sysctl.c revision 88696 
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  "$FreeBSD: head/sbin/sysctl/sysctl.c 88696 2001-12-30 10:33:34Z phk $";
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#include <sys/param.h>
53
54#include <ctype.h>
55#include <err.h>
56#include <errno.h>
57#include <stdio.h>
58#include <stdlib.h>
59#include <string.h>
60#include <unistd.h>
61
62static int	aflag, bflag, dflag, eflag, Nflag, nflag, oflag, xflag;
63
64static int	oidfmt(int *, int, char *, u_int *);
65static void	parse(char *);
66static int	show_var(int *, int);
67static int	sysctl_all (int *oid, int len);
68static int	name2oid(char *, int *);
69
70static void	set_T_dev_t (char *, void **, int *);
71
72static void
73usage(void)
74{
75
76	(void)fprintf(stderr, "%s\n%s\n",
77	    "usage: sysctl [-bdeNnox] variable[=value] ...",
78	    "       sysctl [-bdeNnox] -a");
79	exit(1);
80}
81
82int
83main(int argc, char **argv)
84{
85	int ch;
86	setbuf(stdout,0);
87	setbuf(stderr,0);
88
89	while ((ch = getopt(argc, argv, "AabdeNnowxX")) != -1) {
90		switch (ch) {
91		case 'A':
92			/* compatibility */
93			aflag = oflag = 1;
94			break;
95		case 'a':
96			aflag = 1;
97			break;
98		case 'b':
99			bflag = 1;
100			break;
101		case 'd':
102			dflag = 1;
103			break;
104		case 'e':
105			eflag = 1;
106			break;
107		case 'N':
108			Nflag = 1;
109			break;
110		case 'n':
111			nflag = 1;
112			break;
113		case 'o':
114			oflag = 1;
115			break;
116		case 'w':
117			/* compatibility */
118			/* ignored */
119			break;
120		case 'X':
121			/* compatibility */
122			aflag = xflag = 1;
123			break;
124		case 'x':
125			xflag = 1;
126			break;
127		default:
128			usage();
129		}
130	}
131	argc -= optind;
132	argv += optind;
133
134	if (Nflag && nflag)
135		usage();
136	if (aflag && argc == 0)
137		exit(sysctl_all(0, 0));
138	if (argc == 0)
139		usage();
140	while (argc-- > 0)
141		parse(*argv++);
142	exit(0);
143}
144
145/*
146 * Parse a name into a MIB entry.
147 * Lookup and print out the MIB entry if it exists.
148 * Set a new value if requested.
149 */
150static void
151parse(char *string)
152{
153	int len, i, j;
154	void *newval = 0;
155	int intval;
156	unsigned int uintval;
157	long longval;
158	unsigned long ulongval;
159	size_t newsize = 0;
160	quad_t quadval;
161	int mib[CTL_MAXNAME];
162	char *cp, *bufp, buf[BUFSIZ], fmt[BUFSIZ];
163	u_int kind;
164
165	bufp = buf;
166	snprintf(buf, BUFSIZ, "%s", string);
167	if ((cp = strchr(string, '=')) != NULL) {
168		*strchr(buf, '=') = '\0';
169		*cp++ = '\0';
170		while (isspace(*cp))
171			cp++;
172		newval = cp;
173		newsize = strlen(cp);
174	}
175	len = name2oid(bufp, mib);
176
177	if (len < 0)
178		errx(1, "unknown oid '%s'", bufp);
179
180	if (oidfmt(mib, len, fmt, &kind))
181		err(1, "couldn't find format of oid '%s'", bufp);
182
183	if (newval == NULL) {
