1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
2 | /* |
3 | * AppArmor security module |
4 | * |
5 | * This file contains AppArmor label definitions |
6 | * |
7 | * Copyright 2017 Canonical Ltd. |
8 | */ |
9 | |
10 | #ifndef __AA_LABEL_H |
11 | #define __AA_LABEL_H |
12 | |
13 | #include <linux/atomic.h> |
14 | #include <linux/audit.h> |
15 | #include <linux/rbtree.h> |
16 | #include <linux/rcupdate.h> |
17 | |
18 | #include "apparmor.h" |
19 | #include "lib.h" |
20 | |
21 | struct aa_ns; |
22 | |
23 | #define LOCAL_VEC_ENTRIES 8 |
24 | #define DEFINE_VEC(T, V) \ |
25 | struct aa_ ## T *(_ ## V ## _localtmp)[LOCAL_VEC_ENTRIES]; \ |
26 | struct aa_ ## T **(V) |
27 | |
28 | #define vec_setup(T, V, N, GFP) \ |
29 | ({ \ |
30 | if ((N) <= LOCAL_VEC_ENTRIES) { \ |
31 | typeof(N) i; \ |
32 | (V) = (_ ## V ## _localtmp); \ |
33 | for (i = 0; i < (N); i++) \ |
34 | (V)[i] = NULL; \ |
35 | } else \ |
36 | (V) = kzalloc(sizeof(struct aa_ ## T *) * (N), (GFP)); \ |
37 | (V) ? 0 : -ENOMEM; \ |
38 | }) |
39 | |
40 | #define vec_cleanup(T, V, N) \ |
41 | do { \ |
42 | int i; \ |
43 | for (i = 0; i < (N); i++) { \ |
44 | if (!IS_ERR_OR_NULL((V)[i])) \ |
45 | aa_put_ ## T((V)[i]); \ |
46 | } \ |
47 | if ((V) != _ ## V ## _localtmp) \ |
48 | kfree(V); \ |
49 | } while (0) |
50 | |
51 | #define vec_last(VEC, SIZE) ((VEC)[(SIZE) - 1]) |
52 | #define vec_ns(VEC, SIZE) (vec_last((VEC), (SIZE))->ns) |
53 | #define vec_labelset(VEC, SIZE) (&vec_ns((VEC), (SIZE))->labels) |
54 | #define cleanup_domain_vec(V, L) cleanup_label_vec((V), (L)->size) |
55 | |
56 | struct aa_profile; |
57 | #define VEC_FLAG_TERMINATE 1 |
58 | int aa_vec_unique(struct aa_profile **vec, int n, int flags); |
59 | struct aa_label *aa_vec_find_or_create_label(struct aa_profile **vec, int len, |
60 | gfp_t gfp); |
61 | #define aa_sort_and_merge_vec(N, V) \ |
62 | aa_sort_and_merge_profiles((N), (struct aa_profile **)(V)) |
63 | |
64 | |
65 | /* struct aa_labelset - set of labels for a namespace |
66 | * |
67 | * Labels are reference counted; aa_labelset does not contribute to label |
68 | * reference counts. Once a label's last refcount is put it is removed from |
69 | * the set. |
70 | */ |
71 | struct aa_labelset { |
72 | rwlock_t lock; |
73 | |
74 | struct rb_root root; |
75 | }; |
76 | |
77 | #define __labelset_for_each(LS, N) \ |
78 | for ((N) = rb_first(&(LS)->root); (N); (N) = rb_next(N)) |
79 | |
80 | enum label_flags { |
81 | FLAG_HAT = 1, /* profile is a hat */ |
82 | FLAG_UNCONFINED = 2, /* label unconfined only if all */ |
83 | FLAG_NULL = 4, /* profile is null learning profile */ |
84 | FLAG_IX_ON_NAME_ERROR = 8, /* fallback to ix on name lookup fail */ |
85 | FLAG_IMMUTIBLE = 0x10, /* don't allow changes/replacement */ |
86 | FLAG_USER_DEFINED = 0x20, /* user based profile - lower privs */ |
87 | FLAG_NO_LIST_REF = 0x40, /* list doesn't keep profile ref */ |
88 | FLAG_NS_COUNT = 0x80, /* carries NS ref count */ |
89 | FLAG_IN_TREE = 0x100, /* label is in tree */ |
90 | FLAG_PROFILE = 0x200, /* label is a profile */ |
91 | FLAG_EXPLICIT = 0x400, /* explicit static label */ |
92 | FLAG_STALE = 0x800, /* replaced/removed */ |
