xref: /freebsd/sys/kern/kern_mib.c (revision 6683132d54bd6d589889e43dabdc53d35e38a028)
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, 0,
64 	"Sysctl internal magic");
65 SYSCTL_ROOT_NODE(CTL_KERN,	  kern,   CTLFLAG_RW|CTLFLAG_CAPRD, 0,
66 	"High kernel, proc, limits &c");
67 SYSCTL_ROOT_NODE(CTL_VM,	  vm,     CTLFLAG_RW, 0,
68 	"Virtual memory");
69 SYSCTL_ROOT_NODE(CTL_VFS,	  vfs,     CTLFLAG_RW, 0,
70 	"File system");
71 SYSCTL_ROOT_NODE(CTL_NET,	  net,    CTLFLAG_RW, 0,
72 	"Network, (see socket.h)");
73 SYSCTL_ROOT_NODE(CTL_DEBUG,  debug,  CTLFLAG_RW, 0,
74 	"Debugging");
75 SYSCTL_NODE(_debug, OID_AUTO,  sizeof,  CTLFLAG_RW, 0,
76 	"Sizeof various things");
77 SYSCTL_ROOT_NODE(CTL_HW,	  hw,     CTLFLAG_RW, 0,
78 	"hardware");
79 SYSCTL_ROOT_NODE(CTL_MACHDEP, machdep, CTLFLAG_RW, 0,
80 	"machine dependent");
81 SYSCTL_ROOT_NODE(CTL_USER,	  user,   CTLFLAG_RW, 0,
82 	"user-level");
83 SYSCTL_ROOT_NODE(CTL_P1003_1B,  p1003_1b,   CTLFLAG_RW, 0,
84 	"p1003_1b, (see p1003_1b.h)");
85 
86 SYSCTL_ROOT_NODE(OID_AUTO,  compat, CTLFLAG_RW, 0,
87 	"Compatibility code");
88 SYSCTL_ROOT_NODE(OID_AUTO, security, CTLFLAG_RW, 0,
89      	"Security");
90 #ifdef REGRESSION
91 SYSCTL_ROOT_NODE(OID_AUTO, regression, CTLFLAG_RW, 0,
92      "Regression test MIB");
93 #endif
94 
95 SYSCTL_STRING(_kern, OID_AUTO, ident, CTLFLAG_RD|CTLFLAG_MPSAFE,
96     kern_ident, 0, "Kernel identifier");
97 
98 SYSCTL_INT(_kern, KERN_OSREV, osrevision, CTLFLAG_RD|CTLFLAG_CAPRD,
99     SYSCTL_NULL_INT_PTR, BSD, "Operating system revision");
100 
101 SYSCTL_STRING(_kern, KERN_VERSION, version, CTLFLAG_RD|CTLFLAG_MPSAFE,
102     version, 0, "Kernel version");
103 
104 SYSCTL_STRING(_kern, OID_AUTO, compiler_version, CTLFLAG_RD|CTLFLAG_MPSAFE,
105     compiler_version, 0, "Version of compiler used to compile kernel");
106 
107 SYSCTL_STRING(_kern, KERN_OSTYPE, ostype, CTLFLAG_RD|CTLFLAG_MPSAFE|
108     CTLFLAG_CAPRD, ostype, 0, "Operating system type");
109 
110 SYSCTL_INT(_kern, KERN_MAXPROC, maxproc, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
111     &maxproc, 0, "Maximum number of processes");
112 
113 SYSCTL_INT(_kern, KERN_MAXPROCPERUID, maxprocperuid, CTLFLAG_RW,
114     &maxprocperuid, 0, "Maximum processes allowed per userid");
115 
116 SYSCTL_INT(_kern, OID_AUTO, maxusers, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
117     &maxusers, 0, "Hint for kernel tuning");
118 
119 SYSCTL_INT(_kern, KERN_ARGMAX, argmax, CTLFLAG_RD|CTLFLAG_CAPRD,
120     SYSCTL_NULL_INT_PTR, ARG_MAX, "Maximum bytes of argument to execve(2)");
121 
122 SYSCTL_INT(_kern, KERN_POSIX1, posix1version, CTLFLAG_RD|CTLFLAG_CAPRD,
123     SYSCTL_NULL_INT_PTR, _POSIX_VERSION, "Version of POSIX attempting to comply to");
124 
