xref: /freebsd/sys/kern/kern_mib.c (revision 2f6a179eb910129fb812c1ad1bdc300da1203dc0)
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 
57 SYSCTL_NODE(, 0,	  sysctl, CTLFLAG_RW, 0,
58 	"Sysctl internal magic");
59 SYSCTL_NODE(, CTL_KERN,	  kern,   CTLFLAG_RW, 0,
60 	"High kernel, proc, limits &c");
61 SYSCTL_NODE(, CTL_VM,	  vm,     CTLFLAG_RW, 0,
62 	"Virtual memory");
63 SYSCTL_NODE(, CTL_VFS,	  vfs,     CTLFLAG_RW, 0,
64 	"File system");
65 SYSCTL_NODE(, CTL_NET,	  net,    CTLFLAG_RW, 0,
66 	"Network, (see socket.h)");
67 SYSCTL_NODE(, CTL_DEBUG,  debug,  CTLFLAG_RW, 0,
68 	"Debugging");
69 SYSCTL_NODE(_debug, OID_AUTO,  sizeof,  CTLFLAG_RW, 0,
70 	"Sizeof various things");
71 SYSCTL_NODE(, CTL_HW,	  hw,     CTLFLAG_RW, 0,
72 	"hardware");
73 SYSCTL_NODE(, CTL_MACHDEP, machdep, CTLFLAG_RW, 0,
74 	"machine dependent");
75 SYSCTL_NODE(, CTL_USER,	  user,   CTLFLAG_RW, 0,
76 	"user-level");
77 SYSCTL_NODE(, CTL_P1003_1B,  p1003_1b,   CTLFLAG_RW, 0,
78 	"p1003_1b, (see p1003_1b.h)");
79 
80 SYSCTL_NODE(, OID_AUTO,  compat, CTLFLAG_RW, 0,
81 	"Compatibility code");
82 SYSCTL_NODE(, OID_AUTO, security, CTLFLAG_RW, 0,
83      	"Security");
84 #ifdef REGRESSION
85 SYSCTL_NODE(, OID_AUTO, regression, CTLFLAG_RW, 0,
86      "Regression test MIB");
87 #endif
88 
89 SYSCTL_STRING(_kern, OID_AUTO, ident, CTLFLAG_RD,
90     kern_ident, 0, "Kernel identifier");
91 
92 SYSCTL_STRING(_kern, KERN_OSRELEASE, osrelease, CTLFLAG_RD,
93     osrelease, 0, "Operating system release");
94 
95 SYSCTL_INT(_kern, KERN_OSREV, osrevision, CTLFLAG_RD,
96     0, BSD, "Operating system revision");
97 
98 SYSCTL_STRING(_kern, KERN_VERSION, version, CTLFLAG_RD,
99     version, 0, "Kernel version");
100 
101 SYSCTL_STRING(_kern, KERN_OSTYPE, ostype, CTLFLAG_RD,
102     ostype, 0, "Operating system type");
103 
104 /*
105  * NOTICE: The *userland* release date is available in
106  * /usr/include/osreldate.h
107  */
108 SYSCTL_INT(_kern, KERN_OSRELDATE, osreldate, CTLFLAG_RD,
109     &osreldate, 0, "Kernel release date");
110 
111 SYSCTL_INT(_kern, KERN_MAXPROC, maxproc, CTLFLAG_RDTUN,
112     &maxproc, 0, "Maximum number of processes");
113 
114 SYSCTL_INT(_kern, KERN_MAXPROCPERUID, maxprocperuid, CTLFLAG_RW,
115     &maxprocperuid, 0, "Maximum processes allowed per userid");
116 
117 SYSCTL_INT(_kern, OID_AUTO, maxusers, CTLFLAG_RDTUN,
118     &maxusers, 0, "Hint for kernel tuning");
119 
120 SYSCTL_INT(_kern, KERN_ARGMAX, argmax, CTLFLAG_RD,
121     0, ARG_MAX, "Maximum bytes of argument to execve(2)");
122 
123 SYSCTL_INT(_kern, KERN_POSIX1, posix1version, CTLFLAG_RD,
124     0, _POSIX_VERSION, "Version of POSIX attempting to comply to");
125 
126 SYSCTL_INT(_kern, KERN_NGROUPS, ngroups, CTLFLAG_RD,
