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.
66 * The sysctlmemlock is used to limit the amount of user memory wired for
67 * sysctl requests. This is implemented by serializing any userland
68 * sysctl requests larger than a single page via an exclusive lock.
70 struct lock sysctllock
;
71 static struct lock sysctlmemlock
;
73 #define SYSCTL_INIT() lockinit(&sysctllock, \
74 "sysctl lock", 0, LK_CANRECURSE)
75 #define SYSCTL_SLEEP(ch, wmesg, timo) \
76 lksleep(ch, &sysctllock, 0, wmesg, timo)
78 static int sysctl_root(SYSCTL_HANDLER_ARGS
);
79 static void sysctl_register_oid_int(struct sysctl_oid
*oipd
);
80 static void sysctl_unregister_oid_int(struct sysctl_oid
*oipd
);
82 struct sysctl_oid_list sysctl__children
; /* root list */
84 static int sysctl_remove_oid_locked(struct sysctl_oid
*oidp
, int del
,
87 static struct sysctl_oid
*
88 sysctl_find_oidname(const char *name
, struct sysctl_oid_list
*list
, int lock
)
90 struct sysctl_oid
*oidp
;
92 SLIST_FOREACH(oidp
, list
, oid_link
) {
93 if (strcmp(oidp
->oid_name
, name
) == 0) {
101 * Initialization of the MIB tree.
103 * Order by number in each list.
107 sysctl_register_oid(struct sysctl_oid
*oidp
)
110 sysctl_register_oid_int(oidp
);
115 sysctl_register_oid_int(struct sysctl_oid
*oidp
)
117 struct sysctl_oid_list
*parent
= oidp
->oid_parent
;
118 struct sysctl_oid
*p
;
119 struct sysctl_oid
*q
;
122 * Finish initialization from sysctl_set or add.
124 lockinit(&oidp
->oid_lock
, "oidlk", 0, LK_CANRECURSE
);
127 * First check if another oid with the same name already
128 * exists in the parent's list.
130 p
= sysctl_find_oidname(oidp
->oid_name
, parent
, 0);
132 if ((p
->oid_kind
& CTLTYPE
) == CTLTYPE_NODE
)
135 kprintf("can't re-use a leaf (%s)!\n", p
->oid_name
);
140 * If this oid has a number OID_AUTO, give it a number which
141 * is greater than any current oid. Make sure it is at least
142 * 256 to leave space for pre-assigned oid numbers.
144 if (oidp
->oid_number
== OID_AUTO
) {
145 int newoid
= 0x100; /* minimum AUTO oid */
148 * Adjust based on highest oid in parent list
150 SLIST_FOREACH(p
, parent
, oid_link
) {
151 if (newoid
<= p
->oid_number
)
152 newoid
= p
->oid_number
+ 1;
154 oidp
->oid_number
= newoid
;
158 * Insert the oid into the parent's list in order.
161 SLIST_FOREACH(p
, parent
, oid_link
) {
162 if (oidp
->oid_number
< p
->oid_number
)
167 SLIST_INSERT_AFTER(q
, oidp
, oid_link
);
169 SLIST_INSERT_HEAD(parent
, oidp
, oid_link
);
173 sysctl_unregister_oid(struct sysctl_oid
*oidp
)
176 sysctl_unregister_oid_int(oidp
);
181 sysctl_unregister_oid_int(struct sysctl_oid
*oidp
)
183 struct sysctl_oid
*p
;
185 if (oidp
->oid_number
== OID_AUTO
)
186 panic("Trying to unregister OID_AUTO entry: %p", oidp
);
188 SLIST_FOREACH(p
, oidp
->oid_parent
, oid_link
) {
191 SLIST_REMOVE(oidp
->oid_parent
, oidp
, sysctl_oid
, oid_link
);
196 * This can happen when a module fails to register and is
197 * being unloaded afterwards. It should not be a panic()
200 kprintf("%s: failed to unregister sysctl\n", __func__
);
203 /* Initialize a new context to keep track of dynamically added sysctls. */
205 sysctl_ctx_init(struct sysctl_ctx_list
*c
)
213 /* Free the context, and destroy all dynamic oids registered in this context */
215 sysctl_ctx_free(struct sysctl_ctx_list
*clist
)
217 struct sysctl_ctx_entry
*e
, *e1
;
222 * First perform a "dry run" to check if it's ok to remove oids.
