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 #include "opt_sysctl.h" 55 56 static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic"); 57 static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids"); 58 59 /* 60 * The sysctllock protects the MIB tree. It also protects sysctl 61 * contexts used with dynamic sysctls. The sysctl_register_oid() and 62 * sysctl_unregister_oid() routines require the sysctllock to already 63 * be held, so the sysctl_lock() and sysctl_unlock() routines are 64 * provided for the few places in the kernel which need to use that 65 * API rather than using the dynamic API. Use of the dynamic API is 66 * strongly encouraged for most code. 67 */ 68 69 static int sysctl_root(SYSCTL_HANDLER_ARGS); 70 static void sysctl_register_oid_int(struct sysctl_oid *oipd); 71 static void sysctl_unregister_oid_int(struct sysctl_oid *oipd); 72 73 struct sysctl_oid_list sysctl__children; /* root list */ 74 75 static int sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, 76 int recurse); 77 78 static struct sysctl_oid * 79 sysctl_find_oidname(const char *name, struct sysctl_oid_list *list, int lock) 80 { 81 struct sysctl_oid *oidp; 82 83 SLIST_FOREACH(oidp, list, oid_link) { 84 if (strcmp(oidp->oid_name, name) == 0) { 85 break; 86 } 87 } 88 return (oidp); 89 } 90 91 /* 92 * Initialization of the MIB tree. 93 * 94 * Order by number in each list. 95 */ 96 97 void 98 sysctl_register_oid(struct sysctl_oid *oidp) 99 { 100 SYSCTL_XLOCK(); 101 sysctl_register_oid_int(oidp); 102 SYSCTL_XUNLOCK(); 103 } 104 105 static void 106 sysctl_register_oid_int(struct sysctl_oid *oidp) 107 { 108 struct sysctl_oid_list *parent = oidp->oid_parent; 109 struct sysctl_oid *p; 110 struct sysctl_oid *q; 111 112 /* 113 * Finish initialization from sysctl_set or add. 114 */ 115 lockinit(&oidp->oid_lock, "oidlk", 0, LK_CANRECURSE); 116 117 /* 118 * First check if another oid with the same name already 119 * exists in the parent's list. 120 */ 121 p = sysctl_find_oidname(oidp->oid_name, parent, 0); 122 if (p != NULL) { 123 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) 124 p->oid_refcnt++; 125 else 126 kprintf("can't re-use a leaf (%s)!\n", p->oid_name); 127 return; 128 } 129 130 /* 131 * If this oid has a number OID_AUTO, give it a number which 132 * is greater than any current oid. Make sure it is at least 133 * 256 to leave space for pre-assigned oid numbers. 134 */ 135 if (oidp->oid_number == OID_AUTO) { 136 int newoid = 0x100; /* minimum AUTO oid */ 137 138 /* 139 * Adjust based on highest oid in parent list 140 */ 141 SLIST_FOREACH(p, parent, oid_link) { 142 if (newoid <= p->oid_number) 143 newoid = p->oid_number + 1; 144 } 145 oidp->oid_number = newoid; 146 } 147 148 /* 149 * Insert the oid into the parent's list in order. 150 */ 151 q = NULL; 152 SLIST_FOREACH(p, parent, oid_link) { 153 if (oidp->oid_number < p->oid_number) 154 break; 155 q = p; 156 } 157 if (q) 158 SLIST_INSERT_AFTER(q, oidp, oid_link); 159 else 160 SLIST_INSERT_HEAD(parent, oidp, oid_link); 161 } 162 163 void 164 sysctl_unregister_oid(struct sysctl_oid *oidp) 165 { 166 SYSCTL_XLOCK(); 167 sysctl_unregister_oid_int(oidp); 168 SYSCTL_XUNLOCK(); 169 } 170 171 static void 172 sysctl_unregister_oid_int(struct sysctl_oid *oidp) 173 { 174 struct sysctl_oid *p; 175 176 if (oidp->oid_number == OID_AUTO) 177 panic("Trying to unregister OID_AUTO entry: %p", oidp); 178 179 SLIST_FOREACH(p, oidp->oid_parent, oid_link) { 180 if (p != oidp) 181 continue; 182 SLIST_REMOVE(oidp->oid_parent, oidp, sysctl_oid, oid_link); 183 return; 184 } 185 186 /* 187 * This can happen when a module fails to register and is 188 * being unloaded afterwards. It should not be a panic() 189 * for normal use. 190 */ 191 kprintf("%s: failed to unregister sysctl\n", __func__); 192 } 193 194 /* Initialize a new context to keep track of dynamically added sysctls. */ 195 int 196 sysctl_ctx_init(struct sysctl_ctx_list *c) 197 { 198 if (c == NULL) 199 return(EINVAL); 200 TAILQ_INIT(c); 201 return(0); 202 } 203 204 /* Free the context, and destroy all dynamic oids registered in this context */ 205 int 206 sysctl_ctx_free(struct sysctl_ctx_list *clist) 207 { 208 struct sysctl_ctx_entry *e, *e1; 209 int error; 210 211 error = 0; 212 /* 213 * First perform a "dry run" to check if it's ok to remove oids. 214 * XXX FIXME 215 * XXX This algorithm is a hack. But I don't know any 216 * XXX better solution for now... 217 */ 218 SYSCTL_XLOCK(); 219 TAILQ_FOREACH(e, clist, link) { 220 error = sysctl_remove_oid_locked(e->entry, 0, 0); 221 if (error) 222 break; 223 } 224 /* 225 * Restore deregistered entries, either from the end, 226 * or from the place where error occured. 