if (old) { 1167 req.oldptr= old; 1168 } 1169 1170 if (new != NULL) { 1171 req.newlen = newlen; 1172 req.newptr = new; 1173 } 1174 1175 req.oldfunc = sysctl_old_kernel; 1176 req.newfunc = sysctl_new_kernel; 1177 req.lock = REQ_LOCKED; 1178 1179 SYSCTL_SLOCK(); 1180 error = sysctl_root(0, name, namelen, &req); 1181 SYSCTL_SUNLOCK(); 1182 1183 if (req.lock == REQ_WIRED && req.validlen > 0) 1184 vsunlock(req.oldptr, req.validlen); 1185 1186 if (error && error != ENOMEM) 1187 return (error); 1188 1189 if (retval) { 1190 if (req.oldptr && req.oldidx > req.validlen) 1191 *retval = req.validlen; 1192 else 1193 *retval = req.oldidx; 1194 } 1195 return (error); 1196} 1197 1198int 1199kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp, 1200 void *new, size_t newlen, size_t *retval, int flags) 1201{ 1202 int oid[CTL_MAXNAME]; 1203 size_t oidlen, plen; 1204 int error; 1205 1206 oid[0] = 0; /* sysctl internal magic */ 1207 oid[1] = 3; /* name2oid */ 1208 oidlen = sizeof(oid); 1209 1210 error = kernel_sysctl(td, oid, 2, oid, &oidlen, 1211 (void *)name, strlen(name), &plen, flags); 1212 if (error) 1213 return (error); 1214 1215 error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp, 1216 new, newlen, retval, flags); 1217 return (error); 1218} 1219 1220/* 1221 * Transfer function to/from user space. 1222 */ 1223static int 1224sysctl_old_user(struct sysctl_req *req, const void *p, size_t l) 1225{ 1226 int error = 0; 1227 size_t i, len, origidx; 1228 1229 origidx = req->oldidx; 1230 req->oldidx += l; 1231 if (req->oldptr == NULL) 1232 return (0); 1233 /* 1234 * If we have not wired the user supplied buffer and we are currently 1235 * holding locks, drop a witness warning, as it's possible that 1236 * write operations to the user page can sleep. 1237 */ 1238 if (req->lock != REQ_WIRED) 1239 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1240 "sysctl_old_user()"); 1241 i = l; 1242 len = req->validlen; 1243 if (len <= origidx) 1244 i = 0; 1245 else { 1246 if (i > len - origidx) 1247 i = len - origidx; 1248 error = copyout(p, (char *)req->oldptr + origidx, i); 1249 } 1250 if (error) 1251 return (error); 1252 if (i < l) 1253 return (ENOMEM); 1254 return (0); 1255} 1256 1257static int 1258sysctl_new_user(struct sysctl_req *req, void *p, size_t l) 1259{ 1260 int error; 1261 1262 if (!req->newptr) 1263 return (0); 1264 if (req->newlen - req->newidx < l) 1265 return (EINVAL); 1266 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1267 "sysctl_new_user()"); 1268 error = copyin((char *)req->newptr + req->newidx, p, l); 1269 req->newidx += l; 1270 return (error); 1271} 1272 1273/* 1274 * Wire the user space destination buffer. If set to a value greater than 1275 * zero, the len parameter limits the maximum amount of wired memory. 