xref: /freebsd/sys/kern/kern_mib.c (revision 0957b409)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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  * Quite extensively rewritten by Poul-Henning Kamp of the FreeBSD
11  * project, to make these variables more userfriendly.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  *	@(#)kern_sysctl.c	8.4 (Berkeley) 4/14/94
38  */
39 
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42 
43 #include "opt_posix.h"
44 #include "opt_config.h"
45 
46 #include <sys/param.h>
47 #include <sys/jail.h>
48 #include <sys/kernel.h>
49 #include <sys/limits.h>
50 #include <sys/lock.h>
51 #include <sys/mutex.h>
52 #include <sys/proc.h>
53 #include <sys/random.h>
54 #include <sys/sbuf.h>
55 #include <sys/smp.h>
56 #include <sys/sx.h>
57 #include <sys/vmmeter.h>
58 #include <sys/sysctl.h>
59 #include <sys/systm.h>
60 #include <sys/unistd.h>
61 
62 SYSCTL_ROOT_NODE(0,	  sysctl, CTLFLAG_RW, 0,
63 	"Sysctl internal magic");
64 SYSCTL_ROOT_NODE(CTL_KERN,	  kern,   CTLFLAG_RW|CTLFLAG_CAPRD, 0,
65 	"High kernel, proc, limits &c");
66 SYSCTL_ROOT_NODE(CTL_VM,	  vm,     CTLFLAG_RW, 0,
67 	"Virtual memory");
68 SYSCTL_ROOT_NODE(CTL_VFS,	  vfs,     CTLFLAG_RW, 0,
69 	"File system");
70 SYSCTL_ROOT_NODE(CTL_NET,	  net,    CTLFLAG_RW, 0,
71 	"Network, (see socket.h)");
72 SYSCTL_ROOT_NODE(CTL_DEBUG,  debug,  CTLFLAG_RW, 0,
73 	"Debugging");
74 SYSCTL_NODE(_debug, OID_AUTO,  sizeof,  CTLFLAG_RW, 0,
75 	"Sizeof various things");
76 SYSCTL_ROOT_NODE(CTL_HW,	  hw,     CTLFLAG_RW, 0,
77 	"hardware");
78 SYSCTL_ROOT_NODE(CTL_MACHDEP, machdep, CTLFLAG_RW, 0,
79 	"machine dependent");
80 SYSCTL_ROOT_NODE(CTL_USER,	  user,   CTLFLAG_RW, 0,
81 	"user-level");
82 SYSCTL_ROOT_NODE(CTL_P1003_1B,  p1003_1b,   CTLFLAG_RW, 0,
83 	"p1003_1b, (see p1003_1b.h)");
84 
85 SYSCTL_ROOT_NODE(OID_AUTO,  compat, CTLFLAG_RW, 0,
86 	"Compatibility code");
87 SYSCTL_ROOT_NODE(OID_AUTO, security, CTLFLAG_RW, 0,
88      	"Security");
89 #ifdef REGRESSION
90 SYSCTL_ROOT_NODE(OID_AUTO, regression, CTLFLAG_RW, 0,
91      "Regression test MIB");
92 #endif
93 
94 SYSCTL_STRING(_kern, OID_AUTO, ident, CTLFLAG_RD|CTLFLAG_MPSAFE,
95     kern_ident, 0, "Kernel identifier");
96 
97 SYSCTL_INT(_kern, KERN_OSREV, osrevision, CTLFLAG_RD|CTLFLAG_CAPRD,
98     SYSCTL_NULL_INT_PTR, BSD, "Operating system revision");
99 
100 SYSCTL_STRING(_kern, KERN_VERSION, version, CTLFLAG_RD|CTLFLAG_MPSAFE,
101     version, 0, "Kernel version");
102 
103 SYSCTL_STRING(_kern, OID_AUTO, compiler_version, CTLFLAG_RD|CTLFLAG_MPSAFE,
104     compiler_version, 0, "Version of compiler used to compile kernel");
