xref: /netbsd-src/sys/kern/kern_sysctl.c (revision 1ca5c1b28139779176bd5c13ad7c5f25c0bcd5f8)
1 /*	$NetBSD: kern_sysctl.c,v 1.97 2001/11/12 15:25:17 lukem Exp $	*/
2 
3 /*-
4  * Copyright (c) 1982, 1986, 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Mike Karels at Berkeley Software Design, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	@(#)kern_sysctl.c	8.9 (Berkeley) 5/20/95
39  */
40 
41 /*
42  * sysctl system call.
43  */
44 
45 #include <sys/cdefs.h>
46 __KERNEL_RCSID(0, "$NetBSD: kern_sysctl.c,v 1.97 2001/11/12 15:25:17 lukem Exp $");
47 
48 #include "opt_ddb.h"
49 #include "opt_insecure.h"
50 #include "opt_defcorename.h"
51 #include "opt_new_pipe.h"
52 #include "opt_sysv.h"
53 #include "pty.h"
54 
55 #include <sys/param.h>
56 #include <sys/systm.h>
57 #include <sys/kernel.h>
58 #include <sys/buf.h>
59 #include <sys/device.h>
60 #include <sys/disklabel.h>
61 #include <sys/dkstat.h>
62 #include <sys/exec.h>
63 #include <sys/file.h>
64 #include <sys/ioctl.h>
65 #include <sys/malloc.h>
66 #include <sys/mount.h>
67 #include <sys/msgbuf.h>
68 #include <sys/pool.h>
69 #include <sys/proc.h>
70 #include <sys/resource.h>
71 #include <sys/resourcevar.h>
72 #include <sys/syscallargs.h>
73 #include <sys/tty.h>
74 #include <sys/unistd.h>
75 #include <sys/vnode.h>
76 #include <sys/socketvar.h>
77 #define	__SYSCTL_PRIVATE
78 #include <sys/sysctl.h>
79 #include <sys/lock.h>
80 #include <sys/namei.h>
81 
82 #if defined(SYSVMSG) || defined(SYSVSEM) || defined(SYSVSHM)
83 #include <sys/ipc.h>
84 #endif
85 #ifdef SYSVMSG
86 #include <sys/msg.h>
87 #endif
88 #ifdef SYSVSEM
89 #include <sys/sem.h>
90 #endif
91 #ifdef SYSVSHM
92 #include <sys/shm.h>
93 #endif
94 
95 #include <dev/cons.h>
96 
97 #if defined(DDB)
98 #include <ddb/ddbvar.h>
99 #endif
100 
101 #ifdef NEW_PIPE
102 #include <sys/pipe.h>
103 #endif
104 
105 #define PTRTOINT64(foo)	((u_int64_t)(uintptr_t)(foo))
106 
107 static int sysctl_file(void *, size_t *);
108 #if defined(SYSVMSG) || defined(SYSVSEM) || defined(SYSVSHM)
109 static int sysctl_sysvipc(int *, u_int, void *, size_t *);
110 #endif
111 static int sysctl_msgbuf(void *, size_t *);
112 static int sysctl_doeproc(int *, u_int, void *, size_t *);
113 #ifdef MULTIPROCESSOR
114 static int sysctl_docptime(void *, size_t *, void *);
115 static int sysctl_ncpus(void);
116 #endif
117 static void fill_kproc2(struct proc *, struct kinfo_proc2 *);
118 static int sysctl_procargs(int *, u_int, void *, size_t *, struct proc *);
119 #if NPTY > 0
120 static int sysctl_pty(void *, size_t *, void *, size_t);
121 #endif
122 
123 /*
124  * The `sysctl_memlock' is intended to keep too many processes from
125  * locking down memory by doing sysctls at once.  Whether or not this
126  * is really a good idea to worry about it probably a subject of some
127  * debate.
128  */
129 struct lock sysctl_memlock;
130 
131 void
132 sysctl_init(void)
133 {
134 
135 	lockinit(&sysctl_memlock, PRIBIO|PCATCH, "sysctl", 0, 0);
136 }
137 
138 int
139 sys___sysctl(struct proc *p, void *v, register_t *retval)
140 {
141 	struct sys___sysctl_args /* {
142 		syscallarg(int *) name;
143 		syscallarg(u_int) namelen;
144 		syscallarg(void *) old;
145 		syscallarg(size_t *) oldlenp;
146 		syscallarg(void *) new;
147 		syscallarg(size_t) newlen;
148 	} */ *uap = v;
149 	int error;
150 	size_t savelen = 0, oldlen = 0;
151 	sysctlfn *fn;
152 	int name[CTL_MAXNAME];
153 	size_t *oldlenp;
154 
155 	/*
156 	 * all top-level sysctl names are non-terminal
157 	 */
158 	if (SCARG(uap, namelen) > CTL_MAXNAME || SCARG(uap, namelen) < 2)
159 		return (EINVAL);
160 	error = copyin(SCARG(uap, name), &name,
161 		       SCARG(uap, namelen) * sizeof(int));
162 	if (error)
163 		return (error);
164 
165 	/*
166 	 * For all but CTL_PROC, must be root to change a value.
167 	 * For CTL_PROC, must be root, or owner of the proc (and not suid),
168 	 * this is checked in proc_sysctl() (once we know the targer proc).
169 	 */
170 	if (SCARG(uap, new) != NULL && name[0] != CTL_PROC &&
171 		    (error = suser(p->p_ucred, &p->p_acflag)))
172 			return error;
173 
174 	switch (name[0]) {
175 	case CTL_KERN:
176 		fn = kern_sysctl;
177 		break;
178 	case CTL_HW:
179 		fn = hw_sysctl;
180 		break;
181 	case CTL_VM:
182 		fn = uvm_sysctl;
183 		break;
184 	case CTL_NET:
185 		fn = net_sysctl;
186 		break;
187 	case CTL_VFS:
188 		fn = vfs_sysctl;
189 		break;
190 	case CTL_MACHDEP:
191 		fn = cpu_sysctl;
192 		break;
193 #ifdef DEBUG
194 	case CTL_DEBUG:
195 		fn = debug_sysctl;
196 		break;
197 #endif
198 #ifdef DDB
199 	case CTL_DDB:
200 		fn = ddb_sysctl;
201 		break;
202 #endif
203 	case CTL_PROC:
204 		fn = proc_sysctl;
205 		break;
206 	default:
207 		return (EOPNOTSUPP);
208 	}
209 
210 	/*
211 	 * XXX Hey, we wire `old', but what about `new'?
212 	 */
213 
214 	oldlenp = SCARG(uap, oldlenp);
215 	if (oldlenp) {
216 		if ((error = copyin(oldlenp, &oldlen, sizeof(oldlen))))
217 			return (error);
218 		oldlenp = &oldlen;
219 	}
220 	if (SCARG(uap, old) != NULL) {
221 		error = lockmgr(&sysctl_memlock, LK_EXCLUSIVE, NULL);
222 		if (error)
223 			return (error);
224 		error = uvm_vslock(p, SCARG(uap, old), oldlen,
225 		    VM_PROT_READ|VM_PROT_WRITE);
226 		if (error) {
227 			(void) lockmgr(&sysctl_memlock, LK_RELEASE, NULL);
228 			return error;
229 		}
230 		savelen = oldlen;
231 	}
232 	error = (*fn)(name + 1, SCARG(uap, namelen) - 1, SCARG(uap, old),
233 	    oldlenp, SCARG(uap, new), SCARG(uap, newlen), p);
234 	if (SCARG(uap, old) != NULL) {
235 		uvm_vsunlock(p, SCARG(uap, old), savelen);
236 		(void) lockmgr(&sysctl_memlock, LK_RELEASE, NULL);
237 	}
238 	if (error)
239 		return (error);
240 	if (SCARG(uap, oldlenp))
241 		error = copyout(&oldlen, SCARG(uap, oldlenp), sizeof(oldlen));
242 	return (error);
243 }
244 
245 /*
246  * Attributes stored in the kernel.
247  */
248 char hostname[MAXHOSTNAMELEN];
249 int hostnamelen;
250 
251 char domainname[MAXHOSTNAMELEN];
252 int domainnamelen;
253 
254 long hostid;
255 
256 #ifdef INSECURE
257 int securelevel = -1;
258 #else
259 int securelevel = 0;
260 #endif
261 
262 #ifndef DEFCORENAME
263 #define	DEFCORENAME	"%n.core"
264 #endif
265 char defcorename[MAXPATHLEN] = DEFCORENAME;
266 int defcorenamelen = sizeof(DEFCORENAME);
267 
268 extern	int	kern_logsigexit;
269 extern	fixpt_t	ccpu;
270 
271 #ifndef MULTIPROCESSOR
272 #define sysctl_ncpus() 1
273 #endif
274 
275 #ifdef MULTIPROCESSOR
276 
277 #ifndef CPU_INFO_FOREACH
278 #define CPU_INFO_ITERATOR int
279 #define CPU_INFO_FOREACH(cii, ci) cii = 0, ci = curcpu(); ci != NULL; ci = NULL
280 #endif
281 
282 static int
283 sysctl_docptime(void *oldp, size_t *oldlenp, void *newp)
284 {
285 	u_int64_t cp_time[CPUSTATES];
286 	int i;
287 	struct cpu_info *ci;
288 	CPU_INFO_ITERATOR cii;
289 
290 	for (i=0; i<CPUSTATES; i++)
291 		cp_time[i] = 0;
292 
293 	for (CPU_INFO_FOREACH(cii, ci)) {
294 		for (i=0; i<CPUSTATES; i++)
295 			cp_time[i] += ci->ci_schedstate.spc_cp_time[i];
296 	}
297 	return (sysctl_rdstruct(oldp, oldlenp, newp,
298 	    cp_time, sizeof(cp_time)));
299 }
300 
301 static int
302 sysctl_ncpus(void)
303 {
304 	struct cpu_info *ci;
305 	CPU_INFO_ITERATOR cii;
306 
307 	int ncpus = 0;
308 	for (CPU_INFO_FOREACH(cii, ci))
309 		ncpus++;
310 	return ncpus;
311 }
312 
313 #endif
314 
315 /*
316  * kernel related system variables.
