xref: /netbsd-src/sys/kern/kern_sysctl.c (revision 8a8f936f250a330d54f8a24ed0e92aadf9743a7b)
1 /*	$NetBSD: kern_sysctl.c,v 1.95 2001/09/24 06:01:13 chs 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 "opt_ddb.h"
46 #include "opt_insecure.h"
47 #include "opt_defcorename.h"
48 #include "opt_new_pipe.h"
49 #include "opt_sysv.h"
50 #include "pty.h"
51 
52 #include <sys/param.h>
53 #include <sys/systm.h>
54 #include <sys/kernel.h>
55 #include <sys/buf.h>
56 #include <sys/device.h>
57 #include <sys/disklabel.h>
58 #include <sys/dkstat.h>
59 #include <sys/exec.h>
60 #include <sys/file.h>
61 #include <sys/ioctl.h>
62 #include <sys/malloc.h>
63 #include <sys/mount.h>
64 #include <sys/msgbuf.h>
65 #include <sys/pool.h>
66 #include <sys/proc.h>
67 #include <sys/resource.h>
68 #include <sys/resourcevar.h>
69 #include <sys/syscallargs.h>
70 #include <sys/tty.h>
71 #include <sys/unistd.h>
72 #include <sys/vnode.h>
73 #include <sys/socketvar.h>
74 #define	__SYSCTL_PRIVATE
75 #include <sys/sysctl.h>
76 #include <sys/lock.h>
77 #include <sys/namei.h>
78 
79 #if defined(SYSVMSG) || defined(SYSVSEM) || defined(SYSVSHM)
80 #include <sys/ipc.h>
81 #endif
82 #ifdef SYSVMSG
83 #include <sys/msg.h>
84 #endif
85 #ifdef SYSVSEM
86 #include <sys/sem.h>
87 #endif
88 #ifdef SYSVSHM
89 #include <sys/shm.h>
90 #endif
91 
92 #include <dev/cons.h>
93 
94 #if defined(DDB)
95 #include <ddb/ddbvar.h>
96 #endif
97 
98 #ifdef NEW_PIPE
99 #include <sys/pipe.h>
100 #endif
101 
102 #define PTRTOINT64(foo)	((u_int64_t)(uintptr_t)(foo))
103 
104 static int sysctl_file(void *, size_t *);
105 #if defined(SYSVMSG) || defined(SYSVSEM) || defined(SYSVSHM)
106 static int sysctl_sysvipc(int *, u_int, void *, size_t *);
107 #endif
108 static int sysctl_msgbuf(void *, size_t *);
109 static int sysctl_doeproc(int *, u_int, void *, size_t *);
110 #ifdef MULTIPROCESSOR
111 static int sysctl_docptime(void *, size_t *, void *);
112 static int sysctl_ncpus(void);
113 #endif
114 static void fill_kproc2(struct proc *, struct kinfo_proc2 *);
115 static int sysctl_procargs(int *, u_int, void *, size_t *, struct proc *);
116 #if NPTY > 0
117 static int sysctl_pty(void *, size_t *, void *, size_t);
118 #endif
119 
120 /*
121  * The `sysctl_memlock' is intended to keep too many processes from
122  * locking down memory by doing sysctls at once.  Whether or not this
123  * is really a good idea to worry about it probably a subject of some
124  * debate.
125  */
126 struct lock sysctl_memlock;
127 
128 void
129 sysctl_init(void)
130 {
131 
132 	lockinit(&sysctl_memlock, PRIBIO|PCATCH, "sysctl", 0, 0);
133 }
134 
135 int
136 sys___sysctl(struct proc *p, void *v, register_t *retval)
137 {
138 	struct sys___sysctl_args /* {
139 		syscallarg(int *) name;
140 		syscallarg(u_int) namelen;
141 		syscallarg(void *) old;
142 		syscallarg(size_t *) oldlenp;
143 		syscallarg(void *) new;
144 		syscallarg(size_t) newlen;
145 	} */ *uap = v;
146 	int error;
147 	size_t savelen = 0, oldlen = 0;
148 	sysctlfn *fn;
149 	int name[CTL_MAXNAME];
150 	size_t *oldlenp;
151 
152 	/*
153 	 * all top-level sysctl names are non-terminal
154 	 */
155 	if (SCARG(uap, namelen) > CTL_MAXNAME || SCARG(uap, namelen) < 2)
156 		return (EINVAL);
157 	error = copyin(SCARG(uap, name), &name,
158 		       SCARG(uap, namelen) * sizeof(int));
159 	if (error)
160 		return (error);
161 
162 	/*
163 	 * For all but CTL_PROC, must be root to change a value.
164 	 * For CTL_PROC, must be root, or owner of the proc (and not suid),
165 	 * this is checked in proc_sysctl() (once we know the targer proc).
166 	 */
167 	if (SCARG(uap, new) != NULL && name[0] != CTL_PROC &&
168 		    (error = suser(p->p_ucred, &p->p_acflag)))
169 			return error;
170 
171 	switch (name[0]) {
172 	case CTL_KERN:
173 		fn = kern_sysctl;
174 		break;
175 	case CTL_HW:
176 		fn = hw_sysctl;
177 		break;
178 	case CTL_VM:
179 		fn = uvm_sysctl;
180 		break;
181 	case CTL_NET:
182 		fn = net_sysctl;
183 		break;
184 	case CTL_VFS:
185 		fn = vfs_sysctl;
186 		break;
187 	case CTL_MACHDEP:
188 		fn = cpu_sysctl;
189 		break;
190 #ifdef DEBUG
191 	case CTL_DEBUG:
192 		fn = debug_sysctl;
193 		break;
194 #endif
195 #ifdef DDB
196 	case CTL_DDB:
197 		fn = ddb_sysctl;
198 		break;
199 #endif
200 	case CTL_PROC:
201 		fn = proc_sysctl;
202 		break;
203 	default:
204 		return (EOPNOTSUPP);
205 	}
206 
207 	/*
208 	 * XXX Hey, we wire `old', but what about `new'?
209 	 */
210 
211 	oldlenp = SCARG(uap, oldlenp);
212 	if (oldlenp) {
213 		if ((error = copyin(oldlenp, &oldlen, sizeof(oldlen))))
214 			return (error);
215 		oldlenp = &oldlen;
216 	}
217 	if (SCARG(uap, old) != NULL) {
218 		error = lockmgr(&sysctl_memlock, LK_EXCLUSIVE, NULL);
219 		if (error)
220 			return (error);
221 		error = uvm_vslock(p, SCARG(uap, old), oldlen,
222 		    VM_PROT_READ|VM_PROT_WRITE);
223 		if (error) {
224 			(void) lockmgr(&sysctl_memlock, LK_RELEASE, NULL);
225 			return error;
226 		}
227 		savelen = oldlen;
228 	}
229 	error = (*fn)(name + 1, SCARG(uap, namelen) - 1, SCARG(uap, old),
230 	    oldlenp, SCARG(uap, new), SCARG(uap, newlen), p);
231 	if (SCARG(uap, old) != NULL) {
232 		uvm_vsunlock(p, SCARG(uap, old), savelen);
233 		(void) lockmgr(&sysctl_memlock, LK_RELEASE, NULL);
234 	}
235 	if (error)
236 		return (error);
237 	if (SCARG(uap, oldlenp))
238 		error = copyout(&oldlen, SCARG(uap, oldlenp), sizeof(oldlen));
239 	return (error);
240 }
241 
242 /*
243  * Attributes stored in the kernel.
244  */
245 char hostname[MAXHOSTNAMELEN];
246 int hostnamelen;
247 
248 char domainname[MAXHOSTNAMELEN];
249 int domainnamelen;
250 
251 long hostid;
252 
253 #ifdef INSECURE
254 int securelevel = -1;
255 #else
256 int securelevel = 0;
257 #endif
258 
259 #ifndef DEFCORENAME
260 #define	DEFCORENAME	"%n.core"
261 #endif
262 char defcorename[MAXPATHLEN] = DEFCORENAME;
263 int defcorenamelen = sizeof(DEFCORENAME);
264 
265 extern	int	kern_logsigexit;
266 extern	fixpt_t	ccpu;
267 
268 #ifndef MULTIPROCESSOR
269 #define sysctl_ncpus() 1
270 #endif
271 
272 #ifdef MULTIPROCESSOR
273 
274 #ifndef CPU_INFO_FOREACH
275 #define CPU_INFO_ITERATOR int
276 #define CPU_INFO_FOREACH(cii, ci) cii = 0, ci = curcpu(); ci != NULL; ci = NULL
277 #endif
278 
279 static int
280 sysctl_docptime(void *oldp, size_t *oldlenp, void *newp)
281 {
282 	u_int64_t cp_time[CPUSTATES];
283 	int i;
284 	struct cpu_info *ci;
285 	CPU_INFO_ITERATOR cii;
286 
287 	for (i=0; i<CPUSTATES; i++)
288 		cp_time[i] = 0;
289 
290 	for (CPU_INFO_FOREACH(cii, ci)) {
291 		for (i=0; i<CPUSTATES; i++)
292 			cp_time[i] += ci->ci_schedstate.spc_cp_time[i];
293 	}
294 	return (sysctl_rdstruct(oldp, oldlenp, newp,
295 	    cp_time, sizeof(cp_time)));
296 }
297 
298 static int
299 sysctl_ncpus(void)
300 {
301 	struct cpu_info *ci;
302 	CPU_INFO_ITERATOR cii;
303 
304 	int ncpus = 0;
305 	for (CPU_INFO_FOREACH(cii, ci))
306 		ncpus++;
307 	return ncpus;
308 }
309 
310 #endif
311 
312 /*
313  * kernel related system variables.
