TOMOYO: Fix memory leak upon file open.
[linux-2.6.git] / security / tomoyo / file.c
1 /*
2  * security/tomoyo/file.c
3  *
4  * Pathname restriction functions.
5  *
6  * Copyright (C) 2005-2010  NTT DATA CORPORATION
7  */
8
9 #include "common.h"
10 #include <linux/slab.h>
11
12 /* Keyword array for operations with one pathname. */
13 const char *tomoyo_path_keyword[TOMOYO_MAX_PATH_OPERATION] = {
14         [TOMOYO_TYPE_READ_WRITE] = "read/write",
15         [TOMOYO_TYPE_EXECUTE]    = "execute",
16         [TOMOYO_TYPE_READ]       = "read",
17         [TOMOYO_TYPE_WRITE]      = "write",
18         [TOMOYO_TYPE_UNLINK]     = "unlink",
19         [TOMOYO_TYPE_RMDIR]      = "rmdir",
20         [TOMOYO_TYPE_TRUNCATE]   = "truncate",
21         [TOMOYO_TYPE_SYMLINK]    = "symlink",
22         [TOMOYO_TYPE_REWRITE]    = "rewrite",
23         [TOMOYO_TYPE_CHROOT]     = "chroot",
24         [TOMOYO_TYPE_UMOUNT]     = "unmount",
25 };
26
27 /* Keyword array for operations with one pathname and three numbers. */
28 const char *tomoyo_mkdev_keyword[TOMOYO_MAX_MKDEV_OPERATION] = {
29         [TOMOYO_TYPE_MKBLOCK]    = "mkblock",
30         [TOMOYO_TYPE_MKCHAR]     = "mkchar",
31 };
32
33 /* Keyword array for operations with two pathnames. */
34 const char *tomoyo_path2_keyword[TOMOYO_MAX_PATH2_OPERATION] = {
35         [TOMOYO_TYPE_LINK]       = "link",
36         [TOMOYO_TYPE_RENAME]     = "rename",
37         [TOMOYO_TYPE_PIVOT_ROOT] = "pivot_root",
38 };
39
40 /* Keyword array for operations with one pathname and one number. */
41 const char *tomoyo_path_number_keyword[TOMOYO_MAX_PATH_NUMBER_OPERATION] = {
42         [TOMOYO_TYPE_CREATE]     = "create",
43         [TOMOYO_TYPE_MKDIR]      = "mkdir",
44         [TOMOYO_TYPE_MKFIFO]     = "mkfifo",
45         [TOMOYO_TYPE_MKSOCK]     = "mksock",
46         [TOMOYO_TYPE_IOCTL]      = "ioctl",
47         [TOMOYO_TYPE_CHMOD]      = "chmod",
48         [TOMOYO_TYPE_CHOWN]      = "chown",
49         [TOMOYO_TYPE_CHGRP]      = "chgrp",
50 };
51
52 static const u8 tomoyo_p2mac[TOMOYO_MAX_PATH_OPERATION] = {
53         [TOMOYO_TYPE_READ_WRITE] = TOMOYO_MAC_FILE_OPEN,
54         [TOMOYO_TYPE_EXECUTE]    = TOMOYO_MAC_FILE_EXECUTE,
55         [TOMOYO_TYPE_READ]       = TOMOYO_MAC_FILE_OPEN,
56         [TOMOYO_TYPE_WRITE]      = TOMOYO_MAC_FILE_OPEN,
57         [TOMOYO_TYPE_UNLINK]     = TOMOYO_MAC_FILE_UNLINK,
58         [TOMOYO_TYPE_RMDIR]      = TOMOYO_MAC_FILE_RMDIR,
59         [TOMOYO_TYPE_TRUNCATE]   = TOMOYO_MAC_FILE_TRUNCATE,
60         [TOMOYO_TYPE_SYMLINK]    = TOMOYO_MAC_FILE_SYMLINK,
61         [TOMOYO_TYPE_REWRITE]    = TOMOYO_MAC_FILE_REWRITE,
62         [TOMOYO_TYPE_CHROOT]     = TOMOYO_MAC_FILE_CHROOT,
63         [TOMOYO_TYPE_UMOUNT]     = TOMOYO_MAC_FILE_UMOUNT,
64 };
65
66 static const u8 tomoyo_pnnn2mac[TOMOYO_MAX_MKDEV_OPERATION] = {
67         [TOMOYO_TYPE_MKBLOCK] = TOMOYO_MAC_FILE_MKBLOCK,
68         [TOMOYO_TYPE_MKCHAR]  = TOMOYO_MAC_FILE_MKCHAR,
69 };
70
71 static const u8 tomoyo_pp2mac[TOMOYO_MAX_PATH2_OPERATION] = {
72         [TOMOYO_TYPE_LINK]       = TOMOYO_MAC_FILE_LINK,
73         [TOMOYO_TYPE_RENAME]     = TOMOYO_MAC_FILE_RENAME,
74         [TOMOYO_TYPE_PIVOT_ROOT] = TOMOYO_MAC_FILE_PIVOT_ROOT,
75 };
76
77 static const u8 tomoyo_pn2mac[TOMOYO_MAX_PATH_NUMBER_OPERATION] = {
78         [TOMOYO_TYPE_CREATE] = TOMOYO_MAC_FILE_CREATE,
79         [TOMOYO_TYPE_MKDIR]  = TOMOYO_MAC_FILE_MKDIR,
80         [TOMOYO_TYPE_MKFIFO] = TOMOYO_MAC_FILE_MKFIFO,
81         [TOMOYO_TYPE_MKSOCK] = TOMOYO_MAC_FILE_MKSOCK,
82         [TOMOYO_TYPE_IOCTL]  = TOMOYO_MAC_FILE_IOCTL,
83         [TOMOYO_TYPE_CHMOD]  = TOMOYO_MAC_FILE_CHMOD,
84         [TOMOYO_TYPE_CHOWN]  = TOMOYO_MAC_FILE_CHOWN,
85         [TOMOYO_TYPE_CHGRP]  = TOMOYO_MAC_FILE_CHGRP,
86 };
87
88 void tomoyo_put_name_union(struct tomoyo_name_union *ptr)
89 {
90         if (!ptr)
91                 return;
92         if (ptr->is_group)
93                 tomoyo_put_group(ptr->group);
94         else
95                 tomoyo_put_name(ptr->filename);
96 }
97
98 const struct tomoyo_path_info *
99 tomoyo_compare_name_union(const struct tomoyo_path_info *name,
100                           const struct tomoyo_name_union *ptr)
101 {
102         if (ptr->is_group)
103                 return tomoyo_path_matches_group(name, ptr->group);
104         if (tomoyo_path_matches_pattern(name, ptr->filename))
105                 return ptr->filename;
106         return NULL;
107 }
108
109 void tomoyo_put_number_union(struct tomoyo_number_union *ptr)
110 {
111         if (ptr && ptr->is_group)
112                 tomoyo_put_group(ptr->group);
113 }
114
115 bool tomoyo_compare_number_union(const unsigned long value,
116                                  const struct tomoyo_number_union *ptr)
117 {
118         if (ptr->is_group)
119                 return tomoyo_number_matches_group(value, value, ptr->group);
120         return value >= ptr->values[0] && value <= ptr->values[1];
121 }
122
123 static void tomoyo_add_slash(struct tomoyo_path_info *buf)
124 {
125         if (buf->is_dir)
126                 return;
127         /*
128          * This is OK because tomoyo_encode() reserves space for appending "/".
