kern_sysctl.c revision 195814
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 195814 2009-07-21 21:58:55Z 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#include <sys/vimage.h> 58#ifdef KTRACE 59#include <sys/ktrace.h> 60#endif 61 62#include <net/vnet.h> 63 64#include <security/mac/mac_framework.h> 65 66#include <vm/vm.h> 67#include <vm/vm_extern.h> 68 69static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic"); 70static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids"); 71static MALLOC_DEFINE(M_SYSCTLTMP, "sysctltmp", "sysctl temp output buffer"); 72 73/* 74 * The sysctllock protects the MIB tree. It also protects sysctl 75 * contexts used with dynamic sysctls. The sysctl_register_oid() and 76 * sysctl_unregister_oid() routines require the sysctllock to already 77 * be held, so the sysctl_lock() and sysctl_unlock() routines are 78 * provided for the few places in the kernel which need to use that 79 * API rather than using the dynamic API. Use of the dynamic API is 80 * strongly encouraged for most code. 81 * 82 * The sysctlmemlock is used to limit the amount of user memory wired for 83 * sysctl requests. This is implemented by serializing any userland 84 * sysctl requests larger than a single page via an exclusive lock. 85 */ 86static struct sx sysctllock; 87static struct sx sysctlmemlock; 88 89#define SYSCTL_SLOCK() sx_slock(&sysctllock) 90#define SYSCTL_SUNLOCK() sx_sunlock(&sysctllock) 91#define SYSCTL_XLOCK() sx_xlock(&sysctllock) 92#define SYSCTL_XUNLOCK() sx_xunlock(&sysctllock) 93#define SYSCTL_ASSERT_XLOCKED() sx_assert(&sysctllock, SA_XLOCKED) 94#define SYSCTL_ASSERT_LOCKED() sx_assert(&sysctllock, SA_LOCKED) 95#define SYSCTL_INIT() sx_init(&sysctllock, "sysctl lock") 96 97static int sysctl_root(SYSCTL_HANDLER_ARGS); 98 99struct sysctl_oid_list sysctl__children; /* root list */ 100 101static int sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, 102 int recurse); 103 104static struct sysctl_oid * 105sysctl_find_oidname(const char *name, struct sysctl_oid_list *list) 106{ 107 struct sysctl_oid *oidp; 108 109 SYSCTL_ASSERT_LOCKED(); 110 SLIST_FOREACH(oidp, list, oid_link) { 111 if (strcmp(oidp->oid_name, name) == 0) { 112 return (oidp); 113 } 114 } 115 return (NULL); 116} 117 118/* 119 * Initialization of the MIB tree. 120 * 121 * Order by number in each list. 122 */ 123void 124sysctl_lock(void) 125{ 126 127 SYSCTL_XLOCK(); 128} 129 130void 131sysctl_unlock(void) 132{ 133 134 SYSCTL_XUNLOCK(); 135} 136 137void 138sysctl_register_oid(struct sysctl_oid *oidp) 139{ 140 struct sysctl_oid_list *parent = oidp->oid_parent; 141 struct sysctl_oid *p; 142 struct sysctl_oid *q; 143 144 /* 145 * First check if another oid with the same name already 146 * exists in the parent's list. 147 */ 148 SYSCTL_ASSERT_XLOCKED(); 149 p = sysctl_find_oidname(oidp->oid_name, parent); 150 if (p != NULL) { 151 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 152 p->oid_refcnt++; 153 return; 154 } else { 155 printf("can't re-use a leaf (%s)!\n", p->oid_name); 156 return; 157 } 158 } 159 /* 160 * If this oid has a number OID_AUTO, give it a number which 161 * is greater than any current oid. 162 * NOTE: DO NOT change the starting value here, change it in 163 * <sys/sysctl.h>, and make sure it is at least 256 to 164 * accomodate e.g. net.inet.raw as a static sysctl node. 165 */ 166 if (oidp->oid_number == OID_AUTO) { 167 static int newoid = CTL_AUTO_START; 168 169 oidp->oid_number = newoid++; 170 if (newoid == 0x7fffffff) 171 panic("out of oids"); 172 } 173#if 0 174 else if (oidp->oid_number >= CTL_AUTO_START) { 175 /* do not panic; this happens when unregistering sysctl sets */ 176 printf("static sysctl oid too high: %d", oidp->oid_number); 177 } 178#endif 179 180 /* 181 * Insert the oid into the parent's list in order. 182 */ 183 q = NULL; 184 SLIST_FOREACH(p, parent, oid_link) { 185 if (oidp->oid_number < p->oid_number) 186 break; 187 q = p; 188 } 189 if (q) 190 SLIST_INSERT_AFTER(q, oidp, oid_link); 191 else 192 SLIST_INSERT_HEAD(parent, oidp, oid_link); 193} 194 195void 196sysctl_unregister_oid(struct sysctl_oid *oidp) 197{ 198 struct sysctl_oid *p; 199 int error; 200 201 SYSCTL_ASSERT_XLOCKED(); 202 error = ENOENT; 203 if (oidp->oid_number == OID_AUTO) { 204 error = EINVAL; 205 } else { 206 SLIST_FOREACH(p, oidp->oid_parent, oid_link) { 207 if (p == oidp) { 208 SLIST_REMOVE(oidp->oid_parent, oidp, 209 sysctl_oid, oid_link); 210 error = 0; 211 break; 212 } 213 } 214 } 215 216 /* 217 * This can happen when a module fails to register and is 218 * being unloaded afterwards. It should not be a panic() 219 * for normal use. 220 */ 221 if (error) 222 printf("%s: failed to unregister sysctl\n", __func__); 223} 224 225/* Initialize a new context to keep track of dynamically added sysctls. */ 226int 227sysctl_ctx_init(struct sysctl_ctx_list *c) 228{ 229 230 if (c == NULL) { 231 return (EINVAL); 232 } 233 234 /* 235 * No locking here, the caller is responsible for not adding 236 * new nodes to a context until after this function has 237 * returned. 