xref: /netbsd-src/sys/kern/kern_sysctl.c (revision 8ac07aec990b9d2e483062509d0a9fa5b4f57cf2)
1 /*	$NetBSD: kern_sysctl.c,v 1.215 2008/02/29 02:28:35 matt Exp $	*/
2 
3 /*-
4  * Copyright (c) 2003, 2007, 2008 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Andrew Brown.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *      This product includes software developed by the NetBSD
21  *      Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*-
40  * Copyright (c) 1982, 1986, 1989, 1993
41  *	The Regents of the University of California.  All rights reserved.
42  *
43  * This code is derived from software contributed to Berkeley by
44  * Mike Karels at Berkeley Software Design, Inc.
45  *
46  * Redistribution and use in source and binary forms, with or without
47  * modification, are permitted provided that the following conditions
48  * are met:
49  * 1. Redistributions of source code must retain the above copyright
50  *    notice, this list of conditions and the following disclaimer.
51  * 2. Redistributions in binary form must reproduce the above copyright
52  *    notice, this list of conditions and the following disclaimer in the
53  *    documentation and/or other materials provided with the distribution.
54  * 3. Neither the name of the University nor the names of its contributors
55  *    may be used to endorse or promote products derived from this software
56  *    without specific prior written permission.
57  *
58  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
68  * SUCH DAMAGE.
69  *
70  *	@(#)kern_sysctl.c	8.9 (Berkeley) 5/20/95
71  */
72 
73 /*
74  * sysctl system call.
75  */
76 
77 #include <sys/cdefs.h>
78 __KERNEL_RCSID(0, "$NetBSD: kern_sysctl.c,v 1.215 2008/02/29 02:28:35 matt Exp $");
79 
80 #include "opt_defcorename.h"
81 #include "ksyms.h"
82 
83 #include <sys/param.h>
84 #define __COMPAT_SYSCTL
85 #include <sys/sysctl.h>
86 #include <sys/systm.h>
87 #include <sys/buf.h>
88 #include <sys/ksyms.h>
89 #include <sys/malloc.h>
90 #include <sys/mount.h>
91 #include <sys/syscallargs.h>
92 #include <sys/kauth.h>
93 #include <sys/ktrace.h>
94 #include <machine/stdarg.h>
95 
96 #define	MAXDESCLEN	1024
97 MALLOC_DEFINE(M_SYSCTLNODE, "sysctlnode", "sysctl node structures");
98 MALLOC_DEFINE(M_SYSCTLDATA, "sysctldata", "misc sysctl data");
99 
100 static int sysctl_mmap(SYSCTLFN_PROTO);
101 static int sysctl_alloc(struct sysctlnode *, int);
102 static int sysctl_realloc(struct sysctlnode *);
103 
104 static int sysctl_cvt_in(struct lwp *, int *, const void *, size_t,
105 			 struct sysctlnode *);
106 static int sysctl_cvt_out(struct lwp *, int, const struct sysctlnode *,
107 			  void *, size_t, size_t *);
108 
109 static int sysctl_log_add(struct sysctllog **, const struct sysctlnode *);
110 static int sysctl_log_realloc(struct sysctllog *);
111 
112 struct sysctllog {
113 	const struct sysctlnode *log_root;
114 	int *log_num;
115 	int log_size, log_left;
116 };
117 
118 /*
119  * the "root" of the new sysctl tree
120  */
121 struct sysctlnode sysctl_root = {
122 	.sysctl_flags = SYSCTL_VERSION|
123 	    CTLFLAG_ROOT|CTLFLAG_READWRITE|
124 	    CTLTYPE_NODE,
125 	.sysctl_num = 0,
126 	/*
127 	 * XXX once all ports are on gcc3, we can get rid of this
128 	 * ugliness and simply make it into
129 	 *
130 	 *	.sysctl_size = sizeof(struct sysctlnode),
131 	 */
132 	sysc_init_field(_sysctl_size, sizeof(struct sysctlnode)),
133 	.sysctl_name = "(root)",
134 };
135 
136 /*
137  * link set of functions that add nodes at boot time (see also
138  * sysctl_buildtree())
139  */
140 __link_set_decl(sysctl_funcs, sysctl_setup_func);
141 
142 /*
143  * The `sysctl_treelock' is intended to serialize access to the sysctl
144  * tree.  XXX This has serious problems; allocating memory and
145  * copying data out with the lock held is insane.
146  */
147 krwlock_t sysctl_treelock;
148 
149 /*
150  * Attributes stored in the kernel.
151  */
152 char hostname[MAXHOSTNAMELEN];
153 int hostnamelen;
154 
155 char domainname[MAXHOSTNAMELEN];
156 int domainnamelen;
157 
158 long hostid;
159 
160 #ifndef DEFCORENAME
161 #define	DEFCORENAME	"%n.core"
162 #endif
163 char defcorename[MAXPATHLEN] = DEFCORENAME;
164 
165 /*
166  * ********************************************************************
167  * Section 0: Some simple glue
168  * ********************************************************************
169  * By wrapping copyin(), copyout(), and copyinstr() like this, we can
170  * stop caring about who's calling us and simplify some code a bunch.
171  * ********************************************************************
172  */
173 static inline int
174 sysctl_copyin(struct lwp *l, const void *uaddr, void *kaddr, size_t len)
175 {
176 	int error;
177 
178 	if (l != NULL) {
179 		error = copyin(uaddr, kaddr, len);
180 		ktrmibio(-1, UIO_WRITE, uaddr, len, error);
181 	} else {
182 		error = kcopy(uaddr, kaddr, len);
183 	}
184 
185 	return error;
186 }
187 
188 static inline int
189 sysctl_copyout(struct lwp *l, const void *kaddr, void *uaddr, size_t len)
190 {
191 	int error;
192 
193 	if (l != NULL) {
194 		error = copyout(kaddr, uaddr, len);
195 		ktrmibio(-1, UIO_READ, uaddr, len, error);
196 	} else {
197 		error = kcopy(kaddr, uaddr, len);
198 	}
199 
200 	return error;
201 }
202 
203 static inline int
204 sysctl_copyinstr(struct lwp *l, const void *uaddr, void *kaddr,
205 		 size_t len, size_t *done)
206 {
207 	int error;
208 
209 	if (l != NULL) {
210 		error = copyinstr(uaddr, kaddr, len, done);
211 		ktrmibio(-1, UIO_WRITE, uaddr, len, error);
212 	} else {
213 		error = copystr(uaddr, kaddr, len, done);
214 	}
215 
216 	return error;
217 }
218 
219 /*
220  * ********************************************************************
221  * Initialize sysctl subsystem.
222  * ********************************************************************
223  */
224 void
225 sysctl_init(void)
226 {
227 	sysctl_setup_func * const *sysctl_setup, f;
228 
229 	rw_init(&sysctl_treelock);
230 
231 	/*
232 	 * dynamic mib numbers start here
233 	 */
234 	sysctl_root.sysctl_num = CREATE_BASE;
235 
236         __link_set_foreach(sysctl_setup, sysctl_funcs) {
237 		/*
238 		 * XXX - why do i have to coerce the pointers like this?
239 		 */
240 		f = (void*)*sysctl_setup;
241 		(*f)(NULL);
242 	}
243 
244 	/*
245 	 * setting this means no more permanent nodes can be added,
246 	 * trees that claim to be readonly at the root now are, and if
247 	 * the main tree is readonly, *everything* is.
248 	 */
249 	sysctl_root.sysctl_flags |= CTLFLAG_PERMANENT;
250 
251 }
252 
253 /*
254  * ********************************************************************
255  * The main native sysctl system call itself.
256  * ********************************************************************
257  */
258 int
259 sys___sysctl(struct lwp *l, const struct sys___sysctl_args *uap, register_t *retval)
260 {
261 	/* {
262 		syscallarg(const int *) name;
263 		syscallarg(u_int) namelen;
264 		syscallarg(void *) old;
265 		syscallarg(size_t *) oldlenp;
266 		syscallarg(const void *) new;
267 		syscallarg(size_t) newlen;
268 	} */
269 	int error, nerror, name[CTL_MAXNAME];
270 	size_t oldlen, savelen, *oldlenp;
271 
272 	/*
273 	 * get oldlen
274 	 */
275 	oldlen = 0;
276 	oldlenp = SCARG(uap, oldlenp);
277 	if (oldlenp != NULL) {
278 		error = copyin(oldlenp, &oldlen, sizeof(oldlen));
279 		if (error)
280 			return (error);
281 	}
282 	savelen = oldlen;
283 
284 	/*
285 	 * top-level sysctl names may or may not be non-terminal, but
286 	 * we don't care
287 	 */
288 	if (SCARG(uap, namelen) > CTL_MAXNAME || SCARG(uap, namelen) < 1)
289 		return (EINVAL);
290 	error = copyin(SCARG(uap, name), &name,
291 		       SCARG(uap, namelen) * sizeof(int));
292 	if (error)
293 		return (error);
294 
295 	ktrmib(name, SCARG(uap, namelen));
296 
297 	sysctl_lock(SCARG(uap, new) != NULL);
298 
299 	/*
300 	 * do sysctl work (NULL means main built-in default tree)
301 	 */
302 	error = sysctl_dispatch(&name[0], SCARG(uap, namelen),
303 				SCARG(uap, old), &oldlen,
304 				SCARG(uap, new), SCARG(uap, newlen),
305 				&name[0], l, NULL);
306 
307 	/*
308 	 * release the sysctl lock
309 	 */
310 	sysctl_unlock();
311 
312 	/*
313 	 * set caller's oldlen to new value even in the face of an
314 	 * error (if this gets an error and they didn't have one, they
315 	 * get this one)
316 	 */
317 	if (oldlenp) {
318 		nerror = copyout(&oldlen, oldlenp, sizeof(oldlen));
319 		if (error == 0)
320 			error = nerror;
321 	}
322 
323 	/*
324 	 * if the only problem is that we weren't given enough space,
325 	 * that's an ENOMEM error
326 	 */
327 	if (error == 0 && SCARG(uap, old) != NULL && savelen < oldlen)
328 		error = ENOMEM;
329 
330 	return (error);
331 }
332 
333 /*
334  * ********************************************************************
335  * Section 1: How the tree is used
336  * ********************************************************************
337  * Implementations of sysctl for emulations should typically need only
338  * these three functions in this order: lock the tree, dispatch
339  * request into it, unlock the tree.
340  * ********************************************************************
341  */
342 void
343 sysctl_lock(bool write)
344 {
345 
346 	if (write) {
347 		rw_enter(&sysctl_treelock, RW_WRITER);
348 		curlwp->l_pflag |= LP_SYSCTLWRITE;
349 	} else {
350 		rw_enter(&sysctl_treelock, RW_READER);
351 		curlwp->l_pflag &= ~LP_SYSCTLWRITE;
352 	}
353 }
354 
355 void
356 sysctl_relock(void)
357 {
358 
359 	if ((curlwp->l_pflag & LP_SYSCTLWRITE) != 0) {
360 		rw_enter(&sysctl_treelock, RW_WRITER);
361 	} else {
362 		rw_enter(&sysctl_treelock, RW_READER);
363 	}
364 }
365 
366 /*
367  * ********************************************************************
368  * the main sysctl dispatch routine.  scans the given tree and picks a
369  * function to call based on what it finds.
370  * ********************************************************************
371  */
372 int
373 sysctl_dispatch(SYSCTLFN_ARGS)
374 {
375 	int error;
376 	sysctlfn fn;
377 	int ni;
378 
379 	KASSERT(rw_lock_held(&sysctl_treelock));
380 
381 	if (rnode && SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
382 		printf("sysctl_dispatch: rnode %p wrong version\n", rnode);
383 		error = EINVAL;
384 		goto out;
385 	}
386 
387 	fn = NULL;
388 	error = sysctl_locate(l, name, namelen, &rnode, &ni);
389 
390 	if (rnode->sysctl_func != NULL) {
391 		/*
392 		 * the node we ended up at has a function, so call it.  it can
393 		 * hand off to query or create if it wants to.
394 		 */
395 		fn = rnode->sysctl_func;
396 	} else if (error == 0) {
397 		/*
398 		 * we found the node they were looking for, so do a lookup.
