xref: /freebsd/sbin/sysctl/sysctl.c (revision 2ad872c5794e4c26fdf6ed219ad3f09ca0d5304a)
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
35 static 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
42 static char sccsid[] = "@(#)from: sysctl.c	8.1 (Berkeley) 6/6/93";
43 #endif
44 static const char rcsid[] =
45 	"$Id: sysctl.c,v 1.19 1998/11/08 19:27:43 phk 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 
61 static int	Aflag, aflag, bflag, dflag, nflag, wflag, Xflag;
62 
63 static int	oidfmt(int *, int, char *, u_int *);
64 static void	parse(char *);
65 static int	show_var(int *, int);
66 static int	sysctl_all (int *oid, int len);
67 static int	name2oid(char *, int *);
68 
69 static void
70 usage(void)
71 {
72 
73 	(void)fprintf(stderr, "%s\n%s\n%s\n%s\n%s\n",
74 		"usage: sysctl [-bdn] variable ...",
75 		"       sysctl [-bn] -w variable=value ...",
76 		"       sysctl [-bdn] -a",
77 		"       sysctl [-bdn] -A",
78 		"       sysctl [-bdn] -X");
79 	exit(1);
80 }
81 
82 int
83 main(int argc, char **argv)
84 {
85 	int ch;
86 	setbuf(stdout,0);
87 	setbuf(stderr,0);
88 
89 	while ((ch = getopt(argc, argv, "AabdnwX")) != -1) {
90 		switch (ch) {
91 		case 'A': Aflag = 1; break;
92 		case 'a': aflag = 1; break;
93 		case 'b': bflag = 1; break;
94 		case 'd': dflag = 1; break;
95 		case 'n': nflag = 1; break;
96 		case 'w': wflag = 1; break;
97 		case 'X': Xflag = Aflag = 1; break;
98 		default: usage();
99 		}
100 	}
101 	argc -= optind;
102 	argv += optind;
103 
104 	if (wflag && (Aflag || aflag || dflag))
105 		usage();
106 	if (Aflag || aflag)
107 		exit (sysctl_all(0, 0));
108 	if (argc == 0)
109 		usage();
110 	while (argc-- > 0)
111 		parse(*argv++);
112 	exit(0);
113 }
114 
115 /*
116  * Parse a name into a MIB entry.
117  * Lookup and print out the MIB entry if it exists.
118  * Set a new value if requested.
119  */
120 static void
121 parse(char *string)
122 {
123 	int len, i, j;
124 	void *newval = 0;
125 	int intval, newsize = 0;
126 	quad_t quadval;
127 	int mib[CTL_MAXNAME];
128 	char *cp, *bufp, buf[BUFSIZ];
129 	u_int kind;
130 
131 	bufp = buf;
132 	snprintf(buf, BUFSIZ, "%s", string);
133 	if ((cp = strchr(string, '=')) != NULL) {
134 		if (!wflag)
135 			errx(2, "must specify -w to set variables");
136 		*strchr(buf, '=') = '\0';
137 		*cp++ = '\0';
138 		while (isspace(*cp))
139 			cp++;
140 		newval = cp;
141 		newsize = strlen(cp);
142 	} else {
143 		if (wflag)
144 			usage();
145 	}
146 	len = name2oid(bufp, mib);
147 
148 	if (len < 0)
149 		errx(1, "unknown oid '%s'", bufp);
150 
151 	if (oidfmt(mib, len, 0, &kind))
152 		err(1, "couldn't find format of oid '%s'", bufp);
153 
154 	if (!wflag) {
155 		if ((kind & CTLTYPE) == CTLTYPE_NODE) {
156 			sysctl_all(mib, len);
157 		} else {
158 			i = show_var(mib, len);
159 			if (!i && !bflag)
160 				putchar('\n');
161 		}
162 	} else {
163 		if ((kind & CTLTYPE) == CTLTYPE_NODE)
164 			errx(1, "oid '%s' isn't a leaf node", bufp);
165 
166 		if (!(kind&CTLFLAG_WR))
167 			errx(1, "oid '%s' is read only", bufp);
168 
169 		switch (kind & CTLTYPE) {
170 			case CTLTYPE_INT:
171 				intval = atoi(newval);
172 				newval = &intval;
173 				newsize = sizeof intval;
174 				break;
175 				break;
176 			case CTLTYPE_STRING:
177 				break;
178 			case CTLTYPE_QUAD:
179 				break;
180 				sscanf(newval, "%qd", &quadval);
181 				newval = &quadval;
182 				newsize = sizeof quadval;
183 				break;
184 			default:
185 				errx(1, "oid '%s' is type %d,"
186 					" cannot set that", bufp,
187 					kind & CTLTYPE);
188 		}
189 
190 		i = show_var(mib, len);
191 		if (sysctl(mib, len, 0, 0, newval, newsize) == -1) {
192 			if (!i && !bflag)
