xref: /freebsd/sys/kern/kern_sysctl.c (revision 7660b554bc59a07be0431c17e0e33815818baa69)
1 /*-
2  * Copyright (c) 1982, 1986, 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Mike Karels at Berkeley Software Design, Inc.
7  *
8  * Quite extensively rewritten by Poul-Henning Kamp of the FreeBSD
9  * project, to make these variables more userfriendly.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by the University of
22  *	California, Berkeley and its contributors.
23  * 4. Neither the name of the University nor the names of its contributors
24  *    may be used to endorse or promote products derived from this software
25  *    without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  *
39  *	@(#)kern_sysctl.c	8.4 (Berkeley) 4/14/94
40  */
41 
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
44 
45 #include "opt_compat.h"
46 #include "opt_mac.h"
47 
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/kernel.h>
51 #include <sys/sysctl.h>
52 #include <sys/mac.h>
53 #include <sys/malloc.h>
54 #include <sys/proc.h>
55 #include <sys/lock.h>
56 #include <sys/mutex.h>
57 #include <sys/sx.h>
58 #include <sys/sysproto.h>
59 #include <vm/vm.h>
60 #include <vm/vm_extern.h>
61 
62 static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic");
63 static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids");
64 static MALLOC_DEFINE(M_SYSCTLTMP, "sysctltmp", "sysctl temp output buffer");
65 
66 /*
67  * Locking - this locks the sysctl tree in memory.
68  */
69 static struct sx sysctllock;
70 
71 #define	SYSCTL_LOCK()		sx_xlock(&sysctllock)
72 #define	SYSCTL_UNLOCK()		sx_xunlock(&sysctllock)
73 #define	SYSCTL_INIT()		sx_init(&sysctllock, "sysctl lock")
74 
75 static int sysctl_root(SYSCTL_HANDLER_ARGS);
76 
77 struct sysctl_oid_list sysctl__children; /* root list */
78 
79 static struct sysctl_oid *
80 sysctl_find_oidname(const char *name, struct sysctl_oid_list *list)
81 {
82 	struct sysctl_oid *oidp;
83 
84 	SLIST_FOREACH(oidp, list, oid_link) {
85 		if (strcmp(oidp->oid_name, name) == 0) {
86 			return (oidp);
87 		}
88 	}
89 	return (NULL);
90 }
91 
92 /*
93  * Initialization of the MIB tree.
94  *
95  * Order by number in each list.
96  */
97 
98 void
99 sysctl_register_oid(struct sysctl_oid *oidp)
100 {
101 	struct sysctl_oid_list *parent = oidp->oid_parent;
102 	struct sysctl_oid *p;
103 	struct sysctl_oid *q;
104 
105 	/*
106 	 * First check if another oid with the same name already
107 	 * exists in the parent's list.
108 	 */
109 	p = sysctl_find_oidname(oidp->oid_name, parent);
110 	if (p != NULL) {
111 		if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
112 			p->oid_refcnt++;
113 			return;
114 		} else {
115 			printf("can't re-use a leaf (%s)!\n", p->oid_name);
116 			return;
117 		}
118 	}
119 	/*
120 	 * If this oid has a number OID_AUTO, give it a number which
121 	 * is greater than any current oid.
122 	 * NOTE: DO NOT change the starting value here, change it in
123 	 * <sys/sysctl.h>, and make sure it is at least 256 to
124 	 * accomodate e.g. net.inet.raw as a static sysctl node.
125 	 */
126 	if (oidp->oid_number == OID_AUTO) {
127 		static int newoid = CTL_AUTO_START;
128 
129 		oidp->oid_number = newoid++;
130 		if (newoid == 0x7fffffff)
131 			panic("out of oids");
132 	}
133 #if 0
134 	else if (oidp->oid_number >= CTL_AUTO_START) {
135 		/* do not panic; this happens when unregistering sysctl sets */
136 		printf("static sysctl oid too high: %d", oidp->oid_number);
137 	}
138 #endif
139 
140 	/*
141 	 * Insert the oid into the parent's list in order.
142 	 */
143 	q = NULL;
144 	SLIST_FOREACH(p, parent, oid_link) {
145 		if (oidp->oid_number < p->oid_number)
146 			break;
147 		q = p;
148 	}
149 	if (q)
150 		SLIST_INSERT_AFTER(q, oidp, oid_link);
151 	else
152 		SLIST_INSERT_HEAD(parent, oidp, oid_link);
153 }
154 
155 void
156 sysctl_unregister_oid(struct sysctl_oid *oidp)
157 {
158 	struct sysctl_oid *p;
159 	int error;
160 
161 	error = ENOENT;
162 	if (oidp->oid_number == OID_AUTO) {
163 		error = EINVAL;
164 	} else {
165 		SLIST_FOREACH(p, oidp->oid_parent, oid_link) {
166 			if (p == oidp) {
167 				SLIST_REMOVE(oidp->oid_parent, oidp,
168 				    sysctl_oid, oid_link);
169 				error = 0;
170 				break;
171 			}
172 		}
173 	}
174 
175 	/*
176 	 * This can happen when a module fails to register and is
177 	 * being unloaded afterwards.  It should not be a panic()
178 	 * for normal use.
179 	 */
180 	if (error)
181 		printf("%s: failed to unregister sysctl\n", __func__);
182 }
183 
184 /* Initialize a new context to keep track of dynamically added sysctls. */
185 int
186 sysctl_ctx_init(struct sysctl_ctx_list *c)
187 {
188 
189 	if (c == NULL) {
190 		return (EINVAL);
191 	}
192 	TAILQ_INIT(c);
193 	return (0);
194 }
195 
196 /* Free the context, and destroy all dynamic oids registered in this context */
197 int
198 sysctl_ctx_free(struct sysctl_ctx_list *clist)
199 {
200 	struct sysctl_ctx_entry *e, *e1;
201 	int error;
202 
203 	error = 0;
204 	/*
205 	 * First perform a "dry run" to check if it's ok to remove oids.
