xref: /freebsd/sbin/sysctl/sysctl.c (revision 3047fefe49f57a673de8df152c199de12ec2c6d3)
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 #ifdef __i386__
49 #include <sys/diskslice.h>	/* used for bootdev parsing */
50 #include <sys/reboot.h>		/* used for bootdev parsing */
51 #endif
52 #include <sys/param.h>
53 #include <sys/time.h>
54 #include <sys/resource.h>
55 #include <sys/stat.h>
56 #include <sys/sysctl.h>
57 
58 #include <ctype.h>
59 #include <err.h>
60 #include <errno.h>
61 #include <stdio.h>
62 #include <stdlib.h>
63 #include <string.h>
64 #include <unistd.h>
65 
66 static int	aflag, bflag, dflag, eflag, Nflag, nflag, oflag, xflag;
67 
68 static int	oidfmt(int *, int, char *, u_int *);
69 static void	parse(char *);
70 static int	show_var(int *, int);
71 static int	sysctl_all (int *oid, int len);
72 static int	name2oid(char *, int *);
73 
74 static void	set_T_dev_t (char *, void **, int *);
75 
76 static void
77 usage(void)
78 {
79 
80 	(void)fprintf(stderr, "%s\n%s\n",
81 	    "usage: sysctl [-bdeNnox] variable[=value] ...",
82 	    "       sysctl [-bdeNnox] -a");
83 	exit(1);
84 }
85 
86 int
87 main(int argc, char **argv)
88 {
89 	int ch;
90 	setbuf(stdout,0);
91 	setbuf(stderr,0);
92 
93 	while ((ch = getopt(argc, argv, "AabdeNnowxX")) != -1) {
94 		switch (ch) {
95 		case 'A':
96 			/* compatibility */
97 			aflag = oflag = 1;
98 			break;
99 		case 'a':
100 			aflag = 1;
101 			break;
102 		case 'b':
103 			bflag = 1;
104 			break;
105 		case 'd':
106 			dflag = 1;
107 			break;
108 		case 'e':
109 			eflag = 1;
110 			break;
111 		case 'N':
112 			Nflag = 1;
113 			break;
114 		case 'n':
115 			nflag = 1;
116 			break;
117 		case 'o':
118 			oflag = 1;
119 			break;
120 		case 'w':
121 			/* compatibility */
122 			/* ignored */
123 			break;
124 		case 'X':
125 			/* compatibility */
126 			aflag = xflag = 1;
127 			break;
128 		case 'x':
129 			xflag = 1;
130 			break;
131 		default:
132 			usage();
133 		}
134 	}
135 	argc -= optind;
136 	argv += optind;
137 
138 	if (Nflag && nflag)
139 		usage();
140 	if (aflag && argc == 0)
141 		exit(sysctl_all(0, 0));
142 	if (argc == 0)
143 		usage();
144 	while (argc-- > 0)
145 		parse(*argv++);
146 	exit(0);
147 }
148 
149 /*
150  * Parse a name into a MIB entry.
151  * Lookup and print out the MIB entry if it exists.
152  * Set a new value if requested.
