1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * AppArmor security module
4 *
5 * This file contains AppArmor policy definitions.
6 *
7 * Copyright (C) 1998-2008 Novell/SUSE
8 * Copyright 2009-2010 Canonical Ltd.
9 */
10
11 #ifndef __AA_POLICY_H
12 #define __AA_POLICY_H
13
14 #include <linux/capability.h>
15 #include <linux/cred.h>
16 #include <linux/kref.h>
17 #include <linux/rhashtable.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/socket.h>
21
22 #include "apparmor.h"
23 #include "audit.h"
24 #include "capability.h"
25 #include "domain.h"
26 #include "file.h"
27 #include "lib.h"
28 #include "label.h"
29 #include "net.h"
30 #include "perms.h"
31 #include "resource.h"
32
33
34 struct aa_ns;
35
36 extern int unprivileged_userns_apparmor_policy;
37
38 extern const char *const aa_profile_mode_names[];
39 #define APPARMOR_MODE_NAMES_MAX_INDEX 4
40
41 #define PROFILE_MODE(_profile, _mode) \
42 ((aa_g_profile_mode == (_mode)) || \
43 ((_profile)->mode == (_mode)))
44
45 #define COMPLAIN_MODE(_profile) PROFILE_MODE((_profile), APPARMOR_COMPLAIN)
46
47 #define USER_MODE(_profile) PROFILE_MODE((_profile), APPARMOR_USER)
48
49 #define KILL_MODE(_profile) PROFILE_MODE((_profile), APPARMOR_KILL)
50
51 #define PROFILE_IS_HAT(_profile) ((_profile)->label.flags & FLAG_HAT)
52
53 #define CHECK_DEBUG1(_profile) ((_profile)->label.flags & FLAG_DEBUG1)
54
55 #define CHECK_DEBUG2(_profile) ((_profile)->label.flags & FLAG_DEBUG2)
56
57 #define profile_is_stale(_profile) (label_is_stale(&(_profile)->label))
58
59 #define on_list_rcu(X) (!list_empty(X) && (X)->prev != LIST_POISON2)
60
61 /*
62 * FIXME: currently need a clean way to replace and remove profiles as a
63 * set. It should be done at the namespace level.
64 * Either, with a set of profiles loaded at the namespace level or via
65 * a mark and remove marked interface.
66 */
67 enum profile_mode {
68 APPARMOR_ENFORCE, /* enforce access rules */
69 APPARMOR_COMPLAIN, /* allow and log access violations */
70 APPARMOR_KILL, /* kill task on access violation */
71 APPARMOR_UNCONFINED, /* profile set to unconfined */
72 APPARMOR_USER, /* modified complain mode to userspace */
73 };
74
75
76 /* struct aa_policydb - match engine for a policy
77 * dfa: dfa pattern match
78 * perms: table of permissions
79 * strs: table of strings, index by x
80 * start: set of start states for the different classes of data
81 */
82 struct aa_policydb {
83 struct aa_dfa *dfa;
84 struct {
85 struct aa_perms *perms;
86 u32 size;
87 };
88 struct aa_str_table trans;
89 aa_state_t start[AA_CLASS_LAST + 1];
90 };
91
aa_destroy_policydb(struct aa_policydb * policy)92 static inline void aa_destroy_policydb(struct aa_policydb *policy)
93 {
94 aa_put_dfa(policy->dfa);
95 if (policy->perms)
96 kvfree(policy->perms);
97 aa_free_str_table(&policy->trans);
98
99 }
100
aa_lookup_perms(struct aa_policydb * policy,aa_state_t state)101 static inline struct aa_perms *aa_lookup_perms(struct aa_policydb *policy,
102 aa_state_t state)
103 {
104 unsigned int index = ACCEPT_TABLE(policy->dfa)[state];
105
106 if (!(policy->perms))
107 return &default_perms;
108
109 return &(policy->perms[index]);
110 }
111
112
113 /* struct aa_data - generic data structure
114 * key: name for retrieving this data
115 * size: size of data in bytes
116 * data: binary data
117 * head: reserved for rhashtable
118 */
119 struct aa_data {
120 char *key;
121 u32 size;
122 char *data;
123 struct rhash_head head;
124 };
125
126 /* struct aa_ruleset - data covering mediation rules
127 * @list: list the rule is on
128 * @size: the memory consumed by this ruleset
129 * @policy: general match rules governing policy
130 * @file: The set of rules governing basic file access and domain transitions
131 * @caps: capabilities for the profile
132 * @rlimits: rlimits for the profile
133 * @secmark_count: number of secmark entries
134 * @secmark: secmark label match info
135 */
136 struct aa_ruleset {
137 struct list_head list;
138
139 int size;
140
141 /* TODO: merge policy and file */
142 struct aa_policydb policy;
143 struct aa_policydb file;
144 struct aa_caps caps;
145
146 struct aa_rlimit rlimits;
147
148 int secmark_count;
149 struct aa_secmark *secmark;
150 };
151
152 /* struct aa_attachment - data and rules for a profiles attachment
153 * @list:
154 * @xmatch_str: human readable attachment string
155 * @xmatch: optional extended matching for unconfined executables names
156 * @xmatch_len: xmatch prefix len, used to determine xmatch priority
157 * @xattr_count: number of xattrs in table
158 * @xattrs: table of xattrs
159 */
160 struct aa_attachment {
161 const char *xmatch_str;
162 struct aa_policydb xmatch;
163 unsigned int xmatch_len;
164 int xattr_count;
165 char **xattrs;
166 };
167
168 /* struct aa_profile - basic confinement data
169 * @base - base components of the profile (name, refcount, lists, lock ...)