224 * XXX This algorithm is a hack. But I don't know any
225 * XXX better solution for now...
228 TAILQ_FOREACH(e
, clist
, link
) {
229 error
= sysctl_remove_oid_locked(e
->entry
, 0, 0);
234 * Restore deregistered entries, either from the end,
235 * or from the place where error occured.
236 * e contains the entry that was not unregistered
239 e1
= TAILQ_PREV(e
, sysctl_ctx_list
, link
);
241 e1
= TAILQ_LAST(clist
, sysctl_ctx_list
);
243 sysctl_register_oid(e1
->entry
);
244 e1
= TAILQ_PREV(e1
, sysctl_ctx_list
, link
);
250 /* Now really delete the entries */
251 e
= TAILQ_FIRST(clist
);
253 e1
= TAILQ_NEXT(e
, link
);
254 error
= sysctl_remove_oid_locked(e
->entry
, 1, 0);
256 panic("sysctl_remove_oid: corrupt tree, entry: %s",
258 kfree(e
, M_SYSCTLOID
);
265 /* Add an entry to the context */
266 struct sysctl_ctx_entry
*
267 sysctl_ctx_entry_add(struct sysctl_ctx_list
*clist
, struct sysctl_oid
*oidp
)
269 struct sysctl_ctx_entry
*e
;
271 SYSCTL_ASSERT_LOCKED();
272 if (clist
== NULL
|| oidp
== NULL
)
274 e
= kmalloc(sizeof(struct sysctl_ctx_entry
), M_SYSCTLOID
, M_WAITOK
);
276 TAILQ_INSERT_HEAD(clist
, e
, link
);
280 /* Find an entry in the context */
281 struct sysctl_ctx_entry
*
282 sysctl_ctx_entry_find(struct sysctl_ctx_list
*clist
, struct sysctl_oid
*oidp
)
284 struct sysctl_ctx_entry
*e
;
286 SYSCTL_ASSERT_LOCKED();
287 if (clist
== NULL
|| oidp
== NULL
)
289 TAILQ_FOREACH(e
, clist
, link
) {
297 * Delete an entry from the context.
298 * NOTE: this function doesn't free oidp! You have to remove it
299 * with sysctl_remove_oid().
302 sysctl_ctx_entry_del(struct sysctl_ctx_list
*clist
, struct sysctl_oid
*oidp
)
304 struct sysctl_ctx_entry
*e
;
306 if (clist
== NULL
|| oidp
== NULL
)
309 e
= sysctl_ctx_entry_find(clist
, oidp
);
311 TAILQ_REMOVE(clist
, e
, link
);
313 kfree(e
, M_SYSCTLOID
);
322 * Remove dynamically created sysctl trees.
323 * oidp - top of the tree to be removed
324 * del - if 0 - just deregister, otherwise free up entries as well
325 * recurse - if != 0 traverse the subtree to be deleted
328 sysctl_remove_oid(struct sysctl_oid
*oidp
, int del
, int recurse
)
333 error
= sysctl_remove_oid_locked(oidp
, del
, recurse
);
339 sysctl_remove_oid_locked(struct sysctl_oid
*oidp
, int del
, int recurse
)
341 struct sysctl_oid
*p
, *tmp
;
344 SYSCTL_ASSERT_LOCKED();
347 if ((oidp
->oid_kind
& CTLFLAG_DYN
) == 0) {
348 kprintf("can't remove non-dynamic nodes!\n");
352 * WARNING: normal method to do this should be through
353 * sysctl_ctx_free(). Use recursing as the last resort
354 * method to purge your sysctl tree of leftovers...
355 * However, if some other code still references these nodes,
358 if ((oidp
->oid_kind
& CTLTYPE
) == CTLTYPE_NODE
) {
359 if (oidp
->oid_refcnt
== 1) {
360 SLIST_FOREACH_MUTABLE(p
,
361 SYSCTL_CHILDREN(oidp
), oid_link
, tmp
) {
363 kprintf("Warning: failed attempt to "
364 "remove oid %s with child %s\n",
365 oidp
->oid_name
, p
->oid_name
);
368 error
= sysctl_remove_oid_locked(p
, del
,
374 kfree(SYSCTL_CHILDREN(oidp
), M_SYSCTLOID
);
377 if (oidp
->oid_refcnt
> 1 ) {
380 if (oidp
->oid_refcnt
== 0) {
381 kprintf("Warning: bad oid_refcnt=%u (%s)!\n",
382 oidp
->oid_refcnt
, oidp
->oid_name
);
385 sysctl_unregister_oid(oidp
);
388 * Wait for all threads running the handler to drain.