314  */
315 int
316 kern_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
317     void *newp, size_t newlen, struct proc *p)
318 {
319 	int error, level, inthostid;
320 	int old_autonicetime;
321 	int old_vnodes;
322 	dev_t consdev;
323 
324 	/* All sysctl names at this level, except for a few, are terminal. */
325 	switch (name[0]) {
326 	case KERN_PROC:
327 	case KERN_PROC2:
328 	case KERN_PROF:
329 	case KERN_MBUF:
330 	case KERN_PROC_ARGS:
331 	case KERN_SYSVIPC_INFO:
332 	case KERN_PIPE:
333 		/* Not terminal. */
334 		break;
335 	default:
336 		if (namelen != 1)
337 			return (ENOTDIR);	/* overloaded */
338 	}
339 
340 	switch (name[0]) {
341 	case KERN_OSTYPE:
342 		return (sysctl_rdstring(oldp, oldlenp, newp, ostype));
343 	case KERN_OSRELEASE:
344 		return (sysctl_rdstring(oldp, oldlenp, newp, osrelease));
345 	case KERN_OSREV:
346 		return (sysctl_rdint(oldp, oldlenp, newp, __NetBSD_Version__));
347 	case KERN_VERSION:
348 		return (sysctl_rdstring(oldp, oldlenp, newp, version));
349 	case KERN_MAXVNODES:
350 		old_vnodes = desiredvnodes;
351 		error = sysctl_int(oldp, oldlenp, newp, newlen, &desiredvnodes);
352 		if (old_vnodes > desiredvnodes) {
353 		        desiredvnodes = old_vnodes;
354 			return (EINVAL);
355 		}
356 		if (error == 0) {
357 			vfs_reinit();
358 			nchreinit();
359 		}
360 		return (error);
361 	case KERN_MAXPROC:
362 		return (sysctl_int(oldp, oldlenp, newp, newlen, &maxproc));
363 	case KERN_MAXFILES:
364 		return (sysctl_int(oldp, oldlenp, newp, newlen, &maxfiles));
365 	case KERN_ARGMAX:
366 		return (sysctl_rdint(oldp, oldlenp, newp, ARG_MAX));
367 	case KERN_SECURELVL:
368 		level = securelevel;
369 		if ((error = sysctl_int(oldp, oldlenp, newp, newlen, &level)) ||
370 		    newp == NULL)
371 			return (error);
372 		if (level < securelevel && p->p_pid != 1)
373 			return (EPERM);
374 		securelevel = level;
375 		return (0);
376 	case KERN_HOSTNAME:
377 		error = sysctl_string(oldp, oldlenp, newp, newlen,
378 		    hostname, sizeof(hostname));
379 		if (newp && !error)
380 			hostnamelen = newlen;
381 		return (error);
382 	case KERN_DOMAINNAME:
383 		error = sysctl_string(oldp, oldlenp, newp, newlen,
384 		    domainname, sizeof(domainname));
385 		if (newp && !error)
386 			domainnamelen = newlen;
387 		return (error);
388 	case KERN_HOSTID:
389 		inthostid = hostid;  /* XXX assumes sizeof long <= sizeof int */
390 		error =  sysctl_int(oldp, oldlenp, newp, newlen, &inthostid);
391 		hostid = inthostid;
392 		return (error);
393 	case KERN_CLOCKRATE:
394 		return (sysctl_clockrate(oldp, oldlenp));
395 	case KERN_BOOTTIME:
396 		return (sysctl_rdstruct(oldp, oldlenp, newp, &boottime,
397 		    sizeof(struct timeval)));
398 	case KERN_VNODE:
399 		return (sysctl_vnode(oldp, oldlenp, p));
400 	case KERN_PROC:
401 	case KERN_PROC2:
402 		return (sysctl_doeproc(name, namelen, oldp, oldlenp));
403 	case KERN_PROC_ARGS:
404 		return (sysctl_procargs(name + 1, namelen - 1,
405 		    oldp, oldlenp, p));
406 	case KERN_FILE:
407 		return (sysctl_file(oldp, oldlenp));
408 #ifdef GPROF
409 	case KERN_PROF:
410 		return (sysctl_doprof(name + 1, namelen - 1, oldp, oldlenp,
411 		    newp, newlen));
412 #endif
413 	case KERN_POSIX1:
414 		return (sysctl_rdint(oldp, oldlenp, newp, _POSIX_VERSION));
415 	case KERN_NGROUPS:
416 		return (sysctl_rdint(oldp, oldlenp, newp, NGROUPS_MAX));
417 	case KERN_JOB_CONTROL:
418 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
419 	case KERN_SAVED_IDS:
420 #ifdef _POSIX_SAVED_IDS
421 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
422 #else
423 		return (sysctl_rdint(oldp, oldlenp, newp, 0));
424 #endif
425 	case KERN_MAXPARTITIONS:
426 		return (sysctl_rdint(oldp, oldlenp, newp, MAXPARTITIONS));
427 	case KERN_RAWPARTITION:
428 		return (sysctl_rdint(oldp, oldlenp, newp, RAW_PART));
429 #ifdef NTP
430 	case KERN_NTPTIME:
431 		return (sysctl_ntptime(oldp, oldlenp));
432 #endif
433 	case KERN_AUTONICETIME:
434 	        old_autonicetime = autonicetime;
435 	        error = sysctl_int(oldp, oldlenp, newp, newlen, &autonicetime);
436 		if (autonicetime < 0)
437  		        autonicetime = old_autonicetime;
438 		return (error);
439 	case KERN_AUTONICEVAL:
440 		error = sysctl_int(oldp, oldlenp, newp, newlen, &autoniceval);
441 		if (autoniceval < PRIO_MIN)
442 			autoniceval = PRIO_MIN;
443 		if (autoniceval > PRIO_MAX)
444 			autoniceval = PRIO_MAX;
445 		return (error);
446 	case KERN_RTC_OFFSET:
447 		return (sysctl_rdint(oldp, oldlenp, newp, rtc_offset));
448 	case KERN_ROOT_DEVICE:
449 		return (sysctl_rdstring(oldp, oldlenp, newp,
450 		    root_device->dv_xname));
451 	case KERN_MSGBUFSIZE:
452 		/*
453 		 * deal with cases where the message buffer has
454 		 * become corrupted.
