xref: /netbsd-src/sys/kern/kern_sysctl.c (revision ce2c90c7c172d95d2402a5b3d96d8f8e6d138a21)
1 /*	$NetBSD: kern_sysctl.c,v 1.205 2006/10/12 01:32:17 christos 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 1.205 2006/10/12 01:32:17 christos Exp $");
79 
80 #include "opt_defcorename.h"
81 #include "opt_ktrace.h"
82 #include "ksyms.h"
83 
84 #include <sys/param.h>
85 #define __COMPAT_SYSCTL
86 #include <sys/sysctl.h>
87 #include <sys/systm.h>
88 #include <sys/buf.h>
89 #include <sys/ksyms.h>
90 #include <sys/malloc.h>
91 #include <sys/mount.h>
92 #include <sys/sa.h>
93 #include <sys/syscallargs.h>
94 #include <sys/kauth.h>
95 #ifdef KTRACE
96 #include <sys/ktrace.h>
97 #endif
98 #include <machine/stdarg.h>
99 
100 #define	MAXDESCLEN	1024
101 MALLOC_DEFINE(M_SYSCTLNODE, "sysctlnode", "sysctl node structures");
102 MALLOC_DEFINE(M_SYSCTLDATA, "sysctldata", "misc sysctl data");
103 
104 static int sysctl_mmap(SYSCTLFN_PROTO);
105 static int sysctl_alloc(struct sysctlnode *, int);
106 static int sysctl_realloc(struct sysctlnode *);
107 
108 static int sysctl_cvt_in(struct lwp *, int *, const void *, size_t,
109 			 struct sysctlnode *);
110 static int sysctl_cvt_out(struct lwp *, int, const struct sysctlnode *,
111 			  void *, size_t, size_t *);
112 
113 static int sysctl_log_add(struct sysctllog **, const struct sysctlnode *);
114 static int sysctl_log_realloc(struct sysctllog *);
115 
116 struct sysctllog {
117 	const struct sysctlnode *log_root;
118 	int *log_num;
119 	int log_size, log_left;
120 };
121 
122 /*
123  * the "root" of the new sysctl tree
124  */
125 struct sysctlnode sysctl_root = {
126 	.sysctl_flags = SYSCTL_VERSION|
127 	    CTLFLAG_ROOT|CTLFLAG_READWRITE|
128 	    CTLTYPE_NODE,
129 	.sysctl_num = 0,
130 	/*
131 	 * XXX once all ports are on gcc3, we can get rid of this
132 	 * ugliness and simply make it into
133 	 *
134 	 *	.sysctl_size = sizeof(struct sysctlnode),
135 	 */
136 	sysc_init_field(_sysctl_size, sizeof(struct sysctlnode)),
137 	.sysctl_name = "(root)",
138 };
139 
140 /*
141  * link set of functions that add nodes at boot time (see also
142  * sysctl_buildtree())
143  */
144 __link_set_decl(sysctl_funcs, sysctl_setup_func);
145 
146 /*
147  * The `sysctl_lock' is intended to serialize access to the sysctl
148  * tree.  Given that it is now (a) dynamic, and (b) most consumers of
149  * sysctl are going to be copying data out, the old `sysctl_memlock'
150  * has been `upgraded' to simply guard the whole tree.
151  *
152  * The two new data here are to keep track of the locked chunk of
153  * memory, if there is one, so that it can be released more easily
154  * from anywhere.
155  */
156 struct lock sysctl_treelock;
157 caddr_t sysctl_memaddr;
158 size_t sysctl_memsize;
159 
160 /*
161  * Attributes stored in the kernel.
162  */
163 char hostname[MAXHOSTNAMELEN];
164 int hostnamelen;
165 
166 char domainname[MAXHOSTNAMELEN];
167 int domainnamelen;
168 
169 long hostid;
170 
171 #ifndef DEFCORENAME
172 #define	DEFCORENAME	"%n.core"
173 #endif
174 char defcorename[MAXPATHLEN] = DEFCORENAME;
175 
176 /*
177  * ********************************************************************
178  * Section 0: Some simple glue
179  * ********************************************************************
180  * By wrapping copyin(), copyout(), and copyinstr() like this, we can
181  * stop caring about who's calling us and simplify some code a bunch.
182  * ********************************************************************
183  */
184 static inline int
185 sysctl_copyin(struct lwp *l, const void *uaddr, void *kaddr, size_t len)
186 {
187 	int error;
188 
189 	if (l != NULL) {
190 		error = copyin(uaddr, kaddr, len);
191 #ifdef KTRACE
192 		if (!error && KTRPOINT(l->l_proc, KTR_MIB)) {
193 			struct iovec iov;
194 
195 			iov.iov_base = (void *)(vaddr_t)uaddr;
196 			iov.iov_len = len;
197 			ktrgenio(l, -1, UIO_WRITE, &iov, len, error);
198 		}
199 #endif
200 
201 	} else {
202 		error = kcopy(uaddr, kaddr, len);
203 	}
204 
205 	return error;
206 }
207 
208 static inline int
209 sysctl_copyout(struct lwp *l, const void *kaddr, void *uaddr, size_t len)
210 {
211 	int error;
212 
213 	if (l != NULL) {
214 		error = copyout(kaddr, uaddr, len);
215 #ifdef KTRACE
216 		if (!error && KTRPOINT(l->l_proc, KTR_MIB)) {
217 			struct iovec iov;
218 
219 			iov.iov_base = (void *)(vaddr_t)uaddr;
220 			iov.iov_len = len;
221 			ktrgenio(l, -1, UIO_READ, &iov, len, error);
222 		}
223 #endif
224 	} else {
225 		error = kcopy(kaddr, uaddr, len);
226 	}
227 
228 	return error;
229 }
230 
231 static inline int
232 sysctl_copyinstr(struct lwp *l, const void *uaddr, void *kaddr,
233 		 size_t len, size_t *done)
234 {
235 	int error;
236 
237 	if (l != NULL) {
238 		error = copyinstr(uaddr, kaddr, len, done);
239 #ifdef KTRACE
240 		if (!error && KTRPOINT(l->l_proc, KTR_MIB)) {
241 			struct iovec iov;
242 
243 			iov.iov_base = (void *)(vaddr_t)uaddr;
244 			iov.iov_len = len;
245 			ktrgenio(l, -1, UIO_WRITE, &iov, len, error);
246 		}
247 #endif
248 	} else {
249 		error = copystr(uaddr, kaddr, len, done);
250 	}
251 
252 	return error;
253 }
254 
255 /*
256  * ********************************************************************
257  * Initialize sysctl subsystem.
258  * ********************************************************************
259  */
260 void
261 sysctl_init(void)
262 {
263 	sysctl_setup_func * const *sysctl_setup, f;
264 
265 	lockinit(&sysctl_treelock, PRIBIO|PCATCH, "sysctl", 0, 0);
266 
267 	/*
268 	 * dynamic mib numbers start here
269 	 */
270 	sysctl_root.sysctl_num = CREATE_BASE;
271 
272         __link_set_foreach(sysctl_setup, sysctl_funcs) {
273 		/*
274 		 * XXX - why do i have to coerce the pointers like this?
275 		 */
276 		f = (void*)*sysctl_setup;
277 		(*f)(NULL);
278 	}
279 
280 	/*
281 	 * setting this means no more permanent nodes can be added,
282 	 * trees that claim to be readonly at the root now are, and if
283 	 * the main tree is readonly, *everything* is.
284 	 */
285 	sysctl_root.sysctl_flags |= CTLFLAG_PERMANENT;
286 
287 }
288 
289 /*
290  * ********************************************************************
291  * The main native sysctl system call itself.
292  * ********************************************************************
293  */
294 int
295 sys___sysctl(struct lwp *l, void *v, register_t *retval __unused)
296 {
297 	struct sys___sysctl_args /* {
298 		syscallarg(const int *) name;
299 		syscallarg(u_int) namelen;
300 		syscallarg(void *) old;
301 		syscallarg(size_t *) oldlenp;
302 		syscallarg(const void *) new;
303 		syscallarg(size_t) newlen;
304 	} */ *uap = v;
305 	int error, nerror, name[CTL_MAXNAME];
306 	size_t oldlen, savelen, *oldlenp;
307 
308 	/*
309 	 * get oldlen
310 	 */
311 	oldlen = 0;
312 	oldlenp = SCARG(uap, oldlenp);
313 	if (oldlenp != NULL) {
314 		error = copyin(oldlenp, &oldlen, sizeof(oldlen));
315 		if (error)
316 			return (error);
317 	}
318 	savelen = oldlen;
319 
320 	/*
321 	 * top-level sysctl names may or may not be non-terminal, but
322 	 * we don't care
323 	 */
324 	if (SCARG(uap, namelen) > CTL_MAXNAME || SCARG(uap, namelen) < 1)
325 		return (EINVAL);
326 	error = copyin(SCARG(uap, name), &name,
327 		       SCARG(uap, namelen) * sizeof(int));
328 	if (error)
329 		return (error);
330 
331 #ifdef KTRACE
332 	if (KTRPOINT(l->l_proc, KTR_MIB))
333 		ktrmib(l, name, SCARG(uap, namelen));
334 #endif
335 	/*
336 	 * wire old so that copyout() is less likely to fail?
337 	 */
338 	error = sysctl_lock(l, SCARG(uap, old), savelen);
339 	if (error)
340 		return (error);
341 
342 	/*
343 	 * do sysctl work (NULL means main built-in default tree)
344 	 */
345 	error = sysctl_dispatch(&name[0], SCARG(uap, namelen),
346 				SCARG(uap, old), &oldlen,
347 				SCARG(uap, new), SCARG(uap, newlen),
348 				&name[0], l, NULL);
349 
350 	/*
351 	 * release the sysctl lock
352 	 */
353 	sysctl_unlock(l);
354 
355 	/*
356 	 * set caller's oldlen to new value even in the face of an
357 	 * error (if this gets an error and they didn't have one, they
358 	 * get this one)
359 	 */
360 	if (oldlenp) {
361 		nerror = copyout(&oldlen, oldlenp, sizeof(oldlen));
362 		if (error == 0)
363 			error = nerror;
364 	}
365 
366 	/*
367 	 * if the only problem is that we weren't given enough space,
368 	 * that's an ENOMEM error
369 	 */
370 	if (error == 0 && SCARG(uap, old) != NULL && savelen < oldlen)
371 		error = ENOMEM;
372 
373 	return (error);
374 }
375 
376 /*
377  * ********************************************************************
378  * Section 1: How the tree is used
379  * ********************************************************************
380  * Implementations of sysctl for emulations should typically need only
381  * these three functions in this order: lock the tree, dispatch
382  * request into it, unlock the tree.
383  * ********************************************************************
384  */
385 int
386 sysctl_lock(struct lwp *l, void *oldp, size_t savelen)
387 {
388 	int error = 0;
389 
390 	error = lockmgr(&sysctl_treelock, LK_EXCLUSIVE, NULL);
391 	if (error)
392 		return (error);
393 
394 	if (l != NULL && oldp != NULL && savelen) {
395 
396 		/*
397 		 * be lazy - memory is locked for short time only, so
398 		 * just do a basic check against system limit
399 		 */
400 
401 		if (uvmexp.wired + atop(savelen) > uvmexp.wiredmax) {
402 			lockmgr(&sysctl_treelock, LK_RELEASE, NULL);
403 			return (ENOMEM);
404 		}
405 		error = uvm_vslock(l->l_proc->p_vmspace, oldp, savelen,
406 				   VM_PROT_WRITE);
407 		if (error) {
408 			(void) lockmgr(&sysctl_treelock, LK_RELEASE, NULL);
409 			return (error);
410 		}
411 		sysctl_memaddr = oldp;
412 		sysctl_memsize = savelen;
413 	}
414 
415 	return (0);
416 }
417 
418 /*
419  * ********************************************************************
420  * the main sysctl dispatch routine.  scans the given tree and picks a
421  * function to call based on what it finds.
422  * ********************************************************************
423  */
424 int
425 sysctl_dispatch(SYSCTLFN_ARGS)
426 {
427 	int error;
428 	sysctlfn fn;
429 	int ni;
430 
431 	if (rnode && SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
432 		printf("sysctl_dispatch: rnode %p wrong version\n", rnode);
433 		error = EINVAL;
434 		goto out;
435 	}
436 
437 	fn = NULL;
438 	error = sysctl_locate(l, name, namelen, &rnode, &ni);
439 
440 	if (rnode->sysctl_func != NULL) {
441 		/*
442 		 * the node we ended up at has a function, so call it.  it can
443 		 * hand off to query or create if it wants to.
444 		 */
445 		fn = rnode->sysctl_func;
446 	} else if (error == 0) {
447 		/*
448 		 * we found the node they were looking for, so do a lookup.
