sysctl.c revision 41019 
1/*
2 * Copyright (c) 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef lint
35static const char copyright[] =
36"@(#) Copyright (c) 1993\n\
37	The Regents of the University of California.  All rights reserved.\n";
38#endif /* not lint */
39
40#ifndef lint
41#if 0
42static char sccsid[] = "@(#)from: sysctl.c	8.1 (Berkeley) 6/6/93";
43#endif
44static const char rcsid[] =
45	"$Id: sysctl.c,v 1.18 1998/08/25 07:38:19 dfr Exp $";
46#endif /* not lint */
47
48#include <sys/types.h>
49#include <sys/stat.h>
50#include <sys/sysctl.h>
51#include <sys/resource.h>
52
53#include <ctype.h>
54#include <err.h>
55#include <errno.h>
56#include <stdio.h>
57#include <stdlib.h>
58#include <string.h>
59#include <unistd.h>
60
61static int	Aflag, aflag, nflag, wflag, Xflag, bflag;
62
63static int	oidfmt(int *, int, char *, u_int *);
64static void	parse(char *);
65static int	show_var(int *, int);
66static int	sysctl_all (int *oid, int len);
67static int	name2oid(char *, int *);
68
69static void
70usage(void)
71{
72
73	(void)fprintf(stderr, "%s\n%s\n%s\n%s\n",
74		"usage: sysctl [-bnX] variable ...",
75		"       sysctl [-bnX] -w variable=value ...",
76		"       sysctl [-bnX] -a",
77		"       sysctl [-bnX] -A");
78	exit(1);
79}
80
81int
82main(int argc, char **argv)
83{
84	int ch;
85	setbuf(stdout,0);
86	setbuf(stderr,0);
87
88	while ((ch = getopt(argc, argv, "AabnwX")) != -1) {
89		switch (ch) {
90		case 'A': Aflag = 1; break;
91		case 'a': aflag = 1; break;
92		case 'b': bflag = 1; break;
93		case 'n': nflag = 1; break;
94		case 'w': wflag = 1; break;
95		case 'X': Xflag = Aflag = 1; break;
96		default: usage();
97		}
98	}
99	argc -= optind;
100	argv += optind;
101
102	if (Aflag || aflag)
103		exit (sysctl_all(0, 0));
104	if (argc == 0)
105		usage();
106	while (argc-- > 0)
107		parse(*argv++);
108	exit(0);
109}
110
111/*
112 * Parse a name into a MIB entry.
113 * Lookup and print out the MIB entry if it exists.
114 * Set a new value if requested.
115 */
116static void
117parse(char *string)
118{
119	int len, i, j;
120	void *newval = 0;
121	int intval, newsize = 0;
122	quad_t quadval;
123	int mib[CTL_MAXNAME];
124	char *cp, *bufp, buf[BUFSIZ];
125	u_int kind;
126
127	bufp = buf;
128	snprintf(buf, BUFSIZ, "%s", string);
129	if ((cp = strchr(string, '=')) != NULL) {
130		if (!wflag)
131			errx(2, "must specify -w to set variables");
132		*strchr(buf, '=') = '\0';
133		*cp++ = '\0';
134		while (isspace(*cp))
135			cp++;
136		newval = cp;
137		newsize = strlen(cp);
138	} else {
139		if (wflag)
140			usage();
141	}
142	len = name2oid(bufp, mib);
143
144	if (len < 0)
145		errx(1, "unknown oid '%s'", bufp);
146
147	if (oidfmt(mib, len, 0, &kind))
148		err(1, "couldn't find format of oid '%s'", bufp);
149
150	if (!wflag) {
151		if ((kind & CTLTYPE) == CTLTYPE_NODE) {
152			sysctl_all(mib, len);
153		} else {
154			i = show_var(mib, len);
155			if (!i && !bflag)
156				putchar('\n');
157		}
158	} else {
159		if ((kind & CTLTYPE) == CTLTYPE_NODE)
160			errx(1, "oid '%s' isn't a leaf node", bufp);
161
162		if (!(kind&CTLFLAG_WR))
163			errx(1, "oid '%s' is read only", bufp);
164
165		switch (kind & CTLTYPE) {
166			case CTLTYPE_INT:
167				intval = atoi(newval);
168				newval = &intval;
169				newsize = sizeof intval;
170				break;
171				break;
172			case CTLTYPE_STRING:
173				break;
174			case CTLTYPE_QUAD:
175				break;
176				sscanf(newval, "%qd", &quadval);
177				newval = &quadval;
178				newsize = sizeof quadval;
179				break;
180			default:
181				errx(1, "oid '%s' is type %d,"
182					" cannot set that", bufp,
