xref: /netbsd-src/sys/kern/kern_sysctl.c (revision 48fb7bfab72acd4281a53bbee5ccf3f809019e75)
1 /*	$NetBSD: kern_sysctl.c,v 1.247 2014/02/27 22:50:52 dsl Exp $	*/
2 
3 /*-
4  * Copyright (c) 2003, 2007, 2008 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Andrew Brown.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*-
33  * Copyright (c) 1982, 1986, 1989, 1993
34  *	The Regents of the University of California.  All rights reserved.
35  *
36  * This code is derived from software contributed to Berkeley by
37  * Mike Karels at Berkeley Software Design, Inc.
38  *
39  * Redistribution and use in source and binary forms, with or without
40  * modification, are permitted provided that the following conditions
41  * are met:
42  * 1. Redistributions of source code must retain the above copyright
43  *    notice, this list of conditions and the following disclaimer.
44  * 2. Redistributions in binary form must reproduce the above copyright
45  *    notice, this list of conditions and the following disclaimer in the
46  *    documentation and/or other materials provided with the distribution.
47  * 3. Neither the name of the University nor the names of its contributors
48  *    may be used to endorse or promote products derived from this software
49  *    without specific prior written permission.
50  *
51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
61  * SUCH DAMAGE.
62  *
63  *	@(#)kern_sysctl.c	8.9 (Berkeley) 5/20/95
64  */
65 
66 /*
67  * sysctl system call.
68  */
69 
70 #include <sys/cdefs.h>
71 __KERNEL_RCSID(0, "$NetBSD: kern_sysctl.c,v 1.247 2014/02/27 22:50:52 dsl Exp $");
72 
73 #include "opt_defcorename.h"
74 #include "ksyms.h"
75 
76 #include <sys/param.h>
77 #define __COMPAT_SYSCTL
78 #include <sys/sysctl.h>
79 #include <sys/systm.h>
80 #include <sys/buf.h>
81 #include <sys/ksyms.h>
82 #include <sys/malloc.h>
83 #include <sys/mount.h>
84 #include <sys/syscallargs.h>
85 #include <sys/kauth.h>
86 #include <sys/ktrace.h>
87 
88 #define	MAXDESCLEN	1024
89 MALLOC_DEFINE(M_SYSCTLNODE, "sysctlnode", "sysctl node structures");
90 MALLOC_DEFINE(M_SYSCTLDATA, "sysctldata", "misc sysctl data");
91 
92 static int sysctl_mmap(SYSCTLFN_PROTO);
93 static int sysctl_alloc(struct sysctlnode *, int);
94 static int sysctl_realloc(struct sysctlnode *);
95 
96 static int sysctl_cvt_in(struct lwp *, int *, const void *, size_t,
97 			 struct sysctlnode *);
98 static int sysctl_cvt_out(struct lwp *, int, const struct sysctlnode *,
99 			  void *, size_t, size_t *);
100 
101 static int sysctl_log_add(struct sysctllog **, const struct sysctlnode *);
102 static int sysctl_log_realloc(struct sysctllog *);
103 
104 typedef void sysctl_setup_func(struct sysctllog **);
105 
106 #ifdef SYSCTL_DEBUG
107 #define DPRINTF(a)	printf a
108 #else
109 #define DPRINTF(a)
110 #endif
111 
112 struct sysctllog {
113 	const struct sysctlnode *log_root;
114 	int *log_num;
115 	int log_size, log_left;
116 };
117 
118 /*
119  * the "root" of the new sysctl tree
120  */
121 struct sysctlnode sysctl_root = {
122 	.sysctl_flags = SYSCTL_VERSION|
123 	    CTLFLAG_ROOT|CTLFLAG_READWRITE|
124 	    CTLTYPE_NODE,
125 	.sysctl_num = 0,
126 	/*
127 	 * XXX once all ports are on gcc3, we can get rid of this
128 	 * ugliness and simply make it into
129 	 *
130 	 *	.sysctl_size = sizeof(struct sysctlnode),
131 	 */
132 	sysc_init_field(_sysctl_size, sizeof(struct sysctlnode)),
133 	.sysctl_name = "(root)",
134 };
135 
136 /*
137  * link set of functions that add nodes at boot time (see also
138  * sysctl_buildtree())
139  */
140 __link_set_decl(sysctl_funcs, sysctl_setup_func);
141 
142 /*
143  * The `sysctl_treelock' is intended to serialize access to the sysctl
144  * tree.  XXX This has serious problems; allocating memory and
145  * copying data out with the lock held is insane.
146  */
147 krwlock_t sysctl_treelock;
148 
149 kmutex_t sysctl_file_marker_lock;
150 
151 /*
152  * Attributes stored in the kernel.
153  */
154 char hostname[MAXHOSTNAMELEN];
155 int hostnamelen;
156 
157 char domainname[MAXHOSTNAMELEN];
158 int domainnamelen;
159 
160 long hostid;
161 
162 #ifndef DEFCORENAME
163 #define	DEFCORENAME	"%n.core"
164 #endif
165 char defcorename[MAXPATHLEN] = DEFCORENAME;
166 
167 /*
168  * ********************************************************************
169  * Section 0: Some simple glue
170  * ********************************************************************
171  * By wrapping copyin(), copyout(), and copyinstr() like this, we can
172  * stop caring about who's calling us and simplify some code a bunch.
173  * ********************************************************************
174  */
175 int
176 sysctl_copyin(struct lwp *l, const void *uaddr, void *kaddr, size_t len)
177 {
178 	int error;
179 
180 	if (l != NULL) {
181 		error = copyin(uaddr, kaddr, len);
182 		ktrmibio(-1, UIO_WRITE, uaddr, len, error);
183 	} else {
184 		error = kcopy(uaddr, kaddr, len);
185 	}
186 
187 	return error;
188 }
189 
190 int
191 sysctl_copyout(struct lwp *l, const void *kaddr, void *uaddr, size_t len)
192 {
193 	int error;
194 
195 	if (l != NULL) {
196 		error = copyout(kaddr, uaddr, len);
197 		ktrmibio(-1, UIO_READ, uaddr, len, error);
198 	} else {
199 		error = kcopy(kaddr, uaddr, len);
200 	}
201 
202 	return error;
203 }
204 
205 int
206 sysctl_copyinstr(struct lwp *l, const void *uaddr, void *kaddr,
207 		 size_t len, size_t *done)
208 {
209 	int error;
210 
211 	if (l != NULL) {
212 		error = copyinstr(uaddr, kaddr, len, done);
213 		ktrmibio(-1, UIO_WRITE, uaddr, len, error);
214 	} else {
215 		error = copystr(uaddr, kaddr, len, done);
216 	}
217 
218 	return error;
219 }
220 
221 /*
222  * ********************************************************************
223  * Initialize sysctl subsystem.
224  * ********************************************************************
225  */
226 void
227 sysctl_init(void)
228 {
229 	sysctl_setup_func *const *sysctl_setup;
230 
231 	rw_init(&sysctl_treelock);
232 
233 	/*
234 	 * dynamic mib numbers start here
235 	 */
236 	sysctl_root.sysctl_num = CREATE_BASE;
237 	sysctl_basenode_init();
238 
239         __link_set_foreach(sysctl_setup, sysctl_funcs) {
240 		(**sysctl_setup)(NULL);
241 	}
242 
243 	mutex_init(&sysctl_file_marker_lock, MUTEX_DEFAULT, IPL_NONE);
244 }
245 
246 /*
247  * Setting this means no more permanent nodes can be added,
248  * trees that claim to be readonly at the root now are, and if
249  * the main tree is readonly, *everything* is.
250  *
251  * Also starts up the PRNG used for the "random" sysctl: it's
252  * better to start it later than sooner.
253  *
254  * Call this at the end of kernel init.
255  */
256 void
257 sysctl_finalize(void)
258 {
259 
260 	sysctl_root.sysctl_flags |= CTLFLAG_PERMANENT;
261 }
262 
263 /*
264  * ********************************************************************
265  * The main native sysctl system call itself.
266  * ********************************************************************
267  */
268 int
269 sys___sysctl(struct lwp *l, const struct sys___sysctl_args *uap, register_t *retval)
270 {
271 	/* {
272 		syscallarg(const int *) name;
273 		syscallarg(u_int) namelen;
274 		syscallarg(void *) old;
275 		syscallarg(size_t *) oldlenp;
276 		syscallarg(const void *) new;
277 		syscallarg(size_t) newlen;
278 	} */
279 	int error, nerror, name[CTL_MAXNAME];
280 	size_t oldlen, savelen, *oldlenp;
281 
282 	/*
283 	 * get oldlen
284 	 */
285 	oldlen = 0;
286 	oldlenp = SCARG(uap, oldlenp);
287 	if (oldlenp != NULL) {
288 		error = copyin(oldlenp, &oldlen, sizeof(oldlen));
289 		if (error)
290 			return (error);
291 	}
292 	savelen = oldlen;
293 
294 	/*
295 	 * top-level sysctl names may or may not be non-terminal, but
296 	 * we don't care
297 	 */
298 	if (SCARG(uap, namelen) > CTL_MAXNAME || SCARG(uap, namelen) < 1)
299 		return (EINVAL);
300 	error = copyin(SCARG(uap, name), &name,
301 		       SCARG(uap, namelen) * sizeof(int));
302 	if (error)
303 		return (error);
304 
305 	ktrmib(name, SCARG(uap, namelen));
306 
307 	sysctl_lock(SCARG(uap, new) != NULL);
308 
309 	/*
310 	 * do sysctl work (NULL means main built-in default tree)
311 	 */
312 	error = sysctl_dispatch(&name[0], SCARG(uap, namelen),
313 				SCARG(uap, old), &oldlen,
314 				SCARG(uap, new), SCARG(uap, newlen),
315 				&name[0], l, NULL);
316 
317 	/*
318 	 * release the sysctl lock
319 	 */
320 	sysctl_unlock();
321 
322 	/*
323 	 * set caller's oldlen to new value even in the face of an
324 	 * error (if this gets an error and they didn't have one, they
325 	 * get this one)
326 	 */
327 	if (oldlenp) {
328 		nerror = copyout(&oldlen, oldlenp, sizeof(oldlen));
329 		if (error == 0)
330 			error = nerror;
331 	}
332 
333 	/*
334 	 * if the only problem is that we weren't given enough space,
335 	 * that's an ENOMEM error
336 	 */
337 	if (error == 0 && SCARG(uap, old) != NULL && savelen < oldlen)
338 		error = ENOMEM;
339 
340 	return (error);
341 }
342 
343 /*
344  * ********************************************************************
345  * Section 1: How the tree is used
346  * ********************************************************************
347  * Implementations of sysctl for emulations should typically need only
348  * these three functions in this order: lock the tree, dispatch
349  * request into it, unlock the tree.
350  * ********************************************************************
351  */
352 void
353 sysctl_lock(bool write)
354 {
355 
356 	if (write) {
357 		rw_enter(&sysctl_treelock, RW_WRITER);
358 		curlwp->l_pflag |= LP_SYSCTLWRITE;
359 	} else {
360 		rw_enter(&sysctl_treelock, RW_READER);
361 		curlwp->l_pflag &= ~LP_SYSCTLWRITE;
362 	}
363 }
364 
365 void
366 sysctl_relock(void)
367 {
368 
369 	if ((curlwp->l_pflag & LP_SYSCTLWRITE) != 0) {
370 		rw_enter(&sysctl_treelock, RW_WRITER);
371 	} else {
372 		rw_enter(&sysctl_treelock, RW_READER);
373 	}
374 }
375 
376 /*
377  * ********************************************************************
378  * the main sysctl dispatch routine.  scans the given tree and picks a
379  * function to call based on what it finds.