125 SYSCTL_INT(_kern, KERN_NGROUPS, ngroups, CTLFLAG_RDTUN |
126     CTLFLAG_NOFETCH | CTLFLAG_CAPRD, &ngroups_max, 0,
127     "Maximum number of supplemental groups a user can belong to");
128 
129 SYSCTL_INT(_kern, KERN_JOB_CONTROL, job_control, CTLFLAG_RD|CTLFLAG_CAPRD,
130     SYSCTL_NULL_INT_PTR, 1, "Whether job control is available");
131 
132 #ifdef _POSIX_SAVED_IDS
133 SYSCTL_INT(_kern, KERN_SAVED_IDS, saved_ids, CTLFLAG_RD|CTLFLAG_CAPRD,
134     SYSCTL_NULL_INT_PTR, 1, "Whether saved set-group/user ID is available");
135 #else
136 SYSCTL_INT(_kern, KERN_SAVED_IDS, saved_ids, CTLFLAG_RD|CTLFLAG_CAPRD,
137     SYSCTL_NULL_INT_PTR, 0, "Whether saved set-group/user ID is available");
138 #endif
139 
140 char kernelname[MAXPATHLEN] = PATH_KERNEL;	/* XXX bloat */
141 
142 SYSCTL_STRING(_kern, KERN_BOOTFILE, bootfile, CTLFLAG_RW | CTLFLAG_MPSAFE,
143     kernelname, sizeof kernelname, "Name of kernel file booted");
144 
145 SYSCTL_INT(_kern, KERN_MAXPHYS, maxphys, CTLFLAG_RD | CTLFLAG_CAPRD,
146     SYSCTL_NULL_INT_PTR, MAXPHYS, "Maximum block I/O access size");
147 
148 SYSCTL_INT(_hw, HW_NCPU, ncpu, CTLFLAG_RD|CTLFLAG_CAPRD,
149     &mp_ncpus, 0, "Number of active CPUs");
150 
151 SYSCTL_INT(_hw, HW_BYTEORDER, byteorder, CTLFLAG_RD|CTLFLAG_CAPRD,
152     SYSCTL_NULL_INT_PTR, BYTE_ORDER, "System byte order");
153 
154 SYSCTL_INT(_hw, HW_PAGESIZE, pagesize, CTLFLAG_RD|CTLFLAG_CAPRD,
155     SYSCTL_NULL_INT_PTR, PAGE_SIZE, "System memory page size");
156 
157 static int
158 sysctl_kern_arnd(SYSCTL_HANDLER_ARGS)
159 {
160 	char buf[256];
161 	size_t len;
162 
163 	len = MIN(req->oldlen, sizeof(buf));
164 	read_random(buf, len);
165 	return (SYSCTL_OUT(req, buf, len));
166 }
167 
168 SYSCTL_PROC(_kern, KERN_ARND, arandom,
169     CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD, NULL, 0,
170     sysctl_kern_arnd, "", "arc4rand");
171 
172 static int
173 sysctl_hw_physmem(SYSCTL_HANDLER_ARGS)
174 {
175 	u_long val, p;
176 
177 	p = SIZE_T_MAX >> PAGE_SHIFT;
178 	if (physmem < p)
179 		p = physmem;
180 	val = ctob(p);
181 	return (sysctl_handle_long(oidp, &val, 0, req));
182 }
183 SYSCTL_PROC(_hw, HW_PHYSMEM, physmem, CTLTYPE_ULONG | CTLFLAG_RD,
184     0, 0, sysctl_hw_physmem, "LU",
185     "Amount of physical memory (in bytes)");
186 
187 static int
188 sysctl_hw_realmem(SYSCTL_HANDLER_ARGS)
189 {
190 	u_long val, p;
191 
192 	p = SIZE_T_MAX >> PAGE_SHIFT;
193 	if (realmem < p)
194 		p = realmem;
195 	val = ctob(p);
196 	return (sysctl_handle_long(oidp, &val, 0, req));
197 }
198 SYSCTL_PROC(_hw, HW_REALMEM, realmem, CTLTYPE_ULONG | CTLFLAG_RD,
199     0, 0, sysctl_hw_realmem, "LU",
200     "Amount of memory (in bytes) reported by the firmware");
201 
202 static int
203 sysctl_hw_usermem(SYSCTL_HANDLER_ARGS)
204 {
205 	u_long val, p, p1;