389 * This preserves the previous behavior when the
390 * sysctl lock was held across a handler invocation,
391 * and is necessary for module unload correctness.
393 while (oidp
->oid_running
> 0) {
394 oidp
->oid_kind
|= CTLFLAG_DYING
;
395 SYSCTL_SLEEP(&oidp
->oid_running
, "oidrm", 0);
398 kfree(__DECONST(char *, oidp
->oid_descr
),
400 kfree(__DECONST(char *, oidp
->oid_name
), M_SYSCTLOID
);
401 lockuninit(&oidp
->oid_lock
);
402 kfree(oidp
, M_SYSCTLOID
);
409 sysctl_remove_name(struct sysctl_oid
*parent
, const char *name
,
410 int del
, int recurse
)
412 struct sysctl_oid
*p
, *tmp
;
417 SLIST_FOREACH_MUTABLE(p
, SYSCTL_CHILDREN(parent
), oid_link
, tmp
) {
418 if (strcmp(p
->oid_name
, name
) == 0) {
419 error
= sysctl_remove_oid_locked(p
, del
, recurse
);
429 * Create new sysctls at run time.
430 * clist may point to a valid context initialized with sysctl_ctx_init().
433 sysctl_add_oid(struct sysctl_ctx_list
*clist
, struct sysctl_oid_list
*parent
,
434 int number
, const char *name
, int kind
, void *arg1
, int arg2
,
435 int (*handler
)(SYSCTL_HANDLER_ARGS
), const char *fmt
, const char *descr
)
437 struct sysctl_oid
*oidp
;
441 /* You have to hook up somewhere.. */
445 /* Check if the node already exists, otherwise create it */
446 oidp
= sysctl_find_oidname(name
, parent
, 0);
448 if ((oidp
->oid_kind
& CTLTYPE
) == CTLTYPE_NODE
) {
450 /* Update the context */
452 sysctl_ctx_entry_add(clist
, oidp
);
456 kprintf("can't re-use a leaf (%s)!\n", name
);
461 oidp
= kmalloc(sizeof(struct sysctl_oid
), M_SYSCTLOID
,
463 oidp
->oid_parent
= parent
;
464 SLIST_NEXT(oidp
, oid_link
) = NULL
;
465 oidp
->oid_number
= number
;
466 oidp
->oid_refcnt
= 1;
468 newname
= kmalloc(len
+ 1, M_SYSCTLOID
, M_WAITOK
);
469 bcopy(name
, newname
, len
+ 1);
471 oidp
->oid_name
= newname
;
472 oidp
->oid_handler
= handler
;
473 oidp
->oid_kind
= CTLFLAG_DYN
| kind
;
474 if ((kind
& CTLTYPE
) == CTLTYPE_NODE
) {
475 struct sysctl_oid_list
*children
;
477 /* Allocate space for children */
478 children
= kmalloc(sizeof(*children
), M_SYSCTLOID
, M_WAITOK
);
479 SYSCTL_SET_CHILDREN(oidp
, children
);
480 SLIST_INIT(children
);
482 oidp
->oid_arg1
= arg1
;
483 oidp
->oid_arg2
= arg2
;
487 int len
= strlen(descr
) + 1;
488 oidp
->oid_descr
= kmalloc(len
, M_SYSCTLOID
, M_WAITOK
);
489 strcpy((char *)(uintptr_t)(const void *)oidp
->oid_descr
, descr
);
491 /* Update the context, if used */
493 sysctl_ctx_entry_add(clist
, oidp
);
494 /* Register this oid */
495 sysctl_register_oid_int(oidp
);
501 * Rename an existing oid.
504 sysctl_rename_oid(struct sysctl_oid
*oidp
, const char *name
)
509 newname
= kstrdup(name
, M_SYSCTLOID
);
511 oldname
= __DECONST(char *, oidp
->oid_name
);
512 oidp
->oid_name
= newname
;
514 kfree(oldname
, M_SYSCTLOID
);
518 * Register the kernel's oids on startup.
