2 * Copyright (c) 1982, 1986, 1989, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
6 * Mike Karels at Berkeley Software Design, Inc.
8 * Quite extensively rewritten by Poul-Henning Kamp of the FreeBSD
9 * project, to make these variables more userfriendly.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
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.
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
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 $
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/kernel.h>
43 #include <sys/sysctl.h>
44 #include <sys/malloc.h>
47 #include <sys/sysproto.h>
51 #include <sys/mplock2.h>
54 #include <vm/vm_extern.h>
56 static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic");
57 static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids");
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.
68 * The sysctlmemlock is used to limit the amount of user memory wired for
69 * sysctl requests. This is implemented by serializing any userland
70 * sysctl requests larger than a single page via an exclusive lock.
72 struct lock sysctllock;
73 static struct lock sysctlmemlock;
75 #define SYSCTL_INIT() lockinit(&sysctllock, \
76 "sysctl lock", 0, LK_CANRECURSE)
77 #define SYSCTL_SLEEP(ch, wmesg, timo) \
78 lksleep(ch, &sysctllock, 0, wmesg, timo)
80 static int sysctl_root(SYSCTL_HANDLER_ARGS);
81 static void sysctl_register_oid_int(struct sysctl_oid *oipd);
82 static void sysctl_unregister_oid_int(struct sysctl_oid *oipd);
84 struct sysctl_oid_list sysctl__children; /* root list */
86 static int sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del,
89 static struct sysctl_oid *
90 sysctl_find_oidname(const char *name, struct sysctl_oid_list *list, int lock)
92 struct sysctl_oid *oidp;
94 SLIST_FOREACH(oidp, list, oid_link) {
95 if (strcmp(oidp->oid_name, name) == 0) {
103 * Initialization of the MIB tree.
105 * Order by number in each list.
109 sysctl_register_oid(struct sysctl_oid *oidp)
112 sysctl_register_oid_int(oidp);
117 sysctl_register_oid_int(struct sysctl_oid *oidp)
119 struct sysctl_oid_list *parent = oidp->oid_parent;
120 struct sysctl_oid *p;
121 struct sysctl_oid *q;
124 * Finish initialization from sysctl_set or add.
126 lockinit(&oidp->oid_lock, "oidlk", 0, LK_CANRECURSE);
129 * First check if another oid with the same name already
130 * exists in the parent's list.
132 p = sysctl_find_oidname(oidp->oid_name, parent, 0);
134 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE)
137 kprintf("can't re-use a leaf (%s)!\n", p->oid_name);
142 * If this oid has a number OID_AUTO, give it a number which
143 * is greater than any current oid. Make sure it is at least
144 * 256 to leave space for pre-assigned oid numbers.
146 if (oidp->oid_number == OID_AUTO) {
147 int newoid = 0x100; /* minimum AUTO oid */
150 * Adjust based on highest oid in parent list
152 SLIST_FOREACH(p, parent, oid_link) {
153 if (newoid <= p->oid_number)
154 newoid = p->oid_number + 1;
156 oidp->oid_number = newoid;
160 * Insert the oid into the parent's list in order.
163 SLIST_FOREACH(p, parent, oid_link) {
164 if (oidp->oid_number < p->oid_number)
169 SLIST_INSERT_AFTER(q, oidp, oid_link);
171 SLIST_INSERT_HEAD(parent, oidp, oid_link);
175 sysctl_unregister_oid(struct sysctl_oid *oidp)
178 sysctl_unregister_oid_int(oidp);
183 sysctl_unregister_oid_int(struct sysctl_oid *oidp)
185 struct sysctl_oid *p;
187 if (oidp->oid_number == OID_AUTO)
188 panic("Trying to unregister OID_AUTO entry: %p", oidp);
190 SLIST_FOREACH(p, oidp->oid_parent, oid_link) {
193 SLIST_REMOVE(oidp->oid_parent, oidp, sysctl_oid, oid_link);
198 * This can happen when a module fails to register and is
199 * being unloaded afterwards. It should not be a panic()
202 kprintf("%s: failed to unregister sysctl\n", __func__);
205 /* Initialize a new context to keep track of dynamically added sysctls. */
207 sysctl_ctx_init(struct sysctl_ctx_list *c)
215 /* Free the context, and destroy all dynamic oids registered in this context */
217 sysctl_ctx_free(struct sysctl_ctx_list *clist)
219 struct sysctl_ctx_entry *e, *e1;
224 * First perform a "dry run" to check if it's ok to remove oids.