455 		 */
456 		if (!msgbufenabled || msgbufp->msg_magic != MSG_MAGIC) {
457 			msgbufenabled = 0;
458 			return (ENXIO);
459 		}
460 		return (sysctl_rdint(oldp, oldlenp, newp, msgbufp->msg_bufs));
461 	case KERN_FSYNC:
462 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
463 	case KERN_SYSVMSG:
464 #ifdef SYSVMSG
465 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
466 #else
467 		return (sysctl_rdint(oldp, oldlenp, newp, 0));
468 #endif
469 	case KERN_SYSVSEM:
470 #ifdef SYSVSEM
471 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
472 #else
473 		return (sysctl_rdint(oldp, oldlenp, newp, 0));
474 #endif
475 	case KERN_SYSVSHM:
476 #ifdef SYSVSHM
477 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
478 #else
479 		return (sysctl_rdint(oldp, oldlenp, newp, 0));
480 #endif
481  	case KERN_DEFCORENAME:
482 		if (newp && newlen < 1)
483 			return (EINVAL);
484 		error = sysctl_string(oldp, oldlenp, newp, newlen,
485 		    defcorename, sizeof(defcorename));
486 		if (newp && !error)
487 			defcorenamelen = newlen;
488 		return (error);
489 	case KERN_SYNCHRONIZED_IO:
490 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
491 	case KERN_IOV_MAX:
492 		return (sysctl_rdint(oldp, oldlenp, newp, IOV_MAX));
493 	case KERN_MBUF:
494 		return (sysctl_dombuf(name + 1, namelen - 1, oldp, oldlenp,
495 		    newp, newlen));
496 	case KERN_MAPPED_FILES:
497 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
498 	case KERN_MEMLOCK:
499 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
500 	case KERN_MEMLOCK_RANGE:
501 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
502 	case KERN_MEMORY_PROTECTION:
503 		return (sysctl_rdint(oldp, oldlenp, newp, 1));
504 	case KERN_LOGIN_NAME_MAX:
505 		return (sysctl_rdint(oldp, oldlenp, newp, LOGIN_NAME_MAX));
506 	case KERN_LOGSIGEXIT:
507 		return (sysctl_int(oldp, oldlenp, newp, newlen,
508 		    &kern_logsigexit));
509 	case KERN_FSCALE:
510 		return (sysctl_rdint(oldp, oldlenp, newp, FSCALE));
511 	case KERN_CCPU:
512 		return (sysctl_rdint(oldp, oldlenp, newp, ccpu));
513 	case KERN_CP_TIME:
514 #ifndef MULTIPROCESSOR
515 		return (sysctl_rdstruct(oldp, oldlenp, newp,
516 		    curcpu()->ci_schedstate.spc_cp_time,
517 		    sizeof(curcpu()->ci_schedstate.spc_cp_time)));
518 #else
519 		return (sysctl_docptime(oldp, oldlenp, newp));
520 #endif
521 #if defined(SYSVMSG) || defined(SYSVSEM) || defined(SYSVSHM)
522 	case KERN_SYSVIPC_INFO:
523 		return (sysctl_sysvipc(name + 1, namelen - 1, oldp, oldlenp));
524 #endif
525 	case KERN_MSGBUF:
526 		return (sysctl_msgbuf(oldp, oldlenp));
527 	case KERN_CONSDEV:
528 		if (cn_tab != NULL)
529 			consdev = cn_tab->cn_dev;
530 		else
531 			consdev = NODEV;
532 		return (sysctl_rdstruct(oldp, oldlenp, newp, &consdev,
533 		    sizeof consdev));
534 #if NPTY > 0
535 	case KERN_MAXPTYS:
536 		return sysctl_pty(oldp, oldlenp, newp, newlen);
537 #endif
538 #ifdef NEW_PIPE
539 	case KERN_PIPE:
540 		return (sysctl_dopipe(name + 1, namelen - 1, oldp, oldlenp,
541 		    newp, newlen));
542 #endif
543 	case KERN_MAXPHYS:
544 		return (sysctl_rdint(oldp, oldlenp, newp, MAXPHYS));
545 	case KERN_SBMAX:
546 	    {
547 		int new_sbmax = sb_max;
548 
549 		error = sysctl_int(oldp, oldlenp, newp, newlen, &new_sbmax);
550 		if (error == 0) {
551 			if (new_sbmax < (16 * 1024)) /* sanity */
552 				return (EINVAL);
553 			sb_max = new_sbmax;
554 		}
555 		return (error);
556 	    }
557 	default:
558 		return (EOPNOTSUPP);
559 	}
560 	/* NOTREACHED */
561 }
562 
563 /*
564  * hardware related system variables.
565  */
566 int
567 hw_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
568     void *newp, size_t newlen, struct proc *p)
569 {
570 
571 	/* all sysctl names at this level are terminal */
572 	if (namelen != 1)
573 		return (ENOTDIR);		/* overloaded */
574 
575 	switch (name[0]) {
576 	case HW_MACHINE:
577 		return (sysctl_rdstring(oldp, oldlenp, newp, machine));
578 	case HW_MACHINE_ARCH:
579 		return (sysctl_rdstring(oldp, oldlenp, newp, machine_arch));
580 	case HW_MODEL:
581 		return (sysctl_rdstring(oldp, oldlenp, newp, cpu_model));
582 	case HW_NCPU:
583 		return (sysctl_rdint(oldp, oldlenp, newp, sysctl_ncpus()));
584 	case HW_BYTEORDER:
585 		return (sysctl_rdint(oldp, oldlenp, newp, BYTE_ORDER));
586 	case HW_PHYSMEM:
587 		return (sysctl_rdint(oldp, oldlenp, newp, ctob(physmem)));
588 	case HW_USERMEM:
589 		return (sysctl_rdint(oldp, oldlenp, newp,
590 		    ctob(physmem - uvmexp.wired)));
591 	case HW_PAGESIZE:
592 		return (sysctl_rdint(oldp, oldlenp, newp, PAGE_SIZE));
593 	case HW_ALIGNBYTES:
594 		return (sysctl_rdint(oldp, oldlenp, newp, ALIGNBYTES));
595 	case HW_CNMAGIC: {
596 		char magic[CNS_LEN];
597 		int error;
598 
599 		if (oldp)
600 			cn_get_magic(magic, CNS_LEN);
601 		error = sysctl_string(oldp, oldlenp, newp, newlen,
602 		    magic, sizeof(magic));
603 		if (newp && !error) {
604 			error = cn_set_magic(magic);
605 		}
606 		return (error);
607 	}
608 	default:
609 		return (EOPNOTSUPP);
610 	}
611 	/* NOTREACHED */
612 }
613 
614 #ifdef DEBUG
615 /*
616  * Debugging related system variables.
617  */
618 struct ctldebug debug0, debug1, debug2, debug3, debug4;
619 struct ctldebug debug5, debug6, debug7, debug8, debug9;
620 struct ctldebug debug10, debug11, debug12, debug13, debug14;
621 struct ctldebug debug15, debug16, debug17, debug18, debug19;
622 static struct ctldebug *debugvars[CTL_DEBUG_MAXID] = {
623 	&debug0, &debug1, &debug2, &debug3, &debug4,
624 	&debug5, &debug6, &debug7, &debug8, &debug9,
625 	&debug10, &debug11, &debug12, &debug13, &debug14,
626 	&debug15, &debug16, &debug17, &debug18, &debug19,
627 };
628 
629 int
630 debug_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
631     void *newp, size_t newlen, struct proc *p)
632 {
633 	struct ctldebug *cdp;
634 
635 	/* all sysctl names at this level are name and field */
636 	if (namelen != 2)
637 		return (ENOTDIR);		/* overloaded */
638 	cdp = debugvars[name[0]];
639 	if (name[0] >= CTL_DEBUG_MAXID || cdp->debugname == 0)
640 		return (EOPNOTSUPP);
641 	switch (name[1]) {
642 	case CTL_DEBUG_NAME:
643 		return (sysctl_rdstring(oldp, oldlenp, newp, cdp->debugname));
644 	case CTL_DEBUG_VALUE:
645 		return (sysctl_int(oldp, oldlenp, newp, newlen, cdp->debugvar));
646 	default:
647 		return (EOPNOTSUPP);
648 	}
649 	/* NOTREACHED */
650 }
651 #endif /* DEBUG */
652 
653 int
654 proc_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
655     void *newp, size_t newlen, struct proc *p)
656 {
657 	struct proc *ptmp = NULL;
658 	const struct proclist_desc *pd;
659 	int error = 0;
660 	struct rlimit alim;
661 	struct plimit *newplim;
662 	char *tmps = NULL;
663 	int i, curlen, len;
664 
665 	if (namelen < 2)
666 		return EINVAL;
667 
668 	if (name[0] == PROC_CURPROC) {
669 		ptmp = p;
670 	} else {
671 		proclist_lock_read();
672 		for (pd = proclists; pd->pd_list != NULL; pd++) {
673 			for (ptmp = LIST_FIRST(pd->pd_list); ptmp != NULL;
674 			    ptmp = LIST_NEXT(ptmp, p_list)) {
675 				/* Skip embryonic processes. */
676 				if (ptmp->p_stat == SIDL)
677 					continue;
678 				if (ptmp->p_pid == (pid_t)name[0])
679 					break;
680 			}
681 			if (ptmp != NULL)
682 				break;
683 		}
684 		proclist_unlock_read();
685 		if (ptmp == NULL)
686 			return(ESRCH);
687 		if (p->p_ucred->cr_uid != 0) {
688 			if(p->p_cred->p_ruid != ptmp->p_cred->p_ruid ||
689 			    p->p_cred->p_ruid != ptmp->p_cred->p_svuid)
690 				return EPERM;
691 			if (ptmp->p_cred->p_rgid != ptmp->p_cred->p_svgid)
692 				return EPERM; /* sgid proc */
693 			for (i = 0; i < p->p_ucred->cr_ngroups; i++) {
694 				if (p->p_ucred->cr_groups[i] ==
695 				    ptmp->p_cred->p_rgid)
696 					break;
697 			}
698 			if (i == p->p_ucred->cr_ngroups)
699 				return EPERM;
700 		}
701 	}
702 	if (name[1] == PROC_PID_CORENAME) {
703 		if (namelen != 2)
704 			return EINVAL;
705 		/*
706 		 * Can't use sysctl_string() here because we may malloc a new
707 		 * area during the process, so we have to do it by hand.
