1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Mike Karels at Berkeley Software Design, Inc. 7 * 8 * Quite extensively rewritten by Poul-Henning Kamp of the FreeBSD 9 * project, to make these variables more userfriendly. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. 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 * $FreeBSD: src/sys/kern/kern_sysctl.c,v 1.92.2.9 2003/05/01 22:48:09 trhodes Exp $ 37 */ 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/kernel.h> 42 #include <sys/buf.h> 43 #include <sys/sysctl.h> 44 #include <sys/malloc.h> 45 #include <sys/proc.h> 46 #include <sys/priv.h> 47 #include <sys/sysproto.h> 48 #include <sys/lock.h> 49 #include <sys/sbuf.h> 50 51 #include <vm/vm.h> 52 #include <vm/vm_extern.h> 53 54 static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic"); 55 static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids"); 56 57 /* 58 * The sysctllock protects the MIB tree. It also protects sysctl 59 * contexts used with dynamic sysctls. The sysctl_register_oid() and 60 * sysctl_unregister_oid() routines require the sysctllock to already 61 * be held, so the sysctl_lock() and sysctl_unlock() routines are 62 * provided for the few places in the kernel which need to use that 63 * API rather than using the dynamic API. Use of the dynamic API is 64 * strongly encouraged for most code. 65 */ 66 67 static int sysctl_root(SYSCTL_HANDLER_ARGS); 68 static void sysctl_register_oid_int(struct sysctl_oid *oipd); 69 static void sysctl_unregister_oid_int(struct sysctl_oid *oipd); 70 71 struct sysctl_oid_list sysctl__children; /* root list */ 72 73 static int sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, 74 int recurse); 75 76 static struct sysctl_oid * 77 sysctl_find_oidname(const char *name, struct sysctl_oid_list *list, int lock) 78 { 79 struct sysctl_oid *oidp; 80 81 SLIST_FOREACH(oidp, list, oid_link) { 82 if (strcmp(oidp->oid_name, name) == 0) { 83 break; 84 } 85 } 86 return (oidp); 87 } 88 89 /* 90 * Initialization of the MIB tree. 91 * 92 * Order by number in each list. 93 */ 94 95 void 96 sysctl_register_oid(struct sysctl_oid *oidp) 97 { 98 SYSCTL_XLOCK(); 99 sysctl_register_oid_int(oidp); 100 SYSCTL_XUNLOCK(); 101 } 102 103 static void 104 sysctl_register_oid_int(struct sysctl_oid *oidp) 105 { 106 struct sysctl_oid_list *parent = oidp->oid_parent; 107 struct sysctl_oid *p; 108 struct sysctl_oid *q; 109 110 /* 111 * Finish initialization from sysctl_set or add. 112 */ 113 lockinit(&oidp->oid_lock, "oidlk", 0, LK_CANRECURSE); 114 115 /* 116 * First check if another oid with the same name already 117 * exists in the parent's list. 118 */ 119 p = sysctl_find_oidname(oidp->oid_name, parent, 0); 120 if (p != NULL) { 121 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) 122 p->oid_refcnt++; 123 else 124 kprintf("can't re-use a leaf (%s)!\n", p->oid_name); 125 return; 126 } 127 128 /* 129 * If this oid has a number OID_AUTO, give it a number which 130 * is greater than any current oid. Make sure it is at least 131 * 256 to leave space for pre-assigned oid numbers. 132 */ 133 if (oidp->oid_number == OID_AUTO) { 134 int newoid = 0x100; /* minimum AUTO oid */ 135 136 /* 137 * Adjust based on highest oid in parent list 138 */ 139 SLIST_FOREACH(p, parent, oid_link) { 140 if (newoid <= p->oid_number) 141 newoid = p->oid_number + 1; 142 } 143 oidp->oid_number = newoid; 144 } 145 146 /* 147 * Insert the oid into the parent's list in order. 148 */ 149 q = NULL; 150 SLIST_FOREACH(p, parent, oid_link) { 151 if (oidp->oid_number < p->oid_number) 152 break; 153 q = p; 154 } 155 if (q) 156 SLIST_INSERT_AFTER(q, oidp, oid_link); 157 else 158 SLIST_INSERT_HEAD(parent, oidp, oid_link); 159 } 160 161 void 162 sysctl_unregister_oid(struct sysctl_oid *oidp) 163 { 164 SYSCTL_XLOCK(); 165 sysctl_unregister_oid_int(oidp); 166 SYSCTL_XUNLOCK(); 167 } 168 169 static void 170 sysctl_unregister_oid_int(struct sysctl_oid *oidp) 171 { 172 struct sysctl_oid *p; 173 174 if (oidp->oid_number == OID_AUTO) 175 panic("Trying to unregister OID_AUTO entry: %p", oidp); 176 177 SLIST_FOREACH(p, oidp->oid_parent, oid_link) { 178 if (p != oidp) 179 continue; 180 SLIST_REMOVE(oidp->oid_parent, oidp, sysctl_oid, oid_link); 181 return; 182 } 183 184 /* 185 * This can happen when a module fails to register and is 186 * being unloaded afterwards. It should not be a panic() 187 * for normal use. 188 */ 189 kprintf("%s: failed to unregister sysctl\n", __func__); 190 } 191 192 /* Initialize a new context to keep track