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 * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is 27 * bigger than can be used, and 24 is the next lower multiple 28 * of 8, and there are too many issues if there isn't space set 29 * aside for the terminating null byte. 30 */ 31 #define SMK_MAXLEN 23 32 #define SMK_LABELLEN (SMK_MAXLEN+1) 33 34 struct superblock_smack { 35 char *smk_root; 36 char *smk_floor; 37 char *smk_hat; 38 char *smk_default; 39 int smk_initialized; 40 spinlock_t smk_sblock; /* for initialization */ 41 }; 42 43 struct socket_smack { 44 char *smk_out; /* outbound label */ 45 char *smk_in; /* inbound label */ 46 char *smk_packet; /* TCP peer label */ 47 }; 48 49 /* 50 * Inode smack data 51 */ 52 struct inode_smack { 53 char *smk_inode; /* label of the fso */ 54 char *smk_task; /* label of the task */ 55 char *smk_mmap; /* label of the mmap domain */ 56 struct mutex smk_lock; /* initialization lock */ 57 int smk_flags; /* smack inode flags */ 58 }; 59 60 struct task_smack { 61 char *smk_task; /* label for access control */ 62 char *smk_forked; /* label when forked */ 63 struct list_head smk_rules; /* per task access rules */ 64 struct mutex smk_rules_lock; /* lock for the rules */ 65 }; 66 67 #define SMK_INODE_INSTANT 0x01 /* inode is instantiated */ 68 #define SMK_INODE_TRANSMUTE 0x02 /* directory is transmuting */ 69 70 /* 71 * A label access rule. 72 */ 73 struct smack_rule { 74 struct list_head list; 75 char *smk_subject; 76 char *smk_object; 77 int smk_access; 78 }; 79 80 /* 81 * An entry in the table mapping smack values to 82 * CIPSO level/category-set values. 83 */ 84 struct smack_cipso { 85 int smk_level; 86 char smk_catset[SMK_LABELLEN]; 87 }; 88 89 /* 90 * An entry in the table identifying hosts. 91 */ 92 struct smk_netlbladdr { 93 struct list_head list; 94 struct sockaddr_in smk_host; /* network address */ 95 struct in_addr smk_mask; /* network mask */ 96 char *smk_label; /* label */ 97 }; 98 99 /* 100 * This is the repository for labels seen so that it is 101 * not necessary to keep allocating tiny chuncks of memory 102 * and so that they can be shared. 103 * 104 * Labels are never modified in place. Anytime a label 105 * is imported (e.g. xattrset on a file) the list is checked 106 * for it and it is added if it doesn't exist. The address 107 * is passed out in either case. Entries are added, but 108 * never deleted. 109 * 110 * Since labels are hanging around anyway it doesn't 111 * hurt to maintain a secid for those awkward situations 112 * where kernel components that ought to use LSM independent 113 * interfaces don't. The secid should go away when all of 114 * these components have been repaired. 115 * 116 * If there is a cipso value associated with the label it 117 * gets stored here, too. This will most likely be rare as 118 * the cipso direct mapping in used internally. 119 * 120 * Keep the access rules for this subject label here so that 121 * the entire set of rules does not need to be examined every 122 * time. 123 */ 124 struct smack_known { 125 struct list_head list; 126 char smk_known[SMK_LABELLEN]; 127 u32 smk_secid; 128 struct smack_cipso *smk_cipso; 129 spinlock_t smk_cipsolock; /* for changing cipso map */ 130 struct list_head smk_rules; /* access rules */ 131 struct mutex smk_rules_lock; /* lock for the rules */ 132 }; 133 134 /* 135 * Mount options 136 */ 137 #define SMK_FSDEFAULT "smackfsdef=" 138 #define SMK_FSFLOOR "smackfsfloor=" 139 #define SMK_FSHAT "smackfshat=" 140 #define SMK_FSROOT "smackfsroot=" 141 142 #define SMACK_CIPSO_OPTION "-CIPSO" 143 144 /* 145 * How communications on this socket are treated. 146 * Usually it's determined by the underlying netlabel code 147 * but there are certain cases, including single label hosts 148 * and potentially single label interfaces for which the 149 * treatment can not be known in advance. 150 * 151 * The possibility of additional labeling schemes being 152 * introduced in the future exists as well. 153 */ 154 #define SMACK_UNLABELED_SOCKET 0 155 #define SMACK_CIPSO_SOCKET 1 156 157 /* 158 * smackfs magic number 159 */ 160 #define SMACK_MAGIC 0x43415d53 /* "SMAC" */ 161 162 /* 163 * CIPSO defaults. 