105 
106 SYSCTL_STRING(_kern, KERN_OSTYPE, ostype, CTLFLAG_RD|CTLFLAG_MPSAFE|
107     CTLFLAG_CAPRD, ostype, 0, "Operating system type");
108 
109 SYSCTL_INT(_kern, KERN_MAXPROC, maxproc, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
110     &maxproc, 0, "Maximum number of processes");
111 
112 SYSCTL_INT(_kern, KERN_MAXPROCPERUID, maxprocperuid, CTLFLAG_RW,
113     &maxprocperuid, 0, "Maximum processes allowed per userid");
114 
115 SYSCTL_INT(_kern, OID_AUTO, maxusers, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
116     &maxusers, 0, "Hint for kernel tuning");
117 
118 SYSCTL_INT(_kern, KERN_ARGMAX, argmax, CTLFLAG_RD|CTLFLAG_CAPRD,
119     SYSCTL_NULL_INT_PTR, ARG_MAX, "Maximum bytes of argument to execve(2)");
120 
121 SYSCTL_INT(_kern, KERN_POSIX1, posix1version, CTLFLAG_RD|CTLFLAG_CAPRD,
122     SYSCTL_NULL_INT_PTR, _POSIX_VERSION, "Version of POSIX attempting to comply to");
123 
124 SYSCTL_INT(_kern, KERN_NGROUPS, ngroups, CTLFLAG_RDTUN |
125     CTLFLAG_NOFETCH | CTLFLAG_CAPRD, &ngroups_max, 0,
126     "Maximum number of supplemental groups a user can belong to");
127 
128 SYSCTL_INT(_kern, KERN_JOB_CONTROL, job_control, CTLFLAG_RD|CTLFLAG_CAPRD,
129     SYSCTL_NULL_INT_PTR, 1, "Whether job control is available");
130 
131 #ifdef _POSIX_SAVED_IDS
132 SYSCTL_INT(_kern, KERN_SAVED_IDS, saved_ids, CTLFLAG_RD|CTLFLAG_CAPRD,
133     SYSCTL_NULL_INT_PTR, 1, "Whether saved set-group/user ID is available");
134 #else
135 SYSCTL_INT(_kern, KERN_SAVED_IDS, saved_ids, CTLFLAG_RD|CTLFLAG_CAPRD,
136     SYSCTL_NULL_INT_PTR, 0, "Whether saved set-group/user ID is available");
137 #endif
138 
139 char kernelname[MAXPATHLEN] = "/kernel";	/* XXX bloat */
140 
141 SYSCTL_STRING(_kern, KERN_BOOTFILE, bootfile, CTLFLAG_RW | CTLFLAG_MPSAFE,
142     kernelname, sizeof kernelname, "Name of kernel file booted");
143 
144 SYSCTL_INT(_kern, KERN_MAXPHYS, maxphys, CTLFLAG_RD | CTLFLAG_CAPRD,
145     SYSCTL_NULL_INT_PTR, MAXPHYS, "Maximum block I/O access size");
146 
147 SYSCTL_INT(_hw, HW_NCPU, ncpu, CTLFLAG_RD|CTLFLAG_CAPRD,
148     &mp_ncpus, 0, "Number of active CPUs");
149 
150 SYSCTL_INT(_hw, HW_BYTEORDER, byteorder, CTLFLAG_RD|CTLFLAG_CAPRD,
151     SYSCTL_NULL_INT_PTR, BYTE_ORDER, "System byte order");
152 
153 SYSCTL_INT(_hw, HW_PAGESIZE, pagesize, CTLFLAG_RD|CTLFLAG_CAPRD,
154     SYSCTL_NULL_INT_PTR, PAGE_SIZE, "System memory page size");
155 
156 static int
157 sysctl_kern_arnd(SYSCTL_HANDLER_ARGS)
158 {
159 	char buf[256];
160 	size_t len;
161 
162 	/*-
163 	 * This is one of the very few legitimate uses of read_random(9).
