Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszer...
[sfrench/cifs-2.6.git] / security / tomoyo / file.c
1 /*
2  * security/tomoyo/file.c
3  *
4  * Copyright (C) 2005-2011  NTT DATA CORPORATION
5  */
6
7 #include "common.h"
8 #include <linux/slab.h>
9
10 /*
11  * Mapping table from "enum tomoyo_path_acl_index" to "enum tomoyo_mac_index".
12  */
13 static const u8 tomoyo_p2mac[TOMOYO_MAX_PATH_OPERATION] = {
14         [TOMOYO_TYPE_EXECUTE]    = TOMOYO_MAC_FILE_EXECUTE,
15         [TOMOYO_TYPE_READ]       = TOMOYO_MAC_FILE_OPEN,
16         [TOMOYO_TYPE_WRITE]      = TOMOYO_MAC_FILE_OPEN,
17         [TOMOYO_TYPE_APPEND]     = TOMOYO_MAC_FILE_OPEN,
18         [TOMOYO_TYPE_UNLINK]     = TOMOYO_MAC_FILE_UNLINK,
19         [TOMOYO_TYPE_GETATTR]    = TOMOYO_MAC_FILE_GETATTR,
20         [TOMOYO_TYPE_RMDIR]      = TOMOYO_MAC_FILE_RMDIR,
21         [TOMOYO_TYPE_TRUNCATE]   = TOMOYO_MAC_FILE_TRUNCATE,
22         [TOMOYO_TYPE_SYMLINK]    = TOMOYO_MAC_FILE_SYMLINK,
23         [TOMOYO_TYPE_CHROOT]     = TOMOYO_MAC_FILE_CHROOT,
24         [TOMOYO_TYPE_UMOUNT]     = TOMOYO_MAC_FILE_UMOUNT,
25 };
26
27 /*
28  * Mapping table from "enum tomoyo_mkdev_acl_index" to "enum tomoyo_mac_index".
29  */
30 const u8 tomoyo_pnnn2mac[TOMOYO_MAX_MKDEV_OPERATION] = {
31         [TOMOYO_TYPE_MKBLOCK] = TOMOYO_MAC_FILE_MKBLOCK,
32         [TOMOYO_TYPE_MKCHAR]  = TOMOYO_MAC_FILE_MKCHAR,
33 };
34
35 /*
36  * Mapping table from "enum tomoyo_path2_acl_index" to "enum tomoyo_mac_index".
37  */
38 const u8 tomoyo_pp2mac[TOMOYO_MAX_PATH2_OPERATION] = {
39         [TOMOYO_TYPE_LINK]       = TOMOYO_MAC_FILE_LINK,
40         [TOMOYO_TYPE_RENAME]     = TOMOYO_MAC_FILE_RENAME,
41         [TOMOYO_TYPE_PIVOT_ROOT] = TOMOYO_MAC_FILE_PIVOT_ROOT,
42 };
43
44 /*
45  * Mapping table from "enum tomoyo_path_number_acl_index" to
46  * "enum tomoyo_mac_index".
47  */
48 const u8 tomoyo_pn2mac[TOMOYO_MAX_PATH_NUMBER_OPERATION] = {
49         [TOMOYO_TYPE_CREATE] = TOMOYO_MAC_FILE_CREATE,
50         [TOMOYO_TYPE_MKDIR]  = TOMOYO_MAC_FILE_MKDIR,
51         [TOMOYO_TYPE_MKFIFO] = TOMOYO_MAC_FILE_MKFIFO,
52         [TOMOYO_TYPE_MKSOCK] = TOMOYO_MAC_FILE_MKSOCK,
53         [TOMOYO_TYPE_IOCTL]  = TOMOYO_MAC_FILE_IOCTL,
54         [TOMOYO_TYPE_CHMOD]  = TOMOYO_MAC_FILE_CHMOD,
55         [TOMOYO_TYPE_CHOWN]  = TOMOYO_MAC_FILE_CHOWN,
56         [TOMOYO_TYPE_CHGRP]  = TOMOYO_MAC_FILE_CHGRP,
57 };
58
59 /**
60  * tomoyo_put_name_union - Drop reference on "struct tomoyo_name_union".
61  *
62  * @ptr: Pointer to "struct tomoyo_name_union".
63  *
64  * Returns nothing.
65  */
66 void tomoyo_put_name_union(struct tomoyo_name_union *ptr)
67 {
68         tomoyo_put_group(ptr->group);
69         tomoyo_put_name(ptr->filename);
70 }
71
72 /**
73  * tomoyo_compare_name_union - Check whether a name matches "struct tomoyo_name_union" or not.
74  *
75  * @name: Pointer to "struct tomoyo_path_info".
76  * @ptr:  Pointer to "struct tomoyo_name_union".
77  *
78  * Returns "struct tomoyo_path_info" if @name matches @ptr, NULL otherwise.
79  */
80 const struct tomoyo_path_info *
81 tomoyo_compare_name_union(const struct tomoyo_path_info *name,
82                           const struct tomoyo_name_union *ptr)
83 {
84         if (ptr->group)
85                 return tomoyo_path_matches_group(name, ptr->group);
86         if (tomoyo_path_matches_pattern(name, ptr->filename))
87                 return ptr->filename;
88         return NULL;
89 }
90
91 /**
92  * tomoyo_put_number_union - Drop reference on "struct tomoyo_number_union".
93  *
94  * @ptr: Pointer to "struct tomoyo_number_union".
