kern_sysctl.c revision 189707
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 189707 2009-03-11 21:48:36Z jhb $"); 40 41#include "opt_compat.h" 42#include "opt_ktrace.h" 43#include "opt_mac.h" 44 45#include <sys/param.h> 46#include <sys/systm.h> 47#include <sys/kernel.h> 48#include <sys/sysctl.h> 49#include <sys/malloc.h> 50#include <sys/priv.h> 51#include <sys/proc.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 <security/mac/mac_framework.h> 63 64#include <vm/vm.h> 65#include <vm/vm_extern.h> 66 67static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic"); 68static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids"); 69static MALLOC_DEFINE(M_SYSCTLTMP, "sysctltmp", "sysctl temp output buffer"); 70 71/* 72 * The sysctllock protects the MIB tree. It also protects sysctl 73 * contexts used with dynamic sysctls. The sysctl_register_oid() and 74 * sysctl_unregister_oid() routines require the sysctllock to already 75 * be held, so the sysctl_lock() and sysctl_unlock() routines are 76 * provided for the few places in the kernel which need to use that 77 * API rather than using the dynamic API. Use of the dynamic API is 78 * strongly encouraged for most code. 79 * 80 * This lock is also used to serialize userland sysctl requests. Some 81 * sysctls wire user memory, and serializing the requests limits the 82 * amount of wired user memory in use. 83 */ 84static struct sx sysctllock; 85 86#define SYSCTL_SLOCK() sx_slock(&sysctllock) 87#define SYSCTL_SUNLOCK() sx_sunlock(&sysctllock) 88#define SYSCTL_XLOCK() sx_xlock(&sysctllock) 89#define SYSCTL_XUNLOCK() sx_xunlock(&sysctllock) 90#define SYSCTL_ASSERT_XLOCKED() sx_assert(&sysctllock, SA_XLOCKED) 91#define SYSCTL_ASSERT_LOCKED() sx_assert(&sysctllock, SA_LOCKED) 92#define SYSCTL_INIT() sx_init(&sysctllock, "sysctl lock") 93 94static int sysctl_root(SYSCTL_HANDLER_ARGS); 95 96struct sysctl_oid_list sysctl__children; /* root list */ 97 98static int sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, 99 int recurse); 100 101static struct sysctl_oid * 102sysctl_find_oidname(const char *name, struct sysctl_oid_list *list) 103{ 104 struct sysctl_oid *oidp; 105 106 SYSCTL_ASSERT_LOCKED(); 107 SLIST_FOREACH(oidp, list, oid_link) { 108 if (strcmp(oidp->oid_name, name) == 0) { 109 return (oidp); 110 } 111 } 112 return (NULL); 113} 114 115/* 116 * Initialization of the MIB tree. 117 * 118 * Order by number in each list. 119 */ 120void 121sysctl_lock(void) 122{ 123 124 SYSCTL_XLOCK(); 125} 126 127void 128sysctl_unlock(void) 129{ 130 131 SYSCTL_XUNLOCK(); 132} 133 134void 135sysctl_register_oid(struct sysctl_oid *oidp) 136{ 137 struct sysctl_oid_list *parent = oidp->oid_parent; 138 struct sysctl_oid *p; 139 struct sysctl_oid *q; 140 141 /* 142 * First check if another oid with the same name already 143 * exists in the parent's list. 144 */ 145 SYSCTL_ASSERT_XLOCKED(); 146 p = sysctl_find_oidname(oidp->oid_name, parent); 147 if (p != NULL) { 148 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 149 p->oid_refcnt++; 150 return; 151 } else { 152 printf("can't re-use a leaf (%s)!\n", p->oid_name); 153 return; 154 } 155 } 156 /* 157 * If this oid has a number OID_AUTO, give it a number which 158 * is greater than any current oid. 159 * NOTE: DO NOT change the starting value here, change it in 160 * <sys/sysctl.h>, and make sure it is at least 256 to 161 * accomodate e.g. net.inet.raw as a static sysctl node. 162 */ 163 if (oidp->oid_number == OID_AUTO) { 164 static int newoid = CTL_AUTO_START; 165 166 oidp->oid_number = newoid++; 167 if (newoid == 0x7fffffff) 168 panic("out of oids"); 169 } 170#if 0 171 else if (oidp->oid_number >= CTL_AUTO_START) { 172 /* do not panic; this happens when unregistering sysctl sets */ 173 printf("static sysctl oid too high: %d", oidp->oid_number); 174 } 175#endif 176 177 /* 178 * Insert the oid into the parent's list in order. 