xref: /freebsd/sys/kern/kern_mib.c (revision 4a5216a6dc0c3ce4cf5f2d3ee8af0c3ff3402c4f)
1 /*-
2  * Copyright (c) 1982, 1986, 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Mike Karels at Berkeley Software Design, Inc.
7  *
8  * Quite extensively rewritten by Poul-Henning Kamp of the FreeBSD
9  * project, to make these variables more userfriendly.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	@(#)kern_sysctl.c	8.4 (Berkeley) 4/14/94
36  */
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include "opt_compat.h"
42 #include "opt_posix.h"
43 #include "opt_config.h"
44 
45 #include <sys/param.h>
46 #include <sys/kernel.h>
47 #include <sys/sbuf.h>
48 #include <sys/systm.h>
49 #include <sys/sysctl.h>
50 #include <sys/proc.h>
51 #include <sys/lock.h>
52 #include <sys/mutex.h>
53 #include <sys/jail.h>
54 #include <sys/smp.h>
55 #include <sys/unistd.h>
56 #include <sys/vimage.h>
57 
58 SYSCTL_NODE(, 0,	  sysctl, CTLFLAG_RW, 0,
59 	"Sysctl internal magic");
60 SYSCTL_NODE(, CTL_KERN,	  kern,   CTLFLAG_RW, 0,
61 	"High kernel, proc, limits &c");
62 SYSCTL_NODE(, CTL_VM,	  vm,     CTLFLAG_RW, 0,
63 	"Virtual memory");
64 SYSCTL_NODE(, CTL_VFS,	  vfs,     CTLFLAG_RW, 0,
65 	"File system");
66 SYSCTL_NODE(, CTL_NET,	  net,    CTLFLAG_RW, 0,
67 	"Network, (see socket.h)");
68 SYSCTL_NODE(, CTL_DEBUG,  debug,  CTLFLAG_RW, 0,
69 	"Debugging");
70 SYSCTL_NODE(_debug, OID_AUTO,  sizeof,  CTLFLAG_RW, 0,
71 	"Sizeof various things");
72 SYSCTL_NODE(, CTL_HW,	  hw,     CTLFLAG_RW, 0,
73 	"hardware");
74 SYSCTL_NODE(, CTL_MACHDEP, machdep, CTLFLAG_RW, 0,
75 	"machine dependent");
76 SYSCTL_NODE(, CTL_USER,	  user,   CTLFLAG_RW, 0,
77 	"user-level");
78 SYSCTL_NODE(, CTL_P1003_1B,  p1003_1b,   CTLFLAG_RW, 0,
79 	"p1003_1b, (see p1003_1b.h)");
80 
81 SYSCTL_NODE(, OID_AUTO,  compat, CTLFLAG_RW, 0,
82 	"Compatibility code");
83 SYSCTL_NODE(, OID_AUTO, security, CTLFLAG_RW, 0,
84      	"Security");
85 #ifdef REGRESSION
86 SYSCTL_NODE(, OID_AUTO, regression, CTLFLAG_RW, 0,
87      "Regression test MIB");
88 #endif
89 
90 SYSCTL_STRING(_kern, OID_AUTO, ident, CTLFLAG_RD,
91     kern_ident, 0, "Kernel identifier");
92 
93 SYSCTL_STRING(_kern, KERN_OSRELEASE, osrelease, CTLFLAG_RD,
94     osrelease, 0, "Operating system release");
95 
96 SYSCTL_INT(_kern, KERN_OSREV, osrevision, CTLFLAG_RD,
97     0, BSD, "Operating system revision");
98 
99 SYSCTL_STRING(_kern, KERN_VERSION, version, CTLFLAG_RD,
100     version, 0, "Kernel version");
101 
102 SYSCTL_STRING(_kern, KERN_OSTYPE, ostype, CTLFLAG_RD,
103     ostype, 0, "Operating system type");
104 
105 /*
106  * NOTICE: The *userland* release date is available in
107  * /usr/include/osreldate.h
108  */
109 SYSCTL_INT(_kern, KERN_OSRELDATE, osreldate, CTLFLAG_RD,
110     &osreldate, 0, "Kernel release date");
111 
112 SYSCTL_INT(_kern, KERN_MAXPROC, maxproc, CTLFLAG_RDTUN,
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,
119     &maxusers, 0, "Hint for kernel tuning");
120 
121 SYSCTL_INT(_kern, KERN_ARGMAX, argmax, CTLFLAG_RD,