380  * ********************************************************************
381  */
382 int
383 sysctl_dispatch(SYSCTLFN_ARGS)
384 {
385 	int error;
386 	sysctlfn fn;
387 	int ni;
388 
389 	KASSERT(rw_lock_held(&sysctl_treelock));
390 
391 	if (rnode && SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
392 		printf("sysctl_dispatch: rnode %p wrong version\n", rnode);
393 		error = EINVAL;
394 		goto out;
395 	}
396 
397 	fn = NULL;
398 	error = sysctl_locate(l, name, namelen, &rnode, &ni);
399 
400 	if (rnode->sysctl_func != NULL) {
401 		/*
402 		 * the node we ended up at has a function, so call it.  it can
403 		 * hand off to query or create if it wants to.
404 		 */
405 		fn = rnode->sysctl_func;
406 	} else if (error == 0) {
407 		/*
408 		 * we found the node they were looking for, so do a lookup.
409 		 */
410 		fn = (sysctlfn)sysctl_lookup; /* XXX may write to rnode */
411 	} else if (error == ENOENT && (ni + 1) == namelen && name[ni] < 0) {
412 		/*
413 		 * prospective parent node found, but the terminal node was
414 		 * not.  generic operations associate with the parent.
415 		 */
416 		switch (name[ni]) {
417 		case CTL_QUERY:
418 			fn = sysctl_query;
419 			break;
420 		case CTL_CREATE:
421 #if NKSYMS > 0
422 		case CTL_CREATESYM:
423 #endif /* NKSYMS > 0 */
424 			if (newp == NULL) {
425 				error = EINVAL;
426 				break;
427 			}
428 			KASSERT(rw_write_held(&sysctl_treelock));
429 			fn = (sysctlfn)sysctl_create; /* we own the rnode */
430 			break;
431 		case CTL_DESTROY:
432 			if (newp == NULL) {
433 				error = EINVAL;
434 				break;
435 			}
436 			KASSERT(rw_write_held(&sysctl_treelock));
437 			fn = (sysctlfn)sysctl_destroy; /* we own the rnode */
438 			break;
439 		case CTL_MMAP:
440 			fn = (sysctlfn)sysctl_mmap; /* we own the rnode */
441 			break;
442 		case CTL_DESCRIBE:
443 			fn = sysctl_describe;
444 			break;
445 		default:
446 			error = EOPNOTSUPP;
447 			break;
448 		}
449 	}
450 
451 	/*
452 	 * after all of that, maybe we found someone who knows how to
453 	 * get us what we want?
454 	 */
455 	if (fn != NULL)
456 		error = (*fn)(name + ni, namelen - ni, oldp, oldlenp,
457 			      newp, newlen, name, l, rnode);
458 	else if (error == 0)
459 		error = EOPNOTSUPP;
460 
461 out:
462 	return (error);
463 }
464 
465 /*
466  * ********************************************************************
467  * Releases the tree lock.
468  * ********************************************************************
469  */
470 void
471 sysctl_unlock(void)
472 {
473 
474 	rw_exit(&sysctl_treelock);
475 }
476 
477 /*
478  * ********************************************************************
479  * Section 2: The main tree interfaces
480  * ********************************************************************
481  * This is how sysctl_dispatch() does its work, and you can too, by
482  * calling these routines from helpers (though typically only
483  * sysctl_lookup() will be used).  The tree MUST BE LOCKED when these
484  * are called.
485  * ********************************************************************
486  */
487 
488 /*
489  * sysctl_locate -- Finds the node matching the given mib under the
490  * given tree (via rv).  If no tree is given, we fall back to the
491  * native tree.  The current process (via l) is used for access
492  * control on the tree (some nodes may be traversable only by root) and
493  * on return, nip will show how many numbers in the mib were consumed.
494  */
495 int
496 sysctl_locate(struct lwp *l, const int *name, u_int namelen,
497 	      const struct sysctlnode **rnode, int *nip)
498 {
499 	const struct sysctlnode *node, *pnode;
500 	int tn, si, ni, error, alias;
501 
502 	KASSERT(rw_lock_held(&sysctl_treelock));
503 
504 	/*
505 	 * basic checks and setup
506 	 */
507 	if (*rnode == NULL)
508 		*rnode = &sysctl_root;
509 	if (nip)
510 		*nip = 0;
511 	if (namelen == 0)
512 		return (0);
513 
514 	/*
515 	 * search starts from "root"
516 	 */
517 	pnode = *rnode;
518 	if (SYSCTL_VERS(pnode->sysctl_flags) != SYSCTL_VERSION) {
519 		printf("sysctl_locate: pnode %p wrong version\n", pnode);
520 		return (EINVAL);
521 	}
522 	node = pnode->sysctl_child;
523 	error = 0;
524 
525 	/*
526 	 * scan for node to which new node should be attached
527 	 */
528 	for (ni = 0; ni < namelen; ni++) {
529 		/*
530 		 * walked off bottom of tree
531 		 */
532 		if (node == NULL) {
533 			if (SYSCTL_TYPE(pnode->sysctl_flags) == CTLTYPE_NODE)
534 				error = ENOENT;
535 			else
536 				error = ENOTDIR;
537 			break;
538 		}
539 		/*
540 		 * can anyone traverse this node or only root?
541 		 */
542 		if (l != NULL && (pnode->sysctl_flags & CTLFLAG_PRIVATE) &&
543 		    (error = kauth_authorize_system(l->l_cred,
544 		    KAUTH_SYSTEM_SYSCTL, KAUTH_REQ_SYSTEM_SYSCTL_PRVT,
545 		    NULL, NULL, NULL)) != 0)
546 			return (error);
547 		/*
548 		 * find a child node with the right number
549 		 */
550 		tn = name[ni];
551 		alias = 0;
552 
553 		si = 0;
554 		/*
555 		 * Note: ANYNUMBER only matches positive integers.
556 		 * Since ANYNUMBER is only permitted on single-node
557 		 * sub-trees (eg proc), check before the loop and skip
558 		 * it if we can.
559 		 */
560 		if ((node[si].sysctl_flags & CTLFLAG_ANYNUMBER) && (tn >= 0))
561 			goto foundit;
562 		for (; si < pnode->sysctl_clen; si++) {
563 			if (node[si].sysctl_num == tn) {
564 				if (node[si].sysctl_flags & CTLFLAG_ALIAS) {
565 					if (alias++ == 4)
566 						break;
567 					else {
568 						tn = node[si].sysctl_alias;
569 						si = -1;
570 					}
571 				} else
572 					goto foundit;
573 			}
574 		}
575 		/*
576 		 * if we ran off the end, it obviously doesn't exist
577 		 */
578 		error = ENOENT;
579 		break;
580 
581 		/*
582 		 * so far so good, move on down the line
583 		 */
584 	  foundit:
585 		pnode = &node[si];
586 		if (SYSCTL_TYPE(pnode->sysctl_flags) == CTLTYPE_NODE)
587 			node = node[si].sysctl_child;
588 		else
589 			node = NULL;
590 	}
591 
592 	*rnode = pnode;
593 	if (nip)
594 		*nip = ni;
595 
596 	return (error);
597 }
598 
599 /*
600  * sysctl_query -- The auto-discovery engine.  Copies out the structs
601  * describing nodes under the given node and handles overlay trees.
602  */
603 int
604 sysctl_query(SYSCTLFN_ARGS)
605 {
606 	int error, ni, elim, v;
607 	size_t out, left, t;
608 	const struct sysctlnode *enode, *onode;
609 	struct sysctlnode qnode;
610 
611 	KASSERT(rw_lock_held(&sysctl_treelock));
612 
613 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
614 		printf("sysctl_query: rnode %p wrong version\n", rnode);
615 		return (EINVAL);
616 	}
617 
618 	if (SYSCTL_TYPE(rnode->sysctl_flags) != CTLTYPE_NODE)
619 		return (ENOTDIR);
620 	if (namelen != 1 || name[0] != CTL_QUERY)
621 		return (EINVAL);
622 
623 	error = 0;
624 	out = 0;
625 	left = *oldlenp;
626 	elim = 0;
627 	enode = NULL;
628 
629 	/*
630 	 * translate the given request to a current node
631 	 */
632 	error = sysctl_cvt_in(l, &v, newp, newlen, &qnode);
633 	if (error)
634 		return (error);
635 
636 	/*
637 	 * if the request specifies a version, check it
638 	 */
639 	if (qnode.sysctl_ver != 0) {
640 		enode = rnode;
641 		if (qnode.sysctl_ver != enode->sysctl_ver &&
642 		    qnode.sysctl_ver != sysctl_rootof(enode)->sysctl_ver)
643 			return (EINVAL);
644 	}
645 
646 	/*
647 	 * process has overlay tree
648 	 */
649 	if (l && l->l_proc->p_emul->e_sysctlovly) {
650 		enode = l->l_proc->p_emul->e_sysctlovly;
651 		elim = (name - oname);
652 		error = sysctl_locate(l, oname, elim, &enode, NULL);
653 		if (error == 0) {
654 			/* ah, found parent in overlay */
655 			elim = enode->sysctl_clen;
656 			enode = enode->sysctl_child;
657 		} else {
658 			error = 0;
659 			elim = 0;
660 			enode = NULL;
661 		}
662 	}
663 
664 	for (ni = 0; ni < rnode->sysctl_clen; ni++) {
665 		onode = &rnode->sysctl_child[ni];
666 		if (enode && enode->sysctl_num == onode->sysctl_num) {
667 			if (SYSCTL_TYPE(enode->sysctl_flags) != CTLTYPE_NODE)
668 				onode = enode;
669 			if (--elim > 0)
670 				enode++;
671 			else
672 				enode = NULL;
673 		}
674 		error = sysctl_cvt_out(l, v, onode, oldp, left, &t);
675 		if (error)
676 			return (error);
677 		if (oldp != NULL)
678 			oldp = (char*)oldp + t;
679 		out += t;
680 		left -= MIN(left, t);
681 	}
682 
683 	/*
684 	 * overlay trees *MUST* be entirely consumed
685 	 */
686 	KASSERT(enode == NULL);
687 
688 	*oldlenp = out;
689 
690 	return (error);
691 }
692 
693 /*
694  * sysctl_create -- Adds a node (the description of which is taken
695  * from newp) to the tree, returning a copy of it in the space pointed
696  * to by oldp.  In the event that the requested slot is already taken
697  * (either by name or by number), the offending node is returned
698  * instead.  Yes, this is complex, but we want to make sure everything
699  * is proper.
700  */
701 #ifdef SYSCTL_DEBUG_CREATE
702 int _sysctl_create(SYSCTLFN_ARGS);
703 int
704 _sysctl_create(SYSCTLFN_ARGS)
705 #else
706 int
707 sysctl_create(SYSCTLFN_ARGS)
708 #endif
709 {
710 	struct sysctlnode nnode, *node, *pnode;
711 	int error, ni, at, nm, type, nsz, sz, flags, anum, v;
712 	void *own;
713 
714 	KASSERT(rw_write_held(&sysctl_treelock));
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 of this tree and
750 	 * (the tree itself is not writeable or
751 	 * the entire sysctl system is not writeable)
752 	 */
753 	if ((sysctl_rootof(rnode)->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 
794 	/*
795 	 * the name can't start with a digit
796 	 */
797 	if (nnode.sysctl_name[0] >= '0' &&
798 	    nnode.sysctl_name[0] <= '9')
799 		return (EINVAL);
800 
801 	/*
802 	 * the name must be only alphanumerics or - or _, longer than
803 	 * 0 bytes and less that SYSCTL_NAMELEN
804 	 */
805 	nsz = 0;
806 	while (nsz < SYSCTL_NAMELEN && nnode.sysctl_name[nsz] != '\0') {
807 		if ((nnode.sysctl_name[nsz] >= '0' &&
808 		     nnode.sysctl_name[nsz] <= '9') ||
809 		    (nnode.sysctl_name[nsz] >= 'A' &&
810 		     nnode.sysctl_name[nsz] <= 'Z') ||
811 		    (nnode.sysctl_name[nsz] >= 'a' &&
812 		     nnode.sysctl_name[nsz] <= 'z') ||
813 		    nnode.sysctl_name[nsz] == '-' ||
814 		    nnode.sysctl_name[nsz] == '_')
815 			nsz++;
816 		else
817 			return (EINVAL);
818 	}
819 	if (nsz == 0 || nsz == 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 && type != CTLTYPE_BOOL)
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_BOOL:
981 		/*
982 		 * since an bool is an bool, if the size is not given or
983 		 * is wrong, we can "intuit" it.
