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 * Maximum number of bytes for the levels in a CIPSO IP option. 33 * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is 34 * bigger than can be used, and 24 is the next lower multiple 35 * of 8, and there are too many issues if there isn't space set 36 * aside for the terminating null byte. 37 */ 38 #define SMK_CIPSOLEN 24 39 40 struct superblock_smack { 41 char *smk_root; 42 char *smk_floor; 43 char *smk_hat; 44 char *smk_default; 45 int smk_initialized; 46 spinlock_t smk_sblock; /* for initialization */ 47 }; 48 49 struct socket_smack { 50 char *smk_out; /* outbound label */ 51 char *smk_in; /* inbound label */ 52 char *smk_packet; /* TCP peer label */ 53 }; 54 55 /* 56 * Inode smack data 57 */ 58 struct inode_smack { 59 char *smk_inode; /* label of the fso */ 60 char *smk_task; /* label of the task */ 61 char *smk_mmap; /* label of the mmap domain */ 62 struct mutex smk_lock; /* initialization lock */ 63 int smk_flags; /* smack inode flags */ 64 }; 65 66 struct task_smack { 67 char *smk_task; /* label for access control */ 68 char *smk_forked; /* label when forked */ 69 struct list_head smk_rules; /* per task access rules */ 70 struct mutex smk_rules_lock; /* lock for the rules */ 71 }; 72 73 #define SMK_INODE_INSTANT 0x01 /* inode is instantiated */ 74 #define SMK_INODE_TRANSMUTE 0x02 /* directory is transmuting */ 75 #define SMK_INODE_CHANGED 0x04 /* smack was transmuted */ 76 77 /* 78 * A label access rule. 79 */ 80 struct smack_rule { 81 struct list_head list; 82 char *smk_subject; 83 char *smk_object; 84 int smk_access; 85 }; 86 87 /* 88 * An entry in the table identifying hosts. 89 */ 90 struct smk_netlbladdr { 91 struct list_head list; 92 struct sockaddr_in smk_host; /* network address */ 93 struct in_addr smk_mask; /* network mask */ 94 char *smk_label; /* label */ 95 }; 96 97 /* 98 * This is the repository for labels seen so that it is 99 * not necessary to keep allocating tiny chuncks of memory 100 * and so that they can be shared. 101 * 102 * Labels are never modified in place. Anytime a label 103 * is imported (e.g. xattrset on a file) the list is checked 104 * for it and it is added if it doesn't exist. The address 105 * is passed out in either case. Entries are added, but 106 * never deleted. 107 * 108 * Since labels are hanging around anyway it doesn't 109 * hurt to maintain a secid for those awkward situations 110 * where kernel components that ought to use LSM independent 111 * interfaces don't. The secid should go away when all of 112 * these components have been repaired. 113 * 114 * The cipso value associated with the label gets stored here, too. 115 * 116 * Keep the access rules for this subject label here so that 117 * the entire set of rules does not need to be examined every 118 * time. 119 */ 120 struct smack_known { 121 struct list_head list; 122 char *smk_known; 123 u32 smk_secid; 124 struct netlbl_lsm_secattr smk_netlabel; /* on wire labels */ 125 struct list_head smk_rules; /* access rules */ 126 struct mutex smk_rules_lock; /* lock for rules */ 127 }; 128 129 /* 130 * Mount options 131 */ 132 #define SMK_FSDEFAULT "smackfsdef=" 133 #define SMK_FSFLOOR "smackfsfloor=" 134 #define SMK_FSHAT "smackfshat=" 135 #define SMK_FSROOT "smackfsroot=" 136 137 #define SMACK_CIPSO_OPTION "-CIPSO" 138 139 /* 140 * How communications on this socket are treated. 141 * Usually it's determined by the underlying netlabel code 142 * but there are certain cases, including single label hosts 143 * and potentially single label interfaces for which the 144 * treatment can not be known in advance. 145 * 146 * The possibility of additional labeling schemes being 147 * introduced in the future exists as well. 148 */ 149 #define SMACK_UNLABELED_SOCKET 0 150 #define SMACK_CIPSO_SOCKET 1 151 152 /* 153 * smackfs magic 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_MAPPED_DEFAULT 251 /* Also arbitrary */ 164 #define SMACK_CIPSO_MAXCATVAL 63 /* Bigger gets harder */ 165 #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ 166 #define SMACK_CIPSO_MAXCATNUM 239 /* CIPSO 2.2 standard */ 167 168 /* 169 * Flag for transmute access 170 */ 171 #define MAY_TRANSMUTE 64 172 /* 173 * Just to make the common cases easier to deal with 174 */ 175 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 176 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 177 #define MAY_NOT 0 178 179 /* 180 * Number of access types used by Smack (rwxat) 181 */ 182 #define SMK_NUM_ACCESS_TYPE 5 183 184 /* SMACK data */ 185 struct smack_audit_data { 186 const char *function; 187 char *subject; 188 char *object; 189 char *request; 190 int result; 191 }; 192 193 /* 194 * Smack audit data; is empty if CONFIG_AUDIT not set 195 * to save some stack 