xref: /netbsd/sys/kern/kern_sysctl.c (revision 416a8a0e)
1 /*	$NetBSD: kern_sysctl.c,v 1.269 2023/04/09 09:18:09 riastradh 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 #define __COMPAT_SYSCTL
71 
72 #include <sys/cdefs.h>
73 __KERNEL_RCSID(0, "$NetBSD: kern_sysctl.c,v 1.269 2023/04/09 09:18:09 riastradh Exp $");
74 
75 #ifdef _KERNEL_OPT
76 #include "opt_defcorename.h"
77 #endif
78 
79 #include "ksyms.h"
80 
81 #include <sys/param.h>
82 #include <sys/types.h>
83 
84 #include <sys/buf.h>
85 #include <sys/cprng.h>
86 #include <sys/kauth.h>
87 #include <sys/ksyms.h>
88 #include <sys/ktrace.h>
89 #include <sys/malloc.h>
90 #include <sys/mount.h>
91 #include <sys/once.h>
92 #include <sys/rndsource.h>
93 #include <sys/syscallargs.h>
94 #include <sys/sysctl.h>
95 #include <sys/systm.h>
96 
97 #include <crypto/blake2/blake2s.h>
98 
99 #define	MAXDESCLEN	1024
100 MALLOC_DEFINE(M_SYSCTLNODE, "sysctlnode", "sysctl node structures");
101 MALLOC_DEFINE(M_SYSCTLDATA, "sysctldata", "misc sysctl data");
102 
103 static int sysctl_mmap(SYSCTLFN_PROTO);
104 static int sysctl_alloc(struct sysctlnode *, int);
105 static int sysctl_realloc(struct sysctlnode *);
106 
107 static int sysctl_cvt_in(struct lwp *, int *, const void *, size_t,
108 			 struct sysctlnode *);
109 static int sysctl_cvt_out(struct lwp *, int, const struct sysctlnode *,
110 			  void *, size_t, size_t *);
111 
112 static int sysctl_log_add(struct sysctllog **, const struct sysctlnode *);
113 static int sysctl_log_realloc(struct sysctllog *);
114 
115 typedef void sysctl_setup_func(struct sysctllog **);
116 
117 #ifdef SYSCTL_DEBUG
118 #define DPRINTF(a)	printf a
119 #else
120 #define DPRINTF(a)
121 #endif
122 
123 struct sysctllog {
124 	const struct sysctlnode *log_root;
125 	int *log_num;
126 	int log_size, log_left;
127 };
128 
129 /*
130  * the "root" of the new sysctl tree
131  */
132 struct sysctlnode sysctl_root = {
133 	.sysctl_flags = SYSCTL_VERSION|
134 	    CTLFLAG_ROOT|CTLFLAG_READWRITE|
135 	    CTLTYPE_NODE,
136 	.sysctl_num = 0,
137 	.sysctl_size = sizeof(struct sysctlnode),
138 	.sysctl_name = "(root)",
139 };
140 
141 /*
142  * link set of functions that add nodes at boot time (see also
143  * sysctl_buildtree())
144  */
145 __link_set_decl(sysctl_funcs, sysctl_setup_func);
146 
147 /*
148  * The `sysctl_treelock' is intended to serialize access to the sysctl
149  * tree.  XXX This has serious problems; allocating memory and
150  * copying data out with the lock held is insane.
151  */
152 krwlock_t sysctl_treelock;
153 
154 kmutex_t sysctl_file_marker_lock;
155 
156 /*
157  * Attributes stored in the kernel.
158  */
159 char hostname[MAXHOSTNAMELEN];
160 int hostnamelen;
161 
162 char domainname[MAXHOSTNAMELEN];
163 int domainnamelen;
164 
165 long hostid;
166 
167 #ifndef DEFCORENAME
168 #define	DEFCORENAME	"%n.core"
169 #endif
170 char defcorename[MAXPATHLEN] = DEFCORENAME;
171 
172 /*
173  * ********************************************************************
174  * Section 0: Some simple glue
175  * ********************************************************************
176  * By wrapping copyin(), copyout(), and copyinstr() like this, we can
177  * stop caring about who's calling us and simplify some code a bunch.
178  * ********************************************************************
179  */
180 int
sysctl_copyin(struct lwp * l,const void * uaddr,void * kaddr,size_t len)181 sysctl_copyin(struct lwp *l, const void *uaddr, void *kaddr, size_t len)
182 {
183 	int error;
184 
185 	if (l != NULL) {
186 		error = copyin(uaddr, kaddr, len);
187 		ktrmibio(-1, UIO_WRITE, uaddr, len, error);
188 	} else {
189 		error = kcopy(uaddr, kaddr, len);
190 	}
191 
192 	return error;
193 }
194 
195 int
sysctl_copyout(struct lwp * l,const void * kaddr,void * uaddr,size_t len)196 sysctl_copyout(struct lwp *l, const void *kaddr, void *uaddr, size_t len)
197 {
198 	int error;
199 
200 	if (l != NULL) {
201 		error = copyout(kaddr, uaddr, len);
202 		ktrmibio(-1, UIO_READ, uaddr, len, error);
203 	} else {
204 		error = kcopy(kaddr, uaddr, len);
205 	}
206 
207 	return error;
208 }
209 
210 int
sysctl_copyinstr(struct lwp * l,const void * uaddr,void * kaddr,size_t len,size_t * done)211 sysctl_copyinstr(struct lwp *l, const void *uaddr, void *kaddr,
212 		 size_t len, size_t *done)
213 {
214 	int error;
215 
216 	if (l != NULL) {
217 		error = copyinstr(uaddr, kaddr, len, done);
218 		ktrmibio(-1, UIO_WRITE, uaddr, len, error);
219 	} else {
220 		error = copystr(uaddr, kaddr, len, done);
221 	}
222 
223 	return error;
224 }
225 
226 /*
227  * ********************************************************************
228  * Initialize sysctl subsystem.
229  * ********************************************************************
230  */
231 void
sysctl_init(void)232 sysctl_init(void)
233 {
234 	sysctl_setup_func *const *sysctl_setup;
235 
236 	rw_init(&sysctl_treelock);
237 
238 	/*
239 	 * dynamic mib numbers start here
240 	 */
241 	sysctl_root.sysctl_num = CREATE_BASE;
242 	sysctl_basenode_init();
243 
244         __link_set_foreach(sysctl_setup, sysctl_funcs) {
245 		(**sysctl_setup)(NULL);
246 	}
247 
248 	mutex_init(&sysctl_file_marker_lock, MUTEX_DEFAULT, IPL_NONE);
249 }
250 
251 /*
252  * Setting this means no more permanent nodes can be added,
253  * trees that claim to be readonly at the root now are, and if
254  * the main tree is readonly, *everything* is.
255  *
256  * Also starts up the PRNG used for the "random" sysctl: it's
257  * better to start it later than sooner.
258  *
259  * Call this at the end of kernel init.
260  */
261 void
sysctl_finalize(void)262 sysctl_finalize(void)
263 {
264 
265 	sysctl_root.sysctl_flags |= CTLFLAG_PERMANENT;
266 }
267 
268 /*
269  * ********************************************************************
270  * The main native sysctl system call itself.
271  * ********************************************************************
272  */
273 int
sys___sysctl(struct lwp * l,const struct sys___sysctl_args * uap,register_t * retval)274 sys___sysctl(struct lwp *l, const struct sys___sysctl_args *uap, register_t *retval)
275 {
276 	/* {
277 		syscallarg(const int *) name;
278 		syscallarg(u_int) namelen;
279 		syscallarg(void *) old;
280 		syscallarg(size_t *) oldlenp;
281 		syscallarg(const void *) new;
282 		syscallarg(size_t) newlen;
283 	} */
284 	int error, nerror, name[CTL_MAXNAME];
285 	size_t oldlen, savelen, *oldlenp;
286 
287 	/*
288 	 * get oldlen
289 	 */
290 	oldlen = 0;
291 	oldlenp = SCARG(uap, oldlenp);
292 	if (oldlenp != NULL) {
293 		error = copyin(oldlenp, &oldlen, sizeof(oldlen));
294 		if (error)
295 			return (error);
296 	}
297 	savelen = oldlen;
298 
299 	/*
300 	 * top-level sysctl names may or may not be non-terminal, but
301 	 * we don't care
302 	 */
303 	if (SCARG(uap, namelen) > CTL_MAXNAME || SCARG(uap, namelen) < 1)
304 		return (EINVAL);
305 	error = copyin(SCARG(uap, name), &name,
306 		       SCARG(uap, namelen) * sizeof(int));
307 	if (error)
308 		return (error);
309 
310 	ktrmib(name, SCARG(uap, namelen));
311 
312 	sysctl_lock(SCARG(uap, newv) != NULL);
313 
314 	/*
315 	 * do sysctl work (NULL means main built-in default tree)
316 	 */
317 	error = sysctl_dispatch(&name[0], SCARG(uap, namelen),
318 				SCARG(uap, oldv), &oldlen,
319 				SCARG(uap, newv), SCARG(uap, newlen),
320 				&name[0], l, NULL);
321 
322 	/*
323 	 * release the sysctl lock
324 	 */
325 	sysctl_unlock();
326 
327 	/*
328 	 * set caller's oldlen to new value even in the face of an
329 	 * error (if this gets an error and they didn't have one, they
330 	 * get this one)
331 	 */
332 	if (oldlenp) {
333 		nerror = copyout(&oldlen, oldlenp, sizeof(oldlen));
334 		if (error == 0)
335 			error = nerror;
336 	}
337 
338 	/*
339 	 * if the only problem is that we weren't given enough space,
340 	 * that's an ENOMEM error
341 	 */
342 	if (error == 0 && SCARG(uap, oldv) != NULL && savelen < oldlen)
343 		error = ENOMEM;
344 
345 	return (error);
346 }
347 
348 /*
349  * ********************************************************************
350  * Section 1: How the tree is used
351  * ********************************************************************
352  * Implementations of sysctl for emulations should typically need only
353  * these three functions in this order: lock the tree, dispatch
354  * request into it, unlock the tree.
355  * ********************************************************************
356  */
357 void
sysctl_lock(bool write)358 sysctl_lock(bool write)
359 {
360 
361 	if (write) {
362 		rw_enter(&sysctl_treelock, RW_WRITER);
363 		curlwp->l_pflag |= LP_SYSCTLWRITE;
364 	} else {
365 		rw_enter(&sysctl_treelock, RW_READER);
366 		curlwp->l_pflag &= ~LP_SYSCTLWRITE;
367 	}
368 }
369 
370 void
sysctl_relock(void)371 sysctl_relock(void)
372 {
373 
374 	if ((curlwp->l_pflag & LP_SYSCTLWRITE) != 0) {
375 		rw_enter(&sysctl_treelock, RW_WRITER);
376 	} else {
377 		rw_enter(&sysctl_treelock, RW_READER);
378 	}
379 }
380 
381 /*
382  * ********************************************************************
383  * the main sysctl dispatch routine.  scans the given tree and picks a
384  * function to call based on what it finds.
385  * ********************************************************************
386  */
387 int
sysctl_dispatch(SYSCTLFN_ARGS)388 sysctl_dispatch(SYSCTLFN_ARGS)
389 {
390 	int error;
391 	sysctlfn fn;
392 	int ni;
393 
394 	KASSERT(rw_lock_held(&sysctl_treelock));
395 
396 	if (rnode && SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
397 		printf("sysctl_dispatch: rnode %p wrong version\n", rnode);
398 		error = EINVAL;
399 		goto out;
400 	}
401 
402 	fn = NULL;
403 	error = sysctl_locate(l, name, namelen, &rnode, &ni);
404 
405 	if (rnode->sysctl_func != NULL) {
406 		/*
407 		 * the node we ended up at has a function, so call it.  it can
408 		 * hand off to query or create if it wants to.
409 		 */
410 		fn = rnode->sysctl_func;
411 	} else if (error == 0) {
412 		/*
413 		 * we found the node they were looking for, so do a lookup.
414 		 */
415 		fn = (sysctlfn)sysctl_lookup; /* XXX may write to rnode */
416 	} else if (error == ENOENT && (ni + 1) == namelen && name[ni] < 0) {
417 		/*
418 		 * prospective parent node found, but the terminal node was
419 		 * not.  generic operations associate with the parent.
420 		 */
421 		switch (name[ni]) {
422 		case CTL_QUERY:
423 			fn = sysctl_query;
424 			break;
425 		case CTL_CREATE:
426 #if NKSYMS > 0
427 		case CTL_CREATESYM:
428 #endif /* NKSYMS > 0 */
429 			if (newp == NULL) {
430 				error = EINVAL;
431 				break;
432 			}
433 			KASSERT(rw_write_held(&sysctl_treelock));
434 			fn = (sysctlfn)sysctl_create; /* we own the rnode */
435 			break;
436 		case CTL_DESTROY:
437 			if (newp == NULL) {
438 				error = EINVAL;
439 				break;
440 			}
441 			KASSERT(rw_write_held(&sysctl_treelock));
442 			fn = (sysctlfn)sysctl_destroy; /* we own the rnode */
443 			break;
444 		case CTL_MMAP:
445 			fn = (sysctlfn)sysctl_mmap; /* we own the rnode */
446 			break;
447 		case CTL_DESCRIBE:
448 			fn = sysctl_describe;
449 			break;
450 		default:
451 			error = EOPNOTSUPP;
452 			break;
453 		}
454 	}
455 
456 	/*
457 	 * after all of that, maybe we found someone who knows how to
458 	 * get us what we want?
