xref: /freebsd/usr.sbin/setfmac/setfmac.c (revision 4b2eaea43fec8e8792be611dea204071a10b655a)
1 /*-
2  * Copyright (c) 2002 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/types.h>
37 #include <sys/queue.h>
38 #include <sys/mac.h>
39 #include <sys/stat.h>
40 
41 #include <ctype.h>
42 #include <err.h>
43 #include <errno.h>
44 #include <fts.h>
45 #include <libgen.h>
46 #include <regex.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <unistd.h>
51 
52 struct label_spec {
53 	struct label_spec_entry {
54 		regex_t regex;	/* compiled regular expression to match */
55 		char *regexstr;	/* uncompiled regular expression */
56 		mode_t mode;	/* mode to possibly match */
57 		char *modestr;	/* print-worthy ",-?" mode string */
58 		char *mactext;	/* MAC label to apply */
59 		int flags;	/* miscellaneous flags */
60 #define		F_DONTLABEL	0x01
61 #define		F_ALWAYSMATCH	0x02
62 	} *entries,		/* entries[0..nentries] */
63 	  *match;		/* cached decision for MAC label to apply */
64 	size_t nentries;	/* size of entries list */
65 	STAILQ_ENTRY(label_spec) link;
66 };
67 
68 struct label_specs {
69 	STAILQ_HEAD(label_specs_head, label_spec) head;
70 };
71 
72 void usage(int) __dead2;
73 struct label_specs *new_specs(void);
74 void add_specs(struct label_specs *, const char *, int);
75 void add_setfmac_specs(struct label_specs *, char *);
76 void add_spec_line(const char *, int, struct label_spec_entry *, char *);
77 int apply_specs(struct label_specs *, FTSENT *, int, int);
78 int specs_empty(struct label_specs *);
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 ? "Rh" : "ef:s:vx")) != -1) {
97 		switch (ch) {
98 		case 'R':
99 			Rflag = 1;
100 			break;
101 		case 'e':
102 			eflag = 1;
103 			break;
104 		case 'f':
105 			add_specs(specs, optarg, 0);
106 			break;
107 		case 'h':
108 			hflag = FTS_PHYSICAL;
109 			break;
110 		case 's':
111 			add_specs(specs, optarg, 1);
112 			break;
113 		case 'v':
114 			vflag++;
115 			break;
116 		case 'x':
117 			xflag = FTS_XDEV;
118 			break;
119 		default:
120 			usage(is_setfmac);
121 		}
122 	}
123 	argc -= optind;
124 	argv += optind;
125 
126 	if (is_setfmac) {
127 		if (argc <= 1)
128 			usage(is_setfmac);
129 		add_setfmac_specs(specs, *argv);
130 		argc--;
131 		argv++;
132 	} else {
133 		if (argc == 0 || specs_empty(specs))
134 			usage(is_setfmac);
135 	}
136 	fts = fts_open(argv, hflag | xflag, NULL);
137 	if (fts == NULL)
138 		err(1, "cannot traverse filesystem%s", argc ? "s" : "");
139 	while ((ftsent = fts_read(fts)) != NULL) {
140 		switch (ftsent->fts_info) {
141 		case FTS_DP:		/* skip post-order */
142 			break;
143 		case FTS_D:		/* do pre-order */
144 		case FTS_DC:		/* do cyclic? */
145 			/* don't ever recurse directories as setfmac(8) */
146 			if (is_setfmac && !Rflag)
147 				fts_set(fts, ftsent, FTS_SKIP);
148 		case FTS_DEFAULT:	/* do default */
149 		case FTS_F:		/* do regular */
150 		case FTS_SL:		/* do symlink */
151 		case FTS_SLNONE:	/* do symlink */
152 		case FTS_W:		/* do whiteout */
153 			if (apply_specs(specs, ftsent, hflag, vflag)) {
154 				if (eflag) {
155 					errx(1, "labeling not supported in "
156 					    "%.*s", ftsent->fts_pathlen,
157 					    ftsent->fts_path);
158 				}
159 				warnx("labeling not supported in %.*s",
160 				    ftsent->fts_pathlen, ftsent->fts_path);
