1/*-
2 * Copyright (c) 1982, 1986, 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Mike Karels at Berkeley Software Design, Inc.
7 *
8 * Quite extensively rewritten by Poul-Henning Kamp of the FreeBSD
9 * project, to make these variables more userfriendly.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
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 * 4. 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.
22 *
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
33 * SUCH DAMAGE.
34 *
35 * @(#)kern_sysctl.c 8.4 (Berkeley) 4/14/94
36 */
37
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: head/sys/kern/kern_sysctl.c 217616 2011-01-19 23:00:25Z mdf $");
40
41#include "opt_compat.h"
42#include "opt_ktrace.h"
43
44#include <sys/param.h>
45#include <sys/fail.h>
46#include <sys/systm.h>
47#include <sys/kernel.h>
48#include <sys/sysctl.h>
49#include <sys/malloc.h>
50#include <sys/priv.h>
51#include <sys/proc.h>
52#include <sys/jail.h>
53#include <sys/lock.h>
54#include <sys/mutex.h>
55#include <sys/sbuf.h>
56#include <sys/sx.h>
57#include <sys/sysproto.h>
58#include <sys/uio.h>
59#ifdef KTRACE
60#include <sys/ktrace.h>
61#endif
62
63#include <net/vnet.h>
64
65#include <security/mac/mac_framework.h>
66
67#include <vm/vm.h>
68#include <vm/vm_extern.h>
69
70static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic");
71static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids");
72static MALLOC_DEFINE(M_SYSCTLTMP, "sysctltmp", "sysctl temp output buffer");
73
74/*
75 * The sysctllock protects the MIB tree. It also protects sysctl
76 * contexts used with dynamic sysctls. The sysctl_register_oid() and
77 * sysctl_unregister_oid() routines require the sysctllock to already
78 * be held, so the sysctl_lock() and sysctl_unlock() routines are
79 * provided for the few places in the kernel which need to use that
80 * API rather than using the dynamic API. Use of the dynamic API is
81 * strongly encouraged for most code.
82 *
83 * The sysctlmemlock is used to limit the amount of user memory wired for
84 * sysctl requests. This is implemented by serializing any userland
85 * sysctl requests larger than a single page via an exclusive lock.
86 */
87static struct sx sysctllock;
88static struct sx sysctlmemlock;
89
90#define SYSCTL_XLOCK() sx_xlock(&sysctllock)
91#define SYSCTL_XUNLOCK() sx_xunlock(&sysctllock)
92#define SYSCTL_ASSERT_XLOCKED() sx_assert(&sysctllock, SA_XLOCKED)
93#define SYSCTL_INIT() sx_init(&sysctllock, "sysctl lock")
94#define SYSCTL_SLEEP(ch, wmesg, timo) \
95 sx_sleep(ch, &sysctllock, 0, wmesg, timo)
96
97static int sysctl_root(SYSCTL_HANDLER_ARGS);
98
99struct sysctl_oid_list sysctl__children; /* root list */
100
101static int sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del,
102 int recurse);
103
104static struct sysctl_oid *
105sysctl_find_oidname(const char *name, struct sysctl_oid_list *list)
106{
107 struct sysctl_oid *oidp;
108
109 SYSCTL_ASSERT_XLOCKED();
110 SLIST_FOREACH(oidp, list, oid_link) {
111 if (strcmp(oidp->oid_name, name) == 0) {
112 return (oidp);
113 }
114 }
115 return (NULL);
116}
117
118/*
119 * Initialization of the MIB tree.
120 *
121 * Order by number in each list.
122 */
123void
124sysctl_lock(void)
125{
126
127 SYSCTL_XLOCK();
128}
129
130void
131sysctl_unlock(void)
132{
133
134 SYSCTL_XUNLOCK();
135}
136
137void
138sysctl_register_oid(struct sysctl_oid *oidp)
139{
140 struct sysctl_oid_list *parent = oidp->oid_parent;
141 struct sysctl_oid *p;
142 struct sysctl_oid *q;
143
144 /*
145 * First check if another oid with the same name already
146 * exists in the parent's list.
147 */
148 SYSCTL_ASSERT_XLOCKED();
149 p = sysctl_find_oidname(oidp->oid_name, parent);
150 if (p != NULL) {
151 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
152 p->oid_refcnt++;
153 return;
154 } else {
155 printf("can't re-use a leaf (%s)!\n", p->oid_name);
156 return;
157 }
158 }
159 /*
160 * If this oid has a number OID_AUTO, give it a number which
161 * is greater than any current oid.
162 * NOTE: DO NOT change the starting value here, change it in
163 * <sys/sysctl.h>, and make sure it is at least 256 to
164 * accomodate e.g. net.inet.raw as a static sysctl node.
165 */
166 if (oidp->oid_number == OID_AUTO) {
167 static int newoid = CTL_AUTO_START;
168
169 oidp->oid_number = newoid++;
170 if (newoid == 0x7fffffff)
171 panic("out of oids");
172 }
173#if 0
174 else if (oidp->oid_number >= CTL_AUTO_START) {
175 /* do not panic; this happens when unregistering sysctl sets */
176 printf("static sysctl oid too high: %d", oidp->oid_number);
177 }
178#endif
179
180 /*
181 * Insert the oid into the parent's list in order.
182 */
183 q = NULL;
184 SLIST_FOREACH(p, parent, oid_link) {
185 if (oidp->oid_number < p->oid_number)
186 break;
187 q = p;
188 }
189 if (q)
190 SLIST_INSERT_AFTER(q, oidp, oid_link);
191 else
192 SLIST_INSERT_HEAD(parent, oidp, oid_link);
193}
194
195void
196sysctl_unregister_oid(struct sysctl_oid *oidp)
197{
198 struct sysctl_oid *p;
199 int error;
200
201 SYSCTL_ASSERT_XLOCKED();
202 error = ENOENT;
203 if (oidp->oid_number == OID_AUTO) {
204 error = EINVAL;
205 } else {
206 SLIST_FOREACH(p, oidp->oid_parent, oid_link) {
207 if (p == oidp) {
208 SLIST_REMOVE(oidp->oid_parent, oidp,
209 sysctl_oid, oid_link);
210 error = 0;
211 break;
212 }
213 }
214 }
215
216 /*
217 * This can happen when a module fails to register and is
218 * being unloaded afterwards. It should not be a panic()
219 * for normal use.
220 */
221 if (error)
222 printf("%s: failed to unregister sysctl\n", __func__);
223}
224
225/* Initialize a new context to keep track of dynamically added sysctls. */
226int
227sysctl_ctx_init(struct sysctl_ctx_list *c)
228{
229
230 if (c == NULL) {
231 return (EINVAL);
232 }
233
234 /*
235 * No locking here, the caller is responsible for not adding
236 * new nodes to a context until after this function has
237 * returned.
238 */
239 TAILQ_INIT(c);
240 return (0);
241}
242
243/* Free the context, and destroy all dynamic oids registered in this context */
244int
245sysctl_ctx_free(struct sysctl_ctx_list *clist)
246{
247 struct sysctl_ctx_entry *e, *e1;
248 int error;
249
250 error = 0;
251 /*
252 * First perform a "dry run" to check if it's ok to remove oids.
253 * XXX FIXME
254 * XXX This algorithm is a hack. But I don't know any
255 * XXX better solution for now...
256 */
257 SYSCTL_XLOCK();
258 TAILQ_FOREACH(e, clist, link) {
259 error = sysctl_remove_oid_locked(e->entry, 0, 0);
260 if (error)
261 break;
262 }
263 /*
264 * Restore deregistered entries, either from the end,
265 * or from the place where error occured.
266 * e contains the entry that was not unregistered
267 */
268 if (error)
269 e1 = TAILQ_PREV(e, sysctl_ctx_list, link);
270 else
271 e1 = TAILQ_LAST(clist, sysctl_ctx_list);
272 while (e1 != NULL) {
273 sysctl_register_oid(e1->entry);
274 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link);
275 }
276 if (error) {
277 SYSCTL_XUNLOCK();
278 return(EBUSY);
279 }
280 /* Now really delete the entries */
281 e = TAILQ_FIRST(clist);
282 while (e != NULL) {
283 e1 = TAILQ_NEXT(e, link);
284 error = sysctl_remove_oid_locked(e->entry, 1, 0);
285 if (error)
286 panic("sysctl_remove_oid: corrupt tree, entry: %s",
287 e->entry->oid_name);
288 free(e, M_SYSCTLOID);
289 e = e1;
290 }
291 SYSCTL_XUNLOCK();
292 return (error);
293}
294
295/* Add an entry to the context */
296struct sysctl_ctx_entry *
297sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
298{
299 struct sysctl_ctx_entry *e;
300
301 SYSCTL_ASSERT_XLOCKED();
302 if (clist == NULL || oidp == NULL)
303 return(NULL);
304 e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK);
305 e->entry = oidp;
306 TAILQ_INSERT_HEAD(clist, e, link);
307 return (e);
308}
309
310/* Find an entry in the context */
311struct sysctl_ctx_entry *
312sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
313{
314 struct sysctl_ctx_entry *e;
315
316 SYSCTL_ASSERT_XLOCKED();
317 if (clist == NULL || oidp == NULL)
318 return(NULL);
319 TAILQ_FOREACH(e, clist, link) {
320 if(e->entry == oidp)
321 return(e);
322 }
323 return (e);
324}
325
326/*
327 * Delete an entry from the context.
328 * NOTE: this function doesn't free oidp! You have to remove it
329 * with sysctl_remove_oid().
330 */
331int
332sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
333{
334 struct sysctl_ctx_entry *e;
335
336 if (clist == NULL || oidp == NULL)
337 return (EINVAL);
338 SYSCTL_XLOCK();
339 e = sysctl_ctx_entry_find(clist, oidp);
340 if (e != NULL) {
341 TAILQ_REMOVE(clist, e, link);
342 SYSCTL_XUNLOCK();
343 free(e, M_SYSCTLOID);
344 return (0);
345 } else {
346 SYSCTL_XUNLOCK();
347 return (ENOENT);
348 }
349}
350
351/*
352 * Remove dynamically created sysctl trees.
353 * oidp - top of the tree to be removed
354 * del - if 0 - just deregister, otherwise free up entries as well
355 * recurse - if != 0 traverse the subtree to be deleted
356 */
357int
358sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse)
359{
360 int error;
361
362 SYSCTL_XLOCK();
363 error = sysctl_remove_oid_locked(oidp, del, recurse);
364 SYSCTL_XUNLOCK();
365 return (error);
366}
367
368static int
369sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse)
370{
371 struct sysctl_oid *p;
372 int error;
373
374 SYSCTL_ASSERT_XLOCKED();
375 if (oidp == NULL)
376 return(EINVAL);
377 if ((oidp->oid_kind & CTLFLAG_DYN) == 0) {
378 printf("can't remove non-dynamic nodes!\n");
379 return (EINVAL);
380 }
381 /*
382 * WARNING: normal method to do this should be through
383 * sysctl_ctx_free(). Use recursing as the last resort
384 * method to purge your sysctl tree of leftovers...
385 * However, if some other code still references these nodes,
386 * it will panic.
387 */
388 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
389 if (oidp->oid_refcnt == 1) {
390 SLIST_FOREACH(p, SYSCTL_CHILDREN(oidp), oid_link) {
391 if (!recurse)
392 return (ENOTEMPTY);
393 error = sysctl_remove_oid_locked(p, del,
394 recurse);
395 if (error)
396 return (error);
397 }
398 if (del)
399 free(SYSCTL_CHILDREN(oidp), M_SYSCTLOID);
400 }
401 }
402 if (oidp->oid_refcnt > 1 ) {
403 oidp->oid_refcnt--;
404 } else {
405 if (oidp->oid_refcnt == 0) {
406 printf("Warning: bad oid_refcnt=%u (%s)!\n",
407 oidp->oid_refcnt, oidp->oid_name);
408 return (EINVAL);
409 }
410 sysctl_unregister_oid(oidp);
411 if (del) {
412 /*
413 * Wait for all threads running the handler to drain.