708 		 */
709 		curlen = strlen(ptmp->p_limit->pl_corename) + 1;
710 		if (oldlenp  && *oldlenp < curlen) {
711 			if (!oldp)
712 				*oldlenp = curlen;
713 			return (ENOMEM);
714 		}
715 		if (newp) {
716 			if (securelevel > 2)
717 				return EPERM;
718 			if (newlen > MAXPATHLEN)
719 				return ENAMETOOLONG;
720 			tmps = malloc(newlen + 1, M_TEMP, M_WAITOK);
721 			if (tmps == NULL)
722 				return ENOMEM;
723 			error = copyin(newp, tmps, newlen + 1);
724 			tmps[newlen] = '\0';
725 			if (error)
726 				goto cleanup;
727 			/* Enforce to be either 'core' for end with '.core' */
728 			if (newlen < 4)  { /* c.o.r.e */
729 				error = EINVAL;
730 				goto cleanup;
731 			}
732 			len = newlen - 4;
733 			if (len > 0) {
734 				if (tmps[len - 1] != '.' &&
735 				    tmps[len - 1] != '/') {
736 					error = EINVAL;
737 					goto cleanup;
738 				}
739 			}
740 			if (strcmp(&tmps[len], "core") != 0) {
741 				error = EINVAL;
742 				goto cleanup;
743 			}
744 		}
745 		if (oldp && oldlenp) {
746 			*oldlenp = curlen;
747 			error = copyout(ptmp->p_limit->pl_corename, oldp,
748 			    curlen);
749 		}
750 		if (newp && error == 0) {
751 			/* if the 2 strings are identical, don't limcopy() */
752 			if (strcmp(tmps, ptmp->p_limit->pl_corename) == 0) {
753 				error = 0;
754 				goto cleanup;
755 			}
756 			if (ptmp->p_limit->p_refcnt > 1 &&
757 			    (ptmp->p_limit->p_lflags & PL_SHAREMOD) == 0) {
758 				newplim = limcopy(ptmp->p_limit);
759 				limfree(ptmp->p_limit);
760 				ptmp->p_limit = newplim;
761 			} else if (ptmp->p_limit->pl_corename != defcorename) {
762 				free(ptmp->p_limit->pl_corename, M_TEMP);
763 			}
764 			ptmp->p_limit->pl_corename = tmps;
765 			return (0);
766 		}
767 cleanup:
768 		if (tmps)
769 			free(tmps, M_TEMP);
770 		return (error);
771 	}
772 	if (name[1] == PROC_PID_LIMIT) {
773 		if (namelen != 4 || name[2] >= PROC_PID_LIMIT_MAXID)
774 			return EINVAL;
775 		memcpy(&alim, &ptmp->p_rlimit[name[2] - 1], sizeof(alim));
776 		if (name[3] == PROC_PID_LIMIT_TYPE_HARD)
777 			error = sysctl_quad(oldp, oldlenp, newp, newlen,
778 			    &alim.rlim_max);
779 		else if (name[3] == PROC_PID_LIMIT_TYPE_SOFT)
780 			error = sysctl_quad(oldp, oldlenp, newp, newlen,
781 			    &alim.rlim_cur);
782 		else
783 			error = EINVAL;
784 
785 		if (error)
786 			return error;
787 
788 		if (newp)
789 			error = dosetrlimit(ptmp, p->p_cred,
790 			    name[2] - 1, &alim);
791 		return error;
792 	}
793 	return (EINVAL);
794 }
795 
796 /*
797  * Convenience macros.
798  */
799 
800 #define SYSCTL_SCALAR_CORE_LEN(oldp, oldlenp, valp, len) 		\
801 	if (oldlenp) {							\
802 		if (!oldp)						\
803 			*oldlenp = len;					\
804 		else {							\
805 			if (*oldlenp < len)				\
806 				return(ENOMEM);				\
807 			*oldlenp = len;					\
808 			error = copyout((caddr_t)valp, oldp, len);	\
809 		}							\
810 	}
811 
812 #define SYSCTL_SCALAR_CORE_TYP(oldp, oldlenp, valp, typ) \
813 	SYSCTL_SCALAR_CORE_LEN(oldp, oldlenp, valp, sizeof(typ))
814 
815 #define SYSCTL_SCALAR_NEWPCHECK_LEN(newp, newlen, len)	\
816 	if (newp && newlen != len)			\
817 		return (EINVAL);
818 
819 #define SYSCTL_SCALAR_NEWPCHECK_TYP(newp, newlen, typ)	\
820 	SYSCTL_SCALAR_NEWPCHECK_LEN(newp, newlen, sizeof(typ))
821 
822 #define SYSCTL_SCALAR_NEWPCOP_LEN(newp, valp, len)	\
823 	if (error == 0 && newp)				\
824 		error = copyin(newp, valp, len);
825 
826 #define SYSCTL_SCALAR_NEWPCOP_TYP(newp, valp, typ)      \
827 	SYSCTL_SCALAR_NEWPCOP_LEN(newp, valp, sizeof(typ))
828 
829 #define SYSCTL_STRING_CORE(oldp, oldlenp, str)		\
830 	if (oldlenp) {					\
831 		len = strlen(str) + 1;			\
832 		if (!oldp)				\
833 			*oldlenp = len;			\
834 		else {					\
835 			if (*oldlenp < len) {		\
836 				err2 = ENOMEM;		\
837 				len = *oldlenp;		\
838 			} else				\
839 				*oldlenp = len;		\
840 			error = copyout(str, oldp, len);\
841 			if (error == 0)			\
842 				error = err2;		\
843 		}					\
844 	}
845 
846 /*
847  * Validate parameters and get old / set new parameters
848  * for an integer-valued sysctl function.
849  */
850 int
851 sysctl_int(void *oldp, size_t *oldlenp, void *newp, size_t newlen, int *valp)
852 {
853 	int error = 0;
854 
855 	SYSCTL_SCALAR_NEWPCHECK_TYP(newp, newlen, int)
856 	SYSCTL_SCALAR_CORE_TYP(oldp, oldlenp, valp, int)
857 	SYSCTL_SCALAR_NEWPCOP_TYP(newp, valp, int)
858 
859 	return (error);
860 }
861 
862 
863 /*
864  * As above, but read-only.
865  */
866 int
867 sysctl_rdint(void *oldp, size_t *oldlenp, void *newp, int val)
868 {
869 	int error = 0;
870 
871 	if (newp)
872 		return (EPERM);
873 
874 	SYSCTL_SCALAR_CORE_TYP(oldp, oldlenp, &val, int)
875 
876 	return (error);
877 }
878 
879 /*
880  * Validate parameters and get old / set new parameters
881  * for an quad-valued sysctl function.
882  */
883 int
884 sysctl_quad(void *oldp, size_t *oldlenp, void *newp, size_t newlen,
885     quad_t *valp)
886 {
887 	int error = 0;
888 
889 	SYSCTL_SCALAR_NEWPCHECK_TYP(newp, newlen, quad_t)
890 	SYSCTL_SCALAR_CORE_TYP(oldp, oldlenp, valp, quad_t)
891 	SYSCTL_SCALAR_NEWPCOP_TYP(newp, valp, quad_t)
892 
893 	return (error);
894 }
895 
896 /*
897  * As above, but read-only.
898  */
899 int
900 sysctl_rdquad(void *oldp, size_t *oldlenp, void *newp, quad_t val)
901 {
902 	int error = 0;
903 
904 	if (newp)
905 		return (EPERM);
906 
907 	SYSCTL_SCALAR_CORE_TYP(oldp, oldlenp, &val, quad_t)
908 
909 	return (error);
910 }
911 
912 /*
913  * Validate parameters and get old / set new parameters
914  * for a string-valued sysctl function.
915  */
916 int
917 sysctl_string(void *oldp, size_t *oldlenp, void *newp, size_t newlen, char *str,
918     int maxlen)
919 {
920 	int len, error = 0, err2 = 0;
921 
922 	if (newp && newlen >= maxlen)
923 		return (EINVAL);
924 
925 	SYSCTL_STRING_CORE(oldp, oldlenp, str);
926 
927 	if (error == 0 && newp) {
928 		error = copyin(newp, str, newlen);
929 		str[newlen] = 0;
930 	}
931 	return (error);
932 }
933 
934 /*
935  * As above, but read-only.
936  */
937 int
938 sysctl_rdstring(void *oldp, size_t *oldlenp, void *newp, const char *str)
939 {
940 	int len, error = 0, err2 = 0;
941 
942 	if (newp)
943 		return (EPERM);
944 
945 	SYSCTL_STRING_CORE(oldp, oldlenp, str);
946 
947 	return (error);
948 }
949 
950 /*
951  * Validate parameters and get old / set new parameters
952  * for a structure oriented sysctl function.
953  */
954 int
955 sysctl_struct(void *oldp, size_t *oldlenp, void *newp, size_t newlen, void *sp,
956     int len)
957 {
958 	int error = 0;
959 
960 	SYSCTL_SCALAR_NEWPCHECK_LEN(newp, newlen, len)
961 	SYSCTL_SCALAR_CORE_LEN(oldp, oldlenp, sp, len)
962 	SYSCTL_SCALAR_NEWPCOP_LEN(newp, sp, len)
963 
964 	return (error);
965 }
966 
967 /*
968  * Validate parameters and get old parameters
969  * for a structure oriented sysctl function.
970  */
971 int
972 sysctl_rdstruct(void *oldp, size_t *oldlenp, void *newp, const void *sp,
973     int len)
974 {
975 	int error = 0;
976 
977 	if (newp)
978 		return (EPERM);
979 
980 	SYSCTL_SCALAR_CORE_LEN(oldp, oldlenp, sp, len)
981 
982 	return (error);
983 }
984 
985 /*
986  * As above, but can return a truncated result.
987  */
988 int
989 sysctl_rdminstruct(void *oldp, size_t *oldlenp, void *newp, const void *sp,
990     int len)
991 {
992 	int error = 0;
993 
994 	if (newp)
995 		return (EPERM);
996 
997 	len = min(*oldlenp, len);
998 	SYSCTL_SCALAR_CORE_LEN(oldp, oldlenp, sp, len)
999 
1000 	return (error);
1001 }
1002 
1003 /*
1004  * Get file structures.