206 	 * XXX FIXME
207 	 * XXX This algorithm is a hack. But I don't know any
208 	 * XXX better solution for now...
209 	 */
210 	TAILQ_FOREACH(e, clist, link) {
211 		error = sysctl_remove_oid(e->entry, 0, 0);
212 		if (error)
213 			break;
214 	}
215 	/*
216 	 * Restore deregistered entries, either from the end,
217 	 * or from the place where error occured.
218 	 * e contains the entry that was not unregistered
219 	 */
220 	if (error)
221 		e1 = TAILQ_PREV(e, sysctl_ctx_list, link);
222 	else
223 		e1 = TAILQ_LAST(clist, sysctl_ctx_list);
224 	while (e1 != NULL) {
225 		sysctl_register_oid(e1->entry);
226 		e1 = TAILQ_PREV(e1, sysctl_ctx_list, link);
227 	}
228 	if (error)
229 		return(EBUSY);
230 	/* Now really delete the entries */
231 	e = TAILQ_FIRST(clist);
232 	while (e != NULL) {
233 		e1 = TAILQ_NEXT(e, link);
234 		error = sysctl_remove_oid(e->entry, 1, 0);
235 		if (error)
236 			panic("sysctl_remove_oid: corrupt tree, entry: %s",
237 			    e->entry->oid_name);
238 		free(e, M_SYSCTLOID);
239 		e = e1;
240 	}
241 	return (error);
242 }
243 
244 /* Add an entry to the context */
245 struct sysctl_ctx_entry *
246 sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
247 {
248 	struct sysctl_ctx_entry *e;
249 
250 	if (clist == NULL || oidp == NULL)
251 		return(NULL);
252 	e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK);
253 	e->entry = oidp;
254 	TAILQ_INSERT_HEAD(clist, e, link);
255 	return (e);
256 }
257 
258 /* Find an entry in the context */
259 struct sysctl_ctx_entry *
260 sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
261 {
262 	struct sysctl_ctx_entry *e;
263 
264 	if (clist == NULL || oidp == NULL)
265 		return(NULL);
266 	TAILQ_FOREACH(e, clist, link) {
267 		if(e->entry == oidp)
268 			return(e);
269 	}
270 	return (e);
271 }
272 
273 /*
274  * Delete an entry from the context.
275  * NOTE: this function doesn't free oidp! You have to remove it
276  * with sysctl_remove_oid().
277  */
278 int
279 sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
280 {
281 	struct sysctl_ctx_entry *e;
282 
283 	if (clist == NULL || oidp == NULL)
284 		return (EINVAL);
285 	e = sysctl_ctx_entry_find(clist, oidp);
286 	if (e != NULL) {
287 		TAILQ_REMOVE(clist, e, link);
288 		free(e, M_SYSCTLOID);
289 		return (0);
290 	} else
291 		return (ENOENT);
292 }
293 
294 /*
295  * Remove dynamically created sysctl trees.
296  * oidp - top of the tree to be removed
297  * del - if 0 - just deregister, otherwise free up entries as well
298  * recurse - if != 0 traverse the subtree to be deleted
299  */
300 int
301 sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse)
302 {
303 	struct sysctl_oid *p;
304 	int error;
305 
306 	if (oidp == NULL)
307 		return(EINVAL);
308 	if ((oidp->oid_kind & CTLFLAG_DYN) == 0) {
309 		printf("can't remove non-dynamic nodes!\n");
310 		return (EINVAL);
311 	}
312 	/*
313 	 * WARNING: normal method to do this should be through
314 	 * sysctl_ctx_free(). Use recursing as the last resort
315 	 * method to purge your sysctl tree of leftovers...
316 	 * However, if some other code still references these nodes,
317 	 * it will panic.
318 	 */
319 	if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
320 		if (oidp->oid_refcnt == 1) {
321 			SLIST_FOREACH(p, SYSCTL_CHILDREN(oidp), oid_link) {
322 				if (!recurse)
323 					return (ENOTEMPTY);
324 				error = sysctl_remove_oid(p, del, recurse);
325 				if (error)
326 					return (error);
327 			}
328 			if (del)
329 				free(SYSCTL_CHILDREN(oidp), M_SYSCTLOID);
330 		}
331 	}
332 	if (oidp->oid_refcnt > 1 ) {
333 		oidp->oid_refcnt--;
334 	} else {
335 		if (oidp->oid_refcnt == 0) {
336 			printf("Warning: bad oid_refcnt=%u (%s)!\n",
337 				oidp->oid_refcnt, oidp->oid_name);
338 			return (EINVAL);
339 		}
340 		sysctl_unregister_oid(oidp);
341 		if (del) {
342 			if (oidp->descr)
343 				free((void *)(uintptr_t)(const void *)oidp->descr, M_SYSCTLOID);
344 			free((void *)(uintptr_t)(const void *)oidp->oid_name,
345 			     M_SYSCTLOID);
346 			free(oidp, M_SYSCTLOID);
347 		}
348 	}
349 	return (0);
350 }
351 
352 /*
353  * Create new sysctls at run time.
354  * clist may point to a valid context initialized with sysctl_ctx_init().