184		if ((kind & CTLTYPE) == CTLTYPE_NODE) {
185			sysctl_all(mib, len);
186		} else {
187			i = show_var(mib, len);
188			if (!i && !bflag)
189				putchar('\n');
190		}
191	} else {
192		if ((kind & CTLTYPE) == CTLTYPE_NODE)
193			errx(1, "oid '%s' isn't a leaf node", bufp);
194
195		if (!(kind&CTLFLAG_WR))
196			errx(1, "oid '%s' is read only", bufp);
197
198		switch (kind & CTLTYPE) {
199			case CTLTYPE_INT:
200				intval = (int) strtol(newval, NULL, 0);
201				newval = &intval;
202				newsize = sizeof(intval);
203				break;
204			case CTLTYPE_UINT:
205				uintval = (int) strtoul(newval, NULL, 0);
206				newval = &uintval;
207				newsize = sizeof uintval;
208				break;
209			case CTLTYPE_LONG:
210				longval = strtol(newval, NULL, 0);
211				newval = &longval;
212				newsize = sizeof longval;
213				break;
214			case CTLTYPE_ULONG:
215				ulongval = strtoul(newval, NULL, 0);
216				newval = &ulongval;
217				newsize = sizeof ulongval;
218				break;
219			case CTLTYPE_STRING:
220				break;
221			case CTLTYPE_QUAD:
222				sscanf(newval, "%qd", &quadval);
223				newval = &quadval;
224				newsize = sizeof(quadval);
225				break;
226			case CTLTYPE_OPAQUE:
227				if (strcmp(fmt, "T,dev_t") == 0) {
228					set_T_dev_t ((char*)newval, &newval, &newsize);
229					break;
230				}
231				/* FALLTHROUGH */
232			default:
233				errx(1, "oid '%s' is type %d,"
234					" cannot set that", bufp,
235					kind & CTLTYPE);
236		}
237
238		i = show_var(mib, len);
239		if (sysctl(mib, len, 0, 0, newval, newsize) == -1) {
240			if (!i && !bflag)
241				putchar('\n');
242			switch (errno) {
243			case EOPNOTSUPP:
244				errx(1, "%s: value is not available",
245					string);
246			case ENOTDIR:
247				errx(1, "%s: specification is incomplete",
248					string);
249			case ENOMEM:
250				errx(1, "%s: type is unknown to this program",
251					string);
252			default:
253				warn("%s", string);
254				return;
255			}
256		}
257		if (!bflag)
258			printf(" -> ");
259		i = nflag;
260		nflag = 1;
261		j = show_var(mib, len);
262		if (!j && !bflag)
263			putchar('\n');
264		nflag = i;
265	}
266}
267
268/* These functions will dump out various interesting structures. */
269
270static int
271S_clockinfo(int l2, void *p)
272{
273	struct clockinfo *ci = (struct clockinfo*)p;
274	if (l2 != sizeof(*ci))
275		err(1, "S_clockinfo %d != %d", l2, sizeof(*ci));
276	printf("{ hz = %d, tick = %d, tickadj = %d, profhz = %d, stathz = %d }",
277		ci->hz, ci->tick, ci->tickadj, ci->profhz, ci->stathz);
278	return (0);
279}
280
281static int
282S_loadavg(int l2, void *p)
283{
284	struct loadavg *tv = (struct loadavg*)p;
285
286	if (l2 != sizeof(*tv))
287		err(1, "S_loadavg %d != %d", l2, sizeof(*tv));
288
289	printf("{ %.2f %.2f %.2f }",
290		(double)tv->ldavg[0]/(double)tv->fscale,
291		(double)tv->ldavg[1]/(double)tv->fscale,
292		(double)tv->ldavg[2]/(double)tv->fscale);
