policy.h

  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
 34struct aa_ns;
 35
 36extern int unprivileged_userns_apparmor_policy;
 37extern int aa_unprivileged_unconfined_restricted;
 38
 39extern const char *const aa_profile_mode_names[];
 40#define APPARMOR_MODE_NAMES_MAX_INDEX 4
 41
 42#define PROFILE_MODE(_profile, _mode)		\
 43	((aa_g_profile_mode == (_mode)) ||	\
 44	 ((_profile)->mode == (_mode)))
 45
 46#define COMPLAIN_MODE(_profile)	PROFILE_MODE((_profile), APPARMOR_COMPLAIN)
 47
 48#define USER_MODE(_profile)	PROFILE_MODE((_profile), APPARMOR_USER)
 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 CHECK_DEBUG1(_profile) ((_profile)->label.flags & FLAG_DEBUG1)
 55
 56#define CHECK_DEBUG2(_profile) ((_profile)->label.flags & FLAG_DEBUG2)
 57
 58#define profile_is_stale(_profile) (label_is_stale(&(_profile)->label))
 59
 60#define on_list_rcu(X) (!list_empty(X) && (X)->prev != LIST_POISON2)
 61
 62/* flags in the dfa accept2 table */
 63enum dfa_accept_flags {
 64	ACCEPT_FLAG_OWNER = 1,
 65};
 66
 67/*
 68 * FIXME: currently need a clean way to replace and remove profiles as a
 69 * set.  It should be done at the namespace level.
 70 * Either, with a set of profiles loaded at the namespace level or via
 71 * a mark and remove marked interface.
 72 */
 73enum profile_mode {
 74	APPARMOR_ENFORCE,	/* enforce access rules */
 75	APPARMOR_COMPLAIN,	/* allow and log access violations */
 76	APPARMOR_KILL,		/* kill task on access violation */
 77	APPARMOR_UNCONFINED,	/* profile set to unconfined */
 78	APPARMOR_USER,		/* modified complain mode to userspace */
 79};
 80
 81
 82/* struct aa_policydb - match engine for a policy
 83 * count: refcount for the pdb
 84 * dfa: dfa pattern match
 85 * perms: table of permissions
 86 * strs: table of strings, index by x
 87 * start: set of start states for the different classes of data
 88 */
 89struct aa_policydb {
 90	struct kref count;
 91	struct aa_dfa *dfa;
 92	struct {
 93		struct aa_perms *perms;
 94		u32 size;
 95	};
 96	struct aa_str_table trans;
 97	aa_state_t start[AA_CLASS_LAST + 1];
 98};
 99
100extern struct aa_policydb *nullpdb;
101
102struct aa_policydb *aa_alloc_pdb(gfp_t gfp);
103void aa_pdb_free_kref(struct kref *kref);
104
105/**
106 * aa_get_pdb - increment refcount on @pdb
107 * @pdb: policydb  (MAYBE NULL)
108 *
109 * Returns: pointer to @pdb if @pdb is NULL will return NULL
110 * Requires: @pdb must be held with valid refcount when called
111 */
112static inline struct aa_policydb *aa_get_pdb(struct aa_policydb *pdb)
113{
114	if (pdb)
115		kref_get(&(pdb->count));
116
117	return pdb;
118}
119
120/**
121 * aa_put_pdb - put a pdb refcount
122 * @pdb: pdb to put refcount   (MAYBE NULL)
123 *
124 * Requires: if @pdb != NULL that a valid refcount be held
125 */
126static inline void aa_put_pdb(struct aa_policydb *pdb)
127{
128	if (pdb)
129		kref_put(&pdb->count, aa_pdb_free_kref);
130}
131
132/* lookup perm that doesn't have and object conditional */
133static inline struct aa_perms *aa_lookup_perms(struct aa_policydb *policy,
134					       aa_state_t state)
135{
136	unsigned int index = ACCEPT_TABLE(policy->dfa)[state];
137
138	if (!(policy->perms))
139		return &default_perms;
140
141	return &(policy->perms[index]);
142}
143
144/* struct aa_data - generic data structure
145 * key: name for retrieving this data
146 * size: size of data in bytes
147 * data: binary data
148 * head: reserved for rhashtable
149 */
150struct aa_data {
151	char *key;
152	u32 size;
153	char *data;
154	struct rhash_head head;
155};
156
157/* struct aa_ruleset - data covering mediation rules
158 * @list: list the rule is on
159 * @size: the memory consumed by this ruleset
160 * @policy: general match rules governing policy
161 * @file: The set of rules governing basic file access and domain transitions
162 * @caps: capabilities for the profile
163 * @rlimits: rlimits for the profile
164 * @secmark_count: number of secmark entries
165 * @secmark: secmark label match info
166 */
167struct aa_ruleset {
168	int size;
169
170	/* TODO: merge policy and file */
171	struct aa_policydb *policy;
172	struct aa_policydb *file;
173	struct aa_caps caps;
174
175	struct aa_rlimit rlimits;
176
177	int secmark_count;
178	struct aa_secmark *secmark;
179};
180
181
182/* struct aa_attachment - data and rules for a profiles attachment
183 * @list:
184 * @xmatch_str: human readable attachment string
185 * @xmatch: optional extended matching for unconfined executables names
186 * @xmatch_len: xmatch prefix len, used to determine xmatch priority
187 * @xattr_count: number of xattrs in table
188 * @xattrs: table of xattrs
189 */
190struct aa_attachment {
191	const char *xmatch_str;
192	struct aa_policydb *xmatch;
193	unsigned int xmatch_len;
194	int xattr_count;
195	char **xattrs;
196};
197
198/* struct aa_profile - basic confinement data
199 * @base - base components of the profile (name, refcount, lists, lock ...)
