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>
52 #include <vm/vm_extern.h>
54 static MALLOC_DEFINE(M_SYSCTL
, "sysctl", "sysctl internal magic");
55 static MALLOC_DEFINE(M_SYSCTLOID
, "sysctloid", "sysctl dynamic oids");
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.
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
);
71 struct sysctl_oid_list sysctl__children
; /* root list */
73 static int sysctl_remove_oid_locked(struct sysctl_oid
*oidp
, int del
,
76 static struct sysctl_oid
*
77 sysctl_find_oidname(const char *name
, struct sysctl_oid_list
*list
, int lock
)
79 struct sysctl_oid
*oidp
;
81 SLIST_FOREACH(oidp
, list
, oid_link
) {
82 if (strcmp(oidp
->oid_name
, name
) == 0) {
90 * Initialization of the MIB tree.
92 * Order by number in each list.
96 sysctl_register_oid(struct sysctl_oid
*oidp
)
99 sysctl_register_oid_int(oidp
);
104 sysctl_register_oid_int(struct sysctl_oid
*oidp
)
106 struct sysctl_oid_list
*parent
= oidp
->oid_parent
;
107 struct sysctl_oid
*p
;
108 struct sysctl_oid
*q
;
111 * Finish initialization from sysctl_set or add.
113 lockinit(&oidp
->oid_lock
, "oidlk", 0, LK_CANRECURSE
);
116 * First check if another oid with the same name already
117 * exists in the parent's list.
119 p
= sysctl_find_oidname(oidp
->oid_name
, parent
, 0);
121 if ((p
->oid_kind
& CTLTYPE
) == CTLTYPE_NODE
)
124 kprintf("can't re-use a leaf (%s)!\n", p
->oid_name
);
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.
133 if (oidp
->oid_number
== OID_AUTO
) {
134 int newoid
= 0x100; /* minimum AUTO oid */
137 * Adjust based on highest oid in parent list
139 SLIST_FOREACH(p
, parent
, oid_link
) {
140 if (newoid
<= p
->oid_number
)
141 newoid
= p
->oid_number
+ 1;
143 oidp
->oid_number
= newoid
;
147 * Insert the oid into the parent's list in order.
150 SLIST_FOREACH(p
, parent
, oid_link
) {
151 if (oidp
->oid_number
< p
->oid_number
)
156 SLIST_INSERT_AFTER(q
, oidp
, oid_link
);
158 SLIST_INSERT_HEAD(parent
, oidp
, oid_link
);
162 sysctl_unregister_oid(struct sysctl_oid
*oidp
)
165 sysctl_unregister_oid_int(oidp
);
170 sysctl_unregister_oid_int(struct sysctl_oid
*oidp
)
172 struct sysctl_oid
*p
;
174 if (oidp
->oid_number
== OID_AUTO
)
175 panic("Trying to unregister OID_AUTO entry: %p", oidp
);
177 SLIST_FOREACH(p
, oidp
->oid_parent
, oid_link
) {
180 SLIST_REMOVE(oidp
->oid_parent
, oidp
, sysctl_oid
, oid_link
);
185 * This can happen when a module fails to register and is
186 * being unloaded afterwards. It should not be a panic()
189 kprintf("%s: failed to unregister sysctl\n", __func__
);
192 /* Initialize a new context to keep track of dynamically added sysctls. */
194 sysctl_ctx_init(struct sysctl_ctx_list
*c
)
202 /* Free the context, and destroy all dynamic oids registered in this context */
204 sysctl_ctx_free(struct sysctl_ctx_list
*clist
)
206 struct sysctl_ctx_entry
*e
, *e1
;
211 * First perform a "dry run" to check if it's ok to remove oids.
213 * XXX This algorithm is a hack. But I don't know any
214 * XXX better solution for now...