164 	 * Use of arc4random(9) is not recommended as that will ignore
165 	 * an unsafe (i.e. unseeded) random(4).
166 	 *
167 	 * If random(4) is not seeded, then this returns 0, so the
168 	 * sysctl will return a zero-length buffer.
169 	 */
170 	len = read_random(buf, MIN(req->oldlen, sizeof(buf)));
171 	return (SYSCTL_OUT(req, buf, len));
172 }
173 
174 SYSCTL_PROC(_kern, KERN_ARND, arandom,
175     CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD, NULL, 0,
176     sysctl_kern_arnd, "", "arc4rand");
177 
178 static int
179 sysctl_hw_physmem(SYSCTL_HANDLER_ARGS)
180 {
181 	u_long val, p;
182 
183 	p = SIZE_T_MAX >> PAGE_SHIFT;
184 	if (physmem < p)
185 		p = physmem;
186 	val = ctob(p);
187 	return (sysctl_handle_long(oidp, &val, 0, req));
188 }
189 SYSCTL_PROC(_hw, HW_PHYSMEM, physmem, CTLTYPE_ULONG | CTLFLAG_RD,
190     0, 0, sysctl_hw_physmem, "LU", "");
191 
192 static int
193 sysctl_hw_realmem(SYSCTL_HANDLER_ARGS)
194 {
195 	u_long val, p;
196 
197 	p = SIZE_T_MAX >> PAGE_SHIFT;
198 	if (realmem < p)
199 		p = realmem;
200 	val = ctob(p);
201 	return (sysctl_handle_long(oidp, &val, 0, req));
202 }
203 SYSCTL_PROC(_hw, HW_REALMEM, realmem, CTLTYPE_ULONG | CTLFLAG_RD,
204     0, 0, sysctl_hw_realmem, "LU", "");
205 
206 static int
207 sysctl_hw_usermem(SYSCTL_HANDLER_ARGS)
208 {
209 	u_long val, p, p1;
210 
211 	p1 = physmem - vm_wire_count();
212 	p = SIZE_T_MAX >> PAGE_SHIFT;
213 	if (p1 < p)
214 		p = p1;
215 	val = ctob(p);
216 	return (sysctl_handle_long(oidp, &val, 0, req));
217 }
218 SYSCTL_PROC(_hw, HW_USERMEM, usermem, CTLTYPE_ULONG | CTLFLAG_RD,
219     0, 0, sysctl_hw_usermem, "LU", "");
220 
221 SYSCTL_LONG(_hw, OID_AUTO, availpages, CTLFLAG_RD, &physmem, 0, "");
222 
223 u_long pagesizes[MAXPAGESIZES] = { PAGE_SIZE };
224 
225 static int
226 sysctl_hw_pagesizes(SYSCTL_HANDLER_ARGS)
227 {
228 	int error;
229 #ifdef SCTL_MASK32
230 	int i;
231 	uint32_t pagesizes32[MAXPAGESIZES];
232 
233 	if (req->flags & SCTL_MASK32) {
234 		/*
235 		 * Recreate the "pagesizes" array with 32-bit elements.  Truncate
236 		 * any page size greater than UINT32_MAX to zero.