206 
207 	p1 = physmem - vm_wire_count();
208 	p = SIZE_T_MAX >> PAGE_SHIFT;
209 	if (p1 < p)
210 		p = p1;
211 	val = ctob(p);
212 	return (sysctl_handle_long(oidp, &val, 0, req));
213 }
214 SYSCTL_PROC(_hw, HW_USERMEM, usermem, CTLTYPE_ULONG | CTLFLAG_RD,
215     0, 0, sysctl_hw_usermem, "LU",
216     "Amount of memory (in bytes) which is not wired");
217 
218 SYSCTL_LONG(_hw, OID_AUTO, availpages, CTLFLAG_RD, &physmem, 0,
219     "Amount of physical memory (in pages)");
220 
221 u_long pagesizes[MAXPAGESIZES] = { PAGE_SIZE };
222 
223 static int
224 sysctl_hw_pagesizes(SYSCTL_HANDLER_ARGS)
225 {
226 	int error;
227 #ifdef SCTL_MASK32
228 	int i;
229 	uint32_t pagesizes32[MAXPAGESIZES];
230 
231 	if (req->flags & SCTL_MASK32) {
232 		/*
233 		 * Recreate the "pagesizes" array with 32-bit elements.  Truncate
234 		 * any page size greater than UINT32_MAX to zero.
235 		 */
236 		for (i = 0; i < MAXPAGESIZES; i++)
237 			pagesizes32[i] = (uint32_t)pagesizes[i];
238 
239 		error = SYSCTL_OUT(req, pagesizes32, sizeof(pagesizes32));
240 	} else
241 #endif
242 		error = SYSCTL_OUT(req, pagesizes, sizeof(pagesizes));
243 	return (error);
244 }
245 SYSCTL_PROC(_hw, OID_AUTO, pagesizes, CTLTYPE_ULONG | CTLFLAG_RD,
246     NULL, 0, sysctl_hw_pagesizes, "LU", "Supported page sizes");
247 
248 #ifdef SCTL_MASK32
249 int adaptive_machine_arch = 1;
250 SYSCTL_INT(_debug, OID_AUTO, adaptive_machine_arch, CTLFLAG_RW,
251     &adaptive_machine_arch, 1,
252     "Adapt reported machine architecture to the ABI of the binary");
253 #endif
254 
255 static int
256 sysctl_hw_machine_arch(SYSCTL_HANDLER_ARGS)
257 {
258 	int error;
259 	static const char machine_arch[] = MACHINE_ARCH;
260 #ifdef SCTL_MASK32
261 	static const char machine_arch32[] = MACHINE_ARCH32;
262 
263 	if ((req->flags & SCTL_MASK32) != 0 && adaptive_machine_arch)
264 		error = SYSCTL_OUT(req, machine_arch32, sizeof(machine_arch32));
265 	else
266 #endif
267 		error = SYSCTL_OUT(req, machine_arch, sizeof(machine_arch));
268 	return (error);
269 
270 }
271 SYSCTL_PROC(_hw, HW_MACHINE_ARCH, machine_arch, CTLTYPE_STRING | CTLFLAG_RD |
272     CTLFLAG_MPSAFE, NULL, 0, sysctl_hw_machine_arch, "A",
273     "System architecture");
274 
275 SYSCTL_STRING(_kern, OID_AUTO, supported_archs, CTLFLAG_RD | CTLFLAG_MPSAFE,
276 #ifdef COMPAT_FREEBSD32
277     MACHINE_ARCH " " MACHINE_ARCH32, 0, "Supported architectures for binaries");
278 #else
279     MACHINE_ARCH, 0, "Supported architectures for binaries");
280 #endif
281 
282 static int
283 sysctl_hostname(SYSCTL_HANDLER_ARGS)
284 {
285 	struct prison *pr, *cpr;
286 	size_t pr_offset;
287 	char tmpname[MAXHOSTNAMELEN];
288 	int descend, error, len;
289 
290 	/*
291 	 * This function can set: hostname domainname hostuuid.