226 * XXX This algorithm is a hack. But I don't know any
227 * XXX better solution for now...
230 TAILQ_FOREACH(e, clist, link) {
231 error = sysctl_remove_oid_locked(e->entry, 0, 0);
236 * Restore deregistered entries, either from the end,
237 * or from the place where error occured.
238 * e contains the entry that was not unregistered
241 e1 = TAILQ_PREV(e, sysctl_ctx_list, link);
243 e1 = TAILQ_LAST(clist, sysctl_ctx_list);
245 sysctl_register_oid(e1->entry);
246 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link);
252 /* Now really delete the entries */
253 e = TAILQ_FIRST(clist);
255 e1 = TAILQ_NEXT(e, link);
256 error = sysctl_remove_oid_locked(e->entry, 1, 0);
258 panic("sysctl_remove_oid: corrupt tree, entry: %s",
260 kfree(e, M_SYSCTLOID);
267 /* Add an entry to the context */
268 struct sysctl_ctx_entry *
269 sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
271 struct sysctl_ctx_entry *e;
273 SYSCTL_ASSERT_LOCKED();
274 if (clist == NULL || oidp == NULL)
276 e = kmalloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK);
278 TAILQ_INSERT_HEAD(clist, e, link);
282 /* Find an entry in the context */
283 struct sysctl_ctx_entry *
284 sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
286 struct sysctl_ctx_entry *e;
288 SYSCTL_ASSERT_LOCKED();
289 if (clist == NULL || oidp == NULL)
291 TAILQ_FOREACH(e, clist, link) {
299 * Delete an entry from the context.
300 * NOTE: this function doesn't free oidp! You have to remove it
301 * with sysctl_remove_oid().
304 sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
306 struct sysctl_ctx_entry *e;
308 if (clist == NULL || oidp == NULL)
311 e = sysctl_ctx_entry_find(clist, oidp);
313 TAILQ_REMOVE(clist, e, link);
315 kfree(e, M_SYSCTLOID);
324 * Remove dynamically created sysctl trees.
325 * oidp - top of the tree to be removed
326 * del - if 0 - just deregister, otherwise free up entries as well
327 * recurse - if != 0 traverse the subtree to be deleted
330 sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse)
335 error = sysctl_remove_oid_locked(oidp, del, recurse);
341 sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse)
343 struct sysctl_oid *p, *tmp;
346 SYSCTL_ASSERT_LOCKED();
349 if ((oidp->oid_kind & CTLFLAG_DYN) == 0) {
350 kprintf("can't remove non-dynamic nodes!\n");
354 * WARNING: normal method to do this should be through
355 * sysctl_ctx_free(). Use recursing as the last resort
356 * method to purge your sysctl tree of leftovers...
357 * However, if some other code still references these nodes,
360 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
361 if (oidp->oid_refcnt == 1) {
362 SLIST_FOREACH_MUTABLE(p,
363 SYSCTL_CHILDREN(oidp), oid_link, tmp) {
365 kprintf("Warning: failed attempt to "
366 "remove oid %s with child %s\n",
367 oidp->oid_name, p->oid_name);
370 error = sysctl_remove_oid_locked(p, del,
376 kfree(SYSCTL_CHILDREN(oidp), M_SYSCTLOID);
379 if (oidp->oid_refcnt > 1 ) {
382 if (oidp->oid_refcnt == 0) {
383 kprintf("Warning: bad oid_refcnt=%u (%s)!\n",
384 oidp->oid_refcnt, oidp->oid_name);
387 sysctl_unregister_oid(oidp);
390 * Wait for all threads running the handler to drain.
