summaryrefslogtreecommitdiff
path: root/security/apparmor/include/policy.h
blob: 5c72231d1c4268d0a8aa2525a55530b07849a514 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
/*
 * AppArmor security module
 *
 * This file contains AppArmor policy definitions.
 *
 * Copyright (C) 1998-2008 Novell/SUSE
 * Copyright 2009-2010 Canonical Ltd.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, version 2 of the
 * License.
 */

#ifndef __AA_POLICY_H
#define __AA_POLICY_H

#include <linux/capability.h>
#include <linux/cred.h>
#include <linux/kref.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/socket.h>

#include "apparmor.h"
#include "audit.h"
#include "capability.h"
#include "domain.h"
#include "file.h"
#include "resource.h"

extern const char *const aa_profile_mode_names[];
#define APPARMOR_MODE_NAMES_MAX_INDEX 4

#define PROFILE_MODE(_profile, _mode)		\
	((aa_g_profile_mode == (_mode)) ||	\
	 ((_profile)->mode == (_mode)))

#define COMPLAIN_MODE(_profile)	PROFILE_MODE((_profile), APPARMOR_COMPLAIN)

#define KILL_MODE(_profile) PROFILE_MODE((_profile), APPARMOR_KILL)

#define PROFILE_IS_HAT(_profile) ((_profile)->flags & PFLAG_HAT)

#define PROFILE_INVALID(_profile) ((_profile)->flags & PFLAG_INVALID)

#define on_list_rcu(X) (!list_empty(X) && (X)->prev != LIST_POISON2)

/*
 * FIXME: currently need a clean way to replace and remove profiles as a
 * set.  It should be done at the namespace level.
 * Either, with a set of profiles loaded at the namespace level or via
 * a mark and remove marked interface.
 */
enum profile_mode {
	APPARMOR_ENFORCE,	/* enforce access rules */
	APPARMOR_COMPLAIN,	/* allow and log access violations */
	APPARMOR_KILL,		/* kill task on access violation */
	APPARMOR_UNCONFINED,	/* profile set to unconfined */
};

enum profile_flags {
	PFLAG_HAT = 1,			/* profile is a hat */
	PFLAG_NULL = 4,			/* profile is null learning profile */
	PFLAG_IX_ON_NAME_ERROR = 8,	/* fallback to ix on name lookup fail */
	PFLAG_IMMUTABLE = 0x10,		/* don't allow changes/replacement */
	PFLAG_USER_DEFINED = 0x20,	/* user based profile - lower privs */
	PFLAG_NO_LIST_REF = 0x40,	/* list doesn't keep profile ref */
	PFLAG_OLD_NULL_TRANS = 0x100,	/* use // as the null transition */
	PFLAG_INVALID = 0x200,		/* profile replaced/removed */
	PFLAG_NS_COUNT = 0x400,		/* carries NS ref count */

	/* These flags must correspond with PATH_flags */
	PFLAG_MEDIATE_DELETED = 0x10000, /* mediate instead delegate deleted */
};

struct aa_profile;

/* struct aa_policy - common part of both namespaces and profiles
 * @name: name of the object
 * @hname - The hierarchical name
 * @list: list policy object is on
 * @profiles: head of the profiles list contained in the object
 */
struct aa_policy {
	char *name;
	char *hname;
	struct list_head list;
	struct list_head profiles;
};

/* struct aa_ns_acct - accounting of profiles in namespace
 * @max_size: maximum space allowed for all profiles in namespace
 * @max_count: maximum number of profiles that can be in this namespace
 * @size: current size of profiles
 * @count: current count of profiles (includes null profiles)
 */
struct aa_ns_acct {
	int max_size;
	int max_count;
	int size;
	int count;
};

/* struct aa_namespace - namespace for a set of profiles
 * @base: common policy
 * @parent: parent of namespace
 * @lock: lock for modifying the object
 * @acct: accounting for the namespace
 * @unconfined: special unconfined profile for the namespace
 * @sub_ns: list of namespaces under the current namespace.
 * @uniq_null: uniq value used for null learning profiles
 * @uniq_id: a unique id count for the profiles in the namespace
 * @dents: dentries for the namespaces file entries in apparmorfs
 *
 * An aa_namespace defines the set profiles that are searched to determine
 * which profile to attach to a task.  Profiles can not be shared between
 * aa_namespaces and profile names within a namespace are guaranteed to be
 * unique.  When profiles in separate namespaces have the same name they
 * are NOT considered to be equivalent.
 *
 * Namespaces are hierarchical and only namespaces and profiles below the
 * current namespace are visible.
 *
 * Namespace names must be unique and can not contain the characters :/\0
 *
 * FIXME TODO: add vserver support of namespaces (can it all be done in
 *             userspace?)
 */
struct aa_namespace {
	struct aa_policy base;
	struct aa_namespace *parent;
	struct mutex lock;
	struct aa_ns_acct acct;
	struct aa_profile *unconfined;
	struct list_head sub_ns;
	atomic_t uniq_null;
	long uniq_id;