127     0, NGROUPS_MAX, "Maximum number of groups a user can belong to");
128 
129 SYSCTL_INT(_kern, KERN_JOB_CONTROL, job_control, CTLFLAG_RD,
130     0, 1, "Whether job control is available");
131 
132 #ifdef _POSIX_SAVED_IDS
133 SYSCTL_INT(_kern, KERN_SAVED_IDS, saved_ids, CTLFLAG_RD,
134     0, 1, "Whether saved set-group/user ID is available");
135 #else
136 SYSCTL_INT(_kern, KERN_SAVED_IDS, saved_ids, CTLFLAG_RD,
137     0, 0, "Whether saved set-group/user ID is available");
138 #endif
139 
140 char kernelname[MAXPATHLEN] = "/kernel";	/* XXX bloat */
141 
142 SYSCTL_STRING(_kern, KERN_BOOTFILE, bootfile, CTLFLAG_RW,
143     kernelname, sizeof kernelname, "Name of kernel file booted");
144 
145 SYSCTL_INT(_hw, HW_NCPU, ncpu, CTLFLAG_RD,
146     &mp_ncpus, 0, "Number of active CPUs");
147 
148 SYSCTL_INT(_hw, HW_BYTEORDER, byteorder, CTLFLAG_RD,
149     0, BYTE_ORDER, "System byte order");
150 
151 SYSCTL_INT(_hw, HW_PAGESIZE, pagesize, CTLFLAG_RD,
152     0, PAGE_SIZE, "System memory page size");
153 
154 static int
155 sysctl_kern_arnd(SYSCTL_HANDLER_ARGS)
156 {
157 	char buf[256];
158 	size_t len;
159 
160 	len = req->oldlen;
161 	if (len > sizeof(buf))
162 		len = sizeof(buf);
163 	arc4rand(buf, len, 0);
164 	return (SYSCTL_OUT(req, buf, len));
165 }
166 
167 SYSCTL_PROC(_kern, KERN_ARND, arandom, CTLTYPE_OPAQUE | CTLFLAG_RD,
168     NULL, 0, sysctl_kern_arnd, "", "arc4rand");
169 
170 static int
171 sysctl_hw_physmem(SYSCTL_HANDLER_ARGS)
172 {
173 	u_long val;
174 
175 	val = ctob(physmem);
176 	return (sysctl_handle_long(oidp, &val, 0, req));
177 }
178 
179 SYSCTL_PROC(_hw, HW_PHYSMEM, physmem, CTLTYPE_ULONG | CTLFLAG_RD,
180 	0, 0, sysctl_hw_physmem, "LU", "");
181 
182 static int
183 sysctl_hw_realmem(SYSCTL_HANDLER_ARGS)
184 {
185 	u_long val;
186 	val = ctob(realmem);
187 	return (sysctl_handle_long(oidp, &val, 0, req));
188 }
189 SYSCTL_PROC(_hw, HW_REALMEM, realmem, CTLTYPE_ULONG | CTLFLAG_RD,
190 	0, 0, sysctl_hw_realmem, "LU", "");
191 static int
192 sysctl_hw_usermem(SYSCTL_HANDLER_ARGS)
193 {
194 	u_long val;
195 
196 	val = ctob(physmem - cnt.v_wire_count);
197 	return (sysctl_handle_long(oidp, &val, 0, req));
198 }
199 
200 SYSCTL_PROC(_hw, HW_USERMEM, usermem, CTLTYPE_ULONG | CTLFLAG_RD,
201 	0, 0, sysctl_hw_usermem, "LU", "");
202 
203 SYSCTL_ULONG(_hw, OID_AUTO, availpages, CTLFLAG_RD, &physmem, 0, "");
204 
205 static char	machine_arch[] = MACHINE_ARCH;
206 SYSCTL_STRING(_hw, HW_MACHINE_ARCH, machine_arch, CTLFLAG_RD,
207     machine_arch, 0, "System architecture");
208 
209 char hostname[MAXHOSTNAMELEN];
210 
211 /*
212  * This mutex is used to protect the hostname and domainname variables, and
213  * perhaps in the future should also protect hostid, hostuid, and others.
