1/*
2  setfiles: based on policycoreutils 2.0.19
3  policycoreutils was released under GPL 2.
4  Port to BusyBox (c) 2007 by Yuichi Nakamura <ynakam@hitachisoft.jp>
5*/
6
7#include "libbb.h"
8#if ENABLE_FEATURE_SETFILES_CHECK_OPTION
9#include <sepol/sepol.h>
10#endif
11
12#define MAX_EXCLUDES 50
13
14struct edir {
15	char *directory;
16	size_t size;
17};
18
19struct globals {
20	FILE *outfile;
21	char *policyfile;
22	char *rootpath;
23	int rootpathlen;
24	unsigned count;
25	int excludeCtr;
26	int errors;
27	int verbose; /* getopt32 uses it, has to be int */
28	smallint recurse; /* Recursive descent */
29	smallint follow_mounts;
30	/* Behavior flags determined based on setfiles vs. restorecon */
31	smallint expand_realpath;  /* Expand paths via realpath */
32	smallint abort_on_error; /* Abort the file tree walk upon an error */
33	int add_assoc; /* Track inode associations for conflict detection */
34	int matchpathcon_flags; /* Flags to matchpathcon */
35	dev_t dev_id; /* Device id where target file exists */
36	int nerr;
37	struct edir excludeArray[MAX_EXCLUDES];
38};
39
40#define G (*(struct globals*)&bb_common_bufsiz1)
41void BUG_setfiles_globals_too_big(void);
42#define INIT_G() do { \
43	if (sizeof(G) > COMMON_BUFSIZE) \
44		BUG_setfiles_globals_too_big(); \
45	/* memset(&G, 0, sizeof(G)); - already is */ \
46} while (0)
47#define outfile            (G.outfile           )
48#define policyfile         (G.policyfile        )
49#define rootpath           (G.rootpath          )
50#define rootpathlen        (G.rootpathlen       )
51#define count              (G.count             )
52#define excludeCtr         (G.excludeCtr        )
53#define errors             (G.errors            )
54#define verbose            (G.verbose           )
55#define recurse            (G.recurse           )
56#define follow_mounts      (G.follow_mounts     )
57#define expand_realpath    (G.expand_realpath   )
58#define abort_on_error     (G.abort_on_error    )
59#define add_assoc          (G.add_assoc         )
60#define matchpathcon_flags (G.matchpathcon_flags)
61#define dev_id             (G.dev_id            )
62#define nerr               (G.nerr              )
63#define excludeArray       (G.excludeArray      )
64
65/* Must match getopt32 string! */
66enum {
67	OPT_d = (1 << 0),
68	OPT_e = (1 << 1),
69	OPT_f = (1 << 2),
70	OPT_i = (1 << 3),
71	OPT_l = (1 << 4),
72	OPT_n = (1 << 5),
73	OPT_p = (1 << 6),
74	OPT_q = (1 << 7),
75	OPT_r = (1 << 8),
76	OPT_s = (1 << 9),
77	OPT_v = (1 << 10),
78	OPT_o = (1 << 11),
79	OPT_F = (1 << 12),
80	OPT_W = (1 << 13),
81	OPT_c = (1 << 14), /* c only for setfiles */
82	OPT_R = (1 << 14), /* R only for restorecon */
83};
84#define FLAG_d_debug         (option_mask32 & OPT_d)
85#define FLAG_e               (option_mask32 & OPT_e)
86#define FLAG_f               (option_mask32 & OPT_f)
87#define FLAG_i_ignore_enoent (option_mask32 & OPT_i)
88#define FLAG_l_take_log      (option_mask32 & OPT_l)
89#define FLAG_n_dry_run       (option_mask32 & OPT_n)
90#define FLAG_p_progress      (option_mask32 & OPT_p)
91#define FLAG_q_quiet         (option_mask32 & OPT_q)
92#define FLAG_r               (option_mask32 & OPT_r)
93#define FLAG_s               (option_mask32 & OPT_s)
94#define FLAG_v               (option_mask32 & OPT_v)
95#define FLAG_o               (option_mask32 & OPT_o)
96#define FLAG_F_force         (option_mask32 & OPT_F)
97#define FLAG_W_warn_no_match (option_mask32 & OPT_W)
98#define FLAG_c               (option_mask32 & OPT_c)
99#define FLAG_R               (option_mask32 & OPT_R)
100
101
102static void qprintf(const char *fmt, ...)