317  */
318 int
319 kern_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
320     void *newp, size_t newlen, struct proc *p)
321 {
322 	int error, level, inthostid;
323 	int old_autonicetime;
324 	int old_vnodes;
325 	dev_t consdev;
326 
327 	/* All sysctl names at this level, except for a few, are terminal. */
328 	switch (name[0]) {
329 	case KERN_PROC:
330 	case KERN_PROC2:
331 	case KERN_PROF:
332 	case KERN_MBUF:
333 	case KERN_PROC_ARGS:
334 	case KERN_SYSVIPC_INFO:
335 	case KERN_PIPE:
336 		/* Not terminal. */
337 		break;
338 	default:
339 		if (namelen != 1)
340 			return (ENOTDIR);	/* overloaded */
341 	}
342 
343 	switch (name[0]) {
344 	case KERN_OSTYPE:
345 		return (sysctl_rdstring(oldp, oldlenp, newp, ostype));
346 	case KERN_OSRELEASE:
347 		return (sysctl_rdstring(oldp, oldlenp, newp, osrelease));
348 	case KERN_OSREV:
349 		return (sysctl_rdint(oldp, oldlenp, newp, __NetBSD_Version__));
350 	case KERN_VERSION:
351 		return (sysctl_rdstring(oldp, oldlenp, newp, version));
352 	case KERN_MAXVNODES:
353 		old_vnodes = desiredvnodes;
354 		error = sysctl_int(oldp, oldlenp, newp, newlen, &desiredvnodes);
355 		if (old_vnodes > desiredvnodes) {
356 		        desiredvnodes = old_vnodes;
357 			return (EINVAL);
358 		}
359 		if (error == 0) {
360 			vfs_reinit();
361 			nchreinit();
362 		}
363 		return (error);
364 	case KERN_MAXPROC:
365 		return (sysctl_int(oldp, oldlenp, newp, newlen, &maxproc));
366 	case KERN_MAXFILES:
367 		return (sysctl_int(oldp, oldlenp, newp, newlen, &maxfiles));
368 	case KERN_ARGMAX:
369 		return (sysctl_rdint(oldp, oldlenp, newp, ARG_MAX));
370 	case KERN_SECURELVL:
371 		level = securelevel;
372 		if ((error = sysctl_int(oldp, oldlenp, newp, newlen, &level)) ||
373 		    newp == NULL)
374 			return (error);
375 		if (level < securelevel && p->p_pid != 1)
376 			return (EPERM);
377 		securelevel = level;
378 		return (0);
379 	case KERN_HOSTNAME:
380 		error = sysctl_string(oldp, oldlenp, newp, newlen,
381 		    hostname, sizeof(hostname));
382 		if (newp && !error)
383 			hostnamelen = newlen;
384 		return (error);
385 	case KERN_DOMAINNAME:
386 		error = sysctl_string(oldp, oldlenp, newp, newlen,
387 		    domainname, sizeof(domainname));
388 		if (newp && !error)
389 			domainnamelen = newlen;
390 		return (error);
391 	case KERN_HOSTID:
392 		inthostid = hostid;  /* XXX assumes sizeof long <= sizeof int */
393 		error =  sysctl_int(oldp, oldlenp, newp, newlen, &inthostid);
394 		hostid = inthostid;
395 		return (error);
396 	case KERN_CLOCKRATE:
397 		return (sysctl_clockrate(oldp, oldlenp));
398 	case KERN_BOOTTIME:
399 		return (sysctl_rdstruct(oldp, oldlenp, newp, &boottime,
400 		    sizeof(struct timeval)));
401 	case KERN_VNODE:
402 		return (sysctl_vnode(oldp, oldlenp, p));
403 	case KERN_PROC:
404 	case KERN_PROC2:
405 		return (sysctl_doeproc(name, namelen, oldp, oldlenp));
406 	case KERN_PROC_ARGS:
407 		return (sysctl_procargs(name + 1, namelen - 1,
408 		    oldp, oldlenp, p));
409 	case KERN_FILE:
410 		return (sysctl_file(oldp, oldlenp));
411 #ifdef GPROF
412 	case KERN_PROF:
413 		return (sysctl_doprof(name + 1, namelen - 1, oldp, oldlenp,
414 		    newp, newlen));
415 #endif
416 	case KERN_POSIX1:
417 		return (sysctl_rdint(oldp, oldlenp, newp, _POSIX_VERSION));
418 	case KERN_NGROUPS:
419 		return (sysctl_rdint(oldp, oldlenp, newp, NGROUPS_MAX));
420 	case KERN_JOB_CONTROL:
421 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
422 	case KERN_SAVED_IDS:
423 #ifdef _POSIX_SAVED_IDS
424 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
425 #else
426 		return (sysctl_rdint(oldp, oldlenp, newp, 0));
427 #endif
428 	case KERN_MAXPARTITIONS:
429 		return (sysctl_rdint(oldp, oldlenp, newp, MAXPARTITIONS));
430 	case KERN_RAWPARTITION:
431 		return (sysctl_rdint(oldp, oldlenp, newp, RAW_PART));
432 #ifdef NTP
433 	case KERN_NTPTIME:
434 		return (sysctl_ntptime(oldp, oldlenp));
435 #endif
436 	case KERN_AUTONICETIME:
437 	        old_autonicetime = autonicetime;
438 	        error = sysctl_int(oldp, oldlenp, newp, newlen, &autonicetime);
439 		if (autonicetime < 0)
440  		        autonicetime = old_autonicetime;
441 		return (error);
442 	case KERN_AUTONICEVAL:
443 		error = sysctl_int(oldp, oldlenp, newp, newlen, &autoniceval);
444 		if (autoniceval < PRIO_MIN)
445 			autoniceval = PRIO_MIN;
446 		if (autoniceval > PRIO_MAX)
447 			autoniceval = PRIO_MAX;
448 		return (error);
449 	case KERN_RTC_OFFSET:
450 		return (sysctl_rdint(oldp, oldlenp, newp, rtc_offset));
451 	case KERN_ROOT_DEVICE:
452 		return (sysctl_rdstring(oldp, oldlenp, newp,
453 		    root_device->dv_xname));
454 	case KERN_MSGBUFSIZE:
455 		/*
456 		 * deal with cases where the message buffer has
457 		 * become corrupted.
