xref: /freebsd/sys/kern/kern_mib.c (revision b28624fde638caadd4a89f50c9b7e7da0f98c4d2)
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_posix.h"
42 #include "opt_config.h"
43 
44 #include <sys/param.h>
45 #include <sys/kernel.h>
46 #include <sys/sbuf.h>
47 #include <sys/systm.h>
48 #include <sys/sysctl.h>
49 #include <sys/proc.h>
50 #include <sys/lock.h>
51 #include <sys/mutex.h>
52 #include <sys/jail.h>
53 #include <sys/smp.h>
54 #include <sys/unistd.h>
55 
56 SYSCTL_NODE(, 0,	  sysctl, CTLFLAG_RW, 0,
57 	"Sysctl internal magic");
58 SYSCTL_NODE(, CTL_KERN,	  kern,   CTLFLAG_RW, 0,
59 	"High kernel, proc, limits &c");
60 SYSCTL_NODE(, CTL_VM,	  vm,     CTLFLAG_RW, 0,
61 	"Virtual memory");
62 SYSCTL_NODE(, CTL_VFS,	  vfs,     CTLFLAG_RW, 0,
63 	"File system");
64 SYSCTL_NODE(, CTL_NET,	  net,    CTLFLAG_RW, 0,
65 	"Network, (see socket.h)");
66 SYSCTL_NODE(, CTL_DEBUG,  debug,  CTLFLAG_RW, 0,
67 	"Debugging");
68 SYSCTL_NODE(_debug, OID_AUTO,  sizeof,  CTLFLAG_RW, 0,
69 	"Sizeof various things");
70 SYSCTL_NODE(, CTL_HW,	  hw,     CTLFLAG_RW, 0,
71 	"hardware");
72 SYSCTL_NODE(, CTL_MACHDEP, machdep, CTLFLAG_RW, 0,
73 	"machine dependent");
74 SYSCTL_NODE(, CTL_USER,	  user,   CTLFLAG_RW, 0,
75 	"user-level");
76 SYSCTL_NODE(, CTL_P1003_1B,  p1003_1b,   CTLFLAG_RW, 0,
77 	"p1003_1b, (see p1003_1b.h)");
78 
79 SYSCTL_NODE(, OID_AUTO,  compat, CTLFLAG_RW, 0,
80 	"Compatibility code");
81 SYSCTL_NODE(, OID_AUTO, security, CTLFLAG_RW, 0,
82      	"Security");
83 #ifdef REGRESSION
84 SYSCTL_NODE(, OID_AUTO, regression, CTLFLAG_RW, 0,
85      "Regression test MIB");
86 #endif
87 
88 SYSCTL_STRING(_kern, OID_AUTO, ident, CTLFLAG_RD,
89     kern_ident, 0, "Kernel identifier");
90 
91 SYSCTL_STRING(_kern, KERN_OSRELEASE, osrelease, CTLFLAG_RD,
92     osrelease, 0, "Operating system release");
93 
94 SYSCTL_INT(_kern, KERN_OSREV, osrevision, CTLFLAG_RD,
95     0, BSD, "Operating system revision");
96 
97 SYSCTL_STRING(_kern, KERN_VERSION, version, CTLFLAG_RD,
98     version, 0, "Kernel version");
99 
100 SYSCTL_STRING(_kern, KERN_OSTYPE, ostype, CTLFLAG_RD,
101     ostype, 0, "Operating system type");
102 
103 /*
104  * NOTICE: The *userland* release date is available in
105  * /usr/include/osreldate.h
106  */
107 extern int osreldate;
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 	u_long val;
158 
159 	arc4rand(&val, sizeof(val), 0);
160 	return (sysctl_handle_long(oidp, &val, 0, req));
161 }
162 
163 SYSCTL_PROC(_kern, KERN_ARND, arandom, CTLFLAG_RD,
164 	0, 0, sysctl_kern_arnd, "L", "arc4rand");
165 
166 static int
167 sysctl_hw_physmem(SYSCTL_HANDLER_ARGS)
168 {
169 	u_long val;
170 
171 	val = ctob(physmem);
172 	return (sysctl_handle_long(oidp, &val, 0, req));
173 }
174 
175 SYSCTL_PROC(_hw, HW_PHYSMEM, physmem, CTLTYPE_ULONG | CTLFLAG_RD,
176 	0, 0, sysctl_hw_physmem, "LU", "");
177 
178 static int
179 sysctl_hw_realmem(SYSCTL_HANDLER_ARGS)
