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/rhashtable.h>
22 #include <linux/sched.h>
23 #include <linux/slab.h>
24 #include <linux/socket.h>
25
26 #include "apparmor.h"
27 #include "audit.h"
28 #include "capability.h"
29 #include "domain.h"
30 #include "file.h"
31 #include "lib.h"
32 #include "label.h"
33 #include "perms.h"
34 #include "resource.h"
35
36
37 struct aa_ns;
38
39 extern int unprivileged_userns_apparmor_policy;
40
41 extern const char *const aa_profile_mode_names[];
42 #define APPARMOR_MODE_NAMES_MAX_INDEX 4
43
44 #define PROFILE_MODE(_profile, _mode) \
45 ((aa_g_profile_mode == (_mode)) || \
46 ((_profile)->mode == (_mode)))
47
48 #define COMPLAIN_MODE(_profile) PROFILE_MODE((_profile), APPARMOR_COMPLAIN)
49
50 #define KILL_MODE(_profile) PROFILE_MODE((_profile), APPARMOR_KILL)
51
52 #define PROFILE_IS_HAT(_profile) ((_profile)->label.flags & FLAG_HAT)
53
54 #define profile_is_stale(_profile) (label_is_stale(&(_profile)->label))
55
56 #define on_list_rcu(X) (!list_empty(X) && (X)->prev != LIST_POISON2)
57
58 /*
59 * FIXME: currently need a clean way to replace and remove profiles as a
60 * set. It should be done at the namespace level.
61 * Either, with a set of profiles loaded at the namespace level or via
62 * a mark and remove marked interface.
63 */
64 enum profile_mode {
65 APPARMOR_ENFORCE, /* enforce access rules */
66 APPARMOR_COMPLAIN, /* allow and log access violations */
67 APPARMOR_KILL, /* kill task on access violation */
68 APPARMOR_UNCONFINED, /* profile set to unconfined */
69 };
70
71
72 /* struct aa_policydb - match engine for a policy
73 * dfa: dfa pattern match
74 * start: set of start states for the different classes of data
75 */
76 struct aa_policydb {
77 /* Generic policy DFA specific rule types will be subsections of it */
78 struct aa_dfa *dfa;
79 unsigned int start[AA_CLASS_LAST + 1];
80
81 };
82
83 /* struct aa_data - generic data structure
84 * key: name for retrieving this data
85 * size: size of data in bytes
86 * data: binary data
87 * head: reserved for rhashtable
88 */
89 struct aa_data {
90 char *key;
91 u32 size;
92 char *data;
93 struct rhash_head head;
94 };
95
96
97 /* struct aa_profile - basic confinement data
98 * @base - base components of the profile (name, refcount, lists, lock ...)
99 * @label - label this profile is an extension of
100 * @parent: parent of profile
101 * @ns: namespace the profile is in
102 * @rename: optional profile name that this profile renamed
103 * @attach: human readable attachment string
104 * @xmatch: optional extended matching for unconfined executables names
105 * @xmatch_len: xmatch prefix len, used to determine xmatch priority
106 * @audit: the auditing mode of the profile
107 * @mode: the enforcement mode of the profile
108 * @path_flags: flags controlling path generation behavior
109 * @disconnected: what to prepend if attach_disconnected is specified
110 * @size: the memory consumed by this profiles rules
111 * @policy: general match rules governing policy
112 * @file: The set of rules governing basic file access and domain transitions
113 * @caps: capabilities for the profile
114 * @rlimits: rlimits for the profile
115 *
116 * @dents: dentries for the profiles file entries in apparmorfs
117 * @dirname: name of the profile dir in apparmorfs
118 * @data: hashtable for free-form policy aa_data
119 *
120 * The AppArmor profile contains the basic confinement data. Each profile
121 * has a name, and exists in a namespace. The @name and @exec_match are
122 * used to determine profile attachment against unconfined tasks. All other
123 * attachments are determined by profile X transition rules.
124 *
125 * Profiles have a hierarchy where hats and children profiles keep
126 * a reference to their parent.
127 *
128 * Profile names can not begin with a : and can not contain the \0
129 * character. If a profile name begins with / it will be considered when
130 * determining profile attachment on "unconfined" tasks.
