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 /* 189 * Smack audit data; is empty if CONFIG_AUDIT not set 190 * to save some stack 191 */ 192 struct smk_audit_info { 193 #ifdef CONFIG_AUDIT 194 struct common_audit_data a; 195 #endif 196 }; 197 /* 198 * These functions are in smack_lsm.c 199 */ 200 struct inode_smack *new_inode_smack(char *); 201 202 /* 203 * These functions are in smack_access.c 204 */ 205 int smk_access_entry(char *, char *, struct list_head *); 206 int smk_access(char *, char *, int, struct smk_audit_info *); 207 int smk_curacc(char *, u32, struct smk_audit_info *); 208 int smack_to_cipso(const char *, struct smack_cipso *); 209 char *smack_from_cipso(u32, char *); 210 char *smack_from_secid(const u32); 211 void smk_parse_smack(const char *string, int len, char *smack); 212 char *smk_import(const char *, int); 213 struct smack_known *smk_import_entry(const char *, int); 214 struct smack_known *smk_find_entry(const char *); 215 u32 smack_to_secid(const char *); 216 217 /* 218 * Shared data. 219 */ 220 extern int smack_cipso_direct; 221 extern char *smack_net_ambient; 222 extern char *smack_onlycap; 223 extern const char *smack_cipso_option; 224 225 extern struct smack_known smack_known_floor; 226 extern struct smack_known smack_known_hat; 227 extern struct smack_known smack_known_huh; 228 extern struct smack_known smack_known_invalid; 229 extern struct smack_known smack_known_star; 230 extern struct smack_known smack_known_web; 231 232 extern struct list_head smack_known_list; 233 extern struct list_head smk_netlbladdr_list; 234 235 extern struct security_operations smack_ops; 236 237 /* 238 * Stricly for CIPSO level manipulation. 239 * Set the category bit number in a smack label sized buffer. 240 */ 241 static inline void smack_catset_bit(int cat, char *catsetp) 242 { 243 if (cat > SMK_LABELLEN * 8) 244 return; 245 246 catsetp[(cat - 1) / 8] |= 0x80 >> ((cat - 1) % 8); 247 } 248 249 /* 250 * Is the directory transmuting? 251 */ 252 static inline int smk_inode_transmutable(const struct inode *isp) 253 { 254 struct inode_smack *sip = isp->i_security; 255 return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; 256 } 257 258 /* 259 * Present a pointer to the smack label in an inode blob. 260 */ 261 static inline char *smk_of_inode(const struct inode *isp) 262 { 263 struct inode_smack *sip = isp->i_security; 264 return sip->smk_inode; 265 } 266 267 /* 268 * Present a pointer to the smack label in an task blob. 269 */ 270 static inline char *smk_of_task(const struct task_smack *tsp) 271 { 272 return tsp->smk_task; 273 } 274 275 /* 276 * Present a pointer to the forked smack label in an task blob. 277 */ 278 static inline char *smk_of_forked(const struct task_smack *tsp) 279 { 280 return tsp->smk_forked; 281 } 282 283 /* 284 * Present a pointer to the smack label in the current task blob. 285 */ 286 static inline char *smk_of_current(void) 287 { 288 return smk_of_task(current_security()); 289 } 290 291 /* 292 * logging functions 293 */ 294 #define SMACK_AUDIT_DENIED 0x1 295 #define SMACK_AUDIT_ACCEPT 0x2 296 extern int log_policy; 297 298 void smack_log(char *subject_label, char *object_label, 299 int request, 300 int result, struct smk_audit_info *auditdata); 301 302 #ifdef CONFIG_AUDIT 303 304 /* 305 * some inline functions to set up audit data 306 * they do nothing if CONFIG_AUDIT is not set 307 * 308 */ 309 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 310 char type) 311 { 312 memset(a, 0, sizeof(*a)); 313 a->a.type = type; 314 a->a.smack_audit_data.function = func; 315 } 316 317 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 318 struct task_struct *t) 319 { 320 a->a.u.tsk = t; 321 } 322 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 323 struct dentry *d) 324 { 325 a->a.u.dentry = d; 326 } 327 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 328 struct inode *i) 329 { 330 a->a.u.inode = i; 331 } 332 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 333 struct path p) 334 { 335 a->a.u.path = p; 336 } 337 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 338 struct sock *sk) 339 { 340 a->a.u.net.sk = sk; 341 } 342 343 #else /* no AUDIT */ 344 345 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 346 char type) 347 { 348 } 349 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 350 struct task_struct *t) 351 { 352 } 353 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 354 struct dentry *d) 355 { 356 } 357 static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a, 358 struct vfsmount *m) 359 { 360 } 361 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 362 struct inode *i) 363 { 364 } 365 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 366 struct path p) 367 { 368 } 369 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 370 struct sock *sk) 371 { 372 } 373 #endif 374 375 #endif /* _SECURITY_SMACK_H */ 376