xref: /freebsd/usr.sbin/setfmac/setfmac.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
1 /*-
2  * Copyright (c) 2002, 2004 Networks Associates Technology, Inc.
3  * All rights reserved.
4  *
5  * This software was developed for the FreeBSD Project by NAI Labs, the
6  * Security Research Division of Network Associates, Inc. under
7  * DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA
8  * CHATS research program.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  * $FreeBSD$
32  */
33 
34 #include <sys/types.h>
35 #include <sys/mac.h>
36 #include <sys/queue.h>
37 #include <sys/stat.h>
38 
39 #include <ctype.h>
40 #include <err.h>
41 #include <errno.h>
42 #include <fts.h>
43 #include <libgen.h>
44 #include <regex.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49 
50 struct label_spec {
51 	struct label_spec_entry {
52 		regex_t regex;	/* compiled regular expression to match */
53 		char *regexstr;	/* uncompiled regular expression */
54 		mode_t mode;	/* mode to possibly match */
55 		const char *modestr;	/* print-worthy ",-?" mode string */
56 		char *mactext;	/* MAC label to apply */
57 		int flags;	/* miscellaneous flags */
58 #define		F_DONTLABEL	0x01
59 #define		F_ALWAYSMATCH	0x02
60 	} *entries,		/* entries[0..nentries] */
61 	  *match;		/* cached decision for MAC label to apply */
62 	size_t nentries;	/* size of entries list */
63 	STAILQ_ENTRY(label_spec) link;
64 };
65 
66 struct label_specs {
67 	STAILQ_HEAD(label_specs_head, label_spec) head;
68 };
69 
70 void usage(int) __dead2;
71 struct label_specs *new_specs(void);
72 void add_specs(struct label_specs *, const char *, int);
73 void add_setfmac_specs(struct label_specs *, char *);
74 void add_spec_line(const char *, int, struct label_spec_entry *, char *);
75 int apply_specs(struct label_specs *, FTSENT *, int, int);
76 int specs_empty(struct label_specs *);
77 
78 static int qflag;
79 
80 int
81 main(int argc, char **argv)
82 {
83 	FTSENT *ftsent;
84 	FTS *fts;
85 	struct label_specs *specs;
86 	int eflag = 0, xflag = 0, vflag = 0, Rflag = 0, hflag;
87 	int ch, is_setfmac;
88 	char *bn;
89 
90 	bn = basename(argv[0]);
91 	if (bn == NULL)
92 		err(1, "basename");
93 	is_setfmac = strcmp(bn, "setfmac") == 0;
94 	hflag = is_setfmac ? FTS_LOGICAL : FTS_PHYSICAL;
95 	specs = new_specs();
96 	while ((ch = getopt(argc, argv, is_setfmac ? "Rhq" : "ef:qs:vx")) !=
97 	    -1) {
98 		switch (ch) {
99 		case 'R':
100 			Rflag = 1;
101 			break;
102 		case 'e':
103 			eflag = 1;
104 			break;
105 		case 'f':
106 			add_specs(specs, optarg, 0);
107 			break;
108 		case 'h':
109 			hflag = FTS_PHYSICAL;
110 			break;
111 		case 'q':
112 			qflag = 1;
113 			break;
114 		case 's':
115 			add_specs(specs, optarg, 1);
116 			break;
117 		case 'v':
118 			vflag++;
119 			break;
120 		case 'x':
121 			xflag = FTS_XDEV;
122 			break;
123 		default:
124 			usage(is_setfmac);
125 		}
126 	}
127 	argc -= optind;
128 	argv += optind;
129 
130 	if (is_setfmac) {
131 		if (argc <= 1)
132 			usage(is_setfmac);
133 		add_setfmac_specs(specs, *argv);
134 		argc--;
135 		argv++;
136 	} else {
137 		if (argc == 0 || specs_empty(specs))
138 			usage(is_setfmac);
139 	}
140 	fts = fts_open(argv, hflag | xflag, NULL);
141 	if (fts == NULL)
142 		err(1, "cannot traverse filesystem%s", argc ? "s" : "");
143 	while ((ftsent = fts_read(fts)) != NULL) {
144 		switch (ftsent->fts_info) {
145 		case FTS_DP:		/* skip post-order */
146 			break;
147 		case FTS_D:		/* do pre-order */
148 		case FTS_DC:		/* do cyclic? */
149 			/* don't ever recurse directories as setfmac(8) */
150 			if (is_setfmac && !Rflag)
