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1 : : /*
2 : : * AppArmor security module
3 : : *
4 : : * This file contains AppArmor policy definitions.
5 : : *
6 : : * Copyright (C) 1998-2008 Novell/SUSE
7 : : * Copyright 2009-2010 Canonical Ltd.
8 : : *
9 : : * This program is free software; you can redistribute it and/or
10 : : * modify it under the terms of the GNU General Public License as
11 : : * published by the Free Software Foundation, version 2 of the
12 : : * License.
13 : : */
14 : :
15 : : #ifndef __AA_POLICY_H
16 : : #define __AA_POLICY_H
17 : :
18 : : #include <linux/capability.h>
19 : : #include <linux/cred.h>
20 : : #include <linux/kref.h>
21 : : #include <linux/sched.h>
22 : : #include <linux/slab.h>
23 : : #include <linux/socket.h>
24 : :
25 : : #include "apparmor.h"
26 : : #include "audit.h"
27 : : #include "capability.h"
28 : : #include "domain.h"
29 : : #include "file.h"
30 : : #include "resource.h"
31 : :
32 : : extern const char *const aa_profile_mode_names[];
33 : : #define APPARMOR_MODE_NAMES_MAX_INDEX 4
34 : :
35 : : #define PROFILE_MODE(_profile, _mode) \
36 : : ((aa_g_profile_mode == (_mode)) || \
37 : : ((_profile)->mode == (_mode)))
38 : :
39 : : #define COMPLAIN_MODE(_profile) PROFILE_MODE((_profile), APPARMOR_COMPLAIN)
40 : :
41 : : #define KILL_MODE(_profile) PROFILE_MODE((_profile), APPARMOR_KILL)
42 : :
43 : : #define PROFILE_IS_HAT(_profile) ((_profile)->flags & PFLAG_HAT)
44 : :
45 : : #define PROFILE_INVALID(_profile) ((_profile)->flags & PFLAG_INVALID)
46 : :
47 : : #define on_list_rcu(X) (!list_empty(X) && (X)->prev != LIST_POISON2)
48 : :
49 : : /*
50 : : * FIXME: currently need a clean way to replace and remove profiles as a
51 : : * set. It should be done at the namespace level.
52 : : * Either, with a set of profiles loaded at the namespace level or via
53 : : * a mark and remove marked interface.
54 : : */
55 : : enum profile_mode {
56 : : APPARMOR_ENFORCE, /* enforce access rules */
57 : : APPARMOR_COMPLAIN, /* allow and log access violations */
58 : : APPARMOR_KILL, /* kill task on access violation */
59 : : APPARMOR_UNCONFINED, /* profile set to unconfined */
60 : : };
61 : :
62 : : enum profile_flags {
63 : : PFLAG_HAT = 1, /* profile is a hat */
64 : : PFLAG_NULL = 4, /* profile is null learning profile */
65 : : PFLAG_IX_ON_NAME_ERROR = 8, /* fallback to ix on name lookup fail */
66 : : PFLAG_IMMUTABLE = 0x10, /* don't allow changes/replacement */
67 : : PFLAG_USER_DEFINED = 0x20, /* user based profile - lower privs */
68 : : PFLAG_NO_LIST_REF = 0x40, /* list doesn't keep profile ref */
69 : : PFLAG_OLD_NULL_TRANS = 0x100, /* use // as the null transition */
70 : : PFLAG_INVALID = 0x200, /* profile replaced/removed */
71 : : PFLAG_NS_COUNT = 0x400, /* carries NS ref count */
72 : :
73 : : /* These flags must correspond with PATH_flags */
74 : : PFLAG_MEDIATE_DELETED = 0x10000, /* mediate instead delegate deleted */
75 : : };
76 : :
77 : : struct aa_profile;
78 : :
79 : : /* struct aa_policy - common part of both namespaces and profiles
80 : : * @name: name of the object
81 : : * @hname - The hierarchical name
82 : : * @list: list policy object is on
83 : : * @profiles: head of the profiles list contained in the object
84 : : */
85 : : struct aa_policy {
86 : : char *name;
87 : : char *hname;
88 : : struct list_head list;
89 : : struct list_head profiles;
90 : : };
91 : :
92 : : /* struct aa_ns_acct - accounting of profiles in namespace
93 : : * @max_size: maximum space allowed for all profiles in namespace
94 : : * @max_count: maximum number of profiles that can be in this namespace
95 : : * @size: current size of profiles
96 : : * @count: current count of profiles (includes null profiles)
97 : : */
98 : : struct aa_ns_acct {
99 : : int max_size;
100 : : int max_count;
101 : : int size;
102 : : int count;
103 : : };
104 : :
105 : : /* struct aa_namespace - namespace for a set of profiles
106 : : * @base: common policy
107 : : * @parent: parent of namespace
108 : : * @lock: lock for modifying the object
109 : : * @acct: accounting for the namespace
110 : : * @unconfined: special unconfined profile for the namespace
111 : : * @sub_ns: list of namespaces under the current namespace.
