xref: /freebsd/sys/kern/kern_mib.c (revision 732a02b4e77866604a120a275c082bb6221bd2ff)
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/boot.h>
48 #include <sys/jail.h>
49 #include <sys/kernel.h>
50 #include <sys/limits.h>
51 #include <sys/lock.h>
52 #include <sys/mutex.h>
53 #include <sys/proc.h>
54 #include <sys/random.h>
55 #include <sys/sbuf.h>
56 #include <sys/smp.h>
57 #include <sys/sx.h>
58 #include <sys/vmmeter.h>
59 #include <sys/sysctl.h>
60 #include <sys/systm.h>
61 #include <sys/unistd.h>
62 
63 SYSCTL_ROOT_NODE(0, sysctl, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
64     "Sysctl internal magic");
65 SYSCTL_ROOT_NODE(CTL_KERN, kern, CTLFLAG_RW | CTLFLAG_CAPRD | CTLFLAG_MPSAFE, 0,
66     "High kernel, proc, limits &c");
67 SYSCTL_ROOT_NODE(CTL_VM, vm, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
68     "Virtual memory");
69 SYSCTL_ROOT_NODE(CTL_VFS, vfs, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
70     "File system");
71 SYSCTL_ROOT_NODE(CTL_NET, net, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
72     "Network, (see socket.h)");
73 SYSCTL_ROOT_NODE(CTL_DEBUG, debug, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
74     "Debugging");
75 SYSCTL_NODE(_debug, OID_AUTO,  sizeof,  CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
76     "Sizeof various things");
77 SYSCTL_ROOT_NODE(CTL_HW, hw, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
78     "hardware");
79 SYSCTL_ROOT_NODE(CTL_MACHDEP, machdep, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
80     "machine dependent");
81 SYSCTL_NODE(_machdep, OID_AUTO, mitigations, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
82     "Machine dependent platform mitigations.");
83 SYSCTL_ROOT_NODE(CTL_USER, user, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
84     "user-level");
85 SYSCTL_ROOT_NODE(CTL_P1003_1B, p1003_1b, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
86     "p1003_1b, (see p1003_1b.h)");
87 
88 SYSCTL_ROOT_NODE(OID_AUTO, compat, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
89     "Compatibility code");
90 SYSCTL_ROOT_NODE(OID_AUTO, security, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
91     "Security");
92 #ifdef REGRESSION
93 SYSCTL_ROOT_NODE(OID_AUTO, regression, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
94     "Regression test MIB");
95 #endif
96 
97 SYSCTL_STRING(_kern, OID_AUTO, ident, CTLFLAG_RD|CTLFLAG_MPSAFE,
98     kern_ident, 0, "Kernel identifier");
99 
100 SYSCTL_INT(_kern, KERN_OSREV, osrevision, CTLFLAG_RD|CTLFLAG_CAPRD,
101     SYSCTL_NULL_INT_PTR, BSD, "Operating system revision");
102 
103 SYSCTL_STRING(_kern, KERN_VERSION, version, CTLFLAG_RD|CTLFLAG_MPSAFE,
104     version, 0, "Kernel version");
105 
106 SYSCTL_STRING(_kern, OID_AUTO, compiler_version, CTLFLAG_RD|CTLFLAG_MPSAFE,
107     compiler_version, 0, "Version of compiler used to compile kernel");
108 
109 SYSCTL_STRING(_kern, KERN_OSTYPE, ostype, CTLFLAG_RD|CTLFLAG_MPSAFE|
110     CTLFLAG_CAPRD, ostype, 0, "Operating system type");
111 
112 SYSCTL_INT(_kern, KERN_MAXPROC, maxproc, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
