xref: /freebsd/sbin/sysctl/sysctl.c (revision e627b39baccd1ec9129690167cf5e6d860509655)
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 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 /*static char sccsid[] = "From: @(#)sysctl.c	8.1 (Berkeley) 6/6/93"; */
42 static const char rcsid[] =
43 	"$Id: sysctl.c,v 1.9 1995/12/21 12:39:25 phk Exp $";
44 #endif /* not lint */
45 
46 #include <sys/types.h>
47 #include <sys/stat.h>
48 #include <sys/sysctl.h>
49 #include <sys/resource.h>
50 
51 #include <errno.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <ctype.h>
56 #include <err.h>
57 
58 static int	Aflag, aflag, nflag, wflag, Xflag, bflag;
59 
60 static int	oidfmt(int *, int, char *, u_int *);
61 static void	parse(char *);
62 static int	show_var(int *, int);
63 static int	sysctl_all (int *oid, int len);
64 static int	name2oid(char *, int *);
65 
66 static void
67 usage(void)
68 {
69 
70 	(void)fprintf(stderr, "usage:\n%s",
71 	    "\tsysctl [-bnX] variable ...\n"
72 	    "\tsysctl [-bnX] -w variable=value ...\n"
73 	    "\tsysctl [-bnX] -a\n"
74 	    "\tsysctl [-bnX] -A\n"
75 		);
76 	exit(1);
77 }
78 
79 int
80 main(int argc, char **argv)
81 {
82 	extern char *optarg;
83 	extern int optind;
84 	int ch;
85 	setbuf(stdout,0);
86 	setbuf(stderr,0);
87 
88 	while ((ch = getopt(argc, argv, "AabnwX")) != EOF) {
89 		switch (ch) {
90 		case 'A': Aflag = 1; break;
91 		case 'a': aflag = 1; break;
92 		case 'b': bflag = 1; break;
93 		case 'n': nflag = 1; break;
94 		case 'w': wflag = 1; break;
95 		case 'X': Xflag = Aflag = 1; break;
96 		default: usage();
97 		}
98 	}
99 	argc -= optind;
100 	argv += optind;
101 
102 	if (Aflag || aflag)
103 		exit (sysctl_all(0, 0));
104 	if (argc == 0)
105 		usage();
106 	while (argc-- > 0)
107 		parse(*argv++);
108 	exit(0);
109 }
110 
111 /*
112  * Parse a name into a MIB entry.
113  * Lookup and print out the MIB entry if it exists.
114  * Set a new value if requested.
115  */
116 static void
117 parse(char *string)
118 {
119 	int len, i, j;
120 	void *newval = 0;
121 	int intval, newsize = 0;
122 	quad_t quadval;
123 	int mib[CTL_MAXNAME];
124 	char *cp, *bufp, buf[BUFSIZ];
125 	u_int kind;
126 
127 	bufp = buf;
128 	snprintf(buf, BUFSIZ, "%s", string);
129 	if ((cp = strchr(string, '=')) != NULL) {
130 		if (!wflag) {
131 			fprintf(stderr, "Must specify -w to set variables\n");
132 			exit(2);
133 		}
134 		*strchr(buf, '=') = '\0';
135 		*cp++ = '\0';
136 		while (isspace(*cp))
137 			cp++;
138 		newval = cp;
139 		newsize = strlen(cp);
140 	} else {
141 		if (wflag)
142 			usage();
143 	}
144 	len = name2oid(bufp, mib);
145 
146 	if (len < 0)
147 		errx(1, "Unknown oid '%s'", bufp);
148 
149 	if (oidfmt(mib, len, 0, &kind))
150 		err(1, "Couldn't find format of oid '%s'", bufp);
151 
152 	if (!wflag) {
153 		if ((kind & CTLTYPE) == CTLTYPE_NODE) {
154 			sysctl_all(mib, len);
155 		} else {
156 			i = show_var(mib, len);
157 			if (!i && !bflag)
158 				putchar('\n');
159 		}
160 	} else {
161 		if ((kind & CTLTYPE) == CTLTYPE_NODE)
162 			errx(1, "oid '%s' isn't a leaf node", bufp);
163 
164 		if (!(kind&CTLFLAG_WR))
165 			errx(1, "oid '%s' is read only", bufp);
166 
167 		switch (kind & CTLTYPE) {
168 			case CTLTYPE_INT:
169 				intval = atoi(newval);
170 				newval = &intval;
171 				newsize = sizeof intval;
172 				break;
173 				break;
174 			case CTLTYPE_STRING:
175 				break;
176 			case CTLTYPE_QUAD:
177 				break;
178 				sscanf(newval, "%qd", &quadval);
179 				newval = &quadval;
180 				newsize = sizeof quadval;
181 				break;
182 			default:
183 				errx(1, "oid '%s' is type %d,"