217 TAILQ_FOREACH(e
, clist
, link
) {
218 error
= sysctl_remove_oid_locked(e
->entry
, 0, 0);
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
228 e1
= TAILQ_PREV(e
, sysctl_ctx_list
, link
);
230 e1
= TAILQ_LAST(clist
, sysctl_ctx_list
);
232 sysctl_register_oid(e1
->entry
);
233 e1
= TAILQ_PREV(e1
, sysctl_ctx_list
, link
);
239 /* Now really delete the entries */
240 e
= TAILQ_FIRST(clist
);
242 e1
= TAILQ_NEXT(e
, link
);
243 error
= sysctl_remove_oid_locked(e
->entry
, 1, 0);
245 panic("sysctl_remove_oid: corrupt tree, entry: %s",
247 kfree(e
, M_SYSCTLOID
);
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
)
258 struct sysctl_ctx_entry
*e
;
260 SYSCTL_ASSERT_LOCKED();
261 if (clist
== NULL
|| oidp
== NULL
)
263 e
= kmalloc(sizeof(struct sysctl_ctx_entry
), M_SYSCTLOID
, M_WAITOK
);
265 TAILQ_INSERT_HEAD(clist
, e
, link
);
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
)
273 struct sysctl_ctx_entry
*e
;
275 SYSCTL_ASSERT_LOCKED();
276 if (clist
== NULL
|| oidp
== NULL
)
278 TAILQ_FOREACH(e
, clist
, link
) {
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().
291 sysctl_ctx_entry_del(struct sysctl_ctx_list
*clist
, struct sysctl_oid
*oidp
)
293 struct sysctl_ctx_entry
*e
;
295 if (clist
== NULL
|| oidp
== NULL
)
298 e
= sysctl_ctx_entry_find(clist
, oidp
);
300 TAILQ_REMOVE(clist
, e
, link
);
302 kfree(e
, M_SYSCTLOID
);
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
317 sysctl_remove_oid(struct sysctl_oid
*oidp
, int del
, int recurse
)
322 error
= sysctl_remove_oid_locked(oidp
, del
, recurse
);
328 sysctl_remove_oid_locked(struct sysctl_oid
*oidp
, int del
, int recurse
)
330 struct sysctl_oid
*p
, *tmp
;
333 SYSCTL_ASSERT_LOCKED();
336 if ((oidp
->oid_kind
& CTLFLAG_DYN
) == 0) {
337 kprintf("can't remove non-dynamic nodes!\n");
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,
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
) {
352 kprintf("Warning: failed attempt to "
353 "remove oid %s with child %s\n",
354 oidp
->oid_name
, p
->oid_name
);
357 error
= sysctl_remove_oid_locked(p
, del
,
363 kfree(SYSCTL_CHILDREN(oidp
), M_SYSCTLOID
);
366 if (oidp
->oid_refcnt
> 1 ) {
369 if (oidp
->oid_refcnt
== 0) {
370 kprintf("Warning: bad oid_refcnt=%u (%s)!\n",
371 oidp
->oid_refcnt
, oidp
->oid_name
);
374 sysctl_unregister_oid(oidp
);
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.
382 while (oidp
->oid_running
> 0) {
383 oidp
->oid_kind
|= CTLFLAG_DYING
;
384 tsleep_interlock(&oidp
->oid_running
, 0);
386 tsleep(&oidp
->oid_running
, PINTERLOCKED
,
391 kfree(__DECONST(char *, oidp
->oid_descr
),
393 kfree(__DECONST(char *, oidp
->oid_name
), M_SYSCTLOID
);
394 lockuninit(&oidp
->oid_lock
);
395 kfree(oidp
, M_SYSCTLOID
);
402 sysctl_remove_name(struct sysctl_oid
*parent
, const char *name
,
403 int del
, int recurse
)
405 struct sysctl_oid
*p
, *tmp
;
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
);
422 * Create new sysctls at run time.
423 * clist may point to a valid context initialized with sysctl_ctx_init().