1005  */
1006 static int
1007 sysctl_file(void *vwhere, size_t *sizep)
1008 {
1009 	int buflen, error;
1010 	struct file *fp;
1011 	char *start, *where;
1012 
1013 	start = where = vwhere;
1014 	buflen = *sizep;
1015 	if (where == NULL) {
1016 		/*
1017 		 * overestimate by 10 files
1018 		 */
1019 		*sizep = sizeof(filehead) + (nfiles + 10) * sizeof(struct file);
1020 		return (0);
1021 	}
1022 
1023 	/*
1024 	 * first copyout filehead
1025 	 */
1026 	if (buflen < sizeof(filehead)) {
1027 		*sizep = 0;
1028 		return (0);
1029 	}
1030 	error = copyout((caddr_t)&filehead, where, sizeof(filehead));
1031 	if (error)
1032 		return (error);
1033 	buflen -= sizeof(filehead);
1034 	where += sizeof(filehead);
1035 
1036 	/*
1037 	 * followed by an array of file structures
1038 	 */
1039 	for (fp = filehead.lh_first; fp != 0; fp = fp->f_list.le_next) {
1040 		if (buflen < sizeof(struct file)) {
1041 			*sizep = where - start;
1042 			return (ENOMEM);
1043 		}
1044 		error = copyout((caddr_t)fp, where, sizeof(struct file));
1045 		if (error)
1046 			return (error);
1047 		buflen -= sizeof(struct file);
1048 		where += sizeof(struct file);
1049 	}
1050 	*sizep = where - start;
1051 	return (0);
1052 }
1053 
1054 #if defined(SYSVMSG) || defined(SYSVSEM) || defined(SYSVSHM)
1055 #define	FILL_PERM(src, dst) do { \
1056 		(dst)._key = (src)._key; \
1057 		(dst).uid = (src).uid; \
1058 		(dst).gid = (src).gid; \
1059 		(dst).cuid = (src).cuid; \
1060 		(dst).cgid = (src).cgid; \
1061 		(dst).mode = (src).mode; \
1062 		(dst)._seq = (src)._seq; \
1063 	} while (0);
1064 #define	FILL_MSG(src, dst) do { \
1065 	FILL_PERM((src).msg_perm, (dst).msg_perm); \
1066 	(dst).msg_qnum = (src).msg_qnum; \
1067 	(dst).msg_qbytes = (src).msg_qbytes; \
1068 	(dst)._msg_cbytes = (src)._msg_cbytes; \
1069 	(dst).msg_lspid = (src).msg_lspid; \
1070 	(dst).msg_lrpid = (src).msg_lrpid; \
1071 	(dst).msg_stime = (src).msg_stime; \
1072 	(dst).msg_rtime = (src).msg_rtime; \
1073 	(dst).msg_ctime = (src).msg_ctime; \
1074 	} while (0)
1075 #define	FILL_SEM(src, dst) do { \
1076 	FILL_PERM((src).sem_perm, (dst).sem_perm); \
1077 	(dst).sem_nsems = (src).sem_nsems; \
1078 	(dst).sem_otime = (src).sem_otime; \
1079 	(dst).sem_ctime = (src).sem_ctime; \
1080 	} while (0)
1081 #define	FILL_SHM(src, dst) do { \
1082 	FILL_PERM((src).shm_perm, (dst).shm_perm); \
1083 	(dst).shm_segsz = (src).shm_segsz; \
1084 	(dst).shm_lpid = (src).shm_lpid; \
1085 	(dst).shm_cpid = (src).shm_cpid; \
1086 	(dst).shm_atime = (src).shm_atime; \
1087 	(dst).shm_dtime = (src).shm_dtime; \
1088 	(dst).shm_ctime = (src).shm_ctime; \
1089 	(dst).shm_nattch = (src).shm_nattch; \
1090 	} while (0)
1091 
1092 static int
1093 sysctl_sysvipc(int *name, u_int namelen, void *where, size_t *sizep)
1094 {
1095 #ifdef SYSVMSG
1096 	struct msg_sysctl_info *msgsi;
1097 #endif
1098 #ifdef SYSVSEM
1099 	struct sem_sysctl_info *semsi;
1100 #endif
1101 #ifdef SYSVSHM
1102 	struct shm_sysctl_info *shmsi;
1103 #endif
1104 	size_t infosize, dssize, tsize, buflen;
1105 	void *buf = NULL, *buf2;
1106 	char *start;
1107 	int32_t nds;
1108 	int i, error, ret;
1109 
1110 	if (namelen != 1)
1111 		return (EINVAL);
1112 
1113 	start = where;
1114 	buflen = *sizep;
1115 
1116 	switch (*name) {
1117 	case KERN_SYSVIPC_MSG_INFO:
1118 #ifdef SYSVMSG
1119 		infosize = sizeof(msgsi->msginfo);
1120 		nds = msginfo.msgmni;
1121 		dssize = sizeof(msgsi->msgids[0]);
1122 		break;
1123 #else
1124 		return (EINVAL);
1125 #endif
1126 	case KERN_SYSVIPC_SEM_INFO:
1127 #ifdef SYSVSEM
1128 		infosize = sizeof(semsi->seminfo);
1129 		nds = seminfo.semmni;
1130 		dssize = sizeof(semsi->semids[0]);
1131 		break;
1132 #else
1133 		return (EINVAL);
1134 #endif
1135 	case KERN_SYSVIPC_SHM_INFO:
1136 #ifdef SYSVSHM
1137 		infosize = sizeof(shmsi->shminfo);
1138 		nds = shminfo.shmmni;
1139 		dssize = sizeof(shmsi->shmids[0]);
1140 		break;
1141 #else
1142 		return (EINVAL);
1143 #endif
1144 	default:
1145 		return (EINVAL);
1146 	}
1147 	/*
1148 	 * Round infosize to 64 bit boundary if requesting more than just
1149 	 * the info structure or getting the total data size.
1150 	 */
1151 	if (where == NULL || *sizep > infosize)
1152 		infosize = ((infosize + 7) / 8) * 8;
1153 	tsize = infosize + nds * dssize;
1154 
1155 	/* Return just the total size required. */
1156 	if (where == NULL) {
1157 		*sizep = tsize;
1158 		return (0);
1159 	}
1160 
1161 	/* Not enough room for even the info struct. */
1162 	if (buflen < infosize) {
1163 		*sizep = 0;
1164 		return (ENOMEM);
1165 	}
1166 	buf = malloc(min(tsize, buflen), M_TEMP, M_WAITOK);
1167 	memset(buf, 0, min(tsize, buflen));
1168 
1169 	switch (*name) {
1170 #ifdef SYSVMSG
1171 	case KERN_SYSVIPC_MSG_INFO:
1172 		msgsi = (struct msg_sysctl_info *)buf;
1173 		buf2 = &msgsi->msgids[0];
1174 		msgsi->msginfo = msginfo;
1175 		break;
1176 #endif
1177 #ifdef SYSVSEM
1178 	case KERN_SYSVIPC_SEM_INFO:
1179 		semsi = (struct sem_sysctl_info *)buf;
1180 		buf2 = &semsi->semids[0];
1181 		semsi->seminfo = seminfo;
1182 		break;
1183 #endif
1184 #ifdef SYSVSHM
1185 	case KERN_SYSVIPC_SHM_INFO:
1186 		shmsi = (struct shm_sysctl_info *)buf;
1187 		buf2 = &shmsi->shmids[0];
1188 		shmsi->shminfo = shminfo;
1189 		break;
1190 #endif
1191 	}
1192 	buflen -= infosize;
1193 
1194 	ret = 0;
1195 	if (buflen > 0) {
1196 		/* Fill in the IPC data structures.  */
1197 		for (i = 0; i < nds; i++) {
1198 			if (buflen < dssize) {
1199 				ret = ENOMEM;
1200 				break;
1201 			}
1202 			switch (*name) {
1203 #ifdef SYSVMSG
1204 			case KERN_SYSVIPC_MSG_INFO:
1205 				FILL_MSG(msqids[i], msgsi->msgids[i]);
1206 				break;
1207 #endif
1208 #ifdef SYSVSEM
1209 			case KERN_SYSVIPC_SEM_INFO:
1210 				FILL_SEM(sema[i], semsi->semids[i]);
1211 				break;
1212 #endif
1213 #ifdef SYSVSHM
1214 			case KERN_SYSVIPC_SHM_INFO:
1215 				FILL_SHM(shmsegs[i], shmsi->shmids[i]);
1216 				break;
1217 #endif
1218 			}
1219 			buflen -= dssize;
1220 		}
1221 	}
1222 	*sizep -= buflen;
1223 	error = copyout(buf, start, *sizep);
1224 	/* If copyout succeeded, use return code set earlier. */
1225 	if (error == 0)
1226 		error = ret;
1227 	if (buf)
1228 		free(buf, M_TEMP);
1229 	return (error);
1230 }
1231 #endif /* SYSVMSG || SYSVSEM || SYSVSHM */
1232 
1233 static int
1234 sysctl_msgbuf(void *vwhere, size_t *sizep)
1235 {
1236 	char *where = vwhere;
1237 	size_t len, maxlen = *sizep;
1238 	long beg, end;
1239 	int error;
1240 
1241 	/*
1242 	 * deal with cases where the message buffer has
1243 	 * become corrupted.
