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   */
aa_get_newest_profile(struct aa_profile * p)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  
PROFILE_MEDIATES(struct aa_profile * profile,unsigned char class)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  
PROFILE_MEDIATES_AF(struct aa_profile * profile,u16 AF)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   */
aa_get_profile(struct aa_profile * p)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   */
aa_get_profile_not0(struct aa_profile * p)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   */
aa_get_profile_rcu(struct aa_profile __rcu ** p)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   */
aa_put_profile(struct aa_profile * p)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  
AUDIT_MODE(struct aa_profile * profile)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 policy_view_capable(struct aa_ns *ns);
305  bool policy_admin_capable(struct aa_ns *ns);
306  int aa_may_manage_policy(struct aa_label *label, struct aa_ns *ns,
307  			 u32 mask);
308  
309  #endif /* __AA_POLICY_H */
310