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: releng/9.0/sys/kern/kern_sysctl.c 225617 2011-09-16 13:58:51Z kmacy $");
40
41 #include "opt_capsicum.h"
42 #include "opt_compat.h"
43 #include "opt_ktrace.h"
44
45 #include <sys/param.h>
46 #include <sys/fail.h>
47 #include <sys/systm.h>
48 #include <sys/capability.h>
49 #include <sys/kernel.h>
50 #include <sys/sysctl.h>
51 #include <sys/malloc.h>
52 #include <sys/priv.h>
53 #include <sys/proc.h>
54 #include <sys/jail.h>
55 #include <sys/lock.h>
56 #include <sys/mutex.h>
57 #include <sys/sbuf.h>
58 #include <sys/sx.h>
59 #include <sys/sysproto.h>
60 #include <sys/uio.h>
61 #ifdef KTRACE
62 #include <sys/ktrace.h>
63 #endif
64
65 #include <net/vnet.h>
66
67 #include <security/mac/mac_framework.h>
68
69 #include <vm/vm.h>
70 #include <vm/vm_extern.h>
71
72 static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic");
73 static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids");
74 static MALLOC_DEFINE(M_SYSCTLTMP, "sysctltmp", "sysctl temp output buffer");
75
76 /*
77 * The sysctllock protects the MIB tree. It also protects sysctl
78 * contexts used with dynamic sysctls. The sysctl_register_oid() and
79 * sysctl_unregister_oid() routines require the sysctllock to already
80 * be held, so the sysctl_lock() and sysctl_unlock() routines are
81 * provided for the few places in the kernel which need to use that
82 * API rather than using the dynamic API. Use of the dynamic API is
83 * strongly encouraged for most code.
84 *
85 * The sysctlmemlock is used to limit the amount of user memory wired for
86 * sysctl requests. This is implemented by serializing any userland
87 * sysctl requests larger than a single page via an exclusive lock.
88 */
89 static struct sx sysctllock;
90 static struct sx sysctlmemlock;
91
92 #define SYSCTL_XLOCK() sx_xlock(&sysctllock)
93 #define SYSCTL_XUNLOCK() sx_xunlock(&sysctllock)
94 #define SYSCTL_ASSERT_XLOCKED() sx_assert(&sysctllock, SA_XLOCKED)
95 #define SYSCTL_INIT() sx_init(&sysctllock, "sysctl lock")
96 #define SYSCTL_SLEEP(ch, wmesg, timo) \
97 sx_sleep(ch, &sysctllock, 0, wmesg, timo)
98
99 static int sysctl_root(SYSCTL_HANDLER_ARGS);
100
101 struct sysctl_oid_list sysctl__children; /* root list */
102
103 static int sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del,
104 int recurse);
105
106 static struct sysctl_oid *
107 sysctl_find_oidname(const char *name, struct sysctl_oid_list *list)
108 {
109 struct sysctl_oid *oidp;
110
111 SYSCTL_ASSERT_XLOCKED();
112 SLIST_FOREACH(oidp, list, oid_link) {
113 if (strcmp(oidp->oid_name, name) == 0) {
114 return (oidp);
115 }
116 }
117 return (NULL);
118 }
119
120 /*
121 * Initialization of the MIB tree.
122 *
123 * Order by number in each list.
124 */
125 void
126 sysctl_lock(void)
127 {
128
129 SYSCTL_XLOCK();
130 }
131
132 void
133 sysctl_unlock(void)
134 {
135
136 SYSCTL_XUNLOCK();
137 }
138
139 void
140 sysctl_register_oid(struct sysctl_oid *oidp)
141 {
142 struct sysctl_oid_list *parent = oidp->oid_parent;
143 struct sysctl_oid *p;
144 struct sysctl_oid *q;
145
146 /*
147 * First check if another oid with the same name already
148 * exists in the parent's list.
149 */
150 SYSCTL_ASSERT_XLOCKED();
151 p = sysctl_find_oidname(oidp->oid_name, parent);
152 if (p != NULL) {
153 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
154 p->oid_refcnt++;
155 return;
156 } else {
157 printf("can't re-use a leaf (%s)!\n", p->oid_name);
158 return;
159 }
160 }
161 /*
162 * If this oid has a number OID_AUTO, give it a number which
163 * is greater than any current oid.
164 * NOTE: DO NOT change the starting value here, change it in
165 * <sys/sysctl.h>, and make sure it is at least 256 to
166 * accomodate e.g. net.inet.raw as a static sysctl node.
167 */
168 if (oidp->oid_number == OID_AUTO) {
169 static int newoid = CTL_AUTO_START;
170
171 oidp->oid_number = newoid++;
172 if (newoid == 0x7fffffff)
173 panic("out of oids");
174 }
175 #if 0
176 else if (oidp->oid_number >= CTL_AUTO_START) {
177 /* do not panic; this happens when unregistering sysctl sets */
178 printf("static sysctl oid too high: %d", oidp->oid_number);
179 }
180 #endif
181
182 /*
183 * Insert the oid into the parent's list in order.
184 */
185 q = NULL;
186 SLIST_FOREACH(p, parent, oid_link) {
187 if (oidp->oid_number < p->oid_number)
188 break;
189 q = p;
190 }
191 if (q)
192 SLIST_INSERT_AFTER(q, oidp, oid_link);
193 else
194 SLIST_INSERT_HEAD(parent, oidp, oid_link);
195 }
196
197 void
198 sysctl_unregister_oid(struct sysctl_oid *oidp)
199 {
200 struct sysctl_oid *p;
201 int error;
202
203 SYSCTL_ASSERT_XLOCKED();
204 error = ENOENT;
205 if (oidp->oid_number == OID_AUTO) {
206 error = EINVAL;
207 } else {
208 SLIST_FOREACH(p, oidp->oid_parent, oid_link) {
209 if (p == oidp) {
210 SLIST_REMOVE(oidp->oid_parent, oidp,
211 sysctl_oid, oid_link);
212 error = 0;
213 break;
214 }
215 }
216 }
217
218 /*
219 * This can happen when a module fails to register and is
220 * being unloaded afterwards. It should not be a panic()
221 * for normal use.