458 		 */
459 		if (!msgbufenabled || msgbufp->msg_magic != MSG_MAGIC) {
460 			msgbufenabled = 0;
461 			return (ENXIO);
462 		}
463 		return (sysctl_rdint(oldp, oldlenp, newp, msgbufp->msg_bufs));
464 	case KERN_FSYNC:
465 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
466 	case KERN_SYSVMSG:
467 #ifdef SYSVMSG
468 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
469 #else
470 		return (sysctl_rdint(oldp, oldlenp, newp, 0));
471 #endif
472 	case KERN_SYSVSEM:
473 #ifdef SYSVSEM
474 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
475 #else
476 		return (sysctl_rdint(oldp, oldlenp, newp, 0));
477 #endif
478 	case KERN_SYSVSHM:
479 #ifdef SYSVSHM
480 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
481 #else
482 		return (sysctl_rdint(oldp, oldlenp, newp, 0));
483 #endif
484  	case KERN_DEFCORENAME:
485 		if (newp && newlen < 1)
486 			return (EINVAL);
487 		error = sysctl_string(oldp, oldlenp, newp, newlen,
488 		    defcorename, sizeof(defcorename));
489 		if (newp && !error)
490 			defcorenamelen = newlen;
491 		return (error);
492 	case KERN_SYNCHRONIZED_IO:
493 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
494 	case KERN_IOV_MAX:
495 		return (sysctl_rdint(oldp, oldlenp, newp, IOV_MAX));
496 	case KERN_MBUF:
497 		return (sysctl_dombuf(name + 1, namelen - 1, oldp, oldlenp,
498 		    newp, newlen));
499 	case KERN_MAPPED_FILES:
500 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
501 	case KERN_MEMLOCK:
502 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
503 	case KERN_MEMLOCK_RANGE:
504 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
505 	case KERN_MEMORY_PROTECTION:
506 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
507 	case KERN_LOGIN_NAME_MAX:
508 		return (sysctl_rdint(oldp, oldlenp, newp, LOGIN_NAME_MAX));
509 	case KERN_LOGSIGEXIT:
510 		return (sysctl_int(oldp, oldlenp, newp, newlen,
511 		    &kern_logsigexit));
512 	case KERN_FSCALE:
513 		return (sysctl_rdint(oldp, oldlenp, newp, FSCALE));
514 	case KERN_CCPU:
515 		return (sysctl_rdint(oldp, oldlenp, newp, ccpu));
516 	case KERN_CP_TIME:
517 #ifndef MULTIPROCESSOR
518 		return (sysctl_rdstruct(oldp, oldlenp, newp,
519 		    curcpu()->ci_schedstate.spc_cp_time,
520 		    sizeof(curcpu()->ci_schedstate.spc_cp_time)));
521 #else
522 		return (sysctl_docptime(oldp, oldlenp, newp));
523 #endif
524 #if defined(SYSVMSG) || defined(SYSVSEM) || defined(SYSVSHM)
525 	case KERN_SYSVIPC_INFO:
526 		return (sysctl_sysvipc(name + 1, namelen - 1, oldp, oldlenp));
527 #endif
528 	case KERN_MSGBUF:
529 		return (sysctl_msgbuf(oldp, oldlenp));
530 	case KERN_CONSDEV:
531 		if (cn_tab != NULL)
532 			consdev = cn_tab->cn_dev;
533 		else
534 			consdev = NODEV;
535 		return (sysctl_rdstruct(oldp, oldlenp, newp, &consdev,
536 		    sizeof consdev));
537 #if NPTY > 0
538 	case KERN_MAXPTYS:
539 		return sysctl_pty(oldp, oldlenp, newp, newlen);
540 #endif
541 #ifdef NEW_PIPE
542 	case KERN_PIPE:
543 		return (sysctl_dopipe(name + 1, namelen - 1, oldp, oldlenp,
544 		    newp, newlen));
545 #endif
546 	case KERN_MAXPHYS:
547 		return (sysctl_rdint(oldp, oldlenp, newp, MAXPHYS));
548 	case KERN_SBMAX:
549 	    {
550 		int new_sbmax = sb_max;
551 
552 		error = sysctl_int(oldp, oldlenp, newp, newlen, &new_sbmax);
553 		if (error == 0) {
554 			if (new_sbmax < (16 * 1024)) /* sanity */
555 				return (EINVAL);
556 			sb_max = new_sbmax;
557 		}
558 		return (error);
559 	    }
560 	default:
561 		return (EOPNOTSUPP);
562 	}
563 	/* NOTREACHED */
564 }
565 
566 /*
567  * hardware related system variables.
568  */
569 int
570 hw_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
571     void *newp, size_t newlen, struct proc *p)
572 {
573 
574 	/* all sysctl names at this level are terminal */
575 	if (namelen != 1)
576 		return (ENOTDIR);		/* overloaded */
577 
578 	switch (name[0]) {
579 	case HW_MACHINE:
580 		return (sysctl_rdstring(oldp, oldlenp, newp, machine));
581 	case HW_MACHINE_ARCH:
582 		return (sysctl_rdstring(oldp, oldlenp, newp, machine_arch));
583 	case HW_MODEL:
584 		return (sysctl_rdstring(oldp, oldlenp, newp, cpu_model));
585 	case HW_NCPU:
586 		return (sysctl_rdint(oldp, oldlenp, newp, sysctl_ncpus()));
587 	case HW_BYTEORDER:
588 		return (sysctl_rdint(oldp, oldlenp, newp, BYTE_ORDER));
589 	case HW_PHYSMEM:
590 		return (sysctl_rdint(oldp, oldlenp, newp, ctob(physmem)));
591 	case HW_USERMEM:
592 		return (sysctl_rdint(oldp, oldlenp, newp,
593 		    ctob(physmem - uvmexp.wired)));
594 	case HW_PAGESIZE:
595 		return (sysctl_rdint(oldp, oldlenp, newp, PAGE_SIZE));
596 	case HW_ALIGNBYTES:
597 		return (sysctl_rdint(oldp, oldlenp, newp, ALIGNBYTES));
598 	case HW_CNMAGIC: {
599 		char magic[CNS_LEN];
600 		int error;
601 
602 		if (oldp)
603 			cn_get_magic(magic, CNS_LEN);
604 		error = sysctl_string(oldp, oldlenp, newp, newlen,
605 		    magic, sizeof(magic));
606 		if (newp && !error) {
607 			error = cn_set_magic(magic);
608 		}
609 		return (error);
610 	}
611 	default:
612 		return (EOPNOTSUPP);
613 	}
614 	/* NOTREACHED */
615 }
616 
617 #ifdef DEBUG
618 /*
619  * Debugging related system variables.
620  */
621 struct ctldebug debug0, debug1, debug2, debug3, debug4;
622 struct ctldebug debug5, debug6, debug7, debug8, debug9;
623 struct ctldebug debug10, debug11, debug12, debug13, debug14;
624 struct ctldebug debug15, debug16, debug17, debug18, debug19;
625 static struct ctldebug *debugvars[CTL_DEBUG_MAXID] = {
626 	&debug0, &debug1, &debug2, &debug3, &debug4,
627 	&debug5, &debug6, &debug7, &debug8, &debug9,
628 	&debug10, &debug11, &debug12, &debug13, &debug14,
629 	&debug15, &debug16, &debug17, &debug18, &debug19,
630 };
631 
632 int
633 debug_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
634     void *newp, size_t newlen, struct proc *p)
635 {
636 	struct ctldebug *cdp;
637 
638 	/* all sysctl names at this level are name and field */
639 	if (namelen != 2)
640 		return (ENOTDIR);		/* overloaded */
641 	cdp = debugvars[name[0]];
642 	if (name[0] >= CTL_DEBUG_MAXID || cdp->debugname == 0)
643 		return (EOPNOTSUPP);
644 	switch (name[1]) {
645 	case CTL_DEBUG_NAME:
646 		return (sysctl_rdstring(oldp, oldlenp, newp, cdp->debugname));
647 	case CTL_DEBUG_VALUE:
648 		return (sysctl_int(oldp, oldlenp, newp, newlen, cdp->debugvar));
649 	default:
650 		return (EOPNOTSUPP);
651 	}
652 	/* NOTREACHED */
653 }
654 #endif /* DEBUG */
655 
656 int
657 proc_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
658     void *newp, size_t newlen, struct proc *p)
659 {
660 	struct proc *ptmp = NULL;
661 	const struct proclist_desc *pd;
662 	int error = 0;
663 	struct rlimit alim;
664 	struct plimit *newplim;
665 	char *tmps = NULL;
666 	int i, curlen, len;
667 
668 	if (namelen < 2)
669 		return EINVAL;
670 
671 	if (name[0] == PROC_CURPROC) {
672 		ptmp = p;
673 	} else {
674 		proclist_lock_read();
675 		for (pd = proclists; pd->pd_list != NULL; pd++) {
676 			for (ptmp = LIST_FIRST(pd->pd_list); ptmp != NULL;
677 			    ptmp = LIST_NEXT(ptmp, p_list)) {
678 				/* Skip embryonic processes. */
679 				if (ptmp->p_stat == SIDL)
680 					continue;
681 				if (ptmp->p_pid == (pid_t)name[0])
682 					break;
683 			}
684 			if (ptmp != NULL)
685 				break;
686 		}
687 		proclist_unlock_read();
688 		if (ptmp == NULL)
689 			return(ESRCH);
690 		if (p->p_ucred->cr_uid != 0) {
691 			if(p->p_cred->p_ruid != ptmp->p_cred->p_ruid ||
692 			    p->p_cred->p_ruid != ptmp->p_cred->p_svuid)
693 				return EPERM;
694 			if (ptmp->p_cred->p_rgid != ptmp->p_cred->p_svgid)
695 				return EPERM; /* sgid proc */
696 			for (i = 0; i < p->p_ucred->cr_ngroups; i++) {
697 				if (p->p_ucred->cr_groups[i] ==
698 				    ptmp->p_cred->p_rgid)
699 					break;
700 			}
701 			if (i == p->p_ucred->cr_ngroups)
702 				return EPERM;
703 		}
704 	}
705 	if (name[1] == PROC_PID_CORENAME) {
706 		if (namelen != 2)
707 			return EINVAL;
708 		/*
709 		 * Can't use sysctl_string() here because we may malloc a new
710 		 * area during the process, so we have to do it by hand.