200 * @parent: parent of profile
201 * @ns: namespace the profile is in
202 * @rename: optional profile name that this profile renamed
203 *
204 * @audit: the auditing mode of the profile
205 * @mode: the enforcement mode of the profile
206 * @path_flags: flags controlling path generation behavior
207 * @signal: the signal that should be used when kill is used
208 * @disconnected: what to prepend if attach_disconnected is specified
209 * @attach: attachment rules for the profile
210 * @rules: rules to be enforced
211 *
212 * learning_cache: the accesses learned in complain mode
213 * raw_data: rawdata of the loaded profile policy
214 * hash: cryptographic hash of the profile
215 * @dents: dentries for the profiles file entries in apparmorfs
216 * @dirname: name of the profile dir in apparmorfs
217 * @dents: set of dentries associated with the profile
218 * @data: hashtable for free-form policy aa_data
219 * @label - label this profile is an extension of
220 * @rules - label with the rule vec on its end
221 *
222 * The AppArmor profile contains the basic confinement data.  Each profile
223 * has a name, and exists in a namespace.  The @name and @exec_match are
224 * used to determine profile attachment against unconfined tasks.  All other
225 * attachments are determined by profile X transition rules.
226 *
227 * Profiles have a hierarchy where hats and children profiles keep
228 * a reference to their parent.
229 *
230 * Profile names can not begin with a : and can not contain the \0
231 * character.  If a profile name begins with / it will be considered when
232 * determining profile attachment on "unconfined" tasks.
233 */
234struct aa_profile {
235	struct aa_policy base;
236	struct aa_profile __rcu *parent;
237
238	struct aa_ns *ns;
239	const char *rename;
240
241	enum audit_mode audit;
242	long mode;
243	u32 path_flags;
244	int signal;
245	const char *disconnected;
246
247	struct aa_attachment attach;
248
249	struct aa_loaddata *rawdata;
250	unsigned char *hash;
251	char *dirname;
252	struct dentry *dents[AAFS_PROF_SIZEOF];
253	struct rhashtable *data;
254
255	int n_rules;
256	/* special - variable length must be last entry in profile */
257	struct aa_label label;
258};
259
260extern enum profile_mode aa_g_profile_mode;
261
262#define AA_MAY_LOAD_POLICY	AA_MAY_APPEND
263#define AA_MAY_REPLACE_POLICY	AA_MAY_WRITE
264#define AA_MAY_REMOVE_POLICY	AA_MAY_DELETE
265
266#define profiles_ns(P) ((P)->ns)
267#define name_is_shared(A, B) ((A)->hname && (A)->hname == (B)->hname)
268
269struct aa_ruleset *aa_alloc_ruleset(gfp_t gfp);
270struct aa_profile *aa_alloc_profile(const char *name, struct aa_proxy *proxy,
271				    gfp_t gfp);
272struct aa_profile *aa_alloc_null(struct aa_profile *parent, const char *name,
273				 gfp_t gfp);
274struct aa_profile *aa_new_learning_profile(struct aa_profile *parent, bool hat,
275					   const char *base, gfp_t gfp);
276void aa_free_profile(struct aa_profile *profile);
277struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name);
278struct aa_profile *aa_lookupn_profile(struct aa_ns *ns, const char *hname,
279				      size_t n);
280struct aa_profile *aa_fqlookupn_profile(struct aa_label *base,
281					const char *fqname, size_t n);
282
283ssize_t aa_replace_profiles(struct aa_ns *view, struct aa_label *label,
284			    u32 mask, struct aa_loaddata *udata);
285ssize_t aa_remove_profiles(struct aa_ns *view, struct aa_label *label,
286			   char *name, size_t size);
287void __aa_profile_list_release(struct list_head *head);
288
289#define profile_unconfined(X) ((X)->mode == APPARMOR_UNCONFINED)
290
291/**
292 * aa_get_newest_profile - simple wrapper fn to wrap the label version
293 * @p: profile (NOT NULL)
294 *
295 * Returns refcount to newest version of the profile (maybe @p)
296 *