222 */
223 if (error)
224 printf("%s: failed to unregister sysctl\n", __func__);
225 }
226
227 /* Initialize a new context to keep track of dynamically added sysctls. */
228 int
229 sysctl_ctx_init(struct sysctl_ctx_list *c)
230 {
231
232 if (c == NULL) {
233 return (EINVAL);
234 }
235
236 /*
237 * No locking here, the caller is responsible for not adding
238 * new nodes to a context until after this function has
239 * returned.
240 */
241 TAILQ_INIT(c);
242 return (0);
243 }
244
245 /* Free the context, and destroy all dynamic oids registered in this context */
246 int
247 sysctl_ctx_free(struct sysctl_ctx_list *clist)
248 {
249 struct sysctl_ctx_entry *e, *e1;
250 int error;
251
252 error = 0;
253 /*
254 * First perform a "dry run" to check if it's ok to remove oids.
255 * XXX FIXME
256 * XXX This algorithm is a hack. But I don't know any
257 * XXX better solution for now...
258 */
259 SYSCTL_XLOCK();
260 TAILQ_FOREACH(e, clist, link) {
261 error = sysctl_remove_oid_locked(e->entry, 0, 0);
262 if (error)
263 break;
264 }
265 /*
266 * Restore deregistered entries, either from the end,
267 * or from the place where error occured.
268 * e contains the entry that was not unregistered
269 */
270 if (error)
271 e1 = TAILQ_PREV(e, sysctl_ctx_list, link);
272 else
273 e1 = TAILQ_LAST(clist, sysctl_ctx_list);
274 while (e1 != NULL) {
275 sysctl_register_oid(e1->entry);
276 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link);
277 }
278 if (error) {
279 SYSCTL_XUNLOCK();
280 return(EBUSY);
281 }
282 /* Now really delete the entries */
283 e = TAILQ_FIRST(clist);
284 while (e != NULL) {
285 e1 = TAILQ_NEXT(e, link);
286 error = sysctl_remove_oid_locked(e->entry, 1, 0);
287 if (error)
288 panic("sysctl_remove_oid: corrupt tree, entry: %s",
289 e->entry->oid_name);
290 free(e, M_SYSCTLOID);
291 e = e1;
292 }
293 SYSCTL_XUNLOCK();
294 return (error);
295 }
296
297 /* Add an entry to the context */
298 struct sysctl_ctx_entry *
299 sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
300 {
301 struct sysctl_ctx_entry *e;
302
303 SYSCTL_ASSERT_XLOCKED();
304 if (clist == NULL || oidp == NULL)
305 return(NULL);
306 e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK);
307 e->entry = oidp;
308 TAILQ_INSERT_HEAD(clist, e, link);
309 return (e);
310 }
311
312 /* Find an entry in the context */
313 struct sysctl_ctx_entry *
314 sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
315 {
316 struct sysctl_ctx_entry *e;
317
318 SYSCTL_ASSERT_XLOCKED();
319 if (clist == NULL || oidp == NULL)
320 return(NULL);
321 TAILQ_FOREACH(e, clist, link) {
322 if(e->entry == oidp)
323 return(e);
324 }
325 return (e);
326 }
327
328 /*
329 * Delete an entry from the context.
330 * NOTE: this function doesn't free oidp! You have to remove it
331 * with sysctl_remove_oid().
332 */
333 int
334 sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
335 {
336 struct sysctl_ctx_entry *e;
337
338 if (clist == NULL || oidp == NULL)
339 return (EINVAL);
340 SYSCTL_XLOCK();
341 e = sysctl_ctx_entry_find(clist, oidp);
342 if (e != NULL) {
343 TAILQ_REMOVE(clist, e, link);
344 SYSCTL_XUNLOCK();
345 free(e, M_SYSCTLOID);
346 return (0);
347 } else {
348 SYSCTL_XUNLOCK();
349 return (ENOENT);
350 }
351 }
352
353 /*
354 * Remove dynamically created sysctl trees.
355 * oidp - top of the tree to be removed
356 * del - if 0 - just deregister, otherwise free up entries as well
357 * recurse - if != 0 traverse the subtree to be deleted
358 */
359 int
360 sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse)
361 {
362 int error;
363
364 SYSCTL_XLOCK();
365 error = sysctl_remove_oid_locked(oidp, del, recurse);
366 SYSCTL_XUNLOCK();
367 return (error);
368 }
369
370 int
371 sysctl_remove_name(struct sysctl_oid *parent, const char *name,
372 int del, int recurse)
373 {
374 struct sysctl_oid *p, *tmp;
375 int error;
376
377 error = ENOENT;
378 SYSCTL_XLOCK();
379 SLIST_FOREACH_SAFE(p, SYSCTL_CHILDREN(parent), oid_link, tmp) {
380 if (strcmp(p->oid_name, name) == 0) {
381 error = sysctl_remove_oid_locked(p, del, recurse);
382 break;
383 }
384 }
385 SYSCTL_XUNLOCK();
386
387 return (error);
388 }
389
390
391 static int
392 sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse)
393 {
394 struct sysctl_oid *p, *tmp;
395 int error;
396
397 SYSCTL_ASSERT_XLOCKED();
398 if (oidp == NULL)
399 return(EINVAL);
400 if ((oidp->oid_kind & CTLFLAG_DYN) == 0) {
401 printf("can't remove non-dynamic nodes!\n");
402 return (EINVAL);
403 }
404 /*
405 * WARNING: normal method to do this should be through
406 * sysctl_ctx_free(). Use recursing as the last resort
407 * method to purge your sysctl tree of leftovers...
408 * However, if some other code still references these nodes,
409 * it will panic.
410 */
411 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
412 if (oidp->oid_refcnt == 1) {
413 SLIST_FOREACH_SAFE(p,
414 SYSCTL_CHILDREN(oidp), oid_link, tmp) {
415 if (!recurse)
416 return (ENOTEMPTY);
417 error = sysctl_remove_oid_locked(p, del,
418 recurse);
419 if (error)
420 return (error);
421 }
422 if (del)
423 free(SYSCTL_CHILDREN(oidp), M_SYSCTLOID);
424 }
425 }
426 if (oidp->oid_refcnt > 1 ) {
427 oidp->oid_refcnt--;
428 } else {
429 if (oidp->oid_refcnt == 0) {
430 printf("Warning: bad oid_refcnt=%u (%s)!\n",
431 oidp->oid_refcnt, oidp->oid_name);
432 return (EINVAL);
433 }
434 sysctl_unregister_oid(oidp);
435 if (del) {
436 /*
437 * Wait for all threads running the handler to drain.