103{
104	/* quiet, do nothing */
105}
106
107static void inc_err(void)
108{
109	nerr++;
110	if (nerr > 9 && !FLAG_d_debug) {
111		bb_error_msg_and_die("exiting after 10 errors");
112	}
113}
114
115static void add_exclude(const char *const directory)
116{
117	struct stat sb;
118	size_t len;
119
120	if (directory == NULL || directory[0] != '/') {
121		bb_error_msg_and_die("full path required for exclude: %s", directory);
122
123	}
124	if (lstat(directory, &sb)) {
125		bb_error_msg("directory \"%s\" not found, ignoring", directory);
126		return;
127	}
128	if ((sb.st_mode & S_IFDIR) == 0) {
129		bb_error_msg("\"%s\" is not a directory: mode %o, ignoring",
130			directory, sb.st_mode);
131		return;
132	}
133	if (excludeCtr == MAX_EXCLUDES) {
134		bb_error_msg_and_die("maximum excludes %d exceeded", MAX_EXCLUDES);
135	}
136
137	len = strlen(directory);
138	while (len > 1 && directory[len - 1] == '/') {
139		len--;
140	}
141	excludeArray[excludeCtr].directory = xstrndup(directory, len);
142	excludeArray[excludeCtr++].size = len;
143}
144
145static bool exclude(const char *file)
146{
147	int i = 0;
148	for (i = 0; i < excludeCtr; i++) {
149		if (strncmp(file, excludeArray[i].directory,
150					excludeArray[i].size) == 0) {
151			if (file[excludeArray[i].size] == '\0'
152			 || file[excludeArray[i].size] == '/') {
153				return 1;
154			}
155		}
156	}
157	return 0;
158}
159
160static int match(const char *name, struct stat *sb, char **con)
161{
162	int ret;
163	char path[PATH_MAX + 1];
164	char *tmp_path = xstrdup(name);
165
166	if (excludeCtr > 0 && exclude(name)) {
167		goto err;
168	}
169	ret = lstat(name, sb);
170	if (ret) {
171		if (FLAG_i_ignore_enoent && errno == ENOENT) {
172			free(tmp_path);
173			return 0;
174		}
175		bb_error_msg("stat(%s)", name);
176		goto err;
177	}
178
179	if (expand_realpath) {
180		if (S_ISLNK(sb->st_mode)) {
181			char *p = NULL;
182			char *file_sep;
183
184			size_t len = 0;
185
186			if (verbose > 1)
187				bb_error_msg("warning! %s refers to a symbolic link, not following last component", name);
188
189			file_sep = strrchr(tmp_path, '/');
190			if (file_sep == tmp_path) {
191				file_sep++;
192				path[0] = '\0';
193				p = path;
194			} else if (file_sep) {
195				*file_sep++ = '\0';
196				p = realpath(tmp_path, path);
197			} else {
198				file_sep = tmp_path;
199				p = realpath("./", path);
200			}
201			if (p)
202				len = strlen(p);
203			if (!p || len + strlen(file_sep) + 2 > PATH_MAX) {
204				bb_perror_msg("realpath(%s) failed", name);
205				goto err;
206			}
207			p += len;
208			/* ensure trailing slash of directory name */
209			if (len == 0 || p[-1] != '/') {
210				*p++ = '/';
211			}
212			strcpy(p, file_sep);
213			name = path;
214			if (excludeCtr > 0 && exclude(name))
215				goto err;
216
217		} else {
218			char *p;
219			p = realpath(name, path);
220			if (!p) {
221				bb_perror_msg("realpath(%s)", name);
222				goto err;
223			}
224			name = p;
225			if (excludeCtr > 0 && exclude(name))
226				goto err;
227		}
228	}
229
230	/* name will be what is matched in the policy */
231	if (NULL != rootpath) {
232		if (0 != strncmp(rootpath, name, rootpathlen)) {
233			bb_error_msg("%s is not located in %s",
234				name, rootpath);
235			goto err;
236		}
237		name += rootpathlen;
238	}
239
240	free(tmp_path);
241	if (rootpath != NULL && name[0] == '\0')
242		/* this is actually the root dir of the alt root */
243		return matchpathcon_index("/", sb->st_mode, con);