355  */
356 struct sysctl_oid *
357 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent,
358 	int number, const char *name, int kind, void *arg1, int arg2,
359 	int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr)
360 {
361 	struct sysctl_oid *oidp;
362 	ssize_t len;
363 	char *newname;
364 
365 	/* You have to hook up somewhere.. */
366 	if (parent == NULL)
367 		return(NULL);
368 	/* Check if the node already exists, otherwise create it */
369 	oidp = sysctl_find_oidname(name, parent);
370 	if (oidp != NULL) {
371 		if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
372 			oidp->oid_refcnt++;
373 			/* Update the context */
374 			if (clist != NULL)
375 				sysctl_ctx_entry_add(clist, oidp);
376 			return (oidp);
377 		} else {
378 			printf("can't re-use a leaf (%s)!\n", name);
379 			return (NULL);
380 		}
381 	}
382 	oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO);
383 	oidp->oid_parent = parent;
384 	SLIST_NEXT(oidp, oid_link) = NULL;
385 	oidp->oid_number = number;
386 	oidp->oid_refcnt = 1;
387 	len = strlen(name);
388 	newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK);
389 	bcopy(name, newname, len + 1);
390 	newname[len] = '\0';
391 	oidp->oid_name = newname;
392 	oidp->oid_handler = handler;
393 	oidp->oid_kind = CTLFLAG_DYN | kind;
394 	if ((kind & CTLTYPE) == CTLTYPE_NODE) {
395 		/* Allocate space for children */
396 		SYSCTL_CHILDREN(oidp) = malloc(sizeof(struct sysctl_oid_list),
397 		    M_SYSCTLOID, M_WAITOK);
398 		SLIST_INIT(SYSCTL_CHILDREN(oidp));
399 	} else {
400 		oidp->oid_arg1 = arg1;
401 		oidp->oid_arg2 = arg2;
402 	}
403 	oidp->oid_fmt = fmt;
404 	if (descr) {
405 		int len = strlen(descr) + 1;
406 		oidp->descr = malloc(len, M_SYSCTLOID, M_WAITOK);
407 		if (oidp->descr)
408 			strcpy((char *)(uintptr_t)(const void *)oidp->descr, descr);
409 	}
410 	/* Update the context, if used */
411 	if (clist != NULL)
412 		sysctl_ctx_entry_add(clist, oidp);
413 	/* Register this oid */
414 	sysctl_register_oid(oidp);
415 	return (oidp);
416 }
417 
418 /*
419  * Register the kernel's oids on startup.
420  */
421 SET_DECLARE(sysctl_set, struct sysctl_oid);
422 
423 static void
424 sysctl_register_all(void *arg)
425 {
426 	struct sysctl_oid **oidp;
427 
428 	SYSCTL_INIT();
429 	SET_FOREACH(oidp, sysctl_set)
430 		sysctl_register_oid(*oidp);
431 }
432 SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_ANY, sysctl_register_all, 0);
433 
434 /*
435  * "Staff-functions"
436  *
437  * These functions implement a presently undocumented interface
438  * used by the sysctl program to walk the tree, and get the type
439  * so it can print the value.
440  * This interface is under work and consideration, and should probably
441  * be killed with a big axe by the first person who can find the time.
442  * (be aware though, that the proper interface isn't as obvious as it
443  * may seem, there are various conflicting requirements.
444  *
445  * {0,0}	printf the entire MIB-tree.
446  * {0,1,...}	return the name of the "..." OID.
447  * {0,2,...}	return the next OID.
448  * {0,3}	return the OID of the name in "new"
449  * {0,4,...}	return the kind & format info for the "..." OID.
450  * {0,5,...}	return the description the "..." OID.
451  */
452 
453 static void
454 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i)
455 {
456 	int k;
457 	struct sysctl_oid *oidp;
458 
459 	SLIST_FOREACH(oidp, l, oid_link) {
460 
461 		for (k=0; k<i; k++)
462 			printf(" ");
463 
464 		printf("%d %s ", oidp->oid_number, oidp->oid_name);
465 
466 		printf("%c%c",
467 			oidp->oid_kind & CTLFLAG_RD ? 'R':' ',
468 			oidp->oid_kind & CTLFLAG_WR ? 'W':' ');
469 
470 		if (oidp->oid_handler)
471 			printf(" *Handler");
472 
473 		switch (oidp->oid_kind & CTLTYPE) {
474 			case CTLTYPE_NODE:
475 				printf(" Node\n");
476 				if (!oidp->oid_handler) {
477 					sysctl_sysctl_debug_dump_node(
478 						oidp->oid_arg1, i+2);
479 				}
480 				break;
481 			case CTLTYPE_INT:    printf(" Int\n"); break;
482 			case CTLTYPE_STRING: printf(" String\n"); break;
483 			case CTLTYPE_QUAD:   printf(" Quad\n"); break;
484 			case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break;
485 			default:	     printf("\n");
486 		}
487 
488 	}
489 }
490 
491 static int
492 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS)
493 {
494 	int error;
495 
496 	error = suser(req->td);
497 	if (error)
498 		return error;
499 	sysctl_sysctl_debug_dump_node(&sysctl__children, 0);
500 	return ENOENT;
501 }
502 
503 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD,
504 	0, 0, sysctl_sysctl_debug, "-", "");
505 
506 static int
507 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS)
508 {
509 	int *name = (int *) arg1;
510 	u_int namelen = arg2;
511 	int error = 0;
512 	struct sysctl_oid *oid;
513 	struct sysctl_oid_list *lsp = &sysctl__children, *lsp2;
514 	char buf[10];
515 
516 	while (namelen) {
517 		if (!lsp) {
518 			snprintf(buf,sizeof(buf),"%d",*name);
519 			if (req->oldidx)
520 				error = SYSCTL_OUT(req, ".", 1);
521 			if (!error)
522 				error = SYSCTL_OUT(req, buf, strlen(buf));
523 			if (error)
524 				return (error);
525 			namelen--;
526 			name++;
527 			continue;
528 		}
529 		lsp2 = 0;
530 		SLIST_FOREACH(oid, lsp, oid_link) {
531 			if (oid->oid_number != *name)
532 				continue;
533 
534 			if (req->oldidx)
535 				error = SYSCTL_OUT(req, ".", 1);
536 			if (!error)
537 				error = SYSCTL_OUT(req, oid->oid_name,
538 					strlen(oid->oid_name));
539 			if (error)
540 				return (error);
541 
542 			namelen--;
543 			name++;
544 
545 			if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE)
546 				break;
547 
548 			if (oid->oid_handler)
549 				break;
550 
551 			lsp2 = (struct sysctl_oid_list *)oid->oid_arg1;
552 			break;
553 		}
554 		lsp = lsp2;
555 	}
