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/11.1/sys/kern/kern_sysctl.c 316128 2017-03-29 08:00:13Z ngie $");
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/capsicum.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/rmlock.h>
58 #include <sys/sbuf.h>
59 #include <sys/sx.h>
60 #include <sys/sysproto.h>
61 #include <sys/uio.h>
62 #ifdef KTRACE
63 #include <sys/ktrace.h>
64 #endif
65
66 #include <net/vnet.h>
67
68 #include <security/mac/mac_framework.h>
69
70 #include <vm/vm.h>
71 #include <vm/vm_extern.h>
72
73 static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic");
74 static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids");
75 static MALLOC_DEFINE(M_SYSCTLTMP, "sysctltmp", "sysctl temp output buffer");
76
77 /*
78 * The sysctllock protects the MIB tree. It also protects sysctl
79 * contexts used with dynamic sysctls. The sysctl_register_oid() and
80 * sysctl_unregister_oid() routines require the sysctllock to already
81 * be held, so the sysctl_wlock() and sysctl_wunlock() routines are
82 * provided for the few places in the kernel which need to use that
83 * API rather than using the dynamic API. Use of the dynamic API is
84 * strongly encouraged for most code.
85 *
86 * The sysctlmemlock is used to limit the amount of user memory wired for
87 * sysctl requests. This is implemented by serializing any userland
88 * sysctl requests larger than a single page via an exclusive lock.
89 */
90 static struct rmlock sysctllock;
91 static struct sx sysctlmemlock;
92
93 #define SYSCTL_WLOCK() rm_wlock(&sysctllock)
94 #define SYSCTL_WUNLOCK() rm_wunlock(&sysctllock)
95 #define SYSCTL_RLOCK(tracker) rm_rlock(&sysctllock, (tracker))
96 #define SYSCTL_RUNLOCK(tracker) rm_runlock(&sysctllock, (tracker))
97 #define SYSCTL_WLOCKED() rm_wowned(&sysctllock)
98 #define SYSCTL_ASSERT_LOCKED() rm_assert(&sysctllock, RA_LOCKED)
99 #define SYSCTL_ASSERT_WLOCKED() rm_assert(&sysctllock, RA_WLOCKED)
100 #define SYSCTL_ASSERT_RLOCKED() rm_assert(&sysctllock, RA_RLOCKED)
101 #define SYSCTL_INIT() rm_init_flags(&sysctllock, "sysctl lock", \
102 RM_SLEEPABLE)
103 #define SYSCTL_SLEEP(ch, wmesg, timo) \
104 rm_sleep(ch, &sysctllock, 0, wmesg, timo)
105
106 static int sysctl_root(SYSCTL_HANDLER_ARGS);
107
108 /* Root list */
109 struct sysctl_oid_list sysctl__children = SLIST_HEAD_INITIALIZER(&sysctl__children);
110
111 static int sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del,
112 int recurse);
113 static int sysctl_old_kernel(struct sysctl_req *, const void *, size_t);
114 static int sysctl_new_kernel(struct sysctl_req *, void *, size_t);
115
116 static struct sysctl_oid *
117 sysctl_find_oidname(const char *name, struct sysctl_oid_list *list)
118 {
119 struct sysctl_oid *oidp;
120
121 SYSCTL_ASSERT_LOCKED();
122 SLIST_FOREACH(oidp, list, oid_link) {
123 if (strcmp(oidp->oid_name, name) == 0) {
124 return (oidp);
125 }
126 }
127 return (NULL);
128 }
129
130 /*
131 * Initialization of the MIB tree.
132 *
133 * Order by number in each list.
134 */
135 void
136 sysctl_wlock(void)
137 {
138
139 SYSCTL_WLOCK();
140 }
141
142 void
143 sysctl_wunlock(void)
144 {
145
146 SYSCTL_WUNLOCK();
147 }
148
149 static int
150 sysctl_root_handler_locked(struct sysctl_oid *oid, void *arg1, intmax_t arg2,
151 struct sysctl_req *req, struct rm_priotracker *tracker)
152 {
153 int error;
154
155 if (oid->oid_kind & CTLFLAG_DYN)
156 atomic_add_int(&oid->oid_running, 1);
157
158 if (tracker != NULL)
159 SYSCTL_RUNLOCK(tracker);
160 else
161 SYSCTL_WUNLOCK();
162
163 if (!(oid->oid_kind & CTLFLAG_MPSAFE))
164 mtx_lock(&Giant);
165 error = oid->oid_handler(oid, arg1, arg2, req);
166 if (!(oid->oid_kind & CTLFLAG_MPSAFE))
167 mtx_unlock(&Giant);
168
169 KFAIL_POINT_ERROR(_debug_fail_point, sysctl_running, error);
170
171 if (tracker != NULL)
172 SYSCTL_RLOCK(tracker);
173 else
174 SYSCTL_WLOCK();
175
176 if (oid->oid_kind & CTLFLAG_DYN) {
177 if (atomic_fetchadd_int(&oid->oid_running, -1) == 1 &&
178 (oid->oid_kind & CTLFLAG_DYING) != 0)
179 wakeup(&oid->oid_running);
180 }
181
182 return (error);
183 }
184
185 static void
186 sysctl_load_tunable_by_oid_locked(struct sysctl_oid *oidp)
187 {
188 struct sysctl_req req;
189 struct sysctl_oid *curr;
190 char *penv = NULL;
191 char path[64];
192 ssize_t rem = sizeof(path);
193 ssize_t len;
194 uint8_t val_8;
195 uint16_t val_16;
196 uint32_t val_32;
197 int val_int;
198 long val_long;
199 int64_t val_64;
200 quad_t val_quad;
201 int error;
202
203 path[--rem] = 0;
204
205 for (curr = oidp; curr != NULL; curr = SYSCTL_PARENT(curr)) {
206 len = strlen(curr->oid_name);
207 rem -= len;
208 if (curr != oidp)
209 rem -= 1;
210 if (rem < 0) {
211 printf("OID path exceeds %d bytes\n", (int)sizeof(path));
212 return;
213 }
214 memcpy(path + rem, curr->oid_name, len);
215 if (curr != oidp)
216 path[rem + len] = '.';
217 }
218
219 memset(&req, 0, sizeof(req));
220
221 req.td = curthread;
222 req.oldfunc = sysctl_old_kernel;
223 req.newfunc = sysctl_new_kernel;
224 req.lock = REQ_UNWIRED;
225
226 switch (oidp->oid_kind & CTLTYPE) {
227 case CTLTYPE_INT:
228 if (getenv_int(path + rem, &val_int) == 0)
229 return;
230 req.newlen = sizeof(val_int);
231 req.newptr = &val_int;
232 break;
233 case CTLTYPE_UINT:
234 if (getenv_uint(path + rem, (unsigned int *)&val_int) == 0)
235 return;
236 req.newlen = sizeof(val_int);
237 req.newptr = &val_int;
238 break;
239 case CTLTYPE_LONG:
240 if (getenv_long(path + rem, &val_long) == 0)
241 return;
242 req.newlen = sizeof(val_long);
243 req.newptr = &val_long;
244 break;
245 case CTLTYPE_ULONG:
246 if (getenv_ulong(path + rem, (unsigned long *)&val_long) == 0)
247 return;
248 req.newlen = sizeof(val_long);
249 req.newptr = &val_long;
250 break;
251 case CTLTYPE_S8:
252 if (getenv_int(path + rem, &val_int) == 0)
253 return;
254 val_8 = val_int;
255 req.newlen = sizeof(val_8);
256 req.newptr = &val_8;
257 break;
258 case CTLTYPE_S16:
259 if (getenv_int(path + rem, &val_int) == 0)
260 return;
261 val_16 = val_int;
262 req.newlen = sizeof(val_16);
263 req.newptr = &val_16;
264 break;
265 case CTLTYPE_S32:
266 if (getenv_long(path + rem, &val_long) == 0)
267 return;
268 val_32 = val_long;
269 req.newlen = sizeof(val_32);
270 req.newptr = &val_32;
271 break;
272 case CTLTYPE_S64:
273 if (getenv_quad(path + rem, &val_quad) == 0)
274 return;
275 val_64 = val_quad;
276 req.newlen = sizeof(val_64);
277 req.newptr = &val_64;
278 break;
279 case CTLTYPE_U8:
280 if (getenv_uint(path + rem, (unsigned int *)&val_int) == 0)
281 return;
282 val_8 = val_int;
283 req.newlen = sizeof(val_8);
284 req.newptr = &val_8;
285 break;
286 case CTLTYPE_U16:
287 if (getenv_uint(path + rem, (unsigned int *)&val_int) == 0)
288 return;
289 val_16 = val_int;
290 req.newlen = sizeof(val_16);
291 req.newptr = &val_16;
292 break;
293 case CTLTYPE_U32:
294 if (getenv_ulong(path + rem, (unsigned long *)&val_long) == 0)
295 return;
296 val_32 = val_long;
297 req.newlen = sizeof(val_32);
298 req.newptr = &val_32;
299 break;
300 case CTLTYPE_U64:
301 /* XXX there is no getenv_uquad() */
302 if (getenv_quad(path + rem, &val_quad) == 0)
303 return;
304 val_64 = val_quad;
305 req.newlen = sizeof(val_64);
306 req.newptr = &val_64;
307 break;
308 case CTLTYPE_STRING:
309 penv = kern_getenv(path + rem);
310 if (penv == NULL)
311 return;
312 req.newlen = strlen(penv);
313 req.newptr = penv;
314 break;
315 default:
316 return;
317 }
318 error = sysctl_root_handler_locked(oidp, oidp->oid_arg1,
319 oidp->oid_arg2, &req, NULL);
320 if (error != 0)
321 printf("Setting sysctl %s failed: %d\n", path + rem, error);
322 if (penv != NULL)
323 freeenv(penv);
324 }
325
326 void
327 sysctl_register_oid(struct sysctl_oid *oidp)
328 {
329 struct sysctl_oid_list *parent = oidp->oid_parent;
330 struct sysctl_oid *p;
331 struct sysctl_oid *q;
332 int oid_number;
333 int timeout = 2;
334
335 /*
336 * First check if another oid with the same name already
337 * exists in the parent's list.
338 */
339 SYSCTL_ASSERT_WLOCKED();
340 p = sysctl_find_oidname(oidp->oid_name, parent);
341 if (p != NULL) {
342 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
343 p->oid_refcnt++;
344 return;
345 } else {
346 printf("can't re-use a leaf (%s)!\n", p->oid_name);
347 return;
348 }
349 }
350 /* get current OID number */
351 oid_number = oidp->oid_number;
352
353 #if (OID_AUTO >= 0)
354 #error "OID_AUTO is expected to be a negative value"
355 #endif
356 /*
357 * Any negative OID number qualifies as OID_AUTO. Valid OID
358 * numbers should always be positive.
359 *
360 * NOTE: DO NOT change the starting value here, change it in
361 * <sys/sysctl.h>, and make sure it is at least 256 to
362 * accommodate e.g. net.inet.raw as a static sysctl node.
363 */
364 if (oid_number < 0) {
365 static int newoid;
366
367 /*
368 * By decrementing the next OID number we spend less
369 * time inserting the OIDs into a sorted list.
370 */
371 if (--newoid < CTL_AUTO_START)
372 newoid = 0x7fffffff;
373
374 oid_number = newoid;
375 }
376
377 /*
378 * Insert the OID into the parent's list sorted by OID number.
379 */
380 retry:
381 q = NULL;
382 SLIST_FOREACH(p, parent, oid_link) {
383 /* check if the current OID number is in use */
384 if (oid_number == p->oid_number) {
385 /* get the next valid OID number */
386 if (oid_number < CTL_AUTO_START ||
387 oid_number == 0x7fffffff) {
388 /* wraparound - restart */
389 oid_number = CTL_AUTO_START;
390 /* don't loop forever */
391 if (!timeout--)
392 panic("sysctl: Out of OID numbers\n");
393 goto retry;
394 } else {
395 oid_number++;
396 }
397 } else if (oid_number < p->oid_number)
398 break;
399 q = p;
400 }
401 /* check for non-auto OID number collision */
402 if (oidp->oid_number >= 0 && oidp->oid_number < CTL_AUTO_START &&
403 oid_number >= CTL_AUTO_START) {
404 printf("sysctl: OID number(%d) is already in use for '%s'\n",
405 oidp->oid_number, oidp->oid_name);
406 }
407 /* update the OID number, if any */
408 oidp->oid_number = oid_number;
409 if (q != NULL)
410 SLIST_INSERT_AFTER(q, oidp, oid_link);
411 else
412 SLIST_INSERT_HEAD(parent, oidp, oid_link);
413
414 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE &&
415 #ifdef VIMAGE
416 (oidp->oid_kind & CTLFLAG_VNET) == 0 &&
417 #endif
418 (oidp->oid_kind & CTLFLAG_TUN) != 0 &&
419 (oidp->oid_kind & CTLFLAG_NOFETCH) == 0) {
420 /* only fetch value once */
421 oidp->oid_kind |= CTLFLAG_NOFETCH;
422 /* try to fetch value from kernel environment */
423 sysctl_load_tunable_by_oid_locked(oidp);
424 }
425 }
426
427 void
428 sysctl_unregister_oid(struct sysctl_oid *oidp)
429 {
430 struct sysctl_oid *p;
431 int error;
432
433 SYSCTL_ASSERT_WLOCKED();
434 error = ENOENT;
435 if (oidp->oid_number == OID_AUTO) {
436 error = EINVAL;
437 } else {
438 SLIST_FOREACH(p, oidp->oid_parent, oid_link) {
439 if (p == oidp) {
440 SLIST_REMOVE(oidp->oid_parent, oidp,
441 sysctl_oid, oid_link);
442 error = 0;
443 break;
444 }
445 }
446 }
447
448 /*
449 * This can happen when a module fails to register and is
450 * being unloaded afterwards. It should not be a panic()
451 * for normal use.
452 */
453 if (error)
454 printf("%s: failed to unregister sysctl\n", __func__);
455 }
456
457 /* Initialize a new context to keep track of dynamically added sysctls. */
458 int
459 sysctl_ctx_init(struct sysctl_ctx_list *c)
460 {
461
462 if (c == NULL) {
463 return (EINVAL);
464 }
465
466 /*
467 * No locking here, the caller is responsible for not adding
468 * new nodes to a context until after this function has
469 * returned.
470 */
471 TAILQ_INIT(c);
472 return (0);
473 }
474
475 /* Free the context, and destroy all dynamic oids registered in this context */
476 int
477 sysctl_ctx_free(struct sysctl_ctx_list *clist)
478 {
479 struct sysctl_ctx_entry *e, *e1;
480 int error;
481
482 error = 0;
483 /*
484 * First perform a "dry run" to check if it's ok to remove oids.
485 * XXX FIXME
486 * XXX This algorithm is a hack. But I don't know any
487 * XXX better solution for now...
488 */
489 SYSCTL_WLOCK();
490 TAILQ_FOREACH(e, clist, link) {
491 error = sysctl_remove_oid_locked(e->entry, 0, 0);
492 if (error)
493 break;
494 }
495 /*
496 * Restore deregistered entries, either from the end,
497 * or from the place where error occurred.