113     &maxproc, 0, "Maximum number of processes");
114 
115 SYSCTL_INT(_kern, KERN_MAXPROCPERUID, maxprocperuid, CTLFLAG_RW,
116     &maxprocperuid, 0, "Maximum processes allowed per userid");
117 
118 SYSCTL_INT(_kern, OID_AUTO, maxusers, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
119     &maxusers, 0, "Hint for kernel tuning");
120 
121 SYSCTL_INT(_kern, KERN_ARGMAX, argmax, CTLFLAG_RD|CTLFLAG_CAPRD,
122     SYSCTL_NULL_INT_PTR, ARG_MAX, "Maximum bytes of argument to execve(2)");
123 
124 SYSCTL_INT(_kern, KERN_POSIX1, posix1version, CTLFLAG_RD|CTLFLAG_CAPRD,
125     SYSCTL_NULL_INT_PTR, _POSIX_VERSION, "Version of POSIX attempting to comply to");
126 
127 SYSCTL_INT(_kern, KERN_NGROUPS, ngroups, CTLFLAG_RDTUN |
128     CTLFLAG_NOFETCH | CTLFLAG_CAPRD, &ngroups_max, 0,
129     "Maximum number of supplemental groups a user can belong to");
130 
131 SYSCTL_INT(_kern, KERN_JOB_CONTROL, job_control, CTLFLAG_RD|CTLFLAG_CAPRD,
132     SYSCTL_NULL_INT_PTR, 1, "Whether job control is available");
133 
134 #ifdef _POSIX_SAVED_IDS
135 SYSCTL_INT(_kern, KERN_SAVED_IDS, saved_ids, CTLFLAG_RD|CTLFLAG_CAPRD,
136     SYSCTL_NULL_INT_PTR, 1, "Whether saved set-group/user ID is available");
137 #else
138 SYSCTL_INT(_kern, KERN_SAVED_IDS, saved_ids, CTLFLAG_RD|CTLFLAG_CAPRD,
139     SYSCTL_NULL_INT_PTR, 0, "Whether saved set-group/user ID is available");
140 #endif
141 
142 char kernelname[MAXPATHLEN] = PATH_KERNEL;	/* XXX bloat */
143 
144 SYSCTL_STRING(_kern, KERN_BOOTFILE, bootfile, CTLFLAG_RW | CTLFLAG_MPSAFE,
145     kernelname, sizeof kernelname, "Name of kernel file booted");
146 
147 SYSCTL_INT(_kern, KERN_MAXPHYS, maxphys, CTLFLAG_RD | CTLFLAG_CAPRD,
148     SYSCTL_NULL_INT_PTR, MAXPHYS, "Maximum block I/O access size");
149 
150 SYSCTL_INT(_hw, HW_NCPU, ncpu, CTLFLAG_RD|CTLFLAG_CAPRD,
151     &mp_ncpus, 0, "Number of active CPUs");
152 
153 SYSCTL_INT(_hw, HW_BYTEORDER, byteorder, CTLFLAG_RD|CTLFLAG_CAPRD,
154     SYSCTL_NULL_INT_PTR, BYTE_ORDER, "System byte order");
155 
156 SYSCTL_INT(_hw, HW_PAGESIZE, pagesize, CTLFLAG_RD|CTLFLAG_CAPRD,
157     SYSCTL_NULL_INT_PTR, PAGE_SIZE, "System memory page size");
158 
159 static int
160 sysctl_kern_arnd(SYSCTL_HANDLER_ARGS)
161 {
162 	char buf[256];
163 	size_t len;
164 
165 	len = MIN(req->oldlen, sizeof(buf));
166 	read_random(buf, len);
167 	return (SYSCTL_OUT(req, buf, len));
168 }
169 
170 SYSCTL_PROC(_kern, KERN_ARND, arandom,
171     CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD, NULL, 0,
172     sysctl_kern_arnd, "", "arc4rand");
173 
174 static int
175 sysctl_hw_physmem(SYSCTL_HANDLER_ARGS)
176 {
177 	u_long val, p;
178 
179 	p = SIZE_T_MAX >> PAGE_SHIFT;
180 	if (physmem < p)
181 		p = physmem;
182 	val = ctob(p);
183 	return (sysctl_handle_long(oidp, &val, 0, req));
184 }
185 SYSCTL_PROC(_hw, HW_PHYSMEM, physmem,
186     CTLTYPE_ULONG | CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 0,
187     sysctl_hw_physmem, "LU",
188     "Amount of physical memory (in bytes)");
189 
190 static int
191 sysctl_hw_realmem(SYSCTL_HANDLER_ARGS)
