xref: /freebsd/sys/kern/kern_mib.c (revision b3aaa0cc21c63d388230c7ef2a80abd631ff20d5)
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|CTLFLAG_MPSAFE,
91     kern_ident, 0, "Kernel identifier");
92 
93 SYSCTL_STRING(_kern, KERN_OSRELEASE, osrelease, CTLFLAG_RD|CTLFLAG_MPSAFE,
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|CTLFLAG_MPSAFE,
100     version, 0, "Kernel version");
101 
102 SYSCTL_STRING(_kern, KERN_OSTYPE, ostype, CTLFLAG_RD|CTLFLAG_MPSAFE,
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,
169     CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
170     sysctl_kern_arnd, "", "arc4rand");
171 
172 static int
173 sysctl_hw_physmem(SYSCTL_HANDLER_ARGS)
174 {
175 	u_long val;
176 
177 	val = ctob(physmem);
178 	return (sysctl_handle_long(oidp, &val, 0, req));
179 }
180 
181 SYSCTL_PROC(_hw, HW_PHYSMEM, physmem, CTLTYPE_ULONG | CTLFLAG_RD,
182 	0, 0, sysctl_hw_physmem, "LU", "");
183 
184 static int
185 sysctl_hw_realmem(SYSCTL_HANDLER_ARGS)
186 {
187 	u_long val;
188 	val = ctob(realmem);
189 	return (sysctl_handle_long(oidp, &val, 0, req));
190 }
191 SYSCTL_PROC(_hw, HW_REALMEM, realmem, CTLTYPE_ULONG | CTLFLAG_RD,
192 	0, 0, sysctl_hw_realmem, "LU", "");
193 static int
194 sysctl_hw_usermem(SYSCTL_HANDLER_ARGS)
195 {
196 	u_long val;
197 
198 	val = ctob(physmem - cnt.v_wire_count);
199 	return (sysctl_handle_long(oidp, &val, 0, req));
200 }
201 
202 SYSCTL_PROC(_hw, HW_USERMEM, usermem, CTLTYPE_ULONG | CTLFLAG_RD,
203 	0, 0, sysctl_hw_usermem, "LU", "");
204 
205 SYSCTL_ULONG(_hw, OID_AUTO, availpages, CTLFLAG_RD, &physmem, 0, "");
206 
207 static char	machine_arch[] = MACHINE_ARCH;
208 SYSCTL_STRING(_hw, HW_MACHINE_ARCH, machine_arch, CTLFLAG_RD,
209     machine_arch, 0, "System architecture");
210 
211 #ifndef VIMAGE
212 char hostname[MAXHOSTNAMELEN];
213 #endif
214 
215 /*
216  * This mutex is used to protect the hostname and domainname variables, and
217  * perhaps in the future should also protect hostid, hostuid, and others.
218  */
219 struct mtx hostname_mtx;
220 MTX_SYSINIT(hostname_mtx, &hostname_mtx, "hostname", MTX_DEF);
221 
222 static int
223 sysctl_hostname(SYSCTL_HANDLER_ARGS)
224 {
225 	INIT_VPROCG(TD_TO_VPROCG(req->td));
226 	struct prison *pr;
227 	char tmphostname[MAXHOSTNAMELEN];
228 	int error;
229 
230 	pr = req->td->td_ucred->cr_prison;
231 	if (pr != NULL) {
232 		if (!jail_set_hostname_allowed && req->newptr)
233 			return (EPERM);
234 		/*
235 		 * Process is in jail, so make a local copy of jail
236 		 * hostname to get/set so we don't have to hold the jail
237 		 * mutex during the sysctl copyin/copyout activities.
238 		 */
239 		mtx_lock(&pr->pr_mtx);
240 		bcopy(pr->pr_host, tmphostname, MAXHOSTNAMELEN);
241 		mtx_unlock(&pr->pr_mtx);
242 
243 		error = sysctl_handle_string(oidp, tmphostname,
244 		    sizeof pr->pr_host, req);
245 
246 		if (req->newptr != NULL && error == 0) {
247 			/*
248 			 * Copy the locally set hostname to the jail, if
249 			 * appropriate.