161 				fts_set(fts, ftsent, FTS_SKIP);
162 			}
163 			break;
164 		case FTS_DNR:		/* die on all errors */
165 		case FTS_ERR:
166 		case FTS_NS:
167 			err(1, "traversing %.*s", ftsent->fts_pathlen,
168 			    ftsent->fts_path);
169 		default:
170 			errx(1, "CANNOT HAPPEN (%d) traversing %.*s",
171 			    ftsent->fts_info, ftsent->fts_pathlen,
172 			    ftsent->fts_path);
173 		}
174 	}
175 	fts_close(fts);
176 	exit(0);
177 }
178 
179 void
180 usage(int is_setfmac)
181 {
182 
183 	if (is_setfmac)
184 		fprintf(stderr, "usage: setfmac [-Rh] label file ...\n");
185 	else
186 		fprintf(stderr, "usage: setfsmac [-ehvx] [-f specfile [...]] [-s specfile [...]] file ...\n");
187 	exit(1);
188 }
189 
190 int
191 chomp_line(char **line, size_t *linesize)
192 {
193 	char *s;
194 	int freeme = 0;
195 
196 	for (s = *line; s - *line < *linesize; s++) {
197 		if (!isspace(*s))
198 			break;
199 	}
200 	if (*s == '#') {
201 		**line = '\0';
202 		*linesize = 0;
203 		return (freeme);
204 	}
205 	memmove(*line, s, *linesize - (s - *line));
206 	*linesize -= s - *line;
207 	for (s = &(*line)[*linesize - 1]; s >= *line; s--) {
208 		if (!isspace(*s))
209 			break;
210 	}
211 	if (s != &(*line)[*linesize - 1]) {
212 		*linesize = s - *line + 1;
213 	} else {
214 		s = malloc(*linesize + 1);
215 		if (s == NULL)
216 			err(1, "malloc");
217 		strncpy(s, *line, *linesize);
218 		*line = s;
219 		freeme = 1;
220 	}
221 	(*line)[*linesize] = '\0';
222 	return (freeme);
223 }
224 
225 void
226 add_specs(struct label_specs *specs, const char *file, int is_sebsd)
227 {
228 	struct label_spec *spec;
229 	FILE *fp;
230 	char *line;
231 	size_t nlines = 0, linesize;
232 	int freeline;
233 
234 	spec = malloc(sizeof(*spec));
235 	if (spec == NULL)
236 		err(1, "malloc");
237 	fp = fopen(file, "r");
238 	if (fp == NULL)
239 		err(1, "opening %s", file);
240 	while ((line = fgetln(fp, &linesize)) != NULL) {
241 		freeline = chomp_line(&line, &linesize);
242 		if (linesize > 0) /* only allocate space for non-comments */
243 			nlines++;
244 		if (freeline)
245 			free(line);
246 	}
247 	if (ferror(fp))
248 		err(1, "fgetln on %s", file);
249 	rewind(fp);
250 	spec->entries = calloc(nlines, sizeof(*spec->entries));
251 	if (spec->entries == NULL)
252 		err(1, "malloc");
253 	spec->nentries = nlines;
254 	while (nlines > 0) {
255 		line = fgetln(fp, &linesize);
256 		if (line == NULL) {
257 			if (feof(fp))
258 				errx(1, "%s ended prematurely", file);
259 			else
260 				err(1, "failure reading %s", file);
261 		}
262 		freeline = chomp_line(&line, &linesize);
263 		if (linesize == 0) {
264 			if (freeline)
265 				free(line);
266 			continue;
267 		}
268 		add_spec_line(file, is_sebsd, &spec->entries[--nlines], line);
269 		if (freeline)
270 			free(line);
271 	}
272 	fclose(fp);
273 	warnx("%s: read %lu specifications", file, (long)spec->nentries);
274 	STAILQ_INSERT_TAIL(&specs->head, spec, link);
275 }
276 
277 void
278 add_setfmac_specs(struct label_specs *specs, char *label)
279 {
280 	struct label_spec *spec;
281 
282 	spec = malloc(sizeof(*spec));
283 	if (spec == NULL)
284 		err(1, "malloc");
285 	spec->nentries = 1;
286 	spec->entries = calloc(spec->nentries, sizeof(*spec->entries));
287 	if (spec->entries == NULL)
288 		err(1, "malloc");