122     0, ARG_MAX, "Maximum bytes of argument to execve(2)");
123 
124 SYSCTL_INT(_kern, KERN_POSIX1, posix1version, CTLFLAG_RD,
125     0, _POSIX_VERSION, "Version of POSIX attempting to comply to");
126 
127 SYSCTL_INT(_kern, KERN_NGROUPS, ngroups, CTLFLAG_RD,
128     0, NGROUPS_MAX, "Maximum number of groups a user can belong to");
129 
130 SYSCTL_INT(_kern, KERN_JOB_CONTROL, job_control, CTLFLAG_RD,
131     0, 1, "Whether job control is available");
132 
133 #ifdef _POSIX_SAVED_IDS
134 SYSCTL_INT(_kern, KERN_SAVED_IDS, saved_ids, CTLFLAG_RD,
135     0, 1, "Whether saved set-group/user ID is available");
136 #else
137 SYSCTL_INT(_kern, KERN_SAVED_IDS, saved_ids, CTLFLAG_RD,
138     0, 0, "Whether saved set-group/user ID is available");
139 #endif
140 
141 char kernelname[MAXPATHLEN] = "/kernel";	/* XXX bloat */
142 
143 SYSCTL_STRING(_kern, KERN_BOOTFILE, bootfile, CTLFLAG_RW,
144     kernelname, sizeof kernelname, "Name of kernel file booted");
145 
146 SYSCTL_INT(_hw, HW_NCPU, ncpu, CTLFLAG_RD,
147     &mp_ncpus, 0, "Number of active CPUs");
148 
149 SYSCTL_INT(_hw, HW_BYTEORDER, byteorder, CTLFLAG_RD,
150     0, BYTE_ORDER, "System byte order");
151 
152 SYSCTL_INT(_hw, HW_PAGESIZE, pagesize, CTLFLAG_RD,
153     0, PAGE_SIZE, "System memory page size");
154 
155 static int
156 sysctl_kern_arnd(SYSCTL_HANDLER_ARGS)
157 {
158 	char buf[256];
159 	size_t len;
160 
161 	len = req->oldlen;
162 	if (len > sizeof(buf))
163 		len = sizeof(buf);
164 	arc4rand(buf, len, 0);
165 	return (SYSCTL_OUT(req, buf, len));
166 }
167 
168 SYSCTL_PROC(_kern, KERN_ARND, arandom, CTLTYPE_OPAQUE | CTLFLAG_RD,
169     NULL, 0, sysctl_kern_arnd, "", "arc4rand");
170 
171 static int
172 sysctl_hw_physmem(SYSCTL_HANDLER_ARGS)
173 {
174 	u_long val;
175 
176 	val = ctob(physmem);
177 	return (sysctl_handle_long(oidp, &val, 0, req));
178 }
179 
180 SYSCTL_PROC(_hw, HW_PHYSMEM, physmem, CTLTYPE_ULONG | CTLFLAG_RD,
181 	0, 0, sysctl_hw_physmem, "LU", "");
182 
183 static int
184 sysctl_hw_realmem(SYSCTL_HANDLER_ARGS)
185 {
186 	u_long val;
187 	val = ctob(realmem);
188 	return (sysctl_handle_long(oidp, &val, 0, req));
189 }
190 SYSCTL_PROC(_hw, HW_REALMEM, realmem, CTLTYPE_ULONG | CTLFLAG_RD,
191 	0, 0, sysctl_hw_realmem, "LU", "");
192 static int
193 sysctl_hw_usermem(SYSCTL_HANDLER_ARGS)
194 {
195 	u_long val;
196 
197 	val = ctob(physmem - cnt.v_wire_count);
198 	return (sysctl_handle_long(oidp, &val, 0, req));
199 }
200 
201 SYSCTL_PROC(_hw, HW_USERMEM, usermem, CTLTYPE_ULONG | CTLFLAG_RD,
202 	0, 0, sysctl_hw_usermem, "LU", "");
203 
204 SYSCTL_ULONG(_hw, OID_AUTO, availpages, CTLFLAG_RD, &physmem, 0, "");
205 
206 static char	machine_arch[] = MACHINE_ARCH;
207 SYSCTL_STRING(_hw, HW_MACHINE_ARCH, machine_arch, CTLFLAG_RD,
208     machine_arch, 0, "System architecture");
209 
210 #ifndef VIMAGE
211 char hostname[MAXHOSTNAMELEN];
212 #endif
213 
214 /*
215  * This mutex is used to protect the hostname and domainname variables, and
216  * perhaps in the future should also protect hostid, hostuid, and others.