459 	 */
460 	if (fn != NULL)
461 		error = (*fn)(name + ni, namelen - ni, oldp, oldlenp,
462 			      newp, newlen, name, l, rnode);
463 	else if (error == 0)
464 		error = EOPNOTSUPP;
465 
466 out:
467 	return (error);
468 }
469 
470 /*
471  * ********************************************************************
472  * Releases the tree lock.
473  * ********************************************************************
474  */
475 void
sysctl_unlock(void)476 sysctl_unlock(void)
477 {
478 
479 	rw_exit(&sysctl_treelock);
480 }
481 
482 /*
483  * ********************************************************************
484  * Section 2: The main tree interfaces
485  * ********************************************************************
486  * This is how sysctl_dispatch() does its work, and you can too, by
487  * calling these routines from helpers (though typically only
488  * sysctl_lookup() will be used).  The tree MUST BE LOCKED when these
489  * are called.
490  * ********************************************************************
491  */
492 
493 /*
494  * sysctl_locate -- Finds the node matching the given mib under the
495  * given tree (via rv).  If no tree is given, we fall back to the
496  * native tree.  The current process (via l) is used for access
497  * control on the tree (some nodes may be traversable only by root) and
498  * on return, nip will show how many numbers in the mib were consumed.
499  */
500 int
sysctl_locate(struct lwp * l,const int * name,u_int namelen,const struct sysctlnode ** rnode,int * nip)501 sysctl_locate(struct lwp *l, const int *name, u_int namelen,
502 	      const struct sysctlnode **rnode, int *nip)
503 {
504 	const struct sysctlnode *node, *pnode;
505 	int tn, si, ni, error, alias;
506 
507 	KASSERT(rw_lock_held(&sysctl_treelock));
508 
509 	/*
510 	 * basic checks and setup
511 	 */
512 	if (*rnode == NULL)
513 		*rnode = &sysctl_root;
514 	if (nip)
515 		*nip = 0;
516 	if (namelen == 0)
517 		return (0);
518 
519 	/*
520 	 * search starts from "root"
521 	 */
522 	pnode = *rnode;
523 	if (SYSCTL_VERS(pnode->sysctl_flags) != SYSCTL_VERSION) {
524 		printf("sysctl_locate: pnode %p wrong version\n", pnode);
525 		return (EINVAL);
526 	}
527 	node = pnode->sysctl_child;
528 	error = 0;
529 
530 	/*
531 	 * scan for node to which new node should be attached
532 	 */
533 	for (ni = 0; ni < namelen; ni++) {
534 		/*
535 		 * walked off bottom of tree
536 		 */
537 		if (node == NULL) {
538 			if (SYSCTL_TYPE(pnode->sysctl_flags) == CTLTYPE_NODE)
539 				error = ENOENT;
540 			else
541 				error = ENOTDIR;
542 			break;
543 		}
544 		/*
545 		 * can anyone traverse this node or only root?
546 		 */
547 		if (l != NULL && (pnode->sysctl_flags & CTLFLAG_PRIVATE) &&
548 		    (error = kauth_authorize_system(l->l_cred,
549 		    KAUTH_SYSTEM_SYSCTL, KAUTH_REQ_SYSTEM_SYSCTL_PRVT,
550 		    NULL, NULL, NULL)) != 0)
551 			return (error);
552 		/*
553 		 * find a child node with the right number
554 		 */
555 		tn = name[ni];
556 		alias = 0;
557 
558 		si = 0;
559 		/*
560 		 * Note: ANYNUMBER only matches positive integers.
561 		 * Since ANYNUMBER is only permitted on single-node
562 		 * sub-trees (eg proc), check before the loop and skip
563 		 * it if we can.
564 		 */
565 		if ((node[si].sysctl_flags & CTLFLAG_ANYNUMBER) && (tn >= 0))
566 			goto foundit;
567 		for (; si < pnode->sysctl_clen; si++) {
568 			if (node[si].sysctl_num == tn) {
569 				if (node[si].sysctl_flags & CTLFLAG_ALIAS) {
570 					if (alias++ == 4)
571 						break;
572 					else {
573 						tn = node[si].sysctl_alias;
574 						si = -1;
575 					}
576 				} else
577 					goto foundit;
578 			}
579 		}
580 		/*
581 		 * if we ran off the end, it obviously doesn't exist
582 		 */
583 		error = ENOENT;
584 		break;
585 
586 		/*
587 		 * so far so good, move on down the line
588 		 */
589 	  foundit:
590 		pnode = &node[si];
591 		if (SYSCTL_TYPE(pnode->sysctl_flags) == CTLTYPE_NODE)
592 			node = node[si].sysctl_child;
593 		else
594 			node = NULL;
595 	}
596 
597 	*rnode = pnode;
598 	if (nip)
599 		*nip = ni;
600 
601 	return (error);
602 }
603 
604 /*
605  * sysctl_query -- The auto-discovery engine.  Copies out the structs
606  * describing nodes under the given node and handles overlay trees.
607  */
608 int
sysctl_query(SYSCTLFN_ARGS)609 sysctl_query(SYSCTLFN_ARGS)
610 {
611 	int error, ni, elim, v;
612 	size_t out, left, t;
613 	const struct sysctlnode *enode, *onode;
614 	struct sysctlnode qnode;
615 
616 	KASSERT(rw_lock_held(&sysctl_treelock));
617 
618 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
619 		printf("sysctl_query: rnode %p wrong version\n", rnode);
620 		return (EINVAL);
621 	}
622 
623 	if (SYSCTL_TYPE(rnode->sysctl_flags) != CTLTYPE_NODE)
624 		return (ENOTDIR);
625 	if (namelen != 1 || name[0] != CTL_QUERY)
626 		return (EINVAL);
627 
628 	error = 0;
629 	out = 0;
630 	left = *oldlenp;
631 	elim = 0;
632 	enode = NULL;
633 
634 	/*
635 	 * translate the given request to a current node
636 	 */
637 	error = sysctl_cvt_in(l, &v, newp, newlen, &qnode);
638 	if (error)
639 		return (error);
640 
641 	/*
642 	 * if the request specifies a version, check it
643 	 */
644 	if (qnode.sysctl_ver != 0) {
645 		enode = rnode;
646 		if (qnode.sysctl_ver != enode->sysctl_ver &&
647 		    qnode.sysctl_ver != sysctl_rootof(enode)->sysctl_ver)
648 			return (EINVAL);
649 	}
650 
651 	/*
652 	 * process has overlay tree
653 	 */
654 	if (l && l->l_proc->p_emul->e_sysctlovly) {
655 		enode = l->l_proc->p_emul->e_sysctlovly;
656 		elim = (name - oname);
657 		error = sysctl_locate(l, oname, elim, &enode, NULL);
658 		if (error == 0) {
659 			/* ah, found parent in overlay */
660 			elim = enode->sysctl_clen;
661 			enode = enode->sysctl_child;
662 		} else {
663 			error = 0;
664 			elim = 0;
665 			enode = NULL;
666 		}
667 	}
668 
669 	for (ni = 0; ni < rnode->sysctl_clen; ni++) {
670 		onode = &rnode->sysctl_child[ni];
671 		if (enode && enode->sysctl_num == onode->sysctl_num) {
672 			if (SYSCTL_TYPE(enode->sysctl_flags) != CTLTYPE_NODE)
673 				onode = enode;
674 			if (--elim > 0)
675 				enode++;
676 			else
677 				enode = NULL;
678 		}
679 		error = sysctl_cvt_out(l, v, onode, oldp, left, &t);
680 		if (error)
681 			return (error);
682 		if (oldp != NULL)
683 			oldp = (char*)oldp + t;
684 		out += t;
685 		left -= MIN(left, t);
686 	}
687 
688 	/*
689 	 * overlay trees *MUST* be entirely consumed
690 	 */
691 	KASSERT(enode == NULL);
692 
693 	*oldlenp = out;
694 
695 	return (error);
696 }
697 
698 /*
699  * sysctl_create -- Adds a node (the description of which is taken
700  * from newp) to the tree, returning a copy of it in the space pointed
701  * to by oldp.  In the event that the requested slot is already taken
702  * (either by name or by number), the offending node is returned
703  * instead.  Yes, this is complex, but we want to make sure everything
704  * is proper.
705  */
706 #ifdef SYSCTL_DEBUG_CREATE
707 int _sysctl_create(SYSCTLFN_ARGS);
708 int
_sysctl_create(SYSCTLFN_ARGS)709 _sysctl_create(SYSCTLFN_ARGS)
710 #else
711 int
712 sysctl_create(SYSCTLFN_ARGS)
713 #endif
714 {
715 	struct sysctlnode nnode, *node, *pnode;
716 	int error, ni, at, nm, type, nsz, sz, flags, anum, v;
717 	void *own;
718 
719 	KASSERT(rw_write_held(&sysctl_treelock));
720 
721 	error = 0;
722 	own = NULL;
723 	anum = -1;
724 
725 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
726 		printf("sysctl_create: rnode %p wrong version\n", rnode);
727 		return (EINVAL);
728 	}
729 
730 	if (namelen != 1 || (name[namelen - 1] != CTL_CREATE
731 #if NKSYMS > 0
732 			     && name[namelen - 1] != CTL_CREATESYM
733 #endif /* NKSYMS > 0 */
734 			     ))
735 		return (EINVAL);
736 
737 	/*
738 	 * processes can only add nodes at securelevel 0, must be
739 	 * root, and can't add nodes to a parent that's not writeable
740 	 */
741 	if (l != NULL) {
742 #ifndef SYSCTL_DISALLOW_CREATE
743 		error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
744 		    KAUTH_REQ_SYSTEM_SYSCTL_ADD, NULL, NULL, NULL);
745 		if (error)
746 			return (error);
747 		if (!(rnode->sysctl_flags & CTLFLAG_READWRITE))
748 #endif /* SYSCTL_DISALLOW_CREATE */
749 			return (EPERM);
750 	}
751 
752 	/*
753 	 * nothing can add a node if:
754 	 * we've finished initial set up of this tree and
755 	 * (the tree itself is not writeable or
756 	 * the entire sysctl system is not writeable)
757 	 */
758 	if ((sysctl_rootof(rnode)->sysctl_flags & CTLFLAG_PERMANENT) &&
759 	    (!(sysctl_rootof(rnode)->sysctl_flags & CTLFLAG_READWRITE) ||
760 	     !(sysctl_root.sysctl_flags & CTLFLAG_READWRITE)))
761 		return (EPERM);
762 
763 	/*
764 	 * it must be a "node", not a "int" or something
765 	 */
766 	if (SYSCTL_TYPE(rnode->sysctl_flags) != CTLTYPE_NODE)
767 		return (ENOTDIR);
768 	if (rnode->sysctl_flags & CTLFLAG_ALIAS) {
769 		printf("sysctl_create: attempt to add node to aliased "
770 		       "node %p\n", rnode);
771 		return (EINVAL);
772 	}
773 	pnode = __UNCONST(rnode); /* we are adding children to this node */
774 
775 	if (newp == NULL)
776 		return (EINVAL);
777 	error = sysctl_cvt_in(l, &v, newp, newlen, &nnode);
778 	if (error)
779 		return (error);
780 
781 	/*
782 	 * nodes passed in don't *have* parents
783 	 */
784 	if (nnode.sysctl_parent != NULL)
785 		return (EINVAL);
786 
787 	/*
788 	 * if we are indeed adding it, it should be a "good" name and
789 	 * number
790 	 */
791 	nm = nnode.sysctl_num;
792 #if NKSYMS > 0
793 	if (nm == CTL_CREATESYM)
794 		nm = CTL_CREATE;
795 #endif /* NKSYMS > 0 */
796 	if (nm < 0 && nm != CTL_CREATE)
797 		return (EINVAL);
798 
799 	/*
800 	 * the name can't start with a digit
801 	 */
802 	if (nnode.sysctl_name[0] >= '0' &&
803 	    nnode.sysctl_name[0] <= '9')
804 		return (EINVAL);
805 
806 	/*
807 	 * the name must be only alphanumerics or - or _, longer than
808 	 * 0 bytes and less than SYSCTL_NAMELEN
809 	 */
810 	nsz = 0;
811 	while (nsz < SYSCTL_NAMELEN && nnode.sysctl_name[nsz] != '\0') {
812 		if ((nnode.sysctl_name[nsz] >= '0' &&
813 		     nnode.sysctl_name[nsz] <= '9') ||
814 		    (nnode.sysctl_name[nsz] >= 'A' &&
815 		     nnode.sysctl_name[nsz] <= 'Z') ||
816 		    (nnode.sysctl_name[nsz] >= 'a' &&
817 		     nnode.sysctl_name[nsz] <= 'z') ||
818 		    nnode.sysctl_name[nsz] == '-' ||
819 		    nnode.sysctl_name[nsz] == '_')
820 			nsz++;
821 		else
822 			return (EINVAL);
823 	}
824 	if (nsz == 0 || nsz == SYSCTL_NAMELEN)
825 		return (EINVAL);
826 
827 	/*
828 	 * various checks revolve around size vs type, etc
829 	 */
830 	type = SYSCTL_TYPE(nnode.sysctl_flags);
831 	flags = SYSCTL_FLAGS(nnode.sysctl_flags);
832 	sz = nnode.sysctl_size;
833 
834 	/*
835 	 * find out if there's a collision, and if so, let the caller
836 	 * know what they collided with
837 	 */
838 	node = pnode->sysctl_child;
839 	at = 0;
840 	if (node) {
841 		if ((flags | node->sysctl_flags) & CTLFLAG_ANYNUMBER)
842 			/* No siblings for a CTLFLAG_ANYNUMBER node */
843 			return EINVAL;
844 		for (ni = 0; ni < pnode->sysctl_clen; ni++) {
845 			if (nm == node[ni].sysctl_num ||
846 			    strcmp(nnode.sysctl_name, node[ni].sysctl_name) == 0) {
847 				/*
848 				 * ignore error here, since we
849 				 * are already fixed on EEXIST
850 				 */
851 				(void)sysctl_cvt_out(l, v, &node[ni], oldp,
852 						     *oldlenp, oldlenp);
853 				return (EEXIST);
854 			}
855 			if (nm > node[ni].sysctl_num)
856 				at++;
857 		}
858 	}
859 
860 	/*
861 	 * use sysctl_ver to add to the tree iff it hasn't changed
862 	 */
863 	if (nnode.sysctl_ver != 0) {
864 		/*
865 		 * a specified value must match either the parent
866 		 * node's version or the root node's version
867 		 */
868 		if (nnode.sysctl_ver != sysctl_rootof(rnode)->sysctl_ver &&
869 		    nnode.sysctl_ver != rnode->sysctl_ver) {
870 			return (EINVAL);
871 		}
872 	}
873 
874 	/*
875 	 * only the kernel can assign functions to entries
876 	 */
877 	if (l != NULL && nnode.sysctl_func != NULL)
878 		return (EPERM);
879 
880 	/*
881 	 * only the kernel can create permanent entries, and only then
882 	 * before the kernel is finished setting itself up
883 	 */
884 	if (l != NULL && (flags & ~SYSCTL_USERFLAGS))
885 		return (EPERM);
886 	if ((flags & CTLFLAG_PERMANENT) &
887 	    (sysctl_root.sysctl_flags & CTLFLAG_PERMANENT))
888 		return (EPERM);
889 	if ((flags & (CTLFLAG_OWNDATA | CTLFLAG_IMMEDIATE)) ==
890 	    (CTLFLAG_OWNDATA | CTLFLAG_IMMEDIATE))
891 		return (EINVAL);
892 	if ((flags & CTLFLAG_IMMEDIATE) &&
893 	    type != CTLTYPE_INT && type != CTLTYPE_QUAD && type != CTLTYPE_BOOL)
894 		return (EINVAL);
895 
896 	/*
897 	 * check size, or set it if unset and we can figure it out.