192 {
193 	u_long val, p;
194 
195 	p = SIZE_T_MAX >> PAGE_SHIFT;
196 	if (realmem < p)
197 		p = realmem;
198 	val = ctob(p);
199 	return (sysctl_handle_long(oidp, &val, 0, req));
200 }
201 SYSCTL_PROC(_hw, HW_REALMEM, realmem,
202     CTLTYPE_ULONG | CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 0,
203     sysctl_hw_realmem, "LU",
204     "Amount of memory (in bytes) reported by the firmware");
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,
219     CTLTYPE_ULONG | CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 0,
220     sysctl_hw_usermem, "LU",
221     "Amount of memory (in bytes) which is not wired");
222 
223 SYSCTL_LONG(_hw, OID_AUTO, availpages, CTLFLAG_RD, &physmem, 0,
224     "Amount of physical memory (in pages)");
225 
226 u_long pagesizes[MAXPAGESIZES] = { PAGE_SIZE };
227 
228 static int
229 sysctl_hw_pagesizes(SYSCTL_HANDLER_ARGS)
230 {
231 	int error;
232 #ifdef SCTL_MASK32
233 	int i;
234 	uint32_t pagesizes32[MAXPAGESIZES];
235 
236 	if (req->flags & SCTL_MASK32) {
237 		/*
238 		 * Recreate the "pagesizes" array with 32-bit elements.  Truncate
239 		 * any page size greater than UINT32_MAX to zero.
240 		 */
241 		for (i = 0; i < MAXPAGESIZES; i++)
242 			pagesizes32[i] = (uint32_t)pagesizes[i];
243 
244 		error = SYSCTL_OUT(req, pagesizes32, sizeof(pagesizes32));
245 	} else
246 #endif
247 		error = SYSCTL_OUT(req, pagesizes, sizeof(pagesizes));
248 	return (error);
249 }
250 SYSCTL_PROC(_hw, OID_AUTO, pagesizes,
251     CTLTYPE_ULONG | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
252     sysctl_hw_pagesizes, "LU",
253     "Supported page sizes");
254 
255 #ifdef SCTL_MASK32
256 int adaptive_machine_arch = 1;
257 SYSCTL_INT(_debug, OID_AUTO, adaptive_machine_arch, CTLFLAG_RW,
258     &adaptive_machine_arch, 1,
259     "Adapt reported machine architecture to the ABI of the binary");
260 #endif
261 
262 static int
263 sysctl_hw_machine_arch(SYSCTL_HANDLER_ARGS)
264 {
265 	int error;
266 	static const char machine_arch[] = MACHINE_ARCH;
267 #ifdef SCTL_MASK32
268 	static const char machine_arch32[] = MACHINE_ARCH32;
269 
270 	if ((req->flags & SCTL_MASK32) != 0 && adaptive_machine_arch)
271 		error = SYSCTL_OUT(req, machine_arch32, sizeof(machine_arch32));
272 	else
273 #endif
274 		error = SYSCTL_OUT(req, machine_arch, sizeof(machine_arch));
275 	return (error);
276 
277 }
278 SYSCTL_PROC(_hw, HW_MACHINE_ARCH, machine_arch, CTLTYPE_STRING | CTLFLAG_RD |
279     CTLFLAG_MPSAFE, NULL, 0, sysctl_hw_machine_arch, "A",
280     "System architecture");
281 
282 SYSCTL_STRING(_kern, OID_AUTO, supported_archs, CTLFLAG_RD | CTLFLAG_MPSAFE,
283 #ifdef COMPAT_FREEBSD32
284     MACHINE_ARCH " " MACHINE_ARCH32, 0, "Supported architectures for binaries");
285 #else
286     MACHINE_ARCH, 0, "Supported architectures for binaries");
287 #endif
288 
289 static int
290 sysctl_hostname(SYSCTL_HANDLER_ARGS)
291 {
292 	struct prison *pr, *cpr;
293 	size_t pr_offset;
294 	char tmpname[MAXHOSTNAMELEN];
295 	int descend, error, len;
296 
297 	/*
298 	 * This function can set: hostname domainname hostuuid.