227 * e contains the entry that was not unregistered 228 */ 229 if (error) 230 e1 = TAILQ_PREV(e, sysctl_ctx_list, link); 231 else 232 e1 = TAILQ_LAST(clist, sysctl_ctx_list); 233 while (e1 != NULL) { 234 sysctl_register_oid(e1->entry); 235 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link); 236 } 237 if (error) { 238 SYSCTL_XUNLOCK(); 239 return(EBUSY); 240 } 241 /* Now really delete the entries */ 242 e = TAILQ_FIRST(clist); 243 while (e != NULL) { 244 e1 = TAILQ_NEXT(e, link); 245 error = sysctl_remove_oid_locked(e->entry, 1, 0); 246 if (error) 247 panic("sysctl_remove_oid: corrupt tree, entry: %s", 248 e->entry->oid_name); 249 kfree(e, M_SYSCTLOID); 250 e = e1; 251 } 252 SYSCTL_XUNLOCK(); 253 return (error); 254 } 255 256 /* Add an entry to the context */ 257 struct sysctl_ctx_entry * 258 sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 259 { 260 struct sysctl_ctx_entry *e; 261 262 SYSCTL_ASSERT_LOCKED(); 263 if (clist == NULL || oidp == NULL) 264 return(NULL); 265 e = kmalloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK); 266 e->entry = oidp; 267 TAILQ_INSERT_HEAD(clist, e, link); 268 return (e); 269 } 270 271 /* Find an entry in the context */ 272 struct sysctl_ctx_entry * 273 sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 274 { 275 struct sysctl_ctx_entry *e; 276 277 SYSCTL_ASSERT_LOCKED(); 278 if (clist == NULL || oidp == NULL) 279 return(NULL); 280 TAILQ_FOREACH(e, clist, link) { 281 if(e->entry == oidp) 282 return(e); 283 } 284 return (e); 285 } 286 287 /* 288 * Delete an entry from the context. 289 * NOTE: this function doesn't free oidp! You have to remove it 290 * with sysctl_remove_oid(). 291 */ 292 int 293 sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 294 { 295 struct sysctl_ctx_entry *e; 296 297 if (clist == NULL || oidp == NULL) 298 return (EINVAL); 299 SYSCTL_XLOCK(); 300 e = sysctl_ctx_entry_find(clist, oidp); 301 if (e != NULL) { 302 TAILQ_REMOVE(clist, e, link); 303 SYSCTL_XUNLOCK(); 304 kfree(e, M_SYSCTLOID); 305 return (0); 306 } else { 307 SYSCTL_XUNLOCK(); 308 return (ENOENT); 309 } 310 } 311 312 /* 313 * Remove dynamically created sysctl trees. 314 * oidp - top of the tree to be removed 315 * del - if 0 - just deregister, otherwise free up entries as well 316 * recurse - if != 0 traverse the subtree to be deleted 317 */ 318 int 319 sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse) 320 { 321 int error; 322 323 SYSCTL_XLOCK(); 324 error = sysctl_remove_oid_locked(oidp, del, recurse); 325 SYSCTL_XUNLOCK(); 326 return (error); 327 } 328 329 static int 330 sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse) 331 { 332 struct sysctl_oid *p, *tmp; 333 int error; 334 335 SYSCTL_ASSERT_LOCKED(); 336 if (oidp == NULL) 337 return(EINVAL); 338 if ((oidp->oid_kind & CTLFLAG_DYN) == 0) { 339 kprintf("can't remove non-dynamic nodes!\n"); 340 return (EINVAL); 341 } 342 /* 343 * WARNING: normal method to do this should be through 344 * sysctl_ctx_free(). Use recursing as the last resort 345 * method to purge your sysctl tree of leftovers... 346 * However, if some other code still references these nodes, 347 * it will panic. 348 */ 349 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 350 if (oidp->oid_refcnt == 1) { 351 SLIST_FOREACH_MUTABLE(p, 352 SYSCTL_CHILDREN(oidp), oid_link, tmp) { 353 if (!recurse) { 354 kprintf("Warning: failed attempt to " 355 "remove oid %s with child %s\n", 356 oidp->oid_name, p->oid_name); 357 return (ENOTEMPTY); 358 } 359 error = sysctl_remove_oid_locked(p, del, 360 recurse); 361 if (error) 362 return (error); 363 } 364 if (del) 365 kfree(SYSCTL_CHILDREN(oidp), M_SYSCTLOID); 366 } 367 } 368 if (oidp->oid_refcnt > 1 ) { 369 oidp->oid_refcnt--; 370 } else { 371 if (oidp->oid_refcnt == 0) { 372 kprintf("Warning: bad oid_refcnt=%u (%s)!\n", 373 oidp->oid_refcnt, oidp->oid_name); 374 return (EINVAL); 375 } 376 sysctl_unregister_oid(oidp); 377 if (del) { 378 /* 379 * Wait for all threads running the handler to drain. 380 * This preserves the previous behavior when the 381 * sysctl lock was held across a handler invocation, 382 * and is necessary for module unload correctness. 