237 		 */
238 		for (i = 0; i < MAXPAGESIZES; i++)
239 			pagesizes32[i] = (uint32_t)pagesizes[i];
240 
241 		error = SYSCTL_OUT(req, pagesizes32, sizeof(pagesizes32));
242 	} else
243 #endif
244 		error = SYSCTL_OUT(req, pagesizes, sizeof(pagesizes));
245 	return (error);
246 }
247 SYSCTL_PROC(_hw, OID_AUTO, pagesizes, CTLTYPE_ULONG | CTLFLAG_RD,
248     NULL, 0, sysctl_hw_pagesizes, "LU", "Supported page sizes");
249 
250 #ifdef SCTL_MASK32
251 int adaptive_machine_arch = 1;
252 SYSCTL_INT(_debug, OID_AUTO, adaptive_machine_arch, CTLFLAG_RW,
253     &adaptive_machine_arch, 1,
254     "Adapt reported machine architecture to the ABI of the binary");
255 #endif
256 
257 static int
258 sysctl_hw_machine_arch(SYSCTL_HANDLER_ARGS)
259 {
260 	int error;
261 	static const char machine_arch[] = MACHINE_ARCH;
262 #ifdef SCTL_MASK32
263 	static const char machine_arch32[] = MACHINE_ARCH32;
264 
265 	if ((req->flags & SCTL_MASK32) != 0 && adaptive_machine_arch)
266 		error = SYSCTL_OUT(req, machine_arch32, sizeof(machine_arch32));
267 	else
268 #endif
269 		error = SYSCTL_OUT(req, machine_arch, sizeof(machine_arch));
270 	return (error);
271 
272 }
273 SYSCTL_PROC(_hw, HW_MACHINE_ARCH, machine_arch, CTLTYPE_STRING | CTLFLAG_RD |
274     CTLFLAG_MPSAFE, NULL, 0, sysctl_hw_machine_arch, "A",
275     "System architecture");
276 
277 SYSCTL_STRING(_kern, OID_AUTO, supported_archs, CTLFLAG_RD | CTLFLAG_MPSAFE,
278 #ifdef COMPAT_FREEBSD32
279     MACHINE_ARCH " " MACHINE_ARCH32, 0, "Supported architectures for binaries");
280 #else
281     MACHINE_ARCH, 0, "Supported architectures for binaries");
282 #endif
283 
284 static int
285 sysctl_hostname(SYSCTL_HANDLER_ARGS)
286 {
287 	struct prison *pr, *cpr;
288 	size_t pr_offset;
289 	char tmpname[MAXHOSTNAMELEN];
290 	int descend, error, len;
291 
292 	/*
293 	 * This function can set: hostname domainname hostuuid.
294 	 * Keep that in mind when comments say "hostname".
295 	 */
296 	pr_offset = (size_t)arg1;
297 	len = arg2;
298 	KASSERT(len <= sizeof(tmpname),
299 	    ("length %d too long for %s", len, __func__));
300 
301 	pr = req->td->td_ucred->cr_prison;
302 	if (!(pr->pr_allow & PR_ALLOW_SET_HOSTNAME) && req->newptr)
303 		return (EPERM);
304 	/*
305 	 * Make a local copy of hostname to get/set so we don't have to hold
306 	 * the jail mutex during the sysctl copyin/copyout activities.
307 	 */
308 	mtx_lock(&pr->pr_mtx);
309 	bcopy((char *)pr + pr_offset, tmpname, len);
310 	mtx_unlock(&pr->pr_mtx);
311 
312 	error = sysctl_handle_string(oidp, tmpname, len, req);
313 
314 	if (req->newptr != NULL && error == 0) {
315 		/*
316 		 * Copy the locally set hostname to all jails that share
317 		 * this host info.