449 		 */
450 		fn = (sysctlfn)sysctl_lookup; /* XXX may write to rnode */
451 	} else if (error == ENOENT && (ni + 1) == namelen && name[ni] < 0) {
452 		/*
453 		 * prospective parent node found, but the terminal node was
454 		 * not.  generic operations associate with the parent.
455 		 */
456 		switch (name[ni]) {
457 		case CTL_QUERY:
458 			fn = sysctl_query;
459 			break;
460 		case CTL_CREATE:
461 #if NKSYMS > 0
462 		case CTL_CREATESYM:
463 #endif /* NKSYMS > 0 */
464 			fn = (sysctlfn)sysctl_create; /* we own the rnode */
465 			break;
466 		case CTL_DESTROY:
467 			fn = (sysctlfn)sysctl_destroy; /* we own the rnode */
468 			break;
469 		case CTL_MMAP:
470 			fn = (sysctlfn)sysctl_mmap; /* we own the rnode */
471 			break;
472 		case CTL_DESCRIBE:
473 			fn = sysctl_describe;
474 			break;
475 		default:
476 			error = EOPNOTSUPP;
477 			break;
478 		}
479 	}
480 
481 	/*
482 	 * after all of that, maybe we found someone who knows how to
483 	 * get us what we want?
484 	 */
485 	if (fn != NULL)
486 		error = (*fn)(name + ni, namelen - ni, oldp, oldlenp,
487 			      newp, newlen, name, l, rnode);
488 	else if (error == 0)
489 		error = EOPNOTSUPP;
490 
491 out:
492 	return (error);
493 }
494 
495 /*
496  * ********************************************************************
497  * Releases the tree lock.  Note that if uvm_vslock() was called when
498  * the lock was taken, we release that memory now.  By keeping track
499  * of where and how much by ourselves, the lock can be released much
500  * more easily from anywhere.
501  * ********************************************************************
502  */
503 void
504 sysctl_unlock(struct lwp *l)
505 {
506 
507 	if (l != NULL && sysctl_memsize != 0) {
508 		uvm_vsunlock(l->l_proc->p_vmspace, sysctl_memaddr,
509 			     sysctl_memsize);
510 		sysctl_memsize = 0;
511 	}
512 
513 	(void) lockmgr(&sysctl_treelock, LK_RELEASE, NULL);
514 }
515 
516 /*
517  * ********************************************************************
518  * Section 2: The main tree interfaces
519  * ********************************************************************
520  * This is how sysctl_dispatch() does its work, and you can too, by
521  * calling these routines from helpers (though typically only
522  * sysctl_lookup() will be used).  The tree MUST BE LOCKED when these
523  * are called.
524  * ********************************************************************
525  */
526 
527 /*
528  * sysctl_locate -- Finds the node matching the given mib under the
529  * given tree (via rv).  If no tree is given, we fall back to the
530  * native tree.  The current process (via l) is used for access
531  * control on the tree (some nodes may be traversable only by root) and
532  * on return, nip will show how many numbers in the mib were consumed.
533  */
534 int
535 sysctl_locate(struct lwp *l, const int *name, u_int namelen,
536 	      const struct sysctlnode **rnode, int *nip)
537 {
538 	const struct sysctlnode *node, *pnode;
539 	int tn, si, ni, error, alias;
540 
541 	/*
542 	 * basic checks and setup
543 	 */
544 	if (*rnode == NULL)
545 		*rnode = &sysctl_root;
546 	if (nip)
547 		*nip = 0;
548 	if (namelen == 0)
549 		return (0);
550 
551 	/*
552 	 * search starts from "root"
553 	 */
554 	pnode = *rnode;
555 	if (SYSCTL_VERS(pnode->sysctl_flags) != SYSCTL_VERSION) {
556 		printf("sysctl_locate: pnode %p wrong version\n", pnode);
557 		return (EINVAL);
558 	}
559 	node = pnode->sysctl_child;
560 	error = 0;
561 
562 	/*
563 	 * scan for node to which new node should be attached
564 	 */
565 	for (ni = 0; ni < namelen; ni++) {
566 		/*
567 		 * walked off bottom of tree
568 		 */
569 		if (node == NULL) {
570 			if (SYSCTL_TYPE(pnode->sysctl_flags) == CTLTYPE_NODE)
571 				error = ENOENT;
572 			else
573 				error = ENOTDIR;
574 			break;
575 		}
576 		/*
577 		 * can anyone traverse this node or only root?
578 		 */
579 		if (l != NULL && (pnode->sysctl_flags & CTLFLAG_PRIVATE) &&
580 		    (error = kauth_authorize_system(l->l_cred,
581 		    KAUTH_SYSTEM_SYSCTL, KAUTH_REQ_SYSTEM_SYSCTL_PRVT,
582 		    NULL, NULL, NULL)) != 0)
583 			return (error);
584 		/*
585 		 * find a child node with the right number
586 		 */
587 		tn = name[ni];
588 		alias = 0;
589 
590 		si = 0;
591 		/*
592 		 * Note: ANYNUMBER only matches positive integers.
593 		 * Since ANYNUMBER is only permitted on single-node
594 		 * sub-trees (eg proc), check before the loop and skip
595 		 * it if we can.
596 		 */
597 		if ((node[si].sysctl_flags & CTLFLAG_ANYNUMBER) && (tn >= 0))
598 			goto foundit;
599 		for (; si < pnode->sysctl_clen; si++) {
600 			if (node[si].sysctl_num == tn) {
601 				if (node[si].sysctl_flags & CTLFLAG_ALIAS) {
602 					if (alias++ == 4)
603 						break;
604 					else {
605 						tn = node[si].sysctl_alias;
606 						si = -1;
607 					}
608 				} else
609 					goto foundit;
610 			}
611 		}
612 		/*
613 		 * if we ran off the end, it obviously doesn't exist
614 		 */
615 		error = ENOENT;
616 		break;
617 
618 		/*
619 		 * so far so good, move on down the line
620 		 */
621 	  foundit:
622 		pnode = &node[si];
623 		if (SYSCTL_TYPE(pnode->sysctl_flags) == CTLTYPE_NODE)
624 			node = node[si].sysctl_child;
625 		else
626 			node = NULL;
627 	}
628 
629 	*rnode = pnode;
630 	if (nip)
631 		*nip = ni;
632 
633 	return (error);
634 }
635 
636 /*
637  * sysctl_query -- The auto-discovery engine.  Copies out the structs
638  * describing nodes under the given node and handles overlay trees.
639  */
640 int
641 sysctl_query(SYSCTLFN_ARGS)
642 {
643 	int error, ni, elim, v;
644 	size_t out, left, t;
645 	const struct sysctlnode *enode, *onode;
646 	struct sysctlnode qnode;
647 
648 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
649 		printf("sysctl_query: rnode %p wrong version\n", rnode);
650 		return (EINVAL);
651 	}
652 
653 	if (SYSCTL_TYPE(rnode->sysctl_flags) != CTLTYPE_NODE)
654 		return (ENOTDIR);
655 	if (namelen != 1 || name[0] != CTL_QUERY)
656 		return (EINVAL);
657 
658 	error = 0;
659 	out = 0;
660 	left = *oldlenp;
661 	elim = 0;
662 	enode = NULL;
663 
664 	/*
665 	 * translate the given request to a current node
666 	 */
667 	error = sysctl_cvt_in(l, &v, newp, newlen, &qnode);
668 	if (error)
669 		return (error);
670 
671 	/*
672 	 * if the request specifies a version, check it
673 	 */
674 	if (qnode.sysctl_ver != 0) {
675 		enode = rnode;
676 		if (qnode.sysctl_ver != enode->sysctl_ver &&
677 		    qnode.sysctl_ver != sysctl_rootof(enode)->sysctl_ver)
678 			return (EINVAL);
679 	}
680 
681 	/*
682 	 * process has overlay tree
683 	 */
684 	if (l && l->l_proc->p_emul->e_sysctlovly) {
685 		enode = l->l_proc->p_emul->e_sysctlovly;
686 		elim = (name - oname);
687 		error = sysctl_locate(l, oname, elim, &enode, NULL);
688 		if (error == 0) {
689 			/* ah, found parent in overlay */
690 			elim = enode->sysctl_clen;
691 			enode = enode->sysctl_child;
692 		} else {
693 			error = 0;
694 			elim = 0;
695 			enode = NULL;
696 		}
697 	}
698 
699 	for (ni = 0; ni < rnode->sysctl_clen; ni++) {
700 		onode = &rnode->sysctl_child[ni];
701 		if (enode && enode->sysctl_num == onode->sysctl_num) {
702 			if (SYSCTL_TYPE(enode->sysctl_flags) != CTLTYPE_NODE)
703 				onode = enode;
704 			if (--elim > 0)
705 				enode++;
706 			else
707 				enode = NULL;
708 		}
709 		error = sysctl_cvt_out(l, v, onode, oldp, left, &t);
710 		if (error)
711 			return (error);
712 		if (oldp != NULL)
713 			oldp = (char*)oldp + t;
714 		out += t;
715 		left -= MIN(left, t);
716 	}
717 
718 	/*
719 	 * overlay trees *MUST* be entirely consumed
720 	 */
721 	KASSERT(enode == NULL);
722 
723 	*oldlenp = out;
724 
725 	return (error);
726 }
727 
728 /*
729  * sysctl_create -- Adds a node (the description of which is taken
730  * from newp) to the tree, returning a copy of it in the space pointed
731  * to by oldp.  In the event that the requested slot is already taken
732  * (either by name or by number), the offending node is returned
733  * instead.  Yes, this is complex, but we want to make sure everything
734  * is proper.