984 		 */
985 		if (sz != 0 && sz != sizeof(bool))
986 			return (EINVAL);
987 		sz = sizeof(bool);
988 		break;
989 	case CTLTYPE_STRUCT:
990 		if (sz == 0) {
991 			if (l != NULL || nnode.sysctl_func == NULL)
992 				return (EINVAL);
993 			if (flags & CTLFLAG_OWNDATA)
994 				return (EINVAL);
995 		}
996 		break;
997 	default:
998 		return (EINVAL);
999 	}
1000 
1001 	/*
1002 	 * at this point, if sz is zero, we *must* have a
1003 	 * function to go with it and we can't own it.
1004 	 */
1005 
1006 	/*
1007 	 *  l  ptr own
1008 	 *  0   0   0  -> EINVAL (if no func)
1009 	 *  0   0   1  -> own
1010 	 *  0   1   0  -> kptr
1011 	 *  0   1   1  -> kptr
1012 	 *  1   0   0  -> EINVAL
1013 	 *  1   0   1  -> own
1014 	 *  1   1   0  -> kptr, no own (fault on lookup)
1015 	 *  1   1   1  -> uptr, own
1016 	 */
1017 	if (type != CTLTYPE_NODE) {
1018 		if (sz != 0) {
1019 			if (flags & CTLFLAG_OWNDATA) {
1020 				own = malloc(sz, M_SYSCTLDATA,
1021 					     M_WAITOK|M_CANFAIL);
1022 				if (own == NULL)
1023 					return ENOMEM;
1024 				if (nnode.sysctl_data == NULL)
1025 					memset(own, 0, sz);
1026 				else {
1027 					error = sysctl_copyin(l,
1028 					    nnode.sysctl_data, own, sz);
1029 					if (error != 0) {
1030 						free(own, M_SYSCTLDATA);
1031 						return (error);
1032 					}
1033 				}
1034 			} else if ((nnode.sysctl_data != NULL) &&
1035 				 !(flags & CTLFLAG_IMMEDIATE)) {
1036 #if NKSYMS > 0
1037 				if (name[namelen - 1] == CTL_CREATESYM) {
1038 					char symname[128]; /* XXX enough? */
1039 					u_long symaddr;
1040 					size_t symlen;
1041 
1042 					error = sysctl_copyinstr(l,
1043 					    nnode.sysctl_data, symname,
1044 					    sizeof(symname), &symlen);
1045 					if (error)
1046 						return (error);
1047 					error = ksyms_getval(NULL, symname,
1048 					    &symaddr, KSYMS_EXTERN);
1049 					if (error)
1050 						return (error); /* EINVAL? */
1051 					nnode.sysctl_data = (void*)symaddr;
1052 				}
1053 #endif /* NKSYMS > 0 */
1054 				/*
1055 				 * Ideally, we'd like to verify here
1056 				 * that this address is acceptable,
1057 				 * but...
1058 				 *
1059 				 * - it might be valid now, only to
1060 				 *   become invalid later
1061 				 *
1062 				 * - it might be invalid only for the
1063 				 *   moment and valid later
1064 				 *
1065 				 * - or something else.
1066 				 *
1067 				 * Since we can't get a good answer,
1068 				 * we'll just accept the address as
1069 				 * given, and fault on individual
1070 				 * lookups.
1071 				 */
1072 			}
1073 		} else if (nnode.sysctl_func == NULL)
1074 			return (EINVAL);
1075 	}
1076 
1077 	/*
1078 	 * a process can't assign a function to a node, and the kernel
1079 	 * can't create a node that has no function or data.
1080 	 * (XXX somewhat redundant check)
1081 	 */
1082 	if (l != NULL || nnode.sysctl_func == NULL) {
1083 		if (type != CTLTYPE_NODE &&
1084 		    nnode.sysctl_data == NULL &&
1085 		    !(flags & CTLFLAG_IMMEDIATE) &&
1086 		    own == NULL)
1087 			return (EINVAL);
1088 	}
1089 
1090 #ifdef SYSCTL_DISALLOW_KWRITE
1091 	/*
1092 	 * a process can't create a writable node unless it refers to
1093 	 * new data.
1094 	 */
1095 	if (l != NULL && own == NULL && type != CTLTYPE_NODE &&
1096 	    (flags & CTLFLAG_READWRITE) != CTLFLAG_READONLY &&
1097 	    !(flags & CTLFLAG_IMMEDIATE))
1098 		return (EPERM);
1099 #endif /* SYSCTL_DISALLOW_KWRITE */
1100 
1101 	/*
1102 	 * make sure there's somewhere to put the new stuff.
1103 	 */
1104 	if (pnode->sysctl_child == NULL) {
1105 		if (flags & CTLFLAG_ANYNUMBER)
1106 			error = sysctl_alloc(pnode, 1);
1107 		else
1108 			error = sysctl_alloc(pnode, 0);
1109 		if (error) {
1110 			if (own != NULL)
1111 				free(own, M_SYSCTLDATA);
1112 			return (error);
1113 		}
1114 	}
1115 	node = pnode->sysctl_child;
1116 
1117 	/*
1118 	 * no collisions, so pick a good dynamic number if we need to.
1119 	 */
1120 	if (nm == CTL_CREATE) {
1121 		nm = ++sysctl_root.sysctl_num;
1122 		for (ni = 0; ni < pnode->sysctl_clen; ni++) {
1123 			if (nm == node[ni].sysctl_num) {
1124 				nm++;
1125 				ni = -1;
1126 			} else if (nm > node[ni].sysctl_num)
1127 				at = ni + 1;
1128 		}
1129 	}
1130 
1131 	/*
1132 	 * oops...ran out of space
1133 	 */
1134 	if (pnode->sysctl_clen == pnode->sysctl_csize) {
1135 		error = sysctl_realloc(pnode);
1136 		if (error) {
1137 			if (own != NULL)
1138 				free(own, M_SYSCTLDATA);
1139 			return (error);
1140 		}
1141 		node = pnode->sysctl_child;
1142 	}
1143 
1144 	/*
1145 	 * insert new node data
1146 	 */
1147 	if (at < pnode->sysctl_clen) {
1148 		int t;
1149 
1150 		/*
1151 		 * move the nodes that should come after the new one
1152 		 */
1153 		memmove(&node[at + 1], &node[at],
1154 			(pnode->sysctl_clen - at) * sizeof(struct sysctlnode));
1155 		memset(&node[at], 0, sizeof(struct sysctlnode));
1156 		node[at].sysctl_parent = pnode;
1157 		/*
1158 		 * and...reparent any children of any moved nodes
1159 		 */
1160 		for (ni = at; ni <= pnode->sysctl_clen; ni++)
1161 			if (node[ni].sysctl_child != NULL)
1162 				for (t = 0; t < node[ni].sysctl_csize; t++)
1163 					node[ni].sysctl_child[t].sysctl_parent =
1164 						&node[ni];
1165 	}
1166 	node = &node[at];
1167 	pnode->sysctl_clen++;
1168 
1169 	strlcpy(node->sysctl_name, nnode.sysctl_name,
1170 		sizeof(node->sysctl_name));
1171 	node->sysctl_num = nm;
1172 	node->sysctl_size = sz;
1173 	node->sysctl_flags = SYSCTL_VERSION|type|flags; /* XXX other trees */
1174 	node->sysctl_csize = 0;
1175 	node->sysctl_clen = 0;
1176 	if (own) {
1177 		node->sysctl_data = own;
1178 		node->sysctl_flags |= CTLFLAG_OWNDATA;
1179 	} else if (flags & CTLFLAG_ALIAS) {
1180 		node->sysctl_alias = anum;
1181 	} else if (flags & CTLFLAG_IMMEDIATE) {
1182 		switch (type) {
1183 		case CTLTYPE_BOOL:
1184 			node->sysctl_bdata = nnode.sysctl_bdata;
1185 			break;
1186 		case CTLTYPE_INT:
1187 			node->sysctl_idata = nnode.sysctl_idata;
1188 			break;
1189 		case CTLTYPE_QUAD:
1190 			node->sysctl_qdata = nnode.sysctl_qdata;
1191 			break;
1192 		}
1193 	} else {
1194 		node->sysctl_data = nnode.sysctl_data;
1195 		node->sysctl_flags &= ~CTLFLAG_OWNDATA;
1196 	}
1197         node->sysctl_func = nnode.sysctl_func;
1198         node->sysctl_child = NULL;
1199 	/* node->sysctl_parent should already be done */
1200 
1201 	/*
1202 	 * update "version" on path to "root"
1203 	 */
1204 	for (; rnode->sysctl_parent != NULL; rnode = rnode->sysctl_parent)
1205 		;
1206 	pnode = node;
1207 	for (nm = rnode->sysctl_ver + 1; pnode != NULL;
1208 	     pnode = pnode->sysctl_parent)
1209 		pnode->sysctl_ver = nm;
1210 
1211 	/* If this fails, the node is already added - the user won't know! */
1212 	error = sysctl_cvt_out(l, v, node, oldp, *oldlenp, oldlenp);
1213 
1214 	return (error);
1215 }
1216 
1217 /*
1218  * ********************************************************************
1219  * A wrapper around sysctl_create() that prints the thing we're trying
1220  * to add.
1221  * ********************************************************************
1222  */
1223 #ifdef SYSCTL_DEBUG_CREATE
1224 int
1225 sysctl_create(SYSCTLFN_ARGS)
1226 {
1227 	const struct sysctlnode *node;
1228 	int k, rc, ni, nl = namelen + (name - oname);
1229 
1230 	node = newp;
1231 
1232 	printf("namelen %d (", nl);
1233 	for (ni = 0; ni < nl - 1; ni++)
1234 		printf(" %d", oname[ni]);
1235 	printf(" %d )\t[%s]\tflags %08x (%08x %d %zu)\n",
1236 	       k = node->sysctl_num,
1237 	       node->sysctl_name,
1238 	       node->sysctl_flags,
1239 	       SYSCTL_FLAGS(node->sysctl_flags),
1240 	       SYSCTL_TYPE(node->sysctl_flags),
1241 	       node->sysctl_size);
1242 
1243 	node = rnode;
1244 	rc = _sysctl_create(SYSCTLFN_CALL(rnode));
1245 
1246 	printf("sysctl_create(");
1247 	for (ni = 0; ni < nl - 1; ni++)
1248 		printf(" %d", oname[ni]);
1249 	printf(" %d ) returned %d\n", k, rc);
1250 
1251 	return (rc);
1252 }
1253 #endif /* SYSCTL_DEBUG_CREATE */
1254 
1255 /*
1256  * sysctl_destroy -- Removes a node (as described by newp) from the
1257  * given tree, returning (if successful) a copy of the dead node in
1258  * oldp.  Since we're removing stuff, there's not much to check.