129          */
130         strcat((char *) buf->name, "/");
131         tomoyo_fill_path_info(buf);
132 }
133
134 /**
135  * tomoyo_strendswith - Check whether the token ends with the given token.
136  *
137  * @name: The token to check.
138  * @tail: The token to find.
139  *
140  * Returns true if @name ends with @tail, false otherwise.
141  */
142 static bool tomoyo_strendswith(const char *name, const char *tail)
143 {
144         int len;
145
146         if (!name || !tail)
147                 return false;
148         len = strlen(name) - strlen(tail);
149         return len >= 0 && !strcmp(name + len, tail);
150 }
151
152 /**
153  * tomoyo_get_realpath - Get realpath.
154  *
155  * @buf:  Pointer to "struct tomoyo_path_info".
156  * @path: Pointer to "struct path".
157  *
158  * Returns true on success, false otherwise.
159  */
160 static bool tomoyo_get_realpath(struct tomoyo_path_info *buf, struct path *path)
161 {
162         buf->name = tomoyo_realpath_from_path(path);
163         if (buf->name) {
164                 tomoyo_fill_path_info(buf);
165                 return true;
166         }
167         return false;
168 }
169
170 /**
171  * tomoyo_audit_path_log - Audit path request log.
172  *
173  * @r: Pointer to "struct tomoyo_request_info".
174  *
175  * Returns 0 on success, negative value otherwise.
176  */
177 static int tomoyo_audit_path_log(struct tomoyo_request_info *r)
178 {
179         const char *operation = tomoyo_path_keyword[r->param.path.operation];
180         const struct tomoyo_path_info *filename = r->param.path.filename;
181         if (r->granted)
182                 return 0;
183         tomoyo_warn_log(r, "%s %s", operation, filename->name);
184         return tomoyo_supervisor(r, "allow_%s %s\n", operation,
185                                  tomoyo_pattern(filename));
186 }
187
188 /**
189  * tomoyo_audit_path2_log - Audit path/path request log.
190  *
191  * @r: Pointer to "struct tomoyo_request_info".
192  *
193  * Returns 0 on success, negative value otherwise.
194  */
195 static int tomoyo_audit_path2_log(struct tomoyo_request_info *r)
196 {
197         const char *operation = tomoyo_path2_keyword[r->param.path2.operation];
198         const struct tomoyo_path_info *filename1 = r->param.path2.filename1;
199         const struct tomoyo_path_info *filename2 = r->param.path2.filename2;
200         if (r->granted)
201                 return 0;
202         tomoyo_warn_log(r, "%s %s %s", operation, filename1->name,
203                         filename2->name);
204         return tomoyo_supervisor(r, "allow_%s %s %s\n", operation,
205                                  tomoyo_pattern(filename1),
206                                  tomoyo_pattern(filename2));
207 }
208
209 /**
210  * tomoyo_audit_mkdev_log - Audit path/number/number/number request log.
211  *
212  * @r: Pointer to "struct tomoyo_request_info".
213  *
214  * Returns 0 on success, negative value otherwise.
215  */
216 static int tomoyo_audit_mkdev_log(struct tomoyo_request_info *r)
217 {
218         const char *operation = tomoyo_mkdev_keyword[r->param.mkdev.operation];
219         const struct tomoyo_path_info *filename = r->param.mkdev.filename;
220         const unsigned int major = r->param.mkdev.major;
221         const unsigned int minor = r->param.mkdev.minor;
222         const unsigned int mode = r->param.mkdev.mode;
223         if (r->granted)
224                 return 0;
225         tomoyo_warn_log(r, "%s %s 0%o %u %u", operation, filename->name, mode,
226                         major, minor);
227         return tomoyo_supervisor(r, "allow_%s %s 0%o %u %u\n", operation,
228                                  tomoyo_pattern(filename), mode, major, minor);
229 }
230
231 /**
232  * tomoyo_audit_path_number_log - Audit path/number request log.
233  *
234  * @r:     Pointer to "struct tomoyo_request_info".
235  * @error: Error code.
236  *
237  * Returns 0 on success, negative value otherwise.
238  */
239 static int tomoyo_audit_path_number_log(struct tomoyo_request_info *r)
240 {
241         const u8 type = r->param.path_number.operation;
242         u8 radix;
243         const struct tomoyo_path_info *filename = r->param.path_number.filename;
244         const char *operation = tomoyo_path_number_keyword[type];
245         char buffer[64];
246         if (r->granted)
247                 return 0;
248         switch (type) {
249         case TOMOYO_TYPE_CREATE:
250         case TOMOYO_TYPE_MKDIR:
251         case TOMOYO_TYPE_MKFIFO:
252         case TOMOYO_TYPE_MKSOCK:
253         case TOMOYO_TYPE_CHMOD:
254                 radix = TOMOYO_VALUE_TYPE_OCTAL;
255                 break;
256         case TOMOYO_TYPE_IOCTL:
257                 radix = TOMOYO_VALUE_TYPE_HEXADECIMAL;
258                 break;
259         default:
260                 radix = TOMOYO_VALUE_TYPE_DECIMAL;
261                 break;
262         }
263         tomoyo_print_ulong(buffer, sizeof(buffer), r->param.path_number.number,
264                            radix);
265         tomoyo_warn_log(r, "%s %s %s", operation, filename->name, buffer);
266         return tomoyo_supervisor(r, "allow_%s %s %s\n", operation,
267                                  tomoyo_pattern(filename), buffer);
268 }
269
270 static bool tomoyo_same_globally_readable(const struct tomoyo_acl_head *a,
271                                           const struct tomoyo_acl_head *b)
272 {
273         return container_of(a, struct tomoyo_readable_file,
274                             head)->filename ==
275                 container_of(b, struct tomoyo_readable_file,
276                              head)->filename;
277 }
278
279 /**
280  * tomoyo_update_globally_readable_entry - Update "struct tomoyo_readable_file" list.
