xref: /freebsd/sbin/sysctl/sysctl.c (revision ee41f1b1cf5e3d4f586cb85b46123b416275862c)
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   "$FreeBSD$";
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, Nflag, 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 [-bNn] variable ...",
75 		"       sysctl [-bNn] -w variable=value ...",
76 		"       sysctl [-bNn] -a",
77 		"       sysctl [-bNn] -A",
78 		"       sysctl [-bNn] -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, "AabNnwX")) != -1) {
90 		switch (ch) {
91 		case 'A':
92 			Aflag = 1;
93 			break;
94 		case 'a':
95 			aflag = 1;
96 			break;
97 		case 'b':
98 			bflag = 1;
99 			break;
100 		case 'N':
101 			Nflag = 1;
102 			break;
103 		case 'n':
104 			nflag = 1;
105 			break;
106 		case 'w':
107 			wflag = 1;
108 			break;
109 		case 'X':
110 			Xflag = Aflag = 1;
111 			break;
112 		default:
113 			usage();
114 		}
115 	}
116 	argc -= optind;
117 	argv += optind;
118 
119 	if ((wflag && (Aflag || aflag)) || (Nflag && nflag))
120 		usage();
121 	if (Aflag || aflag)
122 		exit (sysctl_all(0, 0));
123 	if (argc == 0)
124 		usage();
125 	while (argc-- > 0)
126 		parse(*argv++);
127 	exit(0);
128 }
129 
130 /*
131  * Parse a name into a MIB entry.
132  * Lookup and print out the MIB entry if it exists.
133  * Set a new value if requested.
134  */
135 static void
136 parse(char *string)
137 {
138 	int len, i, j;
139 	void *newval = 0;
140 	int intval, newsize = 0;
141 	quad_t quadval;
142 	int mib[CTL_MAXNAME];
143 	char *cp, *bufp, buf[BUFSIZ];
144 	u_int kind;
145 
146 	bufp = buf;
147 	snprintf(buf, BUFSIZ, "%s", string);
148 	if ((cp = strchr(string, '=')) != NULL) {
149 		if (!wflag)
150 			errx(2, "must specify -w to set variables");
151 		*strchr(buf, '=') = '\0';
152 		*cp++ = '\0';
153 		while (isspace(*cp))
154 			cp++;
155 		newval = cp;
156 		newsize = strlen(cp);
157 	} else {
158 		if (wflag)
159 			usage();
160 	}
161 	len = name2oid(bufp, mib);
162 
163 	if (len < 0)
164 		errx(1, "unknown oid '%s'", bufp);
165 
166 	if (oidfmt(mib, len, 0, &kind))
167 		err(1, "couldn't find format of oid '%s'", bufp);
168 
169 	if (!wflag) {
170 		if ((kind & CTLTYPE) == CTLTYPE_NODE) {
171 			sysctl_all(mib, len);
172 		} else {
173 			i = show_var(mib, len);
174 			if (!i && !bflag)
175 				putchar('\n');
176 		}
177 	} else {
178 		if ((kind & CTLTYPE) == CTLTYPE_NODE)
179 			errx(1, "oid '%s' isn't a leaf node", bufp);
180 
181 		if (!(kind&CTLFLAG_WR))
182 			errx(1, "oid '%s' is read only", bufp);
183 
184 		switch (kind & CTLTYPE) {
185 			case CTLTYPE_INT:
186 				intval = (int) strtol(newval, NULL, 0);
187 				newval = &intval;
188 				newsize = sizeof intval;
189 				break;
190 				break;
191 			case CTLTYPE_STRING:
192 				break;
193 			case CTLTYPE_QUAD:
194 				break;
195 				sscanf(newval, "%qd", &quadval);
196 				newval = &quadval;
197 				newsize = sizeof quadval;
198 				break;
199 			default:
200 				errx(1, "oid '%s' is type %d,"
201 					" cannot set that", bufp,
202 					kind & CTLTYPE);
203 		}
204 
205 		i = show_var(mib, len);
206 		if (sysctl(mib, len, 0, 0, newval, newsize) == -1) {
207 			if (!i && !bflag)
208 				putchar('\n');
209 			switch (errno) {
210 			case EOPNOTSUPP:
211 				errx(1, "%s: value is not available",
212 					string);
213 			case ENOTDIR:
214 				errx(1, "%s: specification is incomplete",
215 					string);
216 			case ENOMEM:
217 				errx(1, "%s: type is unknown to this program",
218 					string);
219 			default:
220 				warn("%s", string);
221 				return;
222 			}
223 		}
224 		if (!bflag)
225 			printf(" -> ");
226 		i = nflag;
227 		nflag = 1;
228 		j = show_var(mib, len);
229 		if (!j && !bflag)
230 			putchar('\n');
231 		nflag = i;
232 	}
233 }
234 
235 /* These functions will dump out various interesting structures. */
236 
237 static int
238 S_clockinfo(int l2, void *p)
239 {
240 	struct clockinfo *ci = (struct clockinfo*)p;
241 	if (l2 != sizeof *ci)
242 		err(1, "S_clockinfo %d != %d", l2, sizeof *ci);
243 	printf("{ hz = %d, tick = %d, tickadj = %d, profhz = %d, stathz = %d }",
244 		ci->hz, ci->tick, ci->tickadj, ci->profhz, ci->stathz);
245 	return (0);
246 }
247 
248 static int
249 S_loadavg(int l2, void *p)
250 {
251 	struct loadavg *tv = (struct loadavg*)p;
252 
253 	if (l2 != sizeof *tv)
254 		err(1, "S_loadavg %d != %d", l2, sizeof *tv);
255 
256 	printf("{ %.2f %.2f %.2f }",
257 		(double)tv->ldavg[0]/(double)tv->fscale,
258 		(double)tv->ldavg[1]/(double)tv->fscale,
259 		(double)tv->ldavg[2]/(double)tv->fscale);
260 	return (0);
261 }
262 
263 static int
264 S_timeval(int l2, void *p)
265 {
266 	struct timeval *tv = (struct timeval*)p;
267 	time_t tv_sec;
268 	char *p1, *p2;
269 
270 	if (l2 != sizeof *tv)
271 		err(1, "S_timeval %d != %d", l2, sizeof *tv);
272 	printf("{ sec = %ld, usec = %ld } ",
273 		tv->tv_sec, tv->tv_usec);
274 	tv_sec = tv->tv_sec;
275 	p1 = strdup(ctime(&tv_sec));
276 	for (p2=p1; *p2 ; p2++)
277 		if (*p2 == '\n')
278 			*p2 = '\0';
279 	fputs(p1, stdout);
280 	return (0);
281 }
282 
283 static int
284 T_dev_t(int l2, void *p)
285 {
286 	dev_t *d = (dev_t *)p;
287 	if (l2 != sizeof *d)
288 		err(1, "T_dev_T %d != %d", l2, sizeof *d);
289 	if ((int)(*d) != -1) {
290 		if (minor(*d) > 255 || minor(*d) < 0)
291 			printf("{ major = %d, minor = 0x%x }",
292 				major(*d), minor(*d));
293 		else
294 			printf("{ major = %d, minor = %d }",
295 				major(*d), minor(*d));
296 	}
297 	return (0);
298 }
299 
300 /*
301  * These functions uses a presently undocumented interface to the kernel
302  * to walk the tree and get the type so it can print the value.
303  * This interface is under work and consideration, and should probably
304  * be killed with a big axe by the first person who can find the time.
305  * (be aware though, that the proper interface isn't as obvious as it
306  * may seem, there are various conflicting requirements.
307  */
308 
309 static int
310 name2oid(char *name, int *oidp)
311 {
312 	int oid[2];
313 	int i;
314 	size_t j;
315 
316 	oid[0] = 0;
317 	oid[1] = 3;
318 
319 	j = CTL_MAXNAME * sizeof (int);
320 	i = sysctl(oid, 2, oidp, &j, name, strlen(name));
321 	if (i < 0)
322 		return i;
323 	j /= sizeof (int);
324 	return (j);
325 }
326 
327 static int
328 oidfmt(int *oid, int len, char *fmt, u_int *kind)
329 {
330 	int qoid[CTL_MAXNAME+2];
331 	u_char buf[BUFSIZ];
332 	int i;
333 	size_t j;
334 
335 	qoid[0] = 0;
336 	qoid[1] = 4;
337 	memcpy(qoid + 2, oid, len * sizeof(int));
338 
339 	j = sizeof buf;
340 	i = sysctl(qoid, len + 2, buf, &j, 0, 0);
341 	if (i)
342 		err(1, "sysctl fmt %d %d %d", i, j, errno);
343 
344 	if (kind)
345 		*kind = *(u_int *)buf;
346 
347 	if (fmt)
348 		strcpy(fmt, (char *)(buf + sizeof(u_int)));
349 	return 0;
350 }
351 
352 /*
353  * This formats and outputs the value of one variable
354  *
355  * Returns zero if anything was actually output.
356  * Returns one if didn't know what to do with this.
357  * Return minus one if we had errors.