289 	/* The _only_ thing specified here is the mactext! */
290 	spec->entries->mactext = label;
291 	spec->entries->flags |= F_ALWAYSMATCH;
292 	STAILQ_INSERT_TAIL(&specs->head, spec, link);
293 }
294 
295 void
296 add_spec_line(const char *file, int is_sebsd, struct label_spec_entry *entry,
297     char *line)
298 {
299 	char *regexstr, *modestr, *macstr, *regerrorstr;
300 	size_t size;
301 	int error;
302 
303 	regexstr = strtok(line, " \t");
304 	if (regexstr == NULL)
305 		errx(1, "%s: need regular expression", file);
306 	modestr = strtok(NULL, " \t");
307 	if (modestr == NULL)
308 		errx(1, "%s: need a label", file);
309 	macstr = strtok(NULL, " \t");
310 	if (macstr == NULL) {	/* the mode is just optional */
311 		macstr = modestr;
312 		modestr = NULL;
313 	}
314 	if (strtok(NULL, " \t") != NULL)
315 		errx(1, "%s: extraneous fields at end of line", file);
316 	/* assume we need to anchor this regex */
317 	if (asprintf(&regexstr, "^%s$", regexstr) == -1)
318 		err(1, "%s: processing regular expression", file);
319 	entry->regexstr = regexstr;
320 	error = regcomp(&entry->regex, regexstr, REG_EXTENDED | REG_NOSUB);
321 	if (error) {
322 		size = regerror(error, &entry->regex, NULL, 0);
323 		regerrorstr = malloc(size);
324 		if (regerrorstr == NULL)
325 			err(1, "malloc");
326 		(void)regerror(error, &entry->regex, regerrorstr, size);
327 		errx(1, "%s: %s: %s", file, entry->regexstr, regerrorstr);
328 	}
329 	if (!is_sebsd) {
330 		entry->mactext = strdup(macstr);
331 		if (entry->mactext == NULL)
332 			err(1, "strdup");
333 	} else {
334 		if (asprintf(&entry->mactext, "sebsd/%s", macstr) == -1)
335 			err(1, "asprintf");
336 		if (strcmp(macstr, "<<none>>") == 0)
337 			entry->flags |= F_DONTLABEL;
338 	}
339 	if (modestr != NULL) {
340 		if (strlen(modestr) != 2 || modestr[0] != '-')
341 			errx(1, "%s: invalid mode string: %s", file, modestr);
342 		switch (modestr[1]) {
343 		case 'b':
344 			entry->mode = S_IFBLK;
345 			entry->modestr = ",-b";
346 			break;
347 		case 'c':
348 			entry->mode = S_IFCHR;
349 			entry->modestr = ",-c";
350 			break;
351 		case 'd':
352 			entry->mode = S_IFDIR;
353 			entry->modestr = ",-d";
354 			break;
355 		case 'p':
356 			entry->mode = S_IFIFO;
357 			entry->modestr = ",-p";
358 			break;
359 		case 'l':
360 			entry->mode = S_IFLNK;
361 			entry->modestr = ",-l";
362 			break;
363 		case 's':
364 			entry->mode = S_IFSOCK;
365 			entry->modestr = ",-s";
366 			break;
367 		case '-':
368 			entry->mode = S_IFREG;
369 			entry->modestr = ",--";
370 			break;
371 		default:
372 			errx(1, "%s: invalid mode string: %s", file, modestr);
373 		}
374 	} else {
375 		entry->modestr = "";
376 	}
377 }
378 
379 int
380 specs_empty(struct label_specs *specs)
381 {
382 
383 	return (STAILQ_EMPTY(&specs->head));
384 }
385 
386 int
387 apply_specs(struct label_specs *specs, FTSENT *ftsent, int hflag, int vflag)
388 {
389 	regmatch_t pmatch;
390 	struct label_spec *ls;
391 	struct label_spec_entry *ent;
392 	char *regerrorstr, *macstr;
393 	size_t size;
394 	mac_t mac;
395 	int error, matchedby;
396 
397 	/*
398 	 * Work through file context sources in order of specification
399 	 * on the command line, and through their entries in reverse
400 	 * order to find the "last" (hopefully "best") match.