498 * e contains the entry that was not unregistered
499 */
500 if (error)
501 e1 = TAILQ_PREV(e, sysctl_ctx_list, link);
502 else
503 e1 = TAILQ_LAST(clist, sysctl_ctx_list);
504 while (e1 != NULL) {
505 sysctl_register_oid(e1->entry);
506 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link);
507 }
508 if (error) {
509 SYSCTL_WUNLOCK();
510 return(EBUSY);
511 }
512 /* Now really delete the entries */
513 e = TAILQ_FIRST(clist);
514 while (e != NULL) {
515 e1 = TAILQ_NEXT(e, link);
516 error = sysctl_remove_oid_locked(e->entry, 1, 0);
517 if (error)
518 panic("sysctl_remove_oid: corrupt tree, entry: %s",
519 e->entry->oid_name);
520 free(e, M_SYSCTLOID);
521 e = e1;
522 }
523 SYSCTL_WUNLOCK();
524 return (error);
525 }
526
527 /* Add an entry to the context */
528 struct sysctl_ctx_entry *
529 sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
530 {
531 struct sysctl_ctx_entry *e;
532
533 SYSCTL_ASSERT_WLOCKED();
534 if (clist == NULL || oidp == NULL)
535 return(NULL);
536 e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK);
537 e->entry = oidp;
538 TAILQ_INSERT_HEAD(clist, e, link);
539 return (e);
540 }
541
542 /* Find an entry in the context */
543 struct sysctl_ctx_entry *
544 sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
545 {
546 struct sysctl_ctx_entry *e;
547
548 SYSCTL_ASSERT_WLOCKED();
549 if (clist == NULL || oidp == NULL)
550 return(NULL);
551 TAILQ_FOREACH(e, clist, link) {
552 if(e->entry == oidp)
553 return(e);
554 }
555 return (e);
556 }
557
558 /*
559 * Delete an entry from the context.
560 * NOTE: this function doesn't free oidp! You have to remove it
561 * with sysctl_remove_oid().
562 */
563 int
564 sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
565 {
566 struct sysctl_ctx_entry *e;
567
568 if (clist == NULL || oidp == NULL)
569 return (EINVAL);
570 SYSCTL_WLOCK();
571 e = sysctl_ctx_entry_find(clist, oidp);
572 if (e != NULL) {
573 TAILQ_REMOVE(clist, e, link);
574 SYSCTL_WUNLOCK();
575 free(e, M_SYSCTLOID);
576 return (0);
577 } else {
578 SYSCTL_WUNLOCK();
579 return (ENOENT);
580 }
581 }
582
583 /*
584 * Remove dynamically created sysctl trees.
585 * oidp - top of the tree to be removed
586 * del - if 0 - just deregister, otherwise free up entries as well
587 * recurse - if != 0 traverse the subtree to be deleted
588 */
589 int
590 sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse)
591 {
592 int error;
593
594 SYSCTL_WLOCK();
595 error = sysctl_remove_oid_locked(oidp, del, recurse);
596 SYSCTL_WUNLOCK();
597 return (error);
598 }
599
600 int
601 sysctl_remove_name(struct sysctl_oid *parent, const char *name,
602 int del, int recurse)
603 {
604 struct sysctl_oid *p, *tmp;
605 int error;
606
607 error = ENOENT;
608 SYSCTL_WLOCK();
609 SLIST_FOREACH_SAFE(p, SYSCTL_CHILDREN(parent), oid_link, tmp) {
610 if (strcmp(p->oid_name, name) == 0) {
611 error = sysctl_remove_oid_locked(p, del, recurse);
612 break;
613 }
614 }
615 SYSCTL_WUNLOCK();
616
617 return (error);
618 }
619
620
621 static int
622 sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse)
623 {
624 struct sysctl_oid *p, *tmp;
625 int error;
626
627 SYSCTL_ASSERT_WLOCKED();
628 if (oidp == NULL)
629 return(EINVAL);
630 if ((oidp->oid_kind & CTLFLAG_DYN) == 0) {
631 printf("Warning: can't remove non-dynamic nodes (%s)!\n",
632 oidp->oid_name);
633 return (EINVAL);
634 }
635 /*
636 * WARNING: normal method to do this should be through
637 * sysctl_ctx_free(). Use recursing as the last resort
638 * method to purge your sysctl tree of leftovers...
639 * However, if some other code still references these nodes,
640 * it will panic.
641 */
642 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
643 if (oidp->oid_refcnt == 1) {
644 SLIST_FOREACH_SAFE(p,
645 SYSCTL_CHILDREN(oidp), oid_link, tmp) {
646 if (!recurse) {
647 printf("Warning: failed attempt to "
648 "remove oid %s with child %s\n",
649 oidp->oid_name, p->oid_name);
650 return (ENOTEMPTY);
651 }
652 error = sysctl_remove_oid_locked(p, del,
653 recurse);
654 if (error)
655 return (error);
656 }
657 }
658 }
659 if (oidp->oid_refcnt > 1 ) {
660 oidp->oid_refcnt--;
661 } else {
662 if (oidp->oid_refcnt == 0) {
663 printf("Warning: bad oid_refcnt=%u (%s)!\n",
664 oidp->oid_refcnt, oidp->oid_name);
665 return (EINVAL);
666 }
667 sysctl_unregister_oid(oidp);
668 if (del) {
669 /*
670 * Wait for all threads running the handler to drain.
671 * This preserves the previous behavior when the
672 * sysctl lock was held across a handler invocation,
673 * and is necessary for module unload correctness.
674 */
675 while (oidp->oid_running > 0) {
676 oidp->oid_kind |= CTLFLAG_DYING;
677 SYSCTL_SLEEP(&oidp->oid_running, "oidrm", 0);
678 }
679 if (oidp->oid_descr)
680 free(__DECONST(char *, oidp->oid_descr),
681 M_SYSCTLOID);
682 free(__DECONST(char *, oidp->oid_name), M_SYSCTLOID);
683 free(oidp, M_SYSCTLOID);
684 }
685 }
686 return (0);
687 }
688 /*
689 * Create new sysctls at run time.
690 * clist may point to a valid context initialized with sysctl_ctx_init().
691 */
692 struct sysctl_oid *
693 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent,
694 int number, const char *name, int kind, void *arg1, intmax_t arg2,
695 int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr)
696 {
697 struct sysctl_oid *oidp;
698
699 /* You have to hook up somewhere.. */
700 if (parent == NULL)
701 return(NULL);
702 /* Check if the node already exists, otherwise create it */
703 SYSCTL_WLOCK();
704 oidp = sysctl_find_oidname(name, parent);
705 if (oidp != NULL) {
706 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
707 oidp->oid_refcnt++;
708 /* Update the context */
709 if (clist != NULL)
710 sysctl_ctx_entry_add(clist, oidp);
711 SYSCTL_WUNLOCK();
712 return (oidp);
713 } else {
714 SYSCTL_WUNLOCK();
715 printf("can't re-use a leaf (%s)!\n", name);
716 return (NULL);
717 }
718 }
719 oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO);
720 oidp->oid_parent = parent;
721 SLIST_INIT(&oidp->oid_children);
722 oidp->oid_number = number;
723 oidp->oid_refcnt = 1;
724 oidp->oid_name = strdup(name, M_SYSCTLOID);
725 oidp->oid_handler = handler;
726 oidp->oid_kind = CTLFLAG_DYN | kind;
727 oidp->oid_arg1 = arg1;
728 oidp->oid_arg2 = arg2;
729 oidp->oid_fmt = fmt;
730 if (descr != NULL)
731 oidp->oid_descr = strdup(descr, M_SYSCTLOID);
732 /* Update the context, if used */
733 if (clist != NULL)
734 sysctl_ctx_entry_add(clist, oidp);
735 /* Register this oid */
736 sysctl_register_oid(oidp);
737 SYSCTL_WUNLOCK();
738 return (oidp);
739 }
740
741 /*
742 * Rename an existing oid.