of dynamically added sysctls. */ 193 int 194 sysctl_ctx_init(struct sysctl_ctx_list *c) 195 { 196 if (c == NULL) 197 return(EINVAL); 198 TAILQ_INIT(c); 199 return(0); 200 } 201 202 /* Free the context, and destroy all dynamic oids registered in this context */ 203 int 204 sysctl_ctx_free(struct sysctl_ctx_list *clist) 205 { 206 struct sysctl_ctx_entry *e, *e1; 207 int error; 208 209 error = 0; 210 /* 211 * First perform a "dry run" to check if it's ok to remove oids. 212 * XXX FIXME 213 * XXX This algorithm is a hack. But I don't know any 214 * XXX better solution for now... 215 */ 216 SYSCTL_XLOCK(); 217 TAILQ_FOREACH(e, clist, link) { 218 error = sysctl_remove_oid_locked(e->entry, 0, 0); 219 if (error) 220 break; 221 } 222 /* 223 * Restore deregistered entries, either from the end, 224 * or from the place where error occured. 225 * e contains the entry that was not unregistered 226 */ 227 if (error) 228 e1 = TAILQ_PREV(e, sysctl_ctx_list, link); 229 else 230 e1 = TAILQ_LAST(clist, sysctl_ctx_list); 231 while (e1 != NULL) { 232 sysctl_register_oid(e1->entry); 233 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link); 234 } 235 if (error) { 236 SYSCTL_XUNLOCK(); 237 return(EBUSY); 238 } 239 /* Now really delete the entries */ 240 e = TAILQ_FIRST(clist); 241 while (e != NULL) { 242 e1 = TAILQ_NEXT(e, link); 243 error = sysctl_remove_oid_locked(e->entry, 1, 0); 244 if (error) 245 panic("sysctl_remove_oid: corrupt tree, entry: %s", 246 e->entry->oid_name); 247 kfree(e, M_SYSCTLOID); 248 e = e1; 249 } 250 SYSCTL_XUNLOCK(); 251 return (error); 252 } 253 254 /* Add an entry to the context */ 255 struct sysctl_ctx_entry * 256 sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 257 { 258 struct sysctl_ctx_entry *e; 259 260 SYSCTL_ASSERT_LOCKED(); 261 if (clist == NULL || oidp == NULL) 262 return(NULL); 263 e = kmalloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK); 264 e->entry = oidp; 265 TAILQ_INSERT_HEAD(clist, e, link); 266 return (e); 267 } 268 269 /* Find an entry in the context */ 270 struct sysctl_ctx_entry * 271 sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 272 { 273 struct sysctl_ctx_entry *e; 274 275 SYSCTL_ASSERT_LOCKED(); 276 if (clist == NULL || oidp == NULL) 277 return(NULL); 278 TAILQ_FOREACH(e, clist, link) { 279 if(e->entry == oidp) 280 return(e); 281 } 282 return (e); 283 } 284 285 /* 286 * Delete an entry from the context. 287 * NOTE: this function doesn't free oidp! You have to remove it 288 * with sysctl_remove_oid(). 289 */ 290 int 291 sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 292 { 293 struct sysctl_ctx_entry *e; 294 295 if (clist == NULL || oidp == NULL) 296 return (EINVAL); 297 SYSCTL_XLOCK(); 298 e = sysctl_ctx_entry_find(clist, oidp); 299 if (e != NULL) { 300 TAILQ_REMOVE(clist, e, link); 301 SYSCTL_XUNLOCK(); 302 kfree(e, M_SYSCTLOID); 303 return (0); 304 } else { 305 SYSCTL_XUNLOCK(); 306 return (ENOENT); 307 } 308 } 309 310 /* 311 * Remove dynamically created sysctl trees. 312 * oidp - top of the tree to be removed 313 * del - if 0 - just deregister, otherwise free up entries as well 314 * recurse - if != 0 traverse the subtree to be deleted 315 */ 316 int 317 sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse) 318 { 319 int error; 320 321 SYSCTL_XLOCK(); 322 error = sysctl_remove_oid_locked(oidp, del, recurse); 323 SYSCTL_XUNLOCK(); 324 return (error); 325 } 326 327 static int 328 sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse) 329 { 330 struct sysctl_oid *p, *tmp; 331 int error; 332 333 SYSCTL_ASSERT_LOCKED(); 334 if (oidp == NULL) 335 return(EINVAL); 336 if ((oidp->oid_kind & CTLFLAG_DYN) == 0) { 337 kprintf("can't remove non-dynamic nodes!\n"); 338 return (EINVAL); 339 } 340 /* 341 * WARNING: normal method to do this should be through 342 * sysctl_ctx_free(). Use recursing as the last resort 343 * method to purge your sysctl tree of leftovers... 344 * However, if some other code still references these nodes, 345 * it will panic. 346 */ 347 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 348 if (oidp->oid_refcnt == 1) { 349 SLIST_FOREACH_MUTABLE(p, 350 SYSCTL_CHILDREN(oidp), oid_link, tmp) { 351 if (!recurse) { 352 kprintf("Warning: failed attempt to " 353 "remove oid %s with child %s\n", 354 oidp->oid_name, p->oid_name); 355 return (ENOTEMPTY); 356 } 357 error = sysctl_remove_oid_locked(p, del, 358 recurse); 359 if (error) 360 return (error); 361 } 362 if (del) 363 kfree(SYSCTL_CHILDREN(oidp), M_SYSCTLOID); 364 } 365 } 366 if (oidp->oid_refcnt > 1 ) { 367 oidp->oid_refcnt--; 368 } else { 369 if (oidp->oid_refcnt == 0) { 370 kprintf("Warning: bad oid_refcnt=%u (%s)!