238 */ 239 TAILQ_INIT(c); 240 return (0); 241} 242 243/* Free the context, and destroy all dynamic oids registered in this context */ 244int 245sysctl_ctx_free(struct sysctl_ctx_list *clist) 246{ 247 struct sysctl_ctx_entry *e, *e1; 248 int error; 249 250 error = 0; 251 /* 252 * First perform a "dry run" to check if it's ok to remove oids. 253 * XXX FIXME 254 * XXX This algorithm is a hack. But I don't know any 255 * XXX better solution for now... 256 */ 257 SYSCTL_XLOCK(); 258 TAILQ_FOREACH(e, clist, link) { 259 error = sysctl_remove_oid_locked(e->entry, 0, 0); 260 if (error) 261 break; 262 } 263 /* 264 * Restore deregistered entries, either from the end, 265 * or from the place where error occured. 266 * e contains the entry that was not unregistered 267 */ 268 if (error) 269 e1 = TAILQ_PREV(e, sysctl_ctx_list, link); 270 else 271 e1 = TAILQ_LAST(clist, sysctl_ctx_list); 272 while (e1 != NULL) { 273 sysctl_register_oid(e1->entry); 274 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link); 275 } 276 if (error) { 277 SYSCTL_XUNLOCK(); 278 return(EBUSY); 279 } 280 /* Now really delete the entries */ 281 e = TAILQ_FIRST(clist); 282 while (e != NULL) { 283 e1 = TAILQ_NEXT(e, link); 284 error = sysctl_remove_oid_locked(e->entry, 1, 0); 285 if (error) 286 panic("sysctl_remove_oid: corrupt tree, entry: %s", 287 e->entry->oid_name); 288 free(e, M_SYSCTLOID); 289 e = e1; 290 } 291 SYSCTL_XUNLOCK(); 292 return (error); 293} 294 295/* Add an entry to the context */ 296struct sysctl_ctx_entry * 297sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 298{ 299 struct sysctl_ctx_entry *e; 300 301 SYSCTL_ASSERT_XLOCKED(); 302 if (clist == NULL || oidp == NULL) 303 return(NULL); 304 e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK); 305 e->entry = oidp; 306 TAILQ_INSERT_HEAD(clist, e, link); 307 return (e); 308} 309 310/* Find an entry in the context */ 311struct sysctl_ctx_entry * 312sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 313{ 314 struct sysctl_ctx_entry *e; 315 316 SYSCTL_ASSERT_LOCKED(); 317 if (clist == NULL || oidp == NULL) 318 return(NULL); 319 TAILQ_FOREACH(e, clist, link) { 320 if(e->entry == oidp) 321 return(e); 322 } 323 return (e); 324} 325 326/* 327 * Delete an entry from the context. 328 * NOTE: this function doesn't free oidp! You have to remove it 329 * with sysctl_remove_oid(). 330 */ 331int 332sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 333{ 334 struct sysctl_ctx_entry *e; 335 336 if (clist == NULL || oidp == NULL) 337 return (EINVAL); 338 SYSCTL_XLOCK(); 339 e = sysctl_ctx_entry_find(clist, oidp); 340 if (e != NULL) { 341 TAILQ_REMOVE(clist, e, link); 342 SYSCTL_XUNLOCK(); 343 free(e, M_SYSCTLOID); 344 return (0); 345 } else { 346 SYSCTL_XUNLOCK(); 347 return (ENOENT); 348 } 349} 350 351/* 352 * Remove dynamically created sysctl trees. 353 * oidp - top of the tree to be removed 354 * del - if 0 - just deregister, otherwise free up entries as well 355 * recurse - if != 0 traverse the subtree to be deleted 356 */ 357int 358sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse) 359{ 360 int error; 361 362 SYSCTL_XLOCK(); 363 error = sysctl_remove_oid_locked(oidp, del, recurse); 364 SYSCTL_XUNLOCK(); 365 return (error); 366} 367 368static int 369sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse) 370{ 371 struct sysctl_oid *p; 372 int error; 373 374 SYSCTL_ASSERT_XLOCKED(); 375 if (oidp == NULL) 376 return(EINVAL); 377 if ((oidp->oid_kind & CTLFLAG_DYN) == 0) { 378 printf("can't remove non-dynamic nodes!\n"); 379 return (EINVAL); 380 } 381 /* 382 * WARNING: normal method to do this should be through 383 * sysctl_ctx_free(). Use recursing as the last resort 384 * method to purge your sysctl tree of leftovers... 385 * However, if some other code still references these nodes, 386 * it will panic. 387 */ 388 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 389 if (oidp->oid_refcnt == 1) { 390 SLIST_FOREACH(p, SYSCTL_CHILDREN(oidp), oid_link) { 391 if (!recurse) 392 return (ENOTEMPTY); 393 error = sysctl_remove_oid_locked(p, del, 394 recurse); 395 if (error) 396 return (error); 397 } 398 if (del) 399 free(SYSCTL_CHILDREN(oidp), M_SYSCTLOID); 400 } 401 } 402 if (oidp->oid_refcnt > 1 ) { 403 oidp->oid_refcnt--; 404 } else { 405 if (oidp->oid_refcnt == 0) { 406 printf("Warning: bad oid_refcnt=%u (%s)!