179 */ 180 q = NULL; 181 SLIST_FOREACH(p, parent, oid_link) { 182 if (oidp->oid_number < p->oid_number) 183 break; 184 q = p; 185 } 186 if (q) 187 SLIST_INSERT_AFTER(q, oidp, oid_link); 188 else 189 SLIST_INSERT_HEAD(parent, oidp, oid_link); 190} 191 192void 193sysctl_unregister_oid(struct sysctl_oid *oidp) 194{ 195 struct sysctl_oid *p; 196 int error; 197 198 SYSCTL_ASSERT_XLOCKED(); 199 error = ENOENT; 200 if (oidp->oid_number == OID_AUTO) { 201 error = EINVAL; 202 } else { 203 SLIST_FOREACH(p, oidp->oid_parent, oid_link) { 204 if (p == oidp) { 205 SLIST_REMOVE(oidp->oid_parent, oidp, 206 sysctl_oid, oid_link); 207 error = 0; 208 break; 209 } 210 } 211 } 212 213 /* 214 * This can happen when a module fails to register and is 215 * being unloaded afterwards. It should not be a panic() 216 * for normal use. 217 */ 218 if (error) 219 printf("%s: failed to unregister sysctl\n", __func__); 220} 221 222/* Initialize a new context to keep track of dynamically added sysctls. */ 223int 224sysctl_ctx_init(struct sysctl_ctx_list *c) 225{ 226 227 if (c == NULL) { 228 return (EINVAL); 229 } 230 231 /* 232 * No locking here, the caller is responsible for not adding 233 * new nodes to a context until after this function has 234 * returned. 235 */ 236 TAILQ_INIT(c); 237 return (0); 238} 239 240/* Free the context, and destroy all dynamic oids registered in this context */ 241int 242sysctl_ctx_free(struct sysctl_ctx_list *clist) 243{ 244 struct sysctl_ctx_entry *e, *e1; 245 int error; 246 247 error = 0; 248 /* 249 * First perform a "dry run" to check if it's ok to remove oids. 250 * XXX FIXME 251 * XXX This algorithm is a hack. But I don't know any 252 * XXX better solution for now... 253 */ 254 SYSCTL_XLOCK(); 255 TAILQ_FOREACH(e, clist, link) { 256 error = sysctl_remove_oid_locked(e->entry, 0, 0); 257 if (error) 258 break; 259 } 260 /* 261 * Restore deregistered entries, either from the end, 262 * or from the place where error occured. 263 * e contains the entry that was not unregistered 264 */ 265 if (error) 266 e1 = TAILQ_PREV(e, sysctl_ctx_list, link); 267 else 268 e1 = TAILQ_LAST(clist, sysctl_ctx_list); 269 while (e1 != NULL) { 270 sysctl_register_oid(e1->entry); 271 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link); 272 } 273 if (error) { 274 SYSCTL_XUNLOCK(); 275 return(EBUSY); 276 } 277 /* Now really delete the entries */ 278 e = TAILQ_FIRST(clist); 279 while (e != NULL) { 280 e1 = TAILQ_NEXT(e, link); 281 error = sysctl_remove_oid_locked(e->entry, 1, 0); 282 if (error) 283 panic("sysctl_remove_oid: corrupt tree, entry: %s", 284 e->entry->oid_name); 285 free(e, M_SYSCTLOID); 286 e = e1; 287 } 288 SYSCTL_XUNLOCK(); 289 return (error); 290} 291 292/* Add an entry to the context */ 293struct sysctl_ctx_entry * 294sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 295{ 296 struct sysctl_ctx_entry *e; 297 298 SYSCTL_ASSERT_XLOCKED(); 299 if (clist == NULL || oidp == NULL) 300 return(NULL); 301 e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK); 302 e->entry = oidp; 303 TAILQ_INSERT_HEAD(clist, e, link); 304 return (e); 305} 306 307/* Find an entry in the context */ 308struct sysctl_ctx_entry * 309sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 310{ 311 struct sysctl_ctx_entry *e; 312 313 SYSCTL_ASSERT_LOCKED(); 314 if (clist == NULL || oidp == NULL) 315 return(NULL); 316 TAILQ_FOREACH(e, clist, link) { 317 if(e->entry == oidp) 318 return(e); 319 } 320 return (e); 321} 322 323/* 324 * Delete an entry from the context. 325 * NOTE: this function doesn't free oidp! You have to remove it 326 * with sysctl_remove_oid(). 327 */ 328int 329sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 330{ 331 struct sysctl_ctx_entry *e; 332 333 if (clist == NULL || oidp == NULL) 334 return (EINVAL); 335 SYSCTL_XLOCK(); 336 e = sysctl_ctx_entry_find(clist, oidp); 337 if (e != NULL) { 338 TAILQ_REMOVE(clist, e, link); 339 SYSCTL_XUNLOCK(); 340 free(e, M_SYSCTLOID); 341 return (0); 342 } else { 343 SYSCTL_XUNLOCK(); 344 return (ENOENT); 345 } 346} 347 348/* 349 * Remove dynamically created sysctl trees. 350 * oidp - top of the tree to be removed 351 * del - if 0 - just deregister, otherwise free up entries as well 352 * recurse - if != 0 traverse the subtree to be deleted 353 */ 354int 355sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse) 356{ 357 int error; 358 359 SYSCTL_XLOCK(); 360 error = sysctl_remove_oid_locked(oidp, del, recurse); 361 SYSCTL_XUNLOCK(); 362 return (error); 363} 364 365static int 366sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse) 367{ 368 struct sysctl_oid *p; 369 int error; 370 371 SYSCTL_ASSERT_XLOCKED(); 372 if (oidp == NULL) 373 return(EINVAL); 374 if ((oidp->oid_kind & CTLFLAG_DYN) == 0) { 375 printf("can't remove non-dynamic nodes!