153  */
154 static void
155 parse(char *string)
156 {
157 	int len, i, j;
158 	void *newval = 0;
159 	int intval;
160 	unsigned int uintval;
161 	long longval;
162 	unsigned long ulongval;
163 	size_t newsize = 0;
164 	quad_t quadval;
165 	int mib[CTL_MAXNAME];
166 	char *cp, *bufp, buf[BUFSIZ], fmt[BUFSIZ];
167 	u_int kind;
168 
169 	bufp = buf;
170 	snprintf(buf, BUFSIZ, "%s", string);
171 	if ((cp = strchr(string, '=')) != NULL) {
172 		*strchr(buf, '=') = '\0';
173 		*cp++ = '\0';
174 		while (isspace(*cp))
175 			cp++;
176 		newval = cp;
177 		newsize = strlen(cp);
178 	}
179 	len = name2oid(bufp, mib);
180 
181 	if (len < 0)
182 		errx(1, "unknown oid '%s'", bufp);
183 
184 	if (oidfmt(mib, len, fmt, &kind))
185 		err(1, "couldn't find format of oid '%s'", bufp);
186 
187 	if (newval == NULL) {
188 		if ((kind & CTLTYPE) == CTLTYPE_NODE) {
189 			sysctl_all(mib, len);
190 		} else {
191 			i = show_var(mib, len);
192 			if (!i && !bflag)
193 				putchar('\n');
194 		}
195 	} else {
196 		if ((kind & CTLTYPE) == CTLTYPE_NODE)
197 			errx(1, "oid '%s' isn't a leaf node", bufp);
198 
199 		if (!(kind&CTLFLAG_WR))
200 			errx(1, "oid '%s' is read only", bufp);
201 
202 		switch (kind & CTLTYPE) {
203 			case CTLTYPE_INT:
204 				intval = (int) strtol(newval, NULL, 0);
205 				newval = &intval;
206 				newsize = sizeof(intval);
207 				break;
208 			case CTLTYPE_UINT:
209 				uintval = (int) strtoul(newval, NULL, 0);
210 				newval = &uintval;
211 				newsize = sizeof uintval;
212 				break;
213 			case CTLTYPE_LONG:
214 				longval = strtol(newval, NULL, 0);
215 				newval = &longval;
216 				newsize = sizeof longval;
217 				break;
218 			case CTLTYPE_ULONG:
219 				ulongval = strtoul(newval, NULL, 0);
220 				newval = &ulongval;
221 				newsize = sizeof ulongval;
222 				break;
223 			case CTLTYPE_STRING:
224 				break;
225 			case CTLTYPE_QUAD:
226 				sscanf(newval, "%qd", &quadval);
227 				newval = &quadval;
228 				newsize = sizeof(quadval);
229 				break;
230 			case CTLTYPE_OPAQUE:
231 				if (strcmp(fmt, "T,dev_t") == 0) {
232 					set_T_dev_t ((char*)newval, &newval, &newsize);
233 					break;
234 				}
235 				/* FALLTHROUGH */
236 			default:
237 				errx(1, "oid '%s' is type %d,"
238 					" cannot set that", bufp,
239 					kind & CTLTYPE);
240 		}
241 
242 		i = show_var(mib, len);
243 		if (sysctl(mib, len, 0, 0, newval, newsize) == -1) {
244 			if (!i && !bflag)
245 				putchar('\n');
246 			switch (errno) {
247 			case EOPNOTSUPP:
248 				errx(1, "%s: value is not available",
249 					string);
250 			case ENOTDIR:
251 				errx(1, "%s: specification is incomplete",
252 					string);
253 			case ENOMEM:
254 				errx(1, "%s: type is unknown to this program",
255 					string);
256 			default:
257 				warn("%s", string);
258 				return;
259 			}
260 		}
261 		if (!bflag)
262 			printf(" -> ");
263 		i = nflag;
264 		nflag = 1;
265 		j = show_var(mib, len);
266 		if (!j && !bflag)
267 			putchar('\n');
268 		nflag = i;
269 	}
270 }
271 
272 /* These functions will dump out various interesting structures. */
273 
274 static int
275 S_clockinfo(int l2, void *p)
276 {
277 	struct clockinfo *ci = (struct clockinfo*)p;
278 	if (l2 != sizeof(*ci)) {
279 		warnx("S_clockinfo %d != %d", l2, sizeof(*ci));
280 		return (0);
281 	}
282 	printf("{ hz = %d, tick = %d, profhz = %d, stathz = %d }",