414 * This preserves the previous behavior when the
415 * sysctl lock was held across a handler invocation,
416 * and is necessary for module unload correctness.
417 */
418 while (oidp->oid_running > 0) {
419 oidp->oid_kind |= CTLFLAG_DYING;
420 SYSCTL_SLEEP(&oidp->oid_running, "oidrm", 0);
421 }
422 if (oidp->oid_descr)
423 free((void *)(uintptr_t)(const void *)oidp->oid_descr, M_SYSCTLOID);
424 free((void *)(uintptr_t)(const void *)oidp->oid_name,
425 M_SYSCTLOID);
426 free(oidp, M_SYSCTLOID);
427 }
428 }
429 return (0);
430}
431
432/*
433 * Create new sysctls at run time.
434 * clist may point to a valid context initialized with sysctl_ctx_init().
435 */
436struct sysctl_oid *
437sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent,
438 int number, const char *name, int kind, void *arg1, int arg2,
439 int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr)
440{
441 struct sysctl_oid *oidp;
442 ssize_t len;
443 char *newname;
444
445 /* You have to hook up somewhere.. */
446 if (parent == NULL)
447 return(NULL);
448 /* Check if the node already exists, otherwise create it */
449 SYSCTL_XLOCK();
450 oidp = sysctl_find_oidname(name, parent);
451 if (oidp != NULL) {
452 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
453 oidp->oid_refcnt++;
454 /* Update the context */
455 if (clist != NULL)
456 sysctl_ctx_entry_add(clist, oidp);
457 SYSCTL_XUNLOCK();
458 return (oidp);
459 } else {
460 SYSCTL_XUNLOCK();
461 printf("can't re-use a leaf (%s)!\n", name);
462 return (NULL);
463 }
464 }
465 oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO);
466 oidp->oid_parent = parent;
467 SLIST_NEXT(oidp, oid_link) = NULL;
468 oidp->oid_number = number;
469 oidp->oid_refcnt = 1;
470 len = strlen(name);
471 newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK);
472 bcopy(name, newname, len + 1);
473 newname[len] = '\0';
474 oidp->oid_name = newname;
475 oidp->oid_handler = handler;
476 oidp->oid_kind = CTLFLAG_DYN | kind;
477 if ((kind & CTLTYPE) == CTLTYPE_NODE) {
478 /* Allocate space for children */
479 SYSCTL_CHILDREN_SET(oidp, malloc(sizeof(struct sysctl_oid_list),
480 M_SYSCTLOID, M_WAITOK));
481 SLIST_INIT(SYSCTL_CHILDREN(oidp));
482 } else {
483 oidp->oid_arg1 = arg1;
484 oidp->oid_arg2 = arg2;
485 }
486 oidp->oid_fmt = fmt;
487 if (descr) {
488 int len = strlen(descr) + 1;
489 oidp->oid_descr = malloc(len, M_SYSCTLOID, M_WAITOK);
490 if (oidp->oid_descr)
491 strcpy((char *)(uintptr_t)(const void *)oidp->oid_descr, descr);
492 }
493 /* Update the context, if used */
494 if (clist != NULL)
495 sysctl_ctx_entry_add(clist, oidp);
496 /* Register this oid */
497 sysctl_register_oid(oidp);
498 SYSCTL_XUNLOCK();
499 return (oidp);
500}
501
502/*
503 * Rename an existing oid.
504 */
505void
506sysctl_rename_oid(struct sysctl_oid *oidp, const char *name)
507{
508 ssize_t len;
509 char *newname;
510 void *oldname;
511
512 len = strlen(name);
513 newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK);
514 bcopy(name, newname, len + 1);
515 newname[len] = '\0';
516 SYSCTL_XLOCK();
517 oldname = (void *)(uintptr_t)(const void *)oidp->oid_name;
518 oidp->oid_name = newname;
519 SYSCTL_XUNLOCK();
520 free(oldname, M_SYSCTLOID);
521}
522
523/*
524 * Reparent an existing oid.
525 */
526int
527sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent)
528{
529 struct sysctl_oid *oidp;
530
531 SYSCTL_XLOCK();
532 if (oid->oid_parent == parent) {
533 SYSCTL_XUNLOCK();
534 return (0);
535 }
536 oidp = sysctl_find_oidname(oid->oid_name, parent);
537 if (oidp != NULL) {
538 SYSCTL_XUNLOCK();
539 return (EEXIST);
540 }
541 sysctl_unregister_oid(oid);
542 oid->oid_parent = parent;
543 oid->oid_number = OID_AUTO;
544 sysctl_register_oid(oid);
545 SYSCTL_XUNLOCK();
546 return (0);
547}
548
549/*
550 * Register the kernel's oids on startup.
551 */
552SET_DECLARE(sysctl_set, struct sysctl_oid);
553
554static void
555sysctl_register_all(void *arg)
556{
557 struct sysctl_oid **oidp;
558
559 sx_init(&sysctlmemlock, "sysctl mem");
560 SYSCTL_INIT();
561 SYSCTL_XLOCK();
562 SET_FOREACH(oidp, sysctl_set)
563 sysctl_register_oid(*oidp);
564 SYSCTL_XUNLOCK();
565}
566SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_ANY, sysctl_register_all, 0);
567
568/*
569 * "Staff-functions"
570 *
571 * These functions implement a presently undocumented interface
572 * used by the sysctl program to walk the tree, and get the type
573 * so it can print the value.
574 * This interface is under work and consideration, and should probably
575 * be killed with a big axe by the first person who can find the time.
576 * (be aware though, that the proper interface isn't as obvious as it
577 * may seem, there are various conflicting requirements.
578 *
579 * {0,0} printf the entire MIB-tree.
580 * {0,1,...} return the name of the "..." OID.
581 * {0,2,...} return the next OID.
582 * {0,3} return the OID of the name in "new"
583 * {0,4,...} return the kind & format info for the "..." OID.
584 * {0,5,...} return the description the "..." OID.
585 */
586
587#ifdef SYSCTL_DEBUG
588static void
589sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i)
590{
591 int k;
592 struct sysctl_oid *oidp;
593
594 SYSCTL_ASSERT_XLOCKED();
595 SLIST_FOREACH(oidp, l, oid_link) {
596
597 for (k=0; k<i; k++)
598 printf(" ");
599
600 printf("%d %s ", oidp->oid_number, oidp->oid_name);
601
602 printf("%c%c",
603 oidp->oid_kind & CTLFLAG_RD ? 'R':' ',
604 oidp->oid_kind & CTLFLAG_WR ? 'W':' ');
605
606 if (oidp->oid_handler)
607 printf(" *Handler");
608
609 switch (oidp->oid_kind & CTLTYPE) {
610 case CTLTYPE_NODE:
611 printf(" Node\n");
612 if (!oidp->oid_handler) {
613 sysctl_sysctl_debug_dump_node(
614 oidp->oid_arg1, i+2);
615 }
616 break;
617 case CTLTYPE_INT: printf(" Int\n"); break;
618 case CTLTYPE_UINT: printf(" u_int\n"); break;
619 case CTLTYPE_LONG: printf(" Long\n"); break;
620 case CTLTYPE_ULONG: printf(" u_long\n"); break;
621 case CTLTYPE_STRING: printf(" String\n"); break;
622 case CTLTYPE_U64: printf(" uint64_t\n"); break;
623 case CTLTYPE_S64: printf(" int64_t\n"); break;
624 case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break;
625 default: printf("\n");
626 }
627
628 }
629}
630
631static int
632sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS)
633{
634 int error;
635
636 error = priv_check(req->td, PRIV_SYSCTL_DEBUG);
637 if (error)
638 return (error);
639 SYSCTL_XLOCK();
640 sysctl_sysctl_debug_dump_node(&sysctl__children, 0);
641 SYSCTL_XUNLOCK();
642 return (ENOENT);
643}
644
645SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD,
646 0, 0, sysctl_sysctl_debug, "-", "");
647#endif
648
649static int
650sysctl_sysctl_name(SYSCTL_HANDLER_ARGS)
651{
652 int *name = (int *) arg1;
653 u_int namelen = arg2;
654 int error = 0;
655 struct sysctl_oid *oid;
656 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2;
657 char buf[10];
658
659 SYSCTL_XLOCK();
660 while (namelen) {
661 if (!lsp) {
662 snprintf(buf,sizeof(buf),"%d",*name);
663 if (req->oldidx)
664 error = SYSCTL_OUT(req, ".", 1);
665 if (!error)
666 error = SYSCTL_OUT(req, buf, strlen(buf));
667 if (error)
668 goto out;
669 namelen--;
670 name++;
671 continue;
672 }
673 lsp2 = 0;
674 SLIST_FOREACH(oid, lsp, oid_link) {
675 if (oid->oid_number != *name)
676 continue;
677
678 if (req->oldidx)
679 error = SYSCTL_OUT(req, ".", 1);
680 if (!error)
681 error = SYSCTL_OUT(req, oid->oid_name,
682 strlen(oid->oid_name));
683 if (error)
684 goto out;
685
686 namelen--;
687 name++;
688
689 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE)
690 break;
691
692 if (oid->oid_handler)
693 break;
694
695 lsp2 = SYSCTL_CHILDREN(oid);
696 break;
697 }
698 lsp = lsp2;
699 }
700 error = SYSCTL_OUT(req, "", 1);
701 out:
702 SYSCTL_XUNLOCK();
703 return (error);
704}
705
706static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD, sysctl_sysctl_name, "");
707
708static int
709sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen,
710 int *next, int *len, int level, struct sysctl_oid **oidpp)
711{
712 struct sysctl_oid *oidp;
713
714 SYSCTL_ASSERT_XLOCKED();
715 *len = level;
716 SLIST_FOREACH(oidp, lsp, oid_link) {
717 *next = oidp->oid_number;
718 *oidpp = oidp;
719
720 if (oidp->oid_kind & CTLFLAG_SKIP)
721 continue;
722
723 if (!namelen) {
724 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
725 return (0);
726 if (oidp->oid_handler)
727 /* We really should call the handler here...*/
728 return (0);
729 lsp = SYSCTL_CHILDREN(oidp);
730 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1,
731 len, level+1, oidpp))
732 return (0);
733 goto emptynode;
734 }
735
736 if (oidp->oid_number < *name)
737 continue;
738
739 if (oidp->oid_number > *name) {
740 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
741 return (0);
742 if (oidp->oid_handler)
743 return (0);
744 lsp = SYSCTL_CHILDREN(oidp);
745 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1,
746 next+1, len, level+1, oidpp))
747 return (0);
748 goto next;
749 }
750 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
751 continue;
752
753 if (oidp->oid_handler)
754 continue;
755
756 lsp = SYSCTL_CHILDREN(oidp);
757 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1,
758 len, level+1, oidpp))
759 return (0);
760 next:
761 namelen = 1;
762 emptynode:
763 *len = level;
764 }
765 return (1);
766}
767
768static int
769sysctl_sysctl_next(SYSCTL_HANDLER_ARGS)
770{
771 int *name = (int *) arg1;
772 u_int namelen = arg2;
773 int i, j, error;
774 struct sysctl_oid *oid;
775 struct sysctl_oid_list *lsp = &sysctl__children;
776 int newoid[CTL_MAXNAME];
777
778 SYSCTL_XLOCK();
779 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid);
780 SYSCTL_XUNLOCK();
781 if (i)
782 return (ENOENT);
783 error = SYSCTL_OUT(req, newoid, j * sizeof (int));
784 return (error);
785}
786
787static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD, sysctl_sysctl_next, "");
788
789static int
790name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp)
791{
792 int i;
793 struct sysctl_oid *oidp;
794 struct sysctl_oid_list *lsp = &sysctl__children;
795 char *p;
796
797 SYSCTL_ASSERT_XLOCKED();
798
799 if (!*name)
800 return (ENOENT);
801
802 p = name + strlen(name) - 1 ;
803 if (*p == '.')