170 * @label - label this profile is an extension of
171 * @parent: parent of profile
172 * @ns: namespace the profile is in
173 * @rename: optional profile name that this profile renamed
174 *
175 * @audit: the auditing mode of the profile
176 * @mode: the enforcement mode of the profile
177 * @path_flags: flags controlling path generation behavior
178 * @disconnected: what to prepend if attach_disconnected is specified
179 * @attach: attachment rules for the profile
180 * @rules: rules to be enforced
181 *
182 * @dents: dentries for the profiles file entries in apparmorfs
183 * @dirname: name of the profile dir in apparmorfs
184 * @data: hashtable for free-form policy aa_data
185 *
186 * The AppArmor profile contains the basic confinement data. Each profile
187 * has a name, and exists in a namespace. The @name and @exec_match are
188 * used to determine profile attachment against unconfined tasks. All other
189 * attachments are determined by profile X transition rules.
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 aa_profile __rcu *parent;
201
202 struct aa_ns *ns;
203 const char *rename;
204
205 enum audit_mode audit;
206 long mode;
207 u32 path_flags;
208 const char *disconnected;
209
210 struct aa_attachment attach;
211 struct list_head rules;
212
213 struct aa_loaddata *rawdata;
214 unsigned char *hash;
215 char *dirname;
216 struct dentry *dents[AAFS_PROF_SIZEOF];
217 struct rhashtable *data;
218 struct aa_label label;
219 };
220
221 extern enum profile_mode aa_g_profile_mode;
222
223 #define AA_MAY_LOAD_POLICY AA_MAY_APPEND
224 #define AA_MAY_REPLACE_POLICY AA_MAY_WRITE
225 #define AA_MAY_REMOVE_POLICY AA_MAY_DELETE
226
227 #define profiles_ns(P) ((P)->ns)
228 #define name_is_shared(A, B) ((A)->hname && (A)->hname == (B)->hname)
229
230 void aa_add_profile(struct aa_policy *common, struct aa_profile *profile);
231
232
233 void aa_free_proxy_kref(struct kref *kref);
234 struct aa_ruleset *aa_alloc_ruleset(gfp_t gfp);
235 struct aa_profile *aa_alloc_profile(const char *name, struct aa_proxy *proxy,
236 gfp_t gfp);
237 struct aa_profile *aa_alloc_null(struct aa_profile *parent, const char *name,
238 gfp_t gfp);
239 struct aa_profile *aa_new_learning_profile(struct aa_profile *parent, bool hat,
240 const char *base, gfp_t gfp);
241 void aa_free_profile(struct aa_profile *profile);
242 void aa_free_profile_kref(struct kref *kref);
243 struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name);
244 struct aa_profile *aa_lookupn_profile(struct aa_ns *ns, const char *hname,
245 size_t n);
246 struct aa_profile *aa_lookup_profile(struct aa_ns *ns, const char *name);
247 struct aa_profile *aa_fqlookupn_profile(struct aa_label *base,
248 const char *fqname, size_t n);
249 struct aa_profile *aa_match_profile(struct aa_ns *ns, const char *name);
250
251 ssize_t aa_replace_profiles(struct aa_ns *view, struct aa_label *label,
252 u32 mask, struct aa_loaddata *udata);
253 ssize_t aa_remove_profiles(struct aa_ns *view, struct aa_label *label,
254 char *name, size_t size);
255 void __aa_profile_list_release(struct list_head *head);
256
257 #define PROF_ADD 1
258 #define PROF_REPLACE 0
259
260 #define profile_unconfined(X) ((X)->mode == APPARMOR_UNCONFINED)
261
262 /**
263 * aa_get_newest_profile - simple wrapper fn to wrap the label version
264 * @p: profile (NOT NULL)
265 *
266 * Returns refcount to newest version of the profile (maybe @p)
267 *
268 * Requires: @p must be held with a valid refcount
269 */
aa_get_newest_profile(struct aa_profile * p)270 static inline struct aa_profile *aa_get_newest_profile(struct aa_profile *p)