95  *
96  * Returns nothing.
97  */
98 void tomoyo_put_number_union(struct tomoyo_number_union *ptr)
99 {
100         tomoyo_put_group(ptr->group);
101 }
102
103 /**
104  * tomoyo_compare_number_union - Check whether a value matches "struct tomoyo_number_union" or not.
105  *
106  * @value: Number to check.
107  * @ptr:   Pointer to "struct tomoyo_number_union".
108  *
109  * Returns true if @value matches @ptr, false otherwise.
110  */
111 bool tomoyo_compare_number_union(const unsigned long value,
112                                  const struct tomoyo_number_union *ptr)
113 {
114         if (ptr->group)
115                 return tomoyo_number_matches_group(value, value, ptr->group);
116         return value >= ptr->values[0] && value <= ptr->values[1];
117 }
118
119 /**
120  * tomoyo_add_slash - Add trailing '/' if needed.
121  *
122  * @buf: Pointer to "struct tomoyo_path_info".
123  *
124  * Returns nothing.
125  *
126  * @buf must be generated by tomoyo_encode() because this function does not
127  * allocate memory for adding '/'.
128  */
129 static void tomoyo_add_slash(struct tomoyo_path_info *buf)
130 {
131         if (buf->is_dir)
132                 return;
133         /*
134          * This is OK because tomoyo_encode() reserves space for appending "/".
135          */
136         strcat((char *) buf->name, "/");
137         tomoyo_fill_path_info(buf);
138 }
139
140 /**
141  * tomoyo_get_realpath - Get realpath.
142  *
143  * @buf:  Pointer to "struct tomoyo_path_info".
144  * @path: Pointer to "struct path".
145  *
146  * Returns true on success, false otherwise.
147  */
148 static bool tomoyo_get_realpath(struct tomoyo_path_info *buf, const struct path *path)
149 {
150         buf->name = tomoyo_realpath_from_path(path);
151         if (buf->name) {
152                 tomoyo_fill_path_info(buf);
153                 return true;
154         }
155         return false;
156 }
157
158 /**
159  * tomoyo_audit_path_log - Audit path request log.
160  *
161  * @r: Pointer to "struct tomoyo_request_info".
162  *
163  * Returns 0 on success, negative value otherwise.
164  */
165 static int tomoyo_audit_path_log(struct tomoyo_request_info *r)
166 {
167         return tomoyo_supervisor(r, "file %s %s\n", tomoyo_path_keyword
168                                  [r->param.path.operation],
169                                  r->param.path.filename->name);
170 }
171
172 /**
173  * tomoyo_audit_path2_log - Audit path/path request log.
174  *
175  * @r: Pointer to "struct tomoyo_request_info".
176  *
177  * Returns 0 on success, negative value otherwise.
178  */
179 static int tomoyo_audit_path2_log(struct tomoyo_request_info *r)
180 {
181         return tomoyo_supervisor(r, "file %s %s %s\n", tomoyo_mac_keywords
182                                  [tomoyo_pp2mac[r->param.path2.operation]],
183                                  r->param.path2.filename1->name,
184                                  r->param.path2.filename2->name);
185 }
186
187 /**
188  * tomoyo_audit_mkdev_log - Audit path/number/number/number request log.
189  *
190  * @r: Pointer to "struct tomoyo_request_info".
191  *
192  * Returns 0 on success, negative value otherwise.
193  */
194 static int tomoyo_audit_mkdev_log(struct tomoyo_request_info *r)
195 {
196         return tomoyo_supervisor(r, "file %s %s 0%o %u %u\n",
197                                  tomoyo_mac_keywords
198                                  [tomoyo_pnnn2mac[r->param.mkdev.operation]],
199                                  r->param.mkdev.filename->name,
200                                  r->param.mkdev.mode, r->param.mkdev.major,
201                                  r->param.mkdev.minor);
202 }
203
204 /**
205  * tomoyo_audit_path_number_log - Audit path/number request log.
206  *
207  * @r: Pointer to "struct tomoyo_request_info".
208  *
209  * Returns 0 on success, negative value otherwise.
210  */
211 static int tomoyo_audit_path_number_log(struct tomoyo_request_info *r)
212 {
213         const u8 type = r->param.path_number.operation;
214         u8 radix;
215         char buffer[64];
216         switch (type) {
217         case TOMOYO_TYPE_CREATE:
218         case TOMOYO_TYPE_MKDIR:
219         case TOMOYO_TYPE_MKFIFO:
220         case TOMOYO_TYPE_MKSOCK:
221         case TOMOYO_TYPE_CHMOD:
222                 radix = TOMOYO_VALUE_TYPE_OCTAL;
223                 break;
224         case TOMOYO_TYPE_IOCTL:
225                 radix = TOMOYO_VALUE_TYPE_HEXADECIMAL;
226                 break;
227         default:
228                 radix = TOMOYO_VALUE_TYPE_DECIMAL;
229                 break;
230         }
231         tomoyo_print_ulong(buffer, sizeof(buffer), r->param.path_number.number,
232                            radix);
233         return tomoyo_supervisor(r, "file %s %s %s\n", tomoyo_mac_keywords
234                                  [tomoyo_pn2mac[type]],
235                                  r->param.path_number.filename->name, buffer);
236 }
237
238 /**
239  * tomoyo_check_path_acl - Check permission for path operation.
240  *
241  * @r:   Pointer to "struct tomoyo_request_info".
242  * @ptr: Pointer to "struct tomoyo_acl_info".