735  */
736 #ifdef SYSCTL_DEBUG_CREATE
737 int _sysctl_create(SYSCTLFN_ARGS);
738 int
739 _sysctl_create(SYSCTLFN_ARGS)
740 #else
741 int
742 sysctl_create(SYSCTLFN_ARGS)
743 #endif
744 {
745 	struct sysctlnode nnode, *node, *pnode;
746 	int error, ni, at, nm, type, sz, flags, anum, v;
747 	void *own;
748 
749 	error = 0;
750 	own = NULL;
751 	anum = -1;
752 
753 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
754 		printf("sysctl_create: rnode %p wrong version\n", rnode);
755 		return (EINVAL);
756 	}
757 
758 	if (namelen != 1 || (name[namelen - 1] != CTL_CREATE
759 #if NKSYMS > 0
760 			     && name[namelen - 1] != CTL_CREATESYM
761 #endif /* NKSYMS > 0 */
762 			     ))
763 		return (EINVAL);
764 
765 	/*
766 	 * processes can only add nodes at securelevel 0, must be
767 	 * root, and can't add nodes to a parent that's not writeable
768 	 */
769 	if (l != NULL) {
770 #ifndef SYSCTL_DISALLOW_CREATE
771 		error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
772 		    KAUTH_REQ_SYSTEM_SYSCTL_ADD, NULL, NULL, NULL);
773 		if (error)
774 			return (error);
775 		if (!(rnode->sysctl_flags & CTLFLAG_READWRITE))
776 #endif /* SYSCTL_DISALLOW_CREATE */
777 			return (EPERM);
778 	}
779 
780 	/*
781 	 * nothing can add a node if:
782 	 * we've finished initial set up and
783 	 * the tree itself is not writeable or
784 	 * the entire sysctl system is not writeable
785 	 */
786 	if ((sysctl_root.sysctl_flags & CTLFLAG_PERMANENT) &&
787 	    (!(sysctl_rootof(rnode)->sysctl_flags & CTLFLAG_READWRITE) ||
788 	     !(sysctl_root.sysctl_flags & CTLFLAG_READWRITE)))
789 		return (EPERM);
790 
791 	/*
792 	 * it must be a "node", not a "int" or something
793 	 */
794 	if (SYSCTL_TYPE(rnode->sysctl_flags) != CTLTYPE_NODE)
795 		return (ENOTDIR);
796 	if (rnode->sysctl_flags & CTLFLAG_ALIAS) {
797 		printf("sysctl_create: attempt to add node to aliased "
798 		       "node %p\n", rnode);
799 		return (EINVAL);
800 	}
801 	pnode = __UNCONST(rnode); /* we are adding children to this node */
802 
803 	if (newp == NULL)
804 		return (EINVAL);
805 	error = sysctl_cvt_in(l, &v, newp, newlen, &nnode);
806 	if (error)
807 		return (error);
808 
809 	/*
810 	 * nodes passed in don't *have* parents
811 	 */
812 	if (nnode.sysctl_parent != NULL)
813 		return (EINVAL);
814 
815 	/*
816 	 * if we are indeed adding it, it should be a "good" name and
817 	 * number
818 	 */
819 	nm = nnode.sysctl_num;
820 #if NKSYMS > 0
821 	if (nm == CTL_CREATESYM)
822 		nm = CTL_CREATE;
823 #endif /* NKSYMS > 0 */
824 	if (nm < 0 && nm != CTL_CREATE)
825 		return (EINVAL);
826 	sz = 0;
827 
828 	/*
829 	 * the name can't start with a digit
830 	 */
831 	if (nnode.sysctl_name[sz] >= '0' &&
832 	    nnode.sysctl_name[sz] <= '9')
833 		return (EINVAL);
834 
835 	/*
836 	 * the name must be only alphanumerics or - or _, longer than
837 	 * 0 bytes and less that SYSCTL_NAMELEN
838 	 */
839 	while (sz < SYSCTL_NAMELEN && nnode.sysctl_name[sz] != '\0') {
840 		if ((nnode.sysctl_name[sz] >= '0' &&
841 		     nnode.sysctl_name[sz] <= '9') ||
842 		    (nnode.sysctl_name[sz] >= 'A' &&
843 		     nnode.sysctl_name[sz] <= 'Z') ||
844 		    (nnode.sysctl_name[sz] >= 'a' &&
845 		     nnode.sysctl_name[sz] <= 'z') ||
846 		    nnode.sysctl_name[sz] == '-' ||
847 		    nnode.sysctl_name[sz] == '_')
848 			sz++;
849 		else
850 			return (EINVAL);
851 	}
852 	if (sz == 0 || sz == SYSCTL_NAMELEN)
853 		return (EINVAL);
854 
855 	/*
856 	 * various checks revolve around size vs type, etc
857 	 */
858 	type = SYSCTL_TYPE(nnode.sysctl_flags);
859 	flags = SYSCTL_FLAGS(nnode.sysctl_flags);
860 	sz = nnode.sysctl_size;
861 
862 	/*
863 	 * find out if there's a collision, and if so, let the caller
864 	 * know what they collided with
865 	 */
866 	node = pnode->sysctl_child;
867 	at = 0;
868 	if (node) {
869 		if ((flags | node->sysctl_flags) & CTLFLAG_ANYNUMBER)
870 			/* No siblings for a CTLFLAG_ANYNUMBER node */
871 			return EINVAL;
872 		for (ni = 0; ni < pnode->sysctl_clen; ni++) {
873 			if (nm == node[ni].sysctl_num ||
874 			    strcmp(nnode.sysctl_name, node[ni].sysctl_name) == 0) {
875 				/*
876 				 * ignore error here, since we
877 				 * are already fixed on EEXIST
878 				 */
879 				(void)sysctl_cvt_out(l, v, &node[ni], oldp,
880 						     *oldlenp, oldlenp);
881 				return (EEXIST);
882 			}
883 			if (nm > node[ni].sysctl_num)
884 				at++;
885 		}
886 	}
887 
888 	/*
889 	 * use sysctl_ver to add to the tree iff it hasn't changed
890 	 */
891 	if (nnode.sysctl_ver != 0) {
892 		/*
893 		 * a specified value must match either the parent
894 		 * node's version or the root node's version
895 		 */
896 		if (nnode.sysctl_ver != sysctl_rootof(rnode)->sysctl_ver &&
897 		    nnode.sysctl_ver != rnode->sysctl_ver) {
898 			return (EINVAL);
899 		}
900 	}
901 
902 	/*
903 	 * only the kernel can assign functions to entries
904 	 */
905 	if (l != NULL && nnode.sysctl_func != NULL)
906 		return (EPERM);
907 
908 	/*
909 	 * only the kernel can create permanent entries, and only then
910 	 * before the kernel is finished setting itself up
911 	 */
912 	if (l != NULL && (flags & ~SYSCTL_USERFLAGS))
913 		return (EPERM);
914 	if ((flags & CTLFLAG_PERMANENT) &
915 	    (sysctl_root.sysctl_flags & CTLFLAG_PERMANENT))
916 		return (EPERM);
917 	if ((flags & (CTLFLAG_OWNDATA | CTLFLAG_IMMEDIATE)) ==
918 	    (CTLFLAG_OWNDATA | CTLFLAG_IMMEDIATE))
919 		return (EINVAL);
920 	if ((flags & CTLFLAG_IMMEDIATE) &&
921 	    type != CTLTYPE_INT && type != CTLTYPE_QUAD)
922 		return (EINVAL);
923 
924 	/*
925 	 * check size, or set it if unset and we can figure it out.
926 	 * kernel created nodes are allowed to have a function instead
927 	 * of a size (or a data pointer).
928 	 */
929 	switch (type) {
930 	case CTLTYPE_NODE:
931 		/*
932 		 * only *i* can assert the size of a node
933 		 */
934 		if (flags & CTLFLAG_ALIAS) {
935 			anum = nnode.sysctl_alias;
936 			if (anum < 0)
937 				return (EINVAL);
938 			nnode.sysctl_alias = 0;
939 		}
940 		if (sz != 0 || nnode.sysctl_data != NULL)
941 			return (EINVAL);
942 		if (nnode.sysctl_csize != 0 ||
943 		    nnode.sysctl_clen != 0 ||
944 		    nnode.sysctl_child != 0)
945 			return (EINVAL);
946 		if (flags & CTLFLAG_OWNDATA)
947 			return (EINVAL);
948 		sz = sizeof(struct sysctlnode);
949 		break;
950 	case CTLTYPE_INT:
951 		/*
952 		 * since an int is an int, if the size is not given or
953 		 * is wrong, we can "int-uit" it.
954 		 */
955 		if (sz != 0 && sz != sizeof(int))
956 			return (EINVAL);
957 		sz = sizeof(int);
958 		break;
959 	case CTLTYPE_STRING:
960 		/*
961 		 * strings are a little more tricky
962 		 */
963 		if (sz == 0) {
964 			if (l == NULL) {
965 				if (nnode.sysctl_func == NULL) {
966 					if (nnode.sysctl_data == NULL)
967 						return (EINVAL);
968 					else
969 						sz = strlen(nnode.sysctl_data) +
970 						    1;
971 				}
972 			} else if (nnode.sysctl_data == NULL &&
973 				 flags & CTLFLAG_OWNDATA) {
974 				return (EINVAL);
975 			} else {
976 				char *vp, *e;
977 				size_t s;
978 
979 				/*
980 				 * we want a rough idea of what the
981 				 * size is now
982 				 */
983 				vp = malloc(PAGE_SIZE, M_SYSCTLDATA,
984 					     M_WAITOK|M_CANFAIL);
985 				if (vp == NULL)
986 					return (ENOMEM);
987 				e = nnode.sysctl_data;
988 				do {
989 					error = copyinstr(e, vp, PAGE_SIZE, &s);
990 					if (error) {
991 						if (error != ENAMETOOLONG) {
992 							free(vp, M_SYSCTLDATA);
993 							return (error);
994 						}
995 						e += PAGE_SIZE;
996 						if ((e - 32 * PAGE_SIZE) >
997 						    (char*)nnode.sysctl_data) {
998 							free(vp, M_SYSCTLDATA);
999 							return (ERANGE);
1000 						}
1001 					}
1002 				} while (error != 0);
1003 				sz = s + (e - (char*)nnode.sysctl_data);
1004 				free(vp, M_SYSCTLDATA);
1005 			}
1006 		}
1007 		break;
1008 	case CTLTYPE_QUAD:
1009 		if (sz != 0 && sz != sizeof(u_quad_t))
1010 			return (EINVAL);
1011 		sz = sizeof(u_quad_t);
1012 		break;
1013 	case CTLTYPE_STRUCT:
1014 		if (sz == 0) {
1015 			if (l != NULL || nnode.sysctl_func == NULL)
1016 				return (EINVAL);
1017 			if (flags & CTLFLAG_OWNDATA)
1018 				return (EINVAL);
1019 		}
1020 		break;
1021 	default:
1022 		return (EINVAL);
1023 	}
1024 
1025 	/*
1026 	 * at this point, if sz is zero, we *must* have a
1027 	 * function to go with it and we can't own it.
1028 	 */
1029 
1030 	/*
1031 	 *  l  ptr own
1032 	 *  0   0   0  -> EINVAL (if no func)
1033 	 *  0   0   1  -> own
1034 	 *  0   1   0  -> kptr
1035 	 *  0   1   1  -> kptr
1036 	 *  1   0   0  -> EINVAL
1037 	 *  1   0   1  -> own
1038 	 *  1   1   0  -> kptr, no own (fault on lookup)
1039 	 *  1   1   1  -> uptr, own
1040 	 */
1041 	if (type != CTLTYPE_NODE) {
1042 		if (sz != 0) {
1043 			if (flags & CTLFLAG_OWNDATA) {
1044 				own = malloc(sz, M_SYSCTLDATA,
1045 					     M_WAITOK|M_CANFAIL);
1046 				if (own == NULL)
1047 					return ENOMEM;
1048 				if (nnode.sysctl_data == NULL)
1049 					memset(own, 0, sz);
1050 				else {
1051 					error = sysctl_copyin(l,
1052 					    nnode.sysctl_data, own, sz);
1053 					if (error != 0) {
1054 						free(own, M_SYSCTLDATA);
1055 						return (error);
1056 					}
1057 				}
1058 			} else if ((nnode.sysctl_data != NULL) &&
1059 				 !(flags & CTLFLAG_IMMEDIATE)) {
1060 #if NKSYMS > 0
1061 				if (name[namelen - 1] == CTL_CREATESYM) {
1062 					char symname[128]; /* XXX enough? */
1063 					u_long symaddr;
1064 					size_t symlen;
1065 
1066 					error = sysctl_copyinstr(l,
1067 					    nnode.sysctl_data, symname,
1068 					    sizeof(symname), &symlen);
1069 					if (error)
1070 						return (error);
1071 					error = ksyms_getval(NULL, symname,
1072 					    &symaddr, KSYMS_EXTERN);
1073 					if (error)
1074 						return (error); /* EINVAL? */
1075 					nnode.sysctl_data = (void*)symaddr;
1076 				}
1077 #endif /* NKSYMS > 0 */
1078 				/*
1079 				 * Ideally, we'd like to verify here
1080 				 * that this address is acceptable,
1081 				 * but...
1082 				 *
1083 				 * - it might be valid now, only to
1084 				 *   become invalid later
1085 				 *
1086 				 * - it might be invalid only for the
1087 				 *   moment and valid later
1088 				 *
1089 				 * - or something else.
1090 				 *
1091 				 * Since we can't get a good answer,
1092 				 * we'll just accept the address as
1093 				 * given, and fault on individual
1094 				 * lookups.
1095 				 */
1096 			}
1097 		} else if (nnode.sysctl_func == NULL)
1098 			return (EINVAL);
1099 	}
1100 
1101 	/*
1102 	 * a process can't assign a function to a node, and the kernel
1103 	 * can't create a node that has no function or data.
1104 	 * (XXX somewhat redundant check)
1105 	 */
1106 	if (l != NULL || nnode.sysctl_func == NULL) {
1107 		if (type != CTLTYPE_NODE &&
1108 		    nnode.sysctl_data == NULL &&
1109 		    !(flags & CTLFLAG_IMMEDIATE) &&
1110 		    own == NULL)
1111 			return (EINVAL);
1112 	}
1113 
1114 #ifdef SYSCTL_DISALLOW_KWRITE
1115 	/*
1116 	 * a process can't create a writable node unless it refers to
1117 	 * new data.
1118 	 */
1119 	if (l != NULL && own == NULL && type != CTLTYPE_NODE &&
1120 	    (flags & CTLFLAG_READWRITE) != CTLFLAG_READONLY &&
1121 	    !(flags & CTLFLAG_IMMEDIATE))
1122 		return (EPERM);
1123 #endif /* SYSCTL_DISALLOW_KWRITE */
1124 
1125 	/*
1126 	 * make sure there's somewhere to put the new stuff.
1127 	 */
1128 	if (pnode->sysctl_child == NULL) {
1129 		if (flags & CTLFLAG_ANYNUMBER)
1130 			error = sysctl_alloc(pnode, 1);
1131 		else
1132 			error = sysctl_alloc(pnode, 0);
1133 		if (error) {
1134 			if (own != NULL)
1135 				free(own, M_SYSCTLDATA);
1136 			return (error);
1137 		}
1138 	}
1139 	node = pnode->sysctl_child;
1140 
1141 	/*
1142 	 * no collisions, so pick a good dynamic number if we need to.
