xref: /freebsd/usr.bin/rctl/rctl.c (revision a70cba95822f662d3f9da5119b6a0c433e8f70af)
1 /*-
2  * Copyright (c) 2010 The FreeBSD Foundation
3  * All rights reserved.
4  *
5  * This software was developed by Edward Tomasz Napierala under sponsorship
6  * from the FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/types.h>
36 #include <sys/rctl.h>
37 #include <sys/sysctl.h>
38 #include <assert.h>
39 #include <ctype.h>
40 #include <err.h>
41 #include <errno.h>
42 #include <getopt.h>
43 #include <grp.h>
44 #include <libutil.h>
45 #include <pwd.h>
46 #include <stdbool.h>
47 #include <stdint.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 
52 #define	RCTL_DEFAULT_BUFSIZE	128 * 1024
53 
54 static int
55 parse_user(const char *s, id_t *uidp, const char *unexpanded_rule)
56 {
57 	char *end;
58 	struct passwd *pwd;
59 
60 	pwd = getpwnam(s);
61 	if (pwd != NULL) {
62 		*uidp = pwd->pw_uid;
63 		return (0);
64 	}
65 
66 	if (!isnumber(s[0])) {
67 		warnx("malformed rule '%s': unknown user '%s'",
68 		    unexpanded_rule, s);
69 		return (1);
70 	}
71 
72 	*uidp = strtod(s, &end);
73 	if ((size_t)(end - s) != strlen(s)) {
74 		warnx("malformed rule '%s': trailing characters "
75 		    "after numerical id", unexpanded_rule);
76 		return (1);
77 	}
78 
79 	return (0);
80 }
81 
82 static int
83 parse_group(const char *s, id_t *gidp, const char *unexpanded_rule)
84 {
85 	char *end;
86 	struct group *grp;
87 
88 	grp = getgrnam(s);
89 	if (grp != NULL) {
90 		*gidp = grp->gr_gid;
91 		return (0);
92 	}
93 
94 	if (!isnumber(s[0])) {
95 		warnx("malformed rule '%s': unknown group '%s'",
96 		    unexpanded_rule, s);
97 		return (1);
98 	}
99 
100 	*gidp = strtod(s, &end);
101 	if ((size_t)(end - s) != strlen(s)) {
102 		warnx("malformed rule '%s': trailing characters "
103 		    "after numerical id", unexpanded_rule);
104 		return (1);
105 	}
106 
107 	return (0);
108 }
109 
110 /*
111  * Replace human-readable number with its expanded form.
112  */
113 static char *
114 expand_amount(const char *rule, const char *unexpanded_rule)
115 {
116 	uint64_t num;
117 	const char *subject, *subject_id, *resource, *action, *amount, *per;
118 	char *copy, *expanded, *tofree;
119 	int ret;
120 
121 	tofree = copy = strdup(rule);
122 	if (copy == NULL) {
123 		warn("strdup");
124 		return (NULL);
125 	}
126 
127 	subject = strsep(&copy, ":");
128 	subject_id = strsep(&copy, ":");
129 	resource = strsep(&copy, ":");
130 	action = strsep(&copy, "=/");
131 	amount = strsep(&copy, "/");
132 	per = copy;
133 
134 	if (amount == NULL || strlen(amount) == 0) {
135 		/*
136 		 * The "copy" has already been tinkered with by strsep().