\n", 407 oidp->oid_refcnt, oidp->oid_name); 408 return (EINVAL); 409 } 410 sysctl_unregister_oid(oidp); 411 if (del) { 412 if (oidp->oid_descr) 413 free((void *)(uintptr_t)(const void *)oidp->oid_descr, M_SYSCTLOID); 414 free((void *)(uintptr_t)(const void *)oidp->oid_name, 415 M_SYSCTLOID); 416 free(oidp, M_SYSCTLOID); 417 } 418 } 419 return (0); 420} 421 422/* 423 * Create new sysctls at run time. 424 * clist may point to a valid context initialized with sysctl_ctx_init(). 425 */ 426struct sysctl_oid * 427sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent, 428 int number, const char *name, int kind, void *arg1, int arg2, 429 int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr) 430{ 431 struct sysctl_oid *oidp; 432 ssize_t len; 433 char *newname; 434 435 /* You have to hook up somewhere.. */ 436 if (parent == NULL) 437 return(NULL); 438 /* Check if the node already exists, otherwise create it */ 439 SYSCTL_XLOCK(); 440 oidp = sysctl_find_oidname(name, parent); 441 if (oidp != NULL) { 442 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 443 oidp->oid_refcnt++; 444 /* Update the context */ 445 if (clist != NULL) 446 sysctl_ctx_entry_add(clist, oidp); 447 SYSCTL_XUNLOCK(); 448 return (oidp); 449 } else { 450 SYSCTL_XUNLOCK(); 451 printf("can't re-use a leaf (%s)!\n", name); 452 return (NULL); 453 } 454 } 455 oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO); 456 oidp->oid_parent = parent; 457 SLIST_NEXT(oidp, oid_link) = NULL; 458 oidp->oid_number = number; 459 oidp->oid_refcnt = 1; 460 len = strlen(name); 461 newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK); 462 bcopy(name, newname, len + 1); 463 newname[len] = '\0'; 464 oidp->oid_name = newname; 465 oidp->oid_handler = handler; 466 oidp->oid_kind = CTLFLAG_DYN | kind; 467 if ((kind & CTLTYPE) == CTLTYPE_NODE) { 468 /* Allocate space for children */ 469 SYSCTL_CHILDREN_SET(oidp, malloc(sizeof(struct sysctl_oid_list), 470 M_SYSCTLOID, M_WAITOK)); 471 SLIST_INIT(SYSCTL_CHILDREN(oidp)); 472 } else { 473 oidp->oid_arg1 = arg1; 474 oidp->oid_arg2 = arg2; 475 } 476 oidp->oid_fmt = fmt; 477 if (descr) { 478 int len = strlen(descr) + 1; 479 oidp->oid_descr = malloc(len, M_SYSCTLOID, M_WAITOK); 480 if (oidp->oid_descr) 481 strcpy((char *)(uintptr_t)(const void *)oidp->oid_descr, descr); 482 } 483 /* Update the context, if used */ 484 if (clist != NULL) 485 sysctl_ctx_entry_add(clist, oidp); 486 /* Register this oid */ 487 sysctl_register_oid(oidp); 488 SYSCTL_XUNLOCK(); 489 return (oidp); 490} 491 492/* 493 * Rename an existing oid. 494 */ 495void 496sysctl_rename_oid(struct sysctl_oid *oidp, const char *name) 497{ 498 ssize_t len; 499 char *newname; 500 void *oldname; 501 502 len = strlen(name); 503 newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK); 504 bcopy(name, newname, len + 1); 505 newname[len] = '\0'; 506 SYSCTL_XLOCK(); 507 oldname = (void *)(uintptr_t)(const void *)oidp->oid_name; 508 oidp->oid_name = newname; 509 SYSCTL_XUNLOCK(); 510 free(oldname, M_SYSCTLOID); 511} 512 513/* 514 * Reparent an existing oid. 515 */ 516int 517sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent) 518{ 519 struct sysctl_oid *oidp; 520 521 SYSCTL_XLOCK(); 522 if (oid->oid_parent == parent) { 523 SYSCTL_XUNLOCK(); 524 return (0); 525 } 526 oidp = sysctl_find_oidname(oid->oid_name, parent); 527 if (oidp != NULL) { 528 SYSCTL_XUNLOCK(); 529 return (EEXIST); 530 } 531 sysctl_unregister_oid(oid); 532 oid->oid_parent = parent; 533 oid->oid_number = OID_AUTO; 534 sysctl_register_oid(oid); 535 SYSCTL_XUNLOCK(); 536 return (0); 537} 538 539/* 540 * Register the kernel's oids on startup. 541 */ 542SET_DECLARE(sysctl_set, struct sysctl_oid); 543 544static void 545sysctl_register_all(void *arg) 546{ 547 struct sysctl_oid **oidp; 548 549 sx_init(&sysctlmemlock, "sysctl mem"); 550 SYSCTL_INIT(); 551 SYSCTL_XLOCK(); 552 SET_FOREACH(oidp, sysctl_set) 553 sysctl_register_oid(*oidp); 554 SYSCTL_XUNLOCK(); 555} 556SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_ANY, sysctl_register_all, 0); 557 558/* 559 * "Staff-functions" 560 * 561 * These functions implement a presently undocumented interface 562 * used by the sysctl program to walk the tree, and get the type 563 * so it can print the value. 564 * This interface is under work and consideration, and should probably 565 * be killed with a big axe by the first person who can find the time. 566 * (be aware though, that the proper interface isn't as obvious as it 567 * may seem, there are various conflicting requirements. 