250 			 */
251 			mtx_lock(&pr->pr_mtx);
252 			bcopy(tmphostname, pr->pr_host, MAXHOSTNAMELEN);
253 			mtx_unlock(&pr->pr_mtx);
254 		}
255 	} else {
256 		mtx_lock(&hostname_mtx);
257 		bcopy(V_hostname, tmphostname, MAXHOSTNAMELEN);
258 		mtx_unlock(&hostname_mtx);
259 		error = sysctl_handle_string(oidp, tmphostname,
260 		    sizeof tmphostname, req);
261 		if (req->newptr != NULL && error == 0) {
262 			mtx_lock(&hostname_mtx);
263 			bcopy(tmphostname, V_hostname, MAXHOSTNAMELEN);
264 			mtx_unlock(&hostname_mtx);
265 		}
266 	}
267 	return (error);
268 }
269 
270 SYSCTL_PROC(_kern, KERN_HOSTNAME, hostname,
271        CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_PRISON|CTLFLAG_MPSAFE,
272        0, 0, sysctl_hostname, "A", "Hostname");
273 
274 static int	regression_securelevel_nonmonotonic = 0;
275 
276 #ifdef REGRESSION
277 SYSCTL_INT(_regression, OID_AUTO, securelevel_nonmonotonic, CTLFLAG_RW,
278     &regression_securelevel_nonmonotonic, 0, "securelevel may be lowered");
279 #endif
280 
281 int securelevel = -1;
282 static struct mtx securelevel_mtx;
283 
284 MTX_SYSINIT(securelevel_lock, &securelevel_mtx, "securelevel mutex lock",
285     MTX_DEF);
286 
287 static int
288 sysctl_kern_securelvl(SYSCTL_HANDLER_ARGS)
289 {
290 	struct prison *pr;
291 	int error, level;
292 
293 	pr = req->td->td_ucred->cr_prison;
294 
295 	/*
296 	 * If the process is in jail, return the maximum of the global and
297 	 * local levels; otherwise, return the global level.  Perform a
298 	 * lockless read since the securelevel is an integer.
299 	 */
300 	if (pr != NULL)
301 		level = imax(securelevel, pr->pr_securelevel);
302 	else
303 		level = securelevel;
304 	error = sysctl_handle_int(oidp, &level, 0, req);
305 	if (error || !req->newptr)
306 		return (error);
307 	/*
308 	 * Permit update only if the new securelevel exceeds the
309 	 * global level, and local level if any.
310 	 */
311 	if (pr != NULL) {
312 		mtx_lock(&pr->pr_mtx);
313 		if (!regression_securelevel_nonmonotonic &&
314 		    (level < imax(securelevel, pr->pr_securelevel))) {
315 			mtx_unlock(&pr->pr_mtx);
316 			return (EPERM);
317 		}
318 		pr->pr_securelevel = level;
319 		mtx_unlock(&pr->pr_mtx);
320 	} else {
321 		mtx_lock(&securelevel_mtx);
322 		if (!regression_securelevel_nonmonotonic &&
323 		    (level < securelevel)) {
324 			mtx_unlock(&securelevel_mtx);
325 			return (EPERM);
326 		}
327 		securelevel = level;
328 		mtx_unlock(&securelevel_mtx);
329 	}