137 		 */
138 		free(tofree);
139 		copy = strdup(rule);
140 		if (copy == NULL) {
141 			warn("strdup");
142 			return (NULL);
143 		}
144 		return (copy);
145 	}
146 
147 	assert(subject != NULL);
148 	assert(subject_id != NULL);
149 	assert(resource != NULL);
150 	assert(action != NULL);
151 
152 	if (expand_number(amount, &num)) {
153 		warnx("malformed rule '%s': invalid numeric value '%s'",
154 		    unexpanded_rule, amount);
155 		free(tofree);
156 		return (NULL);
157 	}
158 
159 	if (per == NULL) {
160 		ret = asprintf(&expanded, "%s:%s:%s:%s=%ju",
161 		    subject, subject_id, resource, action, (uintmax_t)num);
162 	} else {
163 		ret = asprintf(&expanded, "%s:%s:%s:%s=%ju/%s",
164 		    subject, subject_id, resource, action, (uintmax_t)num, per);
165 	}
166 
167 	if (ret <= 0) {
168 		warn("asprintf");
169 		free(tofree);
170 		return (NULL);
171 	}
172 
173 	free(tofree);
174 
175 	return (expanded);
176 }
177 
178 static char *
179 expand_rule(const char *rule, bool resolve_ids)
180 {
181 	id_t id;
182 	const char *subject, *textid, *rest;
183 	char *copy, *expanded, *resolved, *tofree;
184 	int error, ret;
185 
186 	tofree = copy = strdup(rule);
187 	if (copy == NULL) {
188 		warn("strdup");
189 		return (NULL);
190 	}
191 
192 	subject = strsep(&copy, ":");
193 	textid = strsep(&copy, ":");
194 	if (textid == NULL) {
195 		warnx("malformed rule '%s': missing subject", rule);
196 		return (NULL);
197 	}
198 	if (copy != NULL)
199 		rest = copy;
200 	else
201 		rest = "";
202 
203 	if (strcasecmp(subject, "u") == 0)
204 		subject = "user";
205 	else if (strcasecmp(subject, "g") == 0)
206 		subject = "group";
207 	else if (strcasecmp(subject, "p") == 0)
208 		subject = "process";
209 	else if (strcasecmp(subject, "l") == 0 ||
210 	    strcasecmp(subject, "c") == 0 ||
211 	    strcasecmp(subject, "class") == 0)
212 		subject = "loginclass";
213 	else if (strcasecmp(subject, "j") == 0)
214 		subject = "jail";
215 
216 	if (resolve_ids &&
217 	    strcasecmp(subject, "user") == 0 && strlen(textid) > 0) {
218 		error = parse_user(textid, &id, rule);
219 		if (error != 0) {
220 			free(tofree);
221 			return (NULL);
222 		}
223 		ret = asprintf(&resolved, "%s:%d:%s", subject, (int)id, rest);
224 	} else if (resolve_ids &&
225 	    strcasecmp(subject, "group") == 0 && strlen(textid) > 0) {
226 		error = parse_group(textid, &id, rule);
227 		if (error != 0) {
228 			free(tofree);
229 			return (NULL);
230 		}
231 		ret = asprintf(&resolved, "%s:%d:%s", subject, (int)id, rest);
232 	} else {
233 		ret = asprintf(&resolved, "%s:%s:%s", subject, textid, rest);
234 	}
235 
236 	if (ret <= 0) {
237 		warn("asprintf");
238 		free(tofree);
239 		return (NULL);
240 	}
241 
242 	free(tofree);
243 
244 	expanded = expand_amount(resolved, rule);
245 	free(resolved);
246 
247 	return (expanded);
248 }
249 
250 static char *
251 humanize_ids(char *rule)
252 {
253 	id_t id;
254 	struct passwd *pwd;
255 	struct group *grp;
256 	const char *subject, *textid, *rest;
257 	char *end, *humanized;
258 	int ret;
259 
260 	subject = strsep(&rule, ":");
261 	textid = strsep(&rule, ":");
262 	if (textid == NULL)
263 		errx(1, "rule passed from the kernel didn't contain subject");
264 	if (rule != NULL)
265 		rest = rule;
266 	else
267 		rest = "";
268 
