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path: root/selinux/setfiles.c (plain)
blob: 9fa5d3f3093a049da7f808bbd5223751f8067e9d
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//config:config SETFILES
7//config: bool "setfiles"
8//config: default n
9//config: depends on SELINUX
10//config: help
11//config: Enable support to modify to relabel files.
12//config: Notice: If you built libselinux with -D_FILE_OFFSET_BITS=64,
13//config: (It is default in libselinux's Makefile), you _must_ enable
14//config: CONFIG_LFS.
15//config:
16//config:config FEATURE_SETFILES_CHECK_OPTION
17//config: bool "Enable check option"
18//config: default n
19//config: depends on SETFILES
20//config: help
21//config: Support "-c" option (check the validity of the contexts against
22//config: the specified binary policy) for setfiles. Requires libsepol.
23//config:
24//config:config RESTORECON
25//config: bool "restorecon"
26//config: default n
27//config: depends on SELINUX
28//config: help
29//config: Enable support to relabel files. The feature is almost
30//config: the same as setfiles, but usage is a little different.
31
32//applet:IF_SETFILES(APPLET(setfiles, BB_DIR_SBIN, BB_SUID_DROP))
33//applet:IF_RESTORECON(APPLET_ODDNAME(restorecon, setfiles, BB_DIR_SBIN, BB_SUID_DROP, restorecon))
34
35//kbuild:lib-$(CONFIG_SETFILES) += setfiles.o
36//kbuild:lib-$(CONFIG_RESTORECON) += setfiles.o
37
38//usage:#define setfiles_trivial_usage
39//usage: "[-dnpqsvW] [-e DIR]... [-o FILE] [-r alt_root_path]"
40//usage: IF_FEATURE_SETFILES_CHECK_OPTION(
41//usage: " [-c policyfile] spec_file"
42//usage: )
43//usage: " pathname"
44//usage:#define setfiles_full_usage "\n\n"
45//usage: "Reset file contexts under pathname according to spec_file\n"
46//usage: IF_FEATURE_SETFILES_CHECK_OPTION(
47//usage: "\n -c FILE Check the validity of the contexts against the specified binary policy"
48//usage: )
49//usage: "\n -d Show which specification matched each file"
50//usage: "\n -l Log changes in file labels to syslog"
51//TODO: log to syslog is not yet implemented, it goes to stdout only now
52//usage: "\n -n Don't change any file labels"
53//usage: "\n -q Suppress warnings"
54//usage: "\n -r DIR Use an alternate root path"
55//usage: "\n -e DIR Exclude DIR"
56//usage: "\n -F Force reset of context to match file_context for customizable files"
57//usage: "\n -o FILE Save list of files with incorrect context"
58//usage: "\n -s Take a list of files from stdin (instead of command line)"
59//usage: "\n -v Show changes in file labels, if type or role are changing"
60//usage: "\n -vv Show changes in file labels, if type, role, or user are changing"
61//usage: "\n -W Display warnings about entries that had no matching files"
62//usage:
63//usage:#define restorecon_trivial_usage
64//usage: "[-iFnRv] [-e EXCLUDEDIR]... [-o FILE] [-f FILE]"
65//usage:#define restorecon_full_usage "\n\n"
66//usage: "Reset security contexts of files in pathname\n"
67//usage: "\n -i Ignore files that don't exist"
68//usage: "\n -f FILE File with list of files to process"
69//usage: "\n -e DIR Directory to exclude"
70//usage: "\n -R,-r Recurse"
71//usage: "\n -n Don't change any file labels"
72//usage: "\n -o FILE Save list of files with incorrect context"
73//usage: "\n -v Verbose"
74//usage: "\n -vv Show changed labels"