\n"); 376 return (EINVAL); 377 } 378 /* 379 * WARNING: normal method to do this should be through 380 * sysctl_ctx_free(). Use recursing as the last resort 381 * method to purge your sysctl tree of leftovers... 382 * However, if some other code still references these nodes, 383 * it will panic. 384 */ 385 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 386 if (oidp->oid_refcnt == 1) { 387 SLIST_FOREACH(p, SYSCTL_CHILDREN(oidp), oid_link) { 388 if (!recurse) 389 return (ENOTEMPTY); 390 error = sysctl_remove_oid_locked(p, del, 391 recurse); 392 if (error) 393 return (error); 394 } 395 if (del) 396 free(SYSCTL_CHILDREN(oidp), M_SYSCTLOID); 397 } 398 } 399 if (oidp->oid_refcnt > 1 ) { 400 oidp->oid_refcnt--; 401 } else { 402 if (oidp->oid_refcnt == 0) { 403 printf("Warning: bad oid_refcnt=%u (%s)!\n", 404 oidp->oid_refcnt, oidp->oid_name); 405 return (EINVAL); 406 } 407 sysctl_unregister_oid(oidp); 408 if (del) { 409 if (oidp->oid_descr) 410 free((void *)(uintptr_t)(const void *)oidp->oid_descr, M_SYSCTLOID); 411 free((void *)(uintptr_t)(const void *)oidp->oid_name, 412 M_SYSCTLOID); 413 free(oidp, M_SYSCTLOID); 414 } 415 } 416 return (0); 417} 418 419/* 420 * Create new sysctls at run time. 421 * clist may point to a valid context initialized with sysctl_ctx_init(). 422 */ 423struct sysctl_oid * 424sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent, 425 int number, const char *name, int kind, void *arg1, int arg2, 426 int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr) 427{ 428 struct sysctl_oid *oidp; 429 ssize_t len; 430 char *newname; 431 432 /* You have to hook up somewhere.. */ 433 if (parent == NULL) 434 return(NULL); 435 /* Check if the node already exists, otherwise create it */ 436 SYSCTL_XLOCK(); 437 oidp = sysctl_find_oidname(name, parent); 438 if (oidp != NULL) { 439 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 440 oidp->oid_refcnt++; 441 /* Update the context */ 442 if (clist != NULL) 443 sysctl_ctx_entry_add(clist, oidp); 444 SYSCTL_XUNLOCK(); 445 return (oidp); 446 } else { 447 SYSCTL_XUNLOCK(); 448 printf("can't re-use a leaf (%s)!\n", name); 449 return (NULL); 450 } 451 } 452 oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO); 453 oidp->oid_parent = parent; 454 SLIST_NEXT(oidp, oid_link) = NULL; 455 oidp->oid_number = number; 456 oidp->oid_refcnt = 1; 457 len = strlen(name); 458 newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK); 459 bcopy(name, newname, len + 1); 460 newname[len] = '\0'; 461 oidp->oid_name = newname; 462 oidp->oid_handler = handler; 463 oidp->oid_kind = CTLFLAG_DYN | kind; 464 if ((kind & CTLTYPE) == CTLTYPE_NODE) { 465 /* Allocate space for children */ 466 SYSCTL_CHILDREN_SET(oidp, malloc(sizeof(struct sysctl_oid_list), 467 M_SYSCTLOID, M_WAITOK)); 468 SLIST_INIT(SYSCTL_CHILDREN(oidp)); 469 } else { 470 oidp->oid_arg1 = arg1; 471 oidp->oid_arg2 = arg2; 472 } 473 oidp->oid_fmt = fmt; 474 if (descr) { 475 int len = strlen(descr) + 1; 476 oidp->oid_descr = malloc(len, M_SYSCTLOID, M_WAITOK); 477 if (oidp->oid_descr) 478 strcpy((char *)(uintptr_t)(const void *)oidp->oid_descr, descr); 479 } 480 /* Update the context, if used */ 481 if (clist != NULL) 482 sysctl_ctx_entry_add(clist, oidp); 483 /* Register this oid */ 484 sysctl_register_oid(oidp); 485 SYSCTL_XUNLOCK(); 486 return (oidp); 487} 488 489/* 490 * Rename an existing oid. 491 */ 492void 493sysctl_rename_oid(struct sysctl_oid *oidp, const char *name) 494{ 495 ssize_t len; 496 char *newname; 497 void *oldname; 498 499 len = strlen(name); 500 newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK); 501 bcopy(name, newname, len + 1); 502 newname[len] = '\0'; 503 SYSCTL_XLOCK(); 504 oldname = (void *)(uintptr_t)(const void *)oidp->oid_name; 505 oidp->oid_name = newname; 506 SYSCTL_XUNLOCK(); 507 free(oldname, M_SYSCTLOID); 508} 509 510/* 511 * Reparent an existing oid. 512 */ 513int 514sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent) 515{ 516 struct sysctl_oid *oidp; 517 518 SYSCTL_XLOCK(); 519 if (oid->oid_parent == parent) { 520 SYSCTL_XUNLOCK(); 521 return (0); 522 } 523 oidp = sysctl_find_oidname(oid->oid_name, parent); 524 if (oidp != NULL) { 525 SYSCTL_XUNLOCK(); 526 return (EEXIST); 527 } 528 sysctl_unregister_oid(oid); 529 oid->oid_parent = parent; 530 oid->oid_number = OID_AUTO; 531 sysctl_register_oid(oid); 532 SYSCTL_XUNLOCK(); 533 return (0); 534} 535 536/* 537 * Register the kernel's oids on startup. 