318 		 */
319 		sx_slock(&allprison_lock);
320 		while (!(pr->pr_flags & PR_HOST))
321 			pr = pr->pr_parent;
322 		mtx_lock(&pr->pr_mtx);
323 		bcopy(tmpname, (char *)pr + pr_offset, len);
324 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, cpr, descend)
325 			if (cpr->pr_flags & PR_HOST)
326 				descend = 0;
327 			else
328 				bcopy(tmpname, (char *)cpr + pr_offset, len);
329 		mtx_unlock(&pr->pr_mtx);
330 		sx_sunlock(&allprison_lock);
331 	}
332 	return (error);
333 }
334 
335 SYSCTL_PROC(_kern, KERN_HOSTNAME, hostname,
336     CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_CAPRD | CTLFLAG_MPSAFE,
337     (void *)(offsetof(struct prison, pr_hostname)), MAXHOSTNAMELEN,
338     sysctl_hostname, "A", "Hostname");
339 SYSCTL_PROC(_kern, KERN_NISDOMAINNAME, domainname,
340     CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_CAPRD | CTLFLAG_MPSAFE,
341     (void *)(offsetof(struct prison, pr_domainname)), MAXHOSTNAMELEN,
342     sysctl_hostname, "A", "Name of the current YP/NIS domain");
343 SYSCTL_PROC(_kern, KERN_HOSTUUID, hostuuid,
344     CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_CAPRD | CTLFLAG_MPSAFE,
345     (void *)(offsetof(struct prison, pr_hostuuid)), HOSTUUIDLEN,
346     sysctl_hostname, "A", "Host UUID");
347 
348 static int	regression_securelevel_nonmonotonic = 0;
349 
350 #ifdef REGRESSION
351 SYSCTL_INT(_regression, OID_AUTO, securelevel_nonmonotonic, CTLFLAG_RW,
352     &regression_securelevel_nonmonotonic, 0, "securelevel may be lowered");
353 #endif
354 
355 static int
356 sysctl_kern_securelvl(SYSCTL_HANDLER_ARGS)
357 {
358 	struct prison *pr, *cpr;
359 	int descend, error, level;
360 
361 	pr = req->td->td_ucred->cr_prison;
362 
363 	/*
364 	 * Reading the securelevel is easy, since the current jail's level
365 	 * is known to be at least as secure as any higher levels.  Perform
366 	 * a lockless read since the securelevel is an integer.
367 	 */
368 	level = pr->pr_securelevel;
369 	error = sysctl_handle_int(oidp, &level, 0, req);
370 	if (error || !req->newptr)
371 		return (error);
372 	/* Permit update only if the new securelevel exceeds the old. */
373 	sx_slock(&allprison_lock);
374 	mtx_lock(&pr->pr_mtx);
375 	if (!regression_securelevel_nonmonotonic &&
376 	    level < pr->pr_securelevel) {
377 		mtx_unlock(&pr->pr_mtx);
378 		sx_sunlock(&allprison_lock);
379 		return (EPERM);
380 	}
381 	pr->pr_securelevel = level;
382 	/*
383 	 * Set all child jails to be at least this level, but do not lower
384 	 * them (even if regression_securelevel_nonmonotonic).
385 	 */
386 	FOREACH_PRISON_DESCENDANT_LOCKED(pr, cpr, descend) {
387 		if (cpr->pr_securelevel < level)
388 			cpr->pr_securelevel = level;
389 	}
390 	mtx_unlock(&pr->pr_mtx);
391 	sx_sunlock(&allprison_lock);
392 	return (error);
393 }
394 
395 SYSCTL_PROC(_kern, KERN_SECURELVL, securelevel,
396     CTLTYPE_INT|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, sysctl_kern_securelvl,
397     "I", "Current secure level");
398 
399 #ifdef INCLUDE_CONFIG_FILE
400 /* Actual kernel configuration options. */
401 extern char kernconfstring[];
402 
403 SYSCTL_STRING(_kern, OID_AUTO, conftxt, CTLFLAG_RD | CTLFLAG_MPSAFE,
404     kernconfstring, 0, "Kernel configuration file");
405 #endif
406 
407 static int
408 sysctl_hostid(SYSCTL_HANDLER_ARGS)
409 {
410 	struct prison *pr, *cpr;
411 	u_long tmpid;
412 	int descend, error;
413 
414 	/*
415 	 * Like sysctl_hostname, except it operates on a u_long
416 	 * instead of a string, and is used only for hostid.