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
)
430 struct sysctl_oid
*oidp
;
434 /* You have to hook up somewhere.. */
438 /* Check if the node already exists, otherwise create it */
439 oidp
= sysctl_find_oidname(name
, parent
, 0);
441 if ((oidp
->oid_kind
& CTLTYPE
) == CTLTYPE_NODE
) {
443 /* Update the context */
445 sysctl_ctx_entry_add(clist
, oidp
);
449 kprintf("can't re-use a leaf (%s)!\n", name
);
454 oidp
= kmalloc(sizeof(struct sysctl_oid
), M_SYSCTLOID
,
456 oidp
->oid_parent
= parent
;
457 SLIST_NEXT(oidp
, oid_link
) = NULL
;
458 oidp
->oid_number
= number
;
459 oidp
->oid_refcnt
= 1;
461 newname
= kmalloc(len
+ 1, M_SYSCTLOID
, M_WAITOK
);
462 bcopy(name
, newname
, len
+ 1);
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
;
470 /* Allocate space for children */
471 children
= kmalloc(sizeof(*children
), M_SYSCTLOID
, M_WAITOK
);
472 SYSCTL_SET_CHILDREN(oidp
, children
);
473 SLIST_INIT(children
);
475 oidp
->oid_arg1
= arg1
;
476 oidp
->oid_arg2
= arg2
;
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
);
484 /* Update the context, if used */
486 sysctl_ctx_entry_add(clist
, oidp
);
487 /* Register this oid */
488 sysctl_register_oid_int(oidp
);
494 * Rename an existing oid.
497 sysctl_rename_oid(struct sysctl_oid
*oidp
, const char *name
)
502 newname
= kstrdup(name
, M_SYSCTLOID
);
504 oldname
= __DECONST(char *, oidp
->oid_name
);
505 oidp
->oid_name
= newname
;
507 kfree(oldname
, M_SYSCTLOID
);
511 * Register the kernel's oids on startup.
513 SET_DECLARE(sysctl_set
, struct sysctl_oid
);
516 sysctl_register_all(void *arg
)
518 struct sysctl_oid
**oidp
;
521 SET_FOREACH(oidp
, sysctl_set
)
522 sysctl_register_oid(*oidp
);
525 SYSINIT(sysctl
, SI_BOOT1_POST
, SI_ORDER_ANY
, sysctl_register_all
, 0);
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.
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.
546 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list
*l
, int i
)
549 struct sysctl_oid
*oidp
;
551 SLIST_FOREACH(oidp
, l
, oid_link
) {
556 kprintf("%d %s ", oidp
->oid_number
, oidp
->oid_name
);
559 oidp
->oid_kind
& CTLFLAG_RD
? 'R':' ',
560 oidp
->oid_kind
& CTLFLAG_WR
? 'W':' ');
562 if (oidp
->oid_handler
)
563 kprintf(" *Handler");
565 switch (oidp
->oid_kind
& CTLTYPE
) {
568 if (!oidp
->oid_handler
) {
569 sysctl_sysctl_debug_dump_node(
570 oidp
->oid_arg1
, i
+2);
573 case CTLTYPE_INT
: kprintf(" Int\n"); break;
574 case CTLTYPE_STRING
: kprintf(" String\n"); break;
575 case CTLTYPE_QUAD
: kprintf(" Quad\n"); break;
576 case CTLTYPE_OPAQUE
: kprintf(" Opaque/struct\n"); break;
577 default: kprintf("\n");
584 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS
)
588 error
= priv_check(req
->td
, PRIV_SYSCTL_DEBUG
);
591 sysctl_sysctl_debug_dump_node(&sysctl__children
, 0);
596 SYSCTL_PROC(_sysctl
, 0, debug
, CTLTYPE_STRING
