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/security.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 /* 142 * Mount options 143 */ 144 #define SMK_FSDEFAULT "smackfsdef=" 145 #define SMK_FSFLOOR "smackfsfloor=" 146 #define SMK_FSHAT "smackfshat=" 147 #define SMK_FSROOT "smackfsroot=" 148 #define SMK_FSTRANS "smackfstransmute=" 149 150 #define SMACK_CIPSO_OPTION "-CIPSO" 151 152 /* 153 * How communications on this socket are treated. 154 * Usually it's determined by the underlying netlabel code 155 * but there are certain cases, including single label hosts 156 * and potentially single label interfaces for which the 157 * treatment can not be known in advance. 158 * 159 * The possibility of additional labeling schemes being 160 * introduced in the future exists as well. 161 */ 162 #define SMACK_UNLABELED_SOCKET 0 163 #define SMACK_CIPSO_SOCKET 1 164 165 /* 166 * CIPSO defaults. 167 */ 168 #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ 169 #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ 170 #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ 171 #define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */ 172 #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ 173 /* 174 * CIPSO 2.2 standard is 239, but Smack wants to use the 175 * categories in a structured way that limits the value to 176 * the bits in 23 bytes, hence the unusual number. 177 */ 178 #define SMACK_CIPSO_MAXCATNUM 184 /* 23 * 8 */ 179 180 /* 181 * Ptrace rules 182 */ 183 #define SMACK_PTRACE_DEFAULT 0 184 #define SMACK_PTRACE_EXACT 1 185 #define SMACK_PTRACE_DRACONIAN 2 186 #define SMACK_PTRACE_MAX SMACK_PTRACE_DRACONIAN 187 188 /* 189 * Flags for untraditional access modes. 190 * It shouldn't be necessary to avoid conflicts with definitions 191 * in fs.h, but do so anyway. 192 */ 193 #define MAY_TRANSMUTE 0x00001000 /* Controls directory labeling */ 194 #define MAY_LOCK 0x00002000 /* Locks should be writes, but ... */ 195 #define MAY_BRINGUP 0x00004000 /* Report use of this rule */ 196 197 #define SMACK_BRINGUP_ALLOW 1 /* Allow bringup mode */ 198 #define SMACK_UNCONFINED_SUBJECT 2 /* Allow unconfined label */ 199 #define SMACK_UNCONFINED_OBJECT 3 /* Allow unconfined label */ 200 201 /* 202 * Just to make the common cases easier to deal with 203 */ 204 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 205 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 206 #define MAY_NOT 0 207 208 /* 209 * Number of access types used by Smack (rwxatlb) 210 */ 211 #define SMK_NUM_ACCESS_TYPE 7 212 213 /* SMACK data */ 214 struct smack_audit_data { 215 const char *function; 216 char *subject; 217 char *object; 218 char *request; 219 int result; 220 }; 221 222 /* 223 * Smack audit data; is empty if CONFIG_AUDIT not set 224 * to save some stack 225 */ 226 struct smk_audit_info { 227 #ifdef CONFIG_AUDIT 228 struct common_audit_data a; 229 struct smack_audit_data sad; 230 #endif 231 }; 232 /* 233 * These functions are in smack_lsm.c 234 */ 235 struct inode_smack *new_inode_smack(struct smack_known *); 236 237 /* 238 * These functions are in smack_access.c 239 */ 240 int smk_access_entry(char *, char *, struct list_head *); 241 int smk_access(struct smack_known *, struct smack_known *, 242 int, struct smk_audit_info *); 243 int smk_tskacc(struct task_smack *, struct smack_known *, 244 u32, struct smk_audit_info *); 245 int smk_curacc(struct smack_known *, u32, struct smk_audit_info *); 246 struct smack_known *smack_from_secid(const u32); 247 char *smk_parse_smack(const char *string, int len); 248 int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); 249 struct smack_known *smk_import_entry(const char *, int); 250 void smk_insert_entry(struct smack_known *skp); 251 struct smack_known *smk_find_entry(const char *); 252 253 /* 254 * Shared data. 255 */ 256 extern int smack_enabled; 257 extern int smack_cipso_direct; 258 extern int smack_cipso_mapped; 259 extern struct smack_known *smack_net_ambient; 260 extern struct smack_known *smack_onlycap; 261 extern struct smack_known *smack_syslog_label; 262 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 263 extern struct smack_known *smack_unconfined; 264 #endif 265 extern struct smack_known smack_cipso_option; 266 extern int smack_ptrace_rule; 267 268 extern struct smack_known smack_known_floor; 269 extern struct smack_known smack_known_hat; 270 extern struct smack_known smack_known_huh; 271 extern struct smack_known smack_known_invalid; 272 extern struct smack_known smack_known_star; 273 extern struct smack_known smack_known_web; 274 275 extern struct mutex smack_known_lock; 276 extern struct list_head smack_known_list; 277 extern struct list_head smk_netlbladdr_list; 278 279 extern struct security_operations smack_ops; 280 281 #define SMACK_HASH_SLOTS 16 282 extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; 283 284 /* 285 * Is the directory transmuting? 