214  */
215 struct mtx hostname_mtx;
216 MTX_SYSINIT(hostname_mtx, &hostname_mtx, "hostname", MTX_DEF);
217 
218 static int
219 sysctl_hostname(SYSCTL_HANDLER_ARGS)
220 {
221 	struct prison *pr;
222 	char tmphostname[MAXHOSTNAMELEN];
223 	int error;
224 
225 	pr = req->td->td_ucred->cr_prison;
226 	if (pr != NULL) {
227 		if (!jail_set_hostname_allowed && req->newptr)
228 			return (EPERM);
229 		/*
230 		 * Process is in jail, so make a local copy of jail
231 		 * hostname to get/set so we don't have to hold the jail
232 		 * mutex during the sysctl copyin/copyout activities.
233 		 */
234 		mtx_lock(&pr->pr_mtx);
235 		bcopy(pr->pr_host, tmphostname, MAXHOSTNAMELEN);
236 		mtx_unlock(&pr->pr_mtx);
237 
238 		error = sysctl_handle_string(oidp, tmphostname,
239 		    sizeof pr->pr_host, req);
240 
241 		if (req->newptr != NULL && error == 0) {
242 			/*
243 			 * Copy the locally set hostname to the jail, if
244 			 * appropriate.
245 			 */
246 			mtx_lock(&pr->pr_mtx);
247 			bcopy(tmphostname, pr->pr_host, MAXHOSTNAMELEN);
248 			mtx_unlock(&pr->pr_mtx);
249 		}
250 	} else {
251 		mtx_lock(&hostname_mtx);
252 		bcopy(hostname, tmphostname, MAXHOSTNAMELEN);
253 		mtx_unlock(&hostname_mtx);
254 		error = sysctl_handle_string(oidp, tmphostname,
255 		    sizeof tmphostname, req);
256 		if (req->newptr != NULL && error == 0) {
257 			mtx_lock(&hostname_mtx);
258 			bcopy(tmphostname, hostname, MAXHOSTNAMELEN);
259 			mtx_unlock(&hostname_mtx);
260 		}
261 	}
262 	return (error);
263 }
264 
265 SYSCTL_PROC(_kern, KERN_HOSTNAME, hostname,
266        CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_PRISON,
267        0, 0, sysctl_hostname, "A", "Hostname");
268 
269 static int	regression_securelevel_nonmonotonic = 0;
270 
271 #ifdef REGRESSION
272 SYSCTL_INT(_regression, OID_AUTO, securelevel_nonmonotonic, CTLFLAG_RW,
273     &regression_securelevel_nonmonotonic, 0, "securelevel may be lowered");
274 #endif
275 
276 int securelevel = -1;
277 static struct mtx securelevel_mtx;
278 
279 MTX_SYSINIT(securelevel_lock, &securelevel_mtx, "securelevel mutex lock",
280     MTX_DEF);
281 
282 static int
283 sysctl_kern_securelvl(SYSCTL_HANDLER_ARGS)
284 {
285 	struct prison *pr;
286 	int error, level;
287 
288 	pr = req->td->td_ucred->cr_prison;
289 
290 	/*
291 	 * If the process is in jail, return the maximum of the global and
292 	 * local levels; otherwise, return the global level.  Perform a
293 	 * lockless read since the securelevel is an integer.
294 	 */
295 	if (pr != NULL)
296 		level = imax(securelevel, pr->pr_securelevel);
297 	else
298 		level = securelevel;
299 	error = sysctl_handle_int(oidp, &level, 0, req);
300 	if (error || !req->newptr)
301 		return (error);
302 	/*
303 	 * Permit update only if the new securelevel exceeds the
304 	 * global level, and local level if any.