299 	 * Keep that in mind when comments say "hostname".
300 	 */
301 	pr_offset = (size_t)arg1;
302 	len = arg2;
303 	KASSERT(len <= sizeof(tmpname),
304 	    ("length %d too long for %s", len, __func__));
305 
306 	pr = req->td->td_ucred->cr_prison;
307 	if (!(pr->pr_allow & PR_ALLOW_SET_HOSTNAME) && req->newptr)
308 		return (EPERM);
309 	/*
310 	 * Make a local copy of hostname to get/set so we don't have to hold
311 	 * the jail mutex during the sysctl copyin/copyout activities.
312 	 */
313 	mtx_lock(&pr->pr_mtx);
314 	bcopy((char *)pr + pr_offset, tmpname, len);
315 	mtx_unlock(&pr->pr_mtx);
316 
317 	error = sysctl_handle_string(oidp, tmpname, len, req);
318 
319 	if (req->newptr != NULL && error == 0) {
320 		/*
321 		 * Copy the locally set hostname to all jails that share
322 		 * this host info.
323 		 */
324 		sx_slock(&allprison_lock);
325 		while (!(pr->pr_flags & PR_HOST))
326 			pr = pr->pr_parent;
327 		mtx_lock(&pr->pr_mtx);
328 		bcopy(tmpname, (char *)pr + pr_offset, len);
329 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, cpr, descend)
330 			if (cpr->pr_flags & PR_HOST)
331 				descend = 0;
332 			else
333 				bcopy(tmpname, (char *)cpr + pr_offset, len);
334 		mtx_unlock(&pr->pr_mtx);
335 		sx_sunlock(&allprison_lock);
336 	}
337 	return (error);
338 }
339 
340 SYSCTL_PROC(_kern, KERN_HOSTNAME, hostname,
341     CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_CAPRD | CTLFLAG_MPSAFE,
342     (void *)(offsetof(struct prison, pr_hostname)), MAXHOSTNAMELEN,
343     sysctl_hostname, "A", "Hostname");
344 SYSCTL_PROC(_kern, KERN_NISDOMAINNAME, domainname,
345     CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_CAPRD | CTLFLAG_MPSAFE,
346     (void *)(offsetof(struct prison, pr_domainname)), MAXHOSTNAMELEN,
347     sysctl_hostname, "A", "Name of the current YP/NIS domain");
348 SYSCTL_PROC(_kern, KERN_HOSTUUID, hostuuid,
349     CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_CAPRD | CTLFLAG_MPSAFE,
350     (void *)(offsetof(struct prison, pr_hostuuid)), HOSTUUIDLEN,
351     sysctl_hostname, "A", "Host UUID");
352 
353 static int	regression_securelevel_nonmonotonic = 0;
354 
355 #ifdef REGRESSION
356 SYSCTL_INT(_regression, OID_AUTO, securelevel_nonmonotonic, CTLFLAG_RW,
357     &regression_securelevel_nonmonotonic, 0, "securelevel may be lowered");
358 #endif
359 
360 static int
361 sysctl_kern_securelvl(SYSCTL_HANDLER_ARGS)
362 {
363 	struct prison *pr, *cpr;
364 	int descend, error, level;
365 
366 	pr = req->td->td_ucred->cr_prison;
367 
368 	/*
369 	 * Reading the securelevel is easy, since the current jail's level
370 	 * is known to be at least as secure as any higher levels.  Perform
371 	 * a lockless read since the securelevel is an integer.
372 	 */
373 	level = pr->pr_securelevel;
374 	error = sysctl_handle_int(oidp, &level, 0, req);
375 	if (error || !req->newptr)
376 		return (error);
377 	/* Permit update only if the new securelevel exceeds the old. */
378 	sx_slock(&allprison_lock);
379 	mtx_lock(&pr->pr_mtx);
380 	if (!regression_securelevel_nonmonotonic &&
381 	    level < pr->pr_securelevel) {
382 		mtx_unlock(&pr->pr_mtx);
383 		sx_sunlock(&allprison_lock);
384 		return (EPERM);
385 	}
386 	pr->pr_securelevel = level;
387 	/*
388 	 * Set all child jails to be at least this level, but do not lower
389 	 * them (even if regression_securelevel_nonmonotonic).