1259  */
1260 int
1261 sysctl_destroy(SYSCTLFN_ARGS)
1262 {
1263 	struct sysctlnode *node, *pnode, onode, nnode;
1264 	int ni, error, v;
1265 
1266 	KASSERT(rw_write_held(&sysctl_treelock));
1267 
1268 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1269 		printf("sysctl_destroy: rnode %p wrong version\n", rnode);
1270 		return (EINVAL);
1271 	}
1272 
1273 	error = 0;
1274 
1275 	if (namelen != 1 || name[namelen - 1] != CTL_DESTROY)
1276 		return (EINVAL);
1277 
1278 	/*
1279 	 * processes can only destroy nodes at securelevel 0, must be
1280 	 * root, and can't remove nodes from a parent that's not
1281 	 * writeable
1282 	 */
1283 	if (l != NULL) {
1284 #ifndef SYSCTL_DISALLOW_CREATE
1285 		error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
1286 		    KAUTH_REQ_SYSTEM_SYSCTL_DELETE, NULL, NULL, NULL);
1287 		if (error)
1288 			return (error);
1289 		if (!(rnode->sysctl_flags & CTLFLAG_READWRITE))
1290 #endif /* SYSCTL_DISALLOW_CREATE */
1291 			return (EPERM);
1292 	}
1293 
1294 	/*
1295 	 * nothing can remove a node if:
1296 	 * the node is permanent (checked later) or
1297 	 * the tree itself is not writeable or
1298 	 * the entire sysctl system is not writeable
1299 	 *
1300 	 * note that we ignore whether setup is complete or not,
1301 	 * because these rules always apply.
1302 	 */
1303 	if (!(sysctl_rootof(rnode)->sysctl_flags & CTLFLAG_READWRITE) ||
1304 	    !(sysctl_root.sysctl_flags & CTLFLAG_READWRITE))
1305 		return (EPERM);
1306 
1307 	if (newp == NULL)
1308 		return (EINVAL);
1309 	error = sysctl_cvt_in(l, &v, newp, newlen, &nnode);
1310 	if (error)
1311 		return (error);
1312 	memset(&onode, 0, sizeof(struct sysctlnode));
1313 
1314 	node = rnode->sysctl_child;
1315 	for (ni = 0; ni < rnode->sysctl_clen; ni++) {
1316 		if (nnode.sysctl_num == node[ni].sysctl_num) {
1317 			/*
1318 			 * if name specified, must match
1319 			 */
1320 			if (nnode.sysctl_name[0] != '\0' &&
1321 			    strcmp(nnode.sysctl_name, node[ni].sysctl_name))
1322 				continue;
1323 			/*
1324 			 * if version specified, must match
1325 			 */
1326 			if (nnode.sysctl_ver != 0 &&
1327 			    nnode.sysctl_ver != node[ni].sysctl_ver)
1328 				continue;
1329 			/*
1330 			 * this must be the one
1331 			 */
1332 			break;
1333 		}
1334 	}
1335 	if (ni == rnode->sysctl_clen)
1336 		return (ENOENT);
1337 	node = &node[ni];
1338 	pnode = node->sysctl_parent;
1339 
1340 	/*
1341 	 * if the kernel says permanent, it is, so there.  nyah.
1342 	 */
1343 	if (SYSCTL_FLAGS(node->sysctl_flags) & CTLFLAG_PERMANENT)
1344 		return (EPERM);
1345 
1346 	/*
1347 	 * can't delete non-empty nodes
1348 	 */
1349 	if (SYSCTL_TYPE(node->sysctl_flags) == CTLTYPE_NODE &&
1350 	    node->sysctl_clen != 0)
1351 		return (ENOTEMPTY);
1352 
1353 	/*
1354 	 * if the node "owns" data, release it now
1355 	 */
1356 	if (node->sysctl_flags & CTLFLAG_OWNDATA) {
1357 		if (node->sysctl_data != NULL)
1358 			free(node->sysctl_data, M_SYSCTLDATA);
1359 		node->sysctl_data = NULL;
1360 	}
1361 	if (node->sysctl_flags & CTLFLAG_OWNDESC) {
1362 		if (node->sysctl_desc != NULL)
1363 			/*XXXUNCONST*/
1364 			free(__UNCONST(node->sysctl_desc), M_SYSCTLDATA);
1365 		node->sysctl_desc = NULL;
1366 	}
1367 
1368 	/*
1369 	 * if the node to be removed is not the last one on the list,
1370 	 * move the remaining nodes up, and reparent any grandchildren
1371 	 */
1372 	onode = *node;
1373 	if (ni < pnode->sysctl_clen - 1) {
1374 		int t;
1375 
1376 		memmove(&pnode->sysctl_child[ni], &pnode->sysctl_child[ni + 1],
1377 			(pnode->sysctl_clen - ni - 1) *
1378 			sizeof(struct sysctlnode));
1379 		for (; ni < pnode->sysctl_clen - 1; ni++)
1380 			if (SYSCTL_TYPE(pnode->sysctl_child[ni].sysctl_flags) ==
1381 			    CTLTYPE_NODE)
1382 				for (t = 0;
1383 				     t < pnode->sysctl_child[ni].sysctl_clen;
1384 				     t++)
1385 					pnode->sysctl_child[ni].sysctl_child[t].
1386 						sysctl_parent =
1387 						&pnode->sysctl_child[ni];
1388 		ni = pnode->sysctl_clen - 1;
1389 		node = &pnode->sysctl_child[ni];
1390 	}
1391 
1392 	/*
1393 	 * reset the space we just vacated
1394 	 */
1395 	memset(node, 0, sizeof(struct sysctlnode));
1396 	node->sysctl_parent = pnode;
1397 	pnode->sysctl_clen--;
1398 
1399 	/*
1400 	 * if this parent just lost its last child, nuke the creche
1401 	 */
1402 	if (pnode->sysctl_clen == 0) {
1403 		free(pnode->sysctl_child, M_SYSCTLNODE);
1404 		pnode->sysctl_csize = 0;
1405 		pnode->sysctl_child = NULL;
1406 	}
1407 
1408 	/*
1409 	 * update "version" on path to "root"
1410 	 */
1411         for (; rnode->sysctl_parent != NULL; rnode = rnode->sysctl_parent)
1412                 ;
1413 	for (ni = rnode->sysctl_ver + 1; pnode != NULL;
1414 	     pnode = pnode->sysctl_parent)
1415 		pnode->sysctl_ver = ni;
1416 
1417 	error = sysctl_cvt_out(l, v, &onode, oldp, *oldlenp, oldlenp);
1418 
1419 	return (error);
1420 }
1421 
1422 /*
1423  * sysctl_lookup -- Handles copyin/copyout of new and old values.
1424  * Partial reads are globally allowed.  Only root can write to things
1425  * unless the node says otherwise.
1426  */
1427 int
1428 sysctl_lookup(SYSCTLFN_ARGS)
1429 {
1430 	int error, rw;
1431 	size_t sz, len;
1432 	void *d, *d_out;
1433 	uint64_t qval;
1434 	int ival;
1435 
1436 	KASSERT(rw_lock_held(&sysctl_treelock));
1437 
1438 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1439 		printf("%s: rnode %p wrong version\n", __func__, rnode);
1440 		return EINVAL;
1441 	}
1442 
1443 	if (newlen == 0)
1444 		newp = NULL;
1445 
1446 	error = 0;
1447 
1448 	/*
1449 	 * you can't "look up" a node.  you can "query" it, but you
1450 	 * can't "look it up".
1451 	 */
1452 	if (SYSCTL_TYPE(rnode->sysctl_flags) == CTLTYPE_NODE || namelen != 0) {
1453 		DPRINTF(("%s: can't lookup a node\n", __func__));
1454 		return EINVAL;
1455 	}
1456 
1457 	/*
1458 	 * some nodes are private, so only root can look into them.
1459 	 */
1460 	if (l != NULL && (rnode->sysctl_flags & CTLFLAG_PRIVATE) &&
1461 	    (error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
1462 	    KAUTH_REQ_SYSTEM_SYSCTL_PRVT, NULL, NULL, NULL)) != 0) {
1463 		DPRINTF(("%s: private node\n", __func__));
1464 		return error;
1465 	}
1466 
1467 	/*
1468 	 * if a node wants to be writable according to different rules
1469 	 * other than "only root can write to stuff unless a flag is
1470 	 * set", then it needs its own function which should have been
1471 	 * called and not us.
1472 	 */
1473 	if (l != NULL && newp != NULL &&
1474 	    !(rnode->sysctl_flags & CTLFLAG_ANYWRITE) &&
1475 	    (error = kauth_authorize_system(l->l_cred,
1476 	    KAUTH_SYSTEM_SYSCTL, KAUTH_REQ_SYSTEM_SYSCTL_MODIFY, NULL, NULL,
1477 	    NULL)) != 0) {
1478 		DPRINTF(("%s: can't modify\n", __func__));
1479 		return error;
1480 	}
1481 
1482 	/*
1483 	 * is this node supposedly writable?
1484 	 */
1485 	rw = (rnode->sysctl_flags & CTLFLAG_READWRITE) ? 1 : 0;
1486 
1487 	/*
1488 	 * it appears not to be writable at this time, so if someone
1489 	 * tried to write to it, we must tell them to go away
1490 	 */
1491 	if (!rw && newp != NULL) {
1492 		DPRINTF(("%s: not writable\n", __func__));
1493 		return EPERM;
1494 	}
1495 
1496 	/*
1497 	 * step one, copy out the stuff we have presently
1498 	 */
1499 	if (rnode->sysctl_flags & CTLFLAG_IMMEDIATE) {
1500 		/*
1501 		 * note that we discard const here because we are
1502 		 * modifying the contents of the node (which is okay
1503 		 * because it's ours)
1504 		 *
1505 		 * It also doesn't matter which field of the union we pick.
1506 		 */
1507 		d = __UNCONST(&rnode->sysctl_qdata);
1508 	} else
1509 		d = rnode->sysctl_data;
1510 	d_out = d;
1511 
1512 	sz = rnode->sysctl_size;
1513 	switch (SYSCTL_TYPE(rnode->sysctl_flags)) {
1514 	case CTLTYPE_INT:
1515 		/* Allow for 64bit read of 32bit value */
1516 		if (*oldlenp == sizeof (uint64_t)) {
1517 			qval = *(int *)d;
1518 			d_out = &qval;
1519 			sz =  sizeof (uint64_t);
1520 		}
1521 		break;
1522 	case CTLTYPE_QUAD:
1523 		/* Allow for 32bit read of 64bit value */
1524 		if (*oldlenp == sizeof (int)) {
1525 			qval = *(uint64_t *)d;
1526 			ival = qval < 0x100000000 ? qval : 0xffffffff;
1527 			d_out = &ival;
1528 			sz =  sizeof (int);
1529 		}
1530 		break;
1531 	case CTLTYPE_STRING:
1532 		sz = strlen(d) + 1; /* XXX@@@ possible fault here */
1533 		break;
1534 	default:
1535 		break;
1536 	}
1537 	if (oldp != NULL) {
1538 		error = sysctl_copyout(l, d_out, oldp, MIN(sz, *oldlenp));
1539 		if (error) {
1540 			DPRINTF(("%s: bad copyout %d\n", __func__, error));
1541 			return error;
1542 		}
1543 	}
1544 	*oldlenp = sz;
1545 
1546 	/*
1547 	 * are we done?
1548 	 */
1549 	if (newp == NULL)
1550 		return 0;
1551 
1552 	/*
1553 	 * hmm...not done.  must now "copy in" new value.  re-adjust
1554 	 * sz to maximum value (strings are "weird").
1555 	 */
1556 	sz = rnode->sysctl_size;
1557 	switch (SYSCTL_TYPE(rnode->sysctl_flags)) {
1558 	case CTLTYPE_BOOL: {
1559 		bool tmp;
1560 		/*
1561 		 * these data must be *exactly* the same size coming
1562 		 * in.  bool may only be true or false.