243  *
244  * Returns true if granted, false otherwise.
245  *
246  * To be able to use wildcard for domain transition, this function sets
247  * matching entry on success. Since the caller holds tomoyo_read_lock(),
248  * it is safe to set matching entry.
249  */
250 static bool tomoyo_check_path_acl(struct tomoyo_request_info *r,
251                                   const struct tomoyo_acl_info *ptr)
252 {
253         const struct tomoyo_path_acl *acl = container_of(ptr, typeof(*acl),
254                                                          head);
255         if (acl->perm & (1 << r->param.path.operation)) {
256                 r->param.path.matched_path =
257                         tomoyo_compare_name_union(r->param.path.filename,
258                                                   &acl->name);
259                 return r->param.path.matched_path != NULL;
260         }
261         return false;
262 }
263
264 /**
265  * tomoyo_check_path_number_acl - Check permission for path number operation.
266  *
267  * @r:   Pointer to "struct tomoyo_request_info".
268  * @ptr: Pointer to "struct tomoyo_acl_info".
269  *
270  * Returns true if granted, false otherwise.
271  */
272 static bool tomoyo_check_path_number_acl(struct tomoyo_request_info *r,
273                                          const struct tomoyo_acl_info *ptr)
274 {
275         const struct tomoyo_path_number_acl *acl =
276                 container_of(ptr, typeof(*acl), head);
277         return (acl->perm & (1 << r->param.path_number.operation)) &&
278                 tomoyo_compare_number_union(r->param.path_number.number,
279                                             &acl->number) &&
280                 tomoyo_compare_name_union(r->param.path_number.filename,
281                                           &acl->name);
282 }
283
284 /**
285  * tomoyo_check_path2_acl - Check permission for path path operation.
286  *
287  * @r:   Pointer to "struct tomoyo_request_info".
288  * @ptr: Pointer to "struct tomoyo_acl_info".
289  *
290  * Returns true if granted, false otherwise.
291  */
292 static bool tomoyo_check_path2_acl(struct tomoyo_request_info *r,
293                                    const struct tomoyo_acl_info *ptr)
294 {
295         const struct tomoyo_path2_acl *acl =
296                 container_of(ptr, typeof(*acl), head);
297         return (acl->perm & (1 << r->param.path2.operation)) &&
298                 tomoyo_compare_name_union(r->param.path2.filename1, &acl->name1)
299                 && tomoyo_compare_name_union(r->param.path2.filename2,
300                                              &acl->name2);
301 }
302
303 /**
304  * tomoyo_check_mkdev_acl - Check permission for path number number number operation.
305  *
306  * @r:   Pointer to "struct tomoyo_request_info".
307  * @ptr: Pointer to "struct tomoyo_acl_info".
308  *
309  * Returns true if granted, false otherwise.
310  */
311 static bool tomoyo_check_mkdev_acl(struct tomoyo_request_info *r,
312                                    const struct tomoyo_acl_info *ptr)
313 {
314         const struct tomoyo_mkdev_acl *acl =
315                 container_of(ptr, typeof(*acl), head);
316         return (acl->perm & (1 << r->param.mkdev.operation)) &&
317                 tomoyo_compare_number_union(r->param.mkdev.mode,
318                                             &acl->mode) &&
319                 tomoyo_compare_number_union(r->param.mkdev.major,
320                                             &acl->major) &&
321                 tomoyo_compare_number_union(r->param.mkdev.minor,
322                                             &acl->minor) &&
323                 tomoyo_compare_name_union(r->param.mkdev.filename,
324                                           &acl->name);
325 }
326
327 /**
328  * tomoyo_same_path_acl - Check for duplicated "struct tomoyo_path_acl" entry.
329  *
330  * @a: Pointer to "struct tomoyo_acl_info".
331  * @b: Pointer to "struct tomoyo_acl_info".
332  *
333  * Returns true if @a == @b except permission bits, false otherwise.
334  */
335 static bool tomoyo_same_path_acl(const struct tomoyo_acl_info *a,
336                                  const struct tomoyo_acl_info *b)
337 {
338         const struct tomoyo_path_acl *p1 = container_of(a, typeof(*p1), head);
339         const struct tomoyo_path_acl *p2 = container_of(b, typeof(*p2), head);
340         return tomoyo_same_name_union(&p1->name, &p2->name);
341 }
342
343 /**
344  * tomoyo_merge_path_acl - Merge duplicated "struct tomoyo_path_acl" entry.
345  *
346  * @a:         Pointer to "struct tomoyo_acl_info".
347  * @b:         Pointer to "struct tomoyo_acl_info".
348  * @is_delete: True for @a &= ~@b, false for @a |= @b.
349  *
350  * Returns true if @a is empty, false otherwise.
351  */
352 static bool tomoyo_merge_path_acl(struct tomoyo_acl_info *a,
353                                   struct tomoyo_acl_info *b,
354                                   const bool is_delete)
355 {
356         u16 * const a_perm = &container_of(a, struct tomoyo_path_acl, head)
357                 ->perm;
358         u16 perm = *a_perm;
359         const u16 b_perm = container_of(b, struct tomoyo_path_acl, head)->perm;
360         if (is_delete)
361                 perm &= ~b_perm;
362         else
363                 perm |= b_perm;
364         *a_perm = perm;
365         return !perm;
366 }
367
368 /**
369  * tomoyo_update_path_acl - Update "struct tomoyo_path_acl" list.