399 		 */
400 		fn = (sysctlfn)sysctl_lookup; /* XXX may write to rnode */
401 	} else if (error == ENOENT && (ni + 1) == namelen && name[ni] < 0) {
402 		/*
403 		 * prospective parent node found, but the terminal node was
404 		 * not.  generic operations associate with the parent.
405 		 */
406 		switch (name[ni]) {
407 		case CTL_QUERY:
408 			fn = sysctl_query;
409 			break;
410 		case CTL_CREATE:
411 #if NKSYMS > 0
412 		case CTL_CREATESYM:
413 #endif /* NKSYMS > 0 */
414 			if (newp == NULL) {
415 				error = EINVAL;
416 				break;
417 			}
418 			KASSERT(rw_write_held(&sysctl_treelock));
419 			fn = (sysctlfn)sysctl_create; /* we own the rnode */
420 			break;
421 		case CTL_DESTROY:
422 			if (newp == NULL) {
423 				error = EINVAL;
424 				break;
425 			}
426 			KASSERT(rw_write_held(&sysctl_treelock));
427 			fn = (sysctlfn)sysctl_destroy; /* we own the rnode */
428 			break;
429 		case CTL_MMAP:
430 			fn = (sysctlfn)sysctl_mmap; /* we own the rnode */
431 			break;
432 		case CTL_DESCRIBE:
433 			fn = sysctl_describe;
434 			break;
435 		default:
436 			error = EOPNOTSUPP;
437 			break;
438 		}
439 	}
440 
441 	/*
442 	 * after all of that, maybe we found someone who knows how to
443 	 * get us what we want?
444 	 */
445 	if (fn != NULL)
446 		error = (*fn)(name + ni, namelen - ni, oldp, oldlenp,
447 			      newp, newlen, name, l, rnode);
448 	else if (error == 0)
449 		error = EOPNOTSUPP;
450 
451 out:
452 	return (error);
453 }
454 
455 /*
456  * ********************************************************************
457  * Releases the tree lock.
458  * ********************************************************************
459  */
460 void
461 sysctl_unlock(void)
462 {
463 
464 	rw_exit(&sysctl_treelock);
465 }
466 
467 /*
468  * ********************************************************************
469  * Section 2: The main tree interfaces
470  * ********************************************************************
471  * This is how sysctl_dispatch() does its work, and you can too, by
472  * calling these routines from helpers (though typically only
473  * sysctl_lookup() will be used).  The tree MUST BE LOCKED when these
474  * are called.
475  * ********************************************************************
476  */
477 
478 /*
479  * sysctl_locate -- Finds the node matching the given mib under the
480  * given tree (via rv).  If no tree is given, we fall back to the
481  * native tree.  The current process (via l) is used for access
482  * control on the tree (some nodes may be traversable only by root) and
483  * on return, nip will show how many numbers in the mib were consumed.
484  */
485 int
486 sysctl_locate(struct lwp *l, const int *name, u_int namelen,
487 	      const struct sysctlnode **rnode, int *nip)
488 {
489 	const struct sysctlnode *node, *pnode;
490 	int tn, si, ni, error, alias;
491 
492 	KASSERT(rw_lock_held(&sysctl_treelock));
493 
494 	/*
495 	 * basic checks and setup
496 	 */
497 	if (*rnode == NULL)
498 		*rnode = &sysctl_root;
499 	if (nip)
500 		*nip = 0;
501 	if (namelen == 0)
502 		return (0);
503 
504 	/*
505 	 * search starts from "root"
506 	 */
507 	pnode = *rnode;
508 	if (SYSCTL_VERS(pnode->sysctl_flags) != SYSCTL_VERSION) {
509 		printf("sysctl_locate: pnode %p wrong version\n", pnode);
510 		return (EINVAL);
511 	}
512 	node = pnode->sysctl_child;
513 	error = 0;
514 
515 	/*
516 	 * scan for node to which new node should be attached
517 	 */
518 	for (ni = 0; ni < namelen; ni++) {
519 		/*
520 		 * walked off bottom of tree
521 		 */
522 		if (node == NULL) {
523 			if (SYSCTL_TYPE(pnode->sysctl_flags) == CTLTYPE_NODE)
524 				error = ENOENT;
525 			else
526 				error = ENOTDIR;
527 			break;
528 		}
529 		/*
530 		 * can anyone traverse this node or only root?
531 		 */
532 		if (l != NULL && (pnode->sysctl_flags & CTLFLAG_PRIVATE) &&
533 		    (error = kauth_authorize_system(l->l_cred,
534 		    KAUTH_SYSTEM_SYSCTL, KAUTH_REQ_SYSTEM_SYSCTL_PRVT,
535 		    NULL, NULL, NULL)) != 0)
536 			return (error);
537 		/*
538 		 * find a child node with the right number
539 		 */
540 		tn = name[ni];
541 		alias = 0;
542 
543 		si = 0;
544 		/*
545 		 * Note: ANYNUMBER only matches positive integers.
546 		 * Since ANYNUMBER is only permitted on single-node
547 		 * sub-trees (eg proc), check before the loop and skip
548 		 * it if we can.
549 		 */
550 		if ((node[si].sysctl_flags & CTLFLAG_ANYNUMBER) && (tn >= 0))
551 			goto foundit;
552 		for (; si < pnode->sysctl_clen; si++) {
553 			if (node[si].sysctl_num == tn) {
554 				if (node[si].sysctl_flags & CTLFLAG_ALIAS) {
555 					if (alias++ == 4)
556 						break;
557 					else {
558 						tn = node[si].sysctl_alias;
559 						si = -1;
560 					}
561 				} else
562 					goto foundit;
563 			}
564 		}
565 		/*
566 		 * if we ran off the end, it obviously doesn't exist
567 		 */
568 		error = ENOENT;
569 		break;
570 
571 		/*
572 		 * so far so good, move on down the line
573 		 */
574 	  foundit:
575 		pnode = &node[si];
576 		if (SYSCTL_TYPE(pnode->sysctl_flags) == CTLTYPE_NODE)
577 			node = node[si].sysctl_child;
578 		else
579 			node = NULL;
580 	}
581 
582 	*rnode = pnode;
583 	if (nip)
584 		*nip = ni;
585 
586 	return (error);
587 }
588 
589 /*
590  * sysctl_query -- The auto-discovery engine.  Copies out the structs
591  * describing nodes under the given node and handles overlay trees.
592  */
593 int
594 sysctl_query(SYSCTLFN_ARGS)
595 {
596 	int error, ni, elim, v;
597 	size_t out, left, t;
598 	const struct sysctlnode *enode, *onode;
599 	struct sysctlnode qnode;
600 
601 	KASSERT(rw_lock_held(&sysctl_treelock));
602 
603 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
604 		printf("sysctl_query: rnode %p wrong version\n", rnode);
605 		return (EINVAL);
606 	}
607 
608 	if (SYSCTL_TYPE(rnode->sysctl_flags) != CTLTYPE_NODE)
609 		return (ENOTDIR);
610 	if (namelen != 1 || name[0] != CTL_QUERY)
611 		return (EINVAL);
612 
613 	error = 0;
614 	out = 0;
615 	left = *oldlenp;
616 	elim = 0;
617 	enode = NULL;
618 
619 	/*
620 	 * translate the given request to a current node
621 	 */
622 	error = sysctl_cvt_in(l, &v, newp, newlen, &qnode);
623 	if (error)
624 		return (error);
625 
626 	/*
627 	 * if the request specifies a version, check it
628 	 */
629 	if (qnode.sysctl_ver != 0) {
630 		enode = rnode;
631 		if (qnode.sysctl_ver != enode->sysctl_ver &&
632 		    qnode.sysctl_ver != sysctl_rootof(enode)->sysctl_ver)
633 			return (EINVAL);
634 	}
635 
636 	/*
637 	 * process has overlay tree
638 	 */
639 	if (l && l->l_proc->p_emul->e_sysctlovly) {
640 		enode = l->l_proc->p_emul->e_sysctlovly;
641 		elim = (name - oname);
642 		error = sysctl_locate(l, oname, elim, &enode, NULL);
643 		if (error == 0) {
644 			/* ah, found parent in overlay */
645 			elim = enode->sysctl_clen;
646 			enode = enode->sysctl_child;
647 		} else {
648 			error = 0;
649 			elim = 0;
650 			enode = NULL;
651 		}
652 	}
653 
654 	for (ni = 0; ni < rnode->sysctl_clen; ni++) {
655 		onode = &rnode->sysctl_child[ni];
656 		if (enode && enode->sysctl_num == onode->sysctl_num) {
657 			if (SYSCTL_TYPE(enode->sysctl_flags) != CTLTYPE_NODE)
658 				onode = enode;
659 			if (--elim > 0)
660 				enode++;
661 			else
662 				enode = NULL;
663 		}
664 		error = sysctl_cvt_out(l, v, onode, oldp, left, &t);
665 		if (error)
666 			return (error);
667 		if (oldp != NULL)
668 			oldp = (char*)oldp + t;
669 		out += t;
670 		left -= MIN(left, t);
671 	}
672 
673 	/*
674 	 * overlay trees *MUST* be entirely consumed
675 	 */
676 	KASSERT(enode == NULL);
677 
678 	*oldlenp = out;
679 
680 	return (error);
681 }
682 
683 /*
684  * sysctl_create -- Adds a node (the description of which is taken
685  * from newp) to the tree, returning a copy of it in the space pointed
686  * to by oldp.  In the event that the requested slot is already taken
687  * (either by name or by number), the offending node is returned
688  * instead.  Yes, this is complex, but we want to make sure everything
689  * is proper.