438 * This preserves the previous behavior when the
439 * sysctl lock was held across a handler invocation,
440 * and is necessary for module unload correctness.
441 */
442 while (oidp->oid_running > 0) {
443 oidp->oid_kind |= CTLFLAG_DYING;
444 SYSCTL_SLEEP(&oidp->oid_running, "oidrm", 0);
445 }
446 if (oidp->oid_descr)
447 free((void *)(uintptr_t)(const void *)oidp->oid_descr, M_SYSCTLOID);
448 free((void *)(uintptr_t)(const void *)oidp->oid_name,
449 M_SYSCTLOID);
450 free(oidp, M_SYSCTLOID);
451 }
452 }
453 return (0);
454 }
455 /*
456 * Create new sysctls at run time.
457 * clist may point to a valid context initialized with sysctl_ctx_init().
458 */
459 struct sysctl_oid *
460 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent,
461 int number, const char *name, int kind, void *arg1, intptr_t arg2,
462 int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr)
463 {
464 struct sysctl_oid *oidp;
465 ssize_t len;
466 char *newname;
467
468 /* You have to hook up somewhere.. */
469 if (parent == NULL)
470 return(NULL);
471 /* Check if the node already exists, otherwise create it */
472 SYSCTL_XLOCK();
473 oidp = sysctl_find_oidname(name, parent);
474 if (oidp != NULL) {
475 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
476 oidp->oid_refcnt++;
477 /* Update the context */
478 if (clist != NULL)
479 sysctl_ctx_entry_add(clist, oidp);
480 SYSCTL_XUNLOCK();
481 return (oidp);
482 } else {
483 SYSCTL_XUNLOCK();
484 printf("can't re-use a leaf (%s)!\n", name);
485 return (NULL);
486 }
487 }
488 oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO);
489 oidp->oid_parent = parent;
490 SLIST_NEXT(oidp, oid_link) = NULL;
491 oidp->oid_number = number;
492 oidp->oid_refcnt = 1;
493 len = strlen(name);
494 newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK);
495 bcopy(name, newname, len + 1);
496 newname[len] = '\0';
497 oidp->oid_name = newname;
498 oidp->oid_handler = handler;
499 oidp->oid_kind = CTLFLAG_DYN | kind;
500 if ((kind & CTLTYPE) == CTLTYPE_NODE) {
501 /* Allocate space for children */
502 SYSCTL_CHILDREN_SET(oidp, malloc(sizeof(struct sysctl_oid_list),
503 M_SYSCTLOID, M_WAITOK));
504 SLIST_INIT(SYSCTL_CHILDREN(oidp));
505 oidp->oid_arg2 = arg2;
506 } else {
507 oidp->oid_arg1 = arg1;
508 oidp->oid_arg2 = arg2;
509 }
510 oidp->oid_fmt = fmt;
511 if (descr) {
512 int len = strlen(descr) + 1;
513 oidp->oid_descr = malloc(len, M_SYSCTLOID, M_WAITOK);
514 if (oidp->oid_descr)
515 strcpy((char *)(uintptr_t)(const void *)oidp->oid_descr, descr);
516 }
517 /* Update the context, if used */
518 if (clist != NULL)
519 sysctl_ctx_entry_add(clist, oidp);
520 /* Register this oid */
521 sysctl_register_oid(oidp);
522 SYSCTL_XUNLOCK();
523 return (oidp);
524 }
525
526 /*
527 * Rename an existing oid.
528 */
529 void
530 sysctl_rename_oid(struct sysctl_oid *oidp, const char *name)
531 {
532 ssize_t len;
533 char *newname;
534 void *oldname;
535
536 len = strlen(name);
537 newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK);
538 bcopy(name, newname, len + 1);
539 newname[len] = '\0';
540 SYSCTL_XLOCK();
541 oldname = (void *)(uintptr_t)(const void *)oidp->oid_name;
542 oidp->oid_name = newname;
543 SYSCTL_XUNLOCK();
544 free(oldname, M_SYSCTLOID);
545 }
546
547 /*
548 * Reparent an existing oid.
549 */
550 int
551 sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent)
552 {
553 struct sysctl_oid *oidp;
554
555 SYSCTL_XLOCK();
556 if (oid->oid_parent == parent) {
557 SYSCTL_XUNLOCK();
558 return (0);
559 }
560 oidp = sysctl_find_oidname(oid->oid_name, parent);
561 if (oidp != NULL) {
562 SYSCTL_XUNLOCK();
563 return (EEXIST);
564 }
565 sysctl_unregister_oid(oid);
566 oid->oid_parent = parent;
567 oid->oid_number = OID_AUTO;
568 sysctl_register_oid(oid);
569 SYSCTL_XUNLOCK();
570 return (0);
571 }
572
573 /*
574 * Register the kernel's oids on startup.
575 */
576 SET_DECLARE(sysctl_set, struct sysctl_oid);
577
578 static void
579 sysctl_register_all(void *arg)
580 {
581 struct sysctl_oid **oidp;
582
583 sx_init(&sysctlmemlock, "sysctl mem");
584 SYSCTL_INIT();
585 SYSCTL_XLOCK();
586 SET_FOREACH(oidp, sysctl_set)
587 sysctl_register_oid(*oidp);
588 SYSCTL_XUNLOCK();
589 }
590 SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_ANY, sysctl_register_all, 0);
591
592 /*
593 * "Staff-functions"
594 *
595 * These functions implement a presently undocumented interface
596 * used by the sysctl program to walk the tree, and get the type
597 * so it can print the value.
598 * This interface is under work and consideration, and should probably
599 * be killed with a big axe by the first person who can find the time.
600 * (be aware though, that the proper interface isn't as obvious as it
601 * may seem, there are various conflicting requirements.
602 *
603 * {0,0} printf the entire MIB-tree.