390 	 */
391 	FOREACH_PRISON_DESCENDANT_LOCKED(pr, cpr, descend) {
392 		if (cpr->pr_securelevel < level)
393 			cpr->pr_securelevel = level;
394 	}
395 	mtx_unlock(&pr->pr_mtx);
396 	sx_sunlock(&allprison_lock);
397 	return (error);
398 }
399 
400 SYSCTL_PROC(_kern, KERN_SECURELVL, securelevel,
401     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE, 0, 0,
402     sysctl_kern_securelvl, "I",
403     "Current secure level");
404 
405 #ifdef INCLUDE_CONFIG_FILE
406 /* Actual kernel configuration options. */
407 extern char kernconfstring[];
408 
409 SYSCTL_STRING(_kern, OID_AUTO, conftxt, CTLFLAG_RD | CTLFLAG_MPSAFE,
410     kernconfstring, 0, "Kernel configuration file");
411 #endif
412 
413 static int
414 sysctl_hostid(SYSCTL_HANDLER_ARGS)
415 {
416 	struct prison *pr, *cpr;
417 	u_long tmpid;
418 	int descend, error;
419 
420 	/*
421 	 * Like sysctl_hostname, except it operates on a u_long
422 	 * instead of a string, and is used only for hostid.
423 	 */
424 	pr = req->td->td_ucred->cr_prison;
425 	if (!(pr->pr_allow & PR_ALLOW_SET_HOSTNAME) && req->newptr)
426 		return (EPERM);
427 	tmpid = pr->pr_hostid;
428 	error = sysctl_handle_long(oidp, &tmpid, 0, req);
429 
430 	if (req->newptr != NULL && error == 0) {
431 		sx_slock(&allprison_lock);
432 		while (!(pr->pr_flags & PR_HOST))
433 			pr = pr->pr_parent;
434 		mtx_lock(&pr->pr_mtx);
435 		pr->pr_hostid = tmpid;
436 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, cpr, descend)
437 			if (cpr->pr_flags & PR_HOST)
438 				descend = 0;
439 			else
440 				cpr->pr_hostid = tmpid;
441 		mtx_unlock(&pr->pr_mtx);
442 		sx_sunlock(&allprison_lock);
443 	}
444 	return (error);
445 }
446 
447 SYSCTL_PROC(_kern, KERN_HOSTID, hostid,
448     CTLTYPE_ULONG | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE | CTLFLAG_CAPRD,
449     NULL, 0, sysctl_hostid, "LU", "Host ID");
450 
451 static struct mtx bootid_lk;
452 MTX_SYSINIT(bootid_lock, &bootid_lk, "bootid generator lock", MTX_DEF);
453 
454 static int
455 sysctl_bootid(SYSCTL_HANDLER_ARGS)
456 {
457 	static uint8_t boot_id[16];
458 	static bool initialized = false;
459 
460 	mtx_lock(&bootid_lk);
461 	if (!initialized) {
462 		if (!is_random_seeded()) {
463 			mtx_unlock(&bootid_lk);
464 			return (ENXIO);
465 		}
466 		arc4random_buf(boot_id, sizeof(boot_id));
467 		initialized = true;
468 	}
469 	mtx_unlock(&bootid_lk);
470 
471 	return (SYSCTL_OUT(req, boot_id, sizeof(boot_id)));
472 }
473 SYSCTL_PROC(_kern, OID_AUTO, boot_id,
474     CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD,
475     NULL, 0, sysctl_bootid, "", "Random boot ID");
476 
477 /*
478  * The osrelease string is copied from the global (osrelease in vers.c) into
479  * prison0 by a sysinit and is inherited by child jails if not changed at jail
480  * creation, so we always return the copy from the current prison data.