690  */
691 #ifdef SYSCTL_DEBUG_CREATE
692 int _sysctl_create(SYSCTLFN_ARGS);
693 int
694 _sysctl_create(SYSCTLFN_ARGS)
695 #else
696 int
697 sysctl_create(SYSCTLFN_ARGS)
698 #endif
699 {
700 	struct sysctlnode nnode, *node, *pnode;
701 	int error, ni, at, nm, type, sz, flags, anum, v;
702 	void *own;
703 
704 	KASSERT(rw_write_held(&sysctl_treelock));
705 
706 	error = 0;
707 	own = NULL;
708 	anum = -1;
709 
710 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
711 		printf("sysctl_create: rnode %p wrong version\n", rnode);
712 		return (EINVAL);
713 	}
714 
715 	if (namelen != 1 || (name[namelen - 1] != CTL_CREATE
716 #if NKSYMS > 0
717 			     && name[namelen - 1] != CTL_CREATESYM
718 #endif /* NKSYMS > 0 */
719 			     ))
720 		return (EINVAL);
721 
722 	/*
723 	 * processes can only add nodes at securelevel 0, must be
724 	 * root, and can't add nodes to a parent that's not writeable
725 	 */
726 	if (l != NULL) {
727 #ifndef SYSCTL_DISALLOW_CREATE
728 		error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
729 		    KAUTH_REQ_SYSTEM_SYSCTL_ADD, NULL, NULL, NULL);
730 		if (error)
731 			return (error);
732 		if (!(rnode->sysctl_flags & CTLFLAG_READWRITE))
733 #endif /* SYSCTL_DISALLOW_CREATE */
734 			return (EPERM);
735 	}
736 
737 	/*
738 	 * nothing can add a node if:
739 	 * we've finished initial set up and
740 	 * the tree itself is not writeable or
741 	 * the entire sysctl system is not writeable
742 	 */
743 	if ((sysctl_root.sysctl_flags & CTLFLAG_PERMANENT) &&
744 	    (!(sysctl_rootof(rnode)->sysctl_flags & CTLFLAG_READWRITE) ||
745 	     !(sysctl_root.sysctl_flags & CTLFLAG_READWRITE)))
746 		return (EPERM);
747 
748 	/*
749 	 * it must be a "node", not a "int" or something
750 	 */
751 	if (SYSCTL_TYPE(rnode->sysctl_flags) != CTLTYPE_NODE)
752 		return (ENOTDIR);
753 	if (rnode->sysctl_flags & CTLFLAG_ALIAS) {
754 		printf("sysctl_create: attempt to add node to aliased "
755 		       "node %p\n", rnode);
756 		return (EINVAL);
757 	}
758 	pnode = __UNCONST(rnode); /* we are adding children to this node */
759 
760 	if (newp == NULL)
761 		return (EINVAL);
762 	error = sysctl_cvt_in(l, &v, newp, newlen, &nnode);
763 	if (error)
764 		return (error);
765 
766 	/*
767 	 * nodes passed in don't *have* parents
768 	 */
769 	if (nnode.sysctl_parent != NULL)
770 		return (EINVAL);
771 
772 	/*
773 	 * if we are indeed adding it, it should be a "good" name and
774 	 * number
775 	 */
776 	nm = nnode.sysctl_num;
777 #if NKSYMS > 0
778 	if (nm == CTL_CREATESYM)
779 		nm = CTL_CREATE;
780 #endif /* NKSYMS > 0 */
781 	if (nm < 0 && nm != CTL_CREATE)
782 		return (EINVAL);
783 	sz = 0;
784 
785 	/*
786 	 * the name can't start with a digit
787 	 */
788 	if (nnode.sysctl_name[sz] >= '0' &&
789 	    nnode.sysctl_name[sz] <= '9')
790 		return (EINVAL);
791 
792 	/*
793 	 * the name must be only alphanumerics or - or _, longer than
794 	 * 0 bytes and less that SYSCTL_NAMELEN
795 	 */
796 	while (sz < SYSCTL_NAMELEN && nnode.sysctl_name[sz] != '\0') {
797 		if ((nnode.sysctl_name[sz] >= '0' &&
798 		     nnode.sysctl_name[sz] <= '9') ||
799 		    (nnode.sysctl_name[sz] >= 'A' &&
800 		     nnode.sysctl_name[sz] <= 'Z') ||
801 		    (nnode.sysctl_name[sz] >= 'a' &&
802 		     nnode.sysctl_name[sz] <= 'z') ||
803 		    nnode.sysctl_name[sz] == '-' ||
804 		    nnode.sysctl_name[sz] == '_')
805 			sz++;
806 		else
807 			return (EINVAL);
808 	}
809 	if (sz == 0 || sz == SYSCTL_NAMELEN)
810 		return (EINVAL);
811 
812 	/*
813 	 * various checks revolve around size vs type, etc
814 	 */
815 	type = SYSCTL_TYPE(nnode.sysctl_flags);
816 	flags = SYSCTL_FLAGS(nnode.sysctl_flags);
817 	sz = nnode.sysctl_size;
818 
819 	/*
820 	 * find out if there's a collision, and if so, let the caller
821 	 * know what they collided with
822 	 */
823 	node = pnode->sysctl_child;
824 	at = 0;
825 	if (node) {
826 		if ((flags | node->sysctl_flags) & CTLFLAG_ANYNUMBER)
827 			/* No siblings for a CTLFLAG_ANYNUMBER node */
828 			return EINVAL;
829 		for (ni = 0; ni < pnode->sysctl_clen; ni++) {
830 			if (nm == node[ni].sysctl_num ||
831 			    strcmp(nnode.sysctl_name, node[ni].sysctl_name) == 0) {
832 				/*
833 				 * ignore error here, since we
834 				 * are already fixed on EEXIST
835 				 */
836 				(void)sysctl_cvt_out(l, v, &node[ni], oldp,
837 						     *oldlenp, oldlenp);
838 				return (EEXIST);
839 			}
840 			if (nm > node[ni].sysctl_num)
841 				at++;
842 		}
843 	}
844 
845 	/*
846 	 * use sysctl_ver to add to the tree iff it hasn't changed
847 	 */
848 	if (nnode.sysctl_ver != 0) {
849 		/*
850 		 * a specified value must match either the parent
851 		 * node's version or the root node's version
852 		 */
853 		if (nnode.sysctl_ver != sysctl_rootof(rnode)->sysctl_ver &&
854 		    nnode.sysctl_ver != rnode->sysctl_ver) {
855 			return (EINVAL);
856 		}
857 	}
858 
859 	/*
860 	 * only the kernel can assign functions to entries
861 	 */
862 	if (l != NULL && nnode.sysctl_func != NULL)
863 		return (EPERM);
864 
865 	/*
866 	 * only the kernel can create permanent entries, and only then
867 	 * before the kernel is finished setting itself up
868 	 */
869 	if (l != NULL && (flags & ~SYSCTL_USERFLAGS))
870 		return (EPERM);
871 	if ((flags & CTLFLAG_PERMANENT) &
872 	    (sysctl_root.sysctl_flags & CTLFLAG_PERMANENT))
873 		return (EPERM);
874 	if ((flags & (CTLFLAG_OWNDATA | CTLFLAG_IMMEDIATE)) ==
875 	    (CTLFLAG_OWNDATA | CTLFLAG_IMMEDIATE))
876 		return (EINVAL);
877 	if ((flags & CTLFLAG_IMMEDIATE) &&
878 	    type != CTLTYPE_INT && type != CTLTYPE_QUAD && type != CTLTYPE_BOOL)
879 		return (EINVAL);
880 
881 	/*
882 	 * check size, or set it if unset and we can figure it out.
883 	 * kernel created nodes are allowed to have a function instead
884 	 * of a size (or a data pointer).
885 	 */
886 	switch (type) {
887 	case CTLTYPE_NODE:
888 		/*
889 		 * only *i* can assert the size of a node
890 		 */
891 		if (flags & CTLFLAG_ALIAS) {
892 			anum = nnode.sysctl_alias;
893 			if (anum < 0)
894 				return (EINVAL);
895 			nnode.sysctl_alias = 0;
896 		}
897 		if (sz != 0 || nnode.sysctl_data != NULL)
898 			return (EINVAL);
899 		if (nnode.sysctl_csize != 0 ||
900 		    nnode.sysctl_clen != 0 ||
901 		    nnode.sysctl_child != 0)
902 			return (EINVAL);
903 		if (flags & CTLFLAG_OWNDATA)
904 			return (EINVAL);
905 		sz = sizeof(struct sysctlnode);
906 		break;
907 	case CTLTYPE_INT:
908 		/*
909 		 * since an int is an int, if the size is not given or
910 		 * is wrong, we can "int-uit" it.
911 		 */
912 		if (sz != 0 && sz != sizeof(int))
913 			return (EINVAL);
914 		sz = sizeof(int);
915 		break;
916 	case CTLTYPE_STRING:
917 		/*
918 		 * strings are a little more tricky
919 		 */
920 		if (sz == 0) {
921 			if (l == NULL) {
922 				if (nnode.sysctl_func == NULL) {
923 					if (nnode.sysctl_data == NULL)
924 						return (EINVAL);
925 					else
926 						sz = strlen(nnode.sysctl_data) +
927 						    1;
928 				}
929 			} else if (nnode.sysctl_data == NULL &&
930 				 flags & CTLFLAG_OWNDATA) {
931 				return (EINVAL);
932 			} else {
933 				char *vp, *e;
934 				size_t s;
935 
936 				/*
937 				 * we want a rough idea of what the
938 				 * size is now
939 				 */
940 				vp = malloc(PAGE_SIZE, M_SYSCTLDATA,
941 					     M_WAITOK|M_CANFAIL);
942 				if (vp == NULL)
943 					return (ENOMEM);
944 				e = nnode.sysctl_data;
945 				do {
946 					error = copyinstr(e, vp, PAGE_SIZE, &s);
947 					if (error) {
948 						if (error != ENAMETOOLONG) {
949 							free(vp, M_SYSCTLDATA);
950 							return (error);
951 						}
952 						e += PAGE_SIZE;
953 						if ((e - 32 * PAGE_SIZE) >
954 						    (char*)nnode.sysctl_data) {
955 							free(vp, M_SYSCTLDATA);
956 							return (ERANGE);
957 						}
958 					}
959 				} while (error != 0);
960 				sz = s + (e - (char*)nnode.sysctl_data);
961 				free(vp, M_SYSCTLDATA);
962 			}
963 		}
964 		break;
965 	case CTLTYPE_QUAD:
966 		if (sz != 0 && sz != sizeof(u_quad_t))
967 			return (EINVAL);
968 		sz = sizeof(u_quad_t);
969 		break;
970 	case CTLTYPE_BOOL:
971 		/*
972 		 * since an bool is an bool, if the size is not given or
973 		 * is wrong, we can "intuit" it.
974 		 */
975 		if (sz != 0 && sz != sizeof(bool))
976 			return (EINVAL);
977 		sz = sizeof(bool);
978 		break;
979 	case CTLTYPE_STRUCT:
980 		if (sz == 0) {
981 			if (l != NULL || nnode.sysctl_func == NULL)
982 				return (EINVAL);
983 			if (flags & CTLFLAG_OWNDATA)
984 				return (EINVAL);
985 		}
986 		break;
987 	default:
988 		return (EINVAL);
989 	}
990 
991 	/*
992 	 * at this point, if sz is zero, we *must* have a
993 	 * function to go with it and we can't own it.
994 	 */
995 
996 	/*
997 	 *  l  ptr own
998 	 *  0   0   0  -> EINVAL (if no func)
999 	 *  0   0   1  -> own
1000 	 *  0   1   0  -> kptr
1001 	 *  0   1   1  -> kptr
1002 	 *  1   0   0  -> EINVAL
1003 	 *  1   0   1  -> own
1004 	 *  1   1   0  -> kptr, no own (fault on lookup)
1005 	 *  1   1   1  -> uptr, own
1006 	 */
1007 	if (type != CTLTYPE_NODE) {
1008 		if (sz != 0) {
1009 			if (flags & CTLFLAG_OWNDATA) {
1010 				own = malloc(sz, M_SYSCTLDATA,
1011 					     M_WAITOK|M_CANFAIL);
1012 				if (own == NULL)
1013 					return ENOMEM;
1014 				if (nnode.sysctl_data == NULL)
1015 					memset(own, 0, sz);
1016 				else {
1017 					error = sysctl_copyin(l,
1018 					    nnode.sysctl_data, own, sz);
1019 					if (error != 0) {
1020 						free(own, M_SYSCTLDATA);
1021 						return (error);
1022 					}
1023 				}
1024 			} else if ((nnode.sysctl_data != NULL) &&
1025 				 !(flags & CTLFLAG_IMMEDIATE)) {
1026 #if NKSYMS > 0
1027 				if (name[namelen - 1] == CTL_CREATESYM) {
1028 					char symname[128]; /* XXX enough? */
1029 					u_long symaddr;
1030 					size_t symlen;
1031 
1032 					error = sysctl_copyinstr(l,
1033 					    nnode.sysctl_data, symname,
1034 					    sizeof(symname), &symlen);
1035 					if (error)
1036 						return (error);
1037 					error = ksyms_getval(NULL, symname,
1038 					    &symaddr, KSYMS_EXTERN);
1039 					if (error)
1040 						return (error); /* EINVAL? */
1041 					nnode.sysctl_data = (void*)symaddr;
1042 				}
1043 #endif /* NKSYMS > 0 */
1044 				/*
1045 				 * Ideally, we'd like to verify here
1046 				 * that this address is acceptable,
1047 				 * but...
1048 				 *
1049 				 * - it might be valid now, only to
1050 				 *   become invalid later
1051 				 *
1052 				 * - it might be invalid only for the
1053 				 *   moment and valid later
1054 				 *
1055 				 * - or something else.
1056 				 *
1057 				 * Since we can't get a good answer,
1058 				 * we'll just accept the address as
1059 				 * given, and fault on individual
1060 				 * lookups.
1061 				 */
1062 			}
1063 		} else if (nnode.sysctl_func == NULL)
1064 			return (EINVAL);
1065 	}
1066 
1067 	/*
1068 	 * a process can't assign a function to a node, and the kernel
1069 	 * can't create a node that has no function or data.
1070 	 * (XXX somewhat redundant check)
1071 	 */
1072 	if (l != NULL || nnode.sysctl_func == NULL) {
1073 		if (type != CTLTYPE_NODE &&
1074 		    nnode.sysctl_data == NULL &&
1075 		    !(flags & CTLFLAG_IMMEDIATE) &&
1076 		    own == NULL)
1077 			return (EINVAL);
1078 	}
1079 
1080 #ifdef SYSCTL_DISALLOW_KWRITE
1081 	/*
1082 	 * a process can't create a writable node unless it refers to
1083 	 * new data.