898 	 * kernel created nodes are allowed to have a function instead
899 	 * of a size (or a data pointer).
900 	 */
901 	switch (type) {
902 	case CTLTYPE_NODE:
903 		/*
904 		 * only *i* can assert the size of a node
905 		 */
906 		if (flags & CTLFLAG_ALIAS) {
907 			anum = nnode.sysctl_alias;
908 			if (anum < 0)
909 				return (EINVAL);
910 			nnode.sysctl_alias = 0;
911 		}
912 		if (sz != 0 || nnode.sysctl_data != NULL)
913 			return (EINVAL);
914 		if (nnode.sysctl_csize != 0 ||
915 		    nnode.sysctl_clen != 0 ||
916 		    nnode.sysctl_child != 0)
917 			return (EINVAL);
918 		if (flags & CTLFLAG_OWNDATA)
919 			return (EINVAL);
920 		sz = sizeof(struct sysctlnode);
921 		break;
922 	case CTLTYPE_INT:
923 		/*
924 		 * since an int is an int, if the size is not given or
925 		 * is wrong, we can "int-uit" it.
926 		 */
927 		if (sz != 0 && sz != sizeof(int))
928 			return (EINVAL);
929 		sz = sizeof(int);
930 		break;
931 	case CTLTYPE_STRING:
932 		/*
933 		 * strings are a little more tricky
934 		 */
935 		if (sz == 0) {
936 			if (l == NULL) {
937 				if (nnode.sysctl_func == NULL) {
938 					if (nnode.sysctl_data == NULL)
939 						return (EINVAL);
940 					else
941 						sz = strlen(nnode.sysctl_data) +
942 						    1;
943 				}
944 			} else if (nnode.sysctl_data == NULL &&
945 				 flags & CTLFLAG_OWNDATA) {
946 				return (EINVAL);
947 			} else {
948 				char *vp, *e;
949 				size_t s;
950 
951 				/*
952 				 * we want a rough idea of what the
953 				 * size is now
954 				 */
955 				vp = malloc(PAGE_SIZE, M_SYSCTLDATA, M_WAITOK);
956 				if (vp == NULL)
957 					return (ENOMEM);
958 				e = nnode.sysctl_data;
959 				do {
960 					error = copyinstr(e, vp, PAGE_SIZE, &s);
961 					if (error) {
962 						if (error != ENAMETOOLONG) {
963 							free(vp, M_SYSCTLDATA);
964 							return (error);
965 						}
966 						e += PAGE_SIZE;
967 						if ((e - 32 * PAGE_SIZE) >
968 						    (char*)nnode.sysctl_data) {
969 							free(vp, M_SYSCTLDATA);
970 							return (ERANGE);
971 						}
972 					}
973 				} while (error != 0);
974 				sz = s + (e - (char*)nnode.sysctl_data);
975 				free(vp, M_SYSCTLDATA);
976 			}
977 		}
978 		break;
979 	case CTLTYPE_QUAD:
980 		if (sz != 0 && sz != sizeof(u_quad_t))
981 			return (EINVAL);
982 		sz = sizeof(u_quad_t);
983 		break;
984 	case CTLTYPE_BOOL:
985 		/*
986 		 * since an bool is an bool, if the size is not given or
987 		 * is wrong, we can "intuit" it.
988 		 */
989 		if (sz != 0 && sz != sizeof(bool))
990 			return (EINVAL);
991 		sz = sizeof(bool);
992 		break;
993 	case CTLTYPE_STRUCT:
994 		if (sz == 0) {
995 			if (l != NULL || nnode.sysctl_func == NULL)
996 				return (EINVAL);
997 			if (flags & CTLFLAG_OWNDATA)
998 				return (EINVAL);
999 		}
1000 		break;
1001 	default:
1002 		return (EINVAL);
1003 	}
1004 
1005 	/*
1006 	 * at this point, if sz is zero, we *must* have a
1007 	 * function to go with it and we can't own it.
1008 	 */
1009 
1010 	/*
1011 	 *  l  ptr own
1012 	 *  0   0   0  -> EINVAL (if no func)
1013 	 *  0   0   1  -> own
1014 	 *  0   1   0  -> kptr
1015 	 *  0   1   1  -> kptr
1016 	 *  1   0   0  -> EINVAL
1017 	 *  1   0   1  -> own
1018 	 *  1   1   0  -> kptr, no own (fault on lookup)
1019 	 *  1   1   1  -> uptr, own
1020 	 */
1021 	if (type != CTLTYPE_NODE) {
1022 		if (sz != 0) {
1023 			if (flags & CTLFLAG_OWNDATA) {
1024 				own = malloc(sz, M_SYSCTLDATA, M_WAITOK);
1025 				if (own == NULL)
1026 					return ENOMEM;
1027 				if (nnode.sysctl_data == NULL)
1028 					memset(own, 0, sz);
1029 				else {
1030 					error = sysctl_copyin(l,
1031 					    nnode.sysctl_data, own, sz);
1032 					if (error != 0) {
1033 						free(own, M_SYSCTLDATA);
1034 						return (error);
1035 					}
1036 				}
1037 			} else if ((nnode.sysctl_data != NULL) &&
1038 				 !(flags & CTLFLAG_IMMEDIATE)) {
1039 #if NKSYMS > 0
1040 				if (name[namelen - 1] == CTL_CREATESYM) {
1041 					char symname[128]; /* XXX enough? */
1042 					u_long symaddr;
1043 					size_t symlen;
1044 
1045 					error = sysctl_copyinstr(l,
1046 					    nnode.sysctl_data, symname,
1047 					    sizeof(symname), &symlen);
1048 					if (error)
1049 						return (error);
1050 					error = ksyms_getval(NULL, symname,
1051 					    &symaddr, KSYMS_EXTERN);
1052 					if (error)
1053 						return (error); /* EINVAL? */
1054 					nnode.sysctl_data = (void*)symaddr;
1055 				}
1056 #endif /* NKSYMS > 0 */
1057 				/*
1058 				 * Ideally, we'd like to verify here
1059 				 * that this address is acceptable,
1060 				 * but...
1061 				 *
1062 				 * - it might be valid now, only to
1063 				 *   become invalid later
1064 				 *
1065 				 * - it might be invalid only for the
1066 				 *   moment and valid later
1067 				 *
1068 				 * - or something else.
1069 				 *
1070 				 * Since we can't get a good answer,
1071 				 * we'll just accept the address as
1072 				 * given, and fault on individual
1073 				 * lookups.
1074 				 */
1075 			}
1076 		} else if (nnode.sysctl_func == NULL)
1077 			return (EINVAL);
1078 	}
1079 
1080 	/*
1081 	 * a process can't assign a function to a node, and the kernel
1082 	 * can't create a node that has no function or data.
1083 	 * (XXX somewhat redundant check)
1084 	 */
1085 	if (l != NULL || nnode.sysctl_func == NULL) {
1086 		if (type != CTLTYPE_NODE &&
1087 		    !(flags & CTLFLAG_IMMEDIATE) &&
1088 		    nnode.sysctl_data == NULL &&
1089 		    own == NULL)
1090 			return (EINVAL);
1091 	}
1092 
1093 #ifdef SYSCTL_DISALLOW_KWRITE
1094 	/*
1095 	 * a process can't create a writable node unless it refers to
1096 	 * new data.
1097 	 */
1098 	if (l != NULL && own == NULL && type != CTLTYPE_NODE &&
1099 	    (flags & CTLFLAG_READWRITE) != CTLFLAG_READONLY &&
1100 	    !(flags & CTLFLAG_IMMEDIATE))
1101 		return (EPERM);
1102 #endif /* SYSCTL_DISALLOW_KWRITE */
1103 
1104 	/*
1105 	 * make sure there's somewhere to put the new stuff.
1106 	 */
1107 	if (pnode->sysctl_child == NULL) {
1108 		if (flags & CTLFLAG_ANYNUMBER)
1109 			error = sysctl_alloc(pnode, 1);
1110 		else
1111 			error = sysctl_alloc(pnode, 0);
1112 		if (error) {
1113 			if (own != NULL)
1114 				free(own, M_SYSCTLDATA);
1115 			return (error);
1116 		}
1117 	}
1118 	node = pnode->sysctl_child;
1119 
1120 	/*
1121 	 * no collisions, so pick a good dynamic number if we need to.