604 * {0,1,...} return the name of the "..." OID.
605 * {0,2,...} return the next OID.
606 * {0,3} return the OID of the name in "new"
607 * {0,4,...} return the kind & format info for the "..." OID.
608 * {0,5,...} return the description the "..." OID.
609 */
610
611 #ifdef SYSCTL_DEBUG
612 static void
613 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i)
614 {
615 int k;
616 struct sysctl_oid *oidp;
617
618 SYSCTL_ASSERT_XLOCKED();
619 SLIST_FOREACH(oidp, l, oid_link) {
620
621 for (k=0; k<i; k++)
622 printf(" ");
623
624 printf("%d %s ", oidp->oid_number, oidp->oid_name);
625
626 printf("%c%c",
627 oidp->oid_kind & CTLFLAG_RD ? 'R':' ',
628 oidp->oid_kind & CTLFLAG_WR ? 'W':' ');
629
630 if (oidp->oid_handler)
631 printf(" *Handler");
632
633 switch (oidp->oid_kind & CTLTYPE) {
634 case CTLTYPE_NODE:
635 printf(" Node\n");
636 if (!oidp->oid_handler) {
637 sysctl_sysctl_debug_dump_node(
638 oidp->oid_arg1, i+2);
639 }
640 break;
641 case CTLTYPE_INT: printf(" Int\n"); break;
642 case CTLTYPE_UINT: printf(" u_int\n"); break;
643 case CTLTYPE_LONG: printf(" Long\n"); break;
644 case CTLTYPE_ULONG: printf(" u_long\n"); break;
645 case CTLTYPE_STRING: printf(" String\n"); break;
646 case CTLTYPE_U64: printf(" uint64_t\n"); break;
647 case CTLTYPE_S64: printf(" int64_t\n"); break;
648 case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break;
649 default: printf("\n");
650 }
651
652 }
653 }
654
655 static int
656 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS)
657 {
658 int error;
659
660 error = priv_check(req->td, PRIV_SYSCTL_DEBUG);
661 if (error)
662 return (error);
663 SYSCTL_XLOCK();
664 sysctl_sysctl_debug_dump_node(&sysctl__children, 0);
665 SYSCTL_XUNLOCK();
666 return (ENOENT);
667 }
668
669 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD,
670 0, 0, sysctl_sysctl_debug, "-", "");
671 #endif
672
673 static int
674 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS)
675 {
676 int *name = (int *) arg1;
677 u_int namelen = arg2;
678 int error = 0;
679 struct sysctl_oid *oid;
680 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2;
681 char buf[10];
682
683 SYSCTL_XLOCK();
684 while (namelen) {
685 if (!lsp) {
686 snprintf(buf,sizeof(buf),"%d",*name);
687 if (req->oldidx)
688 error = SYSCTL_OUT(req, ".", 1);
689 if (!error)
690 error = SYSCTL_OUT(req, buf, strlen(buf));
691 if (error)
692 goto out;
693 namelen--;
694 name++;
695 continue;
696 }
697 lsp2 = 0;
698 SLIST_FOREACH(oid, lsp, oid_link) {
699 if (oid->oid_number != *name)
700 continue;
701
702 if (req->oldidx)
703 error = SYSCTL_OUT(req, ".", 1);
704 if (!error)
705 error = SYSCTL_OUT(req, oid->oid_name,
706 strlen(oid->oid_name));
707 if (error)
708 goto out;
709
710 namelen--;
711 name++;
712
713 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE)
714 break;
715
716 if (oid->oid_handler)
717 break;
718
719 lsp2 = SYSCTL_CHILDREN(oid);
720 break;
721 }
722 lsp = lsp2;
723 }
724 error = SYSCTL_OUT(req, "", 1);
725 out:
726 SYSCTL_XUNLOCK();
727 return (error);
728 }
729
730 /*
731 * XXXRW/JA: Shouldn't return name data for nodes that we don't permit in
732 * capability mode.
733 */
734 static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD | CTLFLAG_CAPRD,
735 sysctl_sysctl_name, "");
736
737 static int
738 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen,
739 int *next, int *len, int level, struct sysctl_oid **oidpp)
740 {
741 struct sysctl_oid *oidp;
742
743 SYSCTL_ASSERT_XLOCKED();
744 *len = level;
745 SLIST_FOREACH(oidp, lsp, oid_link) {
746 *next = oidp->oid_number;
747 *oidpp = oidp;
748
749 if (oidp->oid_kind & CTLFLAG_SKIP)
750 continue;
751
752 if (!namelen) {
753 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
754 return (0);
755 if (oidp->oid_handler)
756 /* We really should call the handler here...*/
757 return (0);
758 lsp = SYSCTL_CHILDREN(oidp);
759 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1,
760 len, level+1, oidpp))
761 return (0);
762 goto emptynode;
763 }
764
765 if (oidp->oid_number < *name)
766 continue;
767
768 if (oidp->oid_number > *name) {
769 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
770 return (0);
771 if (oidp->oid_handler)
772 return (0);
773 lsp = SYSCTL_CHILDREN(oidp);
774 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1,
775 next+1, len, level+1, oidpp))
776 return (0);
777 goto next;
778 }
779 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
780 continue;
781
782 if (oidp->oid_handler)
783 continue;
784
785 lsp = SYSCTL_CHILDREN(oidp);
786 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1,
787 len, level+1, oidpp))
788 return (0);
789 next:
790 namelen = 1;
791 emptynode:
792 *len = level;
793 }
794 return (1);
795 }
796
797 static int
798 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS)
799 {
800 int *name = (int *) arg1;
801 u_int namelen = arg2;
802 int i, j, error;
803 struct sysctl_oid *oid;
804 struct sysctl_oid_list *lsp = &sysctl__children;
805 int newoid[CTL_MAXNAME];
806
807 SYSCTL_XLOCK();
808 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid);
809 SYSCTL_XUNLOCK();
810 if (i)
811 return (ENOENT);
812 error = SYSCTL_OUT(req, newoid, j * sizeof (int));
813 return (error);
814 }
815
816 /*
817 * XXXRW/JA: Shouldn't return next data for nodes that we don't permit in
818 * capability mode.