\n", 371 oidp->oid_refcnt, oidp->oid_name); 372 return (EINVAL); 373 } 374 sysctl_unregister_oid(oidp); 375 if (del) { 376 /* 377 * Wait for all threads running the handler to drain. 378 * This preserves the previous behavior when the 379 * sysctl lock was held across a handler invocation, 380 * and is necessary for module unload correctness. 381 */ 382 while (oidp->oid_running > 0) { 383 oidp->oid_kind |= CTLFLAG_DYING; 384 tsleep_interlock(&oidp->oid_running, 0); 385 SYSCTL_XUNLOCK(); 386 tsleep(&oidp->oid_running, PINTERLOCKED, 387 "oidrm", 0); 388 SYSCTL_XLOCK(); 389 } 390 if (oidp->oid_descr) 391 kfree(__DECONST(char *, oidp->oid_descr), 392 M_SYSCTLOID); 393 kfree(__DECONST(char *, oidp->oid_name), M_SYSCTLOID); 394 lockuninit(&oidp->oid_lock); 395 kfree(oidp, M_SYSCTLOID); 396 } 397 } 398 return (0); 399 } 400 401 int 402 sysctl_remove_name(struct sysctl_oid *parent, const char *name, 403 int del, int recurse) 404 { 405 struct sysctl_oid *p, *tmp; 406 int error; 407 408 error = ENOENT; 409 SYSCTL_XLOCK(); 410 SLIST_FOREACH_MUTABLE(p, SYSCTL_CHILDREN(parent), oid_link, tmp) { 411 if (strcmp(p->oid_name, name) == 0) { 412 error = sysctl_remove_oid_locked(p, del, recurse); 413 break; 414 } 415 } 416 SYSCTL_XUNLOCK(); 417 418 return (error); 419 } 420 421 /* 422 * Create new sysctls at run time. 423 * clist may point to a valid context initialized with sysctl_ctx_init(). 424 */ 425 struct sysctl_oid * 426 sysctl_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 SYSCTL_XLOCK(); 438 /* Check if the node already exists, otherwise create it */ 439 oidp = sysctl_find_oidname(name, parent, 0); 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 kprintf("can't re-use a leaf (%s)!\n", name); 450 SYSCTL_XUNLOCK(); 451 return (NULL); 452 } 453 } 454 oidp = kmalloc(sizeof(struct sysctl_oid), M_SYSCTLOID, 455 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 = kmalloc(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 struct sysctl_oid_list *children; 469 470 /* Allocate space for children */ 471 children = kmalloc(sizeof(*children), M_SYSCTLOID, M_WAITOK); 472 SYSCTL_SET_CHILDREN(oidp, children); 473 SLIST_INIT(children); 474 } else { 475 oidp->oid_arg1 = arg1; 476 oidp->oid_arg2 = arg2; 477 } 478 oidp->oid_fmt = fmt; 479 if (descr) { 480 int len = strlen(descr) + 1; 481 oidp->oid_descr = kmalloc(len, M_SYSCTLOID, M_WAITOK); 482 strcpy((char *)(uintptr_t)(const void *)oidp->oid_descr, descr); 483 }; 484 /* Update the context, if used */ 485 if (clist != NULL) 486 sysctl_ctx_entry_add(clist, oidp); 487 /* Register this oid */ 488 sysctl_register_oid_int(oidp); 489 SYSCTL_XUNLOCK(); 490 return (oidp); 491 } 492 493 /* 494 * Rename an existing oid. 495 */ 496 void 497 sysctl_rename_oid(struct sysctl_oid *oidp, const char *name) 498 { 499 char *newname; 500 char *oldname; 501 502 newname = kstrdup(name, M_SYSCTLOID); 503 SYSCTL_XLOCK(); 504 oldname = __DECONST(char *, oidp->oid_name); 505 oidp->oid_name = newname; 506 SYSCTL_XUNLOCK(); 507 kfree(oldname, M_SYSCTLOID); 508 } 509 510 /* 511 * Register the kernel's oids on startup. 512 */ 513 SET_DECLARE(sysctl_set, struct sysctl_oid); 514 515 static void 516 sysctl_register_all(void *arg) 517 { 518 struct sysctl_oid **oidp; 519 520 SYSCTL_XLOCK(); 521 SET_FOREACH(oidp, sysctl_set) 522 sysctl_register_oid(*oidp); 523 SYSCTL_XUNLOCK(); 524 } 525 SYSINIT(sysctl, SI_BOOT1_POST, SI_ORDER_ANY, sysctl_register_all, 0); 526 527 /* 528 * "Staff-functions" 529 * 530 * These functions implement a presently undocumented interface 531 * used by the sysctl program to walk the tree, and get the type 532 * so it can print the value. 533 * This interface is under work and consideration, and should probably 534 * be killed with a big axe by the first person who can find the time. 535 * (be aware though, that the proper interface isn't as obvious as it 536 * may seem, there are various conflicting requirements. 537 * 538 * {0,0} kprintf the entire MIB-tree. 539 * {0,1,...} return the name of the "..." OID. 540 * {0,2,...} return the next OID. 541 * {0,3} return the OID of the name in "new" 542 * {0,4,...} return the kind & format info for the "..." OID. 543 */ 544 545 static void 546 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i) 547 { 548 int k; 549 struct sysctl_oid *oidp; 550 551 SLIST_FOREACH(oidp, l, oid_link) { 552 553 for (k=0; k<i; k++) 554 kprintf(" "); 555 556 kprintf("%d %s ", oidp->oid_number, oidp->oid_name); 557 558 kprintf("%c%c", 559 oidp->oid_kind & CTLFLAG_RD ? 