743 */
744 void
745 sysctl_rename_oid(struct sysctl_oid *oidp, const char *name)
746 {
747 char *newname;
748 char *oldname;
749
750 newname = strdup(name, M_SYSCTLOID);
751 SYSCTL_WLOCK();
752 oldname = __DECONST(char *, oidp->oid_name);
753 oidp->oid_name = newname;
754 SYSCTL_WUNLOCK();
755 free(oldname, M_SYSCTLOID);
756 }
757
758 /*
759 * Reparent an existing oid.
760 */
761 int
762 sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent)
763 {
764 struct sysctl_oid *oidp;
765
766 SYSCTL_WLOCK();
767 if (oid->oid_parent == parent) {
768 SYSCTL_WUNLOCK();
769 return (0);
770 }
771 oidp = sysctl_find_oidname(oid->oid_name, parent);
772 if (oidp != NULL) {
773 SYSCTL_WUNLOCK();
774 return (EEXIST);
775 }
776 sysctl_unregister_oid(oid);
777 oid->oid_parent = parent;
778 oid->oid_number = OID_AUTO;
779 sysctl_register_oid(oid);
780 SYSCTL_WUNLOCK();
781 return (0);
782 }
783
784 /*
785 * Register the kernel's oids on startup.
786 */
787 SET_DECLARE(sysctl_set, struct sysctl_oid);
788
789 static void
790 sysctl_register_all(void *arg)
791 {
792 struct sysctl_oid **oidp;
793
794 sx_init(&sysctlmemlock, "sysctl mem");
795 SYSCTL_INIT();
796 SYSCTL_WLOCK();
797 SET_FOREACH(oidp, sysctl_set)
798 sysctl_register_oid(*oidp);
799 SYSCTL_WUNLOCK();
800 }
801 SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_FIRST, sysctl_register_all, 0);
802
803 /*
804 * "Staff-functions"
805 *
806 * These functions implement a presently undocumented interface
807 * used by the sysctl program to walk the tree, and get the type
808 * so it can print the value.
809 * This interface is under work and consideration, and should probably
810 * be killed with a big axe by the first person who can find the time.
811 * (be aware though, that the proper interface isn't as obvious as it
812 * may seem, there are various conflicting requirements.
813 *
814 * {0,0} printf the entire MIB-tree.
815 * {0,1,...} return the name of the "..." OID.
816 * {0,2,...} return the next OID.
817 * {0,3} return the OID of the name in "new"
818 * {0,4,...} return the kind & format info for the "..." OID.
819 * {0,5,...} return the description the "..." OID.
820 */
821
822 #ifdef SYSCTL_DEBUG
823 static void
824 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i)
825 {
826 int k;
827 struct sysctl_oid *oidp;
828
829 SYSCTL_ASSERT_LOCKED();
830 SLIST_FOREACH(oidp, l, oid_link) {
831
832 for (k=0; k<i; k++)
833 printf(" ");
834
835 printf("%d %s ", oidp->oid_number, oidp->oid_name);
836
837 printf("%c%c",
838 oidp->oid_kind & CTLFLAG_RD ? 'R':' ',
839 oidp->oid_kind & CTLFLAG_WR ? 'W':' ');
840
841 if (oidp->oid_handler)
842 printf(" *Handler");
843
844 switch (oidp->oid_kind & CTLTYPE) {
845 case CTLTYPE_NODE:
846 printf(" Node\n");
847 if (!oidp->oid_handler) {
848 sysctl_sysctl_debug_dump_node(
849 SYSCTL_CHILDREN(oidp), i + 2);
850 }
851 break;
852 case CTLTYPE_INT: printf(" Int\n"); break;
853 case CTLTYPE_UINT: printf(" u_int\n"); break;
854 case CTLTYPE_LONG: printf(" Long\n"); break;
855 case CTLTYPE_ULONG: printf(" u_long\n"); break;
856 case CTLTYPE_STRING: printf(" String\n"); break;
857 case CTLTYPE_S8: printf(" int8_t\n"); break;
858 case CTLTYPE_S16: printf(" int16_t\n"); break;
859 case CTLTYPE_S32: printf(" int32_t\n"); break;
860 case CTLTYPE_S64: printf(" int64_t\n"); break;
861 case CTLTYPE_U8: printf(" uint8_t\n"); break;
862 case CTLTYPE_U16: printf(" uint16_t\n"); break;
863 case CTLTYPE_U32: printf(" uint32_t\n"); break;
864 case CTLTYPE_U64: printf(" uint64_t\n"); break;
865 case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break;
866 default: printf("\n");
867 }
868
869 }
870 }
871
872 static int
873 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS)
874 {
875 struct rm_priotracker tracker;
876 int error;
877
878 error = priv_check(req->td, PRIV_SYSCTL_DEBUG);
879 if (error)
880 return (error);
881 SYSCTL_RLOCK(&tracker);
882 sysctl_sysctl_debug_dump_node(&sysctl__children, 0);
883 SYSCTL_RUNLOCK(&tracker);
884 return (ENOENT);
885 }
886
887 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE,
888 0, 0, sysctl_sysctl_debug, "-", "");
889 #endif
890
891 static int
892 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS)
893 {
894 int *name = (int *) arg1;
895 u_int namelen = arg2;
896 int error = 0;
897 struct sysctl_oid *oid;
898 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2;
899 struct rm_priotracker tracker;
900 char buf[10];
901
902 SYSCTL_RLOCK(&tracker);
903 while (namelen) {
904 if (!lsp) {
905 snprintf(buf,sizeof(buf),"%d",*name);
906 if (req->oldidx)
907 error = SYSCTL_OUT(req, ".", 1);
908 if (!error)
909 error = SYSCTL_OUT(req, buf, strlen(buf));
910 if (error)
911 goto out;
912 namelen--;
913 name++;
914 continue;
915 }
916 lsp2 = NULL;
917 SLIST_FOREACH(oid, lsp, oid_link) {
918 if (oid->oid_number != *name)
919 continue;
920
921 if (req->oldidx)
922 error = SYSCTL_OUT(req, ".", 1);
923 if (!error)
924 error = SYSCTL_OUT(req, oid->oid_name,
925 strlen(oid->oid_name));
926 if (error)
927 goto out;
928
929 namelen--;
930 name++;
931
932 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE)
933 break;
934
935 if (oid->oid_handler)
936 break;
937
938 lsp2 = SYSCTL_CHILDREN(oid);
939 break;
940 }
941 lsp = lsp2;
942 }
943 error = SYSCTL_OUT(req, "", 1);
944 out:
945 SYSCTL_RUNLOCK(&tracker);
946 return (error);
947 }
948
949 /*
950 * XXXRW/JA: Shouldn't return name data for nodes that we don't permit in
951 * capability mode.