112 : : * @uniq_null: uniq value used for null learning profiles
113 : : * @uniq_id: a unique id count for the profiles in the namespace
114 : : * @dents: dentries for the namespaces file entries in apparmorfs
115 : : *
116 : : * An aa_namespace defines the set profiles that are searched to determine
117 : : * which profile to attach to a task. Profiles can not be shared between
118 : : * aa_namespaces and profile names within a namespace are guaranteed to be
119 : : * unique. When profiles in separate namespaces have the same name they
120 : : * are NOT considered to be equivalent.
121 : : *
122 : : * Namespaces are hierarchical and only namespaces and profiles below the
123 : : * current namespace are visible.
124 : : *
125 : : * Namespace names must be unique and can not contain the characters :/\0
126 : : *
127 : : * FIXME TODO: add vserver support of namespaces (can it all be done in
128 : : * userspace?)
129 : : */
130 : : struct aa_namespace {
131 : : struct aa_policy base;
132 : : struct aa_namespace *parent;
133 : : struct mutex lock;
134 : : struct aa_ns_acct acct;
135 : : struct aa_profile *unconfined;
136 : : struct list_head sub_ns;
137 : : atomic_t uniq_null;
138 : : long uniq_id;
139 : :
140 : : struct dentry *dents[AAFS_NS_SIZEOF];
141 : : };
142 : :
143 : : /* struct aa_policydb - match engine for a policy
144 : : * dfa: dfa pattern match
145 : : * start: set of start states for the different classes of data
146 : : */
147 : : struct aa_policydb {
148 : : /* Generic policy DFA specific rule types will be subsections of it */
149 : : struct aa_dfa *dfa;
150 : : unsigned int start[AA_CLASS_LAST + 1];
151 : :
152 : : };
153 : :
154 : : struct aa_replacedby {
155 : : struct kref count;
156 : : struct aa_profile __rcu *profile;
157 : : };
158 : :
159 : :
160 : : /* struct aa_profile - basic confinement data
161 : : * @base - base components of the profile (name, refcount, lists, lock ...)
162 : : * @count: reference count of the obj
163 : : * @rcu: rcu head used when removing from @list
164 : : * @parent: parent of profile
165 : : * @ns: namespace the profile is in
166 : : * @replacedby: is set to the profile that replaced this profile
167 : : * @rename: optional profile name that this profile renamed
168 : : * @attach: human readable attachment string
169 : : * @xmatch: optional extended matching for unconfined executables names
170 : : * @xmatch_len: xmatch prefix len, used to determine xmatch priority
171 : : * @audit: the auditing mode of the profile
172 : : * @mode: the enforcement mode of the profile
173 : : * @flags: flags controlling profile behavior
174 : : * @path_flags: flags controlling path generation behavior
175 : : * @size: the memory consumed by this profiles rules
176 : : * @policy: general match rules governing policy
177 : : * @file: The set of rules governing basic file access and domain transitions
178 : : * @caps: capabilities for the profile
179 : : * @rlimits: rlimits for the profile
180 : : *
181 : : * @dents: dentries for the profiles file entries in apparmorfs
182 : : * @dirname: name of the profile dir in apparmorfs
183 : : *
184 : : * The AppArmor profile contains the basic confinement data. Each profile
185 : : * has a name, and exists in a namespace. The @name and @exec_match are
186 : : * used to determine profile attachment against unconfined tasks. All other
187 : : * attachments are determined by profile X transition rules.
188 : : *
189 : : * The @replacedby struct is write protected by the profile lock.
190 : : *
191 : : * Profiles have a hierarchy where hats and children profiles keep
192 : : * a reference to their parent.
193 : : *
194 : : * Profile names can not begin with a : and can not contain the \0
195 : : * character. If a profile name begins with / it will be considered when
196 : : * determining profile attachment on "unconfined" tasks.