804 *p = '\0';
805
806 *len = 0;
807
808 for (p = name; *p && *p != '.'; p++)
809 ;
810 i = *p;
811 if (i == '.')
812 *p = '\0';
813
814 oidp = SLIST_FIRST(lsp);
815
816 while (oidp && *len < CTL_MAXNAME) {
817 if (strcmp(name, oidp->oid_name)) {
818 oidp = SLIST_NEXT(oidp, oid_link);
819 continue;
820 }
821 *oid++ = oidp->oid_number;
822 (*len)++;
823
824 if (!i) {
825 if (oidpp)
826 *oidpp = oidp;
827 return (0);
828 }
829
830 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
831 break;
832
833 if (oidp->oid_handler)
834 break;
835
836 lsp = SYSCTL_CHILDREN(oidp);
837 oidp = SLIST_FIRST(lsp);
838 name = p+1;
839 for (p = name; *p && *p != '.'; p++)
840 ;
841 i = *p;
842 if (i == '.')
843 *p = '\0';
844 }
845 return (ENOENT);
846}
847
848static int
849sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS)
850{
851 char *p;
852 int error, oid[CTL_MAXNAME], len = 0;
853 struct sysctl_oid *op = 0;
854
855 if (!req->newlen)
856 return (ENOENT);
857 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */
858 return (ENAMETOOLONG);
859
860 p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK);
861
862 error = SYSCTL_IN(req, p, req->newlen);
863 if (error) {
864 free(p, M_SYSCTL);
865 return (error);
866 }
867
868 p [req->newlen] = '\0';
869
870 SYSCTL_XLOCK();
871 error = name2oid(p, oid, &len, &op);
872 SYSCTL_XUNLOCK();
873
874 free(p, M_SYSCTL);
875
876 if (error)
877 return (error);
878
879 error = SYSCTL_OUT(req, oid, len * sizeof *oid);
880 return (error);
881}
882
883SYSCTL_PROC(_sysctl, 3, name2oid,
884 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_MPSAFE,
885 0, 0, sysctl_sysctl_name2oid, "I", "");
886
887static int
888sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS)
889{
890 struct sysctl_oid *oid;
891 int error;
892
893 SYSCTL_XLOCK();
894 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
895 if (error)
896 goto out;
897
898 if (oid->oid_fmt == NULL) {
899 error = ENOENT;
900 goto out;
901 }
902 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind));
903 if (error)
904 goto out;
905 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1);
906 out:
907 SYSCTL_XUNLOCK();
908 return (error);
909}
910
911
912static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE,
913 sysctl_sysctl_oidfmt, "");
914
915static int
916sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS)
917{
918 struct sysctl_oid *oid;
919 int error;
920
921 SYSCTL_XLOCK();
922 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
923 if (error)
924 goto out;
925
926 if (oid->oid_descr == NULL) {
927 error = ENOENT;
928 goto out;
929 }
930 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1);
931 out:
932 SYSCTL_XUNLOCK();
933 return (error);
934}
935
936static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD, sysctl_sysctl_oiddescr, "");
937
938/*
939 * Default "handler" functions.
940 */
941
942/*
943 * Handle an int, signed or unsigned.
944 * Two cases:
945 * a variable: point arg1 at it.
946 * a constant: pass it in arg2.
947 */
948
949int
950sysctl_handle_int(SYSCTL_HANDLER_ARGS)
951{
952 int tmpout, error = 0;
953
954 /*
955 * Attempt to get a coherent snapshot by making a copy of the data.
956 */
957 if (arg1)
958 tmpout = *(int *)arg1;
959 else
960 tmpout = arg2;
961 error = SYSCTL_OUT(req, &tmpout, sizeof(int));
962
963 if (error || !req->newptr)
964 return (error);
965
966 if (!arg1)
967 error = EPERM;
968 else
969 error = SYSCTL_IN(req, arg1, sizeof(int));
970 return (error);
971}
972
973/*
974 * Based on on sysctl_handle_int() convert milliseconds into ticks.
975 * Note: this is used by TCP.
976 */
977
978int
979sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS)
980{
981 int error, s, tt;
982
983 tt = *(int *)arg1;
984 s = (int)((int64_t)tt * 1000 / hz);
985
986 error = sysctl_handle_int(oidp, &s, 0, req);
987 if (error || !req->newptr)
988 return (error);
989
990 tt = (int)((int64_t)s * hz / 1000);
991 if (tt < 1)
992 return (EINVAL);
993
994 *(int *)arg1 = tt;
995 return (0);
996}
997
998
999/*
1000 * Handle a long, signed or unsigned. arg1 points to it.
1001 */
1002
1003int
1004sysctl_handle_long(SYSCTL_HANDLER_ARGS)
1005{
1006 int error = 0;
1007 long tmplong;
1008#ifdef SCTL_MASK32
1009 int tmpint;
1010#endif
1011
1012 /*
1013 * Attempt to get a coherent snapshot by making a copy of the data.
1014 */
1015 if (!arg1)
1016 return (EINVAL);
1017 tmplong = *(long *)arg1;
1018#ifdef SCTL_MASK32
1019 if (req->flags & SCTL_MASK32) {
1020 tmpint = tmplong;
1021 error = SYSCTL_OUT(req, &tmpint, sizeof(int));
1022 } else
1023#endif
1024 error = SYSCTL_OUT(req, &tmplong, sizeof(long));
1025
1026 if (error || !req->newptr)
1027 return (error);
1028
1029#ifdef SCTL_MASK32
1030 if (req->flags & SCTL_MASK32) {
1031 error = SYSCTL_IN(req, &tmpint, sizeof(int));
1032 *(long *)arg1 = (long)tmpint;
1033 } else
1034#endif
1035 error = SYSCTL_IN(req, arg1, sizeof(long));
1036 return (error);
1037}
1038
1039/*
1040 * Handle a 64 bit int, signed or unsigned. arg1 points to it.
1041 */
1042int
1043sysctl_handle_64(SYSCTL_HANDLER_ARGS)
1044{
1045 int error = 0;
1046 uint64_t tmpout;
1047
1048 /*
1049 * Attempt to get a coherent snapshot by making a copy of the data.
1050 */
1051 if (!arg1)
1052 return (EINVAL);
1053 tmpout = *(uint64_t *)arg1;
1054 error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t));
1055
1056 if (error || !req->newptr)
1057 return (error);
1058
1059 error = SYSCTL_IN(req, arg1, sizeof(uint64_t));
1060 return (error);
1061}
1062
1063/*
1064 * Handle our generic '\0' terminated 'C' string.
1065 * Two cases:
1066 * a variable string: point arg1 at it, arg2 is max length.
1067 * a constant string: point arg1 at it, arg2 is zero.
1068 */
1069
1070int
1071sysctl_handle_string(SYSCTL_HANDLER_ARGS)
1072{
1073 int error=0;
1074 char *tmparg;
1075 size_t outlen;
1076
1077 /*
1078 * Attempt to get a coherent snapshot by copying to a
1079 * temporary kernel buffer.
1080 */
1081retry:
1082 outlen = strlen((char *)arg1)+1;
1083 tmparg = malloc(outlen, M_SYSCTLTMP, M_WAITOK);
1084
1085 if (strlcpy(tmparg, (char *)arg1, outlen) >= outlen) {
1086 free(tmparg, M_SYSCTLTMP);
1087 goto retry;
1088 }
1089
1090 error = SYSCTL_OUT(req, tmparg, outlen);
1091 free(tmparg, M_SYSCTLTMP);
1092
1093 if (error || !req->newptr)
1094 return (error);
1095
1096 if ((req->newlen - req->newidx) >= arg2) {
1097 error = EINVAL;
1098 } else {
1099 arg2 = (req->newlen - req->newidx);
1100 error = SYSCTL_IN(req, arg1, arg2);
1101 ((char *)arg1)[arg2] = '\0';
1102 }
1103
1104 return (error);
1105}
1106
1107/*
1108 * Handle any kind of opaque data.
1109 * arg1 points to it, arg2 is the size.
1110 */
1111
1112int
1113sysctl_handle_opaque(SYSCTL_HANDLER_ARGS)
1114{
1115 int error, tries;
1116 u_int generation;
1117 struct sysctl_req req2;
1118
1119 /*
1120 * Attempt to get a coherent snapshot, by using the thread
1121 * pre-emption counter updated from within mi_switch() to
1122 * determine if we were pre-empted during a bcopy() or
1123 * copyout(). Make 3 attempts at doing this before giving up.
1124 * If we encounter an error, stop immediately.
1125 */
1126 tries = 0;
1127 req2 = *req;
1128retry:
1129 generation = curthread->td_generation;
1130 error = SYSCTL_OUT(req, arg1, arg2);
1131 if (error)
1132 return (error);
1133 tries++;
1134 if (generation != curthread->td_generation && tries < 3) {
1135 *req = req2;
1136 goto retry;
1137 }
1138
1139 error = SYSCTL_IN(req, arg1, arg2);
1140
1141 return (error);
1142}
1143
1144/*
1145 * Transfer functions to/from kernel space.
1146 * XXX: rather untested at this point
1147 */
1148static int
1149sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l)
1150{
1151 size_t i = 0;
1152
1153 if (req->oldptr) {
1154 i = l;
1155 if (req->oldlen <= req->oldidx)
1156 i = 0;
1157 else
1158 if (i > req->oldlen - req->oldidx)
1159 i = req->oldlen - req->oldidx;
1160 if (i > 0)
1161 bcopy(p, (char *)req->oldptr + req->oldidx, i);
1162 }
1163 req->oldidx += l;
1164 if (req->oldptr && i != l)
1165 return (ENOMEM);
1166 return (0);
1167}
1168
1169static int
1170sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l)
1171{
1172 if (!req->newptr)
1173 return (0);
1174 if (req->newlen - req->newidx < l)
1175 return (EINVAL);
1176 bcopy((char *)req->newptr + req->newidx, p, l);
1177 req->newidx += l;
1178 return (0);
1179}
1180
1181int
1182kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old,
1183 size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags)
1184{
1185 int error = 0;
1186 struct sysctl_req req;
1187
1188 bzero(&req, sizeof req);
1189
1190 req.td = td;
1191 req.flags = flags;
1192
1193 if (oldlenp) {
1194 req.oldlen = *oldlenp;
1195 }
1196 req.validlen = req.oldlen;
1197
1198 if (old) {
1199 req.oldptr= old;
1200 }
1201
1202 if (new != NULL) {
1203 req.newlen = newlen;
1204 req.newptr = new;
1205 }
1206
1207 req.oldfunc = sysctl_old_kernel;
1208 req.newfunc = sysctl_new_kernel;
1209 req.lock = REQ_LOCKED;
1210
1211 SYSCTL_XLOCK();
1212 error = sysctl_root(0, name, namelen, &req);
1213 SYSCTL_XUNLOCK();
1214
1215 if (req.lock == REQ_WIRED && req.validlen > 0)
1216 vsunlock(req.oldptr, req.validlen);
1217
1218 if (error && error != ENOMEM)
1219 return (error);
1220
1221 if (retval) {
1222 if (req.oldptr && req.oldidx > req.validlen)
1223 *retval = req.validlen;
1224 else
1225 *retval = req.oldidx;
1226 }
1227 return (error);
1228}
1229
1230int
1231kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp,
1232 void *new, size_t newlen, size_t *retval, int flags)
1233{
1234 int oid[CTL_MAXNAME];
1235 size_t oidlen, plen;
1236 int error;
1237
1238 oid[0] = 0; /* sysctl internal magic */
1239 oid[1] = 3; /* name2oid */
1240 oidlen = sizeof(oid);
1241
1242 error = kernel_sysctl(td, oid, 2, oid, &oidlen,
1243 (void *)name, strlen(name), &plen, flags);
1244 if (error)
1245 return (error);
1246
1247 error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp,
1248 new, newlen, retval, flags);
1249 return (error);
1250}
1251
1252/*
1253 * Transfer function to/from user space.