184 					" cannot set that", bufp);
185 		}
186 
187 		i = show_var(mib, len);
188 		if (sysctl(mib, len, 0, 0, newval, newsize) == -1) {
189 			if (!i && !bflag)
190 				putchar('\n');
191 			switch (errno) {
192 			case EOPNOTSUPP:
193 				errx(1, "%s: value is not available\n",
194 					string);
195 			case ENOTDIR:
196 				errx(1, "%s: specification is incomplete\n",
197 					string);
198 			case ENOMEM:
199 				errx(1, "%s: type is unknown to this program\n",
200 					string);
201 			default:
202 				perror(string);
203 				return;
204 			}
205 		}
206 		if (!bflag)
207 			printf(" -> ");
208 		i = nflag;
209 		nflag = 1;
210 		j = show_var(mib, len);
211 		if (!j && !bflag)
212 			putchar('\n');
213 		nflag = i;
214 	}
215 }
216 
217 /* These functions will dump out various interesting structures. */
218 
219 static int
220 S_clockinfo(int l2, void *p)
221 {
222 	struct clockinfo *ci = (struct clockinfo*)p;
223 	if (l2 != sizeof *ci)
224 		err(-1, "S_clockinfo %d != %d", l2, sizeof *ci);
225 	printf("{ hz = %d, tick = %d, profhz = %d, stathz = %d }",
226 		ci->hz, ci->tick, ci->profhz, ci->stathz);
227 	return (0);
228 }
229 
230 static int
231 S_loadavg(int l2, void *p)
232 {
233 	struct loadavg *tv = (struct loadavg*)p;
234 
235 	if (l2 != sizeof *tv)
236 		err(-1, "S_loadavg %d != %d", l2, sizeof *tv);
237 
238 	printf("{ %.2f %.2f %.2f }",
239 		(double)tv->ldavg[0]/(double)tv->fscale,
240 		(double)tv->ldavg[1]/(double)tv->fscale,
241 		(double)tv->ldavg[2]/(double)tv->fscale);
242 	return (0);
243 }
244 
245 static int
246 S_timeval(int l2, void *p)
247 {
248 	struct timeval *tv = (struct timeval*)p;
249 	char *p1, *p2;
250 
251 	if (l2 != sizeof *tv)
252 		err(-1, "S_timeval %d != %d", l2, sizeof *tv);
253 	printf("{ sec = %ld, usec = %ld } ",
254 		tv->tv_sec, tv->tv_usec);
255 	p1 = strdup(ctime(&tv->tv_sec));
256 	for (p2=p1; *p2 ; p2++)
257 		if (*p2 == '\n')
258 			*p2 = '\0';
259 	fputs(p1, stdout);
260 	return (0);
261 }
262 
263 static int
264 T_dev_t(int l2, void *p)
265 {
266 	dev_t *d = (dev_t *)p;
267 	if (l2 != sizeof *d)
268 		err(-1, "T_dev_T %d != %d", l2, sizeof *d);
269 	printf("{ major = %d, minor = %d }",
270 		major(*d), minor(*d));
271 	return (0);
272 }
273 
274 /*
275  * These functions uses a presently undocumented interface to the kernel
276  * to walk the tree and get the type so it can print the value.
277  * This interface is under work and consideration, and should probably
278  * be killed with a big axe by the first person who can find the time.
279  * (be aware though, that the proper interface isn't as obvious as it
280  * may seem, there are various conflicting requirements.
281  */
282 
283 static int
284 name2oid(char *name, int *oidp)
285 {
286 	int oid[2];
287 	int i, j;
288 
289 	oid[0] = 0;
290 	oid[1] = 3;
291 
292 	j = CTL_MAXNAME * sizeof (int);
293 	i = sysctl(oid, 2, oidp, &j, name, strlen(name));
294 	if (i < 0)
295 		return i;
296 	j /= sizeof (int);
297 	return (j);
298 }
299 
300 static int
301 oidfmt(int *oid, int len, char *fmt, u_int *kind)
302 {
303 	int qoid[CTL_MAXNAME+2];
304 	u_char buf[BUFSIZ];
305 	int i, j;
306 
307 	qoid[0] = 0;
308 	qoid[1] = 4;
309 	memcpy(qoid + 2, oid, len * sizeof(int));
310 
311 	j = sizeof buf;
312 	i = sysctl(qoid, len + 2, buf, &j, 0, 0);
313 	if (i)
314 		err(-1, "sysctl fmt %d %d %d", i, j, errno);
315 
316 	if (kind)
317 		*kind = *(u_int *)buf;
318 
319 	if (fmt)
320 		strcpy(fmt, (char *)(buf + sizeof(u_int)));
321 	return 0;
322 }
323 
324 /*
325  * This formats and outputs the value of one variable
326  *
327  * Returns zero if anything was actually output.
