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
21struct 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)						\
41do {									\
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
56struct aa_profile;
57#define VEC_FLAG_TERMINATE 1
58int aa_vec_unique(struct aa_profile **vec, int n, int flags);
59struct 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 */
71struct 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
80enum 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
102struct aa_label;
103struct aa_proxy {
104	struct kref count;
105	struct aa_label __rcu *label;
106};
107
108struct 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 */
123struct 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)				\
136do {							\
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
153int 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)						\
164do {									\
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)				\
175for ((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
273void aa_labelset_destroy(struct aa_labelset *ls);
274void aa_labelset_init(struct aa_labelset *ls);
275void __aa_labelset_update_subtree(struct aa_ns *ns);
276
277void aa_label_destroy(struct aa_label *label);
278void aa_label_free(struct aa_label *label);
279void aa_label_kref(struct kref *kref);
280bool aa_label_init(struct aa_label *label, int size, gfp_t gfp);
281struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp);
282
283bool aa_label_is_subset(struct aa_label *set, struct aa_label *sub);
284bool aa_label_is_unconfined_subset(struct aa_label *set, struct aa_label *sub);
285struct aa_profile *__aa_label_next_not_in_set(struct label_it *I,
286					     struct aa_label *set,
287					     struct aa_label *sub);
288bool aa_label_remove(struct aa_label *label);
289struct aa_label *aa_label_insert(struct aa_labelset *ls, struct aa_label *l);
290bool aa_label_replace(struct aa_label *old, struct aa_label *new);
291bool aa_label_make_newest(struct aa_labelset *ls, struct aa_label *old,
292			  struct aa_label *new);
293
294struct aa_label *aa_label_find(struct aa_label *l);
295
296struct aa_profile *aa_label_next_in_merge(struct label_it *I,
297					  struct aa_label *a,
298					  struct aa_label *b);
299struct aa_label *aa_label_find_merge(struct aa_label *a, struct aa_label *b);
300struct aa_label *aa_label_merge(struct aa_label *a, struct aa_label *b,
301				gfp_t gfp);
302
303
304bool 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
311int aa_label_snxprint(char *str, size_t size, struct aa_ns *view,
312		      struct aa_label *label, int flags);
313int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label,
314		      int flags, gfp_t gfp);
315int aa_label_acntsxprint(char __counted **strp, struct aa_ns *ns,
316			 struct aa_label *label, int flags, gfp_t gfp);
317void aa_label_xaudit(struct audit_buffer *ab, struct aa_ns *ns,
318		     struct aa_label *label, int flags, gfp_t gfp);
319void aa_label_seq_xprint(struct seq_file *f, struct aa_ns *ns,
320			 struct aa_label *label, int flags, gfp_t gfp);
321void aa_label_xprintk(struct aa_ns *ns, struct aa_label *label, int flags,
322		      gfp_t gfp);
323void aa_label_audit(struct audit_buffer *ab, struct aa_label *label, gfp_t gfp);
324void aa_label_seq_print(struct seq_file *f, struct aa_label *label, gfp_t gfp);
325void aa_label_printk(struct aa_label *label, gfp_t gfp);
326
327struct 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);
330struct aa_label *aa_label_parse(struct aa_label *base, const char *str,
331				gfp_t gfp, bool create, bool force_stack);
332
333static 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(stacksplitdfa, DFA_START, str, n, &pos);
339	if (!ACCEPT_TABLE(stacksplitdfa)[state])
340		return NULL;
341
342	return pos - 3;
343}
344
345static 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(stacksplitdfa, DFA_START, str, &pos);
351	if (!ACCEPT_TABLE(stacksplitdfa)[state])
352		return NULL;
353
354	return pos - 3;
355}
356
357
358
359struct aa_perms;
360struct aa_ruleset;
361int 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 */
374static inline struct aa_label *__aa_get_label(struct aa_label *l)
375{
376	if (l && kref_get_unless_zero(&l->count))
377		return l;
378
379	return NULL;
380}
381
382static inline struct aa_label *aa_get_label(struct aa_label *l)
383{
384	if (l)
385		kref_get(&(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 */
398static 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(&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 */
419static 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->proxy->label);
434		AA_BUG(!tmp);
435
436		return tmp;
437	}
438
439	return aa_get_label(l);
440}
441
442static inline void aa_put_label(struct aa_label *l)
443{
444	if (l)
445		kref_put(&l->count, aa_label_kref);
446}
447
448
449struct aa_proxy *aa_alloc_proxy(struct aa_label *l, gfp_t gfp);
450void aa_proxy_kref(struct kref *kref);
451
452static inline struct aa_proxy *aa_get_proxy(struct aa_proxy *proxy)
453{
454	if (proxy)
455		kref_get(&(proxy->count));
456
457	return proxy;
458}
459
460static inline void aa_put_proxy(struct aa_proxy *proxy)
461{
462	if (proxy)
463		kref_put(&proxy->count, aa_proxy_kref);
464}
465
466void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new);
467
468#endif /* __AA_LABEL_H */
469