1084 	 */
1085 	if (l != NULL && own == NULL && type != CTLTYPE_NODE &&
1086 	    (flags & CTLFLAG_READWRITE) != CTLFLAG_READONLY &&
1087 	    !(flags & CTLFLAG_IMMEDIATE))
1088 		return (EPERM);
1089 #endif /* SYSCTL_DISALLOW_KWRITE */
1090 
1091 	/*
1092 	 * make sure there's somewhere to put the new stuff.
1093 	 */
1094 	if (pnode->sysctl_child == NULL) {
1095 		if (flags & CTLFLAG_ANYNUMBER)
1096 			error = sysctl_alloc(pnode, 1);
1097 		else
1098 			error = sysctl_alloc(pnode, 0);
1099 		if (error) {
1100 			if (own != NULL)
1101 				free(own, M_SYSCTLDATA);
1102 			return (error);
1103 		}
1104 	}
1105 	node = pnode->sysctl_child;
1106 
1107 	/*
1108 	 * no collisions, so pick a good dynamic number if we need to.
1109 	 */
1110 	if (nm == CTL_CREATE) {
1111 		nm = ++sysctl_root.sysctl_num;
1112 		for (ni = 0; ni < pnode->sysctl_clen; ni++) {
1113 			if (nm == node[ni].sysctl_num) {
1114 				nm++;
1115 				ni = -1;
1116 			} else if (nm > node[ni].sysctl_num)
1117 				at = ni + 1;
1118 		}
1119 	}
1120 
1121 	/*
1122 	 * oops...ran out of space
1123 	 */
1124 	if (pnode->sysctl_clen == pnode->sysctl_csize) {
1125 		error = sysctl_realloc(pnode);
1126 		if (error) {
1127 			if (own != NULL)
1128 				free(own, M_SYSCTLDATA);
1129 			return (error);
1130 		}
1131 		node = pnode->sysctl_child;
1132 	}
1133 
1134 	/*
1135 	 * insert new node data
1136 	 */
1137 	if (at < pnode->sysctl_clen) {
1138 		int t;
1139 
1140 		/*
1141 		 * move the nodes that should come after the new one
1142 		 */
1143 		memmove(&node[at + 1], &node[at],
1144 			(pnode->sysctl_clen - at) * sizeof(struct sysctlnode));
1145 		memset(&node[at], 0, sizeof(struct sysctlnode));
1146 		node[at].sysctl_parent = pnode;
1147 		/*
1148 		 * and...reparent any children of any moved nodes
1149 		 */
1150 		for (ni = at; ni <= pnode->sysctl_clen; ni++)
1151 			if (SYSCTL_TYPE(node[ni].sysctl_flags) == CTLTYPE_NODE)
1152 				for (t = 0; t < node[ni].sysctl_clen; t++)
1153 					node[ni].sysctl_child[t].sysctl_parent =
1154 						&node[ni];
1155 	}
1156 	node = &node[at];
1157 	pnode->sysctl_clen++;
1158 
1159 	strlcpy(node->sysctl_name, nnode.sysctl_name,
1160 		sizeof(node->sysctl_name));
1161 	node->sysctl_num = nm;
1162 	node->sysctl_size = sz;
1163 	node->sysctl_flags = SYSCTL_VERSION|type|flags; /* XXX other trees */
1164 	node->sysctl_csize = 0;
1165 	node->sysctl_clen = 0;
1166 	if (own) {
1167 		node->sysctl_data = own;
1168 		node->sysctl_flags |= CTLFLAG_OWNDATA;
1169 	} else if (flags & CTLFLAG_ALIAS) {
1170 		node->sysctl_alias = anum;
1171 	} else if (flags & CTLFLAG_IMMEDIATE) {
1172 		switch (type) {
1173 		case CTLTYPE_BOOL:
1174 			node->sysctl_idata = nnode.sysctl_bdata;
1175 			break;
1176 		case CTLTYPE_INT:
1177 			node->sysctl_idata = nnode.sysctl_idata;
1178 			break;
1179 		case CTLTYPE_QUAD:
1180 			node->sysctl_qdata = nnode.sysctl_qdata;
1181 			break;
1182 		}
1183 	} else {
1184 		node->sysctl_data = nnode.sysctl_data;
1185 		node->sysctl_flags &= ~CTLFLAG_OWNDATA;
1186 	}
1187         node->sysctl_func = nnode.sysctl_func;
1188         node->sysctl_child = NULL;
1189 	/* node->sysctl_parent should already be done */
1190 
1191 	/*
1192 	 * update "version" on path to "root"
1193 	 */
1194 	for (; rnode->sysctl_parent != NULL; rnode = rnode->sysctl_parent)
1195 		;
1196 	pnode = node;
1197 	for (nm = rnode->sysctl_ver + 1; pnode != NULL;
1198 	     pnode = pnode->sysctl_parent)
1199 		pnode->sysctl_ver = nm;
1200 
1201 	/* If this fails, the node is already added - the user won't know! */
1202 	error = sysctl_cvt_out(l, v, node, oldp, *oldlenp, oldlenp);
1203 
1204 	return (error);
1205 }
1206 
1207 /*
1208  * ********************************************************************
1209  * A wrapper around sysctl_create() that prints the thing we're trying
1210  * to add.
1211  * ********************************************************************
1212  */
1213 #ifdef SYSCTL_DEBUG_CREATE
1214 int
1215 sysctl_create(SYSCTLFN_ARGS)
1216 {
1217 	const struct sysctlnode *node;
1218 	int k, rc, ni, nl = namelen + (name - oname);
1219 
1220 	node = newp;
1221 
1222 	printf("namelen %d (", nl);
1223 	for (ni = 0; ni < nl - 1; ni++)
1224 		printf(" %d", oname[ni]);
1225 	printf(" %d )\t[%s]\tflags %08x (%08x %d %zu)\n",
1226 	       k = node->sysctl_num,
1227 	       node->sysctl_name,
1228 	       node->sysctl_flags,
1229 	       SYSCTL_FLAGS(node->sysctl_flags),
1230 	       SYSCTL_TYPE(node->sysctl_flags),
1231 	       node->sysctl_size);
1232 
1233 	node = rnode;
1234 	rc = _sysctl_create(SYSCTLFN_CALL(rnode));
1235 
1236 	printf("sysctl_create(");
1237 	for (ni = 0; ni < nl - 1; ni++)
1238 		printf(" %d", oname[ni]);
1239 	printf(" %d ) returned %d\n", k, rc);
1240 
1241 	return (rc);
1242 }
1243 #endif /* SYSCTL_DEBUG_CREATE */
1244 
1245 /*
1246  * sysctl_destroy -- Removes a node (as described by newp) from the
1247  * given tree, returning (if successful) a copy of the dead node in
1248  * oldp.  Since we're removing stuff, there's not much to check.
1249  */
1250 int
1251 sysctl_destroy(SYSCTLFN_ARGS)
1252 {
1253 	struct sysctlnode *node, *pnode, onode, nnode;
1254 	int ni, error, v;
1255 
1256 	KASSERT(rw_write_held(&sysctl_treelock));
1257 
1258 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1259 		printf("sysctl_destroy: rnode %p wrong version\n", rnode);
1260 		return (EINVAL);
1261 	}
1262 
1263 	error = 0;
1264 
1265 	if (namelen != 1 || name[namelen - 1] != CTL_DESTROY)
1266 		return (EINVAL);
1267 
1268 	/*
1269 	 * processes can only destroy nodes at securelevel 0, must be
1270 	 * root, and can't remove nodes from a parent that's not
1271 	 * writeable
1272 	 */
1273 	if (l != NULL) {
1274 #ifndef SYSCTL_DISALLOW_CREATE
1275 		error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
1276 		    KAUTH_REQ_SYSTEM_SYSCTL_DELETE, NULL, NULL, NULL);
1277 		if (error)
1278 			return (error);
1279 		if (!(rnode->sysctl_flags & CTLFLAG_READWRITE))
1280 #endif /* SYSCTL_DISALLOW_CREATE */
1281 			return (EPERM);
1282 	}
1283 
1284 	/*
1285 	 * nothing can remove a node if:
1286 	 * the node is permanent (checked later) or
1287 	 * the tree itself is not writeable or
1288 	 * the entire sysctl system is not writeable
1289 	 *
1290 	 * note that we ignore whether setup is complete or not,
1291 	 * because these rules always apply.
1292 	 */
1293 	if (!(sysctl_rootof(rnode)->sysctl_flags & CTLFLAG_READWRITE) ||
1294 	    !(sysctl_root.sysctl_flags & CTLFLAG_READWRITE))
1295 		return (EPERM);
1296 
1297 	if (newp == NULL)
1298 		return (EINVAL);
1299 	error = sysctl_cvt_in(l, &v, newp, newlen, &nnode);
1300 	if (error)
1301 		return (error);
1302 	memset(&onode, 0, sizeof(struct sysctlnode));
1303 
1304 	node = rnode->sysctl_child;
1305 	for (ni = 0; ni < rnode->sysctl_clen; ni++) {
1306 		if (nnode.sysctl_num == node[ni].sysctl_num) {
1307 			/*
1308 			 * if name specified, must match
1309 			 */
1310 			if (nnode.sysctl_name[0] != '\0' &&
1311 			    strcmp(nnode.sysctl_name, node[ni].sysctl_name))
1312 				continue;
1313 			/*
1314 			 * if version specified, must match
1315 			 */
1316 			if (nnode.sysctl_ver != 0 &&
1317 			    nnode.sysctl_ver != node[ni].sysctl_ver)
1318 				continue;
1319 			/*
1320 			 * this must be the one
1321 			 */
1322 			break;
1323 		}
1324 	}
1325 	if (ni == rnode->sysctl_clen)
1326 		return (ENOENT);
1327 	node = &node[ni];
1328 	pnode = node->sysctl_parent;
1329 
1330 	/*
1331 	 * if the kernel says permanent, it is, so there.  nyah.
1332 	 */
1333 	if (SYSCTL_FLAGS(node->sysctl_flags) & CTLFLAG_PERMANENT)
1334 		return (EPERM);
1335 
1336 	/*
1337 	 * can't delete non-empty nodes
1338 	 */
1339 	if (SYSCTL_TYPE(node->sysctl_flags) == CTLTYPE_NODE &&
1340 	    node->sysctl_clen != 0)
1341 		return (ENOTEMPTY);
1342 
1343 	/*
1344 	 * if the node "owns" data, release it now
1345 	 */
1346 	if (node->sysctl_flags & CTLFLAG_OWNDATA) {
1347 		if (node->sysctl_data != NULL)
1348 			free(node->sysctl_data, M_SYSCTLDATA);
1349 		node->sysctl_data = NULL;
1350 	}
1351 	if (node->sysctl_flags & CTLFLAG_OWNDESC) {
1352 		if (node->sysctl_desc != NULL)
1353 			/*XXXUNCONST*/
1354 			free(__UNCONST(node->sysctl_desc), M_SYSCTLDATA);
1355 		node->sysctl_desc = NULL;
1356 	}
1357 
1358 	/*
1359 	 * if the node to be removed is not the last one on the list,
1360 	 * move the remaining nodes up, and reparent any grandchildren
1361 	 */
1362 	onode = *node;
1363 	if (ni < pnode->sysctl_clen - 1) {
1364 		int t;
1365 
1366 		memmove(&pnode->sysctl_child[ni], &pnode->sysctl_child[ni + 1],
1367 			(pnode->sysctl_clen - ni - 1) *
1368 			sizeof(struct sysctlnode));
1369 		for (; ni < pnode->sysctl_clen - 1; ni++)
1370 			if (SYSCTL_TYPE(pnode->sysctl_child[ni].sysctl_flags) ==
1371 			    CTLTYPE_NODE)
1372 				for (t = 0;
1373 				     t < pnode->sysctl_child[ni].sysctl_clen;
1374 				     t++)
1375 					pnode->sysctl_child[ni].sysctl_child[t].