383 */ 384 while (oidp->oid_running > 0) { 385 oidp->oid_kind |= CTLFLAG_DYING; 386 tsleep_interlock(&oidp->oid_running, 0); 387 SYSCTL_XUNLOCK(); 388 tsleep(&oidp->oid_running, PINTERLOCKED, 389 "oidrm", 0); 390 SYSCTL_XLOCK(); 391 } 392 if (oidp->oid_descr) 393 kfree(__DECONST(char *, oidp->oid_descr), 394 M_SYSCTLOID); 395 kfree(__DECONST(char *, oidp->oid_name), M_SYSCTLOID); 396 lockuninit(&oidp->oid_lock); 397 kfree(oidp, M_SYSCTLOID); 398 } 399 } 400 return (0); 401 } 402 403 int 404 sysctl_remove_name(struct sysctl_oid *parent, const char *name, 405 int del, int recurse) 406 { 407 struct sysctl_oid *p, *tmp; 408 int error; 409 410 error = ENOENT; 411 SYSCTL_XLOCK(); 412 SLIST_FOREACH_MUTABLE(p, SYSCTL_CHILDREN(parent), oid_link, tmp) { 413 if (strcmp(p->oid_name, name) == 0) { 414 error = sysctl_remove_oid_locked(p, del, recurse); 415 break; 416 } 417 } 418 SYSCTL_XUNLOCK(); 419 420 return (error); 421 } 422 423 /* 424 * Create new sysctls at run time. 425 * clist may point to a valid context initialized with sysctl_ctx_init(). 426 */ 427 struct sysctl_oid * 428 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent, 429 int number, const char *name, int kind, void *arg1, int arg2, 430 int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr) 431 { 432 struct sysctl_oid *oidp; 433 ssize_t len; 434 char *newname; 435 436 /* You have to hook up somewhere.. */ 437 if (parent == NULL) 438 return(NULL); 439 SYSCTL_XLOCK(); 440 /* Check if the node already exists, otherwise create it */ 441 oidp = sysctl_find_oidname(name, parent, 0); 442 if (oidp != NULL) { 443 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 444 oidp->oid_refcnt++; 445 /* Update the context */ 446 if (clist != NULL) 447 sysctl_ctx_entry_add(clist, oidp); 448 SYSCTL_XUNLOCK(); 449 return (oidp); 450 } else { 451 kprintf("can't re-use a leaf (%s)!\n", name); 452 SYSCTL_XUNLOCK(); 453 return (NULL); 454 } 455 } 456 oidp = kmalloc(sizeof(struct sysctl_oid), M_SYSCTLOID, 457 M_WAITOK | M_ZERO); 458 oidp->oid_parent = parent; 459 SLIST_NEXT(oidp, oid_link) = NULL; 460 oidp->oid_number = number; 461 oidp->oid_refcnt = 1; 462 len = strlen(name); 463 newname = kmalloc(len + 1, M_SYSCTLOID, M_WAITOK); 464 bcopy(name, newname, len + 1); 465 newname[len] = '\0'; 466 oidp->oid_name = newname; 467 oidp->oid_handler = handler; 468 oidp->oid_kind = CTLFLAG_DYN | kind; 469 if ((kind & CTLTYPE) == CTLTYPE_NODE) { 470 struct sysctl_oid_list *children; 471 472 /* Allocate space for children */ 473 children = kmalloc(sizeof(*children), M_SYSCTLOID, M_WAITOK); 474 SYSCTL_SET_CHILDREN(oidp, children); 475 SLIST_INIT(children); 476 } else { 477 oidp->oid_arg1 = arg1; 478 oidp->oid_arg2 = arg2; 479 } 480 oidp->oid_fmt = fmt; 481 if (descr) { 482 int len = strlen(descr) + 1; 483 oidp->oid_descr = kmalloc(len, M_SYSCTLOID, M_WAITOK); 484 strcpy((char *)(uintptr_t)(const void *)oidp->oid_descr, descr); 485 }; 486 /* Update the context, if used */ 487 if (clist != NULL) 488 sysctl_ctx_entry_add(clist, oidp); 489 /* Register this oid */ 490 sysctl_register_oid_int(oidp); 491 SYSCTL_XUNLOCK(); 492 return (oidp); 493 } 494 495 /* 496 * Rename an existing oid. 497 */ 498 void 499 sysctl_rename_oid(struct sysctl_oid *oidp, const char *name) 500 { 501 char *newname; 502 char *oldname; 503 504 newname = kstrdup(name, M_SYSCTLOID); 505 SYSCTL_XLOCK(); 506 oldname = __DECONST(char *, oidp->oid_name); 507 oidp->oid_name = newname; 508 SYSCTL_XUNLOCK(); 509 kfree(oldname, M_SYSCTLOID); 510 } 511 512 /* 513 * Register the kernel's oids on startup. 514 */ 515 SET_DECLARE(sysctl_set, struct sysctl_oid); 516 517 static void 518 sysctl_register_all(void *arg) 519 { 520 struct sysctl_oid **oidp; 521 522 SYSCTL_XLOCK(); 523 SET_FOREACH(oidp, sysctl_set) 524 sysctl_register_oid(*oidp); 525 SYSCTL_XUNLOCK(); 526 } 527 SYSINIT(sysctl, SI_BOOT1_POST, SI_ORDER_ANY, sysctl_register_all, 0); 528 529 #ifdef SYSCTL_DEBUG 530 /* 531 * "Staff-functions" 532 * 533 * These functions implement a presently undocumented interface 534 * used by the sysctl program to walk the tree, and get the type 535 * so it can print the value. 536 * This interface is under work and consideration, and should probably 537 * be killed with a big axe by the first person who can find the time. 538 * (be aware though, that the proper interface isn't as obvious as it 539 * may seem, there are various conflicting requirements. 540 * 541 * {CTL_SYSCTL, CTL_SYSCTL_DEBUG} kprintf the entire MIB-tree. 542 * {CTL_SYSCTL, CTL_SYSCTL_NAME, ...} return the name of the "..." 543 * OID. 544 * {CTL_SYSCTL, CTL_SYSCTL_NEXT, ...} return the next OID. 545 * {CTL_SYSCTL, CTL_SYSCTL_NAME2OID} return the OID of the name in 546 * "new" 547 * {CTL_SYSCTL, CTL_SYSCTL_OIDFMT, ...} return the kind & format info 548 * for the "..." OID. 549 * {CTL_SYSCTL, CTL_SYSCTL_OIDDESCR, ...