'R':' ', 560 oidp->oid_kind & CTLFLAG_WR ? 'W':' '); 561 562 if (oidp->oid_handler) 563 kprintf(" *Handler"); 564 565 switch (oidp->oid_kind & CTLTYPE) { 566 case CTLTYPE_NODE: 567 kprintf(" Node\n"); 568 if (!oidp->oid_handler) { 569 sysctl_sysctl_debug_dump_node( 570 oidp->oid_arg1, i+2); 571 } 572 break; 573 case CTLTYPE_INT: kprintf(" Int\n"); break; 574 case CTLTYPE_UINT: kprintf(" u_int\n"); break; 575 case CTLTYPE_LONG: kprintf(" Long\n"); break; 576 case CTLTYPE_ULONG: kprintf(" u_long\n"); break; 577 case CTLTYPE_STRING: kprintf(" String\n"); break; 578 case CTLTYPE_S8: kprintf(" int8_t\n"); break; 579 case CTLTYPE_S16: kprintf(" int16_t\n"); break; 580 case CTLTYPE_S32: kprintf(" int32_t\n"); break; 581 case CTLTYPE_S64: kprintf(" int64_t\n"); break; 582 case CTLTYPE_U8: kprintf(" uint8_t\n"); break; 583 case CTLTYPE_U16: kprintf(" uint16_t\n"); break; 584 case CTLTYPE_U32: kprintf(" uint32_t\n"); break; 585 case CTLTYPE_U64: kprintf(" uint64_t\n"); break; 586 case CTLTYPE_OPAQUE: kprintf(" Opaque/struct\n"); break; 587 default: kprintf("\n"); 588 } 589 590 } 591 } 592 593 static int 594 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS) 595 { 596 int error; 597 598 error = priv_check(req->td, PRIV_SYSCTL_DEBUG); 599 if (error) 600 return (error); 601 sysctl_sysctl_debug_dump_node(&sysctl__children, 0); 602 603 return (ENOENT); 604 } 605 606 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING | CTLFLAG_RD, 607 0, 0, sysctl_sysctl_debug, "-", ""); 608 609 static int 610 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS) 611 { 612 int *name = (int *) arg1; 613 u_int namelen = arg2; 614 int error = 0; 615 struct sysctl_oid *oid; 616 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2; 617 char buf[10]; 618 619 while (namelen) { 620 if (!lsp) { 621 ksnprintf(buf, sizeof(buf), "%d", *name); 622 if (req->oldidx) 623 error = SYSCTL_OUT(req, ".", 1); 624 if (!error) 625 error = SYSCTL_OUT(req, buf, strlen(buf)); 626 if (error) 627 goto out; 628 namelen--; 629 name++; 630 continue; 631 } 632 lsp2 = NULL; 633 SLIST_FOREACH(oid, lsp, oid_link) { 634 if (oid->oid_number != *name) 635 continue; 636 637 if (req->oldidx) 638 error = SYSCTL_OUT(req, ".", 1); 639 if (!error) 640 error = SYSCTL_OUT(req, oid->oid_name, 641 strlen(oid->oid_name)); 642 if (error) 643 goto out; 644 645 namelen--; 646 name++; 647 648 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) 649 break; 650 651 if (oid->oid_handler) 652 break; 653 654 lsp2 = SYSCTL_CHILDREN(oid); 655 break; 656 } 657 lsp = lsp2; 658 } 659 error = SYSCTL_OUT(req, "", 1); 660 out: 661 return (error); 662 } 663 664 SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD | CTLFLAG_NOLOCK, 665 sysctl_sysctl_name, ""); 666 667 static int 668 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 669 int *next, int *len, int level, struct sysctl_oid **oidpp) 670 { 671 struct sysctl_oid *oidp; 672 673 *len = level; 674 SLIST_FOREACH(oidp, lsp, oid_link) { 675 *next = oidp->oid_number; 676 *oidpp = oidp; 677 678 if (oidp->oid_kind & CTLFLAG_SKIP) 679 continue; 680 681 if (!namelen) { 682 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 683 return (0); 684 if (oidp->oid_handler) 685 /* We really should call the handler here...*/ 686 return (0); 687 lsp = SYSCTL_CHILDREN(oidp); 688 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, 689 len, level+1, oidpp)) 690 return (0); 691 goto emptynode; 692 } 693 694 if (oidp->oid_number < *name) 695 continue; 696 697 if (oidp->oid_number > *name) { 698 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 699 return (0); 700 if (oidp->oid_handler) 701 return (0); 702 lsp = SYSCTL_CHILDREN(oidp); 703 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, 704 next+1, len, level+1, oidpp)) 705 return (0); 706 goto next; 707 } 708 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 709 continue; 710 711 if (oidp->oid_handler) 712 continue; 713 714 lsp = SYSCTL_CHILDREN(oidp); 715 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, 716 len, level+1, oidpp)) 717 return (0); 718 next: 719 namelen = 1; 720 emptynode: 721 *len = level; 722 } 723 return (1); 724 } 725 726 static int 727 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS) 728 { 729 int *name = (int *) arg1; 730 u_int namelen = arg2; 731 int i, j, error; 732 struct sysctl_oid *oid; 733 struct sysctl_oid_list *lsp = &sysctl__children; 734 int