819 */
820 static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD | CTLFLAG_CAPRD,
821 sysctl_sysctl_next, "");
822
823 static int
824 name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp)
825 {
826 int i;
827 struct sysctl_oid *oidp;
828 struct sysctl_oid_list *lsp = &sysctl__children;
829 char *p;
830
831 SYSCTL_ASSERT_XLOCKED();
832
833 if (!*name)
834 return (ENOENT);
835
836 p = name + strlen(name) - 1 ;
837 if (*p == '.')
838 *p = '\0';
839
840 *len = 0;
841
842 for (p = name; *p && *p != '.'; p++)
843 ;
844 i = *p;
845 if (i == '.')
846 *p = '\0';
847
848 oidp = SLIST_FIRST(lsp);
849
850 while (oidp && *len < CTL_MAXNAME) {
851 if (strcmp(name, oidp->oid_name)) {
852 oidp = SLIST_NEXT(oidp, oid_link);
853 continue;
854 }
855 *oid++ = oidp->oid_number;
856 (*len)++;
857
858 if (!i) {
859 if (oidpp)
860 *oidpp = oidp;
861 return (0);
862 }
863
864 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
865 break;
866
867 if (oidp->oid_handler)
868 break;
869
870 lsp = SYSCTL_CHILDREN(oidp);
871 oidp = SLIST_FIRST(lsp);
872 name = p+1;
873 for (p = name; *p && *p != '.'; p++)
874 ;
875 i = *p;
876 if (i == '.')
877 *p = '\0';
878 }
879 return (ENOENT);
880 }
881
882 static int
883 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS)
884 {
885 char *p;
886 int error, oid[CTL_MAXNAME], len = 0;
887 struct sysctl_oid *op = 0;
888
889 if (!req->newlen)
890 return (ENOENT);
891 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */
892 return (ENAMETOOLONG);
893
894 p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK);
895
896 error = SYSCTL_IN(req, p, req->newlen);
897 if (error) {
898 free(p, M_SYSCTL);
899 return (error);
900 }
901
902 p [req->newlen] = '\0';
903
904 SYSCTL_XLOCK();
905 error = name2oid(p, oid, &len, &op);
906 SYSCTL_XUNLOCK();
907
908 free(p, M_SYSCTL);
909
910 if (error)
911 return (error);
912
913 error = SYSCTL_OUT(req, oid, len * sizeof *oid);
914 return (error);
915 }
916
917 /*
918 * XXXRW/JA: Shouldn't return name2oid data for nodes that we don't permit in
919 * capability mode.
920 */
921 SYSCTL_PROC(_sysctl, 3, name2oid,
922 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_MPSAFE
923 | CTLFLAG_CAPRW, 0, 0, sysctl_sysctl_name2oid, "I", "");
924
925 static int
926 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS)
927 {
928 struct sysctl_oid *oid;
929 int error;
930
931 SYSCTL_XLOCK();
932 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
933 if (error)
934 goto out;
935
936 if (oid->oid_fmt == NULL) {
937 error = ENOENT;
938 goto out;
939 }
940 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind));
941 if (error)
942 goto out;
943 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1);
944 out:
945 SYSCTL_XUNLOCK();
946 return (error);
947 }
948
949
950 static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD,
951 sysctl_sysctl_oidfmt, "");
952
953 static int
954 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS)
955 {
956 struct sysctl_oid *oid;
957 int error;
958
959 SYSCTL_XLOCK();
960 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
961 if (error)
962 goto out;
963
964 if (oid->oid_descr == NULL) {
965 error = ENOENT;
966 goto out;
967 }
968 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1);
969 out:
970 SYSCTL_XUNLOCK();
971 return (error);
972 }
973
974 static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD|CTLFLAG_CAPRD,
975 sysctl_sysctl_oiddescr, "");
976
977 /*
978 * Default "handler" functions.
979 */
980
981 /*
982 * Handle an int, signed or unsigned.
983 * Two cases:
984 * a variable: point arg1 at it.
985 * a constant: pass it in arg2.
986 */
987
988 int
989 sysctl_handle_int(SYSCTL_HANDLER_ARGS)
990 {
991 int tmpout, error = 0;
992
993 /*
994 * Attempt to get a coherent snapshot by making a copy of the data.
995 */
996 if (arg1)
997 tmpout = *(int *)arg1;
998 else
999 tmpout = arg2;
1000 error = SYSCTL_OUT(req, &tmpout, sizeof(int));
1001
1002 if (error || !req->newptr)
1003 return (error);
1004
1005 if (!arg1)
1006 error = EPERM;
1007 else
1008 error = SYSCTL_IN(req, arg1, sizeof(int));
1009 return (error);
1010 }
1011
1012 /*
1013 * Based on on sysctl_handle_int() convert milliseconds into ticks.
1014 * Note: this is used by TCP.
1015 */
1016
1017 int
1018 sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS)
1019 {
1020 int error, s, tt;
1021
1022 tt = *(int *)arg1;
1023 s = (int)((int64_t)tt * 1000 / hz);
1024
1025 error = sysctl_handle_int(oidp, &s, 0, req);
1026 if (error || !req->newptr)
1027 return (error);
1028
1029 tt = (int)((int64_t)s * hz / 1000);
1030 if (tt < 1)
1031 return (EINVAL);
1032
1033 *(int *)arg1 = tt;
1034 return (0);
1035 }
1036
1037
1038 /*
1039 * Handle a long, signed or unsigned. arg1 points to it.
1040 */
1041
1042 int
1043 sysctl_handle_long(SYSCTL_HANDLER_ARGS)
1044 {
1045 int error = 0;
1046 long tmplong;
1047 #ifdef SCTL_MASK32
1048 int tmpint;
1049 #endif
1050
1051 /*
1052 * Attempt to get a coherent snapshot by making a copy of the data.