292 	 * Keep that in mind when comments say "hostname".
293 	 */
294 	pr_offset = (size_t)arg1;
295 	len = arg2;
296 	KASSERT(len <= sizeof(tmpname),
297 	    ("length %d too long for %s", len, __func__));
298 
299 	pr = req->td->td_ucred->cr_prison;
300 	if (!(pr->pr_allow & PR_ALLOW_SET_HOSTNAME) && req->newptr)
301 		return (EPERM);
302 	/*
303 	 * Make a local copy of hostname to get/set so we don't have to hold
304 	 * the jail mutex during the sysctl copyin/copyout activities.
305 	 */
306 	mtx_lock(&pr->pr_mtx);
307 	bcopy((char *)pr + pr_offset, tmpname, len);
308 	mtx_unlock(&pr->pr_mtx);
309 
310 	error = sysctl_handle_string(oidp, tmpname, len, req);
311 
312 	if (req->newptr != NULL && error == 0) {
313 		/*
314 		 * Copy the locally set hostname to all jails that share
315 		 * this host info.
316 		 */
317 		sx_slock(&allprison_lock);
318 		while (!(pr->pr_flags & PR_HOST))
319 			pr = pr->pr_parent;
320 		mtx_lock(&pr->pr_mtx);
321 		bcopy(tmpname, (char *)pr + pr_offset, len);
322 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, cpr, descend)
323 			if (cpr->pr_flags & PR_HOST)
324 				descend = 0;
325 			else
326 				bcopy(tmpname, (char *)cpr + pr_offset, len);
327 		mtx_unlock(&pr->pr_mtx);
328 		sx_sunlock(&allprison_lock);
329 	}
330 	return (error);
331 }
332 
333 SYSCTL_PROC(_kern, KERN_HOSTNAME, hostname,
334     CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_CAPRD | CTLFLAG_MPSAFE,
335     (void *)(offsetof(struct prison, pr_hostname)), MAXHOSTNAMELEN,
336     sysctl_hostname, "A", "Hostname");
337 SYSCTL_PROC(_kern, KERN_NISDOMAINNAME, domainname,
338     CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_CAPRD | CTLFLAG_MPSAFE,
339     (void *)(offsetof(struct prison, pr_domainname)), MAXHOSTNAMELEN,
340     sysctl_hostname, "A", "Name of the current YP/NIS domain");
341 SYSCTL_PROC(_kern, KERN_HOSTUUID, hostuuid,
342     CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_CAPRD | CTLFLAG_MPSAFE,
343     (void *)(offsetof(struct prison, pr_hostuuid)), HOSTUUIDLEN,
344     sysctl_hostname, "A", "Host UUID");
345 
346 static int	regression_securelevel_nonmonotonic = 0;
347 
348 #ifdef REGRESSION
349 SYSCTL_INT(_regression, OID_AUTO, securelevel_nonmonotonic, CTLFLAG_RW,
350     &regression_securelevel_nonmonotonic, 0, "securelevel may be lowered");
351 #endif
352 
353 static int
354 sysctl_kern_securelvl(SYSCTL_HANDLER_ARGS)
355 {
356 	struct prison *pr, *cpr;
357 	int descend, error, level;
358 
359 	pr = req->td->td_ucred->cr_prison;
360 
361 	/*
362 	 * Reading the securelevel is easy, since the current jail's level
363 	 * is known to be at least as secure as any higher levels.  Perform
364 	 * a lockless read since the securelevel is an integer.