newoid[CTL_MAXNAME]; 735 736 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid); 737 if (i) 738 return ENOENT; 739 error = SYSCTL_OUT(req, newoid, j * sizeof (int)); 740 741 return (error); 742 } 743 744 SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD | CTLFLAG_NOLOCK, 745 sysctl_sysctl_next, ""); 746 747 static int 748 name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp) 749 { 750 struct sysctl_oid *oidp; 751 struct sysctl_oid_list *lsp = &sysctl__children; 752 char *p; 753 754 SYSCTL_ASSERT_LOCKED(); 755 756 for (*len = 0; *len < CTL_MAXNAME;) { 757 p = strsep(&name, "."); 758 759 oidp = SLIST_FIRST(lsp); 760 for (;; oidp = SLIST_NEXT(oidp, oid_link)) { 761 if (oidp == NULL) 762 return (ENOENT); 763 if (strcmp(p, oidp->oid_name) == 0) 764 break; 765 } 766 *oid++ = oidp->oid_number; 767 (*len)++; 768 769 if (name == NULL || *name == '\0') { 770 if (oidpp) 771 *oidpp = oidp; 772 return (0); 773 } 774 775 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 776 break; 777 778 if (oidp->oid_handler) 779 break; 780 781 lsp = SYSCTL_CHILDREN(oidp); 782 } 783 return (ENOENT); 784 } 785 786 static int 787 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS) 788 { 789 char *p; 790 int error, oid[CTL_MAXNAME], len; 791 struct sysctl_oid *op = NULL; 792 793 if (!req->newlen) 794 return ENOENT; 795 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */ 796 return (ENAMETOOLONG); 797 798 p = kmalloc(req->newlen+1, M_SYSCTL, M_WAITOK); 799 800 error = SYSCTL_IN(req, p, req->newlen); 801 if (error) { 802 kfree(p, M_SYSCTL); 803 return (error); 804 } 805 806 p [req->newlen] = '\0'; 807 808 error = name2oid(p, oid, &len, &op); 809 810 kfree(p, M_SYSCTL); 811 812 if (error) 813 return (error); 814 815 error = SYSCTL_OUT(req, oid, len * sizeof *oid); 816 return (error); 817 } 818 819 SYSCTL_PROC(_sysctl, 3, name2oid, CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_NOLOCK, 820 0, 0, sysctl_sysctl_name2oid, "I", ""); 821 822 static int 823 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) 824 { 825 struct sysctl_oid *oid; 826 int error; 827 828 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 829 if (error) 830 return (error); 831 832 if (!oid->oid_fmt) 833 return (ENOENT); 834 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind)); 835 if (error) 836 return (error); 837 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1); 838 return (error); 839 } 840 841 842 SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD | CTLFLAG_NOLOCK, 843 sysctl_sysctl_oidfmt, ""); 844 845 static int 846 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) 847 { 848 struct sysctl_oid *oid; 849 int error; 850 851 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 852 if (error) 853 return (error); 854 855 if (!oid->oid_descr) 856 return (ENOENT); 857 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1); 858 return (error); 859 } 860 861 SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD | CTLFLAG_NOLOCK, 862 sysctl_sysctl_oiddescr, ""); 863 864 /* 865 * Default "handler" functions. 866 */ 867 868 /* 869 * Handle an 8-bit number, signed or unsigned. arg1 points to it. 870 */ 871 872 int 873 sysctl_handle_8(SYSCTL_HANDLER_ARGS) 874 { 875 int error = 0; 876 877 if (!arg1) 878 return (EINVAL); 879 error = SYSCTL_OUT(req, arg1, sizeof(int8_t)); 880 881 if (error || !req->newptr) 882 return (error); 883 884 error = SYSCTL_IN(req, arg1, sizeof(int8_t)); 885 return (error); 886 } 887 888 /* 889 * Handle a 16-bit number, signed or unsigned. arg1 points to it. 890 */ 891 892 int 893 sysctl_handle_16(SYSCTL_HANDLER_ARGS) 894 { 895 int error = 0; 896 897 if (!arg1) 898 return (EINVAL); 899 error = SYSCTL_OUT(req, arg1, sizeof(int16_t)); 900 901 if (error || !req->newptr) 902 return (error); 903 904 error = SYSCTL_IN(req, arg1, sizeof(int16_t)); 905 return (error); 906 } 907 908 /* 909 * Handle a 32-bit number, signed or unsigned. arg1 points to it. 910 */ 911 912 int 913 sysctl_handle_32(SYSCTL_HANDLER_ARGS) 914 { 915 int error = 0; 916 917 if (!arg1) 918 return (EINVAL); 919 error = SYSCTL_OUT(req, arg1, sizeof(int32_t)); 920 921 if (error || !req->newptr) 922 return (error); 923 924 error = SYSCTL_IN(req, arg1, sizeof(int32_t)); 925 return (error); 926 } 927 928 /* 929 * Handle a 64-bit number, signed or unsigned. arg1 points to it. 930 */ 931 932 int 933 sysctl_handle_64(SYSCTL_HANDLER_ARGS) 934 { 935 int error = 0; 936 937 if (!arg1) 938 return (EINVAL); 939 error = SYSCTL_OUT(req, arg1, sizeof(int64_t)); 940 941 if (error || !req->newptr) 942 return (error); 943 944 error = SYSCTL_IN(req, arg1, sizeof(int64_t)); 945 return (error); 946 } 947 948 /* 949 * Handle an int, signed or unsigned. 