1143 	 */
1144 	if (nm == CTL_CREATE) {
1145 		nm = ++sysctl_root.sysctl_num;
1146 		for (ni = 0; ni < pnode->sysctl_clen; ni++) {
1147 			if (nm == node[ni].sysctl_num) {
1148 				nm++;
1149 				ni = -1;
1150 			} else if (nm > node[ni].sysctl_num)
1151 				at = ni + 1;
1152 		}
1153 	}
1154 
1155 	/*
1156 	 * oops...ran out of space
1157 	 */
1158 	if (pnode->sysctl_clen == pnode->sysctl_csize) {
1159 		error = sysctl_realloc(pnode);
1160 		if (error) {
1161 			if (own != NULL)
1162 				free(own, M_SYSCTLDATA);
1163 			return (error);
1164 		}
1165 		node = pnode->sysctl_child;
1166 	}
1167 
1168 	/*
1169 	 * insert new node data
1170 	 */
1171 	if (at < pnode->sysctl_clen) {
1172 		int t;
1173 
1174 		/*
1175 		 * move the nodes that should come after the new one
1176 		 */
1177 		memmove(&node[at + 1], &node[at],
1178 			(pnode->sysctl_clen - at) * sizeof(struct sysctlnode));
1179 		memset(&node[at], 0, sizeof(struct sysctlnode));
1180 		node[at].sysctl_parent = pnode;
1181 		/*
1182 		 * and...reparent any children of any moved nodes
1183 		 */
1184 		for (ni = at; ni <= pnode->sysctl_clen; ni++)
1185 			if (SYSCTL_TYPE(node[ni].sysctl_flags) == CTLTYPE_NODE)
1186 				for (t = 0; t < node[ni].sysctl_clen; t++)
1187 					node[ni].sysctl_child[t].sysctl_parent =
1188 						&node[ni];
1189 	}
1190 	node = &node[at];
1191 	pnode->sysctl_clen++;
1192 
1193 	strlcpy(node->sysctl_name, nnode.sysctl_name,
1194 		sizeof(node->sysctl_name));
1195 	node->sysctl_num = nm;
1196 	node->sysctl_size = sz;
1197 	node->sysctl_flags = SYSCTL_VERSION|type|flags; /* XXX other trees */
1198 	node->sysctl_csize = 0;
1199 	node->sysctl_clen = 0;
1200 	if (own) {
1201 		node->sysctl_data = own;
1202 		node->sysctl_flags |= CTLFLAG_OWNDATA;
1203 	} else if (flags & CTLFLAG_ALIAS) {
1204 		node->sysctl_alias = anum;
1205 	} else if (flags & CTLFLAG_IMMEDIATE) {
1206 		switch (type) {
1207 		case CTLTYPE_INT:
1208 			node->sysctl_idata = nnode.sysctl_idata;
1209 			break;
1210 		case CTLTYPE_QUAD:
1211 			node->sysctl_qdata = nnode.sysctl_qdata;
1212 			break;
1213 		}
1214 	} else {
1215 		node->sysctl_data = nnode.sysctl_data;
1216 		node->sysctl_flags &= ~CTLFLAG_OWNDATA;
1217 	}
1218         node->sysctl_func = nnode.sysctl_func;
1219         node->sysctl_child = NULL;
1220 	/* node->sysctl_parent should already be done */
1221 
1222 	/*
1223 	 * update "version" on path to "root"
1224 	 */
1225 	for (; rnode->sysctl_parent != NULL; rnode = rnode->sysctl_parent)
1226 		;
1227 	pnode = node;
1228 	for (nm = rnode->sysctl_ver + 1; pnode != NULL;
1229 	     pnode = pnode->sysctl_parent)
1230 		pnode->sysctl_ver = nm;
1231 
1232 	/* If this fails, the node is already added - the user won't know! */
1233 	error = sysctl_cvt_out(l, v, node, oldp, *oldlenp, oldlenp);
1234 
1235 	return (error);
1236 }
1237 
1238 /*
1239  * ********************************************************************
1240  * A wrapper around sysctl_create() that prints the thing we're trying
1241  * to add.
1242  * ********************************************************************
1243  */
1244 #ifdef SYSCTL_DEBUG_CREATE
1245 int
1246 sysctl_create(SYSCTLFN_ARGS)
1247 {
1248 	const struct sysctlnode *node;
1249 	int k, rc, ni, nl = namelen + (name - oname);
1250 
1251 	node = newp;
1252 
1253 	printf("namelen %d (", nl);
1254 	for (ni = 0; ni < nl - 1; ni++)
1255 		printf(" %d", oname[ni]);
1256 	printf(" %d )\t[%s]\tflags %08x (%08x %d %zu)\n",
1257 	       k = node->sysctl_num,
1258 	       node->sysctl_name,
1259 	       node->sysctl_flags,
1260 	       SYSCTL_FLAGS(node->sysctl_flags),
1261 	       SYSCTL_TYPE(node->sysctl_flags),
1262 	       node->sysctl_size);
1263 
1264 	node = rnode;
1265 	rc = _sysctl_create(SYSCTLFN_CALL(rnode));
1266 
1267 	printf("sysctl_create(");
1268 	for (ni = 0; ni < nl - 1; ni++)
1269 		printf(" %d", oname[ni]);
1270 	printf(" %d ) returned %d\n", k, rc);
1271 
1272 	return (rc);
1273 }
1274 #endif /* SYSCTL_DEBUG_CREATE */
1275 
1276 /*
1277  * sysctl_destroy -- Removes a node (as described by newp) from the
1278  * given tree, returning (if successful) a copy of the dead node in
1279  * oldp.  Since we're removing stuff, there's not much to check.
1280  */
1281 int
1282 sysctl_destroy(SYSCTLFN_ARGS)
1283 {
1284 	struct sysctlnode *node, *pnode, onode, nnode;
1285 	int ni, error, v;
1286 
1287 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1288 		printf("sysctl_destroy: rnode %p wrong version\n", rnode);
1289 		return (EINVAL);
1290 	}
1291 
1292 	error = 0;
1293 
1294 	if (namelen != 1 || name[namelen - 1] != CTL_DESTROY)
1295 		return (EINVAL);
1296 
1297 	/*
1298 	 * processes can only destroy nodes at securelevel 0, must be
1299 	 * root, and can't remove nodes from a parent that's not
1300 	 * writeable
1301 	 */
1302 	if (l != NULL) {
1303 #ifndef SYSCTL_DISALLOW_CREATE
1304 		error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
1305 		    KAUTH_REQ_SYSTEM_SYSCTL_DELETE, NULL, NULL, NULL);
1306 		if (error)
1307 			return (error);
1308 		if (!(rnode->sysctl_flags & CTLFLAG_READWRITE))
1309 #endif /* SYSCTL_DISALLOW_CREATE */
1310 			return (EPERM);
1311 	}
1312 
1313 	/*
1314 	 * nothing can remove a node if:
1315 	 * the node is permanent (checked later) or
1316 	 * the tree itself is not writeable or
1317 	 * the entire sysctl system is not writeable
1318 	 *
1319 	 * note that we ignore whether setup is complete or not,
1320 	 * because these rules always apply.
1321 	 */
1322 	if (!(sysctl_rootof(rnode)->sysctl_flags & CTLFLAG_READWRITE) ||
1323 	    !(sysctl_root.sysctl_flags & CTLFLAG_READWRITE))
1324 		return (EPERM);
1325 
1326 	if (newp == NULL)
1327 		return (EINVAL);
1328 	error = sysctl_cvt_in(l, &v, newp, newlen, &nnode);
1329 	if (error)
1330 		return (error);
1331 	memset(&onode, 0, sizeof(struct sysctlnode));
1332 
1333 	node = rnode->sysctl_child;
1334 	for (ni = 0; ni < rnode->sysctl_clen; ni++) {
1335 		if (nnode.sysctl_num == node[ni].sysctl_num) {
1336 			/*
1337 			 * if name specified, must match
1338 			 */
1339 			if (nnode.sysctl_name[0] != '\0' &&
1340 			    strcmp(nnode.sysctl_name, node[ni].sysctl_name))
1341 				continue;
1342 			/*
1343 			 * if version specified, must match
1344 			 */
1345 			if (nnode.sysctl_ver != 0 &&
1346 			    nnode.sysctl_ver != node[ni].sysctl_ver)
1347 				continue;
1348 			/*
1349 			 * this must be the one
1350 			 */
1351 			break;
1352 		}
1353 	}
1354 	if (ni == rnode->sysctl_clen)
1355 		return (ENOENT);
1356 	node = &node[ni];
1357 	pnode = node->sysctl_parent;
1358 
1359 	/*
1360 	 * if the kernel says permanent, it is, so there.  nyah.
1361 	 */
1362 	if (SYSCTL_FLAGS(node->sysctl_flags) & CTLFLAG_PERMANENT)
1363 		return (EPERM);
1364 
1365 	/*
1366 	 * can't delete non-empty nodes
1367 	 */
1368 	if (SYSCTL_TYPE(node->sysctl_flags) == CTLTYPE_NODE &&
1369 	    node->sysctl_clen != 0)
1370 		return (ENOTEMPTY);
1371 
1372 	/*
1373 	 * if the node "owns" data, release it now
1374 	 */
1375 	if (node->sysctl_flags & CTLFLAG_OWNDATA) {
1376 		if (node->sysctl_data != NULL)
1377 			free(node->sysctl_data, M_SYSCTLDATA);
1378 		node->sysctl_data = NULL;
1379 	}
1380 	if (node->sysctl_flags & CTLFLAG_OWNDESC) {
1381 		if (node->sysctl_desc != NULL)
1382 			/*XXXUNCONST*/
1383 			free(__UNCONST(node->sysctl_desc), M_SYSCTLDATA);
1384 		node->sysctl_desc = NULL;
1385 	}
1386 
1387 	/*
1388 	 * if the node to be removed is not the last one on the list,
1389 	 * move the remaining nodes up, and reparent any grandchildren
1390 	 */
1391 	onode = *node;
1392 	if (ni < pnode->sysctl_clen - 1) {
1393 		int t;
1394 
1395 		memmove(&pnode->sysctl_child[ni], &pnode->sysctl_child[ni + 1],
1396 			(pnode->sysctl_clen - ni - 1) *
1397 			sizeof(struct sysctlnode));
1398 		for (; ni < pnode->sysctl_clen - 1; ni++)
1399 			if (SYSCTL_TYPE(pnode->sysctl_child[ni].sysctl_flags) ==
1400 			    CTLTYPE_NODE)
1401 				for (t = 0;
1402 				     t < pnode->sysctl_child[ni].sysctl_clen;
1403 				     t++)
1404 					pnode->sysctl_child[ni].sysctl_child[t].
1405 						sysctl_parent =
1406 						&pnode->sysctl_child[ni];
1407 		ni = pnode->sysctl_clen - 1;
1408 		node = &pnode->sysctl_child[ni];
1409 	}
1410 
1411 	/*
1412 	 * reset the space we just vacated
1413 	 */
1414 	memset(node, 0, sizeof(struct sysctlnode));
1415 	node->sysctl_parent = pnode;
1416 	pnode->sysctl_clen--;
1417 
1418 	/*
1419 	 * if this parent just lost its last child, nuke the creche
1420 	 */
1421 	if (pnode->sysctl_clen == 0) {
1422 		free(pnode->sysctl_child, M_SYSCTLNODE);
1423 		pnode->sysctl_csize = 0;
1424 		pnode->sysctl_child = NULL;
1425 	}
1426 
1427 	/*
1428 	 * update "version" on path to "root"
1429 	 */
1430         for (; rnode->sysctl_parent != NULL; rnode = rnode->sysctl_parent)
1431                 ;
1432 	for (ni = rnode->sysctl_ver + 1; pnode != NULL;
1433 	     pnode = pnode->sysctl_parent)
1434 		pnode->sysctl_ver = ni;
1435 
1436 	error = sysctl_cvt_out(l, v, &onode, oldp, *oldlenp, oldlenp);
1437 
1438 	return (error);
1439 }
1440 
1441 /*
1442  * sysctl_lookup -- Handles copyin/copyout of new and old values.
1443  * Partial reads are globally allowed.  Only root can write to things
1444  * unless the node says otherwise.
1445  */
1446 int
1447 sysctl_lookup(SYSCTLFN_ARGS)
1448 {
1449 	int error, rw;
1450 	size_t sz, len;
1451 	void *d;
1452 
1453 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1454 		printf("sysctl_lookup: rnode %p wrong version\n", rnode);
1455 		return (EINVAL);
1456 	}
1457 
1458 	error = 0;
1459 
1460 	/*
1461 	 * you can't "look up" a node.  you can "query" it, but you
1462 	 * can't "look it up".
1463 	 */
1464 	if (SYSCTL_TYPE(rnode->sysctl_flags) == CTLTYPE_NODE || namelen != 0)
1465 		return (EINVAL);
1466 
1467 	/*
1468 	 * some nodes are private, so only root can look into them.
1469 	 */
1470 	if (l != NULL && (rnode->sysctl_flags & CTLFLAG_PRIVATE) &&
1471 	    (error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
1472 	    KAUTH_REQ_SYSTEM_SYSCTL_PRVT, NULL, NULL, NULL)) != 0)
1473 		return (error);
1474 
1475 	/*
1476 	 * if a node wants to be writable according to different rules
1477 	 * other than "only root can write to stuff unless a flag is
1478 	 * set", then it needs its own function which should have been
1479 	 * called and not us.