183					kind & CTLTYPE);
184		}
185
186		i = show_var(mib, len);
187		if (sysctl(mib, len, 0, 0, newval, newsize) == -1) {
188			if (!i && !bflag)
189				putchar('\n');
190			switch (errno) {
191			case EOPNOTSUPP:
192				errx(1, "%s: value is not available",
193					string);
194			case ENOTDIR:
195				errx(1, "%s: specification is incomplete",
196					string);
197			case ENOMEM:
198				errx(1, "%s: type is unknown to this program",
199					string);
200			default:
201				warn("%s", string);
202				return;
203			}
204		}
205		if (!bflag)
206			printf(" -> ");
207		i = nflag;
208		nflag = 1;
209		j = show_var(mib, len);
210		if (!j && !bflag)
211			putchar('\n');
212		nflag = i;
213	}
214}
215
216/* These functions will dump out various interesting structures. */
217
218static int
219S_clockinfo(int l2, void *p)
220{
221	struct clockinfo *ci = (struct clockinfo*)p;
222	if (l2 != sizeof *ci)
223		err(1, "S_clockinfo %d != %d", l2, sizeof *ci);
224	printf("{ hz = %d, tick = %d, tickadj = %d, profhz = %d, stathz = %d }",
225		ci->hz, ci->tick, ci->tickadj, ci->profhz, ci->stathz);
226	return (0);
227}
228
229static int
230S_loadavg(int l2, void *p)
231{
232	struct loadavg *tv = (struct loadavg*)p;
233
234	if (l2 != sizeof *tv)
235		err(1, "S_loadavg %d != %d", l2, sizeof *tv);
236
237	printf("{ %.2f %.2f %.2f }",
238		(double)tv->ldavg[0]/(double)tv->fscale,
239		(double)tv->ldavg[1]/(double)tv->fscale,
240		(double)tv->ldavg[2]/(double)tv->fscale);
241	return (0);
242}
243
244static int
245S_timeval(int l2, void *p)
246{
247	struct timeval *tv = (struct timeval*)p;
248	time_t tv_sec;
249	char *p1, *p2;
250
251	if (l2 != sizeof *tv)
252		err(1, "S_timeval %d != %d", l2, sizeof *tv);
253	printf("{ sec = %ld, usec = %ld } ",
254		tv->tv_sec, tv->tv_usec);
255	tv_sec = tv->tv_sec;
256	p1 = strdup(ctime(&tv_sec));
257	for (p2=p1; *p2 ; p2++)
258		if (*p2 == '\n')
259			*p2 = '\0';
260	fputs(p1, stdout);
261	return (0);
262}
263
264static int
265T_dev_t(int l2, void *p)
266{
267	dev_t *d = (dev_t *)p;
268	if (l2 != sizeof *d)
269		err(1, "T_dev_T %d != %d", l2, sizeof *d);
270	printf("{ major = %d, minor = %d }",
271		major(*d), minor(*d));
272	return (0);
273}
274
275/*
276 * These functions uses a presently undocumented interface to the kernel
277 * to walk the tree and get the type so it can print the value.
278 * This interface is under work and consideration, and should probably
279 * be killed with a big axe by the first person who can find the time.
280 * (be aware though, that the proper interface isn't as obvious as it
281 * may seem, there are various conflicting requirements.
282 */
283
284static int
285name2oid(char *name, int *oidp)
286{
287	int oid[2];
288	int i;
289	size_t j;
290
291	oid[0] = 0;
292	oid[1] = 3;
293
294	j = CTL_MAXNAME * sizeof (int);
295	i = sysctl(oid, 2, oidp, &j, name, strlen(name));
296	if (i < 0)
297		return i;
298	j /= sizeof (int);
299	return (j);
300}
301
302static int
303oidfmt(int *oid, int len, char *fmt, u_int *kind)
304{
305	int qoid[CTL_MAXNAME+2];
306	u_char buf[BUFSIZ];
307	int i;
308	size_t j;
309
310	qoid[0] = 0;
311	qoid[1] = 4;
312	memcpy(qoid + 2, oid, len * sizeof(int));
313
314	j = sizeof buf;
315	i = sysctl(qoid, len + 2, buf, &j, 0, 0);
316	if (i)
317		err(1, "sysctl fmt %d %d %d", i, j, errno);
318
319	if (kind)
320		*kind = *(u_int *)buf;
321
322	if (fmt)
323		strcpy(fmt, (char *)(buf + sizeof(u_int)));
324	return 0;
325}
326
327/*
328 * This formats and outputs the value of one variable
329 *
330 * Returns zero if anything was actually output.