1563 		 */
1564 		if (newlen != sz) {
1565 			DPRINTF(("%s: bad size %zu != %zu\n", __func__, newlen,
1566 			    sz));
1567 			return EINVAL;
1568 		}
1569 		error = sysctl_copyin(l, newp, &tmp, sz);
1570 		if (error)
1571 			break;
1572 		if (tmp != true && tmp != false) {
1573 			DPRINTF(("%s: tmp %d\n", __func__, tmp));
1574 			return EINVAL;
1575 		}
1576 		*(bool *)d = tmp;
1577 		break;
1578 	}
1579 	case CTLTYPE_INT:
1580 	case CTLTYPE_QUAD:
1581 		/* Allow 32bit of 64bit integers */
1582 		if (newlen == sizeof (uint64_t)) {
1583 			error = sysctl_copyin(l, newp, &qval, sizeof qval);
1584 		} else if (newlen == sizeof (int)) {
1585 			error = sysctl_copyin(l, newp, &ival, sizeof ival);
1586 			qval = ival;
1587 		} else {
1588 			goto bad_size;
1589 		}
1590 		if (!error) {
1591 			if (SYSCTL_TYPE(rnode->sysctl_flags) == CTLTYPE_INT) {
1592 				ival = qval;
1593 				/* Error out of range values */
1594 				if (ival != qval)
1595 					goto bad_size;
1596 				*(int *)d = ival;
1597 			} else {
1598 				*(uint64_t *)d = qval;
1599 			}
1600 		}
1601 		break;
1602 	case CTLTYPE_STRUCT:
1603 		/*
1604 		 * these data must be *exactly* the same size coming
1605 		 * in.
1606 		 */
1607 		if (newlen != sz)
1608 			goto bad_size;
1609 		error = sysctl_copyin(l, newp, d, sz);
1610 		break;
1611 	case CTLTYPE_STRING: {
1612 		/*
1613 		 * strings, on the other hand, can be shorter, and we
1614 		 * let userland be sloppy about the trailing nul.
1615 		 */
1616 		char *newbuf;
1617 
1618 		/*
1619 		 * too much new string?
1620 		 */
1621 		if (newlen > sz)
1622 			goto bad_size;
1623 
1624 		/*
1625 		 * temporary copy of new inbound string
1626 		 */
1627 		len = MIN(sz, newlen);
1628 		newbuf = malloc(len, M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
1629 		if (newbuf == NULL) {
1630 			DPRINTF(("%s: oomem %zu\n", __func__, len));
1631 			return ENOMEM;
1632 		}
1633 		error = sysctl_copyin(l, newp, newbuf, len);
1634 		if (error) {
1635 			free(newbuf, M_SYSCTLDATA);
1636 			DPRINTF(("%s: copyin %d\n", __func__, error));
1637 			return error;
1638 		}
1639 
1640 		/*
1641 		 * did they NUL terminate it, or do we have space
1642 		 * left to do it ourselves?
1643 		 */
1644 		if (newbuf[len - 1] != '\0' && len == sz) {
1645 			free(newbuf, M_SYSCTLDATA);
1646 			DPRINTF(("%s: string too long\n", __func__));
1647 			return EINVAL;
1648 		}
1649 
1650 		/*
1651 		 * looks good, so pop it into place and zero the rest.
1652 		 */
1653 		if (len > 0)
1654 			memcpy(d, newbuf, len);
1655 		if (sz != len)
1656 			memset((char*)d + len, 0, sz - len);
1657 		free(newbuf, M_SYSCTLDATA);
1658 		break;
1659 	}
1660 	default:
1661 		DPRINTF(("%s: bad type\n", __func__));
1662 		return EINVAL;
1663 	}
1664 	if (error) {
1665 		DPRINTF(("%s: copyin %d\n", __func__, error));
1666 	}
1667 
1668 	return error;
1669 
1670     bad_size:
1671 	DPRINTF(("%s: bad size %zu > %zu\n", __func__, newlen, sz));
1672 	return EINVAL;
1673 }
1674 
1675 /*
1676  * sysctl_mmap -- Dispatches sysctl mmap requests to those nodes that
1677  * purport to handle it.  This interface isn't fully fleshed out yet,
1678  * unfortunately.
1679  */
1680 static int
1681 sysctl_mmap(SYSCTLFN_ARGS)
1682 {
1683 	const struct sysctlnode *node;
1684 	struct sysctlnode nnode;
1685 	int error;
1686 
1687 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1688 		printf("sysctl_mmap: rnode %p wrong version\n", rnode);
1689 		return (EINVAL);
1690 	}
1691 
1692 	/*
1693 	 * let's just pretend that didn't happen, m'kay?
1694 	 */
1695 	if (l == NULL)
1696 		return (EPERM);
1697 
1698 	/*
1699 	 * is this a sysctlnode description of an mmap request?
1700 	 */
1701 	if (newp == NULL || newlen != sizeof(struct sysctlnode))
1702 		return (EINVAL);
1703 	error = sysctl_copyin(l, newp, &nnode, sizeof(nnode));
1704 	if (error)
1705 		return (error);
1706 
1707 	/*
1708 	 * does the node they asked for exist?
1709 	 */
1710 	if (namelen != 1)
1711 		return (EOPNOTSUPP);
1712 	node = rnode;
1713         error = sysctl_locate(l, &nnode.sysctl_num, 1, &node, NULL);
1714 	if (error)
1715 		return (error);
1716 
1717 	/*
1718 	 * does this node that we have found purport to handle mmap?
1719 	 */
1720 	if (node->sysctl_func == NULL ||
1721 	    !(node->sysctl_flags & CTLFLAG_MMAP))
1722 		return (EOPNOTSUPP);
1723 
1724 	/*
1725 	 * well...okay, they asked for it.
1726 	 */
1727 	return ((*node->sysctl_func)(SYSCTLFN_CALL(node)));
1728 }
1729 
1730 int
1731 sysctl_describe(SYSCTLFN_ARGS)
1732 {
1733 	struct sysctldesc *d;
1734 	void *bf;
1735 	size_t sz, left, tot;
1736 	int i, error, v = -1;
1737 	struct sysctlnode *node;
1738 	struct sysctlnode dnode;
1739 
1740 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1741 		printf("sysctl_query: rnode %p wrong version\n", rnode);
1742 		return (EINVAL);
1743 	}
1744 
1745 	if (SYSCTL_TYPE(rnode->sysctl_flags) != CTLTYPE_NODE)
1746 		return (ENOTDIR);
1747 	if (namelen != 1 || name[0] != CTL_DESCRIBE)
1748 		return (EINVAL);
1749 
1750 	/*
1751 	 * get ready...
1752 	 */
1753 	error = 0;
1754 	d = bf = malloc(MAXDESCLEN, M_TEMP, M_WAITOK|M_CANFAIL);
1755 	if (bf == NULL)
1756 		return ENOMEM;
1757 	tot = 0;
1758 	node = rnode->sysctl_child;
1759 	left = *oldlenp;
1760 
1761 	/*
1762 	 * no request -> all descriptions at this level
1763 	 * request with desc unset -> just this node
1764 	 * request with desc set -> set descr for this node
1765 	 */
1766 	if (newp != NULL) {
1767 		error = sysctl_cvt_in(l, &v, newp, newlen, &dnode);
1768 		if (error)
1769 			goto out;
1770 		if (dnode.sysctl_desc != NULL) {
1771 			/*
1772 			 * processes cannot set descriptions above
1773 			 * securelevel 0.  and must be root.  blah
1774 			 * blah blah.  a couple more checks are made
1775 			 * once we find the node we want.
1776 			 */
1777 			if (l != NULL) {
1778 #ifndef SYSCTL_DISALLOW_CREATE
1779 				error = kauth_authorize_system(l->l_cred,
1780 				    KAUTH_SYSTEM_SYSCTL,
1781 				    KAUTH_REQ_SYSTEM_SYSCTL_DESC, NULL,
1782 				    NULL, NULL);
1783 				if (error)
1784 					goto out;
1785 #else /* SYSCTL_DISALLOW_CREATE */
1786 				error = EPERM;
1787 				goto out;
1788 #endif /* SYSCTL_DISALLOW_CREATE */
1789 			}
1790 
1791 			/*
1792 			 * find node and try to set the description on it
1793 			 */
1794 			for (i = 0; i < rnode->sysctl_clen; i++)
1795 				if (node[i].sysctl_num == dnode.sysctl_num)
1796 					break;
1797 			if (i == rnode->sysctl_clen) {
1798 				error = ENOENT;
1799 				goto out;
1800 			}
1801 			node = &node[i];
1802 
1803 			/*
1804 			 * did the caller specify a node version?
1805 			 */
1806 			if (dnode.sysctl_ver != 0 &&
1807 			    dnode.sysctl_ver != node->sysctl_ver) {
1808 				error = EINVAL;
1809 				goto out;
1810 			}
1811 
1812 			/*
1813 			 * okay...some rules:
1814 			 * (1) if setup is done and the tree is
1815 			 *     read-only or the whole system is
1816 			 *     read-only
1817 			 * (2) no one can set a description on a
1818 			 *     permanent node (it must be set when
1819 			 *     using createv)
1820 			 * (3) processes cannot *change* a description
1821 			 * (4) processes *can*, however, set a
1822 			 *     description on a read-only node so that
1823 			 *     one can be created and then described
1824 			 *     in two steps
1825 			 * anything else come to mind?
1826 			 */
1827 			if ((sysctl_root.sysctl_flags & CTLFLAG_PERMANENT) &&
1828 			    (!(sysctl_rootof(node)->sysctl_flags &
1829 			       CTLFLAG_READWRITE) ||
1830 			     !(sysctl_root.sysctl_flags & CTLFLAG_READWRITE))) {
1831 				error = EPERM;
1832 				goto out;
1833 			}
1834 			if (node->sysctl_flags & CTLFLAG_PERMANENT) {
1835 				error = EPERM;
1836 				goto out;
1837 			}
1838 			if (l != NULL && node->sysctl_desc != NULL) {
1839 				error = EPERM;
1840 				goto out;
1841 			}
1842 
1843 			/*
1844 			 * right, let's go ahead.  the first step is
1845 			 * making the description into something the
1846 			 * node can "own", if need be.
1847 			 */
1848 			if (l != NULL ||
1849 			    dnode.sysctl_flags & CTLFLAG_OWNDESC) {
1850 				char *nd, *k;
1851 
1852 				k = malloc(MAXDESCLEN, M_TEMP,
1853 				    M_WAITOK|M_CANFAIL);
1854 				if (k == NULL) {
1855 					error = ENOMEM;
1856 					goto out;
1857 				}
1858 				error = sysctl_copyinstr(l, dnode.sysctl_desc,
1859 							 k, MAXDESCLEN, &sz);
1860 				if (error) {
1861 					free(k, M_TEMP);
1862 					goto out;
1863 				}
1864 				nd = malloc(sz, M_SYSCTLDATA,
1865 					    M_WAITOK|M_CANFAIL);
1866 				if (nd == NULL) {
1867 					free(k, M_TEMP);
1868 					error = ENOMEM;
1869 					goto out;
1870 				}
1871 				memcpy(nd, k, sz);
1872 				dnode.sysctl_flags |= CTLFLAG_OWNDESC;
1873 				dnode.sysctl_desc = nd;
1874 				free(k, M_TEMP);
1875 			}
1876 
1877 			/*
1878 			 * now "release" the old description and
1879 			 * attach the new one.  ta-da.