271 {
272 return labels_profile(aa_get_newest_label(&p->label));
273 }
274
RULE_MEDIATES(struct aa_ruleset * rules,unsigned char class)275 static inline aa_state_t RULE_MEDIATES(struct aa_ruleset *rules,
276 unsigned char class)
277 {
278 if (class <= AA_CLASS_LAST)
279 return rules->policy.start[class];
280 else
281 return aa_dfa_match_len(rules->policy.dfa,
282 rules->policy.start[0], &class, 1);
283 }
284
RULE_MEDIATES_AF(struct aa_ruleset * rules,u16 AF)285 static inline aa_state_t RULE_MEDIATES_AF(struct aa_ruleset *rules, u16 AF)
286 {
287 aa_state_t state = RULE_MEDIATES(rules, AA_CLASS_NET);
288 __be16 be_af = cpu_to_be16(AF);
289
290 if (!state)
291 return DFA_NOMATCH;
292 return aa_dfa_match_len(rules->policy.dfa, state, (char *) &be_af, 2);
293 }
294
ANY_RULE_MEDIATES(struct list_head * head,unsigned char class)295 static inline aa_state_t ANY_RULE_MEDIATES(struct list_head *head,
296 unsigned char class)
297 {
298 struct aa_ruleset *rule;
299
300 /* TODO: change to list walk */
301 rule = list_first_entry(head, typeof(*rule), list);
302 return RULE_MEDIATES(rule, class);
303 }
304
305 /**
306 * aa_get_profile - increment refcount on profile @p
307 * @p: profile (MAYBE NULL)
308 *
309 * Returns: pointer to @p if @p is NULL will return NULL
310 * Requires: @p must be held with valid refcount when called
311 */
aa_get_profile(struct aa_profile * p)312 static inline struct aa_profile *aa_get_profile(struct aa_profile *p)
313 {
314 if (p)
315 kref_get(&(p->label.count));
316
317 return p;
318 }
319
320 /**
321 * aa_get_profile_not0 - increment refcount on profile @p found via lookup
322 * @p: profile (MAYBE NULL)
323 *
324 * Returns: pointer to @p if @p is NULL will return NULL
325 * Requires: @p must be held with valid refcount when called
326 */
aa_get_profile_not0(struct aa_profile * p)327 static inline struct aa_profile *aa_get_profile_not0(struct aa_profile *p)
328 {
329 if (p && kref_get_unless_zero(&p->label.count))
330 return p;
331
332 return NULL;
333 }
334
335 /**
336 * aa_get_profile_rcu - increment a refcount profile that can be replaced
337 * @p: pointer to profile that can be replaced (NOT NULL)
338 *
339 * Returns: pointer to a refcounted profile.
340 * else NULL if no profile
341 */
aa_get_profile_rcu(struct aa_profile __rcu ** p)342 static inline struct aa_profile *aa_get_profile_rcu(struct aa_profile __rcu **p)
343 {
344 struct aa_profile *c;
345
346 rcu_read_lock();
347 do {
348 c = rcu_dereference(*p);
349 } while (c && !kref_get_unless_zero(&c->label.count));
350 rcu_read_unlock();
351
352 return c;
353 }
354
355 /**
356 * aa_put_profile - decrement refcount on profile @p
357 * @p: profile (MAYBE NULL)
358 */
aa_put_profile(struct aa_profile * p)359 static inline void aa_put_profile(struct aa_profile *p)
360 {
361 if (p)
362 kref_put(&p->label.count, aa_label_kref);
363 }
364
AUDIT_MODE(struct aa_profile * profile)365 static inline int AUDIT_MODE(struct aa_profile *profile)
366 {
367 if (aa_g_audit != AUDIT_NORMAL)
368 return aa_g_audit;
369
370 return profile->audit;
371 }
372
373 bool aa_policy_view_capable(const struct cred *subj_cred,
374 struct aa_label *label, struct aa_ns *ns);
375 bool aa_policy_admin_capable(const struct cred *subj_cred,
376 struct aa_label *label, struct aa_ns *ns);
377 int aa_may_manage_policy(const struct cred *subj_cred,
378 struct aa_label *label, struct aa_ns *ns,
379 u32 mask);
380 bool aa_current_policy_view_capable(struct aa_ns *ns);
381 bool aa_current_policy_admin_capable(struct aa_ns *ns);
382
383 #endif /* __AA_POLICY_H */
384