330 	return (error);
331 }
332 
333 SYSCTL_PROC(_kern, KERN_SECURELVL, securelevel,
334     CTLTYPE_INT|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, sysctl_kern_securelvl,
335     "I", "Current secure level");
336 
337 #ifdef INCLUDE_CONFIG_FILE
338 /* Actual kernel configuration options. */
339 extern char kernconfstring[];
340 
341 static int
342 sysctl_kern_config(SYSCTL_HANDLER_ARGS)
343 {
344 	return (sysctl_handle_string(oidp, kernconfstring,
345 	    strlen(kernconfstring), req));
346 }
347 
348 SYSCTL_PROC(_kern, OID_AUTO, conftxt, CTLTYPE_STRING|CTLFLAG_RW,
349     0, 0, sysctl_kern_config, "", "Kernel configuration file");
350 #endif
351 
352 #ifndef VIMAGE
353 char domainname[MAXHOSTNAMELEN];	/* Protected by hostname_mtx. */
354 #endif
355 
356 static int
357 sysctl_domainname(SYSCTL_HANDLER_ARGS)
358 {
359 	char tmpdomainname[MAXHOSTNAMELEN];
360 	int error;
361 
362 	mtx_lock(&hostname_mtx);
363 	bcopy(V_domainname, tmpdomainname, MAXHOSTNAMELEN);
364 	mtx_unlock(&hostname_mtx);
365 	error = sysctl_handle_string(oidp, tmpdomainname,
366 	    sizeof tmpdomainname, req);
367 	if (req->newptr != NULL && error == 0) {
368 		mtx_lock(&hostname_mtx);
369 		bcopy(tmpdomainname, V_domainname, MAXHOSTNAMELEN);
370 		mtx_unlock(&hostname_mtx);
371 	}
372 	return (error);
373 }
374 
375 SYSCTL_PROC(_kern, KERN_NISDOMAINNAME, domainname, CTLTYPE_STRING|CTLFLAG_RW,
376        0, 0, sysctl_domainname, "A", "Name of the current YP/NIS domain");
377 
378 u_long hostid;
379 SYSCTL_ULONG(_kern, KERN_HOSTID, hostid, CTLFLAG_RW, &hostid, 0, "Host ID");
380 char hostuuid[64] = "00000000-0000-0000-0000-000000000000";
381 SYSCTL_STRING(_kern, KERN_HOSTUUID, hostuuid, CTLFLAG_RW, hostuuid,
382     sizeof(hostuuid), "Host UUID");
383 
384 SYSCTL_NODE(_kern, OID_AUTO, features, CTLFLAG_RD, 0, "Kernel Features");
385 
386 #ifdef COMPAT_FREEBSD4
387 FEATURE(compat_freebsd4, "Compatible with FreeBSD 4");
388 #endif
389 
390 #ifdef COMPAT_FREEBSD5
391 FEATURE(compat_freebsd5, "Compatible with FreeBSD 5");
392 #endif
393 
394 #ifdef COMPAT_FREEBSD6
395 FEATURE(compat_freebsd6, "Compatible with FreeBSD 6");
396 #endif
397 
398 #ifdef COMPAT_FREEBSD7
399 FEATURE(compat_freebsd7, "Compatible with FreeBSD 7");
400 #endif
401 
402 /*
403  * This is really cheating.  These actually live in the libc, something
404  * which I'm not quite sure is a good idea anyway, but in order for
405  * getnext and friends to actually work, we define dummies here.