1254 */
1255static int
1256sysctl_old_user(struct sysctl_req *req, const void *p, size_t l)
1257{
1258 int error = 0;
1259 size_t i, len, origidx;
1260
1261 origidx = req->oldidx;
1262 req->oldidx += l;
1263 if (req->oldptr == NULL)
1264 return (0);
1265 /*
1266 * If we have not wired the user supplied buffer and we are currently
1267 * holding locks, drop a witness warning, as it's possible that
1268 * write operations to the user page can sleep.
1269 */
1270 if (req->lock != REQ_WIRED)
1271 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
1272 "sysctl_old_user()");
1273 i = l;
1274 len = req->validlen;
1275 if (len <= origidx)
1276 i = 0;
1277 else {
1278 if (i > len - origidx)
1279 i = len - origidx;
1280 error = copyout(p, (char *)req->oldptr + origidx, i);
1281 }
1282 if (error)
1283 return (error);
1284 if (i < l)
1285 return (ENOMEM);
1286 return (0);
1287}
1288
1289static int
1290sysctl_new_user(struct sysctl_req *req, void *p, size_t l)
1291{
1292 int error;
1293
1294 if (!req->newptr)
1295 return (0);
1296 if (req->newlen - req->newidx < l)
1297 return (EINVAL);
1298 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
1299 "sysctl_new_user()");
1300 error = copyin((char *)req->newptr + req->newidx, p, l);
1301 req->newidx += l;
1302 return (error);
1303}
1304
1305/*
1306 * Wire the user space destination buffer. If set to a value greater than
1307 * zero, the len parameter limits the maximum amount of wired memory.
1308 */
1309int
1310sysctl_wire_old_buffer(struct sysctl_req *req, size_t len)
1311{
1312 int ret;
1313 size_t wiredlen;
1314
1315 wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen;
1316 ret = 0;
1317 if (req->lock == REQ_LOCKED && req->oldptr &&
1318 req->oldfunc == sysctl_old_user) {
1319 if (wiredlen != 0) {
1320 ret = vslock(req->oldptr, wiredlen);
1321 if (ret != 0) {
1322 if (ret != ENOMEM)
1323 return (ret);
1324 wiredlen = 0;
1325 }
1326 }
1327 req->lock = REQ_WIRED;
1328 req->validlen = wiredlen;
1329 }
1330 return (0);
1331}
1332
1333int
1334sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid,
1335 int *nindx, struct sysctl_req *req)
1336{
1337 struct sysctl_oid_list *lsp;
1338 struct sysctl_oid *oid;
1339 int indx;
1340
1341 SYSCTL_ASSERT_XLOCKED();
1342 lsp = &sysctl__children;
1343 indx = 0;
1344 while (indx < CTL_MAXNAME) {
1345 SLIST_FOREACH(oid, lsp, oid_link) {
1346 if (oid->oid_number == name[indx])
1347 break;
1348 }
1349 if (oid == NULL)
1350 return (ENOENT);
1351
1352 indx++;
1353 if (oid->oid_kind & CTLFLAG_NOLOCK)
1354 req->lock = REQ_UNLOCKED;
1355 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1356 if (oid->oid_handler != NULL || indx == namelen) {
1357 *noid = oid;
1358 if (nindx != NULL)
1359 *nindx = indx;
1360 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0,
1361 ("%s found DYING node %p", __func__, oid));
1362 return (0);
1363 }
1364 lsp = SYSCTL_CHILDREN(oid);
1365 } else if (indx == namelen) {
1366 *noid = oid;
1367 if (nindx != NULL)
1368 *nindx = indx;
1369 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0,
1370 ("%s found DYING node %p", __func__, oid));
1371 return (0);
1372 } else {
1373 return (ENOTDIR);
1374 }
1375 }
1376 return (ENOENT);
1377}
1378
1379/*
1380 * Traverse our tree, and find the right node, execute whatever it points
1381 * to, and return the resulting error code.
1382 */
1383
1384static int
1385sysctl_root(SYSCTL_HANDLER_ARGS)
1386{
1387 struct sysctl_oid *oid;
1388 int error, indx, lvl;
1389
1390 SYSCTL_ASSERT_XLOCKED();
1391
1392 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req);
1393 if (error)
1394 return (error);
1395
1396 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1397 /*
1398 * You can't call a sysctl when it's a node, but has
1399 * no handler. Inform the user that it's a node.
1400 * The indx may or may not be the same as namelen.
1401 */
1402 if (oid->oid_handler == NULL)
1403 return (EISDIR);
1404 }
1405
1406 /* Is this sysctl writable? */
1407 if (req->newptr && !(oid->oid_kind & CTLFLAG_WR))
1408 return (EPERM);
1409
1410 KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL"));
1411
1412 /* Is this sysctl sensitive to securelevels? */
1413 if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) {
1414 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE;
1415 error = securelevel_gt(req->td->td_ucred, lvl);
1416 if (error)
1417 return (error);
1418 }
1419
1420 /* Is this sysctl writable by only privileged users? */
1421 if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) {
1422 int priv;
1423
1424 if (oid->oid_kind & CTLFLAG_PRISON)
1425 priv = PRIV_SYSCTL_WRITEJAIL;
1426#ifdef VIMAGE
1427 else if ((oid->oid_kind & CTLFLAG_VNET) &&
1428 prison_owns_vnet(req->td->td_ucred))
1429 priv = PRIV_SYSCTL_WRITEJAIL;
1430#endif
1431 else
1432 priv = PRIV_SYSCTL_WRITE;
1433 error = priv_check(req->td, priv);
1434 if (error)
1435 return (error);
1436 }
1437
1438 if (!oid->oid_handler)
1439 return (EINVAL);
1440
1441 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1442 arg1 = (int *)arg1 + indx;
1443 arg2 -= indx;
1444 } else {
1445 arg1 = oid->oid_arg1;
1446 arg2 = oid->oid_arg2;
1447 }
1448#ifdef MAC
1449 error = mac_system_check_sysctl(req->td->td_ucred, oid, arg1, arg2,
1450 req);
1451 if (error != 0)
1452 return (error);
1453#endif
1454 oid->oid_running++;
1455 SYSCTL_XUNLOCK();
1456
1457 if (!(oid->oid_kind & CTLFLAG_MPSAFE))
1458 mtx_lock(&Giant);
1459 error = oid->oid_handler(oid, arg1, arg2, req);
1460 if (!(oid->oid_kind & CTLFLAG_MPSAFE))
1461 mtx_unlock(&Giant);
1462
1463 KFAIL_POINT_ERROR(_debug_fail_point, sysctl_running, error);
1464
1465 SYSCTL_XLOCK();
1466 oid->oid_running--;
1467 if (oid->oid_running == 0 && (oid->oid_kind & CTLFLAG_DYING) != 0)
1468 wakeup(&oid->oid_running);
1469 return (error);
1470}
1471
1472#ifndef _SYS_SYSPROTO_H_
1473struct sysctl_args {
1474 int *name;
1475 u_int namelen;
1476 void *old;
1477 size_t *oldlenp;
1478 void *new;
1479 size_t newlen;
1480};
1481#endif
1482int
1483__sysctl(struct thread *td, struct sysctl_args *uap)
1484{
1485 int error, i, name[CTL_MAXNAME];
1486 size_t j;
1487
1488 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2)
1489 return (EINVAL);
1490
1491 error = copyin(uap->name, &name, uap->namelen * sizeof(int));
1492 if (error)
1493 return (error);
1494
1495 error = userland_sysctl(td, name, uap->namelen,
1496 uap->old, uap->oldlenp, 0,
1497 uap->new, uap->newlen, &j, 0);
1498 if (error && error != ENOMEM)
1499 return (error);
1500 if (uap->oldlenp) {
1501 i = copyout(&j, uap->oldlenp, sizeof(j));
1502 if (i)
1503 return (i);
1504 }
1505 return (error);
1506}
1507
1508/*
1509 * This is used from various compatibility syscalls too. That's why name
1510 * must be in kernel space.
1511 */
1512int
1513userland_sysctl(struct thread *td, int *name, u_int namelen, void *old,
1514 size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval,
1515 int flags)
1516{
1517 int error = 0, memlocked;
1518 struct sysctl_req req;
1519
1520 bzero(&req, sizeof req);
1521
1522 req.td = td;
1523 req.flags = flags;
1524
1525 if (oldlenp) {
1526 if (inkernel) {
1527 req.oldlen = *oldlenp;
1528 } else {
1529 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp));
1530 if (error)
1531 return (error);
1532 }
1533 }
1534 req.validlen = req.oldlen;
1535
1536 if (old) {
1537 if (!useracc(old, req.oldlen, VM_PROT_WRITE))
1538 return (EFAULT);
1539 req.oldptr= old;
1540 }
1541
1542 if (new != NULL) {
1543 if (!useracc(new, newlen, VM_PROT_READ))
1544 return (EFAULT);
1545 req.newlen = newlen;
1546 req.newptr = new;
1547 }
1548
1549 req.oldfunc = sysctl_old_user;
1550 req.newfunc = sysctl_new_user;
1551 req.lock = REQ_LOCKED;
1552
1553#ifdef KTRACE
1554 if (KTRPOINT(curthread, KTR_SYSCTL))
1555 ktrsysctl(name, namelen);
1556#endif
1557
1558 if (req.oldlen > PAGE_SIZE) {
1559 memlocked = 1;
1560 sx_xlock(&sysctlmemlock);
1561 } else
1562 memlocked = 0;
1563 CURVNET_SET(TD_TO_VNET(td));
1564
1565 for (;;) {
1566 req.oldidx = 0;
1567 req.newidx = 0;
1568 SYSCTL_XLOCK();
1569 error = sysctl_root(0, name, namelen, &req);
1570 SYSCTL_XUNLOCK();
1571 if (error != EAGAIN)
1572 break;
1573 uio_yield();
1574 }
1575
1576 CURVNET_RESTORE();
1577
1578 if (req.lock == REQ_WIRED && req.validlen > 0)
1579 vsunlock(req.oldptr, req.validlen);
1580 if (memlocked)
1581 sx_xunlock(&sysctlmemlock);
1582
1583 if (error && error != ENOMEM)
1584 return (error);
1585
1586 if (retval) {
1587 if (req.oldptr && req.oldidx > req.validlen)
1588 *retval = req.validlen;
1589 else
1590 *retval = req.oldidx;
1591 }
1592 return (error);
1593}
1594
1595/*
1596 * Drain into a sysctl struct. The user buffer must be wired.
1597 */
1598static int
1599sbuf_sysctl_drain(void *arg, const char *data, int len)
1600{
1601 struct sysctl_req *req = arg;
1602 int error;
1603
1604 error = SYSCTL_OUT(req, data, len);
1605 KASSERT(error >= 0, ("Got unexpected negative value %d", error));
1606 return (error == 0 ? len : -error);
1607}
1608
1609struct sbuf *
1610sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length,
1611 struct sysctl_req *req)
1612{
1613
1614 /* Wire the user buffer, so we can write without blocking. */
1615 sysctl_wire_old_buffer(req, 0);
1616
1617 s = sbuf_new(s, buf, length, SBUF_FIXEDLEN);
1618 sbuf_set_drain(s, sbuf_sysctl_drain, req);
1619 return (s);
1620}
2 * Copyright (c) 1982, 1986, 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Mike Karels at Berkeley Software Design, Inc.