556 	return (SYSCTL_OUT(req, "", 1));
557 }
558 
559 SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD, sysctl_sysctl_name, "");
560 
561 static int
562 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen,
563 	int *next, int *len, int level, struct sysctl_oid **oidpp)
564 {
565 	struct sysctl_oid *oidp;
566 
567 	*len = level;
568 	SLIST_FOREACH(oidp, lsp, oid_link) {
569 		*next = oidp->oid_number;
570 		*oidpp = oidp;
571 
572 		if (oidp->oid_kind & CTLFLAG_SKIP)
573 			continue;
574 
575 		if (!namelen) {
576 			if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
577 				return 0;
578 			if (oidp->oid_handler)
579 				/* We really should call the handler here...*/
580 				return 0;
581 			lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
582 			if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1,
583 				len, level+1, oidpp))
584 				return 0;
585 			goto emptynode;
586 		}
587 
588 		if (oidp->oid_number < *name)
589 			continue;
590 
591 		if (oidp->oid_number > *name) {
592 			if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
593 				return 0;
594 			if (oidp->oid_handler)
595 				return 0;
596 			lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
597 			if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1,
598 				next+1, len, level+1, oidpp))
599 				return (0);
600 			goto next;
601 		}
602 		if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
603 			continue;
604 
605 		if (oidp->oid_handler)
606 			continue;
607 
608 		lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
609 		if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1,
610 			len, level+1, oidpp))
611 			return (0);
612 	next:
613 		namelen = 1;
614 	emptynode:
615 		*len = level;
616 	}
617 	return 1;
618 }
619 
620 static int
621 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS)
622 {
623 	int *name = (int *) arg1;
624 	u_int namelen = arg2;
625 	int i, j, error;
626 	struct sysctl_oid *oid;
627 	struct sysctl_oid_list *lsp = &sysctl__children;
628 	int newoid[CTL_MAXNAME];
629 
630 	i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid);
631 	if (i)
632 		return ENOENT;
633 	error = SYSCTL_OUT(req, newoid, j * sizeof (int));
634 	return (error);
635 }
636 
637 SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD, sysctl_sysctl_next, "");
638 
639 static int
640 name2oid (char *name, int *oid, int *len, struct sysctl_oid **oidpp)
641 {
642 	int i;
643 	struct sysctl_oid *oidp;
644 	struct sysctl_oid_list *lsp = &sysctl__children;
645 	char *p;
646 
647 	if (!*name)
648 		return ENOENT;
649 
650 	p = name + strlen(name) - 1 ;
651 	if (*p == '.')
652 		*p = '\0';
653 
654 	*len = 0;
655 
656 	for (p = name; *p && *p != '.'; p++)
657 		;
658 	i = *p;
659 	if (i == '.')
660 		*p = '\0';
661 
662 	oidp = SLIST_FIRST(lsp);
663 
664 	while (oidp && *len < CTL_MAXNAME) {
665 		if (strcmp(name, oidp->oid_name)) {
666 			oidp = SLIST_NEXT(oidp, oid_link);
667 			continue;
668 		}
669 		*oid++ = oidp->oid_number;
670 		(*len)++;
671 
672 		if (!i) {
673 			if (oidpp)
674 				*oidpp = oidp;
675 			return (0);
676 		}
677 
678 		if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
679 			break;
680 
681 		if (oidp->oid_handler)
682 			break;
683 
684 		lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
685 		oidp = SLIST_FIRST(lsp);
686 		name = p+1;
687 		for (p = name; *p && *p != '.'; p++)
688 				;
689 		i = *p;
690 		if (i == '.')
691 			*p = '\0';
692 	}
693 	return ENOENT;
694 }
695 
696 static int
697 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS)
698 {
699 	char *p;
700 	int error, oid[CTL_MAXNAME], len;
701 	struct sysctl_oid *op = 0;
702 
703 	if (!req->newlen)
704 		return ENOENT;
705 	if (req->newlen >= MAXPATHLEN)	/* XXX arbitrary, undocumented */
706 		return (ENAMETOOLONG);
707 
708 	p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK);
709 
710 	error = SYSCTL_IN(req, p, req->newlen);
711 	if (error) {
712 		free(p, M_SYSCTL);
713 		return (error);
714 	}
715 
716 	p [req->newlen] = '\0';
717 
718 	error = name2oid(p, oid, &len, &op);
719 
720 	free(p, M_SYSCTL);
721 
722 	if (error)
723 		return (error);
724 
725 	error = SYSCTL_OUT(req, oid, len * sizeof *oid);
726 	return (error);
727 }
728 
729 SYSCTL_PROC(_sysctl, 3, name2oid, CTLFLAG_RW|CTLFLAG_ANYBODY, 0, 0,
730 	sysctl_sysctl_name2oid, "I", "");
731 
732 static int
733 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS)
734 {
735 	struct sysctl_oid *oid;
736 	int error;
737 
738 	error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
739 	if (error)
740 		return (error);
741 
742 	if (!oid->oid_fmt)
743 		return (ENOENT);
744 	error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind));
745 	if (error)
746 		return (error);
747 	error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1);
748 	return (error);
749 }
750 
751 
752 SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD, sysctl_sysctl_oidfmt, "");
753 
754 static int
755 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS)
756 {
757 	struct sysctl_oid *oid;
758 	int error;
759 
760 	error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
761 	if (error)
762 		return (error);
763 
764 	if (!oid->descr)
765 		return (ENOENT);
766 	error = SYSCTL_OUT(req, oid->descr, strlen(oid->descr) + 1);
767 	return (error);
768 }
769 
770 SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD, sysctl_sysctl_oiddescr, "");
771 
772 /*
773  * Default "handler" functions.
774  */
775 
776 /*
777  * Handle an int, signed or unsigned.
778  * Two cases:
779  *     a variable:  point arg1 at it.
780  *     a constant:  pass it in arg2.
781  */
782 
783 int
784 sysctl_handle_int(SYSCTL_HANDLER_ARGS)
785 {
786 	int tmpout, error = 0;
787 
788 	/*
789 	 * Attempt to get a coherent snapshot by making a copy of the data.