93 | FLAG_RENAMED = 0x1000, /* label has renaming in it */ |
94 | FLAG_REVOKED = 0x2000, /* label has revocation in it */ |
95 | FLAG_DEBUG1 = 0x4000, |
96 | FLAG_DEBUG2 = 0x8000, |
97 | |
98 | /* These flags must correspond with PATH_flags */ |
99 | /* TODO: add new path flags */ |
100 | }; |
101 | |
102 | struct aa_label; |
103 | struct aa_proxy { |
104 | struct kref count; |
105 | struct aa_label __rcu *label; |
106 | }; |
107 | |
108 | struct label_it { |
109 | int i, j; |
110 | }; |
111 | |
112 | /* struct aa_label - lazy labeling struct |
113 | * @count: ref count of active users |
114 | * @node: rbtree position |
115 | * @rcu: rcu callback struct |
116 | * @proxy: is set to the label that replaced this label |
117 | * @hname: text representation of the label (MAYBE_NULL) |
118 | * @flags: stale and other flags - values may change under label set lock |
119 | * @secid: secid that references this label |
120 | * @size: number of entries in @ent[] |
121 | * @ent: set of profiles for label, actual size determined by @size |
122 | */ |
123 | struct aa_label { |
124 | struct kref count; |
125 | struct rb_node node; |
126 | struct rcu_head rcu; |
127 | struct aa_proxy *proxy; |
128 | __counted char *hname; |
129 | long flags; |
130 | u32 secid; |
131 | int size; |
132 | struct aa_profile *vec[]; |
133 | }; |
134 | |
135 | #define last_error(E, FN) \ |
136 | do { \ |
137 | int __subE = (FN); \ |
138 | if (__subE) \ |
139 | (E) = __subE; \ |
140 | } while (0) |
141 | |
142 | #define label_isprofile(X) ((X)->flags & FLAG_PROFILE) |
143 | #define label_unconfined(X) ((X)->flags & FLAG_UNCONFINED) |
144 | #define unconfined(X) label_unconfined(X) |
145 | #define label_is_stale(X) ((X)->flags & FLAG_STALE) |
146 | #define __label_make_stale(X) ((X)->flags |= FLAG_STALE) |
147 | #define labels_ns(X) (vec_ns(&((X)->vec[0]), (X)->size)) |
148 | #define labels_set(X) (&labels_ns(X)->labels) |
149 | #define labels_view(X) labels_ns(X) |
150 | #define labels_profile(X) ((X)->vec[(X)->size - 1]) |
151 | |
152 | |
153 | int aa_label_next_confined(struct aa_label *l, int i); |
154 | |
155 | /* for each profile in a label */ |
156 | #define label_for_each(I, L, P) \ |
157 | for ((I).i = 0; ((P) = (L)->vec[(I).i]); ++((I).i)) |
158 | |
159 | /* assumes break/goto ended label_for_each */ |
160 | #define label_for_each_cont(I, L, P) \ |
161 | for (++((I).i); ((P) = (L)->vec[(I).i]); ++((I).i)) |
162 | |
163 | #define next_comb(I, L1, L2) \ |
164 | do { \ |
165 | (I).j++; \ |
166 | if ((I).j >= (L2)->size) { \ |
167 | (I).i++; \ |
168 | (I).j = 0; \ |
169 | } \ |
170 | } while (0) |
171 | |
172 | |
173 | /* for each combination of P1 in L1, and P2 in L2 */ |
174 | #define label_for_each_comb(I, L1, L2, P1, P2) \ |
175 | for ((I).i = (I).j = 0; \ |
176 | ((P1) = (L1)->vec[(I).i]) && ((P2) = (L2)->vec[(I).j]); \ |
177 | (I) = next_comb(I, L1, L2)) |
178 | |
179 | #define fn_for_each_comb(L1, L2, P1, P2, FN) \ |
180 | ({ \ |
181 | struct label_it i; \ |
182 | int __E = 0; \ |
183 | label_for_each_comb(i, (L1), (L2), (P1), (P2)) { \ |
184 | last_error(__E, (FN)); \ |
185 | } \ |
186 | __E; \ |
187 | }) |
188 | |