180 {
181 	u_long val;
182 	val = ctob(realmem);
183 	return (sysctl_handle_long(oidp, &val, 0, req));
184 }
185 SYSCTL_PROC(_hw, HW_REALMEM, realmem, CTLTYPE_ULONG | CTLFLAG_RD,
186 	0, 0, sysctl_hw_realmem, "LU", "");
187 static int
188 sysctl_hw_usermem(SYSCTL_HANDLER_ARGS)
189 {
190 	u_long val;
191 
192 	val = ctob(physmem - cnt.v_wire_count);
193 	return (sysctl_handle_long(oidp, &val, 0, req));
194 }
195 
196 SYSCTL_PROC(_hw, HW_USERMEM, usermem, CTLTYPE_ULONG | CTLFLAG_RD,
197 	0, 0, sysctl_hw_usermem, "LU", "");
198 
199 SYSCTL_ULONG(_hw, OID_AUTO, availpages, CTLFLAG_RD, &physmem, 0, "");
200 
201 static char	machine_arch[] = MACHINE_ARCH;
202 SYSCTL_STRING(_hw, HW_MACHINE_ARCH, machine_arch, CTLFLAG_RD,
203     machine_arch, 0, "System architecture");
204 
205 char hostname[MAXHOSTNAMELEN];
206 
207 static int
208 sysctl_hostname(SYSCTL_HANDLER_ARGS)
209 {
210 	struct prison *pr;
211 	char tmphostname[MAXHOSTNAMELEN];
212 	int error;
213 
214 	pr = req->td->td_ucred->cr_prison;
215 	if (pr != NULL) {
216 		if (!jail_set_hostname_allowed && req->newptr)
217 			return (EPERM);
218 		/*
219 		 * Process is in jail, so make a local copy of jail
220 		 * hostname to get/set so we don't have to hold the jail
221 		 * mutex during the sysctl copyin/copyout activities.
222 		 */
223 		mtx_lock(&pr->pr_mtx);
224 		bcopy(pr->pr_host, tmphostname, MAXHOSTNAMELEN);
225 		mtx_unlock(&pr->pr_mtx);
226 
227 		error = sysctl_handle_string(oidp, tmphostname,
228 		    sizeof pr->pr_host, req);
229 
230 		if (req->newptr != NULL && error == 0) {
231 			/*
232 			 * Copy the locally set hostname to the jail, if
233 			 * appropriate.
234 			 */
235 			mtx_lock(&pr->pr_mtx);
236 			bcopy(tmphostname, pr->pr_host, MAXHOSTNAMELEN);
237 			mtx_unlock(&pr->pr_mtx);
238 		}
239 	} else
240 		error = sysctl_handle_string(oidp,
241 		    hostname, sizeof hostname, req);
242 	return (error);
243 }
244 
245 SYSCTL_PROC(_kern, KERN_HOSTNAME, hostname,
246        CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_PRISON,
247        0, 0, sysctl_hostname, "A", "Hostname");
248 
249 static int	regression_securelevel_nonmonotonic = 0;
250 
251 #ifdef REGRESSION
252 SYSCTL_INT(_regression, OID_AUTO, securelevel_nonmonotonic, CTLFLAG_RW,
253     &regression_securelevel_nonmonotonic, 0, "securelevel may be lowered");
254 #endif
255 
256 int securelevel = -1;
257 static struct mtx securelevel_mtx;
258 
259 MTX_SYSINIT(securelevel_lock, &securelevel_mtx, "securelevel mutex lock",
260     MTX_DEF);
261 
262 static int
263 sysctl_kern_securelvl(SYSCTL_HANDLER_ARGS)
264 {
265 	struct prison *pr;
266 	int error, level;
267 
268 	pr = req->td->td_ucred->cr_prison;
269 
270 	/*
271 	 * If the process is in jail, return the maximum of the global and
272 	 * local levels; otherwise, return the global level.  Perform a
273 	 * lockless read since the securelevel is an integer.