568 * 569 * {0,0} printf the entire MIB-tree. 570 * {0,1,...} return the name of the "..." OID. 571 * {0,2,...} return the next OID. 572 * {0,3} return the OID of the name in "new" 573 * {0,4,...} return the kind & format info for the "..." OID. 574 * {0,5,...} return the description the "..." OID. 575 */ 576 577#ifdef SYSCTL_DEBUG 578static void 579sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i) 580{ 581 int k; 582 struct sysctl_oid *oidp; 583 584 SYSCTL_ASSERT_LOCKED(); 585 SLIST_FOREACH(oidp, l, oid_link) { 586 587 for (k=0; k<i; k++) 588 printf(" "); 589 590 printf("%d %s ", oidp->oid_number, oidp->oid_name); 591 592 printf("%c%c", 593 oidp->oid_kind & CTLFLAG_RD ? 'R':' ', 594 oidp->oid_kind & CTLFLAG_WR ? 'W':' '); 595 596 if (oidp->oid_handler) 597 printf(" *Handler"); 598 599 switch (oidp->oid_kind & CTLTYPE) { 600 case CTLTYPE_NODE: 601 printf(" Node\n"); 602 if (!oidp->oid_handler) { 603 sysctl_sysctl_debug_dump_node( 604 oidp->oid_arg1, i+2); 605 } 606 break; 607 case CTLTYPE_INT: printf(" Int\n"); break; 608 case CTLTYPE_STRING: printf(" String\n"); break; 609 case CTLTYPE_QUAD: printf(" Quad\n"); break; 610 case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break; 611 default: printf("\n"); 612 } 613 614 } 615} 616 617static int 618sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS) 619{ 620 int error; 621 622 error = priv_check(req->td, PRIV_SYSCTL_DEBUG); 623 if (error) 624 return (error); 625 sysctl_sysctl_debug_dump_node(&sysctl__children, 0); 626 return (ENOENT); 627} 628 629SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD, 630 0, 0, sysctl_sysctl_debug, "-", ""); 631#endif 632 633static int 634sysctl_sysctl_name(SYSCTL_HANDLER_ARGS) 635{ 636 int *name = (int *) arg1; 637 u_int namelen = arg2; 638 int error = 0; 639 struct sysctl_oid *oid; 640 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2; 641 char buf[10]; 642 643 SYSCTL_ASSERT_LOCKED(); 644 while (namelen) { 645 if (!lsp) { 646 snprintf(buf,sizeof(buf),"%d",*name); 647 if (req->oldidx) 648 error = SYSCTL_OUT(req, ".", 1); 649 if (!error) 650 error = SYSCTL_OUT(req, buf, strlen(buf)); 651 if (error) 652 return (error); 653 namelen--; 654 name++; 655 continue; 656 } 657 lsp2 = 0; 658 SLIST_FOREACH(oid, lsp, oid_link) { 659 if (oid->oid_number != *name) 660 continue; 661 662 if (req->oldidx) 663 error = SYSCTL_OUT(req, ".", 1); 664 if (!error) 665 error = SYSCTL_OUT(req, oid->oid_name, 666 strlen(oid->oid_name)); 667 if (error) 668 return (error); 669 670 namelen--; 671 name++; 672 673 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) 674 break; 675 676 if (oid->oid_handler) 677 break; 678 679 lsp2 = (struct sysctl_oid_list *)oid->oid_arg1; 680 break; 681 } 682 lsp = lsp2; 683 } 684 return (SYSCTL_OUT(req, "", 1)); 685} 686 687static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD, sysctl_sysctl_name, ""); 688 689static int 690sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 691 int *next, int *len, int level, struct sysctl_oid **oidpp) 692{ 693 struct sysctl_oid *oidp; 694 695 SYSCTL_ASSERT_LOCKED(); 696 *len = level; 697 SLIST_FOREACH(oidp, lsp, oid_link) { 698 *next = oidp->oid_number; 699 *oidpp = oidp; 700 701 if (oidp->oid_kind & CTLFLAG_SKIP) 702 continue; 703 704 if (!namelen) { 705 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 706 return (0); 707 if (oidp->oid_handler) 708 /* We really should call the handler here...*/ 709 return (0); 710 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 711 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, 712 len, level+1, oidpp)) 713 return (0); 714 goto emptynode; 715 } 716 717 if (oidp->oid_number < *name) 718 continue; 719 720 if (oidp->oid_number > *name) { 721 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 722 return (0); 723 if (oidp->oid_handler) 724 return (0); 725 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 726 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, 727 next+1, len, level+1, oidpp)) 728 return (0); 729 goto next; 730 } 731 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 732 continue; 733 734 if (oidp->oid_handler) 735 continue; 736 737 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 738 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, 739 len, level+1, oidpp)) 740 return (0); 741 next: 742 namelen = 1; 743 emptynode: 744 *len = level; 745 } 746 return (1); 747} 748 749static int 750sysctl_sysctl_next(SYSCTL_HANDLER_ARGS) 751{ 752 int *name = (int *) arg1; 753 u_int namelen = arg2; 754 int i, j, error; 755 struct sysctl_oid *oid; 756 struct sysctl_oid_list *lsp = &sysctl__children; 757 int newoid[CTL_MAXNAME]; 758 759 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid); 760 if (i) 761 return (ENOENT); 762 error = SYSCTL_OUT(req, newoid, j * sizeof (int)); 763 return (error); 764} 765 766static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD, sysctl_sysctl_next, ""); 767 768static int 769name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp) 770{ 771 int i; 772 struct sysctl_oid *oidp; 773 struct sysctl_oid_list *lsp = &sysctl__children; 774 char *p; 775 776 SYSCTL_ASSERT_LOCKED(); 777 778 if (!