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1 | /* |
2 | * AppArmor security module | |
3 | * | |
4 | * This file contains AppArmor label definitions | |
5 | * | |
6 | * Copyright 2017 Canonical Ltd. | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU General Public License as | |
10 | * published by the Free Software Foundation, version 2 of the | |
11 | * License. | |
12 | */ | |
13 | ||
14 | #ifndef __AA_LABEL_H | |
15 | #define __AA_LABEL_H | |
16 | ||
17 | #include <linux/atomic.h> | |
18 | #include <linux/audit.h> | |
19 | #include <linux/rbtree.h> | |
20 | #include <linux/rcupdate.h> | |
21 | ||
22 | #include "apparmor.h" | |
23 | #include "lib.h" | |
24 | ||
25 | struct aa_ns; | |
26 | ||
27 | #define LOCAL_VEC_ENTRIES 8 | |
28 | #define DEFINE_VEC(T, V) \ | |
29 | struct aa_ ## T *(_ ## V ## _localtmp)[LOCAL_VEC_ENTRIES]; \ | |
30 | struct aa_ ## T **(V) | |
31 | ||
32 | #define vec_setup(T, V, N, GFP) \ | |
33 | ({ \ | |
34 | if ((N) <= LOCAL_VEC_ENTRIES) { \ | |
35 | typeof(N) i; \ | |
36 | (V) = (_ ## V ## _localtmp); \ | |
37 | for (i = 0; i < (N); i++) \ | |
38 | (V)[i] = NULL; \ | |
39 | } else \ | |
40 | (V) = kzalloc(sizeof(struct aa_ ## T *) * (N), (GFP)); \ | |
41 | (V) ? 0 : -ENOMEM; \ | |
42 | }) | |
43 | ||
44 | #define vec_cleanup(T, V, N) \ | |
45 | do { \ | |
46 | int i; \ | |
47 | for (i = 0; i < (N); i++) { \ | |
48 | if (!IS_ERR_OR_NULL((V)[i])) \ | |
49 | aa_put_ ## T((V)[i]); \ | |
50 | } \ | |
51 | if ((V) != _ ## V ## _localtmp) \ | |
52 | kfree(V); \ | |
53 | } while (0) | |
54 | ||
55 | #define vec_last(VEC, SIZE) ((VEC)[(SIZE) - 1]) | |
56 | #define vec_ns(VEC, SIZE) (vec_last((VEC), (SIZE))->ns) | |
57 | #define vec_labelset(VEC, SIZE) (&vec_ns((VEC), (SIZE))->labels) | |
58 | #define cleanup_domain_vec(V, L) cleanup_label_vec((V), (L)->size) | |
59 | ||
60 | struct aa_profile; | |
61 | #define VEC_FLAG_TERMINATE 1 | |
62 | int aa_vec_unique(struct aa_profile **vec, int n, int flags); | |
63 | struct aa_label *aa_vec_find_or_create_label(struct aa_profile **vec, int len, | |
64 | gfp_t gfp); | |
65 | #define aa_sort_and_merge_vec(N, V) \ | |
66 | aa_sort_and_merge_profiles((N), (struct aa_profile **)(V)) | |
67 | ||
68 | ||
69 | /* struct aa_labelset - set of labels for a namespace | |
70 | * | |
71 | * Labels are reference counted; aa_labelset does not contribute to label | |
72 | * reference counts. Once a label's last refcount is put it is removed from | |
73 | * the set. | |
74 | */ | |
75 | struct aa_labelset { | |
76 | rwlock_t lock; | |
77 | ||
78 | struct rb_root root; | |
79 | }; | |
80 | ||
81 | #define __labelset_for_each(LS, N) \ | |
82 | for ((N) = rb_first(&(LS)->root); (N); (N) = rb_next(N)) | |
83 | ||
84 | void aa_labelset_destroy(struct aa_labelset *ls); | |
85 | void aa_labelset_init(struct aa_labelset *ls); | |
86 | ||
87 | ||
88 | enum label_flags { | |
89 | FLAG_HAT = 1, /* profile is a hat */ | |
90 | FLAG_UNCONFINED = 2, /* label unconfined only if all */ | |
91 | FLAG_NULL = 4, /* profile is null learning profile */ | |
92 | FLAG_IX_ON_NAME_ERROR = 8, /* fallback to ix on name lookup fail */ | |