790 	 */
791 	if (arg1)
792 		tmpout = *(int *)arg1;
793 	else
794 		tmpout = arg2;
795 	error = SYSCTL_OUT(req, &tmpout, sizeof(int));
796 
797 	if (error || !req->newptr)
798 		return (error);
799 
800 	if (!arg1)
801 		error = EPERM;
802 	else
803 		error = SYSCTL_IN(req, arg1, sizeof(int));
804 	return (error);
805 }
806 
807 /*
808  * Handle a long, signed or unsigned.  arg1 points to it.
809  */
810 
811 int
812 sysctl_handle_long(SYSCTL_HANDLER_ARGS)
813 {
814 	int error = 0;
815 	long tmpout;
816 
817 	/*
818 	 * Attempt to get a coherent snapshot by making a copy of the data.
819 	 */
820 	if (!arg1)
821 		return (EINVAL);
822 	tmpout = *(long *)arg1;
823 	error = SYSCTL_OUT(req, &tmpout, sizeof(long));
824 
825 	if (error || !req->newptr)
826 		return (error);
827 
828 	error = SYSCTL_IN(req, arg1, sizeof(long));
829 	return (error);
830 }
831 
832 /*
833  * Handle our generic '\0' terminated 'C' string.
834  * Two cases:
835  * 	a variable string:  point arg1 at it, arg2 is max length.
836  * 	a constant string:  point arg1 at it, arg2 is zero.
837  */
838 
839 int
840 sysctl_handle_string(SYSCTL_HANDLER_ARGS)
841 {
842 	int error=0;
843 	char *tmparg;
844 	size_t outlen;
845 
846 	/*
847 	 * Attempt to get a coherent snapshot by copying to a
848 	 * temporary kernel buffer.
849 	 */
850 retry:
851 	outlen = strlen((char *)arg1)+1;
852 	tmparg = malloc(outlen, M_SYSCTLTMP, M_WAITOK);
853 
854 	if (strlcpy(tmparg, (char *)arg1, outlen) >= outlen) {
855 		free(tmparg, M_SYSCTLTMP);
856 		goto retry;
857 	}
858 
859 	error = SYSCTL_OUT(req, tmparg, outlen);
860 	free(tmparg, M_SYSCTLTMP);
861 
862 	if (error || !req->newptr)
863 		return (error);
864 
865 	if ((req->newlen - req->newidx) >= arg2) {
866 		error = EINVAL;
867 	} else {
868 		arg2 = (req->newlen - req->newidx);
869 		error = SYSCTL_IN(req, arg1, arg2);
870 		((char *)arg1)[arg2] = '\0';
871 	}
872 
873 	return (error);
874 }
875 
876 /*
877  * Handle any kind of opaque data.
878  * arg1 points to it, arg2 is the size.
879  */
880 
881 int
882 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS)
883 {
884 	int error;
885 	void *tmparg;
886 
887 	/*
888 	 * Attempt to get a coherent snapshot, either by wiring the
889 	 * user space buffer or copying to a temporary kernel buffer
890 	 * depending on the size of the data.
891 	 */
892 	if (arg2 > PAGE_SIZE) {
893 		sysctl_wire_old_buffer(req, arg2);
894 		error = SYSCTL_OUT(req, arg1, arg2);
895 	} else {
896 		tmparg = malloc(arg2, M_SYSCTLTMP, M_WAITOK);
897 		bcopy(arg1, tmparg, arg2);
898 		error = SYSCTL_OUT(req, tmparg, arg2);
899 		free(tmparg, M_SYSCTLTMP);
900 	}
901 
902 	if (error || !req->newptr)
903 		return (error);
904 
905 	error = SYSCTL_IN(req, arg1, arg2);
906 
907 	return (error);
908 }
909 
910 /*
911  * Transfer functions to/from kernel space.
912  * XXX: rather untested at this point
913  */
914 static int
915 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l)
916 {
917 	size_t i = 0;
918 
919 	if (req->oldptr) {
920 		i = l;
921 		if (req->oldlen <= req->oldidx)
922 			i = 0;
923 		else
924 			if (i > req->oldlen - req->oldidx)
925 				i = req->oldlen - req->oldidx;
926 		if (i > 0)
927 			bcopy(p, (char *)req->oldptr + req->oldidx, i);
928 	}
929 	req->oldidx += l;
930 	if (req->oldptr && i != l)
931 		return (ENOMEM);
932 	return (0);
933 }
934 
935 static int
936 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l)
937 {
938 	if (!req->newptr)
939 		return 0;
940 	if (req->newlen - req->newidx < l)
941 		return (EINVAL);
942 	bcopy((char *)req->newptr + req->newidx, p, l);
943 	req->newidx += l;
944 	return (0);
945 }
946 
947 int
948 kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old,
949     size_t *oldlenp, void *new, size_t newlen, size_t *retval)
950 {
951 	int error = 0;
952 	struct sysctl_req req;
953 
954 	bzero(&req, sizeof req);
955 
956 	req.td = td;
957 
958 	if (oldlenp) {
959 		req.oldlen = *oldlenp;
960 	}
961 
962 	if (old) {
963 		req.oldptr= old;
964 	}
965 
966 	if (new != NULL) {
967 		req.newlen = newlen;
968 		req.newptr = new;
969 	}
970 
971 	req.oldfunc = sysctl_old_kernel;
972 	req.newfunc = sysctl_new_kernel;
973 	req.lock = 1;
974 
975 	SYSCTL_LOCK();
976 
977 	error = sysctl_root(0, name, namelen, &req);
978 
979 	if (req.lock == 2)
980 		vsunlock(req.oldptr, req.oldlen);
981 
982 	SYSCTL_UNLOCK();
983 
984 	if (error && error != ENOMEM)
985 		return (error);
986 
987 	if (retval) {
988 		if (req.oldptr && req.oldidx > req.oldlen)
989 			*retval = req.oldlen;
990 		else
991 			*retval = req.oldidx;
992 	}
993 	return (error);
994 }
995 
996 int
997 kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp,
998     void *new, size_t newlen, size_t *retval)
999 {
1000         int oid[CTL_MAXNAME];
1001         size_t oidlen, plen;
1002 	int error;
1003 
1004 	oid[0] = 0;		/* sysctl internal magic */
1005 	oid[1] = 3;		/* name2oid */
1006 	oidlen = sizeof(oid);
1007 
1008 	error = kernel_sysctl(td, oid, 2, oid, &oidlen,
1009 	    (void *)name, strlen(name), &plen);
1010 	if (error)
1011 		return (error);
1012 
1013 	error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp,
1014 	    new, newlen, retval);
1015 	return (error);
1016 }
1017 
1018 /*
1019  * Transfer function to/from user space.
