1 /* 2 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation, version 2. 7 * 8 * Author: 9 * Casey Schaufler <casey@schaufler-ca.com> 10 * 11 */ 12 13 #ifndef _SECURITY_SMACK_H 14 #define _SECURITY_SMACK_H 15 16 #include <linux/capability.h> 17 #include <linux/spinlock.h> 18 #include <linux/lsm_hooks.h> 19 #include <linux/in.h> 20 #include <net/netlabel.h> 21 #include <linux/list.h> 22 #include <linux/rculist.h> 23 #include <linux/lsm_audit.h> 24 25 /* 26 * Smack labels were limited to 23 characters for a long time. 27 */ 28 #define SMK_LABELLEN 24 29 #define SMK_LONGLABEL 256 30 31 /* 32 * This is the repository for labels seen so that it is 33 * not necessary to keep allocating tiny chuncks of memory 34 * and so that they can be shared. 35 * 36 * Labels are never modified in place. Anytime a label 37 * is imported (e.g. xattrset on a file) the list is checked 38 * for it and it is added if it doesn't exist. The address 39 * is passed out in either case. Entries are added, but 40 * never deleted. 41 * 42 * Since labels are hanging around anyway it doesn't 43 * hurt to maintain a secid for those awkward situations 44 * where kernel components that ought to use LSM independent 45 * interfaces don't. The secid should go away when all of 46 * these components have been repaired. 47 * 48 * The cipso value associated with the label gets stored here, too. 49 * 50 * Keep the access rules for this subject label here so that 51 * the entire set of rules does not need to be examined every 52 * time. 53 */ 54 struct smack_known { 55 struct list_head list; 56 struct hlist_node smk_hashed; 57 char *smk_known; 58 u32 smk_secid; 59 struct netlbl_lsm_secattr smk_netlabel; /* on wire labels */ 60 struct list_head smk_rules; /* access rules */ 61 struct mutex smk_rules_lock; /* lock for rules */ 62 }; 63 64 /* 65 * Maximum number of bytes for the levels in a CIPSO IP option. 66 * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is 67 * bigger than can be used, and 24 is the next lower multiple 68 * of 8, and there are too many issues if there isn't space set 69 * aside for the terminating null byte. 70 */ 71 #define SMK_CIPSOLEN 24 72 73 struct superblock_smack { 74 struct smack_known *smk_root; 75 struct smack_known *smk_floor; 76 struct smack_known *smk_hat; 77 struct smack_known *smk_default; 78 int smk_initialized; 79 }; 80 81 struct socket_smack { 82 struct smack_known *smk_out; /* outbound label */ 83 struct smack_known *smk_in; /* inbound label */ 84 struct smack_known *smk_packet; /* TCP peer label */ 85 }; 86 87 /* 88 * Inode smack data 89 */ 90 struct inode_smack { 91 struct smack_known *smk_inode; /* label of the fso */ 92 struct smack_known *smk_task; /* label of the task */ 93 struct smack_known *smk_mmap; /* label of the mmap domain */ 94 struct mutex smk_lock; /* initialization lock */ 95 int smk_flags; /* smack inode flags */ 96 }; 97 98 struct task_smack { 99 struct smack_known *smk_task; /* label for access control */ 100 struct smack_known *smk_forked; /* label when forked */ 101 struct list_head smk_rules; /* per task access rules */ 102 struct mutex smk_rules_lock; /* lock for the rules */ 103 }; 104 105 #define SMK_INODE_INSTANT 0x01 /* inode is instantiated */ 106 #define SMK_INODE_TRANSMUTE 0x02 /* directory is transmuting */ 107 #define SMK_INODE_CHANGED 0x04 /* smack was transmuted */ 108 #define SMK_INODE_IMPURE 0x08 /* involved in an impure transaction */ 109 110 /* 111 * A label access rule. 112 */ 113 struct smack_rule { 114 struct list_head list; 115 struct smack_known *smk_subject; 116 struct smack_known *smk_object; 117 int smk_access; 118 }; 119 120 /* 121 * An entry in the table identifying hosts. 122 */ 123 struct smk_netlbladdr { 124 struct list_head list; 125 struct sockaddr_in smk_host; /* network address */ 126 struct in_addr smk_mask; /* network mask */ 127 struct smack_known *smk_label; /* label */ 128 }; 129 130 /* 131 * An entry in the table identifying ports. 