xref: /freebsd/sbin/sysctl/sysctl.c (revision 1b6c76a2fe091c74f08427e6c870851025a9cf67)
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, bflag, Nflag, nflag, oflag, 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",
74 	    "usage: sysctl [-bNnox] variable[=value] ...",
75 	    "       sysctl [-bNnox] -a");
76 	exit(1);
77 }
78 
79 int
80 main(int argc, char **argv)
81 {
82 	int ch;
83 	setbuf(stdout,0);
84 	setbuf(stderr,0);
85 
86 	while ((ch = getopt(argc, argv, "AabNnowxX")) != -1) {
87 		switch (ch) {
88 		case 'A':
89 			/* compatibility */
90 			aflag = oflag = 1;
91 			break;
92 		case 'a':
93 			aflag = 1;
94 			break;
95 		case 'b':
96 			bflag = 1;
97 			break;
98 		case 'N':
99 			Nflag = 1;
100 			break;
101 		case 'n':
102 			nflag = 1;
103 			break;
104 		case 'o':
105 			oflag = 1;
106 			break;
107 		case 'w':
108 			/* compatibility */
109 			/* ignored */
110 			break;
111 		case 'X':
112 			/* compatibility */
113 			aflag = xflag = 1;
114 			break;
115 		case 'x':
116 			xflag = 1;
117 			break;
118 		default:
119 			usage();
120 		}
121 	}
122 	argc -= optind;
123 	argv += optind;
124 
125 	if (Nflag && nflag)
126 		usage();
127 	if (aflag && argc == 0)
128 		exit(sysctl_all(0, 0));
129 	if (argc == 0)
130 		usage();
131 	while (argc-- > 0)
132 		parse(*argv++);
133 	exit(0);
134 }
135 
136 /*
137  * Parse a name into a MIB entry.
138  * Lookup and print out the MIB entry if it exists.
139  * Set a new value if requested.
140  */
141 static void
142 parse(char *string)
143 {
144 	int len, i, j;
145 	void *newval = 0;
146 	int intval;
147 	unsigned int uintval;
148 	long longval;
149 	unsigned long ulongval;
150 	size_t newsize = 0;
151 	quad_t quadval;
152 	int mib[CTL_MAXNAME];
153 	char *cp, *bufp, buf[BUFSIZ];
154 	u_int kind;
155 
156 	bufp = buf;
157 	snprintf(buf, BUFSIZ, "%s", string);
158 	if ((cp = strchr(string, '=')) != NULL) {
159 		*strchr(buf, '=') = '\0';
160 		*cp++ = '\0';
161 		while (isspace(*cp))
162 			cp++;
163 		newval = cp;
164 		newsize = strlen(cp);
165 	}
166 	len = name2oid(bufp, mib);
167 
168 	if (len < 0)
169 		errx(1, "unknown oid '%s'", bufp);
170 
171 	if (oidfmt(mib, len, 0, &kind))
172 		err(1, "couldn't find format of oid '%s'", bufp);
173 
174 	if (newval == NULL) {
175 		if ((kind & CTLTYPE) == CTLTYPE_NODE) {
176 			sysctl_all(mib, len);
177 		} else {
178 			i = show_var(mib, len);
179 			if (!i && !bflag)
180 				putchar('\n');
181 		}
182 	} else {
183 		if ((kind & CTLTYPE) == CTLTYPE_NODE)
184 			errx(1, "oid '%s' isn't a leaf node", bufp);
185 
186 		if (!(kind&CTLFLAG_WR))
187 			errx(1, "oid '%s' is read only", bufp);
188 
189 		switch (kind & CTLTYPE) {
190 			case CTLTYPE_INT:
191 				intval = (int) strtol(newval, NULL, 0);
192 				newval = &intval;
193 				newsize = sizeof(intval);
194 				break;
195 			case CTLTYPE_UINT:
196 				uintval = (int) strtoul(newval, NULL, 0);
197 				newval = &uintval;
198 				newsize = sizeof uintval;
199 				break;
200 			case CTLTYPE_LONG:
201 				longval = strtol(newval, NULL, 0);
202 				newval = &longval;
203 				newsize = sizeof longval;
204 				break;
205 			case CTLTYPE_ULONG:
206 				ulongval = strtoul(newval, NULL, 0);
207 				newval = &ulongval;
208 				newsize = sizeof ulongval;
209 				break;
210 			case CTLTYPE_STRING:
211 				break;
212 			case CTLTYPE_QUAD:
213 				break;
214 				sscanf(newval, "%qd", &quadval);
215 				newval = &quadval;
216 				newsize = sizeof(quadval);
217 				break;
218 			default:
219 				errx(1, "oid '%s' is type %d,"
220 					" cannot set that", bufp,
221 					kind & CTLTYPE);
222 		}
223 
224 		i = show_var(mib, len);
225 		if (sysctl(mib, len, 0, 0, newval, newsize) == -1) {
226 			if (!i && !bflag)
227 				putchar('\n');
228 			switch (errno) {