1244 	 */
1245 	if (!msgbufenabled || msgbufp->msg_magic != MSG_MAGIC) {
1246 		msgbufenabled = 0;
1247 		return (ENXIO);
1248 	}
1249 
1250 	if (where == NULL) {
1251 		/* always return full buffer size */
1252 		*sizep = msgbufp->msg_bufs;
1253 		return (0);
1254 	}
1255 
1256 	error = 0;
1257 	maxlen = min(msgbufp->msg_bufs, maxlen);
1258 
1259 	/*
1260 	 * First, copy from the write pointer to the end of
1261 	 * message buffer.
1262 	 */
1263 	beg = msgbufp->msg_bufx;
1264 	end = msgbufp->msg_bufs;
1265 	while (maxlen > 0) {
1266 		len = min(end - beg, maxlen);
1267 		if (len == 0)
1268 			break;
1269 		error = copyout(&msgbufp->msg_bufc[beg], where, len);
1270 		if (error)
1271 			break;
1272 		where += len;
1273 		maxlen -= len;
1274 
1275 		/*
1276 		 * ... then, copy from the beginning of message buffer to
1277 		 * the write pointer.
1278 		 */
1279 		beg = 0;
1280 		end = msgbufp->msg_bufx;
1281 	}
1282 	return (error);
1283 }
1284 
1285 /*
1286  * try over estimating by 5 procs
1287  */
1288 #define KERN_PROCSLOP	(5 * sizeof(struct kinfo_proc))
1289 
1290 static int
1291 sysctl_doeproc(int *name, u_int namelen, void *vwhere, size_t *sizep)
1292 {
1293 	struct eproc eproc;
1294 	struct kinfo_proc2 kproc2;
1295 	struct kinfo_proc *dp;
1296 	struct proc *p;
1297 	const struct proclist_desc *pd;
1298 	char *where, *dp2;
1299 	int type, op, arg, elem_size, elem_count;
1300 	int buflen, needed, error;
1301 
1302 	dp = vwhere;
1303 	dp2 = where = vwhere;
1304 	buflen = where != NULL ? *sizep : 0;
1305 	error = needed = 0;
1306 	type = name[0];
1307 
1308 	if (type == KERN_PROC) {
1309 		if (namelen != 3 && !(namelen == 2 && name[1] == KERN_PROC_ALL))
1310 			return (EINVAL);
1311 		op = name[1];
1312 		if (op != KERN_PROC_ALL)
1313 			arg = name[2];
1314 	} else {
1315 		if (namelen != 5)
1316 			return (EINVAL);
1317 		op = name[1];
1318 		arg = name[2];
1319 		elem_size = name[3];
1320 		elem_count = name[4];
1321 	}
1322 
1323 	proclist_lock_read();
1324 
1325 	pd = proclists;
1326 again:
1327 	for (p = LIST_FIRST(pd->pd_list); p != NULL; p = LIST_NEXT(p, p_list)) {
1328 		/*
1329 		 * Skip embryonic processes.
1330 		 */
1331 		if (p->p_stat == SIDL)
1332 			continue;
1333 		/*
1334 		 * TODO - make more efficient (see notes below).
1335 		 * do by session.
1336 		 */
1337 		switch (op) {
1338 
1339 		case KERN_PROC_PID:
1340 			/* could do this with just a lookup */
1341 			if (p->p_pid != (pid_t)arg)
1342 				continue;
1343 			break;
1344 
1345 		case KERN_PROC_PGRP:
1346 			/* could do this by traversing pgrp */
1347 			if (p->p_pgrp->pg_id != (pid_t)arg)
1348 				continue;
1349 			break;
1350 
1351 		case KERN_PROC_SESSION:
1352 			if (p->p_session->s_sid != (pid_t)arg)
1353 				continue;
1354 			break;
1355 
1356 		case KERN_PROC_TTY:
1357 			if (arg == KERN_PROC_TTY_REVOKE) {
1358 				if ((p->p_flag & P_CONTROLT) == 0 ||
1359 				    p->p_session->s_ttyp == NULL ||
1360 				    p->p_session->s_ttyvp != NULL)
1361 					continue;
1362 			} else if ((p->p_flag & P_CONTROLT) == 0 ||
1363 			    p->p_session->s_ttyp == NULL) {
1364 				if ((dev_t)arg != KERN_PROC_TTY_NODEV)
1365 					continue;
1366 			} else if (p->p_session->s_ttyp->t_dev != (dev_t)arg)
1367 				continue;
1368 			break;
1369 
1370 		case KERN_PROC_UID:
1371 			if (p->p_ucred->cr_uid != (uid_t)arg)
1372 				continue;
1373 			break;
1374 
1375 		case KERN_PROC_RUID:
1376 			if (p->p_cred->p_ruid != (uid_t)arg)
1377 				continue;
1378 			break;
1379 
1380 		case KERN_PROC_GID:
1381 			if (p->p_ucred->cr_gid != (uid_t)arg)
1382 				continue;
1383 			break;
1384 
1385 		case KERN_PROC_RGID:
1386 			if (p->p_cred->p_rgid != (uid_t)arg)
1387 				continue;
1388 			break;
1389 
1390 		case KERN_PROC_ALL:
1391 			/* allow everything */
1392 			break;
1393 
1394 		default:
1395 			error = EINVAL;
1396 			goto cleanup;
1397 		}
1398 		if (type == KERN_PROC) {
1399 			if (buflen >= sizeof(struct kinfo_proc)) {
1400 				fill_eproc(p, &eproc);
1401 				error = copyout((caddr_t)p, &dp->kp_proc,
1402 						sizeof(struct proc));
1403 				if (error)
1404 					goto cleanup;
1405 				error = copyout((caddr_t)&eproc, &dp->kp_eproc,
1406 						sizeof(eproc));
1407 				if (error)
1408 					goto cleanup;
1409 				dp++;
1410 				buflen -= sizeof(struct kinfo_proc);
1411 			}
1412 			needed += sizeof(struct kinfo_proc);
1413 		} else { /* KERN_PROC2 */
1414 			if (buflen >= elem_size && elem_count > 0) {
1415 				fill_kproc2(p, &kproc2);
1416 				/*
1417 				 * Copy out elem_size, but not larger than
1418 				 * the size of a struct kinfo_proc2.
1419 				 */
1420 				error = copyout(&kproc2, dp2,
1421 				    min(sizeof(kproc2), elem_size));
1422 				if (error)
1423 					goto cleanup;
1424 				dp2 += elem_size;
1425 				buflen -= elem_size;
1426 				elem_count--;
1427 			}
1428 			needed += elem_size;
1429 		}
1430 	}
1431 	pd++;
1432 	if (pd->pd_list != NULL)
1433 		goto again;
1434 	proclist_unlock_read();
1435 
1436 	if (where != NULL) {
1437 		if (type == KERN_PROC)
1438 			*sizep = (caddr_t)dp - where;
1439 		else
1440 			*sizep = dp2 - where;
1441 		if (needed > *sizep)
1442 			return (ENOMEM);
1443 	} else {
1444 		needed += KERN_PROCSLOP;
1445 		*sizep = needed;
1446 	}
1447 	return (0);
1448  cleanup:
1449 	proclist_unlock_read();
1450 	return (error);
1451 }
1452 
1453 /*
1454  * Fill in an eproc structure for the specified process.
1455  */
1456 void
1457 fill_eproc(struct proc *p, struct eproc *ep)
1458 {
1459 	struct tty *tp;
1460 
1461 	ep->e_paddr = p;
1462 	ep->e_sess = p->p_session;
1463 	ep->e_pcred = *p->p_cred;
1464 	ep->e_ucred = *p->p_ucred;
1465 	if (p->p_stat == SIDL || P_ZOMBIE(p)) {
1466 		ep->e_vm.vm_rssize = 0;
1467 		ep->e_vm.vm_tsize = 0;
1468 		ep->e_vm.vm_dsize = 0;
1469 		ep->e_vm.vm_ssize = 0;
1470 		/* ep->e_vm.vm_pmap = XXX; */
1471 	} else {
1472 		struct vmspace *vm = p->p_vmspace;
1473 
1474 		ep->e_vm.vm_rssize = vm_resident_count(vm);
1475 		ep->e_vm.vm_tsize = vm->vm_tsize;
1476 		ep->e_vm.vm_dsize = vm->vm_dsize;
1477 		ep->e_vm.vm_ssize = vm->vm_ssize;
1478 	}
1479 	if (p->p_pptr)
1480 		ep->e_ppid = p->p_pptr->p_pid;
1481 	else
1482 		ep->e_ppid = 0;
1483 	ep->e_pgid = p->p_pgrp->pg_id;
1484 	ep->e_sid = ep->e_sess->s_sid;
1485 	ep->e_jobc = p->p_pgrp->pg_jobc;
1486 	if ((p->p_flag & P_CONTROLT) &&
1487 	     (tp = ep->e_sess->s_ttyp)) {
1488 		ep->e_tdev = tp->t_dev;
1489 		ep->e_tpgid = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PID;
1490 		ep->e_tsess = tp->t_session;
1491 	} else
1492 		ep->e_tdev = NODEV;
1493 	if (p->p_wmesg)
1494 		strncpy(ep->e_wmesg, p->p_wmesg, WMESGLEN);
1495 	ep->e_xsize = ep->e_xrssize = 0;
1496 	ep->e_xccount = ep->e_xswrss = 0;
1497 	ep->e_flag = ep->e_sess->s_ttyvp ? EPROC_CTTY : 0;
1498 	if (SESS_LEADER(p))
1499 		ep->e_flag |= EPROC_SLEADER;
1500 	strncpy(ep->e_login, ep->e_sess->s_login, MAXLOGNAME);
1501 }
1502 
1503 /*
1504  * Fill in an eproc structure for the specified process.