| CTLFLAG_RD
,
597 0, 0, sysctl_sysctl_debug
, "-", "");
600 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS
)
602 int *name
= (int *) arg1
;
603 u_int namelen
= arg2
;
605 struct sysctl_oid
*oid
;
606 struct sysctl_oid_list
*lsp
= &sysctl__children
, *lsp2
;
611 ksnprintf(buf
, sizeof(buf
), "%d", *name
);
613 error
= SYSCTL_OUT(req
, ".", 1);
615 error
= SYSCTL_OUT(req
, buf
, strlen(buf
));
623 SLIST_FOREACH(oid
, lsp
, oid_link
) {
624 if (oid
->oid_number
!= *name
)
628 error
= SYSCTL_OUT(req
, ".", 1);
630 error
= SYSCTL_OUT(req
, oid
->oid_name
,
631 strlen(oid
->oid_name
));
638 if ((oid
->oid_kind
& CTLTYPE
) != CTLTYPE_NODE
)
641 if (oid
->oid_handler
)
644 lsp2
= SYSCTL_CHILDREN(oid
);
649 error
= SYSCTL_OUT(req
, "", 1);
654 SYSCTL_NODE(_sysctl
, 1, name
, CTLFLAG_RD
| CTLFLAG_NOLOCK
,
655 sysctl_sysctl_name
, "");
658 sysctl_sysctl_next_ls(struct sysctl_oid_list
*lsp
, int *name
, u_int namelen
,
659 int *next
, int *len
, int level
, struct sysctl_oid
**oidpp
)
661 struct sysctl_oid
*oidp
;
664 SLIST_FOREACH(oidp
, lsp
, oid_link
) {
665 *next
= oidp
->oid_number
;
668 if (oidp
->oid_kind
& CTLFLAG_SKIP
)
672 if ((oidp
->oid_kind
& CTLTYPE
) != CTLTYPE_NODE
)
674 if (oidp
->oid_handler
)
675 /* We really should call the handler here...*/
677 lsp
= SYSCTL_CHILDREN(oidp
);
678 if (!sysctl_sysctl_next_ls(lsp
, 0, 0, next
+1,
679 len
, level
+1, oidpp
))
684 if (oidp
->oid_number
< *name
)
687 if (oidp
->oid_number
> *name
) {
688 if ((oidp
->oid_kind
& CTLTYPE
) != CTLTYPE_NODE
)
690 if (oidp
->oid_handler
)
692 lsp
= SYSCTL_CHILDREN(oidp
);
693 if (!sysctl_sysctl_next_ls(lsp
, name
+1, namelen
-1,
694 next
+1, len
, level
+1, oidpp
))
698 if ((oidp
->oid_kind
& CTLTYPE
) != CTLTYPE_NODE
)
701 if (oidp
->oid_handler
)
704 lsp
= SYSCTL_CHILDREN(oidp
);
705 if (!sysctl_sysctl_next_ls(lsp
, name
+1, namelen
-1, next
+1,
706 len
, level
+1, oidpp
))
717 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS
)
719 int *name
= (int *) arg1
;
720 u_int namelen
= arg2
;
722 struct sysctl_oid
*oid
;
723 struct sysctl_oid_list
*lsp
= &sysctl__children
;
724 int newoid
[CTL_MAXNAME
];
726 i
= sysctl_sysctl_next_ls(lsp
, name
, namelen
, newoid
, &j
, 1, &oid
);
729 error
= SYSCTL_OUT(req
, newoid
, j
* sizeof (int));
734 SYSCTL_NODE(_sysctl
, 2, next
, CTLFLAG_RD
| CTLFLAG_NOLOCK
,
735 sysctl_sysctl_next
, "");
738 name2oid(char *name
, int *oid
, int *len
, struct sysctl_oid
**oidpp
)
740 struct sysctl_oid
*oidp
;
741 struct sysctl_oid_list
*lsp
= &sysctl__children
;
744 SYSCTL_ASSERT_LOCKED();
746 for (*len
= 0; *len
< CTL_MAXNAME
;) {
747 p
= strsep(&name
, ".");
749 oidp
= SLIST_FIRST(lsp
);
750 for (;; oidp
= SLIST_NEXT(oidp
, oid_link
)) {
753 if (strcmp(p
, oidp
->oid_name
) == 0)
756 *oid
++ = oidp
->oid_number
;
759 if (name
== NULL
|| *name
== '\0') {
765 if ((oidp
->oid_kind
& CTLTYPE
