xref: /linux/security/apparmor/include/policy.h (revision 73f488cd903938e78979d50e081a0314ad142351)
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 
152 	int xattr_count;
153 	char **xattrs;
154 
155 	struct aa_rlimit rlimits;
156 
157 	struct aa_loaddata *rawdata;
158 	unsigned char *hash;
159 	char *dirname;
160 	struct dentry *dents[AAFS_PROF_SIZEOF];
161 	struct rhashtable *data;
162 	struct aa_label label;
163 };
164 
165 extern enum profile_mode aa_g_profile_mode;
166 
167 #define AA_MAY_LOAD_POLICY	AA_MAY_APPEND
168 #define AA_MAY_REPLACE_POLICY	AA_MAY_WRITE
169 #define AA_MAY_REMOVE_POLICY	AA_MAY_DELETE
170 
171 #define profiles_ns(P) ((P)->ns)
172 #define name_is_shared(A, B) ((A)->hname && (A)->hname == (B)->hname)
173 
174 void aa_add_profile(struct aa_policy *common, struct aa_profile *profile);
175 
176 
177 void aa_free_proxy_kref(struct kref *kref);
178 struct aa_profile *aa_alloc_profile(const char *name, struct aa_proxy *proxy,
179 				    gfp_t gfp);
180 struct aa_profile *aa_new_null_profile(struct aa_profile *parent, bool hat,
181 				       const char *base, gfp_t gfp);
182 void aa_free_profile(struct aa_profile *profile);
183 void aa_free_profile_kref(struct kref *kref);
184 struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name);
185 struct aa_profile *aa_lookupn_profile(struct aa_ns *ns, const char *hname,
186 				      size_t n);
187 struct aa_profile *aa_lookup_profile(struct aa_ns *ns, const char *name);
188 struct aa_profile *aa_fqlookupn_profile(struct aa_label *base,
189 					const char *fqname, size_t n);
190 struct aa_profile *aa_match_profile(struct aa_ns *ns, const char *name);
191 
192 ssize_t aa_replace_profiles(struct aa_ns *view, struct aa_label *label,
193 			    u32 mask, struct aa_loaddata *udata);
194 ssize_t aa_remove_profiles(struct aa_ns *view, struct aa_label *label,
195 			   char *name, size_t size);
196 void __aa_profile_list_release(struct list_head *head);
197 
198 #define PROF_ADD 1
199 #define PROF_REPLACE 0
200 
201 #define profile_unconfined(X) ((X)->mode == APPARMOR_UNCONFINED)
202 
203 /**
204  * aa_get_newest_profile - simple wrapper fn to wrap the label version
205  * @p: profile (NOT NULL)
206  *
207  * Returns refcount to newest version of the profile (maybe @p)
208  *
209  * Requires: @p must be held with a valid refcount
210  */
211 static inline struct aa_profile *aa_get_newest_profile(struct aa_profile *p)
212 {
213 	return labels_profile(aa_get_newest_label(&p->label));
214 }
215 
216 #define PROFILE_MEDIATES(P, T)  ((P)->policy.start[(T)])
217 /* safe version of POLICY_MEDIATES for full range input */
218 static inline unsigned int PROFILE_MEDIATES_SAFE(struct aa_profile *profile,
219 						 unsigned char class)
220 {
221 	if (profile->policy.dfa)
222 		return aa_dfa_match_len(profile->policy.dfa,
223 					profile->policy.start[0], &class, 1);
224 	return 0;
225 }
226 
227 /**
228  * aa_get_profile - increment refcount on profile @p
229  * @p: profile  (MAYBE NULL)
230  *
231  * Returns: pointer to @p if @p is NULL will return NULL
232  * Requires: @p must be held with valid refcount when called
233  */
234 static inline struct aa_profile *aa_get_profile(struct aa_profile *p)
235 {
236 	if (p)
237 		kref_get(&(p->label.count));
238 
239 	return p;
240 }
241 
242 /**
243  * aa_get_profile_not0 - increment refcount on profile @p found via lookup
244  * @p: profile  (MAYBE NULL)
245  *
246  * Returns: pointer to @p if @p is NULL will return NULL
247  * Requires: @p must be held with valid refcount when called
248  */
249 static inline struct aa_profile *aa_get_profile_not0(struct aa_profile *p)
250 {
251 	if (p && kref_get_unless_zero(&p->label.count))
252 		return p;
253 
254 	return NULL;
255 }
256 
257 /**
258  * aa_get_profile_rcu - increment a refcount profile that can be replaced
259  * @p: pointer to profile that can be replaced (NOT NULL)
260  *
261  * Returns: pointer to a refcounted profile.
262  *     else NULL if no profile
263  */
264 static inline struct aa_profile *aa_get_profile_rcu(struct aa_profile __rcu **p)
265 {
266 	struct aa_profile *c;
267 
268 	rcu_read_lock();
269 	do {
270 		c = rcu_dereference(*p);
271 	} while (c && !kref_get_unless_zero(&c->label.count));
272 	rcu_read_unlock();
273 
274 	return c;
275 }
276 
277 /**
278  * aa_put_profile - decrement refcount on profile @p
279  * @p: profile  (MAYBE NULL)
280  */
281 static inline void aa_put_profile(struct aa_profile *p)
282 {
283 	if (p)
284 		kref_put(&p->label.count, aa_label_kref);
285 }
286 
287 static inline int AUDIT_MODE(struct aa_profile *profile)
288 {
289 	if (aa_g_audit != AUDIT_NORMAL)
290 		return aa_g_audit;
291 
292 	return profile->audit;
293 }
294 
295 bool policy_view_capable(struct aa_ns *ns);
296 bool policy_admin_capable(struct aa_ns *ns);
297 int aa_may_manage_policy(struct aa_label *label, struct aa_ns *ns,
298 			 u32 mask);
299 
300 #endif /* __AA_POLICY_H */
301