1505  */
1506 static void
1507 fill_kproc2(struct proc *p, struct kinfo_proc2 *ki)
1508 {
1509 	struct tty *tp;
1510 
1511 	memset(ki, 0, sizeof(*ki));
1512 
1513 	ki->p_forw = PTRTOINT64(p->p_forw);
1514 	ki->p_back = PTRTOINT64(p->p_back);
1515 	ki->p_paddr = PTRTOINT64(p);
1516 
1517 	ki->p_addr = PTRTOINT64(p->p_addr);
1518 	ki->p_fd = PTRTOINT64(p->p_fd);
1519 	ki->p_cwdi = PTRTOINT64(p->p_cwdi);
1520 	ki->p_stats = PTRTOINT64(p->p_stats);
1521 	ki->p_limit = PTRTOINT64(p->p_limit);
1522 	ki->p_vmspace = PTRTOINT64(p->p_vmspace);
1523 	ki->p_sigacts = PTRTOINT64(p->p_sigacts);
1524 	ki->p_sess = PTRTOINT64(p->p_session);
1525 	ki->p_tsess = 0;	/* may be changed if controlling tty below */
1526 	ki->p_ru = PTRTOINT64(p->p_ru);
1527 
1528 	ki->p_eflag = 0;
1529 	ki->p_exitsig = p->p_exitsig;
1530 	ki->p_flag = p->p_flag;
1531 
1532 	ki->p_pid = p->p_pid;
1533 	if (p->p_pptr)
1534 		ki->p_ppid = p->p_pptr->p_pid;
1535 	else
1536 		ki->p_ppid = 0;
1537 	ki->p_sid = p->p_session->s_sid;
1538 	ki->p__pgid = p->p_pgrp->pg_id;
1539 
1540 	ki->p_tpgid = NO_PID;	/* may be changed if controlling tty below */
1541 
1542 	ki->p_uid = p->p_ucred->cr_uid;
1543 	ki->p_ruid = p->p_cred->p_ruid;
1544 	ki->p_gid = p->p_ucred->cr_gid;
1545 	ki->p_rgid = p->p_cred->p_rgid;
1546 
1547 	memcpy(ki->p_groups, p->p_cred->pc_ucred->cr_groups,
1548 	    min(sizeof(ki->p_groups), sizeof(p->p_cred->pc_ucred->cr_groups)));
1549 	ki->p_ngroups = p->p_cred->pc_ucred->cr_ngroups;
1550 
1551 	ki->p_jobc = p->p_pgrp->pg_jobc;
1552 	if ((p->p_flag & P_CONTROLT) && (tp = p->p_session->s_ttyp)) {
1553 		ki->p_tdev = tp->t_dev;
1554 		ki->p_tpgid = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PID;
1555 		ki->p_tsess = PTRTOINT64(tp->t_session);
1556 	} else {
1557 		ki->p_tdev = NODEV;
1558 	}
1559 
1560 	ki->p_estcpu = p->p_estcpu;
1561 	ki->p_rtime_sec = p->p_rtime.tv_sec;
1562 	ki->p_rtime_usec = p->p_rtime.tv_usec;
1563 	ki->p_cpticks = p->p_cpticks;
1564 	ki->p_pctcpu = p->p_pctcpu;
1565 	ki->p_swtime = p->p_swtime;
1566 	ki->p_slptime = p->p_slptime;
1567 	if (p->p_stat == SONPROC) {
1568 		KDASSERT(p->p_cpu != NULL);
1569 		ki->p_schedflags = p->p_cpu->ci_schedstate.spc_flags;
1570 	} else
1571 		ki->p_schedflags = 0;
1572 
1573 	ki->p_uticks = p->p_uticks;
1574 	ki->p_sticks = p->p_sticks;
1575 	ki->p_iticks = p->p_iticks;
1576 
1577 	ki->p_tracep = PTRTOINT64(p->p_tracep);
1578 	ki->p_traceflag = p->p_traceflag;
1579 
1580 	ki->p_holdcnt = p->p_holdcnt;
1581 
1582 	memcpy(&ki->p_siglist, &p->p_sigctx.ps_siglist, sizeof(ki_sigset_t));
1583 	memcpy(&ki->p_sigmask, &p->p_sigctx.ps_sigmask, sizeof(ki_sigset_t));
1584 	memcpy(&ki->p_sigignore, &p->p_sigctx.ps_sigignore,sizeof(ki_sigset_t));
1585 	memcpy(&ki->p_sigcatch, &p->p_sigctx.ps_sigcatch, sizeof(ki_sigset_t));
1586 
1587 	ki->p_stat = p->p_stat;
1588 	ki->p_priority = p->p_priority;
1589 	ki->p_usrpri = p->p_usrpri;
1590 	ki->p_nice = p->p_nice;
1591 
1592 	ki->p_xstat = p->p_xstat;
1593 	ki->p_acflag = p->p_acflag;
1594 
1595 	strncpy(ki->p_comm, p->p_comm,
1596 	    min(sizeof(ki->p_comm), sizeof(p->p_comm)));
1597 
1598 	if (p->p_wmesg)
1599 		strncpy(ki->p_wmesg, p->p_wmesg, sizeof(ki->p_wmesg));
1600 	ki->p_wchan = PTRTOINT64(p->p_wchan);
1601 
1602 	strncpy(ki->p_login, p->p_session->s_login, sizeof(ki->p_login));
1603 
1604 	if (p->p_stat == SIDL || P_ZOMBIE(p)) {
1605 		ki->p_vm_rssize = 0;
1606 		ki->p_vm_tsize = 0;
1607 		ki->p_vm_dsize = 0;
1608 		ki->p_vm_ssize = 0;
1609 	} else {
1610 		struct vmspace *vm = p->p_vmspace;
1611 
1612 		ki->p_vm_rssize = vm_resident_count(vm);
1613 		ki->p_vm_tsize = vm->vm_tsize;
1614 		ki->p_vm_dsize = vm->vm_dsize;
1615 		ki->p_vm_ssize = vm->vm_ssize;
1616 	}
1617 
1618 	if (p->p_session->s_ttyvp)
1619 		ki->p_eflag |= EPROC_CTTY;
1620 	if (SESS_LEADER(p))
1621 		ki->p_eflag |= EPROC_SLEADER;
1622 
1623 	/* XXX Is this double check necessary? */
1624 	if ((p->p_flag & P_INMEM) == 0 || P_ZOMBIE(p)) {
1625 		ki->p_uvalid = 0;
1626 	} else {
1627 		ki->p_uvalid = 1;
1628 
1629 		ki->p_ustart_sec = p->p_stats->p_start.tv_sec;
1630 		ki->p_ustart_usec = p->p_stats->p_start.tv_usec;
1631 
1632 		ki->p_uutime_sec = p->p_stats->p_ru.ru_utime.tv_sec;
1633 		ki->p_uutime_usec = p->p_stats->p_ru.ru_utime.tv_usec;
1634 		ki->p_ustime_sec = p->p_stats->p_ru.ru_stime.tv_sec;
1635 		ki->p_ustime_usec = p->p_stats->p_ru.ru_stime.tv_usec;
1636 
1637 		ki->p_uru_maxrss = p->p_stats->p_ru.ru_maxrss;
1638 		ki->p_uru_ixrss = p->p_stats->p_ru.ru_ixrss;
1639 		ki->p_uru_idrss = p->p_stats->p_ru.ru_idrss;
1640 		ki->p_uru_isrss = p->p_stats->p_ru.ru_isrss;
1641 		ki->p_uru_minflt = p->p_stats->p_ru.ru_minflt;
1642 		ki->p_uru_majflt = p->p_stats->p_ru.ru_majflt;
1643 		ki->p_uru_nswap = p->p_stats->p_ru.ru_nswap;
1644 		ki->p_uru_inblock = p->p_stats->p_ru.ru_inblock;
1645 		ki->p_uru_oublock = p->p_stats->p_ru.ru_oublock;
1646 		ki->p_uru_msgsnd = p->p_stats->p_ru.ru_msgsnd;
1647 		ki->p_uru_msgrcv = p->p_stats->p_ru.ru_msgrcv;
1648 		ki->p_uru_nsignals = p->p_stats->p_ru.ru_nsignals;
1649 		ki->p_uru_nvcsw = p->p_stats->p_ru.ru_nvcsw;
1650 		ki->p_uru_nivcsw = p->p_stats->p_ru.ru_nivcsw;
1651 
1652 		ki->p_uctime_sec = p->p_stats->p_cru.ru_utime.tv_sec +
1653 		    p->p_stats->p_cru.ru_stime.tv_sec;
1654 		ki->p_uctime_usec = p->p_stats->p_cru.ru_utime.tv_usec +
1655 		    p->p_stats->p_cru.ru_stime.tv_usec;
1656 	}
1657 #ifdef MULTIPROCESSOR
1658 	if (p->p_cpu != NULL)
1659 		ki->p_cpuid = p->p_cpu->ci_cpuid;
1660 	else
1661 #endif
1662 		ki->p_cpuid = KI_NOCPU;
1663 }
1664 
1665 int
1666 sysctl_procargs(int *name, u_int namelen, void *where, size_t *sizep,
1667     struct proc *up)
1668 {