365 	 */
366 	level = pr->pr_securelevel;
367 	error = sysctl_handle_int(oidp, &level, 0, req);
368 	if (error || !req->newptr)
369 		return (error);
370 	/* Permit update only if the new securelevel exceeds the old. */
371 	sx_slock(&allprison_lock);
372 	mtx_lock(&pr->pr_mtx);
373 	if (!regression_securelevel_nonmonotonic &&
374 	    level < pr->pr_securelevel) {
375 		mtx_unlock(&pr->pr_mtx);
376 		sx_sunlock(&allprison_lock);
377 		return (EPERM);
378 	}
379 	pr->pr_securelevel = level;
380 	/*
381 	 * Set all child jails to be at least this level, but do not lower
382 	 * them (even if regression_securelevel_nonmonotonic).
383 	 */
384 	FOREACH_PRISON_DESCENDANT_LOCKED(pr, cpr, descend) {
385 		if (cpr->pr_securelevel < level)
386 			cpr->pr_securelevel = level;
387 	}
388 	mtx_unlock(&pr->pr_mtx);
389 	sx_sunlock(&allprison_lock);
390 	return (error);
391 }
392 
393 SYSCTL_PROC(_kern, KERN_SECURELVL, securelevel,
394     CTLTYPE_INT|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, sysctl_kern_securelvl,
395     "I", "Current secure level");
396 
397 #ifdef INCLUDE_CONFIG_FILE
398 /* Actual kernel configuration options. */
399 extern char kernconfstring[];
400 
401 SYSCTL_STRING(_kern, OID_AUTO, conftxt, CTLFLAG_RD | CTLFLAG_MPSAFE,
402     kernconfstring, 0, "Kernel configuration file");
403 #endif
404 
405 static int
406 sysctl_hostid(SYSCTL_HANDLER_ARGS)
407 {
408 	struct prison *pr, *cpr;
409 	u_long tmpid;
410 	int descend, error;
411 
412 	/*
413 	 * Like sysctl_hostname, except it operates on a u_long
414 	 * instead of a string, and is used only for hostid.
415 	 */
416 	pr = req->td->td_ucred->cr_prison;
417 	if (!(pr->pr_allow & PR_ALLOW_SET_HOSTNAME) && req->newptr)
418 		return (EPERM);
419 	tmpid = pr->pr_hostid;
420 	error = sysctl_handle_long(oidp, &tmpid, 0, req);
421 
422 	if (req->newptr != NULL && error == 0) {
423 		sx_slock(&allprison_lock);
424 		while (!(pr->pr_flags & PR_HOST))
425 			pr = pr->pr_parent;
426 		mtx_lock(&pr->pr_mtx);
427 		pr->pr_hostid = tmpid;
428 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, cpr, descend)
429 			if (cpr->pr_flags & PR_HOST)
430 				descend = 0;
431 			else
432 				cpr->pr_hostid = tmpid;
433 		mtx_unlock(&pr->pr_mtx);
434 		sx_sunlock(&allprison_lock);
435 	}
436 	return (error);
437 }
438 
439 SYSCTL_PROC(_kern, KERN_HOSTID, hostid,
440     CTLTYPE_ULONG | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE | CTLFLAG_CAPRD,
441     NULL, 0, sysctl_hostid, "LU", "Host ID");
442 
443 /*
444  * The osrelease string is copied from the global (osrelease in vers.c) into
445  * prison0 by a sysinit and is inherited by child jails if not changed at jail
446  * creation, so we always return the copy from the current prison data.