1053 */
1054 if (!arg1)
1055 return (EINVAL);
1056 tmplong = *(long *)arg1;
1057 #ifdef SCTL_MASK32
1058 if (req->flags & SCTL_MASK32) {
1059 tmpint = tmplong;
1060 error = SYSCTL_OUT(req, &tmpint, sizeof(int));
1061 } else
1062 #endif
1063 error = SYSCTL_OUT(req, &tmplong, sizeof(long));
1064
1065 if (error || !req->newptr)
1066 return (error);
1067
1068 #ifdef SCTL_MASK32
1069 if (req->flags & SCTL_MASK32) {
1070 error = SYSCTL_IN(req, &tmpint, sizeof(int));
1071 *(long *)arg1 = (long)tmpint;
1072 } else
1073 #endif
1074 error = SYSCTL_IN(req, arg1, sizeof(long));
1075 return (error);
1076 }
1077
1078 /*
1079 * Handle a 64 bit int, signed or unsigned. arg1 points to it.
1080 */
1081 int
1082 sysctl_handle_64(SYSCTL_HANDLER_ARGS)
1083 {
1084 int error = 0;
1085 uint64_t tmpout;
1086
1087 /*
1088 * Attempt to get a coherent snapshot by making a copy of the data.
1089 */
1090 if (!arg1)
1091 return (EINVAL);
1092 tmpout = *(uint64_t *)arg1;
1093 error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t));
1094
1095 if (error || !req->newptr)
1096 return (error);
1097
1098 error = SYSCTL_IN(req, arg1, sizeof(uint64_t));
1099 return (error);
1100 }
1101
1102 /*
1103 * Handle our generic '\0' terminated 'C' string.
1104 * Two cases:
1105 * a variable string: point arg1 at it, arg2 is max length.
1106 * a constant string: point arg1 at it, arg2 is zero.
1107 */
1108
1109 int
1110 sysctl_handle_string(SYSCTL_HANDLER_ARGS)
1111 {
1112 int error=0;
1113 char *tmparg;
1114 size_t outlen;
1115
1116 /*
1117 * Attempt to get a coherent snapshot by copying to a
1118 * temporary kernel buffer.
1119 */
1120 retry:
1121 outlen = strlen((char *)arg1)+1;
1122 tmparg = malloc(outlen, M_SYSCTLTMP, M_WAITOK);
1123
1124 if (strlcpy(tmparg, (char *)arg1, outlen) >= outlen) {
1125 free(tmparg, M_SYSCTLTMP);
1126 goto retry;
1127 }
1128
1129 error = SYSCTL_OUT(req, tmparg, outlen);
1130 free(tmparg, M_SYSCTLTMP);
1131
1132 if (error || !req->newptr)
1133 return (error);
1134
1135 if ((req->newlen - req->newidx) >= arg2) {
1136 error = EINVAL;
1137 } else {
1138 arg2 = (req->newlen - req->newidx);
1139 error = SYSCTL_IN(req, arg1, arg2);
1140 ((char *)arg1)[arg2] = '\0';
1141 }
1142
1143 return (error);
1144 }
1145
1146 /*
1147 * Handle any kind of opaque data.
1148 * arg1 points to it, arg2 is the size.
1149 */
1150
1151 int
1152 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS)
1153 {
1154 int error, tries;
1155 u_int generation;
1156 struct sysctl_req req2;
1157
1158 /*
1159 * Attempt to get a coherent snapshot, by using the thread
1160 * pre-emption counter updated from within mi_switch() to
1161 * determine if we were pre-empted during a bcopy() or
1162 * copyout(). Make 3 attempts at doing this before giving up.
1163 * If we encounter an error, stop immediately.
1164 */
1165 tries = 0;
1166 req2 = *req;
1167 retry:
1168 generation = curthread->td_generation;
1169 error = SYSCTL_OUT(req, arg1, arg2);
1170 if (error)
1171 return (error);
1172 tries++;
1173 if (generation != curthread->td_generation && tries < 3) {
1174 *req = req2;
1175 goto retry;
1176 }
1177
1178 error = SYSCTL_IN(req, arg1, arg2);
1179
1180 return (error);
1181 }
1182
1183 /*
1184 * Transfer functions to/from kernel space.
1185 * XXX: rather untested at this point
1186 */
1187 static int
1188 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l)
1189 {
1190 size_t i = 0;
1191
1192 if (req->oldptr) {
1193 i = l;
1194 if (req->oldlen <= req->oldidx)
1195 i = 0;
1196 else
1197 if (i > req->oldlen - req->oldidx)
1198 i = req->oldlen - req->oldidx;
1199 if (i > 0)
1200 bcopy(p, (char *)req->oldptr + req->oldidx, i);
1201 }
1202 req->oldidx += l;
1203 if (req->oldptr && i != l)
1204 return (ENOMEM);
1205 return (0);
1206 }
1207
1208 static int
1209 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l)
1210 {
1211 if (!req->newptr)
1212 return (0);
1213 if (req->newlen - req->newidx < l)
1214 return (EINVAL);
1215 bcopy((char *)req->newptr + req->newidx, p, l);
1216 req->newidx += l;
1217 return (0);
1218 }
1219
1220 int
1221 kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old,
1222 size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags)
1223 {
1224 int error = 0;
1225 struct sysctl_req req;
1226
1227 bzero(&req, sizeof req);
1228
1229 req.td = td;
1230 req.flags = flags;
1231
1232 if (oldlenp) {
1233 req.oldlen = *oldlenp;
1234 }
1235 req.validlen = req.oldlen;
1236
1237 if (old) {
1238 req.oldptr= old;
1239 }
1240
1241 if (new != NULL) {
1242 req.newlen = newlen;
1243 req.newptr = new;
1244 }
1245
1246 req.oldfunc = sysctl_old_kernel;
1247 req.newfunc = sysctl_new_kernel;
1248 req.lock = REQ_UNWIRED;
1249
1250 SYSCTL_XLOCK();
1251 error = sysctl_root(0, name, namelen, &req);
1252 SYSCTL_XUNLOCK();
1253
1254 if (req.lock == REQ_WIRED && req.validlen > 0)
1255 vsunlock(req.oldptr, req.validlen);
1256
1257 if (error && error != ENOMEM)
1258 return (error);
1259
1260 if (retval) {
1261 if (req.oldptr && req.oldidx > req.validlen)
1262 *retval = req.validlen;
1263 else
1264 *retval = req.oldidx;
1265 }
1266 return (error);
1267 }
1268
1269 int
1270 kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp,
1271 void *new, size_t newlen, size_t *retval, int flags)
1272 {
1273 int oid[CTL_MAXNAME];
1274 size_t oidlen, plen;
1275 int error;
1276
1277 oid[0] = 0; /* sysctl internal magic */
1278 oid[1] = 3; /* name2oid */
1279 oidlen = sizeof(oid);
1280
1281 error = kernel_sysctl(td, oid, 2, oid, &oidlen,
1282 (void *)name, strlen(name), &plen, flags);
1283 if (error)
1284 return (error);
1285
1286 error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp,
1287 new, newlen, retval, flags);
1288 return (error);
1289 }
1290
1291 /*
1292 * Transfer function to/from user space.
