xref: /netbsd-src/sys/kern/kern_sysctl.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: kern_sysctl.c,v 1.210 2007/08/15 12:07:34 ad Exp $	*/
2 
3 /*-
4  * Copyright (c) 2003 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 1.210 2007/08/15 12:07:34 ad 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_lock' is intended to serialize access to the sysctl
144  * tree.  Given that it is now (a) dynamic, and (b) most consumers of
145  * sysctl are going to be copying data out, the old `sysctl_memlock'
146  * has been `upgraded' to simply guard the whole tree.
147  *
148  * The two new data here are to keep track of the locked chunk of
149  * memory, if there is one, so that it can be released more easily
150  * from anywhere.
151  */
152 krwlock_t sysctl_treelock;
153 void *sysctl_memaddr;
154 size_t sysctl_memsize;
155 
156 /*
157  * Attributes stored in the kernel.
158  */
159 char hostname[MAXHOSTNAMELEN];
160 int hostnamelen;
161 
162 char domainname[MAXHOSTNAMELEN];
163 int domainnamelen;
164 
165 long hostid;
166 
167 #ifndef DEFCORENAME
168 #define	DEFCORENAME	"%n.core"
169 #endif
170 char defcorename[MAXPATHLEN] = DEFCORENAME;
171 
172 /*
173  * ********************************************************************
174  * Section 0: Some simple glue
175  * ********************************************************************
176  * By wrapping copyin(), copyout(), and copyinstr() like this, we can
177  * stop caring about who's calling us and simplify some code a bunch.
178  * ********************************************************************
179  */
180 static inline int
181 sysctl_copyin(struct lwp *l, const void *uaddr, void *kaddr, size_t len)
182 {
183 	int error;
184 
185 	if (l != NULL) {
186 		error = copyin(uaddr, kaddr, len);
187 		ktrmibio(-1, UIO_WRITE, uaddr, len, error);
188 	} else {
189 		error = kcopy(uaddr, kaddr, len);
190 	}
191 
192 	return error;
193 }
194 
195 static inline int
196 sysctl_copyout(struct lwp *l, const void *kaddr, void *uaddr, size_t len)
197 {
198 	int error;
199 
200 	if (l != NULL) {
201 		error = copyout(kaddr, uaddr, len);
202 		ktrmibio(-1, UIO_READ, uaddr, len, error);
203 	} else {
204 		error = kcopy(kaddr, uaddr, len);
205 	}
206 
207 	return error;
208 }
209 
210 static inline int
211 sysctl_copyinstr(struct lwp *l, const void *uaddr, void *kaddr,
212 		 size_t len, size_t *done)
213 {
214 	int error;
215 
216 	if (l != NULL) {
217 		error = copyinstr(uaddr, kaddr, len, done);
218 		ktrmibio(-1, UIO_WRITE, uaddr, len, error);
219 	} else {
220 		error = copystr(uaddr, kaddr, len, done);
221 	}
222 
223 	return error;
224 }
225 
226 /*
227  * ********************************************************************
228  * Initialize sysctl subsystem.
229  * ********************************************************************
230  */
231 void
232 sysctl_init(void)
233 {
234 	sysctl_setup_func * const *sysctl_setup, f;
235 
236 	rw_init(&sysctl_treelock);
237 
238 	/*
239 	 * dynamic mib numbers start here
240 	 */
241 	sysctl_root.sysctl_num = CREATE_BASE;
242 
243         __link_set_foreach(sysctl_setup, sysctl_funcs) {
244 		/*
245 		 * XXX - why do i have to coerce the pointers like this?
246 		 */
247 		f = (void*)*sysctl_setup;
248 		(*f)(NULL);
249 	}
250 
251 	/*
252 	 * setting this means no more permanent nodes can be added,
253 	 * trees that claim to be readonly at the root now are, and if
254 	 * the main tree is readonly, *everything* is.
255 	 */
256 	sysctl_root.sysctl_flags |= CTLFLAG_PERMANENT;
257 
258 }
259 
260 /*
261  * ********************************************************************
262  * The main native sysctl system call itself.
263  * ********************************************************************
264  */
265 int
266 sys___sysctl(struct lwp *l, void *v, register_t *retval)
267 {
268 	struct sys___sysctl_args /* {
269 		syscallarg(const int *) name;
270 		syscallarg(u_int) namelen;
271 		syscallarg(void *) old;
272 		syscallarg(size_t *) oldlenp;
273 		syscallarg(const void *) new;
274 		syscallarg(size_t) newlen;
275 	} */ *uap = v;
276 	int error, nerror, name[CTL_MAXNAME];
277 	size_t oldlen, savelen, *oldlenp;
278 
279 	/*
280 	 * get oldlen
281 	 */
282 	oldlen = 0;
283 	oldlenp = SCARG(uap, oldlenp);
284 	if (oldlenp != NULL) {
285 		error = copyin(oldlenp, &oldlen, sizeof(oldlen));
286 		if (error)
287 			return (error);
288 	}
289 	savelen = oldlen;
290 
291 	/*
292 	 * top-level sysctl names may or may not be non-terminal, but
293 	 * we don't care
294 	 */
295 	if (SCARG(uap, namelen) > CTL_MAXNAME || SCARG(uap, namelen) < 1)
296 		return (EINVAL);
297 	error = copyin(SCARG(uap, name), &name,
298 		       SCARG(uap, namelen) * sizeof(int));
299 	if (error)
300 		return (error);
301 
302 	ktrmib(name, SCARG(uap, namelen));
303 
304 	/*
305 	 * wire old so that copyout() is less likely to fail?
306 	 */
307 	error = sysctl_lock(l, SCARG(uap, old), savelen);
308 	if (error)
309 		return (error);
310 
311 	/*
312 	 * do sysctl work (NULL means main built-in default tree)
313 	 */
314 	error = sysctl_dispatch(&name[0], SCARG(uap, namelen),
315 				SCARG(uap, old), &oldlen,
316 				SCARG(uap, new), SCARG(uap, newlen),
317 				&name[0], l, NULL);
318 
319 	/*
320 	 * release the sysctl lock
321 	 */
322 	sysctl_unlock(l);
323 
324 	/*
325 	 * set caller's oldlen to new value even in the face of an
326 	 * error (if this gets an error and they didn't have one, they
327 	 * get this one)
328 	 */
329 	if (oldlenp) {
330 		nerror = copyout(&oldlen, oldlenp, sizeof(oldlen));
331 		if (error == 0)
332 			error = nerror;
333 	}
334 
335 	/*
336 	 * if the only problem is that we weren't given enough space,
337 	 * that's an ENOMEM error
338 	 */
339 	if (error == 0 && SCARG(uap, old) != NULL && savelen < oldlen)
340 		error = ENOMEM;
341 
342 	return (error);
343 }
344 
345 /*
346  * ********************************************************************
347  * Section 1: How the tree is used
348  * ********************************************************************
349  * Implementations of sysctl for emulations should typically need only
350  * these three functions in this order: lock the tree, dispatch
351  * request into it, unlock the tree.
352  * ********************************************************************
353  */
354 int
355 sysctl_lock(struct lwp *l, void *oldp, size_t savelen)
356 {
357 	int error;
358 
359 	rw_enter(&sysctl_treelock, RW_WRITER);	/* XXX write */
360 
361 	if (l != NULL && oldp != NULL && savelen) {
362 
363 		/*
364 		 * be lazy - memory is locked for short time only, so
365 		 * just do a basic check against system limit
366 		 */
367 
368 		if (uvmexp.wired + atop(savelen) > uvmexp.wiredmax) {
369 			rw_exit(&sysctl_treelock);
370 			return (ENOMEM);
371 		}
372 		error = uvm_vslock(l->l_proc->p_vmspace, oldp, savelen,
373 				   VM_PROT_WRITE);
374 		if (error) {
375 			rw_exit(&sysctl_treelock);
376 			return (error);
377 		}
378 		sysctl_memaddr = oldp;
379 		sysctl_memsize = savelen;
380 	}
381 
382 	return (0);
383 }
384 
385 /*
386  * ********************************************************************
387  * the main sysctl dispatch routine.  scans the given tree and picks a
388  * function to call based on what it finds.
389  * ********************************************************************
390  */
391 int
392 sysctl_dispatch(SYSCTLFN_ARGS)
393 {
394 	int error;
395 	sysctlfn fn;
396 	int ni;
397 
398 	if (rnode && SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
399 		printf("sysctl_dispatch: rnode %p wrong version\n", rnode);
400 		error = EINVAL;
401 		goto out;
402 	}
403 
404 	fn = NULL;
405 	error = sysctl_locate(l, name, namelen, &rnode, &ni);
406 
407 	if (rnode->sysctl_func != NULL) {
408 		/*
409 		 * the node we ended up at has a function, so call it.  it can
410 		 * hand off to query or create if it wants to.
411 		 */
412 		fn = rnode->sysctl_func;
413 	} else if (error == 0) {
414 		/*
415 		 * we found the node they were looking for, so do a lookup.
416 		 */
417 		fn = (sysctlfn)sysctl_lookup; /* XXX may write to rnode */
418 	} else if (error == ENOENT && (ni + 1) == namelen && name[ni] < 0) {
419 		/*
420 		 * prospective parent node found, but the terminal node was
421 		 * not.  generic operations associate with the parent.
422 		 */
423 		switch (name[ni]) {
424 		case CTL_QUERY:
425 			fn = sysctl_query;
426 			break;
427 		case CTL_CREATE:
428 #if NKSYMS > 0
429 		case CTL_CREATESYM:
430 #endif /* NKSYMS > 0 */
431 			fn = (sysctlfn)sysctl_create; /* we own the rnode */
432 			break;
433 		case CTL_DESTROY:
434 			fn = (sysctlfn)sysctl_destroy; /* we own the rnode */
435 			break;
436 		case CTL_MMAP:
437 			fn = (sysctlfn)sysctl_mmap; /* we own the rnode */
438 			break;
439 		case CTL_DESCRIBE:
440 			fn = sysctl_describe;
441 			break;
442 		default:
443 			error = EOPNOTSUPP;
444 			break;
445 		}
446 	}
447 
448 	/*
449 	 * after all of that, maybe we found someone who knows how to
450 	 * get us what we want?
451 	 */
452 	if (fn != NULL)
453 		error = (*fn)(name + ni, namelen - ni, oldp, oldlenp,
454 			      newp, newlen, name, l, rnode);
455 	else if (error == 0)
456 		error = EOPNOTSUPP;
457 
458 out:
459 	return (error);
460 }
461 
462 /*
463  * ********************************************************************
464  * Releases the tree lock.  Note that if uvm_vslock() was called when
465  * the lock was taken, we release that memory now.  By keeping track
466  * of where and how much by ourselves, the lock can be released much
467  * more easily from anywhere.
468  * ********************************************************************
469  */
470 void
471 sysctl_unlock(struct lwp *l)
472 {
473 
474 	if (l != NULL && sysctl_memsize != 0) {
475 		uvm_vsunlock(l->l_proc->p_vmspace, sysctl_memaddr,
476 			     sysctl_memsize);
477 		sysctl_memsize = 0;
478 	}
479 
480 	rw_exit(&sysctl_treelock);	/* XXX write */
481 }
482 
483 /*
484  * ********************************************************************
485  * Section 2: The main tree interfaces
486  * ********************************************************************
487  * This is how sysctl_dispatch() does its work, and you can too, by
488  * calling these routines from helpers (though typically only
489  * sysctl_lookup() will be used).  The tree MUST BE LOCKED when these
490  * are called.
491  * ********************************************************************
492  */
493 
494 /*
495  * sysctl_locate -- Finds the node matching the given mib under the
496  * given tree (via rv).  If no tree is given, we fall back to the
497  * native tree.  The current process (via l) is used for access
498  * control on the tree (some nodes may be traversable only by root) and
499  * on return, nip will show how many numbers in the mib were consumed.