7 *
8 * Quite extensively rewritten by Poul-Henning Kamp of the FreeBSD
9 * project, to make these variables more userfriendly.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
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 * 4. 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.
22 *
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
33 * SUCH DAMAGE.
34 *
35 * @(#)kern_sysctl.c 8.4 (Berkeley) 4/14/94
36 */
37
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: head/sys/kern/kern_sysctl.c 217616 2011-01-19 23:00:25Z mdf $");
40
41#include "opt_compat.h"
42#include "opt_ktrace.h"
43
44#include <sys/param.h>
45#include <sys/fail.h>
46#include <sys/systm.h>
47#include <sys/kernel.h>
48#include <sys/sysctl.h>
49#include <sys/malloc.h>
50#include <sys/priv.h>
51#include <sys/proc.h>
52#include <sys/jail.h>
53#include <sys/lock.h>
54#include <sys/mutex.h>
55#include <sys/sbuf.h>
56#include <sys/sx.h>
57#include <sys/sysproto.h>
58#include <sys/uio.h>
59#ifdef KTRACE
60#include <sys/ktrace.h>
61#endif
62
63#include <net/vnet.h>
64
65#include <security/mac/mac_framework.h>
66
67#include <vm/vm.h>
68#include <vm/vm_extern.h>
69
70static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic");
71static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids");
72static MALLOC_DEFINE(M_SYSCTLTMP, "sysctltmp", "sysctl temp output buffer");
73
74/*
75 * The sysctllock protects the MIB tree. It also protects sysctl
76 * contexts used with dynamic sysctls. The sysctl_register_oid() and
77 * sysctl_unregister_oid() routines require the sysctllock to already
78 * be held, so the sysctl_lock() and sysctl_unlock() routines are
79 * provided for the few places in the kernel which need to use that
80 * API rather than using the dynamic API. Use of the dynamic API is
81 * strongly encouraged for most code.
82 *
83 * The sysctlmemlock is used to limit the amount of user memory wired for
84 * sysctl requests. This is implemented by serializing any userland
85 * sysctl requests larger than a single page via an exclusive lock.
86 */
87static struct sx sysctllock;
88static struct sx sysctlmemlock;
89
90#define SYSCTL_XLOCK() sx_xlock(&sysctllock)
91#define SYSCTL_XUNLOCK() sx_xunlock(&sysctllock)
92#define SYSCTL_ASSERT_XLOCKED() sx_assert(&sysctllock, SA_XLOCKED)
93#define SYSCTL_INIT() sx_init(&sysctllock, "sysctl lock")
94#define SYSCTL_SLEEP(ch, wmesg, timo) \
95 sx_sleep(ch, &sysctllock, 0, wmesg, timo)
96
97static int sysctl_root(SYSCTL_HANDLER_ARGS);
98
99struct sysctl_oid_list sysctl__children; /* root list */
100
101static int sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del,
102 int recurse);
103
104static struct sysctl_oid *
105sysctl_find_oidname(const char *name, struct sysctl_oid_list *list)
106{
107 struct sysctl_oid *oidp;
108
109 SYSCTL_ASSERT_XLOCKED();
110 SLIST_FOREACH(oidp, list, oid_link) {
111 if (strcmp(oidp->oid_name, name) == 0) {
112 return (oidp);
113 }
114 }
115 return (NULL);
116}
117
118/*
119 * Initialization of the MIB tree.
120 *
121 * Order by number in each list.
122 */
123void
124sysctl_lock(void)
125{
126
127 SYSCTL_XLOCK();
128}
129
130void
131sysctl_unlock(void)
132{
133
134 SYSCTL_XUNLOCK();
135}
136
137void
138sysctl_register_oid(struct sysctl_oid *oidp)
139{
140 struct sysctl_oid_list *parent = oidp->oid_parent;
141 struct sysctl_oid *p;
142 struct sysctl_oid *q;
143
144 /*
145 * First check if another oid with the same name already
146 * exists in the parent's list.
147 */
148 SYSCTL_ASSERT_XLOCKED();
149 p = sysctl_find_oidname(oidp->oid_name, parent);
150 if (p != NULL) {
151 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
152 p->oid_refcnt++;
153 return;
154 } else {
155 printf("can't re-use a leaf (%s)!\n", p->oid_name);
156 return;
157 }
158 }
159 /*
160 * If this oid has a number OID_AUTO, give it a number which
161 * is greater than any current oid.
162 * NOTE: DO NOT change the starting value here, change it in
163 * <sys/sysctl.h>, and make sure it is at least 256 to
164 * accomodate e.g. net.inet.raw as a static sysctl node.
165 */
166 if (oidp->oid_number == OID_AUTO) {
167 static int newoid = CTL_AUTO_START;
168
169 oidp->oid_number = newoid++;
170 if (newoid == 0x7fffffff)
171 panic("out of oids");
172 }
173#if 0
174 else if (oidp->oid_number >= CTL_AUTO_START) {
175 /* do not panic; this happens when unregistering sysctl sets */
176 printf("static sysctl oid too high: %d", oidp->oid_number);
177 }
178#endif
179
180 /*
181 * Insert the oid into the parent's list in order.
182 */
183 q = NULL;
184 SLIST_FOREACH(p, parent, oid_link) {
185 if (oidp->oid_number < p->oid_number)
186 break;
187 q = p;
188 }
189 if (q)
190 SLIST_INSERT_AFTER(q, oidp, oid_link);
191 else
192 SLIST_INSERT_HEAD(parent, oidp, oid_link);
193}
194
195void
196sysctl_unregister_oid(struct sysctl_oid *oidp)
197{
198 struct sysctl_oid *p;
199 int error;
200
201 SYSCTL_ASSERT_XLOCKED();
202 error = ENOENT;
203 if (oidp->oid_number == OID_AUTO) {
204 error = EINVAL;
205 } else {
206 SLIST_FOREACH(p, oidp->oid_parent, oid_link) {
207 if (p == oidp) {
208 SLIST_REMOVE(oidp->oid_parent, oidp,
209 sysctl_oid, oid_link);
210 error = 0;
211 break;
212 }
213 }
214 }
215
216 /*
217 * This can happen when a module fails to register and is
218 * being unloaded afterwards. It should not be a panic()
219 * for normal use.
220 */
221 if (error)
222 printf("%s: failed to unregister sysctl\n", __func__);
223}
224
225/* Initialize a new context to keep track of dynamically added sysctls. */
226int
227sysctl_ctx_init(struct sysctl_ctx_list *c)
228{
229
230 if (c == NULL) {
231 return (EINVAL);
232 }
233
234 /*
235 * No locking here, the caller is responsible for not adding
236 * new nodes to a context until after this function has
237 * returned.
238 */
239 TAILQ_INIT(c);
240 return (0);
241}
242
243/* Free the context, and destroy all dynamic oids registered in this context */
244int
245sysctl_ctx_free(struct sysctl_ctx_list *clist)
246{
247 struct sysctl_ctx_entry *e, *e1;
248 int error;
249
250 error = 0;
251 /*
252 * First perform a "dry run" to check if it's ok to remove oids.
253 * XXX FIXME
254 * XXX This algorithm is a hack. But I don't know any
255 * XXX better solution for now...
256 */
257 SYSCTL_XLOCK();
258 TAILQ_FOREACH(e, clist, link) {
259 error = sysctl_remove_oid_locked(e->entry, 0, 0);
260 if (error)
261 break;
262 }
263 /*
264 * Restore deregistered entries, either from the end,
265 * or from the place where error occured.
266 * e contains the entry that was not unregistered
267 */
268 if (error)
269 e1 = TAILQ_PREV(e, sysctl_ctx_list, link);
270 else
271 e1 = TAILQ_LAST(clist, sysctl_ctx_list);
272 while (e1 != NULL) {
273 sysctl_register_oid(e1->entry);
274 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link);
275 }
276 if (error) {
277 SYSCTL_XUNLOCK();
278 return(EBUSY);
279 }
280 /* Now really delete the entries */
281 e = TAILQ_FIRST(clist);
282 while (e != NULL) {
283 e1 = TAILQ_NEXT(e, link);
284 error = sysctl_remove_oid_locked(e->entry, 1, 0);
285 if (error)
286 panic("sysctl_remove_oid: corrupt tree, entry: %s",
287 e->entry->oid_name);
288 free(e, M_SYSCTLOID);
289 e = e1;
290 }
291 SYSCTL_XUNLOCK();
292 return (error);
293}
294
295/* Add an entry to the context */
296struct sysctl_ctx_entry *
297sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
298{
299 struct sysctl_ctx_entry *e;
300
301 SYSCTL_ASSERT_XLOCKED();
302 if (clist == NULL || oidp == NULL)
303 return(NULL);
304 e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK);
305 e->entry = oidp;
306 TAILQ_INSERT_HEAD(clist, e, link);
307 return (e);
308}
309
310/* Find an entry in the context */
311struct sysctl_ctx_entry *
312sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
313{
314 struct sysctl_ctx_entry *e;
315
316 SYSCTL_ASSERT_XLOCKED();
317 if (clist == NULL || oidp == NULL)
318 return(NULL);
319 TAILQ_FOREACH(e, clist, link) {
320 if(e->entry == oidp)
321 return(e);
322 }
323 return (e);
324}
325
326/*
327 * Delete an entry from the context.
328 * NOTE: this function doesn't free oidp! You have to remove it
329 * with sysctl_remove_oid().
330 */
331int
332sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
333{
334 struct sysctl_ctx_entry *e;
335
336 if (clist == NULL || oidp == NULL)
337 return (EINVAL);
338 SYSCTL_XLOCK();
339 e = sysctl_ctx_entry_find(clist, oidp);
340 if (e != NULL) {
341 TAILQ_REMOVE(clist, e, link);
342 SYSCTL_XUNLOCK();
343 free(e, M_SYSCTLOID);
344 return (0);
345 } else {
346 SYSCTL_XUNLOCK();
347 return (ENOENT);
348 }
349}
350
351/*
352 * Remove dynamically created sysctl trees.
353 * oidp - top of the tree to be removed
354 * del - if 0 - just deregister, otherwise free up entries as well
355 * recurse - if != 0 traverse the subtree to be deleted
356 */
357int
358sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse)
359{
360 int error;
361
362 SYSCTL_XLOCK();
363 error = sysctl_remove_oid_locked(oidp, del, recurse);
364 SYSCTL_XUNLOCK();
365 return (error);
366}
367
368static int
369sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse)
370{
371 struct sysctl_oid *p;
372 int error;
373
374 SYSCTL_ASSERT_XLOCKED();
375 if (oidp == NULL)
376 return(EINVAL);
377 if ((oidp->oid_kind & CTLFLAG_DYN) == 0) {
378 printf("can't remove non-dynamic nodes!\n");
379 return (EINVAL);
380 }
381 /*
382 * WARNING: normal method to do this should be through
383 * sysctl_ctx_free(). Use recursing as the last resort
384 * method to purge your sysctl tree of leftovers...
385 * However, if some other code still references these nodes,
386 * it will panic.
387 */
388 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
389 if (oidp->oid_refcnt == 1) {
390 SLIST_FOREACH(p, SYSCTL_CHILDREN(oidp), oid_link) {
391 if (!recurse)
392 return (ENOTEMPTY);
393 error = sysctl_remove_oid_locked(p, del,
394 recurse);
395 if (error)
396 return (error);
397 }
398 if (del)
399 free(SYSCTL_CHILDREN(oidp), M_SYSCTLOID);
400 }
401 }
402 if (oidp->oid_refcnt > 1 ) {
403 oidp->oid_refcnt--;
404 } else {
405 if (oidp->oid_refcnt == 0) {
406 printf("Warning: bad oid_refcnt=%u (%s)!\n",
407 oidp->oid_refcnt, oidp->oid_name);
408 return (EINVAL);
409 }
410 sysctl_unregister_oid(oidp);
411 if (del) {
412 /*
413 * Wait for all threads running the handler to drain.