305 	 */
306 	if (pr != NULL) {
307 		mtx_lock(&pr->pr_mtx);
308 		if (!regression_securelevel_nonmonotonic &&
309 		    (level < imax(securelevel, pr->pr_securelevel))) {
310 			mtx_unlock(&pr->pr_mtx);
311 			return (EPERM);
312 		}
313 		pr->pr_securelevel = level;
314 		mtx_unlock(&pr->pr_mtx);
315 	} else {
316 		mtx_lock(&securelevel_mtx);
317 		if (!regression_securelevel_nonmonotonic &&
318 		    (level < securelevel)) {
319 			mtx_unlock(&securelevel_mtx);
320 			return (EPERM);
321 		}
322 		securelevel = level;
323 		mtx_unlock(&securelevel_mtx);
324 	}
325 	return (error);
326 }
327 
328 SYSCTL_PROC(_kern, KERN_SECURELVL, securelevel,
329     CTLTYPE_INT|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, sysctl_kern_securelvl,
330     "I", "Current secure level");
331 
332 #ifdef INCLUDE_CONFIG_FILE
333 /* Actual kernel configuration options. */
334 extern char kernconfstring[];
335 
336 static int
337 sysctl_kern_config(SYSCTL_HANDLER_ARGS)
338 {
339 	return (sysctl_handle_string(oidp, kernconfstring,
340 	    strlen(kernconfstring), req));
341 }
342 
343 SYSCTL_PROC(_kern, OID_AUTO, conftxt, CTLTYPE_STRING|CTLFLAG_RW,
344     0, 0, sysctl_kern_config, "", "Kernel configuration file");
345 #endif
346 
347 char domainname[MAXHOSTNAMELEN];	/* Protected by hostname_mtx. */
348 
349 static int
350 sysctl_domainname(SYSCTL_HANDLER_ARGS)
351 {
352 	char tmpdomainname[MAXHOSTNAMELEN];
353 	int error;
354 
355 	mtx_lock(&hostname_mtx);
356 	bcopy(domainname, tmpdomainname, MAXHOSTNAMELEN);
357 	mtx_unlock(&hostname_mtx);
358 	error = sysctl_handle_string(oidp, tmpdomainname,
359 	    sizeof tmpdomainname, req);
360 	if (req->newptr != NULL && error == 0) {
361 		mtx_lock(&hostname_mtx);
362 		bcopy(tmpdomainname, domainname, MAXHOSTNAMELEN);
363 		mtx_unlock(&hostname_mtx);
364 	}
365 	return (error);
366 }
367 
368 SYSCTL_PROC(_kern, KERN_NISDOMAINNAME, domainname, CTLTYPE_STRING|CTLFLAG_RW,
369        0, 0, sysctl_domainname, "A", "NAme of the current YP/NIS domain");
370 
371 u_long hostid;
372 SYSCTL_ULONG(_kern, KERN_HOSTID, hostid, CTLFLAG_RW, &hostid, 0, "Host ID");
373 char hostuuid[64] = "00000000-0000-0000-0000-000000000000";
374 SYSCTL_STRING(_kern, KERN_HOSTUUID, hostuuid, CTLFLAG_RW, hostuuid,
375     sizeof(hostuuid), "Host UUID");
376 
377 SYSCTL_NODE(_kern, OID_AUTO, features, CTLFLAG_RD, 0, "Kernel Features");
378 
379 #ifdef COMPAT_FREEBSD4
380 FEATURE(compat_freebsd4, "Compatible with FreeBSD 4");
381 #endif
382 
383 #ifdef COMPAT_FREEBSD5
384 FEATURE(compat_freebsd5, "Compatible with FreeBSD 5");
385 #endif
386 
387 #ifdef COMPAT_FREEBSD6
388 FEATURE(compat_freebsd6, "Compatible with FreeBSD 6");
389 #endif
390 
391 #ifdef COMPAT_FREEBSD7
392 FEATURE(compat_freebsd7, "Compatible with FreeBSD 7");
393 #endif
394 
395 /*
396  * This is really cheating.  These actually live in the libc, something
397  * which I'm not quite sure is a good idea anyway, but in order for
398  * getnext and friends to actually work, we define dummies here.