) != CTLTYPE_NODE
)
768 if (oidp
->oid_handler
)
771 lsp
= SYSCTL_CHILDREN(oidp
);
777 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS
)
780 int error
, oid
[CTL_MAXNAME
], len
;
781 struct sysctl_oid
*op
= NULL
;
785 if (req
->newlen
>= MAXPATHLEN
) /* XXX arbitrary, undocumented */
786 return (ENAMETOOLONG
);
788 p
= kmalloc(req
->newlen
+1, M_SYSCTL
, M_WAITOK
);
790 error
= SYSCTL_IN(req
, p
, req
->newlen
);
796 p
[req
->newlen
] = '\0';
798 error
= name2oid(p
, oid
, &len
, &op
);
805 error
= SYSCTL_OUT(req
, oid
, len
* sizeof *oid
);
809 SYSCTL_PROC(_sysctl
, 3, name2oid
, CTLFLAG_RW
| CTLFLAG_ANYBODY
| CTLFLAG_NOLOCK
,
810 0, 0, sysctl_sysctl_name2oid
, "I", "");
813 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS
)
815 struct sysctl_oid
*oid
;
818 error
= sysctl_find_oid(arg1
, arg2
, &oid
, NULL
, req
);
824 error
= SYSCTL_OUT(req
, &oid
->oid_kind
, sizeof(oid
->oid_kind
));
827 error
= SYSCTL_OUT(req
, oid
->oid_fmt
, strlen(oid
->oid_fmt
) + 1);
832 SYSCTL_NODE(_sysctl
, 4, oidfmt
, CTLFLAG_RD
| CTLFLAG_NOLOCK
,
833 sysctl_sysctl_oidfmt
, "");
836 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS
)
838 struct sysctl_oid
*oid
;
841 error
= sysctl_find_oid(arg1
, arg2
, &oid
, NULL
, req
);
847 error
= SYSCTL_OUT(req
, oid
->oid_descr
, strlen(oid
->oid_descr
) + 1);
851 SYSCTL_NODE(_sysctl
, 5, oiddescr
, CTLFLAG_RD
| CTLFLAG_NOLOCK
,
852 sysctl_sysctl_oiddescr
, "");
855 * Default "handler" functions.
859 * Handle an int, signed or unsigned.
861 * a variable: point arg1 at it.
862 * a constant: pass it in arg2.
866 sysctl_handle_int(SYSCTL_HANDLER_ARGS
)
871 error
= SYSCTL_OUT(req
, arg1
, sizeof(int));
873 error
= SYSCTL_OUT(req
, &arg2
, sizeof(int));
875 if (error
|| !req
->newptr
)
881 error
= SYSCTL_IN(req
, arg1
, sizeof(int));
886 * Handle a long, signed or unsigned. arg1 points to it.
890 sysctl_handle_long(SYSCTL_HANDLER_ARGS
)
896 if (req
->oldlen
== sizeof(int) &&
897 *(long *)arg1
>= INT_MIN
&&
898 *(long *)arg1
<= INT_MAX
) {
900 * Backwards compatibility for read-only fields promoted
901 * from int to long. Allow userland to request the field
902 * as an integer if the value is in-range.
904 int val
= (int)*(long *)arg1
;
905 error
= SYSCTL_OUT(req
, &val
, sizeof(int));
908 * Normal operation fo a long
910 error
= SYSCTL_OUT(req
, arg1
, sizeof(long));
913 if (error
|| !req
->newptr
)
916 error
= SYSCTL_IN(req
, arg1
, sizeof(long));
922 * Handle a quad, signed or unsigned. arg1 points to it.
926 sysctl_handle_quad(SYSCTL_HANDLER_ARGS
)
932 error
= SYSCTL_OUT(req
, arg1
, sizeof(quad_t
));
934 if (error
|| !req
->newptr
)
937 error
= SYSCTL_IN(req
, arg1
, sizeof(quad_t
));
942 * Handle our generic '\0' terminated 'C' string.
944 * a variable string: point arg1 at it, arg2 is max length.
945 * a constant string: point arg1 at it, arg2 is zero.