244	return matchpathcon_index(name, sb->st_mode, con);
245 err:
246	free(tmp_path);
247	return -1;
248}
249
250/* Compare two contexts to see if their differences are "significant",
251 * or whether the only difference is in the user. */
252static bool only_changed_user(const char *a, const char *b)
253{
254	if (FLAG_F_force)
255		return 0;
256	if (!a || !b)
257		return 0;
258	a = strchr(a, ':'); /* Rest of the context after the user */
259	b = strchr(b, ':');
260	if (!a || !b)
261		return 0;
262	return (strcmp(a, b) == 0);
263}
264
265static int restore(const char *file)
266{
267	char *my_file;
268	struct stat my_sb;
269	int i, j, ret;
270	char *context = NULL;
271	char *newcon = NULL;
272	bool user_only_changed = 0;
273	int retval = 0;
274
275	my_file = bb_simplify_path(file);
276
277	i = match(my_file, &my_sb, &newcon);
278
279	if (i < 0) /* No matching specification. */
280		goto out;
281
282	if (FLAG_p_progress) {
283		count++;
284		if (count % 0x400 == 0) { /* every 1024 times */
285			count = (count % (80*0x400));
286			if (count == 0)
287				fputc('\n', stdout);
288			fputc('*', stdout);
289			fflush(stdout);
290		}
291	}
292
293	/*
294	 * Try to add an association between this inode and
295	 * this specification. If there is already an association
296	 * for this inode and it conflicts with this specification,
297	 * then use the last matching specification.
298	 */
299	if (add_assoc) {
300		j = matchpathcon_filespec_add(my_sb.st_ino, i, my_file);
301		if (j < 0)
302			goto err;
303
304		if (j != i) {
305			/* There was already an association and it took precedence. */
306			goto out;
307		}
308	}
309
310	if (FLAG_d_debug)
311		printf("%s: %s matched by %s\n", applet_name, my_file, newcon);
312
313	/* Get the current context of the file. */
314	ret = lgetfilecon_raw(my_file, &context);
315	if (ret < 0) {
316		if (errno == ENODATA) {
317			context = NULL; /* paranoia */
318		} else {
319			bb_perror_msg("lgetfilecon_raw on %s", my_file);
320			goto err;
321		}
322		user_only_changed = 0;
323	} else
324		user_only_changed = only_changed_user(context, newcon);
325
326	/*
327	 * Do not relabel the file if the matching specification is
328	 * <<none>> or the file is already labeled according to the
329	 * specification.
330	 */
331	if ((strcmp(newcon, "<<none>>") == 0)
332	 || (context && (strcmp(context, newcon) == 0) && !FLAG_F_force)) {
333		goto out;
334	}
335
336	if (!FLAG_F_force && context && (is_context_customizable(context) > 0)) {
337		if (verbose > 1) {
338			bb_error_msg("skipping %s. %s is customizable_types",
339				my_file, context);
340		}
341		goto out;
342	}
343
344	if (verbose) {
345		/* If we're just doing "-v", trim out any relabels where
346		 * the user has changed but the role and type are the
347		 * same.  For "-vv", emit everything. */
348		if (verbose > 1 || !user_only_changed) {
349			bb_info_msg("%s: reset %s context %s->%s",
350				applet_name, my_file, context ?: "", newcon);
351		}
352	}
353
354	if (FLAG_l_take_log && !user_only_changed) {
355		if (context)
356			bb_info_msg("relabeling %s from %s to %s", my_file, context, newcon);
357		else
358			bb_info_msg("labeling %s to %s", my_file, newcon);
359	}
360
361	if (outfile && !user_only_changed)
362		fprintf(outfile, "%s\n", my_file);
363
364	/*
365	 * Do not relabel the file if -n was used.
366	 */
367	if (FLAG_n_dry_run || user_only_changed)
368		goto out;
369
370	/*
371	 * Relabel the file to the specified context.
