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/lsm_hooks.h> 19 #include <linux/in.h> 20 #if IS_ENABLED(CONFIG_IPV6) 21 #include <linux/in6.h> 22 #endif /* CONFIG_IPV6 */ 23 #include <net/netlabel.h> 24 #include <linux/list.h> 25 #include <linux/rculist.h> 26 #include <linux/lsm_audit.h> 27 28 /* 29 * Use IPv6 port labeling if IPv6 is enabled and secmarks 30 * are not being used. 31 */ 32 #if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER) 33 #define SMACK_IPV6_PORT_LABELING 1 34 #endif 35 36 #if IS_ENABLED(CONFIG_IPV6) && defined(CONFIG_SECURITY_SMACK_NETFILTER) 37 #define SMACK_IPV6_SECMARK_LABELING 1 38 #endif 39 40 /* 41 * Smack labels were limited to 23 characters for a long time. 42 */ 43 #define SMK_LABELLEN 24 44 #define SMK_LONGLABEL 256 45 46 /* 47 * This is the repository for labels seen so that it is 48 * not necessary to keep allocating tiny chuncks of memory 49 * and so that they can be shared. 50 * 51 * Labels are never modified in place. Anytime a label 52 * is imported (e.g. xattrset on a file) the list is checked 53 * for it and it is added if it doesn't exist. The address 54 * is passed out in either case. Entries are added, but 55 * never deleted. 56 * 57 * Since labels are hanging around anyway it doesn't 58 * hurt to maintain a secid for those awkward situations 59 * where kernel components that ought to use LSM independent 60 * interfaces don't. The secid should go away when all of 61 * these components have been repaired. 62 * 63 * The cipso value associated with the label gets stored here, too. 64 * 65 * Keep the access rules for this subject label here so that 66 * the entire set of rules does not need to be examined every 67 * time. 68 */ 69 struct smack_known { 70 struct list_head list; 71 struct hlist_node smk_hashed; 72 char *smk_known; 73 u32 smk_secid; 74 struct netlbl_lsm_secattr smk_netlabel; /* on wire labels */ 75 struct list_head smk_rules; /* access rules */ 76 struct mutex smk_rules_lock; /* lock for rules */ 77 }; 78 79 /* 80 * Maximum number of bytes for the levels in a CIPSO IP option. 81 * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is 82 * bigger than can be used, and 24 is the next lower multiple 83 * of 8, and there are too many issues if there isn't space set 84 * aside for the terminating null byte. 85 */ 86 #define SMK_CIPSOLEN 24 87 88 struct superblock_smack { 89 struct smack_known *smk_root; 90 struct smack_known *smk_floor; 91 struct smack_known *smk_hat; 92 struct smack_known *smk_default; 93 int smk_initialized; 94 }; 95 96 struct socket_smack { 97 struct smack_known *smk_out; /* outbound label */ 98 struct smack_known *smk_in; /* inbound label */ 99 struct smack_known *smk_packet; /* TCP peer label */ 100 }; 101 102 /* 103 * Inode smack data 104 */ 105 struct inode_smack { 106 struct smack_known *smk_inode; /* label of the fso */ 107 struct smack_known *smk_task; /* label of the task */ 108 struct smack_known *smk_mmap; /* label of the mmap domain */ 109 struct mutex smk_lock; /* initialization lock */ 110 int smk_flags; /* smack inode flags */ 111 }; 112 113 struct task_smack { 114 struct smack_known *smk_task; /* label for access control */ 115 struct smack_known *smk_forked; /* label when forked */ 116 struct list_head smk_rules; /* per task access rules */ 117 struct mutex smk_rules_lock; /* lock for the rules */ 118 struct list_head smk_relabel; /* transit allowed labels */ 119 }; 120 121 #define SMK_INODE_INSTANT 0x01 /* inode is instantiated */ 122 #define SMK_INODE_TRANSMUTE 0x02 /* directory is transmuting */ 123 #define SMK_INODE_CHANGED 0x04 /* smack was transmuted */ 124 #define SMK_INODE_IMPURE 0x08 /* involved in an impure transaction */ 125 126 /* 127 * A label access rule. 128 */ 129 struct smack_rule { 130 struct list_head list; 131 struct smack_known *smk_subject; 132 struct smack_known *smk_object; 133 int smk_access; 134 }; 135 136 /* 137 * An entry in the table identifying IPv4 hosts. 138 */ 139 struct smk_net4addr { 140 struct list_head list; 141 struct in_addr smk_host; /* network address */ 142 struct in_addr smk_mask; /* network mask */ 143 int smk_masks; /* mask size */ 144 struct smack_known *smk_label; /* label */ 145 }; 146 147 #if IS_ENABLED(CONFIG_IPV6) 148 /* 149 * An entry in the table identifying IPv6 hosts. 150 */ 151 struct smk_net6addr { 152 struct list_head list; 153 struct in6_addr smk_host; /* network address */ 154 struct in6_addr smk_mask; /* network mask */ 155 int smk_masks; /* mask size */ 156 struct smack_known *smk_label; /* label */ 157 }; 158 #endif /* CONFIG_IPV6 */ 159 160 #ifdef SMACK_IPV6_PORT_LABELING 161 /* 162 * An entry in the table identifying ports. 