281  *
282  * @filename:  Filename unconditionally permitted to open() for reading.
283  * @is_delete: True if it is a delete request.
284  *
285  * Returns 0 on success, negative value otherwise.
286  *
287  * Caller holds tomoyo_read_lock().
288  */
289 static int tomoyo_update_globally_readable_entry(const char *filename,
290                                                  const bool is_delete)
291 {
292         struct tomoyo_readable_file e = { };
293         int error;
294
295         if (!tomoyo_correct_word(filename))
296                 return -EINVAL;
297         e.filename = tomoyo_get_name(filename);
298         if (!e.filename)
299                 return -ENOMEM;
300         error = tomoyo_update_policy(&e.head, sizeof(e), is_delete,
301                                      &tomoyo_policy_list
302                                      [TOMOYO_ID_GLOBALLY_READABLE],
303                                      tomoyo_same_globally_readable);
304         tomoyo_put_name(e.filename);
305         return error;
306 }
307
308 /**
309  * tomoyo_globally_readable_file - Check if the file is unconditionnaly permitted to be open()ed for reading.
310  *
311  * @filename: The filename to check.
312  *
313  * Returns true if any domain can open @filename for reading, false otherwise.
314  *
315  * Caller holds tomoyo_read_lock().
316  */
317 static bool tomoyo_globally_readable_file(const struct tomoyo_path_info *
318                                              filename)
319 {
320         struct tomoyo_readable_file *ptr;
321         bool found = false;
322
323         list_for_each_entry_rcu(ptr, &tomoyo_policy_list
324                                 [TOMOYO_ID_GLOBALLY_READABLE], head.list) {
325                 if (!ptr->head.is_deleted &&
326                     tomoyo_path_matches_pattern(filename, ptr->filename)) {
327                         found = true;
328                         break;
329                 }
330         }
331         return found;
332 }
333
334 /**
335  * tomoyo_write_globally_readable - Write "struct tomoyo_readable_file" list.
336  *
337  * @data:      String to parse.
338  * @is_delete: True if it is a delete request.
339  *
340  * Returns 0 on success, negative value otherwise.
341  *
342  * Caller holds tomoyo_read_lock().
343  */
344 int tomoyo_write_globally_readable(char *data, const bool is_delete)
345 {
346         return tomoyo_update_globally_readable_entry(data, is_delete);
347 }
348
349 static bool tomoyo_same_pattern(const struct tomoyo_acl_head *a,
350                                 const struct tomoyo_acl_head *b)
351 {
352         return container_of(a, struct tomoyo_no_pattern, head)->pattern ==
353                 container_of(b, struct tomoyo_no_pattern, head)->pattern;
354 }
355
356 /**
357  * tomoyo_update_file_pattern_entry - Update "struct tomoyo_no_pattern" list.
358  *
359  * @pattern:   Pathname pattern.
360  * @is_delete: True if it is a delete request.
361  *
362  * Returns 0 on success, negative value otherwise.
363  *
364  * Caller holds tomoyo_read_lock().
365  */
366 static int tomoyo_update_file_pattern_entry(const char *pattern,
367                                             const bool is_delete)
368 {
369         struct tomoyo_no_pattern e = { };
370         int error;
371
372         if (!tomoyo_correct_word(pattern))
373                 return -EINVAL;
374         e.pattern = tomoyo_get_name(pattern);
375         if (!e.pattern)
376                 return -ENOMEM;
377         error = tomoyo_update_policy(&e.head, sizeof(e), is_delete,
378                                      &tomoyo_policy_list[TOMOYO_ID_PATTERN],
379                                      tomoyo_same_pattern);
380         tomoyo_put_name(e.pattern);
381         return error;
382 }
383
384 /**
385  * tomoyo_pattern - Get patterned pathname.
386  *
387  * @filename: The filename to find patterned pathname.
388  *
389  * Returns pointer to pathname pattern if matched, @filename otherwise.
390  *
391  * Caller holds tomoyo_read_lock().
392  */
393 const char *tomoyo_pattern(const struct tomoyo_path_info *filename)
394 {
395         struct tomoyo_no_pattern *ptr;
396         const struct tomoyo_path_info *pattern = NULL;
397
398         list_for_each_entry_rcu(ptr, &tomoyo_policy_list[TOMOYO_ID_PATTERN],
399                                 head.list) {
400                 if (ptr->head.is_deleted)
401                         continue;
402                 if (!tomoyo_path_matches_pattern(filename, ptr->pattern))
403                         continue;
404                 pattern = ptr->pattern;
405                 if (tomoyo_strendswith(pattern->name, "/\\*")) {
406                         /* Do nothing. Try to find the better match. */
407                 } else {
408                         /* This would be the better match. Use this. */
409                         break;
410                 }
411         }
412         if (pattern)
413                 filename = pattern;
414         return filename->name;
415 }
416
417 /**
418  * tomoyo_write_pattern - Write "struct tomoyo_no_pattern" list.
419  *
420  * @data:      String to parse.
421  * @is_delete: True if it is a delete request.
422  *
423  * Returns 0 on success, negative value otherwise.
424  *
425  * Caller holds tomoyo_read_lock().