229 			case EOPNOTSUPP:
230 				errx(1, "%s: value is not available",
231 					string);
232 			case ENOTDIR:
233 				errx(1, "%s: specification is incomplete",
234 					string);
235 			case ENOMEM:
236 				errx(1, "%s: type is unknown to this program",
237 					string);
238 			default:
239 				warn("%s", string);
240 				return;
241 			}
242 		}
243 		if (!bflag)
244 			printf(" -> ");
245 		i = nflag;
246 		nflag = 1;
247 		j = show_var(mib, len);
248 		if (!j && !bflag)
249 			putchar('\n');
250 		nflag = i;
251 	}
252 }
253 
254 /* These functions will dump out various interesting structures. */
255 
256 static int
257 S_clockinfo(int l2, void *p)
258 {
259 	struct clockinfo *ci = (struct clockinfo*)p;
260 	if (l2 != sizeof(*ci))
261 		err(1, "S_clockinfo %d != %d", l2, sizeof(*ci));
262 	printf("{ hz = %d, tick = %d, tickadj = %d, profhz = %d, stathz = %d }",
263 		ci->hz, ci->tick, ci->tickadj, ci->profhz, ci->stathz);
264 	return (0);
265 }
266 
267 static int
268 S_loadavg(int l2, void *p)
269 {
270 	struct loadavg *tv = (struct loadavg*)p;
271 
272 	if (l2 != sizeof(*tv))
273 		err(1, "S_loadavg %d != %d", l2, sizeof(*tv));
274 
275 	printf("{ %.2f %.2f %.2f }",
276 		(double)tv->ldavg[0]/(double)tv->fscale,
277 		(double)tv->ldavg[1]/(double)tv->fscale,
278 		(double)tv->ldavg[2]/(double)tv->fscale);
279 	return (0);
280 }
281 
282 static int
283 S_timeval(int l2, void *p)
284 {
285 	struct timeval *tv = (struct timeval*)p;
286 	time_t tv_sec;
287 	char *p1, *p2;
288 
289 	if (l2 != sizeof(*tv))
290 		err(1, "S_timeval %d != %d", l2, sizeof(*tv));
291 	printf("{ sec = %ld, usec = %ld } ",
292 		tv->tv_sec, tv->tv_usec);
293 	tv_sec = tv->tv_sec;
294 	p1 = strdup(ctime(&tv_sec));
295 	for (p2=p1; *p2 ; p2++)
296 		if (*p2 == '\n')
297 			*p2 = '\0';
298 	fputs(p1, stdout);
299 	return (0);
300 }
301 
302 static int
303 T_dev_t(int l2, void *p)
304 {
305 	dev_t *d = (dev_t *)p;
306 	if (l2 != sizeof(*d))
307 		err(1, "T_dev_T %d != %d", l2, sizeof(*d));
308 	if ((int)(*d) != -1) {
309 		if (minor(*d) > 255 || minor(*d) < 0)
310 			printf("{ major = %d, minor = 0x%x }",
311 				major(*d), minor(*d));
312 		else
313 			printf("{ major = %d, minor = %d }",
314 				major(*d), minor(*d));
315 	}
316 	return (0);
317 }
318 
319 /*
320  * These functions uses a presently undocumented interface to the kernel
321  * to walk the tree and get the type so it can print the value.
322  * This interface is under work and consideration, and should probably
323  * be killed with a big axe by the first person who can find the time.
324  * (be aware though, that the proper interface isn't as obvious as it
325  * may seem, there are various conflicting requirements.
326  */
327 
328 static int
329 name2oid(char *name, int *oidp)
330 {
331 	int oid[2];
332 	int i;
333 	size_t j;
334 
335 	oid[0] = 0;
336 	oid[1] = 3;
337 
338 	j = CTL_MAXNAME * sizeof(int);
339 	i = sysctl(oid, 2, oidp, &j, name, strlen(name));
340 	if (i < 0)
341 		return i;
342 	j /= sizeof(int);
343 	return (j);
344 }
345 
346 static int
347 oidfmt(int *oid, int len, char *fmt, u_int *kind)
348 {
349 	int qoid[CTL_MAXNAME+2];
350 	u_char buf[BUFSIZ];
351 	int i;
352 	size_t j;
353 
354 	qoid[0] = 0;
355 	qoid[1] = 4;
356 	memcpy(qoid + 2, oid, len * sizeof(int));
357 
358 	j = sizeof(buf);
359 	i = sysctl(qoid, len + 2, buf, &j, 0, 0);
360 	if (i)
361 		err(1, "sysctl fmt %d %d %d", i, j, errno);
362 
363 	if (kind)
364 		*kind = *(u_int *)buf;
365 
366 	if (fmt)
367 		strcpy(fmt, (char *)(buf + sizeof(u_int)));
368 	return 0;
369 }
370 
371 /*
372  * This formats and outputs the value of one variable
373  *
374  * Returns zero if anything was actually output.
375  * Returns one if didn't know what to do with this.
376  * Return minus one if we had errors.