1376 						sysctl_parent =
1377 						&pnode->sysctl_child[ni];
1378 		ni = pnode->sysctl_clen - 1;
1379 		node = &pnode->sysctl_child[ni];
1380 	}
1381 
1382 	/*
1383 	 * reset the space we just vacated
1384 	 */
1385 	memset(node, 0, sizeof(struct sysctlnode));
1386 	node->sysctl_parent = pnode;
1387 	pnode->sysctl_clen--;
1388 
1389 	/*
1390 	 * if this parent just lost its last child, nuke the creche
1391 	 */
1392 	if (pnode->sysctl_clen == 0) {
1393 		free(pnode->sysctl_child, M_SYSCTLNODE);
1394 		pnode->sysctl_csize = 0;
1395 		pnode->sysctl_child = NULL;
1396 	}
1397 
1398 	/*
1399 	 * update "version" on path to "root"
1400 	 */
1401         for (; rnode->sysctl_parent != NULL; rnode = rnode->sysctl_parent)
1402                 ;
1403 	for (ni = rnode->sysctl_ver + 1; pnode != NULL;
1404 	     pnode = pnode->sysctl_parent)
1405 		pnode->sysctl_ver = ni;
1406 
1407 	error = sysctl_cvt_out(l, v, &onode, oldp, *oldlenp, oldlenp);
1408 
1409 	return (error);
1410 }
1411 
1412 /*
1413  * sysctl_lookup -- Handles copyin/copyout of new and old values.
1414  * Partial reads are globally allowed.  Only root can write to things
1415  * unless the node says otherwise.
1416  */
1417 int
1418 sysctl_lookup(SYSCTLFN_ARGS)
1419 {
1420 	int error, rw;
1421 	size_t sz, len;
1422 	void *d;
1423 
1424 	KASSERT(rw_lock_held(&sysctl_treelock));
1425 
1426 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1427 		printf("sysctl_lookup: rnode %p wrong version\n", rnode);
1428 		return (EINVAL);
1429 	}
1430 
1431 	error = 0;
1432 
1433 	/*
1434 	 * you can't "look up" a node.  you can "query" it, but you
1435 	 * can't "look it up".
1436 	 */
1437 	if (SYSCTL_TYPE(rnode->sysctl_flags) == CTLTYPE_NODE || namelen != 0)
1438 		return (EINVAL);
1439 
1440 	/*
1441 	 * some nodes are private, so only root can look into them.
1442 	 */
1443 	if (l != NULL && (rnode->sysctl_flags & CTLFLAG_PRIVATE) &&
1444 	    (error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
1445 	    KAUTH_REQ_SYSTEM_SYSCTL_PRVT, NULL, NULL, NULL)) != 0)
1446 		return (error);
1447 
1448 	/*
1449 	 * if a node wants to be writable according to different rules
1450 	 * other than "only root can write to stuff unless a flag is
1451 	 * set", then it needs its own function which should have been
1452 	 * called and not us.
1453 	 */
1454 	if (l != NULL && newp != NULL &&
1455 	    !(rnode->sysctl_flags & CTLFLAG_ANYWRITE) &&
1456 	    (error = kauth_authorize_generic(l->l_cred,
1457 	    KAUTH_GENERIC_ISSUSER, NULL)) != 0)
1458 		return (error);
1459 
1460 	/*
1461 	 * is this node supposedly writable?
1462 	 */
1463 	rw = (rnode->sysctl_flags & CTLFLAG_READWRITE) ? 1 : 0;
1464 
1465 	/*
1466 	 * it appears not to be writable at this time, so if someone
1467 	 * tried to write to it, we must tell them to go away
1468 	 */
1469 	if (!rw && newp != NULL)
1470 		return (EPERM);
1471 
1472 	/*
1473 	 * step one, copy out the stuff we have presently
1474 	 */
1475 	if (rnode->sysctl_flags & CTLFLAG_IMMEDIATE) {
1476 		/*
1477 		 * note that we discard const here because we are
1478 		 * modifying the contents of the node (which is okay
1479 		 * because it's ours)
1480 		 */
1481 		switch (SYSCTL_TYPE(rnode->sysctl_flags)) {
1482 		case CTLTYPE_BOOL:
1483 			d = __UNCONST(&rnode->sysctl_bdata);
1484 			break;
1485 		case CTLTYPE_INT:
1486 			d = __UNCONST(&rnode->sysctl_idata);
1487 			break;
1488 		case CTLTYPE_QUAD:
1489 			d = __UNCONST(&rnode->sysctl_qdata);
1490 			break;
1491 		default:
1492 			return (EINVAL);
1493 		}
1494 	} else
1495 		d = rnode->sysctl_data;
1496 	if (SYSCTL_TYPE(rnode->sysctl_flags) == CTLTYPE_STRING)
1497 		sz = strlen(d) + 1; /* XXX@@@ possible fault here */
1498 	else
1499 		sz = rnode->sysctl_size;
1500 	if (oldp != NULL)
1501 		error = sysctl_copyout(l, d, oldp, MIN(sz, *oldlenp));
1502 	if (error)
1503 		return (error);
1504 	*oldlenp = sz;
1505 
1506 	/*
1507 	 * are we done?
1508 	 */
1509 	if (newp == NULL || newlen == 0)
1510 		return (0);
1511 
1512 	/*
1513 	 * hmm...not done.  must now "copy in" new value.  re-adjust
1514 	 * sz to maximum value (strings are "weird").
1515 	 */
1516 	sz = rnode->sysctl_size;
1517 	switch (SYSCTL_TYPE(rnode->sysctl_flags)) {
1518 	case CTLTYPE_BOOL: {
1519 		u_char tmp;
1520 		/*
1521 		 * these data must be *exactly* the same size coming
1522 		 * in.  bool may only be true or false.
1523 		 */
1524 		if (newlen != sz)
1525 			return (EINVAL);
1526 		error = sysctl_copyin(l, newp, &tmp, sz);
1527 		if (error)
1528 			break;
1529 		*(bool *)d = tmp;
1530 		break;
1531 	}
1532 	case CTLTYPE_INT:
1533 	case CTLTYPE_QUAD:
1534 	case CTLTYPE_STRUCT:
1535 		/*
1536 		 * these data must be *exactly* the same size coming
1537 		 * in.
1538 		 */
1539 		if (newlen != sz)
1540 			return (EINVAL);
1541 		error = sysctl_copyin(l, newp, d, sz);
1542 		break;
1543 	case CTLTYPE_STRING: {
1544 		/*
1545 		 * strings, on the other hand, can be shorter, and we
1546 		 * let userland be sloppy about the trailing nul.
1547 		 */
1548 		char *newbuf;
1549 
1550 		/*
1551 		 * too much new string?
1552 		 */
1553 		if (newlen > sz)
1554 			return (EINVAL);
1555 
1556 		/*
1557 		 * temporary copy of new inbound string
1558 		 */
1559 		len = MIN(sz, newlen);
1560 		newbuf = malloc(len, M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
1561 		if (newbuf == NULL)
1562 			return (ENOMEM);
1563 		error = sysctl_copyin(l, newp, newbuf, len);
1564 		if (error) {
1565 			free(newbuf, M_SYSCTLDATA);
1566 			return (error);
1567 		}
1568 
1569 		/*
1570 		 * did they null terminate it, or do we have space
1571 		 * left to do it ourselves?
1572 		 */
1573 		if (newbuf[len - 1] != '\0' && len == sz) {
1574 			free(newbuf, M_SYSCTLDATA);
1575 			return (EINVAL);
1576 		}
1577 
1578 		/*
1579 		 * looks good, so pop it into place and zero the rest.
1580 		 */
1581 		if (len > 0)
1582 			memcpy(d, newbuf, len);
1583 		if (sz != len)
1584 			memset((char*)d + len, 0, sz - len);
1585 		free(newbuf, M_SYSCTLDATA);
1586 		break;
1587 	}
1588 	default:
1589 		return (EINVAL);
1590 	}
1591 
1592 	return (error);
1593 }
1594 
1595 /*
1596  * sysctl_mmap -- Dispatches sysctl mmap requests to those nodes that
1597  * purport to handle it.  This interface isn't fully fleshed out yet,
1598  * unfortunately.
1599  */
1600 static int
1601 sysctl_mmap(SYSCTLFN_ARGS)
1602 {
1603 	const struct sysctlnode *node;
1604 	struct sysctlnode nnode;
1605 	int error;
1606 
1607 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1608 		printf("sysctl_mmap: rnode %p wrong version\n", rnode);
1609 		return (EINVAL);
1610 	}
1611 
1612 	/*
1613 	 * let's just pretend that didn't happen, m'kay?
1614 	 */
1615 	if (l == NULL)
1616 		return (EPERM);
1617 
1618 	/*
1619 	 * is this a sysctlnode description of an mmap request?
1620 	 */
1621 	if (newp == NULL || newlen != sizeof(struct sysctlnode))
1622 		return (EINVAL);
1623 	error = sysctl_copyin(l, newp, &nnode, sizeof(nnode));
1624 	if (error)
1625 		return (error);
1626 
1627 	/*
1628 	 * does the node they asked for exist?
1629 	 */
1630 	if (namelen != 1)
1631 		return (EOPNOTSUPP);
1632 	node = rnode;
1633         error = sysctl_locate(l, &nnode.sysctl_num, 1, &node, NULL);
1634 	if (error)
1635 		return (error);
1636 
1637 	/*
1638 	 * does this node that we have found purport to handle mmap?
1639 	 */
1640 	if (node->sysctl_func == NULL ||
1641 	    !(node->sysctl_flags & CTLFLAG_MMAP))
1642 		return (EOPNOTSUPP);
1643 
1644 	/*
1645 	 * well...okay, they asked for it.
1646 	 */
1647 	return ((*node->sysctl_func)(SYSCTLFN_CALL(node)));
1648 }
1649 
1650 int
1651 sysctl_describe(SYSCTLFN_ARGS)
1652 {
1653 	struct sysctldesc *d;
1654 	void *bf;
1655 	size_t sz, left, tot;
1656 	int i, error, v = -1;
1657 	struct sysctlnode *node;
1658 	struct sysctlnode dnode;
1659 
1660 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1661 		printf("sysctl_query: rnode %p wrong version\n", rnode);
1662 		return (EINVAL);
1663 	}
1664 
1665 	if (SYSCTL_TYPE(rnode->sysctl_flags) != CTLTYPE_NODE)
1666 		return (ENOTDIR);
1667 	if (namelen != 1 || name[0] != CTL_DESCRIBE)
1668 		return (EINVAL);
1669 
1670 	/*
1671 	 * get ready...
1672 	 */
1673 	error = 0;
1674 	d = bf = malloc(MAXDESCLEN, M_TEMP, M_WAITOK|M_CANFAIL);
1675 	if (bf == NULL)
1676 		return ENOMEM;
1677 	tot = 0;
1678 	node = rnode->sysctl_child;
1679 	left = *oldlenp;
1680 
1681 	/*
1682 	 * no request -> all descriptions at this level
1683 	 * request with desc unset -> just this node
1684 	 * request with desc set -> set descr for this node
1685 	 */
1686 	if (newp != NULL) {
1687 		error = sysctl_cvt_in(l, &v, newp, newlen, &dnode);
1688 		if (error)
1689 			goto out;
1690 		if (dnode.sysctl_desc != NULL) {
1691 			/*
1692 			 * processes cannot set descriptions above
1693 			 * securelevel 0.  and must be root.  blah
1694 			 * blah blah.  a couple more checks are made
1695 			 * once we find the node we want.
1696 			 */
1697 			if (l != NULL) {
1698 #ifndef SYSCTL_DISALLOW_CREATE
1699 				error = kauth_authorize_system(l->l_cred,
1700 				    KAUTH_SYSTEM_SYSCTL,
1701 				    KAUTH_REQ_SYSTEM_SYSCTL_DESC, NULL,
1702 				    NULL, NULL);
1703 				if (error)
1704 					goto out;
1705 #else /* SYSCTL_DISALLOW_CREATE */
1706 				error = EPERM;
1707 				goto out;
1708 #endif /* SYSCTL_DISALLOW_CREATE */
1709 			}
1710 
1711 			/*
1712 			 * find node and try to set the description on it
1713 			 */
1714 			for (i = 0; i < rnode->sysctl_clen; i++)
1715 				if (node[i].sysctl_num == dnode.sysctl_num)
1716 					break;
1717 			if (i == rnode->sysctl_clen) {
1718 				error = ENOENT;
1719 				goto out;
1720 			}
1721 			node = &node[i];
1722 
1723 			/*
1724 			 * did the caller specify a node version?