500  */
501 int
502 sysctl_locate(struct lwp *l, const int *name, u_int namelen,
503 	      const struct sysctlnode **rnode, int *nip)
504 {
505 	const struct sysctlnode *node, *pnode;
506 	int tn, si, ni, error, alias;
507 
508 	/*
509 	 * basic checks and setup
510 	 */
511 	if (*rnode == NULL)
512 		*rnode = &sysctl_root;
513 	if (nip)
514 		*nip = 0;
515 	if (namelen == 0)
516 		return (0);
517 
518 	/*
519 	 * search starts from "root"
520 	 */
521 	pnode = *rnode;
522 	if (SYSCTL_VERS(pnode->sysctl_flags) != SYSCTL_VERSION) {
523 		printf("sysctl_locate: pnode %p wrong version\n", pnode);
524 		return (EINVAL);
525 	}
526 	node = pnode->sysctl_child;
527 	error = 0;
528 
529 	/*
530 	 * scan for node to which new node should be attached
531 	 */
532 	for (ni = 0; ni < namelen; ni++) {
533 		/*
534 		 * walked off bottom of tree
535 		 */
536 		if (node == NULL) {
537 			if (SYSCTL_TYPE(pnode->sysctl_flags) == CTLTYPE_NODE)
538 				error = ENOENT;
539 			else
540 				error = ENOTDIR;
541 			break;
542 		}
543 		/*
544 		 * can anyone traverse this node or only root?
545 		 */
546 		if (l != NULL && (pnode->sysctl_flags & CTLFLAG_PRIVATE) &&
547 		    (error = kauth_authorize_system(l->l_cred,
548 		    KAUTH_SYSTEM_SYSCTL, KAUTH_REQ_SYSTEM_SYSCTL_PRVT,
549 		    NULL, NULL, NULL)) != 0)
550 			return (error);
551 		/*
552 		 * find a child node with the right number
553 		 */
554 		tn = name[ni];
555 		alias = 0;
556 
557 		si = 0;
558 		/*
559 		 * Note: ANYNUMBER only matches positive integers.
560 		 * Since ANYNUMBER is only permitted on single-node
561 		 * sub-trees (eg proc), check before the loop and skip
562 		 * it if we can.
563 		 */
564 		if ((node[si].sysctl_flags & CTLFLAG_ANYNUMBER) && (tn >= 0))
565 			goto foundit;
566 		for (; si < pnode->sysctl_clen; si++) {
567 			if (node[si].sysctl_num == tn) {
568 				if (node[si].sysctl_flags & CTLFLAG_ALIAS) {
569 					if (alias++ == 4)
570 						break;
571 					else {
572 						tn = node[si].sysctl_alias;
573 						si = -1;
574 					}
575 				} else
576 					goto foundit;
577 			}
578 		}
579 		/*
580 		 * if we ran off the end, it obviously doesn't exist
581 		 */
582 		error = ENOENT;
583 		break;
584 
585 		/*
586 		 * so far so good, move on down the line
587 		 */
588 	  foundit:
589 		pnode = &node[si];
590 		if (SYSCTL_TYPE(pnode->sysctl_flags) == CTLTYPE_NODE)
591 			node = node[si].sysctl_child;
592 		else
593 			node = NULL;
594 	}
595 
596 	*rnode = pnode;
597 	if (nip)
598 		*nip = ni;
599 
600 	return (error);
601 }
602 
603 /*
604  * sysctl_query -- The auto-discovery engine.  Copies out the structs
605  * describing nodes under the given node and handles overlay trees.
606  */
607 int
608 sysctl_query(SYSCTLFN_ARGS)
609 {
610 	int error, ni, elim, v;
611 	size_t out, left, t;
612 	const struct sysctlnode *enode, *onode;
613 	struct sysctlnode qnode;
614 
615 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
616 		printf("sysctl_query: rnode %p wrong version\n", rnode);
617 		return (EINVAL);
618 	}
619 
620 	if (SYSCTL_TYPE(rnode->sysctl_flags) != CTLTYPE_NODE)
621 		return (ENOTDIR);
622 	if (namelen != 1 || name[0] != CTL_QUERY)
623 		return (EINVAL);
624 
625 	error = 0;
626 	out = 0;
627 	left = *oldlenp;
628 	elim = 0;
629 	enode = NULL;
630 
631 	/*
632 	 * translate the given request to a current node
633 	 */
634 	error = sysctl_cvt_in(l, &v, newp, newlen, &qnode);
635 	if (error)
636 		return (error);
637 
638 	/*
639 	 * if the request specifies a version, check it
640 	 */
641 	if (qnode.sysctl_ver != 0) {
642 		enode = rnode;
643 		if (qnode.sysctl_ver != enode->sysctl_ver &&
644 		    qnode.sysctl_ver != sysctl_rootof(enode)->sysctl_ver)
645 			return (EINVAL);
646 	}
647 
648 	/*
649 	 * process has overlay tree
650 	 */
651 	if (l && l->l_proc->p_emul->e_sysctlovly) {
652 		enode = l->l_proc->p_emul->e_sysctlovly;
653 		elim = (name - oname);
654 		error = sysctl_locate(l, oname, elim, &enode, NULL);
655 		if (error == 0) {
656 			/* ah, found parent in overlay */
657 			elim = enode->sysctl_clen;
658 			enode = enode->sysctl_child;
659 		} else {
660 			error = 0;
661 			elim = 0;
662 			enode = NULL;
663 		}
664 	}
665 
666 	for (ni = 0; ni < rnode->sysctl_clen; ni++) {
667 		onode = &rnode->sysctl_child[ni];
668 		if (enode && enode->sysctl_num == onode->sysctl_num) {
669 			if (SYSCTL_TYPE(enode->sysctl_flags) != CTLTYPE_NODE)
670 				onode = enode;
671 			if (--elim > 0)
672 				enode++;
673 			else
674 				enode = NULL;
675 		}
676 		error = sysctl_cvt_out(l, v, onode, oldp, left, &t);
677 		if (error)
678 			return (error);
679 		if (oldp != NULL)
680 			oldp = (char*)oldp + t;
681 		out += t;
682 		left -= MIN(left, t);
683 	}
684 
685 	/*
686 	 * overlay trees *MUST* be entirely consumed
687 	 */
688 	KASSERT(enode == NULL);
689 
690 	*oldlenp = out;
691 
692 	return (error);
693 }
694 
695 /*
696  * sysctl_create -- Adds a node (the description of which is taken
697  * from newp) to the tree, returning a copy of it in the space pointed
698  * to by oldp.  In the event that the requested slot is already taken
699  * (either by name or by number), the offending node is returned
700  * instead.  Yes, this is complex, but we want to make sure everything
701  * is proper.
702  */
703 #ifdef SYSCTL_DEBUG_CREATE
704 int _sysctl_create(SYSCTLFN_ARGS);
705 int
706 _sysctl_create(SYSCTLFN_ARGS)
707 #else
708 int
709 sysctl_create(SYSCTLFN_ARGS)
710 #endif
711 {
712 	struct sysctlnode nnode, *node, *pnode;
713 	int error, ni, at, nm, type, sz, flags, anum, v;
714 	void *own;
715 
716 	error = 0;
717 	own = NULL;
718 	anum = -1;
719 
720 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
721 		printf("sysctl_create: rnode %p wrong version\n", rnode);
722 		return (EINVAL);
723 	}
724 
725 	if (namelen != 1 || (name[namelen - 1] != CTL_CREATE
726 #if NKSYMS > 0
727 			     && name[namelen - 1] != CTL_CREATESYM
728 #endif /* NKSYMS > 0 */
729 			     ))
730 		return (EINVAL);
731 
732 	/*
733 	 * processes can only add nodes at securelevel 0, must be
734 	 * root, and can't add nodes to a parent that's not writeable
735 	 */
736 	if (l != NULL) {
737 #ifndef SYSCTL_DISALLOW_CREATE
738 		error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
739 		    KAUTH_REQ_SYSTEM_SYSCTL_ADD, NULL, NULL, NULL);
740 		if (error)
741 			return (error);
742 		if (!(rnode->sysctl_flags & CTLFLAG_READWRITE))
743 #endif /* SYSCTL_DISALLOW_CREATE */
744 			return (EPERM);
745 	}
746 
747 	/*
748 	 * nothing can add a node if:
749 	 * we've finished initial set up and
750 	 * the tree itself is not writeable or
751 	 * the entire sysctl system is not writeable
752 	 */
753 	if ((sysctl_root.sysctl_flags & CTLFLAG_PERMANENT) &&
754 	    (!(sysctl_rootof(rnode)->sysctl_flags & CTLFLAG_READWRITE) ||
755 	     !(sysctl_root.sysctl_flags & CTLFLAG_READWRITE)))
756 		return (EPERM);
757 
758 	/*
759 	 * it must be a "node", not a "int" or something
760 	 */
761 	if (SYSCTL_TYPE(rnode->sysctl_flags) != CTLTYPE_NODE)
762 		return (ENOTDIR);
763 	if (rnode->sysctl_flags & CTLFLAG_ALIAS) {
764 		printf("sysctl_create: attempt to add node to aliased "
765 		       "node %p\n", rnode);
766 		return (EINVAL);
767 	}
768 	pnode = __UNCONST(rnode); /* we are adding children to this node */
769 
770 	if (newp == NULL)
771 		return (EINVAL);
772 	error = sysctl_cvt_in(l, &v, newp, newlen, &nnode);
773 	if (error)
774 		return (error);
775 
776 	/*
777 	 * nodes passed in don't *have* parents
778 	 */
779 	if (nnode.sysctl_parent != NULL)
780 		return (EINVAL);
781 
782 	/*
783 	 * if we are indeed adding it, it should be a "good" name and
784 	 * number
785 	 */
786 	nm = nnode.sysctl_num;
787 #if NKSYMS > 0
788 	if (nm == CTL_CREATESYM)
789 		nm = CTL_CREATE;
790 #endif /* NKSYMS > 0 */
791 	if (nm < 0 && nm != CTL_CREATE)
792 		return (EINVAL);
793 	sz = 0;
794 
795 	/*
796 	 * the name can't start with a digit
797 	 */
798 	if (nnode.sysctl_name[sz] >= '0' &&
799 	    nnode.sysctl_name[sz] <= '9')
800 		return (EINVAL);
801 
802 	/*
803 	 * the name must be only alphanumerics or - or _, longer than
804 	 * 0 bytes and less that SYSCTL_NAMELEN
805 	 */
806 	while (sz < SYSCTL_NAMELEN && nnode.sysctl_name[sz] != '\0') {
807 		if ((nnode.sysctl_name[sz] >= '0' &&
808 		     nnode.sysctl_name[sz] <= '9') ||
809 		    (nnode.sysctl_name[sz] >= 'A' &&
810 		     nnode.sysctl_name[sz] <= 'Z') ||
811 		    (nnode.sysctl_name[sz] >= 'a' &&
812 		     nnode.sysctl_name[sz] <= 'z') ||
813 		    nnode.sysctl_name[sz] == '-' ||
814 		    nnode.sysctl_name[sz] == '_')
815 			sz++;
816 		else
817 			return (EINVAL);
818 	}
819 	if (sz == 0 || sz == SYSCTL_NAMELEN)
820 		return (EINVAL);
821 
822 	/*
823 	 * various checks revolve around size vs type, etc
824 	 */
825 	type = SYSCTL_TYPE(nnode.sysctl_flags);
826 	flags = SYSCTL_FLAGS(nnode.sysctl_flags);
827 	sz = nnode.sysctl_size;
828 
829 	/*
830 	 * find out if there's a collision, and if so, let the caller
831 	 * know what they collided with
832 	 */
833 	node = pnode->sysctl_child;
834 	at = 0;
835 	if (node) {
836 		if ((flags | node->sysctl_flags) & CTLFLAG_ANYNUMBER)
837 			/* No siblings for a CTLFLAG_ANYNUMBER node */
838 			return EINVAL;
839 		for (ni = 0; ni < pnode->sysctl_clen; ni++) {
840 			if (nm == node[ni].sysctl_num ||
841 			    strcmp(nnode.sysctl_name, node[ni].sysctl_name) == 0) {
842 				/*
843 				 * ignore error here, since we
844 				 * are already fixed on EEXIST
845 				 */
846 				(void)sysctl_cvt_out(l, v, &node[ni], oldp,
847 						     *oldlenp, oldlenp);
848 				return (EEXIST);
849 			}
850 			if (nm > node[ni].sysctl_num)
851 				at++;
852 		}
853 	}
854 
855 	/*
856 	 * use sysctl_ver to add to the tree iff it hasn't changed
857 	 */
858 	if (nnode.sysctl_ver != 0) {
859 		/*
860 		 * a specified value must match either the parent
861 		 * node's version or the root node's version
862 		 */
863 		if (nnode.sysctl_ver != sysctl_rootof(rnode)->sysctl_ver &&
864 		    nnode.sysctl_ver != rnode->sysctl_ver) {
865 			return (EINVAL);
866 		}
867 	}
868 
869 	/*
870 	 * only the kernel can assign functions to entries
871 	 */
872 	if (l != NULL && nnode.sysctl_func != NULL)
873 		return (EPERM);
874 
875 	/*
876 	 * only the kernel can create permanent entries, and only then
877 	 * before the kernel is finished setting itself up
878 	 */
879 	if (l != NULL && (flags & ~SYSCTL_USERFLAGS))
880 		return (EPERM);
881 	if ((flags & CTLFLAG_PERMANENT) &
882 	    (sysctl_root.sysctl_flags & CTLFLAG_PERMANENT))
883 		return (EPERM);
884 	if ((flags & (CTLFLAG_OWNDATA | CTLFLAG_IMMEDIATE)) ==
885 	    (CTLFLAG_OWNDATA | CTLFLAG_IMMEDIATE))
886 		return (EINVAL);
887 	if ((flags & CTLFLAG_IMMEDIATE) &&
888 	    type != CTLTYPE_INT && type != CTLTYPE_QUAD)
889 		return (EINVAL);
890 
891 	/*
892 	 * check size, or set it if unset and we can figure it out.