370  *
371  * @perm:  Permission.
372  * @param: Pointer to "struct tomoyo_acl_param".
373  *
374  * Returns 0 on success, negative value otherwise.
375  *
376  * Caller holds tomoyo_read_lock().
377  */
378 static int tomoyo_update_path_acl(const u16 perm,
379                                   struct tomoyo_acl_param *param)
380 {
381         struct tomoyo_path_acl e = {
382                 .head.type = TOMOYO_TYPE_PATH_ACL,
383                 .perm = perm
384         };
385         int error;
386         if (!tomoyo_parse_name_union(param, &e.name))
387                 error = -EINVAL;
388         else
389                 error = tomoyo_update_domain(&e.head, sizeof(e), param,
390                                              tomoyo_same_path_acl,
391                                              tomoyo_merge_path_acl);
392         tomoyo_put_name_union(&e.name);
393         return error;
394 }
395
396 /**
397  * tomoyo_same_mkdev_acl - Check for duplicated "struct tomoyo_mkdev_acl" entry.
398  *
399  * @a: Pointer to "struct tomoyo_acl_info".
400  * @b: Pointer to "struct tomoyo_acl_info".
401  *
402  * Returns true if @a == @b except permission bits, false otherwise.
403  */
404 static bool tomoyo_same_mkdev_acl(const struct tomoyo_acl_info *a,
405                                          const struct tomoyo_acl_info *b)
406 {
407         const struct tomoyo_mkdev_acl *p1 = container_of(a, typeof(*p1), head);
408         const struct tomoyo_mkdev_acl *p2 = container_of(b, typeof(*p2), head);
409         return tomoyo_same_name_union(&p1->name, &p2->name) &&
410                 tomoyo_same_number_union(&p1->mode, &p2->mode) &&
411                 tomoyo_same_number_union(&p1->major, &p2->major) &&
412                 tomoyo_same_number_union(&p1->minor, &p2->minor);
413 }
414
415 /**
416  * tomoyo_merge_mkdev_acl - Merge duplicated "struct tomoyo_mkdev_acl" entry.
417  *
418  * @a:         Pointer to "struct tomoyo_acl_info".
419  * @b:         Pointer to "struct tomoyo_acl_info".
420  * @is_delete: True for @a &= ~@b, false for @a |= @b.
421  *
422  * Returns true if @a is empty, false otherwise.
423  */
424 static bool tomoyo_merge_mkdev_acl(struct tomoyo_acl_info *a,
425                                    struct tomoyo_acl_info *b,
426                                    const bool is_delete)
427 {
428         u8 *const a_perm = &container_of(a, struct tomoyo_mkdev_acl,
429                                          head)->perm;
430         u8 perm = *a_perm;
431         const u8 b_perm = container_of(b, struct tomoyo_mkdev_acl, head)
432                 ->perm;
433         if (is_delete)
434                 perm &= ~b_perm;
435         else
436                 perm |= b_perm;
437         *a_perm = perm;
438         return !perm;
439 }
440
441 /**
442  * tomoyo_update_mkdev_acl - Update "struct tomoyo_mkdev_acl" list.
443  *
444  * @perm:  Permission.
445  * @param: Pointer to "struct tomoyo_acl_param".
446  *
447  * Returns 0 on success, negative value otherwise.
448  *
449  * Caller holds tomoyo_read_lock().
450  */
451 static int tomoyo_update_mkdev_acl(const u8 perm,
452                                    struct tomoyo_acl_param *param)
453 {
454         struct tomoyo_mkdev_acl e = {
455                 .head.type = TOMOYO_TYPE_MKDEV_ACL,
456                 .perm = perm
457         };
458         int error;
459         if (!tomoyo_parse_name_union(param, &e.name) ||
460             !tomoyo_parse_number_union(param, &e.mode) ||
461             !tomoyo_parse_number_union(param, &e.major) ||
462             !tomoyo_parse_number_union(param, &e.minor))
463                 error = -EINVAL;
464         else
465                 error = tomoyo_update_domain(&e.head, sizeof(e), param,
466                                              tomoyo_same_mkdev_acl,
467                                              tomoyo_merge_mkdev_acl);
468         tomoyo_put_name_union(&e.name);
469         tomoyo_put_number_union(&e.mode);
470         tomoyo_put_number_union(&e.major);
471         tomoyo_put_number_union(&e.minor);
472         return error;
473 }
474
475 /**
476  * tomoyo_same_path2_acl - Check for duplicated "struct tomoyo_path2_acl" entry.
477  *
478  * @a: Pointer to "struct tomoyo_acl_info".
479  * @b: Pointer to "struct tomoyo_acl_info".
480  *
481  * Returns true if @a == @b except permission bits, false otherwise.
482  */
483 static bool tomoyo_same_path2_acl(const struct tomoyo_acl_info *a,
484                                   const struct tomoyo_acl_info *b)
485 {
486         const struct tomoyo_path2_acl *p1 = container_of(a, typeof(*p1), head);
487         const struct tomoyo_path2_acl *p2 = container_of(b, typeof(*p2), head);
488         return tomoyo_same_name_union(&p1->name1, &p2->name1) &&
489                 tomoyo_same_name_union(&p1->name2, &p2->name2);
490 }
491
492 /**
493  * tomoyo_merge_path2_acl - Merge duplicated "struct tomoyo_path2_acl" entry.
494  *
495  * @a:         Pointer to "struct tomoyo_acl_info".
496  * @b:         Pointer to "struct tomoyo_acl_info".