1480 	 */
1481 	if (l != NULL && newp != NULL &&
1482 	    !(rnode->sysctl_flags & CTLFLAG_ANYWRITE) &&
1483 	    (error = kauth_authorize_generic(l->l_cred,
1484 	    KAUTH_GENERIC_ISSUSER, &l->l_acflag)) != 0)
1485 		return (error);
1486 
1487 	/*
1488 	 * is this node supposedly writable?
1489 	 */
1490 	rw = (rnode->sysctl_flags & CTLFLAG_READWRITE) ? 1 : 0;
1491 
1492 	/*
1493 	 * it appears not to be writable at this time, so if someone
1494 	 * tried to write to it, we must tell them to go away
1495 	 */
1496 	if (!rw && newp != NULL)
1497 		return (EPERM);
1498 
1499 	/*
1500 	 * step one, copy out the stuff we have presently
1501 	 */
1502 	if (rnode->sysctl_flags & CTLFLAG_IMMEDIATE) {
1503 		/*
1504 		 * note that we discard const here because we are
1505 		 * modifying the contents of the node (which is okay
1506 		 * because it's ours)
1507 		 */
1508 		switch (SYSCTL_TYPE(rnode->sysctl_flags)) {
1509 		case CTLTYPE_INT:
1510 			d = __UNCONST(&rnode->sysctl_idata);
1511 			break;
1512 		case CTLTYPE_QUAD:
1513 			d = __UNCONST(&rnode->sysctl_qdata);
1514 			break;
1515 		default:
1516 			return (EINVAL);
1517 		}
1518 	} else
1519 		d = rnode->sysctl_data;
1520 	if (SYSCTL_TYPE(rnode->sysctl_flags) == CTLTYPE_STRING)
1521 		sz = strlen(d) + 1; /* XXX@@@ possible fault here */
1522 	else
1523 		sz = rnode->sysctl_size;
1524 	if (oldp != NULL)
1525 		error = sysctl_copyout(l, d, oldp, MIN(sz, *oldlenp));
1526 	if (error)
1527 		return (error);
1528 	*oldlenp = sz;
1529 
1530 	/*
1531 	 * are we done?
1532 	 */
1533 	if (newp == NULL || newlen == 0)
1534 		return (0);
1535 
1536 	/*
1537 	 * hmm...not done.  must now "copy in" new value.  re-adjust
1538 	 * sz to maximum value (strings are "weird").
1539 	 */
1540 	sz = rnode->sysctl_size;
1541 	switch (SYSCTL_TYPE(rnode->sysctl_flags)) {
1542 	case CTLTYPE_INT:
1543 	case CTLTYPE_QUAD:
1544 	case CTLTYPE_STRUCT:
1545 		/*
1546 		 * these data must be *exactly* the same size coming
1547 		 * in.
1548 		 */
1549 		if (newlen != sz)
1550 			return (EINVAL);
1551 		error = sysctl_copyin(l, newp, d, sz);
1552 		break;
1553 	case CTLTYPE_STRING: {
1554 		/*
1555 		 * strings, on the other hand, can be shorter, and we
1556 		 * let userland be sloppy about the trailing nul.
1557 		 */
1558 		char *newbuf;
1559 
1560 		/*
1561 		 * too much new string?
1562 		 */
1563 		if (newlen > sz)
1564 			return (EINVAL);
1565 
1566 		/*
1567 		 * temporary copy of new inbound string
1568 		 */
1569 		len = MIN(sz, newlen);
1570 		newbuf = malloc(len, M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
1571 		if (newbuf == NULL)
1572 			return (ENOMEM);
1573 		error = sysctl_copyin(l, newp, newbuf, len);
1574 		if (error) {
1575 			free(newbuf, M_SYSCTLDATA);
1576 			return (error);
1577 		}
1578 
1579 		/*
1580 		 * did they null terminate it, or do we have space
1581 		 * left to do it ourselves?
1582 		 */
1583 		if (newbuf[len - 1] != '\0' && len == sz) {
1584 			free(newbuf, M_SYSCTLDATA);
1585 			return (EINVAL);
1586 		}
1587 
1588 		/*
1589 		 * looks good, so pop it into place and zero the rest.
1590 		 */
1591 		if (len > 0)
1592 			memcpy(d, newbuf, len);
1593 		if (sz != len)
1594 			memset((char*)d + len, 0, sz - len);
1595 		free(newbuf, M_SYSCTLDATA);
1596 		break;
1597 	}
1598 	default:
1599 		return (EINVAL);
1600 	}
1601 
1602 	return (error);
1603 }
1604 
1605 /*
1606  * sysctl_mmap -- Dispatches sysctl mmap requests to those nodes that
1607  * purport to handle it.  This interface isn't fully fleshed out yet,
1608  * unfortunately.
1609  */
1610 static int
1611 sysctl_mmap(SYSCTLFN_ARGS)
1612 {
1613 	const struct sysctlnode *node;
1614 	struct sysctlnode nnode;
1615 	int error;
1616 
1617 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1618 		printf("sysctl_mmap: rnode %p wrong version\n", rnode);
1619 		return (EINVAL);
1620 	}
1621 
1622 	/*
1623 	 * let's just pretend that didn't happen, m'kay?
1624 	 */
1625 	if (l == NULL)
1626 		return (EPERM);
1627 
1628 	/*
1629 	 * is this a sysctlnode description of an mmap request?
1630 	 */
1631 	if (newp == NULL || newlen != sizeof(struct sysctlnode))
1632 		return (EINVAL);
1633 	error = sysctl_copyin(l, newp, &nnode, sizeof(nnode));
1634 	if (error)
1635 		return (error);
1636 
1637 	/*
1638 	 * does the node they asked for exist?
1639 	 */
1640 	if (namelen != 1)
1641 		return (EOPNOTSUPP);
1642 	node = rnode;
1643         error = sysctl_locate(l, &nnode.sysctl_num, 1, &node, NULL);
1644 	if (error)
1645 		return (error);
1646 
1647 	/*
1648 	 * does this node that we have found purport to handle mmap?
1649 	 */
1650 	if (node->sysctl_func == NULL ||
1651 	    !(node->sysctl_flags & CTLFLAG_MMAP))
1652 		return (EOPNOTSUPP);
1653 
1654 	/*
1655 	 * well...okay, they asked for it.
1656 	 */
1657 	return ((*node->sysctl_func)(SYSCTLFN_CALL(node)));
1658 }
1659 
1660 int
1661 sysctl_describe(SYSCTLFN_ARGS)
1662 {
1663 	struct sysctldesc *d;
1664 	void *bf;
1665 	size_t sz, left, tot;
1666 	int i, error, v = -1;
1667 	struct sysctlnode *node;
1668 	struct sysctlnode dnode;
1669 
1670 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1671 		printf("sysctl_query: rnode %p wrong version\n", rnode);
1672 		return (EINVAL);
1673 	}
1674 
1675 	if (SYSCTL_TYPE(rnode->sysctl_flags) != CTLTYPE_NODE)
1676 		return (ENOTDIR);
1677 	if (namelen != 1 || name[0] != CTL_DESCRIBE)
1678 		return (EINVAL);
1679 
1680 	/*
1681 	 * get ready...
1682 	 */
1683 	error = 0;
1684 	d = bf = malloc(MAXDESCLEN, M_TEMP, M_WAITOK|M_CANFAIL);
1685 	if (bf == NULL)
1686 		return ENOMEM;
1687 	tot = 0;
1688 	node = rnode->sysctl_child;
1689 	left = *oldlenp;
1690 
1691 	/*
1692 	 * no request -> all descriptions at this level
1693 	 * request with desc unset -> just this node
1694 	 * request with desc set -> set descr for this node
1695 	 */
1696 	if (newp != NULL) {
1697 		error = sysctl_cvt_in(l, &v, newp, newlen, &dnode);
1698 		if (error)
1699 			goto out;
1700 		if (dnode.sysctl_desc != NULL) {
1701 			/*
1702 			 * processes cannot set descriptions above
1703 			 * securelevel 0.  and must be root.  blah
1704 			 * blah blah.  a couple more checks are made
1705 			 * once we find the node we want.
1706 			 */
1707 			if (l != NULL) {
1708 #ifndef SYSCTL_DISALLOW_CREATE
1709 				error = kauth_authorize_system(l->l_cred,
1710 				    KAUTH_SYSTEM_SYSCTL,
1711 				    KAUTH_REQ_SYSTEM_SYSCTL_DESC, NULL,
1712 				    NULL, NULL);
1713 				if (error)
1714 					goto out;
1715 #else /* SYSCTL_DISALLOW_CREATE */
1716 				error = EPERM;
1717 				goto out;
1718 #endif /* SYSCTL_DISALLOW_CREATE */
1719 			}
1720 
1721 			/*
1722 			 * find node and try to set the description on it
1723 			 */
1724 			for (i = 0; i < rnode->sysctl_clen; i++)
1725 				if (node[i].sysctl_num == dnode.sysctl_num)
1726 					break;
1727 			if (i == rnode->sysctl_clen) {
1728 				error = ENOENT;
1729 				goto out;
1730 			}
1731 			node = &node[i];
1732 
1733 			/*
1734 			 * did the caller specify a node version?
1735 			 */
1736 			if (dnode.sysctl_ver != 0 &&
1737 			    dnode.sysctl_ver != node->sysctl_ver) {
1738 				error = EINVAL;
1739 				goto out;
1740 			}
1741 
1742 			/*
1743 			 * okay...some rules:
1744 			 * (1) if setup is done and the tree is
1745 			 *     read-only or the whole system is
1746 			 *     read-only
1747 			 * (2) no one can set a description on a
1748 			 *     permanent node (it must be set when
1749 			 *     using createv)
1750 			 * (3) processes cannot *change* a description
1751 			 * (4) processes *can*, however, set a
1752 			 *     description on a read-only node so that
1753 			 *     one can be created and then described
1754 			 *     in two steps
1755 			 * anything else come to mind?
1756 			 */
1757 			if ((sysctl_root.sysctl_flags & CTLFLAG_PERMANENT) &&
1758 			    (!(sysctl_rootof(node)->sysctl_flags &
1759 			       CTLFLAG_READWRITE) ||
1760 			     !(sysctl_root.sysctl_flags & CTLFLAG_READWRITE))) {
1761 				error = EPERM;
1762 				goto out;
1763 			}
1764 			if (node->sysctl_flags & CTLFLAG_PERMANENT) {
1765 				error = EPERM;
1766 				goto out;
1767 			}
1768 			if (l != NULL && node->sysctl_desc != NULL) {
1769 				error = EPERM;
1770 				goto out;
1771 			}
1772 
1773 			/*
1774 			 * right, let's go ahead.  the first step is
1775 			 * making the description into something the
1776 			 * node can "own", if need be.
1777 			 */
1778 			if (l != NULL ||
1779 			    dnode.sysctl_flags & CTLFLAG_OWNDESC) {
1780 				char *nd, *k;
1781 
1782 				k = malloc(MAXDESCLEN, M_TEMP,
1783 				    M_WAITOK|M_CANFAIL);
1784 				if (k == NULL) {
1785 					error = ENOMEM;
1786 					goto out;
1787 				}
1788 				error = sysctl_copyinstr(l, dnode.sysctl_desc,
1789 							 k, MAXDESCLEN, &sz);
1790 				if (error) {
1791 					free(k, M_TEMP);
1792 					goto out;
1793 				}
1794 				nd = malloc(sz, M_SYSCTLDATA,
1795 					    M_WAITOK|M_CANFAIL);
1796 				if (nd == NULL) {
1797 					free(k, M_TEMP);
1798 					error = ENOMEM;
1799 					goto out;
1800 				}
1801 				memcpy(nd, k, sz);
1802 				dnode.sysctl_flags |= CTLFLAG_OWNDESC;
1803 				dnode.sysctl_desc = nd;
1804 				free(k, M_TEMP);
1805 			}
1806 
1807 			/*
1808 			 * now "release" the old description and
1809 			 * attach the new one.  ta-da.
1810 			 */
1811 			if ((node->sysctl_flags & CTLFLAG_OWNDESC) &&
1812 			    node->sysctl_desc != NULL)
1813 				/*XXXUNCONST*/
1814 				free(__UNCONST(node->sysctl_desc), M_SYSCTLDATA);
1815 			node->sysctl_desc = dnode.sysctl_desc;
1816 			node->sysctl_flags |=
1817 				(dnode.sysctl_flags & CTLFLAG_OWNDESC);
1818 
1819 			/*
1820 			 * now we "fall out" and into the loop which
1821 			 * will copy the new description back out for
1822 			 * those interested parties
1823 			 */
1824 		}
1825 	}
1826 
1827 	/*
1828 	 * scan for one description or just retrieve all descriptions
1829 	 */
1830 	for (i = 0; i < rnode->sysctl_clen; i++) {
1831 		/*
1832 		 * did they ask for the description of only one node?