164 */ 165 #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ 166 #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ 167 #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ 168 #define SMACK_CIPSO_MAXCATVAL 63 /* Bigger gets harder */ 169 #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ 170 #define SMACK_CIPSO_MAXCATNUM 239 /* CIPSO 2.2 standard */ 171 172 /* 173 * Flag for transmute access 174 */ 175 #define MAY_TRANSMUTE 64 176 /* 177 * Just to make the common cases easier to deal with 178 */ 179 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 180 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 181 #define MAY_NOT 0 182 183 /* 184 * Number of access types used by Smack (rwxat) 185 */ 186 #define SMK_NUM_ACCESS_TYPE 5 187 188 /* SMACK data */ 189 struct smack_audit_data { 190 const char *function; 191 char *subject; 192 char *object; 193 char *request; 194 int result; 195 }; 196 197 /* 198 * Smack audit data; is empty if CONFIG_AUDIT not set 199 * to save some stack 200 */ 201 struct smk_audit_info { 202 #ifdef CONFIG_AUDIT 203 struct common_audit_data a; 204 struct smack_audit_data sad; 205 #endif 206 }; 207 /* 208 * These functions are in smack_lsm.c 209 */ 210 struct inode_smack *new_inode_smack(char *); 211 212 /* 213 * These functions are in smack_access.c 214 */ 215 int smk_access_entry(char *, char *, struct list_head *); 216 int smk_access(char *, char *, int, struct smk_audit_info *); 217 int smk_curacc(char *, u32, struct smk_audit_info *); 218 int smack_to_cipso(const char *, struct smack_cipso *); 219 char *smack_from_cipso(u32, char *); 220 char *smack_from_secid(const u32); 221 void smk_parse_smack(const char *string, int len, char *smack); 222 char *smk_import(const char *, int); 223 struct smack_known *smk_import_entry(const char *, int); 224 struct smack_known *smk_find_entry(const char *); 225 u32 smack_to_secid(const char *); 226 227 /* 228 * Shared data. 229 */ 230 extern int smack_cipso_direct; 231 extern char *smack_net_ambient; 232 extern char *smack_onlycap; 233 extern const char *smack_cipso_option; 234 235 extern struct smack_known smack_known_floor; 236 extern struct smack_known smack_known_hat; 237 extern struct smack_known smack_known_huh; 238 extern struct smack_known smack_known_invalid; 239 extern struct smack_known smack_known_star; 240 extern struct smack_known smack_known_web; 241 242 extern struct list_head smack_known_list; 243 extern struct list_head smk_netlbladdr_list; 244 245 extern struct security_operations smack_ops; 246 247 /* 248 * Stricly for CIPSO level manipulation. 249 * Set the category bit number in a smack label sized buffer. 250 */ 251 static inline void smack_catset_bit(int cat, char *catsetp) 252 { 253 if (cat > SMK_LABELLEN * 8) 254 return; 255 256 catsetp[(cat - 1) / 8] |= 0x80 >> ((cat - 1) % 8); 257 } 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 in an task blob. 279 */ 280 static inline char *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 in an task blob. 287 */ 288 static inline char *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 char *smk_of_current(void) 297 { 298 return smk_of_task(current_security()); 299 } 300 301 /* 302 * logging functions 303 */ 304 #define SMACK_AUDIT_DENIED 0x1 305 #define SMACK_AUDIT_ACCEPT 0x2 306 extern int log_policy; 307 308 void smack_log(char *subject_label, char *object_label, 309 int request, 310 int result, struct smk_audit_info *auditdata); 311 312 #ifdef CONFIG_AUDIT 313 314 /* 315 * some inline functions to set up audit data 316 * they do nothing if CONFIG_AUDIT is not set 317 * 318 */ 319 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 320 char type) 321 { 322 memset(a, 0, sizeof(*a)); 323 a->a.type = type; 324 a->a.smack_audit_data = &a->sad; 325 a->a.smack_audit_data->function = func; 326 } 327 328 static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func, 329 char type, struct lsm_network_audit *net) 330 { 331 smk_ad_init(a, func, type); 332 memset(net, 0, sizeof(*net)); 333 a->a.u.net = net; 334 } 335 336 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 337 struct task_struct *t) 338 { 339 a->a.u.tsk = t; 340 } 341 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 342 struct dentry *d) 343 { 344 a->a.u.dentry = d; 345 } 346 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 347 struct inode *i) 348 { 349 a->a.u.inode = i; 350 } 351 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 352 struct path p) 353 { 354 a->a.u.path = p; 355 } 356 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 357 struct sock *sk) 358 { 359 a->a.u.net->sk = sk; 360 } 361 362 #else /* no AUDIT */ 363 364 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 365 char type) 366 { 367 } 368 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 369 struct task_struct *t) 370 { 371 } 372 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 373 struct dentry *d) 374 { 375 } 376 static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a, 377 struct vfsmount *m) 378 { 379 } 380 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 381 struct inode *i) 382 { 383 } 384 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 385 struct path p) 386 { 387 } 388 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 389 struct sock *sk) 390 { 391 } 392 #endif 393 394 #endif /* _SECURITY_SMACK_H */ 395