328  * Returns one if didn't know what to do with this.
329  * Return minus one if we had errors.
330  */
331 
332 static int
333 show_var(int *oid, int nlen)
334 {
335 	u_char buf[BUFSIZ], *val, *p;
336 	char name[BUFSIZ], *fmt;
337 	int qoid[CTL_MAXNAME+2];
338 	int i, j, len;
339 	u_int kind;
340 	int (*func)(int, void *) = 0;
341 
342 	/* find an estimate of how much we need for this var */
343 	j = 0;
344 	i = sysctl(oid, nlen, 0, &j, 0, 0);
345 	j += j; /* we want to be sure :-) */
346 
347 	val = alloca(j);
348 	len = j;
349 	i = sysctl(oid, nlen, val, &len, 0, 0);
350 	if (i || !len)
351 		return (1);
352 
353 	if (bflag) {
354 		fwrite(val, 1, len, stdout);
355 		return (0);
356 	}
357 
358 	qoid[0] = 0;
359 	qoid[1] = 4;
360 	memcpy(qoid + 2, oid, nlen * sizeof(int));
361 
362 	j = sizeof buf;
363 	i = sysctl(qoid, nlen + 2, buf, &j, 0, 0);
364 	if (i || !j)
365 		err(-1, "sysctl fmt %d %d %d", i, j, errno);
366 
367 	kind = *(u_int *)buf;
368 
369 	fmt = (char *)(buf + sizeof(u_int));
370 
371 	qoid[1] = 1;
372 	j = sizeof name;
373 	i = sysctl(qoid, nlen + 2, name, &j, 0, 0);
374 	if (i || !j)
375 		err(-1, "sysctl name %d %d %d", i, j, errno);
376 
377 	p = val;
378 	switch (*fmt) {
379 	case 'A':
380 		if (!nflag)
381 			printf("%s: ", name);
382 		printf("%s", p);
383 		return (0);
384 
385 	case 'I':
386 		if (!nflag)
387 			printf("%s: ", name);
388 		printf("%d", *(int *)p);
389 		return (0);
390 
391 	case 'T':
392 	case 'S':
393 		i = 0;
394 		if (!strcmp(fmt, "S,clockinfo"))	func = S_clockinfo;
395 		else if (!strcmp(fmt, "S,timeval"))	func = S_timeval;
396 		else if (!strcmp(fmt, "S,loadavg"))	func = S_loadavg;
397 		else if (!strcmp(fmt, "T,dev_t"))	func = T_dev_t;
398 		if (func) {
399 			if (!nflag)
400 				printf("%s: ", name);
401 			return ((*func)(len, p));
402 		}
403 		/* FALL THROUGH */
404 	default:
405 		if (!Aflag)
406 			return (1);
407 		if (!nflag)
408 			printf("%s: ", name);
409 		printf("Format:%s Length:%d Dump:0x", fmt, len);
410 		while (len--) {
411 			printf("%02x", *p++);
412 			if (Xflag || p < val+16)
413 				continue;
414 			printf("...");
415 			break;
416 		}
417 		return (0);
418 	}
419 	return (1);
420 }
421 
422 static int
423 sysctl_all (int *oid, int len)
424 {
425 	int name1[22], name2[22];
426 	int i, j, l1, l2;
427 
428 	name1[0] = 0;
429 	name1[1] = 2;
430 	l1 = 2;
431 	if (len) {
432 		memcpy(name1+2, oid, len*sizeof (int));
433 		l1 += len;
434 	} else {
435 		name1[2] = 1;
436 		l1++;
437 	}
438 	while (1) {
439 		l2 = sizeof name2;
440 		j = sysctl(name1, l1, name2, &l2, 0, 0);
441 		if (j < 0)
442 			if (errno == ENOENT)
443 				return 0;
444 			else
445 				err(-1, "sysctl(getnext) %d %d", j, l2);
446 
447 		l2 /= sizeof (int);
448 
449 		if (l2 < len)
450 			return 0;
451 
452 		for (i = 0; i < len; i++)
453 			if (name2[i] != oid[i])
454 				return 0;
455 
456 		i = show_var(name2, l2);
457 		if (!i && !bflag)
458 			putchar('\n');
459 
460 		memcpy(name1+2, name2, l2*sizeof (int));
461 		l1 = 2 + l2;
462 	}
463 }
464