151 				fts_set(fts, ftsent, FTS_SKIP);
152 		case FTS_DEFAULT:	/* do default */
153 		case FTS_F:		/* do regular */
154 		case FTS_SL:		/* do symlink */
155 		case FTS_SLNONE:	/* do symlink */
156 		case FTS_W:		/* do whiteout */
157 			if (apply_specs(specs, ftsent, hflag, vflag)) {
158 				if (eflag) {
159 					errx(1, "labeling not supported in "
160 					    "%.*s", ftsent->fts_pathlen,
161 					    ftsent->fts_path);
162 				}
163 				if (!qflag)
164 					warnx("labeling not supported in %.*s",
165 					    ftsent->fts_pathlen,
166 					    ftsent->fts_path);
167 				fts_set(fts, ftsent, FTS_SKIP);
168 			}
169 			break;
170 		case FTS_DNR:		/* die on all errors */
171 		case FTS_ERR:
172 		case FTS_NS:
173 			err(1, "traversing %.*s", ftsent->fts_pathlen,
174 			    ftsent->fts_path);
175 		default:
176 			errx(1, "CANNOT HAPPEN (%d) traversing %.*s",
177 			    ftsent->fts_info, ftsent->fts_pathlen,
178 			    ftsent->fts_path);
179 		}
180 	}
181 	fts_close(fts);
182 	exit(0);
183 }
184 
185 void
186 usage(int is_setfmac)
187 {
188 
189 	if (is_setfmac)
190 		fprintf(stderr, "usage: setfmac [-Rhq] label file ...\n");
191 	else
192 		fprintf(stderr, "usage: setfsmac [-ehqvx] [-f specfile [...]] [-s specfile [...]] file ...\n");
193 	exit(1);
194 }
195 
196 static int
197 chomp_line(char **line, size_t *linesize)
198 {
199 	char *s;
200 	int freeme = 0;
201 
202 	for (s = *line; (unsigned)(s - *line) < *linesize; s++) {
203 		if (!isspace(*s))
204 			break;
205 	}
206 	if (*s == '#') {
207 		**line = '\0';
208 		*linesize = 0;
209 		return (freeme);
210 	}
211 	memmove(*line, s, *linesize - (s - *line));
212 	*linesize -= s - *line;
213 	for (s = &(*line)[*linesize - 1]; s >= *line; s--) {
214 		if (!isspace(*s))
215 			break;
216 	}
217 	if (s != &(*line)[*linesize - 1]) {
218 		*linesize = s - *line + 1;
219 	} else {
220 		s = malloc(*linesize + 1);
221 		if (s == NULL)
222 			err(1, "malloc");
223 		strncpy(s, *line, *linesize);
224 		*line = s;
225 		freeme = 1;
226 	}
227 	(*line)[*linesize] = '\0';
228 	return (freeme);
229 }
230 
231 void
232 add_specs(struct label_specs *specs, const char *file, int is_sebsd)
233 {
234 	struct label_spec *spec;
235 	FILE *fp;
236 	char *line;
237 	size_t nlines = 0, linesize;
238 	int freeline;
239 
240 	spec = malloc(sizeof(*spec));
241 	if (spec == NULL)
242 		err(1, "malloc");
243 	fp = fopen(file, "r");
244 	if (fp == NULL)
245 		err(1, "opening %s", file);
246 	while ((line = fgetln(fp, &linesize)) != NULL) {
247 		freeline = chomp_line(&line, &linesize);
248 		if (linesize > 0) /* only allocate space for non-comments */
249 			nlines++;
250 		if (freeline)
251 			free(line);
252 	}
253 	if (ferror(fp))
254 		err(1, "fgetln on %s", file);
255 	rewind(fp);
256 	spec->entries = calloc(nlines, sizeof(*spec->entries));
257 	if (spec->entries == NULL)
258 		err(1, "malloc");
259 	spec->nentries = nlines;
260 	while (nlines > 0) {
261 		line = fgetln(fp, &linesize);
262 		if (line == NULL) {
263 			if (feof(fp))
264 				errx(1, "%s ended prematurely", file);
265 			else
266 				err(1, "failure reading %s", file);
267 		}
268 		freeline = chomp_line(&line, &linesize);
269 		if (linesize == 0) {
270 			if (freeline)
271 				free(line);
272 			continue;
273 		}
274 		add_spec_line(file, is_sebsd, &spec->entries[--nlines], line);
275 		if (freeline)
276 			free(line);
277 	}
278 	fclose(fp);
279 	if (!qflag)
280 		warnx("%s: read %lu specifications", file,
281 		    (long)spec->nentries);
282 	STAILQ_INSERT_TAIL(&specs->head, spec, link);
283 }
284 
285 void