1833 		 */
1834 		if (v != -1 && node[i].sysctl_num != dnode.sysctl_num)
1835 			continue;
1836 
1837 		/*
1838 		 * don't describe "private" nodes to non-suser users
1839 		 */
1840 		if ((node[i].sysctl_flags & CTLFLAG_PRIVATE) && (l != NULL) &&
1841 		    !(kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
1842 		    KAUTH_REQ_SYSTEM_SYSCTL_PRVT, NULL, NULL, NULL)))
1843 			continue;
1844 
1845 		/*
1846 		 * is this description "valid"?
1847 		 */
1848 		memset(bf, 0, MAXDESCLEN);
1849 		if (node[i].sysctl_desc == NULL)
1850 			sz = 1;
1851 		else if (copystr(node[i].sysctl_desc, &d->descr_str[0],
1852 				 MAXDESCLEN - sizeof(*d), &sz) != 0) {
1853 			/*
1854 			 * erase possible partial description
1855 			 */
1856 			memset(bf, 0, MAXDESCLEN);
1857 			sz = 1;
1858 		}
1859 
1860 		/*
1861 		 * we've got it, stuff it into the caller's buffer
1862 		 */
1863 		d->descr_num = node[i].sysctl_num;
1864 		d->descr_ver = node[i].sysctl_ver;
1865 		d->descr_len = sz; /* includes trailing nul */
1866 		sz = (caddr_t)NEXT_DESCR(d) - (caddr_t)d;
1867 		if (oldp != NULL && left >= sz) {
1868 			error = sysctl_copyout(l, d, oldp, sz);
1869 			if (error)
1870 				goto out;
1871 			left -= sz;
1872 			oldp = (void *)__sysc_desc_adv(oldp, d->descr_len);
1873 		}
1874 		tot += sz;
1875 
1876 		/*
1877 		 * if we get this far with v not "unset", they asked
1878 		 * for a specific node and we found it
1879 		 */
1880 		if (v != -1)
1881 			break;
1882 	}
1883 
1884 	/*
1885 	 * did we find it after all?
1886 	 */
1887 	if (v != -1 && tot == 0)
1888 		error = ENOENT;
1889 	else
1890 		*oldlenp = tot;
1891 
1892 out:
1893 	free(bf, M_TEMP);
1894 	return (error);
1895 }
1896 
1897 /*
1898  * ********************************************************************
1899  * Section 3: Create and destroy from inside the kernel
1900  * ********************************************************************
1901  * sysctl_createv() and sysctl_destroyv() are simpler-to-use
1902  * interfaces for the kernel to fling new entries into the mib and rip
1903  * them out later.  In the case of sysctl_createv(), the returned copy
1904  * of the node (see sysctl_create()) will be translated back into a
1905  * pointer to the actual node.
1906  *
1907  * Note that sysctl_createv() will return 0 if the create request
1908  * matches an existing node (ala mkdir -p), and that sysctl_destroyv()
1909  * will return 0 if the node to be destroyed already does not exist
1910  * (aka rm -f) or if it is a parent of other nodes.
1911  *
1912  * This allows two (or more) different subsystems to assert sub-tree
1913  * existence before populating their own nodes, and to remove their
1914  * own nodes without orphaning the others when they are done.
1915  * ********************************************************************
1916  */
1917 int
1918 sysctl_createv(struct sysctllog **log, int cflags,
1919 	       const struct sysctlnode **rnode, const struct sysctlnode **cnode,
1920 	       int flags, int type, const char *namep, const char *descr,
1921 	       sysctlfn func, u_quad_t qv, void *newp, size_t newlen,
1922 	       ...)
1923 {
1924 	va_list ap;
1925 	int error, ni, namelen, name[CTL_MAXNAME];
1926 	const struct sysctlnode *root, *pnode;
1927 	struct sysctlnode nnode, onode, *dnode;
1928 	size_t sz;
1929 
1930 	/*
1931 	 * where are we putting this?
1932 	 */
1933 	if (rnode != NULL && *rnode == NULL) {
1934 		printf("sysctl_createv: rnode NULL\n");
1935 		return (EINVAL);
1936 	}
1937 	root = rnode ? *rnode : NULL;
1938 	if (cnode != NULL)
1939 		*cnode = NULL;
1940 	if (cflags != 0)
1941 		return (EINVAL);
1942 
1943 	/*
1944 	 * what is it?
1945 	 */
1946 	flags = SYSCTL_VERSION|SYSCTL_TYPE(type)|SYSCTL_FLAGS(flags);
1947 	if (log != NULL)
1948 		flags &= ~CTLFLAG_PERMANENT;
1949 
1950 	/*
1951 	 * where do we put it?
1952 	 */
1953 	va_start(ap, newlen);
1954 	namelen = 0;
1955 	ni = -1;
1956 	do {
1957 		if (++ni == CTL_MAXNAME)
1958 			return (ENAMETOOLONG);
1959 		name[ni] = va_arg(ap, int);
1960 		/*
1961 		 * sorry, this is not supported from here
1962 		 */
1963 		if (name[ni] == CTL_CREATESYM)
1964 			return (EINVAL);
1965 	} while (name[ni] != CTL_EOL && name[ni] != CTL_CREATE);
1966 	namelen = ni + (name[ni] == CTL_CREATE ? 1 : 0);
1967 	va_end(ap);
1968 
1969 	/*
1970 	 * what's it called
1971 	 */
1972 	if (strlcpy(nnode.sysctl_name, namep, sizeof(nnode.sysctl_name)) >=
1973 	    sizeof(nnode.sysctl_name))
1974 		return (ENAMETOOLONG);
1975 
1976 	/*
1977 	 * cons up the description of the new node
1978 	 */
1979 	nnode.sysctl_num = name[namelen - 1];
1980 	name[namelen - 1] = CTL_CREATE;
1981 	nnode.sysctl_size = newlen;
1982 	nnode.sysctl_flags = flags;
1983 	if (type == CTLTYPE_NODE) {
1984 		nnode.sysctl_csize = 0;
1985 		nnode.sysctl_clen = 0;
1986 		nnode.sysctl_child = NULL;
1987 		if (flags & CTLFLAG_ALIAS)
1988 			nnode.sysctl_alias = qv;
1989 	} else if (flags & CTLFLAG_IMMEDIATE) {
1990 		switch (type) {
1991 		case CTLTYPE_INT:
1992 			nnode.sysctl_idata = qv;
1993 			break;
1994 		case CTLTYPE_QUAD:
1995 			nnode.sysctl_qdata = qv;
1996 			break;
1997 		default:
1998 			return (EINVAL);
1999 		}
2000 	} else {
2001 		nnode.sysctl_data = newp;
2002 	}
2003 	nnode.sysctl_func = func;
2004 	nnode.sysctl_parent = NULL;
2005 	nnode.sysctl_ver = 0;
2006 
2007 	/*
2008 	 * initialize lock state -- we need locks if the main tree has
2009 	 * been marked as complete, but since we could be called from
2010 	 * either there, or from a device driver (say, at device
2011 	 * insertion), or from an lkm (at lkm load time, say), we
2012 	 * don't really want to "wait"...
2013 	 */
2014 	error = sysctl_lock(NULL, NULL, 0);
2015 	if (error)
2016 		return (error);
2017 
2018 	/*
2019 	 * locate the prospective parent of the new node, and if we
2020 	 * find it, add the new node.
2021 	 */
2022 	sz = sizeof(onode);
2023 	pnode = root;
2024 	error = sysctl_locate(NULL, &name[0], namelen - 1, &pnode, &ni);
2025 	if (error) {
2026 		printf("sysctl_createv: sysctl_locate(%s) returned %d\n",
2027 		       nnode.sysctl_name, error);
2028 		sysctl_unlock(NULL);
2029 		return (error);
2030 	}
2031 	error = sysctl_create(&name[ni], namelen - ni, &onode, &sz,
2032 			      &nnode, sizeof(nnode), &name[0], NULL,
2033 			      pnode);
2034 
2035 	/*
2036 	 * unfortunately the node we wanted to create is already
2037 	 * there.  if the node that's already there is a reasonable
2038 	 * facsimile of the node we wanted to create, just pretend
2039 	 * (for the caller's benefit) that we managed to create the
2040 	 * node they wanted.
2041 	 */
2042 	if (error == EEXIST) {
2043 		/* name is the same as requested... */
2044 		if (strcmp(nnode.sysctl_name, onode.sysctl_name) == 0 &&
2045 		    /* they want the same function... */
2046 		    nnode.sysctl_func == onode.sysctl_func &&
2047 		    /* number is the same as requested, or... */
2048 		    (nnode.sysctl_num == onode.sysctl_num ||
2049 		     /* they didn't pick a number... */
2050 		     nnode.sysctl_num == CTL_CREATE)) {
2051 			/*
2052 			 * collision here from trying to create
2053 			 * something that already existed; let's give
2054 			 * our customers a hand and tell them they got
2055 			 * what they wanted.
2056 			 */
2057 #ifdef SYSCTL_DEBUG_CREATE
2058 			printf("cleared\n");
2059 #endif /* SYSCTL_DEBUG_CREATE */
2060 			error = 0;
2061 		}
2062 	}
2063 
2064 	if (error == 0 &&
2065 	    (cnode != NULL || log != NULL || descr != NULL)) {
2066 		/*
2067 		 * sysctl_create() gave us back a copy of the node,
2068 		 * but we need to know where it actually is...
2069 		 */
2070 		pnode = root;
2071 		error = sysctl_locate(NULL, &name[0], namelen - 1, &pnode, &ni);
2072 
2073 		/*
2074 		 * manual scan of last layer so that aliased nodes
2075 		 * aren't followed.
2076 		 */
2077 		if (error == 0) {
2078 			for (ni = 0; ni < pnode->sysctl_clen; ni++)
2079 				if (pnode->sysctl_child[ni].sysctl_num ==
2080 				    onode.sysctl_num)
2081 					break;
2082 			if (ni < pnode->sysctl_clen)
2083 				pnode = &pnode->sysctl_child[ni];
2084 			else
2085 				error = ENOENT;
2086 		}
2087 
2088 		/*
2089 		 * not expecting an error here, but...
2090 		 */
2091 		if (error == 0) {
2092 			if (log != NULL)
2093 				sysctl_log_add(log, pnode);
2094 			if (cnode != NULL)
2095 				*cnode = pnode;
2096 			if (descr != NULL) {
2097 				/*
2098 				 * allow first caller to *set* a
2099 				 * description actually to set it
2100 				 *
2101 				 * discard const here so we can attach
2102 				 * the description
2103 				 */
2104 				dnode = __UNCONST(pnode);
2105 				if (pnode->sysctl_desc != NULL)
2106 					/* skip it...we've got one */;
2107 				else if (flags & CTLFLAG_OWNDESC) {
2108 					size_t l = strlen(descr) + 1;
2109 					char *d = malloc(l, M_SYSCTLDATA,
2110 							 M_WAITOK|M_CANFAIL);
2111 					if (d != NULL) {
2112 						memcpy(d, descr, l);
2113 						dnode->sysctl_desc = d;
2114 						dnode->sysctl_flags |=
2115 						    CTLFLAG_OWNDESC;
2116 					}
2117 				} else
2118 					dnode->sysctl_desc = descr;
2119 			}
2120 		} else {
2121 			printf("sysctl_create succeeded but node not found?!\n");
2122 			/*
2123 			 *  confusing, but the create said it
2124 			 * succeeded, so...
2125 			 */
2126 			error = 0;
2127 		}
2128 	}
2129 
2130 	/*
2131 	 * now it should be safe to release the lock state.  note that
2132 	 * the pointer to the newly created node being passed back may
2133 	 * not be "good" for very long.
2134 	 */
2135 	sysctl_unlock(NULL);
2136 
2137 	if (error != 0) {
2138 		printf("sysctl_createv: sysctl_create(%s) returned %d\n",
2139 		       nnode.sysctl_name, error);
2140 #if 0
2141 		if (error != ENOENT)
2142 			sysctl_dump(&onode);
2143 #endif
2144 	}
2145 
2146 	return (error);
2147 }
2148 
2149 int
2150 sysctl_destroyv(struct sysctlnode *rnode, ...)
2151 {
2152 	va_list ap;
2153 	int error, name[CTL_MAXNAME], namelen, ni;
2154 	const struct sysctlnode *pnode, *node;
2155 	struct sysctlnode dnode, *onode;
2156 	size_t sz;
2157 
2158 	va_start(ap, rnode);
2159 	namelen = 0;
2160 	ni = 0;
2161 	do {
2162 		if (ni == CTL_MAXNAME)
2163 			return (ENAMETOOLONG);
2164 		name[ni] = va_arg(ap, int);
2165 	} while (name[ni++] != CTL_EOL);
2166 	namelen = ni - 1;
2167 	va_end(ap);
2168 
2169 	/*
2170 	 * i can't imagine why we'd be destroying a node when the tree
2171 	 * wasn't complete, but who knows?
2172 	 */
2173 	error = sysctl_lock(NULL, NULL, 0);
2174 	if (error)
2175 		return (error);
2176 
2177 	/*
2178 	 * where is it?