414 * This preserves the previous behavior when the
415 * sysctl lock was held across a handler invocation,
416 * and is necessary for module unload correctness.
417 */
418 while (oidp->oid_running > 0) {
419 oidp->oid_kind |= CTLFLAG_DYING;
420 SYSCTL_SLEEP(&oidp->oid_running, "oidrm", 0);
421 }
422 if (oidp->oid_descr)
423 free((void *)(uintptr_t)(const void *)oidp->oid_descr, M_SYSCTLOID);
424 free((void *)(uintptr_t)(const void *)oidp->oid_name,
425 M_SYSCTLOID);
426 free(oidp, M_SYSCTLOID);
427 }
428 }
429 return (0);
430}
431
432/*
433 * Create new sysctls at run time.
434 * clist may point to a valid context initialized with sysctl_ctx_init().
435 */
436struct sysctl_oid *
437sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent,
438 int number, const char *name, int kind, void *arg1, int arg2,
439 int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr)
440{
441 struct sysctl_oid *oidp;
442 ssize_t len;
443 char *newname;
444
445 /* You have to hook up somewhere.. */
446 if (parent == NULL)
447 return(NULL);
448 /* Check if the node already exists, otherwise create it */
449 SYSCTL_XLOCK();
450 oidp = sysctl_find_oidname(name, parent);
451 if (oidp != NULL) {
452 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
453 oidp->oid_refcnt++;
454 /* Update the context */
455 if (clist != NULL)
456 sysctl_ctx_entry_add(clist, oidp);
457 SYSCTL_XUNLOCK();
458 return (oidp);
459 } else {
460 SYSCTL_XUNLOCK();
461 printf("can't re-use a leaf (%s)!\n", name);
462 return (NULL);
463 }
464 }
465 oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO);
466 oidp->oid_parent = parent;
467 SLIST_NEXT(oidp, oid_link) = NULL;
468 oidp->oid_number = number;
469 oidp->oid_refcnt = 1;
470 len = strlen(name);
471 newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK);
472 bcopy(name, newname, len + 1);
473 newname[len] = '\0';
474 oidp->oid_name = newname;
475 oidp->oid_handler = handler;
476 oidp->oid_kind = CTLFLAG_DYN | kind;
477 if ((kind & CTLTYPE) == CTLTYPE_NODE) {
478 /* Allocate space for children */
479 SYSCTL_CHILDREN_SET(oidp, malloc(sizeof(struct sysctl_oid_list),
480 M_SYSCTLOID, M_WAITOK));
481 SLIST_INIT(SYSCTL_CHILDREN(oidp));
482 } else {
483 oidp->oid_arg1 = arg1;
484 oidp->oid_arg2 = arg2;
485 }
486 oidp->oid_fmt = fmt;
487 if (descr) {
488 int len = strlen(descr) + 1;
489 oidp->oid_descr = malloc(len, M_SYSCTLOID, M_WAITOK);
490 if (oidp->oid_descr)
491 strcpy((char *)(uintptr_t)(const void *)oidp->oid_descr, descr);
492 }
493 /* Update the context, if used */
494 if (clist != NULL)
495 sysctl_ctx_entry_add(clist, oidp);
496 /* Register this oid */
497 sysctl_register_oid(oidp);
498 SYSCTL_XUNLOCK();
499 return (oidp);
500}
501
502/*
503 * Rename an existing oid.
504 */
505void
506sysctl_rename_oid(struct sysctl_oid *oidp, const char *name)
507{
508 ssize_t len;
509 char *newname;
510 void *oldname;
511
512 len = strlen(name);
513 newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK);
514 bcopy(name, newname, len + 1);
515 newname[len] = '\0';
516 SYSCTL_XLOCK();
517 oldname = (void *)(uintptr_t)(const void *)oidp->oid_name;
518 oidp->oid_name = newname;
519 SYSCTL_XUNLOCK();
520 free(oldname, M_SYSCTLOID);
521}
522
523/*
524 * Reparent an existing oid.
525 */
526int
527sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent)
528{
529 struct sysctl_oid *oidp;
530
531 SYSCTL_XLOCK();
532 if (oid->oid_parent == parent) {
533 SYSCTL_XUNLOCK();
534 return (0);
535 }
536 oidp = sysctl_find_oidname(oid->oid_name, parent);
537 if (oidp != NULL) {
538 SYSCTL_XUNLOCK();
539 return (EEXIST);
540 }
541 sysctl_unregister_oid(oid);
542 oid->oid_parent = parent;
543 oid->oid_number = OID_AUTO;
544 sysctl_register_oid(oid);
545 SYSCTL_XUNLOCK();
546 return (0);
547}
548
549/*
550 * Register the kernel's oids on startup.
551 */
552SET_DECLARE(sysctl_set, struct sysctl_oid);
553
554static void
555sysctl_register_all(void *arg)
556{
557 struct sysctl_oid **oidp;
558
559 sx_init(&sysctlmemlock, "sysctl mem");
560 SYSCTL_INIT();
561 SYSCTL_XLOCK();
562 SET_FOREACH(oidp, sysctl_set)
563 sysctl_register_oid(*oidp);
564 SYSCTL_XUNLOCK();
565}
566SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_ANY, sysctl_register_all, 0);
567
568/*
569 * "Staff-functions"
570 *
571 * These functions implement a presently undocumented interface
572 * used by the sysctl program to walk the tree, and get the type
573 * so it can print the value.
574 * This interface is under work and consideration, and should probably
575 * be killed with a big axe by the first person who can find the time.
576 * (be aware though, that the proper interface isn't as obvious as it
577 * may seem, there are various conflicting requirements.
578 *
579 * {0,0} printf the entire MIB-tree.
580 * {0,1,...} return the name of the "..." OID.
581 * {0,2,...} return the next OID.
582 * {0,3} return the OID of the name in "new"
583 * {0,4,...} return the kind & format info for the "..." OID.
584 * {0,5,...} return the description the "..." OID.
585 */
586
587#ifdef SYSCTL_DEBUG
588static void
589sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i)
590{
591 int k;
592 struct sysctl_oid *oidp;
593
594 SYSCTL_ASSERT_XLOCKED();
595 SLIST_FOREACH(oidp, l, oid_link) {
596
597 for (k=0; k<i; k++)
598 printf(" ");
599
600 printf("%d %s ", oidp->oid_number, oidp->oid_name);
601
602 printf("%c%c",
603 oidp->oid_kind & CTLFLAG_RD ? 'R':' ',
604 oidp->oid_kind & CTLFLAG_WR ? 'W':' ');
605
606 if (oidp->oid_handler)
607 printf(" *Handler");
608
609 switch (oidp->oid_kind & CTLTYPE) {
610 case CTLTYPE_NODE:
611 printf(" Node\n");
612 if (!oidp->oid_handler) {
613 sysctl_sysctl_debug_dump_node(
614 oidp->oid_arg1, i+2);
615 }
616 break;
617 case CTLTYPE_INT: printf(" Int\n"); break;
618 case CTLTYPE_UINT: printf(" u_int\n"); break;
619 case CTLTYPE_LONG: printf(" Long\n"); break;
620 case CTLTYPE_ULONG: printf(" u_long\n"); break;
621 case CTLTYPE_STRING: printf(" String\n"); break;
622 case CTLTYPE_U64: printf(" uint64_t\n"); break;
623 case CTLTYPE_S64: printf(" int64_t\n"); break;
624 case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break;
625 default: printf("\n");
626 }
627
628 }
629}
630
631static int
632sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS)
633{
634 int error;
635
636 error = priv_check(req->td, PRIV_SYSCTL_DEBUG);
637 if (error)
638 return (error);
639 SYSCTL_XLOCK();
640 sysctl_sysctl_debug_dump_node(&sysctl__children, 0);
641 SYSCTL_XUNLOCK();
642 return (ENOENT);
643}
644
645SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD,
646 0, 0, sysctl_sysctl_debug, "-", "");
647#endif
648
649static int
650sysctl_sysctl_name(SYSCTL_HANDLER_ARGS)
651{
652 int *name = (int *) arg1;
653 u_int namelen = arg2;
654 int error = 0;
655 struct sysctl_oid *oid;
656 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2;
657 char buf[10];
658
659 SYSCTL_XLOCK();
660 while (namelen) {
661 if (!lsp) {
662 snprintf(buf,sizeof(buf),"%d",*name);
663 if (req->oldidx)
664 error = SYSCTL_OUT(req, ".", 1);
665 if (!error)
666 error = SYSCTL_OUT(req, buf, strlen(buf));
667 if (error)
668 goto out;
669 namelen--;
670 name++;
671 continue;
672 }
673 lsp2 = 0;
674 SLIST_FOREACH(oid, lsp, oid_link) {
675 if (oid->oid_number != *name)
676 continue;
677
678 if (req->oldidx)
679 error = SYSCTL_OUT(req, ".", 1);
680 if (!error)
681 error = SYSCTL_OUT(req, oid->oid_name,
682 strlen(oid->oid_name));
683 if (error)
684 goto out;
685
686 namelen--;
687 name++;
688
689 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE)
690 break;
691
692 if (oid->oid_handler)
693 break;
694
695 lsp2 = SYSCTL_CHILDREN(oid);
696 break;
697 }
698 lsp = lsp2;
699 }
700 error = SYSCTL_OUT(req, "", 1);
701 out:
702 SYSCTL_XUNLOCK();
703 return (error);
704}
705
706static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD, sysctl_sysctl_name, "");
707
708static int
709sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen,
710 int *next, int *len, int level, struct sysctl_oid **oidpp)
711{
712 struct sysctl_oid *oidp;
713
714 SYSCTL_ASSERT_XLOCKED();
715 *len = level;
716 SLIST_FOREACH(oidp, lsp, oid_link) {
717 *next = oidp->oid_number;
718 *oidpp = oidp;
719
720 if (oidp->oid_kind & CTLFLAG_SKIP)
721 continue;
722
723 if (!namelen) {
724 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
725 return (0);
726 if (oidp->oid_handler)
727 /* We really should call the handler here...*/
728 return (0);
729 lsp = SYSCTL_CHILDREN(oidp);
730 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1,
731 len, level+1, oidpp))
732 return (0);
733 goto emptynode;
734 }
735
736 if (oidp->oid_number < *name)
737 continue;
738
739 if (oidp->oid_number > *name) {
740 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
741 return (0);
742 if (oidp->oid_handler)
743 return (0);
744 lsp = SYSCTL_CHILDREN(oidp);
745 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1,
746 next+1, len, level+1, oidpp))
747 return (0);
748 goto next;
749 }
750 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
751 continue;
752
753 if (oidp->oid_handler)
754 continue;
755
756 lsp = SYSCTL_CHILDREN(oidp);
757 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1,
758 len, level+1, oidpp))
759 return (0);
760 next:
761 namelen = 1;
762 emptynode:
763 *len = level;
764 }
765 return (1);
766}
767
768static int
769sysctl_sysctl_next(SYSCTL_HANDLER_ARGS)
770{
771 int *name = (int *) arg1;
772 u_int namelen = arg2;
773 int i, j, error;
774 struct sysctl_oid *oid;
775 struct sysctl_oid_list *lsp = &sysctl__children;
776 int newoid[CTL_MAXNAME];
777
778 SYSCTL_XLOCK();
779 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid);
780 SYSCTL_XUNLOCK();
781 if (i)
782 return (ENOENT);
783 error = SYSCTL_OUT(req, newoid, j * sizeof (int));
784 return (error);
785}
786
787static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD, sysctl_sysctl_next, "");
788
789static int
790name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp)
791{
792 int i;
793 struct sysctl_oid *oidp;
794 struct sysctl_oid_list *lsp = &sysctl__children;
795 char *p;
796
797 SYSCTL_ASSERT_XLOCKED();
798
799 if (!*name)
800 return (ENOENT);
801
802 p = name + strlen(name) - 1 ;
803 if (*p == '.')