286 add_setfmac_specs(struct label_specs *specs, char *label)
287 {
288 	struct label_spec *spec;
289 
290 	spec = malloc(sizeof(*spec));
291 	if (spec == NULL)
292 		err(1, "malloc");
293 	spec->nentries = 1;
294 	spec->entries = calloc(spec->nentries, sizeof(*spec->entries));
295 	if (spec->entries == NULL)
296 		err(1, "malloc");
297 	/* The _only_ thing specified here is the mactext! */
298 	spec->entries->mactext = label;
299 	spec->entries->flags |= F_ALWAYSMATCH;
300 	STAILQ_INSERT_TAIL(&specs->head, spec, link);
301 }
302 
303 void
304 add_spec_line(const char *file, int is_sebsd, struct label_spec_entry *entry,
305     char *line)
306 {
307 	char *regexstr, *modestr, *macstr, *regerrorstr;
308 	size_t size;
309 	int error;
310 
311 	regexstr = strtok(line, " \t");
312 	if (regexstr == NULL)
313 		errx(1, "%s: need regular expression", file);
314 	modestr = strtok(NULL, " \t");
315 	if (modestr == NULL)
316 		errx(1, "%s: need a label", file);
317 	macstr = strtok(NULL, " \t");
318 	if (macstr == NULL) {	/* the mode is just optional */
319 		macstr = modestr;
320 		modestr = NULL;
321 	}
322 	if (strtok(NULL, " \t") != NULL)
323 		errx(1, "%s: extraneous fields at end of line", file);
324 	/* assume we need to anchor this regex */
325 	if (asprintf(&regexstr, "^%s$", regexstr) == -1)
326 		err(1, "%s: processing regular expression", file);
327 	entry->regexstr = regexstr;
328 	error = regcomp(&entry->regex, regexstr, REG_EXTENDED | REG_NOSUB);
329 	if (error) {
330 		size = regerror(error, &entry->regex, NULL, 0);
331 		regerrorstr = malloc(size);
332 		if (regerrorstr == NULL)
333 			err(1, "malloc");
334 		(void)regerror(error, &entry->regex, regerrorstr, size);
335 		errx(1, "%s: %s: %s", file, entry->regexstr, regerrorstr);
336 	}
337 	if (!is_sebsd) {
338 		entry->mactext = strdup(macstr);
339 		if (entry->mactext == NULL)
340 			err(1, "strdup");
341 	} else {
342 		if (asprintf(&entry->mactext, "sebsd/%s", macstr) == -1)
343 			err(1, "asprintf");
344 		if (strcmp(macstr, "<<none>>") == 0)
345 			entry->flags |= F_DONTLABEL;
346 	}
347 	if (modestr != NULL) {
348 		if (strlen(modestr) != 2 || modestr[0] != '-')
349 			errx(1, "%s: invalid mode string: %s", file, modestr);
350 		switch (modestr[1]) {
351 		case 'b':
352 			entry->mode = S_IFBLK;
353 			entry->modestr = ",-b";
354 			break;
355 		case 'c':
356 			entry->mode = S_IFCHR;
357 			entry->modestr = ",-c";
358 			break;
359 		case 'd':
360 			entry->mode = S_IFDIR;
361 			entry->modestr = ",-d";
362 			break;
363 		case 'p':
364 			entry->mode = S_IFIFO;
365 			entry->modestr = ",-p";
366 			break;
367 		case 'l':
368 			entry->mode = S_IFLNK;
369 			entry->modestr = ",-l";
370 			break;
371 		case 's':
372 			entry->mode = S_IFSOCK;
373 			entry->modestr = ",-s";
374 			break;
375 		case '-':
376 			entry->mode = S_IFREG;
377 			entry->modestr = ",--";
378 			break;
379 		default:
380 			errx(1, "%s: invalid mode string: %s", file, modestr);
381 		}
382 	} else {
383 		entry->modestr = "";
384 	}
385 }
386 
387 int
388 specs_empty(struct label_specs *specs)
389 {
390 
391 	return (STAILQ_EMPTY(&specs->head));
392 }
393 
394 int
395 apply_specs(struct label_specs *specs, FTSENT *ftsent, int hflag, int vflag)
396 {
397 	regmatch_t pmatch;
398 	struct label_spec *ls;
399 	struct label_spec_entry *ent;
400 	char *regerrorstr, *macstr;
401 	size_t size;
402 	mac_t mac;
403 	int error, matchedby;
404 
405 	/*
406 	 * Work through file context sources in order of specification
407 	 * on the command line, and through their entries in reverse
408 	 * order to find the "last" (hopefully "best") match.