391 * This preserves the previous behavior when the
392 * sysctl lock was held across a handler invocation,
393 * and is necessary for module unload correctness.
395 while (oidp->oid_running > 0) {
396 oidp->oid_kind |= CTLFLAG_DYING;
397 SYSCTL_SLEEP(&oidp->oid_running, "oidrm", 0);
400 kfree(__DECONST(char *, oidp->oid_descr),
402 kfree(__DECONST(char *, oidp->oid_name), M_SYSCTLOID);
403 lockuninit(&oidp->oid_lock);
404 kfree(oidp, M_SYSCTLOID);
411 sysctl_remove_name(struct sysctl_oid *parent, const char *name,
412 int del, int recurse)
414 struct sysctl_oid *p, *tmp;
419 SLIST_FOREACH_MUTABLE(p, SYSCTL_CHILDREN(parent), oid_link, tmp) {
420 if (strcmp(p->oid_name, name) == 0) {
421 error = sysctl_remove_oid_locked(p, del, recurse);
431 * Create new sysctls at run time.
432 * clist may point to a valid context initialized with sysctl_ctx_init().
435 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent,
436 int number, const char *name, int kind, void *arg1, int arg2,
437 int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr)
439 struct sysctl_oid *oidp;
443 /* You have to hook up somewhere.. */
447 /* Check if the node already exists, otherwise create it */
448 oidp = sysctl_find_oidname(name, parent, 0);
450 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
452 /* Update the context */
454 sysctl_ctx_entry_add(clist, oidp);
458 kprintf("can't re-use a leaf (%s)!\n", name);
463 oidp = kmalloc(sizeof(struct sysctl_oid), M_SYSCTLOID,
465 oidp->oid_parent = parent;
466 SLIST_NEXT(oidp, oid_link) = NULL;
467 oidp->oid_number = number;
468 oidp->oid_refcnt = 1;
470 newname = kmalloc(len + 1, M_SYSCTLOID, M_WAITOK);
471 bcopy(name, newname, len + 1);
473 oidp->oid_name = newname;
474 oidp->oid_handler = handler;
475 oidp->oid_kind = CTLFLAG_DYN | kind;
476 if ((kind & CTLTYPE) == CTLTYPE_NODE) {
477 struct sysctl_oid_list *children;
479 /* Allocate space for children */
480 children = kmalloc(sizeof(*children), M_SYSCTLOID, M_WAITOK);
481 SYSCTL_SET_CHILDREN(oidp, children);
482 SLIST_INIT(children);
484 oidp->oid_arg1 = arg1;
485 oidp->oid_arg2 = arg2;
489 int len = strlen(descr) + 1;
490 oidp->oid_descr = kmalloc(len, M_SYSCTLOID, M_WAITOK);
491 strcpy((char *)(uintptr_t)(const void *)oidp->oid_descr, descr);
493 /* Update the context, if used */
495 sysctl_ctx_entry_add(clist, oidp);
496 /* Register this oid */
497 sysctl_register_oid_int(oidp);
503 * Rename an existing oid.
506 sysctl_rename_oid(struct sysctl_oid *oidp, const char *name)
511 newname = kstrdup(name, M_SYSCTLOID);
513 oldname = __DECONST(char *, oidp->oid_name);
514 oidp->oid_name = newname;
516 kfree(oldname, M_SYSCTLOID);
520 * Register the kernel's oids on startup.
522 SET_DECLARE(sysctl_set, struct sysctl_oid);
525 sysctl_register_all(void *arg)
527 struct sysctl_oid **oidp;
529 lockinit(&sysctlmemlock, "sysctl mem", 0, LK_CANRECURSE);
532 SET_FOREACH(oidp, sysctl_set)
533 sysctl_register_oid(*oidp);
536 SYSINIT(sysctl, SI_BOOT1_POST, SI_ORDER_ANY, sysctl_register_all, 0);
541 * These functions implement a presently undocumented interface
542 * used by the sysctl program to walk the tree, and get the type
543 * so it can print the value.