950 * Two cases: 951 * a variable: point arg1 at it. 952 * a constant: pass it in arg2. 953 */ 954 955 int 956 sysctl_handle_int(SYSCTL_HANDLER_ARGS) 957 { 958 int error = 0; 959 960 if (arg1) 961 error = SYSCTL_OUT(req, arg1, sizeof(int)); 962 else 963 error = SYSCTL_OUT(req, &arg2, sizeof(int)); 964 965 if (error || !req->newptr) 966 return (error); 967 968 if (!arg1) 969 error = EPERM; 970 else 971 error = SYSCTL_IN(req, arg1, sizeof(int)); 972 return (error); 973 } 974 975 /* 976 * Handle a long, signed or unsigned. arg1 points to it. 977 */ 978 979 int 980 sysctl_handle_long(SYSCTL_HANDLER_ARGS) 981 { 982 int error = 0; 983 984 if (!arg1) 985 return (EINVAL); 986 if (req->oldlen == sizeof(int) && 987 *(long *)arg1 >= INT_MIN && 988 *(long *)arg1 <= INT_MAX) { 989 /* 990 * Backwards compatibility for read-only fields promoted 991 * from int to long. Allow userland to request the field 992 * as an integer if the value is in-range. 993 */ 994 int val = (int)*(long *)arg1; 995 error = SYSCTL_OUT(req, &val, sizeof(int)); 996 } else { 997 /* 998 * Normal operation fo a long 999 */ 1000 error = SYSCTL_OUT(req, arg1, sizeof(long)); 1001 } 1002 1003 if (error || !req->newptr) 1004 return (error); 1005 1006 error = SYSCTL_IN(req, arg1, sizeof(long)); 1007 1008 return (error); 1009 } 1010 1011 /* 1012 * Handle a quad, signed or unsigned. arg1 points to it. 1013 */ 1014 1015 int 1016 sysctl_handle_quad(SYSCTL_HANDLER_ARGS) 1017 { 1018 int error = 0; 1019 1020 if (!arg1) 1021 return (EINVAL); 1022 error = SYSCTL_OUT(req, arg1, sizeof(quad_t)); 1023 1024 if (error || !req->newptr) 1025 return (error); 1026 1027 error = SYSCTL_IN(req, arg1, sizeof(quad_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 1038 int 1039 sysctl_handle_string(SYSCTL_HANDLER_ARGS) 1040 { 1041 int error=0; 1042 1043 error = SYSCTL_OUT(req, arg1, strlen((char *)arg1)+1); 1044 1045 if (error || !req->newptr) 1046 return (error); 1047 1048 if ((req->newlen - req->newidx) >= arg2) { 1049 error = EINVAL; 1050 } else { 1051 arg2 = (req->newlen - req->newidx); 1052 error = SYSCTL_IN(req, arg1, arg2); 1053 ((char *)arg1)[arg2] = '\0'; 1054 } 1055 1056 return (error); 1057 } 1058 1059 /* 1060 * Handle any kind of opaque data. 1061 * arg1 points to it, arg2 is the size. 1062 */ 1063 1064 int 1065 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS) 1066 { 1067 int error; 1068 1069 error = SYSCTL_OUT(req, arg1, arg2); 1070 1071 if (error || !req->newptr) 1072 return (error); 1073 1074 error = SYSCTL_IN(req, arg1, arg2); 1075 1076 return (error); 1077 } 1078 1079 /* 1080 * Transfer functions to/from kernel space. 1081 * XXX: rather untested at this point 1082 */ 1083 static int 1084 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l) 1085 { 1086 size_t i = 0; 1087 1088 if (req->oldptr) { 1089 i = l; 1090 if (i > req->oldlen - req->oldidx) 1091 i = req->oldlen - req->oldidx; 1092 if (i > 0) 1093 bcopy(p, (char *)req->oldptr + req->oldidx, i); 1094 } 1095 req->oldidx += l; 1096 if (req->oldptr && i != l) 1097 return (ENOMEM); 1098 return (0); 1099 } 1100 1101 static int 1102 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l) 1103 { 1104 1105 if (!req->newptr) 1106 return 0; 1107 if (req->newlen - req->newidx < l) 1108 return (EINVAL); 1109 bcopy((char *)req->newptr + req->newidx, p, l); 1110 req->newidx += l; 1111 return (0); 1112 } 1113 1114 int 1115 kernel_sysctl(int *name, u_int namelen, 1116 void *old, size_t *oldlenp, 1117 void *new, size_t newlen, size_t *retval) 1118 { 1119 int error = 0; 1120 struct sysctl_req req; 1121 1122 bzero(&req, sizeof req); 1123 1124 req.td = curthread; 1125 1126 if (oldlenp) { 1127 req.oldlen = *oldlenp; 1128 } 1129 req.validlen = req.oldlen; 1130 1131 if (old) { 1132 req.oldptr= old; 1133 } 1134 1135 if (new != NULL) { 1136 req.newlen = newlen; 1137 req.newptr = new; 1138 } 1139 1140 req.oldfunc = sysctl_old_kernel; 1141 req.newfunc = sysctl_new_kernel; 1142 #if 0 1143 req.lock = REQ_UNWIRED; 1144 #endif 1145 1146 SYSCTL_SLOCK(); 1147 error = sysctl_root(0, name, namelen, &req); 1148 SYSCTL_SUNLOCK(); 1149 1150 #if 0 1151 if (req.lock == REQ_WIRED && req.validlen > 0) 1152 vsunlock(req.oldptr, req.validlen); 1153 #endif 1154 1155 if (error && error != ENOMEM) 1156 return (error); 1157 1158 if (retval) { 1159 if (req.oldptr && req.oldidx > req.validlen) 