1020  */
1021 static int
1022 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l)
1023 {
1024 	int error = 0;
1025 	size_t i = 0;
1026 
1027 	if (req->lock == 1 && req->oldptr)
1028 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
1029 		    "sysctl_old_user()");
1030 	if (req->oldptr) {
1031 		i = l;
1032 		if (req->oldlen <= req->oldidx)
1033 			i = 0;
1034 		else
1035 			if (i > req->oldlen - req->oldidx)
1036 				i = req->oldlen - req->oldidx;
1037 		if (i > 0)
1038 			error = copyout(p, (char *)req->oldptr + req->oldidx,
1039 					i);
1040 	}
1041 	req->oldidx += l;
1042 	if (error)
1043 		return (error);
1044 	if (req->oldptr && i < l)
1045 		return (ENOMEM);
1046 	return (0);
1047 }
1048 
1049 static int
1050 sysctl_new_user(struct sysctl_req *req, void *p, size_t l)
1051 {
1052 	int error;
1053 
1054 	if (!req->newptr)
1055 		return 0;
1056 	if (req->newlen - req->newidx < l)
1057 		return (EINVAL);
1058 	error = copyin((char *)req->newptr + req->newidx, p, l);
1059 	req->newidx += l;
1060 	return (error);
1061 }
1062 
1063 /*
1064  * Wire the user space destination buffer.  If set to a value greater than
1065  * zero, the len parameter limits the maximum amount of wired memory.
1066  *
1067  * XXX - The len parameter is currently ignored due to the lack of
1068  * a place to save it in the sysctl_req structure so that the matching
1069  * amount of memory can be unwired in the sysctl exit code.
1070  */
1071 void
1072 sysctl_wire_old_buffer(struct sysctl_req *req, size_t len)
1073 {
1074 	if (req->lock == 1 && req->oldptr && req->oldfunc == sysctl_old_user) {
1075 		vslock(req->oldptr, req->oldlen);
1076 		req->lock = 2;
1077 	}
1078 }
1079 
1080 int
1081 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid,
1082     int *nindx, struct sysctl_req *req)
1083 {
1084 	struct sysctl_oid *oid;
1085 	int indx;
1086 
1087 	oid = SLIST_FIRST(&sysctl__children);
1088 	indx = 0;
1089 	while (oid && indx < CTL_MAXNAME) {
1090 		if (oid->oid_number == name[indx]) {
1091 			indx++;
1092 			if (oid->oid_kind & CTLFLAG_NOLOCK)
1093 				req->lock = 0;
1094 			if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1095 				if (oid->oid_handler != NULL ||
1096 				    indx == namelen) {
1097 					*noid = oid;
1098 					if (nindx != NULL)
1099 						*nindx = indx;
1100 					return (0);
1101 				}
1102 				oid = SLIST_FIRST(
1103 				    (struct sysctl_oid_list *)oid->oid_arg1);
1104 			} else if (indx == namelen) {
1105 				*noid = oid;
1106 				if (nindx != NULL)
1107 					*nindx = indx;
1108 				return (0);
1109 			} else {
1110 				return (ENOTDIR);
1111 			}
1112 		} else {
1113 			oid = SLIST_NEXT(oid, oid_link);
1114 		}
1115 	}
1116 	return (ENOENT);
1117 }
1118 
1119 /*
1120  * Traverse our tree, and find the right node, execute whatever it points
1121  * to, and return the resulting error code.
1122  */
1123 
1124 static int
1125 sysctl_root(SYSCTL_HANDLER_ARGS)
1126 {
1127 	struct sysctl_oid *oid;
1128 	int error, indx, lvl;
1129 
1130 	error = sysctl_find_oid(arg1, arg2, &oid, &indx, req);
1131 	if (error)
1132 		return (error);
1133 
1134 	if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1135 		/*
1136 		 * You can't call a sysctl when it's a node, but has
1137 		 * no handler.  Inform the user that it's a node.
1138 		 * The indx may or may not be the same as namelen.