952 */
953 static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD,
954 sysctl_sysctl_name, "");
955
956 static int
957 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen,
958 int *next, int *len, int level, struct sysctl_oid **oidpp)
959 {
960 struct sysctl_oid *oidp;
961
962 SYSCTL_ASSERT_LOCKED();
963 *len = level;
964 SLIST_FOREACH(oidp, lsp, oid_link) {
965 *next = oidp->oid_number;
966 *oidpp = oidp;
967
968 if (oidp->oid_kind & CTLFLAG_SKIP)
969 continue;
970
971 if (!namelen) {
972 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
973 return (0);
974 if (oidp->oid_handler)
975 /* We really should call the handler here...*/
976 return (0);
977 lsp = SYSCTL_CHILDREN(oidp);
978 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1,
979 len, level+1, oidpp))
980 return (0);
981 goto emptynode;
982 }
983
984 if (oidp->oid_number < *name)
985 continue;
986
987 if (oidp->oid_number > *name) {
988 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
989 return (0);
990 if (oidp->oid_handler)
991 return (0);
992 lsp = SYSCTL_CHILDREN(oidp);
993 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1,
994 next+1, len, level+1, oidpp))
995 return (0);
996 goto next;
997 }
998 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
999 continue;
1000
1001 if (oidp->oid_handler)
1002 continue;
1003
1004 lsp = SYSCTL_CHILDREN(oidp);
1005 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1,
1006 len, level+1, oidpp))
1007 return (0);
1008 next:
1009 namelen = 1;
1010 emptynode:
1011 *len = level;
1012 }
1013 return (1);
1014 }
1015
1016 static int
1017 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS)
1018 {
1019 int *name = (int *) arg1;
1020 u_int namelen = arg2;
1021 int i, j, error;
1022 struct sysctl_oid *oid;
1023 struct sysctl_oid_list *lsp = &sysctl__children;
1024 struct rm_priotracker tracker;
1025 int newoid[CTL_MAXNAME];
1026
1027 SYSCTL_RLOCK(&tracker);
1028 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid);
1029 SYSCTL_RUNLOCK(&tracker);
1030 if (i)
1031 return (ENOENT);
1032 error = SYSCTL_OUT(req, newoid, j * sizeof (int));
1033 return (error);
1034 }
1035
1036 /*
1037 * XXXRW/JA: Shouldn't return next data for nodes that we don't permit in
1038 * capability mode.
1039 */
1040 static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD,
1041 sysctl_sysctl_next, "");
1042
1043 static int
1044 name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp)
1045 {
1046 struct sysctl_oid *oidp;
1047 struct sysctl_oid_list *lsp = &sysctl__children;
1048 char *p;
1049
1050 SYSCTL_ASSERT_LOCKED();
1051
1052 for (*len = 0; *len < CTL_MAXNAME;) {
1053 p = strsep(&name, ".");
1054
1055 oidp = SLIST_FIRST(lsp);
1056 for (;; oidp = SLIST_NEXT(oidp, oid_link)) {
1057 if (oidp == NULL)
1058 return (ENOENT);
1059 if (strcmp(p, oidp->oid_name) == 0)
1060 break;
1061 }
1062 *oid++ = oidp->oid_number;
1063 (*len)++;
1064
1065 if (name == NULL || *name == '\0') {
1066 if (oidpp)
1067 *oidpp = oidp;
1068 return (0);
1069 }
1070
1071 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
1072 break;
1073
1074 if (oidp->oid_handler)
1075 break;
1076
1077 lsp = SYSCTL_CHILDREN(oidp);
1078 }
1079 return (ENOENT);
1080 }
1081
1082 static int
1083 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS)
1084 {
1085 char *p;
1086 int error, oid[CTL_MAXNAME], len = 0;
1087 struct sysctl_oid *op = NULL;
1088 struct rm_priotracker tracker;
1089
1090 if (!req->newlen)
1091 return (ENOENT);
1092 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */
1093 return (ENAMETOOLONG);
1094
1095 p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK);
1096
1097 error = SYSCTL_IN(req, p, req->newlen);
1098 if (error) {
1099 free(p, M_SYSCTL);
1100 return (error);
1101 }
1102
1103 p [req->newlen] = '\0';
1104
1105 SYSCTL_RLOCK(&tracker);
1106 error = name2oid(p, oid, &len, &op);
1107 SYSCTL_RUNLOCK(&tracker);
1108
1109 free(p, M_SYSCTL);
1110
1111 if (error)
1112 return (error);
1113
1114 error = SYSCTL_OUT(req, oid, len * sizeof *oid);
1115 return (error);
1116 }
1117
1118 /*
1119 * XXXRW/JA: Shouldn't return name2oid data for nodes that we don't permit in
1120 * capability mode.
1121 */
1122 SYSCTL_PROC(_sysctl, 3, name2oid,
1123 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_MPSAFE
1124 | CTLFLAG_CAPRW, 0, 0, sysctl_sysctl_name2oid, "I", "");
1125
1126 static int
1127 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS)
1128 {
1129 struct sysctl_oid *oid;
1130 struct rm_priotracker tracker;
1131 int error;
1132
1133 SYSCTL_RLOCK(&tracker);
1134 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
1135 if (error)
1136 goto out;
1137
1138 if (oid->oid_fmt == NULL) {
1139 error = ENOENT;
1140 goto out;
1141 }
1142 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind));
1143 if (error)
1144 goto out;
1145 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1);
1146 out:
1147 SYSCTL_RUNLOCK(&tracker);
1148 return (error);
1149 }
1150
1151
1152 static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD,
1153 sysctl_sysctl_oidfmt, "");
1154
1155 static int
1156 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS)
1157 {
1158 struct sysctl_oid *oid;
1159 struct rm_priotracker tracker;
1160 int error;
1161
1162 SYSCTL_RLOCK(&tracker);
1163 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
1164 if (error)
1165 goto out;
1166
1167 if (oid->oid_descr == NULL) {
1168 error = ENOENT;
1169 goto out;
1170 }
1171 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1);
1172 out:
1173 SYSCTL_RUNLOCK(&tracker);
1174 return (error);
1175 }
1176
1177 static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD,
1178 sysctl_sysctl_oiddescr, "");
1179
1180 /*
1181 * Default "handler" functions.
1182 */
1183
1184 /*
1185 * Handle a bool.
1186 * Two cases:
1187 * a variable: point arg1 at it.
1188 * a constant: pass it in arg2.
1189 */
1190
1191 int
1192 sysctl_handle_bool(SYSCTL_HANDLER_ARGS)
1193 {
1194 uint8_t temp;
1195 int error;
1196
1197 /*
1198 * Attempt to get a coherent snapshot by making a copy of the data.
1199 */
1200 if (arg1)
1201 temp = *(bool *)arg1 ? 1 : 0;
1202 else
1203 temp = arg2 ? 1 : 0;
1204
1205 error = SYSCTL_OUT(req, &temp, sizeof(temp));
1206 if (error || !req->newptr)
1207 return (error);
1208
1209 if (!arg1)
1210 error = EPERM;
1211 else {
1212 error = SYSCTL_IN(req, &temp, sizeof(temp));
1213 if (!error)
1214 *(bool *)arg1 = temp ? 1 : 0;
1215 }
1216 return (error);
1217 }
1218
1219 /*
1220 * Handle an int8_t, signed or unsigned.
1221 * Two cases:
1222 * a variable: point arg1 at it.
1223 * a constant: pass it in arg2.
1224 */
1225
1226 int
1227 sysctl_handle_8(SYSCTL_HANDLER_ARGS)
1228 {
1229 int8_t tmpout;
1230 int error = 0;
1231
1232 /*
1233 * Attempt to get a coherent snapshot by making a copy of the data.
1234 */
1235 if (arg1)
1236 tmpout = *(int8_t *)arg1;
1237 else
1238 tmpout = arg2;
1239 error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout));
1240
1241 if (error || !req->newptr)
1242 return (error);
1243
1244 if (!arg1)
1245 error = EPERM;
1246 else
1247 error = SYSCTL_IN(req, arg1, sizeof(tmpout));
1248 return (error);
1249 }
1250
1251 /*
1252 * Handle an int16_t, signed or unsigned.
1253 * Two cases:
1254 * a variable: point arg1 at it.
1255 * a constant: pass it in arg2.
1256 */
1257
1258 int
1259 sysctl_handle_16(SYSCTL_HANDLER_ARGS)
1260 {
1261 int16_t tmpout;
1262 int error = 0;
1263
1264 /*
1265 * Attempt to get a coherent snapshot by making a copy of the data.