217  */
218 struct mtx hostname_mtx;
219 MTX_SYSINIT(hostname_mtx, &hostname_mtx, "hostname", MTX_DEF);
220 
221 static int
222 sysctl_hostname(SYSCTL_HANDLER_ARGS)
223 {
224 	INIT_VPROCG(TD_TO_VPROCG(req->td));
225 	struct prison *pr;
226 	char tmphostname[MAXHOSTNAMELEN];
227 	int error;
228 
229 	pr = req->td->td_ucred->cr_prison;
230 	if (pr != NULL) {
231 		if (!jail_set_hostname_allowed && req->newptr)
232 			return (EPERM);
233 		/*
234 		 * Process is in jail, so make a local copy of jail
235 		 * hostname to get/set so we don't have to hold the jail
236 		 * mutex during the sysctl copyin/copyout activities.
237 		 */
238 		mtx_lock(&pr->pr_mtx);
239 		bcopy(pr->pr_host, tmphostname, MAXHOSTNAMELEN);
240 		mtx_unlock(&pr->pr_mtx);
241 
242 		error = sysctl_handle_string(oidp, tmphostname,
243 		    sizeof pr->pr_host, req);
244 
245 		if (req->newptr != NULL && error == 0) {
246 			/*
247 			 * Copy the locally set hostname to the jail, if
248 			 * appropriate.
249 			 */
250 			mtx_lock(&pr->pr_mtx);
251 			bcopy(tmphostname, pr->pr_host, MAXHOSTNAMELEN);
252 			mtx_unlock(&pr->pr_mtx);
253 		}
254 	} else {
255 		mtx_lock(&hostname_mtx);
256 		bcopy(V_hostname, tmphostname, MAXHOSTNAMELEN);
257 		mtx_unlock(&hostname_mtx);
258 		error = sysctl_handle_string(oidp, tmphostname,
259 		    sizeof tmphostname, req);
260 		if (req->newptr != NULL && error == 0) {
261 			mtx_lock(&hostname_mtx);
262 			bcopy(tmphostname, V_hostname, MAXHOSTNAMELEN);
263 			mtx_unlock(&hostname_mtx);
264 		}
265 	}
266 	return (error);
267 }
268 
269 SYSCTL_PROC(_kern, KERN_HOSTNAME, hostname,
270        CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_PRISON,
271        0, 0, sysctl_hostname, "A", "Hostname");
272 
273 static int	regression_securelevel_nonmonotonic = 0;
274 
275 #ifdef REGRESSION
276 SYSCTL_INT(_regression, OID_AUTO, securelevel_nonmonotonic, CTLFLAG_RW,
277     &regression_securelevel_nonmonotonic, 0, "securelevel may be lowered");
278 #endif
279 
280 int securelevel = -1;
281 static struct mtx securelevel_mtx;
282 
283 MTX_SYSINIT(securelevel_lock, &securelevel_mtx, "securelevel mutex lock",
284     MTX_DEF);
285 
286 static int
287 sysctl_kern_securelvl(SYSCTL_HANDLER_ARGS)
288 {
289 	struct prison *pr;
290 	int error, level;
291 
292 	pr = req->td->td_ucred->cr_prison;
293 
294 	/*
295 	 * If the process is in jail, return the maximum of the global and
296 	 * local levels; otherwise, return the global level.  Perform a
297 	 * lockless read since the securelevel is an integer.
298 	 */
299 	if (pr != NULL)
300 		level = imax(securelevel, pr->pr_securelevel);
301 	else
302 		level = securelevel;
303 	error = sysctl_handle_int(oidp, &level, 0, req);
304 	if (error || !req->newptr)
305 		return (error);
306 	/*
307 	 * Permit update only if the new securelevel exceeds the
308 	 * global level, and local level if any.