409 	 */
410 	matchedby = 0;
411 	STAILQ_FOREACH(ls, &specs->head, link) {
412 		for (ls->match = NULL, ent = ls->entries;
413 		    ent < &ls->entries[ls->nentries]; ent++) {
414 			if (ent->flags & F_ALWAYSMATCH)
415 				goto matched;
416 			if (ent->mode != 0 &&
417 			    (ftsent->fts_statp->st_mode & S_IFMT) != ent->mode)
418 				continue;
419 			pmatch.rm_so = 0;
420 			pmatch.rm_eo = ftsent->fts_pathlen;
421 			error = regexec(&ent->regex, ftsent->fts_path, 1,
422 			    &pmatch, REG_STARTEND);
423 			switch (error) {
424 			case REG_NOMATCH:
425 				continue;
426 			case 0:
427 				break;
428 			default:
429 				size = regerror(error, &ent->regex, NULL, 0);
430 				regerrorstr = malloc(size);
431 				if (regerrorstr == NULL)
432 					err(1, "malloc");
433 				(void)regerror(error, &ent->regex, regerrorstr,
434 				    size);
435 				errx(1, "%s: %s", ent->regexstr, regerrorstr);
436 			}
437 		matched:
438 			ls->match = ent;
439 			if (vflag) {
440 				if (matchedby == 0) {
441 					printf("%.*s matched by ",
442 					    ftsent->fts_pathlen,
443 					    ftsent->fts_path);
444 					matchedby = 1;
445 				}
446 				printf("%s(%s%s,%s)", matchedby == 2 ? "," : "",
447 				    ent->regexstr, ent->modestr, ent->mactext);
448 				if (matchedby == 1)
449 					matchedby = 2;
450 			}
451 			break;
452 		}
453 	}
454 	if (vflag && matchedby)
455 		printf("\n");
456 	size = 0;
457 	STAILQ_FOREACH(ls, &specs->head, link) {
458 		/* cached match decision */
459 		if (ls->match && (ls->match->flags & F_DONTLABEL) == 0)
460 			 /* add length of "x\0"/"y," */
461 			size += strlen(ls->match->mactext) + 1;
462 	}
463 	if (size == 0)
464 		return (0);
465 	macstr = malloc(size);
466 	if (macstr == NULL)
467 		err(1, "malloc");
468 	*macstr = '\0';
469 	STAILQ_FOREACH(ls, &specs->head, link) {
470 		/* cached match decision */
471 		if (ls->match && (ls->match->flags & F_DONTLABEL) == 0) {
472 			if (*macstr != '\0')
473 				strcat(macstr, ",");
474 			strcat(macstr, ls->match->mactext);
475 		}
476 	}
477 	if (mac_from_text(&mac, macstr))
478 		err(1, "mac_from_text(%s)", macstr);
479 	if ((hflag == FTS_PHYSICAL ? mac_set_link(ftsent->fts_accpath, mac) :
480 	    mac_set_file(ftsent->fts_accpath, mac)) != 0) {
481 		if (errno == EOPNOTSUPP) {
482 			mac_free(mac);
483 			free(macstr);
484 			return (1);
485 		}
486 		err(1, "mac_set_link(%.*s, %s)", ftsent->fts_pathlen,
487 		    ftsent->fts_path, macstr);
488 	}
489 	mac_free(mac);
490 	free(macstr);
491 	return (0);
492 }
493 
494 struct label_specs *
495 new_specs(void)
496 {
497 	struct label_specs *specs;
498 
499 	specs = malloc(sizeof(*specs));
500 	if (specs == NULL)
501 		err(1, "malloc");
502 	STAILQ_INIT(&specs->head);
503 	return (specs);
504 }
505