xref: /freebsd/sbin/sysctl/sysctl.c (revision 77a0943ded95b9e6438f7db70c4a28e4d93946d4)
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, 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 [-bn] variable ...",
75 		"       sysctl [-bn] -w variable=value ...",
76 		"       sysctl [-bn] -a",
77 		"       sysctl [-bn] -A",
78 		"       sysctl [-bn] -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, "AabnwX")) != -1) {
90 		switch (ch) {
91 		case 'A': Aflag = 1; break;
92 		case 'a': aflag = 1; break;
93 		case 'b': bflag = 1; break;
94 		case 'n': nflag = 1; break;
95 		case 'w': wflag = 1; break;
96 		case 'X': Xflag = Aflag = 1; break;
97 		default: usage();
98 		}
99 	}
100 	argc -= optind;
101 	argv += optind;
102 
103 	if (wflag && (Aflag || aflag))
104 		usage();
105 	if (Aflag || aflag)
106 		exit (sysctl_all(0, 0));
107 	if (argc == 0)
108 		usage();
109 	while (argc-- > 0)
110 		parse(*argv++);
111 	exit(0);
112 }
113 
114 /*
115  * Parse a name into a MIB entry.
116  * Lookup and print out the MIB entry if it exists.
117  * Set a new value if requested.
118  */
119 static void
120 parse(char *string)
121 {
122 	int len, i, j;
123 	void *newval = 0;
124 	int intval, newsize = 0;
125 	quad_t quadval;
126 	int mib[CTL_MAXNAME];
127 	char *cp, *bufp, buf[BUFSIZ];
128 	u_int kind;
129 
130 	bufp = buf;
131 	snprintf(buf, BUFSIZ, "%s", string);
132 	if ((cp = strchr(string, '=')) != NULL) {
133 		if (!wflag)
134 			errx(2, "must specify -w to set variables");
135 		*strchr(buf, '=') = '\0';
136 		*cp++ = '\0';
137 		while (isspace(*cp))
138 			cp++;
139 		newval = cp;
140 		newsize = strlen(cp);
141 	} else {
142 		if (wflag)
143 			usage();
144 	}
145 	len = name2oid(bufp, mib);
146 
147 	if (len < 0)
148 		errx(1, "unknown oid '%s'", bufp);
149 
150 	if (oidfmt(mib, len, 0, &kind))
151 		err(1, "couldn't find format of oid '%s'", bufp);
152 
153 	if (!wflag) {
154 		if ((kind & CTLTYPE) == CTLTYPE_NODE) {
155 			sysctl_all(mib, len);
156 		} else {
157 			i = show_var(mib, len);
158 			if (!i && !bflag)
159 				putchar('\n');
160 		}
161 	} else {
162 		if ((kind & CTLTYPE) == CTLTYPE_NODE)
163 			errx(1, "oid '%s' isn't a leaf node", bufp);
164 
165 		if (!(kind&CTLFLAG_WR))
166 			errx(1, "oid '%s' is read only", bufp);
167 
168 		switch (kind & CTLTYPE) {
169 			case CTLTYPE_INT:
170 				intval = (int) strtol(newval, NULL, 0);
171 				newval = &intval;
172 				newsize = sizeof intval;
173 				break;
174 				break;
175 			case CTLTYPE_STRING:
176 				break;
177 			case CTLTYPE_QUAD:
178 				break;
179 				sscanf(newval, "%qd", &quadval);
180 				newval = &quadval;
181 				newsize = sizeof quadval;
182 				break;
183 			default:
184 				errx(1, "oid '%s' is type %d,"
185 					" cannot set that", bufp,
186 					kind & CTLTYPE);
187 		}
188 
189 		i = show_var(mib, len);
190 		if (sysctl(mib, len, 0, 0, newval, newsize) == -1) {
191 			if (!i && !bflag)
192 				putchar('\n');
193 			switch (errno) {
194 			case EOPNOTSUPP:
195 				errx(1, "%s: value is not available",
196 					string);
197 			case ENOTDIR:
198 				errx(1, "%s: specification is incomplete",
199 					string);
200 			case ENOMEM:
201 				errx(1, "%s: type is unknown to this program",
202 					string);
203 			default:
204 				warn("%s", string);
205 				return;
206 			}
207 		}
208 		if (!bflag)
209 			printf(" -> ");
210 		i = nflag;
