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 char *smk_root; 75 char *smk_floor; 76 char *smk_hat; 77 char *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 char *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 */ 108 109 /* 110 * A label access rule. 111 */ 112 struct smack_rule { 113 struct list_head list; 114 struct smack_known *smk_subject; 115 char *smk_object; 116 int smk_access; 117 }; 118 119 /* 120 * An entry in the table identifying hosts. 121 */ 122 struct smk_netlbladdr { 123 struct list_head list; 124 struct sockaddr_in smk_host; /* network address */ 125 struct in_addr smk_mask; /* network mask */ 126 char *smk_label; /* label */ 127 }; 128 129 /* 130 * An entry in the table identifying ports. 131 */ 132 struct smk_port_label { 133 struct list_head list; 134 struct sock *smk_sock; /* socket initialized on */ 135 unsigned short smk_port; /* the port number */ 136 struct smack_known *smk_in; /* inbound label */ 137 struct smack_known *smk_out; /* outgoing label */ 138 }; 139 140 /* 141 * Mount options 142 */ 143 #define SMK_FSDEFAULT "smackfsdef=" 144 #define SMK_FSFLOOR "smackfsfloor=" 145 #define SMK_FSHAT "smackfshat=" 146 #define SMK_FSROOT "smackfsroot=" 147 #define SMK_FSTRANS "smackfstransmute=" 148 149 #define SMACK_CIPSO_OPTION "-CIPSO" 150 151 /* 152 * How communications on this socket are treated. 153 * Usually it's determined by the underlying netlabel code 154 * but there are certain cases, including single label hosts 155 * and potentially single label interfaces for which the 156 * treatment can not be known in advance. 157 * 158 * The possibility of additional labeling schemes being 159 * introduced in the future exists as well. 160 */ 161 #define SMACK_UNLABELED_SOCKET 0 162 #define SMACK_CIPSO_SOCKET 1 163 164 /* 165 * CIPSO defaults. 166 */ 167 #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ 168 #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ 169 #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ 170 #define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */ 171 #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ 172 /* 173 * CIPSO 2.2 standard is 239, but Smack wants to use the 174 * categories in a structured way that limits the value to 175 * the bits in 23 bytes, hence the unusual number. 176 */ 177 #define SMACK_CIPSO_MAXCATNUM 184 /* 23 * 8 */ 178 179 /* 180 * Ptrace rules 181 */ 182 #define SMACK_PTRACE_DEFAULT 0 183 #define SMACK_PTRACE_EXACT 1 184 #define SMACK_PTRACE_DRACONIAN 2 185 #define SMACK_PTRACE_MAX SMACK_PTRACE_DRACONIAN 186 187 /* 188 * Flags for untraditional access modes. 189 * It shouldn't be necessary to avoid conflicts with definitions 190 * in fs.h, but do so anyway. 191 */ 192 #define MAY_TRANSMUTE 0x00001000 /* Controls directory labeling */ 193 #define MAY_LOCK 0x00002000 /* Locks should be writes, but ... */ 194 195 /* 196 * Just to make the common cases easier to deal with 197 */ 198 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 199 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 200 #define MAY_NOT 0 201 202 /* 203 * Number of access types used by Smack (rwxatl) 204 */ 205 #define SMK_NUM_ACCESS_TYPE 6 206 207 /* SMACK data */ 208 struct smack_audit_data { 209 const char *function; 210 char *subject; 211 char *object; 212 char *request; 213 int result; 214 }; 215 216 /* 217 * Smack audit data; is empty if CONFIG_AUDIT not set 218 * to save some stack 219 */ 220 struct smk_audit_info { 221 #ifdef CONFIG_AUDIT 222 struct common_audit_data a; 223 struct smack_audit_data sad; 224 #endif 225 }; 226 /* 227 * These functions are in smack_lsm.c 228 */ 229 struct inode_smack *new_inode_smack(char *); 230 231 /* 232 * These functions are in smack_access.c 233 */ 234 int smk_access_entry(char *, char *, struct list_head *); 235 int smk_access(struct smack_known *, char *, int, struct smk_audit_info *); 236 int smk_tskacc(struct task_smack *, char *, u32, struct smk_audit_info *); 237 int smk_curacc(char *, u32, struct smk_audit_info *); 238 struct smack_known *smack_from_secid(const u32); 239 char *smk_parse_smack(const char *string, int len); 240 int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); 241 char *smk_import(const char *, int); 242 struct smack_known *smk_import_entry(const char *, int); 243 void smk_insert_entry(struct smack_known *skp); 244 struct smack_known *smk_find_entry(const char *); 245 u32 smack_to_secid(const char *); 246 247 /* 248 * Shared data. 249 */ 250 