893 	 * kernel created nodes are allowed to have a function instead
894 	 * of a size (or a data pointer).
895 	 */
896 	switch (type) {
897 	case CTLTYPE_NODE:
898 		/*
899 		 * only *i* can assert the size of a node
900 		 */
901 		if (flags & CTLFLAG_ALIAS) {
902 			anum = nnode.sysctl_alias;
903 			if (anum < 0)
904 				return (EINVAL);
905 			nnode.sysctl_alias = 0;
906 		}
907 		if (sz != 0 || nnode.sysctl_data != NULL)
908 			return (EINVAL);
909 		if (nnode.sysctl_csize != 0 ||
910 		    nnode.sysctl_clen != 0 ||
911 		    nnode.sysctl_child != 0)
912 			return (EINVAL);
913 		if (flags & CTLFLAG_OWNDATA)
914 			return (EINVAL);
915 		sz = sizeof(struct sysctlnode);
916 		break;
917 	case CTLTYPE_INT:
918 		/*
919 		 * since an int is an int, if the size is not given or
920 		 * is wrong, we can "int-uit" it.
921 		 */
922 		if (sz != 0 && sz != sizeof(int))
923 			return (EINVAL);
924 		sz = sizeof(int);
925 		break;
926 	case CTLTYPE_STRING:
927 		/*
928 		 * strings are a little more tricky
929 		 */
930 		if (sz == 0) {
931 			if (l == NULL) {
932 				if (nnode.sysctl_func == NULL) {
933 					if (nnode.sysctl_data == NULL)
934 						return (EINVAL);
935 					else
936 						sz = strlen(nnode.sysctl_data) +
937 						    1;
938 				}
939 			} else if (nnode.sysctl_data == NULL &&
940 				 flags & CTLFLAG_OWNDATA) {
941 				return (EINVAL);
942 			} else {
943 				char *vp, *e;
944 				size_t s;
945 
946 				/*
947 				 * we want a rough idea of what the
948 				 * size is now
949 				 */
950 				vp = malloc(PAGE_SIZE, M_SYSCTLDATA,
951 					     M_WAITOK|M_CANFAIL);
952 				if (vp == NULL)
953 					return (ENOMEM);
954 				e = nnode.sysctl_data;
955 				do {
956 					error = copyinstr(e, vp, PAGE_SIZE, &s);
957 					if (error) {
958 						if (error != ENAMETOOLONG) {
959 							free(vp, M_SYSCTLDATA);
960 							return (error);
961 						}
962 						e += PAGE_SIZE;
963 						if ((e - 32 * PAGE_SIZE) >
964 						    (char*)nnode.sysctl_data) {
965 							free(vp, M_SYSCTLDATA);
966 							return (ERANGE);
967 						}
968 					}
969 				} while (error != 0);
970 				sz = s + (e - (char*)nnode.sysctl_data);
971 				free(vp, M_SYSCTLDATA);
972 			}
973 		}
974 		break;
975 	case CTLTYPE_QUAD:
976 		if (sz != 0 && sz != sizeof(u_quad_t))
977 			return (EINVAL);
978 		sz = sizeof(u_quad_t);
979 		break;
980 	case CTLTYPE_STRUCT:
981 		if (sz == 0) {
982 			if (l != NULL || nnode.sysctl_func == NULL)
983 				return (EINVAL);
984 			if (flags & CTLFLAG_OWNDATA)
985 				return (EINVAL);
986 		}
987 		break;
988 	default:
989 		return (EINVAL);
990 	}
991 
992 	/*
993 	 * at this point, if sz is zero, we *must* have a
994 	 * function to go with it and we can't own it.
995 	 */
996 
997 	/*
998 	 *  l  ptr own
999 	 *  0   0   0  -> EINVAL (if no func)
1000 	 *  0   0   1  -> own
1001 	 *  0   1   0  -> kptr
1002 	 *  0   1   1  -> kptr
1003 	 *  1   0   0  -> EINVAL
1004 	 *  1   0   1  -> own
1005 	 *  1   1   0  -> kptr, no own (fault on lookup)
1006 	 *  1   1   1  -> uptr, own
1007 	 */
1008 	if (type != CTLTYPE_NODE) {
1009 		if (sz != 0) {
1010 			if (flags & CTLFLAG_OWNDATA) {
1011 				own = malloc(sz, M_SYSCTLDATA,
1012 					     M_WAITOK|M_CANFAIL);
1013 				if (own == NULL)
1014 					return ENOMEM;
1015 				if (nnode.sysctl_data == NULL)
1016 					memset(own, 0, sz);
1017 				else {
1018 					error = sysctl_copyin(l,
1019 					    nnode.sysctl_data, own, sz);
1020 					if (error != 0) {
1021 						free(own, M_SYSCTLDATA);
1022 						return (error);
1023 					}
1024 				}
1025 			} else if ((nnode.sysctl_data != NULL) &&
1026 				 !(flags & CTLFLAG_IMMEDIATE)) {
1027 #if NKSYMS > 0
1028 				if (name[namelen - 1] == CTL_CREATESYM) {
1029 					char symname[128]; /* XXX enough? */
1030 					u_long symaddr;
1031 					size_t symlen;
1032 
1033 					error = sysctl_copyinstr(l,
1034 					    nnode.sysctl_data, symname,
1035 					    sizeof(symname), &symlen);
1036 					if (error)
1037 						return (error);
1038 					error = ksyms_getval(NULL, symname,
1039 					    &symaddr, KSYMS_EXTERN);
1040 					if (error)
1041 						return (error); /* EINVAL? */
1042 					nnode.sysctl_data = (void*)symaddr;
1043 				}
1044 #endif /* NKSYMS > 0 */
1045 				/*
1046 				 * Ideally, we'd like to verify here
1047 				 * that this address is acceptable,
1048 				 * but...
1049 				 *
1050 				 * - it might be valid now, only to
1051 				 *   become invalid later
1052 				 *
1053 				 * - it might be invalid only for the
1054 				 *   moment and valid later
1055 				 *
1056 				 * - or something else.
1057 				 *
1058 				 * Since we can't get a good answer,
1059 				 * we'll just accept the address as
1060 				 * given, and fault on individual
1061 				 * lookups.
1062 				 */
1063 			}
1064 		} else if (nnode.sysctl_func == NULL)
1065 			return (EINVAL);
1066 	}
1067 
1068 	/*
1069 	 * a process can't assign a function to a node, and the kernel
1070 	 * can't create a node that has no function or data.
1071 	 * (XXX somewhat redundant check)
1072 	 */
1073 	if (l != NULL || nnode.sysctl_func == NULL) {
1074 		if (type != CTLTYPE_NODE &&
1075 		    nnode.sysctl_data == NULL &&
1076 		    !(flags & CTLFLAG_IMMEDIATE) &&
1077 		    own == NULL)
1078 			return (EINVAL);
1079 	}
1080 
1081 #ifdef SYSCTL_DISALLOW_KWRITE
1082 	/*
1083 	 * a process can't create a writable node unless it refers to
1084 	 * new data.
1085 	 */
1086 	if (l != NULL && own == NULL && type != CTLTYPE_NODE &&
1087 	    (flags & CTLFLAG_READWRITE) != CTLFLAG_READONLY &&
1088 	    !(flags & CTLFLAG_IMMEDIATE))
1089 		return (EPERM);
1090 #endif /* SYSCTL_DISALLOW_KWRITE */
1091 
1092 	/*
1093 	 * make sure there's somewhere to put the new stuff.
1094 	 */
1095 	if (pnode->sysctl_child == NULL) {
1096 		if (flags & CTLFLAG_ANYNUMBER)
1097 			error = sysctl_alloc(pnode, 1);
1098 		else
1099 			error = sysctl_alloc(pnode, 0);
1100 		if (error) {
1101 			if (own != NULL)
1102 				free(own, M_SYSCTLDATA);
1103 			return (error);
1104 		}
1105 	}
1106 	node = pnode->sysctl_child;
1107 
1108 	/*
1109 	 * no collisions, so pick a good dynamic number if we need to.
1110 	 */
1111 	if (nm == CTL_CREATE) {
1112 		nm = ++sysctl_root.sysctl_num;
1113 		for (ni = 0; ni < pnode->sysctl_clen; ni++) {
1114 			if (nm == node[ni].sysctl_num) {
1115 				nm++;
1116 				ni = -1;
1117 			} else if (nm > node[ni].sysctl_num)
1118 				at = ni + 1;
1119 		}
1120 	}
1121 
1122 	/*
1123 	 * oops...ran out of space
1124 	 */
1125 	if (pnode->sysctl_clen == pnode->sysctl_csize) {
1126 		error = sysctl_realloc(pnode);
1127 		if (error) {
1128 			if (own != NULL)
1129 				free(own, M_SYSCTLDATA);
1130 			return (error);
1131 		}
1132 		node = pnode->sysctl_child;
1133 	}
1134 
1135 	/*
1136 	 * insert new node data
1137 	 */
1138 	if (at < pnode->sysctl_clen) {
1139 		int t;
1140 
1141 		/*
1142 		 * move the nodes that should come after the new one
1143 		 */
1144 		memmove(&node[at + 1], &node[at],
1145 			(pnode->sysctl_clen - at) * sizeof(struct sysctlnode));
1146 		memset(&node[at], 0, sizeof(struct sysctlnode));
1147 		node[at].sysctl_parent = pnode;
1148 		/*
1149 		 * and...reparent any children of any moved nodes
1150 		 */
1151 		for (ni = at; ni <= pnode->sysctl_clen; ni++)
1152 			if (SYSCTL_TYPE(node[ni].sysctl_flags) == CTLTYPE_NODE)
1153 				for (t = 0; t < node[ni].sysctl_clen; t++)
1154 					node[ni].sysctl_child[t].sysctl_parent =
1155 						&node[ni];
1156 	}
1157 	node = &node[at];
1158 	pnode->sysctl_clen++;
1159 
1160 	strlcpy(node->sysctl_name, nnode.sysctl_name,
1161 		sizeof(node->sysctl_name));
1162 	node->sysctl_num = nm;
1163 	node->sysctl_size = sz;
1164 	node->sysctl_flags = SYSCTL_VERSION|type|flags; /* XXX other trees */
1165 	node->sysctl_csize = 0;
1166 	node->sysctl_clen = 0;
1167 	if (own) {
1168 		node->sysctl_data = own;
1169 		node->sysctl_flags |= CTLFLAG_OWNDATA;
1170 	} else if (flags & CTLFLAG_ALIAS) {
1171 		node->sysctl_alias = anum;
1172 	} else if (flags & CTLFLAG_IMMEDIATE) {
1173 		switch (type) {
1174 		case CTLTYPE_INT:
1175 			node->sysctl_idata = nnode.sysctl_idata;
1176 			break;
1177 		case CTLTYPE_QUAD:
1178 			node->sysctl_qdata = nnode.sysctl_qdata;
1179 			break;
1180 		}
1181 	} else {
1182 		node->sysctl_data = nnode.sysctl_data;
1183 		node->sysctl_flags &= ~CTLFLAG_OWNDATA;
1184 	}
1185         node->sysctl_func = nnode.sysctl_func;
1186         node->sysctl_child = NULL;
1187 	/* node->sysctl_parent should already be done */
1188 
1189 	/*
1190 	 * update "version" on path to "root"
1191 	 */
1192 	for (; rnode->sysctl_parent != NULL; rnode = rnode->sysctl_parent)
1193 		;
1194 	pnode = node;
1195 	for (nm = rnode->sysctl_ver + 1; pnode != NULL;
1196 	     pnode = pnode->sysctl_parent)
1197 		pnode->sysctl_ver = nm;
1198 
1199 	/* If this fails, the node is already added - the user won't know! */
1200 	error = sysctl_cvt_out(l, v, node, oldp, *oldlenp, oldlenp);
1201 
1202 	return (error);
1203 }
1204 
1205 /*
1206  * ********************************************************************
1207  * A wrapper around sysctl_create() that prints the thing we're trying
1208  * to add.