274 	 */
275 	if (pr != NULL)
276 		level = imax(securelevel, pr->pr_securelevel);
277 	else
278 		level = securelevel;
279 	error = sysctl_handle_int(oidp, &level, 0, req);
280 	if (error || !req->newptr)
281 		return (error);
282 	/*
283 	 * Permit update only if the new securelevel exceeds the
284 	 * global level, and local level if any.
285 	 */
286 	if (pr != NULL) {
287 		mtx_lock(&pr->pr_mtx);
288 		if (!regression_securelevel_nonmonotonic &&
289 		    (level < imax(securelevel, pr->pr_securelevel))) {
290 			mtx_unlock(&pr->pr_mtx);
291 			return (EPERM);
292 		}
293 		pr->pr_securelevel = level;
294 		mtx_unlock(&pr->pr_mtx);
295 	} else {
296 		mtx_lock(&securelevel_mtx);
297 		if (!regression_securelevel_nonmonotonic &&
298 		    (level < securelevel)) {
299 			mtx_unlock(&securelevel_mtx);
300 			return (EPERM);
301 		}
302 		securelevel = level;
303 		mtx_unlock(&securelevel_mtx);
304 	}
305 	return (error);
306 }
307 
308 SYSCTL_PROC(_kern, KERN_SECURELVL, securelevel,
309     CTLTYPE_INT|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, sysctl_kern_securelvl,
310     "I", "Current secure level");
311 
312 #ifdef INCLUDE_CONFIG_FILE
313 /* Actual kernel configuration options. */
314 extern char kernconfstring[];
315 
316 static int
317 sysctl_kern_config(SYSCTL_HANDLER_ARGS)
318 {
319 	return (sysctl_handle_string(oidp, kernconfstring,
320 	    strlen(kernconfstring), req));
321 }
322 
323 SYSCTL_PROC(_kern, OID_AUTO, conftxt, CTLTYPE_STRING|CTLFLAG_RW,
324     0, 0, sysctl_kern_config, "", "Kernel configuration file");
325 #endif
326 
327 char domainname[MAXHOSTNAMELEN];
328 SYSCTL_STRING(_kern, KERN_NISDOMAINNAME, domainname, CTLFLAG_RW,
329     &domainname, sizeof(domainname), "Name of the current YP/NIS domain");
330 
331 u_long hostid;
332 SYSCTL_ULONG(_kern, KERN_HOSTID, hostid, CTLFLAG_RW, &hostid, 0, "Host ID");
333 char hostuuid[64] = "00000000-0000-0000-0000-000000000000";
334 SYSCTL_STRING(_kern, KERN_HOSTUUID, hostuuid, CTLFLAG_RW, hostuuid,
335     sizeof(hostuuid), "Host UUID");
336 
337 /*
338  * This is really cheating.  These actually live in the libc, something
339  * which I'm not quite sure is a good idea anyway, but in order for
340  * getnext and friends to actually work, we define dummies here.