extern int smack_cipso_direct; 251 extern int smack_cipso_mapped; 252 extern struct smack_known *smack_net_ambient; 253 extern struct smack_known *smack_onlycap; 254 extern struct smack_known *smack_syslog_label; 255 extern const char *smack_cipso_option; 256 extern int smack_ptrace_rule; 257 258 extern struct smack_known smack_known_floor; 259 extern struct smack_known smack_known_hat; 260 extern struct smack_known smack_known_huh; 261 extern struct smack_known smack_known_invalid; 262 extern struct smack_known smack_known_star; 263 extern struct smack_known smack_known_web; 264 265 extern struct mutex smack_known_lock; 266 extern struct list_head smack_known_list; 267 extern struct list_head smk_netlbladdr_list; 268 269 extern struct security_operations smack_ops; 270 271 #define SMACK_HASH_SLOTS 16 272 extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; 273 274 /* 275 * Is the directory transmuting? 276 */ 277 static inline int smk_inode_transmutable(const struct inode *isp) 278 { 279 struct inode_smack *sip = isp->i_security; 280 return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; 281 } 282 283 /* 284 * Present a pointer to the smack label in an inode blob. 285 */ 286 static inline char *smk_of_inode(const struct inode *isp) 287 { 288 struct inode_smack *sip = isp->i_security; 289 return sip->smk_inode; 290 } 291 292 /* 293 * Present a pointer to the smack label entry in an task blob. 294 */ 295 static inline struct smack_known *smk_of_task(const struct task_smack *tsp) 296 { 297 return tsp->smk_task; 298 } 299 300 /* 301 * Present a pointer to the forked smack label entry in an task blob. 302 */ 303 static inline struct smack_known *smk_of_forked(const struct task_smack *tsp) 304 { 305 return tsp->smk_forked; 306 } 307 308 /* 309 * Present a pointer to the smack label in the current task blob. 310 */ 311 static inline struct smack_known *smk_of_current(void) 312 { 313 return smk_of_task(current_security()); 314 } 315 316 /* 317 * Is the task privileged and allowed to be privileged 318 * by the onlycap rule. 319 */ 320 static inline int smack_privileged(int cap) 321 { 322 struct smack_known *skp = smk_of_current(); 323 324 if (!capable(cap)) 325 return 0; 326 if (smack_onlycap == NULL || smack_onlycap == skp) 327 return 1; 328 return 0; 329 } 330 331 /* 332 * logging functions 333 */ 334 #define SMACK_AUDIT_DENIED 0x1 335 #define SMACK_AUDIT_ACCEPT 0x2 336 extern int log_policy; 337 338 void smack_log(char *subject_label, char *object_label, 339 int request, 340 int result, struct smk_audit_info *auditdata); 341 342 #ifdef CONFIG_AUDIT 343 344 /* 345 * some inline functions to set up audit data 346 * they do nothing if CONFIG_AUDIT is not set 347 * 348 */ 349 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 350 char type) 351 { 352 memset(&a->sad, 0, sizeof(a->sad)); 353 a->a.type = type; 354 a->a.smack_audit_data = &a->sad; 355 a->a.smack_audit_data->function = func; 356 } 357 358 static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func, 359 char type, struct lsm_network_audit *net) 360 { 361 smk_ad_init(a, func, type); 362 memset(net, 0, sizeof(*net)); 363 a->a.u.net = net; 364 } 365 366 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 367 struct task_struct *t) 368 { 369 a->a.u.tsk = t; 370 } 371 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 372 struct dentry *d) 373 { 374 a->a.u.dentry = d; 375 } 376 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 377 struct inode *i) 378 { 379 a->a.u.inode = i; 380 } 381 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 382 struct path p) 383 { 384 a->a.u.path = p; 385 } 386 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 387 struct sock *sk) 388 { 389 a->a.u.net->sk = sk; 390 } 391 392 #else /* no AUDIT */ 393 394 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 395 char type) 396 { 397 } 398 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 399 struct task_struct *t) 400 { 401 } 402 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 403 struct dentry *d) 404 { 405 } 406 static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a, 407 struct vfsmount *m) 408 { 409 } 410 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 411 struct inode *i) 412 { 413 } 414 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 415 struct path p) 416 { 417 } 418 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 419 struct sock *sk) 420 { 421 } 422 #endif 423 424 #endif /* _SECURITY_SMACK_H */ 425