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_flags; 94 }; 95 96 /* 97 * Superblock flags 98 */ 99 #define SMK_SB_INITIALIZED 0x01 100 #define SMK_SB_UNTRUSTED 0x02 101 102 struct socket_smack { 103 struct smack_known *smk_out; /* outbound label */ 104 struct smack_known *smk_in; /* inbound label */ 105 struct smack_known *smk_packet; /* TCP peer label */ 106 }; 107 108 /* 109 * Inode smack data 110 */ 111 struct inode_smack { 112 struct smack_known *smk_inode; /* label of the fso */ 113 struct smack_known *smk_task; /* label of the task */ 114 struct smack_known *smk_mmap; /* label of the mmap domain */ 115 struct mutex smk_lock; /* initialization lock */ 116 int smk_flags; /* smack inode flags */ 117 struct rcu_head smk_rcu; /* for freeing inode_smack */ 118 }; 119 120 struct task_smack { 121 struct smack_known *smk_task; /* label for access control */ 122 struct smack_known *smk_forked; /* label when forked */ 123 struct list_head smk_rules; /* per task access rules */ 124 struct mutex smk_rules_lock; /* lock for the rules */ 125 struct list_head smk_relabel; /* transit allowed labels */ 126 }; 127 128 #define SMK_INODE_INSTANT 0x01 /* inode is instantiated */ 129 #define SMK_INODE_TRANSMUTE 0x02 /* directory is transmuting */ 130 #define SMK_INODE_CHANGED 0x04 /* smack was transmuted */ 131 #define SMK_INODE_IMPURE 0x08 /* involved in an impure transaction */ 132 133 /* 134 * A label access rule. 135 */ 136 struct smack_rule { 137 struct list_head list; 138 struct smack_known *smk_subject; 139 struct smack_known *smk_object; 140 int smk_access; 141 }; 142 143 /* 144 * An entry in the table identifying IPv4 hosts. 145 */ 146 struct smk_net4addr { 147 struct list_head list; 148 struct in_addr smk_host; /* network address */ 149 struct in_addr smk_mask; /* network mask */ 150 int smk_masks; /* mask size */ 151 struct smack_known *smk_label; /* label */ 152 }; 153 154 #if IS_ENABLED(CONFIG_IPV6) 155 /* 156 * An entry in the table identifying IPv6 hosts. 157 */ 158 struct smk_net6addr { 159 struct list_head list; 160 struct in6_addr smk_host; /* network address */ 161 struct in6_addr smk_mask; /* network mask */ 162 int smk_masks; /* mask size */ 163 struct smack_known *smk_label; /* label */ 164 }; 165 #endif /* CONFIG_IPV6 */ 166 167 #ifdef SMACK_IPV6_PORT_LABELING 168 /* 169 * An entry in the table identifying ports. 170 */ 171 struct smk_port_label { 172 struct list_head list; 173 struct sock *smk_sock; /* socket initialized on */ 174 unsigned short smk_port; /* the port number */ 175 struct smack_known *smk_in; /* inbound label */ 176 struct smack_known *smk_out; /* outgoing label */ 177 short smk_sock_type; /* Socket type */ 178 short smk_can_reuse; 179 }; 180 #endif /* SMACK_IPV6_PORT_LABELING */ 181 182 struct smack_known_list_elem { 183 struct list_head list; 184 struct smack_known *smk_label; 185 }; 186 187 /* Super block security struct flags for mount options */ 188 #define FSDEFAULT_MNT 0x01 189 #define FSFLOOR_MNT 0x02 190 #define FSHAT_MNT 0x04 191 #define FSROOT_MNT 0x08 192 #define FSTRANS_MNT 0x10 193 194 #define NUM_SMK_MNT_OPTS 5 195 196 enum { 197 Opt_error = -1, 198 Opt_fsdefault = 1, 199 Opt_fsfloor = 2, 200 Opt_fshat = 3, 201 Opt_fsroot = 4, 202 Opt_fstransmute = 5, 203 }; 204 205 /* 206 * Mount options 207 */ 208 #define SMK_FSDEFAULT "smackfsdef=" 209 #define SMK_FSFLOOR "smackfsfloor=" 210 #define SMK_FSHAT "smackfshat=" 211 #define SMK_FSROOT "smackfsroot=" 212 #define SMK_FSTRANS "smackfstransmute=" 213 214 #define SMACK_DELETE_OPTION "-DELETE" 215 #define SMACK_CIPSO_OPTION "-CIPSO" 216 217 /* 218 * How communications on this socket are treated. 