189 | /* for each profile that is enforcing confinement in a label */ |
190 | #define label_for_each_confined(I, L, P) \ |
191 | for ((I).i = aa_label_next_confined((L), 0); \ |
192 | ((P) = (L)->vec[(I).i]); \ |
193 | (I).i = aa_label_next_confined((L), (I).i + 1)) |
194 | |
195 | #define label_for_each_in_merge(I, A, B, P) \ |
196 | for ((I).i = (I).j = 0; \ |
197 | ((P) = aa_label_next_in_merge(&(I), (A), (B))); \ |
198 | ) |
199 | |
200 | #define label_for_each_not_in_set(I, SET, SUB, P) \ |
201 | for ((I).i = (I).j = 0; \ |
202 | ((P) = __aa_label_next_not_in_set(&(I), (SET), (SUB))); \ |
203 | ) |
204 | |
205 | #define next_in_ns(i, NS, L) \ |
206 | ({ \ |
207 | typeof(i) ___i = (i); \ |
208 | while ((L)->vec[___i] && (L)->vec[___i]->ns != (NS)) \ |
209 | (___i)++; \ |
210 | (___i); \ |
211 | }) |
212 | |
213 | #define label_for_each_in_ns(I, NS, L, P) \ |
214 | for ((I).i = next_in_ns(0, (NS), (L)); \ |
215 | ((P) = (L)->vec[(I).i]); \ |
216 | (I).i = next_in_ns((I).i + 1, (NS), (L))) |
217 | |
218 | #define fn_for_each_in_ns(L, P, FN) \ |
219 | ({ \ |
220 | struct label_it __i; \ |
221 | struct aa_ns *__ns = labels_ns(L); \ |
222 | int __E = 0; \ |
223 | label_for_each_in_ns(__i, __ns, (L), (P)) { \ |
224 | last_error(__E, (FN)); \ |
225 | } \ |
226 | __E; \ |
227 | }) |
228 | |
229 | |
230 | #define fn_for_each_XXX(L, P, FN, ...) \ |
231 | ({ \ |
232 | struct label_it i; \ |
233 | int __E = 0; \ |
234 | label_for_each ## __VA_ARGS__(i, (L), (P)) { \ |
235 | last_error(__E, (FN)); \ |
236 | } \ |
237 | __E; \ |
238 | }) |
239 | |
240 | #define fn_for_each(L, P, FN) fn_for_each_XXX(L, P, FN) |
241 | #define fn_for_each_confined(L, P, FN) fn_for_each_XXX(L, P, FN, _confined) |
242 | |
243 | #define fn_for_each2_XXX(L1, L2, P, FN, ...) \ |
244 | ({ \ |
245 | struct label_it i; \ |
246 | int __E = 0; \ |
247 | label_for_each ## __VA_ARGS__(i, (L1), (L2), (P)) { \ |
248 | last_error(__E, (FN)); \ |
249 | } \ |
250 | __E; \ |
251 | }) |
252 | |
253 | #define fn_for_each_in_merge(L1, L2, P, FN) \ |
254 | fn_for_each2_XXX((L1), (L2), P, FN, _in_merge) |
255 | #define fn_for_each_not_in_set(L1, L2, P, FN) \ |
256 | fn_for_each2_XXX((L1), (L2), P, FN, _not_in_set) |
257 | |
258 | #define LABEL_MEDIATES(L, C) \ |
259 | ({ \ |
260 | struct aa_profile *profile; \ |
261 | struct label_it i; \ |
262 | int ret = 0; \ |
263 | label_for_each(i, (L), profile) { \ |
264 | if (RULE_MEDIATES(&profile->rules, (C))) { \ |
265 | ret = 1; \ |
266 | break; \ |
267 | } \ |
268 | } \ |
269 | ret; \ |
270 | }) |
271 | |
272 | |
273 | void aa_labelset_destroy(struct aa_labelset *ls); |
274 | void aa_labelset_init(struct aa_labelset *ls); |
275 | void __aa_labelset_update_subtree(struct aa_ns *ns); |
276 | |
277 | void aa_label_destroy(struct aa_label *label); |
278 | void aa_label_free(struct aa_label *label); |
279 | void aa_label_kref(struct kref *kref); |
280 | bool aa_label_init(struct aa_label *label, int size, gfp_t gfp); |
281 | struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp); |
282 | |
283 | bool aa_label_is_subset(struct aa_label *set, struct aa_label *sub); |
284 | bool aa_label_is_unconfined_subset(struct aa_label *set, struct aa_label *sub); |