481  */
482 static int
483 sysctl_osrelease(SYSCTL_HANDLER_ARGS)
484 {
485 	struct prison *pr;
486 
487 	pr = req->td->td_ucred->cr_prison;
488 	return (SYSCTL_OUT(req, pr->pr_osrelease, strlen(pr->pr_osrelease) + 1));
489 
490 }
491 
492 SYSCTL_PROC(_kern, KERN_OSRELEASE, osrelease,
493     CTLTYPE_STRING | CTLFLAG_CAPRD | CTLFLAG_RD | CTLFLAG_MPSAFE,
494     NULL, 0, sysctl_osrelease, "A", "Operating system release");
495 
496 /*
497  * The osreldate number is copied from the global (osreldate in vers.c) into
498  * prison0 by a sysinit and is inherited by child jails if not changed at jail
499  * creation, so we always return the value from the current prison data.
500  */
501 static int
502 sysctl_osreldate(SYSCTL_HANDLER_ARGS)
503 {
504 	struct prison *pr;
505 
506 	pr = req->td->td_ucred->cr_prison;
507 	return (SYSCTL_OUT(req, &pr->pr_osreldate, sizeof(pr->pr_osreldate)));
508 
509 }
510 
511 /*
512  * NOTICE: The *userland* release date is available in
513  * /usr/include/osreldate.h
514  */
515 SYSCTL_PROC(_kern, KERN_OSRELDATE, osreldate,
516     CTLTYPE_INT | CTLFLAG_CAPRD | CTLFLAG_RD | CTLFLAG_MPSAFE,
517     NULL, 0, sysctl_osreldate, "I", "Kernel release date");
518 
519 /*
520  * The build-id is copied from the ELF section .note.gnu.build-id.  The linker
521  * script defines two variables to expose the beginning and end.  LLVM
522  * currently uses a SHA-1 hash, but other formats can be supported by checking
523  * the length of the section.
524  */
525 
526 extern char __build_id_start[];
527 extern char __build_id_end[];
528 
529 #define	BUILD_ID_HEADER_LEN	0x10
530 #define	BUILD_ID_HASH_MAXLEN	0x14
531 
532 static int
533 sysctl_build_id(SYSCTL_HANDLER_ARGS)
534 {
535 	uintptr_t sectionlen = (uintptr_t)(__build_id_end - __build_id_start);
536 	int hashlen;
537 	char buf[2*BUILD_ID_HASH_MAXLEN+1];
538 
539 	/*
540 	 * The ELF note section has a four byte length for the vendor name,
541 	 * four byte length for the value, and a four byte vendor specific
542 	 * type.  The name for the build id is "GNU\0".  We skip the first 16
543 	 * bytes to read the build hash.  We will return the remaining bytes up
544 	 * to 20 (SHA-1) hash size.  If the hash happens to be a custom number
545 	 * of bytes we will pad the value with zeros, as the section should be
546 	 * four byte aligned.
547 	 */
548 	if (sectionlen <= BUILD_ID_HEADER_LEN ||
549 	    sectionlen > (BUILD_ID_HEADER_LEN + BUILD_ID_HASH_MAXLEN)) {
550 		return (ENOENT);
551 	}
552 
553 	hashlen = sectionlen - BUILD_ID_HEADER_LEN;
554 	for (int i = 0; i < hashlen; i++) {
555 		uint8_t c = __build_id_start[i+BUILD_ID_HEADER_LEN];
556 		snprintf(&buf[2*i], 3, "%02x", c);
557 	}
558 
559 	return (SYSCTL_OUT(req, buf, strlen(buf) + 1));
560 }
561 
562 SYSCTL_PROC(_kern, OID_AUTO, build_id,
563     CTLTYPE_STRING | CTLFLAG_CAPRD | CTLFLAG_RD | CTLFLAG_MPSAFE,
564     NULL, 0, sysctl_build_id, "A", "Operating system build-id");
565 
566 SYSCTL_NODE(_kern, OID_AUTO, features, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
567     "Kernel Features");
568 
569 #ifdef COMPAT_FREEBSD4
570 FEATURE(compat_freebsd4, "Compatible with FreeBSD 4");
571 #endif
572 
573 #ifdef COMPAT_FREEBSD5
574 FEATURE(compat_freebsd5, "Compatible with FreeBSD 5");
575 #endif
576 
577 #ifdef COMPAT_FREEBSD6
578 FEATURE(compat_freebsd6, "Compatible with FreeBSD 6");
579 #endif
580 
581 #ifdef COMPAT_FREEBSD7
582 FEATURE(compat_freebsd7, "Compatible with FreeBSD 7");
583 #endif
584 
585 /*
586  * This is really cheating.  These actually live in the libc, something
587  * which I'm not quite sure is a good idea anyway, but in order for
588  * getnext and friends to actually work, we define dummies here.