426  */
427 int tomoyo_write_pattern(char *data, const bool is_delete)
428 {
429         return tomoyo_update_file_pattern_entry(data, is_delete);
430 }
431
432 static bool tomoyo_same_no_rewrite(const struct tomoyo_acl_head *a,
433                                    const struct tomoyo_acl_head *b)
434 {
435         return container_of(a, struct tomoyo_no_rewrite, head)->pattern
436                 == container_of(b, struct tomoyo_no_rewrite, head)
437                 ->pattern;
438 }
439
440 /**
441  * tomoyo_update_no_rewrite_entry - Update "struct tomoyo_no_rewrite" list.
442  *
443  * @pattern:   Pathname pattern that are not rewritable by default.
444  * @is_delete: True if it is a delete request.
445  *
446  * Returns 0 on success, negative value otherwise.
447  *
448  * Caller holds tomoyo_read_lock().
449  */
450 static int tomoyo_update_no_rewrite_entry(const char *pattern,
451                                           const bool is_delete)
452 {
453         struct tomoyo_no_rewrite e = { };
454         int error;
455
456         if (!tomoyo_correct_word(pattern))
457                 return -EINVAL;
458         e.pattern = tomoyo_get_name(pattern);
459         if (!e.pattern)
460                 return -ENOMEM;
461         error = tomoyo_update_policy(&e.head, sizeof(e), is_delete,
462                                      &tomoyo_policy_list[TOMOYO_ID_NO_REWRITE],
463                                      tomoyo_same_no_rewrite);
464         tomoyo_put_name(e.pattern);
465         return error;
466 }
467
468 /**
469  * tomoyo_no_rewrite_file - Check if the given pathname is not permitted to be rewrited.
470  *
471  * @filename: Filename to check.
472  *
473  * Returns true if @filename is specified by "deny_rewrite" directive,
474  * false otherwise.
475  *
476  * Caller holds tomoyo_read_lock().
477  */
478 static bool tomoyo_no_rewrite_file(const struct tomoyo_path_info *filename)
479 {
480         struct tomoyo_no_rewrite *ptr;
481         bool found = false;
482
483         list_for_each_entry_rcu(ptr, &tomoyo_policy_list[TOMOYO_ID_NO_REWRITE],
484                                 head.list) {
485                 if (ptr->head.is_deleted)
486                         continue;
487                 if (!tomoyo_path_matches_pattern(filename, ptr->pattern))
488                         continue;
489                 found = true;
490                 break;
491         }
492         return found;
493 }
494
495 /**
496  * tomoyo_write_no_rewrite - Write "struct tomoyo_no_rewrite" list.
497  *
498  * @data:      String to parse.
499  * @is_delete: True if it is a delete request.
500  *
501  * Returns 0 on success, negative value otherwise.
502  *
503  * Caller holds tomoyo_read_lock().
504  */
505 int tomoyo_write_no_rewrite(char *data, const bool is_delete)
506 {
507         return tomoyo_update_no_rewrite_entry(data, is_delete);
508 }
509
510 static bool tomoyo_check_path_acl(struct tomoyo_request_info *r,
511                                   const struct tomoyo_acl_info *ptr)
512 {
513         const struct tomoyo_path_acl *acl = container_of(ptr, typeof(*acl),
514                                                          head);
515         if (acl->perm & (1 << r->param.path.operation)) {
516                 r->param.path.matched_path =
517                         tomoyo_compare_name_union(r->param.path.filename,
518                                                   &acl->name);
519                 return r->param.path.matched_path != NULL;
520         }
521         return false;
522 }
523
524 static bool tomoyo_check_path_number_acl(struct tomoyo_request_info *r,
525                                          const struct tomoyo_acl_info *ptr)
526 {
527         const struct tomoyo_path_number_acl *acl =
528                 container_of(ptr, typeof(*acl), head);
529         return (acl->perm & (1 << r->param.path_number.operation)) &&
530                 tomoyo_compare_number_union(r->param.path_number.number,
531                                             &acl->number) &&
532                 tomoyo_compare_name_union(r->param.path_number.filename,
533                                           &acl->name);
534 }
535
536 static bool tomoyo_check_path2_acl(struct tomoyo_request_info *r,
537                                    const struct tomoyo_acl_info *ptr)
538 {
539         const struct tomoyo_path2_acl *acl =
540                 container_of(ptr, typeof(*acl), head);
541         return (acl->perm & (1 << r->param.path2.operation)) &&
542                 tomoyo_compare_name_union(r->param.path2.filename1, &acl->name1)
543                 && tomoyo_compare_name_union(r->param.path2.filename2,
544                                              &acl->name2);
545 }
546
547 static bool tomoyo_check_mkdev_acl(struct tomoyo_request_info *r,
548                                 const struct tomoyo_acl_info *ptr)
549 {
550         const struct tomoyo_mkdev_acl *acl =
551                 container_of(ptr, typeof(*acl), head);
552         return (acl->perm & (1 << r->param.mkdev.operation)) &&
553                 tomoyo_compare_number_union(r->param.mkdev.mode,
554                                             &acl->mode) &&
555                 tomoyo_compare_number_union(r->param.mkdev.major,
556                                             &acl->major) &&
557                 tomoyo_compare_number_union(r->param.mkdev.minor,
558                                             &acl->minor) &&
559                 tomoyo_compare_name_union(r->param.mkdev.filename,
560                                           &acl->name);
561 }
562
563 static bool tomoyo_same_path_acl(const struct tomoyo_acl_info *a,
564                                  const struct tomoyo_acl_info *b)
565 {
566         const struct tomoyo_path_acl *p1 = container_of(a, typeof(*p1), head);
567         const struct tomoyo_path_acl *p2 = container_of(b, typeof(*p2), head);
568         return tomoyo_same_acl_head(&p1->head, &p2->head) &&
569                 tomoyo_same_name_union(&p1->name, &p2->name);
570 }
571
572 static bool tomoyo_merge_path_acl(struct tomoyo_acl_info *a,
573                                   struct tomoyo_acl_info *b,
574                                   const bool is_delete)
575 {
576         u16 * const a_perm = &container_of(a, struct tomoyo_path_acl, head)
577                 ->perm;
578         u16 perm = *a_perm;
579         const u16 b_perm = container_of(b, struct tomoyo_path_acl, head)->perm;
580         if (is_delete) {
581                 perm &= ~b_perm;
582                 if ((perm & TOMOYO_RW_MASK) != TOMOYO_RW_MASK)
583                         perm &= ~(1 << TOMOYO_TYPE_READ_WRITE);
584                 else if (!(perm & (1 << TOMOYO_TYPE_READ_WRITE)))
585                         perm &= ~TOMOYO_RW_MASK;
586         } else {
587                 perm |= b_perm;
588                 if ((perm & TOMOYO_RW_MASK) == TOMOYO_RW_MASK)
589                         perm |= (1 << TOMOYO_TYPE_READ_WRITE);
590                 else if (perm & (1 << TOMOYO_TYPE_READ_WRITE))
591                         perm |= TOMOYO_RW_MASK;
592         }
593         *a_perm = perm;
594         return !perm;
595 }
596
597 /**
598  * tomoyo_update_path_acl - Update "struct tomoyo_path_acl" list.