447  */
448 static int
449 sysctl_osrelease(SYSCTL_HANDLER_ARGS)
450 {
451 	struct prison *pr;
452 
453 	pr = req->td->td_ucred->cr_prison;
454 	return (SYSCTL_OUT(req, pr->pr_osrelease, strlen(pr->pr_osrelease) + 1));
455 
456 }
457 
458 SYSCTL_PROC(_kern, KERN_OSRELEASE, osrelease,
459     CTLTYPE_STRING | CTLFLAG_CAPRD | CTLFLAG_RD | CTLFLAG_MPSAFE,
460     NULL, 0, sysctl_osrelease, "A", "Operating system release");
461 
462 /*
463  * The osreldate number is copied from the global (osreldate in vers.c) into
464  * prison0 by a sysinit and is inherited by child jails if not changed at jail
465  * creation, so we always return the value from the current prison data.
466  */
467 static int
468 sysctl_osreldate(SYSCTL_HANDLER_ARGS)
469 {
470 	struct prison *pr;
471 
472 	pr = req->td->td_ucred->cr_prison;
473 	return (SYSCTL_OUT(req, &pr->pr_osreldate, sizeof(pr->pr_osreldate)));
474 
475 }
476 
477 /*
478  * NOTICE: The *userland* release date is available in
479  * /usr/include/osreldate.h
480  */
481 SYSCTL_PROC(_kern, KERN_OSRELDATE, osreldate,
482     CTLTYPE_INT | CTLFLAG_CAPRD | CTLFLAG_RD | CTLFLAG_MPSAFE,
483     NULL, 0, sysctl_osreldate, "I", "Kernel release date");
484 
485 /*
486  * The build-id is copied from the ELF section .note.gnu.build-id.  The linker
487  * script defines two variables to expose the beginning and end.  LLVM
488  * currently uses a SHA-1 hash, but other formats can be supported by checking
489  * the length of the section.
490  */
491 
492 extern char __build_id_start[];
493 extern char __build_id_end[];
494 
495 #define	BUILD_ID_HEADER_LEN	0x10
496 #define	BUILD_ID_HASH_MAXLEN	0x14
497 
498 static int
499 sysctl_build_id(SYSCTL_HANDLER_ARGS)
500 {
501 	uintptr_t sectionlen = (uintptr_t)(__build_id_end - __build_id_start);
502 	int hashlen;
503 	char buf[2*BUILD_ID_HASH_MAXLEN+1];
504 
505 	/*
506 	 * The ELF note section has a four byte length for the vendor name,
507 	 * four byte length for the value, and a four byte vendor specific
508 	 * type.  The name for the build id is "GNU\0".  We skip the first 16
509 	 * bytes to read the build hash.  We will return the remaining bytes up
510 	 * to 20 (SHA-1) hash size.  If the hash happens to be a custom number
511 	 * of bytes we will pad the value with zeros, as the section should be
512 	 * four byte aligned.
513 	 */
514 	if (sectionlen <= BUILD_ID_HEADER_LEN ||
515 	    sectionlen > (BUILD_ID_HEADER_LEN + BUILD_ID_HASH_MAXLEN)) {
516 		return (ENOENT);
517 	}
518 
519 
520 	hashlen = sectionlen - BUILD_ID_HEADER_LEN;
521 	for (int i = 0; i < hashlen; i++) {
522 		uint8_t c = __build_id_start[i+BUILD_ID_HEADER_LEN];
523 		snprintf(&buf[2*i], 3, "%02x", c);
524 	}
525 
526 	return (SYSCTL_OUT(req, buf, strlen(buf) + 1));
527 }
528 
529 SYSCTL_PROC(_kern, OID_AUTO, build_id,
530     CTLTYPE_STRING | CTLFLAG_CAPRD | CTLFLAG_RD | CTLFLAG_MPSAFE,
531     NULL, 0, sysctl_build_id, "A", "Operating system build-id");
532 
533 SYSCTL_NODE(_kern, OID_AUTO, features, CTLFLAG_RD, 0, "Kernel Features");
534 
535 #ifdef COMPAT_FREEBSD4
536 FEATURE(compat_freebsd4, "Compatible with FreeBSD 4");
537 #endif
538 
539 #ifdef COMPAT_FREEBSD5
540 FEATURE(compat_freebsd5, "Compatible with FreeBSD 5");
541 #endif
542 
543 #ifdef COMPAT_FREEBSD6
544 FEATURE(compat_freebsd6, "Compatible with FreeBSD 6");
545 #endif
546 
547 #ifdef COMPAT_FREEBSD7
548 FEATURE(compat_freebsd7, "Compatible with FreeBSD 7");
549 #endif
550 
551 /*
552  * This is really cheating.  These actually live in the libc, something
553  * which I'm not quite sure is a good idea anyway, but in order for
554  * getnext and friends to actually work, we define dummies here.
