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/sched.h> 22 #include <linux/slab.h> 23 #include <linux/socket.h> 24 25 #include "apparmor.h" 26 #include "audit.h" 27 #include "capability.h" 28 #include "domain.h" 29 #include "file.h" 30 #include "resource.h" 31 32 extern const char *const aa_profile_mode_names[]; 33 #define APPARMOR_MODE_NAMES_MAX_INDEX 4 34 35 #define PROFILE_MODE(_profile, _mode) \ 36 ((aa_g_profile_mode == (_mode)) || \ 37 ((_profile)->mode == (_mode))) 38 39 #define COMPLAIN_MODE(_profile) PROFILE_MODE((_profile), APPARMOR_COMPLAIN) 40 41 #define KILL_MODE(_profile) PROFILE_MODE((_profile), APPARMOR_KILL) 42 43 #define PROFILE_IS_HAT(_profile) ((_profile)->flags & PFLAG_HAT) 44 45 #define PROFILE_INVALID(_profile) ((_profile)->flags & PFLAG_INVALID) 46 47 #define on_list_rcu(X) (!list_empty(X) && (X)->prev != LIST_POISON2) 48 49 /* 50 * FIXME: currently need a clean way to replace and remove profiles as a 51 * set. It should be done at the namespace level. 52 * Either, with a set of profiles loaded at the namespace level or via 53 * a mark and remove marked interface. 54 */ 55 enum profile_mode { 56 APPARMOR_ENFORCE, /* enforce access rules */ 57 APPARMOR_COMPLAIN, /* allow and log access violations */ 58 APPARMOR_KILL, /* kill task on access violation */ 59 APPARMOR_UNCONFINED, /* profile set to unconfined */ 60 }; 61 62 enum profile_flags { 63 PFLAG_HAT = 1, /* profile is a hat */ 64 PFLAG_NULL = 4, /* profile is null learning profile */ 65 PFLAG_IX_ON_NAME_ERROR = 8, /* fallback to ix on name lookup fail */ 66 PFLAG_IMMUTABLE = 0x10, /* don't allow changes/replacement */ 67 PFLAG_USER_DEFINED = 0x20, /* user based profile - lower privs */ 68 PFLAG_NO_LIST_REF = 0x40, /* list doesn't keep profile ref */ 69 PFLAG_OLD_NULL_TRANS = 0x100, /* use // as the null transition */ 70 PFLAG_INVALID = 0x200, /* profile replaced/removed */ 71 PFLAG_NS_COUNT = 0x400, /* carries NS ref count */ 72 73 /* These flags must correspond with PATH_flags */ 74 PFLAG_MEDIATE_DELETED = 0x10000, /* mediate instead delegate deleted */ 75 }; 76 77 struct aa_profile; 78 79 /* struct aa_policy - common part of both namespaces and profiles 80 * @name: name of the object 81 * @hname - The hierarchical name 82 * @list: list policy object is on 83 * @profiles: head of the profiles list contained in the object 84 */ 85 struct aa_policy { 86 char *name; 87 char *hname; 88 struct list_head list; 89 struct list_head profiles; 90 }; 91 92 /* struct aa_ns_acct - accounting of profiles in namespace 93 * @max_size: maximum space allowed for all profiles in namespace 94 * @max_count: maximum number of profiles that can be in this namespace 95 * @size: current size of profiles 96 * @count: current count of profiles (includes null profiles) 97 */ 98 struct aa_ns_acct { 99 int max_size; 100 int max_count; 101 int size; 102 int count; 103 }; 104 105 /* struct aa_namespace - namespace for a set of profiles 106 * @base: common policy 107 * @parent: parent of namespace 108 * @lock: lock for modifying the object 109 * @acct: accounting for the namespace 110 * @unconfined: special unconfined profile for the namespace 111 * @sub_ns: list of namespaces under the current namespace. 112 * @uniq_null: uniq value used for null learning profiles 113 * @uniq_id: a unique id count for the profiles in the namespace 114 * @dents: dentries for the namespaces file entries in apparmorfs 115 * 116 * An aa_namespace defines the set profiles that are searched to determine 117 * which profile to attach to a task. Profiles can not be shared between 118 * aa_namespaces and profile names within a namespace are guaranteed to be 119 * unique. When profiles in separate namespaces have the same name they 120 * are NOT considered to be equivalent. 121 * 122 * Namespaces are hierarchical and only namespaces and profiles below the 123 * current namespace are visible. 124 * 125 * Namespace names must be unique and can not contain the characters :/\0 126 * 127 * FIXME TODO: add vserver support of namespaces (can it all be done in 128 * userspace?) 