538 */ 539SET_DECLARE(sysctl_set, struct sysctl_oid); 540 541static void 542sysctl_register_all(void *arg) 543{ 544 struct sysctl_oid **oidp; 545 546 SYSCTL_INIT(); 547 SYSCTL_XLOCK(); 548 SET_FOREACH(oidp, sysctl_set) 549 sysctl_register_oid(*oidp); 550 SYSCTL_XUNLOCK(); 551} 552SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_ANY, sysctl_register_all, 0); 553 554/* 555 * "Staff-functions" 556 * 557 * These functions implement a presently undocumented interface 558 * used by the sysctl program to walk the tree, and get the type 559 * so it can print the value. 560 * This interface is under work and consideration, and should probably 561 * be killed with a big axe by the first person who can find the time. 562 * (be aware though, that the proper interface isn't as obvious as it 563 * may seem, there are various conflicting requirements. 564 * 565 * {0,0} printf the entire MIB-tree. 566 * {0,1,...} return the name of the "..." OID. 567 * {0,2,...} return the next OID. 568 * {0,3} return the OID of the name in "new" 569 * {0,4,...} return the kind & format info for the "..." OID. 570 * {0,5,...} return the description the "..." OID. 571 */ 572 573#ifdef SYSCTL_DEBUG 574static void 575sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i) 576{ 577 int k; 578 struct sysctl_oid *oidp; 579 580 SYSCTL_ASSERT_LOCKED(); 581 SLIST_FOREACH(oidp, l, oid_link) { 582 583 for (k=0; k<i; k++) 584 printf(" "); 585 586 printf("%d %s ", oidp->oid_number, oidp->oid_name); 587 588 printf("%c%c", 589 oidp->oid_kind & CTLFLAG_RD ? 'R':' ', 590 oidp->oid_kind & CTLFLAG_WR ? 'W':' '); 591 592 if (oidp->oid_handler) 593 printf(" *Handler"); 594 595 switch (oidp->oid_kind & CTLTYPE) { 596 case CTLTYPE_NODE: 597 printf(" Node\n"); 598 if (!oidp->oid_handler) { 599 sysctl_sysctl_debug_dump_node( 600 oidp->oid_arg1, i+2); 601 } 602 break; 603 case CTLTYPE_INT: printf(" Int\n"); break; 604 case CTLTYPE_STRING: printf(" String\n"); break; 605 case CTLTYPE_QUAD: printf(" Quad\n"); break; 606 case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break; 607 default: printf("\n"); 608 } 609 610 } 611} 612 613static int 614sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS) 615{ 616 int error; 617 618 error = priv_check(req->td, PRIV_SYSCTL_DEBUG); 619 if (error) 620 return (error); 621 sysctl_sysctl_debug_dump_node(&sysctl__children, 0); 622 return (ENOENT); 623} 624 625SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD, 626 0, 0, sysctl_sysctl_debug, "-", ""); 627#endif 628 629static int 630sysctl_sysctl_name(SYSCTL_HANDLER_ARGS) 631{ 632 int *name = (int *) arg1; 633 u_int namelen = arg2; 634 int error = 0; 635 struct sysctl_oid *oid; 636 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2; 637 char buf[10]; 638 639 SYSCTL_ASSERT_LOCKED(); 640 while (namelen) { 641 if (!lsp) { 642 snprintf(buf,sizeof(buf),"%d",*name); 643 if (req->oldidx) 644 error = SYSCTL_OUT(req, ".", 1); 645 if (!error) 646 error = SYSCTL_OUT(req, buf, strlen(buf)); 647 if (error) 648 return (error); 649 namelen--; 650 name++; 651 continue; 652 } 653 lsp2 = 0; 654 SLIST_FOREACH(oid, lsp, oid_link) { 655 if (oid->oid_number != *name) 656 continue; 657 658 if (req->oldidx) 659 error = SYSCTL_OUT(req, ".", 1); 660 if (!error) 661 error = SYSCTL_OUT(req, oid->oid_name, 662 strlen(oid->oid_name)); 663 if (error) 664 return (error); 665 666 namelen--; 667 name++; 668 669 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) 670 break; 671 672 if (oid->oid_handler) 673 break; 674 675 lsp2 = (struct sysctl_oid_list *)oid->oid_arg1; 676 break; 677 } 678 lsp = lsp2; 679 } 680 return (SYSCTL_OUT(req, "", 1)); 681} 682 683static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD, sysctl_sysctl_name, ""); 684 685static int 686sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 687 int *next, int *len, int level, struct sysctl_oid **oidpp) 688{ 689 struct sysctl_oid *oidp; 690 691 SYSCTL_ASSERT_LOCKED(); 692 *len = level; 693 SLIST_FOREACH(oidp, lsp, oid_link) { 694 *next = oidp->oid_number; 695 *oidpp = oidp; 696 697 if (oidp->oid_kind & CTLFLAG_SKIP) 698 continue; 699 700 if (!namelen) { 701 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 702 return (0); 703 if (oidp->oid_handler) 704 /* We really should call the handler here...