197 : : */
198 : : struct aa_profile {
199 : : struct aa_policy base;
200 : : struct kref count;
201 : : struct rcu_head rcu;
202 : : struct aa_profile __rcu *parent;
203 : :
204 : : struct aa_namespace *ns;
205 : : struct aa_replacedby *replacedby;
206 : : const char *rename;
207 : :
208 : : const char *attach;
209 : : struct aa_dfa *xmatch;
210 : : int xmatch_len;
211 : : enum audit_mode audit;
212 : : long mode;
213 : : long flags;
214 : : u32 path_flags;
215 : : int size;
216 : :
217 : : struct aa_policydb policy;
218 : : struct aa_file_rules file;
219 : : struct aa_caps caps;
220 : : struct aa_rlimit rlimits;
221 : :
222 : : unsigned char *hash;
223 : : char *dirname;
224 : : struct dentry *dents[AAFS_PROF_SIZEOF];
225 : : };
226 : :
227 : : extern struct aa_namespace *root_ns;
228 : : extern enum profile_mode aa_g_profile_mode;
229 : :
230 : : void aa_add_profile(struct aa_policy *common, struct aa_profile *profile);
231 : :
232 : : bool aa_ns_visible(struct aa_namespace *curr, struct aa_namespace *view);
233 : : const char *aa_ns_name(struct aa_namespace *parent, struct aa_namespace *child);
234 : : int aa_alloc_root_ns(void);
235 : : void aa_free_root_ns(void);
236 : : void aa_free_namespace_kref(struct kref *kref);
237 : :
238 : : struct aa_namespace *aa_find_namespace(struct aa_namespace *root,
239 : : const char *name);
240 : :
241 : :
242 : : void aa_free_replacedby_kref(struct kref *kref);
243 : : struct aa_profile *aa_alloc_profile(const char *name);
244 : : struct aa_profile *aa_new_null_profile(struct aa_profile *parent, int hat);
245 : : void aa_free_profile(struct aa_profile *profile);
246 : : void aa_free_profile_kref(struct kref *kref);
247 : : struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name);
248 : : struct aa_profile *aa_lookup_profile(struct aa_namespace *ns, const char *name);
249 : : struct aa_profile *aa_match_profile(struct aa_namespace *ns, const char *name);
250 : :
251 : : ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace);
252 : : ssize_t aa_remove_profiles(char *name, size_t size);
253 : :
254 : : #define PROF_ADD 1
255 : : #define PROF_REPLACE 0
256 : :
257 : : #define unconfined(X) ((X)->mode == APPARMOR_UNCONFINED)
258 : :
259 : :
260 : : static inline struct aa_profile *aa_deref_parent(struct aa_profile *p)
261 : : {
262 : : return rcu_dereference_protected(p->parent,
263 : : mutex_is_locked(&p->ns->lock));
264 : : }
265 : :
266 : : /**
267 : : * aa_get_profile - increment refcount on profile @p
268 : : * @p: profile (MAYBE NULL)
269 : : *
270 : : * Returns: pointer to @p if @p is NULL will return NULL
271 : : * Requires: @p must be held with valid refcount when called
272 : : */
273 : : static inline struct aa_profile *aa_get_profile(struct aa_profile *p)
274 : : {
275 [ # # ][ # # ]: 2809119 : if (p)
[ + - ][ # # ]
[ + - ][ + + ]
[ - + ][ - + ]
[ # # ][ # # ]
[ + ][ # # ]
[ # # ][ # # ]
[ # # ][ - + ]
[ # # # #
# # # #
# ][ # # ]
[ # # # #
# # # # #
# # # # #
# # # # ]
[ # # # #
# # ][ # #
# # # # #
# ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ]
276 : : kref_get(&(p->count));
277 : :
278 : : return p;
279 : : }
280 : :
281 : : /**
282 : : * aa_get_profile_not0 - increment refcount on profile @p found via lookup
283 : : * @p: profile (MAYBE NULL)
284 : : *
285 : : * Returns: pointer to @p if @p is NULL will return NULL
286 : : * Requires: @p must be held with valid refcount when called
287 : : */
288 : : static inline struct aa_profile *aa_get_profile_not0(struct aa_profile *p)
289 : : {
290 [ # # ][ # # ]: 0 : if (p && kref_get_not0(&p->count))
291 : : return p;
292 : :
293 : : return NULL;
294 : : }
295 : :
296 : : /**
297 : : * aa_get_profile_rcu - increment a refcount profile that can be replaced
298 : : * @p: pointer to profile that can be replaced (NOT NULL)
299 : : *
300 : : * Returns: pointer to a refcounted profile.