1276 */ 1277int 1278sysctl_wire_old_buffer(struct sysctl_req *req, size_t len) 1279{ 1280 int ret; 1281 size_t wiredlen; 1282 1283 wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen; 1284 ret = 0; 1285 if (req->lock == REQ_LOCKED && req->oldptr && 1286 req->oldfunc == sysctl_old_user) { 1287 if (wiredlen != 0) { 1288 ret = vslock(req->oldptr, wiredlen); 1289 if (ret != 0) { 1290 if (ret != ENOMEM) 1291 return (ret); 1292 wiredlen = 0; 1293 } 1294 } 1295 req->lock = REQ_WIRED; 1296 req->validlen = wiredlen; 1297 } 1298 return (0); 1299} 1300 1301int 1302sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid, 1303 int *nindx, struct sysctl_req *req) 1304{ 1305 struct sysctl_oid *oid; 1306 int indx; 1307 1308 SYSCTL_ASSERT_LOCKED(); 1309 oid = SLIST_FIRST(&sysctl__children); 1310 indx = 0; 1311 while (oid && indx < CTL_MAXNAME) { 1312 if (oid->oid_number == name[indx]) { 1313 indx++; 1314 if (oid->oid_kind & CTLFLAG_NOLOCK) 1315 req->lock = REQ_UNLOCKED; 1316 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1317 if (oid->oid_handler != NULL || 1318 indx == namelen) { 1319 *noid = oid; 1320 if (nindx != NULL) 1321 *nindx = indx; 1322 return (0); 1323 } 1324 oid = SLIST_FIRST( 1325 (struct sysctl_oid_list *)oid->oid_arg1); 1326 } else if (indx == namelen) { 1327 *noid = oid; 1328 if (nindx != NULL) 1329 *nindx = indx; 1330 return (0); 1331 } else { 1332 return (ENOTDIR); 1333 } 1334 } else { 1335 oid = SLIST_NEXT(oid, oid_link); 1336 } 1337 } 1338 return (ENOENT); 1339} 1340 1341/* 1342 * Traverse our tree, and find the right node, execute whatever it points 1343 * to, and return the resulting error code. 1344 */ 1345 1346static int 1347sysctl_root(SYSCTL_HANDLER_ARGS) 1348{ 1349 struct sysctl_oid *oid; 1350 int error, indx, lvl; 1351 1352 SYSCTL_ASSERT_LOCKED(); 1353 1354 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req); 1355 if (error) 1356 return (error); 1357 1358 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1359 /* 1360 * You can't call a sysctl when it's a node, but has 1361 * no handler. Inform the user that it's a node. 1362 * The indx may or may not be the same as namelen. 1363 */ 1364 if (oid->oid_handler == NULL) 1365 return (EISDIR); 1366 } 1367 1368 /* Is this sysctl writable? */ 1369 if (req->newptr && !(oid->oid_kind & CTLFLAG_WR)) 1370 return (EPERM); 1371 1372 KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL")); 1373 1374 /* Is this sysctl sensitive to securelevels? */ 1375 if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) { 1376 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE; 1377 error = securelevel_gt(req->td->td_ucred, lvl); 1378 if (error) 1379 return (error); 1380 } 1381 1382 /* Is this sysctl writable by only privileged users? */ 1383 if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) { 1384 int priv; 1385 1386 if (oid->oid_kind & CTLFLAG_PRISON) 1387 priv = PRIV_SYSCTL_WRITEJAIL; 1388#ifdef VIMAGE 1389 else if ((oid->oid_kind & CTLFLAG_VNET) && 1390 prison_owns_vnet(req->td->td_ucred)) 1391 priv = PRIV_SYSCTL_WRITEJAIL; 1392#endif 1393 else 1394 priv = PRIV_SYSCTL_WRITE; 1395 error = priv_check(req->td, priv); 1396 if (error) 1397 return (error); 1398 } 1399 1400 if (!oid->oid_handler) 1401 return (EINVAL); 1402 1403 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1404 arg1 = (int *)arg1 + indx; 1405 arg2 -= indx; 1406 } else { 1407 arg1 = oid->oid_arg1; 1408 arg2 = oid->oid_arg2; 1409 } 1410#ifdef MAC 1411 error = mac_system_check_sysctl(req->td->td_ucred, oid, arg1, arg2, 1412 req); 1413 if (error != 0) 1414 return (error); 1415#endif 1416 if (!