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 char *smk_in; /* inbound label */ 84 char *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 char *smk_in; /* incoming 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 * Flag for transmute access 181 */ 182 #define MAY_TRANSMUTE 64 183 /* 184 * Just to make the common cases easier to deal with 185 */ 186 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 187 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 188 #define MAY_NOT 0 189 190 /* 191 * Number of access types used by Smack (rwxat) 192 */ 193 #define SMK_NUM_ACCESS_TYPE 5 194 195 /* SMACK data */ 196 struct smack_audit_data { 197 const char *function; 198 char *subject; 199 char *object; 200 char *request; 201 int result; 202 }; 203 204 /* 205 * Smack audit data; is empty if CONFIG_AUDIT not set 206 * to save some stack 207 */ 208 struct smk_audit_info { 209 #ifdef CONFIG_AUDIT 210 struct common_audit_data a; 211 struct smack_audit_data sad; 212 #endif 213 }; 214 /* 215 * These functions are in smack_lsm.c 216 */ 217 struct inode_smack *new_inode_smack(char *); 218 219 /* 220 * These functions are in smack_access.c 221 */ 222 int smk_access_entry(char *, char *, struct list_head *); 223 int smk_access(struct smack_known *, char *, int, struct smk_audit_info *); 224 int smk_curacc(char *, u32, struct smk_audit_info *); 225 struct smack_known *smack_from_secid(const u32); 226 char *smk_parse_smack(const char *string, int len); 227 int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); 228 char *smk_import(const char *, int); 229 struct smack_known *smk_import_entry(const char *, int); 230 void smk_insert_entry(struct smack_known *skp); 231 struct smack_known *smk_find_entry(const char *); 232 u32 smack_to_secid(const char *); 233 234 /* 235 * Shared data. 236 */ 237 extern int smack_cipso_direct; 238 extern int smack_cipso_mapped; 239 extern struct smack_known *smack_net_ambient; 240 extern char *smack_onlycap; 241 extern const char *smack_cipso_option; 242 243 extern struct smack_known smack_known_floor; 244 extern struct smack_known smack_known_hat; 245 extern struct smack_known smack_known_huh; 246 extern struct smack_known smack_known_invalid; 247 extern struct smack_known smack_known_star; 248 extern struct smack_known smack_known_web; 249 250 extern struct mutex smack_known_lock; 251 extern struct list_head smack_known_list; 252 extern struct list_head smk_netlbladdr_list; 253 254 extern struct security_operations smack_ops; 255 256 #define SMACK_HASH_SLOTS 16 257 extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; 258 259 /* 260 * Is the directory transmuting? 261 */ 262 static inline int smk_inode_transmutable(const struct inode *isp) 263 { 264 struct inode_smack *sip = isp->i_security; 265 return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; 266 } 267 268 /* 269 * Present a pointer to the smack label in an inode blob. 270 */ 271 static inline char *smk_of_inode(const struct inode *isp) 272 { 273 struct inode_smack *sip = isp->i_security; 274 return sip->smk_inode; 275 } 276 277 /* 278 * Present a pointer to the smack label entry in an task blob. 279 */ 280 static inline struct smack_known *smk_of_task(const struct task_smack *tsp) 281 { 282 return tsp->smk_task; 283 } 284 285 /* 286 * Present a pointer to the forked smack label entry in an task blob. 287 */ 288 static inline struct smack_known *smk_of_forked(const struct task_smack *tsp) 289 { 290 return tsp->smk_forked; 291 } 292 293 /* 294 * Present a pointer to the smack label in the current task blob. 295 */ 296 static inline struct smack_known *smk_of_current(void) 297 { 298 return smk_of_task(current_security()); 299 } 300 301 /* 302 * Is the task privileged and allowed to be privileged 303 * by the onlycap rule. 304 */ 305 static inline int smack_privileged(int cap) 306 { 307 struct smack_known *skp = smk_of_current(); 308 309 if (!capable(cap)) 310 return 0; 311 if (smack_onlycap == NULL || smack_onlycap == skp->smk_known) 312 return 1; 313 return 0; 314 } 315 316 /* 317 * logging functions 318 */ 319 #define SMACK_AUDIT_DENIED 0x1 320 #define SMACK_AUDIT_ACCEPT 0x2 321 extern int log_policy; 322 323 void smack_log(char *subject_label, char *object_label, 324 int request, 325 int result, struct smk_audit_info *auditdata); 326 327 #ifdef CONFIG_AUDIT 328 329 /* 330 * some inline functions to set up audit data 331 * they do nothing if CONFIG_AUDIT is not set 332 * 333 */ 334 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 335 char type) 336 { 337 memset(&a->sad, 0, sizeof(a->sad)); 338 a->a.type = type; 339 a->a.smack_audit_data = &a->sad; 340 a->a.smack_audit_data->function = func; 341 } 342 343 static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func, 344 char type, struct lsm_network_audit *net) 345 { 346 smk_ad_init(a, func, type); 347 memset(net, 0, sizeof(*net)); 348 a->a.u.net = net; 349 } 350 351 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 352 struct task_struct *t) 353 { 354 a->a.u.tsk = t; 355 } 356 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 357 struct dentry *d) 358 { 359 a->a.u.dentry = d; 360 } 361 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 362 struct inode *i) 363 { 364 a->a.u.inode = i; 365 } 366 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 367 struct path p) 368 { 369 a->a.u.path = p; 370 } 371 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 372 struct sock *sk) 373 { 374 a->a.u.net->sk = sk; 375 } 376 377 #else /* no AUDIT */ 378 379 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 380 char type) 381 { 382 } 383 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 384 struct task_struct *t) 385 { 386 } 387 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 388 struct dentry *d) 389 { 390 } 391 static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a, 392 struct vfsmount *m) 393 { 394 } 395 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 396 struct inode *i) 397 { 398 } 399 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 400 struct path p) 401 { 402 } 403 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 404 struct sock *sk) 405 { 406 } 407 #endif 408 409 #endif /* _SECURITY_SMACK_H */ 410