269 	/* Replace numerical user and group ids with names. */
270 	if (strcasecmp(subject, "user") == 0) {
271 		id = strtod(textid, &end);
272 		if ((size_t)(end - textid) != strlen(textid))
273 			errx(1, "malformed uid '%s'", textid);
274 		pwd = getpwuid(id);
275 		if (pwd != NULL)
276 			textid = pwd->pw_name;
277 	} else if (strcasecmp(subject, "group") == 0) {
278 		id = strtod(textid, &end);
279 		if ((size_t)(end - textid) != strlen(textid))
280 			errx(1, "malformed gid '%s'", textid);
281 		grp = getgrgid(id);
282 		if (grp != NULL)
283 			textid = grp->gr_name;
284 	}
285 
286 	ret = asprintf(&humanized, "%s:%s:%s", subject, textid, rest);
287 	if (ret <= 0)
288 		err(1, "asprintf");
289 
290 	return (humanized);
291 }
292 
293 static int
294 str2int64(const char *str, int64_t *value)
295 {
296 	char *end;
297 
298 	if (str == NULL)
299 		return (EINVAL);
300 
301 	*value = strtoul(str, &end, 10);
302 	if ((size_t)(end - str) != strlen(str))
303 		return (EINVAL);
304 
305 	return (0);
306 }
307 
308 static char *
309 humanize_amount(char *rule)
310 {
311 	int64_t num;
312 	const char *subject, *subject_id, *resource, *action, *amount, *per;
313 	char *copy, *humanized, buf[6], *tofree;
314 	int ret;
315 
316 	tofree = copy = strdup(rule);
317 	if (copy == NULL)
318 		err(1, "strdup");
319 
320 	subject = strsep(&copy, ":");
321 	subject_id = strsep(&copy, ":");
322 	resource = strsep(&copy, ":");
323 	action = strsep(&copy, "=/");
324 	amount = strsep(&copy, "/");
325 	per = copy;
326 
327 	if (amount == NULL || strlen(amount) == 0 ||
328 	    str2int64(amount, &num) != 0) {
329 		free(tofree);
330 		return (rule);
331 	}
332 
333 	assert(subject != NULL);
334 	assert(subject_id != NULL);
335 	assert(resource != NULL);
336 	assert(action != NULL);
337 
338 	if (humanize_number(buf, sizeof(buf), num, "", HN_AUTOSCALE,
339 	    HN_DECIMAL | HN_NOSPACE) == -1)
340 		err(1, "humanize_number");
341 
342 	if (per == NULL) {
343 		ret = asprintf(&humanized, "%s:%s:%s:%s=%s",
344 		    subject, subject_id, resource, action, buf);
345 	} else {
346 		ret = asprintf(&humanized, "%s:%s:%s:%s=%s/%s",
347 		    subject, subject_id, resource, action, buf, per);
348 	}
349 
350 	if (ret <= 0)
351 		err(1, "asprintf");
352 
353 	free(tofree);
354 	return (humanized);
355 }
356 
357 /*
358  * Print rules, one per line.
359  */
360 static void
361 print_rules(char *rules, int hflag, int nflag)
362 {
363 	char *rule;
364 
365 	while ((rule = strsep(&rules, ",")) != NULL) {
366 		if (rule[0] == '\0')
367 			break; /* XXX */
368 		if (nflag == 0)
369 			rule = humanize_ids(rule);
370 		if (hflag)
371 			rule = humanize_amount(rule);
372 		printf("%s\n", rule);
373 	}
374 }
375 
376 static void
377 enosys(void)
378 {
379 	int error, racct_enable;
380 	size_t racct_enable_len;
381 
382 	racct_enable_len = sizeof(racct_enable);
383 	error = sysctlbyname("kern.racct.enable",
384 	    &racct_enable, &racct_enable_len, NULL, 0);
385 
386 	if (error != 0) {
387 		if (errno == ENOENT)
388 			errx(1, "RACCT/RCTL support not present in kernel; see rctl(8) for details");
389 
390 		err(1, "sysctlbyname");
391 	}
392 
393 	if (racct_enable == 0)
394 		errx(1, "RACCT/RCTL present, but disabled; enable using kern.racct.enable=1 tunable");
395 }
396 
397 static int
