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Annotation of /tags/mkinitrd-6_1_11/busybox/selinux/setfiles.c

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Revision 928 - (hide annotations) (download)
Wed Oct 28 13:31:19 2009 UTC (14 years, 7 months ago) by niro
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tagged 'mkinitrd-6_1_11'
1 niro 816 /*
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    
14     struct edir {
15     char *directory;
16     size_t size;
17     };
18    
19     struct 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)
41     void 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! */
66     enum {
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    
102     static void qprintf(const char *fmt UNUSED_PARAM, ...)
103     {
104     /* quiet, do nothing */
105     }
106    
107     static 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    
115     static 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    
145     static 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    
160     static 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. */
252     static 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    
265     static 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     bb_putchar('\n');
288     bb_putchar('*');
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     */
394     static int FAST_FUNC apply_spec(
395     const char *file,
396     struct stat *sb,
397     void *userData UNUSED_PARAM,
398     int depth UNUSED_PARAM)
399     {
400     if (!follow_mounts) {
401     /* setfiles does not process across different mount points */
402     if (sb->st_dev != dev_id) {
403     return SKIP;
404     }
405     }
406     errors |= restore(file);
407     if (abort_on_error && errors)
408     return FALSE;
409     return TRUE;
410     }
411    
412    
413     static int canoncon(const char *path, unsigned lineno, char **contextp)
414     {
415     static const char err_msg[] ALIGN1 = "%s: line %u has invalid context %s";
416    
417     char *tmpcon;
418     char *context = *contextp;
419     int invalid = 0;
420    
421     #if ENABLE_FEATURE_SETFILES_CHECK_OPTION
422     if (policyfile) {
423     if (sepol_check_context(context) >= 0)
424     return 0;
425     /* Exit immediately if we're in checking mode. */
426     bb_error_msg_and_die(err_msg, path, lineno, context);
427     }
428     #endif
429    
430     if (security_canonicalize_context_raw(context, &tmpcon) < 0) {
431     if (errno != ENOENT) {
432     invalid = 1;
433     inc_err();
434     }
435     } else {
436     free(context);
437     *contextp = tmpcon;
438     }
439    
440     if (invalid) {
441     bb_error_msg(err_msg, path, lineno, context);
442     }
443    
444     return invalid;
445     }
446    
447     static int process_one(char *name)
448     {
449     struct stat sb;
450     int rc;
451    
452     rc = lstat(name, &sb);
453     if (rc < 0) {
454     if (FLAG_i_ignore_enoent && errno == ENOENT)
455     return 0;
456     bb_perror_msg("stat(%s)", name);
457     goto err;
458     }
459     dev_id = sb.st_dev;
460    
461     if (S_ISDIR(sb.st_mode) && recurse) {
462     if (recursive_action(name,
463     ACTION_RECURSE,
464     apply_spec,
465     apply_spec,
466     NULL, 0) != TRUE) {
467     bb_error_msg("error while labeling %s", name);
468     goto err;
469     }
470     } else {
471     rc = restore(name);
472     if (rc)
473     goto err;
474     }
475    
476     out:
477     if (add_assoc) {
478     if (FLAG_q_quiet)
479     set_matchpathcon_printf(&qprintf);
480     matchpathcon_filespec_eval();
481     set_matchpathcon_printf(NULL);
482     matchpathcon_filespec_destroy();
483     }
484    
485     return rc;
486    
487     err:
488     rc = -1;
489     goto out;
490     }
491    
492     int setfiles_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
493     int setfiles_main(int argc, char **argv)
494     {
495     struct stat sb;
496     int rc, i = 0;
497     const char *input_filename = NULL;
498     char *buf = NULL;
499     size_t buf_len;
500     int flags;
501     llist_t *exclude_dir = NULL;
502     char *out_filename = NULL;
503    
504     INIT_G();
505    
506     if (applet_name[0] == 's') { /* "setfiles" */
507     /*
508     * setfiles:
509     * Recursive descent,
510     * Does not expand paths via realpath,
511     * Aborts on errors during the file tree walk,
512     * Try to track inode associations for conflict detection,
513     * Does not follow mounts,
514     * Validates all file contexts at init time.
515     */
516     recurse = 1;
517     abort_on_error = 1;
518     add_assoc = 1;
519     /* follow_mounts = 0; - already is */
520     matchpathcon_flags = MATCHPATHCON_VALIDATE | MATCHPATHCON_NOTRANS;
521     } else {
522     /*
523     * restorecon:
524     * No recursive descent unless -r/-R,
525     * Expands paths via realpath,
526     * Do not abort on errors during the file tree walk,
527     * Do not try to track inode associations for conflict detection,
528     * Follows mounts,
529     * Does lazy validation of contexts upon use.