} return the description of the 550 * "..." OID. 551 */ 552 553 static void 554 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i) 555 { 556 int k; 557 struct sysctl_oid *oidp; 558 559 SLIST_FOREACH(oidp, l, oid_link) { 560 561 for (k=0; k<i; k++) 562 kprintf(" "); 563 564 kprintf("%d %s ", oidp->oid_number, oidp->oid_name); 565 566 kprintf("%c%c", 567 oidp->oid_kind & CTLFLAG_RD ? 'R':' ', 568 oidp->oid_kind & CTLFLAG_WR ? 'W':' '); 569 570 if (oidp->oid_handler) 571 kprintf(" *Handler"); 572 573 switch (oidp->oid_kind & CTLTYPE) { 574 case CTLTYPE_NODE: 575 kprintf(" Node\n"); 576 if (!oidp->oid_handler) { 577 sysctl_sysctl_debug_dump_node( 578 oidp->oid_arg1, i+2); 579 } 580 break; 581 case CTLTYPE_INT: kprintf(" Int\n"); break; 582 case CTLTYPE_UINT: kprintf(" u_int\n"); break; 583 case CTLTYPE_LONG: kprintf(" Long\n"); break; 584 case CTLTYPE_ULONG: kprintf(" u_long\n"); break; 585 case CTLTYPE_STRING: kprintf(" String\n"); break; 586 case CTLTYPE_S8: kprintf(" int8_t\n"); break; 587 case CTLTYPE_S16: kprintf(" int16_t\n"); break; 588 case CTLTYPE_S32: kprintf(" int32_t\n"); break; 589 case CTLTYPE_S64: kprintf(" int64_t\n"); break; 590 case CTLTYPE_U8: kprintf(" uint8_t\n"); break; 591 case CTLTYPE_U16: kprintf(" uint16_t\n"); break; 592 case CTLTYPE_U32: kprintf(" uint32_t\n"); break; 593 case CTLTYPE_U64: kprintf(" uint64_t\n"); break; 594 case CTLTYPE_OPAQUE: kprintf(" Opaque/struct\n"); break; 595 default: kprintf("\n"); 596 } 597 598 } 599 } 600 601 static int 602 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS) 603 { 604 int error; 605 606 error = priv_check(req->td, PRIV_SYSCTL_DEBUG); 607 if (error) 608 return (error); 609 sysctl_sysctl_debug_dump_node(&sysctl__children, 0); 610 611 return (ENOENT); 612 } 613 614 SYSCTL_PROC(_sysctl, CTL_SYSCTL_DEBUG, debug, CTLTYPE_STRING | CTLFLAG_RD, 615 0, 0, sysctl_sysctl_debug, "-", ""); 616 #endif /* SYSCTL_DEBUG */ 617 618 static int 619 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS) 620 { 621 int *name = (int *) arg1; 622 u_int namelen = arg2; 623 int error = 0; 624 struct sysctl_oid *oid; 625 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2; 626 char buf[10]; 627 628 while (namelen) { 629 if (!lsp) { 630 ksnprintf(buf, sizeof(buf), "%d", *name); 631 if (req->oldidx) 632 error = SYSCTL_OUT(req, ".", 1); 633 if (!error) 634 error = SYSCTL_OUT(req, buf, strlen(buf)); 635 if (error) 636 goto out; 637 namelen--; 638 name++; 639 continue; 640 } 641 lsp2 = NULL; 642 SLIST_FOREACH(oid, lsp, oid_link) { 643 if (oid->oid_number != *name) 644 continue; 645 646 if (req->oldidx) 647 error = SYSCTL_OUT(req, ".", 1); 648 if (!error) 649 error = SYSCTL_OUT(req, oid->oid_name, 650 strlen(oid->oid_name)); 651 if (error) 652 goto out; 653 654 namelen--; 655 name++; 656 657 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) 658 break; 659 660 if (oid->oid_handler) 661 break; 662 663 lsp2 = SYSCTL_CHILDREN(oid); 664 break; 665 } 666 lsp = lsp2; 667 } 668 error = SYSCTL_OUT(req, "", 1); 669 out: 670 return (error); 671 } 672 673 SYSCTL_NODE(_sysctl, CTL_SYSCTL_NAME, name, CTLFLAG_RD | CTLFLAG_NOLOCK, 674 sysctl_sysctl_name, ""); 675 676 static int 677 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 678 int *next, int *len, int level, struct sysctl_oid **oidpp) 679 { 680 struct sysctl_oid *oidp; 681 682 *len = level; 683 SLIST_FOREACH(oidp, lsp, oid_link) { 684 *next = oidp->oid_number; 685 *oidpp = oidp; 686 687 if (oidp->oid_kind & CTLFLAG_SKIP) 688 continue; 689 690 if (!namelen) { 691 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 692 return (0); 693 if (oidp->oid_handler) 694 /* We really should call the handler here...*/ 695 return (0); 696 lsp = SYSCTL_CHILDREN(oidp); 697 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, 698 len, level+1, oidpp)) 699 return (0); 700 goto emptynode; 701 } 702 703 if (oidp->oid_number < *name) 704 continue; 705 706 if (oidp->oid_number > *name) { 707 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 708 return (0); 709 if (oidp->oid_handler) 710 return (0); 711 lsp = SYSCTL_CHILDREN(oidp); 712 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, 713 next+1, len, level+1, oidpp)) 714 return (0); 715 goto next; 716 } 717 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 718 continue; 719 720 if (oidp->oid_handler) 721 continue; 722 723 lsp = SYSCTL_CHILDREN(oidp); 724 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, 725 len, level+1, oidpp)) 726 return (0); 727 next: 728 namelen = 1; 729 emptynode: 730 *len = level; 731 } 732 return (1); 733 } 734 735 static int 736 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS) 737 { 738 int *name = (int *) arg1; 739 u_int namelen = arg2; 740 int