75//usage: "\n -F Force reset of context to match file_context"
76//usage: "\n for customizable files, or the user section,"
77//usage: "\n if it has changed"
78
79#include "libbb.h"
80#include "common_bufsiz.h"
81#if ENABLE_FEATURE_SETFILES_CHECK_OPTION
82#include <sepol/sepol.h>
83#endif
84
85#define MAX_EXCLUDES 50
86
87struct edir {
88 char *directory;
89 size_t size;
90};
91
92struct globals {
93 FILE *outfile;
94 char *policyfile;
95 char *rootpath;
96 int rootpathlen;
97 unsigned count;
98 int excludeCtr;
99 int errors;
100 int verbose; /* getopt32 uses it, has to be int */
101 smallint recurse; /* Recursive descent */
102 smallint follow_mounts;
103 /* Behavior flags determined based on setfiles vs. restorecon */
104 smallint expand_realpath; /* Expand paths via realpath */
105 smallint abort_on_error; /* Abort the file tree walk upon an error */
106 int add_assoc; /* Track inode associations for conflict detection */
107 int matchpathcon_flags; /* Flags to matchpathcon */
108 dev_t dev_id; /* Device id where target file exists */
109 int nerr;
110 struct edir excludeArray[MAX_EXCLUDES];
111} FIX_ALIASING;
112#define G (*(struct globals*)bb_common_bufsiz1)
113void BUG_setfiles_globals_too_big(void);
114#define INIT_G() do { \
115 setup_common_bufsiz(); \
116 if (sizeof(G) > COMMON_BUFSIZE) \
117 BUG_setfiles_globals_too_big(); \
118 /* memset(&G, 0, sizeof(G)); - already is */ \
119} while (0)
120#define outfile (G.outfile )
121#define policyfile (G.policyfile )
122#define rootpath (G.rootpath )
123#define rootpathlen (G.rootpathlen )
124#define count (G.count )
125#define excludeCtr (G.excludeCtr )
126#define errors (G.errors )
127#define verbose (G.verbose )
128#define recurse (G.recurse )
129#define follow_mounts (G.follow_mounts )
130#define expand_realpath (G.expand_realpath )
131#define abort_on_error (G.abort_on_error )
132#define add_assoc (G.add_assoc )
133#define matchpathcon_flags (G.matchpathcon_flags)
134#define dev_id (G.dev_id )
135#define nerr (G.nerr )
136#define excludeArray (G.excludeArray )
137
138/* Must match getopt32 string! */
139enum {
140 OPT_d = (1 << 0),
141 OPT_e = (1 << 1),
142 OPT_f = (1 << 2),
143 OPT_i = (1 << 3),
144 OPT_l = (1 << 4),
145 OPT_n = (1 << 5),
146 OPT_p = (1 << 6),
147 OPT_q = (1 << 7),
148 OPT_r = (1 << 8),
149 OPT_s = (1 << 9),
150 OPT_v = (1 << 10),
151 OPT_o = (1 << 11),
152 OPT_F = (1 << 12),
153 OPT_W = (1 << 13),
154 OPT_c = (1 << 14), /* c only for setfiles */
155 OPT_R = (1 << 14), /* R only for restorecon */
156};
157#define FLAG_d_debug (option_mask32 & OPT_d)
158#define FLAG_e (option_mask32 & OPT_e)
159#define FLAG_f (option_mask32 & OPT_f)
160#define FLAG_i_ignore_enoent (option_mask32 & OPT_i)
161#define FLAG_l_take_log (option_mask32 & OPT_l)
162#define FLAG_n_dry_run (option_mask32 & OPT_n)
163#define FLAG_p_progress (option_mask32 & OPT_p)
164#define FLAG_q_quiet (option_mask32 & OPT_q)
165#define FLAG_r (option_mask32 & OPT_r)
166#define FLAG_s (option_mask32 & OPT_s)
167#define FLAG_v (option_mask32 & OPT_v)
168#define FLAG_o (option_mask32 & OPT_o)
169#define FLAG_F_force (option_mask32 & OPT_F)
170#define FLAG_W_warn_no_match (option_mask32 & OPT_W)
171#define FLAG_c (option_mask32 & OPT_c)
172#define FLAG_R (option_mask32 & OPT_R)
173
174
175static void qprintf(const char *fmt UNUSED_PARAM, ...)