1139 		 */
1140 		if (oid->oid_handler == NULL)
1141 			return (EISDIR);
1142 	}
1143 
1144 	/* Is this sysctl writable? */
1145 	if (req->newptr && !(oid->oid_kind & CTLFLAG_WR))
1146 		return (EPERM);
1147 
1148 	KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL"));
1149 
1150 	/* Is this sysctl sensitive to securelevels? */
1151 	if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) {
1152 		lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE;
1153 		error = securelevel_gt(req->td->td_ucred, lvl);
1154 		if (error)
1155 			return (error);
1156 	}
1157 
1158 	/* Is this sysctl writable by only privileged users? */
1159 	if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) {
1160 		int flags;
1161 
1162 		if (oid->oid_kind & CTLFLAG_PRISON)
1163 			flags = PRISON_ROOT;
1164 		else
1165 			flags = 0;
1166 		error = suser_cred(req->td->td_ucred, flags);
1167 		if (error)
1168 			return (error);
1169 	}
1170 
1171 	if (!oid->oid_handler)
1172 		return EINVAL;
1173 
1174 	if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE)
1175 		error = oid->oid_handler(oid, (int *)arg1 + indx, arg2 - indx,
1176 		    req);
1177 	else
1178 		error = oid->oid_handler(oid, oid->oid_arg1, oid->oid_arg2,
1179 		    req);
1180 	return (error);
1181 }
1182 
1183 #ifndef _SYS_SYSPROTO_H_
1184 struct sysctl_args {
1185 	int	*name;
1186 	u_int	namelen;
1187 	void	*old;
1188 	size_t	*oldlenp;
1189 	void	*new;
1190 	size_t	newlen;
1191 };
1192 #endif
1193 
1194 /*
1195  * MPSAFE
1196  */
1197 int
1198 __sysctl(struct thread *td, struct sysctl_args *uap)
1199 {
1200 	int error, name[CTL_MAXNAME];
1201 	size_t j;
1202 
1203 	if (uap->namelen > CTL_MAXNAME || uap->namelen < 2)
1204 		return (EINVAL);
1205 
1206  	error = copyin(uap->name, &name, uap->namelen * sizeof(int));
1207  	if (error)
1208 		return (error);
1209 
1210 	mtx_lock(&Giant);
1211 
1212 	error = userland_sysctl(td, name, uap->namelen,
1213 		uap->old, uap->oldlenp, 0,
1214 		uap->new, uap->newlen, &j);
1215 	if (error && error != ENOMEM)
1216 		goto done2;
1217 	if (uap->oldlenp) {
1218 		int i = copyout(&j, uap->oldlenp, sizeof(j));
1219 		if (i)
1220 			error = i;
1221 	}
1222 done2:
1223 	mtx_unlock(&Giant);
1224 	return (error);
1225 }
1226 
1227 /*
1228  * This is used from various compatibility syscalls too.  That's why name
1229  * must be in kernel space.
1230  */
1231 int
1232 userland_sysctl(struct thread *td, int *name, u_int namelen, void *old,
1233     size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval)
1234 {
1235 	int error = 0;
1236 	struct sysctl_req req, req2;
1237 
1238 	bzero(&req, sizeof req);
1239 
1240 	req.td = td;
1241 
1242 	if (oldlenp) {
1243 		if (inkernel) {
1244 			req.oldlen = *oldlenp;
1245 		} else {
1246 			error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp));
1247 			if (error)
1248 				return (error);
1249 		}
1250 	}
1251 
1252 	if (old) {
1253 		if (!useracc(old, req.oldlen, VM_PROT_WRITE))
1254 			return (EFAULT);
1255 		req.oldptr= old;
1256 	}
1257 
1258 	if (new != NULL) {
1259 		if (!useracc(new, req.newlen, VM_PROT_READ))
1260 			return (EFAULT);
1261 		req.newlen = newlen;
1262 		req.newptr = new;
1263 	}
1264 
1265 	req.oldfunc = sysctl_old_user;
1266 	req.newfunc = sysctl_new_user;
1267 	req.lock = 1;
1268 
1269 	SYSCTL_LOCK();
1270 
1271 #ifdef MAC
1272 	error = mac_check_system_sysctl(td->td_ucred, name, namelen, old,
1273 	    oldlenp, inkernel, new, newlen);
1274 	if (error) {
1275 		SYSCTL_UNLOCK();
1276 		return (error);
1277 	}
1278 #endif
1279 
1280 	do {
1281 	    req2 = req;
1282 	    error = sysctl_root(0, name, namelen, &req2);
1283 	} while (error == EAGAIN);
1284 
1285 	req = req2;
1286 	if (req.lock == 2)
1287 		vsunlock(req.oldptr, req.oldlen);
1288 
1289 	SYSCTL_UNLOCK();
1290 
1291 	if (error && error != ENOMEM)
1292 		return (error);
1293 
1294 	if (retval) {
1295 		if (req.oldptr && req.oldidx > req.oldlen)
1296 			*retval = req.oldlen;
1297 		else
1298 			*retval = req.oldidx;
1299 	}
1300 	return (error);
1301 }
1302 
1303 #ifdef COMPAT_43
1304 #include <sys/socket.h>
1305 #include <vm/vm_param.h>
1306 
1307 #define	KINFO_PROC		(0<<8)
1308 #define	KINFO_RT		(1<<8)
1309 #define	KINFO_VNODE		(2<<8)
1310 #define	KINFO_FILE		(3<<8)
1311 #define	KINFO_METER		(4<<8)
1312 #define	KINFO_LOADAVG		(5<<8)
1313 #define	KINFO_CLOCKRATE		(6<<8)
1314 
1315 /* Non-standard BSDI extension - only present on their 4.3 net-2 releases */
1316 #define	KINFO_BSDI_SYSINFO	(101<<8)
1317 
1318 /*
1319  * XXX this is bloat, but I hope it's better here than on the potentially
1320  * limited kernel stack...  -Peter
1321  */
1322 
1323 static struct {
1324 	int	bsdi_machine;		/* "i386" on BSD/386 */
1325 /*      ^^^ this is an offset to the string, relative to the struct start */
1326 	char	*pad0;
1327 	long	pad1;
1328 	long	pad2;
1329 	long	pad3;
1330 	u_long	pad4;
1331 	u_long	pad5;
1332 	u_long	pad6;
1333 
1334 	int	bsdi_ostype;		/* "BSD/386" on BSD/386 */
1335 	int	bsdi_osrelease;		/* "1.1" on BSD/386 */
1336 	long	pad7;
1337 	long	pad8;
1338 	char	*pad9;
1339 
1340 	long	pad10;
1341 	long	pad11;
1342 	int	pad12;
1343 	long	pad13;
1344 	quad_t	pad14;
1345 	long	pad15;
1346 
1347 	struct	timeval pad16;
1348 	/* we dont set this, because BSDI's uname used gethostname() instead */
1349 	int	bsdi_hostname;		/* hostname on BSD/386 */
1350 
1351 	/* the actual string data is appended here */
1352 
1353 } bsdi_si;
1354 /*
1355  * this data is appended to the end of the bsdi_si structure during copyout.
1356  * The "char *" offsets are relative to the base of the bsdi_si struct.