589  *
590  * XXXRW: These probably should be CTLFLAG_CAPRD.
591  */
592 SYSCTL_STRING(_user, USER_CS_PATH, cs_path, CTLFLAG_RD,
593     "", 0, "PATH that finds all the standard utilities");
594 SYSCTL_INT(_user, USER_BC_BASE_MAX, bc_base_max, CTLFLAG_RD,
595     SYSCTL_NULL_INT_PTR, 0, "Max ibase/obase values in bc(1)");
596 SYSCTL_INT(_user, USER_BC_DIM_MAX, bc_dim_max, CTLFLAG_RD,
597     SYSCTL_NULL_INT_PTR, 0, "Max array size in bc(1)");
598 SYSCTL_INT(_user, USER_BC_SCALE_MAX, bc_scale_max, CTLFLAG_RD,
599     SYSCTL_NULL_INT_PTR, 0, "Max scale value in bc(1)");
600 SYSCTL_INT(_user, USER_BC_STRING_MAX, bc_string_max, CTLFLAG_RD,
601     SYSCTL_NULL_INT_PTR, 0, "Max string length in bc(1)");
602 SYSCTL_INT(_user, USER_COLL_WEIGHTS_MAX, coll_weights_max, CTLFLAG_RD,
603     SYSCTL_NULL_INT_PTR, 0, "Maximum number of weights assigned to an LC_COLLATE locale entry");
604 SYSCTL_INT(_user, USER_EXPR_NEST_MAX, expr_nest_max, CTLFLAG_RD,
605     SYSCTL_NULL_INT_PTR, 0, "");
606 SYSCTL_INT(_user, USER_LINE_MAX, line_max, CTLFLAG_RD,
607     SYSCTL_NULL_INT_PTR, 0, "Max length (bytes) of a text-processing utility's input line");
608 SYSCTL_INT(_user, USER_RE_DUP_MAX, re_dup_max, CTLFLAG_RD,
609     SYSCTL_NULL_INT_PTR, 0, "Maximum number of repeats of a regexp permitted");
610 SYSCTL_INT(_user, USER_POSIX2_VERSION, posix2_version, CTLFLAG_RD,
611     SYSCTL_NULL_INT_PTR, 0,
612     "The version of POSIX 1003.2 with which the system attempts to comply");
613 SYSCTL_INT(_user, USER_POSIX2_C_BIND, posix2_c_bind, CTLFLAG_RD,
614     SYSCTL_NULL_INT_PTR, 0, "Whether C development supports the C bindings option");
615 SYSCTL_INT(_user, USER_POSIX2_C_DEV, posix2_c_dev, CTLFLAG_RD,
616     SYSCTL_NULL_INT_PTR, 0, "Whether system supports the C development utilities option");
617 SYSCTL_INT(_user, USER_POSIX2_CHAR_TERM, posix2_char_term, CTLFLAG_RD,
618     SYSCTL_NULL_INT_PTR, 0, "");
619 SYSCTL_INT(_user, USER_POSIX2_FORT_DEV, posix2_fort_dev, CTLFLAG_RD,
620     SYSCTL_NULL_INT_PTR, 0, "Whether system supports FORTRAN development utilities");
621 SYSCTL_INT(_user, USER_POSIX2_FORT_RUN, posix2_fort_run, CTLFLAG_RD,
622     SYSCTL_NULL_INT_PTR, 0, "Whether system supports FORTRAN runtime utilities");
623 SYSCTL_INT(_user, USER_POSIX2_LOCALEDEF, posix2_localedef, CTLFLAG_RD,
624     SYSCTL_NULL_INT_PTR, 0, "Whether system supports creation of locales");
625 SYSCTL_INT(_user, USER_POSIX2_SW_DEV, posix2_sw_dev, CTLFLAG_RD,
626     SYSCTL_NULL_INT_PTR, 0, "Whether system supports software development utilities");