1880 			 */
1881 			if ((node->sysctl_flags & CTLFLAG_OWNDESC) &&
1882 			    node->sysctl_desc != NULL)
1883 				/*XXXUNCONST*/
1884 				free(__UNCONST(node->sysctl_desc), M_SYSCTLDATA);
1885 			node->sysctl_desc = dnode.sysctl_desc;
1886 			node->sysctl_flags |=
1887 				(dnode.sysctl_flags & CTLFLAG_OWNDESC);
1888 
1889 			/*
1890 			 * now we "fall out" and into the loop which
1891 			 * will copy the new description back out for
1892 			 * those interested parties
1893 			 */
1894 		}
1895 	}
1896 
1897 	/*
1898 	 * scan for one description or just retrieve all descriptions
1899 	 */
1900 	for (i = 0; i < rnode->sysctl_clen; i++) {
1901 		/*
1902 		 * did they ask for the description of only one node?
1903 		 */
1904 		if (v != -1 && node[i].sysctl_num != dnode.sysctl_num)
1905 			continue;
1906 
1907 		/*
1908 		 * don't describe "private" nodes to non-suser users
1909 		 */
1910 		if ((node[i].sysctl_flags & CTLFLAG_PRIVATE) && (l != NULL) &&
1911 		    !(kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
1912 		    KAUTH_REQ_SYSTEM_SYSCTL_PRVT, NULL, NULL, NULL)))
1913 			continue;
1914 
1915 		/*
1916 		 * is this description "valid"?
1917 		 */
1918 		memset(bf, 0, MAXDESCLEN);
1919 		if (node[i].sysctl_desc == NULL)
1920 			sz = 1;
1921 		else if (copystr(node[i].sysctl_desc, &d->descr_str[0],
1922 				 MAXDESCLEN - sizeof(*d), &sz) != 0) {
1923 			/*
1924 			 * erase possible partial description
1925 			 */
1926 			memset(bf, 0, MAXDESCLEN);
1927 			sz = 1;
1928 		}
1929 
1930 		/*
1931 		 * we've got it, stuff it into the caller's buffer
1932 		 */
1933 		d->descr_num = node[i].sysctl_num;
1934 		d->descr_ver = node[i].sysctl_ver;
1935 		d->descr_len = sz; /* includes trailing nul */
1936 		sz = (char *)NEXT_DESCR(d) - (char *)d;
1937 		if (oldp != NULL && left >= sz) {
1938 			error = sysctl_copyout(l, d, oldp, sz);
1939 			if (error)
1940 				goto out;
1941 			left -= sz;
1942 			oldp = (void *)__sysc_desc_adv(oldp, d->descr_len);
1943 		}
1944 		tot += sz;
1945 
1946 		/*
1947 		 * if we get this far with v not "unset", they asked
1948 		 * for a specific node and we found it
1949 		 */
1950 		if (v != -1)
1951 			break;
1952 	}
1953 
1954 	/*
1955 	 * did we find it after all?
1956 	 */
1957 	if (v != -1 && tot == 0)
1958 		error = ENOENT;
1959 	else
1960 		*oldlenp = tot;
1961 
1962 out:
1963 	free(bf, M_TEMP);
1964 	return (error);
1965 }
1966 
1967 /*
1968  * ********************************************************************
1969  * Section 3: Create and destroy from inside the kernel
1970  * ********************************************************************
1971  * sysctl_createv() and sysctl_destroyv() are simpler-to-use
1972  * interfaces for the kernel to fling new entries into the mib and rip
1973  * them out later.  In the case of sysctl_createv(), the returned copy
1974  * of the node (see sysctl_create()) will be translated back into a
1975  * pointer to the actual node.
1976  *
1977  * Note that sysctl_createv() will return 0 if the create request
1978  * matches an existing node (ala mkdir -p), and that sysctl_destroyv()
1979  * will return 0 if the node to be destroyed already does not exist
1980  * (aka rm -f) or if it is a parent of other nodes.
1981  *
1982  * This allows two (or more) different subsystems to assert sub-tree
1983  * existence before populating their own nodes, and to remove their
1984  * own nodes without orphaning the others when they are done.
1985  * ********************************************************************
1986  */
1987 #undef sysctl_createv
1988 int
1989 sysctl_createv(struct sysctllog **log, int cflags,
1990 	       const struct sysctlnode **rnode, const struct sysctlnode **cnode,
1991 	       int flags, int type, const char *namep, const char *descr,
1992 	       sysctlfn func, u_quad_t qv, void *newp, size_t newlen,
1993 	       ...)
1994 {
1995 	va_list ap;
1996 	int error, ni, namelen, name[CTL_MAXNAME];
1997 	const struct sysctlnode *root, *pnode;
1998 	struct sysctlnode nnode, onode, *dnode;
1999 	size_t sz;
2000 
2001 	/*
2002 	 * where are we putting this?
2003 	 */
2004 	if (rnode != NULL && *rnode == NULL) {
2005 		printf("sysctl_createv: rnode NULL\n");
2006 		return (EINVAL);
2007 	}
2008 	root = rnode ? *rnode : NULL;
2009 	if (cnode != NULL)
2010 		*cnode = NULL;
2011 	if (cflags != 0)
2012 		return (EINVAL);
2013 
2014 	/*
2015 	 * what is it?
2016 	 */
2017 	flags = SYSCTL_VERSION|SYSCTL_TYPE(type)|SYSCTL_FLAGS(flags);
2018 	if (log != NULL)
2019 		flags &= ~CTLFLAG_PERMANENT;
2020 
2021 	/*
2022 	 * where do we put it?
2023 	 */
2024 	va_start(ap, newlen);
2025 	namelen = 0;
2026 	error = 0;
2027 	ni = -1;
2028 	do {
2029 		if (++ni == CTL_MAXNAME) {
2030 			error = ENAMETOOLONG;
2031 			break;
2032 		}
2033 		name[ni] = va_arg(ap, int);
2034 		/*
2035 		 * sorry, this is not supported from here
2036 		 */
2037 		if (name[ni] == CTL_CREATESYM) {
2038 			error = EINVAL;
2039 			break;
2040 		}
2041 	} while (name[ni] != CTL_EOL && name[ni] != CTL_CREATE);
2042 	va_end(ap);
2043 	if (error)
2044 		return error;
2045 	namelen = ni + (name[ni] == CTL_CREATE ? 1 : 0);
2046 
2047 	/*
2048 	 * what's it called
2049 	 */
2050 	if (strlcpy(nnode.sysctl_name, namep, sizeof(nnode.sysctl_name)) >=
2051 	    sizeof(nnode.sysctl_name))
2052 		return (ENAMETOOLONG);
2053 
2054 	/*
2055 	 * cons up the description of the new node
2056 	 */
2057 	nnode.sysctl_num = name[namelen - 1];
2058 	name[namelen - 1] = CTL_CREATE;
2059 	nnode.sysctl_size = newlen;
2060 	nnode.sysctl_flags = flags;
2061 	if (type == CTLTYPE_NODE) {
2062 		nnode.sysctl_csize = 0;
2063 		nnode.sysctl_clen = 0;
2064 		nnode.sysctl_child = NULL;
2065 		if (flags & CTLFLAG_ALIAS)
2066 			nnode.sysctl_alias = qv;
2067 	} else if (flags & CTLFLAG_IMMEDIATE) {
2068 		switch (type) {
2069 		case CTLTYPE_BOOL:
2070 			nnode.sysctl_bdata = qv;
2071 			break;
2072 		case CTLTYPE_INT:
2073 			nnode.sysctl_idata = qv;
2074 			break;
2075 		case CTLTYPE_QUAD:
2076 			nnode.sysctl_qdata = qv;
2077 			break;
2078 		default:
2079 			return (EINVAL);
2080 		}
2081 	} else {
2082 		nnode.sysctl_data = newp;
2083 	}
2084 	nnode.sysctl_func = func;
2085 	nnode.sysctl_parent = NULL;
2086 	nnode.sysctl_ver = 0;
2087 
2088 	/*
2089 	 * initialize lock state -- we need locks if the main tree has
2090 	 * been marked as complete, but since we could be called from
2091 	 * either there, or from a device driver (say, at device
2092 	 * insertion), or from a module (at module load time, say), we
2093 	 * don't really want to "wait"...
2094 	 */
2095 	sysctl_lock(true);
2096 
2097 	/*
2098 	 * locate the prospective parent of the new node, and if we
2099 	 * find it, add the new node.
2100 	 */
2101 	sz = sizeof(onode);
2102 	pnode = root;
2103 	error = sysctl_locate(NULL, &name[0], namelen - 1, &pnode, &ni);
2104 	if (error) {
2105 		printf("sysctl_createv: sysctl_locate(%s) returned %d\n",
2106 		       nnode.sysctl_name, error);
2107 		sysctl_unlock();
2108 		return (error);
2109 	}
2110 	error = sysctl_create(&name[ni], namelen - ni, &onode, &sz,
2111 			      &nnode, sizeof(nnode), &name[0], NULL,
2112 			      pnode);
2113 
2114 	/*
2115 	 * unfortunately the node we wanted to create is already
2116 	 * there.  if the node that's already there is a reasonable
2117 	 * facsimile of the node we wanted to create, just pretend
2118 	 * (for the caller's benefit) that we managed to create the
2119 	 * node they wanted.
2120 	 */
2121 	if (error == EEXIST) {
2122 		/* name is the same as requested... */
2123 		if (strcmp(nnode.sysctl_name, onode.sysctl_name) == 0 &&
2124 		    /* they want the same function... */
2125 		    nnode.sysctl_func == onode.sysctl_func &&
2126 		    /* number is the same as requested, or... */
2127 		    (nnode.sysctl_num == onode.sysctl_num ||
2128 		     /* they didn't pick a number... */
2129 		     nnode.sysctl_num == CTL_CREATE)) {
2130 			/*
2131 			 * collision here from trying to create
2132 			 * something that already existed; let's give
2133 			 * our customers a hand and tell them they got
2134 			 * what they wanted.
2135 			 */
2136 #ifdef SYSCTL_DEBUG_CREATE
2137 			printf("cleared\n");
2138 #endif /* SYSCTL_DEBUG_CREATE */
2139 			error = 0;
2140 		}
2141 	}
2142 
2143 	if (error == 0 &&
2144 	    (cnode != NULL || log != NULL || descr != NULL)) {
2145 		/*
2146 		 * sysctl_create() gave us back a copy of the node,
2147 		 * but we need to know where it actually is...
2148 		 */
2149 		pnode = root;
2150 		error = sysctl_locate(NULL, &name[0], namelen - 1, &pnode, &ni);
2151 
2152 		/*
2153 		 * manual scan of last layer so that aliased nodes
2154 		 * aren't followed.
2155 		 */
2156 		if (error == 0) {
2157 			for (ni = 0; ni < pnode->sysctl_clen; ni++)
2158 				if (pnode->sysctl_child[ni].sysctl_num ==
2159 				    onode.sysctl_num)
2160 					break;
2161 			if (ni < pnode->sysctl_clen)
2162 				pnode = &pnode->sysctl_child[ni];
2163 			else
2164 				error = ENOENT;
2165 		}
2166 
2167 		/*
2168 		 * not expecting an error here, but...
2169 		 */
2170 		if (error == 0) {
2171 			if (log != NULL)
2172 				sysctl_log_add(log, pnode);
2173 			if (cnode != NULL)
2174 				*cnode = pnode;
2175 			if (descr != NULL) {
2176 				/*
2177 				 * allow first caller to *set* a
2178 				 * description actually to set it
2179 				 *
2180 				 * discard const here so we can attach
2181 				 * the description
2182 				 */
2183 				dnode = __UNCONST(pnode);
2184 				if (pnode->sysctl_desc != NULL)
2185 					/* skip it...we've got one */;
2186 				else if (flags & CTLFLAG_OWNDESC) {
2187 					size_t l = strlen(descr) + 1;
2188 					char *d = malloc(l, M_SYSCTLDATA,
2189 							 M_WAITOK|M_CANFAIL);
2190 					if (d != NULL) {
2191 						memcpy(d, descr, l);
2192 						dnode->sysctl_desc = d;
2193 						dnode->sysctl_flags |=
2194 						    CTLFLAG_OWNDESC;
2195 					}
2196 				} else
2197 					dnode->sysctl_desc = descr;
2198 			}
2199 		} else {
2200 			printf("sysctl_create succeeded but node not found?!\n");
2201 			/*
2202 			 *  confusing, but the create said it
2203 			 * succeeded, so...