358  */
359 
360 static int
361 show_var(int *oid, int nlen)
362 {
363 	u_char buf[BUFSIZ], *val, *p;
364 	char name[BUFSIZ], descr[BUFSIZ], *fmt;
365 	int qoid[CTL_MAXNAME+2];
366 	int i;
367 	size_t j, len;
368 	u_int kind;
369 	int (*func)(int, void *) = 0;
370 
371 	qoid[0] = 0;
372 	memcpy(qoid + 2, oid, nlen * sizeof(int));
373 
374 	qoid[1] = 1;
375 	j = sizeof name;
376 	i = sysctl(qoid, nlen + 2, name, &j, 0, 0);
377 	if (i || !j)
378 		err(1, "sysctl name %d %d %d", i, j, errno);
379 
380 	if (Nflag) {
381 		printf("%s", name);
382 		return (0);
383 	}
384 
385 	/* find an estimate of how much we need for this var */
386 	j = 0;
387 	i = sysctl(oid, nlen, 0, &j, 0, 0);
388 	j += j; /* we want to be sure :-) */
389 
390 	val = alloca(j);
391 	len = j;
392 	i = sysctl(oid, nlen, val, &len, 0, 0);
393 	if (i || !len)
394 		return (1);
395 
396 	if (bflag) {
397 		fwrite(val, 1, len, stdout);
398 		return (0);
399 	}
400 
401 	qoid[1] = 4;
402 	j = sizeof buf;
403 	i = sysctl(qoid, nlen + 2, buf, &j, 0, 0);
404 	if (i || !j)
405 		err(1, "sysctl fmt %d %d %d", i, j, errno);
406 
407 	kind = *(u_int *)buf;
408 
409 	fmt = (char *)(buf + sizeof(u_int));
410 
411 	p = val;
412 	switch (*fmt) {
413 	case 'A':
414 		if (!nflag)
415 			printf("%s: ", name);
416 		printf("%s", p);
417 		return (0);
418 
419 	case 'I':
420 		if (!nflag)
421 			printf("%s: ", name);
422 		fmt++;
423 		val = "";
424 		while (len >= sizeof(int)) {
425 			if(*fmt == 'U')
426 				printf("%s%u", val, *(unsigned int *)p);
427 			else
428 				printf("%s%d", val, *(int *)p);
429 			val = " ";
430 			len -= sizeof (int);
431 			p += sizeof (int);
432 		}
433 		return (0);
434 
435 	case 'L':
436 		if (!nflag)
437 			printf("%s: ", name);
438 		fmt++;
439 		val = "";
440 		while (len >= sizeof(long)) {
441 			if(*fmt == 'U')
442 				printf("%s%lu", val, *(unsigned long *)p);
443 			else
444 				printf("%s%ld", val, *(long *)p);
445 			val = " ";
446 			len -= sizeof (long);
447 			p += sizeof (long);
448 		}
449 		return (0);
450 
451 	case 'P':
452 		if (!nflag)
453 			printf("%s: ", name);
454 		printf("%p", *(void **)p);
455 		return (0);
456 
457 	case 'T':
458 	case 'S':
459 		i = 0;
460 		if (!strcmp(fmt, "S,clockinfo"))	func = S_clockinfo;
461 		else if (!strcmp(fmt, "S,timeval"))	func = S_timeval;
462 		else if (!strcmp(fmt, "S,loadavg"))	func = S_loadavg;
463 		else if (!strcmp(fmt, "T,dev_t"))	func = T_dev_t;
464 		if (func) {
465 			if (!nflag)
466 				printf("%s: ", name);
467 			return ((*func)(len, p));
468 		}
469 		/* FALL THROUGH */
470 	default:
471 		if (!Aflag)
472 			return (1);
473 		if (!nflag)
474 			printf("%s: ", name);
475 		printf("Format:%s Length:%d Dump:0x", fmt, len);
476 		while (len--) {
477 			printf("%02x", *p++);
478 			if (Xflag || p < val+16)
479 				continue;
480 			printf("...");
481 			break;
482 		}
483 		return (0);
484 	}
485 	return (1);
486 }
487 
488 static int
489 sysctl_all (int *oid, int len)
490 {
491 	int name1[22], name2[22];
492 	int i, j;
493 	size_t l1, l2;
494 
495 	name1[0] = 0;
496 	name1[1] = 2;
497 	l1 = 2;
498 	if (len) {
499 		memcpy(name1+2, oid, len*sizeof (int));
500 		l1 += len;
501 	} else {
502 		name1[2] = 1;
503 		l1++;
504 	}
505 	while (1) {
506 		l2 = sizeof name2;
507 		j = sysctl(name1, l1, name2, &l2, 0, 0);
508 		if (j < 0) {
509 			if (errno == ENOENT)
510 				return 0;
511 			else
512 				err(1, "sysctl(getnext) %d %d", j, l2);
513 		}
514 
515 		l2 /= sizeof (int);
516 
517 		if (l2 < len)
518 			return 0;
519 
520 		for (i = 0; i < len; i++)
521 			if (name2[i] != oid[i])
522 				return 0;
523 
524 		i = show_var(name2, l2);
525 		if (!i && !bflag)
526 			putchar('\n');
527 
528 		memcpy(name1+2, name2, l2*sizeof (int));
529 		l1 = 2 + l2;
530 	}
531 }
532