599  *
600  * @type:      Type of operation.
601  * @filename:  Filename.
602  * @domain:    Pointer to "struct tomoyo_domain_info".
603  * @is_delete: True if it is a delete request.
604  *
605  * Returns 0 on success, negative value otherwise.
606  *
607  * Caller holds tomoyo_read_lock().
608  */
609 static int tomoyo_update_path_acl(const u8 type, const char *filename,
610                                   struct tomoyo_domain_info * const domain,
611                                   const bool is_delete)
612 {
613         struct tomoyo_path_acl e = {
614                 .head.type = TOMOYO_TYPE_PATH_ACL,
615                 .perm = 1 << type
616         };
617         int error;
618         if (e.perm == (1 << TOMOYO_TYPE_READ_WRITE))
619                 e.perm |= TOMOYO_RW_MASK;
620         if (!tomoyo_parse_name_union(filename, &e.name))
621                 return -EINVAL;
622         error = tomoyo_update_domain(&e.head, sizeof(e), is_delete, domain,
623                                      tomoyo_same_path_acl,
624                                      tomoyo_merge_path_acl);
625         tomoyo_put_name_union(&e.name);
626         return error;
627 }
628
629 static bool tomoyo_same_mkdev_acl(const struct tomoyo_acl_info *a,
630                                          const struct tomoyo_acl_info *b)
631 {
632         const struct tomoyo_mkdev_acl *p1 = container_of(a, typeof(*p1),
633                                                                 head);
634         const struct tomoyo_mkdev_acl *p2 = container_of(b, typeof(*p2),
635                                                                 head);
636         return tomoyo_same_acl_head(&p1->head, &p2->head)
637                 && tomoyo_same_name_union(&p1->name, &p2->name)
638                 && tomoyo_same_number_union(&p1->mode, &p2->mode)
639                 && tomoyo_same_number_union(&p1->major, &p2->major)
640                 && tomoyo_same_number_union(&p1->minor, &p2->minor);
641 }
642
643 static bool tomoyo_merge_mkdev_acl(struct tomoyo_acl_info *a,
644                                           struct tomoyo_acl_info *b,
645                                           const bool is_delete)
646 {
647         u8 *const a_perm = &container_of(a, struct tomoyo_mkdev_acl,
648                                          head)->perm;
649         u8 perm = *a_perm;
650         const u8 b_perm = container_of(b, struct tomoyo_mkdev_acl, head)
651                 ->perm;
652         if (is_delete)
653                 perm &= ~b_perm;
654         else
655                 perm |= b_perm;
656         *a_perm = perm;
657         return !perm;
658 }
659
660 /**
661  * tomoyo_update_mkdev_acl - Update "struct tomoyo_mkdev_acl" list.
662  *
663  * @type:      Type of operation.
664  * @filename:  Filename.
665  * @mode:      Create mode.
666  * @major:     Device major number.
667  * @minor:     Device minor number.
668  * @domain:    Pointer to "struct tomoyo_domain_info".
669  * @is_delete: True if it is a delete request.
670  *
671  * Returns 0 on success, negative value otherwise.
672  *
673  * Caller holds tomoyo_read_lock().
674  */
675 static int tomoyo_update_mkdev_acl(const u8 type, const char *filename,
676                                           char *mode, char *major, char *minor,
677                                           struct tomoyo_domain_info * const
678                                           domain, const bool is_delete)
679 {
680         struct tomoyo_mkdev_acl e = {
681                 .head.type = TOMOYO_TYPE_MKDEV_ACL,
682                 .perm = 1 << type
683         };
684         int error = is_delete ? -ENOENT : -ENOMEM;
685         if (!tomoyo_parse_name_union(filename, &e.name) ||
686             !tomoyo_parse_number_union(mode, &e.mode) ||
687             !tomoyo_parse_number_union(major, &e.major) ||
688             !tomoyo_parse_number_union(minor, &e.minor))
689                 goto out;
690         error = tomoyo_update_domain(&e.head, sizeof(e), is_delete, domain,
691                                      tomoyo_same_mkdev_acl,
692                                      tomoyo_merge_mkdev_acl);
693  out:
694         tomoyo_put_name_union(&e.name);
695         tomoyo_put_number_union(&e.mode);
696         tomoyo_put_number_union(&e.major);
697         tomoyo_put_number_union(&e.minor);
698         return error;
699 }
700
701 static bool tomoyo_same_path2_acl(const struct tomoyo_acl_info *a,
702                                   const struct tomoyo_acl_info *b)
703 {
704         const struct tomoyo_path2_acl *p1 = container_of(a, typeof(*p1), head);
705         const struct tomoyo_path2_acl *p2 = container_of(b, typeof(*p2), head);
706         return tomoyo_same_acl_head(&p1->head, &p2->head)
707                 && tomoyo_same_name_union(&p1->name1, &p2->name1)
708                 && tomoyo_same_name_union(&p1->name2, &p2->name2);
709 }
710
711 static bool tomoyo_merge_path2_acl(struct tomoyo_acl_info *a,
712                                    struct tomoyo_acl_info *b,
713                                    const bool is_delete)
714 {
715         u8 * const a_perm = &container_of(a, struct tomoyo_path2_acl, head)
716                 ->perm;
717         u8 perm = *a_perm;
718         const u8 b_perm = container_of(b, struct tomoyo_path2_acl, head)->perm;
719         if (is_delete)
720                 perm &= ~b_perm;
721         else
722                 perm |= b_perm;
723         *a_perm = perm;
724         return !perm;
725 }
726
727 /**
728  * tomoyo_update_path2_acl - Update "struct tomoyo_path2_acl" list.