1725 			 */
1726 			if (dnode.sysctl_ver != 0 &&
1727 			    dnode.sysctl_ver != node->sysctl_ver) {
1728 				error = EINVAL;
1729 				goto out;
1730 			}
1731 
1732 			/*
1733 			 * okay...some rules:
1734 			 * (1) if setup is done and the tree is
1735 			 *     read-only or the whole system is
1736 			 *     read-only
1737 			 * (2) no one can set a description on a
1738 			 *     permanent node (it must be set when
1739 			 *     using createv)
1740 			 * (3) processes cannot *change* a description
1741 			 * (4) processes *can*, however, set a
1742 			 *     description on a read-only node so that
1743 			 *     one can be created and then described
1744 			 *     in two steps
1745 			 * anything else come to mind?
1746 			 */
1747 			if ((sysctl_root.sysctl_flags & CTLFLAG_PERMANENT) &&
1748 			    (!(sysctl_rootof(node)->sysctl_flags &
1749 			       CTLFLAG_READWRITE) ||
1750 			     !(sysctl_root.sysctl_flags & CTLFLAG_READWRITE))) {
1751 				error = EPERM;
1752 				goto out;
1753 			}
1754 			if (node->sysctl_flags & CTLFLAG_PERMANENT) {
1755 				error = EPERM;
1756 				goto out;
1757 			}
1758 			if (l != NULL && node->sysctl_desc != NULL) {
1759 				error = EPERM;
1760 				goto out;
1761 			}
1762 
1763 			/*
1764 			 * right, let's go ahead.  the first step is
1765 			 * making the description into something the
1766 			 * node can "own", if need be.
1767 			 */
1768 			if (l != NULL ||
1769 			    dnode.sysctl_flags & CTLFLAG_OWNDESC) {
1770 				char *nd, *k;
1771 
1772 				k = malloc(MAXDESCLEN, M_TEMP,
1773 				    M_WAITOK|M_CANFAIL);
1774 				if (k == NULL) {
1775 					error = ENOMEM;
1776 					goto out;
1777 				}
1778 				error = sysctl_copyinstr(l, dnode.sysctl_desc,
1779 							 k, MAXDESCLEN, &sz);
1780 				if (error) {
1781 					free(k, M_TEMP);
1782 					goto out;
1783 				}
1784 				nd = malloc(sz, M_SYSCTLDATA,
1785 					    M_WAITOK|M_CANFAIL);
1786 				if (nd == NULL) {
1787 					free(k, M_TEMP);
1788 					error = ENOMEM;
1789 					goto out;
1790 				}
1791 				memcpy(nd, k, sz);
1792 				dnode.sysctl_flags |= CTLFLAG_OWNDESC;
1793 				dnode.sysctl_desc = nd;
1794 				free(k, M_TEMP);
1795 			}
1796 
1797 			/*
1798 			 * now "release" the old description and
1799 			 * attach the new one.  ta-da.
1800 			 */
1801 			if ((node->sysctl_flags & CTLFLAG_OWNDESC) &&
1802 			    node->sysctl_desc != NULL)
1803 				/*XXXUNCONST*/
1804 				free(__UNCONST(node->sysctl_desc), M_SYSCTLDATA);
1805 			node->sysctl_desc = dnode.sysctl_desc;
1806 			node->sysctl_flags |=
1807 				(dnode.sysctl_flags & CTLFLAG_OWNDESC);
1808 
1809 			/*
1810 			 * now we "fall out" and into the loop which
1811 			 * will copy the new description back out for
1812 			 * those interested parties
1813 			 */
1814 		}
1815 	}
1816 
1817 	/*
1818 	 * scan for one description or just retrieve all descriptions
1819 	 */
1820 	for (i = 0; i < rnode->sysctl_clen; i++) {
1821 		/*
1822 		 * did they ask for the description of only one node?
1823 		 */
1824 		if (v != -1 && node[i].sysctl_num != dnode.sysctl_num)
1825 			continue;
1826 
1827 		/*
1828 		 * don't describe "private" nodes to non-suser users
1829 		 */
1830 		if ((node[i].sysctl_flags & CTLFLAG_PRIVATE) && (l != NULL) &&
1831 		    !(kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
1832 		    KAUTH_REQ_SYSTEM_SYSCTL_PRVT, NULL, NULL, NULL)))
1833 			continue;
1834 
1835 		/*
1836 		 * is this description "valid"?
1837 		 */
1838 		memset(bf, 0, MAXDESCLEN);
1839 		if (node[i].sysctl_desc == NULL)
1840 			sz = 1;
1841 		else if (copystr(node[i].sysctl_desc, &d->descr_str[0],
1842 				 MAXDESCLEN - sizeof(*d), &sz) != 0) {
1843 			/*
1844 			 * erase possible partial description
1845 			 */
1846 			memset(bf, 0, MAXDESCLEN);
1847 			sz = 1;
1848 		}
1849 
1850 		/*
1851 		 * we've got it, stuff it into the caller's buffer
1852 		 */
1853 		d->descr_num = node[i].sysctl_num;
1854 		d->descr_ver = node[i].sysctl_ver;
1855 		d->descr_len = sz; /* includes trailing nul */
1856 		sz = (char *)NEXT_DESCR(d) - (char *)d;
1857 		if (oldp != NULL && left >= sz) {
1858 			error = sysctl_copyout(l, d, oldp, sz);
1859 			if (error)
1860 				goto out;
1861 			left -= sz;
1862 			oldp = (void *)__sysc_desc_adv(oldp, d->descr_len);
1863 		}
1864 		tot += sz;
1865 
1866 		/*
1867 		 * if we get this far with v not "unset", they asked
1868 		 * for a specific node and we found it
1869 		 */
1870 		if (v != -1)
1871 			break;
1872 	}
1873 
1874 	/*
1875 	 * did we find it after all?
1876 	 */
1877 	if (v != -1 && tot == 0)
1878 		error = ENOENT;
1879 	else
1880 		*oldlenp = tot;
1881 
1882 out:
1883 	free(bf, M_TEMP);
1884 	return (error);
1885 }
1886 
1887 /*
1888  * ********************************************************************
1889  * Section 3: Create and destroy from inside the kernel
1890  * ********************************************************************
1891  * sysctl_createv() and sysctl_destroyv() are simpler-to-use
1892  * interfaces for the kernel to fling new entries into the mib and rip
1893  * them out later.  In the case of sysctl_createv(), the returned copy
1894  * of the node (see sysctl_create()) will be translated back into a
1895  * pointer to the actual node.
1896  *
1897  * Note that sysctl_createv() will return 0 if the create request
1898  * matches an existing node (ala mkdir -p), and that sysctl_destroyv()
1899  * will return 0 if the node to be destroyed already does not exist
1900  * (aka rm -f) or if it is a parent of other nodes.
1901  *
1902  * This allows two (or more) different subsystems to assert sub-tree
1903  * existence before populating their own nodes, and to remove their
1904  * own nodes without orphaning the others when they are done.
1905  * ********************************************************************
1906  */
1907 int
1908 sysctl_createv(struct sysctllog **log, int cflags,
1909 	       const struct sysctlnode **rnode, const struct sysctlnode **cnode,
1910 	       int flags, int type, const char *namep, const char *descr,
1911 	       sysctlfn func, u_quad_t qv, void *newp, size_t newlen,
1912 	       ...)
1913 {
1914 	va_list ap;
1915 	int error, ni, namelen, name[CTL_MAXNAME];
1916 	const struct sysctlnode *root, *pnode;
1917 	struct sysctlnode nnode, onode, *dnode;
1918 	size_t sz;
1919 
1920 	/*
1921 	 * where are we putting this?
1922 	 */
1923 	if (rnode != NULL && *rnode == NULL) {
1924 		printf("sysctl_createv: rnode NULL\n");
1925 		return (EINVAL);
1926 	}
1927 	root = rnode ? *rnode : NULL;
1928 	if (cnode != NULL)
1929 		*cnode = NULL;
1930 	if (cflags != 0)
1931 		return (EINVAL);
1932 
1933 	/*
1934 	 * what is it?
1935 	 */
1936 	flags = SYSCTL_VERSION|SYSCTL_TYPE(type)|SYSCTL_FLAGS(flags);
1937 	if (log != NULL)
1938 		flags &= ~CTLFLAG_PERMANENT;
1939 
1940 	/*
1941 	 * where do we put it?
1942 	 */
1943 	va_start(ap, newlen);
1944 	namelen = 0;
1945 	ni = -1;
1946 	do {
1947 		if (++ni == CTL_MAXNAME)
1948 			return (ENAMETOOLONG);
1949 		name[ni] = va_arg(ap, int);
1950 		/*
1951 		 * sorry, this is not supported from here
1952 		 */
1953 		if (name[ni] == CTL_CREATESYM)
1954 			return (EINVAL);
1955 	} while (name[ni] != CTL_EOL && name[ni] != CTL_CREATE);
1956 	namelen = ni + (name[ni] == CTL_CREATE ? 1 : 0);
1957 	va_end(ap);
1958 
1959 	/*
1960 	 * what's it called
1961 	 */
1962 	if (strlcpy(nnode.sysctl_name, namep, sizeof(nnode.sysctl_name)) >=
1963 	    sizeof(nnode.sysctl_name))
1964 		return (ENAMETOOLONG);
1965 
1966 	/*
1967 	 * cons up the description of the new node
1968 	 */
1969 	nnode.sysctl_num = name[namelen - 1];
1970 	name[namelen - 1] = CTL_CREATE;
1971 	nnode.sysctl_size = newlen;
1972 	nnode.sysctl_flags = flags;
1973 	if (type == CTLTYPE_NODE) {
1974 		nnode.sysctl_csize = 0;
1975 		nnode.sysctl_clen = 0;
1976 		nnode.sysctl_child = NULL;
1977 		if (flags & CTLFLAG_ALIAS)
1978 			nnode.sysctl_alias = qv;
1979 	} else if (flags & CTLFLAG_IMMEDIATE) {
1980 		switch (type) {
1981 		case CTLTYPE_BOOL:
1982 			nnode.sysctl_bdata = qv;
1983 			break;
1984 		case CTLTYPE_INT:
1985 			nnode.sysctl_idata = qv;
1986 			break;
1987 		case CTLTYPE_QUAD:
1988 			nnode.sysctl_qdata = qv;
1989 			break;
1990 		default:
1991 			return (EINVAL);
1992 		}
1993 	} else {
1994 		nnode.sysctl_data = newp;
1995 	}
1996 	nnode.sysctl_func = func;
1997 	nnode.sysctl_parent = NULL;
1998 	nnode.sysctl_ver = 0;
1999 
2000 	/*
2001 	 * initialize lock state -- we need locks if the main tree has
2002 	 * been marked as complete, but since we could be called from
2003 	 * either there, or from a device driver (say, at device
2004 	 * insertion), or from an lkm (at lkm load time, say), we
2005 	 * don't really want to "wait"...
2006 	 */
2007 	sysctl_lock(true);
2008 
2009 	/*
2010 	 * locate the prospective parent of the new node, and if we
2011 	 * find it, add the new node.
2012 	 */
2013 	sz = sizeof(onode);
2014 	pnode = root;
2015 	error = sysctl_locate(NULL, &name[0], namelen - 1, &pnode, &ni);
2016 	if (error) {
2017 		printf("sysctl_createv: sysctl_locate(%s) returned %d\n",
2018 		       nnode.sysctl_name, error);
2019 		sysctl_unlock();
2020 		return (error);
2021 	}
2022 	error = sysctl_create(&name[ni], namelen - ni, &onode, &sz,
2023 			      &nnode, sizeof(nnode), &name[0], NULL,
2024 			      pnode);
2025 
2026 	/*
2027 	 * unfortunately the node we wanted to create is already
2028 	 * there.  if the node that's already there is a reasonable
2029 	 * facsimile of the node we wanted to create, just pretend
2030 	 * (for the caller's benefit) that we managed to create the
2031 	 * node they wanted.