401 	 */
402 	matchedby = 0;
403 	STAILQ_FOREACH(ls, &specs->head, link) {
404 		for (ls->match = NULL, ent = ls->entries;
405 		    ent < &ls->entries[ls->nentries]; ent++) {
406 			if (ent->flags & F_ALWAYSMATCH)
407 				goto matched;
408 			if (ent->mode != 0 &&
409 			    (ftsent->fts_statp->st_mode & S_IFMT) != ent->mode)
410 				continue;
411 			pmatch.rm_so = 0;
412 			pmatch.rm_eo = ftsent->fts_pathlen;
413 			error = regexec(&ent->regex, ftsent->fts_path, 1,
414 			    &pmatch, REG_STARTEND);
415 			switch (error) {
416 			case REG_NOMATCH:
417 				continue;
418 			case 0:
419 				break;
420 			default:
421 				size = regerror(error, &ent->regex, NULL, 0);
422 				regerrorstr = malloc(size);
423 				if (regerrorstr == NULL)
424 					err(1, "malloc");
425 				(void)regerror(error, &ent->regex, regerrorstr,
426 				    size);
427 				errx(1, "%s: %s", ent->regexstr, regerrorstr);
428 			}
429 		matched:
430 			ls->match = ent;
431 			if (vflag) {
432 				if (matchedby == 0) {
433 					printf("%.*s matched by ",
434 					    ftsent->fts_pathlen,
435 					    ftsent->fts_path);
436 					matchedby = 1;
437 				}
438 				printf("%s(%s%s,%s)", matchedby == 2 ? "," : "",
439 				    ent->regexstr, ent->modestr, ent->mactext);
440 				if (matchedby == 1)
441 					matchedby = 2;
442 			}
443 			break;
444 		}
445 	}
446 	if (vflag && matchedby)
447 		printf("\n");
448 	size = 0;
449 	STAILQ_FOREACH(ls, &specs->head, link) {
450 		/* cached match decision */
451 		if (ls->match && (ls->match->flags & F_DONTLABEL) == 0)
452 			 /* add length of "x\0"/"y," */
453 			size += strlen(ls->match->mactext) + 1;
454 	}
455 	if (size == 0)
456 		return (0);
457 	macstr = malloc(size);
458 	if (macstr == NULL)
459 		err(1, "malloc");
460 	*macstr = '\0';
461 	STAILQ_FOREACH(ls, &specs->head, link) {
462 		/* cached match decision */
463 		if (ls->match && (ls->match->flags & F_DONTLABEL) == 0) {
464 			if (*macstr != '\0')
465 				strcat(macstr, ",");
466 			strcat(macstr, ls->match->mactext);
467 		}
468 	}
469 	if (mac_from_text(&mac, macstr))
470 		err(1, "mac_from_text(%s)", macstr);
471 	if ((hflag == FTS_PHYSICAL ? mac_set_link(ftsent->fts_accpath, mac) :
472 	    mac_set_file(ftsent->fts_accpath, mac)) != 0) {
473 		if (errno == EOPNOTSUPP) {
474 			mac_free(mac);
475 			free(macstr);
476 			return (1);
477 		}
478 		err(1, "mac_set_link(%.*s, %s)", ftsent->fts_pathlen,
479 		    ftsent->fts_path, macstr);
480 	}
481 	mac_free(mac);
482 	free(macstr);
483 	return (0);
484 }
485 
486 struct label_specs *
487 new_specs(void)
488 {
489 	struct label_specs *specs;
490 
491 	specs = malloc(sizeof(*specs));
492 	if (specs == NULL)
493 		err(1, "malloc");
494 	STAILQ_INIT(&specs->head);
495 	return (specs);
496 }
497