417 	 */
418 	pr = req->td->td_ucred->cr_prison;
419 	if (!(pr->pr_allow & PR_ALLOW_SET_HOSTNAME) && req->newptr)
420 		return (EPERM);
421 	tmpid = pr->pr_hostid;
422 	error = sysctl_handle_long(oidp, &tmpid, 0, req);
423 
424 	if (req->newptr != NULL && error == 0) {
425 		sx_slock(&allprison_lock);
426 		while (!(pr->pr_flags & PR_HOST))
427 			pr = pr->pr_parent;
428 		mtx_lock(&pr->pr_mtx);
429 		pr->pr_hostid = tmpid;
430 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, cpr, descend)
431 			if (cpr->pr_flags & PR_HOST)
432 				descend = 0;
433 			else
434 				cpr->pr_hostid = tmpid;
435 		mtx_unlock(&pr->pr_mtx);
436 		sx_sunlock(&allprison_lock);
437 	}
438 	return (error);
439 }
440 
441 SYSCTL_PROC(_kern, KERN_HOSTID, hostid,
442     CTLTYPE_ULONG | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE | CTLFLAG_CAPRD,
443     NULL, 0, sysctl_hostid, "LU", "Host ID");
444 
445 /*
446  * The osrelease string is copied from the global (osrelease in vers.c) into
447  * prison0 by a sysinit and is inherited by child jails if not changed at jail
448  * creation, so we always return the copy from the current prison data.
449  */
450 static int
451 sysctl_osrelease(SYSCTL_HANDLER_ARGS)
452 {
453 	struct prison *pr;
454 
455 	pr = req->td->td_ucred->cr_prison;
456 	return (SYSCTL_OUT(req, pr->pr_osrelease, strlen(pr->pr_osrelease) + 1));
457 
458 }
459 
460 SYSCTL_PROC(_kern, KERN_OSRELEASE, osrelease,
461     CTLTYPE_STRING | CTLFLAG_CAPRD | CTLFLAG_RD | CTLFLAG_MPSAFE,
462     NULL, 0, sysctl_osrelease, "A", "Operating system release");
463 
464 /*
465  * The osreldate number is copied from the global (osreldate in vers.c) into
466  * prison0 by a sysinit and is inherited by child jails if not changed at jail
467  * creation, so we always return the value from the current prison data.
468  */
469 static int
470 sysctl_osreldate(SYSCTL_HANDLER_ARGS)
471 {
472 	struct prison *pr;
473 
474 	pr = req->td->td_ucred->cr_prison;
475 	return (SYSCTL_OUT(req, &pr->pr_osreldate, sizeof(pr->pr_osreldate)));
476 
477 }
478 
479 /*
480  * NOTICE: The *userland* release date is available in
481  * /usr/include/osreldate.h
482  */
483 SYSCTL_PROC(_kern, KERN_OSRELDATE, osreldate,
484     CTLTYPE_INT | CTLFLAG_CAPRD | CTLFLAG_RD | CTLFLAG_MPSAFE,
485     NULL, 0, sysctl_osreldate, "I", "Kernel release date");
486 
487 SYSCTL_NODE(_kern, OID_AUTO, features, CTLFLAG_RD, 0, "Kernel Features");
488 
489 #ifdef COMPAT_FREEBSD4
490 FEATURE(compat_freebsd4, "Compatible with FreeBSD 4");
491 #endif
492 
493 #ifdef COMPAT_FREEBSD5
494 FEATURE(compat_freebsd5, "Compatible with FreeBSD 5");
495 #endif
496 
497 #ifdef COMPAT_FREEBSD6
498 FEATURE(compat_freebsd6, "Compatible with FreeBSD 6");
499 #endif
500 
501 #ifdef COMPAT_FREEBSD7
502 FEATURE(compat_freebsd7, "Compatible with FreeBSD 7");
503 #endif
504 
505 /*
506  * This is really cheating.  These actually live in the libc, something
507  * which I'm not quite sure is a good idea anyway, but in order for
508  * getnext and friends to actually work, we define dummies here.