2032 	 */
2033 	if (error == EEXIST) {
2034 		/* name is the same as requested... */
2035 		if (strcmp(nnode.sysctl_name, onode.sysctl_name) == 0 &&
2036 		    /* they want the same function... */
2037 		    nnode.sysctl_func == onode.sysctl_func &&
2038 		    /* number is the same as requested, or... */
2039 		    (nnode.sysctl_num == onode.sysctl_num ||
2040 		     /* they didn't pick a number... */
2041 		     nnode.sysctl_num == CTL_CREATE)) {
2042 			/*
2043 			 * collision here from trying to create
2044 			 * something that already existed; let's give
2045 			 * our customers a hand and tell them they got
2046 			 * what they wanted.
2047 			 */
2048 #ifdef SYSCTL_DEBUG_CREATE
2049 			printf("cleared\n");
2050 #endif /* SYSCTL_DEBUG_CREATE */
2051 			error = 0;
2052 		}
2053 	}
2054 
2055 	if (error == 0 &&
2056 	    (cnode != NULL || log != NULL || descr != NULL)) {
2057 		/*
2058 		 * sysctl_create() gave us back a copy of the node,
2059 		 * but we need to know where it actually is...
2060 		 */
2061 		pnode = root;
2062 		error = sysctl_locate(NULL, &name[0], namelen - 1, &pnode, &ni);
2063 
2064 		/*
2065 		 * manual scan of last layer so that aliased nodes
2066 		 * aren't followed.
2067 		 */
2068 		if (error == 0) {
2069 			for (ni = 0; ni < pnode->sysctl_clen; ni++)
2070 				if (pnode->sysctl_child[ni].sysctl_num ==
2071 				    onode.sysctl_num)
2072 					break;
2073 			if (ni < pnode->sysctl_clen)
2074 				pnode = &pnode->sysctl_child[ni];
2075 			else
2076 				error = ENOENT;
2077 		}
2078 
2079 		/*
2080 		 * not expecting an error here, but...
2081 		 */
2082 		if (error == 0) {
2083 			if (log != NULL)
2084 				sysctl_log_add(log, pnode);
2085 			if (cnode != NULL)
2086 				*cnode = pnode;
2087 			if (descr != NULL) {
2088 				/*
2089 				 * allow first caller to *set* a
2090 				 * description actually to set it
2091 				 *
2092 				 * discard const here so we can attach
2093 				 * the description
2094 				 */
2095 				dnode = __UNCONST(pnode);
2096 				if (pnode->sysctl_desc != NULL)
2097 					/* skip it...we've got one */;
2098 				else if (flags & CTLFLAG_OWNDESC) {
2099 					size_t l = strlen(descr) + 1;
2100 					char *d = malloc(l, M_SYSCTLDATA,
2101 							 M_WAITOK|M_CANFAIL);
2102 					if (d != NULL) {
2103 						memcpy(d, descr, l);
2104 						dnode->sysctl_desc = d;
2105 						dnode->sysctl_flags |=
2106 						    CTLFLAG_OWNDESC;
2107 					}
2108 				} else
2109 					dnode->sysctl_desc = descr;
2110 			}
2111 		} else {
2112 			printf("sysctl_create succeeded but node not found?!\n");
2113 			/*
2114 			 *  confusing, but the create said it
2115 			 * succeeded, so...
2116 			 */
2117 			error = 0;
2118 		}
2119 	}
2120 
2121 	/*
2122 	 * now it should be safe to release the lock state.  note that
2123 	 * the pointer to the newly created node being passed back may
2124 	 * not be "good" for very long.
2125 	 */
2126 	sysctl_unlock();
2127 
2128 	if (error != 0) {
2129 		printf("sysctl_createv: sysctl_create(%s) returned %d\n",
2130 		       nnode.sysctl_name, error);
2131 #if 0
2132 		if (error != ENOENT)
2133 			sysctl_dump(&onode);
2134 #endif
2135 	}
2136 
2137 	return (error);
2138 }
2139 
2140 int
2141 sysctl_destroyv(struct sysctlnode *rnode, ...)
2142 {
2143 	va_list ap;
2144 	int error, name[CTL_MAXNAME], namelen, ni;
2145 	const struct sysctlnode *pnode, *node;
2146 	struct sysctlnode dnode, *onode;
2147 	size_t sz;
2148 
2149 	va_start(ap, rnode);
2150 	namelen = 0;
2151 	ni = 0;
2152 	do {
2153 		if (ni == CTL_MAXNAME)
2154 			return (ENAMETOOLONG);
2155 		name[ni] = va_arg(ap, int);
2156 	} while (name[ni++] != CTL_EOL);
2157 	namelen = ni - 1;
2158 	va_end(ap);
2159 
2160 	/*
2161 	 * i can't imagine why we'd be destroying a node when the tree
2162 	 * wasn't complete, but who knows?
2163 	 */
2164 	sysctl_lock(true);
2165 
2166 	/*
2167 	 * where is it?
2168 	 */
2169 	node = rnode;
2170 	error = sysctl_locate(NULL, &name[0], namelen - 1, &node, &ni);
2171 	if (error) {
2172 		/* they want it gone and it's not there, so... */
2173 		sysctl_unlock();
2174 		return (error == ENOENT ? 0 : error);
2175 	}
2176 
2177 	/*
2178 	 * set up the deletion
2179 	 */
2180 	pnode = node;
2181 	node = &dnode;
2182 	memset(&dnode, 0, sizeof(dnode));
2183 	dnode.sysctl_flags = SYSCTL_VERSION;
2184 	dnode.sysctl_num = name[namelen - 1];
2185 
2186 	/*
2187 	 * we found it, now let's nuke it
2188 	 */
2189 	name[namelen - 1] = CTL_DESTROY;
2190 	sz = 0;
2191 	error = sysctl_destroy(&name[namelen - 1], 1, NULL, &sz,
2192 			       node, sizeof(*node), &name[0], NULL,
2193 			       pnode);
2194 	if (error == ENOTEMPTY) {
2195 		/*
2196 		 * think of trying to delete "foo" when "foo.bar"
2197 		 * (which someone else put there) is still in
2198 		 * existence
2199 		 */
2200 		error = 0;
2201 
2202 		/*
2203 		 * dunno who put the description there, but if this
2204 		 * node can ever be removed, we need to make sure the
2205 		 * string doesn't go out of context.  that means we
2206 		 * need to find the node that's still there (don't use
2207 		 * sysctl_locate() because that follows aliasing).
2208 		 */
2209 		node = pnode->sysctl_child;
2210 		for (ni = 0; ni < pnode->sysctl_clen; ni++)
2211 			if (node[ni].sysctl_num == dnode.sysctl_num)
2212 				break;
2213 		node = (ni < pnode->sysctl_clen) ? &node[ni] : NULL;
2214 
2215 		/*
2216 		 * if we found it, and this node has a description,
2217 		 * and this node can be released, and it doesn't
2218 		 * already own its own description...sigh.  :)
2219 		 */
2220 		if (node != NULL && node->sysctl_desc != NULL &&
2221 		    !(node->sysctl_flags & CTLFLAG_PERMANENT) &&
2222 		    !(node->sysctl_flags & CTLFLAG_OWNDESC)) {
2223 			char *d;
2224 
2225 			sz = strlen(node->sysctl_desc) + 1;
2226 			d = malloc(sz, M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
2227 			if (d != NULL) {
2228 				/*
2229 				 * discard const so that we can
2230 				 * re-attach the description
2231 				 */
2232 				memcpy(d, node->sysctl_desc, sz);
2233 				onode = __UNCONST(node);
2234 				onode->sysctl_desc = d;
2235 				onode->sysctl_flags |= CTLFLAG_OWNDESC;
2236 			} else {
2237 				/*
2238 				 * XXX drop the description?  be
2239 				 * afraid?  don't care?
2240 				 */
2241 			}
2242 		}
2243 	}
2244 
2245         sysctl_unlock();
2246 
2247 	return (error);
2248 }
2249 
2250 /*
2251  * ********************************************************************
2252  * Deletes an entire n-ary tree.  Not recommended unless you know why
2253  * you're doing it.  Personally, I don't know why you'd even think
2254  * about it.
2255  * ********************************************************************
2256  */
2257 void
2258 sysctl_free(struct sysctlnode *rnode)
2259 {
2260 	struct sysctlnode *node, *pnode;
2261 
2262 	rw_enter(&sysctl_treelock, RW_WRITER);
2263 
2264 	if (rnode == NULL)
2265 		rnode = &sysctl_root;
2266 
2267 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
2268 		printf("sysctl_free: rnode %p wrong version\n", rnode);
2269 		rw_exit(&sysctl_treelock);
2270 		return;
2271 	}
2272 
2273 	pnode = rnode;
2274 
2275 	node = pnode->sysctl_child;
2276 	do {
2277 		while (node != NULL && pnode->sysctl_csize > 0) {
2278 			while (node <
2279 			       &pnode->sysctl_child[pnode->sysctl_clen] &&
2280 			       (SYSCTL_TYPE(node->sysctl_flags) !=
2281 				CTLTYPE_NODE ||
2282 				node->sysctl_csize == 0)) {
2283 				if (SYSCTL_FLAGS(node->sysctl_flags) &
2284 				    CTLFLAG_OWNDATA) {
2285 					if (node->sysctl_data != NULL) {
2286 						free(node->sysctl_data,
2287 						     M_SYSCTLDATA);
2288 						node->sysctl_data = NULL;
2289 					}
2290 				}
2291 				if (SYSCTL_FLAGS(node->sysctl_flags) &
2292 				    CTLFLAG_OWNDESC) {
2293 					if (node->sysctl_desc != NULL) {
2294 						/*XXXUNCONST*/
2295 						free(__UNCONST(node->sysctl_desc),
2296 						     M_SYSCTLDATA);
2297 						node->sysctl_desc = NULL;
2298 					}
2299 				}
2300 				node++;
2301 			}
2302 			if (node < &pnode->sysctl_child[pnode->sysctl_clen]) {
2303 				pnode = node;
2304 				node = node->sysctl_child;
2305 			} else
2306 				break;
2307 		}
2308 		if (pnode->sysctl_child != NULL)
2309 			free(pnode->sysctl_child, M_SYSCTLNODE);
2310 		pnode->sysctl_clen = 0;
2311 		pnode->sysctl_csize = 0;
2312 		pnode->sysctl_child = NULL;
2313 		node = pnode;
2314 		pnode = node->sysctl_parent;
2315 	} while (pnode != NULL && node != rnode);
2316 
2317 	rw_exit(&sysctl_treelock);
2318 }
2319 
2320 int
2321 sysctl_log_add(struct sysctllog **logp, const struct sysctlnode *node)
2322 {
2323 	int name[CTL_MAXNAME], namelen, i;
2324 	const struct sysctlnode *pnode;
2325 	struct sysctllog *log;
2326 
2327 	if (node->sysctl_flags & CTLFLAG_PERMANENT)
2328 		return (0);
2329 
2330 	if (logp == NULL)
2331 		return (0);
2332 
2333 	if (*logp == NULL) {
2334 		log = malloc(sizeof(struct sysctllog),
2335 		       M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
2336 		if (log == NULL) {
2337 			/* XXX print error message? */
2338 			return (-1);
2339 		}
2340 		log->log_num = malloc(16 * sizeof(int),
2341 		       M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
2342 		if (log->log_num == NULL) {
2343 			/* XXX print error message? */
2344 			free(log, M_SYSCTLDATA);
2345 			return (-1);
2346 		}
2347 		memset(log->log_num, 0, 16 * sizeof(int));
2348 		log->log_root = NULL;
2349 		log->log_size = 16;
2350 		log->log_left = 16;
2351 		*logp = log;
2352 	} else
2353 		log = *logp;
2354 
2355 	/*
2356 	 * check that the root is proper.  it's okay to record the
2357 	 * address of the root of a tree.  it's the only thing that's
2358 	 * guaranteed not to shift around as nodes come and go.
2359 	 */
2360 	if (log->log_root == NULL)
2361 		log->log_root = sysctl_rootof(node);
2362 	else if (log->log_root != sysctl_rootof(node)) {
2363 		printf("sysctl: log %p root mismatch (%p)\n",
2364 		       log->log_root, sysctl_rootof(node));
2365 		return (-1);
2366 	}
2367 
2368 	/*
2369 	 * we will copy out name in reverse order
2370 	 */
2371 	for (pnode = node, namelen = 0;
2372 	     pnode != NULL && !(pnode->sysctl_flags & CTLFLAG_ROOT);
2373 	     pnode = pnode->sysctl_parent)
2374 		name[namelen++] = pnode->sysctl_num;
2375 
2376 	/*
2377 	 * do we have space?