406  */
407 SYSCTL_STRING(_user, USER_CS_PATH, cs_path, CTLFLAG_RD,
408     "", 0, "PATH that finds all the standard utilities");
409 SYSCTL_INT(_user, USER_BC_BASE_MAX, bc_base_max, CTLFLAG_RD,
410     0, 0, "Max ibase/obase values in bc(1)");
411 SYSCTL_INT(_user, USER_BC_DIM_MAX, bc_dim_max, CTLFLAG_RD,
412     0, 0, "Max array size in bc(1)");
413 SYSCTL_INT(_user, USER_BC_SCALE_MAX, bc_scale_max, CTLFLAG_RD,
414     0, 0, "Max scale value in bc(1)");
415 SYSCTL_INT(_user, USER_BC_STRING_MAX, bc_string_max, CTLFLAG_RD,
416     0, 0, "Max string length in bc(1)");
417 SYSCTL_INT(_user, USER_COLL_WEIGHTS_MAX, coll_weights_max, CTLFLAG_RD,
418     0, 0, "Maximum number of weights assigned to an LC_COLLATE locale entry");
419 SYSCTL_INT(_user, USER_EXPR_NEST_MAX, expr_nest_max, CTLFLAG_RD, 0, 0, "");
420 SYSCTL_INT(_user, USER_LINE_MAX, line_max, CTLFLAG_RD,
421     0, 0, "Max length (bytes) of a text-processing utility's input line");
422 SYSCTL_INT(_user, USER_RE_DUP_MAX, re_dup_max, CTLFLAG_RD,
423     0, 0, "Maximum number of repeats of a regexp permitted");
424 SYSCTL_INT(_user, USER_POSIX2_VERSION, posix2_version, CTLFLAG_RD,
425     0, 0,
426     "The version of POSIX 1003.2 with which the system attempts to comply");
427 SYSCTL_INT(_user, USER_POSIX2_C_BIND, posix2_c_bind, CTLFLAG_RD,
428     0, 0, "Whether C development supports the C bindings option");
429 SYSCTL_INT(_user, USER_POSIX2_C_DEV, posix2_c_dev, CTLFLAG_RD,
430     0, 0, "Whether system supports the C development utilities option");
431 SYSCTL_INT(_user, USER_POSIX2_CHAR_TERM, posix2_char_term, CTLFLAG_RD,
432     0, 0, "");
433 SYSCTL_INT(_user, USER_POSIX2_FORT_DEV, posix2_fort_dev, CTLFLAG_RD,
434     0, 0, "Whether system supports FORTRAN development utilities");
435 SYSCTL_INT(_user, USER_POSIX2_FORT_RUN, posix2_fort_run, CTLFLAG_RD,
436     0, 0, "Whether system supports FORTRAN runtime utilities");
437 SYSCTL_INT(_user, USER_POSIX2_LOCALEDEF, posix2_localedef, CTLFLAG_RD,
438     0, 0, "Whether system supports creation of locales");
439 SYSCTL_INT(_user, USER_POSIX2_SW_DEV, posix2_sw_dev, CTLFLAG_RD,
440     0, 0, "Whether system supports software development utilities");
441 SYSCTL_INT(_user, USER_POSIX2_UPE, posix2_upe, CTLFLAG_RD,
442     0, 0, "Whether system supports the user portability utilities");
443 SYSCTL_INT(_user, USER_STREAM_MAX, stream_max, CTLFLAG_RD,
444     0, 0, "Min Maximum number of streams a process may have open at one time");
445 SYSCTL_INT(_user, USER_TZNAME_MAX, tzname_max, CTLFLAG_RD,
446     0, 0, "Min Maximum number of types supported for timezone names");
447 
448 #include <sys/vnode.h>
449 SYSCTL_INT(_debug_sizeof, OID_AUTO, vnode, CTLFLAG_RD,
450     0, sizeof(struct vnode), "sizeof(struct vnode)");
451 
452 SYSCTL_INT(_debug_sizeof, OID_AUTO, proc, CTLFLAG_RD,
453     0, sizeof(struct proc), "sizeof(struct proc)");
454 
455 #include <sys/bio.h>
456 #include <sys/buf.h>
457 SYSCTL_INT(_debug_sizeof, OID_AUTO, bio, CTLFLAG_RD,
458     0, sizeof(struct bio), "sizeof(struct bio)");
459 SYSCTL_INT(_debug_sizeof, OID_AUTO, buf, CTLFLAG_RD,
460     0, sizeof(struct buf), "sizeof(struct buf)");
461 
462 #include <sys/user.h>
463 SYSCTL_INT(_debug_sizeof, OID_AUTO, kinfo_proc, CTLFLAG_RD,
464     0, sizeof(struct kinfo_proc), "sizeof(struct kinfo_proc)");
465 
466 /* XXX compatibility, remove for 6.0 */
467 #include <sys/imgact.h>
468 #include <sys/imgact_elf.h>
469 SYSCTL_INT(_kern, OID_AUTO, fallback_elf_brand, CTLFLAG_RW,
470     &__elfN(fallback_brand), sizeof(__elfN(fallback_brand)),
471     "compatibility for kern.fallback_elf_brand");
472