544 * This interface is under work and consideration, and should probably
545 * be killed with a big axe by the first person who can find the time.
546 * (be aware though, that the proper interface isn't as obvious as it
547 * may seem, there are various conflicting requirements.
549 * {0,0} kprintf the entire MIB-tree.
550 * {0,1,...} return the name of the "..." OID.
551 * {0,2,...} return the next OID.
552 * {0,3} return the OID of the name in "new"
553 * {0,4,...} return the kind & format info for the "..." OID.
557 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i)
560 struct sysctl_oid *oidp;
562 SLIST_FOREACH(oidp, l, oid_link) {
567 kprintf("%d %s ", oidp->oid_number, oidp->oid_name);
570 oidp->oid_kind & CTLFLAG_RD ? 'R':' ',
571 oidp->oid_kind & CTLFLAG_WR ? 'W':' ');
573 if (oidp->oid_handler)
574 kprintf(" *Handler");
576 switch (oidp->oid_kind & CTLTYPE) {
579 if (!oidp->oid_handler) {
580 sysctl_sysctl_debug_dump_node(
581 oidp->oid_arg1, i+2);
584 case CTLTYPE_INT: kprintf(" Int\n"); break;
585 case CTLTYPE_STRING: kprintf(" String\n"); break;
586 case CTLTYPE_QUAD: kprintf(" Quad\n"); break;
587 case CTLTYPE_OPAQUE: kprintf(" Opaque/struct\n"); break;
588 default: kprintf("\n");
595 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS)
599 error = priv_check(req->td, PRIV_SYSCTL_DEBUG);
602 sysctl_sysctl_debug_dump_node(&sysctl__children, 0);
607 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD,
608 0, 0, sysctl_sysctl_debug, "-", "");
611 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS)
613 int *name = (int *) arg1;
614 u_int namelen = arg2;
616 struct sysctl_oid *oid;
617 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2;
622 ksnprintf(buf, sizeof(buf), "%d", *name);
624 error = SYSCTL_OUT(req, ".", 1);
626 error = SYSCTL_OUT(req, buf, strlen(buf));
634 SLIST_FOREACH(oid, lsp, oid_link) {
635 if (oid->oid_number != *name)
639 error = SYSCTL_OUT(req, ".", 1);
641 error = SYSCTL_OUT(req, oid->oid_name,
642 strlen(oid->oid_name));
649 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE)
652 if (oid->oid_handler)
655 lsp2 = SYSCTL_CHILDREN(oid);
660 error = SYSCTL_OUT(req, "", 1);
665 SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD, sysctl_sysctl_name, "");
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)
671 struct sysctl_oid *oidp;
674 SLIST_FOREACH(oidp, lsp, oid_link) {
675 *next = oidp->oid_number;
678 if (oidp->oid_kind & CTLFLAG_SKIP)
682 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
684 if (oidp->oid_handler)
685 /* We really should call the handler here...*/
687 lsp = SYSCTL_CHILDREN(oidp);
688 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1,
689 len, level+1, oidpp))
694 if (oidp->oid_number < *name)
697 if (oidp->oid_number > *name) {
698 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
700 if (oidp->oid_handler)
702 lsp = SYSCTL_CHILDREN(oidp);
703 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1,
704 next+1, len, level+1, oidpp))
708 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
711 if (oidp->oid_handler)
714 lsp = SYSCTL_CHILDREN(oidp);
715 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1,
716 len, level+1, oidpp))
727 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS)
729 int *name = (int *) arg1;
730 u_int namelen = arg2;
732 struct sysctl_oid *oid;
733 struct sysctl_oid_list *lsp = &sysctl__children;
734 int newoid[CTL_MAXNAME];
736 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid);