163 */ 164 struct smk_port_label { 165 struct list_head list; 166 struct sock *smk_sock; /* socket initialized on */ 167 unsigned short smk_port; /* the port number */ 168 struct smack_known *smk_in; /* inbound label */ 169 struct smack_known *smk_out; /* outgoing label */ 170 }; 171 #endif /* SMACK_IPV6_PORT_LABELING */ 172 173 struct smack_known_list_elem { 174 struct list_head list; 175 struct smack_known *smk_label; 176 }; 177 178 /* Super block security struct flags for mount options */ 179 #define FSDEFAULT_MNT 0x01 180 #define FSFLOOR_MNT 0x02 181 #define FSHAT_MNT 0x04 182 #define FSROOT_MNT 0x08 183 #define FSTRANS_MNT 0x10 184 185 #define NUM_SMK_MNT_OPTS 5 186 187 enum { 188 Opt_error = -1, 189 Opt_fsdefault = 1, 190 Opt_fsfloor = 2, 191 Opt_fshat = 3, 192 Opt_fsroot = 4, 193 Opt_fstransmute = 5, 194 }; 195 196 /* 197 * Mount options 198 */ 199 #define SMK_FSDEFAULT "smackfsdef=" 200 #define SMK_FSFLOOR "smackfsfloor=" 201 #define SMK_FSHAT "smackfshat=" 202 #define SMK_FSROOT "smackfsroot=" 203 #define SMK_FSTRANS "smackfstransmute=" 204 205 #define SMACK_DELETE_OPTION "-DELETE" 206 #define SMACK_CIPSO_OPTION "-CIPSO" 207 208 /* 209 * How communications on this socket are treated. 210 * Usually it's determined by the underlying netlabel code 211 * but there are certain cases, including single label hosts 212 * and potentially single label interfaces for which the 213 * treatment can not be known in advance. 214 * 215 * The possibility of additional labeling schemes being 216 * introduced in the future exists as well. 217 */ 218 #define SMACK_UNLABELED_SOCKET 0 219 #define SMACK_CIPSO_SOCKET 1 220 221 /* 222 * CIPSO defaults. 223 */ 224 #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ 225 #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ 226 #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ 227 #define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */ 228 #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ 229 /* 230 * CIPSO 2.2 standard is 239, but Smack wants to use the 231 * categories in a structured way that limits the value to 232 * the bits in 23 bytes, hence the unusual number. 233 */ 234 #define SMACK_CIPSO_MAXCATNUM 184 /* 23 * 8 */ 235 236 /* 237 * Ptrace rules 238 */ 239 #define SMACK_PTRACE_DEFAULT 0 240 #define SMACK_PTRACE_EXACT 1 241 #define SMACK_PTRACE_DRACONIAN 2 242 #define SMACK_PTRACE_MAX SMACK_PTRACE_DRACONIAN 243 244 /* 245 * Flags for untraditional access modes. 246 * It shouldn't be necessary to avoid conflicts with definitions 247 * in fs.h, but do so anyway. 248 */ 249 #define MAY_TRANSMUTE 0x00001000 /* Controls directory labeling */ 250 #define MAY_LOCK 0x00002000 /* Locks should be writes, but ... */ 251 #define MAY_BRINGUP 0x00004000 /* Report use of this rule */ 252 253 #define SMACK_BRINGUP_ALLOW 1 /* Allow bringup mode */ 254 #define SMACK_UNCONFINED_SUBJECT 2 /* Allow unconfined label */ 255 #define SMACK_UNCONFINED_OBJECT 3 /* Allow unconfined label */ 256 257 /* 258 * Just to make the common cases easier to deal with 259 */ 260 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 261 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 262 #define MAY_NOT 0 263 264 /* 265 * Number of access types used by Smack (rwxatlb) 266 */ 267 #define SMK_NUM_ACCESS_TYPE 7 268 269 /* SMACK data */ 270 struct smack_audit_data { 271 const char *function; 272 char *subject; 273 char *object; 274 char *request; 275 int result; 276 }; 277 278 /* 279 * Smack audit data; is empty if CONFIG_AUDIT not set 280 * to save some stack 281 */ 282 struct smk_audit_info { 283 #ifdef CONFIG_AUDIT 284 struct common_audit_data a; 285 struct smack_audit_data sad; 286 #endif 287 }; 288 289 /* 290 * These functions are in smack_access.c 291 */ 292 int smk_access_entry(char *, char *, struct list_head *); 293 int smk_access(struct smack_known *, struct smack_known *, 294 int, struct smk_audit_info *); 295 int smk_tskacc(struct task_smack *, struct smack_known *, 296 u32, struct smk_audit_info *); 297 int smk_curacc(struct smack_known *, u32, struct smk_audit_info *); 298 struct smack_known *smack_from_secid(const u32); 299 char *smk_parse_smack(const char *string, int len); 300 int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); 301 struct smack_known *smk_import_entry(const char *, int); 302 void smk_insert_entry(struct smack_known *skp); 303 struct smack_known *smk_find_entry(const char *); 304 int smack_privileged(int cap); 305 void smk_destroy_label_list(struct list_head *list); 306 307 /* 308 * Shared data. 309 */ 310 