2378 	 */
2379 	if (log->log_left < (namelen + 3))
2380 		sysctl_log_realloc(log);
2381 	if (log->log_left < (namelen + 3))
2382 		return (-1);
2383 
2384 	/*
2385 	 * stuff name in, then namelen, then node type, and finally,
2386 	 * the version for non-node nodes.
2387 	 */
2388 	for (i = 0; i < namelen; i++)
2389 		log->log_num[--log->log_left] = name[i];
2390 	log->log_num[--log->log_left] = namelen;
2391 	log->log_num[--log->log_left] = SYSCTL_TYPE(node->sysctl_flags);
2392 	if (log->log_num[log->log_left] != CTLTYPE_NODE)
2393 		log->log_num[--log->log_left] = node->sysctl_ver;
2394 	else
2395 		log->log_num[--log->log_left] = 0;
2396 
2397 	return (0);
2398 }
2399 
2400 void
2401 sysctl_teardown(struct sysctllog **logp)
2402 {
2403 	const struct sysctlnode *rnode;
2404 	struct sysctlnode node;
2405 	struct sysctllog *log;
2406 	uint namelen;
2407 	int *name, t, v, error, ni;
2408 	size_t sz;
2409 
2410 	if (logp == NULL || *logp == NULL)
2411 		return;
2412 	log = *logp;
2413 
2414 	rw_enter(&sysctl_treelock, RW_WRITER);
2415 	memset(&node, 0, sizeof(node));
2416 
2417 	while (log->log_left < log->log_size) {
2418 		KASSERT((log->log_left + 3 < log->log_size) &&
2419 			(log->log_left + log->log_num[log->log_left + 2] <=
2420 			 log->log_size));
2421 		v = log->log_num[log->log_left++];
2422 		t = log->log_num[log->log_left++];
2423 		namelen = log->log_num[log->log_left++];
2424 		name = &log->log_num[log->log_left];
2425 
2426 		node.sysctl_num = name[namelen - 1];
2427 		node.sysctl_flags = SYSCTL_VERSION|t;
2428 		node.sysctl_ver = v;
2429 
2430 		rnode = log->log_root;
2431 		error = sysctl_locate(NULL, &name[0], namelen, &rnode, &ni);
2432 		if (error == 0) {
2433 			name[namelen - 1] = CTL_DESTROY;
2434 			rnode = rnode->sysctl_parent;
2435 			sz = 0;
2436 			(void)sysctl_destroy(&name[namelen - 1], 1, NULL,
2437 					     &sz, &node, sizeof(node),
2438 					     &name[0], NULL, rnode);
2439 		}
2440 
2441 		log->log_left += namelen;
2442 	}
2443 
2444 	KASSERT(log->log_size == log->log_left);
2445 	free(log->log_num, M_SYSCTLDATA);
2446 	free(log, M_SYSCTLDATA);
2447 	*logp = NULL;
2448 
2449 	rw_exit(&sysctl_treelock);
2450 }
2451 
2452 /*
2453  * ********************************************************************
2454  * old_sysctl -- A routine to bridge old-style internal calls to the
2455  * new infrastructure.
2456  * ********************************************************************
2457  */
2458 int
2459 old_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
2460 	   void *newp, size_t newlen, struct lwp *l)
2461 {
2462 	int error;
2463 	size_t oldlen = 0;
2464 	size_t savelen;
2465 
2466 	if (oldlenp) {
2467 		oldlen = *oldlenp;
2468 	}
2469 	savelen = oldlen;
2470 
2471 	sysctl_lock(newp != NULL);
2472 	error = sysctl_dispatch(name, namelen, oldp, &oldlen,
2473 				newp, newlen, name, l, NULL);
2474 	sysctl_unlock();
2475 	if (error == 0 && oldp != NULL && savelen < oldlen)
2476 		error = ENOMEM;
2477 	if (oldlenp) {
2478 		*oldlenp = oldlen;
2479 	}
2480 
2481 	return (error);
2482 }
2483 
2484 /*
2485  * ********************************************************************
2486  * Section 4: Generic helper routines
2487  * ********************************************************************
2488  * "helper" routines that can do more finely grained access control,
2489  * construct structures from disparate information, create the
2490  * appearance of more nodes and sub-trees, etc.  for example, if
2491  * CTL_PROC wanted a helper function, it could respond to a CTL_QUERY
2492  * with a dynamically created list of nodes that represented the
2493  * currently running processes at that instant.
2494  * ********************************************************************
2495  */
2496 
2497 /*
2498  * first, a few generic helpers that provide:
2499  *
2500  * sysctl_needfunc()		a readonly interface that emits a warning
2501  * sysctl_notavail()		returns EOPNOTSUPP (generic error)
2502  * sysctl_null()		an empty return buffer with no error
2503  */
2504 int
2505 sysctl_needfunc(SYSCTLFN_ARGS)
2506 {
2507 	int error;
2508 
2509 	printf("!!SYSCTL_NEEDFUNC!!\n");
2510 
2511 	if (newp != NULL || namelen != 0)
2512 		return (EOPNOTSUPP);
2513 
2514 	error = 0;
2515 	if (oldp != NULL)
2516 		error = sysctl_copyout(l, rnode->sysctl_data, oldp,
2517 				       MIN(rnode->sysctl_size, *oldlenp));
2518 	*oldlenp = rnode->sysctl_size;
2519 
2520 	return (error);
2521 }
2522 
2523 int
2524 sysctl_notavail(SYSCTLFN_ARGS)
2525 {
2526 
2527 	if (namelen == 1 && name[0] == CTL_QUERY)
2528 		return (sysctl_query(SYSCTLFN_CALL(rnode)));
2529 
2530 	return (EOPNOTSUPP);
2531 }
2532 
2533 int
2534 sysctl_null(SYSCTLFN_ARGS)
2535 {
2536 
2537 	*oldlenp = 0;
2538 
2539 	return (0);
2540 }
2541 
2542 /*
2543  * ********************************************************************
2544  * Section 5: The machinery that makes it all go
2545  * ********************************************************************
2546  * Memory "manglement" routines.  Not much to this, eh?
2547  * ********************************************************************
2548  */
2549 static int
2550 sysctl_alloc(struct sysctlnode *p, int x)
2551 {
2552 	int i;
2553 	struct sysctlnode *n;
2554 
2555 	assert(p->sysctl_child == NULL);
2556 
2557 	if (x == 1)
2558 		n = malloc(sizeof(struct sysctlnode),
2559 		       M_SYSCTLNODE, M_WAITOK|M_CANFAIL);
2560 	else
2561 		n = malloc(SYSCTL_DEFSIZE * sizeof(struct sysctlnode),
2562 		       M_SYSCTLNODE, M_WAITOK|M_CANFAIL);
2563 	if (n == NULL)
2564 		return (ENOMEM);
2565 
2566 	if (x == 1) {
2567 		memset(n, 0, sizeof(struct sysctlnode));
2568 		p->sysctl_csize = 1;
2569 	} else {
2570 		memset(n, 0, SYSCTL_DEFSIZE * sizeof(struct sysctlnode));
2571 		p->sysctl_csize = SYSCTL_DEFSIZE;
2572 	}
2573 	p->sysctl_clen = 0;
2574 
2575 	for (i = 0; i < p->sysctl_csize; i++)
2576 		n[i].sysctl_parent = p;
2577 
2578 	p->sysctl_child = n;
2579 	return (0);
2580 }
2581 
2582 static int
2583 sysctl_realloc(struct sysctlnode *p)
2584 {
2585 	int i, j;
2586 	struct sysctlnode *n;
2587 
2588 	assert(p->sysctl_csize == p->sysctl_clen);
2589 
2590 	/*
2591 	 * how many do we have...how many should we make?
2592 	 */
2593 	i = p->sysctl_clen;
2594 	n = malloc(2 * i * sizeof(struct sysctlnode), M_SYSCTLNODE,
2595 		   M_WAITOK|M_CANFAIL);
2596 	if (n == NULL)
2597 		return (ENOMEM);
2598 
2599 	/*
2600 	 * move old children over...initialize new children
2601 	 */
2602 	memcpy(n, p->sysctl_child, i * sizeof(struct sysctlnode));
2603 	memset(&n[i], 0, i * sizeof(struct sysctlnode));
2604 	p->sysctl_csize = 2 * i;
2605 
2606 	/*
2607 	 * reattach moved (and new) children to parent; if a moved
2608 	 * child node has children, reattach the parent pointers of
2609 	 * grandchildren
2610 	 */
2611         for (i = 0; i < p->sysctl_csize; i++) {
2612                 n[i].sysctl_parent = p;
2613 		if (n[i].sysctl_child != NULL) {
2614 			for (j = 0; j < n[i].sysctl_csize; j++)
2615 				n[i].sysctl_child[j].sysctl_parent = &n[i];
2616 		}
2617 	}
2618 
2619 	/*
2620 	 * get out with the old and in with the new
2621 	 */
2622 	free(p->sysctl_child, M_SYSCTLNODE);
2623 	p->sysctl_child = n;
2624 
2625 	return (0);
2626 }
2627 
2628 static int
2629 sysctl_log_realloc(struct sysctllog *log)
2630 {
2631 	int *n, s, d;
2632 
2633 	s = log->log_size * 2;
2634 	d = log->log_size;
2635 
2636 	n = malloc(s * sizeof(int), M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
2637 	if (n == NULL)
2638 		return (-1);
2639 
2640 	memset(n, 0, s * sizeof(int));
2641 	memcpy(&n[d], log->log_num, d * sizeof(int));
2642 	free(log->log_num, M_SYSCTLDATA);
2643 	log->log_num = n;
2644 	if (d)
2645 		log->log_left += d;
2646 	else
2647 		log->log_left = s;
2648 	log->log_size = s;
2649 
2650 	return (0);
2651 }
2652 
2653 /*
2654  * ********************************************************************
2655  * Section 6: Conversion between API versions wrt the sysctlnode
2656  * ********************************************************************
2657  */
2658 static int
2659 sysctl_cvt_in(struct lwp *l, int *vp, const void *i, size_t sz,
2660 	      struct sysctlnode *node)
2661 {
2662 	int error, flags;
2663 
2664 	if (i == NULL || sz < sizeof(flags))
2665 		return (EINVAL);
2666 
2667 	error = sysctl_copyin(l, i, &flags, sizeof(flags));
2668 	if (error)
2669 		return (error);
2670 
2671 #if (SYSCTL_VERSION != SYSCTL_VERS_1)
2672 #error sysctl_cvt_in: no support for SYSCTL_VERSION
2673 #endif /*  (SYSCTL_VERSION != SYSCTL_VERS_1) */
2674 
2675 	if (sz == sizeof(*node) &&
2676 	    SYSCTL_VERS(flags) == SYSCTL_VERSION) {
2677 		error = sysctl_copyin(l, i, node, sizeof(*node));
2678 		if (error)
2679 			return (error);
2680 		*vp = SYSCTL_VERSION;
2681 		return (0);
2682 	}
2683 
2684 	return (EINVAL);
2685 }
2686 
2687 static int
2688 sysctl_cvt_out(struct lwp *l, int v, const struct sysctlnode *i,
2689 	       void *ovp, size_t left, size_t *szp)
2690 {
2691 	size_t sz = sizeof(*i);
2692 	const void *src = i;
2693 	int error;
2694 
2695 	switch (v) {
2696 	case SYSCTL_VERS_0:
2697 		return (EINVAL);
2698 
2699 #if (SYSCTL_VERSION != SYSCTL_VERS_1)
2700 #error sysctl_cvt_out: no support for SYSCTL_VERSION
2701 #endif /*  (SYSCTL_VERSION != SYSCTL_VERS_1) */
2702 
2703 	case SYSCTL_VERSION:
2704 		/* nothing more to do here */
2705 		break;
2706 	}
2707 
2708 	if (ovp != NULL && left >= sz) {
2709 		error = sysctl_copyout(l, src, ovp, sz);
2710 		if (error)
2711 			return (error);
2712 	}
2713 
2714 	if (szp != NULL)
2715 		*szp = sz;
2716 
2717 	return (0);
2718 }
2719