729  *
730  * @type:      Type of operation.
731  * @filename1: First filename.
732  * @filename2: Second filename.
733  * @domain:    Pointer to "struct tomoyo_domain_info".
734  * @is_delete: True if it is a delete request.
735  *
736  * Returns 0 on success, negative value otherwise.
737  *
738  * Caller holds tomoyo_read_lock().
739  */
740 static int tomoyo_update_path2_acl(const u8 type, const char *filename1,
741                                    const char *filename2,
742                                    struct tomoyo_domain_info * const domain,
743                                    const bool is_delete)
744 {
745         struct tomoyo_path2_acl e = {
746                 .head.type = TOMOYO_TYPE_PATH2_ACL,
747                 .perm = 1 << type
748         };
749         int error = is_delete ? -ENOENT : -ENOMEM;
750         if (!tomoyo_parse_name_union(filename1, &e.name1) ||
751             !tomoyo_parse_name_union(filename2, &e.name2))
752                 goto out;
753         error = tomoyo_update_domain(&e.head, sizeof(e), is_delete, domain,
754                                      tomoyo_same_path2_acl,
755                                      tomoyo_merge_path2_acl);
756  out:
757         tomoyo_put_name_union(&e.name1);
758         tomoyo_put_name_union(&e.name2);
759         return error;
760 }
761
762 /**
763  * tomoyo_path_permission - Check permission for single path operation.
764  *
765  * @r:         Pointer to "struct tomoyo_request_info".
766  * @operation: Type of operation.
767  * @filename:  Filename to check.
768  *
769  * Returns 0 on success, negative value otherwise.
770  *
771  * Caller holds tomoyo_read_lock().
772  */
773 int tomoyo_path_permission(struct tomoyo_request_info *r, u8 operation,
774                            const struct tomoyo_path_info *filename)
775 {
776         int error;
777
778  next:
779         r->type = tomoyo_p2mac[operation];
780         r->mode = tomoyo_get_mode(r->profile, r->type);
781         if (r->mode == TOMOYO_CONFIG_DISABLED)
782                 return 0;
783         r->param_type = TOMOYO_TYPE_PATH_ACL;
784         r->param.path.filename = filename;
785         r->param.path.operation = operation;
786         do {
787                 tomoyo_check_acl(r, tomoyo_check_path_acl);
788                 if (!r->granted && operation == TOMOYO_TYPE_READ &&
789                     !r->domain->ignore_global_allow_read &&
790                     tomoyo_globally_readable_file(filename))
791                         r->granted = true;
792                 error = tomoyo_audit_path_log(r);
793                 /*
794                  * Do not retry for execute request, for alias may have
795                  * changed.
796                  */
797         } while (error == TOMOYO_RETRY_REQUEST &&
798                  operation != TOMOYO_TYPE_EXECUTE);
799         /*
800          * Since "allow_truncate" doesn't imply "allow_rewrite" permission,
801          * we need to check "allow_rewrite" permission if the filename is
802          * specified by "deny_rewrite" keyword.
803          */
804         if (!error && operation == TOMOYO_TYPE_TRUNCATE &&
805             tomoyo_no_rewrite_file(filename)) {
806                 operation = TOMOYO_TYPE_REWRITE;
807                 goto next;
808         }
809         return error;
810 }
811
812 static bool tomoyo_same_path_number_acl(const struct tomoyo_acl_info *a,
813                                         const struct tomoyo_acl_info *b)
814 {
815         const struct tomoyo_path_number_acl *p1 = container_of(a, typeof(*p1),
816                                                                head);
817         const struct tomoyo_path_number_acl *p2 = container_of(b, typeof(*p2),
818                                                                head);
819         return tomoyo_same_acl_head(&p1->head, &p2->head)
820                 && tomoyo_same_name_union(&p1->name, &p2->name)
821                 && tomoyo_same_number_union(&p1->number, &p2->number);
822 }
823
824 static bool tomoyo_merge_path_number_acl(struct tomoyo_acl_info *a,
825                                          struct tomoyo_acl_info *b,
826                                          const bool is_delete)
827 {
828         u8 * const a_perm = &container_of(a, struct tomoyo_path_number_acl,
829                                           head)->perm;
830         u8 perm = *a_perm;
831         const u8 b_perm = container_of(b, struct tomoyo_path_number_acl, head)
832                 ->perm;
833         if (is_delete)
834                 perm &= ~b_perm;
835         else
836                 perm |= b_perm;
837         *a_perm = perm;
838         return !perm;
839 }
840
841 /**
842  * tomoyo_update_path_number_acl - Update ioctl/chmod/chown/chgrp ACL.
843  *
844  * @type:      Type of operation.
845  * @filename:  Filename.
846  * @number:    Number.
847  * @domain:    Pointer to "struct tomoyo_domain_info".
848  * @is_delete: True if it is a delete request.
849  *
850  * Returns 0 on success, negative value otherwise.
851  */
852 static int tomoyo_update_path_number_acl(const u8 type, const char *filename,
853                                          char *number,
854                                          struct tomoyo_domain_info * const
855                                          domain,
856                                          const bool is_delete)
857 {
858         struct tomoyo_path_number_acl e = {
859                 .head.type = TOMOYO_TYPE_PATH_NUMBER_ACL,
860                 .perm = 1 << type
861         };
862         int error = is_delete ? -ENOENT : -ENOMEM;
863         if (!tomoyo_parse_name_union(filename, &e.name))
864                 return -EINVAL;
865         if (!tomoyo_parse_number_union(number, &e.number))
866                 goto out;
867         error = tomoyo_update_domain(&e.head, sizeof(e), is_delete, domain,
868                                      tomoyo_same_path_number_acl,
869                                      tomoyo_merge_path_number_acl);
870  out:
871         tomoyo_put_name_union(&e.name);
872         tomoyo_put_number_union(&e.number);
873         return error;
874 }
875
876 /**
877  * tomoyo_path_number_perm - Check permission for "create", "mkdir", "mkfifo", "mksock", "ioctl", "chmod", "chown", "chgrp".
878  *
879  * @type:   Type of operation.
880  * @path:   Pointer to "struct path".