1122 	 */
1123 	if (nm == CTL_CREATE) {
1124 		nm = ++sysctl_root.sysctl_num;
1125 		for (ni = 0; ni < pnode->sysctl_clen; ni++) {
1126 			if (nm == node[ni].sysctl_num) {
1127 				nm++;
1128 				ni = -1;
1129 			} else if (nm > node[ni].sysctl_num)
1130 				at = ni + 1;
1131 		}
1132 	}
1133 
1134 	/*
1135 	 * oops...ran out of space
1136 	 */
1137 	if (pnode->sysctl_clen == pnode->sysctl_csize) {
1138 		error = sysctl_realloc(pnode);
1139 		if (error) {
1140 			if (own != NULL)
1141 				free(own, M_SYSCTLDATA);
1142 			return (error);
1143 		}
1144 		node = pnode->sysctl_child;
1145 	}
1146 
1147 	/*
1148 	 * insert new node data
1149 	 */
1150 	if (at < pnode->sysctl_clen) {
1151 		int t;
1152 
1153 		/*
1154 		 * move the nodes that should come after the new one
1155 		 */
1156 		memmove(&node[at + 1], &node[at],
1157 			(pnode->sysctl_clen - at) * sizeof(struct sysctlnode));
1158 		memset(&node[at], 0, sizeof(struct sysctlnode));
1159 		node[at].sysctl_parent = pnode;
1160 		/*
1161 		 * and...reparent any children of any moved nodes
1162 		 */
1163 		for (ni = at; ni <= pnode->sysctl_clen; ni++)
1164 			if (node[ni].sysctl_child != NULL)
1165 				for (t = 0; t < node[ni].sysctl_csize; t++)
1166 					node[ni].sysctl_child[t].sysctl_parent =
1167 						&node[ni];
1168 	}
1169 	node = &node[at];
1170 	pnode->sysctl_clen++;
1171 
1172 	strlcpy(node->sysctl_name, nnode.sysctl_name,
1173 		sizeof(node->sysctl_name));
1174 	node->sysctl_num = nm;
1175 	node->sysctl_size = sz;
1176 	node->sysctl_flags = SYSCTL_VERSION|type|flags; /* XXX other trees */
1177 	node->sysctl_csize = 0;
1178 	node->sysctl_clen = 0;
1179 	if (own) {
1180 		node->sysctl_data = own;
1181 		node->sysctl_flags |= CTLFLAG_OWNDATA;
1182 	} else if (flags & CTLFLAG_ALIAS) {
1183 		node->sysctl_alias = anum;
1184 	} else if (flags & CTLFLAG_IMMEDIATE) {
1185 		switch (type) {
1186 		case CTLTYPE_BOOL:
1187 			node->sysctl_bdata = nnode.sysctl_bdata;
1188 			break;
1189 		case CTLTYPE_INT:
1190 			node->sysctl_idata = nnode.sysctl_idata;
1191 			break;
1192 		case CTLTYPE_QUAD:
1193 			node->sysctl_qdata = nnode.sysctl_qdata;
1194 			break;
1195 		}
1196 	} else {
1197 		node->sysctl_data = nnode.sysctl_data;
1198 		node->sysctl_flags &= ~CTLFLAG_OWNDATA;
1199 	}
1200         node->sysctl_func = nnode.sysctl_func;
1201         node->sysctl_child = NULL;
1202 	/* node->sysctl_parent should already be done */
1203 
1204 	/*
1205 	 * update "version" on path to "root"
1206 	 */
1207 	for (; rnode->sysctl_parent != NULL; rnode = rnode->sysctl_parent)
1208 		;
1209 	pnode = node;
1210 	for (nm = rnode->sysctl_ver + 1; pnode != NULL;
1211 	     pnode = pnode->sysctl_parent)
1212 		pnode->sysctl_ver = nm;
1213 
1214 	/* If this fails, the node is already added - the user won't know! */
1215 	error = sysctl_cvt_out(l, v, node, oldp, *oldlenp, oldlenp);
1216 
1217 	return (error);
1218 }
1219 
1220 /*
1221  * ********************************************************************
1222  * A wrapper around sysctl_create() that prints the thing we're trying
1223  * to add.
1224  * ********************************************************************
1225  */
1226 #ifdef SYSCTL_DEBUG_CREATE
1227 int
sysctl_create(SYSCTLFN_ARGS)1228 sysctl_create(SYSCTLFN_ARGS)
1229 {
1230 	const struct sysctlnode *node;
1231 	int k, v, rc, ni, nl = namelen + (name - oname);
1232 	struct sysctlnode nnode;
1233 
1234 	if (newp == NULL)
1235 		return EINVAL;
1236 	int error = sysctl_cvt_in(l, &v, newp, newlen, &nnode);
1237 	if (error)
1238 		return error;
1239 
1240 	node = &nnode;
1241 
1242 	printf("namelen %d (", nl);
1243 	for (ni = 0; ni < nl - 1; ni++)
1244 		printf(" %d", oname[ni]);
1245 	printf(" %d )\t[%s]\tflags %08x (%08x %d %zu)\n",
1246 	       k = node->sysctl_num,
1247 	       node->sysctl_name,
1248 	       node->sysctl_flags,
1249 	       SYSCTL_FLAGS(node->sysctl_flags),
1250 	       SYSCTL_TYPE(node->sysctl_flags),
1251 	       node->sysctl_size);
1252 
1253 	node = rnode;
1254 	rc = _sysctl_create(SYSCTLFN_CALL(rnode));
1255 
1256 	printf("sysctl_create(");
1257 	for (ni = 0; ni < nl - 1; ni++)
1258 		printf(" %d", oname[ni]);
1259 	printf(" %d ) returned %d\n", k, rc);
1260 
1261 	return (rc);
1262 }
1263 #endif /* SYSCTL_DEBUG_CREATE */
1264 
1265 /*
1266  * sysctl_destroy -- Removes a node (as described by newp) from the
1267  * given tree, returning (if successful) a copy of the dead node in
1268  * oldp.  Since we're removing stuff, there's not much to check.
1269  */
1270 int
sysctl_destroy(SYSCTLFN_ARGS)1271 sysctl_destroy(SYSCTLFN_ARGS)
1272 {
1273 	struct sysctlnode *node, *pnode, onode, nnode;
1274 	int ni, error, v;
1275 
1276 	KASSERT(rw_write_held(&sysctl_treelock));
1277 
1278 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1279 		printf("sysctl_destroy: rnode %p wrong version\n", rnode);
1280 		return (EINVAL);
1281 	}
1282 
1283 	error = 0;
1284 
1285 	if (namelen != 1 || name[namelen - 1] != CTL_DESTROY)
1286 		return (EINVAL);
1287 
1288 	/*
1289 	 * processes can only destroy nodes at securelevel 0, must be
1290 	 * root, and can't remove nodes from a parent that's not
1291 	 * writeable
1292 	 */
1293 	if (l != NULL) {
1294 #ifndef SYSCTL_DISALLOW_CREATE
1295 		error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
1296 		    KAUTH_REQ_SYSTEM_SYSCTL_DELETE, NULL, NULL, NULL);
1297 		if (error)
1298 			return (error);
1299 		if (!(rnode->sysctl_flags & CTLFLAG_READWRITE))
1300 #endif /* SYSCTL_DISALLOW_CREATE */
1301 			return (EPERM);
1302 	}
1303 
1304 	/*
1305 	 * nothing can remove a node if:
1306 	 * the node is permanent (checked later) or
1307 	 * the tree itself is not writeable or
1308 	 * the entire sysctl system is not writeable
1309 	 *
1310 	 * note that we ignore whether setup is complete or not,
1311 	 * because these rules always apply.
1312 	 */
1313 	if (!(sysctl_rootof(rnode)->sysctl_flags & CTLFLAG_READWRITE) ||
1314 	    !(sysctl_root.sysctl_flags & CTLFLAG_READWRITE))
1315 		return (EPERM);
1316 
1317 	if (newp == NULL)
1318 		return (EINVAL);
1319 	error = sysctl_cvt_in(l, &v, newp, newlen, &nnode);
1320 	if (error)
1321 		return (error);
1322 	memset(&onode, 0, sizeof(struct sysctlnode));
1323 
1324 	node = rnode->sysctl_child;
1325 	for (ni = 0; ni < rnode->sysctl_clen; ni++) {
1326 		if (nnode.sysctl_num == node[ni].sysctl_num) {
1327 			/*
1328 			 * if name specified, must match
1329 			 */
1330 			if (nnode.sysctl_name[0] != '\0' &&
1331 			    strcmp(nnode.sysctl_name, node[ni].sysctl_name))
1332 				continue;
1333 			/*
1334 			 * if version specified, must match
1335 			 */
1336 			if (nnode.sysctl_ver != 0 &&
1337 			    nnode.sysctl_ver != node[ni].sysctl_ver)
1338 				continue;
1339 			/*
1340 			 * this must be the one
1341 			 */
1342 			break;
1343 		}
1344 	}
1345 	if (ni == rnode->sysctl_clen)
1346 		return (ENOENT);
1347 	node = &node[ni];
1348 	pnode = node->sysctl_parent;
1349 
1350 	/*
1351 	 * if the kernel says permanent, it is, so there.  nyah.
1352 	 */
1353 	if (SYSCTL_FLAGS(node->sysctl_flags) & CTLFLAG_PERMANENT)
1354 		return (EPERM);
1355 
1356 	/*
1357 	 * can't delete non-empty nodes
1358 	 */
1359 	if (SYSCTL_TYPE(node->sysctl_flags) == CTLTYPE_NODE &&
1360 	    node->sysctl_clen != 0)
1361 		return (ENOTEMPTY);
1362 
1363 	/*
1364 	 * if the node "owns" data, release it now
1365 	 */
1366 	if (node->sysctl_flags & CTLFLAG_OWNDATA) {
1367 		if (node->sysctl_data != NULL)
1368 			free(node->sysctl_data, M_SYSCTLDATA);
1369 		node->sysctl_data = NULL;
1370 	}
1371 	if (node->sysctl_flags & CTLFLAG_OWNDESC) {
1372 		if (node->sysctl_desc != NULL)
1373 			/*XXXUNCONST*/
1374 			free(__UNCONST(node->sysctl_desc), M_SYSCTLDATA);
1375 		node->sysctl_desc = NULL;
1376 	}
1377 
1378 	/*
1379 	 * if the node to be removed is not the last one on the list,
1380 	 * move the remaining nodes up, and reparent any grandchildren
1381 	 */
1382 	onode = *node;
1383 	if (ni < pnode->sysctl_clen - 1) {
1384 		int t;
1385 
1386 		memmove(&pnode->sysctl_child[ni], &pnode->sysctl_child[ni + 1],
1387 			(pnode->sysctl_clen - ni - 1) *
1388 			sizeof(struct sysctlnode));
1389 		for (; ni < pnode->sysctl_clen - 1; ni++)
1390 			if (SYSCTL_TYPE(pnode->sysctl_child[ni].sysctl_flags) ==
1391 			    CTLTYPE_NODE)
1392 				for (t = 0;
1393 				     t < pnode->sysctl_child[ni].sysctl_clen;
1394 				     t++)
1395 					pnode->sysctl_child[ni].sysctl_child[t].
1396 						sysctl_parent =
1397 						&pnode->sysctl_child[ni];
1398 		ni = pnode->sysctl_clen - 1;
1399 		node = &pnode->sysctl_child[ni];
1400 	}
1401 
1402 	/*
1403 	 * reset the space we just vacated
1404 	 */
1405 	memset(node, 0, sizeof(struct sysctlnode));
1406 	node->sysctl_parent = pnode;
1407 	pnode->sysctl_clen--;
1408 
1409 	/*
1410 	 * if this parent just lost its last child, nuke the creche
1411 	 */
1412 	if (pnode->sysctl_clen == 0) {
1413 		free(pnode->sysctl_child, M_SYSCTLNODE);
1414 		pnode->sysctl_csize = 0;
1415 		pnode->sysctl_child = NULL;
1416 	}
1417 
1418 	/*
1419 	 * update "version" on path to "root"
1420 	 */
1421         for (; rnode->sysctl_parent != NULL; rnode = rnode->sysctl_parent)
1422                 ;
1423 	for (ni = rnode->sysctl_ver + 1; pnode != NULL;
1424 	     pnode = pnode->sysctl_parent)
1425 		pnode->sysctl_ver = ni;
1426 
1427 	error = sysctl_cvt_out(l, v, &onode, oldp, *oldlenp, oldlenp);
1428 
1429 	return (error);
1430 }
1431 
1432 /*
1433  * sysctl_lookup -- Handles copyin/copyout of new and old values.
1434  * Partial reads are globally allowed.  Only root can write to things
1435  * unless the node says otherwise.
1436  */
1437 int
sysctl_lookup(SYSCTLFN_ARGS)1438 sysctl_lookup(SYSCTLFN_ARGS)
1439 {
1440 	int error, rw;
1441 	size_t sz, len;
1442 	void *d;
1443 
1444 	KASSERT(rw_lock_held(&sysctl_treelock));
1445 
1446 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1447 		printf("%s: rnode %p wrong version\n", __func__, rnode);
1448 		return EINVAL;
1449 	}
1450 
1451 	if (newlen == 0)
1452 		newp = NULL;
1453 
1454 	error = 0;
1455 
1456 	/*
1457 	 * you can't "look up" a node.  you can "query" it, but you
1458 	 * can't "look it up".
1459 	 */
1460 	if (SYSCTL_TYPE(rnode->sysctl_flags) == CTLTYPE_NODE || namelen != 0) {
1461 		DPRINTF(("%s: can't lookup a node\n", __func__));
1462 		return EINVAL;
1463 	}
1464 
1465 	/*
1466 	 * some nodes are private, so only root can look into them.