i, j, error; 741 struct sysctl_oid *oid; 742 struct sysctl_oid_list *lsp = &sysctl__children; 743 int newoid[CTL_MAXNAME]; 744 745 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid); 746 if (i) 747 return ENOENT; 748 error = SYSCTL_OUT(req, newoid, j * sizeof (int)); 749 750 return (error); 751 } 752 753 SYSCTL_NODE(_sysctl, CTL_SYSCTL_NEXT, next, CTLFLAG_RD | CTLFLAG_NOLOCK, 754 sysctl_sysctl_next, ""); 755 756 static int 757 name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp) 758 { 759 struct sysctl_oid *oidp; 760 struct sysctl_oid_list *lsp = &sysctl__children; 761 char *p; 762 763 SYSCTL_ASSERT_LOCKED(); 764 765 for (*len = 0; *len < CTL_MAXNAME;) { 766 p = strsep(&name, "."); 767 768 oidp = SLIST_FIRST(lsp); 769 for (;; oidp = SLIST_NEXT(oidp, oid_link)) { 770 if (oidp == NULL) 771 return (ENOENT); 772 if (strcmp(p, oidp->oid_name) == 0) 773 break; 774 } 775 *oid++ = oidp->oid_number; 776 (*len)++; 777 778 if (name == NULL || *name == '\0') { 779 if (oidpp) 780 *oidpp = oidp; 781 return (0); 782 } 783 784 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 785 break; 786 787 if (oidp->oid_handler) 788 break; 789 790 lsp = SYSCTL_CHILDREN(oidp); 791 } 792 return (ENOENT); 793 } 794 795 static int 796 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS) 797 { 798 char *p; 799 int error, oid[CTL_MAXNAME], len; 800 struct sysctl_oid *op = NULL; 801 802 if (!req->newlen) 803 return ENOENT; 804 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */ 805 return (ENAMETOOLONG); 806 807 p = kmalloc(req->newlen+1, M_SYSCTL, M_WAITOK); 808 809 error = SYSCTL_IN(req, p, req->newlen); 810 if (error) { 811 kfree(p, M_SYSCTL); 812 return (error); 813 } 814 815 p [req->newlen] = '\0'; 816 817 error = name2oid(p, oid, &len, &op); 818 819 kfree(p, M_SYSCTL); 820 821 if (error) 822 return (error); 823 824 error = SYSCTL_OUT(req, oid, len * sizeof *oid); 825 return (error); 826 } 827 828 SYSCTL_PROC(_sysctl, CTL_SYSCTL_NAME2OID, name2oid, 829 CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_NOLOCK, 830 0, 0, sysctl_sysctl_name2oid, "I", ""); 831 832 static int 833 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) 834 { 835 struct sysctl_oid *oid; 836 int error; 837 838 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 839 if (error) 840 return (error); 841 842 if (!oid->oid_fmt) 843 return (ENOENT); 844 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind)); 845 if (error) 846 return (error); 847 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1); 848 return (error); 849 } 850 851 852 SYSCTL_NODE(_sysctl, CTL_SYSCTL_OIDFMT, oidfmt, CTLFLAG_RD | CTLFLAG_NOLOCK, 853 sysctl_sysctl_oidfmt, ""); 854 855 static int 856 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) 857 { 858 struct sysctl_oid *oid; 859 int error; 860 861 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 862 if (error) 863 return (error); 864 865 if (!oid->oid_descr) 866 return (ENOENT); 867 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1); 868 return (error); 869 } 870 871 SYSCTL_NODE(_sysctl, CTL_SYSCTL_OIDDESCR, oiddescr, 872 CTLFLAG_RD | CTLFLAG_NOLOCK, 873 sysctl_sysctl_oiddescr, ""); 874 875 /* 876 * Default "handler" functions. 877 */ 878 879 /* 880 * Handle an 8-bit number, signed or unsigned. arg1 points to it. 881 */ 882 883 int 884 sysctl_handle_8(SYSCTL_HANDLER_ARGS) 885 { 886 int error = 0; 887 888 if (!arg1) 889 return (EINVAL); 890 error = SYSCTL_OUT(req, arg1, sizeof(int8_t)); 891 892 if (error || !req->newptr) 893 return (error); 894 895 error = SYSCTL_IN(req, arg1, sizeof(int8_t)); 896 return (error); 897 } 898 899 /* 900 * Handle a 16-bit number, signed or unsigned. arg1 points to it. 901 */ 902 903 int 904 sysctl_handle_16(SYSCTL_HANDLER_ARGS) 905 { 906 int error = 0; 907 908 if (!arg1) 909 return (EINVAL); 910 error = SYSCTL_OUT(req, arg1, sizeof(int16_t)); 911 912 if (error || !req->newptr) 913 return (error); 914 915 error = SYSCTL_IN(req, arg1, sizeof(int16_t)); 916 return (error); 917 } 918 919 /* 920 * Handle a 32-bit number, signed or unsigned. arg1 points to it. 921 */ 922 923 int 924 sysctl_handle_32(SYSCTL_HANDLER_ARGS) 925 { 926 int error = 0; 927 928 if (!arg1) 929 return (EINVAL); 930 error = SYSCTL_OUT(req, arg1, sizeof(int32_t)); 931 932 if (error || !req->newptr) 933 return (error); 934 935 error = SYSCTL_IN(req, arg1, sizeof(int32_t)); 936 return (error); 937 } 938 939 /* 940 * Handle a 64-bit number, signed or unsigned. arg1 points to it. 941 */ 942 943 int 944 sysctl_handle_64(SYSCTL_HANDLER_ARGS) 945 { 946 int error = 0; 947 948 if (!arg1) 949 return (EINVAL); 950 error = SYSCTL_OUT(req, arg1, sizeof(int64_t)); 951 952 if (error || !req->newptr) 953 return (error); 954 955 error = SYSCTL_IN(req, arg1, sizeof(int64_t)); 956 return (error); 957 } 958 959 /* 960 * Handle an int, signed or unsigned. 