132 */ 133 struct smk_port_label { 134 struct list_head list; 135 struct sock *smk_sock; /* socket initialized on */ 136 unsigned short smk_port; /* the port number */ 137 struct smack_known *smk_in; /* inbound label */ 138 struct smack_known *smk_out; /* outgoing label */ 139 }; 140 141 struct smack_onlycap { 142 struct list_head list; 143 struct smack_known *smk_label; 144 }; 145 146 /* 147 * Mount options 148 */ 149 #define SMK_FSDEFAULT "smackfsdef=" 150 #define SMK_FSFLOOR "smackfsfloor=" 151 #define SMK_FSHAT "smackfshat=" 152 #define SMK_FSROOT "smackfsroot=" 153 #define SMK_FSTRANS "smackfstransmute=" 154 155 #define SMACK_CIPSO_OPTION "-CIPSO" 156 157 /* 158 * How communications on this socket are treated. 159 * Usually it's determined by the underlying netlabel code 160 * but there are certain cases, including single label hosts 161 * and potentially single label interfaces for which the 162 * treatment can not be known in advance. 163 * 164 * The possibility of additional labeling schemes being 165 * introduced in the future exists as well. 166 */ 167 #define SMACK_UNLABELED_SOCKET 0 168 #define SMACK_CIPSO_SOCKET 1 169 170 /* 171 * CIPSO defaults. 172 */ 173 #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ 174 #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ 175 #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ 176 #define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */ 177 #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ 178 /* 179 * CIPSO 2.2 standard is 239, but Smack wants to use the 180 * categories in a structured way that limits the value to 181 * the bits in 23 bytes, hence the unusual number. 182 */ 183 #define SMACK_CIPSO_MAXCATNUM 184 /* 23 * 8 */ 184 185 /* 186 * Ptrace rules 187 */ 188 #define SMACK_PTRACE_DEFAULT 0 189 #define SMACK_PTRACE_EXACT 1 190 #define SMACK_PTRACE_DRACONIAN 2 191 #define SMACK_PTRACE_MAX SMACK_PTRACE_DRACONIAN 192 193 /* 194 * Flags for untraditional access modes. 195 * It shouldn't be necessary to avoid conflicts with definitions 196 * in fs.h, but do so anyway. 197 */ 198 #define MAY_TRANSMUTE 0x00001000 /* Controls directory labeling */ 199 #define MAY_LOCK 0x00002000 /* Locks should be writes, but ... */ 200 #define MAY_BRINGUP 0x00004000 /* Report use of this rule */ 201 202 #define SMACK_BRINGUP_ALLOW 1 /* Allow bringup mode */ 203 #define SMACK_UNCONFINED_SUBJECT 2 /* Allow unconfined label */ 204 #define SMACK_UNCONFINED_OBJECT 3 /* Allow unconfined label */ 205 206 /* 207 * Just to make the common cases easier to deal with 208 */ 209 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 210 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 211 #define MAY_NOT 0 212 213 /* 214 * Number of access types used by Smack (rwxatlb) 215 */ 216 #define SMK_NUM_ACCESS_TYPE 7 217 218 /* SMACK data */ 219 struct smack_audit_data { 220 const char *function; 221 char *subject; 222 char *object; 223 char *request; 224 int result; 225 }; 226 227 /* 228 * Smack audit data; is empty if CONFIG_AUDIT not set 229 * to save some stack 230 */ 231 struct smk_audit_info { 232 #ifdef CONFIG_AUDIT 233 struct common_audit_data a; 234 struct smack_audit_data sad; 235 #endif 236 }; 237 /* 238 * These functions are in smack_lsm.c 239 */ 240 struct inode_smack *new_inode_smack(struct smack_known *); 241 242 /* 243 * These functions are in smack_access.c 244 */ 245 int smk_access_entry(char *, char *, struct list_head *); 246 int smk_access(struct smack_known *, struct smack_known *, 247 int, struct smk_audit_info *); 248 int smk_tskacc(struct task_smack *, struct smack_known *, 249 u32, struct smk_audit_info *); 250 int smk_curacc(struct smack_known *, u32, struct smk_audit_info *); 251 struct smack_known *smack_from_secid(const u32); 252 char *smk_parse_smack(const char *string, int len); 253 int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); 254 struct smack_known *smk_import_entry(const char *, int); 255 void smk_insert_entry(struct smack_known *skp); 256 struct smack_known *smk_find_entry(const char *); 257 int smack_privileged(int cap); 258 259 /* 260 * Shared data. 261 */ 262 extern int smack_enabled; 263 extern int smack_cipso_direct; 264 extern int smack_cipso_mapped; 265 extern struct smack_known *smack_net_ambient; 266 extern struct smack_known *smack_syslog_label; 267 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 268 extern struct smack_known *smack_unconfined; 269 #endif 270 extern struct smack_known