711 		 */
712 		curlen = strlen(ptmp->p_limit->pl_corename) + 1;
713 		if (oldlenp  && *oldlenp < curlen) {
714 			if (!oldp)
715 				*oldlenp = curlen;
716 			return (ENOMEM);
717 		}
718 		if (newp) {
719 			if (securelevel > 2)
720 				return EPERM;
721 			if (newlen > MAXPATHLEN)
722 				return ENAMETOOLONG;
723 			tmps = malloc(newlen + 1, M_TEMP, M_WAITOK);
724 			if (tmps == NULL)
725 				return ENOMEM;
726 			error = copyin(newp, tmps, newlen + 1);
727 			tmps[newlen] = '\0';
728 			if (error)
729 				goto cleanup;
730 			/* Enforce to be either 'core' for end with '.core' */
731 			if (newlen < 4)  { /* c.o.r.e */
732 				error = EINVAL;
733 				goto cleanup;
734 			}
735 			len = newlen - 4;
736 			if (len > 0) {
737 				if (tmps[len - 1] != '.' &&
738 				    tmps[len - 1] != '/') {
739 					error = EINVAL;
740 					goto cleanup;
741 				}
742 			}
743 			if (strcmp(&tmps[len], "core") != 0) {
744 				error = EINVAL;
745 				goto cleanup;
746 			}
747 		}
748 		if (oldp && oldlenp) {
749 			*oldlenp = curlen;
750 			error = copyout(ptmp->p_limit->pl_corename, oldp,
751 			    curlen);
752 		}
753 		if (newp && error == 0) {
754 			/* if the 2 strings are identical, don't limcopy() */
755 			if (strcmp(tmps, ptmp->p_limit->pl_corename) == 0) {
756 				error = 0;
757 				goto cleanup;
758 			}
759 			if (ptmp->p_limit->p_refcnt > 1 &&
760 			    (ptmp->p_limit->p_lflags & PL_SHAREMOD) == 0) {
761 				newplim = limcopy(ptmp->p_limit);
762 				limfree(ptmp->p_limit);
763 				ptmp->p_limit = newplim;
764 			}
765 			if (ptmp->p_limit->pl_corename != defcorename) {
766 				free(ptmp->p_limit->pl_corename, M_TEMP);
767 			}
768 			ptmp->p_limit->pl_corename = tmps;
769 			return (0);
770 		}
771 cleanup:
772 		if (tmps)
773 			free(tmps, M_TEMP);
774 		return (error);
775 	}
776 	if (name[1] == PROC_PID_LIMIT) {
777 		if (namelen != 4 || name[2] >= PROC_PID_LIMIT_MAXID)
778 			return EINVAL;
779 		memcpy(&alim, &ptmp->p_rlimit[name[2] - 1], sizeof(alim));
780 		if (name[3] == PROC_PID_LIMIT_TYPE_HARD)
781 			error = sysctl_quad(oldp, oldlenp, newp, newlen,
782 			    &alim.rlim_max);
783 		else if (name[3] == PROC_PID_LIMIT_TYPE_SOFT)
784 			error = sysctl_quad(oldp, oldlenp, newp, newlen,
785 			    &alim.rlim_cur);
786 		else
787 			error = EINVAL;
788 
789 		if (error)
790 			return error;
791 
792 		if (newp)
793 			error = dosetrlimit(ptmp, p->p_cred,
794 			    name[2] - 1, &alim);
795 		return error;
796 	}
797 	return (EINVAL);
798 }
799 
800 /*
801  * Convenience macros.
802  */
803 
804 #define SYSCTL_SCALAR_CORE_LEN(oldp, oldlenp, valp, len) 		\
805 	if (oldlenp) {							\
806 		if (!oldp)						\
807 			*oldlenp = len;					\
808 		else {							\
809 			if (*oldlenp < len)				\
810 				return(ENOMEM);				\
811 			*oldlenp = len;					\
812 			error = copyout((caddr_t)valp, oldp, len);	\
813 		}							\
814 	}
815 
816 #define SYSCTL_SCALAR_CORE_TYP(oldp, oldlenp, valp, typ) \
817 	SYSCTL_SCALAR_CORE_LEN(oldp, oldlenp, valp, sizeof(typ))
818 
819 #define SYSCTL_SCALAR_NEWPCHECK_LEN(newp, newlen, len)	\
820 	if (newp && newlen != len)			\
821 		return (EINVAL);
822 
823 #define SYSCTL_SCALAR_NEWPCHECK_TYP(newp, newlen, typ)	\
824 	SYSCTL_SCALAR_NEWPCHECK_LEN(newp, newlen, sizeof(typ))
825 
826 #define SYSCTL_SCALAR_NEWPCOP_LEN(newp, valp, len)	\
827 	if (error == 0 && newp)				\
828 		error = copyin(newp, valp, len);
829 
830 #define SYSCTL_SCALAR_NEWPCOP_TYP(newp, valp, typ)      \
831 	SYSCTL_SCALAR_NEWPCOP_LEN(newp, valp, sizeof(typ))
832 
833 #define SYSCTL_STRING_CORE(oldp, oldlenp, str)		\
834 	if (oldlenp) {					\
835 		len = strlen(str) + 1;			\
836 		if (!oldp)				\
837 			*oldlenp = len;			\
838 		else {					\
839 			if (*oldlenp < len) {		\
840 				err2 = ENOMEM;		\
841 				len = *oldlenp;		\
842 			} else				\
843 				*oldlenp = len;		\
844 			error = copyout(str, oldp, len);\
845 			if (error == 0)			\
846 				error = err2;		\
847 		}					\
848 	}
849 
850 /*
851  * Validate parameters and get old / set new parameters
852  * for an integer-valued sysctl function.
853  */
854 int
855 sysctl_int(void *oldp, size_t *oldlenp, void *newp, size_t newlen, int *valp)
856 {
857 	int error = 0;
858 
859 	SYSCTL_SCALAR_NEWPCHECK_TYP(newp, newlen, int)
860 	SYSCTL_SCALAR_CORE_TYP(oldp, oldlenp, valp, int)
861 	SYSCTL_SCALAR_NEWPCOP_TYP(newp, valp, int)
862 
863 	return (error);
864 }
865 
866 
867 /*
868  * As above, but read-only.
869  */
870 int
871 sysctl_rdint(void *oldp, size_t *oldlenp, void *newp, int val)
872 {
873 	int error = 0;
874 
875 	if (newp)
876 		return (EPERM);
877 
878 	SYSCTL_SCALAR_CORE_TYP(oldp, oldlenp, &val, int)
879 
880 	return (error);
881 }
882 
883 /*
884  * Validate parameters and get old / set new parameters
885  * for an quad-valued sysctl function.
886  */
887 int
888 sysctl_quad(void *oldp, size_t *oldlenp, void *newp, size_t newlen,
889     quad_t *valp)
890 {
891 	int error = 0;
892 
893 	SYSCTL_SCALAR_NEWPCHECK_TYP(newp, newlen, quad_t)
894 	SYSCTL_SCALAR_CORE_TYP(oldp, oldlenp, valp, quad_t)
895 	SYSCTL_SCALAR_NEWPCOP_TYP(newp, valp, quad_t)
896 
897 	return (error);
898 }
899 
900 /*
901  * As above, but read-only.
902  */
903 int
904 sysctl_rdquad(void *oldp, size_t *oldlenp, void *newp, quad_t val)
905 {
906 	int error = 0;
907 
908 	if (newp)
909 		return (EPERM);
910 
911 	SYSCTL_SCALAR_CORE_TYP(oldp, oldlenp, &val, quad_t)
912 
913 	return (error);
914 }
915 
916 /*
917  * Validate parameters and get old / set new parameters
918  * for a string-valued sysctl function.
919  */
920 int
921 sysctl_string(void *oldp, size_t *oldlenp, void *newp, size_t newlen, char *str,
922     int maxlen)
923 {
924 	int len, error = 0, err2 = 0;
925 
926 	if (newp && newlen >= maxlen)
927 		return (EINVAL);
928 
929 	SYSCTL_STRING_CORE(oldp, oldlenp, str);
930 
931 	if (error == 0 && newp) {
932 		error = copyin(newp, str, newlen);
933 		str[newlen] = 0;
934 	}
935 	return (error);
936 }
937 
938 /*
939  * As above, but read-only.
940  */
941 int
942 sysctl_rdstring(void *oldp, size_t *oldlenp, void *newp, const char *str)
943 {
944 	int len, error = 0, err2 = 0;
945 
946 	if (newp)
947 		return (EPERM);
948 
949 	SYSCTL_STRING_CORE(oldp, oldlenp, str);
950 
951 	return (error);
952 }
953 
954 /*
955  * Validate parameters and get old / set new parameters
956  * for a structure oriented sysctl function.
957  */
958 int
959 sysctl_struct(void *oldp, size_t *oldlenp, void *newp, size_t newlen, void *sp,
960     int len)
961 {
962 	int error = 0;
963 
964 	SYSCTL_SCALAR_NEWPCHECK_LEN(newp, newlen, len)
965 	SYSCTL_SCALAR_CORE_LEN(oldp, oldlenp, sp, len)
966 	SYSCTL_SCALAR_NEWPCOP_LEN(newp, sp, len)
967 
968 	return (error);
969 }
970 
971 /*
972  * Validate parameters and get old parameters
973  * for a structure oriented sysctl function.
974  */
975 int
976 sysctl_rdstruct(void *oldp, size_t *oldlenp, void *newp, const void *sp,
977     int len)
978 {
979 	int error = 0;
980 
981 	if (newp)
982 		return (EPERM);
983 
984 	SYSCTL_SCALAR_CORE_LEN(oldp, oldlenp, sp, len)
985 
986 	return (error);
987 }
988 
989 /*
990  * As above, but can return a truncated result.