297 * Requires: @p must be held with a valid refcount
298 */
299static inline struct aa_profile *aa_get_newest_profile(struct aa_profile *p)
300{
301	return labels_profile(aa_get_newest_label(&p->label));
302}
303
304static inline aa_state_t RULE_MEDIATES(struct aa_ruleset *rules,
305				       unsigned char class)
306{
307	if (class <= AA_CLASS_LAST)
308		return rules->policy->start[class];
309	else
310		return aa_dfa_match_len(rules->policy->dfa,
311					rules->policy->start[0], &class, 1);
312}
313
314static inline aa_state_t RULE_MEDIATES_v9NET(struct aa_ruleset *rules)
315{
316	return RULE_MEDIATES(rules, AA_CLASS_NETV9);
317}
318
319static inline aa_state_t RULE_MEDIATES_NET(struct aa_ruleset *rules)
320{
321	/* can not use RULE_MEDIATE_v9AF here, because AF match fail
322	 * can not be distiguished from class match fail, and we only
323	 * fallback to checking older class on class match failure
324	 */
325	aa_state_t state = RULE_MEDIATES(rules, AA_CLASS_NETV9);
326
327	/* fallback and check v7/8 if v9 is NOT mediated */
328	if (!state)
329		state = RULE_MEDIATES(rules, AA_CLASS_NET);
330
331	return state;
332}
333
334
335void aa_compute_profile_mediates(struct aa_profile *profile);
336static inline bool profile_mediates(struct aa_profile *profile,
337				    unsigned char class)
338{
339	return label_mediates(&profile->label, class);
340}
341
342static inline bool profile_mediates_safe(struct aa_profile *profile,
343					 unsigned char class)
344{
345	return label_mediates_safe(&profile->label, class);
346}
347
348/**
349 * aa_get_profile - increment refcount on profile @p
350 * @p: profile  (MAYBE NULL)
351 *
352 * Returns: pointer to @p if @p is NULL will return NULL
353 * Requires: @p must be held with valid refcount when called
354 */
355static inline struct aa_profile *aa_get_profile(struct aa_profile *p)
356{
357	if (p)
358		kref_get(&(p->label.count.count));
359
360	return p;
361}
362
363/**
364 * aa_get_profile_not0 - increment refcount on profile @p found via lookup
365 * @p: profile  (MAYBE NULL)
366 *
367 * Returns: pointer to @p if @p is NULL will return NULL
368 * Requires: @p must be held with valid refcount when called
369 */
370static inline struct aa_profile *aa_get_profile_not0(struct aa_profile *p)
371{
372	if (p && kref_get_unless_zero(&p->label.count.count))
373		return p;
374
375	return NULL;
376}
377
378/**
379 * aa_get_profile_rcu - increment a refcount profile that can be replaced
380 * @p: pointer to profile that can be replaced (NOT NULL)
381 *
382 * Returns: pointer to a refcounted profile.
383 *     else NULL if no profile
384 */
385static inline struct aa_profile *aa_get_profile_rcu(struct aa_profile __rcu **p)
386{
387	struct aa_profile *c;
388
389	rcu_read_lock();
390	do {
391		c = rcu_dereference(*p);
392	} while (c && !kref_get_unless_zero(&c->label.count.count));
393	rcu_read_unlock();
394
395	return c;
396}
397
398/**
399 * aa_put_profile - decrement refcount on profile @p
400 * @p: profile  (MAYBE NULL)
401 */
402static inline void aa_put_profile(struct aa_profile *p)
403{
404	if (p)
405		kref_put(&p->label.count.count, aa_label_kref);
406}
407
408static inline int AUDIT_MODE(struct aa_profile *profile)
409{
410	if (aa_g_audit != AUDIT_NORMAL)
411		return aa_g_audit;
412
413	return profile->audit;
414}
415
416bool aa_policy_view_capable(const struct cred *subj_cred,
417			    struct aa_label *label, struct aa_ns *ns);
418bool aa_policy_admin_capable(const struct cred *subj_cred,
419			     struct aa_label *label, struct aa_ns *ns);
420int aa_may_manage_policy(const struct cred *subj_cred,
421			 struct aa_label *label, struct aa_ns *ns,
422			 const struct cred *ocred, u32 mask);
423bool aa_current_policy_view_capable(struct aa_ns *ns);
424bool aa_current_policy_admin_capable(struct aa_ns *ns);
425
426#endif /* __AA_POLICY_H */