309 	 */
310 	if (pr != NULL) {
311 		mtx_lock(&pr->pr_mtx);
312 		if (!regression_securelevel_nonmonotonic &&
313 		    (level < imax(securelevel, pr->pr_securelevel))) {
314 			mtx_unlock(&pr->pr_mtx);
315 			return (EPERM);
316 		}
317 		pr->pr_securelevel = level;
318 		mtx_unlock(&pr->pr_mtx);
319 	} else {
320 		mtx_lock(&securelevel_mtx);
321 		if (!regression_securelevel_nonmonotonic &&
322 		    (level < securelevel)) {
323 			mtx_unlock(&securelevel_mtx);
324 			return (EPERM);
325 		}
326 		securelevel = level;
327 		mtx_unlock(&securelevel_mtx);
328 	}
329 	return (error);
330 }
331 
332 SYSCTL_PROC(_kern, KERN_SECURELVL, securelevel,
333     CTLTYPE_INT|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, sysctl_kern_securelvl,
334     "I", "Current secure level");
335 
336 #ifdef INCLUDE_CONFIG_FILE
337 /* Actual kernel configuration options. */
338 extern char kernconfstring[];
339 
340 static int
341 sysctl_kern_config(SYSCTL_HANDLER_ARGS)
342 {
343 	return (sysctl_handle_string(oidp, kernconfstring,
344 	    strlen(kernconfstring), req));
345 }
346 
347 SYSCTL_PROC(_kern, OID_AUTO, conftxt, CTLTYPE_STRING|CTLFLAG_RW,
348     0, 0, sysctl_kern_config, "", "Kernel configuration file");
349 #endif
350 
351 #ifndef VIMAGE
352 char domainname[MAXHOSTNAMELEN];	/* Protected by hostname_mtx. */
353 #endif
354 
355 static int
356 sysctl_domainname(SYSCTL_HANDLER_ARGS)
357 {
358 	char tmpdomainname[MAXHOSTNAMELEN];
359 	int error;
360 
361 	mtx_lock(&hostname_mtx);
362 	bcopy(V_domainname, tmpdomainname, MAXHOSTNAMELEN);
363 	mtx_unlock(&hostname_mtx);
364 	error = sysctl_handle_string(oidp, tmpdomainname,
365 	    sizeof tmpdomainname, req);
366 	if (req->newptr != NULL && error == 0) {
367 		mtx_lock(&hostname_mtx);
368 		bcopy(tmpdomainname, V_domainname, MAXHOSTNAMELEN);
369 		mtx_unlock(&hostname_mtx);
370 	}
371 	return (error);
372 }
373 
374 SYSCTL_PROC(_kern, KERN_NISDOMAINNAME, domainname, CTLTYPE_STRING|CTLFLAG_RW,
375        0, 0, sysctl_domainname, "A", "Name of the current YP/NIS domain");
376 
377 u_long hostid;
378 SYSCTL_ULONG(_kern, KERN_HOSTID, hostid, CTLFLAG_RW, &hostid, 0, "Host ID");
379 char hostuuid[64] = "00000000-0000-0000-0000-000000000000";
380 SYSCTL_STRING(_kern, KERN_HOSTUUID, hostuuid, CTLFLAG_RW, hostuuid,
381     sizeof(hostuuid), "Host UUID");
382 
383 SYSCTL_NODE(_kern, OID_AUTO, features, CTLFLAG_RD, 0, "Kernel Features");
384 
385 #ifdef COMPAT_FREEBSD4
386 FEATURE(compat_freebsd4, "Compatible with FreeBSD 4");
387 #endif
388 
389 #ifdef COMPAT_FREEBSD5
390 FEATURE(compat_freebsd5, "Compatible with FreeBSD 5");
391 #endif
392 
393 #ifdef COMPAT_FREEBSD6
394 FEATURE(compat_freebsd6, "Compatible with FreeBSD 6");
395 #endif
396 
397 #ifdef COMPAT_FREEBSD7
398 FEATURE(compat_freebsd7, "Compatible with FreeBSD 7");
399 #endif
400 
401 /*
402  * This is really cheating.  These actually live in the libc, something
403  * which I'm not quite sure is a good idea anyway, but in order for
404  * getnext and friends to actually work, we define dummies here.
