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 CHECK_DEBUG1(_profile) ((_profile)->label.flags & FLAG_DEBUG1)
52 
53 #define CHECK_DEBUG2(_profile) ((_profile)->label.flags & FLAG_DEBUG2)
54 
55 #define profile_is_stale(_profile) (label_is_stale(&(_profile)->label))
56 
57 #define on_list_rcu(X) (!list_empty(X) && (X)->prev != LIST_POISON2)
58 
59 /*
60  * FIXME: currently need a clean way to replace and remove profiles as a
61  * set.  It should be done at the namespace level.
62  * Either, with a set of profiles loaded at the namespace level or via
63  * a mark and remove marked interface.
64  */
65 enum profile_mode {
66 	APPARMOR_ENFORCE,	/* enforce access rules */
67 	APPARMOR_COMPLAIN,	/* allow and log access violations */
68 	APPARMOR_KILL,		/* kill task on access violation */
69 	APPARMOR_UNCONFINED,	/* profile set to unconfined */
70 };
71 
72 
73 /* struct aa_policydb - match engine for a policy
74  * dfa: dfa pattern match
75  * start: set of start states for the different classes of data
76  */
77 struct aa_policydb {
78 	/* Generic policy DFA specific rule types will be subsections of it */
79 	struct aa_dfa *dfa;
80 	unsigned int start[AA_CLASS_LAST + 1];
81 
82 };
83 
84 /* struct aa_data - generic data structure
85  * key: name for retrieving this data
86  * size: size of data in bytes
87  * data: binary data
88  * head: reserved for rhashtable
89  */
90 struct aa_data {
91 	char *key;
92 	u32 size;
93 	char *data;
94 	struct rhash_head head;
95 };
96 
97 
98 /* struct aa_profile - basic confinement data
99  * @base - base components of the profile (name, refcount, lists, lock ...)
100  * @label - label this profile is an extension of
101  * @parent: parent of profile
102  * @ns: namespace the profile is in
103  * @rename: optional profile name that this profile renamed
104  * @attach: human readable attachment string
105  * @xmatch: optional extended matching for unconfined executables names
106  * @xmatch_len: xmatch prefix len, used to determine xmatch priority
107  * @audit: the auditing mode of the profile
108  * @mode: the enforcement mode of the profile
109  * @path_flags: flags controlling path generation behavior
110  * @disconnected: what to prepend if attach_disconnected is specified
111  * @size: the memory consumed by this profiles rules
112  * @policy: general match rules governing policy
113  * @file: The set of rules governing basic file access and domain transitions
114  * @caps: capabilities for the profile
115  * @rlimits: rlimits for the profile
116  *
117  * @dents: dentries for the profiles file entries in apparmorfs
118  * @dirname: name of the profile dir in apparmorfs
119  * @data: hashtable for free-form policy aa_data
120  *
121  * The AppArmor profile contains the basic confinement data.  Each profile
122  * has a name, and exists in a namespace.  The @name and @exec_match are
123  * used to determine profile attachment against unconfined tasks.  All other
124  * attachments are determined by profile X transition rules.
125  *
126  * Profiles have a hierarchy where hats and children profiles keep
127  * a reference to their parent.
128  *
129  * Profile names can not begin with a : and can not contain the \0
130  * character.  If a profile name begins with / it will be considered when
131  * determining profile attachment on "unconfined" tasks.
132  */
133 struct aa_profile {
134 	struct aa_policy base;
135 	struct aa_profile __rcu *parent;
136 
137 	struct aa_ns *ns;
138 	const char *rename;
139 
140 	const char *attach;
141 	struct aa_dfa *xmatch;
142 	unsigned int xmatch_len;
143 	enum audit_mode audit;
144 	long mode;
145 	u32 path_flags;
146 	const char *disconnected;
147 	int size;
148 
149 	struct aa_policydb policy;
150 	struct aa_file_rules file;
151 	struct aa_caps caps;
152 
153 	int xattr_count;
154 	char **xattrs;
155 
156 	struct aa_rlimit rlimits;
157 
158 	int secmark_count;
159 	struct aa_secmark *secmark;
160 
161 	struct aa_loaddata *rawdata;
162 	unsigned char *hash;
163 	char *dirname;
164 	struct dentry *dents[AAFS_PROF_SIZEOF];
165 	struct rhashtable *data;
166 	struct aa_label label;
167 };
168 
169 extern enum profile_mode aa_g_profile_mode;
170 
171 #define AA_MAY_LOAD_POLICY	AA_MAY_APPEND
172 #define AA_MAY_REPLACE_POLICY	AA_MAY_WRITE
173 #define AA_MAY_REMOVE_POLICY	AA_MAY_DELETE
174 
175 #define profiles_ns(P) ((P)->ns)
176 #define name_is_shared(A, B) ((A)->hname && (A)->hname == (B)->hname)
177 
178 void aa_add_profile(struct aa_policy *common, struct aa_profile *profile);
