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);