285 | struct aa_profile *__aa_label_next_not_in_set(struct label_it *I, |
286 | struct aa_label *set, |
287 | struct aa_label *sub); |
288 | bool aa_label_remove(struct aa_label *label); |
289 | struct aa_label *aa_label_insert(struct aa_labelset *ls, struct aa_label *l); |
290 | bool aa_label_replace(struct aa_label *old, struct aa_label *new); |
291 | bool aa_label_make_newest(struct aa_labelset *ls, struct aa_label *old, |
292 | struct aa_label *new); |
293 | |
294 | struct aa_label *aa_label_find(struct aa_label *l); |
295 | |
296 | struct aa_profile *aa_label_next_in_merge(struct label_it *I, |
297 | struct aa_label *a, |
298 | struct aa_label *b); |
299 | struct aa_label *aa_label_find_merge(struct aa_label *a, struct aa_label *b); |
300 | struct aa_label *aa_label_merge(struct aa_label *a, struct aa_label *b, |
301 | gfp_t gfp); |
302 | |
303 | |
304 | bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp); |
305 | |
306 | #define FLAGS_NONE 0 |
307 | #define FLAG_SHOW_MODE 1 |
308 | #define FLAG_VIEW_SUBNS 2 |
309 | #define FLAG_HIDDEN_UNCONFINED 4 |
310 | #define FLAG_ABS_ROOT 8 |
311 | int aa_label_snxprint(char *str, size_t size, struct aa_ns *view, |
312 | struct aa_label *label, int flags); |
313 | int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label, |
314 | int flags, gfp_t gfp); |
315 | int aa_label_acntsxprint(char __counted **strp, struct aa_ns *ns, |
316 | struct aa_label *label, int flags, gfp_t gfp); |
317 | void aa_label_xaudit(struct audit_buffer *ab, struct aa_ns *ns, |
318 | struct aa_label *label, int flags, gfp_t gfp); |
319 | void aa_label_seq_xprint(struct seq_file *f, struct aa_ns *ns, |
320 | struct aa_label *label, int flags, gfp_t gfp); |
321 | void aa_label_xprintk(struct aa_ns *ns, struct aa_label *label, int flags, |
322 | gfp_t gfp); |
323 | void aa_label_audit(struct audit_buffer *ab, struct aa_label *label, gfp_t gfp); |
324 | void aa_label_seq_print(struct seq_file *f, struct aa_label *label, gfp_t gfp); |
325 | void aa_label_printk(struct aa_label *label, gfp_t gfp); |
326 | |
327 | struct aa_label *aa_label_strn_parse(struct aa_label *base, const char *str, |
328 | size_t n, gfp_t gfp, bool create, |
329 | bool force_stack); |
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 | static inline const char *aa_label_strn_split(const char *str, int n) |
334 | { |
335 | const char *pos; |
336 | aa_state_t state; |
337 | |
338 | state = aa_dfa_matchn_until(dfa: stacksplitdfa, DFA_START, str, n, retpos: &pos); |
339 | if (!ACCEPT_TABLE(stacksplitdfa)[state]) |
340 | return NULL; |
341 | |
342 | return pos - 3; |
343 | } |
344 | |
345 | static inline const char *aa_label_str_split(const char *str) |
346 | { |
347 | const char *pos; |
348 | aa_state_t state; |
349 | |
350 | state = aa_dfa_match_until(dfa: stacksplitdfa, DFA_START, str, retpos: &pos); |
351 | if (!ACCEPT_TABLE(stacksplitdfa)[state]) |
352 | return NULL; |
353 | |
354 | return pos - 3; |
355 | } |
356 | |
357 | |
358 | |
359 | struct aa_perms; |
360 | struct aa_ruleset; |
361 | int aa_label_match(struct aa_profile *profile, struct aa_ruleset *rules, |