*/ 705 return (0); 706 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 707 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, 708 len, level+1, oidpp)) 709 return (0); 710 goto emptynode; 711 } 712 713 if (oidp->oid_number < *name) 714 continue; 715 716 if (oidp->oid_number > *name) { 717 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 718 return (0); 719 if (oidp->oid_handler) 720 return (0); 721 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 722 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, 723 next+1, len, level+1, oidpp)) 724 return (0); 725 goto next; 726 } 727 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 728 continue; 729 730 if (oidp->oid_handler) 731 continue; 732 733 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 734 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, 735 len, level+1, oidpp)) 736 return (0); 737 next: 738 namelen = 1; 739 emptynode: 740 *len = level; 741 } 742 return (1); 743} 744 745static int 746sysctl_sysctl_next(SYSCTL_HANDLER_ARGS) 747{ 748 int *name = (int *) arg1; 749 u_int namelen = arg2; 750 int i, j, error; 751 struct sysctl_oid *oid; 752 struct sysctl_oid_list *lsp = &sysctl__children; 753 int newoid[CTL_MAXNAME]; 754 755 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid); 756 if (i) 757 return (ENOENT); 758 error = SYSCTL_OUT(req, newoid, j * sizeof (int)); 759 return (error); 760} 761 762static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD, sysctl_sysctl_next, ""); 763 764static int 765name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp) 766{ 767 int i; 768 struct sysctl_oid *oidp; 769 struct sysctl_oid_list *lsp = &sysctl__children; 770 char *p; 771 772 SYSCTL_ASSERT_LOCKED(); 773 774 if (!*name) 775 return (ENOENT); 776 777 p = name + strlen(name) - 1 ; 778 if (*p == '.') 779 *p = '\0'; 780 781 *len = 0; 782 783 for (p = name; *p && *p != '.'; p++) 784 ; 785 i = *p; 786 if (i == '.') 787 *p = '\0'; 788 789 oidp = SLIST_FIRST(lsp); 790 791 while (oidp && *len < CTL_MAXNAME) { 792 if (strcmp(name, oidp->oid_name)) { 793 oidp = SLIST_NEXT(oidp, oid_link); 794 continue; 795 } 796 *oid++ = oidp->oid_number; 797 (*len)++; 798 799 if (!i) { 800 if (oidpp) 801 *oidpp = oidp; 802 return (0); 803 } 804 805 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 806 break; 807 808 if (oidp->oid_handler) 809 break; 810 811 lsp = (struct sysctl_oid_list *)oidp->oid_arg1; 812 oidp = SLIST_FIRST(lsp); 813 name = p+1; 814 for (p = name; *p && *p != '.'; p++) 815 ; 816 i = *p; 817 if (i == '.') 818 *p = '\0'; 819 } 820 return (ENOENT); 821} 822 823static int 824sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS) 825{ 826 char *p; 827 int error, oid[CTL_MAXNAME], len; 828 struct sysctl_oid *op = 0; 829 830 SYSCTL_ASSERT_LOCKED(); 831 832 if (!req->newlen) 833 return (ENOENT); 834 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */ 835 return (ENAMETOOLONG); 836 837 p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK); 838 839 error = SYSCTL_IN(req, p, req->newlen); 840 if (error) { 841 free(p, M_SYSCTL); 842 return (error); 843 } 844 845 p [req->newlen] = '\0'; 846 847 error = name2oid(p, oid, &len, &op); 848 849 free(p, M_SYSCTL); 850 851 if (error) 852 return (error); 853 854 error = SYSCTL_OUT(req, oid, len * sizeof *oid); 855 return (error); 856} 857 858SYSCTL_PROC(_sysctl, 3, name2oid, CTLFLAG_RW|CTLFLAG_ANYBODY|CTLFLAG_MPSAFE, 859 0, 0, sysctl_sysctl_name2oid, "I", ""); 860 861static int 862sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) 863{ 864 struct sysctl_oid *oid; 865 int error; 866 867 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 868 if (error) 869 return (error); 870 871 if (!oid->oid_fmt) 872 return (ENOENT); 873 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind)); 874 if (error) 875 return (error); 876 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1); 877 return (error); 878} 879 880 881static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE, 882 sysctl_sysctl_oidfmt, ""); 883 884static int 885sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) 886{ 887 struct sysctl_oid *oid; 888 int error; 889 890 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 891 if (error) 892 return (error); 893 894 if (!oid->oid_descr) 895 return (ENOENT); 896 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1); 897 return (error); 898} 899 900static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD, sysctl_sysctl_oiddescr, ""); 901 902/* 903 * Default "handler" functions. 