1669 	struct ps_strings pss;
1670 	struct proc *p;
1671 	size_t len, upper_bound, xlen;
1672 	struct uio auio;
1673 	struct iovec aiov;
1674 	vaddr_t argv;
1675 	pid_t pid;
1676 	int nargv, type, error, i;
1677 	char *arg;
1678 	char *tmp;
1679 
1680 	if (namelen != 2)
1681 		return (EINVAL);
1682 	pid = name[0];
1683 	type = name[1];
1684 
1685 	switch (type) {
1686 	  case KERN_PROC_ARGV:
1687 	  case KERN_PROC_NARGV:
1688 	  case KERN_PROC_ENV:
1689 	  case KERN_PROC_NENV:
1690 		/* ok */
1691 		break;
1692 	  default:
1693 		return (EINVAL);
1694 	}
1695 
1696 	/* check pid */
1697 	if ((p = pfind(pid)) == NULL)
1698 		return (EINVAL);
1699 
1700 	/* only root or same user change look at the environment */
1701 	if (type == KERN_PROC_ENV || type == KERN_PROC_NENV) {
1702 		if (up->p_ucred->cr_uid != 0) {
1703 			if (up->p_cred->p_ruid != p->p_cred->p_ruid ||
1704 			    up->p_cred->p_ruid != p->p_cred->p_svuid)
1705 				return (EPERM);
1706 		}
1707 	}
1708 
1709 	if (sizep != NULL && where == NULL) {
1710 		if (type == KERN_PROC_NARGV || type == KERN_PROC_NENV)
1711 			*sizep = sizeof (int);
1712 		else
1713 			*sizep = ARG_MAX;	/* XXX XXX XXX */
1714 		return (0);
1715 	}
1716 	if (where == NULL || sizep == NULL)
1717 		return (EINVAL);
1718 
1719 	/*
1720 	 * Zombies don't have a stack, so we can't read their psstrings.
1721 	 * System processes also don't have a user stack.
1722 	 */
1723 	if (P_ZOMBIE(p) || (p->p_flag & P_SYSTEM) != 0)
1724 		return (EINVAL);
1725 
1726 	/*
1727 	 * Lock the process down in memory.
1728 	 */
1729 	/* XXXCDC: how should locking work here? */
1730 	if ((p->p_flag & P_WEXIT) || (p->p_vmspace->vm_refcnt < 1))
1731 		return (EFAULT);
1732 	p->p_vmspace->vm_refcnt++;	/* XXX */
1733 
1734 	/*
1735 	 * Allocate a temporary buffer to hold the arguments.
1736 	 */
1737 	arg = malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
1738 
1739 	/*
1740 	 * Read in the ps_strings structure.
1741 	 */
1742 	aiov.iov_base = &pss;
1743 	aiov.iov_len = sizeof(pss);
1744 	auio.uio_iov = &aiov;
1745 	auio.uio_iovcnt = 1;
1746 	auio.uio_offset = (vaddr_t)p->p_psstr;
1747 	auio.uio_resid = sizeof(pss);
1748 	auio.uio_segflg = UIO_SYSSPACE;
1749 	auio.uio_rw = UIO_READ;
1750 	auio.uio_procp = NULL;
1751 	error = uvm_io(&p->p_vmspace->vm_map, &auio);
1752 	if (error)
1753 		goto done;
1754 
1755 	if (type == KERN_PROC_ARGV || type == KERN_PROC_NARGV)
1756 		memcpy(&nargv, (char *)&pss + p->p_psnargv, sizeof(nargv));
1757 	else
1758 		memcpy(&nargv, (char *)&pss + p->p_psnenv, sizeof(nargv));
1759 	if (type == KERN_PROC_NARGV || type == KERN_PROC_NENV) {
1760 		error = copyout(&nargv, where, sizeof(nargv));
1761 		*sizep = sizeof(nargv);
1762 		goto done;
1763 	}
1764 	/*
1765 	 * Now read the address of the argument vector.
1766 	 */
1767 	switch (type) {
1768 	case KERN_PROC_ARGV:
1769 		/* XXX compat32 stuff here */
1770 		memcpy(&tmp, (char *)&pss + p->p_psargv, sizeof(tmp));
1771 		break;
1772 	case KERN_PROC_ENV:
1773 		memcpy(&tmp, (char *)&pss + p->p_psenv, sizeof(tmp));
1774 		break;
1775 	default:
1776 		return (EINVAL);
1777 	}
1778 	auio.uio_offset = (off_t)(long)tmp;
1779 	aiov.iov_base = &argv;
1780 	aiov.iov_len = sizeof(argv);
1781 	auio.uio_iov = &aiov;
1782 	auio.uio_iovcnt = 1;
1783 	auio.uio_resid = sizeof(argv);
1784 	auio.uio_segflg = UIO_SYSSPACE;
1785 	auio.uio_rw = UIO_READ;
1786 	auio.uio_procp = NULL;
1787 	error = uvm_io(&p->p_vmspace->vm_map, &auio);
1788 	if (error)
1789 		goto done;
1790 
1791 	/*
1792 	 * Now copy in the actual argument vector, one page at a time,
1793 	 * since we don't know how long the vector is (though, we do
1794 	 * know how many NUL-terminated strings are in the vector).
1795 	 */
1796 	len = 0;
1797 	upper_bound = *sizep;
1798 	for (; nargv != 0 && len < upper_bound; len += xlen) {
1799 		aiov.iov_base = arg;
1800 		aiov.iov_len = PAGE_SIZE;
1801 		auio.uio_iov = &aiov;
1802 		auio.uio_iovcnt = 1;
1803 		auio.uio_offset = argv + len;
1804 		xlen = PAGE_SIZE - ((argv + len) & PAGE_MASK);
1805 		auio.uio_resid = xlen;
1806 		auio.uio_segflg = UIO_SYSSPACE;
1807 		auio.uio_rw = UIO_READ;
1808 		auio.uio_procp = NULL;
1809 		error = uvm_io(&p->p_vmspace->vm_map, &auio);
1810 		if (error)
1811 			goto done;
1812 
1813 		for (i = 0; i < xlen && nargv != 0; i++) {
1814 			if (arg[i] == '\0')
1815 				nargv--;	/* one full string */
1816 		}
1817 
1818 		/* make sure we don't copyout past the end of the user's buffer */
1819 		if (len + i > upper_bound)
1820 			i = upper_bound - len;
1821 
1822 		error = copyout(arg, (char *)where + len, i);
1823 		if (error)
1824 			break;
1825 
1826 		if (nargv == 0) {
1827 			len += i;
1828 			break;
1829 		}
1830 	}
1831 	*sizep = len;
1832 
1833 done:
1834 	uvmspace_free(p->p_vmspace);
1835 
1836 	free(arg, M_TEMP);
1837 	return (error);
1838 }
1839 
1840 #if NPTY > 0
1841 int pty_maxptys(int, int);		/* defined in kern/tty_pty.c */
1842 
1843 /*
1844  * Validate parameters and get old / set new parameters
1845  * for pty sysctl function.
1846  */
1847 static int
1848 sysctl_pty(void *oldp, size_t *oldlenp, void *newp, size_t newlen)
1849 {
1850 	int error = 0;
1851 	int oldmax = 0, newmax = 0;
1852 
1853 	/* get current value of maxptys */
1854 	oldmax = pty_maxptys(0, 0);
1855 
1856 	SYSCTL_SCALAR_CORE_TYP(oldp, oldlenp, &oldmax, int)
1857 
1858 	if (!error && newp) {
1859 		SYSCTL_SCALAR_NEWPCHECK_TYP(newp, newlen, int)
1860 		SYSCTL_SCALAR_NEWPCOP_TYP(newp, &newmax, int)
1861 
1862 		if (newmax != pty_maxptys(newmax, (newp != NULL)))
1863 			return (EINVAL);
1864 
1865 	}
1866 
1867 	return (error);
1868 }
1869 #endif /* NPTY > 0 */
1870