991  */
992 int
993 sysctl_rdminstruct(void *oldp, size_t *oldlenp, void *newp, const void *sp,
994     int len)
995 {
996 	int error = 0;
997 
998 	if (newp)
999 		return (EPERM);
1000 
1001 	len = min(*oldlenp, len);
1002 	SYSCTL_SCALAR_CORE_LEN(oldp, oldlenp, sp, len)
1003 
1004 	return (error);
1005 }
1006 
1007 /*
1008  * Get file structures.
1009  */
1010 static int
1011 sysctl_file(void *vwhere, size_t *sizep)
1012 {
1013 	int buflen, error;
1014 	struct file *fp;
1015 	char *start, *where;
1016 
1017 	start = where = vwhere;
1018 	buflen = *sizep;
1019 	if (where == NULL) {
1020 		/*
1021 		 * overestimate by 10 files
1022 		 */
1023 		*sizep = sizeof(filehead) + (nfiles + 10) * sizeof(struct file);
1024 		return (0);
1025 	}
1026 
1027 	/*
1028 	 * first copyout filehead
1029 	 */
1030 	if (buflen < sizeof(filehead)) {
1031 		*sizep = 0;
1032 		return (0);
1033 	}
1034 	error = copyout((caddr_t)&filehead, where, sizeof(filehead));
1035 	if (error)
1036 		return (error);
1037 	buflen -= sizeof(filehead);
1038 	where += sizeof(filehead);
1039 
1040 	/*
1041 	 * followed by an array of file structures
1042 	 */
1043 	for (fp = filehead.lh_first; fp != 0; fp = fp->f_list.le_next) {
1044 		if (buflen < sizeof(struct file)) {
1045 			*sizep = where - start;
1046 			return (ENOMEM);
1047 		}
1048 		error = copyout((caddr_t)fp, where, sizeof(struct file));
1049 		if (error)
1050 			return (error);
1051 		buflen -= sizeof(struct file);
1052 		where += sizeof(struct file);
1053 	}
1054 	*sizep = where - start;
1055 	return (0);
1056 }
1057 
1058 #if defined(SYSVMSG) || defined(SYSVSEM) || defined(SYSVSHM)
1059 #define	FILL_PERM(src, dst) do { \
1060 		(dst)._key = (src)._key; \
1061 		(dst).uid = (src).uid; \
1062 		(dst).gid = (src).gid; \
1063 		(dst).cuid = (src).cuid; \
1064 		(dst).cgid = (src).cgid; \
1065 		(dst).mode = (src).mode; \
1066 		(dst)._seq = (src)._seq; \
1067 	} while (0);
1068 #define	FILL_MSG(src, dst) do { \
1069 	FILL_PERM((src).msg_perm, (dst).msg_perm); \
1070 	(dst).msg_qnum = (src).msg_qnum; \
1071 	(dst).msg_qbytes = (src).msg_qbytes; \
1072 	(dst)._msg_cbytes = (src)._msg_cbytes; \
1073 	(dst).msg_lspid = (src).msg_lspid; \
1074 	(dst).msg_lrpid = (src).msg_lrpid; \
1075 	(dst).msg_stime = (src).msg_stime; \
1076 	(dst).msg_rtime = (src).msg_rtime; \
1077 	(dst).msg_ctime = (src).msg_ctime; \
1078 	} while (0)
1079 #define	FILL_SEM(src, dst) do { \
1080 	FILL_PERM((src).sem_perm, (dst).sem_perm); \
1081 	(dst).sem_nsems = (src).sem_nsems; \
1082 	(dst).sem_otime = (src).sem_otime; \
1083 	(dst).sem_ctime = (src).sem_ctime; \
1084 	} while (0)
1085 #define	FILL_SHM(src, dst) do { \
1086 	FILL_PERM((src).shm_perm, (dst).shm_perm); \
1087 	(dst).shm_segsz = (src).shm_segsz; \
1088 	(dst).shm_lpid = (src).shm_lpid; \
1089 	(dst).shm_cpid = (src).shm_cpid; \
1090 	(dst).shm_atime = (src).shm_atime; \
1091 	(dst).shm_dtime = (src).shm_dtime; \
1092 	(dst).shm_ctime = (src).shm_ctime; \
1093 	(dst).shm_nattch = (src).shm_nattch; \
1094 	} while (0)
1095 
1096 static int
1097 sysctl_sysvipc(int *name, u_int namelen, void *where, size_t *sizep)
1098 {
1099 #ifdef SYSVMSG
1100 	struct msg_sysctl_info *msgsi;
1101 #endif
1102 #ifdef SYSVSEM
1103 	struct sem_sysctl_info *semsi;
1104 #endif
1105 #ifdef SYSVSHM
1106 	struct shm_sysctl_info *shmsi;
1107 #endif
1108 	size_t infosize, dssize, tsize, buflen;
1109 	void *buf = NULL, *buf2;
1110 	char *start;
1111 	int32_t nds;
1112 	int i, error, ret;
1113 
1114 	if (namelen != 1)
1115 		return (EINVAL);
1116 
1117 	start = where;
1118 	buflen = *sizep;
1119 
1120 	switch (*name) {
1121 	case KERN_SYSVIPC_MSG_INFO:
1122 #ifdef SYSVMSG
1123 		infosize = sizeof(msgsi->msginfo);
1124 		nds = msginfo.msgmni;
1125 		dssize = sizeof(msgsi->msgids[0]);
1126 		break;
1127 #else
1128 		return (EINVAL);
1129 #endif
1130 	case KERN_SYSVIPC_SEM_INFO:
1131 #ifdef SYSVSEM
1132 		infosize = sizeof(semsi->seminfo);
1133 		nds = seminfo.semmni;
1134 		dssize = sizeof(semsi->semids[0]);
1135 		break;
1136 #else
1137 		return (EINVAL);
1138 #endif
1139 	case KERN_SYSVIPC_SHM_INFO:
1140 #ifdef SYSVSHM
1141 		infosize = sizeof(shmsi->shminfo);
1142 		nds = shminfo.shmmni;
1143 		dssize = sizeof(shmsi->shmids[0]);
1144 		break;
1145 #else
1146 		return (EINVAL);
1147 #endif
1148 	default:
1149 		return (EINVAL);
1150 	}
1151 	/*
1152 	 * Round infosize to 64 bit boundary if requesting more than just
1153 	 * the info structure or getting the total data size.
1154 	 */
1155 	if (where == NULL || *sizep > infosize)
1156 		infosize = ((infosize + 7) / 8) * 8;
1157 	tsize = infosize + nds * dssize;
1158 
1159 	/* Return just the total size required. */
1160 	if (where == NULL) {
1161 		*sizep = tsize;
1162 		return (0);
1163 	}
1164 
1165 	/* Not enough room for even the info struct. */
1166 	if (buflen < infosize) {
1167 		*sizep = 0;
1168 		return (ENOMEM);
1169 	}
1170 	buf = malloc(min(tsize, buflen), M_TEMP, M_WAITOK);
1171 	memset(buf, 0, min(tsize, buflen));
1172 
1173 	switch (*name) {
1174 #ifdef SYSVMSG
1175 	case KERN_SYSVIPC_MSG_INFO:
1176 		msgsi = (struct msg_sysctl_info *)buf;
1177 		buf2 = &msgsi->msgids[0];
1178 		msgsi->msginfo = msginfo;
1179 		break;
1180 #endif
1181 #ifdef SYSVSEM
1182 	case KERN_SYSVIPC_SEM_INFO:
1183 		semsi = (struct sem_sysctl_info *)buf;
1184 		buf2 = &semsi->semids[0];
1185 		semsi->seminfo = seminfo;
1186 		break;
1187 #endif
1188 #ifdef SYSVSHM
1189 	case KERN_SYSVIPC_SHM_INFO:
1190 		shmsi = (struct shm_sysctl_info *)buf;
1191 		buf2 = &shmsi->shmids[0];
1192 		shmsi->shminfo = shminfo;
1193 		break;
1194 #endif
1195 	}
1196 	buflen -= infosize;
1197 
1198 	ret = 0;
1199 	if (buflen > 0) {
1200 		/* Fill in the IPC data structures.  */
1201 		for (i = 0; i < nds; i++) {
1202 			if (buflen < dssize) {
1203 				ret = ENOMEM;
1204 				break;
1205 			}
1206 			switch (*name) {
1207 #ifdef SYSVMSG
1208 			case KERN_SYSVIPC_MSG_INFO:
1209 				FILL_MSG(msqids[i], msgsi->msgids[i]);
1210 				break;
1211 #endif
1212 #ifdef SYSVSEM
1213 			case KERN_SYSVIPC_SEM_INFO:
1214 				FILL_SEM(sema[i], semsi->semids[i]);
1215 				break;
1216 #endif
1217 #ifdef SYSVSHM
1218 			case KERN_SYSVIPC_SHM_INFO:
1219 				FILL_SHM(shmsegs[i], shmsi->shmids[i]);
1220 				break;
1221 #endif
1222 			}
1223 			buflen -= dssize;
1224 		}
1225 	}
1226 	*sizep -= buflen;
1227 	error = copyout(buf, start, *sizep);
1228 	/* If copyout succeeded, use return code set earlier. */
1229 	if (error == 0)
1230 		error = ret;
1231 	if (buf)
1232 		free(buf, M_TEMP);
1233 	return (error);
1234 }
1235 #endif /* SYSVMSG || SYSVSEM || SYSVSHM */
1236 
1237 static int
1238 sysctl_msgbuf(void *vwhere, size_t *sizep)
1239 {
1240 	char *where = vwhere;
1241 	size_t len, maxlen = *sizep;
1242 	long beg, end;
1243 	int error;
1244 
1245 	/*
1246 	 * deal with cases where the message buffer has
1247 	 * become corrupted.