904 */ 905 906/* 907 * Handle an int, signed or unsigned. 908 * Two cases: 909 * a variable: point arg1 at it. 910 * a constant: pass it in arg2. 911 */ 912 913int 914sysctl_handle_int(SYSCTL_HANDLER_ARGS) 915{ 916 int tmpout, error = 0; 917 918 /* 919 * Attempt to get a coherent snapshot by making a copy of the data. 920 */ 921 if (arg1) 922 tmpout = *(int *)arg1; 923 else 924 tmpout = arg2; 925 error = SYSCTL_OUT(req, &tmpout, sizeof(int)); 926 927 if (error || !req->newptr) 928 return (error); 929 930 if (!arg1) 931 error = EPERM; 932 else 933 error = SYSCTL_IN(req, arg1, sizeof(int)); 934 return (error); 935} 936 937 938/* 939 * Based on on sysctl_handle_int() convert milliseconds into ticks. 940 */ 941 942int 943sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS) 944{ 945 int error, s, tt; 946 947 tt = *(int *)oidp->oid_arg1; 948 s = (int)((int64_t)tt * 1000 / hz); 949 950 error = sysctl_handle_int(oidp, &s, 0, req); 951 if (error || !req->newptr) 952 return (error); 953 954 tt = (int)((int64_t)s * hz / 1000); 955 if (tt < 1) 956 return (EINVAL); 957 958 *(int *)oidp->oid_arg1 = tt; 959 return (0); 960} 961 962 963/* 964 * Handle a long, signed or unsigned. arg1 points to it. 965 */ 966 967int 968sysctl_handle_long(SYSCTL_HANDLER_ARGS) 969{ 970 int error = 0; 971 long tmplong; 972#ifdef SCTL_MASK32 973 int tmpint; 974#endif 975 976 /* 977 * Attempt to get a coherent snapshot by making a copy of the data. 978 */ 979 if (!arg1) 980 return (EINVAL); 981 tmplong = *(long *)arg1; 982#ifdef SCTL_MASK32 983 if (req->flags & SCTL_MASK32) { 984 tmpint = tmplong; 985 error = SYSCTL_OUT(req, &tmpint, sizeof(int)); 986 } else 987#endif 988 error = SYSCTL_OUT(req, &tmplong, sizeof(long)); 989 990 if (error || !req->newptr) 991 return (error); 992 993#ifdef SCTL_MASK32 994 if (req->flags & SCTL_MASK32) { 995 error = SYSCTL_IN(req, &tmpint, sizeof(int)); 996 *(long *)arg1 = (long)tmpint; 997 } else 998#endif 999 error = SYSCTL_IN(req, arg1, sizeof(long)); 1000 return (error); 1001} 1002 1003/* 1004 * Handle a 64 bit int, signed or unsigned. arg1 points to it. 1005 */ 1006 1007int 1008sysctl_handle_quad(SYSCTL_HANDLER_ARGS) 1009{ 1010 int error = 0; 1011 uint64_t tmpout; 1012 1013 /* 1014 * Attempt to get a coherent snapshot by making a copy of the data. 1015 */ 1016 if (!arg1) 1017 return (EINVAL); 1018 tmpout = *(uint64_t *)arg1; 1019 error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t)); 1020 1021 if (error || !req->newptr) 1022 return (error); 1023 1024 error = SYSCTL_IN(req, arg1, sizeof(uint64_t)); 1025 return (error); 1026} 1027 1028/* 1029 * Handle our generic '\0' terminated 'C' string. 1030 * Two cases: 1031 * a variable string: point arg1 at it, arg2 is max length. 1032 * a constant string: point arg1 at it, arg2 is zero. 1033 */ 1034 1035int 1036sysctl_handle_string(SYSCTL_HANDLER_ARGS) 1037{ 1038 int error=0; 1039 char *tmparg; 1040 size_t outlen; 1041 1042 /* 1043 * Attempt to get a coherent snapshot by copying to a 1044 * temporary kernel buffer. 1045 */ 1046retry: 1047 outlen = strlen((char *)arg1)+1; 1048 tmparg = malloc(outlen, M_SYSCTLTMP, M_WAITOK); 1049 1050 if (strlcpy(tmparg, (char *)arg1, outlen) >= outlen) { 1051 free(tmparg, M_SYSCTLTMP); 1052 goto retry; 1053 } 1054 1055 error = SYSCTL_OUT(req, tmparg, outlen); 1056 free(tmparg, M_SYSCTLTMP); 1057 1058 if (error || !req->newptr) 1059 return (error); 1060 1061 if ((req->newlen - req->newidx) >= arg2) { 1062 error = EINVAL; 1063 } else { 1064 arg2 = (req->newlen - req->newidx); 1065 error = SYSCTL_IN(req, arg1, arg2); 1066 ((char *)arg1)[arg2] = '\0'; 1067 } 1068 1069 return (error); 1070} 1071 1072/* 1073 * Handle any kind of opaque data. 1074 * arg1 points to it, arg2 is the size. 1075 */ 1076 1077int 1078sysctl_handle_opaque(SYSCTL_HANDLER_ARGS) 1079{ 1080 int error, tries; 1081 u_int generation; 1082 struct sysctl_req req2; 1083 1084 /* 1085 * Attempt to get a coherent snapshot, by using the thread 1086 * pre-emption counter updated from within mi_switch() to 1087 * determine if we were pre-empted during a bcopy() or 1088 * copyout(). Make 3 attempts at doing this before giving up. 1089 * If we encounter an error, stop immediately. 