283 		ci->hz, ci->tick, ci->profhz, ci->stathz);
284 	return (0);
285 }
286 
287 static int
288 S_loadavg(int l2, void *p)
289 {
290 	struct loadavg *tv = (struct loadavg*)p;
291 
292 	if (l2 != sizeof(*tv)) {
293 		warnx("S_loadavg %d != %d", l2, sizeof(*tv));
294 		return (0);
295 	}
296 	printf("{ %.2f %.2f %.2f }",
297 		(double)tv->ldavg[0]/(double)tv->fscale,
298 		(double)tv->ldavg[1]/(double)tv->fscale,
299 		(double)tv->ldavg[2]/(double)tv->fscale);
300 	return (0);
301 }
302 
303 static int
304 S_timeval(int l2, void *p)
305 {
306 	struct timeval *tv = (struct timeval*)p;
307 	time_t tv_sec;
308 	char *p1, *p2;
309 
310 	if (l2 != sizeof(*tv)) {
311 		warnx("S_timeval %d != %d", l2, sizeof(*tv));
312 		return (0);
313 	}
314 	printf("{ sec = %ld, usec = %ld } ",
315 		tv->tv_sec, tv->tv_usec);
316 	tv_sec = tv->tv_sec;
317 	p1 = strdup(ctime(&tv_sec));
318 	for (p2=p1; *p2 ; p2++)
319 		if (*p2 == '\n')
320 			*p2 = '\0';
321 	fputs(p1, stdout);
322 	return (0);
323 }
324 
325 static int
326 T_dev_t(int l2, void *p)
327 {
328 	dev_t *d = (dev_t *)p;
329 	if (l2 != sizeof(*d)) {
330 		warnx("T_dev_T %d != %d", l2, sizeof(*d));
331 		return (0);
332 	}
333 	if ((int)(*d) != -1) {
334 		if (minor(*d) > 255 || minor(*d) < 0)
335 			printf("{ major = %d, minor = 0x%x }",
336 				major(*d), minor(*d));
337 		else
338 			printf("{ major = %d, minor = %d }",
339 				major(*d), minor(*d));
340 	}
341 	return (0);
342 }
343 
344 static void
345 set_T_dev_t (char *path, void **val, int *size)
346 {
347 	static struct stat statb;
348 
349 	if (strcmp(path, "none") && strcmp(path, "off")) {
350 		int rc = stat (path, &statb);
351 		if (rc) {
352 			err(1, "cannot stat %s", path);
353 		}
354 
355 		if (!S_ISCHR(statb.st_mode)) {
356 			errx(1, "must specify a device special file.");
357 		}
358 	} else {
359 		statb.st_rdev = NODEV;
360 	}
361 	*val = (char*) &statb.st_rdev;
362 	*size = sizeof statb.st_rdev;
363 }
364 
365 /*
366  * These functions uses a presently undocumented interface to the kernel
367  * to walk the tree and get the type so it can print the value.
368  * This interface is under work and consideration, and should probably
369  * be killed with a big axe by the first person who can find the time.
370  * (be aware though, that the proper interface isn't as obvious as it
371  * may seem, there are various conflicting requirements.
372  */
373 
374 static int
375 name2oid(char *name, int *oidp)
376 {
377 	int oid[2];
378 	int i;
379 	size_t j;
380 
381 	oid[0] = 0;
382 	oid[1] = 3;
383 
384 	j = CTL_MAXNAME * sizeof(int);
385 	i = sysctl(oid, 2, oidp, &j, name, strlen(name));
386 	if (i < 0)
387 		return i;
388 	j /= sizeof(int);
389 	return (j);
390 }
391 
392 static int
393 oidfmt(int *oid, int len, char *fmt, u_int *kind)
394 {
395 	int qoid[CTL_MAXNAME+2];
396 	u_char buf[BUFSIZ];
397 	int i;
398 	size_t j;
399 
400 	qoid[0] = 0;
401 	qoid[1] = 4;
402 	memcpy(qoid + 2, oid, len * sizeof(int));
403 
404 	j = sizeof(buf);
405 	i = sysctl(qoid, len + 2, buf, &j, 0, 0);
406 	if (i)
407 		err(1, "sysctl fmt %d %d %d", i, j, errno);
408 
409 	if (kind)
410 		*kind = *(u_int *)buf;
411 
412 	if (fmt)
413 		strcpy(fmt, (char *)(buf + sizeof(u_int)));
414 	return 0;
415 }
416 
417 #ifdef __i386__
418 /*
419  * Code to map a bootdev major number into a suitable device name.