398 add_rule(const char *rule, const char *unexpanded_rule)
399 {
400 	int error;
401 
402 	error = rctl_add_rule(rule, strlen(rule) + 1, NULL, 0);
403 	if (error != 0) {
404 		if (errno == ENOSYS)
405 			enosys();
406 		warn("failed to add rule '%s'", unexpanded_rule);
407 	}
408 
409 	return (error);
410 }
411 
412 static int
413 show_limits(const char *filter, const char *unexpanded_rule,
414     int hflag, int nflag)
415 {
416 	int error;
417 	char *outbuf = NULL;
418 	size_t outbuflen = RCTL_DEFAULT_BUFSIZE / 4;
419 
420 	for (;;) {
421 		outbuflen *= 4;
422 		outbuf = realloc(outbuf, outbuflen);
423 		if (outbuf == NULL)
424 			err(1, "realloc");
425 		error = rctl_get_limits(filter, strlen(filter) + 1,
426 		    outbuf, outbuflen);
427 		if (error == 0)
428 			break;
429 		if (errno == ERANGE)
430 			continue;
431 		if (errno == ENOSYS)
432 			enosys();
433 		warn("failed to get limits for '%s'", unexpanded_rule);
434 		free(outbuf);
435 
436 		return (error);
437 	}
438 
439 	print_rules(outbuf, hflag, nflag);
440 	free(outbuf);
441 
442 	return (error);
443 }
444 
445 static int
446 remove_rule(const char *filter, const char *unexpanded_rule)
447 {
448 	int error;
449 
450 	error = rctl_remove_rule(filter, strlen(filter) + 1, NULL, 0);
451 	if (error != 0) {
452 		if (errno == ENOSYS)
453 			enosys();
454 		warn("failed to remove rule '%s'", unexpanded_rule);
455 	}
456 
457 	return (error);
458 }
459 
460 static char *
461 humanize_usage_amount(char *usage)
462 {
463 	int64_t num;
464 	const char *resource, *amount;
465 	char *copy, *humanized, buf[6], *tofree;
466 	int ret;
467 
468 	tofree = copy = strdup(usage);
469 	if (copy == NULL)
470 		err(1, "strdup");
471 
472 	resource = strsep(&copy, "=");
473 	amount = copy;
474 
475 	assert(resource != NULL);
476 	assert(amount != NULL);
477 
478 	if (str2int64(amount, &num) != 0 ||
479 	    humanize_number(buf, sizeof(buf), num, "", HN_AUTOSCALE,
480 	    HN_DECIMAL | HN_NOSPACE) == -1) {
481 		free(tofree);
482 		return (usage);
483 	}
484 
485 	ret = asprintf(&humanized, "%s=%s", resource, buf);
486 	if (ret <= 0)
487 		err(1, "asprintf");
488 
489 	free(tofree);
490 	return (humanized);
491 }
492 
493 /*
494  * Query the kernel about a resource usage and print it out.
495  */
496 static int
497 show_usage(const char *filter, const char *unexpanded_rule, int hflag)
498 {
499 	int error;
500 	char *copy, *outbuf = NULL, *tmp;
501 	size_t outbuflen = RCTL_DEFAULT_BUFSIZE / 4;
502 
503 	for (;;) {
504 		outbuflen *= 4;
505 		outbuf = realloc(outbuf, outbuflen);
506 		if (outbuf == NULL)
507 			err(1, "realloc");
508 		error = rctl_get_racct(filter, strlen(filter) + 1,
509 		    outbuf, outbuflen);
510 		if (error == 0)
511 			break;
512 		if (errno == ERANGE)
513 			continue;
514 		if (errno == ENOSYS)
515 			enosys();
516 		warn("failed to show resource consumption for '%s'",
517 		    unexpanded_rule);
518 		free(outbuf);
519 
520 		return (error);
521 	}
522 
523 	copy = outbuf;
524 	while ((tmp = strsep(&copy, ",")) != NULL) {
525 		if (tmp[0] == '\0')
526 			break; /* XXX */
527 
528 		if (hflag)
529 			tmp = humanize_usage_amount(tmp);
530 
531 		printf("%s\n", tmp);
532 	}
533 
534 	free(outbuf);
535 
536 	return (error);
537 }
538 
539 /*
540  * Query the kernel about resource limit rules and print them out.