*name) 779 return (ENOENT); 780 781 p = name + strlen(name) - 1 ; 782 if (*p == '.') 783 *p = '\0'; 784 785 *len = 0; 786 787 for (p = name; *p && *p != '.'; p++) 788 ; 789 i = *p; 790 if (i == '.') 791 *p = '\0'; 792 793 oidp = SLIST_FIRST(lsp); 794 795 while (oidp && *len < CTL_MAXNAME) { 796 if (strcmp(name, oidp->oid_name)) { 797 oidp = SLIST_NEXT(oidp, oid_link); 798 continue; 799 } 800 *oid++ = oidp->oid_number; 801 (*len)++; 802 803 if (!i) { 804 if (oidpp) 805 *oidpp = oidp; 806 return (0); 807 } 808 809 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 810 break; 811 812 if (oidp->oid_handler) 813 break; 814 815 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 816 oidp = SLIST_FIRST(lsp); 817 name = p+1; 818 for (p = name; *p && *p != '.'; p++) 819 ; 820 i = *p; 821 if (i == '.') 822 *p = '\0'; 823 } 824 return (ENOENT); 825} 826 827static int 828sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS) 829{ 830 char *p; 831 int error, oid[CTL_MAXNAME], len; 832 struct sysctl_oid *op = 0; 833 834 SYSCTL_ASSERT_LOCKED(); 835 836 if (!req->newlen) 837 return (ENOENT); 838 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */ 839 return (ENAMETOOLONG); 840 841 p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK); 842 843 error = SYSCTL_IN(req, p, req->newlen); 844 if (error) { 845 free(p, M_SYSCTL); 846 return (error); 847 } 848 849 p [req->newlen] = '\0'; 850 851 error = name2oid(p, oid, &len, &op); 852 853 free(p, M_SYSCTL); 854 855 if (error) 856 return (error); 857 858 error = SYSCTL_OUT(req, oid, len * sizeof *oid); 859 return (error); 860} 861 862SYSCTL_PROC(_sysctl, 3, name2oid, CTLFLAG_RW|CTLFLAG_ANYBODY|CTLFLAG_MPSAFE, 863 0, 0, sysctl_sysctl_name2oid, "I", ""); 864 865static int 866sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) 867{ 868 struct sysctl_oid *oid; 869 int error; 870 871 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 872 if (error) 873 return (error); 874 875 if (!oid->oid_fmt) 876 return (ENOENT); 877 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind)); 878 if (error) 879 return (error); 880 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1); 881 return (error); 882} 883 884 885static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE, 886 sysctl_sysctl_oidfmt, ""); 887 888static int 889sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) 890{ 891 struct sysctl_oid *oid; 892 int error; 893 894 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 895 if (error) 896 return (error); 897 898 if (!oid->oid_descr) 899 return (ENOENT); 900 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1); 901 return (error); 902} 903 904static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD, sysctl_sysctl_oiddescr, ""); 905 906/* 907 * Default "handler" functions. 908 */ 909 910/* 911 * Handle an int, signed or unsigned. 912 * Two cases: 913 * a variable: point arg1 at it. 914 * a constant: pass it in arg2. 915 */ 916 917int 918sysctl_handle_int(SYSCTL_HANDLER_ARGS) 919{ 920 int tmpout, error = 0; 921 922 /* 923 * Attempt to get a coherent snapshot by making a copy of the data. 924 */ 925 if (arg1) 926 tmpout = *(int *)arg1; 927 else 928 tmpout = arg2; 929 error = SYSCTL_OUT(req, &tmpout, sizeof(int)); 930 931 if (error || !req->newptr) 932 return (error); 933 934 if (!arg1) 935 error = EPERM; 936 else 937 error = SYSCTL_IN(req, arg1, sizeof(int)); 938 return (error); 939} 940 941/* 942 * Based on on sysctl_handle_int() convert milliseconds into ticks. 