1266 */
1267 if (arg1)
1268 tmpout = *(int16_t *)arg1;
1269 else
1270 tmpout = arg2;
1271 error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout));
1272
1273 if (error || !req->newptr)
1274 return (error);
1275
1276 if (!arg1)
1277 error = EPERM;
1278 else
1279 error = SYSCTL_IN(req, arg1, sizeof(tmpout));
1280 return (error);
1281 }
1282
1283 /*
1284 * Handle an int32_t, signed or unsigned.
1285 * Two cases:
1286 * a variable: point arg1 at it.
1287 * a constant: pass it in arg2.
1288 */
1289
1290 int
1291 sysctl_handle_32(SYSCTL_HANDLER_ARGS)
1292 {
1293 int32_t tmpout;
1294 int error = 0;
1295
1296 /*
1297 * Attempt to get a coherent snapshot by making a copy of the data.
1298 */
1299 if (arg1)
1300 tmpout = *(int32_t *)arg1;
1301 else
1302 tmpout = arg2;
1303 error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout));
1304
1305 if (error || !req->newptr)
1306 return (error);
1307
1308 if (!arg1)
1309 error = EPERM;
1310 else
1311 error = SYSCTL_IN(req, arg1, sizeof(tmpout));
1312 return (error);
1313 }
1314
1315 /*
1316 * Handle an int, signed or unsigned.
1317 * Two cases:
1318 * a variable: point arg1 at it.
1319 * a constant: pass it in arg2.
1320 */
1321
1322 int
1323 sysctl_handle_int(SYSCTL_HANDLER_ARGS)
1324 {
1325 int tmpout, error = 0;
1326
1327 /*
1328 * Attempt to get a coherent snapshot by making a copy of the data.
1329 */
1330 if (arg1)
1331 tmpout = *(int *)arg1;
1332 else
1333 tmpout = arg2;
1334 error = SYSCTL_OUT(req, &tmpout, sizeof(int));
1335
1336 if (error || !req->newptr)
1337 return (error);
1338
1339 if (!arg1)
1340 error = EPERM;
1341 else
1342 error = SYSCTL_IN(req, arg1, sizeof(int));
1343 return (error);
1344 }
1345
1346 /*
1347 * Based on on sysctl_handle_int() convert milliseconds into ticks.
1348 * Note: this is used by TCP.
1349 */
1350
1351 int
1352 sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS)
1353 {
1354 int error, s, tt;
1355
1356 tt = *(int *)arg1;
1357 s = (int)((int64_t)tt * 1000 / hz);
1358
1359 error = sysctl_handle_int(oidp, &s, 0, req);
1360 if (error || !req->newptr)
1361 return (error);
1362
1363 tt = (int)((int64_t)s * hz / 1000);
1364 if (tt < 1)
1365 return (EINVAL);
1366
1367 *(int *)arg1 = tt;
1368 return (0);
1369 }
1370
1371
1372 /*
1373 * Handle a long, signed or unsigned.
1374 * Two cases:
1375 * a variable: point arg1 at it.
1376 * a constant: pass it in arg2.
1377 */
1378
1379 int
1380 sysctl_handle_long(SYSCTL_HANDLER_ARGS)
1381 {
1382 int error = 0;
1383 long tmplong;
1384 #ifdef SCTL_MASK32
1385 int tmpint;
1386 #endif
1387
1388 /*
1389 * Attempt to get a coherent snapshot by making a copy of the data.
1390 */
1391 if (arg1)
1392 tmplong = *(long *)arg1;
1393 else
1394 tmplong = arg2;
1395 #ifdef SCTL_MASK32
1396 if (req->flags & SCTL_MASK32) {
1397 tmpint = tmplong;
1398 error = SYSCTL_OUT(req, &tmpint, sizeof(int));
1399 } else
1400 #endif
1401 error = SYSCTL_OUT(req, &tmplong, sizeof(long));
1402
1403 if (error || !req->newptr)
1404 return (error);
1405
1406 if (!arg1)
1407 error = EPERM;
1408 #ifdef SCTL_MASK32
1409 else if (req->flags & SCTL_MASK32) {
1410 error = SYSCTL_IN(req, &tmpint, sizeof(int));
1411 *(long *)arg1 = (long)tmpint;
1412 }
1413 #endif
1414 else
1415 error = SYSCTL_IN(req, arg1, sizeof(long));
1416 return (error);
1417 }
1418
1419 /*
1420 * Handle a 64 bit int, signed or unsigned.
1421 * Two cases:
1422 * a variable: point arg1 at it.
1423 * a constant: pass it in arg2.
1424 */
1425 int
1426 sysctl_handle_64(SYSCTL_HANDLER_ARGS)
1427 {
1428 int error = 0;
1429 uint64_t tmpout;
1430
1431 /*
1432 * Attempt to get a coherent snapshot by making a copy of the data.
1433 */
1434 if (arg1)
1435 tmpout = *(uint64_t *)arg1;
1436 else
1437 tmpout = arg2;
1438 error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t));
1439
1440 if (error || !req->newptr)
1441 return (error);
1442
1443 if (!arg1)
1444 error = EPERM;
1445 else
1446 error = SYSCTL_IN(req, arg1, sizeof(uint64_t));
1447 return (error);
1448 }
1449
1450 /*
1451 * Handle our generic '\0' terminated 'C' string.
1452 * Two cases:
1453 * a variable string: point arg1 at it, arg2 is max length.
1454 * a constant string: point arg1 at it, arg2 is zero.
1455 */
1456
1457 int
1458 sysctl_handle_string(SYSCTL_HANDLER_ARGS)
1459 {
1460 size_t outlen;
1461 int error = 0, ro_string = 0;
1462
1463 /*
1464 * A zero-length buffer indicates a fixed size read-only
1465 * string:
1466 */
1467 if (arg2 == 0) {
1468 arg2 = strlen((char *)arg1) + 1;
1469 ro_string = 1;
1470 }
1471
1472 if (req->oldptr != NULL) {
1473 char *tmparg;
1474
1475 if (ro_string) {
1476 tmparg = arg1;
1477 } else {
1478 /* try to make a coherent snapshot of the string */
1479 tmparg = malloc(arg2, M_SYSCTLTMP, M_WAITOK);
1480 memcpy(tmparg, arg1, arg2);
1481 }
1482
1483 outlen = strnlen(tmparg, arg2 - 1) + 1;
1484 error = SYSCTL_OUT(req, tmparg, outlen);
1485
1486 if (!ro_string)
1487 free(tmparg, M_SYSCTLTMP);
1488 } else {
1489 outlen = strnlen((char *)arg1, arg2 - 1) + 1;
1490 error = SYSCTL_OUT(req, NULL, outlen);
1491 }
1492 if (error || !req->newptr)
1493 return (error);
1494
1495 if ((req->newlen - req->newidx) >= arg2) {
1496 error = EINVAL;
1497 } else {
1498 arg2 = (req->newlen - req->newidx);
1499 error = SYSCTL_IN(req, arg1, arg2);
1500 ((char *)arg1)[arg2] = '\0';
1501 }
1502 return (error);
1503 }
1504
1505 /*
1506 * Handle any kind of opaque data.
1507 * arg1 points to it, arg2 is the size.
1508 */
1509
1510 int
1511 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS)
1512 {
1513 int error, tries;
1514 u_int generation;
1515 struct sysctl_req req2;
1516
1517 /*
1518 * Attempt to get a coherent snapshot, by using the thread
1519 * pre-emption counter updated from within mi_switch() to
1520 * determine if we were pre-empted during a bcopy() or
1521 * copyout(). Make 3 attempts at doing this before giving up.