530     */
531     expand_realpath = 1;
532     follow_mounts = 1;
533     matchpathcon_flags = MATCHPATHCON_NOTRANS;
534     /* restorecon only */
535     selinux_or_die();
536     }
537    
538     set_matchpathcon_flags(matchpathcon_flags);
539    
540     opt_complementary = "e::vv:v--p:p--v:v--q:q--v";
541     /* Option order must match OPT_x definitions! */
542     if (applet_name[0] == 'r') { /* restorecon */
543     flags = getopt32(argv, "de:f:ilnpqrsvo:FWR",
544     &exclude_dir, &input_filename, &out_filename, &verbose);
545     } else { /* setfiles */
546     flags = getopt32(argv, "de:f:ilnpqr:svo:FW"
547     USE_FEATURE_SETFILES_CHECK_OPTION("c:"),
548     &exclude_dir, &input_filename, &rootpath, &out_filename,
549     USE_FEATURE_SETFILES_CHECK_OPTION(&policyfile,)
550     &verbose);
551     }
552    
553     #if ENABLE_FEATURE_SETFILES_CHECK_OPTION
554     if ((applet_name[0] == 's') && (flags & OPT_c)) {
555     FILE *policystream;
556    
557     policystream = xfopen_for_read(policyfile);
558     if (sepol_set_policydb_from_file(policystream) < 0) {
559     bb_error_msg_and_die("sepol_set_policydb_from_file on %s", policyfile);
560     }
561     fclose(policystream);
562    
563     /* Only process the specified file_contexts file, not
564     any .homedirs or .local files, and do not perform
565     context translations. */
566     set_matchpathcon_flags(MATCHPATHCON_BASEONLY |
567     MATCHPATHCON_NOTRANS |
568     MATCHPATHCON_VALIDATE);
569     }
570     #endif
571    
572     while (exclude_dir)
573     add_exclude(llist_pop(&exclude_dir));
574    
575     if (flags & OPT_o) {
576     outfile = stdout;
577     if (NOT_LONE_CHAR(out_filename, '-')) {
578     outfile = xfopen_for_write(out_filename);
579     }
580     }
581     if (applet_name[0] == 'r') { /* restorecon */
582     if (flags & (OPT_r | OPT_R))
583     recurse = 1;
584     } else { /* setfiles */
585     if (flags & OPT_r)
586     rootpathlen = strlen(rootpath);
587     }
588     if (flags & OPT_s) {
589     input_filename = "-";
590     add_assoc = 0;
591     }
592    
593     if (applet_name[0] == 's') { /* setfiles */
594     /* Use our own invalid context checking function so that
595     we can support either checking against the active policy or
596     checking against a binary policy file. */
597     set_matchpathcon_canoncon(&canoncon);
598     if (argc == 1)
599     bb_show_usage();
600     if (stat(argv[optind], &sb) < 0) {
601     bb_simple_perror_msg_and_die(argv[optind]);
602     }
603     if (!S_ISREG(sb.st_mode)) {
604     bb_error_msg_and_die("spec file %s is not a regular file", argv[optind]);
605     }
606     /* Load the file contexts configuration and check it. */
607     rc = matchpathcon_init(argv[optind]);
608     if (rc < 0) {
609     bb_simple_perror_msg_and_die(argv[optind]);
610     }
611    
612     optind++;
613    
614     if (nerr)
615     exit(EXIT_FAILURE);
616     }
617    
618     if (input_filename) {
619     ssize_t len;
620     FILE *f = stdin;
621    
622     if (NOT_LONE_CHAR(input_filename, '-'))
623     f = xfopen_for_read(input_filename);
624     while ((len = getline(&buf, &buf_len, f)) > 0) {
625     buf[len - 1] = '\0';
626     errors |= process_one(buf);
627     }
628     if (ENABLE_FEATURE_CLEAN_UP)
629     fclose_if_not_stdin(f);
630     } else {
631     if (optind >= argc)
632     bb_show_usage();
633     for (i = optind; i < argc; i++) {
634     errors |= process_one(argv[i]);
635     }
636     }
637    
638     if (FLAG_W_warn_no_match)
639     matchpathcon_checkmatches(argv[0]);
640    
641     if (ENABLE_FEATURE_CLEAN_UP && outfile)
642     fclose(outfile);
643    
644     return errors;
645     }