961 * Two cases: 962 * a variable: point arg1 at it. 963 * a constant: pass it in arg2. 964 */ 965 966 int 967 sysctl_handle_int(SYSCTL_HANDLER_ARGS) 968 { 969 int error = 0; 970 971 if (arg1) 972 error = SYSCTL_OUT(req, arg1, sizeof(int)); 973 else 974 error = SYSCTL_OUT(req, &arg2, sizeof(int)); 975 976 if (error || !req->newptr) 977 return (error); 978 979 if (!arg1) 980 error = EPERM; 981 else 982 error = SYSCTL_IN(req, arg1, sizeof(int)); 983 return (error); 984 } 985 986 /* 987 * Handle a long, signed or unsigned. arg1 points to it. 988 */ 989 990 int 991 sysctl_handle_long(SYSCTL_HANDLER_ARGS) 992 { 993 int error = 0; 994 995 if (!arg1) 996 return (EINVAL); 997 if (req->oldlen == sizeof(int) && 998 *(long *)arg1 >= INT_MIN && 999 *(long *)arg1 <= INT_MAX) { 1000 /* 1001 * Backwards compatibility for read-only fields promoted 1002 * from int to long. Allow userland to request the field 1003 * as an integer if the value is in-range. 1004 */ 1005 int val = (int)*(long *)arg1; 1006 error = SYSCTL_OUT(req, &val, sizeof(int)); 1007 } else { 1008 /* 1009 * Normal operation fo a long 1010 */ 1011 error = SYSCTL_OUT(req, arg1, sizeof(long)); 1012 } 1013 1014 if (error || !req->newptr) 1015 return (error); 1016 1017 error = SYSCTL_IN(req, arg1, sizeof(long)); 1018 1019 return (error); 1020 } 1021 1022 /* 1023 * Handle a quad, signed or unsigned. arg1 points to it. 1024 */ 1025 1026 int 1027 sysctl_handle_quad(SYSCTL_HANDLER_ARGS) 1028 { 1029 int error = 0; 1030 1031 if (!arg1) 1032 return (EINVAL); 1033 error = SYSCTL_OUT(req, arg1, sizeof(quad_t)); 1034 1035 if (error || !req->newptr) 1036 return (error); 1037 1038 error = SYSCTL_IN(req, arg1, sizeof(quad_t)); 1039 return (error); 1040 } 1041 1042 /* 1043 * Handle our generic '\0' terminated 'C' string. 1044 * Two cases: 1045 * a variable string: point arg1 at it, arg2 is max length. 1046 * a constant string: point arg1 at it, arg2 is zero. 1047 */ 1048 1049 int 1050 sysctl_handle_string(SYSCTL_HANDLER_ARGS) 1051 { 1052 int error=0; 1053 1054 error = SYSCTL_OUT(req, arg1, strlen((char *)arg1)+1); 1055 1056 if (error || !req->newptr) 1057 return (error); 1058 1059 if ((req->newlen - req->newidx) >= arg2) { 1060 error = EINVAL; 1061 } else { 1062 arg2 = (req->newlen - req->newidx); 1063 error = SYSCTL_IN(req, arg1, arg2); 1064 ((char *)arg1)[arg2] = '\0'; 1065 } 1066 1067 return (error); 1068 } 1069 1070 /* 1071 * Handle any kind of opaque data. 1072 * arg1 points to it, arg2 is the size. 1073 */ 1074 1075 int 1076 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS) 1077 { 1078 int error; 1079 1080 error = SYSCTL_OUT(req, arg1, arg2); 1081 1082 if (error || !req->newptr) 1083 return (error); 1084 1085 error = SYSCTL_IN(req, arg1, arg2); 1086 1087 return (error); 1088 } 1089 1090 /* 1091 * Transfer functions to/from kernel space. 1092 * XXX: rather untested at this point 1093 */ 1094 static int 1095 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l) 1096 { 1097 size_t i = 0; 1098 1099 if (req->oldptr) { 1100 i = l; 1101 if (i > req->oldlen - req->oldidx) 1102 i = req->oldlen - req->oldidx; 1103 if (i > 0) 1104 bcopy(p, (char *)req->oldptr + req->oldidx, i); 1105 } 1106 req->oldidx += l; 1107 if (req->oldptr && i != l) 1108 return (ENOMEM); 1109 return (0); 1110 } 1111 1112 static int 1113 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l) 1114 { 1115 1116 if (!req->newptr) 1117 return 0; 1118 if (req->newlen - req->newidx < l) 1119 return (EINVAL); 1120 bcopy((char *)req->newptr + req->newidx, p, l); 1121 req->newidx += l; 1122 return (0); 1123 } 1124 1125 int 1126 kernel_sysctl(int *name, u_int namelen, 1127 void *old, size_t *oldlenp, 1128 void *new, size_t newlen, size_t *retval) 1129 { 1130 int error = 0; 1131 struct sysctl_req req; 1132 1133 bzero(&req, sizeof req); 1134 1135 req.td = curthread; 1136 1137 if (oldlenp) { 1138 req.oldlen = *oldlenp; 1139 } 1140 req.validlen = req.oldlen; 1141 1142 if (old) { 1143 req.oldptr= old; 1144 } 1145 1146 if (new != NULL) { 1147 req.newlen = newlen; 1148 req.newptr = new; 1149 } 1150 1151 req.oldfunc = sysctl_old_kernel; 1152 req.newfunc = sysctl_new_kernel; 1153 #if 0 1154 req.lock = REQ_UNWIRED; 1155 #endif 1156 1157 SYSCTL_SLOCK(); 1158 error = sysctl_root(0, name, namelen, &req); 1159 SYSCTL_SUNLOCK(); 1160 1161 #if 0 1162 if (req.lock == REQ_WIRED && req.validlen > 0) 1163 