405  */
406 SYSCTL_STRING(_user, USER_CS_PATH, cs_path, CTLFLAG_RD,
407     "", 0, "PATH that finds all the standard utilities");
408 SYSCTL_INT(_user, USER_BC_BASE_MAX, bc_base_max, CTLFLAG_RD,
409     0, 0, "Max ibase/obase values in bc(1)");
410 SYSCTL_INT(_user, USER_BC_DIM_MAX, bc_dim_max, CTLFLAG_RD,
411     0, 0, "Max array size in bc(1)");
412 SYSCTL_INT(_user, USER_BC_SCALE_MAX, bc_scale_max, CTLFLAG_RD,
413     0, 0, "Max scale value in bc(1)");
414 SYSCTL_INT(_user, USER_BC_STRING_MAX, bc_string_max, CTLFLAG_RD,
415     0, 0, "Max string length in bc(1)");
416 SYSCTL_INT(_user, USER_COLL_WEIGHTS_MAX, coll_weights_max, CTLFLAG_RD,
417     0, 0, "Maximum number of weights assigned to an LC_COLLATE locale entry");
418 SYSCTL_INT(_user, USER_EXPR_NEST_MAX, expr_nest_max, CTLFLAG_RD, 0, 0, "");
419 SYSCTL_INT(_user, USER_LINE_MAX, line_max, CTLFLAG_RD,
420     0, 0, "Max length (bytes) of a text-processing utility's input line");
421 SYSCTL_INT(_user, USER_RE_DUP_MAX, re_dup_max, CTLFLAG_RD,
422     0, 0, "Maximum number of repeats of a regexp permitted");
423 SYSCTL_INT(_user, USER_POSIX2_VERSION, posix2_version, CTLFLAG_RD,
424     0, 0,
425     "The version of POSIX 1003.2 with which the system attempts to comply");
426 SYSCTL_INT(_user, USER_POSIX2_C_BIND, posix2_c_bind, CTLFLAG_RD,
427     0, 0, "Whether C development supports the C bindings option");
428 SYSCTL_INT(_user, USER_POSIX2_C_DEV, posix2_c_dev, CTLFLAG_RD,
429     0, 0, "Whether system supports the C development utilities option");
430 SYSCTL_INT(_user, USER_POSIX2_CHAR_TERM, posix2_char_term, CTLFLAG_RD,
431     0, 0, "");
432 SYSCTL_INT(_user, USER_POSIX2_FORT_DEV, posix2_fort_dev, CTLFLAG_RD,
433     0, 0, "Whether system supports FORTRAN development utilities");
434 SYSCTL_INT(_user, USER_POSIX2_FORT_RUN, posix2_fort_run, CTLFLAG_RD,
435     0, 0, "Whether system supports FORTRAN runtime utilities");
436 SYSCTL_INT(_user, USER_POSIX2_LOCALEDEF, posix2_localedef, CTLFLAG_RD,
437     0, 0, "Whether system supports creation of locales");
438 SYSCTL_INT(_user, USER_POSIX2_SW_DEV, posix2_sw_dev, CTLFLAG_RD,
439     0, 0, "Whether system supports software development utilities");
440 SYSCTL_INT(_user, USER_POSIX2_UPE, posix2_upe, CTLFLAG_RD,
441     0, 0, "Whether system supports the user portability utilities");
442 SYSCTL_INT(_user, USER_STREAM_MAX, stream_max, CTLFLAG_RD,
443     0, 0, "Min Maximum number of streams a process may have open at one time");
444 SYSCTL_INT(_user, USER_TZNAME_MAX, tzname_max, CTLFLAG_RD,
445     0, 0, "Min Maximum number of types supported for timezone names");
446 
447 #include <sys/vnode.h>
448 SYSCTL_INT(_debug_sizeof, OID_AUTO, vnode, CTLFLAG_RD,
449     0, sizeof(struct vnode), "sizeof(struct vnode)");
450 
451 SYSCTL_INT(_debug_sizeof, OID_AUTO, proc, CTLFLAG_RD,
452     0, sizeof(struct proc), "sizeof(struct proc)");
453 
454 #include <sys/bio.h>
455 #include <sys/buf.h>
456 SYSCTL_INT(_debug_sizeof, OID_AUTO, bio, CTLFLAG_RD,
457     0, sizeof(struct bio), "sizeof(struct bio)");
458 SYSCTL_INT(_debug_sizeof, OID_AUTO, buf, CTLFLAG_RD,
459     0, sizeof(struct buf), "sizeof(struct buf)");
460 
461 #include <sys/user.h>
462 SYSCTL_INT(_debug_sizeof, OID_AUTO, kinfo_proc, CTLFLAG_RD,
463     0, sizeof(struct kinfo_proc), "sizeof(struct kinfo_proc)");
464 
465 /* XXX compatibility, remove for 6.0 */
466 #include <sys/imgact.h>
467 #include <sys/imgact_elf.h>
468 SYSCTL_INT(_kern, OID_AUTO, fallback_elf_brand, CTLFLAG_RW,
469     &__elfN(fallback_brand), sizeof(__elfN(fallback_brand)),
470     "compatibility for kern.fallback_elf_brand");
471