497  * @is_delete: True for @a &= ~@b, false for @a |= @b.
498  *
499  * Returns true if @a is empty, false otherwise.
500  */
501 static bool tomoyo_merge_path2_acl(struct tomoyo_acl_info *a,
502                                    struct tomoyo_acl_info *b,
503                                    const bool is_delete)
504 {
505         u8 * const a_perm = &container_of(a, struct tomoyo_path2_acl, head)
506                 ->perm;
507         u8 perm = *a_perm;
508         const u8 b_perm = container_of(b, struct tomoyo_path2_acl, head)->perm;
509         if (is_delete)
510                 perm &= ~b_perm;
511         else
512                 perm |= b_perm;
513         *a_perm = perm;
514         return !perm;
515 }
516
517 /**
518  * tomoyo_update_path2_acl - Update "struct tomoyo_path2_acl" list.
519  *
520  * @perm:  Permission.
521  * @param: Pointer to "struct tomoyo_acl_param".
522  *
523  * Returns 0 on success, negative value otherwise.
524  *
525  * Caller holds tomoyo_read_lock().
526  */
527 static int tomoyo_update_path2_acl(const u8 perm,
528                                    struct tomoyo_acl_param *param)
529 {
530         struct tomoyo_path2_acl e = {
531                 .head.type = TOMOYO_TYPE_PATH2_ACL,
532                 .perm = perm
533         };
534         int error;
535         if (!tomoyo_parse_name_union(param, &e.name1) ||
536             !tomoyo_parse_name_union(param, &e.name2))
537                 error = -EINVAL;
538         else
539                 error = tomoyo_update_domain(&e.head, sizeof(e), param,
540                                              tomoyo_same_path2_acl,
541                                              tomoyo_merge_path2_acl);
542         tomoyo_put_name_union(&e.name1);
543         tomoyo_put_name_union(&e.name2);
544         return error;
545 }
546
547 /**
548  * tomoyo_path_permission - Check permission for single path operation.
549  *
550  * @r:         Pointer to "struct tomoyo_request_info".
551  * @operation: Type of operation.
552  * @filename:  Filename to check.
553  *
554  * Returns 0 on success, negative value otherwise.
555  *
556  * Caller holds tomoyo_read_lock().
557  */
558 static int tomoyo_path_permission(struct tomoyo_request_info *r, u8 operation,
559                                   const struct tomoyo_path_info *filename)
560 {
561         int error;
562
563         r->type = tomoyo_p2mac[operation];
564         r->mode = tomoyo_get_mode(r->domain->ns, r->profile, r->type);
565         if (r->mode == TOMOYO_CONFIG_DISABLED)
566                 return 0;
567         r->param_type = TOMOYO_TYPE_PATH_ACL;
568         r->param.path.filename = filename;
569         r->param.path.operation = operation;
570         do {
571                 tomoyo_check_acl(r, tomoyo_check_path_acl);
572                 error = tomoyo_audit_path_log(r);
573         } while (error == TOMOYO_RETRY_REQUEST);
574         return error;
575 }
576
577 /**
578  * tomoyo_execute_permission - Check permission for execute operation.
579  *
580  * @r:         Pointer to "struct tomoyo_request_info".
581  * @filename:  Filename to check.
582  *
583  * Returns 0 on success, negative value otherwise.
584  *
585  * Caller holds tomoyo_read_lock().
586  */
587 int tomoyo_execute_permission(struct tomoyo_request_info *r,
588                               const struct tomoyo_path_info *filename)
589 {
590         /*
591          * Unlike other permission checks, this check is done regardless of
592          * profile mode settings in order to check for domain transition
593          * preference.
594          */
595         r->type = TOMOYO_MAC_FILE_EXECUTE;
596         r->mode = tomoyo_get_mode(r->domain->ns, r->profile, r->type);
597         r->param_type = TOMOYO_TYPE_PATH_ACL;
598         r->param.path.filename = filename;
599         r->param.path.operation = TOMOYO_TYPE_EXECUTE;
600         tomoyo_check_acl(r, tomoyo_check_path_acl);
601         r->ee->transition = r->matched_acl && r->matched_acl->cond ?
602                 r->matched_acl->cond->transit : NULL;
603         if (r->mode != TOMOYO_CONFIG_DISABLED)
604                 return tomoyo_audit_path_log(r);
605         return 0;
606 }
607
608 /**
609  * tomoyo_same_path_number_acl - Check for duplicated "struct tomoyo_path_number_acl" entry.
610  *
611  * @a: Pointer to "struct tomoyo_acl_info".
612  * @b: Pointer to "struct tomoyo_acl_info".
613  *
614  * Returns true if @a == @b except permission bits, false otherwise.
615  */
616 static bool tomoyo_same_path_number_acl(const struct tomoyo_acl_info *a,
617                                         const struct tomoyo_acl_info *b)
618 {
619         const struct tomoyo_path_number_acl *p1 = container_of(a, typeof(*p1),
620                                                                head);
621         const struct tomoyo_path_number_acl *p2 = container_of(b, typeof(*p2),
622                                                                head);
623         return tomoyo_same_name_union(&p1->name, &p2->name) &&
624                 tomoyo_same_number_union(&p1->number, &p2->number);
625 }
626
627 /**
628  * tomoyo_merge_path_number_acl - Merge duplicated "struct tomoyo_path_number_acl" entry.
629  *
630  * @a:         Pointer to "struct tomoyo_acl_info".