520 SET_DECLARE(sysctl_set
, struct sysctl_oid
);
523 sysctl_register_all(void *arg
)
525 struct sysctl_oid
**oidp
;
527 lockinit(&sysctlmemlock
, "sysctl mem", 0, LK_CANRECURSE
);
530 SET_FOREACH(oidp
, sysctl_set
)
531 sysctl_register_oid(*oidp
);
534 SYSINIT(sysctl
, SI_BOOT1_POST
, SI_ORDER_ANY
, sysctl_register_all
, 0);
539 * These functions implement a presently undocumented interface
540 * used by the sysctl program to walk the tree, and get the type
541 * so it can print the value.
542 * This interface is under work and consideration, and should probably
543 * be killed with a big axe by the first person who can find the time.
544 * (be aware though, that the proper interface isn't as obvious as it
545 * may seem, there are various conflicting requirements.
547 * {0,0} kprintf the entire MIB-tree.
548 * {0,1,...} return the name of the "..." OID.
549 * {0,2,...} return the next OID.
550 * {0,3} return the OID of the name in "new"
551 * {0,4,...} return the kind & format info for the "..." OID.
555 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list
*l
, int i
)
558 struct sysctl_oid
*oidp
;
560 SLIST_FOREACH(oidp
, l
, oid_link
) {
565 kprintf("%d %s ", oidp
->oid_number
, oidp
->oid_name
);
568 oidp
->oid_kind
& CTLFLAG_RD
? 'R':' ',
569 oidp
->oid_kind
& CTLFLAG_WR
? 'W':' ');
571 if (oidp
->oid_handler
)
572 kprintf(" *Handler");
574 switch (oidp
->oid_kind
& CTLTYPE
) {
577 if (!oidp
->oid_handler
) {
578 sysctl_sysctl_debug_dump_node(
579 oidp
->oid_arg1
, i
+2);
582 case CTLTYPE_INT
: kprintf(" Int\n"); break;
583 case CTLTYPE_STRING
: kprintf(" String\n"); break;
584 case CTLTYPE_QUAD
: kprintf(" Quad\n"); break;
585 case CTLTYPE_OPAQUE
: kprintf(" Opaque/struct\n"); break;
586 default: kprintf("\n");
593 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS
)
597 error
= priv_check(req
->td
, PRIV_SYSCTL_DEBUG
);
600 sysctl_sysctl_debug_dump_node(&sysctl__children
, 0);
605 SYSCTL_PROC(_sysctl
, 0, debug
, CTLTYPE_STRING
|CTLFLAG_RD
,
606 0, 0, sysctl_sysctl_debug
, "-", "");
609 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS
)
611 int *name
= (int *) arg1
;
612 u_int namelen
= arg2
;
614 struct sysctl_oid
*oid
;
615 struct sysctl_oid_list
*lsp
= &sysctl__children
, *lsp2
;
620 ksnprintf(buf
, sizeof(buf
), "%d", *name
);
622 error
= SYSCTL_OUT(req
, ".", 1);
624 error
= SYSCTL_OUT(req
, buf
, strlen(buf
));
632 SLIST_FOREACH(oid
, lsp
, oid_link
) {
633 if (oid
->oid_number
!= *name
)
637 error
= SYSCTL_OUT(req
, ".", 1);
639 error
= SYSCTL_OUT(req
, oid
->oid_name
,
640 strlen(oid
->oid_name
));
647 if ((oid
->oid_kind
& CTLTYPE
) != CTLTYPE_NODE
)
650 if (oid
->oid_handler
)
653 lsp2
= SYSCTL_CHILDREN(oid
);
658 error
= SYSCTL_OUT(req
, "", 1);
663 SYSCTL_NODE(_sysctl
, 1, name
, CTLFLAG_RD
, sysctl_sysctl_name
, "");
666 sysctl_sysctl_next_ls(struct sysctl_oid_list
*lsp
, int *name
, u_int namelen
,
667 int *next
, int *len
, int level
, struct sysctl_oid
**oidpp
)
669 struct sysctl_oid
*oidp
;
672 SLIST_FOREACH(oidp
, lsp
, oid_link
) {
673 *next
= oidp
->oid_number
;
676 if (oidp
->oid_kind
& CTLFLAG_SKIP
)