93 | FLAG_IMMUTIBLE = 0x10, /* don't allow changes/replacement */ | |
94 | FLAG_USER_DEFINED = 0x20, /* user based profile - lower privs */ | |
95 | FLAG_NO_LIST_REF = 0x40, /* list doesn't keep profile ref */ | |
96 | FLAG_NS_COUNT = 0x80, /* carries NS ref count */ | |
97 | FLAG_IN_TREE = 0x100, /* label is in tree */ | |
98 | FLAG_PROFILE = 0x200, /* label is a profile */ | |
99 | FLAG_EXPLICIT = 0x400, /* explicit static label */ | |
100 | FLAG_STALE = 0x800, /* replaced/removed */ | |
101 | FLAG_RENAMED = 0x1000, /* label has renaming in it */ | |
102 | FLAG_REVOKED = 0x2000, /* label has revocation in it */ | |
103 | ||
104 | /* These flags must correspond with PATH_flags */ | |
105 | /* TODO: add new path flags */ | |
106 | }; | |
107 | ||
108 | struct aa_label; | |
109 | struct aa_proxy { | |
110 | struct kref count; | |
111 | struct aa_label __rcu *label; | |
112 | }; | |
113 | ||
114 | struct label_it { | |
115 | int i, j; | |
116 | }; | |
117 | ||
118 | /* struct aa_label - lazy labeling struct | |
119 | * @count: ref count of active users | |
120 | * @node: rbtree position | |
121 | * @rcu: rcu callback struct | |
122 | * @proxy: is set to the label that replaced this label | |
123 | * @hname: text representation of the label (MAYBE_NULL) | |
124 | * @flags: stale and other flags - values may change under label set lock | |
125 | * @secid: secid that references this label | |
126 | * @size: number of entries in @ent[] | |
127 | * @ent: set of profiles for label, actual size determined by @size | |
128 | */ | |
129 | struct aa_label { | |
130 | struct kref count; | |
131 | struct rb_node node; | |
132 | struct rcu_head rcu; | |
133 | struct aa_proxy *proxy; | |
134 | __counted char *hname; | |
135 | long flags; | |
136 | u32 secid; | |
137 | int size; | |
138 | struct aa_profile *vec[]; | |
139 | }; | |
140 | ||
141 | #define last_error(E, FN) \ | |
142 | do { \ | |
143 | int __subE = (FN); \ | |
144 | if (__subE) \ | |
145 | (E) = __subE; \ | |
146 | } while (0) | |
147 | ||
148 | #define label_isprofile(X) ((X)->flags & FLAG_PROFILE) | |
149 | #define label_unconfined(X) ((X)->flags & FLAG_UNCONFINED) | |
150 | #define unconfined(X) label_unconfined(X) | |
151 | #define label_is_stale(X) ((X)->flags & FLAG_STALE) | |
152 | #define __label_make_stale(X) ((X)->flags |= FLAG_STALE) | |
153 | #define labels_ns(X) (vec_ns(&((X)->vec[0]), (X)->size)) | |
154 | #define labels_set(X) (&labels_ns(X)->labels) | |
155 | #define labels_profile(X) ((X)->vec[(X)->size - 1]) | |
156 | ||
157 | ||
158 | int aa_label_next_confined(struct aa_label *l, int i); | |
159 | ||
160 | /* for each profile in a label */ | |
161 | #define label_for_each(I, L, P) \ | |
162 | for ((I).i = 0; ((P) = (L)->vec[(I).i]); ++((I).i)) | |
163 | ||
164 | /* assumes break/goto ended label_for_each */ | |
165 | #define label_for_each_cont(I, L, P) \ | |
166 | for (++((I).i); ((P) = (L)->vec[(I).i]); ++((I).i)) | |
167 | ||
168 | #define next_comb(I, L1, L2) \ | |
169 | do { \ | |
170 | (I).j++; \ | |
171 | if ((I).j >= (L2)->size) { \ | |
172 | (I).i++; \ | |
173 | (I).j = 0; \ | |
174 | } \ | |
175 | } while (0) | |
176 | ||
177 | ||