1522 * If we encounter an error, stop immediately.
1523 */
1524 tries = 0;
1525 req2 = *req;
1526 retry:
1527 generation = curthread->td_generation;
1528 error = SYSCTL_OUT(req, arg1, arg2);
1529 if (error)
1530 return (error);
1531 tries++;
1532 if (generation != curthread->td_generation && tries < 3) {
1533 *req = req2;
1534 goto retry;
1535 }
1536
1537 error = SYSCTL_IN(req, arg1, arg2);
1538
1539 return (error);
1540 }
1541
1542 /*
1543 * Transfer functions to/from kernel space.
1544 * XXX: rather untested at this point
1545 */
1546 static int
1547 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l)
1548 {
1549 size_t i = 0;
1550
1551 if (req->oldptr) {
1552 i = l;
1553 if (req->oldlen <= req->oldidx)
1554 i = 0;
1555 else
1556 if (i > req->oldlen - req->oldidx)
1557 i = req->oldlen - req->oldidx;
1558 if (i > 0)
1559 bcopy(p, (char *)req->oldptr + req->oldidx, i);
1560 }
1561 req->oldidx += l;
1562 if (req->oldptr && i != l)
1563 return (ENOMEM);
1564 return (0);
1565 }
1566
1567 static int
1568 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l)
1569 {
1570 if (!req->newptr)
1571 return (0);
1572 if (req->newlen - req->newidx < l)
1573 return (EINVAL);
1574 bcopy((char *)req->newptr + req->newidx, p, l);
1575 req->newidx += l;
1576 return (0);
1577 }
1578
1579 int
1580 kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old,
1581 size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags)
1582 {
1583 int error = 0;
1584 struct sysctl_req req;
1585
1586 bzero(&req, sizeof req);
1587
1588 req.td = td;
1589 req.flags = flags;
1590
1591 if (oldlenp) {
1592 req.oldlen = *oldlenp;
1593 }
1594 req.validlen = req.oldlen;
1595
1596 if (old) {
1597 req.oldptr= old;
1598 }
1599
1600 if (new != NULL) {
1601 req.newlen = newlen;
1602 req.newptr = new;
1603 }
1604
1605 req.oldfunc = sysctl_old_kernel;
1606 req.newfunc = sysctl_new_kernel;
1607 req.lock = REQ_UNWIRED;
1608
1609 error = sysctl_root(0, name, namelen, &req);
1610
1611 if (req.lock == REQ_WIRED && req.validlen > 0)
1612 vsunlock(req.oldptr, req.validlen);
1613
1614 if (error && error != ENOMEM)
1615 return (error);
1616
1617 if (retval) {
1618 if (req.oldptr && req.oldidx > req.validlen)
1619 *retval = req.validlen;
1620 else
1621 *retval = req.oldidx;
1622 }
1623 return (error);
1624 }
1625
1626 int
1627 kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp,
1628 void *new, size_t newlen, size_t *retval, int flags)
1629 {
1630 int oid[CTL_MAXNAME];
1631 size_t oidlen, plen;
1632 int error;
1633
1634 oid[0] = 0; /* sysctl internal magic */
1635 oid[1] = 3; /* name2oid */
1636 oidlen = sizeof(oid);
1637
1638 error = kernel_sysctl(td, oid, 2, oid, &oidlen,
1639 (void *)name, strlen(name), &plen, flags);
1640 if (error)
1641 return (error);
1642
1643 error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp,
1644 new, newlen, retval, flags);
1645 return (error);
1646 }
1647
1648 /*
1649 * Transfer function to/from user space.
1650 */
1651 static int
1652 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l)
1653 {
1654 size_t i, len, origidx;
1655 int error;
1656
1657 origidx = req->oldidx;
1658 req->oldidx += l;
1659 if (req->oldptr == NULL)
1660 return (0);
1661 /*
1662 * If we have not wired the user supplied buffer and we are currently
1663 * holding locks, drop a witness warning, as it's possible that
1664 * write operations to the user page can sleep.
1665 */
1666 if (req->lock != REQ_WIRED)
1667 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
1668 "sysctl_old_user()");
1669 i = l;
1670 len = req->validlen;
1671 if (len <= origidx)
1672 i = 0;
1673 else {
1674 if (i > len - origidx)
1675 i = len - origidx;
1676 if (req->lock == REQ_WIRED) {
1677 error = copyout_nofault(p, (char *)req->oldptr +
1678 origidx, i);
1679 } else
1680 error = copyout(p, (char *)req->oldptr + origidx, i);
1681 if (error != 0)
1682 return (error);
1683 }
1684 if (i < l)
1685 return (ENOMEM);
1686 return (0);
1687 }
1688
1689 static int
1690 sysctl_new_user(struct sysctl_req *req, void *p, size_t l)
1691 {
1692 int error;
1693
1694 if (!req->newptr)
1695 return (0);
1696 if (req->newlen - req->newidx < l)
1697 return (EINVAL);
1698 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
1699 "sysctl_new_user()");
1700 error = copyin((char *)req->newptr + req->newidx, p, l);
1701 req->newidx += l;
1702 return (error);
1703 }
1704
1705 /*
1706 * Wire the user space destination buffer. If set to a value greater than
1707 * zero, the len parameter limits the maximum amount of wired memory.
1708 */
1709 int
1710 sysctl_wire_old_buffer(struct sysctl_req *req, size_t len)
1711 {
1712 int ret;
1713 size_t wiredlen;
1714
1715 wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen;
1716 ret = 0;
1717 if (req->lock != REQ_WIRED && req->oldptr &&
1718 req->oldfunc == sysctl_old_user) {
1719 if (wiredlen != 0) {
1720 ret = vslock(req->oldptr, wiredlen);
1721 if (ret != 0) {
1722 if (ret != ENOMEM)
1723 return (ret);
1724 wiredlen = 0;
1725 }
1726 }
1727 req->lock = REQ_WIRED;
1728 req->validlen = wiredlen;
1729 }
1730 return (0);
1731 }
1732
1733 int
1734 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid,
1735 int *nindx, struct sysctl_req *req)
1736 {
1737 struct sysctl_oid_list *lsp;
1738 struct sysctl_oid *oid;
1739 int indx;
1740
1741 SYSCTL_ASSERT_LOCKED();
1742 lsp = &sysctl__children;
1743 indx = 0;
1744 while (indx < CTL_MAXNAME) {
1745 SLIST_FOREACH(oid, lsp, oid_link) {
1746 if (oid->oid_number == name[indx])
1747 break;
1748 }
1749 if (oid == NULL)
1750 return (ENOENT);
1751
1752 indx++;
1753 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1754 if (oid->oid_handler != NULL || indx == namelen) {
1755 *noid = oid;
1756 if (nindx != NULL)
1757 *nindx = indx;
1758 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0,
1759 ("%s found DYING node %p", __func__, oid));
1760 return (0);
1761 }
1762 lsp = SYSCTL_CHILDREN(oid);
1763 } else if (indx == namelen) {
1764 *noid = oid;
1765 if (nindx != NULL)
1766 *nindx = indx;
1767 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0,
1768 ("%s found DYING node %p", __func__, oid));
1769 return (0);
1770 } else {
1771 return (ENOTDIR);
1772 }
1773 }
1774 return (ENOENT);
1775 }
1776
1777 /*
1778 * Traverse our tree, and find the right node, execute whatever it points
1779 * to, and return the resulting error code.
1780 */
1781
1782 static int
1783 sysctl_root(SYSCTL_HANDLER_ARGS)
1784 {
1785 struct sysctl_oid *oid;
1786 struct rm_priotracker tracker;
1787 int error, indx, lvl;
1788
1789 SYSCTL_RLOCK(&tracker);
1790
1791 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req);
1792 if (error)
1793 goto out;
1794
1795 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1796 /*
1797 * You can't call a sysctl when it's a node, but has
1798 * no handler. Inform the user that it's a node.