509  *
510  * XXXRW: These probably should be CTLFLAG_CAPRD.
511  */
512 SYSCTL_STRING(_user, USER_CS_PATH, cs_path, CTLFLAG_RD,
513     "", 0, "PATH that finds all the standard utilities");
514 SYSCTL_INT(_user, USER_BC_BASE_MAX, bc_base_max, CTLFLAG_RD,
515     SYSCTL_NULL_INT_PTR, 0, "Max ibase/obase values in bc(1)");
516 SYSCTL_INT(_user, USER_BC_DIM_MAX, bc_dim_max, CTLFLAG_RD,
517     SYSCTL_NULL_INT_PTR, 0, "Max array size in bc(1)");
518 SYSCTL_INT(_user, USER_BC_SCALE_MAX, bc_scale_max, CTLFLAG_RD,
519     SYSCTL_NULL_INT_PTR, 0, "Max scale value in bc(1)");
520 SYSCTL_INT(_user, USER_BC_STRING_MAX, bc_string_max, CTLFLAG_RD,
521     SYSCTL_NULL_INT_PTR, 0, "Max string length in bc(1)");
522 SYSCTL_INT(_user, USER_COLL_WEIGHTS_MAX, coll_weights_max, CTLFLAG_RD,
523     SYSCTL_NULL_INT_PTR, 0, "Maximum number of weights assigned to an LC_COLLATE locale entry");
524 SYSCTL_INT(_user, USER_EXPR_NEST_MAX, expr_nest_max, CTLFLAG_RD,
525     SYSCTL_NULL_INT_PTR, 0, "");
526 SYSCTL_INT(_user, USER_LINE_MAX, line_max, CTLFLAG_RD,
527     SYSCTL_NULL_INT_PTR, 0, "Max length (bytes) of a text-processing utility's input line");
528 SYSCTL_INT(_user, USER_RE_DUP_MAX, re_dup_max, CTLFLAG_RD,
529     SYSCTL_NULL_INT_PTR, 0, "Maximum number of repeats of a regexp permitted");
530 SYSCTL_INT(_user, USER_POSIX2_VERSION, posix2_version, CTLFLAG_RD,
531     SYSCTL_NULL_INT_PTR, 0,
532     "The version of POSIX 1003.2 with which the system attempts to comply");
533 SYSCTL_INT(_user, USER_POSIX2_C_BIND, posix2_c_bind, CTLFLAG_RD,
534     SYSCTL_NULL_INT_PTR, 0, "Whether C development supports the C bindings option");
535 SYSCTL_INT(_user, USER_POSIX2_C_DEV, posix2_c_dev, CTLFLAG_RD,
536     SYSCTL_NULL_INT_PTR, 0, "Whether system supports the C development utilities option");
537 SYSCTL_INT(_user, USER_POSIX2_CHAR_TERM, posix2_char_term, CTLFLAG_RD,
538     SYSCTL_NULL_INT_PTR, 0, "");
539 SYSCTL_INT(_user, USER_POSIX2_FORT_DEV, posix2_fort_dev, CTLFLAG_RD,
540     SYSCTL_NULL_INT_PTR, 0, "Whether system supports FORTRAN development utilities");
541 SYSCTL_INT(_user, USER_POSIX2_FORT_RUN, posix2_fort_run, CTLFLAG_RD,
542     SYSCTL_NULL_INT_PTR, 0, "Whether system supports FORTRAN runtime utilities");
543 SYSCTL_INT(_user, USER_POSIX2_LOCALEDEF, posix2_localedef, CTLFLAG_RD,
544     SYSCTL_NULL_INT_PTR, 0, "Whether system supports creation of locales");
545 SYSCTL_INT(_user, USER_POSIX2_SW_DEV, posix2_sw_dev, CTLFLAG_RD,
546     SYSCTL_NULL_INT_PTR, 0, "Whether system supports software development utilities");
