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[SMK_LABELLEN]; /* 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 struct smack_known { 121 struct list_head list; 122 char smk_known[SMK_LABELLEN]; 123 u32 smk_secid; 124 struct smack_cipso *smk_cipso; 125 spinlock_t smk_cipsolock; /* for changing cipso map */ 126 }; 127 128 /* 129 * Mount options 130 */ 131 #define SMK_FSDEFAULT "smackfsdef=" 132 #define SMK_FSFLOOR "smackfsfloor=" 133 #define SMK_FSHAT "smackfshat=" 134 #define SMK_FSROOT "smackfsroot=" 135 136 #define SMACK_CIPSO_OPTION "-CIPSO" 137 138 /* 139 * How communications on this socket are treated. 140 * Usually it's determined by the underlying netlabel code 141 * but there are certain cases, including single label hosts 142 * and potentially single label interfaces for which the 143 * treatment can not be known in advance. 144 * 145 * The possibility of additional labeling schemes being 146 * introduced in the future exists as well. 147 */ 148 #define SMACK_UNLABELED_SOCKET 0 149 #define SMACK_CIPSO_SOCKET 1 150 151 /* 152 * smackfs magic number 153 * smackfs macic number 154 */ 155 #define SMACK_MAGIC 0x43415d53 /* "SMAC" */ 156 157 /* 158 * CIPSO defaults. 159 */ 160 #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ 161 #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ 162 #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ 163 #define SMACK_CIPSO_MAXCATVAL 63 /* Bigger gets harder */ 164 #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ 165 #define SMACK_CIPSO_MAXCATNUM 239 /* CIPSO 2.2 standard */ 166 167 /* 168 * Flag for transmute access 169 */ 170 #define MAY_TRANSMUTE 64 171 /* 172 * Just to make the common cases easier to deal with 173 */ 174 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 175 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 176 #define MAY_NOT 0 177 178 /* 179 * Number of access types used by Smack (rwxa) 180 */ 181 #define SMK_NUM_ACCESS_TYPE 4 182 183 /* 184 * Smack audit data; is empty if CONFIG_AUDIT not set 185 * to save some stack 186 */ 187 struct smk_audit_info { 188 #ifdef CONFIG_AUDIT 189 struct common_audit_data a; 190 #endif 191 }; 192 /* 193 * These functions are in smack_lsm.c 194 */ 195 struct inode_smack *new_inode_smack(char *); 196 197 /* 198 * These functions are in smack_access.c 199 */ 200 int smk_access_entry(char *, char *, struct list_head *); 201 int smk_access(char *, char *, int, struct smk_audit_info *); 202 int smk_curacc(char *, u32, struct smk_audit_info *); 203 int smack_to_cipso(const char *, struct smack_cipso *); 204 void smack_from_cipso(u32, char *, char *); 205 char *smack_from_secid(const u32); 206 char *smk_import(const char *, int); 207 struct smack_known *smk_import_entry(const char *, int); 208 u32 smack_to_secid(const char *); 209 210 /* 211 * Shared data. 212 */ 213 extern int smack_cipso_direct; 214 extern char *smack_net_ambient; 215 extern char *smack_onlycap; 216 extern const char *smack_cipso_option; 217 218 extern struct smack_known smack_known_floor; 219 extern struct smack_known smack_known_hat; 220 extern struct smack_known smack_known_huh; 221 extern struct smack_known smack_known_invalid; 222 extern struct smack_known smack_known_star; 223 extern struct smack_known smack_known_web; 224 225 extern struct list_head smack_known_list; 226 extern struct list_head smack_rule_list; 227 extern struct list_head smk_netlbladdr_list; 228 229 extern struct security_operations smack_ops; 230 231 /* 232 * Stricly for CIPSO level manipulation. 233 * Set the category bit number in a smack label sized buffer. 234 */ 235 static inline void smack_catset_bit(int cat, char *catsetp) 236 { 237 if (cat > SMK_LABELLEN * 8) 238 return; 239 240 catsetp[(cat - 1) / 8] |= 0x80 >> ((cat - 1) % 8); 241 } 242 243 /* 244 * Is the directory transmuting? 245 */ 246 static inline int smk_inode_transmutable(const struct inode *isp) 247 { 248 struct inode_smack *sip = isp->i_security; 249 return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; 250 } 251 252 /* 253 * Present a pointer to the smack label in an inode blob. 254 */ 255 static inline char *smk_of_inode(const struct inode *isp) 256 { 257 struct inode_smack *sip = isp->i_security; 258 return sip->smk_inode; 259 } 260 261 /* 262 * Present a pointer to the smack label in an task blob. 263 */ 264 static inline char *smk_of_task(const struct task_smack *tsp) 265 { 266 return tsp->smk_task; 267 } 268 269 /* 270 * Present a pointer to the forked smack label in an task blob. 271 */ 272 static inline char *smk_of_forked(const struct task_smack *tsp) 273 { 274 return tsp->smk_forked; 275 } 276 277 /* 278 * Present a pointer to the smack label in the current task blob. 279 */ 280 static inline char *smk_of_current(void) 281 { 282 return smk_of_task(current_security()); 283 } 284 285 /* 286 * logging functions 287 */ 288 #define SMACK_AUDIT_DENIED 0x1 289 #define SMACK_AUDIT_ACCEPT 0x2 290 extern int log_policy; 291 292 void smack_log(char *subject_label, char *object_label, 293 int request, 294 int result, struct smk_audit_info *auditdata); 295 296 #ifdef CONFIG_AUDIT 297 298 /* 299 * some inline functions to set up audit data 300 * they do nothing if CONFIG_AUDIT is not set 301 * 302 */ 303 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 304 char type) 305 { 306 memset(a, 0, sizeof(*a)); 307 a->a.type = type; 308 a->a.smack_audit_data.function = func; 309 } 310 311 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 312 struct task_struct *t) 313 { 314 a->a.u.tsk = t; 315 } 316 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 317 struct dentry *d) 318 { 319 a->a.u.dentry = d; 320 } 321 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 322 struct inode *i) 323 { 324 a->a.u.inode = i; 325 } 326 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 327 struct path p) 328 { 329 a->a.u.path = p; 330 } 331 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 332 struct sock *sk) 333 { 334 a->a.u.net.sk = sk; 335 } 336 337 #else /* no AUDIT */ 338 339 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 340 char type) 341 { 342 } 343 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 344 struct task_struct *t) 345 { 346 } 347 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 348 struct dentry *d) 349 { 350 } 351 static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a, 352 struct vfsmount *m) 353 { 354 } 355 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 356 struct inode *i) 357 { 358 } 359 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 360 struct path p) 361 { 362 } 363 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 364 struct sock *sk) 365 { 366 } 367 #endif 368 369 #endif /* _SECURITY_SMACK_H */ 370