286 */ 287 static inline int smk_inode_transmutable(const struct inode *isp) 288 { 289 struct inode_smack *sip = isp->i_security; 290 return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; 291 } 292 293 /* 294 * Present a pointer to the smack label entry in an inode blob. 295 */ 296 static inline struct smack_known *smk_of_inode(const struct inode *isp) 297 { 298 struct inode_smack *sip = isp->i_security; 299 return sip->smk_inode; 300 } 301 302 /* 303 * Present a pointer to the smack label entry in an task blob. 304 */ 305 static inline struct smack_known *smk_of_task(const struct task_smack *tsp) 306 { 307 return tsp->smk_task; 308 } 309 310 static inline struct smack_known *smk_of_task_struct(const struct task_struct *t) 311 { 312 struct smack_known *skp; 313 314 rcu_read_lock(); 315 skp = smk_of_task(__task_cred(t)->security); 316 rcu_read_unlock(); 317 return skp; 318 } 319 320 /* 321 * Present a pointer to the forked smack label entry in an task blob. 322 */ 323 static inline struct smack_known *smk_of_forked(const struct task_smack *tsp) 324 { 325 return tsp->smk_forked; 326 } 327 328 /* 329 * Present a pointer to the smack label in the current task blob. 330 */ 331 static inline struct smack_known *smk_of_current(void) 332 { 333 return smk_of_task(current_security()); 334 } 335 336 /* 337 * Is the task privileged and allowed to be privileged 338 * by the onlycap rule. 339 */ 340 static inline int smack_privileged(int cap) 341 { 342 struct smack_known *skp = smk_of_current(); 343 344 if (!capable(cap)) 345 return 0; 346 if (smack_onlycap == NULL || smack_onlycap == skp) 347 return 1; 348 return 0; 349 } 350 351 /* 352 * logging functions 353 */ 354 #define SMACK_AUDIT_DENIED 0x1 355 #define SMACK_AUDIT_ACCEPT 0x2 356 extern int log_policy; 357 358 void smack_log(char *subject_label, char *object_label, 359 int request, 360 int result, struct smk_audit_info *auditdata); 361 362 #ifdef CONFIG_AUDIT 363 364 /* 365 * some inline functions to set up audit data 366 * they do nothing if CONFIG_AUDIT is not set 367 * 368 */ 369 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 370 char type) 371 { 372 memset(&a->sad, 0, sizeof(a->sad)); 373 a->a.type = type; 374 a->a.smack_audit_data = &a->sad; 375 a->a.smack_audit_data->function = func; 376 } 377 378 static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func, 379 char type, struct lsm_network_audit *net) 380 { 381 smk_ad_init(a, func, type); 382 memset(net, 0, sizeof(*net)); 383 a->a.u.net = net; 384 } 385 386 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 387 struct task_struct *t) 388 { 389 a->a.u.tsk = t; 390 } 391 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 392 struct dentry *d) 393 { 394 a->a.u.dentry = d; 395 } 396 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 397 struct inode *i) 398 { 399 a->a.u.inode = i; 400 } 401 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 402 struct path p) 403 { 404 a->a.u.path = p; 405 } 406 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 407 struct sock *sk) 408 { 409 a->a.u.net->sk = sk; 410 } 411 412 #else /* no AUDIT */ 413 414 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 415 char type) 416 { 417 } 418 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 419 struct task_struct *t) 420 { 421 } 422 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 423 struct dentry *d) 424 { 425 } 426 static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a, 427 struct vfsmount *m) 428 { 429 } 430 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 431 struct inode *i) 432 { 433 } 434 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 435 struct path p) 436 { 437 } 438 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 439 struct sock *sk) 440 { 441 } 442 #endif 443 444 #endif /* _SECURITY_SMACK_H */ 445