1467 	 */
1468 	if (l != NULL && (rnode->sysctl_flags & CTLFLAG_PRIVATE) &&
1469 	    (error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
1470 	    KAUTH_REQ_SYSTEM_SYSCTL_PRVT, NULL, NULL, NULL)) != 0) {
1471 		DPRINTF(("%s: private node\n", __func__));
1472 		return error;
1473 	}
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_system(l->l_cred,
1484 	    KAUTH_SYSTEM_SYSCTL, KAUTH_REQ_SYSTEM_SYSCTL_MODIFY, NULL, NULL,
1485 	    NULL)) != 0) {
1486 		DPRINTF(("%s: can't modify\n", __func__));
1487 		return error;
1488 	}
1489 
1490 	/*
1491 	 * is this node supposedly writable?
1492 	 */
1493 	rw = (rnode->sysctl_flags & CTLFLAG_READWRITE) ? 1 : 0;
1494 
1495 	/*
1496 	 * it appears not to be writable at this time, so if someone
1497 	 * tried to write to it, we must tell them to go away
1498 	 */
1499 	if (!rw && newp != NULL) {
1500 		DPRINTF(("%s: not writable\n", __func__));
1501 		return EPERM;
1502 	}
1503 
1504 	/*
1505 	 * step one, copy out the stuff we have presently
1506 	 */
1507 	if (rnode->sysctl_flags & CTLFLAG_IMMEDIATE) {
1508 		/*
1509 		 * note that we discard const here because we are
1510 		 * modifying the contents of the node (which is okay
1511 		 * because it's ours)
1512 		 *
1513 		 * It also doesn't matter which field of the union we pick.
1514 		 */
1515 		d = __UNCONST(&rnode->sysctl_qdata);
1516 	} else
1517 		d = rnode->sysctl_data;
1518 
1519 	if (SYSCTL_TYPE(rnode->sysctl_flags) == CTLTYPE_STRING)
1520 		sz = strlen(d) + 1; /* XXX@@@ possible fault here */
1521 	else
1522 		sz = rnode->sysctl_size;
1523 	if (oldp != NULL) {
1524 		error = sysctl_copyout(l, d, oldp, MIN(sz, *oldlenp));
1525 		if (error) {
1526 			DPRINTF(("%s: bad copyout %d\n", __func__, error));
1527 			return error;
1528 		}
1529 	}
1530 	*oldlenp = sz;
1531 
1532 	/*
1533 	 * are we done?
1534 	 */
1535 	if (newp == NULL)
1536 		return 0;
1537 
1538 	/*
1539 	 * hmm...not done.  must now "copy in" new value.  re-adjust
1540 	 * sz to maximum value (strings are "weird").
1541 	 */
1542 	sz = rnode->sysctl_size;
1543 	switch (SYSCTL_TYPE(rnode->sysctl_flags)) {
1544 	case CTLTYPE_BOOL: {
1545 		bool tmp;
1546 		/*
1547 		 * these data must be *exactly* the same size coming
1548 		 * in.  bool may only be true or false.
1549 		 */
1550 		if (newlen != sz) {
1551 			DPRINTF(("%s: bad size %zu != %zu\n", __func__, newlen,
1552 			    sz));
1553 			return EINVAL;
1554 		}
1555 		error = sysctl_copyin(l, newp, &tmp, sz);
1556 		if (error)
1557 			break;
1558 		if (tmp != true && tmp != false) {
1559 			DPRINTF(("%s: tmp %d\n", __func__, tmp));
1560 			return EINVAL;
1561 		}
1562 		*(bool *)d = tmp;
1563 		break;
1564 	}
1565 	case CTLTYPE_INT:
1566 	case CTLTYPE_QUAD:
1567 	case CTLTYPE_STRUCT:
1568 		/*
1569 		 * these data must be *exactly* the same size coming
1570 		 * in.
1571 		 */
1572 		if (newlen != sz)
1573 			goto bad_size;
1574 		error = sysctl_copyin(l, newp, d, sz);
1575 		rnd_add_data(NULL, d, sz, 0);
1576 		break;
1577 	case CTLTYPE_STRING: {
1578 		/*
1579 		 * strings, on the other hand, can be shorter, and we
1580 		 * let userland be sloppy about the trailing nul.
1581 		 */
1582 		char *newbuf;
1583 
1584 		/*
1585 		 * too much new string?
1586 		 */
1587 		if (newlen > sz)
1588 			goto bad_size;
1589 
1590 		/*
1591 		 * temporary copy of new inbound string
1592 		 */
1593 		len = MIN(sz, newlen);
1594 		newbuf = malloc(len, M_SYSCTLDATA, M_WAITOK);
1595 		if (newbuf == NULL) {
1596 			DPRINTF(("%s: oomem %zu\n", __func__, len));
1597 			return ENOMEM;
1598 		}
1599 		error = sysctl_copyin(l, newp, newbuf, len);
1600 		if (error) {
1601 			free(newbuf, M_SYSCTLDATA);
1602 			DPRINTF(("%s: copyin %d\n", __func__, error));
1603 			return error;
1604 		}
1605 
1606 		/*
1607 		 * did they NUL terminate it, or do we have space
1608 		 * left to do it ourselves?
1609 		 */
1610 		if (newbuf[len - 1] != '\0' && len == sz) {
1611 			free(newbuf, M_SYSCTLDATA);
1612 			DPRINTF(("%s: string too long\n", __func__));
1613 			return EINVAL;
1614 		}
1615 
1616 		/*
1617 		 * looks good, so pop it into place and zero the rest.
1618 		 */
1619 		if (len > 0) {
1620 			memcpy(d, newbuf, len);
1621 			rnd_add_data(NULL, d, len, 0);
1622 		}
1623 		if (sz != len)
1624 			memset((char*)d + len, 0, sz - len);
1625 		free(newbuf, M_SYSCTLDATA);
1626 		break;
1627 	}
1628 	default:
1629 		DPRINTF(("%s: bad type\n", __func__));
1630 		return EINVAL;
1631 	}
1632 	if (error) {
1633 		DPRINTF(("%s: copyin %d\n", __func__, error));
1634 	}
1635 
1636 	return error;
1637 
1638     bad_size:
1639 	DPRINTF(("%s: bad size %zu > %zu\n", __func__, newlen, sz));
1640 	return EINVAL;
1641 }
1642 
1643 /*
1644  * sysctl_mmap -- Dispatches sysctl mmap requests to those nodes that
1645  * purport to handle it.  This interface isn't fully fleshed out yet,
1646  * unfortunately.
1647  */
1648 static int
sysctl_mmap(SYSCTLFN_ARGS)1649 sysctl_mmap(SYSCTLFN_ARGS)
1650 {
1651 	const struct sysctlnode *node;
1652 	struct sysctlnode nnode;
1653 	int error;
1654 	int sysctl_num;
1655 
1656 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1657 		printf("sysctl_mmap: rnode %p wrong version\n", rnode);
1658 		return (EINVAL);
1659 	}
1660 
1661 	/*
1662 	 * let's just pretend that didn't happen, m'kay?
1663 	 */
1664 	if (l == NULL)
1665 		return (EPERM);
1666 
1667 	/*
1668 	 * is this a sysctlnode description of an mmap request?
1669 	 */
1670 	if (newp == NULL || newlen != sizeof(struct sysctlnode))
1671 		return (EINVAL);
1672 	error = sysctl_copyin(l, newp, &nnode, sizeof(nnode));
1673 	if (error)
1674 		return (error);
1675 
1676 	/*
1677 	 * does the node they asked for exist?
1678 	 */
1679 	if (namelen != 1)
1680 		return (EOPNOTSUPP);
1681 	node = rnode;
1682 	sysctl_num = nnode.sysctl_num;
1683 	error = sysctl_locate(l, &sysctl_num, 1, &node, NULL);
1684 	if (error)
1685 		return (error);
1686 
1687 	/*
1688 	 * does this node that we have found purport to handle mmap?
1689 	 */
1690 	if (node->sysctl_func == NULL ||
1691 	    !(node->sysctl_flags & CTLFLAG_MMAP))
1692 		return (EOPNOTSUPP);
1693 
1694 	/*
1695 	 * well...okay, they asked for it.
1696 	 */
1697 	return ((*node->sysctl_func)(SYSCTLFN_CALL(node)));
1698 }
1699 
1700 int
sysctl_describe(SYSCTLFN_ARGS)1701 sysctl_describe(SYSCTLFN_ARGS)
1702 {
1703 	struct sysctldesc *d;
1704 	void *bf;
1705 	size_t sz, left, tot;
1706 	int i, error, v = -1;
1707 	struct sysctlnode *node;
1708 	struct sysctlnode dnode;
1709 
1710 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
1711 		printf("sysctl_query: rnode %p wrong version\n", rnode);
1712 		return (EINVAL);
1713 	}
1714 
1715 	if (SYSCTL_TYPE(rnode->sysctl_flags) != CTLTYPE_NODE)
1716 		return (ENOTDIR);
1717 	if (namelen != 1 || name[0] != CTL_DESCRIBE)
1718 		return (EINVAL);
1719 
1720 	/*
1721 	 * get ready...
1722 	 */
1723 	error = 0;
1724 	d = bf = malloc(MAXDESCLEN, M_TEMP, M_WAITOK);
1725 	if (bf == NULL)
1726 		return ENOMEM;
1727 	tot = 0;
1728 	node = rnode->sysctl_child;
1729 	left = *oldlenp;
1730 
1731 	/*
1732 	 * no request -> all descriptions at this level
1733 	 * request with desc unset -> just this node
1734 	 * request with desc set -> set descr for this node
1735 	 */
1736 	if (newp != NULL) {
1737 		error = sysctl_cvt_in(l, &v, newp, newlen, &dnode);
1738 		if (error)
1739 			goto out;
1740 		if (dnode.sysctl_desc != NULL) {
1741 			/*
1742 			 * processes cannot set descriptions above
1743 			 * securelevel 0.  and must be root.  blah
1744 			 * blah blah.  a couple more checks are made
1745 			 * once we find the node we want.
1746 			 */
1747 			if (l != NULL) {
1748 #ifndef SYSCTL_DISALLOW_CREATE
1749 				error = kauth_authorize_system(l->l_cred,
1750 				    KAUTH_SYSTEM_SYSCTL,
1751 				    KAUTH_REQ_SYSTEM_SYSCTL_DESC, NULL,
1752 				    NULL, NULL);
1753 				if (error)
1754 					goto out;
1755 #else /* SYSCTL_DISALLOW_CREATE */
1756 				error = EPERM;
1757 				goto out;
1758 #endif /* SYSCTL_DISALLOW_CREATE */
1759 			}
1760 
1761 			/*
1762 			 * find node and try to set the description on it
1763 			 */
1764 			for (i = 0; i < rnode->sysctl_clen; i++)
1765 				if (node[i].sysctl_num == dnode.sysctl_num)
1766 					break;
1767 			if (i == rnode->sysctl_clen) {
1768 				error = ENOENT;
1769 				goto out;
1770 			}
1771 			node = &node[i];
1772 
1773 			/*
1774 			 * did the caller specify a node version?
1775 			 */
1776 			if (dnode.sysctl_ver != 0 &&
1777 			    dnode.sysctl_ver != node->sysctl_ver) {
1778 				error = EINVAL;
1779 				goto out;
1780 			}
1781 
1782 			/*
1783 			 * okay...some rules:
1784 			 * (1) if setup is done and the tree is
1785 			 *     read-only or the whole system is
1786 			 *     read-only
1787 			 * (2) no one can set a description on a
1788 			 *     permanent node (it must be set when
1789 			 *     using createv)
1790 			 * (3) processes cannot *change* a description
1791 			 * (4) processes *can*, however, set a
1792 			 *     description on a read-only node so that
1793 			 *     one can be created and then described
1794 			 *     in two steps
1795 			 * anything else come to mind?
1796 			 */
1797 			if ((sysctl_root.sysctl_flags & CTLFLAG_PERMANENT) &&
1798 			    (!(sysctl_rootof(node)->sysctl_flags &
1799 			       CTLFLAG_READWRITE) ||
1800 			     !(sysctl_root.sysctl_flags & CTLFLAG_READWRITE))) {
1801 				error = EPERM;
1802 				goto out;
1803 			}
1804 			if (node->sysctl_flags & CTLFLAG_PERMANENT) {
1805 				error = EPERM;
1806 				goto out;
1807 			}
1808 			if (l != NULL && node->sysctl_desc != NULL) {
1809 				error = EPERM;
1810 				goto out;
1811 			}
1812 
1813 			/*
1814 			 * right, let's go ahead.  the first step is
1815 			 * making the description into something the
1816 			 * node can "own", if need be.