1799 * The indx may or may not be the same as namelen.
1800 */
1801 if (oid->oid_handler == NULL) {
1802 error = EISDIR;
1803 goto out;
1804 }
1805 }
1806
1807 /* Is this sysctl writable? */
1808 if (req->newptr && !(oid->oid_kind & CTLFLAG_WR)) {
1809 error = EPERM;
1810 goto out;
1811 }
1812
1813 KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL"));
1814
1815 #ifdef CAPABILITY_MODE
1816 /*
1817 * If the process is in capability mode, then don't permit reading or
1818 * writing unless specifically granted for the node.
1819 */
1820 if (IN_CAPABILITY_MODE(req->td)) {
1821 if ((req->oldptr && !(oid->oid_kind & CTLFLAG_CAPRD)) ||
1822 (req->newptr && !(oid->oid_kind & CTLFLAG_CAPWR))) {
1823 error = EPERM;
1824 goto out;
1825 }
1826 }
1827 #endif
1828
1829 /* Is this sysctl sensitive to securelevels? */
1830 if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) {
1831 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE;
1832 error = securelevel_gt(req->td->td_ucred, lvl);
1833 if (error)
1834 goto out;
1835 }
1836
1837 /* Is this sysctl writable by only privileged users? */
1838 if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) {
1839 int priv;
1840
1841 if (oid->oid_kind & CTLFLAG_PRISON)
1842 priv = PRIV_SYSCTL_WRITEJAIL;
1843 #ifdef VIMAGE
1844 else if ((oid->oid_kind & CTLFLAG_VNET) &&
1845 prison_owns_vnet(req->td->td_ucred))
1846 priv = PRIV_SYSCTL_WRITEJAIL;
1847 #endif
1848 else
1849 priv = PRIV_SYSCTL_WRITE;
1850 error = priv_check(req->td, priv);
1851 if (error)
1852 goto out;
1853 }
1854
1855 if (!oid->oid_handler) {
1856 error = EINVAL;
1857 goto out;
1858 }
1859
1860 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1861 arg1 = (int *)arg1 + indx;
1862 arg2 -= indx;
1863 } else {
1864 arg1 = oid->oid_arg1;
1865 arg2 = oid->oid_arg2;
1866 }
1867 #ifdef MAC
1868 error = mac_system_check_sysctl(req->td->td_ucred, oid, arg1, arg2,
1869 req);
1870 if (error != 0)
1871 goto out;
1872 #endif
1873 #ifdef VIMAGE
1874 if ((oid->oid_kind & CTLFLAG_VNET) && arg1 != NULL)
1875 arg1 = (void *)(curvnet->vnet_data_base + (uintptr_t)arg1);
1876 #endif
1877 error = sysctl_root_handler_locked(oid, arg1, arg2, req, &tracker);
1878
1879 out:
1880 SYSCTL_RUNLOCK(&tracker);
1881 return (error);
1882 }
1883
1884 #ifndef _SYS_SYSPROTO_H_
1885 struct sysctl_args {
1886 int *name;
1887 u_int namelen;
1888 void *old;
1889 size_t *oldlenp;
1890 void *new;
1891 size_t newlen;
1892 };
1893 #endif
1894 int
1895 sys___sysctl(struct thread *td, struct sysctl_args *uap)
1896 {
1897 int error, i, name[CTL_MAXNAME];
1898 size_t j;
1899
1900 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2)
1901 return (EINVAL);
1902
1903 error = copyin(uap->name, &name, uap->namelen * sizeof(int));
1904 if (error)
1905 return (error);
1906
1907 error = userland_sysctl(td, name, uap->namelen,
1908 uap->old, uap->oldlenp, 0,
1909 uap->new, uap->newlen, &j, 0);
1910 if (error && error != ENOMEM)
1911 return (error);
1912 if (uap->oldlenp) {
1913 i = copyout(&j, uap->oldlenp, sizeof(j));
1914 if (i)
1915 return (i);
1916 }
1917 return (error);
1918 }
1919
1920 /*
1921 * This is used from various compatibility syscalls too. That's why name
1922 * must be in kernel space.
1923 */
1924 int
1925 userland_sysctl(struct thread *td, int *name, u_int namelen, void *old,
1926 size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval,
1927 int flags)
1928 {
1929 int error = 0, memlocked;
1930 struct sysctl_req req;
1931
1932 bzero(&req, sizeof req);
1933
1934 req.td = td;
1935 req.flags = flags;
1936
1937 if (oldlenp) {
1938 if (inkernel) {
1939 req.oldlen = *oldlenp;
1940 } else {
1941 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp));
1942 if (error)
1943 return (error);
1944 }
1945 }
1946 req.validlen = req.oldlen;
1947
1948 if (old) {
1949 if (!useracc(old, req.oldlen, VM_PROT_WRITE))
1950 return (EFAULT);
1951 req.oldptr= old;
1952 }
1953
1954 if (new != NULL) {
1955 if (!useracc(new, newlen, VM_PROT_READ))
1956 return (EFAULT);
1957 req.newlen = newlen;
1958 req.newptr = new;
1959 }
1960
1961 req.oldfunc = sysctl_old_user;
1962 req.newfunc = sysctl_new_user;
1963 req.lock = REQ_UNWIRED;
1964
1965 #ifdef KTRACE
1966 if (KTRPOINT(curthread, KTR_SYSCTL))
1967 ktrsysctl(name, namelen);
1968 #endif
1969
1970 if (req.oldptr && req.oldlen > PAGE_SIZE) {
1971 memlocked = 1;
1972 sx_xlock(&sysctlmemlock);
1973 } else
1974 memlocked = 0;
1975 CURVNET_SET(TD_TO_VNET(td));
1976
1977 for (;;) {
1978 req.oldidx = 0;
1979 req.newidx = 0;
1980 error = sysctl_root(0, name, namelen, &req);
1981 if (error != EAGAIN)
1982 break;
1983 kern_yield(PRI_USER);
1984 }
1985
1986 CURVNET_RESTORE();
1987
1988 if (req.lock == REQ_WIRED && req.validlen > 0)
1989 vsunlock(req.oldptr, req.validlen);
1990 if (memlocked)
1991 sx_xunlock(&sysctlmemlock);
1992
1993 if (error && error != ENOMEM)
1994 return (error);
1995
1996 if (retval) {
1997 if (req.oldptr && req.oldidx > req.validlen)
1998 *retval = req.validlen;
1999 else
2000 *retval = req.oldidx;
2001 }
2002 return (error);
2003 }
2004
2005 /*
2006 * Drain into a sysctl struct. The user buffer should be wired if a page
2007 * fault would cause issue.
2008 */
2009 static int
2010 sbuf_sysctl_drain(void *arg, const char *data, int len)
2011 {
2012 struct sysctl_req *req = arg;
2013 int error;
2014
2015 error = SYSCTL_OUT(req, data, len);
2016 KASSERT(error >= 0, ("Got unexpected negative value %d", error));
2017 return (error == 0 ? len : -error);
2018 }
2019
2020 struct sbuf *
2021 sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length,
2022 struct sysctl_req *req)
2023 {
2024
2025 /* Supply a default buffer size if none given. */
2026 if (buf == NULL && length == 0)
2027 length = 64;
2028 s = sbuf_new(s, buf, length, SBUF_FIXEDLEN | SBUF_INCLUDENUL);
2029 sbuf_set_drain(s, sbuf_sysctl_drain, req);
2030 return (s);
2031 }
Cache object: 5f3eff33c4fb93c211779e5dc32c74fd
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