555  *
556  * XXXRW: These probably should be CTLFLAG_CAPRD.
557  */
558 SYSCTL_STRING(_user, USER_CS_PATH, cs_path, CTLFLAG_RD,
559     "", 0, "PATH that finds all the standard utilities");
560 SYSCTL_INT(_user, USER_BC_BASE_MAX, bc_base_max, CTLFLAG_RD,
561     SYSCTL_NULL_INT_PTR, 0, "Max ibase/obase values in bc(1)");
562 SYSCTL_INT(_user, USER_BC_DIM_MAX, bc_dim_max, CTLFLAG_RD,
563     SYSCTL_NULL_INT_PTR, 0, "Max array size in bc(1)");
564 SYSCTL_INT(_user, USER_BC_SCALE_MAX, bc_scale_max, CTLFLAG_RD,
565     SYSCTL_NULL_INT_PTR, 0, "Max scale value in bc(1)");
566 SYSCTL_INT(_user, USER_BC_STRING_MAX, bc_string_max, CTLFLAG_RD,
567     SYSCTL_NULL_INT_PTR, 0, "Max string length in bc(1)");
568 SYSCTL_INT(_user, USER_COLL_WEIGHTS_MAX, coll_weights_max, CTLFLAG_RD,
569     SYSCTL_NULL_INT_PTR, 0, "Maximum number of weights assigned to an LC_COLLATE locale entry");
570 SYSCTL_INT(_user, USER_EXPR_NEST_MAX, expr_nest_max, CTLFLAG_RD,
571     SYSCTL_NULL_INT_PTR, 0, "");
572 SYSCTL_INT(_user, USER_LINE_MAX, line_max, CTLFLAG_RD,
573     SYSCTL_NULL_INT_PTR, 0, "Max length (bytes) of a text-processing utility's input line");
574 SYSCTL_INT(_user, USER_RE_DUP_MAX, re_dup_max, CTLFLAG_RD,
575     SYSCTL_NULL_INT_PTR, 0, "Maximum number of repeats of a regexp permitted");
576 SYSCTL_INT(_user, USER_POSIX2_VERSION, posix2_version, CTLFLAG_RD,
577     SYSCTL_NULL_INT_PTR, 0,
578     "The version of POSIX 1003.2 with which the system attempts to comply");
579 SYSCTL_INT(_user, USER_POSIX2_C_BIND, posix2_c_bind, CTLFLAG_RD,
580     SYSCTL_NULL_INT_PTR, 0, "Whether C development supports the C bindings option");
581 SYSCTL_INT(_user, USER_POSIX2_C_DEV, posix2_c_dev, CTLFLAG_RD,
582     SYSCTL_NULL_INT_PTR, 0, "Whether system supports the C development utilities option");
583 SYSCTL_INT(_user, USER_POSIX2_CHAR_TERM, posix2_char_term, CTLFLAG_RD,
584     SYSCTL_NULL_INT_PTR, 0, "");
585 SYSCTL_INT(_user, USER_POSIX2_FORT_DEV, posix2_fort_dev, CTLFLAG_RD,
586     SYSCTL_NULL_INT_PTR, 0, "Whether system supports FORTRAN development utilities");
587 SYSCTL_INT(_user, USER_POSIX2_FORT_RUN, posix2_fort_run, CTLFLAG_RD,
588     SYSCTL_NULL_INT_PTR, 0, "Whether system supports FORTRAN runtime utilities");
589 SYSCTL_INT(_user, USER_POSIX2_LOCALEDEF, posix2_localedef, CTLFLAG_RD,
590     SYSCTL_NULL_INT_PTR, 0, "Whether system supports creation of locales");
591 SYSCTL_INT(_user, USER_POSIX2_SW_DEV, posix2_sw_dev, CTLFLAG_RD,
592     SYSCTL_NULL_INT_PTR, 0, "Whether system supports software development utilities");