1209  * ********************************************************************
1210  */
1211 #ifdef SYSCTL_DEBUG_CREATE
1212 int
1213 sysctl_create(SYSCTLFN_ARGS)
1214 {
1215 	const struct sysctlnode *node;
1216 	int k, rc, ni, nl = namelen + (name - oname);
1217 
1218 	node = newp;
1219 
1220 	printf("namelen %d (", nl);
1221 	for (ni = 0; ni < nl - 1; ni++)
1222 		printf(" %d", oname[ni]);
1223 	printf(" %d )\t[%s]\tflags %08x (%08x %d %zu)\n",
1224 	       k = node->sysctl_num,
1225 	       node->sysctl_name,
1226 	       node->sysctl_flags,
1227 	       SYSCTL_FLAGS(node->sysctl_flags),
1228 	       SYSCTL_TYPE(node->sysctl_flags),
1229 	       node->sysctl_size);
1230 
1231 	node = rnode;
1232 	rc = _sysctl_create(SYSCTLFN_CALL(rnode));
1233 
1234 	printf("sysctl_create(");
1235 	for (ni = 0; ni < nl - 1; ni++)
1236 		printf(" %d", oname[ni]);
1237 	printf(" %d ) returned %d\n", k, rc);
1238 
1239 	return (rc);
1240 }
1241 #endif /* SYSCTL_DEBUG_CREATE */
1242 
1243 /*
1244  * sysctl_destroy -- Removes a node (as described by newp) from the
1245  * given tree, returning (if successful) a copy of the dead node in
1246  * oldp.  Since we're removing stuff, there's not much to check.
1247  */
1248 int
1249 sysctl_destroy(SYSCTLFN_ARGS)
1250 {
1251 	struct sysctlnode *node, *pnode, onode, nnode;
1252 	int ni, error, v;
1253 
1254 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1255 		printf("sysctl_destroy: rnode %p wrong version\n", rnode);
1256 		return (EINVAL);
1257 	}
1258 
1259 	error = 0;
1260 
1261 	if (namelen != 1 || name[namelen - 1] != CTL_DESTROY)
1262 		return (EINVAL);
1263 
1264 	/*
1265 	 * processes can only destroy nodes at securelevel 0, must be
1266 	 * root, and can't remove nodes from a parent that's not
1267 	 * writeable
1268 	 */
1269 	if (l != NULL) {
1270 #ifndef SYSCTL_DISALLOW_CREATE
1271 		error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
1272 		    KAUTH_REQ_SYSTEM_SYSCTL_DELETE, NULL, NULL, NULL);
1273 		if (error)
1274 			return (error);
1275 		if (!(rnode->sysctl_flags & CTLFLAG_READWRITE))
1276 #endif /* SYSCTL_DISALLOW_CREATE */
1277 			return (EPERM);
1278 	}
1279 
1280 	/*
1281 	 * nothing can remove a node if:
1282 	 * the node is permanent (checked later) or
1283 	 * the tree itself is not writeable or
1284 	 * the entire sysctl system is not writeable
1285 	 *
1286 	 * note that we ignore whether setup is complete or not,
1287 	 * because these rules always apply.
1288 	 */
1289 	if (!(sysctl_rootof(rnode)->sysctl_flags & CTLFLAG_READWRITE) ||
1290 	    !(sysctl_root.sysctl_flags & CTLFLAG_READWRITE))
1291 		return (EPERM);
1292 
1293 	if (newp == NULL)
1294 		return (EINVAL);
1295 	error = sysctl_cvt_in(l, &v, newp, newlen, &nnode);
1296 	if (error)
1297 		return (error);
1298 	memset(&onode, 0, sizeof(struct sysctlnode));
1299 
1300 	node = rnode->sysctl_child;
1301 	for (ni = 0; ni < rnode->sysctl_clen; ni++) {
1302 		if (nnode.sysctl_num == node[ni].sysctl_num) {
1303 			/*
1304 			 * if name specified, must match
1305 			 */
1306 			if (nnode.sysctl_name[0] != '\0' &&
1307 			    strcmp(nnode.sysctl_name, node[ni].sysctl_name))
1308 				continue;
1309 			/*
1310 			 * if version specified, must match
1311 			 */
1312 			if (nnode.sysctl_ver != 0 &&
1313 			    nnode.sysctl_ver != node[ni].sysctl_ver)
1314 				continue;
1315 			/*
1316 			 * this must be the one
1317 			 */
1318 			break;
1319 		}
1320 	}
1321 	if (ni == rnode->sysctl_clen)
1322 		return (ENOENT);
1323 	node = &node[ni];
1324 	pnode = node->sysctl_parent;
1325 
1326 	/*
1327 	 * if the kernel says permanent, it is, so there.  nyah.
1328 	 */
1329 	if (SYSCTL_FLAGS(node->sysctl_flags) & CTLFLAG_PERMANENT)
1330 		return (EPERM);
1331 
1332 	/*
1333 	 * can't delete non-empty nodes
1334 	 */
1335 	if (SYSCTL_TYPE(node->sysctl_flags) == CTLTYPE_NODE &&
1336 	    node->sysctl_clen != 0)
1337 		return (ENOTEMPTY);
1338 
1339 	/*
1340 	 * if the node "owns" data, release it now
1341 	 */
1342 	if (node->sysctl_flags & CTLFLAG_OWNDATA) {
1343 		if (node->sysctl_data != NULL)
1344 			free(node->sysctl_data, M_SYSCTLDATA);
1345 		node->sysctl_data = NULL;
1346 	}
1347 	if (node->sysctl_flags & CTLFLAG_OWNDESC) {
1348 		if (node->sysctl_desc != NULL)
1349 			/*XXXUNCONST*/
1350 			free(__UNCONST(node->sysctl_desc), M_SYSCTLDATA);
1351 		node->sysctl_desc = NULL;
1352 	}
1353 
1354 	/*
1355 	 * if the node to be removed is not the last one on the list,
1356 	 * move the remaining nodes up, and reparent any grandchildren
1357 	 */
1358 	onode = *node;
1359 	if (ni < pnode->sysctl_clen - 1) {
1360 		int t;
1361 
1362 		memmove(&pnode->sysctl_child[ni], &pnode->sysctl_child[ni + 1],
1363 			(pnode->sysctl_clen - ni - 1) *
1364 			sizeof(struct sysctlnode));
1365 		for (; ni < pnode->sysctl_clen - 1; ni++)
1366 			if (SYSCTL_TYPE(pnode->sysctl_child[ni].sysctl_flags) ==
1367 			    CTLTYPE_NODE)
1368 				for (t = 0;
1369 				     t < pnode->sysctl_child[ni].sysctl_clen;
1370 				     t++)
1371 					pnode->sysctl_child[ni].sysctl_child[t].
1372 						sysctl_parent =
1373 						&pnode->sysctl_child[ni];
1374 		ni = pnode->sysctl_clen - 1;
1375 		node = &pnode->sysctl_child[ni];
1376 	}
1377 
1378 	/*
1379 	 * reset the space we just vacated
1380 	 */
1381 	memset(node, 0, sizeof(struct sysctlnode));
1382 	node->sysctl_parent = pnode;
1383 	pnode->sysctl_clen--;
1384 
1385 	/*
1386 	 * if this parent just lost its last child, nuke the creche
1387 	 */
1388 	if (pnode->sysctl_clen == 0) {
1389 		free(pnode->sysctl_child, M_SYSCTLNODE);
1390 		pnode->sysctl_csize = 0;
1391 		pnode->sysctl_child = NULL;
1392 	}
1393 
1394 	/*
1395 	 * update "version" on path to "root"
1396 	 */
1397         for (; rnode->sysctl_parent != NULL; rnode = rnode->sysctl_parent)
1398                 ;
1399 	for (ni = rnode->sysctl_ver + 1; pnode != NULL;
1400 	     pnode = pnode->sysctl_parent)
1401 		pnode->sysctl_ver = ni;
1402 
1403 	error = sysctl_cvt_out(l, v, &onode, oldp, *oldlenp, oldlenp);
1404 
1405 	return (error);
1406 }
1407 
1408 /*
1409  * sysctl_lookup -- Handles copyin/copyout of new and old values.
1410  * Partial reads are globally allowed.  Only root can write to things
1411  * unless the node says otherwise.
1412  */
1413 int
1414 sysctl_lookup(SYSCTLFN_ARGS)
1415 {
1416 	int error, rw;
1417 	size_t sz, len;
1418 	void *d;
1419 
1420 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1421 		printf("sysctl_lookup: rnode %p wrong version\n", rnode);
1422 		return (EINVAL);
1423 	}
1424 
1425 	error = 0;
1426 
1427 	/*
1428 	 * you can't "look up" a node.  you can "query" it, but you
1429 	 * can't "look it up".
1430 	 */
1431 	if (SYSCTL_TYPE(rnode->sysctl_flags) == CTLTYPE_NODE || namelen != 0)
1432 		return (EINVAL);
1433 
1434 	/*
1435 	 * some nodes are private, so only root can look into them.
1436 	 */
1437 	if (l != NULL && (rnode->sysctl_flags & CTLFLAG_PRIVATE) &&
1438 	    (error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
1439 	    KAUTH_REQ_SYSTEM_SYSCTL_PRVT, NULL, NULL, NULL)) != 0)
1440 		return (error);
1441 
1442 	/*
1443 	 * if a node wants to be writable according to different rules
1444 	 * other than "only root can write to stuff unless a flag is
1445 	 * set", then it needs its own function which should have been
1446 	 * called and not us.
1447 	 */
1448 	if (l != NULL && newp != NULL &&
1449 	    !(rnode->sysctl_flags & CTLFLAG_ANYWRITE) &&
1450 	    (error = kauth_authorize_generic(l->l_cred,
1451 	    KAUTH_GENERIC_ISSUSER, NULL)) != 0)
1452 		return (error);
1453 
1454 	/*
1455 	 * is this node supposedly writable?
1456 	 */
1457 	rw = (rnode->sysctl_flags & CTLFLAG_READWRITE) ? 1 : 0;
1458 
1459 	/*
1460 	 * it appears not to be writable at this time, so if someone
1461 	 * tried to write to it, we must tell them to go away
1462 	 */
1463 	if (!rw && newp != NULL)
1464 		return (EPERM);
1465 
1466 	/*
1467 	 * step one, copy out the stuff we have presently
1468 	 */
1469 	if (rnode->sysctl_flags & CTLFLAG_IMMEDIATE) {
1470 		/*
1471 		 * note that we discard const here because we are
1472 		 * modifying the contents of the node (which is okay
1473 		 * because it's ours)
1474 		 */
1475 		switch (SYSCTL_TYPE(rnode->sysctl_flags)) {
1476 		case CTLTYPE_INT:
1477 			d = __UNCONST(&rnode->sysctl_idata);
1478 			break;
1479 		case CTLTYPE_QUAD:
1480 			d = __UNCONST(&rnode->sysctl_qdata);
1481 			break;
1482 		default:
1483 			return (EINVAL);
1484 		}
1485 	} else
1486 		d = rnode->sysctl_data;
1487 	if (SYSCTL_TYPE(rnode->sysctl_flags) == CTLTYPE_STRING)
1488 		sz = strlen(d) + 1; /* XXX@@@ possible fault here */
1489 	else
1490 		sz = rnode->sysctl_size;
1491 	if (oldp != NULL)
1492 		error = sysctl_copyout(l, d, oldp, MIN(sz, *oldlenp));
1493 	if (error)
1494 		return (error);
1495 	*oldlenp = sz;
1496 
1497 	/*
1498 	 * are we done?