1090 */ 1091 tries = 0; 1092 req2 = *req; 1093retry: 1094 generation = curthread->td_generation; 1095 error = SYSCTL_OUT(req, arg1, arg2); 1096 if (error) 1097 return (error); 1098 tries++; 1099 if (generation != curthread->td_generation && tries < 3) { 1100 *req = req2; 1101 goto retry; 1102 } 1103 1104 error = SYSCTL_IN(req, arg1, arg2); 1105 1106 return (error); 1107} 1108 1109/* 1110 * Transfer functions to/from kernel space. 1111 * XXX: rather untested at this point 1112 */ 1113static int 1114sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l) 1115{ 1116 size_t i = 0; 1117 1118 if (req->oldptr) { 1119 i = l; 1120 if (req->oldlen <= req->oldidx) 1121 i = 0; 1122 else 1123 if (i > req->oldlen - req->oldidx) 1124 i = req->oldlen - req->oldidx; 1125 if (i > 0) 1126 bcopy(p, (char *)req->oldptr + req->oldidx, i); 1127 } 1128 req->oldidx += l; 1129 if (req->oldptr && i != l) 1130 return (ENOMEM); 1131 return (0); 1132} 1133 1134static int 1135sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l) 1136{ 1137 if (!req->newptr) 1138 return (0); 1139 if (req->newlen - req->newidx < l) 1140 return (EINVAL); 1141 bcopy((char *)req->newptr + req->newidx, p, l); 1142 req->newidx += l; 1143 return (0); 1144} 1145 1146int 1147kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1148 size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags) 1149{ 1150 int error = 0; 1151 struct sysctl_req req; 1152 1153 bzero(&req, sizeof req); 1154 1155 req.td = td; 1156 req.flags = flags; 1157 1158 if (oldlenp) { 1159 req.oldlen = *oldlenp; 1160 } 1161 req.validlen = req.oldlen; 1162 1163 if (old) { 1164 req.oldptr= old; 1165 } 1166 1167 if (new != NULL) { 1168 req.newlen = newlen; 1169 req.newptr = new; 1170 } 1171 1172 req.oldfunc = sysctl_old_kernel; 1173 req.newfunc = sysctl_new_kernel; 1174 req.lock = REQ_LOCKED; 1175 1176 SYSCTL_SLOCK(); 1177 error = sysctl_root(0, name, namelen, &req); 1178 SYSCTL_SUNLOCK(); 1179 1180 if (req.lock == REQ_WIRED && req.validlen > 0) 1181 vsunlock(req.oldptr, req.validlen); 1182 1183 if (error && error != ENOMEM) 1184 return (error); 1185 1186 if (retval) { 1187 if (req.oldptr && req.oldidx > req.validlen) 1188 *retval = req.validlen; 1189 else 1190 *retval = req.oldidx; 1191 } 1192 return (error); 1193} 1194 1195int 1196kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp, 1197 void *new, size_t newlen, size_t *retval, int flags) 1198{ 1199 int oid[CTL_MAXNAME]; 1200 size_t oidlen, plen; 1201 int error; 1202 1203 oid[0] = 0; /* sysctl internal magic */ 1204 oid[1] = 3; /* name2oid */ 1205 oidlen = sizeof(oid); 1206 1207 error = kernel_sysctl(td, oid, 2, oid, &oidlen, 1208 (void *)name, strlen(name), &plen, flags); 1209 if (error) 1210 return (error); 1211 1212 error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp, 1213 new, newlen, retval, flags); 1214 return (error); 1215} 1216 1217/* 1218 * Transfer function to/from user space. 1219 */ 1220static int 1221sysctl_old_user(struct sysctl_req *req, const void *p, size_t l) 1222{ 1223 int error = 0; 1224 size_t i, len, origidx; 1225 1226 origidx = req->oldidx; 1227 req->oldidx += l; 1228 if (req->oldptr == NULL) 1229 return (0); 1230 /* 1231 * If we have not wired the user supplied buffer and we are currently 1232 * holding locks, drop a witness warning, as it's possible that 1233 * write operations to the user page can sleep. 1234 */ 1235 if (req->lock != REQ_WIRED) 1236 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1237 "sysctl_old_user()"); 1238 i = l; 1239 len = req->validlen; 1240 if (len <= origidx) 1241 i = 0; 1242 else { 1243 if (i > len - origidx) 1244 i = len - origidx; 1245 error = copyout(p, (char *)req->oldptr + origidx, i); 1246 } 1247 if (error) 1248 return (error); 1249 if (i < l) 1250 return (ENOMEM); 1251 return (0); 1252} 1253 1254static int 1255sysctl_new_user(struct sysctl_req *req, void *p, size_t l) 1256{ 1257 int error; 1258 1259 if (!req->newptr) 1260 return (0); 1261 if (req->newlen - req->newidx < l) 1262 return (EINVAL); 1263 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1264 "sysctl_new_user()"); 1265 error = copyin((char *)req->newptr + req->newidx, p, l); 1266 req->newidx += l; 1267 return (error); 1268} 1269 1270/* 1271 * Wire the user space destination buffer. If set to a value greater than 1272 * zero, the len parameter limits the maximum amount of wired memory. 