1248 	 */
1249 	if (!msgbufenabled || msgbufp->msg_magic != MSG_MAGIC) {
1250 		msgbufenabled = 0;
1251 		return (ENXIO);
1252 	}
1253 
1254 	if (where == NULL) {
1255 		/* always return full buffer size */
1256 		*sizep = msgbufp->msg_bufs;
1257 		return (0);
1258 	}
1259 
1260 	error = 0;
1261 	maxlen = min(msgbufp->msg_bufs, maxlen);
1262 
1263 	/*
1264 	 * First, copy from the write pointer to the end of
1265 	 * message buffer.
1266 	 */
1267 	beg = msgbufp->msg_bufx;
1268 	end = msgbufp->msg_bufs;
1269 	while (maxlen > 0) {
1270 		len = min(end - beg, maxlen);
1271 		if (len == 0)
1272 			break;
1273 		error = copyout(&msgbufp->msg_bufc[beg], where, len);
1274 		if (error)
1275 			break;
1276 		where += len;
1277 		maxlen -= len;
1278 
1279 		/*
1280 		 * ... then, copy from the beginning of message buffer to
1281 		 * the write pointer.
1282 		 */
1283 		beg = 0;
1284 		end = msgbufp->msg_bufx;
1285 	}
1286 	return (error);
1287 }
1288 
1289 /*
1290  * try over estimating by 5 procs
1291  */
1292 #define KERN_PROCSLOP	(5 * sizeof(struct kinfo_proc))
1293 
1294 static int
1295 sysctl_doeproc(int *name, u_int namelen, void *vwhere, size_t *sizep)
1296 {
1297 	struct eproc eproc;
1298 	struct kinfo_proc2 kproc2;
1299 	struct kinfo_proc *dp;
1300 	struct proc *p;
1301 	const struct proclist_desc *pd;
1302 	char *where, *dp2;
1303 	int type, op, arg, elem_size, elem_count;
1304 	int buflen, needed, error;
1305 
1306 	dp = vwhere;
1307 	dp2 = where = vwhere;
1308 	buflen = where != NULL ? *sizep : 0;
1309 	error = needed = 0;
1310 	type = name[0];
1311 
1312 	if (type == KERN_PROC) {
1313 		if (namelen != 3 && !(namelen == 2 && name[1] == KERN_PROC_ALL))
1314 			return (EINVAL);
1315 		op = name[1];
1316 		if (op != KERN_PROC_ALL)
1317 			arg = name[2];
1318 	} else {
1319 		if (namelen != 5)
1320 			return (EINVAL);
1321 		op = name[1];
1322 		arg = name[2];
1323 		elem_size = name[3];
1324 		elem_count = name[4];
1325 	}
1326 
1327 	proclist_lock_read();
1328 
1329 	pd = proclists;
1330 again:
1331 	for (p = LIST_FIRST(pd->pd_list); p != NULL; p = LIST_NEXT(p, p_list)) {
1332 		/*
1333 		 * Skip embryonic processes.
1334 		 */
1335 		if (p->p_stat == SIDL)
1336 			continue;
1337 		/*
1338 		 * TODO - make more efficient (see notes below).
1339 		 * do by session.
1340 		 */
1341 		switch (op) {
1342 
1343 		case KERN_PROC_PID:
1344 			/* could do this with just a lookup */
1345 			if (p->p_pid != (pid_t)arg)
1346 				continue;
1347 			break;
1348 
1349 		case KERN_PROC_PGRP:
1350 			/* could do this by traversing pgrp */
1351 			if (p->p_pgrp->pg_id != (pid_t)arg)
1352 				continue;
1353 			break;
1354 
1355 		case KERN_PROC_SESSION:
1356 			if (p->p_session->s_sid != (pid_t)arg)
1357 				continue;
1358 			break;
1359 
1360 		case KERN_PROC_TTY:
1361 			if (arg == KERN_PROC_TTY_REVOKE) {
1362 				if ((p->p_flag & P_CONTROLT) == 0 ||
1363 				    p->p_session->s_ttyp == NULL ||
1364 				    p->p_session->s_ttyvp != NULL)
1365 					continue;
1366 			} else if ((p->p_flag & P_CONTROLT) == 0 ||
1367 			    p->p_session->s_ttyp == NULL) {
1368 				if ((dev_t)arg != KERN_PROC_TTY_NODEV)
1369 					continue;
1370 			} else if (p->p_session->s_ttyp->t_dev != (dev_t)arg)
1371 				continue;
1372 			break;
1373 
1374 		case KERN_PROC_UID:
1375 			if (p->p_ucred->cr_uid != (uid_t)arg)
1376 				continue;
1377 			break;
1378 
1379 		case KERN_PROC_RUID:
1380 			if (p->p_cred->p_ruid != (uid_t)arg)
1381 				continue;
1382 			break;
1383 
1384 		case KERN_PROC_GID:
1385 			if (p->p_ucred->cr_gid != (uid_t)arg)
1386 				continue;
1387 			break;
1388 
1389 		case KERN_PROC_RGID:
1390 			if (p->p_cred->p_rgid != (uid_t)arg)
1391 				continue;
1392 			break;
1393 
1394 		case KERN_PROC_ALL:
1395 			/* allow everything */
1396 			break;
1397 
1398 		default:
1399 			error = EINVAL;
1400 			goto cleanup;
1401 		}
1402 		if (type == KERN_PROC) {
1403 			if (buflen >= sizeof(struct kinfo_proc)) {
1404 				fill_eproc(p, &eproc);
1405 				error = copyout((caddr_t)p, &dp->kp_proc,
1406 						sizeof(struct proc));
1407 				if (error)
1408 					goto cleanup;
1409 				error = copyout((caddr_t)&eproc, &dp->kp_eproc,
1410 						sizeof(eproc));
1411 				if (error)
1412 					goto cleanup;
1413 				dp++;
1414 				buflen -= sizeof(struct kinfo_proc);
1415 			}
1416 			needed += sizeof(struct kinfo_proc);
1417 		} else { /* KERN_PROC2 */
1418 			if (buflen >= elem_size && elem_count > 0) {
1419 				fill_kproc2(p, &kproc2);
1420 				/*
1421 				 * Copy out elem_size, but not larger than
1422 				 * the size of a struct kinfo_proc2.
1423 				 */
1424 				error = copyout(&kproc2, dp2,
1425 				    min(sizeof(kproc2), elem_size));
1426 				if (error)
1427 					goto cleanup;
1428 				dp2 += elem_size;
1429 				buflen -= elem_size;
1430 				elem_count--;
1431 			}
1432 			needed += elem_size;
1433 		}
1434 	}
1435 	pd++;
1436 	if (pd->pd_list != NULL)
1437 		goto again;
1438 	proclist_unlock_read();
1439 
1440 	if (where != NULL) {
1441 		if (type == KERN_PROC)
1442 			*sizep = (caddr_t)dp - where;
1443 		else
1444 			*sizep = dp2 - where;
1445 		if (needed > *sizep)
1446 			return (ENOMEM);
1447 	} else {
1448 		needed += KERN_PROCSLOP;
1449 		*sizep = needed;
1450 	}
1451 	return (0);
1452  cleanup:
1453 	proclist_unlock_read();
1454 	return (error);
1455 }
1456 
1457 /*
1458  * Fill in an eproc structure for the specified process.
1459  */
1460 void
1461 fill_eproc(struct proc *p, struct eproc *ep)
1462 {
1463 	struct tty *tp;
1464 
1465 	ep->e_paddr = p;
1466 	ep->e_sess = p->p_session;
1467 	ep->e_pcred = *p->p_cred;
1468 	ep->e_ucred = *p->p_ucred;
1469 	if (p->p_stat == SIDL || P_ZOMBIE(p)) {
1470 		ep->e_vm.vm_rssize = 0;
1471 		ep->e_vm.vm_tsize = 0;
1472 		ep->e_vm.vm_dsize = 0;
1473 		ep->e_vm.vm_ssize = 0;
1474 		/* ep->e_vm.vm_pmap = XXX; */
1475 	} else {
1476 		struct vmspace *vm = p->p_vmspace;
1477 
1478 		ep->e_vm.vm_rssize = vm_resident_count(vm);
1479 		ep->e_vm.vm_tsize = vm->vm_tsize;
1480 		ep->e_vm.vm_dsize = vm->vm_dsize;
1481 		ep->e_vm.vm_ssize = vm->vm_ssize;
1482 	}
1483 	if (p->p_pptr)
1484 		ep->e_ppid = p->p_pptr->p_pid;
1485 	else
1486 		ep->e_ppid = 0;
1487 	ep->e_pgid = p->p_pgrp->pg_id;
1488 	ep->e_sid = ep->e_sess->s_sid;
1489 	ep->e_jobc = p->p_pgrp->pg_jobc;
1490 	if ((p->p_flag & P_CONTROLT) &&
1491 	     (tp = ep->e_sess->s_ttyp)) {
1492 		ep->e_tdev = tp->t_dev;
1493 		ep->e_tpgid = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PID;
1494 		ep->e_tsess = tp->t_session;
1495 	} else
1496 		ep->e_tdev = NODEV;
1497 	if (p->p_wmesg)
1498 		strncpy(ep->e_wmesg, p->p_wmesg, WMESGLEN);
1499 	ep->e_xsize = ep->e_xrssize = 0;
1500 	ep->e_xccount = ep->e_xswrss = 0;
1501 	ep->e_flag = ep->e_sess->s_ttyvp ? EPROC_CTTY : 0;
1502 	if (SESS_LEADER(p))
1503 		ep->e_flag |= EPROC_SLEADER;
1504 	strncpy(ep->e_login, ep->e_sess->s_login, MAXLOGNAME);
1505 }
1506 
1507 /*
1508  * Fill in an eproc structure for the specified process.