1499 	 */
1500 	if (newp == NULL || newlen == 0)
1501 		return (0);
1502 
1503 	/*
1504 	 * hmm...not done.  must now "copy in" new value.  re-adjust
1505 	 * sz to maximum value (strings are "weird").
1506 	 */
1507 	sz = rnode->sysctl_size;
1508 	switch (SYSCTL_TYPE(rnode->sysctl_flags)) {
1509 	case CTLTYPE_INT:
1510 	case CTLTYPE_QUAD:
1511 	case CTLTYPE_STRUCT:
1512 		/*
1513 		 * these data must be *exactly* the same size coming
1514 		 * in.
1515 		 */
1516 		if (newlen != sz)
1517 			return (EINVAL);
1518 		error = sysctl_copyin(l, newp, d, sz);
1519 		break;
1520 	case CTLTYPE_STRING: {
1521 		/*
1522 		 * strings, on the other hand, can be shorter, and we
1523 		 * let userland be sloppy about the trailing nul.
1524 		 */
1525 		char *newbuf;
1526 
1527 		/*
1528 		 * too much new string?
1529 		 */
1530 		if (newlen > sz)
1531 			return (EINVAL);
1532 
1533 		/*
1534 		 * temporary copy of new inbound string
1535 		 */
1536 		len = MIN(sz, newlen);
1537 		newbuf = malloc(len, M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
1538 		if (newbuf == NULL)
1539 			return (ENOMEM);
1540 		error = sysctl_copyin(l, newp, newbuf, len);
1541 		if (error) {
1542 			free(newbuf, M_SYSCTLDATA);
1543 			return (error);
1544 		}
1545 
1546 		/*
1547 		 * did they null terminate it, or do we have space
1548 		 * left to do it ourselves?
1549 		 */
1550 		if (newbuf[len - 1] != '\0' && len == sz) {
1551 			free(newbuf, M_SYSCTLDATA);
1552 			return (EINVAL);
1553 		}
1554 
1555 		/*
1556 		 * looks good, so pop it into place and zero the rest.
1557 		 */
1558 		if (len > 0)
1559 			memcpy(d, newbuf, len);
1560 		if (sz != len)
1561 			memset((char*)d + len, 0, sz - len);
1562 		free(newbuf, M_SYSCTLDATA);
1563 		break;
1564 	}
1565 	default:
1566 		return (EINVAL);
1567 	}
1568 
1569 	return (error);
1570 }
1571 
1572 /*
1573  * sysctl_mmap -- Dispatches sysctl mmap requests to those nodes that
1574  * purport to handle it.  This interface isn't fully fleshed out yet,
1575  * unfortunately.
1576  */
1577 static int
1578 sysctl_mmap(SYSCTLFN_ARGS)
1579 {
1580 	const struct sysctlnode *node;
1581 	struct sysctlnode nnode;
1582 	int error;
1583 
1584 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1585 		printf("sysctl_mmap: rnode %p wrong version\n", rnode);
1586 		return (EINVAL);
1587 	}
1588 
1589 	/*
1590 	 * let's just pretend that didn't happen, m'kay?
1591 	 */
1592 	if (l == NULL)
1593 		return (EPERM);
1594 
1595 	/*
1596 	 * is this a sysctlnode description of an mmap request?
1597 	 */
1598 	if (newp == NULL || newlen != sizeof(struct sysctlnode))
1599 		return (EINVAL);
1600 	error = sysctl_copyin(l, newp, &nnode, sizeof(nnode));
1601 	if (error)
1602 		return (error);
1603 
1604 	/*
1605 	 * does the node they asked for exist?
1606 	 */
1607 	if (namelen != 1)
1608 		return (EOPNOTSUPP);
1609 	node = rnode;
1610         error = sysctl_locate(l, &nnode.sysctl_num, 1, &node, NULL);
1611 	if (error)
1612 		return (error);
1613 
1614 	/*
1615 	 * does this node that we have found purport to handle mmap?
1616 	 */
1617 	if (node->sysctl_func == NULL ||
1618 	    !(node->sysctl_flags & CTLFLAG_MMAP))
1619 		return (EOPNOTSUPP);
1620 
1621 	/*
1622 	 * well...okay, they asked for it.
1623 	 */
1624 	return ((*node->sysctl_func)(SYSCTLFN_CALL(node)));
1625 }
1626 
1627 int
1628 sysctl_describe(SYSCTLFN_ARGS)
1629 {
1630 	struct sysctldesc *d;
1631 	void *bf;
1632 	size_t sz, left, tot;
1633 	int i, error, v = -1;
1634 	struct sysctlnode *node;
1635 	struct sysctlnode dnode;
1636 
1637 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1638 		printf("sysctl_query: rnode %p wrong version\n", rnode);
1639 		return (EINVAL);
1640 	}
1641 
1642 	if (SYSCTL_TYPE(rnode->sysctl_flags) != CTLTYPE_NODE)
1643 		return (ENOTDIR);
1644 	if (namelen != 1 || name[0] != CTL_DESCRIBE)
1645 		return (EINVAL);
1646 
1647 	/*
1648 	 * get ready...
1649 	 */
1650 	error = 0;
1651 	d = bf = malloc(MAXDESCLEN, M_TEMP, M_WAITOK|M_CANFAIL);
1652 	if (bf == NULL)
1653 		return ENOMEM;
1654 	tot = 0;
1655 	node = rnode->sysctl_child;
1656 	left = *oldlenp;
1657 
1658 	/*
1659 	 * no request -> all descriptions at this level
1660 	 * request with desc unset -> just this node
1661 	 * request with desc set -> set descr for this node
1662 	 */
1663 	if (newp != NULL) {
1664 		error = sysctl_cvt_in(l, &v, newp, newlen, &dnode);
1665 		if (error)
1666 			goto out;
1667 		if (dnode.sysctl_desc != NULL) {
1668 			/*
1669 			 * processes cannot set descriptions above
1670 			 * securelevel 0.  and must be root.  blah
1671 			 * blah blah.  a couple more checks are made
1672 			 * once we find the node we want.
1673 			 */
1674 			if (l != NULL) {
1675 #ifndef SYSCTL_DISALLOW_CREATE
1676 				error = kauth_authorize_system(l->l_cred,
1677 				    KAUTH_SYSTEM_SYSCTL,
1678 				    KAUTH_REQ_SYSTEM_SYSCTL_DESC, NULL,
1679 				    NULL, NULL);
1680 				if (error)
1681 					goto out;
1682 #else /* SYSCTL_DISALLOW_CREATE */
1683 				error = EPERM;
1684 				goto out;
1685 #endif /* SYSCTL_DISALLOW_CREATE */
1686 			}
1687 
1688 			/*
1689 			 * find node and try to set the description on it
1690 			 */
1691 			for (i = 0; i < rnode->sysctl_clen; i++)
1692 				if (node[i].sysctl_num == dnode.sysctl_num)
1693 					break;
1694 			if (i == rnode->sysctl_clen) {
1695 				error = ENOENT;
1696 				goto out;
1697 			}
1698 			node = &node[i];
1699 
1700 			/*
1701 			 * did the caller specify a node version?
1702 			 */
1703 			if (dnode.sysctl_ver != 0 &&
1704 			    dnode.sysctl_ver != node->sysctl_ver) {
1705 				error = EINVAL;
1706 				goto out;
1707 			}
1708 
1709 			/*
1710 			 * okay...some rules:
1711 			 * (1) if setup is done and the tree is
1712 			 *     read-only or the whole system is
1713 			 *     read-only
1714 			 * (2) no one can set a description on a
1715 			 *     permanent node (it must be set when
1716 			 *     using createv)
1717 			 * (3) processes cannot *change* a description
1718 			 * (4) processes *can*, however, set a
1719 			 *     description on a read-only node so that
1720 			 *     one can be created and then described
1721 			 *     in two steps
1722 			 * anything else come to mind?
1723 			 */
1724 			if ((sysctl_root.sysctl_flags & CTLFLAG_PERMANENT) &&
1725 			    (!(sysctl_rootof(node)->sysctl_flags &
1726 			       CTLFLAG_READWRITE) ||
1727 			     !(sysctl_root.sysctl_flags & CTLFLAG_READWRITE))) {
1728 				error = EPERM;
1729 				goto out;
1730 			}
1731 			if (node->sysctl_flags & CTLFLAG_PERMANENT) {
1732 				error = EPERM;
1733 				goto out;
1734 			}
1735 			if (l != NULL && node->sysctl_desc != NULL) {
1736 				error = EPERM;
1737 				goto out;
1738 			}
1739 
1740 			/*
1741 			 * right, let's go ahead.  the first step is
1742 			 * making the description into something the
1743 			 * node can "own", if need be.
1744 			 */
1745 			if (l != NULL ||
1746 			    dnode.sysctl_flags & CTLFLAG_OWNDESC) {
1747 				char *nd, *k;
1748 
1749 				k = malloc(MAXDESCLEN, M_TEMP,
1750 				    M_WAITOK|M_CANFAIL);
1751 				if (k == NULL) {
1752 					error = ENOMEM;
1753 					goto out;
1754 				}
1755 				error = sysctl_copyinstr(l, dnode.sysctl_desc,
1756 							 k, MAXDESCLEN, &sz);
1757 				if (error) {
1758 					free(k, M_TEMP);
1759 					goto out;
1760 				}
1761 				nd = malloc(sz, M_SYSCTLDATA,
1762 					    M_WAITOK|M_CANFAIL);
1763 				if (nd == NULL) {
1764 					free(k, M_TEMP);
1765 					error = ENOMEM;
1766 					goto out;
1767 				}
1768 				memcpy(nd, k, sz);
1769 				dnode.sysctl_flags |= CTLFLAG_OWNDESC;
1770 				dnode.sysctl_desc = nd;
1771 				free(k, M_TEMP);
1772 			}
1773 
1774 			/*
1775 			 * now "release" the old description and
1776 			 * attach the new one.  ta-da.
1777 			 */
1778 			if ((node->sysctl_flags & CTLFLAG_OWNDESC) &&
1779 			    node->sysctl_desc != NULL)
1780 				/*XXXUNCONST*/
1781 				free(__UNCONST(node->sysctl_desc), M_SYSCTLDATA);
1782 			node->sysctl_desc = dnode.sysctl_desc;
1783 			node->sysctl_flags |=
1784 				(dnode.sysctl_flags & CTLFLAG_OWNDESC);
1785 
1786 			/*
1787 			 * now we "fall out" and into the loop which
1788 			 * will copy the new description back out for
1789 			 * those interested parties
1790 			 */
1791 		}
1792 	}
1793 
1794 	/*
1795 	 * scan for one description or just retrieve all descriptions
1796 	 */
1797 	for (i = 0; i < rnode->sysctl_clen; i++) {
1798 		/*
1799 		 * did they ask for the description of only one node?
1800 		 */
1801 		if (v != -1 && node[i].sysctl_num != dnode.sysctl_num)
1802 			continue;
1803 
1804 		/*
1805 		 * don't describe "private" nodes to non-suser users
1806 		 */
1807 		if ((node[i].sysctl_flags & CTLFLAG_PRIVATE) && (l != NULL) &&
1808 		    !(kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
1809 		    KAUTH_REQ_SYSTEM_SYSCTL_PRVT, NULL, NULL, NULL)))
1810 			continue;
1811 
1812 		/*
1813 		 * is this description "valid"?
1814 		 */
1815 		memset(bf, 0, MAXDESCLEN);
1816 		if (node[i].sysctl_desc == NULL)
1817 			sz = 1;
1818 		else if (copystr(node[i].sysctl_desc, &d->descr_str[0],
1819 				 MAXDESCLEN - sizeof(*d), &sz) != 0) {
1820 			/*
1821 			 * erase possible partial description
1822 			 */
1823 			memset(bf, 0, MAXDESCLEN);
1824 			sz = 1;
1825 		}
1826 
1827 		/*
1828 		 * we've got it, stuff it into the caller's buffer
1829 		 */
1830 		d->descr_num = node[i].sysctl_num;
1831 		d->descr_ver = node[i].sysctl_ver;
1832 		d->descr_len = sz; /* includes trailing nul */
1833 		sz = (char *)NEXT_DESCR(d) - (char *)d;
1834 		if (oldp != NULL && left >= sz) {
1835 			error = sysctl_copyout(l, d, oldp, sz);
1836 			if (error)
1837 				goto out;
1838 			left -= sz;
1839 			oldp = (void *)__sysc_desc_adv(oldp, d->descr_len);
1840 		}
1841 		tot += sz;
1842 
1843 		/*
1844 		 * if we get this far with v not "unset", they asked
1845 		 * for a specific node and we found it
1846 		 */
1847 		if (v != -1)
1848 			break;
1849 	}
1850 
1851 	/*
1852 	 * did we find it after all?