631  * @b:         Pointer to "struct tomoyo_acl_info".
632  * @is_delete: True for @a &= ~@b, false for @a |= @b.
633  *
634  * Returns true if @a is empty, false otherwise.
635  */
636 static bool tomoyo_merge_path_number_acl(struct tomoyo_acl_info *a,
637                                          struct tomoyo_acl_info *b,
638                                          const bool is_delete)
639 {
640         u8 * const a_perm = &container_of(a, struct tomoyo_path_number_acl,
641                                           head)->perm;
642         u8 perm = *a_perm;
643         const u8 b_perm = container_of(b, struct tomoyo_path_number_acl, head)
644                 ->perm;
645         if (is_delete)
646                 perm &= ~b_perm;
647         else
648                 perm |= b_perm;
649         *a_perm = perm;
650         return !perm;
651 }
652
653 /**
654  * tomoyo_update_path_number_acl - Update ioctl/chmod/chown/chgrp ACL.
655  *
656  * @perm:  Permission.
657  * @param: Pointer to "struct tomoyo_acl_param".
658  *
659  * Returns 0 on success, negative value otherwise.
660  */
661 static int tomoyo_update_path_number_acl(const u8 perm,
662                                          struct tomoyo_acl_param *param)
663 {
664         struct tomoyo_path_number_acl e = {
665                 .head.type = TOMOYO_TYPE_PATH_NUMBER_ACL,
666                 .perm = perm
667         };
668         int error;
669         if (!tomoyo_parse_name_union(param, &e.name) ||
670             !tomoyo_parse_number_union(param, &e.number))
671                 error = -EINVAL;
672         else
673                 error = tomoyo_update_domain(&e.head, sizeof(e), param,
674                                              tomoyo_same_path_number_acl,
675                                              tomoyo_merge_path_number_acl);
676         tomoyo_put_name_union(&e.name);
677         tomoyo_put_number_union(&e.number);
678         return error;
679 }
680
681 /**
682  * tomoyo_path_number_perm - Check permission for "create", "mkdir", "mkfifo", "mksock", "ioctl", "chmod", "chown", "chgrp".
683  *
684  * @type:   Type of operation.
685  * @path:   Pointer to "struct path".
686  * @number: Number.
687  *
688  * Returns 0 on success, negative value otherwise.
689  */
690 int tomoyo_path_number_perm(const u8 type, const struct path *path,
691                             unsigned long number)
692 {
693         struct tomoyo_request_info r;
694         struct tomoyo_obj_info obj = {
695                 .path1 = *path,
696         };
697         int error = -ENOMEM;
698         struct tomoyo_path_info buf;
699         int idx;
700
701         if (tomoyo_init_request_info(&r, NULL, tomoyo_pn2mac[type])
702             == TOMOYO_CONFIG_DISABLED || !path->dentry)
703                 return 0;
704         idx = tomoyo_read_lock();
705         if (!tomoyo_get_realpath(&buf, path))
706                 goto out;
707         r.obj = &obj;
708         if (type == TOMOYO_TYPE_MKDIR)
709                 tomoyo_add_slash(&buf);
710         r.param_type = TOMOYO_TYPE_PATH_NUMBER_ACL;
711         r.param.path_number.operation = type;
712         r.param.path_number.filename = &buf;
713         r.param.path_number.number = number;
714         do {
715                 tomoyo_check_acl(&r, tomoyo_check_path_number_acl);
716                 error = tomoyo_audit_path_number_log(&r);
717         } while (error == TOMOYO_RETRY_REQUEST);
718         kfree(buf.name);
719  out:
720         tomoyo_read_unlock(idx);
721         if (r.mode != TOMOYO_CONFIG_ENFORCING)
722                 error = 0;
723         return error;
724 }
725
726 /**
727  * tomoyo_check_open_permission - Check permission for "read" and "write".
728  *
729  * @domain: Pointer to "struct tomoyo_domain_info".
730  * @path:   Pointer to "struct path".
731  * @flag:   Flags for open().
732  *
733  * Returns 0 on success, negative value otherwise.
734  */
735 int tomoyo_check_open_permission(struct tomoyo_domain_info *domain,
736                                  const struct path *path, const int flag)
737 {
738         const u8 acc_mode = ACC_MODE(flag);
739         int error = 0;
740         struct tomoyo_path_info buf;
741         struct tomoyo_request_info r;
742         struct tomoyo_obj_info obj = {
743                 .path1 = *path,
744         };
745         int idx;
746
747         buf.name = NULL;
748         r.mode = TOMOYO_CONFIG_DISABLED;
749         idx = tomoyo_read_lock();
750         if (acc_mode &&
751             tomoyo_init_request_info(&r, domain, TOMOYO_MAC_FILE_OPEN)
752             != TOMOYO_CONFIG_DISABLED) {
753                 if (!tomoyo_get_realpath(&buf, path)) {
754                         error = -ENOMEM;
755                         goto out;
756                 }
757                 r.obj = &obj;
758                 if (acc_mode & MAY_READ)
759                         error = tomoyo_path_permission(&r, TOMOYO_TYPE_READ,
760                                                        &buf);
761                 if (!error && (acc_mode & MAY_WRITE))
762                         error = tomoyo_path_permission(&r, (flag & O_APPEND) ?