176{
177 /* quiet, do nothing */
178}
179
180static void inc_err(void)
181{
182 nerr++;
183 if (nerr > 9 && !FLAG_d_debug) {
184 bb_error_msg_and_die("exiting after 10 errors");
185 }
186}
187
188static void add_exclude(const char *directory)
189{
190 struct stat sb;
191 size_t len;
192
193 if (directory == NULL || directory[0] != '/') {
194 bb_error_msg_and_die("full path required for exclude: %s", directory);
195 }
196 if (lstat(directory, &sb)) {
197 bb_error_msg("directory \"%s\" not found, ignoring", directory);
198 return;
199 }
200 if ((sb.st_mode & S_IFDIR) == 0) {
201 bb_error_msg("\"%s\" is not a directory: mode %o, ignoring",
202 directory, sb.st_mode);
203 return;
204 }
205 if (excludeCtr == MAX_EXCLUDES) {
206 bb_error_msg_and_die("maximum excludes %d exceeded", MAX_EXCLUDES);
207 }
208
209 len = strlen(directory);
210 while (len > 1 && directory[len - 1] == '/') {
211 len--;
212 }
213 excludeArray[excludeCtr].directory = xstrndup(directory, len);
214 excludeArray[excludeCtr++].size = len;
215}
216
217static bool exclude(const char *file)
218{
219 int i = 0;
220 for (i = 0; i < excludeCtr; i++) {
221 if (strncmp(file, excludeArray[i].directory,
222 excludeArray[i].size) == 0) {
223 if (file[excludeArray[i].size] == '\0'
224 || file[excludeArray[i].size] == '/') {
225 return 1;
226 }
227 }
228 }
229 return 0;
230}
231
232static int match(const char *name, struct stat *sb, char **con)
233{
234 int ret;
235 char path[PATH_MAX + 1];
236 char *tmp_path = xstrdup(name);
237
238 if (excludeCtr > 0 && exclude(name)) {
239 goto err;
240 }
241 ret = lstat(name, sb);
242 if (ret) {
243 if (FLAG_i_ignore_enoent && errno == ENOENT) {
244 free(tmp_path);
245 return 0;
246 }
247 bb_error_msg("stat(%s)", name);
248 goto err;
249 }
250
251 if (expand_realpath) {
252 if (S_ISLNK(sb->st_mode)) {
253 char *p = NULL;
254 char *file_sep;
255
256 size_t len = 0;
257
258 if (verbose > 1)
259 bb_error_msg("warning! %s refers to a symbolic link, not following last component", name);
260
261 file_sep = strrchr(tmp_path, '/');
262 if (file_sep == tmp_path) {
263 file_sep++;
264 path[0] = '\0';
265 p = path;
266 } else if (file_sep) {
267 *file_sep++ = '\0';
268 p = realpath(tmp_path, path);
269 } else {
270 file_sep = tmp_path;
271 p = realpath("./", path);
272 }
273 if (p)
274 len = strlen(p);
275 if (!p || len + strlen(file_sep) + 2 > PATH_MAX) {
276 bb_perror_msg("realpath(%s) failed", name);
277 goto err;
278 }
279 p += len;
280 /* ensure trailing slash of directory name */
281 if (len == 0 || p[-1] != '/') {
282 *p++ = '/';
283 }
284 strcpy(p, file_sep);
285 name = path;
286 if (excludeCtr > 0 && exclude(name))
287 goto err;
288 } else {
289 char *p;
290 p = realpath(name, path);
291 if (!p) {
292 bb_perror_msg("realpath(%s)", name);
293 goto err;
294 }
295 name = p;
296 if (excludeCtr > 0 && exclude(name))
297 goto err;
298 }
299 }
300
301 /* name will be what is matched in the policy */
302 if (NULL != rootpath) {
303 if (0 != strncmp(rootpath, name, rootpathlen)) {
304 bb_error_msg("%s is not located in %s",
305 name, rootpath);
306 goto err;
307 }
308 name += rootpathlen;
309 }
310
311 free(tmp_path);
312 if (rootpath != NULL && name[0] == '\0')
313 /* this is actually the root dir of the alt root */
314 return matchpathcon_index("/", sb->st_mode, con);
315 return matchpathcon_index(name, sb->st_mode, con);
316 err:
317 free(tmp_path);
318 return -1;
319}
320
321/* Compare two contexts to see if their differences are "significant",
322 * or whether the only difference is in the user. */