1853 	 */
1854 	if (v != -1 && tot == 0)
1855 		error = ENOENT;
1856 	else
1857 		*oldlenp = tot;
1858 
1859 out:
1860 	free(bf, M_TEMP);
1861 	return (error);
1862 }
1863 
1864 /*
1865  * ********************************************************************
1866  * Section 3: Create and destroy from inside the kernel
1867  * ********************************************************************
1868  * sysctl_createv() and sysctl_destroyv() are simpler-to-use
1869  * interfaces for the kernel to fling new entries into the mib and rip
1870  * them out later.  In the case of sysctl_createv(), the returned copy
1871  * of the node (see sysctl_create()) will be translated back into a
1872  * pointer to the actual node.
1873  *
1874  * Note that sysctl_createv() will return 0 if the create request
1875  * matches an existing node (ala mkdir -p), and that sysctl_destroyv()
1876  * will return 0 if the node to be destroyed already does not exist
1877  * (aka rm -f) or if it is a parent of other nodes.
1878  *
1879  * This allows two (or more) different subsystems to assert sub-tree
1880  * existence before populating their own nodes, and to remove their
1881  * own nodes without orphaning the others when they are done.
1882  * ********************************************************************
1883  */
1884 int
1885 sysctl_createv(struct sysctllog **log, int cflags,
1886 	       const struct sysctlnode **rnode, const struct sysctlnode **cnode,
1887 	       int flags, int type, const char *namep, const char *descr,
1888 	       sysctlfn func, u_quad_t qv, void *newp, size_t newlen,
1889 	       ...)
1890 {
1891 	va_list ap;
1892 	int error, ni, namelen, name[CTL_MAXNAME];
1893 	const struct sysctlnode *root, *pnode;
1894 	struct sysctlnode nnode, onode, *dnode;
1895 	size_t sz;
1896 
1897 	/*
1898 	 * where are we putting this?
1899 	 */
1900 	if (rnode != NULL && *rnode == NULL) {
1901 		printf("sysctl_createv: rnode NULL\n");
1902 		return (EINVAL);
1903 	}
1904 	root = rnode ? *rnode : NULL;
1905 	if (cnode != NULL)
1906 		*cnode = NULL;
1907 	if (cflags != 0)
1908 		return (EINVAL);
1909 
1910 	/*
1911 	 * what is it?
1912 	 */
1913 	flags = SYSCTL_VERSION|SYSCTL_TYPE(type)|SYSCTL_FLAGS(flags);
1914 	if (log != NULL)
1915 		flags &= ~CTLFLAG_PERMANENT;
1916 
1917 	/*
1918 	 * where do we put it?
1919 	 */
1920 	va_start(ap, newlen);
1921 	namelen = 0;
1922 	ni = -1;
1923 	do {
1924 		if (++ni == CTL_MAXNAME)
1925 			return (ENAMETOOLONG);
1926 		name[ni] = va_arg(ap, int);
1927 		/*
1928 		 * sorry, this is not supported from here
1929 		 */
1930 		if (name[ni] == CTL_CREATESYM)
1931 			return (EINVAL);
1932 	} while (name[ni] != CTL_EOL && name[ni] != CTL_CREATE);
1933 	namelen = ni + (name[ni] == CTL_CREATE ? 1 : 0);
1934 	va_end(ap);
1935 
1936 	/*
1937 	 * what's it called
1938 	 */
1939 	if (strlcpy(nnode.sysctl_name, namep, sizeof(nnode.sysctl_name)) >=
1940 	    sizeof(nnode.sysctl_name))
1941 		return (ENAMETOOLONG);
1942 
1943 	/*
1944 	 * cons up the description of the new node
1945 	 */
1946 	nnode.sysctl_num = name[namelen - 1];
1947 	name[namelen - 1] = CTL_CREATE;
1948 	nnode.sysctl_size = newlen;
1949 	nnode.sysctl_flags = flags;
1950 	if (type == CTLTYPE_NODE) {
1951 		nnode.sysctl_csize = 0;
1952 		nnode.sysctl_clen = 0;
1953 		nnode.sysctl_child = NULL;
1954 		if (flags & CTLFLAG_ALIAS)
1955 			nnode.sysctl_alias = qv;
1956 	} else if (flags & CTLFLAG_IMMEDIATE) {
1957 		switch (type) {
1958 		case CTLTYPE_INT:
1959 			nnode.sysctl_idata = qv;
1960 			break;
1961 		case CTLTYPE_QUAD:
1962 			nnode.sysctl_qdata = qv;
1963 			break;
1964 		default:
1965 			return (EINVAL);
1966 		}
1967 	} else {
1968 		nnode.sysctl_data = newp;
1969 	}
1970 	nnode.sysctl_func = func;
1971 	nnode.sysctl_parent = NULL;
1972 	nnode.sysctl_ver = 0;
1973 
1974 	/*
1975 	 * initialize lock state -- we need locks if the main tree has
1976 	 * been marked as complete, but since we could be called from
1977 	 * either there, or from a device driver (say, at device
1978 	 * insertion), or from an lkm (at lkm load time, say), we
1979 	 * don't really want to "wait"...
1980 	 */
1981 	error = sysctl_lock(NULL, NULL, 0);
1982 	if (error)
1983 		return (error);
1984 
1985 	/*
1986 	 * locate the prospective parent of the new node, and if we
1987 	 * find it, add the new node.
1988 	 */
1989 	sz = sizeof(onode);
1990 	pnode = root;
1991 	error = sysctl_locate(NULL, &name[0], namelen - 1, &pnode, &ni);
1992 	if (error) {
1993 		printf("sysctl_createv: sysctl_locate(%s) returned %d\n",
1994 		       nnode.sysctl_name, error);
1995 		sysctl_unlock(NULL);
1996 		return (error);
1997 	}
1998 	error = sysctl_create(&name[ni], namelen - ni, &onode, &sz,
1999 			      &nnode, sizeof(nnode), &name[0], NULL,
2000 			      pnode);
2001 
2002 	/*
2003 	 * unfortunately the node we wanted to create is already
2004 	 * there.  if the node that's already there is a reasonable
2005 	 * facsimile of the node we wanted to create, just pretend
2006 	 * (for the caller's benefit) that we managed to create the
2007 	 * node they wanted.
2008 	 */
2009 	if (error == EEXIST) {
2010 		/* name is the same as requested... */
2011 		if (strcmp(nnode.sysctl_name, onode.sysctl_name) == 0 &&
2012 		    /* they want the same function... */
2013 		    nnode.sysctl_func == onode.sysctl_func &&
2014 		    /* number is the same as requested, or... */
2015 		    (nnode.sysctl_num == onode.sysctl_num ||
2016 		     /* they didn't pick a number... */
2017 		     nnode.sysctl_num == CTL_CREATE)) {
2018 			/*
2019 			 * collision here from trying to create
2020 			 * something that already existed; let's give
2021 			 * our customers a hand and tell them they got
2022 			 * what they wanted.
2023 			 */
2024 #ifdef SYSCTL_DEBUG_CREATE
2025 			printf("cleared\n");
2026 #endif /* SYSCTL_DEBUG_CREATE */
2027 			error = 0;
2028 		}
2029 	}
2030 
2031 	if (error == 0 &&
2032 	    (cnode != NULL || log != NULL || descr != NULL)) {
2033 		/*
2034 		 * sysctl_create() gave us back a copy of the node,
2035 		 * but we need to know where it actually is...
2036 		 */
2037 		pnode = root;
2038 		error = sysctl_locate(NULL, &name[0], namelen - 1, &pnode, &ni);
2039 
2040 		/*
2041 		 * manual scan of last layer so that aliased nodes
2042 		 * aren't followed.
2043 		 */
2044 		if (error == 0) {
2045 			for (ni = 0; ni < pnode->sysctl_clen; ni++)
2046 				if (pnode->sysctl_child[ni].sysctl_num ==
2047 				    onode.sysctl_num)
2048 					break;
2049 			if (ni < pnode->sysctl_clen)
2050 				pnode = &pnode->sysctl_child[ni];
2051 			else
2052 				error = ENOENT;
2053 		}
2054 
2055 		/*
2056 		 * not expecting an error here, but...
2057 		 */
2058 		if (error == 0) {
2059 			if (log != NULL)
2060 				sysctl_log_add(log, pnode);
2061 			if (cnode != NULL)
2062 				*cnode = pnode;
2063 			if (descr != NULL) {
2064 				/*
2065 				 * allow first caller to *set* a
2066 				 * description actually to set it
2067 				 *
2068 				 * discard const here so we can attach
2069 				 * the description
2070 				 */
2071 				dnode = __UNCONST(pnode);
2072 				if (pnode->sysctl_desc != NULL)
2073 					/* skip it...we've got one */;
2074 				else if (flags & CTLFLAG_OWNDESC) {
2075 					size_t l = strlen(descr) + 1;
2076 					char *d = malloc(l, M_SYSCTLDATA,
2077 							 M_WAITOK|M_CANFAIL);
2078 					if (d != NULL) {
2079 						memcpy(d, descr, l);
2080 						dnode->sysctl_desc = d;
2081 						dnode->sysctl_flags |=
2082 						    CTLFLAG_OWNDESC;
2083 					}
2084 				} else
2085 					dnode->sysctl_desc = descr;
2086 			}
2087 		} else {
2088 			printf("sysctl_create succeeded but node not found?!\n");
2089 			/*
2090 			 *  confusing, but the create said it
2091 			 * succeeded, so...
2092 			 */
2093 			error = 0;
2094 		}
2095 	}
2096 
2097 	/*
2098 	 * now it should be safe to release the lock state.  note that
2099 	 * the pointer to the newly created node being passed back may
2100 	 * not be "good" for very long.
2101 	 */
2102 	sysctl_unlock(NULL);
2103 
2104 	if (error != 0) {
2105 		printf("sysctl_createv: sysctl_create(%s) returned %d\n",
2106 		       nnode.sysctl_name, error);
2107 #if 0
2108 		if (error != ENOENT)
2109 			sysctl_dump(&onode);
2110 #endif
2111 	}
2112 
2113 	return (error);
2114 }
2115 
2116 int
2117 sysctl_destroyv(struct sysctlnode *rnode, ...)
2118 {
2119 	va_list ap;
2120 	int error, name[CTL_MAXNAME], namelen, ni;
2121 	const struct sysctlnode *pnode, *node;
2122 	struct sysctlnode dnode, *onode;
2123 	size_t sz;
2124 
2125 	va_start(ap, rnode);
2126 	namelen = 0;
2127 	ni = 0;
2128 	do {
2129 		if (ni == CTL_MAXNAME)
2130 			return (ENAMETOOLONG);
2131 		name[ni] = va_arg(ap, int);
2132 	} while (name[ni++] != CTL_EOL);
2133 	namelen = ni - 1;
2134 	va_end(ap);
2135 
2136 	/*
2137 	 * i can't imagine why we'd be destroying a node when the tree
2138 	 * wasn't complete, but who knows?
2139 	 */
2140 	error = sysctl_lock(NULL, NULL, 0);
2141 	if (error)
2142 		return (error);
2143 
2144 	/*
2145 	 * where is it?
2146 	 */
2147 	node = rnode;
2148 	error = sysctl_locate(NULL, &name[0], namelen - 1, &node, &ni);
2149 	if (error) {
2150 		/* they want it gone and it's not there, so... */
2151 		sysctl_unlock(NULL);
2152 		return (error == ENOENT ? 0 : error);
2153 	}
2154 
2155 	/*
2156 	 * set up the deletion
2157 	 */
2158 	pnode = node;
2159 	node = &dnode;
2160 	memset(&dnode, 0, sizeof(dnode));
2161 	dnode.sysctl_flags = SYSCTL_VERSION;
2162 	dnode.sysctl_num = name[namelen - 1];
2163 
2164 	/*
2165 	 * we found it, now let's nuke it
2166 	 */
2167 	name[namelen - 1] = CTL_DESTROY;
2168 	sz = 0;
2169 	error = sysctl_destroy(&name[namelen - 1], 1, NULL, &sz,
2170 			       node, sizeof(*node), &name[0], NULL,
2171 			       pnode);
2172 	if (error == ENOTEMPTY) {
2173 		/*
2174 		 * think of trying to delete "foo" when "foo.bar"
2175 		 * (which someone else put there) is still in
2176 		 * existence
2177 		 */
2178 		error = 0;
2179 
2180 		/*
2181 		 * dunno who put the description there, but if this
2182 		 * node can ever be removed, we need to make sure the
2183 		 * string doesn't go out of context.  that means we
2184 		 * need to find the node that's still there (don't use
2185 		 * sysctl_locate() because that follows aliasing).