	struct dentry *dents[AAFS_NS_SIZEOF];
};

/* struct aa_policydb - match engine for a policy
 * dfa: dfa pattern match
 * start: set of start states for the different classes of data
 */
struct aa_policydb {
	/* Generic policy DFA specific rule types will be subsections of it */
	struct aa_dfa *dfa;
	unsigned int start[AA_CLASS_LAST + 1];

};

struct aa_replacedby {
	struct kref count;
	struct aa_profile __rcu *profile;
};


/* struct aa_profile - basic confinement data
 * @base - base components of the profile (name, refcount, lists, lock ...)
 * @count: reference count of the obj
 * @rcu: rcu head used when removing from @list
 * @parent: parent of profile
 * @ns: namespace the profile is in
 * @replacedby: is set to the profile that replaced this profile
 * @rename: optional profile name that this profile renamed
 * @xmatch: optional extended matching for unconfined executables names
 * @xmatch_len: xmatch prefix len, used to determine xmatch priority
 * @audit: the auditing mode of the profile
 * @mode: the enforcement mode of the profile
 * @flags: flags controlling profile behavior
 * @path_flags: flags controlling path generation behavior
 * @size: the memory consumed by this profiles rules
 * @policy: general match rules governing policy
 * @file: The set of rules governing basic file access and domain transitions
 * @caps: capabilities for the profile
 * @rlimits: rlimits for the profile
 *
 * @dents: dentries for the profiles file entries in apparmorfs
 * @dirname: name of the profile dir in apparmorfs
 *
 * The AppArmor profile contains the basic confinement data.  Each profile
 * has a name, and exists in a namespace.  The @name and @exec_match are
 * used to determine profile attachment against unconfined tasks.  All other
 * attachments are determined by profile X transition rules.
 *
 * The @replacedby struct is write protected by the profile lock.
 *
 * Profiles have a hierarchy where hats and children profiles keep
 * a reference to their parent.
 *
 * Profile names can not begin with a : and can not contain the \0
 * character.  If a profile name begins with / it will be considered when
 * determining profile attachment on "unconfined" tasks.
 */
struct aa_profile {
	struct aa_policy base;
	struct kref count;
	struct rcu_head rcu;
	struct aa_profile __rcu *parent;

	struct aa_namespace *ns;
	struct aa_replacedby *replacedby;
	const char *rename;

	struct aa_dfa *xmatch;
	int xmatch_len;
	enum audit_mode audit;
	long mode;
	long flags;
	u32 path_flags;
	int size;

	struct aa_policydb policy;
	struct aa_file_rules file;
	struct aa_caps caps;
	struct aa_rlimit rlimits;

	char *dirname;
	struct dentry *dents[AAFS_PROF_SIZEOF];
};

extern struct aa_namespace *root_ns;
extern enum profile_mode aa_g_profile_mode;

void aa_add_profile(struct aa_policy *common, struct aa_profile *profile);

bool aa_ns_visible(struct aa_namespace *curr, struct aa_namespace *view);
const char *aa_ns_name(struct aa_namespace *parent, struct aa_namespace *child);
int aa_alloc_root_ns(void);
void aa_free_root_ns(void);
void aa_free_namespace_kref(struct kref *kref);

struct aa_namespace *aa_find_namespace(struct aa_namespace *root,
				       const char *name);


void aa_free_replacedby_kref(struct kref *kref);
struct aa_profile *aa_alloc_profile(const char *name);
struct aa_profile *aa_new_null_profile(struct aa_profile *parent, int hat);
void aa_free_profile(struct aa_profile *profile);
void aa_free_profile_kref(struct kref *kref);
struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name);
struct aa_profile *aa_lookup_profile(struct aa_namespace *ns, const char *name);
struct aa_profile *aa_match_profile(struct aa_namespace *ns, const char *name);

ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace);
ssize_t aa_remove_profiles(char *name, size_t size);

#define PROF_ADD 1
#define PROF_REPLACE 0

#define unconfined(X) ((X)->mode == APPARMOR_UNCONFINED)


static inline struct aa_profile *aa_deref_parent(struct aa_profile *p)
{
	return rcu_dereference_protected(p->parent,
					 mutex_is_locked(&p->ns->lock));
}

/**
 * aa_get_profile - increment refcount on profile @p
 * @p: profile  (MAYBE NULL)
 *
 * Returns: pointer to @p if @p is NULL will return NULL
 * Requires: @p must be held with valid refcount when called
 */
static inline struct aa_profile *aa_get_profile(struct aa_profile *p)
{
	if (p)
		kref_get(&(p->count));

	return p;
}

/**
 * aa_get_profile_not0 - increment refcount on profile @p found via lookup
 * @p: profile  (MAYBE NULL)
 *
 * Returns: pointer to @p if @p is NULL will return NULL
 * Requires: @p must be held with valid refcount when called
 */
static inline struct aa_profile *aa_get_profile_not0(struct aa_profile *p)
{
	if (p && kref_get_not0(&p->count))
		return p;

	return NULL;
}

/**
 * aa_get_profile_rcu - increment a refcount profile that can be replaced
 * @p: pointer to profile that can be replaced (NOT NULL)
 *
 * Returns: pointer to a refcounted profile.
 *     else NULL if no profile
 */
static inline struct aa_profile *aa_get_profile_rcu(struct aa_profile __rcu **p)
{
	struct aa_profile *c;

	rcu_read_lock();
	do {
		c = rcu_dereference(*p);
	} while (c && !kref_get_not0(&c->count));
	rcu_read_unlock();

	return c;
}

/**
 * aa_get_newest_profile - find the newest version of @profile
 * @profile: the profile to check for newer versions of
 *
 * Returns: refcounted newest version of @profile taking into account
 *          replacement, renames and removals
 *          return @profile.
 */
static inline struct aa_profile *aa_get_newest_profile(struct aa_profile *p)
{
	if (!p)
		return NULL;

	if (PROFILE_INVALID(p))
		return aa_get_profile_rcu(&p->replacedby->profile);

	return aa_get_profile(p);
}

/**
 * aa_put_profile - decrement refcount on profile @p
 * @p: profile  (MAYBE NULL)
 */
static inline void aa_put_profile(struct aa_profile *p)
{
	if (p)
		kref_put(&p->count, aa_free_profile_kref);
}

static inline struct aa_replacedby *aa_get_replacedby(struct aa_replacedby *p)
{
	if (p)
		kref_get(&(p->count));

	return p;
}

static inline void aa_put_replacedby(struct aa_replacedby *p)
{
	if (p)
		kref_put(&p->count, aa_free_replacedby_kref);
}

/* requires profile list write lock held */
static inline void __aa_update_replacedby(struct aa_profile *orig,
					  struct aa_profile *new)
{
	struct aa_profile *tmp = rcu_dereference(orig->replacedby->profile);
	rcu_assign_pointer(orig->replacedby->profile, aa_get_profile(new));
	orig->flags |= PFLAG_INVALID;
	aa_put_profile(tmp);
}

/**
 * aa_get_namespace - increment references count on @ns
 * @ns: namespace to increment reference count of (MAYBE NULL)
 *
 * Returns: pointer to @ns, if @ns is NULL returns NULL
 * Requires: @ns must be held with valid refcount when called
 */
static inline struct aa_namespace *aa_get_namespace(struct aa_namespace *ns)
{
	if (ns)
		aa_get_profile(ns->unconfined);

	return ns;
}

/**
 * aa_put_namespace - decrement refcount on @ns
 * @ns: namespace to put reference of
 *
 * Decrement reference count of @ns and if no longer in use free it
 */
static inline void aa_put_namespace(struct aa_namespace *ns)
{
	if (ns)
		aa_put_profile(ns->unconfined);
}

static inline int AUDIT_MODE(struct aa_profile *profile)
{
	if (aa_g_audit != AUDIT_NORMAL)
		return aa_g_audit;

	return profile->audit;
}

bool aa_may_manage_policy(int op);

#endif /* __AA_POLICY_H */