881  * @number: Number.
882  *
883  * Returns 0 on success, negative value otherwise.
884  */
885 int tomoyo_path_number_perm(const u8 type, struct path *path,
886                             unsigned long number)
887 {
888         struct tomoyo_request_info r;
889         int error = -ENOMEM;
890         struct tomoyo_path_info buf;
891         int idx;
892
893         if (tomoyo_init_request_info(&r, NULL, tomoyo_pn2mac[type])
894             == TOMOYO_CONFIG_DISABLED || !path->mnt || !path->dentry)
895                 return 0;
896         idx = tomoyo_read_lock();
897         if (!tomoyo_get_realpath(&buf, path))
898                 goto out;
899         if (type == TOMOYO_TYPE_MKDIR)
900                 tomoyo_add_slash(&buf);
901         r.param_type = TOMOYO_TYPE_PATH_NUMBER_ACL;
902         r.param.path_number.operation = type;
903         r.param.path_number.filename = &buf;
904         r.param.path_number.number = number;
905         do {
906                 tomoyo_check_acl(&r, tomoyo_check_path_number_acl);
907                 error = tomoyo_audit_path_number_log(&r);
908         } while (error == TOMOYO_RETRY_REQUEST);
909         kfree(buf.name);
910  out:
911         tomoyo_read_unlock(idx);
912         if (r.mode != TOMOYO_CONFIG_ENFORCING)
913                 error = 0;
914         return error;
915 }
916
917 /**
918  * tomoyo_check_open_permission - Check permission for "read" and "write".
919  *
920  * @domain: Pointer to "struct tomoyo_domain_info".
921  * @path:   Pointer to "struct path".
922  * @flag:   Flags for open().
923  *
924  * Returns 0 on success, negative value otherwise.
925  */
926 int tomoyo_check_open_permission(struct tomoyo_domain_info *domain,
927                                  struct path *path, const int flag)
928 {
929         const u8 acc_mode = ACC_MODE(flag);
930         int error = 0;
931         struct tomoyo_path_info buf;
932         struct tomoyo_request_info r;
933         int idx;
934
935         if (!path->mnt ||
936             (path->dentry->d_inode && S_ISDIR(path->dentry->d_inode->i_mode)))
937                 return 0;
938         buf.name = NULL;
939         r.mode = TOMOYO_CONFIG_DISABLED;
940         idx = tomoyo_read_lock();
941         /*
942          * If the filename is specified by "deny_rewrite" keyword,
943          * we need to check "allow_rewrite" permission when the filename is not
944          * opened for append mode or the filename is truncated at open time.
945          */
946         if ((acc_mode & MAY_WRITE) && !(flag & O_APPEND)
947             && tomoyo_init_request_info(&r, domain, TOMOYO_MAC_FILE_REWRITE)
948             != TOMOYO_CONFIG_DISABLED) {
949                 if (!tomoyo_get_realpath(&buf, path)) {
950                         error = -ENOMEM;
951                         goto out;
952                 }
953                 if (tomoyo_no_rewrite_file(&buf))
954                         error = tomoyo_path_permission(&r, TOMOYO_TYPE_REWRITE,
955                                                        &buf);
956         }
957         if (!error && acc_mode &&
958             tomoyo_init_request_info(&r, domain, TOMOYO_MAC_FILE_OPEN)
959             != TOMOYO_CONFIG_DISABLED) {
960                 u8 operation;
961                 if (!buf.name && !tomoyo_get_realpath(&buf, path)) {
962                         error = -ENOMEM;
963                         goto out;
964                 }
965                 if (acc_mode == (MAY_READ | MAY_WRITE))
966                         operation = TOMOYO_TYPE_READ_WRITE;
967                 else if (acc_mode == MAY_READ)
968                         operation = TOMOYO_TYPE_READ;
969                 else
970                         operation = TOMOYO_TYPE_WRITE;
971                 error = tomoyo_path_permission(&r, operation, &buf);
972         }
973  out:
974         kfree(buf.name);
975         tomoyo_read_unlock(idx);
976         if (r.mode != TOMOYO_CONFIG_ENFORCING)
977                 error = 0;
978         return error;
979 }
980
981 /**
982  * tomoyo_path_perm - Check permission for "unlink", "rmdir", "truncate", "symlink", "rewrite", "chroot" and "unmount".
983  *
984  * @operation: Type of operation.
985  * @path:      Pointer to "struct path".
986  *
987  * Returns 0 on success, negative value otherwise.
988  */
989 int tomoyo_path_perm(const u8 operation, struct path *path)
990 {
991         int error = -ENOMEM;
992         struct tomoyo_path_info buf;
993         struct tomoyo_request_info r;
994         int idx;
995
996         if (!path->mnt)
997                 return 0;
998         if (tomoyo_init_request_info(&r, NULL, tomoyo_p2mac[operation])
999             == TOMOYO_CONFIG_DISABLED)
1000                 return 0;
1001         buf.name = NULL;
1002         idx = tomoyo_read_lock();
1003         if (!tomoyo_get_realpath(&buf, path))
1004                 goto out;
1005         switch (operation) {
1006         case TOMOYO_TYPE_REWRITE:
1007                 if (!tomoyo_no_rewrite_file(&buf)) {
1008                         error = 0;
1009                         goto out;
1010                 }
1011                 break;
1012         case TOMOYO_TYPE_RMDIR:
1013         case TOMOYO_TYPE_CHROOT:
1014         case TOMOYO_TYPE_UMOUNT:
1015                 tomoyo_add_slash(&buf);
1016                 break;
1017         }
1018         error = tomoyo_path_permission(&r, operation, &buf);
1019  out:
1020         kfree(buf.name);
1021         tomoyo_read_unlock(idx);
1022         if (r.mode != TOMOYO_CONFIG_ENFORCING)
1023                 error = 0;
1024         return error;
1025 }
1026
1027 /**
1028  * tomoyo_mkdev_perm - Check permission for "mkblock" and "mkchar".
1029  *
1030  * @operation: Type of operation. (TOMOYO_TYPE_MKCHAR or TOMOYO_TYPE_MKBLOCK)
1031  * @path:      Pointer to "struct path".
1032  * @mode:      Create mode.
1033  * @dev:       Device number.