179 
180 
181 void aa_free_proxy_kref(struct kref *kref);
182 struct aa_profile *aa_alloc_profile(const char *name, struct aa_proxy *proxy,
183 				    gfp_t gfp);
184 struct aa_profile *aa_new_null_profile(struct aa_profile *parent, bool hat,
185 				       const char *base, gfp_t gfp);
186 void aa_free_profile(struct aa_profile *profile);
187 void aa_free_profile_kref(struct kref *kref);
188 struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name);
189 struct aa_profile *aa_lookupn_profile(struct aa_ns *ns, const char *hname,
190 				      size_t n);
191 struct aa_profile *aa_lookup_profile(struct aa_ns *ns, const char *name);
192 struct aa_profile *aa_fqlookupn_profile(struct aa_label *base,
193 					const char *fqname, size_t n);
194 struct aa_profile *aa_match_profile(struct aa_ns *ns, const char *name);
195 
196 ssize_t aa_replace_profiles(struct aa_ns *view, struct aa_label *label,
197 			    u32 mask, struct aa_loaddata *udata);
198 ssize_t aa_remove_profiles(struct aa_ns *view, struct aa_label *label,
199 			   char *name, size_t size);
200 void __aa_profile_list_release(struct list_head *head);
201 
202 #define PROF_ADD 1
203 #define PROF_REPLACE 0
204 
205 #define profile_unconfined(X) ((X)->mode == APPARMOR_UNCONFINED)
206 
207 /**
208  * aa_get_newest_profile - simple wrapper fn to wrap the label version
209  * @p: profile (NOT NULL)
210  *
211  * Returns refcount to newest version of the profile (maybe @p)
212  *
213  * Requires: @p must be held with a valid refcount
214  */
215 static inline struct aa_profile *aa_get_newest_profile(struct aa_profile *p)
216 {
217 	return labels_profile(aa_get_newest_label(&p->label));
218 }
219 
220 static inline unsigned int PROFILE_MEDIATES(struct aa_profile *profile,
221 					    unsigned char class)
222 {
223 	if (class <= AA_CLASS_LAST)
224 		return profile->policy.start[class];
225 	else
226 		return aa_dfa_match_len(profile->policy.dfa,
227 					profile->policy.start[0], &class, 1);
228 }
229 
230 static inline unsigned int PROFILE_MEDIATES_AF(struct aa_profile *profile,
231 					       u16 AF) {
232 	unsigned int state = PROFILE_MEDIATES(profile, AA_CLASS_NET);
233 	__be16 be_af = cpu_to_be16(AF);
234 
235 	if (!state)
236 		return 0;
237 	return aa_dfa_match_len(profile->policy.dfa, state, (char *) &be_af, 2);
238 }
239 
240 /**
241  * aa_get_profile - increment refcount on profile @p
242  * @p: profile  (MAYBE NULL)
243  *
244  * Returns: pointer to @p if @p is NULL will return NULL
245  * Requires: @p must be held with valid refcount when called
246  */
247 static inline struct aa_profile *aa_get_profile(struct aa_profile *p)
248 {
249 	if (p)
250 		kref_get(&(p->label.count));
251 
252 	return p;
253 }
254 
255 /**
256  * aa_get_profile_not0 - increment refcount on profile @p found via lookup
257  * @p: profile  (MAYBE NULL)
258  *
259  * Returns: pointer to @p if @p is NULL will return NULL
260  * Requires: @p must be held with valid refcount when called
261  */
262 static inline struct aa_profile *aa_get_profile_not0(struct aa_profile *p)
263 {
264 	if (p && kref_get_unless_zero(&p->label.count))
265 		return p;
266 
267 	return NULL;
268 }
269 
270 /**
271  * aa_get_profile_rcu - increment a refcount profile that can be replaced
272  * @p: pointer to profile that can be replaced (NOT NULL)
273  *
274  * Returns: pointer to a refcounted profile.
275  *     else NULL if no profile
276  */
277 static inline struct aa_profile *aa_get_profile_rcu(struct aa_profile __rcu **p)
278 {
279 	struct aa_profile *c;
280 
281 	rcu_read_lock();
282 	do {
283 		c = rcu_dereference(*p);
284 	} while (c && !kref_get_unless_zero(&c->label.count));
285 	rcu_read_unlock();
286 
287 	return c;
288 }
289 
290 /**
291  * aa_put_profile - decrement refcount on profile @p
292  * @p: profile  (MAYBE NULL)
293  */
294 static inline void aa_put_profile(struct aa_profile *p)
295 {
296 	if (p)
297 		kref_put(&p->label.count, aa_label_kref);
298 }
299 
300 static inline int AUDIT_MODE(struct aa_profile *profile)
301 {
302 	if (aa_g_audit != AUDIT_NORMAL)
303 		return aa_g_audit;
304 
305 	return profile->audit;
306 }
307 
308 bool aa_policy_view_capable(struct aa_label *label, struct aa_ns *ns);
309 bool aa_policy_admin_capable(struct aa_label *label, struct aa_ns *ns);
310 int aa_may_manage_policy(struct aa_label *label, struct aa_ns *ns,
311 			 u32 mask);
312 bool aa_current_policy_view_capable(struct aa_ns *ns);
313 bool aa_current_policy_admin_capable(struct aa_ns *ns);
314 
315 #endif /* __AA_POLICY_H */
316