680 if ((oidp
->oid_kind
& CTLTYPE
) != CTLTYPE_NODE
)
682 if (oidp
->oid_handler
)
683 /* We really should call the handler here...*/
685 lsp
= SYSCTL_CHILDREN(oidp
);
686 if (!sysctl_sysctl_next_ls(lsp
, 0, 0, next
+1,
687 len
, level
+1, oidpp
))
692 if (oidp
->oid_number
< *name
)
695 if (oidp
->oid_number
> *name
) {
696 if ((oidp
->oid_kind
& CTLTYPE
) != CTLTYPE_NODE
)
698 if (oidp
->oid_handler
)
700 lsp
= SYSCTL_CHILDREN(oidp
);
701 if (!sysctl_sysctl_next_ls(lsp
, name
+1, namelen
-1,
702 next
+1, len
, level
+1, oidpp
))
706 if ((oidp
->oid_kind
& CTLTYPE
) != CTLTYPE_NODE
)
709 if (oidp
->oid_handler
)
712 lsp
= SYSCTL_CHILDREN(oidp
);
713 if (!sysctl_sysctl_next_ls(lsp
, name
+1, namelen
-1, next
+1,
714 len
, level
+1, oidpp
))
725 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS
)
727 int *name
= (int *) arg1
;
728 u_int namelen
= arg2
;
730 struct sysctl_oid
*oid
;
731 struct sysctl_oid_list
*lsp
= &sysctl__children
;
732 int newoid
[CTL_MAXNAME
];
734 i
= sysctl_sysctl_next_ls(lsp
, name
, namelen
, newoid
, &j
, 1, &oid
);
737 error
= SYSCTL_OUT(req
, newoid
, j
* sizeof (int));
742 SYSCTL_NODE(_sysctl
, 2, next
, CTLFLAG_RD
, sysctl_sysctl_next
, "");
745 name2oid(char *name
, int *oid
, int *len
, struct sysctl_oid
**oidpp
)
747 struct sysctl_oid
*oidp
;
748 struct sysctl_oid_list
*lsp
= &sysctl__children
;
751 SYSCTL_ASSERT_LOCKED();
753 for (*len
= 0; *len
< CTL_MAXNAME
;) {
754 p
= strsep(&name
, ".");
756 oidp
= SLIST_FIRST(lsp
);
757 for (;; oidp
= SLIST_NEXT(oidp
, oid_link
)) {
760 if (strcmp(p
, oidp
->oid_name
) == 0)
763 *oid
++ = oidp
->oid_number
;
766 if (name
== NULL
|| *name
== '\0') {
772 if ((oidp
->oid_kind
& CTLTYPE
) != CTLTYPE_NODE
)
775 if (oidp
->oid_handler
)
778 lsp
= SYSCTL_CHILDREN(oidp
);
784 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS
)
787 int error
, oid
[CTL_MAXNAME
], len
;
788 struct sysctl_oid
*op
= NULL
;
792 if (req
->newlen
>= MAXPATHLEN
) /* XXX arbitrary, undocumented */
793 return (ENAMETOOLONG
);
795 p
= kmalloc(req
->newlen
+1, M_SYSCTL
, M_WAITOK
);
797 error
= SYSCTL_IN(req
, p
, req
->newlen
);
803 p
[req
->newlen
] = '\0';
805 error
= name2oid(p
, oid
, &len
, &op
);
812 error
= SYSCTL_OUT(req
, oid
, len
* sizeof *oid
);
816 SYSCTL_PROC(_sysctl
, 3, name2oid
, CTLFLAG_RW
|CTLFLAG_ANYBODY
|CTLFLAG_SHLOCK
,
817 0, 0, sysctl_sysctl_name2oid
, "I", "");
820 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS
)
822 struct sysctl_oid
*oid
;
825 error
= sysctl_find_oid(arg1
, arg2
, &oid
, NULL
, req
);
831 error
= SYSCTL_OUT(req
, &oid
->oid_kind
, sizeof(oid
->oid_kind
));
834 error
= SYSCTL_OUT(req
, oid
->oid_fmt
, strlen(oid
->oid_fmt
) + 1);
839 SYSCTL_NODE(_sysctl
, 4, oidfmt
, CTLFLAG_RD
, sysctl_sysctl_oidfmt
, "");
842 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS
)
844 struct sysctl_oid
*oid
;
847 error
= sysctl_find_oid(arg1
, arg2
, &oid
, NULL
, req
);
853 error
= SYSCTL_OUT(req
, oid
->oid_descr
, strlen(oid
->oid_descr
) + 1);
857 SYSCTL_NODE(_sysctl
, 5, oiddescr
, CTLFLAG_RD
, sysctl_sysctl_oiddescr
, "");
860 * Default "handler" functions.