377  */
378 
379 static int
380 show_var(int *oid, int nlen)
381 {
382 	u_char buf[BUFSIZ], *val, *p;
383 	char name[BUFSIZ], *fmt;
384 	int qoid[CTL_MAXNAME+2];
385 	int i;
386 	size_t j, len;
387 	u_int kind;
388 	int (*func)(int, void *);
389 
390 	qoid[0] = 0;
391 	memcpy(qoid + 2, oid, nlen * sizeof(int));
392 
393 	qoid[1] = 1;
394 	j = sizeof(name);
395 	i = sysctl(qoid, nlen + 2, name, &j, 0, 0);
396 	if (i || !j)
397 		err(1, "sysctl name %d %d %d", i, j, errno);
398 
399 	if (Nflag) {
400 		printf("%s", name);
401 		return (0);
402 	}
403 
404 	/* find an estimate of how much we need for this var */
405 	j = 0;
406 	i = sysctl(oid, nlen, 0, &j, 0, 0);
407 	j += j; /* we want to be sure :-) */
408 
409 	val = alloca(j);
410 	len = j;
411 	i = sysctl(oid, nlen, val, &len, 0, 0);
412 	if (i || !len)
413 		return (1);
414 
415 	if (bflag) {
416 		fwrite(val, 1, len, stdout);
417 		return (0);
418 	}
419 
420 	qoid[1] = 4;
421 	j = sizeof(buf);
422 	i = sysctl(qoid, nlen + 2, buf, &j, 0, 0);
423 	if (i || !j)
424 		err(1, "sysctl fmt %d %d %d", i, j, errno);
425 
426 	kind = *(u_int *)buf;
427 
428 	fmt = (char *)(buf + sizeof(u_int));
429 
430 	p = val;
431 	switch (*fmt) {
432 	case 'A':
433 		if (!nflag)
434 			printf("%s: ", name);
435 		printf("%s", p);
436 		return (0);
437 
438 	case 'I':
439 		if (!nflag)
440 			printf("%s: ", name);
441 		fmt++;
442 		val = "";
443 		while (len >= sizeof(int)) {
444 			if(*fmt == 'U')
445 				printf("%s%u", val, *(unsigned int *)p);
446 			else
447 				printf("%s%d", val, *(int *)p);
448 			val = " ";
449 			len -= sizeof(int);
450 			p += sizeof(int);
451 		}
452 		return (0);
453 
454 	case 'L':
455 		if (!nflag)
456 			printf("%s: ", name);
457 		fmt++;
458 		val = "";
459 		while (len >= sizeof(long)) {
460 			if(*fmt == 'U')
461 				printf("%s%lu", val, *(unsigned long *)p);
462 			else
463 				printf("%s%ld", val, *(long *)p);
464 			val = " ";
465 			len -= sizeof(long);
466 			p += sizeof(long);
467 		}
468 		return (0);
469 
470 	case 'P':
471 		if (!nflag)
472 			printf("%s: ", name);
473 		printf("%p", *(void **)p);
474 		return (0);
475 
476 	case 'T':
477 	case 'S':
478 		i = 0;
479 		if (strcmp(fmt, "S,clockinfo") == 0)
480 			func = S_clockinfo;
481 		else if (strcmp(fmt, "S,timeval") == 0)
482 			func = S_timeval;
483 		else if (strcmp(fmt, "S,loadavg") == 0)
484 			func = S_loadavg;
485 		else if (strcmp(fmt, "T,dev_t") == 0)
486 			func = T_dev_t;
487 		else
488 			func = NULL;
489 		if (func) {
490 			if (!nflag)
491 				printf("%s: ", name);
492 			return ((*func)(len, p));
493 		}
494 		/* FALL THROUGH */
495 	default:
496 		if (!oflag && !xflag)
497 			return (1);
498 		if (!nflag)
499 			printf("%s: ", name);
500 		printf("Format:%s Length:%d Dump:0x", fmt, len);
501 		while (len-- && (xflag || p < val + 16))
502 			printf("%02x", *p++);
503 		if (!xflag && len > 16)
504 			printf("...");
505 		return (0);
506 	}
507 	return (1);
508 }
509 
510 static int
511 sysctl_all (int *oid, int len)
512 {
513 	int name1[22], name2[22];
514 	int i, j;
515 	size_t l1, l2;
516 
517 	name1[0] = 0;
518 	name1[1] = 2;
519 	l1 = 2;
520 	if (len) {
521 		memcpy(name1+2, oid, len * sizeof(int));
522 		l1 += len;
523 	} else {
524 		name1[2] = 1;
525 		l1++;
526 	}
527 	for (;;) {
528 		l2 = sizeof(name2);
529 		j = sysctl(name1, l1, name2, &l2, 0, 0);
530 		if (j < 0) {
531 			if (errno == ENOENT)
532 				return 0;
533 			else
534 				err(1, "sysctl(getnext) %d %d", j, l2);
535 		}
536 
537 		l2 /= sizeof(int);
538 
539 		if (l2 < len)
540 			return 0;
541 
542 		for (i = 0; i < len; i++)
543 			if (name2[i] != oid[i])
544 				return 0;
545 
546 		i = show_var(name2, l2);
547 		if (!i && !bflag)
548 			putchar('\n');
549 
550 		memcpy(name1+2, name2, l2 * sizeof(int));
551 		l1 = 2 + l2;
552 	}
553 }
554