129 */ 130 struct aa_namespace { 131 struct aa_policy base; 132 struct aa_namespace *parent; 133 struct mutex lock; 134 struct aa_ns_acct acct; 135 struct aa_profile *unconfined; 136 struct list_head sub_ns; 137 atomic_t uniq_null; 138 long uniq_id; 139 140 struct dentry *dents[AAFS_NS_SIZEOF]; 141 }; 142 143 /* struct aa_policydb - match engine for a policy 144 * dfa: dfa pattern match 145 * start: set of start states for the different classes of data 146 */ 147 struct aa_policydb { 148 /* Generic policy DFA specific rule types will be subsections of it */ 149 struct aa_dfa *dfa; 150 unsigned int start[AA_CLASS_LAST + 1]; 151 152 }; 153 154 struct aa_replacedby { 155 struct kref count; 156 struct aa_profile __rcu *profile; 157 }; 158 159 160 /* struct aa_profile - basic confinement data 161 * @base - base components of the profile (name, refcount, lists, lock ...) 162 * @count: reference count of the obj 163 * @rcu: rcu head used when removing from @list 164 * @parent: parent of profile 165 * @ns: namespace the profile is in 166 * @replacedby: is set to the profile that replaced this profile 167 * @rename: optional profile name that this profile renamed 168 * @attach: human readable attachment string 169 * @xmatch: optional extended matching for unconfined executables names 170 * @xmatch_len: xmatch prefix len, used to determine xmatch priority 171 * @audit: the auditing mode of the profile 172 * @mode: the enforcement mode of the profile 173 * @flags: flags controlling profile behavior 174 * @path_flags: flags controlling path generation behavior 175 * @size: the memory consumed by this profiles rules 176 * @policy: general match rules governing policy 177 * @file: The set of rules governing basic file access and domain transitions 178 * @caps: capabilities for the profile 179 * @rlimits: rlimits for the profile 180 * 181 * @dents: dentries for the profiles file entries in apparmorfs 182 * @dirname: name of the profile dir in apparmorfs 183 * 184 * The AppArmor profile contains the basic confinement data. Each profile 185 * has a name, and exists in a namespace. The @name and @exec_match are 186 * used to determine profile attachment against unconfined tasks. All other 187 * attachments are determined by profile X transition rules. 188 * 189 * The @replacedby struct is write protected by the profile lock. 190 * 191 * Profiles have a hierarchy where hats and children profiles keep 192 * a reference to their parent. 193 * 194 * Profile names can not begin with a : and can not contain the \0 195 * character. If a profile name begins with / it will be considered when 196 * determining profile attachment on "unconfined" tasks. 197 */ 198 struct aa_profile { 199 struct aa_policy base; 200 struct kref count; 201 struct rcu_head rcu; 202 struct aa_profile __rcu *parent; 203 204 struct aa_namespace *ns; 205 struct aa_replacedby *replacedby; 206 const char *rename; 207 208 const char *attach; 209 struct aa_dfa *xmatch; 210 int xmatch_len; 211 enum audit_mode audit; 212 long mode; 213 long flags; 214 u32 path_flags; 215 int size; 216 217 struct aa_policydb policy; 218 struct aa_file_rules file; 219 struct aa_caps caps; 220 struct aa_rlimit rlimits; 221 222 unsigned char *hash; 223 char *dirname; 224 struct dentry *dents[AAFS_PROF_SIZEOF]; 225 }; 226 227 extern struct aa_namespace *root_ns; 228 extern enum profile_mode aa_g_profile_mode; 229 230 void aa_add_profile(struct aa_policy *common, struct aa_profile *profile); 231 232 bool aa_ns_visible(struct aa_namespace *curr, struct aa_namespace *view); 233 const char *aa_ns_name(struct aa_namespace *parent, struct aa_namespace *child); 234 int aa_alloc_root_ns(void); 235 void aa_free_root_ns(void); 236 void aa_free_namespace_kref(struct kref *kref); 237 238 struct aa_namespace *aa_find_namespace(struct aa_namespace *root, 239 const char *name); 240 241 242 void aa_free_replacedby_kref(struct kref *kref); 243 struct aa_profile *aa_alloc_profile(const char *name); 244 struct aa_profile *aa_new_null_profile(struct aa_profile *parent, int hat); 245 void aa_free_profile(struct aa_profile *profile); 246 void aa_free_profile_kref(struct kref *kref); 247 struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name); 248 struct aa_profile *aa_lookup_profile(struct aa_namespace *ns, const char *name); 249 struct aa_profile *aa_match_profile(struct aa_namespace *ns, const char *name); 250 251 ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace); 252 ssize_t aa_remove_profiles(char *name, size_t size); 253 254 #define PROF_ADD 1 255 #define PROF_REPLACE 0 256 257 #define unconfined(X) ((X)->mode == APPARMOR_UNCONFINED) 258 259 260 static inline struct aa_profile *aa_deref_parent(struct aa_profile *p) 261 { 262 return rcu_dereference_protected(p->parent, 263 mutex_is_locked(&p->ns->lock)); 264 } 265 266 /** 267 * aa_get_profile - increment refcount on profile @p 268 * @p: profile (MAYBE NULL) 269 * 270 * Returns: pointer to @p if @p is NULL will return NULL 271 * Requires: @p must be held with valid refcount when called 272 */ 273 static inline struct aa_profile *aa_get_profile(struct aa_profile *p) 274 { 275 if (p) 276 kref_get(&(p->count)); 277 278 return p; 279 } 280 281 /** 282 * aa_get_profile_not0 - increment refcount on profile @p found via lookup 283 * @p: profile (MAYBE NULL) 284 * 285 * Returns: pointer to @p if @p is NULL will return NULL 286 * Requires: @p must be held with valid refcount when called 287 */ 288 static inline struct aa_profile *aa_get_profile_not0(struct aa_profile *p) 289 { 290 if (p && kref_get_not0(&p->count)) 291 return p; 292 293 return NULL; 294 } 295 296 /** 297 * aa_get_profile_rcu - increment a refcount profile that can be replaced 298 * @p: pointer to profile that can be replaced (NOT NULL) 299 * 300 * Returns: pointer to a refcounted profile. 301 * else NULL if no profile 302 */ 303 static inline struct aa_profile *aa_get_profile_rcu(struct aa_profile __rcu **p) 304 { 305 struct aa_profile *c; 306 307 rcu_read_lock(); 308 do { 309 c = rcu_dereference(*p); 310 } while (c && !kref_get_not0(&c->count)); 311 rcu_read_unlock(); 312 313 return c; 314 } 315 316 /** 317 * aa_get_newest_profile - find the newest version of @profile 318 * @profile: the profile to check for newer versions of 319 * 320 * Returns: refcounted newest version of @profile taking into account 321 * replacement, renames and removals 322 * return @profile. 323 */ 324 static inline struct aa_profile *aa_get_newest_profile(struct aa_profile *p) 325 { 326 if (!p) 327 return NULL; 328 329 if (PROFILE_INVALID(p)) 330 return aa_get_profile_rcu(&p->replacedby->profile); 331 332 return aa_get_profile(p); 333 } 334 335 /** 336 * aa_put_profile - decrement refcount on profile @p 337 * @p: profile (MAYBE NULL) 338 */ 339 static inline void aa_put_profile(struct aa_profile *p) 340 { 341 if (p) 342 kref_put(&p->count, aa_free_profile_kref); 343 } 344 345 static inline struct aa_replacedby *aa_get_replacedby(struct aa_replacedby *p) 346 { 347 if (p) 348 kref_get(&(p->count)); 349 350 return p; 351 } 352 353 static inline void aa_put_replacedby(struct aa_replacedby *p) 354 { 355 if (p) 356 kref_put(&p->count, aa_free_replacedby_kref); 357 } 358 359 /* requires profile list write lock held */ 360 static inline void __aa_update_replacedby(struct aa_profile *orig, 361 struct aa_profile *new) 362 { 363 struct aa_profile *tmp; 364 tmp = rcu_dereference_protected(orig->replacedby->profile, 365 mutex_is_locked(&orig->ns->lock)); 366 rcu_assign_pointer(orig->replacedby->profile, aa_get_profile(new)); 367 orig->flags |= PFLAG_INVALID; 368 aa_put_profile(tmp); 369 } 370 371 /** 372 * aa_get_namespace - increment references count on @ns 373 * @ns: namespace to increment reference count of (MAYBE NULL) 374 * 375 * Returns: pointer to @ns, if @ns is NULL returns NULL 376 * Requires: @ns must be held with valid refcount when called 377 */ 378 static inline struct aa_namespace *aa_get_namespace(struct aa_namespace *ns) 379 { 380 if (ns) 381 aa_get_profile(ns->unconfined); 382 383 return ns; 384 } 385 386 /** 387 * aa_put_namespace - decrement refcount on @ns 388 * @ns: namespace to put reference of 389 * 390 * Decrement reference count of @ns and if no longer in use free it 391 */ 392 static inline void aa_put_namespace(struct aa_namespace *ns) 393 { 394 if (ns) 395 aa_put_profile(ns->unconfined); 396 } 397 398 static inline int AUDIT_MODE(struct aa_profile *profile) 399 { 400 if (aa_g_audit != AUDIT_NORMAL) 401 return aa_g_audit; 402 403 return profile->audit; 404 } 405 406 bool aa_may_manage_policy(int op); 407 408 #endif /* __AA_POLICY_H */ 409