763                                                        TOMOYO_TYPE_APPEND :
764                                                        TOMOYO_TYPE_WRITE,
765                                                        &buf);
766         }
767  out:
768         kfree(buf.name);
769         tomoyo_read_unlock(idx);
770         if (r.mode != TOMOYO_CONFIG_ENFORCING)
771                 error = 0;
772         return error;
773 }
774
775 /**
776  * tomoyo_path_perm - Check permission for "unlink", "rmdir", "truncate", "symlink", "append", "chroot" and "unmount".
777  *
778  * @operation: Type of operation.
779  * @path:      Pointer to "struct path".
780  * @target:    Symlink's target if @operation is TOMOYO_TYPE_SYMLINK,
781  *             NULL otherwise.
782  *
783  * Returns 0 on success, negative value otherwise.
784  */
785 int tomoyo_path_perm(const u8 operation, const struct path *path, const char *target)
786 {
787         struct tomoyo_request_info r;
788         struct tomoyo_obj_info obj = {
789                 .path1 = *path,
790         };
791         int error;
792         struct tomoyo_path_info buf;
793         bool is_enforce;
794         struct tomoyo_path_info symlink_target;
795         int idx;
796
797         if (tomoyo_init_request_info(&r, NULL, tomoyo_p2mac[operation])
798             == TOMOYO_CONFIG_DISABLED)
799                 return 0;
800         is_enforce = (r.mode == TOMOYO_CONFIG_ENFORCING);
801         error = -ENOMEM;
802         buf.name = NULL;
803         idx = tomoyo_read_lock();
804         if (!tomoyo_get_realpath(&buf, path))
805                 goto out;
806         r.obj = &obj;
807         switch (operation) {
808         case TOMOYO_TYPE_RMDIR:
809         case TOMOYO_TYPE_CHROOT:
810                 tomoyo_add_slash(&buf);
811                 break;
812         case TOMOYO_TYPE_SYMLINK:
813                 symlink_target.name = tomoyo_encode(target);
814                 if (!symlink_target.name)
815                         goto out;
816                 tomoyo_fill_path_info(&symlink_target);
817                 obj.symlink_target = &symlink_target;
818                 break;
819         }
820         error = tomoyo_path_permission(&r, operation, &buf);
821         if (operation == TOMOYO_TYPE_SYMLINK)
822                 kfree(symlink_target.name);
823  out:
824         kfree(buf.name);
825         tomoyo_read_unlock(idx);
826         if (!is_enforce)
827                 error = 0;
828         return error;
829 }
830
831 /**
832  * tomoyo_mkdev_perm - Check permission for "mkblock" and "mkchar".
833  *
834  * @operation: Type of operation. (TOMOYO_TYPE_MKCHAR or TOMOYO_TYPE_MKBLOCK)
835  * @path:      Pointer to "struct path".
836  * @mode:      Create mode.
837  * @dev:       Device number.
838  *
839  * Returns 0 on success, negative value otherwise.
840  */
841 int tomoyo_mkdev_perm(const u8 operation, const struct path *path,
842                       const unsigned int mode, unsigned int dev)
843 {
844         struct tomoyo_request_info r;
845         struct tomoyo_obj_info obj = {
846                 .path1 = *path,
847         };
848         int error = -ENOMEM;
849         struct tomoyo_path_info buf;
850         int idx;
851
852         if (tomoyo_init_request_info(&r, NULL, tomoyo_pnnn2mac[operation])
853             == TOMOYO_CONFIG_DISABLED)
854                 return 0;
855         idx = tomoyo_read_lock();
856         error = -ENOMEM;
857         if (tomoyo_get_realpath(&buf, path)) {
858                 r.obj = &obj;
859                 dev = new_decode_dev(dev);
860                 r.param_type = TOMOYO_TYPE_MKDEV_ACL;
861                 r.param.mkdev.filename = &buf;
862                 r.param.mkdev.operation = operation;
863                 r.param.mkdev.mode = mode;
864                 r.param.mkdev.major = MAJOR(dev);
865                 r.param.mkdev.minor = MINOR(dev);
866                 tomoyo_check_acl(&r, tomoyo_check_mkdev_acl);
867                 error = tomoyo_audit_mkdev_log(&r);
868                 kfree(buf.name);
869         }
870         tomoyo_read_unlock(idx);
871         if (r.mode != TOMOYO_CONFIG_ENFORCING)
872                 error = 0;
873         return error;
874 }
875
876 /**
877  * tomoyo_path2_perm - Check permission for "rename", "link" and "pivot_root".
878  *
879  * @operation: Type of operation.
880  * @path1:      Pointer to "struct path".
881  * @path2:      Pointer to "struct path".
882  *
883  * Returns 0 on success, negative value otherwise.