739 error = SYSCTL_OUT(req, newoid, j * sizeof (int));
744 SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD, sysctl_sysctl_next, "");
747 name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp)
749 struct sysctl_oid *oidp;
750 struct sysctl_oid_list *lsp = &sysctl__children;
753 SYSCTL_ASSERT_LOCKED();
755 for (*len = 0; *len < CTL_MAXNAME;) {
756 p = strsep(&name, ".");
758 oidp = SLIST_FIRST(lsp);
759 for (;; oidp = SLIST_NEXT(oidp, oid_link)) {
762 if (strcmp(p, oidp->oid_name) == 0)
765 *oid++ = oidp->oid_number;
768 if (name == NULL || *name == '\0') {
774 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
777 if (oidp->oid_handler)
780 lsp = SYSCTL_CHILDREN(oidp);
786 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS)
789 int error, oid[CTL_MAXNAME], len;
790 struct sysctl_oid *op = NULL;
794 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */
795 return (ENAMETOOLONG);
797 p = kmalloc(req->newlen+1, M_SYSCTL, M_WAITOK);
799 error = SYSCTL_IN(req, p, req->newlen);
805 p [req->newlen] = '\0';
807 error = name2oid(p, oid, &len, &op);
814 error = SYSCTL_OUT(req, oid, len * sizeof *oid);
818 SYSCTL_PROC(_sysctl, 3, name2oid, CTLFLAG_RW|CTLFLAG_ANYBODY|CTLFLAG_SHLOCK,
819 0, 0, sysctl_sysctl_name2oid, "I", "");
822 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS)
824 struct sysctl_oid *oid;
827 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
833 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind));
836 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1);
841 SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD, sysctl_sysctl_oidfmt, "");
844 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS)
846 struct sysctl_oid *oid;
849 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
855 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1);
859 SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD, sysctl_sysctl_oiddescr, "");
862 * Default "handler" functions.
866 * Handle an int, signed or unsigned.
868 * a variable: point arg1 at it.
869 * a constant: pass it in arg2.
873 sysctl_handle_int(SYSCTL_HANDLER_ARGS)
878 error = SYSCTL_OUT(req, arg1, sizeof(int));
880 error = SYSCTL_OUT(req, &arg2, sizeof(int));
882 if (error || !req->newptr)
888 error = SYSCTL_IN(req, arg1, sizeof(int));
893 * Handle a long, signed or unsigned. arg1 points to it.
897 sysctl_handle_long(SYSCTL_HANDLER_ARGS)
903 error = SYSCTL_OUT(req, arg1, sizeof(long));
905 if (error || !req->newptr)
908 error = SYSCTL_IN(req, arg1, sizeof(long));
913 * Handle a quad, signed or unsigned. arg1 points to it.
917 sysctl_handle_quad(SYSCTL_HANDLER_ARGS)
923 error = SYSCTL_OUT(req, arg1, sizeof(quad_t));
925 if (error || !req->newptr)
928 error = SYSCTL_IN(req, arg1, sizeof(quad_t));
933 * Handle our generic '\0' terminated 'C' string.
935 * a variable string: point arg1 at it, arg2 is max length.
936 * a constant string: point arg1 at it, arg2 is zero.
940 sysctl_handle_string(SYSCTL_HANDLER_ARGS)
944 error = SYSCTL_OUT(req, arg1, strlen((char *)arg1)+1);
946 if (error || !req->newptr)
949 if ((req->newlen - req->newidx) >= arg2) {
952 arg2 = (req->newlen - req->newidx);
953 error = SYSCTL_IN(req, arg1, arg2);
954 ((char *)arg1)[arg2] = '\0';
961 * Handle any kind of opaque data.
962 * arg1 points to it, arg2 is the size.
966 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS)
970 error = SYSCTL_OUT(req, arg1, arg2);
972 if (error || !req->newptr)
975 error = SYSCTL_IN(req, arg1, arg2);
981 * Transfer functions to/from kernel space.