1509  */
1510 static void
1511 fill_kproc2(struct proc *p, struct kinfo_proc2 *ki)
1512 {
1513 	struct tty *tp;
1514 
1515 	memset(ki, 0, sizeof(*ki));
1516 
1517 	ki->p_forw = PTRTOINT64(p->p_forw);
1518 	ki->p_back = PTRTOINT64(p->p_back);
1519 	ki->p_paddr = PTRTOINT64(p);
1520 
1521 	ki->p_addr = PTRTOINT64(p->p_addr);
1522 	ki->p_fd = PTRTOINT64(p->p_fd);
1523 	ki->p_cwdi = PTRTOINT64(p->p_cwdi);
1524 	ki->p_stats = PTRTOINT64(p->p_stats);
1525 	ki->p_limit = PTRTOINT64(p->p_limit);
1526 	ki->p_vmspace = PTRTOINT64(p->p_vmspace);
1527 	ki->p_sigacts = PTRTOINT64(p->p_sigacts);
1528 	ki->p_sess = PTRTOINT64(p->p_session);
1529 	ki->p_tsess = 0;	/* may be changed if controlling tty below */
1530 	ki->p_ru = PTRTOINT64(p->p_ru);
1531 
1532 	ki->p_eflag = 0;
1533 	ki->p_exitsig = p->p_exitsig;
1534 	ki->p_flag = p->p_flag;
1535 
1536 	ki->p_pid = p->p_pid;
1537 	if (p->p_pptr)
1538 		ki->p_ppid = p->p_pptr->p_pid;
1539 	else
1540 		ki->p_ppid = 0;
1541 	ki->p_sid = p->p_session->s_sid;
1542 	ki->p__pgid = p->p_pgrp->pg_id;
1543 
1544 	ki->p_tpgid = NO_PID;	/* may be changed if controlling tty below */
1545 
1546 	ki->p_uid = p->p_ucred->cr_uid;
1547 	ki->p_ruid = p->p_cred->p_ruid;
1548 	ki->p_gid = p->p_ucred->cr_gid;
1549 	ki->p_rgid = p->p_cred->p_rgid;
1550 
1551 	memcpy(ki->p_groups, p->p_cred->pc_ucred->cr_groups,
1552 	    min(sizeof(ki->p_groups), sizeof(p->p_cred->pc_ucred->cr_groups)));
1553 	ki->p_ngroups = p->p_cred->pc_ucred->cr_ngroups;
1554 
1555 	ki->p_jobc = p->p_pgrp->pg_jobc;
1556 	if ((p->p_flag & P_CONTROLT) && (tp = p->p_session->s_ttyp)) {
1557 		ki->p_tdev = tp->t_dev;
1558 		ki->p_tpgid = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PID;
1559 		ki->p_tsess = PTRTOINT64(tp->t_session);
1560 	} else {
1561 		ki->p_tdev = NODEV;
1562 	}
1563 
1564 	ki->p_estcpu = p->p_estcpu;
1565 	ki->p_rtime_sec = p->p_rtime.tv_sec;
1566 	ki->p_rtime_usec = p->p_rtime.tv_usec;
1567 	ki->p_cpticks = p->p_cpticks;
1568 	ki->p_pctcpu = p->p_pctcpu;
1569 	ki->p_swtime = p->p_swtime;
1570 	ki->p_slptime = p->p_slptime;
1571 	if (p->p_stat == SONPROC) {
1572 		KDASSERT(p->p_cpu != NULL);
1573 		ki->p_schedflags = p->p_cpu->ci_schedstate.spc_flags;
1574 	} else
1575 		ki->p_schedflags = 0;
1576 
1577 	ki->p_uticks = p->p_uticks;
1578 	ki->p_sticks = p->p_sticks;
1579 	ki->p_iticks = p->p_iticks;
1580 
1581 	ki->p_tracep = PTRTOINT64(p->p_tracep);
1582 	ki->p_traceflag = p->p_traceflag;
1583 
1584 	ki->p_holdcnt = p->p_holdcnt;
1585 
1586 	memcpy(&ki->p_siglist, &p->p_sigctx.ps_siglist, sizeof(ki_sigset_t));
1587 	memcpy(&ki->p_sigmask, &p->p_sigctx.ps_sigmask, sizeof(ki_sigset_t));
1588 	memcpy(&ki->p_sigignore, &p->p_sigctx.ps_sigignore,sizeof(ki_sigset_t));
1589 	memcpy(&ki->p_sigcatch, &p->p_sigctx.ps_sigcatch, sizeof(ki_sigset_t));
1590 
1591 	ki->p_stat = p->p_stat;
1592 	ki->p_priority = p->p_priority;
1593 	ki->p_usrpri = p->p_usrpri;
1594 	ki->p_nice = p->p_nice;
1595 
1596 	ki->p_xstat = p->p_xstat;
1597 	ki->p_acflag = p->p_acflag;
1598 
1599 	strncpy(ki->p_comm, p->p_comm,
1600 	    min(sizeof(ki->p_comm), sizeof(p->p_comm)));
1601 
1602 	if (p->p_wmesg)
1603 		strncpy(ki->p_wmesg, p->p_wmesg, sizeof(ki->p_wmesg));
1604 	ki->p_wchan = PTRTOINT64(p->p_wchan);
1605 
1606 	strncpy(ki->p_login, p->p_session->s_login, sizeof(ki->p_login));
1607 
1608 	if (p->p_stat == SIDL || P_ZOMBIE(p)) {
1609 		ki->p_vm_rssize = 0;
1610 		ki->p_vm_tsize = 0;
1611 		ki->p_vm_dsize = 0;
1612 		ki->p_vm_ssize = 0;
1613 	} else {
1614 		struct vmspace *vm = p->p_vmspace;
1615 
1616 		ki->p_vm_rssize = vm_resident_count(vm);
1617 		ki->p_vm_tsize = vm->vm_tsize;
1618 		ki->p_vm_dsize = vm->vm_dsize;
1619 		ki->p_vm_ssize = vm->vm_ssize;
1620 	}
1621 
1622 	if (p->p_session->s_ttyvp)
1623 		ki->p_eflag |= EPROC_CTTY;
1624 	if (SESS_LEADER(p))
1625 		ki->p_eflag |= EPROC_SLEADER;
1626 
1627 	/* XXX Is this double check necessary? */
1628 	if ((p->p_flag & P_INMEM) == 0 || P_ZOMBIE(p)) {
1629 		ki->p_uvalid = 0;
1630 	} else {
1631 		ki->p_uvalid = 1;
1632 
1633 		ki->p_ustart_sec = p->p_stats->p_start.tv_sec;
1634 		ki->p_ustart_usec = p->p_stats->p_start.tv_usec;
1635 
1636 		ki->p_uutime_sec = p->p_stats->p_ru.ru_utime.tv_sec;
1637 		ki->p_uutime_usec = p->p_stats->p_ru.ru_utime.tv_usec;
1638 		ki->p_ustime_sec = p->p_stats->p_ru.ru_stime.tv_sec;
1639 		ki->p_ustime_usec = p->p_stats->p_ru.ru_stime.tv_usec;
1640 
1641 		ki->p_uru_maxrss = p->p_stats->p_ru.ru_maxrss;
1642 		ki->p_uru_ixrss = p->p_stats->p_ru.ru_ixrss;
1643 		ki->p_uru_idrss = p->p_stats->p_ru.ru_idrss;
1644 		ki->p_uru_isrss = p->p_stats->p_ru.ru_isrss;
1645 		ki->p_uru_minflt = p->p_stats->p_ru.ru_minflt;
1646 		ki->p_uru_majflt = p->p_stats->p_ru.ru_majflt;
1647 		ki->p_uru_nswap = p->p_stats->p_ru.ru_nswap;
1648 		ki->p_uru_inblock = p->p_stats->p_ru.ru_inblock;
1649 		ki->p_uru_oublock = p->p_stats->p_ru.ru_oublock;
1650 		ki->p_uru_msgsnd = p->p_stats->p_ru.ru_msgsnd;
1651 		ki->p_uru_msgrcv = p->p_stats->p_ru.ru_msgrcv;
1652 		ki->p_uru_nsignals = p->p_stats->p_ru.ru_nsignals;
1653 		ki->p_uru_nvcsw = p->p_stats->p_ru.ru_nvcsw;
1654 		ki->p_uru_nivcsw = p->p_stats->p_ru.ru_nivcsw;
1655 
1656 		ki->p_uctime_sec = p->p_stats->p_cru.ru_utime.tv_sec +
1657 		    p->p_stats->p_cru.ru_stime.tv_sec;
1658 		ki->p_uctime_usec = p->p_stats->p_cru.ru_utime.tv_usec +
1659 		    p->p_stats->p_cru.ru_stime.tv_usec;
1660 	}
1661 #ifdef MULTIPROCESSOR
1662 	if (p->p_cpu != NULL)
1663 		ki->p_cpuid = p->p_cpu->ci_cpuid;
1664 	else
1665 #endif
1666 		ki->p_cpuid = KI_NOCPU;
1667 }
1668 
1669 int
1670 sysctl_procargs(int *name, u_int namelen, void *where, size_t *sizep,
1671     struct proc *up)
1672 {