196 */ 197 struct smk_audit_info { 198 #ifdef CONFIG_AUDIT 199 struct common_audit_data a; 200 struct smack_audit_data sad; 201 #endif 202 }; 203 /* 204 * These functions are in smack_lsm.c 205 */ 206 struct inode_smack *new_inode_smack(char *); 207 208 /* 209 * These functions are in smack_access.c 210 */ 211 int smk_access_entry(char *, char *, struct list_head *); 212 int smk_access(char *, char *, int, struct smk_audit_info *); 213 int smk_curacc(char *, u32, struct smk_audit_info *); 214 char *smack_from_secid(const u32); 215 char *smk_parse_smack(const char *string, int len); 216 int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); 217 char *smk_import(const char *, int); 218 struct smack_known *smk_import_entry(const char *, int); 219 struct smack_known *smk_find_entry(const char *); 220 u32 smack_to_secid(const char *); 221 222 /* 223 * Shared data. 224 */ 225 extern int smack_cipso_direct; 226 extern int smack_cipso_mapped; 227 extern char *smack_net_ambient; 228 extern char *smack_onlycap; 229 extern const char *smack_cipso_option; 230 231 extern struct smack_known smack_known_floor; 232 extern struct smack_known smack_known_hat; 233 extern struct smack_known smack_known_huh; 234 extern struct smack_known smack_known_invalid; 235 extern struct smack_known smack_known_star; 236 extern struct smack_known smack_known_web; 237 238 extern struct mutex smack_known_lock; 239 extern struct list_head smack_known_list; 240 extern struct list_head smk_netlbladdr_list; 241 242 extern struct security_operations smack_ops; 243 244 /* 245 * Is the directory transmuting? 246 */ 247 static inline int smk_inode_transmutable(const struct inode *isp) 248 { 249 struct inode_smack *sip = isp->i_security; 250 return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; 251 } 252 253 /* 254 * Present a pointer to the smack label in an inode blob. 255 */ 256 static inline char *smk_of_inode(const struct inode *isp) 257 { 258 struct inode_smack *sip = isp->i_security; 259 return sip->smk_inode; 260 } 261 262 /* 263 * Present a pointer to the smack label in an task blob. 264 */ 265 static inline char *smk_of_task(const struct task_smack *tsp) 266 { 267 return tsp->smk_task; 268 } 269 270 /* 271 * Present a pointer to the forked smack label in an task blob. 272 */ 273 static inline char *smk_of_forked(const struct task_smack *tsp) 274 { 275 return tsp->smk_forked; 276 } 277 278 /* 279 * Present a pointer to the smack label in the current task blob. 280 */ 281 static inline char *smk_of_current(void) 282 { 283 return smk_of_task(current_security()); 284 } 285 286 /* 287 * logging functions 288 */ 289 #define SMACK_AUDIT_DENIED 0x1 290 #define SMACK_AUDIT_ACCEPT 0x2 291 extern int log_policy; 292 293 void smack_log(char *subject_label, char *object_label, 294 int request, 295 int result, struct smk_audit_info *auditdata); 296 297 #ifdef CONFIG_AUDIT 298 299 /* 300 * some inline functions to set up audit data 301 * they do nothing if CONFIG_AUDIT is not set 302 * 303 */ 304 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 305 char type) 306 { 307 memset(&a->sad, 0, sizeof(a->sad)); 308 a->a.type = type; 309 a->a.smack_audit_data = &a->sad; 310 a->a.smack_audit_data->function = func; 311 } 312 313 static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func, 314 char type, struct lsm_network_audit *net) 315 { 316 smk_ad_init(a, func, type); 317 memset(net, 0, sizeof(*net)); 318 a->a.u.net = net; 319 } 320 321 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 322 struct task_struct *t) 323 { 324 a->a.u.tsk = t; 325 } 326 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 327 struct dentry *d) 328 { 329 a->a.u.dentry = d; 330 } 331 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 332 struct inode *i) 333 { 334 a->a.u.inode = i; 335 } 336 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 337 struct path p) 338 { 339 a->a.u.path = p; 340 } 341 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 342 struct sock *sk) 343 { 344 a->a.u.net->sk = sk; 345 } 346 347 #else /* no AUDIT */ 348 349 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 350 char type) 351 { 352 } 353 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 354 struct task_struct *t) 355 { 356 } 357 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 358 struct dentry *d) 359 { 360 } 361 static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a, 362 struct vfsmount *m) 363 { 364 } 365 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 366 struct inode *i) 367 { 368 } 369 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 370 struct path p) 371 { 372 } 373 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 374 struct sock *sk) 375 { 376 } 377 #endif 378 379 #endif /* _SECURITY_SMACK_H */ 380