1273 */ 1274int 1275sysctl_wire_old_buffer(struct sysctl_req *req, size_t len) 1276{ 1277 int ret; 1278 size_t i, wiredlen; 1279 char *cp, dummy; 1280 1281 wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen; 1282 ret = 0; 1283 if (req->lock == REQ_LOCKED && req->oldptr && 1284 req->oldfunc == sysctl_old_user) { 1285 if (wiredlen != 0) { 1286 ret = vslock(req->oldptr, wiredlen); 1287 if (ret != 0) { 1288 if (ret != ENOMEM) 1289 return (ret); 1290 wiredlen = 0; 1291 } 1292 /* 1293 * Touch all the wired pages to avoid PTE modified 1294 * bit emulation traps on Alpha while holding locks 1295 * in the sysctl handler. 1296 */ 1297 for (i = (wiredlen + PAGE_SIZE - 1) / PAGE_SIZE, 1298 cp = req->oldptr; i > 0; i--, cp += PAGE_SIZE) { 1299 copyin(cp, &dummy, 1); 1300 copyout(&dummy, cp, 1); 1301 } 1302 } 1303 req->lock = REQ_WIRED; 1304 req->validlen = wiredlen; 1305 } 1306 return (0); 1307} 1308 1309int 1310sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid, 1311 int *nindx, struct sysctl_req *req) 1312{ 1313 struct sysctl_oid *oid; 1314 int indx; 1315 1316 SYSCTL_ASSERT_LOCKED(); 1317 oid = SLIST_FIRST(&sysctl__children); 1318 indx = 0; 1319 while (oid && indx < CTL_MAXNAME) { 1320 if (oid->oid_number == name[indx]) { 1321 indx++; 1322 if (oid->oid_kind & CTLFLAG_NOLOCK) 1323 req->lock = REQ_UNLOCKED; 1324 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1325 if (oid->oid_handler != NULL || 1326 indx == namelen) { 1327 *noid = oid; 1328 if (nindx != NULL) 1329 *nindx = indx; 1330 return (0); 1331 } 1332 oid = SLIST_FIRST( 1333 (struct sysctl_oid_list *)oid->oid_arg1); 1334 } else if (indx == namelen) { 1335 *noid = oid; 1336 if (nindx != NULL) 1337 *nindx = indx; 1338 return (0); 1339 } else { 1340 return (ENOTDIR); 1341 } 1342 } else { 1343 oid = SLIST_NEXT(oid, oid_link); 1344 } 1345 } 1346 return (ENOENT); 1347} 1348 1349/* 1350 * Traverse our tree, and find the right node, execute whatever it points 1351 * to, and return the resulting error code. 1352 */ 1353 1354static int 1355sysctl_root(SYSCTL_HANDLER_ARGS) 1356{ 1357 struct sysctl_oid *oid; 1358 int error, indx, lvl; 1359 1360 SYSCTL_ASSERT_LOCKED(); 1361 1362 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req); 1363 if (error) 1364 return (error); 1365 1366 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1367 /* 1368 * You can't call a sysctl when it's a node, but has 1369 * no handler. Inform the user that it's a node. 1370 * The indx may or may not be the same as namelen. 1371 */ 1372 if (oid->oid_handler == NULL) 1373 return (EISDIR); 1374 } 1375 1376 /* Is this sysctl writable? */ 1377 if (req->newptr && !(oid->oid_kind & CTLFLAG_WR)) 1378 return (EPERM); 1379 1380 KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL")); 1381 1382 /* Is this sysctl sensitive to securelevels? */ 1383 if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) { 1384 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE; 1385 error = securelevel_gt(req->td->td_ucred, lvl); 1386 if (error) 1387 return (error); 1388 } 1389 1390 /* Is this sysctl writable by only privileged users? */ 1391 if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) { 1392 if (oid->oid_kind & CTLFLAG_PRISON) 1393 error = priv_check(req->td, PRIV_SYSCTL_WRITEJAIL); 1394 else 1395 error = priv_check(req->td, PRIV_SYSCTL_WRITE); 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; 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 SYSCTL_XLOCK(); 1512 CURVNET_SET(TD_TO_VNET(curthread)); 1513 1514 for (;;) { 1515 req.oldidx = 0; 1516 req.newidx = 0; 1517 error = sysctl_root(0, name, namelen, &req); 1518 if (error != EAGAIN) 1519 break; 1520 uio_yield(); 1521 } 1522 1523 CURVNET_RESTORE(); 1524 1525 if (req.lock == REQ_WIRED && req.validlen > 0) 1526 vsunlock(req.oldptr, req.validlen); 1527 SYSCTL_XUNLOCK(); 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