804 *p = '\0';
805
806 *len = 0;
807
808 for (p = name; *p && *p != '.'; p++)
809 ;
810 i = *p;
811 if (i == '.')
812 *p = '\0';
813
814 oidp = SLIST_FIRST(lsp);
815
816 while (oidp && *len < CTL_MAXNAME) {
817 if (strcmp(name, oidp->oid_name)) {
818 oidp = SLIST_NEXT(oidp, oid_link);
819 continue;
820 }
821 *oid++ = oidp->oid_number;
822 (*len)++;
823
824 if (!i) {
825 if (oidpp)
826 *oidpp = oidp;
827 return (0);
828 }
829
830 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
831 break;
832
833 if (oidp->oid_handler)
834 break;
835
836 lsp = SYSCTL_CHILDREN(oidp);
837 oidp = SLIST_FIRST(lsp);
838 name = p+1;
839 for (p = name; *p && *p != '.'; p++)
840 ;
841 i = *p;
842 if (i == '.')
843 *p = '\0';
844 }
845 return (ENOENT);
846}
847
848static int
849sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS)
850{
851 char *p;
852 int error, oid[CTL_MAXNAME], len = 0;
853 struct sysctl_oid *op = 0;
854
855 if (!req->newlen)
856 return (ENOENT);
857 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */
858 return (ENAMETOOLONG);
859
860 p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK);
861
862 error = SYSCTL_IN(req, p, req->newlen);
863 if (error) {
864 free(p, M_SYSCTL);
865 return (error);
866 }
867
868 p [req->newlen] = '\0';
869
870 SYSCTL_XLOCK();
871 error = name2oid(p, oid, &len, &op);
872 SYSCTL_XUNLOCK();
873
874 free(p, M_SYSCTL);
875
876 if (error)
877 return (error);
878
879 error = SYSCTL_OUT(req, oid, len * sizeof *oid);
880 return (error);
881}
882
883SYSCTL_PROC(_sysctl, 3, name2oid,
884 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_MPSAFE,
885 0, 0, sysctl_sysctl_name2oid, "I", "");
886
887static int
888sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS)
889{
890 struct sysctl_oid *oid;
891 int error;
892
893 SYSCTL_XLOCK();
894 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
895 if (error)
896 goto out;
897
898 if (oid->oid_fmt == NULL) {
899 error = ENOENT;
900 goto out;
901 }
902 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind));
903 if (error)
904 goto out;
905 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1);
906 out:
907 SYSCTL_XUNLOCK();
908 return (error);
909}
910
911
912static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE,
913 sysctl_sysctl_oidfmt, "");
914
915static int
916sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS)
917{
918 struct sysctl_oid *oid;
919 int error;
920
921 SYSCTL_XLOCK();
922 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
923 if (error)
924 goto out;
925
926 if (oid->oid_descr == NULL) {
927 error = ENOENT;
928 goto out;
929 }
930 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1);
931 out:
932 SYSCTL_XUNLOCK();
933 return (error);
934}
935
936static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD, sysctl_sysctl_oiddescr, "");
937
938/*
939 * Default "handler" functions.
940 */
941
942/*
943 * Handle an int, signed or unsigned.
944 * Two cases:
945 * a variable: point arg1 at it.
946 * a constant: pass it in arg2.
947 */
948
949int
950sysctl_handle_int(SYSCTL_HANDLER_ARGS)
951{
952 int tmpout, error = 0;
953
954 /*
955 * Attempt to get a coherent snapshot by making a copy of the data.
956 */
957 if (arg1)
958 tmpout = *(int *)arg1;
959 else
960 tmpout = arg2;
961 error = SYSCTL_OUT(req, &tmpout, sizeof(int));
962
963 if (error || !req->newptr)
964 return (error);
965
966 if (!arg1)
967 error = EPERM;
968 else
969 error = SYSCTL_IN(req, arg1, sizeof(int));
970 return (error);
971}
972
973/*
974 * Based on on sysctl_handle_int() convert milliseconds into ticks.
975 * Note: this is used by TCP.
976 */
977
978int
979sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS)
980{
981 int error, s, tt;
982
983 tt = *(int *)arg1;
984 s = (int)((int64_t)tt * 1000 / hz);
985
986 error = sysctl_handle_int(oidp, &s, 0, req);
987 if (error || !req->newptr)
988 return (error);
989
990 tt = (int)((int64_t)s * hz / 1000);
991 if (tt < 1)
992 return (EINVAL);
993
994 *(int *)arg1 = tt;
995 return (0);
996}
997
998
999/*
1000 * Handle a long, signed or unsigned. arg1 points to it.
1001 */
1002
1003int
1004sysctl_handle_long(SYSCTL_HANDLER_ARGS)
1005{
1006 int error = 0;
1007 long tmplong;
1008#ifdef SCTL_MASK32
1009 int tmpint;
1010#endif
1011
1012 /*
1013 * Attempt to get a coherent snapshot by making a copy of the data.
1014 */
1015 if (!arg1)
1016 return (EINVAL);
1017 tmplong = *(long *)arg1;
1018#ifdef SCTL_MASK32
1019 if (req->flags & SCTL_MASK32) {
1020 tmpint = tmplong;
1021 error = SYSCTL_OUT(req, &tmpint, sizeof(int));
1022 } else
1023#endif
1024 error = SYSCTL_OUT(req, &tmplong, sizeof(long));
1025
1026 if (error || !req->newptr)
1027 return (error);
1028
1029#ifdef SCTL_MASK32
1030 if (req->flags & SCTL_MASK32) {
1031 error = SYSCTL_IN(req, &tmpint, sizeof(int));
1032 *(long *)arg1 = (long)tmpint;
1033 } else
1034#endif
1035 error = SYSCTL_IN(req, arg1, sizeof(long));
1036 return (error);
1037}
1038
1039/*
1040 * Handle a 64 bit int, signed or unsigned. arg1 points to it.
1041 */
1042int
1043sysctl_handle_64(SYSCTL_HANDLER_ARGS)
1044{
1045 int error = 0;
1046 uint64_t tmpout;
1047
1048 /*
1049 * Attempt to get a coherent snapshot by making a copy of the data.
1050 */
1051 if (!arg1)
1052 return (EINVAL);
1053 tmpout = *(uint64_t *)arg1;
1054 error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t));
1055
1056 if (error || !req->newptr)
1057 return (error);
1058
1059 error = SYSCTL_IN(req, arg1, sizeof(uint64_t));
1060 return (error);
1061}
1062
1063/*
1064 * Handle our generic '\0' terminated 'C' string.
1065 * Two cases:
1066 * a variable string: point arg1 at it, arg2 is max length.
1067 * a constant string: point arg1 at it, arg2 is zero.
1068 */
1069
1070int
1071sysctl_handle_string(SYSCTL_HANDLER_ARGS)
1072{
1073 int error=0;
1074 char *tmparg;
1075 size_t outlen;
1076
1077 /*
1078 * Attempt to get a coherent snapshot by copying to a
1079 * temporary kernel buffer.
1080 */
1081retry:
1082 outlen = strlen((char *)arg1)+1;
1083 tmparg = malloc(outlen, M_SYSCTLTMP, M_WAITOK);
1084
1085 if (strlcpy(tmparg, (char *)arg1, outlen) >= outlen) {
1086 free(tmparg, M_SYSCTLTMP);
1087 goto retry;
1088 }
1089
1090 error = SYSCTL_OUT(req, tmparg, outlen);
1091 free(tmparg, M_SYSCTLTMP);
1092
1093 if (error || !req->newptr)
1094 return (error);
1095
1096 if ((req->newlen - req->newidx) >= arg2) {
1097 error = EINVAL;
1098 } else {
1099 arg2 = (req->newlen - req->newidx);
1100 error = SYSCTL_IN(req, arg1, arg2);
1101 ((char *)arg1)[arg2] = '\0';
1102 }
1103
1104 return (error);
1105}
1106
1107/*
1108 * Handle any kind of opaque data.
1109 * arg1 points to it, arg2 is the size.
1110 */
1111
1112int
1113sysctl_handle_opaque(SYSCTL_HANDLER_ARGS)
1114{
1115 int error, tries;
1116 u_int generation;
1117 struct sysctl_req req2;
1118
1119 /*
1120 * Attempt to get a coherent snapshot, by using the thread
1121 * pre-emption counter updated from within mi_switch() to
1122 * determine if we were pre-empted during a bcopy() or
1123 * copyout(). Make 3 attempts at doing this before giving up.
1124 * If we encounter an error, stop immediately.
1125 */
1126 tries = 0;
1127 req2 = *req;
1128retry:
1129 generation = curthread->td_generation;
1130 error = SYSCTL_OUT(req, arg1, arg2);
1131 if (error)
1132 return (error);
1133 tries++;
1134 if (generation != curthread->td_generation && tries < 3) {
1135 *req = req2;
1136 goto retry;
1137 }
1138
1139 error = SYSCTL_IN(req, arg1, arg2);
1140
1141 return (error);
1142}
1143
1144/*
1145 * Transfer functions to/from kernel space.
1146 * XXX: rather untested at this point
1147 */
1148static int
1149sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l)
1150{
1151 size_t i = 0;
1152
1153 if (req->oldptr) {
1154 i = l;
1155 if (req->oldlen <= req->oldidx)
1156 i = 0;
1157 else
1158 if (i > req->oldlen - req->oldidx)
1159 i = req->oldlen - req->oldidx;
1160 if (i > 0)
1161 bcopy(p, (char *)req->oldptr + req->oldidx, i);
1162 }
1163 req->oldidx += l;
1164 if (req->oldptr && i != l)
1165 return (ENOMEM);
1166 return (0);
1167}
1168
1169static int
1170sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l)
1171{
1172 if (!req->newptr)
1173 return (0);
1174 if (req->newlen - req->newidx < l)
1175 return (EINVAL);
1176 bcopy((char *)req->newptr + req->newidx, p, l);
1177 req->newidx += l;
1178 return (0);
1179}
1180
1181int
1182kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old,
1183 size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags)
1184{
1185 int error = 0;
1186 struct sysctl_req req;
1187
1188 bzero(&req, sizeof req);
1189
1190 req.td = td;
1191 req.flags = flags;
1192
1193 if (oldlenp) {
1194 req.oldlen = *oldlenp;
1195 }
1196 req.validlen = req.oldlen;
1197
1198 if (old) {
1199 req.oldptr= old;
1200 }
1201
1202 if (new != NULL) {
1203 req.newlen = newlen;
1204 req.newptr = new;
1205 }
1206
1207 req.oldfunc = sysctl_old_kernel;
1208 req.newfunc = sysctl_new_kernel;
1209 req.lock = REQ_LOCKED;
1210
1211 SYSCTL_XLOCK();
1212 error = sysctl_root(0, name, namelen, &req);
1213 SYSCTL_XUNLOCK();
1214
1215 if (req.lock == REQ_WIRED && req.validlen > 0)
1216 vsunlock(req.oldptr, req.validlen);
1217
1218 if (error && error != ENOMEM)
1219 return (error);
1220
1221 if (retval) {
1222 if (req.oldptr && req.oldidx > req.validlen)
1223 *retval = req.validlen;
1224 else
1225 *retval = req.oldidx;
1226 }
1227 return (error);
1228}
1229
1230int
1231kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp,
1232 void *new, size_t newlen, size_t *retval, int flags)
1233{
1234 int oid[CTL_MAXNAME];
1235 size_t oidlen, plen;
1236 int error;
1237
1238 oid[0] = 0; /* sysctl internal magic */
1239 oid[1] = 3; /* name2oid */
1240 oidlen = sizeof(oid);
1241
1242 error = kernel_sysctl(td, oid, 2, oid, &oidlen,
1243 (void *)name, strlen(name), &plen, flags);
1244 if (error)
1245 return (error);
1246
1247 error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp,
1248 new, newlen, retval, flags);
1249 return (error);
1250}
1251
1252/*
1253 * Transfer function to/from user space.