593 SYSCTL_INT(_user, USER_POSIX2_UPE, posix2_upe, CTLFLAG_RD,
594     SYSCTL_NULL_INT_PTR, 0, "Whether system supports the user portability utilities");
595 SYSCTL_INT(_user, USER_STREAM_MAX, stream_max, CTLFLAG_RD,
596     SYSCTL_NULL_INT_PTR, 0, "Min Maximum number of streams a process may have open at one time");
597 SYSCTL_INT(_user, USER_TZNAME_MAX, tzname_max, CTLFLAG_RD,
598     SYSCTL_NULL_INT_PTR, 0, "Min Maximum number of types supported for timezone names");
599 
600 #include <sys/vnode.h>
601 SYSCTL_INT(_debug_sizeof, OID_AUTO, vnode, CTLFLAG_RD,
602     SYSCTL_NULL_INT_PTR, sizeof(struct vnode), "sizeof(struct vnode)");
603 
604 SYSCTL_INT(_debug_sizeof, OID_AUTO, proc, CTLFLAG_RD,
605     SYSCTL_NULL_INT_PTR, sizeof(struct proc), "sizeof(struct proc)");
606 
607 static int
608 sysctl_kern_pid_max(SYSCTL_HANDLER_ARGS)
609 {
610 	int error, pm;
611 
612 	pm = pid_max;
613 	error = sysctl_handle_int(oidp, &pm, 0, req);
614 	if (error || !req->newptr)
615 		return (error);
616 	sx_xlock(&proctree_lock);
617 	sx_xlock(&allproc_lock);
618 
619 	/*
620 	 * Only permit the values less then PID_MAX.
621 	 * As a safety measure, do not allow to limit the pid_max too much.
622 	 */
623 	if (pm < 300 || pm > PID_MAX)
624 		error = EINVAL;
625 	else
626 		pid_max = pm;
627 	sx_xunlock(&allproc_lock);
628 	sx_xunlock(&proctree_lock);
629 	return (error);
630 }
631 SYSCTL_PROC(_kern, OID_AUTO, pid_max, CTLTYPE_INT |
632     CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE,
633     0, 0, sysctl_kern_pid_max, "I", "Maximum allowed pid");
634 
635 #include <sys/bio.h>
636 #include <sys/buf.h>
637 SYSCTL_INT(_debug_sizeof, OID_AUTO, bio, CTLFLAG_RD,
638     SYSCTL_NULL_INT_PTR, sizeof(struct bio), "sizeof(struct bio)");
639 SYSCTL_INT(_debug_sizeof, OID_AUTO, buf, CTLFLAG_RD,
640     SYSCTL_NULL_INT_PTR, sizeof(struct buf), "sizeof(struct buf)");
641 
642 #include <sys/user.h>
643 SYSCTL_INT(_debug_sizeof, OID_AUTO, kinfo_proc, CTLFLAG_RD,
644     SYSCTL_NULL_INT_PTR, sizeof(struct kinfo_proc), "sizeof(struct kinfo_proc)");
645 
646 /* Used by kernel debuggers. */
647 const int pcb_size = sizeof(struct pcb);
648 SYSCTL_INT(_debug_sizeof, OID_AUTO, pcb, CTLFLAG_RD,
649     SYSCTL_NULL_INT_PTR, sizeof(struct pcb), "sizeof(struct pcb)");
650 
651 /* XXX compatibility, remove for 6.0 */
652 #include <sys/imgact.h>
653 #include <sys/imgact_elf.h>
654 SYSCTL_INT(_kern, OID_AUTO, fallback_elf_brand, CTLFLAG_RW,
655     &__elfN(fallback_brand), sizeof(__elfN(fallback_brand)),
656     "compatibility for kern.fallback_elf_brand");
657