2186 		 */
2187 		node = pnode->sysctl_child;
2188 		for (ni = 0; ni < pnode->sysctl_clen; ni++)
2189 			if (node[ni].sysctl_num == dnode.sysctl_num)
2190 				break;
2191 		node = (ni < pnode->sysctl_clen) ? &node[ni] : NULL;
2192 
2193 		/*
2194 		 * if we found it, and this node has a description,
2195 		 * and this node can be released, and it doesn't
2196 		 * already own its own description...sigh.  :)
2197 		 */
2198 		if (node != NULL && node->sysctl_desc != NULL &&
2199 		    !(node->sysctl_flags & CTLFLAG_PERMANENT) &&
2200 		    !(node->sysctl_flags & CTLFLAG_OWNDESC)) {
2201 			char *d;
2202 
2203 			sz = strlen(node->sysctl_desc) + 1;
2204 			d = malloc(sz, M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
2205 			if (d != NULL) {
2206 				/*
2207 				 * discard const so that we can
2208 				 * re-attach the description
2209 				 */
2210 				memcpy(d, node->sysctl_desc, sz);
2211 				onode = __UNCONST(node);
2212 				onode->sysctl_desc = d;
2213 				onode->sysctl_flags |= CTLFLAG_OWNDESC;
2214 			} else {
2215 				/*
2216 				 * XXX drop the description?  be
2217 				 * afraid?  don't care?
2218 				 */
2219 			}
2220 		}
2221 	}
2222 
2223         sysctl_unlock(NULL);
2224 
2225 	return (error);
2226 }
2227 
2228 #if 0
2229 /*
2230  * ********************************************************************
2231  * the dump routine.  i haven't yet decided how (if at all) i'll call
2232  * this from userland when it's in the kernel.
2233  * ********************************************************************
2234  */
2235 static const char *
2236 sf(int f)
2237 {
2238 	static char s[256];
2239 	char *c;
2240 
2241 	s[0] = '\0';
2242 	c = "";
2243 
2244 #define print_flag(_f, _s, _c, _q, _x) \
2245 	if (((_f) & (__CONCAT(CTLFLAG_,_x))) == (__CONCAT(CTLFLAG_,_q))) { \
2246 		strlcat((_s), (_c), sizeof(_s)); \
2247 		strlcat((_s), __STRING(_q), sizeof(_s)); \
2248 		(_c) = ","; \
2249 		(_f) &= ~__CONCAT(CTLFLAG_,_x); \
2250 	}
2251 
2252 	print_flag(f, s, c, READONLY,  READWRITE);
2253 	print_flag(f, s, c, READWRITE, READWRITE);
2254 	print_flag(f, s, c, ANYWRITE,  ANYWRITE);
2255 	print_flag(f, s, c, PRIVATE,   PRIVATE);
2256 	print_flag(f, s, c, PERMANENT, PERMANENT);
2257 	print_flag(f, s, c, OWNDATA,   OWNDATA);
2258 	print_flag(f, s, c, IMMEDIATE, IMMEDIATE);
2259 	print_flag(f, s, c, HEX,       HEX);
2260 	print_flag(f, s, c, ROOT,      ROOT);
2261 	print_flag(f, s, c, ANYNUMBER, ANYNUMBER);
2262 	print_flag(f, s, c, HIDDEN,    HIDDEN);
2263 	print_flag(f, s, c, ALIAS,     ALIAS);
2264 #undef print_flag
2265 
2266 	if (f) {
2267 		char foo[9];
2268 		snprintf(foo, sizeof(foo), "%x", f);
2269 		strlcat(s, c, sizeof(s));
2270 		strlcat(s, foo, sizeof(s));
2271 	}
2272 
2273 	return (s);
2274 }
2275 
2276 static const char *
2277 st(int t)
2278 {
2279 
2280 	switch (t) {
2281 	case CTLTYPE_NODE:
2282 		return "NODE";
2283 	case CTLTYPE_INT:
2284 		return "INT";
2285 	case CTLTYPE_STRING:
2286 		return "STRING";
2287 	case CTLTYPE_QUAD:
2288 		return "QUAD";
2289 	case CTLTYPE_STRUCT:
2290 		return "STRUCT";
2291 	}
2292 
2293 	return "???";
2294 }
2295 
2296 void
2297 sysctl_dump(const struct sysctlnode *d)
2298 {
2299 	static char nmib[64], smib[256];
2300 	static int indent;
2301 	struct sysctlnode *n;
2302 	char *np, *sp, tmp[20];
2303 	int i;
2304 
2305 	if (d == NULL)
2306 		return;
2307 
2308 	np = &nmib[strlen(nmib)];
2309 	sp = &smib[strlen(smib)];
2310 
2311 	if (!(d->sysctl_flags & CTLFLAG_ROOT)) {
2312 		snprintf(tmp, sizeof(tmp), "%d", d->sysctl_num);
2313 		strcat(nmib, ".");
2314 		strcat(smib, ".");
2315 		strcat(nmib, tmp);
2316 		strcat(smib, d->sysctl_name);
2317 		printf("%s -> %s (%d)\n", &nmib[1], &smib[1],
2318 		       SYSCTL_TYPE(d->sysctl_flags));
2319 	}
2320 
2321 	if (1) {
2322 		printf("%*s%p:\tsysctl_name  [%s]\n", indent, "",
2323 		       d, d->sysctl_name);
2324 		printf("%*s\t\tsysctl_num    %d\n",   indent, "",
2325 		       d->sysctl_num);
2326 		printf("%*s\t\tsysctl_flags  %x (flags=%x<%s> type=%d<%s> "
2327 		       "size=%zu)\n",
2328 		       indent, "", d->sysctl_flags,
2329 		       SYSCTL_FLAGS(d->sysctl_flags),
2330 		       sf(SYSCTL_FLAGS(d->sysctl_flags)),
2331 		       SYSCTL_TYPE(d->sysctl_flags),
2332 		       st(SYSCTL_TYPE(d->sysctl_flags)),
2333 		       d->sysctl_size);
2334 		if (SYSCTL_TYPE(d->sysctl_flags) == CTLTYPE_NODE) {
2335 			printf("%*s\t\tsysctl_csize  %d\n",   indent, "",
2336 			       d->sysctl_csize);
2337 			printf("%*s\t\tsysctl_clen   %d\n",   indent, "",
2338 			       d->sysctl_clen);
2339 			printf("%*s\t\tsysctl_child  %p\n",   indent, "",
2340 			       d->sysctl_child);
2341 		} else
2342 			printf("%*s\t\tsysctl_data   %p\n",   indent, "",
2343 			       d->sysctl_data);
2344 		printf("%*s\t\tsysctl_func   %p\n",   indent, "",
2345 		       d->sysctl_func);
2346 		printf("%*s\t\tsysctl_parent %p\n",   indent, "",
2347 		       d->sysctl_parent);
2348 		printf("%*s\t\tsysctl_ver    %d\n",   indent, "",
2349 		       d->sysctl_ver);
2350 	}
2351 
2352 	if (SYSCTL_TYPE(d->sysctl_flags) == CTLTYPE_NODE) {
2353 		indent += 8;
2354 		n = d->sysctl_child;
2355 		for (i = 0; i < d->sysctl_clen; i++) {
2356 			sysctl_dump(&n[i]);
2357 		}
2358 		indent -= 8;
2359 	}
2360 
2361 	np[0] = '\0';
2362 	sp[0] = '\0';
2363 }
2364 #endif /* 0 */
2365 
2366 /*
2367  * ********************************************************************
2368  * Deletes an entire n-ary tree.  Not recommended unless you know why
2369  * you're doing it.  Personally, I don't know why you'd even think
2370  * about it.
2371  * ********************************************************************
2372  */
2373 void
2374 sysctl_free(struct sysctlnode *rnode)
2375 {
2376 	struct sysctlnode *node, *pnode;
2377 
2378 	if (rnode == NULL)
2379 		rnode = &sysctl_root;
2380 
2381 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
2382 		printf("sysctl_free: rnode %p wrong version\n", rnode);
2383 		return;
2384 	}
2385 
2386 	pnode = rnode;
2387 
2388 	node = pnode->sysctl_child;
2389 	do {
2390 		while (node != NULL && pnode->sysctl_csize > 0) {
2391 			while (node <
2392 			       &pnode->sysctl_child[pnode->sysctl_clen] &&
2393 			       (SYSCTL_TYPE(node->sysctl_flags) !=
2394 				CTLTYPE_NODE ||
2395 				node->sysctl_csize == 0)) {
2396 				if (SYSCTL_FLAGS(node->sysctl_flags) &
2397 				    CTLFLAG_OWNDATA) {
2398 					if (node->sysctl_data != NULL) {
2399 						free(node->sysctl_data,
2400 						     M_SYSCTLDATA);
2401 						node->sysctl_data = NULL;
2402 					}
2403 				}
2404 				if (SYSCTL_FLAGS(node->sysctl_flags) &
2405 				    CTLFLAG_OWNDESC) {
2406 					if (node->sysctl_desc != NULL) {
2407 						/*XXXUNCONST*/
2408 						free(__UNCONST(node->sysctl_desc),
2409 						     M_SYSCTLDATA);
2410 						node->sysctl_desc = NULL;
2411 					}
2412 				}
2413 				node++;
2414 			}
2415 			if (node < &pnode->sysctl_child[pnode->sysctl_clen]) {
2416 				pnode = node;
2417 				node = node->sysctl_child;
2418 			} else
2419 				break;
2420 		}
2421 		if (pnode->sysctl_child != NULL)
2422 			free(pnode->sysctl_child, M_SYSCTLNODE);
2423 		pnode->sysctl_clen = 0;
2424 		pnode->sysctl_csize = 0;
2425 		pnode->sysctl_child = NULL;
2426 		node = pnode;
2427 		pnode = node->sysctl_parent;
2428 	} while (pnode != NULL && node != rnode);
2429 }
2430 
2431 int
2432 sysctl_log_add(struct sysctllog **logp, const struct sysctlnode *node)
2433 {
2434 	int name[CTL_MAXNAME], namelen, i;
2435 	const struct sysctlnode *pnode;
2436 	struct sysctllog *log;
2437 
2438 	if (node->sysctl_flags & CTLFLAG_PERMANENT)
2439 		return (0);
2440 
2441 	if (logp == NULL)
2442 		return (0);
2443 
2444 	if (*logp == NULL) {
2445 		log = malloc(sizeof(struct sysctllog),
2446 		       M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
2447 		if (log == NULL) {
2448 			/* XXX print error message? */
2449 			return (-1);
2450 		}
2451 		log->log_num = malloc(16 * sizeof(int),
2452 		       M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
2453 		if (log->log_num == NULL) {
2454 			/* XXX print error message? */
2455 			free(log, M_SYSCTLDATA);
2456 			return (-1);
2457 		}
2458 		memset(log->log_num, 0, 16 * sizeof(int));
2459 		log->log_root = NULL;
2460 		log->log_size = 16;
2461 		log->log_left = 16;
2462 		*logp = log;
2463 	} else
2464 		log = *logp;
2465 
2466 	/*
2467 	 * check that the root is proper.  it's okay to record the
2468 	 * address of the root of a tree.  it's the only thing that's
2469 	 * guaranteed not to shift around as nodes come and go.
2470 	 */
2471 	if (log->log_root == NULL)
2472 		log->log_root = sysctl_rootof(node);
2473 	else if (log->log_root != sysctl_rootof(node)) {
2474 		printf("sysctl: log %p root mismatch (%p)\n",
2475 		       log->log_root, sysctl_rootof(node));
2476 		return (-1);
2477 	}
2478 
2479 	/*
2480 	 * we will copy out name in reverse order
2481 	 */
2482 	for (pnode = node, namelen = 0;
2483 	     pnode != NULL && !(pnode->sysctl_flags & CTLFLAG_ROOT);
2484 	     pnode = pnode->sysctl_parent)
2485 		name[namelen++] = pnode->sysctl_num;
2486 
2487 	/*
2488 	 * do we have space?