178 | /* for each combination of P1 in L1, and P2 in L2 */ | |
179 | #define label_for_each_comb(I, L1, L2, P1, P2) \ | |
180 | for ((I).i = (I).j = 0; \ | |
181 | ((P1) = (L1)->vec[(I).i]) && ((P2) = (L2)->vec[(I).j]); \ | |
182 | (I) = next_comb(I, L1, L2)) | |
183 | ||
184 | #define fn_for_each_comb(L1, L2, P1, P2, FN) \ | |
185 | ({ \ | |
186 | struct label_it i; \ | |
187 | int __E = 0; \ | |
188 | label_for_each_comb(i, (L1), (L2), (P1), (P2)) { \ | |
189 | last_error(__E, (FN)); \ | |
190 | } \ | |
191 | __E; \ | |
192 | }) | |
193 | ||
194 | /* for each profile that is enforcing confinement in a label */ | |
195 | #define label_for_each_confined(I, L, P) \ | |
196 | for ((I).i = aa_label_next_confined((L), 0); \ | |
197 | ((P) = (L)->vec[(I).i]); \ | |
198 | (I).i = aa_label_next_confined((L), (I).i + 1)) | |
199 | ||
200 | #define label_for_each_in_merge(I, A, B, P) \ | |
201 | for ((I).i = (I).j = 0; \ | |
202 | ((P) = aa_label_next_in_merge(&(I), (A), (B))); \ | |
203 | ) | |
204 | ||
205 | #define label_for_each_not_in_set(I, SET, SUB, P) \ | |
206 | for ((I).i = (I).j = 0; \ | |
207 | ((P) = __aa_label_next_not_in_set(&(I), (SET), (SUB))); \ | |
208 | ) | |
209 | ||
210 | #define next_in_ns(i, NS, L) \ | |
211 | ({ \ | |
212 | typeof(i) ___i = (i); \ | |
213 | while ((L)->vec[___i] && (L)->vec[___i]->ns != (NS)) \ | |
214 | (___i)++; \ | |
215 | (___i); \ | |
216 | }) | |
217 | ||
218 | #define label_for_each_in_ns(I, NS, L, P) \ | |
219 | for ((I).i = next_in_ns(0, (NS), (L)); \ | |
220 | ((P) = (L)->vec[(I).i]); \ | |
221 | (I).i = next_in_ns((I).i + 1, (NS), (L))) | |
222 | ||
223 | #define fn_for_each_in_ns(L, P, FN) \ | |
224 | ({ \ | |
225 | struct label_it __i; \ | |
226 | struct aa_ns *__ns = labels_ns(L); \ | |
227 | int __E = 0; \ | |
228 | label_for_each_in_ns(__i, __ns, (L), (P)) { \ | |
229 | last_error(__E, (FN)); \ | |
230 | } \ | |
231 | __E; \ | |
232 | }) | |
233 | ||
234 | ||
235 | #define fn_for_each_XXX(L, P, FN, ...) \ | |
236 | ({ \ | |
237 | struct label_it i; \ | |
238 | int __E = 0; \ | |
239 | label_for_each ## __VA_ARGS__(i, (L), (P)) { \ | |
240 | last_error(__E, (FN)); \ | |
241 | } \ | |
242 | __E; \ | |
243 | }) | |
244 | ||
245 | #define fn_for_each(L, P, FN) fn_for_each_XXX(L, P, FN) | |
246 | #define fn_for_each_confined(L, P, FN) fn_for_each_XXX(L, P, FN, _confined) | |
247 | ||
248 | #define fn_for_each2_XXX(L1, L2, P, FN, ...) \ | |
249 | ({ \ | |
250 | struct label_it i; \ | |
251 | int __E = 0; \ | |
252 | label_for_each ## __VA_ARGS__(i, (L1), (L2), (P)) { \ | |
253 | last_error(__E, (FN)); \ | |
254 | } \ | |
255 | __E; \ | |
256 | }) | |
257 | ||
258 | #define fn_for_each_in_merge(L1, L2, P, FN) \ | |
259 | fn_for_each2_XXX((L1), (L2), P, FN, _in_merge) | |
260 | #define fn_for_each_not_in_set(L1, L2, P, FN) \ | |
261 | fn_for_each2_XXX((L1), (L2), P, FN, _not_in_set) | |
262 | ||
263 | #define LABEL_MEDIATES(L, C) \ | |
264 | ({ \ | |
265 | struct aa_profile *profile; \ | |
266 | struct label_it i; \ | |
267 | int ret = 0; \ | |
268 | label_for_each(i, (L), profile) { \ | |
269 | if (PROFILE_MEDIATES(profile, (C))) { \ | |