1817 			 */
1818 			if (l != NULL ||
1819 			    dnode.sysctl_flags & CTLFLAG_OWNDESC) {
1820 				char *nd, *k;
1821 
1822 				k = malloc(MAXDESCLEN, M_TEMP, M_WAITOK);
1823 				if (k == NULL) {
1824 					error = ENOMEM;
1825 					goto out;
1826 				}
1827 				error = sysctl_copyinstr(l, dnode.sysctl_desc,
1828 							 k, MAXDESCLEN, &sz);
1829 				if (error) {
1830 					free(k, M_TEMP);
1831 					goto out;
1832 				}
1833 				nd = malloc(sz, M_SYSCTLDATA, M_WAITOK);
1834 				if (nd == NULL) {
1835 					free(k, M_TEMP);
1836 					error = ENOMEM;
1837 					goto out;
1838 				}
1839 				memcpy(nd, k, sz);
1840 				dnode.sysctl_flags |= CTLFLAG_OWNDESC;
1841 				dnode.sysctl_desc = nd;
1842 				free(k, M_TEMP);
1843 			}
1844 
1845 			/*
1846 			 * now "release" the old description and
1847 			 * attach the new one.  ta-da.
1848 			 */
1849 			if ((node->sysctl_flags & CTLFLAG_OWNDESC) &&
1850 			    node->sysctl_desc != NULL)
1851 				/*XXXUNCONST*/
1852 				free(__UNCONST(node->sysctl_desc), M_SYSCTLDATA);
1853 			node->sysctl_desc = dnode.sysctl_desc;
1854 			node->sysctl_flags |=
1855 				(dnode.sysctl_flags & CTLFLAG_OWNDESC);
1856 
1857 			/*
1858 			 * now we "fall out" and into the loop which
1859 			 * will copy the new description back out for
1860 			 * those interested parties
1861 			 */
1862 		}
1863 	}
1864 
1865 	/*
1866 	 * scan for one description or just retrieve all descriptions
1867 	 */
1868 	for (i = 0; i < rnode->sysctl_clen; i++) {
1869 		/*
1870 		 * did they ask for the description of only one node?
1871 		 */
1872 		if (v != -1 && node[i].sysctl_num != dnode.sysctl_num)
1873 			continue;
1874 
1875 		/*
1876 		 * don't describe "private" nodes to non-suser users
1877 		 */
1878 		if ((node[i].sysctl_flags & CTLFLAG_PRIVATE) && (l != NULL) &&
1879 		    !(kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_SYSCTL,
1880 		    KAUTH_REQ_SYSTEM_SYSCTL_PRVT, NULL, NULL, NULL)))
1881 			continue;
1882 
1883 		/*
1884 		 * is this description "valid"?
1885 		 */
1886 		memset(bf, 0, MAXDESCLEN);
1887 		if (node[i].sysctl_desc == NULL)
1888 			sz = 1;
1889 		else if (copystr(node[i].sysctl_desc, &d->descr_str[0],
1890 				 MAXDESCLEN - sizeof(*d), &sz) != 0) {
1891 			/*
1892 			 * erase possible partial description
1893 			 */
1894 			memset(bf, 0, MAXDESCLEN);
1895 			sz = 1;
1896 		}
1897 
1898 		/*
1899 		 * we've got it, stuff it into the caller's buffer
1900 		 */
1901 		d->descr_num = node[i].sysctl_num;
1902 		d->descr_ver = node[i].sysctl_ver;
1903 		d->descr_len = sz; /* includes trailing nul */
1904 		sz = (char *)NEXT_DESCR(d) - (char *)d;
1905 		if (oldp != NULL && left >= sz) {
1906 			error = sysctl_copyout(l, d, oldp, sz);
1907 			if (error)
1908 				goto out;
1909 			left -= sz;
1910 			oldp = (void *)__sysc_desc_adv(oldp, d->descr_len);
1911 		}
1912 		tot += sz;
1913 
1914 		/*
1915 		 * if we get this far with v not "unset", they asked
1916 		 * for a specific node and we found it
1917 		 */
1918 		if (v != -1)
1919 			break;
1920 	}
1921 
1922 	/*
1923 	 * did we find it after all?
1924 	 */
1925 	if (v != -1 && tot == 0)
1926 		error = ENOENT;
1927 	else
1928 		*oldlenp = tot;
1929 
1930 out:
1931 	free(bf, M_TEMP);
1932 	return (error);
1933 }
1934 
1935 /*
1936  * ********************************************************************
1937  * Section 3: Create and destroy from inside the kernel
1938  * ********************************************************************
1939  * sysctl_createv() and sysctl_destroyv() are simpler-to-use
1940  * interfaces for the kernel to fling new entries into the mib and rip
1941  * them out later.  In the case of sysctl_createv(), the returned copy
1942  * of the node (see sysctl_create()) will be translated back into a
1943  * pointer to the actual node.
1944  *
1945  * Note that sysctl_createv() will return 0 if the create request
1946  * matches an existing node (ala mkdir -p), and that sysctl_destroyv()
1947  * will return 0 if the node to be destroyed already does not exist
1948  * (aka rm -f) or if it is a parent of other nodes.
1949  *
1950  * This allows two (or more) different subsystems to assert sub-tree
1951  * existence before populating their own nodes, and to remove their
1952  * own nodes without orphaning the others when they are done.
1953  * ********************************************************************
1954  */
1955 #undef sysctl_createv
1956 int
sysctl_createv(struct sysctllog ** log,int cflags,const struct sysctlnode ** rnode,const struct sysctlnode ** cnode,int flags,int type,const char * namep,const char * descr,sysctlfn func,u_quad_t qv,void * newp,size_t newlen,...)1957 sysctl_createv(struct sysctllog **log, int cflags,
1958 	       const struct sysctlnode **rnode, const struct sysctlnode **cnode,
1959 	       int flags, int type, const char *namep, const char *descr,
1960 	       sysctlfn func, u_quad_t qv, void *newp, size_t newlen,
1961 	       ...)
1962 {
1963 	va_list ap;
1964 	int error, ni, namelen, name[CTL_MAXNAME];
1965 	const struct sysctlnode *root, *pnode;
1966 	struct sysctlnode nnode, onode, *dnode;
1967 	size_t sz;
1968 	const struct sysctlnode *snode __diagused;
1969 
1970 	/*
1971 	 * where are we putting this?
1972 	 */
1973 	if (rnode != NULL && *rnode == NULL) {
1974 		printf("sysctl_createv: rnode NULL\n");
1975 		return (EINVAL);
1976 	}
1977 	root = rnode ? *rnode : NULL;
1978 	if (cnode != NULL)
1979 		*cnode = NULL;
1980 	if (cflags != 0)
1981 		return (EINVAL);
1982 
1983 	/*
1984 	 * what is it?
1985 	 */
1986 	flags = SYSCTL_VERSION|SYSCTL_TYPE(type)|SYSCTL_FLAGS(flags);
1987 	if (log != NULL)
1988 		flags &= ~CTLFLAG_PERMANENT;
1989 
1990 	/*
1991 	 * where do we put it?
1992 	 */
1993 	va_start(ap, newlen);
1994 	namelen = 0;
1995 	error = 0;
1996 	ni = -1;
1997 	do {
1998 		if (++ni == CTL_MAXNAME) {
1999 			error = ENAMETOOLONG;
2000 			break;
2001 		}
2002 		name[ni] = va_arg(ap, int);
2003 		/*
2004 		 * sorry, this is not supported from here
2005 		 */
2006 		if (name[ni] == CTL_CREATESYM) {
2007 			error = EINVAL;
2008 			break;
2009 		}
2010 	} while (name[ni] != CTL_EOL && name[ni] != CTL_CREATE);
2011 	va_end(ap);
2012 	if (error)
2013 		return error;
2014 	namelen = ni + (name[ni] == CTL_CREATE ? 1 : 0);
2015 
2016 	/*
2017 	 * what's it called
2018 	 */
2019 	if (strlcpy(nnode.sysctl_name, namep, sizeof(nnode.sysctl_name)) >=
2020 	    sizeof(nnode.sysctl_name))
2021 		return (ENAMETOOLONG);
2022 
2023 	/*
2024 	 * cons up the description of the new node
2025 	 */
2026 	nnode.sysctl_num = name[namelen - 1];
2027 	name[namelen - 1] = CTL_CREATE;
2028 	nnode.sysctl_size = newlen;
2029 	nnode.sysctl_flags = flags;
2030 	if (type == CTLTYPE_NODE) {
2031 		nnode.sysctl_csize = 0;
2032 		nnode.sysctl_clen = 0;
2033 		nnode.sysctl_child = NULL;
2034 		if (flags & CTLFLAG_ALIAS)
2035 			nnode.sysctl_alias = qv;
2036 	} else if (flags & CTLFLAG_IMMEDIATE) {
2037 		switch (type) {
2038 		case CTLTYPE_BOOL:
2039 			nnode.sysctl_bdata = qv;
2040 			break;
2041 		case CTLTYPE_INT:
2042 			nnode.sysctl_idata = qv;
2043 			break;
2044 		case CTLTYPE_QUAD:
2045 			nnode.sysctl_qdata = qv;
2046 			break;
2047 		default:
2048 			return (EINVAL);
2049 		}
2050 	} else {
2051 		nnode.sysctl_data = newp;
2052 	}
2053 	nnode.sysctl_func = func;
2054 	nnode.sysctl_parent = NULL;
2055 	nnode.sysctl_ver = 0;
2056 
2057 	/*
2058 	 * initialize lock state -- we need locks if the main tree has
2059 	 * been marked as complete, but since we could be called from
2060 	 * either there, or from a device driver (say, at device
2061 	 * insertion), or from a module (at module load time, say), we
2062 	 * don't really want to "wait"...
2063 	 */
2064 	sysctl_lock(true);
2065 
2066 	/*
2067 	 * locate the prospective parent of the new node, and if we
2068 	 * find it, add the new node.
2069 	 */
2070 	sz = sizeof(onode);
2071 	pnode = root;
2072 	error = sysctl_locate(NULL, &name[0], namelen - 1, &pnode, &ni);
2073 	if (error) {
2074 		/*
2075 		 * XXX: If you are seeing this printf in early bringup
2076 		 * stages, perhaps your setfault is not functioning and
2077 		 * thus kcopy() is mis-behaving.
2078 		 */
2079 		printf("sysctl_createv: sysctl_locate(%s) returned %d\n",
2080 		       nnode.sysctl_name, error);
2081 		sysctl_unlock();
2082 		return (error);
2083 	}
2084 	error = sysctl_create(&name[ni], namelen - ni, &onode, &sz,
2085 			      &nnode, sizeof(nnode), &name[0], NULL,
2086 			      pnode);
2087 
2088 	/*
2089 	 * unfortunately the node we wanted to create is already
2090 	 * there.  if the node that's already there is a reasonable
2091 	 * facsimile of the node we wanted to create, just pretend
2092 	 * (for the caller's benefit) that we managed to create the
2093 	 * node they wanted.
2094 	 */
2095 	if (error == EEXIST) {
2096 		/* name is the same as requested... */
2097 		if (strcmp(nnode.sysctl_name, onode.sysctl_name) == 0 &&
2098 		    /* they want the same function... */
2099 		    nnode.sysctl_func == onode.sysctl_func &&
2100 		    /* number is the same as requested, or... */
2101 		    (nnode.sysctl_num == onode.sysctl_num ||
2102 		     /* they didn't pick a number... */
2103 		     nnode.sysctl_num == CTL_CREATE)) {
2104 			/*
2105 			 * collision here from trying to create
2106 			 * something that already existed; let's give
2107 			 * our customers a hand and tell them they got
2108 			 * what they wanted.
2109 			 */
2110 #ifdef SYSCTL_DEBUG_CREATE
2111 			printf("cleared\n");
2112 #endif /* SYSCTL_DEBUG_CREATE */
2113 			error = 0;
2114 		}
2115 	}
2116 
2117 	if (error == 0 &&
2118 	    (cnode != NULL || log != NULL || descr != NULL)) {
2119 		/*
2120 		 * sysctl_create() gave us back a copy of the node,
2121 		 * but we need to know where it actually is...
2122 		 */
2123 		pnode = root;
2124 		error = sysctl_locate(NULL, &name[0], namelen - 1, &pnode, &ni);
2125 		snode = pnode;
2126 
2127 		/*
2128 		 * manual scan of last layer so that aliased nodes
2129 		 * aren't followed.
2130 		 */
2131 		if (error == 0) {
2132 			for (ni = 0; ni < pnode->sysctl_clen; ni++)
2133 				if (pnode->sysctl_child[ni].sysctl_num ==
2134 				    onode.sysctl_num)
2135 					break;
2136 			if (ni < pnode->sysctl_clen)
2137 				pnode = &pnode->sysctl_child[ni];
2138 			else
2139 				error = ENOENT;
2140 		}
2141 
2142 		/*
2143 		 * not expecting an error here, but...