2179 	 */
2180 	node = rnode;
2181 	error = sysctl_locate(NULL, &name[0], namelen - 1, &node, &ni);
2182 	if (error) {
2183 		/* they want it gone and it's not there, so... */
2184 		sysctl_unlock(NULL);
2185 		return (error == ENOENT ? 0 : error);
2186 	}
2187 
2188 	/*
2189 	 * set up the deletion
2190 	 */
2191 	pnode = node;
2192 	node = &dnode;
2193 	memset(&dnode, 0, sizeof(dnode));
2194 	dnode.sysctl_flags = SYSCTL_VERSION;
2195 	dnode.sysctl_num = name[namelen - 1];
2196 
2197 	/*
2198 	 * we found it, now let's nuke it
2199 	 */
2200 	name[namelen - 1] = CTL_DESTROY;
2201 	sz = 0;
2202 	error = sysctl_destroy(&name[namelen - 1], 1, NULL, &sz,
2203 			       node, sizeof(*node), &name[0], NULL,
2204 			       pnode);
2205 	if (error == ENOTEMPTY) {
2206 		/*
2207 		 * think of trying to delete "foo" when "foo.bar"
2208 		 * (which someone else put there) is still in
2209 		 * existence
2210 		 */
2211 		error = 0;
2212 
2213 		/*
2214 		 * dunno who put the description there, but if this
2215 		 * node can ever be removed, we need to make sure the
2216 		 * string doesn't go out of context.  that means we
2217 		 * need to find the node that's still there (don't use
2218 		 * sysctl_locate() because that follows aliasing).
2219 		 */
2220 		node = pnode->sysctl_child;
2221 		for (ni = 0; ni < pnode->sysctl_clen; ni++)
2222 			if (node[ni].sysctl_num == dnode.sysctl_num)
2223 				break;
2224 		node = (ni < pnode->sysctl_clen) ? &node[ni] : NULL;
2225 
2226 		/*
2227 		 * if we found it, and this node has a description,
2228 		 * and this node can be released, and it doesn't
2229 		 * already own its own description...sigh.  :)
2230 		 */
2231 		if (node != NULL && node->sysctl_desc != NULL &&
2232 		    !(node->sysctl_flags & CTLFLAG_PERMANENT) &&
2233 		    !(node->sysctl_flags & CTLFLAG_OWNDESC)) {
2234 			char *d;
2235 
2236 			sz = strlen(node->sysctl_desc) + 1;
2237 			d = malloc(sz, M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
2238 			if (d != NULL) {
2239 				/*
2240 				 * discard const so that we can
2241 				 * re-attach the description
2242 				 */
2243 				memcpy(d, node->sysctl_desc, sz);
2244 				onode = __UNCONST(node);
2245 				onode->sysctl_desc = d;
2246 				onode->sysctl_flags |= CTLFLAG_OWNDESC;
2247 			} else {
2248 				/*
2249 				 * XXX drop the description?  be
2250 				 * afraid?  don't care?
2251 				 */
2252 			}
2253 		}
2254 	}
2255 
2256         sysctl_unlock(NULL);
2257 
2258 	return (error);
2259 }
2260 
2261 #if 0
2262 /*
2263  * ********************************************************************
2264  * the dump routine.  i haven't yet decided how (if at all) i'll call
2265  * this from userland when it's in the kernel.
2266  * ********************************************************************
2267  */
2268 static const char *
2269 sf(int f)
2270 {
2271 	static char s[256];
2272 	char *c;
2273 
2274 	s[0] = '\0';
2275 	c = "";
2276 
2277 #define print_flag(_f, _s, _c, _q, _x) \
2278 	if (((_f) & (__CONCAT(CTLFLAG_,_x))) == (__CONCAT(CTLFLAG_,_q))) { \
2279 		strlcat((_s), (_c), sizeof(_s)); \
2280 		strlcat((_s), __STRING(_q), sizeof(_s)); \
2281 		(_c) = ","; \
2282 		(_f) &= ~__CONCAT(CTLFLAG_,_x); \
2283 	}
2284 
2285 	print_flag(f, s, c, READONLY,  READWRITE);
2286 	print_flag(f, s, c, READWRITE, READWRITE);
2287 	print_flag(f, s, c, ANYWRITE,  ANYWRITE);
2288 	print_flag(f, s, c, PRIVATE,   PRIVATE);
2289 	print_flag(f, s, c, PERMANENT, PERMANENT);
2290 	print_flag(f, s, c, OWNDATA,   OWNDATA);
2291 	print_flag(f, s, c, IMMEDIATE, IMMEDIATE);
2292 	print_flag(f, s, c, HEX,       HEX);
2293 	print_flag(f, s, c, ROOT,      ROOT);
2294 	print_flag(f, s, c, ANYNUMBER, ANYNUMBER);
2295 	print_flag(f, s, c, HIDDEN,    HIDDEN);
2296 	print_flag(f, s, c, ALIAS,     ALIAS);
2297 #undef print_flag
2298 
2299 	if (f) {
2300 		char foo[9];
2301 		snprintf(foo, sizeof(foo), "%x", f);
2302 		strlcat(s, c, sizeof(s));
2303 		strlcat(s, foo, sizeof(s));
2304 	}
2305 
2306 	return (s);
2307 }
2308 
2309 static const char *
2310 st(int t)
2311 {
2312 
2313 	switch (t) {
2314 	case CTLTYPE_NODE:
2315 		return "NODE";
2316 	case CTLTYPE_INT:
2317 		return "INT";
2318 	case CTLTYPE_STRING:
2319 		return "STRING";
2320 	case CTLTYPE_QUAD:
2321 		return "QUAD";
2322 	case CTLTYPE_STRUCT:
2323 		return "STRUCT";
2324 	}
2325 
2326 	return "???";
2327 }
2328 
2329 void
2330 sysctl_dump(const struct sysctlnode *d)
2331 {
2332 	static char nmib[64], smib[256];
2333 	static int indent;
2334 	struct sysctlnode *n;
2335 	char *np, *sp, tmp[20];
2336 	int i;
2337 
2338 	if (d == NULL)
2339 		return;
2340 
2341 	np = &nmib[strlen(nmib)];
2342 	sp = &smib[strlen(smib)];
2343 
2344 	if (!(d->sysctl_flags & CTLFLAG_ROOT)) {
2345 		snprintf(tmp, sizeof(tmp), "%d", d->sysctl_num);
2346 		strcat(nmib, ".");
2347 		strcat(smib, ".");
2348 		strcat(nmib, tmp);
2349 		strcat(smib, d->sysctl_name);
2350 		printf("%s -> %s (%d)\n", &nmib[1], &smib[1],
2351 		       SYSCTL_TYPE(d->sysctl_flags));
2352 	}
2353 
2354 	if (1) {
2355 		printf("%*s%p:\tsysctl_name  [%s]\n", indent, "",
2356 		       d, d->sysctl_name);
2357 		printf("%*s\t\tsysctl_num    %d\n",   indent, "",
2358 		       d->sysctl_num);
2359 		printf("%*s\t\tsysctl_flags  %x (flags=%x<%s> type=%d<%s> "
2360 		       "size=%zu)\n",
2361 		       indent, "", d->sysctl_flags,
2362 		       SYSCTL_FLAGS(d->sysctl_flags),
2363 		       sf(SYSCTL_FLAGS(d->sysctl_flags)),
2364 		       SYSCTL_TYPE(d->sysctl_flags),
2365 		       st(SYSCTL_TYPE(d->sysctl_flags)),
2366 		       d->sysctl_size);
2367 		if (SYSCTL_TYPE(d->sysctl_flags) == CTLTYPE_NODE) {
2368 			printf("%*s\t\tsysctl_csize  %d\n",   indent, "",
2369 			       d->sysctl_csize);
2370 			printf("%*s\t\tsysctl_clen   %d\n",   indent, "",
2371 			       d->sysctl_clen);
2372 			printf("%*s\t\tsysctl_child  %p\n",   indent, "",
2373 			       d->sysctl_child);
2374 		} else
2375 			printf("%*s\t\tsysctl_data   %p\n",   indent, "",
2376 			       d->sysctl_data);
2377 		printf("%*s\t\tsysctl_func   %p\n",   indent, "",
2378 		       d->sysctl_func);
2379 		printf("%*s\t\tsysctl_parent %p\n",   indent, "",
2380 		       d->sysctl_parent);
2381 		printf("%*s\t\tsysctl_ver    %d\n",   indent, "",
2382 		       d->sysctl_ver);
2383 	}
2384 
2385 	if (SYSCTL_TYPE(d->sysctl_flags) == CTLTYPE_NODE) {
2386 		indent += 8;
2387 		n = d->sysctl_child;
2388 		for (i = 0; i < d->sysctl_clen; i++) {
2389 			sysctl_dump(&n[i]);
2390 		}
2391 		indent -= 8;
2392 	}
2393 
2394 	np[0] = '\0';
2395 	sp[0] = '\0';
2396 }
2397 #endif /* 0 */
2398 
2399 /*
2400  * ********************************************************************
2401  * Deletes an entire n-ary tree.  Not recommended unless you know why
2402  * you're doing it.  Personally, I don't know why you'd even think
2403  * about it.
2404  * ********************************************************************
2405  */
2406 void
2407 sysctl_free(struct sysctlnode *rnode)
2408 {
2409 	struct sysctlnode *node, *pnode;
2410 
2411 	if (rnode == NULL)
2412 		rnode = &sysctl_root;
2413 
2414 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
2415 		printf("sysctl_free: rnode %p wrong version\n", rnode);
2416 		return;
2417 	}
2418 
2419 	pnode = rnode;
2420 
2421 	node = pnode->sysctl_child;
2422 	do {
2423 		while (node != NULL && pnode->sysctl_csize > 0) {
2424 			while (node <
2425 			       &pnode->sysctl_child[pnode->sysctl_clen] &&
2426 			       (SYSCTL_TYPE(node->sysctl_flags) !=
2427 				CTLTYPE_NODE ||
2428 				node->sysctl_csize == 0)) {
2429 				if (SYSCTL_FLAGS(node->sysctl_flags) &
2430 				    CTLFLAG_OWNDATA) {
2431 					if (node->sysctl_data != NULL) {
2432 						free(node->sysctl_data,
2433 						     M_SYSCTLDATA);
2434 						node->sysctl_data = NULL;
2435 					}
2436 				}
2437 				if (SYSCTL_FLAGS(node->sysctl_flags) &
2438 				    CTLFLAG_OWNDESC) {
2439 					if (node->sysctl_desc != NULL) {
2440 						/*XXXUNCONST*/
2441 						free(__UNCONST(node->sysctl_desc),
2442 						     M_SYSCTLDATA);
2443 						node->sysctl_desc = NULL;
2444 					}
2445 				}
2446 				node++;
2447 			}
2448 			if (node < &pnode->sysctl_child[pnode->sysctl_clen]) {
2449 				pnode = node;
2450 				node = node->sysctl_child;
2451 			} else
2452 				break;
2453 		}
2454 		if (pnode->sysctl_child != NULL)
2455 			free(pnode->sysctl_child, M_SYSCTLNODE);
2456 		pnode->sysctl_clen = 0;
2457 		pnode->sysctl_csize = 0;
2458 		pnode->sysctl_child = NULL;
2459 		node = pnode;
2460 		pnode = node->sysctl_parent;
2461 	} while (pnode != NULL && node != rnode);
2462 }
2463 
2464 int
2465 sysctl_log_add(struct sysctllog **logp, const struct sysctlnode *node)
2466 {
2467 	int name[CTL_MAXNAME], namelen, i;
2468 	const struct sysctlnode *pnode;
2469 	struct sysctllog *log;
2470 
2471 	if (node->sysctl_flags & CTLFLAG_PERMANENT)
2472 		return (0);
2473 
2474 	if (logp == NULL)
2475 		return (0);
2476 
2477 	if (*logp == NULL) {
2478 		log = malloc(sizeof(struct sysctllog),
2479 		       M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
2480 		if (log == NULL) {
2481 			/* XXX print error message? */
2482 			return (-1);
2483 		}
2484 		log->log_num = malloc(16 * sizeof(int),
2485 		       M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
2486 		if (log->log_num == NULL) {
2487 			/* XXX print error message? */
2488 			free(log, M_SYSCTLDATA);
2489 			return (-1);
2490 		}
2491 		memset(log->log_num, 0, 16 * sizeof(int));
2492 		log->log_root = NULL;
2493 		log->log_size = 16;
2494 		log->log_left = 16;
2495 		*logp = log;
2496 	} else
2497 		log = *logp;
2498 
2499 	/*
2500 	 * check that the root is proper.  it's okay to record the
2501 	 * address of the root of a tree.  it's the only thing that's
2502 	 * guaranteed not to shift around as nodes come and go.