1160 *retval = req.validlen; 1161 else 1162 *retval = req.oldidx; 1163 } 1164 return (error); 1165 } 1166 1167 int 1168 kernel_sysctlbyname(char *name, 1169 void *old, size_t *oldlenp, 1170 void *new, size_t newlen, size_t *retval) 1171 { 1172 int oid[CTL_MAXNAME]; 1173 size_t oidlen, plen; 1174 int error; 1175 1176 oid[0] = 0; /* sysctl internal magic */ 1177 oid[1] = 3; /* name2oid */ 1178 oidlen = sizeof(oid); 1179 1180 error = kernel_sysctl(oid, 2, oid, &oidlen, name, strlen(name), &plen); 1181 if (error) 1182 return (error); 1183 1184 error = kernel_sysctl(oid, plen / sizeof(int), old, oldlenp, 1185 new, newlen, retval); 1186 return (error); 1187 } 1188 1189 /* 1190 * Transfer function to/from user space. 1191 */ 1192 static int 1193 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l) 1194 { 1195 int error = 0; 1196 size_t i = 0; 1197 1198 #if 0 1199 if (req->lock == 1 && req->oldptr) { 1200 vslock(req->oldptr, req->oldlen); 1201 req->lock = 2; 1202 } 1203 #endif 1204 if (req->oldptr) { 1205 i = l; 1206 if (i > req->oldlen - req->oldidx) 1207 i = req->oldlen - req->oldidx; 1208 if (i > 0) 1209 error = copyout(p, (char *)req->oldptr + req->oldidx, 1210 i); 1211 } 1212 req->oldidx += l; 1213 if (error) 1214 return (error); 1215 if (req->oldptr && i < l) 1216 return (ENOMEM); 1217 return (0); 1218 } 1219 1220 static int 1221 sysctl_new_user(struct sysctl_req *req, void *p, size_t l) 1222 { 1223 int error; 1224 1225 if (!req->newptr) 1226 return 0; 1227 if (req->newlen - req->newidx < l) 1228 return (EINVAL); 1229 error = copyin((char *)req->newptr + req->newidx, p, l); 1230 req->newidx += l; 1231 return (error); 1232 } 1233 1234 int 1235 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid, 1236 int *nindx, struct sysctl_req *req) 1237 { 1238 struct sysctl_oid_list *lsp; 1239 struct sysctl_oid *oid; 1240 int indx; 1241 1242 lsp = &sysctl__children; 1243 indx = 0; 1244 while (indx < CTL_MAXNAME) { 1245 SLIST_FOREACH(oid, lsp, oid_link) { 1246 if (oid->oid_number == name[indx]) 1247 break; 1248 } 1249 if (oid == NULL) 1250 return (ENOENT); 1251 1252 indx++; 1253 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1254 if (oid->oid_handler != NULL || indx == namelen) { 1255 *noid = oid; 1256 if (nindx != NULL) 1257 *nindx = indx; 1258 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1259 ("%s found DYING node %p", __func__, oid)); 1260 return (0); 1261 } 1262 lsp = SYSCTL_CHILDREN(oid); 1263 } else if (indx == namelen) { 1264 *noid = oid; 1265 if (nindx != NULL) 1266 *nindx = indx; 1267 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1268 ("%s found DYING node %p", __func__, oid)); 1269 return (0); 1270 } else { 1271 return (ENOTDIR); 1272 } 1273 } 1274 return (ENOENT); 1275 } 1276 1277 /* 1278 * Traverse our tree, and find the right node, execute whatever it points 1279 * to, and return the resulting error code. 1280 */ 1281 static int 1282 sysctl_root(SYSCTL_HANDLER_ARGS) 1283 { 1284 struct thread *td = req->td; 1285 struct proc *p = td ? td->td_proc : NULL; 1286 struct sysctl_oid *oid; 1287 int error, indx; 1288 int lktype; 1289 1290 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req); 1291 if (error) 1292 return (error); 1293 1294 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1295 /* 1296 * You can't call a sysctl when it's a node, but has 1297 * no handler. Inform the user that it's a node. 1298 * The indx may or may not be the same as namelen. 1299 */ 1300 if (oid->oid_handler == NULL) 1301 return (EISDIR); 1302 } 1303 1304 /* If writing isn't allowed */ 1305 if (req->newptr && (!(oid->oid_kind & CTLFLAG_WR) || 1306 ((oid->oid_kind & CTLFLAG_SECURE) && securelevel > 0))) 1307 return (EPERM); 1308 1309 /* Most likely only root can write */ 1310 if (!(oid->oid_kind & CTLFLAG_ANYBODY) && req->newptr && p && 1311 (error = priv_check_cred(td->td_ucred, 1312 (oid->oid_kind & CTLFLAG_PRISON) ? PRIV_SYSCTL_WRITEJAIL : 1313 PRIV_SYSCTL_WRITE, 0))) 1314 return (error); 1315 1316 if (oid->oid_handler == NULL) 1317 return EINVAL; 1318 1319 /* 1320 * Default oid locking is exclusive when modifying (newptr), 1321 * shared otherwise, unless overridden with a control flag. 1322 */ 1323 if ((oid->oid_kind & CTLFLAG_NOLOCK) == 0) { 1324 lktype = (req->newptr != NULL) ? LK_EXCLUSIVE : LK_SHARED; 1325 if (oid->oid_kind & CTLFLAG_SHLOCK) 1326 lktype = LK_SHARED; 1327 if (oid->oid_kind & CTLFLAG_EXLOCK) 1328 lktype = LK_EXCLUSIVE; 1329 #if 1 1330 lockmgr(&oid->oid_lock, lktype); 1331 #else 1332 /* DEBUGGING */ 