1293 */
1294 static int
1295 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l)
1296 {
1297 int error = 0;
1298 size_t i, len, origidx;
1299
1300 origidx = req->oldidx;
1301 req->oldidx += l;
1302 if (req->oldptr == NULL)
1303 return (0);
1304 /*
1305 * If we have not wired the user supplied buffer and we are currently
1306 * holding locks, drop a witness warning, as it's possible that
1307 * write operations to the user page can sleep.
1308 */
1309 if (req->lock != REQ_WIRED)
1310 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
1311 "sysctl_old_user()");
1312 i = l;
1313 len = req->validlen;
1314 if (len <= origidx)
1315 i = 0;
1316 else {
1317 if (i > len - origidx)
1318 i = len - origidx;
1319 error = copyout(p, (char *)req->oldptr + origidx, i);
1320 }
1321 if (error)
1322 return (error);
1323 if (i < l)
1324 return (ENOMEM);
1325 return (0);
1326 }
1327
1328 static int
1329 sysctl_new_user(struct sysctl_req *req, void *p, size_t l)
1330 {
1331 int error;
1332
1333 if (!req->newptr)
1334 return (0);
1335 if (req->newlen - req->newidx < l)
1336 return (EINVAL);
1337 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
1338 "sysctl_new_user()");
1339 error = copyin((char *)req->newptr + req->newidx, p, l);
1340 req->newidx += l;
1341 return (error);
1342 }
1343
1344 /*
1345 * Wire the user space destination buffer. If set to a value greater than
1346 * zero, the len parameter limits the maximum amount of wired memory.
1347 */
1348 int
1349 sysctl_wire_old_buffer(struct sysctl_req *req, size_t len)
1350 {
1351 int ret;
1352 size_t wiredlen;
1353
1354 wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen;
1355 ret = 0;
1356 if (req->lock != REQ_WIRED && req->oldptr &&
1357 req->oldfunc == sysctl_old_user) {
1358 if (wiredlen != 0) {
1359 ret = vslock(req->oldptr, wiredlen);
1360 if (ret != 0) {
1361 if (ret != ENOMEM)
1362 return (ret);
1363 wiredlen = 0;
1364 }
1365 }
1366 req->lock = REQ_WIRED;
1367 req->validlen = wiredlen;
1368 }
1369 return (0);
1370 }
1371
1372 int
1373 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid,
1374 int *nindx, struct sysctl_req *req)
1375 {
1376 struct sysctl_oid_list *lsp;
1377 struct sysctl_oid *oid;
1378 int indx;
1379
1380 SYSCTL_ASSERT_XLOCKED();
1381 lsp = &sysctl__children;
1382 indx = 0;
1383 while (indx < CTL_MAXNAME) {
1384 SLIST_FOREACH(oid, lsp, oid_link) {
1385 if (oid->oid_number == name[indx])
1386 break;
1387 }
1388 if (oid == NULL)
1389 return (ENOENT);
1390
1391 indx++;
1392 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1393 if (oid->oid_handler != NULL || indx == namelen) {
1394 *noid = oid;
1395 if (nindx != NULL)
1396 *nindx = indx;
1397 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0,
1398 ("%s found DYING node %p", __func__, oid));
1399 return (0);
1400 }
1401 lsp = SYSCTL_CHILDREN(oid);
1402 } else if (indx == namelen) {
1403 *noid = oid;
1404 if (nindx != NULL)
1405 *nindx = indx;
1406 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0,
1407 ("%s found DYING node %p", __func__, oid));
1408 return (0);
1409 } else {
1410 return (ENOTDIR);
1411 }
1412 }
1413 return (ENOENT);
1414 }
1415
1416 /*
1417 * Traverse our tree, and find the right node, execute whatever it points
1418 * to, and return the resulting error code.
1419 */
1420
1421 static int
1422 sysctl_root(SYSCTL_HANDLER_ARGS)
1423 {
1424 struct sysctl_oid *oid;
1425 int error, indx, lvl;
1426
1427 SYSCTL_ASSERT_XLOCKED();
1428
1429 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req);
1430 if (error)
1431 return (error);
1432
1433 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1434 /*
1435 * You can't call a sysctl when it's a node, but has
1436 * no handler. Inform the user that it's a node.
1437 * The indx may or may not be the same as namelen.
1438 */
1439 if (oid->oid_handler == NULL)
1440 return (EISDIR);
1441 }
1442
1443 /* Is this sysctl writable? */
1444 if (req->newptr && !(oid->oid_kind & CTLFLAG_WR))
1445 return (EPERM);
1446
1447 KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL"));
1448
1449 #ifdef CAPABILITY_MODE
1450 /*
1451 * If the process is in capability mode, then don't permit reading or
1452 * writing unless specifically granted for the node.