vsunlock(req.oldptr, req.validlen); 1164 #endif 1165 1166 if (error && error != ENOMEM) 1167 return (error); 1168 1169 if (retval) { 1170 if (req.oldptr && req.oldidx > req.validlen) 1171 *retval = req.validlen; 1172 else 1173 *retval = req.oldidx; 1174 } 1175 return (error); 1176 } 1177 1178 int 1179 kernel_sysctlbyname(char *name, 1180 void *old, size_t *oldlenp, 1181 void *new, size_t newlen, size_t *retval) 1182 { 1183 int oid[CTL_MAXNAME]; 1184 size_t oidlen, plen; 1185 int error; 1186 1187 oid[0] = CTL_SYSCTL; 1188 oid[1] = CTL_SYSCTL_NAME2OID; 1189 oidlen = sizeof(oid); 1190 1191 error = kernel_sysctl(oid, 2, oid, &oidlen, name, strlen(name), &plen); 1192 if (error) 1193 return (error); 1194 1195 error = kernel_sysctl(oid, plen / sizeof(int), old, oldlenp, 1196 new, newlen, retval); 1197 return (error); 1198 } 1199 1200 /* 1201 * Transfer function to/from user space. 1202 */ 1203 static int 1204 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l) 1205 { 1206 int error = 0; 1207 size_t i = 0; 1208 1209 #if 0 1210 if (req->lock == 1 && req->oldptr) { 1211 vslock(req->oldptr, req->oldlen); 1212 req->lock = 2; 1213 } 1214 #endif 1215 if (req->oldptr) { 1216 i = l; 1217 if (i > req->oldlen - req->oldidx) 1218 i = req->oldlen - req->oldidx; 1219 if (i > 0) 1220 error = copyout(p, (char *)req->oldptr + req->oldidx, 1221 i); 1222 } 1223 req->oldidx += l; 1224 if (error) 1225 return (error); 1226 if (req->oldptr && i < l) 1227 return (ENOMEM); 1228 return (0); 1229 } 1230 1231 static int 1232 sysctl_new_user(struct sysctl_req *req, void *p, size_t l) 1233 { 1234 int error; 1235 1236 if (!req->newptr) 1237 return 0; 1238 if (req->newlen - req->newidx < l) 1239 return (EINVAL); 1240 error = copyin((char *)req->newptr + req->newidx, p, l); 1241 req->newidx += l; 1242 return (error); 1243 } 1244 1245 int 1246 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid, 1247 int *nindx, struct sysctl_req *req) 1248 { 1249 struct sysctl_oid_list *lsp; 1250 struct sysctl_oid *oid; 1251 int indx; 1252 1253 lsp = &sysctl__children; 1254 indx = 0; 1255 while (indx < CTL_MAXNAME) { 1256 SLIST_FOREACH(oid, lsp, oid_link) { 1257 if (oid->oid_number == name[indx]) 1258 break; 1259 } 1260 if (oid == NULL) 1261 return (ENOENT); 1262 1263 indx++; 1264 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1265 if (oid->oid_handler != NULL || indx == namelen) { 1266 *noid = oid; 1267 if (nindx != NULL) 1268 *nindx = indx; 1269 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1270 ("%s found DYING node %p", __func__, oid)); 1271 return (0); 1272 } 1273 lsp = SYSCTL_CHILDREN(oid); 1274 } else if (indx == namelen) { 1275 *noid = oid; 1276 if (nindx != NULL) 1277 *nindx = indx; 1278 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1279 ("%s found DYING node %p", __func__, oid)); 1280 return (0); 1281 } else { 1282 return (ENOTDIR); 1283 } 1284 } 1285 return (ENOENT); 1286 } 1287 1288 /* 1289 * Traverse our tree, and find the right node, execute whatever it points 1290 * to, and return the resulting error code. 1291 */ 1292 static int 1293 sysctl_root(SYSCTL_HANDLER_ARGS) 1294 { 1295 struct thread *td = req->td; 1296 struct proc *p = td ? td->td_proc : NULL; 1297 struct sysctl_oid *oid; 1298 int error, indx; 1299 int lktype; 1300 1301 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req); 1302 if (error) 1303 return (error); 1304 1305 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1306 /* 1307 * You can't call a sysctl when it's a node, but has 1308 * no handler. Inform the user that it's a node. 1309 * The indx may or may not be the same as namelen. 1310 */ 1311 if (oid->oid_handler == NULL) 1312 return (EISDIR); 1313 } 1314 1315 /* If writing isn't allowed */ 1316 if (req->newptr && (!(oid->oid_kind & CTLFLAG_WR) || 1317 ((oid->oid_kind & CTLFLAG_SECURE) && securelevel > 0))) 1318 return (EPERM); 1319 1320 /* Most likely only root can write */ 1321 if (!