547 SYSCTL_INT(_user, USER_POSIX2_UPE, posix2_upe, CTLFLAG_RD,
548     SYSCTL_NULL_INT_PTR, 0, "Whether system supports the user portability utilities");
549 SYSCTL_INT(_user, USER_STREAM_MAX, stream_max, CTLFLAG_RD,
550     SYSCTL_NULL_INT_PTR, 0, "Min Maximum number of streams a process may have open at one time");
551 SYSCTL_INT(_user, USER_TZNAME_MAX, tzname_max, CTLFLAG_RD,
552     SYSCTL_NULL_INT_PTR, 0, "Min Maximum number of types supported for timezone names");
553 
554 #include <sys/vnode.h>
555 SYSCTL_INT(_debug_sizeof, OID_AUTO, vnode, CTLFLAG_RD,
556     SYSCTL_NULL_INT_PTR, sizeof(struct vnode), "sizeof(struct vnode)");
557 
558 SYSCTL_INT(_debug_sizeof, OID_AUTO, proc, CTLFLAG_RD,
559     SYSCTL_NULL_INT_PTR, sizeof(struct proc), "sizeof(struct proc)");
560 
561 static int
562 sysctl_kern_pid_max(SYSCTL_HANDLER_ARGS)
563 {
564 	int error, pm;
565 
566 	pm = pid_max;
567 	error = sysctl_handle_int(oidp, &pm, 0, req);
568 	if (error || !req->newptr)
569 		return (error);
570 	sx_xlock(&proctree_lock);
571 	sx_xlock(&allproc_lock);
572 
573 	/*
574 	 * Only permit the values less then PID_MAX.
575 	 * As a safety measure, do not allow to limit the pid_max too much.
576 	 */
577 	if (pm < 300 || pm > PID_MAX)
578 		error = EINVAL;
579 	else
580 		pid_max = pm;
581 	sx_xunlock(&allproc_lock);
582 	sx_xunlock(&proctree_lock);
583 	return (error);
584 }
585 SYSCTL_PROC(_kern, OID_AUTO, pid_max, CTLTYPE_INT |
586     CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE,
587     0, 0, sysctl_kern_pid_max, "I", "Maximum allowed pid");
588 
589 #include <sys/bio.h>
590 #include <sys/buf.h>
591 SYSCTL_INT(_debug_sizeof, OID_AUTO, bio, CTLFLAG_RD,
592     SYSCTL_NULL_INT_PTR, sizeof(struct bio), "sizeof(struct bio)");
593 SYSCTL_INT(_debug_sizeof, OID_AUTO, buf, CTLFLAG_RD,
594     SYSCTL_NULL_INT_PTR, sizeof(struct buf), "sizeof(struct buf)");
595 
596 #include <sys/user.h>
597 SYSCTL_INT(_debug_sizeof, OID_AUTO, kinfo_proc, CTLFLAG_RD,
598     SYSCTL_NULL_INT_PTR, sizeof(struct kinfo_proc), "sizeof(struct kinfo_proc)");
599 
600 /* Used by kernel debuggers. */
601 const int pcb_size = sizeof(struct pcb);
602 SYSCTL_INT(_debug_sizeof, OID_AUTO, pcb, CTLFLAG_RD,
603     SYSCTL_NULL_INT_PTR, sizeof(struct pcb), "sizeof(struct pcb)");
604 
605 /* XXX compatibility, remove for 6.0 */
606 #include <sys/imgact.h>
607 #include <sys/imgact_elf.h>
608 SYSCTL_INT(_kern, OID_AUTO, fallback_elf_brand, CTLFLAG_RW,
609     &__elfN(fallback_brand), sizeof(__elfN(fallback_brand)),
610     "compatibility for kern.fallback_elf_brand");
611