(oid->oid_kind & CTLFLAG_MPSAFE)) 1417 mtx_lock(&Giant); 1418 error = oid->oid_handler(oid, arg1, arg2, req); 1419 if (!(oid->oid_kind & CTLFLAG_MPSAFE)) 1420 mtx_unlock(&Giant); 1421 1422 return (error); 1423} 1424 1425#ifndef _SYS_SYSPROTO_H_ 1426struct sysctl_args { 1427 int *name; 1428 u_int namelen; 1429 void *old; 1430 size_t *oldlenp; 1431 void *new; 1432 size_t newlen; 1433}; 1434#endif 1435int 1436__sysctl(struct thread *td, struct sysctl_args *uap) 1437{ 1438 int error, i, name[CTL_MAXNAME]; 1439 size_t j; 1440 1441 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2) 1442 return (EINVAL); 1443 1444 error = copyin(uap->name, &name, uap->namelen * sizeof(int)); 1445 if (error) 1446 return (error); 1447 1448 error = userland_sysctl(td, name, uap->namelen, 1449 uap->old, uap->oldlenp, 0, 1450 uap->new, uap->newlen, &j, 0); 1451 if (error && error != ENOMEM) 1452 return (error); 1453 if (uap->oldlenp) { 1454 i = copyout(&j, uap->oldlenp, sizeof(j)); 1455 if (i) 1456 return (i); 1457 } 1458 return (error); 1459} 1460 1461/* 1462 * This is used from various compatibility syscalls too. That's why name 1463 * must be in kernel space. 1464 */ 1465int 1466userland_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1467 size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval, 1468 int flags) 1469{ 1470 int error = 0, memlocked; 1471 struct sysctl_req req; 1472 1473 bzero(&req, sizeof req); 1474 1475 req.td = td; 1476 req.flags = flags; 1477 1478 if (oldlenp) { 1479 if (inkernel) { 1480 req.oldlen = *oldlenp; 1481 } else { 1482 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp)); 1483 if (error) 1484 return (error); 1485 } 1486 } 1487 req.validlen = req.oldlen; 1488 1489 if (old) { 1490 if (!useracc(old, req.oldlen, VM_PROT_WRITE)) 1491 return (EFAULT); 1492 req.oldptr= old; 1493 } 1494 1495 if (new != NULL) { 1496 if (!useracc(new, newlen, VM_PROT_READ)) 1497 return (EFAULT); 1498 req.newlen = newlen; 1499 req.newptr = new; 1500 } 1501 1502 req.oldfunc = sysctl_old_user; 1503 req.newfunc = sysctl_new_user; 1504 req.lock = REQ_LOCKED; 1505 1506#ifdef KTRACE 1507 if (KTRPOINT(curthread, KTR_SYSCTL)) 1508 ktrsysctl(name, namelen); 1509#endif 1510 1511 if (req.oldlen > PAGE_SIZE) { 1512 memlocked = 1; 1513 sx_xlock(&sysctlmemlock); 1514 } else 1515 memlocked = 0; 1516 CURVNET_SET(TD_TO_VNET(td)); 1517 1518 for (;;) { 1519 req.oldidx = 0; 1520 req.newidx = 0; 1521 SYSCTL_SLOCK(); 1522 error = sysctl_root(0, name, namelen, &req); 1523 SYSCTL_SUNLOCK(); 1524 if (error != EAGAIN) 1525 break; 1526 uio_yield(); 1527 } 1528 1529 CURVNET_RESTORE(); 1530 1531 if (req.lock == REQ_WIRED && req.validlen > 0) 1532 vsunlock(req.oldptr, req.validlen); 1533 if (memlocked) 1534 sx_xunlock(&sysctlmemlock); 1535 1536 if (error && error != ENOMEM) 1537 return (error); 1538 1539 if (retval) { 1540 if (req.oldptr && req.oldidx > req.validlen) 1541 *retval = req.validlen; 1542 else 1543 *retval = req.oldidx; 1544 } 1545 return (error); 1546} 1547