323static bool only_changed_user(const char *a, const char *b)
324{
325 if (FLAG_F_force)
326 return 0;
327 if (!a || !b)
328 return 0;
329 a = strchr(a, ':'); /* Rest of the context after the user */
330 b = strchr(b, ':');
331 if (!a || !b)
332 return 0;
333 return (strcmp(a, b) == 0);
334}
335
336static int restore(const char *file)
337{
338 char *my_file;
339 struct stat my_sb;
340 int i, j, ret;
341 char *context = NULL;
342 char *newcon = NULL;
343 bool user_only_changed = 0;
344 int retval = 0;
345
346 my_file = bb_simplify_path(file);
347
348 i = match(my_file, &my_sb, &newcon);
349
350 if (i < 0) /* No matching specification. */
351 goto out;
352
353 if (FLAG_p_progress) {
354 count++;
355 if (count % 0x400 == 0) { /* every 1024 times */
356 count = (count % (80*0x400));
357 if (count == 0)
358 bb_putchar('\n');
359 bb_putchar('*');
360 fflush_all();
361 }
362 }
363
364 /*
365 * Try to add an association between this inode and
366 * this specification. If there is already an association
367 * for this inode and it conflicts with this specification,
368 * then use the last matching specification.
369 */
370 if (add_assoc) {
371 j = matchpathcon_filespec_add(my_sb.st_ino, i, my_file);
372 if (j < 0)
373 goto err;
374
375 if (j != i) {
376 /* There was already an association and it took precedence. */
377 goto out;
378 }
379 }
380
381 if (FLAG_d_debug)
382 printf("%s: %s matched by %s\n", applet_name, my_file, newcon);
383
384 /* Get the current context of the file. */
385 ret = lgetfilecon_raw(my_file, &context);
386 if (ret < 0) {
387 if (errno == ENODATA) {
388 context = NULL; /* paranoia */
389 } else {
390 bb_perror_msg("lgetfilecon_raw on %s", my_file);
391 goto err;
392 }
393 user_only_changed = 0;
394 } else
395 user_only_changed = only_changed_user(context, newcon);
396
397 /*
398 * Do not relabel the file if the matching specification is
399 * <<none>> or the file is already labeled according to the
400 * specification.
401 */
402 if ((strcmp(newcon, "<<none>>") == 0)
403 || (context && (strcmp(context, newcon) == 0) && !FLAG_F_force)) {
404 goto out;
405 }
406
407 if (!FLAG_F_force && context && (is_context_customizable(context) > 0)) {
408 if (verbose > 1) {
409 bb_error_msg("skipping %s. %s is customizable_types",
410 my_file, context);
411 }
412 goto out;
413 }
414
415 if (verbose) {
416 /* If we're just doing "-v", trim out any relabels where
417 * the user has changed but the role and type are the
418 * same. For "-vv", emit everything. */
419 if (verbose > 1 || !user_only_changed) {
420 printf("%s: reset %s context %s->%s\n",
421 applet_name, my_file, context ? context : "", newcon);
422 }
423 }
424
425 if (FLAG_l_take_log && !user_only_changed) {
426 if (context)
427 printf("relabeling %s from %s to %s\n", my_file, context, newcon);
428 else
429 printf("labeling %s to %s\n", my_file, newcon);
430 }
431
432 if (outfile && !user_only_changed)
433 fprintf(outfile, "%s\n", my_file);
434
435 /*
436 * Do not relabel the file if -n was used.
437 */
438 if (FLAG_n_dry_run || user_only_changed)
439 goto out;
440
441 /*
442 * Relabel the file to the specified context.
443 */
444 ret = lsetfilecon(my_file, newcon);
445 if (ret) {
446 bb_perror_msg("lsetfileconon(%s,%s)", my_file, newcon);
447 goto err;
448 }
449
450 out:
451 freecon(context);
452 freecon(newcon);
453 free(my_file);
454 return retval;
455 err:
456 retval--; /* -1 */
457 goto out;
458}
459
460/*
461 * Apply the last matching specification to a file.