949 sysctl_handle_string(SYSCTL_HANDLER_ARGS
)
953 error
= SYSCTL_OUT(req
, arg1
, strlen((char *)arg1
)+1);
955 if (error
|| !req
->newptr
)
958 if ((req
->newlen
- req
->newidx
) >= arg2
) {
961 arg2
= (req
->newlen
- req
->newidx
);
962 error
= SYSCTL_IN(req
, arg1
, arg2
);
963 ((char *)arg1
)[arg2
] = '\0';
970 * Handle any kind of opaque data.
971 * arg1 points to it, arg2 is the size.
975 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS
)
979 error
= SYSCTL_OUT(req
, arg1
, arg2
);
981 if (error
|| !req
->newptr
)
984 error
= SYSCTL_IN(req
, arg1
, arg2
);
990 * Transfer functions to/from kernel space.
991 * XXX: rather untested at this point
994 sysctl_old_kernel(struct sysctl_req
*req
, const void *p
, size_t l
)
1000 if (i
> req
->oldlen
- req
->oldidx
)
1001 i
= req
->oldlen
- req
->oldidx
;
1003 bcopy(p
, (char *)req
->oldptr
+ req
->oldidx
, i
);
1006 if (req
->oldptr
&& i
!= l
)
1012 sysctl_new_kernel(struct sysctl_req
*req
, void *p
, size_t l
)
1017 if (req
->newlen
- req
->newidx
< l
)
1019 bcopy((char *)req
->newptr
+ req
->newidx
, p
, l
);
1025 kernel_sysctl(int *name
, u_int namelen
,
1026 void *old
, size_t *oldlenp
,
1027 void *new, size_t newlen
, size_t *retval
)
1030 struct sysctl_req req
;
1032 bzero(&req
, sizeof req
);
1037 req
.oldlen
= *oldlenp
;
1039 req
.validlen
= req
.oldlen
;
1046 req
.newlen
= newlen
;
1050 req
.oldfunc
= sysctl_old_kernel
;
1051 req
.newfunc
= sysctl_new_kernel
;
1053 req
.lock
= REQ_UNWIRED
;
1057 error
= sysctl_root(0, name
, namelen
, &req
);
1061 if (req
.lock
== REQ_WIRED
&& req
.validlen
> 0)
1062 vsunlock(req
.oldptr
, req
.validlen
);
1065 if (error
&& error
!= ENOMEM
)
1069 if (req
.oldptr
&& req
.oldidx
> req
.validlen
)
1070 *retval
= req
.validlen
;
1072 *retval
= req
.oldidx
;
1078 kernel_sysctlbyname(char *name
,
1079 void *old
, size_t *oldlenp
,
1080 void *new, size_t newlen
, size_t *retval
)
1082 int oid
[CTL_MAXNAME
];
1083 size_t oidlen
, plen
;
1086 oid
[0] = 0; /* sysctl internal magic */
1087 oid
[1] = 3; /* name2oid */
1088 oidlen
= sizeof(oid
);
1090 error
= kernel_sysctl(oid
, 2, oid
, &oidlen
, name
, strlen(name
), &plen
);
1094 error
= kernel_sysctl(oid
, plen
/ sizeof(int), old
, oldlenp
,
1095 new, newlen
, retval
);
1100 * Transfer function to/from user space.