193 				putchar('\n');
194 			switch (errno) {
195 			case EOPNOTSUPP:
196 				errx(1, "%s: value is not available",
197 					string);
198 			case ENOTDIR:
199 				errx(1, "%s: specification is incomplete",
200 					string);
201 			case ENOMEM:
202 				errx(1, "%s: type is unknown to this program",
203 					string);
204 			default:
205 				warn("%s", string);
206 				return;
207 			}
208 		}
209 		if (!bflag)
210 			printf(" -> ");
211 		i = nflag;
212 		nflag = 1;
213 		j = show_var(mib, len);
214 		if (!j && !bflag)
215 			putchar('\n');
216 		nflag = i;
217 	}
218 }
219 
220 /* These functions will dump out various interesting structures. */
221 
222 static int
223 S_clockinfo(int l2, void *p)
224 {
225 	struct clockinfo *ci = (struct clockinfo*)p;
226 	if (l2 != sizeof *ci)
227 		err(1, "S_clockinfo %d != %d", l2, sizeof *ci);
228 	printf("{ hz = %d, tick = %d, tickadj = %d, profhz = %d, stathz = %d }",
229 		ci->hz, ci->tick, ci->tickadj, ci->profhz, ci->stathz);
230 	return (0);
231 }
232 
233 static int
234 S_loadavg(int l2, void *p)
235 {
236 	struct loadavg *tv = (struct loadavg*)p;
237 
238 	if (l2 != sizeof *tv)
239 		err(1, "S_loadavg %d != %d", l2, sizeof *tv);
240 
241 	printf("{ %.2f %.2f %.2f }",
242 		(double)tv->ldavg[0]/(double)tv->fscale,
243 		(double)tv->ldavg[1]/(double)tv->fscale,
244 		(double)tv->ldavg[2]/(double)tv->fscale);
245 	return (0);
246 }
247 
248 static int
249 S_timeval(int l2, void *p)
250 {
251 	struct timeval *tv = (struct timeval*)p;
252 	time_t tv_sec;
253 	char *p1, *p2;
254 
255 	if (l2 != sizeof *tv)
256 		err(1, "S_timeval %d != %d", l2, sizeof *tv);
257 	printf("{ sec = %ld, usec = %ld } ",
258 		tv->tv_sec, tv->tv_usec);
259 	tv_sec = tv->tv_sec;
260 	p1 = strdup(ctime(&tv_sec));
261 	for (p2=p1; *p2 ; p2++)
262 		if (*p2 == '\n')
263 			*p2 = '\0';
264 	fputs(p1, stdout);
265 	return (0);
266 }
267 
268 static int
269 T_dev_t(int l2, void *p)
270 {
271 	dev_t *d = (dev_t *)p;
272 	if (l2 != sizeof *d)
273 		err(1, "T_dev_T %d != %d", l2, sizeof *d);
274 	printf("{ major = %d, minor = %d }",
275 		major(*d), minor(*d));
276 	return (0);
277 }
278 
279 /*
280  * These functions uses a presently undocumented interface to the kernel
281  * to walk the tree and get the type so it can print the value.
282  * This interface is under work and consideration, and should probably
283  * be killed with a big axe by the first person who can find the time.
284  * (be aware though, that the proper interface isn't as obvious as it
285  * may seem, there are various conflicting requirements.
286  */
287 
288 static int
289 name2oid(char *name, int *oidp)
290 {
291 	int oid[2];
292 	int i;
293 	size_t j;
294 
295 	oid[0] = 0;
296 	oid[1] = 3;
297 
298 	j = CTL_MAXNAME * sizeof (int);
299 	i = sysctl(oid, 2, oidp, &j, name, strlen(name));
300 	if (i < 0)
301 		return i;
302 	j /= sizeof (int);
303 	return (j);
304 }
305 
306 static int
307 oidfmt(int *oid, int len, char *fmt, u_int *kind)
308 {
309 	int qoid[CTL_MAXNAME+2];
310 	u_char buf[BUFSIZ];
311 	int i;
312 	size_t j;
313 
314 	qoid[0] = 0;
315 	qoid[1] = 4;
316 	memcpy(qoid + 2, oid, len * sizeof(int));
317 
318 	j = sizeof buf;
319 	i = sysctl(qoid, len + 2, buf, &j, 0, 0);
320 	if (i)
321 		err(1, "sysctl fmt %d %d %d", i, j, errno);
322 
323 	if (kind)
324 		*kind = *(u_int *)buf;
325 
326 	if (fmt)
327 		strcpy(fmt, (char *)(buf + sizeof(u_int)));
328 	return 0;
329 }
330 
331 /*
332  * This formats and outputs the value of one variable
333  *
334  * Returns zero if anything was actually output.
335  * Returns one if didn't know what to do with this.
336  * Return minus one if we had errors.