943 * Note: this is used by TCP. 944 */ 945 946int 947sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS) 948{ 949 int error, s, tt; 950 951 tt = *(int *)arg1; 952 s = (int)((int64_t)tt * 1000 / hz); 953 954 error = sysctl_handle_int(oidp, &s, 0, req); 955 if (error || !req->newptr) 956 return (error); 957 958 tt = (int)((int64_t)s * hz / 1000); 959 if (tt < 1) 960 return (EINVAL); 961 962 *(int *)arg1 = tt; 963 return (0); 964} 965 966 967/* 968 * Handle a long, signed or unsigned. arg1 points to it. 969 */ 970 971int 972sysctl_handle_long(SYSCTL_HANDLER_ARGS) 973{ 974 int error = 0; 975 long tmplong; 976#ifdef SCTL_MASK32 977 int tmpint; 978#endif 979 980 /* 981 * Attempt to get a coherent snapshot by making a copy of the data. 982 */ 983 if (!arg1) 984 return (EINVAL); 985 tmplong = *(long *)arg1; 986#ifdef SCTL_MASK32 987 if (req->flags & SCTL_MASK32) { 988 tmpint = tmplong; 989 error = SYSCTL_OUT(req, &tmpint, sizeof(int)); 990 } else 991#endif 992 error = SYSCTL_OUT(req, &tmplong, sizeof(long)); 993 994 if (error || !req->newptr) 995 return (error); 996 997#ifdef SCTL_MASK32 998 if (req->flags & SCTL_MASK32) { 999 error = SYSCTL_IN(req, &tmpint, sizeof(int)); 1000 *(long *)arg1 = (long)tmpint; 1001 } else 1002#endif 1003 error = SYSCTL_IN(req, arg1, sizeof(long)); 1004 return (error); 1005} 1006 1007/* 1008 * Handle a 64 bit int, signed or unsigned. arg1 points to it. 1009 */ 1010 1011int 1012sysctl_handle_quad(SYSCTL_HANDLER_ARGS) 1013{ 1014 int error = 0; 1015 uint64_t tmpout; 1016 1017 /* 1018 * Attempt to get a coherent snapshot by making a copy of the data. 1019 */ 1020 if (!arg1) 1021 return (EINVAL); 1022 tmpout = *(uint64_t *)arg1; 1023 error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t)); 1024 1025 if (error || !req->newptr) 1026 return (error); 1027 1028 error = SYSCTL_IN(req, arg1, sizeof(uint64_t)); 1029 return (error); 1030} 1031 1032/* 1033 * Handle our generic '\0' terminated 'C' string. 1034 * Two cases: 1035 * a variable string: point arg1 at it, arg2 is max length. 1036 * a constant string: point arg1 at it, arg2 is zero. 1037 */ 1038 1039int 1040sysctl_handle_string(SYSCTL_HANDLER_ARGS) 1041{ 1042 int error=0; 1043 char *tmparg; 1044 size_t outlen; 1045 1046 /* 1047 * Attempt to get a coherent snapshot by copying to a 1048 * temporary kernel buffer. 1049 */ 1050retry: 1051 outlen = strlen((char *)arg1)+1; 1052 tmparg = malloc(outlen, M_SYSCTLTMP, M_WAITOK); 1053 1054 if (strlcpy(tmparg, (char *)arg1, outlen) >= outlen) { 1055 free(tmparg, M_SYSCTLTMP); 1056 goto retry; 1057 } 1058 1059 error = SYSCTL_OUT(req, tmparg, outlen); 1060 free(tmparg, M_SYSCTLTMP); 1061 1062 if (error || !req->newptr) 1063 return (error); 1064 1065 if ((req->newlen - req->newidx) >= arg2) { 1066 error = EINVAL; 1067 } else { 1068 arg2 = (req->newlen - req->newidx); 1069 error = SYSCTL_IN(req, arg1, arg2); 1070 ((char *)arg1)[arg2] = '\0'; 1071 } 1072 1073 return (error); 1074} 1075 1076/* 1077 * Handle any kind of opaque data. 1078 * arg1 points to it, arg2 is the size. 1079 */ 1080 1081int 1082sysctl_handle_opaque(SYSCTL_HANDLER_ARGS) 1083{ 1084 int error, tries; 1085 u_int generation; 1086 struct sysctl_req req2; 1087 1088 /* 1089 * Attempt to get a coherent snapshot, by using the thread 1090 * pre-emption counter updated from within mi_switch() to 1091 * determine if we were pre-empted during a bcopy() or 1092 * copyout(). Make 3 attempts at doing this before giving up. 1093 * If we encounter an error, stop immediately. 1094 */ 1095 tries = 0; 1096 req2 = *req; 1097retry: 1098 generation = curthread->td_generation; 1099 error = SYSCTL_OUT(req, arg1, arg2); 1100 if (error) 1101 return (error); 1102 tries++; 1103 if (generation != curthread->td_generation && tries < 3) { 1104 *req = req2; 1105 goto retry; 1106 } 1107 1108 error = SYSCTL_IN(req, arg1, arg2); 1109 1110 return (error); 1111} 1112 1113/* 1114 * Transfer functions to/from kernel space. 1115 * XXX: rather untested at this point 1116 */ 1117static int 1118sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l) 1119{ 1120 size_t i = 0; 1121 1122 if (req->oldptr) { 1123 i = l; 1124 if (req->oldlen <= req->oldidx) 1125 i = 0; 1126 else 1127 if (i > req->oldlen - req->oldidx) 1128 i = req->oldlen - req->oldidx; 1129 if (i > 0) 1130 bcopy(p, (char *)req->oldptr + req->oldidx, i); 1131 } 1132 req->oldidx += l; 1133 if (req->oldptr && i != l) 1134 return (ENOMEM); 1135 return (0); 1136} 1137 1138static int 1139sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l) 1140{ 1141 if (!req->newptr) 1142 return (0); 1143 if (req->newlen - req->newidx < l) 1144 return (EINVAL); 1145 bcopy((char *)req->newptr + req->newidx, p, l); 1146 req->newidx += l; 1147 return (0); 1148} 1149 1150int 1151kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1152 size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags) 1153{ 1154 int error = 0; 1155 struct sysctl_req req; 1156 1157 bzero(&req, sizeof req); 1158 1159 req.td = td; 1160 req.flags = flags; 1161 1162 if (oldlenp) { 1163 req.oldlen = *oldlenp; 1164 } 1165 req.validlen = req.oldlen; 1166 1167 if (old) { 1168 req.oldptr= old; 1169 } 1170 1171 if (new != NULL) { 1172 req.newlen = newlen; 1173 req.newptr = new; 1174 } 1175 1176 req.oldfunc = sysctl_old_kernel; 1177 req.newfunc = sysctl_new_kernel; 1178 req.lock = REQ_LOCKED; 1179 1180 SYSCTL_SLOCK(); 1181 error = sysctl_root(0, name, namelen, &req); 1182 SYSCTL_SUNLOCK(); 1183 1184 if (req.lock == REQ_WIRED && req.validlen > 0) 1185 vsunlock(req.oldptr, req.validlen); 1186 1187 if (error && error != ENOMEM) 1188 return (error); 1189 1190 if (retval) { 1191 if (req.oldptr && req.oldidx > req.validlen) 1192 *retval = req.validlen; 1193 else 1194 *retval = req.oldidx; 1195 } 1196 return (error); 1197} 1198 1199int 1200kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp, 1201 void *new, size_t newlen, size_t *retval, int flags) 1202{ 1203 int oid[CTL_MAXNAME]; 1204 size_t oidlen, plen; 1205 int error; 1206 1207 oid[0] = 0; /* sysctl internal magic */ 1208 oid[1] = 3; /* name2oid */ 1209 oidlen = sizeof(oid); 1210 1211 error = kernel_sysctl(td, oid, 2, oid, &oidlen, 1212 (void *)name, strlen(name), &plen, flags); 1213 if (error) 1214 return (error); 1215 1216 error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp, 1217 new, newlen, retval, flags); 1218 return (error); 1219} 1220 1221/* 1222 * Transfer function to/from user space. 1223 */ 1224static int 1225sysctl_old_user(struct sysctl_req *req, const void *p, size_t l) 1226{ 1227 int error = 0; 1228 size_t i, len, origidx; 1229 1230 origidx = req->oldidx; 1231 req->oldidx += l; 1232 if (req->oldptr == NULL) 1233 return (0); 1234 /* 1235 * If we have not wired the user supplied buffer and we are currently 1236 * holding locks, drop a witness warning, as it's possible that 1237 * write operations to the user page can sleep. 1238 */ 1239 if (req->lock != REQ_WIRED) 1240 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1241 "sysctl_old_user()"); 1242 i = l; 1243 len = req->validlen; 1244 if (len <= origidx) 1245 i = 0; 1246 else { 1247 if (i > len - origidx) 1248 i = len - origidx; 1249 error = copyout(p, (char *)req->oldptr + origidx, i); 1250 } 1251 if (error) 1252 return (error); 1253 if (i < l) 1254 return (ENOMEM); 1255 return (0); 1256} 1257 1258static int 1259sysctl_new_user(struct sysctl_req *req, void *p, size_t l) 1260{ 1261 int error; 1262 1263 if (!req->newptr) 1264 return (0); 1265 if (req->newlen - req->newidx < l) 1266 return (EINVAL); 1267 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1268 "sysctl_new_user()"); 1269 error = copyin((char *)req->newptr + req->newidx, p, l); 1270 req->newidx += l; 1271 return (error); 1272} 1273 1274/* 1275 * Wire the user space destination buffer. If set to a value greater than 1276 * zero, the len parameter limits the maximum amount of wired memory. 1277 */ 1278int 1279sysctl_wire_old_buffer(struct sysctl_req *req, size_t len) 1280{ 1281 int ret; 1282 size_t wiredlen; 1283 1284 wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen; 1285 ret = 0; 1286 if (req->lock == REQ_LOCKED && req->oldptr && 1287 req->oldfunc == sysctl_old_user) { 1288 if (wiredlen != 0) { 1289 ret = vslock(req->oldptr, wiredlen); 1290 if (ret != 0) { 1291 if (ret != ENOMEM) 1292 return (ret); 1293 wiredlen = 0; 1294 } 1295 } 1296 req->lock = REQ_WIRED; 1297 req->validlen = wiredlen; 1298 } 1299 return (0); 1300} 1301 1302int 1303sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid, 1304 int *nindx, struct sysctl_req *req) 1305{ 1306 struct sysctl_oid *oid; 1307 int indx; 1308 1309 SYSCTL_ASSERT_LOCKED(); 1310 oid = SLIST_FIRST(&sysctl__children); 1311 indx = 0; 1312 while (oid && indx < CTL_MAXNAME) { 1313 if (oid->oid_number == name[indx]) { 1314 indx++; 1315 if (oid->oid_kind & CTLFLAG_NOLOCK) 1316 req->lock = REQ_UNLOCKED; 1317 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1318 if (oid->oid_handler != NULL || 1319 indx == namelen) { 1320 *noid = oid; 1321 if (nindx != NULL) 1322 *nindx = indx; 1323 return (0); 1324 } 1325 oid = SLIST_FIRST( 1326 (struct sysctl_oid_list *)oid->oid_arg1); 1327 } else if (indx == namelen) { 1328 *noid = oid; 1329 if (nindx != NULL) 1330 *nindx = indx; 1331 return (0); 1332 } else { 1333 return (ENOTDIR); 1334 } 1335 } else { 1336 oid = SLIST_NEXT(oid, oid_link); 1337 } 1338 } 1339 return (ENOENT); 1340} 1341 1342/* 1343 * Traverse our tree, and find the right node, execute whatever it points 1344 * to, and return the resulting error code. 1345 */ 1346 1347static int 1348sysctl_root(SYSCTL_HANDLER_ARGS) 1349{ 1350 struct sysctl_oid *oid; 1351 int error, indx, lvl; 1352 1353 SYSCTL_ASSERT_LOCKED(); 1354 1355 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req); 1356 if (error) 1357 return (error); 1358 1359 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1360 /* 1361 * You can't call a sysctl when it's a node, but has 1362 * no handler. Inform the user that it's a node. 1363 * The indx may or may not be the same as namelen. 