293	return (0);
294}
295
296static int
297S_timeval(int l2, void *p)
298{
299	struct timeval *tv = (struct timeval*)p;
300	time_t tv_sec;
301	char *p1, *p2;
302
303	if (l2 != sizeof(*tv))
304		err(1, "S_timeval %d != %d", l2, sizeof(*tv));
305	printf("{ sec = %ld, usec = %ld } ",
306		tv->tv_sec, tv->tv_usec);
307	tv_sec = tv->tv_sec;
308	p1 = strdup(ctime(&tv_sec));
309	for (p2=p1; *p2 ; p2++)
310		if (*p2 == '\n')
311			*p2 = '\0';
312	fputs(p1, stdout);
313	return (0);
314}
315
316static int
317T_dev_t(int l2, void *p)
318{
319	dev_t *d = (dev_t *)p;
320	if (l2 != sizeof(*d))
321		err(1, "T_dev_T %d != %d", l2, sizeof(*d));
322	if ((int)(*d) != -1) {
323		if (minor(*d) > 255 || minor(*d) < 0)
324			printf("{ major = %d, minor = 0x%x }",
325				major(*d), minor(*d));
326		else
327			printf("{ major = %d, minor = %d }",
328				major(*d), minor(*d));
329	}
330	return (0);
331}
332
333static void
334set_T_dev_t (char *path, void **val, int *size)
335{
336	static struct stat statb;
337
338	if (strcmp(path, "none") && strcmp(path, "off")) {
339		int rc = stat (path, &statb);
340		if (rc) {
341			err(1, "cannot stat %s", path);
342		}
343
344		if (!S_ISCHR(statb.st_mode)) {
345			errx(1, "must specify a device special file.");
346		}
347	} else {
348		statb.st_rdev = NODEV;
349	}
350	*val = (char*) &statb.st_rdev;
351	*size = sizeof statb.st_rdev;
352}
353
354/*
355 * These functions uses a presently undocumented interface to the kernel
356 * to walk the tree and get the type so it can print the value.
357 * This interface is under work and consideration, and should probably
358 * be killed with a big axe by the first person who can find the time.
359 * (be aware though, that the proper interface isn't as obvious as it
360 * may seem, there are various conflicting requirements.
361 */
362
363static int
364name2oid(char *name, int *oidp)
365{
366	int oid[2];
367	int i;
368	size_t j;
369
370	oid[0] = 0;
371	oid[1] = 3;
372
373	j = CTL_MAXNAME * sizeof(int);
374	i = sysctl(oid, 2, oidp, &j, name, strlen(name));
375	if (i < 0)
376		return i;
377	j /= sizeof(int);
378	return (j);
379}
380
381static int
382oidfmt(int *oid, int len, char *fmt, u_int *kind)
383{
384	int qoid[CTL_MAXNAME+2];
385	u_char buf[BUFSIZ];
386	int i;
387	size_t j;
388
389	qoid[0] = 0;
390	qoid[1] = 4;
391	memcpy(qoid + 2, oid, len * sizeof(int));
392
393	j = sizeof(buf);
394	i = sysctl(qoid, len + 2, buf, &j, 0, 0);
395	if (i)
396		err(1, "sysctl fmt %d %d %d", i, j, errno);
397
398	if (kind)
399		*kind = *(u_int *)buf;
400
401	if (fmt)
402		strcpy(fmt, (char *)(buf + sizeof(u_int)));
403	return 0;
404}
405
406/*
407 * This formats and outputs the value of one variable
408 *
409 * Returns zero if anything was actually output.
410 * Returns one if didn't know what to do with this.
411 * Return minus one if we had errors.