(oid->oid_kind & CTLFLAG_ANYBODY) && req->newptr && p && 1322 (error = priv_check_cred(td->td_ucred, 1323 (oid->oid_kind & CTLFLAG_PRISON) ? PRIV_SYSCTL_WRITEJAIL : 1324 PRIV_SYSCTL_WRITE, 0))) 1325 return (error); 1326 1327 if (oid->oid_handler == NULL) 1328 return EINVAL; 1329 1330 /* 1331 * Default oid locking is exclusive when modifying (newptr), 1332 * shared otherwise, unless overridden with a control flag. 1333 */ 1334 if ((oid->oid_kind & CTLFLAG_NOLOCK) == 0) { 1335 lktype = (req->newptr != NULL) ? LK_EXCLUSIVE : LK_SHARED; 1336 if (oid->oid_kind & CTLFLAG_SHLOCK) 1337 lktype = LK_SHARED; 1338 if (oid->oid_kind & CTLFLAG_EXLOCK) 1339 lktype = LK_EXCLUSIVE; 1340 #if 1 1341 lockmgr(&oid->oid_lock, lktype); 1342 #else 1343 /* DEBUGGING */ 1344 if (lockmgr(&oid->oid_lock, lktype | LK_SLEEPFAIL)) { 1345 kprintf("%s\n", oid->oid_name); 1346 lockmgr(&oid->oid_lock, lktype); 1347 } 1348 #endif 1349 } 1350 1351 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) 1352 error = oid->oid_handler(oid, (int *)arg1 + indx, arg2 - indx, 1353 req); 1354 else 1355 error = oid->oid_handler(oid, oid->oid_arg1, oid->oid_arg2, 1356 req); 1357 1358 if ((oid->oid_kind & CTLFLAG_NOLOCK) == 0) 1359 lockmgr(&oid->oid_lock, LK_RELEASE); 1360 return (error); 1361 } 1362 1363 int 1364 sys___sysctl(struct sysctl_args *uap) 1365 { 1366 int error, i, name[CTL_MAXNAME]; 1367 size_t j; 1368 1369 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2) 1370 return (EINVAL); 1371 1372 error = copyin(uap->name, &name, uap->namelen * sizeof(int)); 1373 if (error) 1374 return (error); 1375 1376 error = userland_sysctl(name, uap->namelen, 1377 uap->old, uap->oldlenp, 0, 1378 uap->new, uap->newlen, &j); 1379 if (error && error != ENOMEM) 1380 return (error); 1381 if (uap->oldlenp) { 1382 i = copyout(&j, uap->oldlenp, sizeof(j)); 1383 if (i) 1384 return (i); 1385 } 1386 return (error); 1387 } 1388 1389 /* 1390 * This is used from various compatibility syscalls too. That's why name 1391 * must be in kernel space. 1392 */ 1393 int 1394 userland_sysctl(int *name, u_int namelen, 1395 void *old, size_t *oldlenp, int inkernel, 1396 void *new, size_t newlen, size_t *retval) 1397 { 1398 int error = 0; 1399 struct sysctl_req req; 1400 1401 bzero(&req, sizeof req); 1402 1403 req.td = curthread; 1404 req.flags = 0; 1405 1406 if (oldlenp) { 1407 if (inkernel) { 1408 req.oldlen = *oldlenp; 1409 } else { 1410 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp)); 1411 if (error) 1412 return (error); 1413 } 1414 } 1415 req.validlen = req.oldlen; 1416 1417 /* 1418 * NOTE: User supplied buffers are not guaranteed to be good, 1419 * the sysctl copyins and copyouts can fail. 1420 */ 1421 if (old) 1422 req.oldptr= old; 1423 1424 if (new != NULL) { 1425 req.newlen = newlen; 1426 req.newptr = new; 1427 } 1428 1429 req.oldfunc = sysctl_old_user; 1430 req.newfunc = sysctl_new_user; 1431 #if 0 1432 req.lock = REQ_UNWIRED; 1433 #endif 1434 1435 #ifdef KTRACE 1436 if (KTRPOINT(curthread, KTR_SYSCTL)) 1437 ktrsysctl(name, namelen); 1438 #endif 1439 1440 for (;;) { 1441 req.oldidx = 0; 1442 req.newidx = 0; 1443 SYSCTL_SLOCK(); 1444 error = sysctl_root(0, name, namelen, &req); 1445 SYSCTL_SUNLOCK(); 1446 if (error != EAGAIN) 1447 break; 1448 lwkt_yield(); 1449 } 1450 1451 #if 0 1452 if (req.lock == REQ_WIRED && req.validlen > 0) 1453 vsunlock(req.oldptr, req.validlen); 1454 #endif 1455 if (error && error != ENOMEM) 1456 return (error); 1457 1458 if (retval) { 1459 if (req.oldptr && req.oldidx > req.validlen) 1460 *retval = req.validlen; 1461 else 1462 *retval = req.oldidx; 1463 } 1464 return (error); 1465 } 1466 1467 int 1468 sysctl_int_range(SYSCTL_HANDLER_ARGS, int low, int high) 1469 { 1470 int error, value; 1471 1472 value = *(int *)arg1; 1473 error = sysctl_handle_int(oidp, &value, 0, req); 1474 if (error || !req->newptr) 1475 return (error); 1476 if (value < low || value > high) 1477 return (EINVAL); 1478 *(int *)arg1 = value; 1479 return (0); 1480 } 1481 1482 /* 1483 * Drain into a sysctl struct. The user buffer should be wired if a page 1484 * fault would cause issue. 1485 */ 1486 static int 1487 sbuf_sysctl_drain(void *arg, const char *data, int len) 1488 { 1489 struct sysctl_req *req = arg; 1490 int error; 1491 1492 error = SYSCTL_OUT(req, data, len); 1493 KASSERT(error >= 0, ("Got unexpected negative value %d", error)); 1494 return (error == 0 ? len : -error); 1495 } 1496 1497 struct sbuf * 1498 sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length, 1499 struct sysctl_req *req) 1500 { 1501 1502 s = sbuf_new(s, buf, length, SBUF_FIXEDLEN); 1503 sbuf_set_drain(s, sbuf_sysctl_drain, req); 1504 return (s); 1505 } 1506 1507 /* 1508 * The exclusive sysctl lock only protects its topology, and is 1509 * very expensive, but allows us to use a pcpu shared lock for 1510 * critical path accesses. 1511 */ 1512 void 1513 _sysctl_xlock(void) 1514 { 1515 globaldata_t gd; 1516 int i; 1517 1518 for (i = 0; i < ncpus; ++i) { 1519 gd = globaldata_find(i); 1520 lockmgr(&gd->gd_sysctllock, LK_EXCLUSIVE); 1521 } 1522 } 1523 1524 void 1525 _sysctl_xunlock(void) 1526 { 1527 globaldata_t gd; 1528 int i; 1529 1530 for (i = 0; i < ncpus; ++i) { 1531 gd = globaldata_find(i); 1532 lockmgr(&gd->gd_sysctllock, LK_RELEASE); 1533 } 1534 } 1535