2144 		 */
2145 		if (error == 0) {
2146 			KASSERTMSG(pnode->sysctl_parent == snode,
2147 			    "sysctl parent mis-match pnode %s, snode %s",
2148 			    pnode->sysctl_name, snode->sysctl_name);
2149 			if (log != NULL)
2150 				sysctl_log_add(log, pnode);
2151 			if (cnode != NULL)
2152 				*cnode = pnode;
2153 			if (descr != NULL) {
2154 				/*
2155 				 * allow first caller to *set* a
2156 				 * description actually to set it
2157 				 *
2158 				 * discard const here so we can attach
2159 				 * the description
2160 				 */
2161 				dnode = __UNCONST(pnode);
2162 				if (pnode->sysctl_desc != NULL)
2163 					/* skip it...we've got one */;
2164 				else if (flags & CTLFLAG_OWNDESC) {
2165 					size_t l = strlen(descr) + 1;
2166 					char *d = malloc(l, M_SYSCTLDATA,
2167 							 M_WAITOK);
2168 					if (d != NULL) {
2169 						memcpy(d, descr, l);
2170 						dnode->sysctl_desc = d;
2171 						dnode->sysctl_flags |=
2172 						    CTLFLAG_OWNDESC;
2173 					}
2174 				} else
2175 					dnode->sysctl_desc = descr;
2176 			}
2177 		} else {
2178 			printf("sysctl_create succeeded but node not found?!\n");
2179 			/*
2180 			 *  confusing, but the create said it
2181 			 * succeeded, so...
2182 			 */
2183 			error = 0;
2184 		}
2185 	}
2186 
2187 	/*
2188 	 * now it should be safe to release the lock state.  note that
2189 	 * the pointer to the newly created node being passed back may
2190 	 * not be "good" for very long.
2191 	 */
2192 	sysctl_unlock();
2193 
2194 	if (error != 0) {
2195 		printf("sysctl_createv: sysctl_create(%s) returned %d\n",
2196 		       nnode.sysctl_name, error);
2197 #if 0
2198 		if (error != ENOENT)
2199 			sysctl_dump(&onode);
2200 #endif
2201 	}
2202 
2203 	return (error);
2204 }
2205 
2206 int
sysctl_destroyv(struct sysctlnode * rnode,...)2207 sysctl_destroyv(struct sysctlnode *rnode, ...)
2208 {
2209 	va_list ap;
2210 	int error, name[CTL_MAXNAME], namelen, ni;
2211 	const struct sysctlnode *pnode, *node;
2212 	struct sysctlnode dnode, *onode;
2213 	size_t sz;
2214 
2215 	va_start(ap, rnode);
2216 	namelen = 0;
2217 	ni = 0;
2218 	do {
2219 		if (ni == CTL_MAXNAME) {
2220 			va_end(ap);
2221 			return (ENAMETOOLONG);
2222 		}
2223 		name[ni] = va_arg(ap, int);
2224 	} while (name[ni++] != CTL_EOL);
2225 	namelen = ni - 1;
2226 	va_end(ap);
2227 
2228 	/*
2229 	 * i can't imagine why we'd be destroying a node when the tree
2230 	 * wasn't complete, but who knows?
2231 	 */
2232 	sysctl_lock(true);
2233 
2234 	/*
2235 	 * where is it?
2236 	 */
2237 	node = rnode;
2238 	error = sysctl_locate(NULL, &name[0], namelen - 1, &node, &ni);
2239 	if (error) {
2240 		/* they want it gone and it's not there, so... */
2241 		sysctl_unlock();
2242 		return (error == ENOENT ? 0 : error);
2243 	}
2244 
2245 	/*
2246 	 * set up the deletion
2247 	 */
2248 	pnode = node;
2249 	node = &dnode;
2250 	memset(&dnode, 0, sizeof(dnode));
2251 	dnode.sysctl_flags = SYSCTL_VERSION;
2252 	dnode.sysctl_num = name[namelen - 1];
2253 
2254 	/*
2255 	 * we found it, now let's nuke it
2256 	 */
2257 	name[namelen - 1] = CTL_DESTROY;
2258 	sz = 0;
2259 	error = sysctl_destroy(&name[namelen - 1], 1, NULL, &sz,
2260 			       node, sizeof(*node), &name[0], NULL,
2261 			       pnode);
2262 	if (error == ENOTEMPTY) {
2263 		/*
2264 		 * think of trying to delete "foo" when "foo.bar"
2265 		 * (which someone else put there) is still in
2266 		 * existence
2267 		 */
2268 		error = 0;
2269 
2270 		/*
2271 		 * dunno who put the description there, but if this
2272 		 * node can ever be removed, we need to make sure the
2273 		 * string doesn't go out of context.  that means we
2274 		 * need to find the node that's still there (don't use
2275 		 * sysctl_locate() because that follows aliasing).
2276 		 */
2277 		node = pnode->sysctl_child;
2278 		for (ni = 0; ni < pnode->sysctl_clen; ni++)
2279 			if (node[ni].sysctl_num == dnode.sysctl_num)
2280 				break;
2281 		node = (ni < pnode->sysctl_clen) ? &node[ni] : NULL;
2282 
2283 		/*
2284 		 * if we found it, and this node has a description,
2285 		 * and this node can be released, and it doesn't
2286 		 * already own its own description...sigh.  :)
2287 		 */
2288 		if (node != NULL && node->sysctl_desc != NULL &&
2289 		    !(node->sysctl_flags & CTLFLAG_PERMANENT) &&
2290 		    !(node->sysctl_flags & CTLFLAG_OWNDESC)) {
2291 			char *d;
2292 
2293 			sz = strlen(node->sysctl_desc) + 1;
2294 			d = malloc(sz, M_SYSCTLDATA, M_WAITOK);
2295 			if (d != NULL) {
2296 				/*
2297 				 * discard const so that we can
2298 				 * re-attach the description
2299 				 */
2300 				memcpy(d, node->sysctl_desc, sz);
2301 				onode = __UNCONST(node);
2302 				onode->sysctl_desc = d;
2303 				onode->sysctl_flags |= CTLFLAG_OWNDESC;
2304 			} else {
2305 				/*
2306 				 * XXX drop the description?  be
2307 				 * afraid?  don't care?
2308 				 */
2309 			}
2310 		}
2311 	}
2312 
2313         sysctl_unlock();
2314 
2315 	return (error);
2316 }
2317 
2318 /*
2319  * ********************************************************************
2320  * Deletes an entire n-ary tree.  Not recommended unless you know why
2321  * you're doing it.  Personally, I don't know why you'd even think
2322  * about it.
2323  * ********************************************************************
2324  */
2325 void
sysctl_free(struct sysctlnode * rnode)2326 sysctl_free(struct sysctlnode *rnode)
2327 {
2328 	struct sysctlnode *node, *pnode;
2329 
2330 	rw_enter(&sysctl_treelock, RW_WRITER);
2331 
2332 	if (rnode == NULL)
2333 		rnode = &sysctl_root;
2334 
2335 	if (SYSCTL_VERS(rnode->sysctl_flags) != SYSCTL_VERSION) {
2336 		printf("sysctl_free: rnode %p wrong version\n", rnode);
2337 		rw_exit(&sysctl_treelock);
2338 		return;
2339 	}
2340 
2341 	pnode = rnode;
2342 
2343 	node = pnode->sysctl_child;
2344 	do {
2345 		while (node != NULL && pnode->sysctl_csize > 0) {
2346 			while (node <
2347 			       &pnode->sysctl_child[pnode->sysctl_clen] &&
2348 			       (SYSCTL_TYPE(node->sysctl_flags) !=
2349 				CTLTYPE_NODE ||
2350 				node->sysctl_csize == 0)) {
2351 				if (SYSCTL_FLAGS(node->sysctl_flags) &
2352 				    CTLFLAG_OWNDATA) {
2353 					if (node->sysctl_data != NULL) {
2354 						free(node->sysctl_data,
2355 						     M_SYSCTLDATA);
2356 						node->sysctl_data = NULL;
2357 					}
2358 				}
2359 				if (SYSCTL_FLAGS(node->sysctl_flags) &
2360 				    CTLFLAG_OWNDESC) {
2361 					if (node->sysctl_desc != NULL) {
2362 						/*XXXUNCONST*/
2363 						free(__UNCONST(node->sysctl_desc),
2364 						     M_SYSCTLDATA);
2365 						node->sysctl_desc = NULL;
2366 					}
2367 				}
2368 				node++;
2369 			}
2370 			if (node < &pnode->sysctl_child[pnode->sysctl_clen]) {
2371 				pnode = node;
2372 				node = node->sysctl_child;
2373 			} else
2374 				break;
2375 		}
2376 		if (pnode->sysctl_child != NULL)
2377 			free(pnode->sysctl_child, M_SYSCTLNODE);
2378 		pnode->sysctl_clen = 0;
2379 		pnode->sysctl_csize = 0;
2380 		pnode->sysctl_child = NULL;
2381 		node = pnode;
2382 		pnode = node->sysctl_parent;
2383 	} while (pnode != NULL && node != rnode);
2384 
2385 	rw_exit(&sysctl_treelock);
2386 }
2387 
2388 void
sysctl_log_print(const struct sysctllog * slog)2389 sysctl_log_print(const struct sysctllog *slog)
2390 {
2391 	int i, len;
2392 
2393 	printf("root %p left %d size %d content", (const void *)slog->log_root,
2394 	    slog->log_left, slog->log_size);
2395 
2396 	for (len = 0, i = slog->log_left; i < slog->log_size; i++) {
2397 		switch (len) {
2398 		case 0:
2399 			len = -1;
2400 			printf(" version %d", slog->log_num[i]);
2401 			break;
2402 		case -1:
2403 			len = -2;
2404 			printf(" type %d", slog->log_num[i]);
2405 			break;
2406 		case -2:
2407 			len =  slog->log_num[i];
2408 			printf(" len %d:", slog->log_num[i]);
2409 			if (len <= 0)
2410 				len = -1;
2411 			break;
2412 		default:
2413 			len--;
2414 			printf(" %d", slog->log_num[i]);
2415 			break;
2416 		}
2417 	}
2418 	printf(" end\n");
2419 }
2420 
2421 int
sysctl_log_add(struct sysctllog ** logp,const struct sysctlnode * node)2422 sysctl_log_add(struct sysctllog **logp, const struct sysctlnode *node)
2423 {
2424 	const int size0 = 16;
2425 	int name[CTL_MAXNAME], namelen, i;
2426 	const struct sysctlnode *pnode;
2427 	struct sysctllog *log;
2428 
2429 	if (node->sysctl_flags & CTLFLAG_PERMANENT)
2430 		return (0);
2431 
2432 	if (logp == NULL)
2433 		return (0);
2434 
2435 	if (*logp == NULL) {
2436 		log = malloc(sizeof(struct sysctllog),
2437 		       M_SYSCTLDATA, M_WAITOK);
2438 		if (log == NULL) {
2439 			/* XXX print error message? */
2440 			return (-1);
2441 		}
2442 		log->log_num = malloc(size0 * sizeof(int),
2443 		       M_SYSCTLDATA, M_WAITOK);
2444 		if (log->log_num == NULL) {
2445 			/* XXX print error message? */
2446 			free(log, M_SYSCTLDATA);
2447 			return (-1);
2448 		}
2449 		memset(log->log_num, 0, size0 * sizeof(int));
2450 		log->log_root = NULL;
2451 		log->log_size = size0;
2452 		log->log_left = size0;
2453 		*logp = log;
2454 	} else
2455 		log = *logp;
2456 
2457 	/*
2458 	 * check that the root is proper.  it's okay to record the
2459 	 * address of the root of a tree.  it's the only thing that's
2460 	 * guaranteed not to shift around as nodes come and go.
2461 	 */
2462 	if (log->log_root == NULL)
2463 		log->log_root = sysctl_rootof(node);
2464 	else if (log->log_root != sysctl_rootof(node)) {
2465 		printf("sysctl: log %p root mismatch (%p)\n",
2466 		       log->log_root, sysctl_rootof(node));
2467 		return (-1);
2468 	}
2469 
2470 	/*
2471 	 * we will copy out name in reverse order
2472 	 */
2473 	for (pnode = node, namelen = 0;
2474 	     pnode != NULL && !(pnode->sysctl_flags & CTLFLAG_ROOT);
2475 	     pnode = pnode->sysctl_parent)
2476 		name[namelen++] = pnode->sysctl_num;
2477 
2478 	/*
2479 	 * do we have space?
2480 	 */
2481 	if (log->log_left < (namelen + 3))
2482 		sysctl_log_realloc(log);
2483 	if (log->log_left < (namelen + 3))
2484 		return (-1);
2485 
2486 	/*
2487 	 * stuff name in, then namelen, then node type, and finally,
2488 	 * the version for non-node nodes.