462 * This function is called by recursive_action on each file during
463 * the directory traversal.
464 */
465static int FAST_FUNC apply_spec(
466 const char *file,
467 struct stat *sb,
468 void *userData UNUSED_PARAM,
469 int depth UNUSED_PARAM)
470{
471 if (!follow_mounts) {
472 /* setfiles does not process across different mount points */
473 if (sb->st_dev != dev_id) {
474 return SKIP;
475 }
476 }
477 errors |= restore(file);
478 if (abort_on_error && errors)
479 return FALSE;
480 return TRUE;
481}
482
483
484static int canoncon(const char *path, unsigned lineno, char **contextp)
485{
486 static const char err_msg[] ALIGN1 = "%s: line %u has invalid context %s";
487
488 char *tmpcon;
489 char *context = *contextp;
490 int invalid = 0;
491
492#if ENABLE_FEATURE_SETFILES_CHECK_OPTION
493 if (policyfile) {
494 if (sepol_check_context(context) >= 0)
495 return 0;
496 /* Exit immediately if we're in checking mode. */
497 bb_error_msg_and_die(err_msg, path, lineno, context);
498 }
499#endif
500
501 if (security_canonicalize_context_raw(context, &tmpcon) < 0) {
502 if (errno != ENOENT) {
503 invalid = 1;
504 inc_err();
505 }
506 } else {
507 free(context);
508 *contextp = tmpcon;
509 }
510
511 if (invalid) {
512 bb_error_msg(err_msg, path, lineno, context);
513 }
514
515 return invalid;
516}
517
518static int process_one(char *name)
519{
520 struct stat sb;
521 int rc;
522
523 rc = lstat(name, &sb);
524 if (rc < 0) {
525 if (FLAG_i_ignore_enoent && errno == ENOENT)
526 return 0;
527 bb_perror_msg("stat(%s)", name);
528 goto err;
529 }
530 dev_id = sb.st_dev;
531
532 if (S_ISDIR(sb.st_mode) && recurse) {
533 if (recursive_action(name,
534 ACTION_RECURSE,
535 apply_spec,
536 apply_spec,
537 NULL, 0) != TRUE
538 ) {
539 bb_error_msg("error while labeling %s", name);
540 goto err;
541 }
542 } else {
543 rc = restore(name);
544 if (rc)
545 goto err;
546 }
547
548 out:
549 if (add_assoc) {
550 if (FLAG_q_quiet)
551 set_matchpathcon_printf(&qprintf);
552 matchpathcon_filespec_eval();
553 set_matchpathcon_printf(NULL);
554 matchpathcon_filespec_destroy();
555 }
556
557 return rc;
558
559 err:
560 rc = -1;
561 goto out;
562}
563
564int setfiles_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
565int setfiles_main(int argc UNUSED_PARAM, char **argv)
566{
567 struct stat sb;
568 int rc, i = 0;
569 const char *input_filename = NULL;
570 char *buf = NULL;
571 size_t buf_len;
572 int flags;
573 llist_t *exclude_dir = NULL;
574 char *out_filename = NULL;
575
576 INIT_G();
577
578 if (applet_name[0] == 's') { /* "setfiles" */
579 /*
580 * setfiles:
581 * Recursive descent,
582 * Does not expand paths via realpath,
583 * Aborts on errors during the file tree walk,
584 * Try to track inode associations for conflict detection,
585 * Does not follow mounts,
586 * Validates all file contexts at init time.
587 */
588 recurse = 1;
589 abort_on_error = 1;
590 add_assoc = 1;
591 /* follow_mounts = 0; - already is */
592 matchpathcon_flags = MATCHPATHCON_VALIDATE | MATCHPATHCON_NOTRANS;
593 } else {
594 /*
595 * restorecon:
596 * No recursive descent unless -r/-R,
597 * Expands paths via realpath,
598 * Do not abort on errors during the file tree walk,
599 * Do not try to track inode associations for conflict detection,
600 * Follows mounts,
601 * Does lazy validation of contexts upon use.