1453 */
1454 if (IN_CAPABILITY_MODE(req->td)) {
1455 if (req->oldptr && !(oid->oid_kind & CTLFLAG_CAPRD))
1456 return (EPERM);
1457 if (req->newptr && !(oid->oid_kind & CTLFLAG_CAPWR))
1458 return (EPERM);
1459 }
1460 #endif
1461
1462 /* Is this sysctl sensitive to securelevels? */
1463 if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) {
1464 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE;
1465 error = securelevel_gt(req->td->td_ucred, lvl);
1466 if (error)
1467 return (error);
1468 }
1469
1470 /* Is this sysctl writable by only privileged users? */
1471 if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) {
1472 int priv;
1473
1474 if (oid->oid_kind & CTLFLAG_PRISON)
1475 priv = PRIV_SYSCTL_WRITEJAIL;
1476 #ifdef VIMAGE
1477 else if ((oid->oid_kind & CTLFLAG_VNET) &&
1478 prison_owns_vnet(req->td->td_ucred))
1479 priv = PRIV_SYSCTL_WRITEJAIL;
1480 #endif
1481 else
1482 priv = PRIV_SYSCTL_WRITE;
1483 error = priv_check(req->td, priv);
1484 if (error)
1485 return (error);
1486 }
1487
1488 if (!oid->oid_handler)
1489 return (EINVAL);
1490
1491 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1492 arg1 = (int *)arg1 + indx;
1493 arg2 -= indx;
1494 } else {
1495 arg1 = oid->oid_arg1;
1496 arg2 = oid->oid_arg2;
1497 }
1498 #ifdef MAC
1499 error = mac_system_check_sysctl(req->td->td_ucred, oid, arg1, arg2,
1500 req);
1501 if (error != 0)
1502 return (error);
1503 #endif
1504 oid->oid_running++;
1505 SYSCTL_XUNLOCK();
1506
1507 if (!(oid->oid_kind & CTLFLAG_MPSAFE))
1508 mtx_lock(&Giant);
1509 error = oid->oid_handler(oid, arg1, arg2, req);
1510 if (!(oid->oid_kind & CTLFLAG_MPSAFE))
1511 mtx_unlock(&Giant);
1512
1513 KFAIL_POINT_ERROR(_debug_fail_point, sysctl_running, error);
1514
1515 SYSCTL_XLOCK();
1516 oid->oid_running--;
1517 if (oid->oid_running == 0 && (oid->oid_kind & CTLFLAG_DYING) != 0)
1518 wakeup(&oid->oid_running);
1519 return (error);
1520 }
1521
1522 #ifndef _SYS_SYSPROTO_H_
1523 struct sysctl_args {
1524 int *name;
1525 u_int namelen;
1526 void *old;
1527 size_t *oldlenp;
1528 void *new;
1529 size_t newlen;
1530 };
1531 #endif
1532 int
1533 sys___sysctl(struct thread *td, struct sysctl_args *uap)
1534 {
1535 int error, i, name[CTL_MAXNAME];
1536 size_t j;
1537
1538 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2)
1539 return (EINVAL);
1540
1541 error = copyin(uap->name, &name, uap->namelen * sizeof(int));
1542 if (error)
1543 return (error);
1544
1545 error = userland_sysctl(td, name, uap->namelen,
1546 uap->old, uap->oldlenp, 0,
1547 uap->new, uap->newlen, &j, 0);
1548 if (error && error != ENOMEM)
1549 return (error);
1550 if (uap->oldlenp) {
1551 i = copyout(&j, uap->oldlenp, sizeof(j));
1552 if (i)
1553 return (i);
1554 }
1555 return (error);
1556 }
1557
1558 /*
1559 * This is used from various compatibility syscalls too. That's why name
1560 * must be in kernel space.
1561 */
1562 int
1563 userland_sysctl(struct thread *td, int *name, u_int namelen, void *old,
1564 size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval,
1565 int flags)
1566 {
1567 int error = 0, memlocked;
1568 struct sysctl_req req;
1569
1570 bzero(&req, sizeof req);
1571
1572 req.td = td;
1573 req.flags = flags;
1574
1575 if (oldlenp) {
1576 if (inkernel) {
1577 req.oldlen = *oldlenp;
1578 } else {
1579 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp));
1580 if (error)
1581 return (error);
1582 }
1583 }
1584 req.validlen = req.oldlen;
1585
1586 if (old) {
1587 if (!useracc(old, req.oldlen, VM_PROT_WRITE))
1588 return (EFAULT);
1589 req.oldptr= old;
1590 }
1591
1592 if (new != NULL) {
1593 if (!useracc(new, newlen, VM_PROT_READ))
1594 return (EFAULT);
1595 req.newlen = newlen;
1596 req.newptr = new;
1597 }
1598
1599 req.oldfunc = sysctl_old_user;
1600 req.newfunc = sysctl_new_user;
1601 req.lock = REQ_UNWIRED;
1602
1603 #ifdef KTRACE
1604 if (KTRPOINT(curthread, KTR_SYSCTL))
1605 ktrsysctl(name, namelen);
1606 #endif
1607
1608 if (req.oldlen > PAGE_SIZE) {
1609 memlocked = 1;
1610 sx_xlock(&sysctlmemlock);
1611 } else
1612 memlocked = 0;
1613 CURVNET_SET(TD_TO_VNET(td));
1614
1615 for (;;) {
1616 req.oldidx = 0;
1617 req.newidx = 0;
1618 SYSCTL_XLOCK();
1619 error = sysctl_root(0, name, namelen, &req);
1620 SYSCTL_XUNLOCK();
1621 if (error != EAGAIN)
1622 break;
1623 kern_yield(PRI_USER);
1624 }
1625
1626 CURVNET_RESTORE();
1627
1628 if (req.lock == REQ_WIRED && req.validlen > 0)
1629 vsunlock(req.oldptr, req.validlen);
1630 if (memlocked)
1631 sx_xunlock(&sysctlmemlock);
1632
1633 if (error && error != ENOMEM)
1634 return (error);
1635
1636 if (retval) {
1637 if (req.oldptr && req.oldidx > req.validlen)
1638 *retval = req.validlen;
1639 else
1640 *retval = req.oldidx;
1641 }
1642 return (error);
1643 }
1644
1645 /*
1646 * Drain into a sysctl struct. The user buffer should be wired if a page
1647 * fault would cause issue.
1648 */
1649 static int
1650 sbuf_sysctl_drain(void *arg, const char *data, int len)
1651 {
1652 struct sysctl_req *req = arg;
1653 int error;
1654
1655 error = SYSCTL_OUT(req, data, len);
1656 KASSERT(error >= 0, ("Got unexpected negative value %d", error));
1657 return (error == 0 ? len : -error);
1658 }
1659
1660 struct sbuf *
1661 sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length,
1662 struct sysctl_req *req)
1663 {
1664
1665 s = sbuf_new(s, buf, length, SBUF_FIXEDLEN);
1666 sbuf_set_drain(s, sbuf_sysctl_drain, req);
1667 return (s);
1668 }
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