301 : : * else NULL if no profile
302 : : */
303 : : static inline struct aa_profile *aa_get_profile_rcu(struct aa_profile __rcu **p)
304 : : {
305 : : struct aa_profile *c;
306 : :
307 : : rcu_read_lock();
308 : : do {
309 : 0 : c = rcu_dereference(*p);
310 [ # # ][ # # ]: 5304 : } while (c && !kref_get_not0(&c->count));
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # - ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
311 : : rcu_read_unlock();
312 : :
313 : : return c;
314 : : }
315 : :
316 : : /**
317 : : * aa_get_newest_profile - find the newest version of @profile
318 : : * @profile: the profile to check for newer versions of
319 : : *
320 : : * Returns: refcounted newest version of @profile taking into account
321 : : * replacement, renames and removals
322 : : * return @profile.
323 : : */
324 : : static inline struct aa_profile *aa_get_newest_profile(struct aa_profile *p)
325 : : {
326 [ + + ][ + - ]: 27248 : if (!p)
[ # # ][ # # ]
[ # # ][ # # ]
327 : : return NULL;
328 : :
329 [ - + ][ - + ]: 27232 : if (PROFILE_INVALID(p))
[ # # ][ # # ]
[ # # ][ # # ]
330 : 0 : return aa_get_profile_rcu(&p->replacedby->profile);
331 : :
332 : : return aa_get_profile(p);
333 : : }
334 : :
335 : : /**
336 : : * aa_put_profile - decrement refcount on profile @p
337 : : * @p: profile (MAYBE NULL)
338 : : */
339 : : static inline void aa_put_profile(struct aa_profile *p)
340 : : {
341 [ # # ][ # # ]: 2778816 : if (p)
[ # # ][ # # ]
[ # # ][ + +
# # # # ]
[ # # # #
# # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ + - ]
[ # # # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ + + ]
[ - + ][ - + ]
[ # # ][ # # ]
[ # # # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # # # ]
[ # # ]
342 : 1446983 : kref_put(&p->count, aa_free_profile_kref);
343 : : }
344 : :
345 : : static inline struct aa_replacedby *aa_get_replacedby(struct aa_replacedby *p)
346 : : {
347 [ # # ][ # # ]: 0 : if (p)
348 : : kref_get(&(p->count));
349 : :
350 : : return p;
351 : : }
352 : :
353 : : static inline void aa_put_replacedby(struct aa_replacedby *p)
354 : : {
355 [ # # ]: 0 : if (p)
[ # # # # ]
[ # # ]
356 : 0 : kref_put(&p->count, aa_free_replacedby_kref);
357 : : }
358 : :
359 : : /* requires profile list write lock held */
360 : : static inline void __aa_update_replacedby(struct aa_profile *orig,
361 : : struct aa_profile *new)
362 : : {
363 : : struct aa_profile *tmp;
364 : 0 : tmp = rcu_dereference_protected(orig->replacedby->profile,
365 : : mutex_is_locked(&orig->ns->lock));
366 : 0 : rcu_assign_pointer(orig->replacedby->profile, aa_get_profile(new));
367 : 0 : orig->flags |= PFLAG_INVALID;
368 : : aa_put_profile(tmp);
369 : : }
370 : :
371 : : /**
372 : : * aa_get_namespace - increment references count on @ns
373 : : * @ns: namespace to increment reference count of (MAYBE NULL)
374 : : *
375 : : * Returns: pointer to @ns, if @ns is NULL returns NULL
376 : : * Requires: @ns must be held with valid refcount when called
377 : : */
378 : : static inline struct aa_namespace *aa_get_namespace(struct aa_namespace *ns)
379 : : {
380 [ # # ][ # # ]: 0 : if (ns)
[ # # ]
[ # # # # ]
[ # # # #
# # ]
381 : 0 : aa_get_profile(ns->unconfined);
382 : :
383 : : return ns;
384 : : }
385 : :
386 : : /**
387 : : * aa_put_namespace - decrement refcount on @ns
388 : : * @ns: namespace to put reference of
389 : : *
390 : : * Decrement reference count of @ns and if no longer in use free it
391 : : */
392 : : static inline void aa_put_namespace(struct aa_namespace *ns)
393 : : {
394 [ # # ]: 0 : if (ns)
[ # # # # ]
[ # # ][ # # ]
[ # # # #
# # # # ]
395 : 0 : aa_put_profile(ns->unconfined);
396 : : }
397 : :
398 : : static inline int AUDIT_MODE(struct aa_profile *profile)
399 : : {
400 [ # # ][ # # ]: 0 : if (aa_g_audit != AUDIT_NORMAL)
[ # # ]
401 : 0 : return aa_g_audit;
402 : :
403 : 0 : return profile->audit;
404 : : }
405 : :
406 : : bool aa_may_manage_policy(int op);
407 : :
408 : : #endif /* __AA_POLICY_H */
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