2489 	 */
2490 	if (log->log_left < (namelen + 3))
2491 		sysctl_log_realloc(log);
2492 	if (log->log_left < (namelen + 3))
2493 		return (-1);
2494 
2495 	/*
2496 	 * stuff name in, then namelen, then node type, and finally,
2497 	 * the version for non-node nodes.
2498 	 */
2499 	for (i = 0; i < namelen; i++)
2500 		log->log_num[--log->log_left] = name[i];
2501 	log->log_num[--log->log_left] = namelen;
2502 	log->log_num[--log->log_left] = SYSCTL_TYPE(node->sysctl_flags);
2503 	if (log->log_num[log->log_left] != CTLTYPE_NODE)
2504 		log->log_num[--log->log_left] = node->sysctl_ver;
2505 	else
2506 		log->log_num[--log->log_left] = 0;
2507 
2508 	return (0);
2509 }
2510 
2511 void
2512 sysctl_teardown(struct sysctllog **logp)
2513 {
2514 	const struct sysctlnode *rnode;
2515 	struct sysctlnode node;
2516 	struct sysctllog *log;
2517 	uint namelen;
2518 	int *name, t, v, error, ni;
2519 	size_t sz;
2520 
2521 	if (logp == NULL || *logp == NULL)
2522 		return;
2523 	log = *logp;
2524 
2525 	error = sysctl_lock(NULL, NULL, 0);
2526 	if (error)
2527 		return;
2528 
2529 	memset(&node, 0, sizeof(node));
2530 
2531 	while (log->log_left < log->log_size) {
2532 		KASSERT((log->log_left + 3 < log->log_size) &&
2533 			(log->log_left + log->log_num[log->log_left + 2] <=
2534 			 log->log_size));
2535 		v = log->log_num[log->log_left++];
2536 		t = log->log_num[log->log_left++];
2537 		namelen = log->log_num[log->log_left++];
2538 		name = &log->log_num[log->log_left];
2539 
2540 		node.sysctl_num = name[namelen - 1];
2541 		node.sysctl_flags = SYSCTL_VERSION|t;
2542 		node.sysctl_ver = v;
2543 
2544 		rnode = log->log_root;
2545 		error = sysctl_locate(NULL, &name[0], namelen, &rnode, &ni);
2546 		if (error == 0) {
2547 			name[namelen - 1] = CTL_DESTROY;
2548 			rnode = rnode->sysctl_parent;
2549 			sz = 0;
2550 			(void)sysctl_destroy(&name[namelen - 1], 1, NULL,
2551 					     &sz, &node, sizeof(node),
2552 					     &name[0], NULL, rnode);
2553 		}
2554 
2555 		log->log_left += namelen;
2556 	}
2557 
2558 	KASSERT(log->log_size == log->log_left);
2559 	free(log->log_num, M_SYSCTLDATA);
2560 	free(log, M_SYSCTLDATA);
2561 	*logp = NULL;
2562 
2563 	sysctl_unlock(NULL);
2564 }
2565 
2566 /*
2567  * ********************************************************************
2568  * old_sysctl -- A routine to bridge old-style internal calls to the
2569  * new infrastructure.
2570  * ********************************************************************
2571  */
2572 int
2573 old_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
2574 	   void *newp, size_t newlen, struct lwp *l)
2575 {
2576 	int error;
2577 	size_t oldlen = 0;
2578 	size_t savelen;
2579 
2580 	if (oldlenp) {
2581 		oldlen = *oldlenp;
2582 	}
2583 	savelen = oldlen;
2584 
2585 	error = sysctl_lock(l, oldp, savelen);
2586 	if (error)
2587 		return (error);
2588 	error = sysctl_dispatch(name, namelen, oldp, &oldlen,
2589 				newp, newlen, name, l, NULL);
2590 	sysctl_unlock(l);
2591 	if (error == 0 && oldp != NULL && savelen < oldlen)
2592 		error = ENOMEM;
2593 
2594 	if (oldlenp) {
2595 		*oldlenp = oldlen;
2596 	}
2597 
2598 	return (error);
2599 }
2600 
2601 /*
2602  * ********************************************************************
2603  * Section 4: Generic helper routines
2604  * ********************************************************************
2605  * "helper" routines that can do more finely grained access control,
2606  * construct structures from disparate information, create the
2607  * appearance of more nodes and sub-trees, etc.  for example, if
2608  * CTL_PROC wanted a helper function, it could respond to a CTL_QUERY
2609  * with a dynamically created list of nodes that represented the
2610  * currently running processes at that instant.
2611  * ********************************************************************
2612  */
2613 
2614 /*
2615  * first, a few generic helpers that provide:
2616  *
2617  * sysctl_needfunc()		a readonly interface that emits a warning
2618  * sysctl_notavail()		returns EOPNOTSUPP (generic error)
2619  * sysctl_null()		an empty return buffer with no error
2620  */
2621 int
2622 sysctl_needfunc(SYSCTLFN_ARGS)
2623 {
2624 	int error;
2625 
2626 	printf("!!SYSCTL_NEEDFUNC!!\n");
2627 
2628 	if (newp != NULL || namelen != 0)
2629 		return (EOPNOTSUPP);
2630 
2631 	error = 0;
2632 	if (oldp != NULL)
2633 		error = sysctl_copyout(l, rnode->sysctl_data, oldp,
2634 				       MIN(rnode->sysctl_size, *oldlenp));
2635 	*oldlenp = rnode->sysctl_size;
2636 
2637 	return (error);
2638 }
2639 
2640 int
2641 sysctl_notavail(SYSCTLFN_ARGS)
2642 {
2643 
2644 	if (namelen == 1 && name[0] == CTL_QUERY)
2645 		return (sysctl_query(SYSCTLFN_CALL(rnode)));
2646 
2647 	return (EOPNOTSUPP);
2648 }
2649 
2650 int
2651 sysctl_null(SYSCTLFN_ARGS)
2652 {
2653 
2654 	*oldlenp = 0;
2655 
2656 	return (0);
2657 }
2658 
2659 /*
2660  * ********************************************************************
2661  * Section 5: The machinery that makes it all go
2662  * ********************************************************************
2663  * Memory "manglement" routines.  Not much to this, eh?
2664  * ********************************************************************
2665  */
2666 static int
2667 sysctl_alloc(struct sysctlnode *p, int x)
2668 {
2669 	int i;
2670 	struct sysctlnode *n;
2671 
2672 	assert(p->sysctl_child == NULL);
2673 
2674 	if (x == 1)
2675 		n = malloc(sizeof(struct sysctlnode),
2676 		       M_SYSCTLNODE, M_WAITOK|M_CANFAIL);
2677 	else
2678 		n = malloc(SYSCTL_DEFSIZE * sizeof(struct sysctlnode),
2679 		       M_SYSCTLNODE, M_WAITOK|M_CANFAIL);
2680 	if (n == NULL)
2681 		return (ENOMEM);
2682 
2683 	if (x == 1) {
2684 		memset(n, 0, sizeof(struct sysctlnode));
2685 		p->sysctl_csize = 1;
2686 	} else {
2687 		memset(n, 0, SYSCTL_DEFSIZE * sizeof(struct sysctlnode));
2688 		p->sysctl_csize = SYSCTL_DEFSIZE;
2689 	}
2690 	p->sysctl_clen = 0;
2691 
2692 	for (i = 0; i < p->sysctl_csize; i++)
2693 		n[i].sysctl_parent = p;
2694 
2695 	p->sysctl_child = n;
2696 	return (0);
2697 }
2698 
2699 static int
2700 sysctl_realloc(struct sysctlnode *p)
2701 {
2702 	int i, j;
2703 	struct sysctlnode *n;
2704 
2705 	assert(p->sysctl_csize == p->sysctl_clen);
2706 
2707 	/*
2708 	 * how many do we have...how many should we make?
2709 	 */
2710 	i = p->sysctl_clen;
2711 	n = malloc(2 * i * sizeof(struct sysctlnode), M_SYSCTLNODE,
2712 		   M_WAITOK|M_CANFAIL);
2713 	if (n == NULL)
2714 		return (ENOMEM);
2715 
2716 	/*
2717 	 * move old children over...initialize new children
2718 	 */
2719 	memcpy(n, p->sysctl_child, i * sizeof(struct sysctlnode));
2720 	memset(&n[i], 0, i * sizeof(struct sysctlnode));
2721 	p->sysctl_csize = 2 * i;
2722 
2723 	/*
2724 	 * reattach moved (and new) children to parent; if a moved
2725 	 * child node has children, reattach the parent pointers of
2726 	 * grandchildren
2727 	 */
2728         for (i = 0; i < p->sysctl_csize; i++) {
2729                 n[i].sysctl_parent = p;
2730 		if (n[i].sysctl_child != NULL) {
2731 			for (j = 0; j < n[i].sysctl_csize; j++)
2732 				n[i].sysctl_child[j].sysctl_parent = &n[i];
2733 		}
2734 	}
2735 
2736 	/*
2737 	 * get out with the old and in with the new
2738 	 */
2739 	free(p->sysctl_child, M_SYSCTLNODE);
2740 	p->sysctl_child = n;
2741 
2742 	return (0);
2743 }
2744 
2745 static int
2746 sysctl_log_realloc(struct sysctllog *log)
2747 {
2748 	int *n, s, d;
2749 
2750 	s = log->log_size * 2;
2751 	d = log->log_size;
2752 
2753 	n = malloc(s * sizeof(int), M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
2754 	if (n == NULL)
2755 		return (-1);
2756 
2757 	memset(n, 0, s * sizeof(int));
2758 	memcpy(&n[d], log->log_num, d * sizeof(int));
2759 	free(log->log_num, M_SYSCTLDATA);
2760 	log->log_num = n;
2761 	if (d)
2762 		log->log_left += d;
2763 	else
2764 		log->log_left = s;
2765 	log->log_size = s;
2766 
2767 	return (0);
2768 }
2769 
2770 /*
2771  * ********************************************************************
2772  * Section 6: Conversion between API versions wrt the sysctlnode
2773  * ********************************************************************
2774  */
2775 static int
2776 sysctl_cvt_in(struct lwp *l, int *vp, const void *i, size_t sz,
2777 	      struct sysctlnode *node)
2778 {
2779 	int error, flags;
2780 
2781 	if (i == NULL || sz < sizeof(flags))
2782 		return (EINVAL);
2783 
2784 	error = sysctl_copyin(l, i, &flags, sizeof(flags));
2785 	if (error)
2786 		return (error);
2787 
2788 #if (SYSCTL_VERSION != SYSCTL_VERS_1)
2789 #error sysctl_cvt_in: no support for SYSCTL_VERSION
2790 #endif /*  (SYSCTL_VERSION != SYSCTL_VERS_1) */
2791 
2792 	if (sz == sizeof(*node) &&
2793 	    SYSCTL_VERS(flags) == SYSCTL_VERSION) {
2794 		error = sysctl_copyin(l, i, node, sizeof(*node));
2795 		if (error)
2796 			return (error);
2797 		*vp = SYSCTL_VERSION;
2798 		return (0);
2799 	}
2800 
2801 	return (EINVAL);
2802 }
2803 
2804 static int
2805 sysctl_cvt_out(struct lwp *l, int v, const struct sysctlnode *i,
2806 	       void *ovp, size_t left, size_t *szp)
2807 {
2808 	size_t sz = sizeof(*i);
2809 	const void *src = i;
2810 	int error;
2811 
2812 	switch (v) {
2813 	case SYSCTL_VERS_0:
2814 		return (EINVAL);
2815 
2816 #if (SYSCTL_VERSION != SYSCTL_VERS_1)
2817 #error sysctl_cvt_out: no support for SYSCTL_VERSION
2818 #endif /*  (SYSCTL_VERSION != SYSCTL_VERS_1) */
2819 
2820 	case SYSCTL_VERSION:
2821 		/* nothing more to do here */
2822 		break;
2823 	}
2824 
2825 	if (ovp != NULL && left >= sz) {
2826 		error = sysctl_copyout(l, src, ovp, sz);
2827 		if (error)
2828 			return (error);
2829 	}
2830 
2831 	if (szp != NULL)
2832 		*szp = sz;
2833 
2834 	return (0);
2835 }
2836