1673 	struct ps_strings pss;
1674 	struct proc *p;
1675 	size_t len, upper_bound, xlen;
1676 	struct uio auio;
1677 	struct iovec aiov;
1678 	vaddr_t argv;
1679 	pid_t pid;
1680 	int nargv, type, error, i;
1681 	char *arg;
1682 	char *tmp;
1683 
1684 	if (namelen != 2)
1685 		return (EINVAL);
1686 	pid = name[0];
1687 	type = name[1];
1688 
1689 	switch (type) {
1690 	  case KERN_PROC_ARGV:
1691 	  case KERN_PROC_NARGV:
1692 	  case KERN_PROC_ENV:
1693 	  case KERN_PROC_NENV:
1694 		/* ok */
1695 		break;
1696 	  default:
1697 		return (EINVAL);
1698 	}
1699 
1700 	/* check pid */
1701 	if ((p = pfind(pid)) == NULL)
1702 		return (EINVAL);
1703 
1704 	/* only root or same user change look at the environment */
1705 	if (type == KERN_PROC_ENV || type == KERN_PROC_NENV) {
1706 		if (up->p_ucred->cr_uid != 0) {
1707 			if (up->p_cred->p_ruid != p->p_cred->p_ruid ||
1708 			    up->p_cred->p_ruid != p->p_cred->p_svuid)
1709 				return (EPERM);
1710 		}
1711 	}
1712 
1713 	if (sizep != NULL && where == NULL) {
1714 		if (type == KERN_PROC_NARGV || type == KERN_PROC_NENV)
1715 			*sizep = sizeof (int);
1716 		else
1717 			*sizep = ARG_MAX;	/* XXX XXX XXX */
1718 		return (0);
1719 	}
1720 	if (where == NULL || sizep == NULL)
1721 		return (EINVAL);
1722 
1723 	/*
1724 	 * Zombies don't have a stack, so we can't read their psstrings.
1725 	 * System processes also don't have a user stack.
1726 	 */
1727 	if (P_ZOMBIE(p) || (p->p_flag & P_SYSTEM) != 0)
1728 		return (EINVAL);
1729 
1730 	/*
1731 	 * Lock the process down in memory.
1732 	 */
1733 	/* XXXCDC: how should locking work here? */
1734 	if ((p->p_flag & P_WEXIT) || (p->p_vmspace->vm_refcnt < 1))
1735 		return (EFAULT);
1736 	p->p_vmspace->vm_refcnt++;	/* XXX */
1737 
1738 	/*
1739 	 * Allocate a temporary buffer to hold the arguments.
1740 	 */
1741 	arg = malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
1742 
1743 	/*
1744 	 * Read in the ps_strings structure.
1745 	 */
1746 	aiov.iov_base = &pss;
1747 	aiov.iov_len = sizeof(pss);
1748 	auio.uio_iov = &aiov;
1749 	auio.uio_iovcnt = 1;
1750 	auio.uio_offset = (vaddr_t)p->p_psstr;
1751 	auio.uio_resid = sizeof(pss);
1752 	auio.uio_segflg = UIO_SYSSPACE;
1753 	auio.uio_rw = UIO_READ;
1754 	auio.uio_procp = NULL;
1755 	error = uvm_io(&p->p_vmspace->vm_map, &auio);
1756 	if (error)
1757 		goto done;
1758 
1759 	if (type == KERN_PROC_ARGV || type == KERN_PROC_NARGV)
1760 		memcpy(&nargv, (char *)&pss + p->p_psnargv, sizeof(nargv));
1761 	else
1762 		memcpy(&nargv, (char *)&pss + p->p_psnenv, sizeof(nargv));
1763 	if (type == KERN_PROC_NARGV || type == KERN_PROC_NENV) {
1764 		error = copyout(&nargv, where, sizeof(nargv));
1765 		*sizep = sizeof(nargv);
1766 		goto done;
1767 	}
1768 	/*
1769 	 * Now read the address of the argument vector.
1770 	 */
1771 	switch (type) {
1772 	case KERN_PROC_ARGV:
1773 		/* XXX compat32 stuff here */
1774 		memcpy(&tmp, (char *)&pss + p->p_psargv, sizeof(tmp));
1775 		break;
1776 	case KERN_PROC_ENV:
1777 		memcpy(&tmp, (char *)&pss + p->p_psenv, sizeof(tmp));
1778 		break;
1779 	default:
1780 		return (EINVAL);
1781 	}
1782 	auio.uio_offset = (off_t)(long)tmp;
1783 	aiov.iov_base = &argv;
1784 	aiov.iov_len = sizeof(argv);
1785 	auio.uio_iov = &aiov;
1786 	auio.uio_iovcnt = 1;
1787 	auio.uio_resid = sizeof(argv);
1788 	auio.uio_segflg = UIO_SYSSPACE;
1789 	auio.uio_rw = UIO_READ;
1790 	auio.uio_procp = NULL;
1791 	error = uvm_io(&p->p_vmspace->vm_map, &auio);
1792 	if (error)
1793 		goto done;
1794 
1795 	/*
1796 	 * Now copy in the actual argument vector, one page at a time,
1797 	 * since we don't know how long the vector is (though, we do
1798 	 * know how many NUL-terminated strings are in the vector).
1799 	 */
1800 	len = 0;
1801 	upper_bound = *sizep;
1802 	for (; nargv != 0 && len < upper_bound; len += xlen) {
1803 		aiov.iov_base = arg;
1804 		aiov.iov_len = PAGE_SIZE;
1805 		auio.uio_iov = &aiov;
1806 		auio.uio_iovcnt = 1;
1807 		auio.uio_offset = argv + len;
1808 		xlen = PAGE_SIZE - ((argv + len) & PAGE_MASK);
1809 		auio.uio_resid = xlen;
1810 		auio.uio_segflg = UIO_SYSSPACE;
1811 		auio.uio_rw = UIO_READ;
1812 		auio.uio_procp = NULL;
1813 		error = uvm_io(&p->p_vmspace->vm_map, &auio);
1814 		if (error)
1815 			goto done;
1816 
1817 		for (i = 0; i < xlen && nargv != 0; i++) {
1818 			if (arg[i] == '\0')
1819 				nargv--;	/* one full string */
1820 		}
1821 
1822 		/* make sure we don't copyout past the end of the user's buffer */
1823 		if (len + i > upper_bound)
1824 			i = upper_bound - len;
1825 
1826 		error = copyout(arg, (char *)where + len, i);
1827 		if (error)
1828 			break;
1829 
1830 		if (nargv == 0) {
1831 			len += i;
1832 			break;
1833 		}
1834 	}
1835 	*sizep = len;
1836 
1837 done:
1838 	uvmspace_free(p->p_vmspace);
1839 
1840 	free(arg, M_TEMP);
1841 	return (error);
1842 }
1843 
1844 #if NPTY > 0
1845 int pty_maxptys(int, int);		/* defined in kern/tty_pty.c */
1846 
1847 /*
1848  * Validate parameters and get old / set new parameters
1849  * for pty sysctl function.
1850  */
1851 static int
1852 sysctl_pty(void *oldp, size_t *oldlenp, void *newp, size_t newlen)
1853 {
1854 	int error = 0;
1855 	int oldmax = 0, newmax = 0;
1856 
1857 	/* get current value of maxptys */
1858 	oldmax = pty_maxptys(0, 0);
1859 
1860 	SYSCTL_SCALAR_CORE_TYP(oldp, oldlenp, &oldmax, int)
1861 
1862 	if (!error && newp) {
1863 		SYSCTL_SCALAR_NEWPCHECK_TYP(newp, newlen, int)
1864 		SYSCTL_SCALAR_NEWPCOP_TYP(newp, &newmax, int)
1865 
1866 		if (newmax != pty_maxptys(newmax, (newp != NULL)))
1867 			return (EINVAL);
1868 
1869 	}
1870 
1871 	return (error);
1872 }
1873 #endif /* NPTY > 0 */
1874