362 | struct aa_label *label, aa_state_t state, bool subns, |
363 | u32 request, struct aa_perms *perms); |
364 | |
365 | |
366 | /** |
367 | * __aa_get_label - get a reference count to uncounted label reference |
368 | * @l: reference to get a count on |
369 | * |
370 | * Returns: pointer to reference OR NULL if race is lost and reference is |
371 | * being repeated. |
372 | * Requires: lock held, and the return code MUST be checked |
373 | */ |
374 | static inline struct aa_label *__aa_get_label(struct aa_label *l) |
375 | { |
376 | if (l && kref_get_unless_zero(kref: &l->count)) |
377 | return l; |
378 | |
379 | return NULL; |
380 | } |
381 | |
382 | static inline struct aa_label *aa_get_label(struct aa_label *l) |
383 | { |
384 | if (l) |
385 | kref_get(kref: &(l->count)); |
386 | |
387 | return l; |
388 | } |
389 | |
390 | |
391 | /** |
392 | * aa_get_label_rcu - increment refcount on a label that can be replaced |
393 | * @l: pointer to label that can be replaced (NOT NULL) |
394 | * |
395 | * Returns: pointer to a refcounted label. |
396 | * else NULL if no label |
397 | */ |
398 | static inline struct aa_label *aa_get_label_rcu(struct aa_label __rcu **l) |
399 | { |
400 | struct aa_label *c; |
401 | |
402 | rcu_read_lock(); |
403 | do { |
404 | c = rcu_dereference(*l); |
405 | } while (c && !kref_get_unless_zero(kref: &c->count)); |
406 | rcu_read_unlock(); |
407 | |
408 | return c; |
409 | } |
410 | |
411 | /** |
412 | * aa_get_newest_label - find the newest version of @l |
413 | * @l: the label to check for newer versions of |
414 | * |
415 | * Returns: refcounted newest version of @l taking into account |
416 | * replacement, renames and removals |
417 | * return @l. |
418 | */ |
419 | static inline struct aa_label *aa_get_newest_label(struct aa_label *l) |
420 | { |
421 | if (!l) |
422 | return NULL; |
423 | |
424 | if (label_is_stale(l)) { |
425 | struct aa_label *tmp; |
426 | |
427 | AA_BUG(!l->proxy); |
428 | AA_BUG(!l->proxy->label); |
429 | /* BUG: only way this can happen is @l ref count and its |
430 | * replacement count have gone to 0 and are on their way |
431 | * to destruction. ie. we have a refcounting error |
432 | */ |
433 | tmp = aa_get_label_rcu(l: &l->proxy->label); |
434 | AA_BUG(!tmp); |
435 | |
436 | return tmp; |
437 | } |
438 | |
439 | return aa_get_label(l); |
440 | } |
441 | |
442 | static inline void aa_put_label(struct aa_label *l) |
443 | { |
444 | if (l) |
445 | kref_put(kref: &l->count, release: aa_label_kref); |
446 | } |
447 | |
448 | |
449 | struct aa_proxy *aa_alloc_proxy(struct aa_label *l, gfp_t gfp); |
450 | void aa_proxy_kref(struct kref *kref); |
451 | |
452 | static inline struct aa_proxy *aa_get_proxy(struct aa_proxy *proxy) |
453 | { |
454 | if (proxy) |
455 | kref_get(kref: &(proxy->count)); |
456 | |
457 | return proxy; |
458 | } |
459 | |
460 | static inline void aa_put_proxy(struct aa_proxy *proxy) |
461 | { |
462 | if (proxy) |
463 | kref_put(kref: &proxy->count, release: aa_proxy_kref); |
464 | } |
465 | |
466 | void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new); |
467 | |
468 | #endif /* __AA_LABEL_H */ |
469 | |