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 KILL_MODE(_profile) PROFILE_MODE((_profile), APPARMOR_KILL)
48 
49 #define PROFILE_IS_HAT(_profile) ((_profile)->label.flags & FLAG_HAT)
50 
51 #define profile_is_stale(_profile) (label_is_stale(&(_profile)->label))
52 
53 #define on_list_rcu(X) (!list_empty(X) && (X)->prev != LIST_POISON2)
54 
55 /*
56  * FIXME: currently need a clean way to replace and remove profiles as a
57  * set.  It should be done at the namespace level.
58  * Either, with a set of profiles loaded at the namespace level or via
59  * a mark and remove marked interface.
60  */
61 enum profile_mode {
62 	APPARMOR_ENFORCE,	/* enforce access rules */
63 	APPARMOR_COMPLAIN,	/* allow and log access violations */
64 	APPARMOR_KILL,		/* kill task on access violation */
65 	APPARMOR_UNCONFINED,	/* profile set to unconfined */
66 };
67 
68 
69 /* struct aa_policydb - match engine for a policy
70  * dfa: dfa pattern match
71  * start: set of start states for the different classes of data
72  */
73 struct aa_policydb {
74 	/* Generic policy DFA specific rule types will be subsections of it */
75 	struct aa_dfa *dfa;
76 	unsigned int start[AA_CLASS_LAST + 1];
77 
78 };
79 
80 /* struct aa_data - generic data structure
81  * key: name for retrieving this data
82  * size: size of data in bytes
83  * data: binary data
84  * head: reserved for rhashtable
85  */
86 struct aa_data {
87 	char *key;
88 	u32 size;
89 	char *data;
90 	struct rhash_head head;
91 };
92 
93 
94 /* struct aa_profile - basic confinement data
95  * @base - base components of the profile (name, refcount, lists, lock ...)
96  * @label - label this profile is an extension of
97  * @parent: parent of profile
98  * @ns: namespace the profile is in
99  * @rename: optional profile name that this profile renamed
100  * @attach: human readable attachment string
101  * @xmatch: optional extended matching for unconfined executables names
102  * @xmatch_len: xmatch prefix len, used to determine xmatch priority
103  * @audit: the auditing mode of the profile
104  * @mode: the enforcement mode of the profile
105  * @path_flags: flags controlling path generation behavior
106  * @disconnected: what to prepend if attach_disconnected is specified
107  * @size: the memory consumed by this profiles rules
108  * @policy: general match rules governing policy
109  * @file: The set of rules governing basic file access and domain transitions
110  * @caps: capabilities for the profile
111  * @rlimits: rlimits for the profile
112  *
113  * @dents: dentries for the profiles file entries in apparmorfs
114  * @dirname: name of the profile dir in apparmorfs
115  * @data: hashtable for free-form policy aa_data
116  *
117  * The AppArmor profile contains the basic confinement data.  Each profile
118  * has a name, and exists in a namespace.  The @name and @exec_match are
119  * used to determine profile attachment against unconfined tasks.  All other
120  * attachments are determined by profile X transition rules.
121  *
122  * Profiles have a hierarchy where hats and children profiles keep
123  * a reference to their parent.
124  *
125  * Profile names can not begin with a : and can not contain the \0
126  * character.  If a profile name begins with / it will be considered when
127  * determining profile attachment on "unconfined" tasks.
128  */
129 struct aa_profile {
130 	struct aa_policy base;
131 	struct aa_profile __rcu *parent;
132 
133 	struct aa_ns *ns;
134 	const char *rename;
135 
136 	const char *attach;
137 	struct aa_dfa *xmatch;
138 	int xmatch_len;
139 	enum audit_mode audit;
140 	long mode;
141 	u32 path_flags;
142 	const char *disconnected;
143 	int size;
144 
145 	struct aa_policydb policy;
146 	struct aa_file_rules file;
147 	struct aa_caps caps;
148 
149 	int xattr_count;
150 	char **xattrs;
151 
152 	struct aa_rlimit rlimits;
153 
154 	int secmark_count;
155 	struct aa_secmark *secmark;
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 static inline unsigned int PROFILE_MEDIATES(struct aa_profile *profile,
217 					    unsigned char class)
218 {
219 	if (class <= AA_CLASS_LAST)
220 		return profile->policy.start[class];
221 	else
222 		return aa_dfa_match_len(profile->policy.dfa,
223 					profile->policy.start[0], &class, 1);
224 }
225 
226 static inline unsigned int PROFILE_MEDIATES_AF(struct aa_profile *profile,
227 					       u16 AF) {
228 	unsigned int state = PROFILE_MEDIATES(profile, AA_CLASS_NET);
229 	__be16 be_af = cpu_to_be16(AF);
230 
231 	if (!state)
232 		return 0;
233 	return aa_dfa_match_len(profile->policy.dfa, state, (char *) &be_af, 2);
234 }
235 
236 /**
237  * aa_get_profile - increment refcount on profile @p
238  * @p: profile  (MAYBE NULL)
239  *
240  * Returns: pointer to @p if @p is NULL will return NULL
241  * Requires: @p must be held with valid refcount when called
242  */
243 static inline struct aa_profile *aa_get_profile(struct aa_profile *p)
244 {
245 	if (p)
246 		kref_get(&(p->label.count));
247 
248 	return p;
249 }
250 
251 /**
252  * aa_get_profile_not0 - increment refcount on profile @p found via lookup
253  * @p: profile  (MAYBE NULL)
254  *
255  * Returns: pointer to @p if @p is NULL will return NULL
256  * Requires: @p must be held with valid refcount when called
257  */
258 static inline struct aa_profile *aa_get_profile_not0(struct aa_profile *p)
259 {
260 	if (p && kref_get_unless_zero(&p->label.count))
261 		return p;
262 
263 	return NULL;
264 }
265 
266 /**
267  * aa_get_profile_rcu - increment a refcount profile that can be replaced
268  * @p: pointer to profile that can be replaced (NOT NULL)
269  *
270  * Returns: pointer to a refcounted profile.
271  *     else NULL if no profile
272  */
273 static inline struct aa_profile *aa_get_profile_rcu(struct aa_profile __rcu **p)
274 {
275 	struct aa_profile *c;
276 
277 	rcu_read_lock();
278 	do {
279 		c = rcu_dereference(*p);
280 	} while (c && !kref_get_unless_zero(&c->label.count));
281 	rcu_read_unlock();
282 
283 	return c;
284 }
285 
286 /**
287  * aa_put_profile - decrement refcount on profile @p
288  * @p: profile  (MAYBE NULL)
289  */
290 static inline void aa_put_profile(struct aa_profile *p)
291 {
292 	if (p)
293 		kref_put(&p->label.count, aa_label_kref);
294 }
295 
296 static inline int AUDIT_MODE(struct aa_profile *profile)
297 {
298 	if (aa_g_audit != AUDIT_NORMAL)
299 		return aa_g_audit;
300 
301 	return profile->audit;
302 }
303 
304 bool aa_policy_view_capable(struct aa_label *label, struct aa_ns *ns);
305 bool aa_policy_admin_capable(struct aa_label *label, struct aa_ns *ns);
306 int aa_may_manage_policy(struct aa_label *label, struct aa_ns *ns,
307 			 u32 mask);
308 bool aa_current_policy_view_capable(struct aa_ns *ns);
309 bool aa_current_policy_admin_capable(struct aa_ns *ns);
310 
311 #endif /* __AA_POLICY_H */
312