341  */
342 SYSCTL_STRING(_user, USER_CS_PATH, cs_path, CTLFLAG_RD,
343     "", 0, "PATH that finds all the standard utilities");
344 SYSCTL_INT(_user, USER_BC_BASE_MAX, bc_base_max, CTLFLAG_RD,
345     0, 0, "Max ibase/obase values in bc(1)");
346 SYSCTL_INT(_user, USER_BC_DIM_MAX, bc_dim_max, CTLFLAG_RD,
347     0, 0, "Max array size in bc(1)");
348 SYSCTL_INT(_user, USER_BC_SCALE_MAX, bc_scale_max, CTLFLAG_RD,
349     0, 0, "Max scale value in bc(1)");
350 SYSCTL_INT(_user, USER_BC_STRING_MAX, bc_string_max, CTLFLAG_RD,
351     0, 0, "Max string length in bc(1)");
352 SYSCTL_INT(_user, USER_COLL_WEIGHTS_MAX, coll_weights_max, CTLFLAG_RD,
353     0, 0, "Maximum number of weights assigned to an LC_COLLATE locale entry");
354 SYSCTL_INT(_user, USER_EXPR_NEST_MAX, expr_nest_max, CTLFLAG_RD, 0, 0, "");
355 SYSCTL_INT(_user, USER_LINE_MAX, line_max, CTLFLAG_RD,
356     0, 0, "Max length (bytes) of a text-processing utility's input line");
357 SYSCTL_INT(_user, USER_RE_DUP_MAX, re_dup_max, CTLFLAG_RD,
358     0, 0, "Maximum number of repeats of a regexp permitted");
359 SYSCTL_INT(_user, USER_POSIX2_VERSION, posix2_version, CTLFLAG_RD,
360     0, 0,
361     "The version of POSIX 1003.2 with which the system attempts to comply");
362 SYSCTL_INT(_user, USER_POSIX2_C_BIND, posix2_c_bind, CTLFLAG_RD,
363     0, 0, "Whether C development supports the C bindings option");
364 SYSCTL_INT(_user, USER_POSIX2_C_DEV, posix2_c_dev, CTLFLAG_RD,
365     0, 0, "Whether system supports the C development utilities option");
366 SYSCTL_INT(_user, USER_POSIX2_CHAR_TERM, posix2_char_term, CTLFLAG_RD,
367     0, 0, "");
368 SYSCTL_INT(_user, USER_POSIX2_FORT_DEV, posix2_fort_dev, CTLFLAG_RD,
369     0, 0, "Whether system supports FORTRAN development utilities");
370 SYSCTL_INT(_user, USER_POSIX2_FORT_RUN, posix2_fort_run, CTLFLAG_RD,
371     0, 0, "Whether system supports FORTRAN runtime utilities");
372 SYSCTL_INT(_user, USER_POSIX2_LOCALEDEF, posix2_localedef, CTLFLAG_RD,
373     0, 0, "Whether system supports creation of locales");
374 SYSCTL_INT(_user, USER_POSIX2_SW_DEV, posix2_sw_dev, CTLFLAG_RD,
375     0, 0, "Whether system supports software development utilities");
376 SYSCTL_INT(_user, USER_POSIX2_UPE, posix2_upe, CTLFLAG_RD,
377     0, 0, "Whether system supports the user portability utilities");
378 SYSCTL_INT(_user, USER_STREAM_MAX, stream_max, CTLFLAG_RD,
379     0, 0, "Min Maximum number of streams a process may have open at one time");
380 SYSCTL_INT(_user, USER_TZNAME_MAX, tzname_max, CTLFLAG_RD,
381     0, 0, "Min Maximum number of types supported for timezone names");
382 
383 #include <sys/vnode.h>
384 SYSCTL_INT(_debug_sizeof, OID_AUTO, vnode, CTLFLAG_RD,
385     0, sizeof(struct vnode), "sizeof(struct vnode)");
386 
387 SYSCTL_INT(_debug_sizeof, OID_AUTO, proc, CTLFLAG_RD,
388     0, sizeof(struct proc), "sizeof(struct proc)");
389 
390 #include <sys/bio.h>
391 #include <sys/buf.h>
392 SYSCTL_INT(_debug_sizeof, OID_AUTO, bio, CTLFLAG_RD,
393     0, sizeof(struct bio), "sizeof(struct bio)");
394 SYSCTL_INT(_debug_sizeof, OID_AUTO, buf, CTLFLAG_RD,
395     0, sizeof(struct buf), "sizeof(struct buf)");
396 
397 #include <sys/user.h>
398 SYSCTL_INT(_debug_sizeof, OID_AUTO, kinfo_proc, CTLFLAG_RD,
399     0, sizeof(struct kinfo_proc), "sizeof(struct kinfo_proc)");
400 
401 /* XXX compatibility, remove for 6.0 */
402 #include <sys/imgact.h>
403 #include <sys/imgact_elf.h>
404 SYSCTL_INT(_kern, OID_AUTO, fallback_elf_brand, CTLFLAG_RW,
405     &__elfN(fallback_brand), sizeof(__elfN(fallback_brand)),
406     "compatibility for kern.fallback_elf_brand");
407