1357  * This contains "FreeBSD\02.0-BUILT-nnnnnn\0i386\0", and these strings
1358  * should not exceed the length of the buffer here... (or else!! :-)
1359  */
1360 static char bsdi_strings[80];	/* It had better be less than this! */
1361 
1362 #ifndef _SYS_SYSPROTO_H_
1363 struct getkerninfo_args {
1364 	int	op;
1365 	char	*where;
1366 	size_t	*size;
1367 	int	arg;
1368 };
1369 #endif
1370 
1371 /*
1372  * MPSAFE
1373  */
1374 int
1375 ogetkerninfo(struct thread *td, struct getkerninfo_args *uap)
1376 {
1377 	int error, name[6];
1378 	size_t size;
1379 	u_int needed = 0;
1380 
1381 	mtx_lock(&Giant);
1382 
1383 	switch (uap->op & 0xff00) {
1384 
1385 	case KINFO_RT:
1386 		name[0] = CTL_NET;
1387 		name[1] = PF_ROUTE;
1388 		name[2] = 0;
1389 		name[3] = (uap->op & 0xff0000) >> 16;
1390 		name[4] = uap->op & 0xff;
1391 		name[5] = uap->arg;
1392 		error = userland_sysctl(td, name, 6, uap->where, uap->size,
1393 			0, 0, 0, &size);
1394 		break;
1395 
1396 	case KINFO_VNODE:
1397 		name[0] = CTL_KERN;
1398 		name[1] = KERN_VNODE;
1399 		error = userland_sysctl(td, name, 2, uap->where, uap->size,
1400 			0, 0, 0, &size);
1401 		break;
1402 
1403 	case KINFO_PROC:
1404 		name[0] = CTL_KERN;
1405 		name[1] = KERN_PROC;
1406 		name[2] = uap->op & 0xff;
1407 		name[3] = uap->arg;
1408 		error = userland_sysctl(td, name, 4, uap->where, uap->size,
1409 			0, 0, 0, &size);
1410 		break;
1411 
1412 	case KINFO_FILE:
1413 		name[0] = CTL_KERN;
1414 		name[1] = KERN_FILE;
1415 		error = userland_sysctl(td, name, 2, uap->where, uap->size,
1416 			0, 0, 0, &size);
1417 		break;
1418 
1419 	case KINFO_METER:
1420 		name[0] = CTL_VM;
1421 		name[1] = VM_TOTAL;
1422 		error = userland_sysctl(td, name, 2, uap->where, uap->size,
1423 			0, 0, 0, &size);
1424 		break;
1425 
1426 	case KINFO_LOADAVG:
1427 		name[0] = CTL_VM;
1428 		name[1] = VM_LOADAVG;
1429 		error = userland_sysctl(td, name, 2, uap->where, uap->size,
1430 			0, 0, 0, &size);
1431 		break;
1432 
1433 	case KINFO_CLOCKRATE:
1434 		name[0] = CTL_KERN;
1435 		name[1] = KERN_CLOCKRATE;
1436 		error = userland_sysctl(td, name, 2, uap->where, uap->size,
1437 			0, 0, 0, &size);
1438 		break;
1439 
1440 	case KINFO_BSDI_SYSINFO: {
1441 		/*
1442 		 * this is pretty crude, but it's just enough for uname()
1443 		 * from BSDI's 1.x libc to work.
1444 		 *
1445 		 * *size gives the size of the buffer before the call, and
1446 		 * the amount of data copied after a successful call.
1447 		 * If successful, the return value is the amount of data
1448 		 * available, which can be larger than *size.
1449 		 *
1450 		 * BSDI's 2.x product apparently fails with ENOMEM if *size
1451 		 * is too small.
1452 		 */
1453 
1454 		u_int left;
1455 		char *s;
1456 
1457 		bzero((char *)&bsdi_si, sizeof(bsdi_si));
1458 		bzero(bsdi_strings, sizeof(bsdi_strings));
1459 
1460 		s = bsdi_strings;
1461 
1462 		bsdi_si.bsdi_ostype = (s - bsdi_strings) + sizeof(bsdi_si);
1463 		strcpy(s, ostype);
1464 		s += strlen(s) + 1;
1465 
1466 		bsdi_si.bsdi_osrelease = (s - bsdi_strings) + sizeof(bsdi_si);
1467 		strcpy(s, osrelease);
1468 		s += strlen(s) + 1;
1469 
1470 		bsdi_si.bsdi_machine = (s - bsdi_strings) + sizeof(bsdi_si);
1471 		strcpy(s, machine);
1472 		s += strlen(s) + 1;
1473 
1474 		needed = sizeof(bsdi_si) + (s - bsdi_strings);
1475 
1476 		if ((uap->where == NULL) || (uap->size == NULL)) {
1477 			/* process is asking how much buffer to supply.. */
1478 			size = needed;
1479 			error = 0;
1480 			break;
1481 		}
1482 
1483 		if ((error = copyin(uap->size, &size, sizeof(size))) != 0)
1484 			break;
1485 
1486 		/* if too much buffer supplied, trim it down */
1487 		if (size > needed)
1488 			size = needed;
1489 
1490 		/* how much of the buffer is remaining */
1491 		left = size;
1492 
1493 		if ((error = copyout((char *)&bsdi_si, uap->where, left)) != 0)
1494 			break;
1495 
1496 		/* is there any point in continuing? */
1497 		if (left > sizeof(bsdi_si)) {
1498 			left -= sizeof(bsdi_si);
1499 			error = copyout(&bsdi_strings,
1500 					uap->where + sizeof(bsdi_si), left);
1501 		}
1502 		break;
1503 	}
1504 
1505 	default:
1506 		error = EOPNOTSUPP;
1507 		break;
1508 	}
1509 	if (error == 0) {
1510 		td->td_retval[0] = needed ? needed : size;
1511 		if (uap->size) {
1512 			error = copyout(&size, uap->size, sizeof(size));
1513 		}
1514 	}
1515 	mtx_unlock(&Giant);
1516 	return (error);
1517 }
1518 #endif /* COMPAT_43 */
1519