2204 			 */
2205 			error = 0;
2206 		}
2207 	}
2208 
2209 	/*
2210 	 * now it should be safe to release the lock state.  note that
2211 	 * the pointer to the newly created node being passed back may
2212 	 * not be "good" for very long.
2213 	 */
2214 	sysctl_unlock();
2215 
2216 	if (error != 0) {
2217 		printf("sysctl_createv: sysctl_create(%s) returned %d\n",
2218 		       nnode.sysctl_name, error);
2219 #if 0
2220 		if (error != ENOENT)
2221 			sysctl_dump(&onode);
2222 #endif
2223 	}
2224 
2225 	return (error);
2226 }
2227 
2228 int
2229 sysctl_destroyv(struct sysctlnode *rnode, ...)
2230 {
2231 	va_list ap;
2232 	int error, name[CTL_MAXNAME], namelen, ni;
2233 	const struct sysctlnode *pnode, *node;
2234 	struct sysctlnode dnode, *onode;
2235 	size_t sz;
2236 
2237 	va_start(ap, rnode);
2238 	namelen = 0;
2239 	ni = 0;
2240 	do {
2241 		if (ni == CTL_MAXNAME) {
2242 			va_end(ap);
2243 			return (ENAMETOOLONG);
2244 		}
2245 		name[ni] = va_arg(ap, int);
2246 	} while (name[ni++] != CTL_EOL);
2247 	namelen = ni - 1;
2248 	va_end(ap);
2249 
2250 	/*
2251 	 * i can't imagine why we'd be destroying a node when the tree
2252 	 * wasn't complete, but who knows?
2253 	 */
2254 	sysctl_lock(true);
2255 
2256 	/*
2257 	 * where is it?
2258 	 */
2259 	node = rnode;
2260 	error = sysctl_locate(NULL, &name[0], namelen - 1, &node, &ni);
2261 	if (error) {
2262 		/* they want it gone and it's not there, so... */
2263 		sysctl_unlock();
2264 		return (error == ENOENT ? 0 : error);
2265 	}
2266 
2267 	/*
2268 	 * set up the deletion
2269 	 */
2270 	pnode = node;
2271 	node = &dnode;
2272 	memset(&dnode, 0, sizeof(dnode));
2273 	dnode.sysctl_flags = SYSCTL_VERSION;
2274 	dnode.sysctl_num = name[namelen - 1];
2275 
2276 	/*
2277 	 * we found it, now let's nuke it
2278 	 */
2279 	name[namelen - 1] = CTL_DESTROY;
2280 	sz = 0;
2281 	error = sysctl_destroy(&name[namelen - 1], 1, NULL, &sz,
2282 			       node, sizeof(*node), &name[0], NULL,
2283 			       pnode);
2284 	if (error == ENOTEMPTY) {
2285 		/*
2286 		 * think of trying to delete "foo" when "foo.bar"
2287 		 * (which someone else put there) is still in
2288 		 * existence
2289 		 */
2290 		error = 0;
2291 
2292 		/*
2293 		 * dunno who put the description there, but if this
2294 		 * node can ever be removed, we need to make sure the
2295 		 * string doesn't go out of context.  that means we
2296 		 * need to find the node that's still there (don't use
2297 		 * sysctl_locate() because that follows aliasing).
2298 		 */
2299 		node = pnode->sysctl_child;
2300 		for (ni = 0; ni < pnode->sysctl_clen; ni++)
2301 			if (node[ni].sysctl_num == dnode.sysctl_num)
2302 				break;
2303 		node = (ni < pnode->sysctl_clen) ? &node[ni] : NULL;
2304 
2305 		/*
2306 		 * if we found it, and this node has a description,
2307 		 * and this node can be released, and it doesn't
2308 		 * already own its own description...sigh.  :)
2309 		 */
2310 		if (node != NULL && node->sysctl_desc != NULL &&
2311 		    !(node->sysctl_flags & CTLFLAG_PERMANENT) &&
2312 		    !(node->sysctl_flags & CTLFLAG_OWNDESC)) {
2313 			char *d;
2314 
2315 			sz = strlen(node->sysctl_desc) + 1;
2316 			d = malloc(sz, M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
2317 			if (d != NULL) {
2318 				/*
2319 				 * discard const so that we can
2320 				 * re-attach the description
2321 				 */
2322 				memcpy(d, node->sysctl_desc, sz);
2323 				onode = __UNCONST(node);
2324 				onode->sysctl_desc = d;
2325 				onode->sysctl_flags |= CTLFLAG_OWNDESC;
2326 			} else {
2327 				/*
2328 				 * XXX drop the description?  be
2329 				 * afraid?  don't care?
2330 				 */
2331 			}
2332 		}
2333 	}
2334 
2335         sysctl_unlock();
2336 
2337 	return (error);
2338 }
2339 
2340 /*
2341  * ********************************************************************
2342  * Deletes an entire n-ary tree.  Not recommended unless you know why
2343  * you're doing it.  Personally, I don't know why you'd even think
2344  * about it.
2345  * ********************************************************************
2346  */
2347 void
2348 sysctl_free(struct sysctlnode *rnode)
2349 {
2350 	struct sysctlnode *node, *pnode;
2351 
2352 	rw_enter(&sysctl_treelock, RW_WRITER);
2353 
2354 	if (rnode == NULL)
2355 		rnode = &sysctl_root;
2356 
2357 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
2358 		printf("sysctl_free: rnode %p wrong version\n", rnode);
2359 		rw_exit(&sysctl_treelock);
2360 		return;
2361 	}
2362 
2363 	pnode = rnode;
2364 
2365 	node = pnode->sysctl_child;
2366 	do {
2367 		while (node != NULL && pnode->sysctl_csize > 0) {
2368 			while (node <
2369 			       &pnode->sysctl_child[pnode->sysctl_clen] &&
2370 			       (SYSCTL_TYPE(node->sysctl_flags) !=
2371 				CTLTYPE_NODE ||
2372 				node->sysctl_csize == 0)) {
2373 				if (SYSCTL_FLAGS(node->sysctl_flags) &
2374 				    CTLFLAG_OWNDATA) {
2375 					if (node->sysctl_data != NULL) {
2376 						free(node->sysctl_data,
2377 						     M_SYSCTLDATA);
2378 						node->sysctl_data = NULL;
2379 					}
2380 				}
2381 				if (SYSCTL_FLAGS(node->sysctl_flags) &
2382 				    CTLFLAG_OWNDESC) {
2383 					if (node->sysctl_desc != NULL) {
2384 						/*XXXUNCONST*/
2385 						free(__UNCONST(node->sysctl_desc),
2386 						     M_SYSCTLDATA);
2387 						node->sysctl_desc = NULL;
2388 					}
2389 				}
2390 				node++;
2391 			}
2392 			if (node < &pnode->sysctl_child[pnode->sysctl_clen]) {
2393 				pnode = node;
2394 				node = node->sysctl_child;
2395 			} else
2396 				break;
2397 		}
2398 		if (pnode->sysctl_child != NULL)
2399 			free(pnode->sysctl_child, M_SYSCTLNODE);
2400 		pnode->sysctl_clen = 0;
2401 		pnode->sysctl_csize = 0;
2402 		pnode->sysctl_child = NULL;
2403 		node = pnode;
2404 		pnode = node->sysctl_parent;
2405 	} while (pnode != NULL && node != rnode);
2406 
2407 	rw_exit(&sysctl_treelock);
2408 }
2409 
2410 void
2411 sysctl_log_print(const struct sysctllog *slog)
2412 {
2413 	int i, len;
2414 
2415 	printf("root %p left %d size %d content", (const void *)slog->log_root,
2416 	    slog->log_left, slog->log_size);
2417 
2418 	for (len = 0, i = slog->log_left; i < slog->log_size; i++) {
2419 		switch (len) {
2420 		case 0:
2421 			len = -1;
2422 			printf(" version %d", slog->log_num[i]);
2423 			break;
2424 		case -1:
2425 			len = -2;
2426 			printf(" type %d", slog->log_num[i]);
2427 			break;
2428 		case -2:
2429 			len =  slog->log_num[i];
2430 			printf(" len %d:", slog->log_num[i]);
2431 			if (len <= 0)
2432 				len = -1;
2433 			break;
2434 		default:
2435 			len--;
2436 			printf(" %d", slog->log_num[i]);
2437 			break;
2438 		}
2439 	}
2440 	printf(" end\n");
2441 }
2442 
2443 int
2444 sysctl_log_add(struct sysctllog **logp, const struct sysctlnode *node)
2445 {
2446 	const int size0 = 16;
2447 	int name[CTL_MAXNAME], namelen, i;
2448 	const struct sysctlnode *pnode;
2449 	struct sysctllog *log;
2450 
2451 	if (node->sysctl_flags & CTLFLAG_PERMANENT)
2452 		return (0);
2453 
2454 	if (logp == NULL)
2455 		return (0);
2456 
2457 	if (*logp == NULL) {
2458 		log = malloc(sizeof(struct sysctllog),
2459 		       M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
2460 		if (log == NULL) {
2461 			/* XXX print error message? */
2462 			return (-1);
2463 		}
2464 		log->log_num = malloc(size0 * sizeof(int),
2465 		       M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
2466 		if (log->log_num == NULL) {
2467 			/* XXX print error message? */
2468 			free(log, M_SYSCTLDATA);
2469 			return (-1);
2470 		}
2471 		memset(log->log_num, 0, size0 * sizeof(int));
2472 		log->log_root = NULL;
2473 		log->log_size = size0;
2474 		log->log_left = size0;
2475 		*logp = log;
2476 	} else
2477 		log = *logp;
2478 
2479 	/*
2480 	 * check that the root is proper.  it's okay to record the
2481 	 * address of the root of a tree.  it's the only thing that's
2482 	 * guaranteed not to shift around as nodes come and go.
2483 	 */
2484 	if (log->log_root == NULL)
2485 		log->log_root = sysctl_rootof(node);
2486 	else if (log->log_root != sysctl_rootof(node)) {
2487 		printf("sysctl: log %p root mismatch (%p)\n",
2488 		       log->log_root, sysctl_rootof(node));
2489 		return (-1);
2490 	}
2491 
2492 	/*
2493 	 * we will copy out name in reverse order
2494 	 */
2495 	for (pnode = node, namelen = 0;
2496 	     pnode != NULL && !(pnode->sysctl_flags & CTLFLAG_ROOT);
2497 	     pnode = pnode->sysctl_parent)
2498 		name[namelen++] = pnode->sysctl_num;
2499 
2500 	/*
2501 	 * do we have space?
2502 	 */
2503 	if (log->log_left < (namelen + 3))
2504 		sysctl_log_realloc(log);
2505 	if (log->log_left < (namelen + 3))
2506 		return (-1);
2507 
2508 	/*
2509 	 * stuff name in, then namelen, then node type, and finally,
2510 	 * the version for non-node nodes.