982 * XXX: rather untested at this point
985 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l)
991 if (i > req->oldlen - req->oldidx)
992 i = req->oldlen - req->oldidx;
994 bcopy(p, (char *)req->oldptr + req->oldidx, i);
997 if (req->oldptr && i != l)
1003 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l)
1008 if (req->newlen - req->newidx < l)
1010 bcopy((char *)req->newptr + req->newidx, p, l);
1016 kernel_sysctl(int *name, u_int namelen,
1017 void *old, size_t *oldlenp,
1018 void *new, size_t newlen, size_t *retval)
1021 struct sysctl_req req;
1023 bzero(&req, sizeof req);
1028 req.oldlen = *oldlenp;
1030 req.validlen = req.oldlen;
1037 req.newlen = newlen;
1041 req.oldfunc = sysctl_old_kernel;
1042 req.newfunc = sysctl_new_kernel;
1044 req.lock = REQ_UNWIRED;
1048 error = sysctl_root(0, name, namelen, &req);
1052 if (req.lock == REQ_WIRED && req.validlen > 0)
1053 vsunlock(req.oldptr, req.validlen);
1056 if (error && error != ENOMEM)
1060 if (req.oldptr && req.oldidx > req.validlen)
1061 *retval = req.validlen;
1063 *retval = req.oldidx;
1069 kernel_sysctlbyname(char *name,
1070 void *old, size_t *oldlenp,
1071 void *new, size_t newlen, size_t *retval)
1073 int oid[CTL_MAXNAME];
1074 size_t oidlen, plen;
1077 oid[0] = 0; /* sysctl internal magic */
1078 oid[1] = 3; /* name2oid */
1079 oidlen = sizeof(oid);
1081 error = kernel_sysctl(oid, 2, oid, &oidlen, name, strlen(name), &plen);
1085 error = kernel_sysctl(oid, plen / sizeof(int), old, oldlenp,
1086 new, newlen, retval);
1091 * Transfer function to/from user space.
1094 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l)
1100 if (req->lock == 1 && req->oldptr) {
1101 vslock(req->oldptr, req->oldlen);
1107 if (i > req->oldlen - req->oldidx)
1108 i = req->oldlen - req->oldidx;
1110 error = copyout(p, (char *)req->oldptr + req->oldidx,
1116 if (req->oldptr && i < l)
1122 sysctl_new_user(struct sysctl_req *req, void *p, size_t l)
1128 if (req->newlen - req->newidx < l)
1130 error = copyin((char *)req->newptr + req->newidx, p, l);
1136 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid,
1137 int *nindx, struct sysctl_req *req)
1139 struct sysctl_oid_list *lsp;
1140 struct sysctl_oid *oid;
1143 lsp = &sysctl__children;
1145 while (indx < CTL_MAXNAME) {
1146 SLIST_FOREACH(oid, lsp, oid_link) {
1147 if (oid->oid_number == name[indx])
1154 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1155 if (oid->oid_handler != NULL || indx == namelen) {
1159 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0,
1160 ("%s found DYING node %p", __func__, oid));
1163 lsp = SYSCTL_CHILDREN(oid);
1164 } else if (indx == namelen) {
1168 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0,
1169 ("%s found DYING node %p", __func__, oid));
1179 * Traverse our tree, and find the right node, execute whatever it points
1180 * to, and return the resulting error code.
1183 sysctl_root(SYSCTL_HANDLER_ARGS)
1185 struct thread *td = req->td;
1186 struct proc *p = td ? td->td_proc : NULL;
1187 struct sysctl_oid *oid;
1191 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req);
1195 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1197 * You can't call a sysctl when it's a node, but has
1198 * no handler. Inform the user that it's a node.
1199 * The indx may or may not be the same as namelen.
1201 if (oid->oid_handler == NULL)
1205 /* If writing isn't allowed */
1206 if (req->newptr && (!(oid->oid_kind & CTLFLAG_WR) ||
1207 ((oid->oid_kind & CTLFLAG_SECURE) && securelevel > 0)))
1210 /* Most likely only root can write */
1211 if (!(oid->oid_kind & CTLFLAG_ANYBODY) && req->newptr && p &&
1212 (error = priv_check_cred(td->td_ucred,
1213 (oid->oid_kind & CTLFLAG_PRISON) ? PRIV_SYSCTL_WRITEJAIL :
1214 PRIV_SYSCTL_WRITE, 0)))
1217 if (oid->oid_handler == NULL)
1221 * Default oid locking is exclusive when modifying (newptr),
1222 * shared otherwise, unless overridden with a control flag.