864 * Handle an int, signed or unsigned.
866 * a variable: point arg1 at it.
867 * a constant: pass it in arg2.
871 sysctl_handle_int(SYSCTL_HANDLER_ARGS
)
876 error
= SYSCTL_OUT(req
, arg1
, sizeof(int));
878 error
= SYSCTL_OUT(req
, &arg2
, sizeof(int));
880 if (error
|| !req
->newptr
)
886 error
= SYSCTL_IN(req
, arg1
, sizeof(int));
891 * Handle a long, signed or unsigned. arg1 points to it.
895 sysctl_handle_long(SYSCTL_HANDLER_ARGS
)
901 error
= SYSCTL_OUT(req
, arg1
, sizeof(long));
903 if (error
|| !req
->newptr
)
906 error
= SYSCTL_IN(req
, arg1
, sizeof(long));
911 * Handle a quad, signed or unsigned. arg1 points to it.
915 sysctl_handle_quad(SYSCTL_HANDLER_ARGS
)
921 error
= SYSCTL_OUT(req
, arg1
, sizeof(quad_t
));
923 if (error
|| !req
->newptr
)
926 error
= SYSCTL_IN(req
, arg1
, sizeof(quad_t
));
931 * Handle our generic '\0' terminated 'C' string.
933 * a variable string: point arg1 at it, arg2 is max length.
934 * a constant string: point arg1 at it, arg2 is zero.
938 sysctl_handle_string(SYSCTL_HANDLER_ARGS
)
942 error
= SYSCTL_OUT(req
, arg1
, strlen((char *)arg1
)+1);
944 if (error
|| !req
->newptr
)
947 if ((req
->newlen
- req
->newidx
) >= arg2
) {
950 arg2
= (req
->newlen
- req
->newidx
);
951 error
= SYSCTL_IN(req
, arg1
, arg2
);
952 ((char *)arg1
)[arg2
] = '\0';
959 * Handle any kind of opaque data.
960 * arg1 points to it, arg2 is the size.
964 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS
)
968 error
= SYSCTL_OUT(req
, arg1
, arg2
);
970 if (error
|| !req
->newptr
)
973 error
= SYSCTL_IN(req
, arg1
, arg2
);
979 * Transfer functions to/from kernel space.
980 * XXX: rather untested at this point
983 sysctl_old_kernel(struct sysctl_req
*req
, const void *p
, size_t l
)
989 if (i
> req
->oldlen
- req
->oldidx
)
990 i
= req
->oldlen
- req
->oldidx
;
992 bcopy(p
, (char *)req
->oldptr
+ req
->oldidx
, i
);
995 if (req
->oldptr
&& i
!= l
)
1001 sysctl_new_kernel(struct sysctl_req
*req
, void *p
, size_t l
)
1006 if (req
->newlen
- req
->newidx
< l
)
1008 bcopy((char *)req
->newptr
+ req
->newidx
, p
, l
);
1014 kernel_sysctl(int *name
, u_int namelen
,
1015 void *old
, size_t *oldlenp
,
1016 void *new, size_t newlen
, size_t *retval
)
1019 struct sysctl_req req
;
1021 bzero(&req
, sizeof req
);
1026 req
.oldlen
= *oldlenp
;
1028 req
.validlen
= req
.oldlen
;
1035 req
.newlen
= newlen
;
1039 req
.oldfunc
= sysctl_old_kernel
;
1040 req
.newfunc
= sysctl_new_kernel
;
1042 req
.lock
= REQ_UNWIRED
;
1046 error
= sysctl_root(0, name
, namelen
, &req
);
1050 if (req
.lock
== REQ_WIRED
&& req
.validlen
> 0)
1051 vsunlock(req
.oldptr
, req
.validlen
);
1054 if (error
&& error
!= ENOMEM
)
1058 if (req
.oldptr
&& req
.oldidx
> req
.validlen
)
1059 *retval
= req
.validlen
;
1061 *retval
= req
.oldidx
;
1067 kernel_sysctlbyname(char *name
,
1068 void *old
, size_t *oldlenp
,
1069 void *new, size_t newlen
, size_t *retval
)
1071 int oid
[CTL_MAXNAME
];
1072 size_t oidlen
, plen
;
1075 oid
[0] = 0; /* sysctl internal magic */
1076 oid
[1] = 3; /* name2oid */
1077 oidlen
= sizeof(oid
);
1079 error
= kernel_sysctl(oid
, 2, oid
, &oidlen
, name
, strlen(name
), &plen
);
1083 error
= kernel_sysctl(oid
, plen
/ sizeof(int), old
, oldlenp
,
1084 new, newlen
, retval
);
1089 * Transfer function to/from user space.
