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
);