1333 if (lockmgr(&oid->oid_lock, lktype | LK_SLEEPFAIL)) { 1334 kprintf("%s\n", oid->oid_name); 1335 lockmgr(&oid->oid_lock, lktype); 1336 } 1337 #endif 1338 } 1339 1340 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) 1341 error = oid->oid_handler(oid, (int *)arg1 + indx, arg2 - indx, 1342 req); 1343 else 1344 error = oid->oid_handler(oid, oid->oid_arg1, oid->oid_arg2, 1345 req); 1346 1347 if ((oid->oid_kind & CTLFLAG_NOLOCK) == 0) 1348 lockmgr(&oid->oid_lock, LK_RELEASE); 1349 return (error); 1350 } 1351 1352 int 1353 sys___sysctl(struct sysctl_args *uap) 1354 { 1355 int error, i, name[CTL_MAXNAME]; 1356 size_t j; 1357 1358 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2) 1359 return (EINVAL); 1360 1361 error = copyin(uap->name, &name, uap->namelen * sizeof(int)); 1362 if (error) 1363 return (error); 1364 1365 error = userland_sysctl(name, uap->namelen, 1366 uap->old, uap->oldlenp, 0, 1367 uap->new, uap->newlen, &j); 1368 if (error && error != ENOMEM) 1369 return (error); 1370 if (uap->oldlenp) { 1371 i = copyout(&j, uap->oldlenp, sizeof(j)); 1372 if (i) 1373 return (i); 1374 } 1375 return (error); 1376 } 1377 1378 /* 1379 * This is used from various compatibility syscalls too. That's why name 1380 * must be in kernel space. 1381 */ 1382 int 1383 userland_sysctl(int *name, u_int namelen, 1384 void *old, size_t *oldlenp, int inkernel, 1385 void *new, size_t newlen, size_t *retval) 1386 { 1387 int error = 0; 1388 struct sysctl_req req; 1389 1390 bzero(&req, sizeof req); 1391 1392 req.td = curthread; 1393 req.flags = 0; 1394 1395 if (oldlenp) { 1396 if (inkernel) { 1397 req.oldlen = *oldlenp; 1398 } else { 1399 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp)); 1400 if (error) 1401 return (error); 1402 } 1403 } 1404 req.validlen = req.oldlen; 1405 1406 /* 1407 * NOTE: User supplied buffers are not guaranteed to be good, 1408 * the sysctl copyins and copyouts can fail. 1409 */ 1410 if (old) 1411 req.oldptr= old; 1412 1413 if (new != NULL) { 1414 req.newlen = newlen; 1415 req.newptr = new; 1416 } 1417 1418 req.oldfunc = sysctl_old_user; 1419 req.newfunc = sysctl_new_user; 1420 #if 0 1421 req.lock = REQ_UNWIRED; 1422 #endif 1423 1424 #ifdef KTRACE 1425 if (KTRPOINT(curthread, KTR_SYSCTL)) 1426 ktrsysctl(name, namelen); 1427 #endif 1428 1429 for (;;) { 1430 req.oldidx = 0; 1431 req.newidx = 0; 1432 SYSCTL_SLOCK(); 1433 error = sysctl_root(0, name, namelen, &req); 1434 SYSCTL_SUNLOCK(); 1435 if (error != EAGAIN) 1436 break; 1437 lwkt_yield(); 1438 } 1439 1440 #if 0 1441 if (req.lock == REQ_WIRED && req.validlen > 0) 1442 vsunlock(req.oldptr, req.validlen); 1443 #endif 1444 if (error && error != ENOMEM) 1445 return (error); 1446 1447 if (retval) { 1448 if (req.oldptr && req.oldidx > req.validlen) 1449 *retval = req.validlen; 1450 else 1451 *retval = req.oldidx; 1452 } 1453 return (error); 1454 } 1455 1456 int 1457 sysctl_int_range(SYSCTL_HANDLER_ARGS, int low, int high) 1458 { 1459 int error, value; 1460 1461 value = *(int *)arg1; 1462 error = sysctl_handle_int(oidp, &value, 0, req); 1463 if (error || !req->newptr) 1464 return (error); 1465 if (value < low || value > high) 1466 return (EINVAL); 1467 *(int *)arg1 = value; 1468 return (0); 1469 } 1470 1471 /* 1472 * Drain into a sysctl struct. The user buffer should be wired if a page 1473 * fault would cause issue. 1474 */ 1475 static int 1476 sbuf_sysctl_drain(void *arg, const char *data, int len) 1477 { 1478 struct sysctl_req *req = arg; 1479 int error; 1480 1481 error = SYSCTL_OUT(req, data, len); 1482 KASSERT(error >= 0, ("Got unexpected negative value %d", error)); 1483 return (error == 0 ? len : -error); 1484 } 1485 1486 struct sbuf * 1487 sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length, 1488 struct sysctl_req *req) 1489 { 1490 1491 s = sbuf_new(s, buf, length, SBUF_FIXEDLEN); 1492 sbuf_set_drain(s, sbuf_sysctl_drain, req); 1493 return (s); 1494 } 1495 1496 /* 1497 * The exclusive sysctl lock only protects its topology, and is 1498 * very expensive, but allows us to use a pcpu shared lock for 1499 * critical path accesses. 1500 */ 1501 void 1502 _sysctl_xlock(void) 1503 { 1504 globaldata_t gd; 1505 int i; 1506 1507 for (i = 0; i < ncpus; ++i) { 1508 gd = globaldata_find(i); 1509 lockmgr(&gd->gd_sysctllock, LK_EXCLUSIVE); 1510 } 1511 } 1512 1513 void 1514 _sysctl_xunlock(void) 1515 { 1516 globaldata_t gd; 1517 int i; 1518 1519 for (i = 0; i < ncpus; ++i) { 1520 gd = globaldata_find(i); 1521 lockmgr(&gd->gd_sysctllock, LK_RELEASE); 1522 } 1523 } 1524