1254 */
1255static int
1256sysctl_old_user(struct sysctl_req *req, const void *p, size_t l)
1257{
1258 int error = 0;
1259 size_t i, len, origidx;
1260
1261 origidx = req->oldidx;
1262 req->oldidx += l;
1263 if (req->oldptr == NULL)
1264 return (0);
1265 /*
1266 * If we have not wired the user supplied buffer and we are currently
1267 * holding locks, drop a witness warning, as it's possible that
1268 * write operations to the user page can sleep.
1269 */
1270 if (req->lock != REQ_WIRED)
1271 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
1272 "sysctl_old_user()");
1273 i = l;
1274 len = req->validlen;
1275 if (len <= origidx)
1276 i = 0;
1277 else {
1278 if (i > len - origidx)
1279 i = len - origidx;
1280 error = copyout(p, (char *)req->oldptr + origidx, i);
1281 }
1282 if (error)
1283 return (error);
1284 if (i < l)
1285 return (ENOMEM);
1286 return (0);
1287}
1288
1289static int
1290sysctl_new_user(struct sysctl_req *req, void *p, size_t l)
1291{
1292 int error;
1293
1294 if (!req->newptr)
1295 return (0);
1296 if (req->newlen - req->newidx < l)
1297 return (EINVAL);
1298 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
1299 "sysctl_new_user()");
1300 error = copyin((char *)req->newptr + req->newidx, p, l);
1301 req->newidx += l;
1302 return (error);
1303}
1304
1305/*
1306 * Wire the user space destination buffer. If set to a value greater than
1307 * zero, the len parameter limits the maximum amount of wired memory.
1308 */
1309int
1310sysctl_wire_old_buffer(struct sysctl_req *req, size_t len)
1311{
1312 int ret;
1313 size_t wiredlen;
1314
1315 wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen;
1316 ret = 0;
1317 if (req->lock == REQ_LOCKED && req->oldptr &&
1318 req->oldfunc == sysctl_old_user) {
1319 if (wiredlen != 0) {
1320 ret = vslock(req->oldptr, wiredlen);
1321 if (ret != 0) {
1322 if (ret != ENOMEM)
1323 return (ret);
1324 wiredlen = 0;
1325 }
1326 }
1327 req->lock = REQ_WIRED;
1328 req->validlen = wiredlen;
1329 }
1330 return (0);
1331}
1332
1333int
1334sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid,
1335 int *nindx, struct sysctl_req *req)
1336{
1337 struct sysctl_oid_list *lsp;
1338 struct sysctl_oid *oid;
1339 int indx;
1340
1341 SYSCTL_ASSERT_XLOCKED();
1342 lsp = &sysctl__children;
1343 indx = 0;
1344 while (indx < CTL_MAXNAME) {
1345 SLIST_FOREACH(oid, lsp, oid_link) {
1346 if (oid->oid_number == name[indx])
1347 break;
1348 }
1349 if (oid == NULL)
1350 return (ENOENT);
1351
1352 indx++;
1353 if (oid->oid_kind & CTLFLAG_NOLOCK)
1354 req->lock = REQ_UNLOCKED;
1355 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1356 if (oid->oid_handler != NULL || indx == namelen) {
1357 *noid = oid;
1358 if (nindx != NULL)
1359 *nindx = indx;
1360 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0,
1361 ("%s found DYING node %p", __func__, oid));
1362 return (0);
1363 }
1364 lsp = SYSCTL_CHILDREN(oid);
1365 } else if (indx == namelen) {
1366 *noid = oid;
1367 if (nindx != NULL)
1368 *nindx = indx;
1369 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0,
1370 ("%s found DYING node %p", __func__, oid));
1371 return (0);
1372 } else {
1373 return (ENOTDIR);
1374 }
1375 }
1376 return (ENOENT);
1377}
1378
1379/*
1380 * Traverse our tree, and find the right node, execute whatever it points
1381 * to, and return the resulting error code.
1382 */
1383
1384static int
1385sysctl_root(SYSCTL_HANDLER_ARGS)
1386{
1387 struct sysctl_oid *oid;
1388 int error, indx, lvl;
1389
1390 SYSCTL_ASSERT_XLOCKED();
1391
1392 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req);
1393 if (error)
1394 return (error);
1395
1396 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1397 /*
1398 * You can't call a sysctl when it's a node, but has
1399 * no handler. Inform the user that it's a node.
1400 * The indx may or may not be the same as namelen.
1401 */
1402 if (oid->oid_handler == NULL)
1403 return (EISDIR);
1404 }
1405
1406 /* Is this sysctl writable? */
1407 if (req->newptr && !(oid->oid_kind & CTLFLAG_WR))
1408 return (EPERM);
1409
1410 KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL"));
1411
1412 /* Is this sysctl sensitive to securelevels? */
1413 if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) {
1414 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE;
1415 error = securelevel_gt(req->td->td_ucred, lvl);
1416 if (error)
1417 return (error);
1418 }
1419
1420 /* Is this sysctl writable by only privileged users? */
1421 if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) {
1422 int priv;
1423
1424 if (oid->oid_kind & CTLFLAG_PRISON)
1425 priv = PRIV_SYSCTL_WRITEJAIL;
1426#ifdef VIMAGE
1427 else if ((oid->oid_kind & CTLFLAG_VNET) &&
1428 prison_owns_vnet(req->td->td_ucred))
1429 priv = PRIV_SYSCTL_WRITEJAIL;
1430#endif
1431 else
1432 priv = PRIV_SYSCTL_WRITE;
1433 error = priv_check(req->td, priv);
1434 if (error)
1435 return (error);
1436 }
1437
1438 if (!oid->oid_handler)
1439 return (EINVAL);
1440
1441 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1442 arg1 = (int *)arg1 + indx;
1443 arg2 -= indx;
1444 } else {
1445 arg1 = oid->oid_arg1;
1446 arg2 = oid->oid_arg2;
1447 }
1448#ifdef MAC
1449 error = mac_system_check_sysctl(req->td->td_ucred, oid, arg1, arg2,
1450 req);
1451 if (error != 0)
1452 return (error);
1453#endif
1454 oid->oid_running++;
1455 SYSCTL_XUNLOCK();
1456
1457 if (!(oid->oid_kind & CTLFLAG_MPSAFE))
1458 mtx_lock(&Giant);
1459 error = oid->oid_handler(oid, arg1, arg2, req);
1460 if (!(oid->oid_kind & CTLFLAG_MPSAFE))
1461 mtx_unlock(&Giant);
1462
1463 KFAIL_POINT_ERROR(_debug_fail_point, sysctl_running, error);
1464
1465 SYSCTL_XLOCK();
1466 oid->oid_running--;
1467 if (oid->oid_running == 0 && (oid->oid_kind & CTLFLAG_DYING) != 0)
1468 wakeup(&oid->oid_running);
1469 return (error);
1470}
1471
1472#ifndef _SYS_SYSPROTO_H_
1473struct sysctl_args {
1474 int *name;
1475 u_int namelen;
1476 void *old;
1477 size_t *oldlenp;
1478 void *new;
1479 size_t newlen;
1480};
1481#endif
1482int
1483__sysctl(struct thread *td, struct sysctl_args *uap)
1484{
1485 int error, i, name[CTL_MAXNAME];
1486 size_t j;
1487
1488 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2)
1489 return (EINVAL);
1490
1491 error = copyin(uap->name, &name, uap->namelen * sizeof(int));
1492 if (error)
1493 return (error);
1494
1495 error = userland_sysctl(td, name, uap->namelen,
1496 uap->old, uap->oldlenp, 0,
1497 uap->new, uap->newlen, &j, 0);
1498 if (error && error != ENOMEM)
1499 return (error);
1500 if (uap->oldlenp) {
1501 i = copyout(&j, uap->oldlenp, sizeof(j));
1502 if (i)
1503 return (i);
1504 }
1505 return (error);
1506}
1507
1508/*
1509 * This is used from various compatibility syscalls too. That's why name
1510 * must be in kernel space.
1511 */
1512int
1513userland_sysctl(struct thread *td, int *name, u_int namelen, void *old,
1514 size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval,
1515 int flags)
1516{
1517 int error = 0, memlocked;
1518 struct sysctl_req req;
1519
1520 bzero(&req, sizeof req);
1521
1522 req.td = td;
1523 req.flags = flags;
1524
1525 if (oldlenp) {
1526 if (inkernel) {
1527 req.oldlen = *oldlenp;
1528 } else {
1529 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp));
1530 if (error)
1531 return (error);
1532 }
1533 }
1534 req.validlen = req.oldlen;
1535
1536 if (old) {
1537 if (!useracc(old, req.oldlen, VM_PROT_WRITE))
1538 return (EFAULT);
1539 req.oldptr= old;
1540 }
1541
1542 if (new != NULL) {
1543 if (!useracc(new, newlen, VM_PROT_READ))
1544 return (EFAULT);
1545 req.newlen = newlen;
1546 req.newptr = new;
1547 }
1548
1549 req.oldfunc = sysctl_old_user;
1550 req.newfunc = sysctl_new_user;
1551 req.lock = REQ_LOCKED;
1552
1553#ifdef KTRACE
1554 if (KTRPOINT(curthread, KTR_SYSCTL))
1555 ktrsysctl(name, namelen);
1556#endif
1557
1558 if (req.oldlen > PAGE_SIZE) {
1559 memlocked = 1;
1560 sx_xlock(&sysctlmemlock);
1561 } else
1562 memlocked = 0;
1563 CURVNET_SET(TD_TO_VNET(td));
1564
1565 for (;;) {
1566 req.oldidx = 0;
1567 req.newidx = 0;
1568 SYSCTL_XLOCK();
1569 error = sysctl_root(0, name, namelen, &req);
1570 SYSCTL_XUNLOCK();
1571 if (error != EAGAIN)
1572 break;
1573 uio_yield();
1574 }
1575
1576 CURVNET_RESTORE();
1577
1578 if (req.lock == REQ_WIRED && req.validlen > 0)
1579 vsunlock(req.oldptr, req.validlen);
1580 if (memlocked)
1581 sx_xunlock(&sysctlmemlock);
1582
1583 if (error && error != ENOMEM)
1584 return (error);
1585
1586 if (retval) {
1587 if (req.oldptr && req.oldidx > req.validlen)
1588 *retval = req.validlen;
1589 else
1590 *retval = req.oldidx;
1591 }
1592 return (error);
1593}
1594
1595/*
1596 * Drain into a sysctl struct. The user buffer must be wired.
1597 */
1598static int
1599sbuf_sysctl_drain(void *arg, const char *data, int len)
1600{
1601 struct sysctl_req *req = arg;
1602 int error;
1603
1604 error = SYSCTL_OUT(req, data, len);
1605 KASSERT(error >= 0, ("Got unexpected negative value %d", error));
1606 return (error == 0 ? len : -error);
1607}
1608
1609struct sbuf *
1610sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length,
1611 struct sysctl_req *req)
1612{
1613
1614 /* Wire the user buffer, so we can write without blocking. */
1615 sysctl_wire_old_buffer(req, 0);
1616
1617 s = sbuf_new(s, buf, length, SBUF_FIXEDLEN);
1618 sbuf_set_drain(s, sbuf_sysctl_drain, req);
1619 return (s);
1620}