1364 */ 1365 if (oid->oid_handler == NULL) 1366 return (EISDIR); 1367 } 1368 1369 /* Is this sysctl writable? */ 1370 if (req->newptr && !(oid->oid_kind & CTLFLAG_WR)) 1371 return (EPERM); 1372 1373 KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL")); 1374 1375 /* Is this sysctl sensitive to securelevels? */ 1376 if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) { 1377 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE; 1378 error = securelevel_gt(req->td->td_ucred, lvl); 1379 if (error) 1380 return (error); 1381 } 1382 1383 /* Is this sysctl writable by only privileged users? */ 1384 if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) { 1385 if (oid->oid_kind & CTLFLAG_PRISON) 1386 error = priv_check(req->td, PRIV_SYSCTL_WRITEJAIL); 1387 else 1388 error = priv_check(req->td, PRIV_SYSCTL_WRITE); 1389 if (error) 1390 return (error); 1391 } 1392 1393 if (!oid->oid_handler) 1394 return (EINVAL); 1395 1396 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1397 arg1 = (int *)arg1 + indx; 1398 arg2 -= indx; 1399 } else { 1400 arg1 = oid->oid_arg1; 1401 arg2 = oid->oid_arg2; 1402 } 1403#ifdef MAC 1404 error = mac_system_check_sysctl(req->td->td_ucred, oid, arg1, arg2, 1405 req); 1406 if (error != 0) 1407 return (error); 1408#endif 1409 if (!(oid->oid_kind & CTLFLAG_MPSAFE)) 1410 mtx_lock(&Giant); 1411 error = oid->oid_handler(oid, arg1, arg2, req); 1412 if (!(oid->oid_kind & CTLFLAG_MPSAFE)) 1413 mtx_unlock(&Giant); 1414 1415 return (error); 1416} 1417 1418#ifndef _SYS_SYSPROTO_H_ 1419struct sysctl_args { 1420 int *name; 1421 u_int namelen; 1422 void *old; 1423 size_t *oldlenp; 1424 void *new; 1425 size_t newlen; 1426}; 1427#endif 1428int 1429__sysctl(struct thread *td, struct sysctl_args *uap) 1430{ 1431 int error, i, name[CTL_MAXNAME]; 1432 size_t j; 1433 1434 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2) 1435 return (EINVAL); 1436 1437 error = copyin(uap->name, &name, uap->namelen * sizeof(int)); 1438 if (error) 1439 return (error); 1440 1441 error = userland_sysctl(td, name, uap->namelen, 1442 uap->old, uap->oldlenp, 0, 1443 uap->new, uap->newlen, &j, 0); 1444 if (error && error != ENOMEM) 1445 return (error); 1446 if (uap->oldlenp) { 1447 i = copyout(&j, uap->oldlenp, sizeof(j)); 1448 if (i) 1449 return (i); 1450 } 1451 return (error); 1452} 1453 1454/* 1455 * This is used from various compatibility syscalls too. That's why name 1456 * must be in kernel space. 1457 */ 1458int 1459userland_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1460 size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval, 1461 int flags) 1462{ 1463 int error = 0, memlocked; 1464 struct sysctl_req req; 1465 1466 bzero(&req, sizeof req); 1467 1468 req.td = td; 1469 req.flags = flags; 1470 1471 if (oldlenp) { 1472 if (inkernel) { 1473 req.oldlen = *oldlenp; 1474 } else { 1475 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp)); 1476 if (error) 1477 return (error); 1478 } 1479 } 1480 req.validlen = req.oldlen; 1481 1482 if (old) { 1483 if (!useracc(old, req.oldlen, VM_PROT_WRITE)) 1484 return (EFAULT); 1485 req.oldptr= old; 1486 } 1487 1488 if (new != NULL) { 1489 if (!useracc(new, newlen, VM_PROT_READ)) 1490 return (EFAULT); 1491 req.newlen = newlen; 1492 req.newptr = new; 1493 } 1494 1495 req.oldfunc = sysctl_old_user; 1496 req.newfunc = sysctl_new_user; 1497 req.lock = REQ_LOCKED; 1498 1499#ifdef KTRACE 1500 if (KTRPOINT(curthread, KTR_SYSCTL)) 1501 ktrsysctl(name, namelen); 1502#endif 1503 1504 if (req.oldlen > PAGE_SIZE) { 1505 memlocked = 1; 1506 sx_xlock(&sysctlmemlock); 1507 } else 1508 memlocked = 0; 1509 CURVNET_SET(TD_TO_VNET(td)); 1510 1511 for (;;) { 1512 req.oldidx = 0; 1513 req.newidx = 0; 1514 SYSCTL_SLOCK(); 1515 error = sysctl_root(0, name, namelen, &req); 1516 SYSCTL_SUNLOCK(); 1517 if (error != EAGAIN) 1518 break; 1519 uio_yield(); 1520 } 1521 1522 CURVNET_RESTORE(); 1523 1524 if (req.lock == REQ_WIRED && req.validlen > 0) 1525 vsunlock(req.oldptr, req.validlen); 1526 if (memlocked) 1527 sx_xunlock(&sysctlmemlock); 1528 1529 if (error && error != ENOMEM) 1530 return (error); 1531 1532 if (retval) { 1533 if (req.oldptr && req.oldidx > req.validlen) 1534 *retval = req.validlen; 1535 else 1536 *retval = req.oldidx; 1537 } 1538 return (error); 1539} 1540