smack_cipso_option; 271 extern int smack_ptrace_rule; 272 273 extern struct smack_known smack_known_floor; 274 extern struct smack_known smack_known_hat; 275 extern struct smack_known smack_known_huh; 276 extern struct smack_known smack_known_invalid; 277 extern struct smack_known smack_known_star; 278 extern struct smack_known smack_known_web; 279 280 extern struct mutex smack_known_lock; 281 extern struct list_head smack_known_list; 282 extern struct list_head smk_netlbladdr_list; 283 284 extern struct mutex smack_onlycap_lock; 285 extern struct list_head smack_onlycap_list; 286 287 #define SMACK_HASH_SLOTS 16 288 extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; 289 290 /* 291 * Is the directory transmuting? 292 */ 293 static inline int smk_inode_transmutable(const struct inode *isp) 294 { 295 struct inode_smack *sip = isp->i_security; 296 return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; 297 } 298 299 /* 300 * Present a pointer to the smack label entry in an inode blob. 301 */ 302 static inline struct smack_known *smk_of_inode(const struct inode *isp) 303 { 304 struct inode_smack *sip = isp->i_security; 305 return sip->smk_inode; 306 } 307 308 /* 309 * Present a pointer to the smack label entry in an task blob. 310 */ 311 static inline struct smack_known *smk_of_task(const struct task_smack *tsp) 312 { 313 return tsp->smk_task; 314 } 315 316 static inline struct smack_known *smk_of_task_struct(const struct task_struct *t) 317 { 318 struct smack_known *skp; 319 320 rcu_read_lock(); 321 skp = smk_of_task(__task_cred(t)->security); 322 rcu_read_unlock(); 323 return skp; 324 } 325 326 /* 327 * Present a pointer to the forked smack label entry in an task blob. 328 */ 329 static inline struct smack_known *smk_of_forked(const struct task_smack *tsp) 330 { 331 return tsp->smk_forked; 332 } 333 334 /* 335 * Present a pointer to the smack label in the current task blob. 336 */ 337 static inline struct smack_known *smk_of_current(void) 338 { 339 return smk_of_task(current_security()); 340 } 341 342 /* 343 * logging functions 344 */ 345 #define SMACK_AUDIT_DENIED 0x1 346 #define SMACK_AUDIT_ACCEPT 0x2 347 extern int log_policy; 348 349 void smack_log(char *subject_label, char *object_label, 350 int request, 351 int result, struct smk_audit_info *auditdata); 352 353 #ifdef CONFIG_AUDIT 354 355 /* 356 * some inline functions to set up audit data 357 * they do nothing if CONFIG_AUDIT is not set 358 * 359 */ 360 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 361 char type) 362 { 363 memset(&a->sad, 0, sizeof(a->sad)); 364 a->a.type = type; 365 a->a.smack_audit_data = &a->sad; 366 a->a.smack_audit_data->function = func; 367 } 368 369 static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func, 370 char type, struct lsm_network_audit *net) 371 { 372 smk_ad_init(a, func, type); 373 memset(net, 0, sizeof(*net)); 374 a->a.u.net = net; 375 } 376 377 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 378 struct task_struct *t) 379 { 380 a->a.u.tsk = t; 381 } 382 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 383 struct dentry *d) 384 { 385 a->a.u.dentry = d; 386 } 387 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 388 struct inode *i) 389 { 390 a->a.u.inode = i; 391 } 392 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 393 struct path p) 394 { 395 a->a.u.path = p; 396 } 397 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 398 struct sock *sk) 399 { 400 a->a.u.net->sk = sk; 401 } 402 403 #else /* no AUDIT */ 404 405 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 406 char type) 407 { 408 } 409 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 410 struct task_struct *t) 411 { 412 } 413 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 414 struct dentry *d) 415 { 416 } 417 static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a, 418 struct vfsmount *m) 419 { 420 } 421 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 422 struct inode *i) 423 { 424 } 425 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 426 struct path p) 427 { 428 } 429 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 430 struct sock *sk) 431 { 432 } 433 #endif 434 435 #endif /* _SECURITY_SMACK_H */ 436