131 */
132 struct aa_profile {
133 struct aa_policy base;
134 struct aa_profile __rcu *parent;
135
136 struct aa_ns *ns;
137 const char *rename;
138
139 const char *attach;
140 struct aa_dfa *xmatch;
141 int xmatch_len;
142 enum audit_mode audit;
143 long mode;
144 u32 path_flags;
145 const char *disconnected;
146 int size;
147
148 struct aa_policydb policy;
149 struct aa_file_rules file;
150 struct aa_caps caps;
151 struct aa_rlimit rlimits;
152
153 struct aa_loaddata *rawdata;
154 unsigned char *hash;
155 char *dirname;
156 struct dentry *dents[AAFS_PROF_SIZEOF];
157 struct rhashtable *data;
158 struct aa_label label;
159 };
160
161 extern enum profile_mode aa_g_profile_mode;
162
163 #define AA_MAY_LOAD_POLICY AA_MAY_APPEND
164 #define AA_MAY_REPLACE_POLICY AA_MAY_WRITE
165 #define AA_MAY_REMOVE_POLICY AA_MAY_DELETE
166
167 #define profiles_ns(P) ((P)->ns)
168 #define name_is_shared(A, B) ((A)->hname && (A)->hname == (B)->hname)
169
170 void aa_add_profile(struct aa_policy *common, struct aa_profile *profile);
171
172
173 void aa_free_proxy_kref(struct kref *kref);
174 struct aa_profile *aa_alloc_profile(const char *name, struct aa_proxy *proxy,
175 gfp_t gfp);
176 struct aa_profile *aa_new_null_profile(struct aa_profile *parent, bool hat,
177 const char *base, gfp_t gfp);
178 void aa_free_profile(struct aa_profile *profile);
179 void aa_free_profile_kref(struct kref *kref);
180 struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name);
181 struct aa_profile *aa_lookupn_profile(struct aa_ns *ns, const char *hname,
182 size_t n);
183 struct aa_profile *aa_lookup_profile(struct aa_ns *ns, const char *name);
184 struct aa_profile *aa_fqlookupn_profile(struct aa_label *base,
185 const char *fqname, size_t n);
186 struct aa_profile *aa_match_profile(struct aa_ns *ns, const char *name);
187
188 ssize_t aa_replace_profiles(struct aa_ns *view, struct aa_label *label,
189 u32 mask, struct aa_loaddata *udata);
190 ssize_t aa_remove_profiles(struct aa_ns *view, struct aa_label *label,
191 char *name, size_t size);
192 void __aa_profile_list_release(struct list_head *head);
193
194 #define PROF_ADD 1
195 #define PROF_REPLACE 0
196
197 #define profile_unconfined(X) ((X)->mode == APPARMOR_UNCONFINED)
198
199 /**
200 * aa_get_newest_profile - simple wrapper fn to wrap the label version
201 * @p: profile (NOT NULL)
202 *
203 * Returns refcount to newest version of the profile (maybe @p)
204 *
205 * Requires: @p must be held with a valid refcount
206 */
aa_get_newest_profile(struct aa_profile * p)207 static inline struct aa_profile *aa_get_newest_profile(struct aa_profile *p)
208 {
209 return labels_profile(aa_get_newest_label(&p->label));
210 }
211
212 #define PROFILE_MEDIATES(P, T) ((P)->policy.start[(T)])
213 /* safe version of POLICY_MEDIATES for full range input */
PROFILE_MEDIATES_SAFE(struct aa_profile * profile,unsigned char class)214 static inline unsigned int PROFILE_MEDIATES_SAFE(struct aa_profile *profile,
215 unsigned char class)
216 {
217 if (profile->policy.dfa)
218 return aa_dfa_match_len(profile->policy.dfa,
219 profile->policy.start[0], &class, 1);
220 return 0;
221 }
222
223 /**
224 * aa_get_profile - increment refcount on profile @p
225 * @p: profile (MAYBE NULL)
226 *
227 * Returns: pointer to @p if @p is NULL will return NULL
228 * Requires: @p must be held with valid refcount when called
229 */
aa_get_profile(struct aa_profile * p)230 static inline struct aa_profile *aa_get_profile(struct aa_profile *p)
231 {
232 if (p)
233 kref_get(&(p->label.count));
234
235 return p;
236 }
237
238 /**
239 * aa_get_profile_not0 - increment refcount on profile @p found via lookup
240 * @p: profile (MAYBE NULL)
241 *
242 * Returns: pointer to @p if @p is NULL will return NULL
243 * Requires: @p must be held with valid refcount when called
244 */
aa_get_profile_not0(struct aa_profile * p)245 static inline struct aa_profile *aa_get_profile_not0(struct aa_profile *p)
246 {
247 if (p && kref_get_unless_zero(&p->label.count))
248 return p;
249
250 return NULL;
251 }
252
253 /**
254 * aa_get_profile_rcu - increment a refcount profile that can be replaced
255 * @p: pointer to profile that can be replaced (NOT NULL)
256 *
257 * Returns: pointer to a refcounted profile.
258 * else NULL if no profile
259 */
aa_get_profile_rcu(struct aa_profile __rcu ** p)260 static inline struct aa_profile *aa_get_profile_rcu(struct aa_profile __rcu **p)
261 {
262 struct aa_profile *c;
263
264 rcu_read_lock();
265 do {
266 c = rcu_dereference(*p);
267 } while (c && !kref_get_unless_zero(&c->label.count));
268 rcu_read_unlock();
269
270 return c;
271 }
272
273 /**
274 * aa_put_profile - decrement refcount on profile @p
275 * @p: profile (MAYBE NULL)
276 */
aa_put_profile(struct aa_profile * p)277 static inline void aa_put_profile(struct aa_profile *p)
278 {
279 if (p)
280 kref_put(&p->label.count, aa_label_kref);
281 }
282
AUDIT_MODE(struct aa_profile * profile)283 static inline int AUDIT_MODE(struct aa_profile *profile)
284 {
285 if (aa_g_audit != AUDIT_NORMAL)
286 return aa_g_audit;
287
288 return profile->audit;
289 }
290
291 bool policy_view_capable(struct aa_ns *ns);
292 bool policy_admin_capable(struct aa_ns *ns);
293 int aa_may_manage_policy(struct aa_label *label, struct aa_ns *ns,
294 u32 mask);
295
296 #endif /* __AA_POLICY_H */
297