1103 sysctl_old_user(struct sysctl_req
*req
, const void *p
, size_t l
)
1109 if (req
->lock
== 1 && req
->oldptr
) {
1110 vslock(req
->oldptr
, req
->oldlen
);
1116 if (i
> req
->oldlen
- req
->oldidx
)
1117 i
= req
->oldlen
- req
->oldidx
;
1119 error
= copyout(p
, (char *)req
->oldptr
+ req
->oldidx
,
1125 if (req
->oldptr
&& i
< l
)
1131 sysctl_new_user(struct sysctl_req
*req
, void *p
, size_t l
)
1137 if (req
->newlen
- req
->newidx
< l
)
1139 error
= copyin((char *)req
->newptr
+ req
->newidx
, p
, l
);
1145 sysctl_find_oid(int *name
, u_int namelen
, struct sysctl_oid
**noid
,
1146 int *nindx
, struct sysctl_req
*req
)
1148 struct sysctl_oid_list
*lsp
;
1149 struct sysctl_oid
*oid
;
1152 lsp
= &sysctl__children
;
1154 while (indx
< CTL_MAXNAME
) {
1155 SLIST_FOREACH(oid
, lsp
, oid_link
) {
1156 if (oid
->oid_number
== name
[indx
])
1163 if ((oid
->oid_kind
& CTLTYPE
) == CTLTYPE_NODE
) {
1164 if (oid
->oid_handler
!= NULL
|| indx
== namelen
) {
1168 KASSERT((oid
->oid_kind
& CTLFLAG_DYING
) == 0,
1169 ("%s found DYING node %p", __func__
, oid
));
1172 lsp
= SYSCTL_CHILDREN(oid
);
1173 } else if (indx
== namelen
) {
1177 KASSERT((oid
->oid_kind
& CTLFLAG_DYING
) == 0,
1178 ("%s found DYING node %p", __func__
, oid
));
1188 * Traverse our tree, and find the right node, execute whatever it points
1189 * to, and return the resulting error code.
1192 sysctl_root(SYSCTL_HANDLER_ARGS
)
1194 struct thread
*td
= req
->td
;
1195 struct proc
*p
= td
? td
->td_proc
: NULL
;
1196 struct sysctl_oid
*oid
;
1200 error
= sysctl_find_oid(arg1
, arg2
, &oid
, &indx
, req
);
1204 if ((oid
->oid_kind
& CTLTYPE
) == CTLTYPE_NODE
) {
1206 * You can't call a sysctl when it's a node, but has
1207 * no handler. Inform the user that it's a node.
1208 * The indx may or may not be the same as namelen.
1210 if (oid
->oid_handler
== NULL
)
1214 /* If writing isn't allowed */
1215 if (req
->newptr
&& (!(oid
->oid_kind
& CTLFLAG_WR
) ||
1216 ((oid
->oid_kind
& CTLFLAG_SECURE
) && securelevel
> 0)))
1219 /* Most likely only root can write */
1220 if (!(oid
->oid_kind
& CTLFLAG_ANYBODY
) && req
->newptr
&& p
&&
1221 (error
= priv_check_cred(td
->td_ucred
,
1222 (oid
->oid_kind
& CTLFLAG_PRISON
) ? PRIV_SYSCTL_WRITEJAIL
:
1223 PRIV_SYSCTL_WRITE
, 0)))
1226 if (oid
->oid_handler
== NULL
)
1230 * Default oid locking is exclusive when modifying (newptr),
1231 * shared otherwise, unless overridden with a control flag.
1233 if ((oid
->oid_kind
& CTLFLAG_NOLOCK
) == 0) {
1234 lktype
= (req
->newptr
!= NULL
) ? LK_EXCLUSIVE
: LK_SHARED
;
1235 if (oid
->oid_kind
& CTLFLAG_SHLOCK
)
1237 if (oid
->oid_kind
& CTLFLAG_EXLOCK
)
1238 lktype
= LK_EXCLUSIVE
;
1240 lockmgr(&oid
->oid_lock
, lktype
);
1243 if (lockmgr(&oid
->oid_lock
, lktype
| LK_SLEEPFAIL
)) {
1244 kprintf("%s\n", oid
->oid_name
);
1245 lockmgr(&oid
->oid_lock
, lktype
);
1250 if ((oid
->oid_kind
& CTLTYPE
) == CTLTYPE_NODE
)
1251 error
= oid
->oid_handler(oid
, (int *)arg1
+ indx
, arg2
- indx
,
1254 error
= oid
->oid_handler(oid
, oid
->oid_arg1
, oid
->oid_arg2
,
1257 if ((oid
->oid_kind
& CTLFLAG_NOLOCK
) == 0)
1258 lockmgr(&oid
->oid_lock
, LK_RELEASE
);
1263 sys___sysctl(struct sysctl_args
*uap
)
1265 int error
, i
, name
[CTL_MAXNAME
];
1268 if (uap
->namelen
> CTL_MAXNAME
|| uap
->namelen
< 2)
1271 error
= copyin(uap
->name
, &name
, uap
->namelen
* sizeof(int));
1275 error
= userland_sysctl(name
, uap
->namelen
,
1276 uap
->old
, uap
->oldlenp
, 0,
1277 uap
->new, uap
->newlen
, &j
);
1278 if (error
&& error
!= ENOMEM
)
1281 i
= copyout(&j
, uap
->oldlenp
, sizeof(j
));
1289 * This is used from various compatibility syscalls too. That's why name
1290 * must be in kernel space.