372	 */
373	ret = lsetfilecon(my_file, newcon);
374	if (ret) {
375		bb_perror_msg("lsetfileconon(%s,%s)", my_file, newcon);
376		goto err;
377	}
378
379 out:
380	freecon(context);
381	freecon(newcon);
382	free(my_file);
383	return retval;
384 err:
385	retval--; /* -1 */
386	goto out;
387}
388
389/*
390 * Apply the last matching specification to a file.
391 * This function is called by recursive_action on each file during
392 * the directory traversal.
393 */
394static int apply_spec(const char *file,
395		      struct stat *sb, void *userData, int depth)
396{
397	if (!follow_mounts) {
398		/* setfiles does not process across different mount points */
399		if (sb->st_dev != dev_id) {
400			return SKIP;
401		}
402	}
403	errors |= restore(file);
404	if (abort_on_error && errors)
405		return FALSE;
406	return TRUE;
407}
408
409
410static int canoncon(const char *path, unsigned lineno, char **contextp)
411{
412	static const char err_msg[] ALIGN1 = "%s: line %u has invalid context %s";
413
414	char *tmpcon;
415	char *context = *contextp;
416	int invalid = 0;
417
418#if ENABLE_FEATURE_SETFILES_CHECK_OPTION
419	if (policyfile) {
420		if (sepol_check_context(context) >= 0)
421			return 0;
422		/* Exit immediately if we're in checking mode. */
423		bb_error_msg_and_die(err_msg, path, lineno, context);
424	}
425#endif
426
427	if (security_canonicalize_context_raw(context, &tmpcon) < 0) {
428		if (errno != ENOENT) {
429			invalid = 1;
430			inc_err();
431		}
432	} else {
433		free(context);
434		*contextp = tmpcon;
435	}
436
437	if (invalid) {
438		bb_error_msg(err_msg, path, lineno, context);
439	}
440
441	return invalid;
442}
443
444static int process_one(char *name)
445{
446	struct stat sb;
447	int rc;
448
449	rc = lstat(name, &sb);
450	if (rc < 0) {
451		if (FLAG_i_ignore_enoent && errno == ENOENT)
452			return 0;
453		bb_perror_msg("stat(%s)", name);
454		goto err;
455	}
456	dev_id = sb.st_dev;
457
458	if (S_ISDIR(sb.st_mode) && recurse) {
459		if (recursive_action(name,
460				     ACTION_RECURSE,
461				     apply_spec,
462				     apply_spec,
463				     NULL, 0) != TRUE) {
464			bb_error_msg("error while labeling %s", name);
465			goto err;
466		}
467	} else {
468		rc = restore(name);
469		if (rc)
470			goto err;
471	}
472
473 out:
474	if (add_assoc) {
475		if (FLAG_q_quiet)
476			set_matchpathcon_printf(&qprintf);
477		matchpathcon_filespec_eval();
478		set_matchpathcon_printf(NULL);
479		matchpathcon_filespec_destroy();
480	}
481
482	return rc;
483
484 err:
485	rc = -1;
486	goto out;
487}
488
489int setfiles_main(int argc, char **argv);
490int setfiles_main(int argc, char **argv)
491{
492	struct stat sb;
493	int rc, i = 0;
494	const char *input_filename = NULL;
495	char *buf = NULL;
496	size_t buf_len;
497	int flags;
498	llist_t *exclude_dir = NULL;
499	char *out_filename = NULL;
500
501	INIT_G();
502
503	if (applet_name[0] == 's') { /* "setfiles" */
504		/*
505		 * setfiles:
506		 * Recursive descent,
507		 * Does not expand paths via realpath,
508		 * Aborts on errors during the file tree walk,
509		 * Try to track inode associations for conflict detection,
510		 * Does not follow mounts,
511		 * Validates all file contexts at init time.
512		 */
513		recurse = 1;
514		abort_on_error = 1;
515		add_assoc = 1;
516		/* follow_mounts = 0; - already is */
517		matchpathcon_flags = MATCHPATHCON_VALIDATE | MATCHPATHCON_NOTRANS;
518	} else {
519		/*
520		 * restorecon:
521		 * No recursive descent unless -r/-R,
522		 * Expands paths via realpath,
523		 * Do not abort on errors during the file tree walk,
524		 * Do not try to track inode associations for conflict detection,
525		 * Follows mounts,
526		 * Does lazy validation of contexts upon use.