extern int smack_enabled; 311 extern int smack_cipso_direct; 312 extern int smack_cipso_mapped; 313 extern struct smack_known *smack_net_ambient; 314 extern struct smack_known *smack_syslog_label; 315 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 316 extern struct smack_known *smack_unconfined; 317 #endif 318 extern int smack_ptrace_rule; 319 320 extern struct smack_known smack_known_floor; 321 extern struct smack_known smack_known_hat; 322 extern struct smack_known smack_known_huh; 323 extern struct smack_known smack_known_invalid; 324 extern struct smack_known smack_known_star; 325 extern struct smack_known smack_known_web; 326 327 extern struct mutex smack_known_lock; 328 extern struct list_head smack_known_list; 329 extern struct list_head smk_net4addr_list; 330 #if IS_ENABLED(CONFIG_IPV6) 331 extern struct list_head smk_net6addr_list; 332 #endif /* CONFIG_IPV6 */ 333 334 extern struct mutex smack_onlycap_lock; 335 extern struct list_head smack_onlycap_list; 336 337 #define SMACK_HASH_SLOTS 16 338 extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; 339 340 /* 341 * Is the directory transmuting? 342 */ 343 static inline int smk_inode_transmutable(const struct inode *isp) 344 { 345 struct inode_smack *sip = isp->i_security; 346 return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; 347 } 348 349 /* 350 * Present a pointer to the smack label entry in an inode blob. 351 */ 352 static inline struct smack_known *smk_of_inode(const struct inode *isp) 353 { 354 struct inode_smack *sip = isp->i_security; 355 return sip->smk_inode; 356 } 357 358 /* 359 * Present a pointer to the smack label entry in an task blob. 360 */ 361 static inline struct smack_known *smk_of_task(const struct task_smack *tsp) 362 { 363 return tsp->smk_task; 364 } 365 366 static inline struct smack_known *smk_of_task_struct(const struct task_struct *t) 367 { 368 struct smack_known *skp; 369 370 rcu_read_lock(); 371 skp = smk_of_task(__task_cred(t)->security); 372 rcu_read_unlock(); 373 return skp; 374 } 375 376 /* 377 * Present a pointer to the forked smack label entry in an task blob. 378 */ 379 static inline struct smack_known *smk_of_forked(const struct task_smack *tsp) 380 { 381 return tsp->smk_forked; 382 } 383 384 /* 385 * Present a pointer to the smack label in the current task blob. 386 */ 387 static inline struct smack_known *smk_of_current(void) 388 { 389 return smk_of_task(current_security()); 390 } 391 392 /* 393 * logging functions 394 */ 395 #define SMACK_AUDIT_DENIED 0x1 396 #define SMACK_AUDIT_ACCEPT 0x2 397 extern int log_policy; 398 399 void smack_log(char *subject_label, char *object_label, 400 int request, 401 int result, struct smk_audit_info *auditdata); 402 403 #ifdef CONFIG_AUDIT 404 405 /* 406 * some inline functions to set up audit data 407 * they do nothing if CONFIG_AUDIT is not set 408 * 409 */ 410 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 411 char type) 412 { 413 memset(&a->sad, 0, sizeof(a->sad)); 414 a->a.type = type; 415 a->a.smack_audit_data = &a->sad; 416 a->a.smack_audit_data->function = func; 417 } 418 419 static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func, 420 char type, struct lsm_network_audit *net) 421 { 422 smk_ad_init(a, func, type); 423 memset(net, 0, sizeof(*net)); 424 a->a.u.net = net; 425 } 426 427 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 428 struct task_struct *t) 429 { 430 a->a.u.tsk = t; 431 } 432 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 433 struct dentry *d) 434 { 435 a->a.u.dentry = d; 436 } 437 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 438 struct inode *i) 439 { 440 a->a.u.inode = i; 441 } 442 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 443 struct path p) 444 { 445 a->a.u.path = p; 446 } 447 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 448 struct sock *sk) 449 { 450 a->a.u.net->sk = sk; 451 } 452 453 #else /* no AUDIT */ 454 455 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 456 char type) 457 { 458 } 459 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 460 struct task_struct *t) 461 { 462 } 463 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 464 struct dentry *d) 465 { 466 } 467 static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a, 468 struct vfsmount *m) 469 { 470 } 471 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 472 struct inode *i) 473 { 474 } 475 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 476 struct path p) 477 { 478 } 479 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 480 struct sock *sk) 481 { 482 } 483 #endif 484 485 #endif /* _SECURITY_SMACK_H */ 486