1224 lktype = (req->newptr != NULL) ? LK_EXCLUSIVE : LK_SHARED;
1225 if (oid->oid_kind & CTLFLAG_SHLOCK)
1227 if (oid->oid_kind & CTLFLAG_EXLOCK)
1228 lktype = LK_EXCLUSIVE;
1229 lockmgr(&oid->oid_lock, lktype);
1231 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE)
1232 error = oid->oid_handler(oid, (int *)arg1 + indx, arg2 - indx,
1235 error = oid->oid_handler(oid, oid->oid_arg1, oid->oid_arg2,
1237 lockmgr(&oid->oid_lock, LK_RELEASE);
1243 sys___sysctl(struct sysctl_args *uap)
1245 int error, i, name[CTL_MAXNAME];
1248 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2)
1251 error = copyin(uap->name, &name, uap->namelen * sizeof(int));
1255 error = userland_sysctl(name, uap->namelen,
1256 uap->old, uap->oldlenp, 0,
1257 uap->new, uap->newlen, &j);
1258 if (error && error != ENOMEM)
1261 i = copyout(&j, uap->oldlenp, sizeof(j));
1269 * This is used from various compatibility syscalls too. That's why name
1270 * must be in kernel space.
1273 userland_sysctl(int *name, u_int namelen,
1274 void *old, size_t *oldlenp, int inkernel,
1275 void *new, size_t newlen, size_t *retval)
1277 int error = 0, memlocked;
1278 struct sysctl_req req;
1280 bzero(&req, sizeof req);
1287 req.oldlen = *oldlenp;
1289 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp));
1294 req.validlen = req.oldlen;
1297 if (!useracc(old, req.oldlen, VM_PROT_WRITE))
1303 if (!useracc(new, newlen, VM_PROT_READ))
1305 req.newlen = newlen;
1309 req.oldfunc = sysctl_old_user;
1310 req.newfunc = sysctl_new_user;
1312 req.lock = REQ_UNWIRED;
1316 if (KTRPOINT(curthread, KTR_SYSCTL))
1317 ktrsysctl(name, namelen);
1320 if (req.oldlen > PAGE_SIZE) {
1322 lockmgr(&sysctlmemlock, LK_EXCLUSIVE);
1330 error = sysctl_root(0, name, namelen, &req);
1332 if (error != EAGAIN)
1338 if (req.lock == REQ_WIRED && req.validlen > 0)
1339 vsunlock(req.oldptr, req.validlen);
1342 lockmgr(&sysctlmemlock, LK_RELEASE);
1344 if (error && error != ENOMEM)
1348 if (req.oldptr && req.oldidx > req.validlen)
1349 *retval = req.validlen;
1351 *retval = req.oldidx;
1357 sysctl_int_range(SYSCTL_HANDLER_ARGS, int low, int high)
1361 value = *(int *)arg1;
1362 error = sysctl_handle_int(oidp, &value, 0, req);
1363 if (error || !req->newptr)
1365 if (value < low || value > high)
1367 *(int *)arg1 = value;
1372 * Drain into a sysctl struct. The user buffer should be wired if a page
1373 * fault would cause issue.
1376 sbuf_sysctl_drain(void *arg, const char *data, int len)
1378 struct sysctl_req *req = arg;
1381 error = SYSCTL_OUT(req, data, len);
1382 KASSERT(error >= 0, ("Got unexpected negative value %d", error));
1383 return (error == 0 ? len : -error);
1387 sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length,
1388 struct sysctl_req *req)
1391 s = sbuf_new(s, buf, length, SBUF_FIXEDLEN);
1392 sbuf_set_drain(s, sbuf_sysctl_drain, req);