211 		nflag = 1;
212 		j = show_var(mib, len);
213 		if (!j && !bflag)
214 			putchar('\n');
215 		nflag = i;
216 	}
217 }
218 
219 /* These functions will dump out various interesting structures. */
220 
221 static int
222 S_clockinfo(int l2, void *p)
223 {
224 	struct clockinfo *ci = (struct clockinfo*)p;
225 	if (l2 != sizeof *ci)
226 		err(1, "S_clockinfo %d != %d", l2, sizeof *ci);
227 	printf("{ hz = %d, tick = %d, tickadj = %d, profhz = %d, stathz = %d }",
228 		ci->hz, ci->tick, ci->tickadj, ci->profhz, ci->stathz);
229 	return (0);
230 }
231 
232 static int
233 S_loadavg(int l2, void *p)
234 {
235 	struct loadavg *tv = (struct loadavg*)p;
236 
237 	if (l2 != sizeof *tv)
238 		err(1, "S_loadavg %d != %d", l2, sizeof *tv);
239 
240 	printf("{ %.2f %.2f %.2f }",
241 		(double)tv->ldavg[0]/(double)tv->fscale,
242 		(double)tv->ldavg[1]/(double)tv->fscale,
243 		(double)tv->ldavg[2]/(double)tv->fscale);
244 	return (0);
245 }
246 
247 static int
248 S_timeval(int l2, void *p)
249 {
250 	struct timeval *tv = (struct timeval*)p;
251 	time_t tv_sec;
252 	char *p1, *p2;
253 
254 	if (l2 != sizeof *tv)
255 		err(1, "S_timeval %d != %d", l2, sizeof *tv);
256 	printf("{ sec = %ld, usec = %ld } ",
257 		tv->tv_sec, tv->tv_usec);
258 	tv_sec = tv->tv_sec;
259 	p1 = strdup(ctime(&tv_sec));
260 	for (p2=p1; *p2 ; p2++)
261 		if (*p2 == '\n')
262 			*p2 = '\0';
263 	fputs(p1, stdout);
264 	return (0);
265 }
266 
267 static int
268 T_dev_t(int l2, void *p)
269 {
270 	dev_t *d = (dev_t *)p;
271 	if (l2 != sizeof *d)
272 		err(1, "T_dev_T %d != %d", l2, sizeof *d);
273 	if ((int)(*d) != -1) {
274 		if (minor(*d) > 255 || minor(*d) < 0)
275 			printf("{ major = %d, minor = 0x%x }",
276 				major(*d), minor(*d));
277 		else
278 			printf("{ major = %d, minor = %d }",
279 				major(*d), minor(*d));
280 	}
281 	return (0);
282 }
283 
284 /*
285  * These functions uses a presently undocumented interface to the kernel
286  * to walk the tree and get the type so it can print the value.
287  * This interface is under work and consideration, and should probably
288  * be killed with a big axe by the first person who can find the time.
289  * (be aware though, that the proper interface isn't as obvious as it
290  * may seem, there are various conflicting requirements.
291  */
292 
293 static int
294 name2oid(char *name, int *oidp)
295 {
296 	int oid[2];
297 	int i;
298 	size_t j;
299 
300 	oid[0] = 0;
301 	oid[1] = 3;
302 
303 	j = CTL_MAXNAME * sizeof (int);
304 	i = sysctl(oid, 2, oidp, &j, name, strlen(name));
305 	if (i < 0)
306 		return i;
307 	j /= sizeof (int);
308 	return (j);
309 }
310 
311 static int
312 oidfmt(int *oid, int len, char *fmt, u_int *kind)
313 {
314 	int qoid[CTL_MAXNAME+2];
315 	u_char buf[BUFSIZ];
316 	int i;
317 	size_t j;
318 
319 	qoid[0] = 0;
320 	qoid[1] = 4;
321 	memcpy(qoid + 2, oid, len * sizeof(int));
322 
323 	j = sizeof buf;
324 	i = sysctl(qoid, len + 2, buf, &j, 0, 0);
325 	if (i)
326 		err(1, "sysctl fmt %d %d %d", i, j, errno);
327 
328 	if (kind)
329 		*kind = *(u_int *)buf;
330 
331 	if (fmt)
332 		strcpy(fmt, (char *)(buf + sizeof(u_int)));
333 	return 0;
334 }
335 
336 /*
337  * This formats and outputs the value of one variable
338  *
339  * Returns zero if anything was actually output.
340  * Returns one if didn't know what to do with this.
341  * Return minus one if we had errors.