541  */
542 static int
543 show_rules(const char *filter, const char *unexpanded_rule,
544     int hflag, int nflag)
545 {
546 	int error;
547 	char *outbuf = NULL;
548 	size_t filterlen, outbuflen = RCTL_DEFAULT_BUFSIZE / 4;
549 
550 	if (filter != NULL)
551 		filterlen = strlen(filter) + 1;
552 	else
553 		filterlen = 0;
554 
555 	for (;;) {
556 		outbuflen *= 4;
557 		outbuf = realloc(outbuf, outbuflen);
558 		if (outbuf == NULL)
559 			err(1, "realloc");
560 		error = rctl_get_rules(filter, filterlen, outbuf, outbuflen);
561 		if (error == 0)
562 			break;
563 		if (errno == ERANGE)
564 			continue;
565 		if (errno == ENOSYS)
566 			enosys();
567 		warn("failed to show rules for '%s'", unexpanded_rule);
568 		free(outbuf);
569 
570 		return (error);
571 	}
572 
573 	print_rules(outbuf, hflag, nflag);
574 	free(outbuf);
575 
576 	return (error);
577 }
578 
579 static void
580 usage(void)
581 {
582 
583 	fprintf(stderr, "usage: rctl [ -h ] [-a rule | -l filter | -r filter "
584 	    "| -u filter | filter]\n");
585 	exit(1);
586 }
587 
588 int
589 main(int argc __unused, char **argv __unused)
590 {
591 	int ch, aflag = 0, hflag = 0, nflag = 0, lflag = 0, rflag = 0,
592 	    uflag = 0;
593 	char *rule = NULL, *unexpanded_rule;
594 	int i, cumulated_error, error;
595 
596 	while ((ch = getopt(argc, argv, "ahlnru")) != -1) {
597 		switch (ch) {
598 		case 'a':
599 			aflag = 1;
600 			break;
601 		case 'h':
602 			hflag = 1;
603 			break;
604 		case 'l':
605 			lflag = 1;
606 			break;
607 		case 'n':
608 			nflag = 1;
609 			break;
610 		case 'r':
611 			rflag = 1;
612 			break;
613 		case 'u':
614 			uflag = 1;
615 			break;
616 
617 		case '?':
618 		default:
619 			usage();
620 		}
621 	}
622 
623 	argc -= optind;
624 	argv += optind;
625 
626 	if (aflag + lflag + rflag + uflag > 1)
627 		errx(1, "at most one of -a, -l, -r, or -u may be specified");
628 
629 	if (argc == 0) {
630 		if (aflag + lflag + rflag + uflag == 0) {
631 			rule = strdup("::");
632 			show_rules(rule, rule, hflag, nflag);
633 
634 			return (0);
635 		}
636 
637 		usage();
638 	}
639 
640 	cumulated_error = 0;
641 
642 	for (i = 0; i < argc; i++) {
643 		unexpanded_rule = argv[i];
644 
645 		/*
646 		 * Skip resolving if passed -n _and_ -a.  Ignore -n otherwise,
647 		 * so we can still do "rctl -n u:root" and see the rules without
648 		 * resolving the UID.
649 		 */
650 		if (aflag != 0 && nflag != 0)
651 			rule = expand_rule(unexpanded_rule, false);
652 		else
653 			rule = expand_rule(unexpanded_rule, true);
654 
655 		if (rule == NULL) {
656 			cumulated_error++;
657 			continue;
658 		}
659 
660 		/*
661 		 * The reason for passing the unexpanded_rule is to make
662 		 * it easier for the user to search for the problematic
663 		 * rule in the passed input.
664 		 */
665 		if (aflag) {
666 			error = add_rule(rule, unexpanded_rule);
667 		} else if (lflag) {
668 			error = show_limits(rule, unexpanded_rule,
669 			    hflag, nflag);
670 		} else if (rflag) {
671 			error = remove_rule(rule, unexpanded_rule);
672 		} else if (uflag) {
673 			error = show_usage(rule, unexpanded_rule, hflag);
674 		} else  {
675 			error = show_rules(rule, unexpanded_rule,
676 			    hflag, nflag);
677 		}
678 
679 		if (error != 0)
680 			cumulated_error++;
681 
682 		free(rule);
683 	}
684 
685 	return (cumulated_error);
686 }
687