337  */
338 
339 static int
340 show_var(int *oid, int nlen)
341 {
342 	u_char buf[BUFSIZ], *val, *p;
343 	char name[BUFSIZ], descr[BUFSIZ], *fmt;
344 	int qoid[CTL_MAXNAME+2];
345 	int i;
346 	size_t j, len;
347 	u_int kind;
348 	int (*func)(int, void *) = 0;
349 
350 	qoid[0] = 0;
351 	memcpy(qoid + 2, oid, nlen * sizeof(int));
352 
353 	qoid[1] = 1;
354 	j = sizeof name;
355 	i = sysctl(qoid, nlen + 2, name, &j, 0, 0);
356 	if (i || !j)
357 		err(1, "sysctl name %d %d %d", i, j, errno);
358 
359 	if (dflag) {
360 		qoid[1] = 5;
361 		j = sizeof descr;
362 		i = sysctl(qoid, nlen + 2, descr, &j, 0, 0);
363 		if (i || !j)
364 			err(1, "sysctl name %d %d %d", i, j, errno);
365 		if (!nflag)
366 			printf("%s: ", name);
367 		printf("%s", descr[0] ? descr : "[no description]");
368 		return (0);
369 	}
370 
371 	/* find an estimate of how much we need for this var */
372 	j = 0;
373 	i = sysctl(oid, nlen, 0, &j, 0, 0);
374 	j += j; /* we want to be sure :-) */
375 
376 	val = alloca(j);
377 	len = j;
378 	i = sysctl(oid, nlen, val, &len, 0, 0);
379 	if (i || !len)
380 		return (1);
381 
382 	if (bflag) {
383 		fwrite(val, 1, len, stdout);
384 		return (0);
385 	}
386 
387 	qoid[1] = 4;
388 	j = sizeof buf;
389 	i = sysctl(qoid, nlen + 2, buf, &j, 0, 0);
390 	if (i || !j)
391 		err(1, "sysctl fmt %d %d %d", i, j, errno);
392 
393 	kind = *(u_int *)buf;
394 
395 	fmt = (char *)(buf + sizeof(u_int));
396 
397 	p = val;
398 	switch (*fmt) {
399 	case 'A':
400 		if (!nflag)
401 			printf("%s: ", name);
402 		printf("%s", p);
403 		return (0);
404 
405 	case 'I':
406 		if (!nflag)
407 			printf("%s: ", name);
408 		val = "";
409 		while (len >= sizeof(int)) {
410 			printf("%s%d", val, *(int *)p);
411 			val = " ";
412 			len -= sizeof (int);
413 			p += sizeof (int);
414 		}
415 		return (0);
416 
417 	case 'L':
418 		if (!nflag)
419 			printf("%s: ", name);
420 		printf("%ld", *(long *)p);
421 		return (0);
422 
423 	case 'P':
424 		if (!nflag)
425 			printf("%s: ", name);
426 		printf("%p", *(void **)p);
427 		return (0);
428 
429 	case 'T':
430 	case 'S':
431 		i = 0;
432 		if (!strcmp(fmt, "S,clockinfo"))	func = S_clockinfo;
433 		else if (!strcmp(fmt, "S,timeval"))	func = S_timeval;
434 		else if (!strcmp(fmt, "S,loadavg"))	func = S_loadavg;
435 		else if (!strcmp(fmt, "T,dev_t"))	func = T_dev_t;
436 		if (func) {
437 			if (!nflag)
438 				printf("%s: ", name);
439 			return ((*func)(len, p));
440 		}
441 		/* FALL THROUGH */
442 	default:
443 		if (!Aflag)
444 			return (1);
445 		if (!nflag)
446 			printf("%s: ", name);
447 		printf("Format:%s Length:%d Dump:0x", fmt, len);
448 		while (len--) {
449 			printf("%02x", *p++);
450 			if (Xflag || p < val+16)
451 				continue;
452 			printf("...");
453 			break;
454 		}
455 		return (0);
456 	}
457 	return (1);
458 }
459 
460 static int
461 sysctl_all (int *oid, int len)
462 {
463 	int name1[22], name2[22];
464 	int i, j;
465 	size_t l1, l2;
466 
467 	name1[0] = 0;
468 	name1[1] = 2;
469 	l1 = 2;
470 	if (len) {
471 		memcpy(name1+2, oid, len*sizeof (int));
472 		l1 += len;
473 	} else {
474 		name1[2] = 1;
475 		l1++;
476 	}
477 	while (1) {
478 		l2 = sizeof name2;
479 		j = sysctl(name1, l1, name2, &l2, 0, 0);
480 		if (j < 0)
481 			if (errno == ENOENT)
482 				return 0;
483 			else
484 				err(1, "sysctl(getnext) %d %d", j, l2);
485 
486 		l2 /= sizeof (int);
487 
488 		if (l2 < len)
489 			return 0;
490 
491 		for (i = 0; i < len; i++)
492 			if (name2[i] != oid[i])
493 				return 0;
494 
495 		i = show_var(name2, l2);
496 		if (!i && !bflag)
497 			putchar('\n');
498 
499 		memcpy(name1+2, name2, l2*sizeof (int));
500 		l1 = 2 + l2;
501 	}
502 }
503