412 */
413
414static int
415show_var(int *oid, int nlen)
416{
417	u_char buf[BUFSIZ], *val, *p;
418	char name[BUFSIZ], *fmt, *sep;
419	int qoid[CTL_MAXNAME+2];
420	int i;
421	size_t j, len;
422	u_int kind;
423	int (*func)(int, void *);
424
425	qoid[0] = 0;
426	memcpy(qoid + 2, oid, nlen * sizeof(int));
427
428	qoid[1] = 1;
429	j = sizeof(name);
430	i = sysctl(qoid, nlen + 2, name, &j, 0, 0);
431	if (i || !j)
432		err(1, "sysctl name %d %d %d", i, j, errno);
433
434	if (Nflag) {
435		printf("%s", name);
436		return (0);
437	}
438
439	if (eflag)
440		sep = "=";
441	else
442		sep = ": ";
443
444	if (dflag) {	/* just print description */
445		qoid[1] = 5;
446		j = sizeof(buf);
447		i = sysctl(qoid, nlen + 2, buf, &j, 0, 0);
448		if (!nflag)
449			printf("%s%s", name, sep);
450		printf("%s", buf);
451		return (0);
452	}
453	/* find an estimate of how much we need for this var */
454	j = 0;
455	i = sysctl(oid, nlen, 0, &j, 0, 0);
456	j += j; /* we want to be sure :-) */
457
458	val = alloca(j);
459	len = j;
460	i = sysctl(oid, nlen, val, &len, 0, 0);
461	if (i || !len)
462		return (1);
463
464	if (bflag) {
465		fwrite(val, 1, len, stdout);
466		return (0);
467	}
468
469	fmt = buf;
470	oidfmt(oid, nlen, fmt, &kind);
471	p = val;
472	switch (*fmt) {
473	case 'A':
474		if (!nflag)
475			printf("%s%s", name, sep);
476		printf("%s", p);
477		return (0);
478
479	case 'I':
480		if (!nflag)
481			printf("%s%s", name, sep);
482		fmt++;
483		val = "";
484		while (len >= sizeof(int)) {
485			if(*fmt == 'U')
486				printf("%s%u", val, *(unsigned int *)p);
487			else
488				printf("%s%d", val, *(int *)p);
489			val = " ";
490			len -= sizeof(int);
491			p += sizeof(int);
492		}
493		return (0);
494
495	case 'L':
496		if (!nflag)
497			printf("%s%s", name, sep);
498		fmt++;
499		val = "";
500		while (len >= sizeof(long)) {
501			if(*fmt == 'U')
502				printf("%s%lu", val, *(unsigned long *)p);
503			else
504				printf("%s%ld", val, *(long *)p);
505			val = " ";
506			len -= sizeof(long);
507			p += sizeof(long);
508		}
509		return (0);
510
511	case 'P':
512		if (!nflag)
513			printf("%s%s", name, sep);
514		printf("%p", *(void **)p);
515		return (0);
516
517	case 'T':
518	case 'S':
519		i = 0;
520		if (strcmp(fmt, "S,clockinfo") == 0)
521			func = S_clockinfo;
522		else if (strcmp(fmt, "S,timeval") == 0)
523			func = S_timeval;
524		else if (strcmp(fmt, "S,loadavg") == 0)
525			func = S_loadavg;
526		else if (strcmp(fmt, "T,dev_t") == 0)
527			func = T_dev_t;
528		else
529			func = NULL;
530		if (func) {
531			if (!nflag)
532				printf("%s%s", name, sep);
533			return ((*func)(len, p));
534		}
535		/* FALL THROUGH */
536	default:
537		if (!oflag && !xflag)
538			return (1);
539		if (!nflag)
540			printf("%s%s", name, sep);
541		printf("Format:%s Length:%d Dump:0x", fmt, len);
542		while (len-- && (xflag || p < val + 16))
543			printf("%02x", *p++);
544		if (!xflag && len > 16)
545			printf("...");
546		return (0);
547	}
548	return (1);
549}
550
551static int
552sysctl_all (int *oid, int len)
553{
554	int name1[22], name2[22];
555	int i, j;
556	size_t l1, l2;
557
558	name1[0] = 0;
559	name1[1] = 2;
560	l1 = 2;
561	if (len) {
562		memcpy(name1+2, oid, len * sizeof(int));
563		l1 += len;
564	} else {
565		name1[2] = 1;
566		l1++;
567	}
568	for (;;) {
569		l2 = sizeof(name2);
570		j = sysctl(name1, l1, name2, &l2, 0, 0);
571		if (j < 0) {
572			if (errno == ENOENT)
573				return 0;
574			else
575				err(1, "sysctl(getnext) %d %d", j, l2);
576		}
577
578		l2 /= sizeof(int);
579
580		if (l2 < len)
581			return 0;
582
583		for (i = 0; i < len; i++)
584			if (name2[i] != oid[i])
585				return 0;
586
587		i = show_var(name2, l2);
588		if (!i && !bflag)
589			putchar('\n');
590
591		memcpy(name1+2, name2, l2 * sizeof(int));
592		l1 = 2 + l2;
593	}
594}
595