1092 sysctl_old_user(struct sysctl_req
*req
, const void *p
, size_t l
)
1098 if (req
->lock
== 1 && req
->oldptr
) {
1099 vslock(req
->oldptr
, req
->oldlen
);
1105 if (i
> req
->oldlen
- req
->oldidx
)
1106 i
= req
->oldlen
- req
->oldidx
;
1108 error
= copyout(p
, (char *)req
->oldptr
+ req
->oldidx
,
1114 if (req
->oldptr
&& i
< l
)
1120 sysctl_new_user(struct sysctl_req
*req
, void *p
, size_t l
)
1126 if (req
->newlen
- req
->newidx
< l
)
1128 error
= copyin((char *)req
->newptr
+ req
->newidx
, p
, l
);
1134 sysctl_find_oid(int *name
, u_int namelen
, struct sysctl_oid
**noid
,
1135 int *nindx
, struct sysctl_req
*req
)
1137 struct sysctl_oid_list
*lsp
;
1138 struct sysctl_oid
*oid
;
1141 lsp
= &sysctl__children
;
1143 while (indx
< CTL_MAXNAME
) {
1144 SLIST_FOREACH(oid
, lsp
, oid_link
) {
1145 if (oid
->oid_number
== name
[indx
])
1152 if ((oid
->oid_kind
& CTLTYPE
) == CTLTYPE_NODE
) {
1153 if (oid
->oid_handler
!= NULL
|| indx
== namelen
) {
1157 KASSERT((oid
->oid_kind
& CTLFLAG_DYING
) == 0,
1158 ("%s found DYING node %p", __func__
, oid
));
1161 lsp
= SYSCTL_CHILDREN(oid
);
1162 } else if (indx
== namelen
) {
1166 KASSERT((oid
->oid_kind
& CTLFLAG_DYING
) == 0,
1167 ("%s found DYING node %p", __func__
, oid
));
1177 * Traverse our tree, and find the right node, execute whatever it points
1178 * to, and return the resulting error code.
1181 sysctl_root(SYSCTL_HANDLER_ARGS
)
1183 struct thread
*td
= req
->td
;
1184 struct proc
*p
= td
? td
->td_proc
: NULL
;
1185 struct sysctl_oid
*oid
;
1189 error
= sysctl_find_oid(arg1
, arg2
, &oid
, &indx
, req
);
1193 if ((oid
->oid_kind
& CTLTYPE
) == CTLTYPE_NODE
) {
1195 * You can't call a sysctl when it's a node, but has
1196 * no handler. Inform the user that it's a node.
1197 * The indx may or may not be the same as namelen.
1199 if (oid
->oid_handler
== NULL
)
1203 /* If writing isn't allowed */
1204 if (req
->newptr
&& (!(oid
->oid_kind
& CTLFLAG_WR
) ||
1205 ((oid
->oid_kind
& CTLFLAG_SECURE
) && securelevel
> 0)))
1208 /* Most likely only root can write */
1209 if (!(oid
->oid_kind
& CTLFLAG_ANYBODY
) && req
->newptr
&& p
&&
1210 (error
= priv_check_cred(td
->td_ucred
,
1211 (oid
->oid_kind
& CTLFLAG_PRISON
) ? PRIV_SYSCTL_WRITEJAIL
:
1212 PRIV_SYSCTL_WRITE
, 0)))
1215 if (oid
->oid_handler
== NULL
)
1219 * Default oid locking is exclusive when modifying (newptr),
1220 * shared otherwise, unless overridden with a control flag.