527		 */
528		expand_realpath = 1;
529		follow_mounts = 1;
530		matchpathcon_flags = MATCHPATHCON_NOTRANS;
531		/* restorecon only */
532		selinux_or_die();
533	}
534
535	set_matchpathcon_flags(matchpathcon_flags);
536
537	opt_complementary = "e::vv:v--p:p--v:v--q:q--v";
538	/* Option order must match OPT_x definitions! */
539	if (applet_name[0] == 'r') { /* restorecon */
540		flags = getopt32(argv, "de:f:ilnpqrsvo:FWR",
541			&exclude_dir, &input_filename, &out_filename, &verbose);
542	} else { /* setfiles */
543		flags = getopt32(argv, "de:f:ilnpqr:svo:FW"
544				USE_FEATURE_SETFILES_CHECK_OPTION("c:"),
545			&exclude_dir, &input_filename, &rootpath, &out_filename,
546				 USE_FEATURE_SETFILES_CHECK_OPTION(&policyfile,)
547			&verbose);
548	}
549
550#if ENABLE_FEATURE_SETFILES_CHECK_OPTION
551	if ((applet_name[0] == 's') && (flags & OPT_c)) {
552		FILE *policystream;
553
554		policystream = xfopen(policyfile, "r");
555		if (sepol_set_policydb_from_file(policystream) < 0) {
556			bb_error_msg_and_die("sepol_set_policydb_from_file on %s", policyfile);
557		}
558		fclose(policystream);
559
560		/* Only process the specified file_contexts file, not
561		   any .homedirs or .local files, and do not perform
562		   context translations. */
563		set_matchpathcon_flags(MATCHPATHCON_BASEONLY |
564				       MATCHPATHCON_NOTRANS |
565				       MATCHPATHCON_VALIDATE);
566	}
567#endif
568
569	while (exclude_dir)
570		add_exclude(llist_pop(&exclude_dir));
571
572	if (flags & OPT_o) {
573		outfile = stdout;
574		if (NOT_LONE_CHAR(out_filename, '-')) {
575			outfile = xfopen(out_filename, "w");
576		}
577	}
578	if (applet_name[0] == 'r') { /* restorecon */
579		if (flags & (OPT_r | OPT_R))
580			recurse = 1;
581	} else { /* setfiles */
582		if (flags & OPT_r)
583			rootpathlen = strlen(rootpath);
584	}
585	if (flags & OPT_s) {
586		input_filename = "-";
587		add_assoc = 0;
588	}
589
590	if (applet_name[0] == 's') { /* setfiles */
591		/* Use our own invalid context checking function so that
592		   we can support either checking against the active policy or
593		   checking against a binary policy file. */
594		set_matchpathcon_canoncon(&canoncon);
595		if (argc == 1)
596			bb_show_usage();
597		if (stat(argv[optind], &sb) < 0) {
598			bb_perror_msg_and_die("%s", argv[optind]);
599		}
600		if (!S_ISREG(sb.st_mode)) {
601			bb_error_msg_and_die("spec file %s is not a regular file", argv[optind]);
602		}
603		/* Load the file contexts configuration and check it. */
604		rc = matchpathcon_init(argv[optind]);
605		if (rc < 0) {
606			bb_perror_msg_and_die("%s", argv[optind]);
607		}
608
609		optind++;
610
611		if (nerr)
612			exit(1);
613	}
614
615	if (input_filename) {
616		ssize_t len;
617		FILE *f = stdin;
618
619		if (NOT_LONE_CHAR(input_filename, '-'))
620			f = xfopen(input_filename, "r");
621		while ((len = getline(&buf, &buf_len, f)) > 0) {
622			buf[len - 1] = '\0';
623			errors |= process_one(buf);
624		}
625		if (ENABLE_FEATURE_CLEAN_UP)
626			fclose_if_not_stdin(f);
627	} else {
628		if (optind >= argc)
629			bb_show_usage();
630		for (i = optind; i < argc; i++) {
631			errors |= process_one(argv[i]);
632		}
633	}
634
635	if (FLAG_W_warn_no_match)
636		matchpathcon_checkmatches(argv[0]);
637
638	if (ENABLE_FEATURE_CLEAN_UP && outfile)
639		fclose(outfile);
640
641	return errors;
642}
643