2489 	 */
2490 	for (i = 0; i < namelen && i < CTL_MAXNAME; i++)
2491 		log->log_num[--log->log_left] = name[i];
2492 	log->log_num[--log->log_left] = namelen;
2493 	log->log_num[--log->log_left] = SYSCTL_TYPE(node->sysctl_flags);
2494 	if (log->log_num[log->log_left] != CTLTYPE_NODE)
2495 		log->log_num[--log->log_left] = node->sysctl_ver;
2496 	else
2497 		log->log_num[--log->log_left] = 0;
2498 
2499 	return (0);
2500 }
2501 
2502 void
sysctl_teardown(struct sysctllog ** logp)2503 sysctl_teardown(struct sysctllog **logp)
2504 {
2505 	const struct sysctlnode *rnode;
2506 	struct sysctlnode node;
2507 	struct sysctllog *log;
2508 	uint namelen;
2509 	int *name, t, v, error, ni;
2510 	size_t sz;
2511 
2512 	if (logp == NULL || *logp == NULL)
2513 		return;
2514 	log = *logp;
2515 
2516 	rw_enter(&sysctl_treelock, RW_WRITER);
2517 	memset(&node, 0, sizeof(node));
2518 
2519 	while (log->log_left < log->log_size) {
2520 		KASSERT(log->log_left + 3 < log->log_size);
2521 		KASSERT(log->log_left + log->log_num[log->log_left + 2] <=
2522 		    log->log_size);
2523 		v = log->log_num[log->log_left++];
2524 		t = log->log_num[log->log_left++];
2525 		namelen = log->log_num[log->log_left++];
2526 		name = &log->log_num[log->log_left];
2527 
2528 		node.sysctl_num = name[namelen - 1];
2529 		node.sysctl_flags = SYSCTL_VERSION|t;
2530 		node.sysctl_ver = v;
2531 
2532 		rnode = log->log_root;
2533 		error = sysctl_locate(NULL, &name[0], namelen, &rnode, &ni);
2534 		if (error == 0) {
2535 			name[namelen - 1] = CTL_DESTROY;
2536 			rnode = rnode->sysctl_parent;
2537 			sz = 0;
2538 			(void)sysctl_destroy(&name[namelen - 1], 1, NULL,
2539 					     &sz, &node, sizeof(node),
2540 					     &name[0], NULL, rnode);
2541 		}
2542 
2543 		log->log_left += namelen;
2544 	}
2545 
2546 	KASSERT(log->log_size == log->log_left);
2547 	free(log->log_num, M_SYSCTLDATA);
2548 	free(log, M_SYSCTLDATA);
2549 	*logp = NULL;
2550 
2551 	rw_exit(&sysctl_treelock);
2552 }
2553 
2554 /*
2555  * ********************************************************************
2556  * old_sysctl -- A routine to bridge old-style internal calls to the
2557  * new infrastructure.
2558  * ********************************************************************
2559  */
2560 int
old_sysctl(int * name,u_int namelen,void * oldp,size_t * oldlenp,void * newp,size_t newlen,struct lwp * l)2561 old_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
2562 	   void *newp, size_t newlen, struct lwp *l)
2563 {
2564 	int error;
2565 	size_t oldlen = 0;
2566 	size_t savelen;
2567 
2568 	if (oldlenp) {
2569 		oldlen = *oldlenp;
2570 	}
2571 	savelen = oldlen;
2572 
2573 	sysctl_lock(newp != NULL);
2574 	error = sysctl_dispatch(name, namelen, oldp, &oldlen,
2575 				newp, newlen, name, l, NULL);
2576 	sysctl_unlock();
2577 	if (error == 0 && oldp != NULL && savelen < oldlen)
2578 		error = ENOMEM;
2579 	if (oldlenp) {
2580 		*oldlenp = oldlen;
2581 	}
2582 
2583 	return (error);
2584 }
2585 
2586 /*
2587  * ********************************************************************
2588  * Section 4: Generic helper routines
2589  * ********************************************************************
2590  * "helper" routines that can do more finely grained access control,
2591  * construct structures from disparate information, create the
2592  * appearance of more nodes and sub-trees, etc.  for example, if
2593  * CTL_PROC wanted a helper function, it could respond to a CTL_QUERY
2594  * with a dynamically created list of nodes that represented the
2595  * currently running processes at that instant.
2596  * ********************************************************************
2597  */
2598 
2599 /*
2600  * first, a few generic helpers that provide:
2601  *
2602  * sysctl_needfunc()		a readonly interface that emits a warning
2603  * sysctl_notavail()		returns EOPNOTSUPP (generic error)
2604  * sysctl_null()		an empty return buffer with no error
2605  */
2606 int
sysctl_needfunc(SYSCTLFN_ARGS)2607 sysctl_needfunc(SYSCTLFN_ARGS)
2608 {
2609 	int error;
2610 
2611 	printf("!!SYSCTL_NEEDFUNC!!\n");
2612 
2613 	if (newp != NULL || namelen != 0)
2614 		return (EOPNOTSUPP);
2615 
2616 	error = 0;
2617 	if (oldp != NULL)
2618 		error = sysctl_copyout(l, rnode->sysctl_data, oldp,
2619 				       MIN(rnode->sysctl_size, *oldlenp));
2620 	*oldlenp = rnode->sysctl_size;
2621 
2622 	return (error);
2623 }
2624 
2625 int
sysctl_notavail(SYSCTLFN_ARGS)2626 sysctl_notavail(SYSCTLFN_ARGS)
2627 {
2628 
2629 	if (namelen == 1 && name[0] == CTL_QUERY)
2630 		return (sysctl_query(SYSCTLFN_CALL(rnode)));
2631 
2632 	return (EOPNOTSUPP);
2633 }
2634 
2635 int
sysctl_null(SYSCTLFN_ARGS)2636 sysctl_null(SYSCTLFN_ARGS)
2637 {
2638 
2639 	*oldlenp = 0;
2640 
2641 	return (0);
2642 }
2643 
2644 u_int
sysctl_map_flags(const u_int * map,u_int word)2645 sysctl_map_flags(const u_int *map, u_int word)
2646 {
2647 	u_int rv;
2648 
2649 	for (rv = 0; *map != 0; map += 2)
2650 		if ((word & map[0]) != 0)
2651 			rv |= map[1];
2652 
2653 	return rv;
2654 }
2655 
2656 /*
2657  * ********************************************************************
2658  * Section 5: The machinery that makes it all go
2659  * ********************************************************************
2660  * Memory "manglement" routines.  Not much to this, eh?
2661  * ********************************************************************
2662  */
2663 static int
sysctl_alloc(struct sysctlnode * p,int x)2664 sysctl_alloc(struct sysctlnode *p, int x)
2665 {
2666 	int i;
2667 	struct sysctlnode *n;
2668 
2669 	assert(p->sysctl_child == NULL);
2670 
2671 	if (x == 1)
2672 		n = malloc(sizeof(struct sysctlnode),
2673 		       M_SYSCTLNODE, M_WAITOK);
2674 	else
2675 		n = malloc(SYSCTL_DEFSIZE * sizeof(struct sysctlnode),
2676 		       M_SYSCTLNODE, M_WAITOK);
2677 	if (n == NULL)
2678 		return (ENOMEM);
2679 
2680 	if (x == 1) {
2681 		memset(n, 0, sizeof(struct sysctlnode));
2682 		p->sysctl_csize = 1;
2683 	} else {
2684 		memset(n, 0, SYSCTL_DEFSIZE * sizeof(struct sysctlnode));
2685 		p->sysctl_csize = SYSCTL_DEFSIZE;
2686 	}
2687 	p->sysctl_clen = 0;
2688 
2689 	for (i = 0; i < p->sysctl_csize; i++)
2690 		n[i].sysctl_parent = p;
2691 
2692 	p->sysctl_child = n;
2693 	return (0);
2694 }
2695 
2696 static int
sysctl_realloc(struct sysctlnode * p)2697 sysctl_realloc(struct sysctlnode *p)
2698 {
2699 	int i, j, olen;
2700 	struct sysctlnode *n;
2701 
2702 	assert(p->sysctl_csize == p->sysctl_clen);
2703 
2704 	/*
2705 	 * how many do we have...how many should we make?
2706 	 */
2707 	olen = p->sysctl_clen;
2708 	n = malloc(2 * olen * sizeof(struct sysctlnode), M_SYSCTLNODE,
2709 		   M_WAITOK);
2710 	if (n == NULL)
2711 		return (ENOMEM);
2712 
2713 	/*
2714 	 * move old children over...initialize new children
2715 	 */
2716 	memcpy(n, p->sysctl_child, olen * sizeof(struct sysctlnode));
2717 	memset(&n[olen], 0, olen * sizeof(struct sysctlnode));
2718 	p->sysctl_csize = 2 * olen;
2719 
2720 	/*
2721 	 * reattach moved (and new) children to parent; if a moved
2722 	 * child node has children, reattach the parent pointers of
2723 	 * grandchildren
2724 	 */
2725         for (i = 0; i < p->sysctl_csize; i++) {
2726                 n[i].sysctl_parent = p;
2727 		if (n[i].sysctl_child != NULL) {
2728 			for (j = 0; j < n[i].sysctl_csize; j++)
2729 				n[i].sysctl_child[j].sysctl_parent = &n[i];
2730 		}
2731 	}
2732 
2733 	/*
2734 	 * get out with the old and in with the new
2735 	 */
2736 	free(p->sysctl_child, M_SYSCTLNODE);
2737 	p->sysctl_child = n;
2738 
2739 	return (0);
2740 }
2741 
2742 static int
sysctl_log_realloc(struct sysctllog * log)2743 sysctl_log_realloc(struct sysctllog *log)
2744 {
2745 	int *n, s, d;
2746 
2747 	s = log->log_size * 2;
2748 	d = log->log_size;
2749 
2750 	n = malloc(s * sizeof(int), M_SYSCTLDATA, M_WAITOK);
2751 	if (n == NULL)
2752 		return (-1);
2753 
2754 	memset(n, 0, s * sizeof(int));
2755 	memcpy(&n[d], log->log_num, d * sizeof(int));
2756 	free(log->log_num, M_SYSCTLDATA);
2757 	log->log_num = n;
2758 	if (d)
2759 		log->log_left += d;
2760 	else
2761 		log->log_left = s;
2762 	log->log_size = s;
2763 
2764 	return (0);
2765 }
2766 
2767 /*
2768  * ********************************************************************
2769  * Section 6: Conversion between API versions wrt the sysctlnode
2770  * ********************************************************************
2771  */
2772 static int
sysctl_cvt_in(struct lwp * l,int * vp,const void * i,size_t sz,struct sysctlnode * node)2773 sysctl_cvt_in(struct lwp *l, int *vp, const void *i, size_t sz,
2774 	      struct sysctlnode *node)
2775 {
2776 	int error, flags;
2777 
2778 	if (i == NULL || sz < sizeof(flags))
2779 		return (EINVAL);
2780 
2781 	error = sysctl_copyin(l, i, &flags, sizeof(flags));
2782 	if (error)
2783 		return (error);
2784 
2785 #if (SYSCTL_VERSION != SYSCTL_VERS_1)
2786 #error sysctl_cvt_in: no support for SYSCTL_VERSION
2787 #endif /*  (SYSCTL_VERSION != SYSCTL_VERS_1) */
2788 
2789 	if (sz == sizeof(*node) &&
2790 	    SYSCTL_VERS(flags) == SYSCTL_VERSION) {
2791 		error = sysctl_copyin(l, i, node, sizeof(*node));
2792 		if (error)
2793 			return (error);
2794 		*vp = SYSCTL_VERSION;
2795 		return (0);
2796 	}
2797 
2798 	return (EINVAL);
2799 }
2800 
2801 static int
sysctl_cvt_out(struct lwp * l,int v,const struct sysctlnode * i,void * ovp,size_t left,size_t * szp)2802 sysctl_cvt_out(struct lwp *l, int v, const struct sysctlnode *i,
2803 	       void *ovp, size_t left, size_t *szp)
2804 {
2805 	size_t sz = sizeof(*i);
2806 	const void *src = i;
2807 	int error;
2808 
2809 	switch (v) {
2810 	case SYSCTL_VERS_0:
2811 		return (EINVAL);
2812 
2813 #if (SYSCTL_VERSION != SYSCTL_VERS_1)
2814 #error sysctl_cvt_out: no support for SYSCTL_VERSION
2815 #endif /*  (SYSCTL_VERSION != SYSCTL_VERS_1) */
2816 
2817 	case SYSCTL_VERSION:
2818 		/* nothing more to do here */
2819 		break;
2820 	}
2821 
2822 	if (ovp != NULL && left >= sz) {
2823 		error = sysctl_copyout(l, src, ovp, sz);
2824 		if (error)
2825 			return (error);
2826 	}
2827 
2828 	if (szp != NULL)
2829 		*szp = sz;
2830 
2831 	return (0);
2832 }
2833 
2834 static uint8_t address_key[32];	/* key used in address hashing */
2835 static ONCE_DECL(random_inithook);
2836 
2837 static int
random_address_init(void)2838 random_address_init(void)
2839 {
2840 
2841 	cprng_strong(kern_cprng, address_key, sizeof(address_key), 0);
2842 	return 0;
2843 }
2844 
2845 void
hash_value(void * d,size_t ds,const void * s,size_t ss)2846 hash_value(void *d, size_t ds, const void *s, size_t ss)
2847 {
2848 
2849 	RUN_ONCE(&random_inithook, random_address_init);
2850 	blake2s(d, ds, address_key, sizeof(address_key), s, ss);
2851 }
2852