399  */
400 SYSCTL_STRING(_user, USER_CS_PATH, cs_path, CTLFLAG_RD,
401     "", 0, "PATH that finds all the standard utilities");
402 SYSCTL_INT(_user, USER_BC_BASE_MAX, bc_base_max, CTLFLAG_RD,
403     0, 0, "Max ibase/obase values in bc(1)");
404 SYSCTL_INT(_user, USER_BC_DIM_MAX, bc_dim_max, CTLFLAG_RD,
405     0, 0, "Max array size in bc(1)");
406 SYSCTL_INT(_user, USER_BC_SCALE_MAX, bc_scale_max, CTLFLAG_RD,
407     0, 0, "Max scale value in bc(1)");
408 SYSCTL_INT(_user, USER_BC_STRING_MAX, bc_string_max, CTLFLAG_RD,
409     0, 0, "Max string length in bc(1)");
410 SYSCTL_INT(_user, USER_COLL_WEIGHTS_MAX, coll_weights_max, CTLFLAG_RD,
411     0, 0, "Maximum number of weights assigned to an LC_COLLATE locale entry");
412 SYSCTL_INT(_user, USER_EXPR_NEST_MAX, expr_nest_max, CTLFLAG_RD, 0, 0, "");
413 SYSCTL_INT(_user, USER_LINE_MAX, line_max, CTLFLAG_RD,
414     0, 0, "Max length (bytes) of a text-processing utility's input line");
415 SYSCTL_INT(_user, USER_RE_DUP_MAX, re_dup_max, CTLFLAG_RD,
416     0, 0, "Maximum number of repeats of a regexp permitted");
417 SYSCTL_INT(_user, USER_POSIX2_VERSION, posix2_version, CTLFLAG_RD,
418     0, 0,
419     "The version of POSIX 1003.2 with which the system attempts to comply");
420 SYSCTL_INT(_user, USER_POSIX2_C_BIND, posix2_c_bind, CTLFLAG_RD,
421     0, 0, "Whether C development supports the C bindings option");
422 SYSCTL_INT(_user, USER_POSIX2_C_DEV, posix2_c_dev, CTLFLAG_RD,
423     0, 0, "Whether system supports the C development utilities option");
424 SYSCTL_INT(_user, USER_POSIX2_CHAR_TERM, posix2_char_term, CTLFLAG_RD,
425     0, 0, "");
426 SYSCTL_INT(_user, USER_POSIX2_FORT_DEV, posix2_fort_dev, CTLFLAG_RD,
427     0, 0, "Whether system supports FORTRAN development utilities");
428 SYSCTL_INT(_user, USER_POSIX2_FORT_RUN, posix2_fort_run, CTLFLAG_RD,
429     0, 0, "Whether system supports FORTRAN runtime utilities");
430 SYSCTL_INT(_user, USER_POSIX2_LOCALEDEF, posix2_localedef, CTLFLAG_RD,
431     0, 0, "Whether system supports creation of locales");
432 SYSCTL_INT(_user, USER_POSIX2_SW_DEV, posix2_sw_dev, CTLFLAG_RD,
433     0, 0, "Whether system supports software development utilities");
434 SYSCTL_INT(_user, USER_POSIX2_UPE, posix2_upe, CTLFLAG_RD,
435     0, 0, "Whether system supports the user portability utilities");
436 SYSCTL_INT(_user, USER_STREAM_MAX, stream_max, CTLFLAG_RD,
437     0, 0, "Min Maximum number of streams a process may have open at one time");
438 SYSCTL_INT(_user, USER_TZNAME_MAX, tzname_max, CTLFLAG_RD,
439     0, 0, "Min Maximum number of types supported for timezone names");
440 
441 #include <sys/vnode.h>
442 SYSCTL_INT(_debug_sizeof, OID_AUTO, vnode, CTLFLAG_RD,
443     0, sizeof(struct vnode), "sizeof(struct vnode)");
444 
445 SYSCTL_INT(_debug_sizeof, OID_AUTO, proc, CTLFLAG_RD,
446     0, sizeof(struct proc), "sizeof(struct proc)");
447 
448 #include <sys/bio.h>
449 #include <sys/buf.h>
450 SYSCTL_INT(_debug_sizeof, OID_AUTO, bio, CTLFLAG_RD,
451     0, sizeof(struct bio), "sizeof(struct bio)");
452 SYSCTL_INT(_debug_sizeof, OID_AUTO, buf, CTLFLAG_RD,
453     0, sizeof(struct buf), "sizeof(struct buf)");
454 
455 #include <sys/user.h>
456 SYSCTL_INT(_debug_sizeof, OID_AUTO, kinfo_proc, CTLFLAG_RD,
457     0, sizeof(struct kinfo_proc), "sizeof(struct kinfo_proc)");
458 
459 /* XXX compatibility, remove for 6.0 */
460 #include <sys/imgact.h>
461 #include <sys/imgact_elf.h>
462 SYSCTL_INT(_kern, OID_AUTO, fallback_elf_brand, CTLFLAG_RW,
463     &__elfN(fallback_brand), sizeof(__elfN(fallback_brand)),
464     "compatibility for kern.fallback_elf_brand");
465