331 * Returns one if didn't know what to do with this.
332 * Return minus one if we had errors.
333 */
334
335static int
336show_var(int *oid, int nlen)
337{
338	u_char buf[BUFSIZ], *val, *p;
339	char name[BUFSIZ], *fmt;
340	int qoid[CTL_MAXNAME+2];
341	int i;
342	size_t j, len;
343	u_int kind;
344	int (*func)(int, void *) = 0;
345
346	/* find an estimate of how much we need for this var */
347	j = 0;
348	i = sysctl(oid, nlen, 0, &j, 0, 0);
349	j += j; /* we want to be sure :-) */
350
351	val = alloca(j);
352	len = j;
353	i = sysctl(oid, nlen, val, &len, 0, 0);
354	if (i || !len)
355		return (1);
356
357	if (bflag) {
358		fwrite(val, 1, len, stdout);
359		return (0);
360	}
361
362	qoid[0] = 0;
363	qoid[1] = 4;
364	memcpy(qoid + 2, oid, nlen * sizeof(int));
365
366	j = sizeof buf;
367	i = sysctl(qoid, nlen + 2, buf, &j, 0, 0);
368	if (i || !j)
369		err(1, "sysctl fmt %d %d %d", i, j, errno);
370
371	kind = *(u_int *)buf;
372
373	fmt = (char *)(buf + sizeof(u_int));
374
375	qoid[1] = 1;
376	j = sizeof name;
377	i = sysctl(qoid, nlen + 2, name, &j, 0, 0);
378	if (i || !j)
379		err(1, "sysctl name %d %d %d", i, j, errno);
380
381	p = val;
382	switch (*fmt) {
383	case 'A':
384		if (!nflag)
385			printf("%s: ", name);
386		printf("%s", p);
387		return (0);
388
389	case 'I':
390		if (!nflag)
391			printf("%s: ", name);
392		val = "";
393		while (len >= sizeof(int)) {
394			printf("%s%d", val, *(int *)p);
395			val = " ";
396			len -= sizeof (int);
397			p += sizeof (int);
398		}
399		return (0);
400
401	case 'L':
402		if (!nflag)
403			printf("%s: ", name);
404		printf("%ld", *(long *)p);
405		return (0);
406
407	case 'P':
408		if (!nflag)
409			printf("%s: ", name);
410		printf("%p", *(void **)p);
411		return (0);
412
413	case 'T':
414	case 'S':
415		i = 0;
416		if (!strcmp(fmt, "S,clockinfo"))	func = S_clockinfo;
417		else if (!strcmp(fmt, "S,timeval"))	func = S_timeval;
418		else if (!strcmp(fmt, "S,loadavg"))	func = S_loadavg;
419		else if (!strcmp(fmt, "T,dev_t"))	func = T_dev_t;
420		if (func) {
421			if (!nflag)
422				printf("%s: ", name);
423			return ((*func)(len, p));
424		}
425		/* FALL THROUGH */
426	default:
427		if (!Aflag)
428			return (1);
429		if (!nflag)
430			printf("%s: ", name);
431		printf("Format:%s Length:%d Dump:0x", fmt, len);
432		while (len--) {
433			printf("%02x", *p++);
434			if (Xflag || p < val+16)
435				continue;
436			printf("...");
437			break;
438		}
439		return (0);
440	}
441	return (1);
442}
443
444static int
445sysctl_all (int *oid, int len)
446{
447	int name1[22], name2[22];
448	int i, j;
449	size_t l1, l2;
450
451	name1[0] = 0;
452	name1[1] = 2;
453	l1 = 2;
454	if (len) {
455		memcpy(name1+2, oid, len*sizeof (int));
456		l1 += len;
457	} else {
458		name1[2] = 1;
459		l1++;
460	}
461	while (1) {
462		l2 = sizeof name2;
463		j = sysctl(name1, l1, name2, &l2, 0, 0);
464		if (j < 0)
465			if (errno == ENOENT)
466				return 0;
467			else
468				err(1, "sysctl(getnext) %d %d", j, l2);
469
470		l2 /= sizeof (int);
471
472		if (l2 < len)
473			return 0;
474
475		for (i = 0; i < len; i++)
476			if (name2[i] != oid[i])
477				return 0;
478
479		i = show_var(name2, l2);
480		if (!i && !bflag)
481			putchar('\n');
482
483		memcpy(name1+2, name2, l2*sizeof (int));
484		l1 = 2 + l2;
485	}
486}
487