270 | ret = 1; \ | |
271 | break; \ | |
272 | } \ | |
273 | } \ | |
274 | ret; \ | |
275 | }) | |
276 | ||
277 | ||
278 | void aa_labelset_destroy(struct aa_labelset *ls); | |
279 | void aa_labelset_init(struct aa_labelset *ls); | |
280 | void __aa_labelset_update_subtree(struct aa_ns *ns); | |
281 | ||
282 | void aa_label_free(struct aa_label *label); | |
283 | void aa_label_kref(struct kref *kref); | |
284 | bool aa_label_init(struct aa_label *label, int size); | |
285 | struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp); | |
286 | ||
287 | bool aa_label_is_subset(struct aa_label *set, struct aa_label *sub); | |
288 | struct aa_profile *__aa_label_next_not_in_set(struct label_it *I, | |
289 | struct aa_label *set, | |
290 | struct aa_label *sub); | |
291 | bool aa_label_remove(struct aa_label *label); | |
292 | struct aa_label *aa_label_insert(struct aa_labelset *ls, struct aa_label *l); | |
293 | bool aa_label_replace(struct aa_label *old, struct aa_label *new); | |
294 | bool aa_label_make_newest(struct aa_labelset *ls, struct aa_label *old, | |
295 | struct aa_label *new); | |
296 | ||
297 | struct aa_label *aa_label_find(struct aa_label *l); | |
298 | ||
299 | struct aa_profile *aa_label_next_in_merge(struct label_it *I, | |
300 | struct aa_label *a, | |
301 | struct aa_label *b); | |
302 | struct aa_label *aa_label_find_merge(struct aa_label *a, struct aa_label *b); | |
303 | struct aa_label *aa_label_merge(struct aa_label *a, struct aa_label *b, | |
304 | gfp_t gfp); | |
305 | ||
306 | ||
307 | bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp); | |
308 | ||
309 | #define FLAGS_NONE 0 | |
310 | #define FLAG_SHOW_MODE 1 | |
311 | #define FLAG_VIEW_SUBNS 2 | |
312 | #define FLAG_HIDDEN_UNCONFINED 4 | |
26b78995 | 313 | #define FLAG_ABS_ROOT 8 |
f1bd9041 JJ |
314 | int aa_label_snxprint(char *str, size_t size, struct aa_ns *view, |
315 | struct aa_label *label, int flags); | |
316 | int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label, | |
317 | int flags, gfp_t gfp); | |
318 | int aa_label_acntsxprint(char __counted **strp, struct aa_ns *ns, | |
319 | struct aa_label *label, int flags, gfp_t gfp); | |
320 | void aa_label_xaudit(struct audit_buffer *ab, struct aa_ns *ns, | |
321 | struct aa_label *label, int flags, gfp_t gfp); | |
322 | void aa_label_seq_xprint(struct seq_file *f, struct aa_ns *ns, | |
323 | struct aa_label *label, int flags, gfp_t gfp); | |
324 | void aa_label_xprintk(struct aa_ns *ns, struct aa_label *label, int flags, | |
325 | gfp_t gfp); | |
326 | void aa_label_audit(struct audit_buffer *ab, struct aa_label *label, gfp_t gfp); | |
327 | void aa_label_seq_print(struct seq_file *f, struct aa_label *label, gfp_t gfp); | |
328 | void aa_label_printk(struct aa_label *label, gfp_t gfp); | |
329 | ||
330 | struct aa_label *aa_label_parse(struct aa_label *base, const char *str, | |
331 | gfp_t gfp, bool create, bool force_stack); | |
332 | ||
333 | ||
334 | struct aa_perms; | |
335 | int aa_label_match(struct aa_profile *profile, struct aa_label *label, | |
336 | unsigned int state, bool subns, u32 request, | |
337 | struct aa_perms *perms); | |
338 | ||