1034  *
1035  * Returns 0 on success, negative value otherwise.
1036  */
1037 int tomoyo_mkdev_perm(const u8 operation, struct path *path,
1038                              const unsigned int mode, unsigned int dev)
1039 {
1040         struct tomoyo_request_info r;
1041         int error = -ENOMEM;
1042         struct tomoyo_path_info buf;
1043         int idx;
1044
1045         if (!path->mnt ||
1046             tomoyo_init_request_info(&r, NULL, tomoyo_pnnn2mac[operation])
1047             == TOMOYO_CONFIG_DISABLED)
1048                 return 0;
1049         idx = tomoyo_read_lock();
1050         error = -ENOMEM;
1051         if (tomoyo_get_realpath(&buf, path)) {
1052                 dev = new_decode_dev(dev);
1053                 r.param_type = TOMOYO_TYPE_MKDEV_ACL;
1054                 r.param.mkdev.filename = &buf;
1055                 r.param.mkdev.operation = operation;
1056                 r.param.mkdev.mode = mode;
1057                 r.param.mkdev.major = MAJOR(dev);
1058                 r.param.mkdev.minor = MINOR(dev);
1059                 tomoyo_check_acl(&r, tomoyo_check_mkdev_acl);
1060                 error = tomoyo_audit_mkdev_log(&r);
1061                 kfree(buf.name);
1062         }
1063         tomoyo_read_unlock(idx);
1064         if (r.mode != TOMOYO_CONFIG_ENFORCING)
1065                 error = 0;
1066         return error;
1067 }
1068
1069 /**
1070  * tomoyo_path2_perm - Check permission for "rename", "link" and "pivot_root".
1071  *
1072  * @operation: Type of operation.
1073  * @path1:      Pointer to "struct path".
1074  * @path2:      Pointer to "struct path".
1075  *
1076  * Returns 0 on success, negative value otherwise.
1077  */
1078 int tomoyo_path2_perm(const u8 operation, struct path *path1,
1079                       struct path *path2)
1080 {
1081         int error = -ENOMEM;
1082         struct tomoyo_path_info buf1;
1083         struct tomoyo_path_info buf2;
1084         struct tomoyo_request_info r;
1085         int idx;
1086
1087         if (!path1->mnt || !path2->mnt ||
1088             tomoyo_init_request_info(&r, NULL, tomoyo_pp2mac[operation])
1089             == TOMOYO_CONFIG_DISABLED)
1090                 return 0;
1091         buf1.name = NULL;
1092         buf2.name = NULL;
1093         idx = tomoyo_read_lock();
1094         if (!tomoyo_get_realpath(&buf1, path1) ||
1095             !tomoyo_get_realpath(&buf2, path2))
1096                 goto out;
1097         switch (operation) {
1098                 struct dentry *dentry;
1099         case TOMOYO_TYPE_RENAME:
1100         case TOMOYO_TYPE_LINK:
1101                 dentry = path1->dentry;
1102                 if (!dentry->d_inode || !S_ISDIR(dentry->d_inode->i_mode))
1103                         break;
1104                 /* fall through */
1105         case TOMOYO_TYPE_PIVOT_ROOT:
1106                 tomoyo_add_slash(&buf1);
1107                 tomoyo_add_slash(&buf2);
1108                 break;
1109         }
1110         r.param_type = TOMOYO_TYPE_PATH2_ACL;
1111         r.param.path2.operation = operation;
1112         r.param.path2.filename1 = &buf1;
1113         r.param.path2.filename2 = &buf2;
1114         do {
1115                 tomoyo_check_acl(&r, tomoyo_check_path2_acl);
1116                 error = tomoyo_audit_path2_log(&r);
1117         } while (error == TOMOYO_RETRY_REQUEST);
1118  out:
1119         kfree(buf1.name);
1120         kfree(buf2.name);
1121         tomoyo_read_unlock(idx);
1122         if (r.mode != TOMOYO_CONFIG_ENFORCING)
1123                 error = 0;
1124         return error;
1125 }
1126
1127 /**
1128  * tomoyo_write_file - Update file related list.
1129  *
1130  * @data:      String to parse.
1131  * @domain:    Pointer to "struct tomoyo_domain_info".
1132  * @is_delete: True if it is a delete request.
1133  *
1134  * Returns 0 on success, negative value otherwise.
1135  *
1136  * Caller holds tomoyo_read_lock().
1137  */
1138 int tomoyo_write_file(char *data, struct tomoyo_domain_info *domain,
1139                       const bool is_delete)
1140 {
1141         char *w[5];
1142         u8 type;
1143         if (!tomoyo_tokenize(data, w, sizeof(w)) || !w[1][0])
1144                 return -EINVAL;
1145         if (strncmp(w[0], "allow_", 6))
1146                 goto out;
1147         w[0] += 6;
1148         for (type = 0; type < TOMOYO_MAX_PATH_OPERATION; type++) {
1149                 if (strcmp(w[0], tomoyo_path_keyword[type]))
1150                         continue;
1151                 return tomoyo_update_path_acl(type, w[1], domain, is_delete);
1152         }
1153         if (!w[2][0])
1154                 goto out;
1155         for (type = 0; type < TOMOYO_MAX_PATH2_OPERATION; type++) {
1156                 if (strcmp(w[0], tomoyo_path2_keyword[type]))
1157                         continue;
1158                 return tomoyo_update_path2_acl(type, w[1], w[2], domain,
1159                                                is_delete);
1160         }
1161         for (type = 0; type < TOMOYO_MAX_PATH_NUMBER_OPERATION; type++) {
1162                 if (strcmp(w[0], tomoyo_path_number_keyword[type]))
1163                         continue;
1164                 return tomoyo_update_path_number_acl(type, w[1], w[2], domain,
1165                                                      is_delete);
1166         }
1167         if (!w[3][0] || !w[4][0])
1168                 goto out;
1169         for (type = 0; type < TOMOYO_MAX_MKDEV_OPERATION; type++) {
1170                 if (strcmp(w[0], tomoyo_mkdev_keyword[type]))
1171                         continue;
1172                 return tomoyo_update_mkdev_acl(type, w[1], w[2], w[3],
1173                                                w[4], domain, is_delete);
1174         }
1175  out:
1176         return -EINVAL;
1177 }