2511 	 */
2512 	for (i = 0; i < namelen; i++)
2513 		log->log_num[--log->log_left] = name[i];
2514 	log->log_num[--log->log_left] = namelen;
2515 	log->log_num[--log->log_left] = SYSCTL_TYPE(node->sysctl_flags);
2516 	if (log->log_num[log->log_left] != CTLTYPE_NODE)
2517 		log->log_num[--log->log_left] = node->sysctl_ver;
2518 	else
2519 		log->log_num[--log->log_left] = 0;
2520 
2521 	return (0);
2522 }
2523 
2524 void
2525 sysctl_teardown(struct sysctllog **logp)
2526 {
2527 	const struct sysctlnode *rnode;
2528 	struct sysctlnode node;
2529 	struct sysctllog *log;
2530 	uint namelen;
2531 	int *name, t, v, error, ni;
2532 	size_t sz;
2533 
2534 	if (logp == NULL || *logp == NULL)
2535 		return;
2536 	log = *logp;
2537 
2538 	rw_enter(&sysctl_treelock, RW_WRITER);
2539 	memset(&node, 0, sizeof(node));
2540 
2541 	while (log->log_left < log->log_size) {
2542 		KASSERT((log->log_left + 3 < log->log_size) &&
2543 			(log->log_left + log->log_num[log->log_left + 2] <=
2544 			 log->log_size));
2545 		v = log->log_num[log->log_left++];
2546 		t = log->log_num[log->log_left++];
2547 		namelen = log->log_num[log->log_left++];
2548 		name = &log->log_num[log->log_left];
2549 
2550 		node.sysctl_num = name[namelen - 1];
2551 		node.sysctl_flags = SYSCTL_VERSION|t;
2552 		node.sysctl_ver = v;
2553 
2554 		rnode = log->log_root;
2555 		error = sysctl_locate(NULL, &name[0], namelen, &rnode, &ni);
2556 		if (error == 0) {
2557 			name[namelen - 1] = CTL_DESTROY;
2558 			rnode = rnode->sysctl_parent;
2559 			sz = 0;
2560 			(void)sysctl_destroy(&name[namelen - 1], 1, NULL,
2561 					     &sz, &node, sizeof(node),
2562 					     &name[0], NULL, rnode);
2563 		}
2564 
2565 		log->log_left += namelen;
2566 	}
2567 
2568 	KASSERT(log->log_size == log->log_left);
2569 	free(log->log_num, M_SYSCTLDATA);
2570 	free(log, M_SYSCTLDATA);
2571 	*logp = NULL;
2572 
2573 	rw_exit(&sysctl_treelock);
2574 }
2575 
2576 /*
2577  * ********************************************************************
2578  * old_sysctl -- A routine to bridge old-style internal calls to the
2579  * new infrastructure.
2580  * ********************************************************************
2581  */
2582 int
2583 old_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
2584 	   void *newp, size_t newlen, struct lwp *l)
2585 {
2586 	int error;
2587 	size_t oldlen = 0;
2588 	size_t savelen;
2589 
2590 	if (oldlenp) {
2591 		oldlen = *oldlenp;
2592 	}
2593 	savelen = oldlen;
2594 
2595 	sysctl_lock(newp != NULL);
2596 	error = sysctl_dispatch(name, namelen, oldp, &oldlen,
2597 				newp, newlen, name, l, NULL);
2598 	sysctl_unlock();
2599 	if (error == 0 && oldp != NULL && savelen < oldlen)
2600 		error = ENOMEM;
2601 	if (oldlenp) {
2602 		*oldlenp = oldlen;
2603 	}
2604 
2605 	return (error);
2606 }
2607 
2608 /*
2609  * ********************************************************************
2610  * Section 4: Generic helper routines
2611  * ********************************************************************
2612  * "helper" routines that can do more finely grained access control,
2613  * construct structures from disparate information, create the
2614  * appearance of more nodes and sub-trees, etc.  for example, if
2615  * CTL_PROC wanted a helper function, it could respond to a CTL_QUERY
2616  * with a dynamically created list of nodes that represented the
2617  * currently running processes at that instant.
2618  * ********************************************************************
2619  */
2620 
2621 /*
2622  * first, a few generic helpers that provide:
2623  *
2624  * sysctl_needfunc()		a readonly interface that emits a warning
2625  * sysctl_notavail()		returns EOPNOTSUPP (generic error)
2626  * sysctl_null()		an empty return buffer with no error
2627  */
2628 int
2629 sysctl_needfunc(SYSCTLFN_ARGS)
2630 {
2631 	int error;
2632 
2633 	printf("!!SYSCTL_NEEDFUNC!!\n");
2634 
2635 	if (newp != NULL || namelen != 0)
2636 		return (EOPNOTSUPP);
2637 
2638 	error = 0;
2639 	if (oldp != NULL)
2640 		error = sysctl_copyout(l, rnode->sysctl_data, oldp,
2641 				       MIN(rnode->sysctl_size, *oldlenp));
2642 	*oldlenp = rnode->sysctl_size;
2643 
2644 	return (error);
2645 }
2646 
2647 int
2648 sysctl_notavail(SYSCTLFN_ARGS)
2649 {
2650 
2651 	if (namelen == 1 && name[0] == CTL_QUERY)
2652 		return (sysctl_query(SYSCTLFN_CALL(rnode)));
2653 
2654 	return (EOPNOTSUPP);
2655 }
2656 
2657 int
2658 sysctl_null(SYSCTLFN_ARGS)
2659 {
2660 
2661 	*oldlenp = 0;
2662 
2663 	return (0);
2664 }
2665 
2666 u_int
2667 sysctl_map_flags(const u_int *map, u_int word)
2668 {
2669 	u_int rv;
2670 
2671 	for (rv = 0; *map != 0; map += 2)
2672 		if ((word & map[0]) != 0)
2673 			rv |= map[1];
2674 
2675 	return rv;
2676 }
2677 
2678 /*
2679  * ********************************************************************
2680  * Section 5: The machinery that makes it all go
2681  * ********************************************************************
2682  * Memory "manglement" routines.  Not much to this, eh?
2683  * ********************************************************************
2684  */
2685 static int
2686 sysctl_alloc(struct sysctlnode *p, int x)
2687 {
2688 	int i;
2689 	struct sysctlnode *n;
2690 
2691 	assert(p->sysctl_child == NULL);
2692 
2693 	if (x == 1)
2694 		n = malloc(sizeof(struct sysctlnode),
2695 		       M_SYSCTLNODE, M_WAITOK|M_CANFAIL);
2696 	else
2697 		n = malloc(SYSCTL_DEFSIZE * sizeof(struct sysctlnode),
2698 		       M_SYSCTLNODE, M_WAITOK|M_CANFAIL);
2699 	if (n == NULL)
2700 		return (ENOMEM);
2701 
2702 	if (x == 1) {
2703 		memset(n, 0, sizeof(struct sysctlnode));
2704 		p->sysctl_csize = 1;
2705 	} else {
2706 		memset(n, 0, SYSCTL_DEFSIZE * sizeof(struct sysctlnode));
2707 		p->sysctl_csize = SYSCTL_DEFSIZE;
2708 	}
2709 	p->sysctl_clen = 0;
2710 
2711 	for (i = 0; i < p->sysctl_csize; i++)
2712 		n[i].sysctl_parent = p;
2713 
2714 	p->sysctl_child = n;
2715 	return (0);
2716 }
2717 
2718 static int
2719 sysctl_realloc(struct sysctlnode *p)
2720 {
2721 	int i, j, olen;
2722 	struct sysctlnode *n;
2723 
2724 	assert(p->sysctl_csize == p->sysctl_clen);
2725 
2726 	/*
2727 	 * how many do we have...how many should we make?
2728 	 */
2729 	olen = p->sysctl_clen;
2730 	n = malloc(2 * olen * sizeof(struct sysctlnode), M_SYSCTLNODE,
2731 		   M_WAITOK|M_CANFAIL);
2732 	if (n == NULL)
2733 		return (ENOMEM);
2734 
2735 	/*
2736 	 * move old children over...initialize new children
2737 	 */
2738 	memcpy(n, p->sysctl_child, olen * sizeof(struct sysctlnode));
2739 	memset(&n[olen], 0, olen * sizeof(struct sysctlnode));
2740 	p->sysctl_csize = 2 * olen;
2741 
2742 	/*
2743 	 * reattach moved (and new) children to parent; if a moved
2744 	 * child node has children, reattach the parent pointers of
2745 	 * grandchildren
2746 	 */
2747         for (i = 0; i < p->sysctl_csize; i++) {
2748                 n[i].sysctl_parent = p;
2749 		if (n[i].sysctl_child != NULL) {
2750 			for (j = 0; j < n[i].sysctl_csize; j++)
2751 				n[i].sysctl_child[j].sysctl_parent = &n[i];
2752 		}
2753 	}
2754 
2755 	/*
2756 	 * get out with the old and in with the new
2757 	 */
2758 	free(p->sysctl_child, M_SYSCTLNODE);
2759 	p->sysctl_child = n;
2760 
2761 	return (0);
2762 }
2763 
2764 static int
2765 sysctl_log_realloc(struct sysctllog *log)
2766 {
2767 	int *n, s, d;
2768 
2769 	s = log->log_size * 2;
2770 	d = log->log_size;
2771 
2772 	n = malloc(s * sizeof(int), M_SYSCTLDATA, M_WAITOK|M_CANFAIL);
2773 	if (n == NULL)
2774 		return (-1);
2775 
2776 	memset(n, 0, s * sizeof(int));
2777 	memcpy(&n[d], log->log_num, d * sizeof(int));
2778 	free(log->log_num, M_SYSCTLDATA);
2779 	log->log_num = n;
2780 	if (d)
2781 		log->log_left += d;
2782 	else
2783 		log->log_left = s;
2784 	log->log_size = s;
2785 
2786 	return (0);
2787 }
2788 
2789 /*
2790  * ********************************************************************
2791  * Section 6: Conversion between API versions wrt the sysctlnode
2792  * ********************************************************************
2793  */
2794 static int
2795 sysctl_cvt_in(struct lwp *l, int *vp, const void *i, size_t sz,
2796 	      struct sysctlnode *node)
2797 {
2798 	int error, flags;
2799 
2800 	if (i == NULL || sz < sizeof(flags))
2801 		return (EINVAL);
2802 
2803 	error = sysctl_copyin(l, i, &flags, sizeof(flags));
2804 	if (error)
2805 		return (error);
2806 
2807 #if (SYSCTL_VERSION != SYSCTL_VERS_1)
2808 #error sysctl_cvt_in: no support for SYSCTL_VERSION
2809 #endif /*  (SYSCTL_VERSION != SYSCTL_VERS_1) */
2810 
2811 	if (sz == sizeof(*node) &&
2812 	    SYSCTL_VERS(flags) == SYSCTL_VERSION) {
2813 		error = sysctl_copyin(l, i, node, sizeof(*node));
2814 		if (error)
2815 			return (error);
2816 		*vp = SYSCTL_VERSION;
2817 		return (0);
2818 	}
2819 
2820 	return (EINVAL);
2821 }
2822 
2823 static int
2824 sysctl_cvt_out(struct lwp *l, int v, const struct sysctlnode *i,
2825 	       void *ovp, size_t left, size_t *szp)
2826 {
2827 	size_t sz = sizeof(*i);
2828 	const void *src = i;
2829 	int error;
2830 
2831 	switch (v) {
2832 	case SYSCTL_VERS_0:
2833 		return (EINVAL);
2834 
2835 #if (SYSCTL_VERSION != SYSCTL_VERS_1)
2836 #error sysctl_cvt_out: no support for SYSCTL_VERSION
2837 #endif /*  (SYSCTL_VERSION != SYSCTL_VERS_1) */
2838 
2839 	case SYSCTL_VERSION:
2840 		/* nothing more to do here */
2841 		break;
2842 	}
2843 
2844 	if (ovp != NULL && left >= sz) {
2845 		error = sysctl_copyout(l, src, ovp, sz);
2846 		if (error)
2847 			return (error);
2848 	}
2849 
2850 	if (szp != NULL)
2851 		*szp = sz;
2852 
2853 	return (0);
2854 }
2855