884  */
885 int tomoyo_path2_perm(const u8 operation, const struct path *path1,
886                       const struct path *path2)
887 {
888         int error = -ENOMEM;
889         struct tomoyo_path_info buf1;
890         struct tomoyo_path_info buf2;
891         struct tomoyo_request_info r;
892         struct tomoyo_obj_info obj = {
893                 .path1 = *path1,
894                 .path2 = *path2,
895         };
896         int idx;
897
898         if (tomoyo_init_request_info(&r, NULL, tomoyo_pp2mac[operation])
899             == TOMOYO_CONFIG_DISABLED)
900                 return 0;
901         buf1.name = NULL;
902         buf2.name = NULL;
903         idx = tomoyo_read_lock();
904         if (!tomoyo_get_realpath(&buf1, path1) ||
905             !tomoyo_get_realpath(&buf2, path2))
906                 goto out;
907         switch (operation) {
908         case TOMOYO_TYPE_RENAME:
909         case TOMOYO_TYPE_LINK:
910                 if (!d_is_dir(path1->dentry))
911                         break;
912                 /* fall through */
913         case TOMOYO_TYPE_PIVOT_ROOT:
914                 tomoyo_add_slash(&buf1);
915                 tomoyo_add_slash(&buf2);
916                 break;
917         }
918         r.obj = &obj;
919         r.param_type = TOMOYO_TYPE_PATH2_ACL;
920         r.param.path2.operation = operation;
921         r.param.path2.filename1 = &buf1;
922         r.param.path2.filename2 = &buf2;
923         do {
924                 tomoyo_check_acl(&r, tomoyo_check_path2_acl);
925                 error = tomoyo_audit_path2_log(&r);
926         } while (error == TOMOYO_RETRY_REQUEST);
927  out:
928         kfree(buf1.name);
929         kfree(buf2.name);
930         tomoyo_read_unlock(idx);
931         if (r.mode != TOMOYO_CONFIG_ENFORCING)
932                 error = 0;
933         return error;
934 }
935
936 /**
937  * tomoyo_same_mount_acl - Check for duplicated "struct tomoyo_mount_acl" entry.
938  *
939  * @a: Pointer to "struct tomoyo_acl_info".
940  * @b: Pointer to "struct tomoyo_acl_info".
941  *
942  * Returns true if @a == @b, false otherwise.
943  */
944 static bool tomoyo_same_mount_acl(const struct tomoyo_acl_info *a,
945                                   const struct tomoyo_acl_info *b)
946 {
947         const struct tomoyo_mount_acl *p1 = container_of(a, typeof(*p1), head);
948         const struct tomoyo_mount_acl *p2 = container_of(b, typeof(*p2), head);
949         return tomoyo_same_name_union(&p1->dev_name, &p2->dev_name) &&
950                 tomoyo_same_name_union(&p1->dir_name, &p2->dir_name) &&
951                 tomoyo_same_name_union(&p1->fs_type, &p2->fs_type) &&
952                 tomoyo_same_number_union(&p1->flags, &p2->flags);
953 }
954
955 /**
956  * tomoyo_update_mount_acl - Write "struct tomoyo_mount_acl" list.
957  *
958  * @param: Pointer to "struct tomoyo_acl_param".
959  *
960  * Returns 0 on success, negative value otherwise.
961  *
962  * Caller holds tomoyo_read_lock().
963  */
964 static int tomoyo_update_mount_acl(struct tomoyo_acl_param *param)
965 {
966         struct tomoyo_mount_acl e = { .head.type = TOMOYO_TYPE_MOUNT_ACL };
967         int error;
968         if (!tomoyo_parse_name_union(param, &e.dev_name) ||
969             !tomoyo_parse_name_union(param, &e.dir_name) ||
970             !tomoyo_parse_name_union(param, &e.fs_type) ||
971             !tomoyo_parse_number_union(param, &e.flags))
972                 error = -EINVAL;
973         else
974                 error = tomoyo_update_domain(&e.head, sizeof(e), param,
975                                              tomoyo_same_mount_acl, NULL);
976         tomoyo_put_name_union(&e.dev_name);
977         tomoyo_put_name_union(&e.dir_name);
978         tomoyo_put_name_union(&e.fs_type);
979         tomoyo_put_number_union(&e.flags);
980         return error;
981 }
982
983 /**
984  * tomoyo_write_file - Update file related list.
985  *
986  * @param: Pointer to "struct tomoyo_acl_param".
987  *
988  * Returns 0 on success, negative value otherwise.
989  *
990  * Caller holds tomoyo_read_lock().
991  */
992 int tomoyo_write_file(struct tomoyo_acl_param *param)
993 {
994         u16 perm = 0;
995         u8 type;
996         const char *operation = tomoyo_read_token(param);
997         for (type = 0; type < TOMOYO_MAX_PATH_OPERATION; type++)
998                 if (tomoyo_permstr(operation, tomoyo_path_keyword[type]))
999                         perm |= 1 << type;
1000         if (perm)
1001                 return tomoyo_update_path_acl(perm, param);
1002         for (type = 0; type < TOMOYO_MAX_PATH2_OPERATION; type++)
1003                 if (tomoyo_permstr(operation,
1004                                    tomoyo_mac_keywords[tomoyo_pp2mac[type]]))
1005                         perm |= 1 << type;
1006         if (perm)
1007                 return tomoyo_update_path2_acl(perm, param);
1008         for (type = 0; type < TOMOYO_MAX_PATH_NUMBER_OPERATION; type++)
1009                 if (tomoyo_permstr(operation,
1010                                    tomoyo_mac_keywords[tomoyo_pn2mac[type]]))
1011                         perm |= 1 << type;
1012         if (perm)
1013                 return tomoyo_update_path_number_acl(perm, param);
1014         for (type = 0; type < TOMOYO_MAX_MKDEV_OPERATION; type++)
1015                 if (tomoyo_permstr(operation,
1016                                    tomoyo_mac_keywords[tomoyo_pnnn2mac[type]]))
1017                         perm |= 1 << type;
1018         if (perm)
1019                 return tomoyo_update_mkdev_acl(perm, param);
1020         if (tomoyo_permstr(operation,
1021                            tomoyo_mac_keywords[TOMOYO_MAC_FILE_MOUNT]))
1022                 return tomoyo_update_mount_acl(param);
1023         return -EINVAL;
1024 }