1222 lktype
= (req
->newptr
!= NULL
) ? LK_EXCLUSIVE
: LK_SHARED
;
1223 if (oid
->oid_kind
& CTLFLAG_SHLOCK
)
1225 if (oid
->oid_kind
& CTLFLAG_EXLOCK
)
1226 lktype
= LK_EXCLUSIVE
;
1227 lockmgr(&oid
->oid_lock
, lktype
);
1229 if ((oid
->oid_kind
& CTLTYPE
) == CTLTYPE_NODE
)
1230 error
= oid
->oid_handler(oid
, (int *)arg1
+ indx
, arg2
- indx
,
1233 error
= oid
->oid_handler(oid
, oid
->oid_arg1
, oid
->oid_arg2
,
1235 lockmgr(&oid
->oid_lock
, LK_RELEASE
);
1241 sys___sysctl(struct sysctl_args
*uap
)
1243 int error
, i
, name
[CTL_MAXNAME
];
1246 if (uap
->namelen
> CTL_MAXNAME
|| uap
->namelen
< 2)
1249 error
= copyin(uap
->name
, &name
, uap
->namelen
* sizeof(int));
1253 error
= userland_sysctl(name
, uap
->namelen
,
1254 uap
->old
, uap
->oldlenp
, 0,
1255 uap
->new, uap
->newlen
, &j
);
1256 if (error
&& error
!= ENOMEM
)
1259 i
= copyout(&j
, uap
->oldlenp
, sizeof(j
));
1267 * This is used from various compatibility syscalls too. That's why name
1268 * must be in kernel space.
1271 userland_sysctl(int *name
, u_int namelen
,
1272 void *old
, size_t *oldlenp
, int inkernel
,
1273 void *new, size_t newlen
, size_t *retval
)
1275 int error
= 0, memlocked
;
1276 struct sysctl_req req
;
1278 bzero(&req
, sizeof req
);
1285 req
.oldlen
= *oldlenp
;
1287 error
= copyin(oldlenp
, &req
.oldlen
, sizeof(*oldlenp
));
1292 req
.validlen
= req
.oldlen
;
1295 if (!useracc(old
, req
.oldlen
, VM_PROT_WRITE
))
1301 if (!useracc(new, newlen
, VM_PROT_READ
))
1303 req
.newlen
= newlen
;
1307 req
.oldfunc
= sysctl_old_user
;
1308 req
.newfunc
= sysctl_new_user
;
1310 req
.lock
= REQ_UNWIRED
;
1314 if (KTRPOINT(curthread
, KTR_SYSCTL
))
1315 ktrsysctl(name
, namelen
);
1318 if (req
.oldlen
> PAGE_SIZE
) {
1320 lockmgr(&sysctlmemlock
, LK_EXCLUSIVE
);
1328 error
= sysctl_root(0, name
, namelen
, &req
);
1330 if (error
!= EAGAIN
)
1336 if (req
.lock
== REQ_WIRED
&& req
.validlen
> 0)
1337 vsunlock(req
.oldptr
, req
.validlen
);
1340 lockmgr(&sysctlmemlock
, LK_RELEASE
);
1342 if (error
&& error
!= ENOMEM
)
1346 if (req
.oldptr
&& req
.oldidx
> req
.validlen
)
1347 *retval
= req
.validlen
;
1349 *retval
= req
.oldidx
;
1355 sysctl_int_range(SYSCTL_HANDLER_ARGS
, int low
, int high
)
1359 value
= *(int *)arg1
;
1360 error
= sysctl_handle_int(oidp
, &value
, 0, req
);
1361 if (error
|| !req
->newptr
)
1363 if (value
< low
|| value
> high
)
1365 *(int *)arg1
= value
;
1370 * Drain into a sysctl struct. The user buffer should be wired if a page
1371 * fault would cause issue.
1374 sbuf_sysctl_drain(void *arg
, const char *data
, int len
)
1376 struct sysctl_req
*req
= arg
;
1379 error
= SYSCTL_OUT(req
, data
, len
);
1380 KASSERT(error
>= 0, ("Got unexpected negative value %d", error
));
1381 return (error
== 0 ? len
: -error
);
1385 sbuf_new_for_sysctl(struct sbuf
*s
, char *buf
, int length
,
1386 struct sysctl_req
*req
)
1389 s
= sbuf_new(s
, buf
, length
, SBUF_FIXEDLEN
);
1390 sbuf_set_drain(s
, sbuf_sysctl_drain
, req
);