2503 	 */
2504 	if (log->log_root == NULL)
2505 		log->log_root = sysctl_rootof(node);
2506 	else if (log->log_root != sysctl_rootof(node)) {
2507 		printf("sysctl: log %p root mismatch (%p)\n",
2508 		       log->log_root, sysctl_rootof(node));
2509 		return (-1);
2510 	}
2511 
2512 	/*
2513 	 * we will copy out name in reverse order
2514 	 */
2515 	for (pnode = node, namelen = 0;
2516 	     pnode != NULL && !(pnode->sysctl_flags & CTLFLAG_ROOT);
2517 	     pnode = pnode->sysctl_parent)
2518 		name[namelen++] = pnode->sysctl_num;
2519 
2520 	/*
2521 	 * do we have space?
2522 	 */
2523 	if (log->log_left < (namelen + 3))
2524 		sysctl_log_realloc(log);
2525 	if (log->log_left < (namelen + 3))
2526 		return (-1);
2527 
2528 	/*
2529 	 * stuff name in, then namelen, then node type, and finally,
2530 	 * the version for non-node nodes.
2531 	 */
2532 	for (i = 0; i < namelen; i++)
2533 		log->log_num[--log->log_left] = name[i];
2534 	log->log_num[--log->log_left] = namelen;
2535 	log->log_num[--log->log_left] = SYSCTL_TYPE(node->sysctl_flags);
2536 	if (log->log_num[log->log_left] != CTLTYPE_NODE)
2537 		log->log_num[--log->log_left] = node->sysctl_ver;
2538 	else
2539 		log->log_num[--log->log_left] = 0;
2540 
2541 	return (0);
2542 }
2543 
2544 void
2545 sysctl_teardown(struct sysctllog **logp)
2546 {
2547 	const struct sysctlnode *rnode;
2548 	struct sysctlnode node;
2549 	struct sysctllog *log;
2550 	uint namelen;
2551 	int *name, t, v, error, ni;
2552 	size_t sz;
2553 
2554 	if (logp == NULL || *logp == NULL)
2555 		return;
2556 	log = *logp;
2557 
2558 	error = sysctl_lock(NULL, NULL, 0);
2559 	if (error)
2560 		return;
2561 
2562 	memset(&node, 0, sizeof(node));
2563 
2564 	while (log->log_left < log->log_size) {
2565 		KASSERT((log->log_left + 3 < log->log_size) &&
2566 			(log->log_left + log->log_num[log->log_left + 2] <=
2567 			 log->log_size));
2568 		v = log->log_num[log->log_left++];
2569 		t = log->log_num[log->log_left++];
2570 		namelen = log->log_num[log->log_left++];
2571 		name = &log->log_num[log->log_left];
2572 
2573 		node.sysctl_num = name[namelen - 1];
2574 		node.sysctl_flags = SYSCTL_VERSION|t;
2575 		node.sysctl_ver = v;
2576 
2577 		rnode = log->log_root;
2578 		error = sysctl_locate(NULL, &name[0], namelen, &rnode, &ni);
2579 		if (error == 0) {
2580 			name[namelen - 1] = CTL_DESTROY;
2581 			rnode = rnode->sysctl_parent;
2582 			sz = 0;
2583 			(void)sysctl_destroy(&name[namelen - 1], 1, NULL,
2584 					     &sz, &node, sizeof(node),
2585 					     &name[0], NULL, rnode);
2586 		}
2587 
2588 		log->log_left += namelen;
2589 	}
2590 
2591 	KASSERT(log->log_size == log->log_left);
2592 	free(log->log_num, M_SYSCTLDATA);
2593 	free(log, M_SYSCTLDATA);
2594 	*logp = NULL;
2595 
2596 	sysctl_unlock(NULL);
2597 }
2598 
2599 /*
2600  * ********************************************************************
2601  * old_sysctl -- A routine to bridge old-style internal calls to the
2602  * new infrastructure.
2603  * ********************************************************************
2604  */
2605 int
2606 old_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
2607 	   void *newp, size_t newlen, struct lwp *l)
2608 {
2609 	int error;
2610 	size_t oldlen = 0;
2611 	size_t savelen;
2612 
2613 	if (oldlenp) {
2614 		oldlen = *oldlenp;
2615 	}
2616 	savelen = oldlen;
2617 
2618 	error = sysctl_lock(l, oldp, savelen);
2619 	if (error)
2620 		return (error);
2621 	error = sysctl_dispatch(name, namelen, oldp, &oldlen,
2622 				newp, newlen, name, l, NULL);
2623 	sysctl_unlock(l);
2624 	if (error == 0 && oldp != NULL && savelen < oldlen)
2625 		error = ENOMEM;
2626 
2627 	if (oldlenp) {
2628 		*oldlenp = oldlen;
2629 	}
2630 
2631 	return (error);
2632 }
2633 
2634 /*
2635  * ********************************************************************
2636  * Section 4: Generic helper routines
2637  * ********************************************************************
2638  * "helper" routines that can do more finely grained access control,
2639  * construct structures from disparate information, create the
2640  * appearance of more nodes and sub-trees, etc.  for example, if
2641  * CTL_PROC wanted a helper function, it could respond to a CTL_QUERY
2642  * with a dynamically created list of nodes that represented the
2643  * currently running processes at that instant.
2644  * ********************************************************************
2645  */
2646 
2647 /*
2648  * first, a few generic helpers that provide:
2649  *
2650  * sysctl_needfunc()		a readonly interface that emits a warning
2651  * sysctl_notavail()		returns EOPNOTSUPP (generic error)
2652  * sysctl_null()		an empty return buffer with no error
2653  */
2654 int
2655 sysctl_needfunc(SYSCTLFN_ARGS)
2656 {
2657 	int error;
2658 
2659 	printf("!!SYSCTL_NEEDFUNC!!\n");
2660 
2661 	if (newp != NULL || namelen != 0)
2662 		return (EOPNOTSUPP);
2663 
2664 	error = 0;
2665 	if (oldp != NULL)
2666 		error = sysctl_copyout(l, rnode->sysctl_data, oldp,
2667 				       MIN(rnode->sysctl_size, *oldlenp));
2668 	*oldlenp = rnode->sysctl_size;
2669 
2670 	return (error);
2671 }
2672 
2673 int
2674 sysctl_notavail(SYSCTLFN_ARGS)
2675 {
2676 
2677 	if (namelen == 1 && name[0] == CTL_QUERY)
2678 		return (sysctl_query(SYSCTLFN_CALL(rnode)));
2679 
2680 	return (EOPNOTSUPP);
2681 }
2682 
2683 int
2684 sysctl_null(SYSCTLFN_ARGS)
2685 {
2686 
2687 	*oldlenp = 0;
2688 
2689 	return (0);
2690 }
2691 
2692 /*
2693  * ********************************************************************
2694  * Section 5: The machinery that makes it all go
2695  * ********************************************************************
2696  * Memory "manglement" routines.  Not much to this, eh?
2697  * ********************************************************************
2698  */
2699 static int
2700 sysctl_alloc(struct sysctlnode *p, int x)
2701 {
2702 	int i;
2703 	struct sysctlnode *n;
2704 
2705 	assert(p->sysctl_child == NULL);
2706 
2707 	if (x == 1)
2708 		n = malloc(sizeof(struct sysctlnode),
2709 		       M_SYSCTLNODE, M_WAITOK|M_CANFAIL);
2710 	else
2711 		n = malloc(SYSCTL_DEFSIZE * sizeof(struct sysctlnode),
2712 		       M_SYSCTLNODE, M_WAITOK|M_CANFAIL);
2713 	if (n == NULL)
2714 		return (ENOMEM);
2715 
2716 	if (x == 1) {
2717 		memset(n, 0, sizeof(struct sysctlnode));
2718 		p->sysctl_csize = 1;
2719 	} else {
2720 		memset(n, 0, SYSCTL_DEFSIZE * sizeof(struct sysctlnode));
2721 		p->sysctl_csize = SYSCTL_DEFSIZE;
2722 	}
2723 	p->sysctl_clen = 0;
2724 
2725 	for (i = 0; i < p->sysctl_csize; i++)
2726 		n[i].sysctl_parent = p;
2727 
2728 	p->sysctl_child = n;
2729 	return (0);
2730 }
2731 
2732 static int
2733 sysctl_realloc(struct sysctlnode *p)
2734 {
2735 	int i, j;
2736 	struct sysctlnode *n;
2737 
2738 	assert(p->sysctl_csize == p->sysctl_clen);
2739 
2740 	/*
2741 	 * how many do we have...how many should we make?
2742 	 */
2743 	i = p->sysctl_clen;
2744 	n = malloc(2 * i * sizeof(struct sysctlnode), M_SYSCTLNODE,
2745 		   M_WAITOK|M_CANFAIL);
2746 	if (n == NULL)
2747 		return (ENOMEM);
2748 
2749 	/*
2750 	 * move old children over...initialize new children
2751 	 */
2752 	memcpy(n, p->sysctl_child, i * sizeof(struct sysctlnode));
2753 	memset(&n[i], 0, i * sizeof(struct sysctlnode));
2754 	p->sysctl_csize = 2 * i;
2755 
2756 	/*
2757 	 * reattach moved (and new) children to parent; if a moved
2758 	 * child node has children, reattach the parent pointers of
2759 	 * grandchildren
2760 	 */
2761         for (i = 0; i < p->sysctl_csize; i++) {
2762                 n[i].sysctl_parent = p;
2763 		if (n[i].sysctl_child != NULL) {
2764 			for (j = 0; j < n[i].sysctl_csize; j++)
2765 				n[i].sysctl_child[j].sysctl_parent = &n[i];
2766 		}
2767 	}
2768 
2769 	/*
2770 	 * get out with the old and in with the new
2771 	 */
2772 	free(p->sysctl_child, M_SYSCTLNODE);
2773 	p->sysctl_child = n;
2774 
2775 	return (0);
2776 }
2777 
2778 static int
2779 sysctl_log_realloc(struct sysctllog *log)
2780 {
2781 	int *n, s, d;
2782 
2783 	s = log->log_size * 2;
2784 	d = log->log_size;
2785 
2786 	n = malloc(s * sizeof(int), M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
2787 	if (n == NULL)
2788 		return (-1);
2789 
2790 	memset(n, 0, s * sizeof(int));
2791 	memcpy(&n[d], log->log_num, d * sizeof(int));
2792 	free(log->log_num, M_SYSCTLDATA);
2793 	log->log_num = n;
2794 	if (d)
2795 		log->log_left += d;
2796 	else
2797 		log->log_left = s;
2798 	log->log_size = s;
2799 
2800 	return (0);
2801 }
2802 
2803 /*
2804  * ********************************************************************
2805  * Section 6: Conversion between API versions wrt the sysctlnode
2806  * ********************************************************************
2807  */
2808 static int
2809 sysctl_cvt_in(struct lwp *l, int *vp, const void *i, size_t sz,
2810 	      struct sysctlnode *node)
2811 {
2812 	int error, flags;
2813 
2814 	if (i == NULL || sz < sizeof(flags))
2815 		return (EINVAL);
2816 
2817 	error = sysctl_copyin(l, i, &flags, sizeof(flags));
2818 	if (error)
2819 		return (error);
2820 
2821 #if (SYSCTL_VERSION != SYSCTL_VERS_1)
2822 #error sysctl_cvt_in: no support for SYSCTL_VERSION
2823 #endif /*  (SYSCTL_VERSION != SYSCTL_VERS_1) */
2824 
2825 	if (sz == sizeof(*node) &&
2826 	    SYSCTL_VERS(flags) == SYSCTL_VERSION) {
2827 		error = sysctl_copyin(l, i, node, sizeof(*node));
2828 		if (error)
2829 			return (error);
2830 		*vp = SYSCTL_VERSION;
2831 		return (0);
2832 	}
2833 
2834 	return (EINVAL);
2835 }
2836 
2837 static int
2838 sysctl_cvt_out(struct lwp *l, int v, const struct sysctlnode *i,
2839 	       void *ovp, size_t left, size_t *szp)
2840 {
2841 	size_t sz = sizeof(*i);
2842 	const void *src = i;
2843 	int error;
2844 
2845 	switch (v) {
2846 	case SYSCTL_VERS_0:
2847 		return (EINVAL);
2848 
2849 #if (SYSCTL_VERSION != SYSCTL_VERS_1)
2850 #error sysctl_cvt_out: no support for SYSCTL_VERSION
2851 #endif /*  (SYSCTL_VERSION != SYSCTL_VERS_1) */
2852 
2853 	case SYSCTL_VERSION:
2854 		/* nothing more to do here */
2855 		break;
2856 	}
2857 
2858 	if (ovp != NULL && left >= sz) {
2859 		error = sysctl_copyout(l, src, ovp, sz);
2860 		if (error)
2861 			return (error);
2862 	}
2863 
2864 	if (szp != NULL)
2865 		*szp = sz;
2866 
2867 	return (0);
2868 }
2869