420  * Major numbers are mapped into names as in boot2.c
421  */
422 struct _foo {
423 	int majdev;
424 	char *name;
425 } maj2name[] = {
426 	30,	"ad",
427 	0,	"wd",
428 	1,	"wfd",
429 	2,	"fd",
430 	4,	"da",
431 	-1,	NULL	/* terminator */
432 };
433 
434 static int
435 machdep_bootdev(u_long value)
436 {
437 	int majdev, unit, slice, part;
438 	struct _foo *p;
439 
440 	if (value & B_MAGICMASK != B_DEVMAGIC) {
441 		printf("invalid (0x%08x)", value);
442 		return 0;
443 	}
444 	majdev = B_TYPE(value);
445 	unit = B_UNIT(value);
446 	slice = B_SLICE(value);
447 	part = B_PARTITION(value);
448 	if (majdev == 2) {	/* floppy, as known to the boot block... */
449 		printf("/dev/fd%d", unit);
450 		return 0;
451 	}
452 	for (p = maj2name; p->name != NULL && p->majdev != majdev ; p++) ;
453 	if (p->name != NULL) {	/* found */
454 		if (slice == WHOLE_DISK_SLICE)
455 			printf("/dev/%s%d%c", p->name, unit, part);
456 		else
457 			printf("/dev/%s%ds%d%c",
458 			    p->name, unit, slice - BASE_SLICE + 1, part + 'a');
459 	} else
460 		printf("unknown (major %d unit %d slice %d part %d)",
461 			majdev, unit, slice, part);
462 	return 0;
463 }
464 #endif
465 
466 /*
467  * This formats and outputs the value of one variable
468  *
469  * Returns zero if anything was actually output.
470  * Returns one if didn't know what to do with this.
471  * Return minus one if we had errors.
472  */
473 
474 static int
475 show_var(int *oid, int nlen)
476 {
477 	u_char buf[BUFSIZ], *val, *p;
478 	char name[BUFSIZ], *fmt, *sep;
479 	int qoid[CTL_MAXNAME+2];
480 	int i;
481 	size_t j, len;
482 	u_int kind;
483 	int (*func)(int, void *);
484 
485 	qoid[0] = 0;
486 	memcpy(qoid + 2, oid, nlen * sizeof(int));
487 
488 	qoid[1] = 1;
489 	j = sizeof(name);
490 	i = sysctl(qoid, nlen + 2, name, &j, 0, 0);
491 	if (i || !j)
492 		err(1, "sysctl name %d %d %d", i, j, errno);
493 
494 	if (Nflag) {
495 		printf("%s", name);
496 		return (0);
497 	}
498 
499 	if (eflag)
500 		sep = "=";
501 	else
502 		sep = ": ";
503 
504 	if (dflag) {	/* just print description */
505 		qoid[1] = 5;
506 		j = sizeof(buf);
507 		i = sysctl(qoid, nlen + 2, buf, &j, 0, 0);
508 		if (!nflag)
509 			printf("%s%s", name, sep);
510 		printf("%s", buf);
511 		return (0);
512 	}
513 	/* find an estimate of how much we need for this var */
514 	j = 0;
515 	i = sysctl(oid, nlen, 0, &j, 0, 0);
516 	j += j; /* we want to be sure :-) */
517 
518 	val = alloca(j);
519 	len = j;
520 	i = sysctl(oid, nlen, val, &len, 0, 0);
521 	if (i || !len)
522 		return (1);
523 
524 	if (bflag) {
525 		fwrite(val, 1, len, stdout);
526 		return (0);
527 	}
528 	val[len] = '\0';
529 	fmt = buf;
530 	oidfmt(oid, nlen, fmt, &kind);
531 	p = val;
532 	switch (*fmt) {
533 	case 'A':
534 		if (!nflag)