602 */
603 expand_realpath = 1;
604 follow_mounts = 1;
605 matchpathcon_flags = MATCHPATHCON_NOTRANS;
606 /* restorecon only */
607 selinux_or_die();
608 }
609
610 set_matchpathcon_flags(matchpathcon_flags);
611
612 opt_complementary = "vv:v--p:p--v:v--q:q--v";
613 /* Option order must match OPT_x definitions! */
614 if (applet_name[0] == 'r') { /* restorecon */
615 flags = getopt32(argv, "de:*f:ilnpqrsvo:FWR",
616 &exclude_dir, &input_filename, &out_filename, &verbose);
617 } else { /* setfiles */
618 flags = getopt32(argv, "de:*f:ilnpqr:svo:FW"
619 IF_FEATURE_SETFILES_CHECK_OPTION("c:"),
620 &exclude_dir, &input_filename, &rootpath, &out_filename,
621 IF_FEATURE_SETFILES_CHECK_OPTION(&policyfile,)
622 &verbose);
623 }
624 argv += optind;
625
626#if ENABLE_FEATURE_SETFILES_CHECK_OPTION
627 if ((applet_name[0] == 's') && (flags & OPT_c)) {
628 FILE *policystream;
629
630 policystream = xfopen_for_read(policyfile);
631 if (sepol_set_policydb_from_file(policystream) < 0) {
632 bb_error_msg_and_die("sepol_set_policydb_from_file on %s", policyfile);
633 }
634 fclose(policystream);
635
636 /* Only process the specified file_contexts file, not
637 * any .homedirs or .local files, and do not perform
638 * context translations. */
639 set_matchpathcon_flags(MATCHPATHCON_BASEONLY |
640 MATCHPATHCON_NOTRANS |
641 MATCHPATHCON_VALIDATE);
642 }
643#endif
644
645 while (exclude_dir)
646 add_exclude(llist_pop(&exclude_dir));
647
648 if (flags & OPT_o) {
649 outfile = stdout;
650 if (NOT_LONE_CHAR(out_filename, '-')) {
651 outfile = xfopen_for_write(out_filename);
652 }
653 }
654 if (applet_name[0] == 'r') { /* restorecon */
655 if (flags & (OPT_r | OPT_R))
656 recurse = 1;
657 } else { /* setfiles */
658 if (flags & OPT_r)
659 rootpathlen = strlen(rootpath);
660 }
661 if (flags & OPT_s) {
662 input_filename = "-";
663 add_assoc = 0;
664 }
665
666 if (applet_name[0] == 's') { /* setfiles */
667 /* Use our own invalid context checking function so that
668 * we can support either checking against the active policy or
669 * checking against a binary policy file. */
670 set_matchpathcon_canoncon(&canoncon);
671 if (!argv[0])
672 bb_show_usage();
673 xstat(argv[0], &sb);
674 if (!S_ISREG(sb.st_mode)) {
675 bb_error_msg_and_die("spec file %s is not a regular file", argv[0]);
676 }
677 /* Load the file contexts configuration and check it. */
678 rc = matchpathcon_init(argv[0]);
679 if (rc < 0) {
680 bb_simple_perror_msg_and_die(argv[0]);
681 }
682 if (nerr)
683 exit(EXIT_FAILURE);
684 argv++;
685 }
686
687 if (input_filename) {
688 ssize_t len;
689 FILE *f = stdin;
690
691 if (NOT_LONE_CHAR(input_filename, '-'))
692 f = xfopen_for_read(input_filename);
693 while ((len = getline(&buf, &buf_len, f)) > 0) {
694 buf[len - 1] = '\0';
695 errors |= process_one(buf);
696 }
697 if (ENABLE_FEATURE_CLEAN_UP)
698 fclose_if_not_stdin(f);
699 } else {
700 if (!argv[0])
701 bb_show_usage();
702 for (i = 0; argv[i]; i++) {
703 errors |= process_one(argv[i]);
704 }
705 }
706
707 if (FLAG_W_warn_no_match)
708 matchpathcon_checkmatches(argv[0]);
709
710 if (ENABLE_FEATURE_CLEAN_UP && outfile)
711 fclose(outfile);
712
713 return errors;
714}
715
generated by cgit at 2024-05-14 08:21:31 (GMT)