342  */
343 
344 static int
345 show_var(int *oid, int nlen)
346 {
347 	u_char buf[BUFSIZ], *val, *p;
348 	char name[BUFSIZ], descr[BUFSIZ], *fmt;
349 	int qoid[CTL_MAXNAME+2];
350 	int i;
351 	size_t j, len;
352 	u_int kind;
353 	int (*func)(int, void *) = 0;
354 
355 	qoid[0] = 0;
356 	memcpy(qoid + 2, oid, nlen * sizeof(int));
357 
358 	qoid[1] = 1;
359 	j = sizeof name;
360 	i = sysctl(qoid, nlen + 2, name, &j, 0, 0);
361 	if (i || !j)
362 		err(1, "sysctl name %d %d %d", i, j, errno);
363 
364 	/* find an estimate of how much we need for this var */
365 	j = 0;
366 	i = sysctl(oid, nlen, 0, &j, 0, 0);
367 	j += j; /* we want to be sure :-) */
368 
369 	val = alloca(j);
370 	len = j;
371 	i = sysctl(oid, nlen, val, &len, 0, 0);
372 	if (i || !len)
373 		return (1);
374 
375 	if (bflag) {
376 		fwrite(val, 1, len, stdout);
377 		return (0);
378 	}
379 
380 	qoid[1] = 4;
381 	j = sizeof buf;
382 	i = sysctl(qoid, nlen + 2, buf, &j, 0, 0);
383 	if (i || !j)
384 		err(1, "sysctl fmt %d %d %d", i, j, errno);
385 
386 	kind = *(u_int *)buf;
387 
388 	fmt = (char *)(buf + sizeof(u_int));
389 
390 	p = val;
391 	switch (*fmt) {
392 	case 'A':
393 		if (!nflag)
394 			printf("%s: ", name);
395 		printf("%s", p);
396 		return (0);
397 
398 	case 'I':
399 		if (!nflag)
400 			printf("%s: ", name);
401 		fmt++;
402 		val = "";
403 		while (len >= sizeof(int)) {
404 			if(*fmt == 'U')
405 				printf("%s%u", val, *(unsigned int *)p);
406 			else
407 				printf("%s%d", val, *(int *)p);
408 			val = " ";
409 			len -= sizeof (int);
410 			p += sizeof (int);
411 		}
412 		return (0);
413 
414 	case 'L':
415 		if (!nflag)
416 			printf("%s: ", name);
417 		fmt++;
418 		val = "";
419 		while (len >= sizeof(long)) {
420 			if(*fmt == 'U')
421 				printf("%s%lu", val, *(unsigned long *)p);
422 			else
423 				printf("%s%ld", val, *(long *)p);
424 			val = " ";
425 			len -= sizeof (long);
426 			p += sizeof (long);
427 		}
428 		return (0);
429 
430 	case 'P':
431 		if (!nflag)
432 			printf("%s: ", name);
433 		printf("%p", *(void **)p);
434 		return (0);
435 
436 	case 'T':
437 	case 'S':
438 		i = 0;
439 		if (!strcmp(fmt, "S,clockinfo"))	func = S_clockinfo;
440 		else if (!strcmp(fmt, "S,timeval"))	func = S_timeval;
441 		else if (!strcmp(fmt, "S,loadavg"))	func = S_loadavg;
442 		else if (!strcmp(fmt, "T,dev_t"))	func = T_dev_t;
443 		if (func) {
444 			if (!nflag)
445 				printf("%s: ", name);
446 			return ((*func)(len, p));
447 		}
448 		/* FALL THROUGH */
449 	default:
450 		if (!Aflag)
451 			return (1);
452 		if (!nflag)
453 			printf("%s: ", name);
454 		printf("Format:%s Length:%d Dump:0x", fmt, len);
455 		while (len--) {
456 			printf("%02x", *p++);
457 			if (Xflag || p < val+16)
458 				continue;
459 			printf("...");
460 			break;
461 		}
462 		return (0);
463 	}
464 	return (1);
465 }
466 
467 static int
468 sysctl_all (int *oid, int len)
469 {
470 	int name1[22], name2[22];
471 	int i, j;
472 	size_t l1, l2;
473 
474 	name1[0] = 0;
475 	name1[1] = 2;
476 	l1 = 2;
477 	if (len) {
478 		memcpy(name1+2, oid, len*sizeof (int));
479 		l1 += len;
480 	} else {
481 		name1[2] = 1;
482 		l1++;
483 	}
484 	while (1) {
485 		l2 = sizeof name2;
486 		j = sysctl(name1, l1, name2, &l2, 0, 0);
487 		if (j < 0) {
488 			if (errno == ENOENT)
489 				return 0;
490 			else
491 				err(1, "sysctl(getnext) %d %d", j, l2);
492 		}
493 
494 		l2 /= sizeof (int);
495 
496 		if (l2 < len)
497 			return 0;
498 
499 		for (i = 0; i < len; i++)
500 			if (name2[i] != oid[i])
501 				return 0;
502 
503 		i = show_var(name2, l2);
504 		if (!i && !bflag)
505 			putchar('\n');
506 
507 		memcpy(name1+2, name2, l2*sizeof (int));
508 		l1 = 2 + l2;
509 	}
510 }
511