339 | ||
340 | /** | |
341 | * __aa_get_label - get a reference count to uncounted label reference | |
342 | * @l: reference to get a count on | |
343 | * | |
344 | * Returns: pointer to reference OR NULL if race is lost and reference is | |
345 | * being repeated. | |
346 | * Requires: lock held, and the return code MUST be checked | |
347 | */ | |
348 | static inline struct aa_label *__aa_get_label(struct aa_label *l) | |
349 | { | |
350 | if (l && kref_get_unless_zero(&l->count)) | |
351 | return l; | |
352 | ||
353 | return NULL; | |
354 | } | |
355 | ||
356 | static inline struct aa_label *aa_get_label(struct aa_label *l) | |
357 | { | |
358 | if (l) | |
359 | kref_get(&(l->count)); | |
360 | ||
361 | return l; | |
362 | } | |
363 | ||
364 | ||
365 | /** | |
366 | * aa_get_label_rcu - increment refcount on a label that can be replaced | |
367 | * @l: pointer to label that can be replaced (NOT NULL) | |
368 | * | |
369 | * Returns: pointer to a refcounted label. | |
370 | * else NULL if no label | |
371 | */ | |
372 | static inline struct aa_label *aa_get_label_rcu(struct aa_label __rcu **l) | |
373 | { | |
374 | struct aa_label *c; | |
375 | ||
376 | rcu_read_lock(); | |
377 | do { | |
378 | c = rcu_dereference(*l); | |
379 | } while (c && !kref_get_unless_zero(&c->count)); | |
380 | rcu_read_unlock(); | |
381 | ||
382 | return c; | |
383 | } | |
384 | ||
385 | /** | |
386 | * aa_get_newest_label - find the newest version of @l | |
387 | * @l: the label to check for newer versions of | |
388 | * | |
389 | * Returns: refcounted newest version of @l taking into account | |
390 | * replacement, renames and removals | |
391 | * return @l. | |
392 | */ | |
393 | static inline struct aa_label *aa_get_newest_label(struct aa_label *l) | |
394 | { | |
395 | if (!l) | |
396 | return NULL; | |
397 | ||
398 | if (label_is_stale(l)) { | |
399 | struct aa_label *tmp; | |
400 | ||
401 | AA_BUG(!l->proxy); | |
402 | AA_BUG(!l->proxy->label); | |
403 | /* BUG: only way this can happen is @l ref count and its | |
404 | * replacement count have gone to 0 and are on their way | |
405 | * to destruction. ie. we have a refcounting error | |
406 | */ | |
407 | tmp = aa_get_label_rcu(&l->proxy->label); | |
408 | AA_BUG(!tmp); | |
409 | ||
410 | return tmp; | |
411 | } | |
412 | ||
413 | return aa_get_label(l); | |
414 | } | |
415 | ||
416 | static inline void aa_put_label(struct aa_label *l) | |
417 | { | |
418 | if (l) | |
419 | kref_put(&l->count, aa_label_kref); | |
420 | } | |
421 | ||
422 | ||
423 | struct aa_proxy *aa_alloc_proxy(struct aa_label *l, gfp_t gfp); | |
424 | void aa_proxy_kref(struct kref *kref); | |
425 | ||
426 | static inline struct aa_proxy *aa_get_proxy(struct aa_proxy *proxy) | |
427 | { | |
428 | if (proxy) | |
429 | kref_get(&(proxy->count)); | |
430 | ||
431 | return proxy; | |
432 | } | |
433 | ||
434 | static inline void aa_put_proxy(struct aa_proxy *proxy) | |
435 | { | |
436 | if (proxy) | |
437 | kref_put(&proxy->count, aa_proxy_kref); | |
438 | } | |
439 | ||
440 | void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new); | |
441 | ||
442 | #endif /* __AA_LABEL_H */ |