627 SYSCTL_INT(_user, USER_POSIX2_UPE, posix2_upe, CTLFLAG_RD,
628     SYSCTL_NULL_INT_PTR, 0, "Whether system supports the user portability utilities");
629 SYSCTL_INT(_user, USER_STREAM_MAX, stream_max, CTLFLAG_RD,
630     SYSCTL_NULL_INT_PTR, 0, "Min Maximum number of streams a process may have open at one time");
631 SYSCTL_INT(_user, USER_TZNAME_MAX, tzname_max, CTLFLAG_RD,
632     SYSCTL_NULL_INT_PTR, 0, "Min Maximum number of types supported for timezone names");
633 
634 #include <sys/vnode.h>
635 SYSCTL_INT(_debug_sizeof, OID_AUTO, vnode, CTLFLAG_RD,
636     SYSCTL_NULL_INT_PTR, sizeof(struct vnode), "sizeof(struct vnode)");
637 
638 SYSCTL_INT(_debug_sizeof, OID_AUTO, proc, CTLFLAG_RD,
639     SYSCTL_NULL_INT_PTR, sizeof(struct proc), "sizeof(struct proc)");
640 
641 static int
642 sysctl_kern_pid_max(SYSCTL_HANDLER_ARGS)
643 {
644 	int error, pm;
645 
646 	pm = pid_max;
647 	error = sysctl_handle_int(oidp, &pm, 0, req);
648 	if (error || !req->newptr)
649 		return (error);
650 	sx_xlock(&proctree_lock);
651 	sx_xlock(&allproc_lock);
652 
653 	/*
654 	 * Only permit the values less then PID_MAX.
655 	 * As a safety measure, do not allow to limit the pid_max too much.
656 	 */
657 	if (pm < 300 || pm > PID_MAX)
658 		error = EINVAL;
659 	else
660 		pid_max = pm;
661 	sx_xunlock(&allproc_lock);
662 	sx_xunlock(&proctree_lock);
663 	return (error);
664 }
665 SYSCTL_PROC(_kern, OID_AUTO, pid_max, CTLTYPE_INT |
666     CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE,
667     0, 0, sysctl_kern_pid_max, "I", "Maximum allowed pid");
668 
669 #include <sys/bio.h>
670 #include <sys/buf.h>
671 SYSCTL_INT(_debug_sizeof, OID_AUTO, bio, CTLFLAG_RD,
672     SYSCTL_NULL_INT_PTR, sizeof(struct bio), "sizeof(struct bio)");
673 SYSCTL_INT(_debug_sizeof, OID_AUTO, buf, CTLFLAG_RD,
674     SYSCTL_NULL_INT_PTR, sizeof(struct buf), "sizeof(struct buf)");
675 
676 #include <sys/user.h>
677 SYSCTL_INT(_debug_sizeof, OID_AUTO, kinfo_proc, CTLFLAG_RD,
678     SYSCTL_NULL_INT_PTR, sizeof(struct kinfo_proc), "sizeof(struct kinfo_proc)");
679 
680 /* Used by kernel debuggers. */
681 const int pcb_size = sizeof(struct pcb);
682 SYSCTL_INT(_debug_sizeof, OID_AUTO, pcb, CTLFLAG_RD,
683     SYSCTL_NULL_INT_PTR, sizeof(struct pcb), "sizeof(struct pcb)");
684 
685 /* XXX compatibility, remove for 6.0 */
686 #include <sys/imgact.h>
687 #include <sys/imgact_elf.h>
688 SYSCTL_INT(_kern, OID_AUTO, fallback_elf_brand, CTLFLAG_RW,
689     &__elfN(fallback_brand), sizeof(__elfN(fallback_brand)),
690     "compatibility for kern.fallback_elf_brand");
691