1293 userland_sysctl(int *name
, u_int namelen
,
1294 void *old
, size_t *oldlenp
, int inkernel
,
1295 void *new, size_t newlen
, size_t *retval
)
1298 struct sysctl_req req
;
1300 bzero(&req
, sizeof req
);
1307 req
.oldlen
= *oldlenp
;
1309 error
= copyin(oldlenp
, &req
.oldlen
, sizeof(*oldlenp
));
1314 req
.validlen
= req
.oldlen
;
1317 * NOTE: User supplied buffers are not guaranteed to be good,
1318 * the sysctl copyins and copyouts can fail.
1324 req
.newlen
= newlen
;
1328 req
.oldfunc
= sysctl_old_user
;
1329 req
.newfunc
= sysctl_new_user
;
1331 req
.lock
= REQ_UNWIRED
;
1335 if (KTRPOINT(curthread
, KTR_SYSCTL
))
1336 ktrsysctl(name
, namelen
);
1343 error
= sysctl_root(0, name
, namelen
, &req
);
1345 if (error
!= EAGAIN
)
1351 if (req
.lock
== REQ_WIRED
&& req
.validlen
> 0)
1352 vsunlock(req
.oldptr
, req
.validlen
);
1354 if (error
&& error
!= ENOMEM
)
1358 if (req
.oldptr
&& req
.oldidx
> req
.validlen
)
1359 *retval
= req
.validlen
;
1361 *retval
= req
.oldidx
;
1367 sysctl_int_range(SYSCTL_HANDLER_ARGS
, int low
, int high
)
1371 value
= *(int *)arg1
;
1372 error
= sysctl_handle_int(oidp
, &value
, 0, req
);
1373 if (error
|| !req
->newptr
)
1375 if (value
< low
|| value
> high
)
1377 *(int *)arg1
= value
;
1382 * Drain into a sysctl struct. The user buffer should be wired if a page
1383 * fault would cause issue.
1386 sbuf_sysctl_drain(void *arg
, const char *data
, int len
)
1388 struct sysctl_req
*req
= arg
;
1391 error
= SYSCTL_OUT(req
, data
, len
);
1392 KASSERT(error
>= 0, ("Got unexpected negative value %d", error
));
1393 return (error
== 0 ? len
: -error
);
1397 sbuf_new_for_sysctl(struct sbuf
*s
, char *buf
, int length
,
1398 struct sysctl_req
*req
)
1401 s
= sbuf_new(s
, buf
, length
, SBUF_FIXEDLEN
);
1402 sbuf_set_drain(s
, sbuf_sysctl_drain
, req
);
1407 * The exclusive sysctl lock only protects its topology, and is
1408 * very expensive, but allows us to use a pcpu shared lock for
1409 * critical path accesses.
1417 for (i
= 0; i
< ncpus
; ++i
) {
1418 gd
= globaldata_find(i
);
1419 lockmgr(&gd
->gd_sysctllock
, LK_EXCLUSIVE
);
1424 _sysctl_xunlock(void)
1429 for (i
= 0; i
< ncpus
; ++i
) {
1430 gd
= globaldata_find(i
);
1431 lockmgr(&gd
->gd_sysctllock
, LK_RELEASE
);