535 			printf("%s%s", name, sep);
536 		printf("%s", p);
537 		return (0);
538 
539 	case 'I':
540 		if (!nflag)
541 			printf("%s%s", name, sep);
542 		fmt++;
543 		val = "";
544 		while (len >= sizeof(int)) {
545 			if(*fmt == 'U')
546 				printf("%s%u", val, *(unsigned int *)p);
547 			else
548 				printf("%s%d", val, *(int *)p);
549 			val = " ";
550 			len -= sizeof(int);
551 			p += sizeof(int);
552 		}
553 		return (0);
554 
555 	case 'L':
556 		if (!nflag)
557 			printf("%s%s", name, sep);
558 		fmt++;
559 #ifdef __i386__
560 		if (!strcmp(name, "machdep.guessed_bootdev"))
561 			return machdep_bootdev(*(unsigned long *)p);
562 #endif
563 		val = "";
564 		while (len >= sizeof(long)) {
565 			if(*fmt == 'U')
566 				printf("%s%lu", val, *(unsigned long *)p);
567 			else
568 				printf("%s%ld", val, *(long *)p);
569 			val = " ";
570 			len -= sizeof(long);
571 			p += sizeof(long);
572 		}
573 		return (0);
574 
575 	case 'P':
576 		if (!nflag)
577 			printf("%s%s", name, sep);
578 		printf("%p", *(void **)p);
579 		return (0);
580 
581 	case 'T':
582 	case 'S':
583 		i = 0;
584 		if (strcmp(fmt, "S,clockinfo") == 0)
585 			func = S_clockinfo;
586 		else if (strcmp(fmt, "S,timeval") == 0)
587 			func = S_timeval;
588 		else if (strcmp(fmt, "S,loadavg") == 0)
589 			func = S_loadavg;
590 		else if (strcmp(fmt, "T,dev_t") == 0)
591 			func = T_dev_t;
592 		else
593 			func = NULL;
594 		if (func) {
595 			if (!nflag)
596 				printf("%s%s", name, sep);
597 			return ((*func)(len, p));
598 		}
599 		/* FALLTHROUGH */
600 	default:
601 		if (!oflag && !xflag)
602 			return (1);
603 		if (!nflag)
604 			printf("%s%s", name, sep);
605 		printf("Format:%s Length:%d Dump:0x", fmt, len);
606 		while (len-- && (xflag || p < val + 16))
607 			printf("%02x", *p++);
608 		if (!xflag && len > 16)
609 			printf("...");
610 		return (0);
611 	}
612 	return (1);
613 }
614 
615 static int
616 sysctl_all (int *oid, int len)
617 {
618 	int name1[22], name2[22];
619 	int i, j;
620 	size_t l1, l2;
621 
622 	name1[0] = 0;
623 	name1[1] = 2;
624 	l1 = 2;
625 	if (len) {
626 		memcpy(name1+2, oid, len * sizeof(int));
627 		l1 += len;
628 	} else {
629 		name1[2] = 1;
630 		l1++;
631 	}
632 	for (;;) {
633 		l2 = sizeof(name2);
634 		j = sysctl(name1, l1, name2, &l2, 0, 0);
635 		if (j < 0) {
636 			if (errno == ENOENT)
637 				return 0;
638 			else
639 				err(1, "sysctl(getnext) %d %d", j, l2);
640 		}
641 
642 		l2 /= sizeof(int);
643 
644 		if (l2 < len)
645 			return 0;
646 
647 		for (i = 0; i < len; i++)
648 			if (name2[i] != oid[i])
649 				return 0;
650 
651 		i = show_var(name2, l2);
652 		if (!i && !bflag)
653 			putchar('\n');
654 
655 		memcpy(name1+2, name2, l2 * sizeof(int));
656 		l1 = 2 + l2;
657 	}
658 }
659