219 * Usually it's determined by the underlying netlabel code 220 * but there are certain cases, including single label hosts 221 * and potentially single label interfaces for which the 222 * treatment can not be known in advance. 223 * 224 * The possibility of additional labeling schemes being 225 * introduced in the future exists as well. 226 */ 227 #define SMACK_UNLABELED_SOCKET 0 228 #define SMACK_CIPSO_SOCKET 1 229 230 /* 231 * CIPSO defaults. 232 */ 233 #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ 234 #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ 235 #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ 236 #define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */ 237 #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ 238 /* 239 * CIPSO 2.2 standard is 239, but Smack wants to use the 240 * categories in a structured way that limits the value to 241 * the bits in 23 bytes, hence the unusual number. 242 */ 243 #define SMACK_CIPSO_MAXCATNUM 184 /* 23 * 8 */ 244 245 /* 246 * Ptrace rules 247 */ 248 #define SMACK_PTRACE_DEFAULT 0 249 #define SMACK_PTRACE_EXACT 1 250 #define SMACK_PTRACE_DRACONIAN 2 251 #define SMACK_PTRACE_MAX SMACK_PTRACE_DRACONIAN 252 253 /* 254 * Flags for untraditional access modes. 255 * It shouldn't be necessary to avoid conflicts with definitions 256 * in fs.h, but do so anyway. 257 */ 258 #define MAY_TRANSMUTE 0x00001000 /* Controls directory labeling */ 259 #define MAY_LOCK 0x00002000 /* Locks should be writes, but ... */ 260 #define MAY_BRINGUP 0x00004000 /* Report use of this rule */ 261 262 /* 263 * The policy for delivering signals is configurable. 264 * It is usually "write", but can be "append". 265 */ 266 #ifdef CONFIG_SECURITY_SMACK_APPEND_SIGNALS 267 #define MAY_DELIVER MAY_APPEND /* Signal delivery requires append */ 268 #else 269 #define MAY_DELIVER MAY_WRITE /* Signal delivery requires write */ 270 #endif 271 272 #define SMACK_BRINGUP_ALLOW 1 /* Allow bringup mode */ 273 #define SMACK_UNCONFINED_SUBJECT 2 /* Allow unconfined label */ 274 #define SMACK_UNCONFINED_OBJECT 3 /* Allow unconfined label */ 275 276 /* 277 * Just to make the common cases easier to deal with 278 */ 279 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 280 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 281 #define MAY_NOT 0 282 283 /* 284 * Number of access types used by Smack (rwxatlb) 285 */ 286 #define SMK_NUM_ACCESS_TYPE 7 287 288 /* SMACK data */ 289 struct smack_audit_data { 290 const char *function; 291 char *subject; 292 char *object; 293 char *request; 294 int result; 295 }; 296 297 /* 298 * Smack audit data; is empty if CONFIG_AUDIT not set 299 * to save some stack 300 */ 301 struct smk_audit_info { 302 #ifdef CONFIG_AUDIT 303 struct common_audit_data a; 304 struct smack_audit_data sad; 305 #endif 306 }; 307 308 /* 309 * These functions are in smack_access.c 310 */ 311 int smk_access_entry(char *, char *, struct list_head *); 312 int smk_access(struct smack_known *, struct smack_known *, 313 int, struct smk_audit_info *); 314 int smk_tskacc(struct task_smack *, struct smack_known *, 315 u32, struct smk_audit_info *); 316 int smk_curacc(struct smack_known *, u32, struct smk_audit_info *); 317 struct smack_known *smack_from_secid(const u32); 318 char *smk_parse_smack(const char *string, int len); 319 int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); 320 struct smack_known *smk_import_entry(const char *, int); 321 void smk_insert_entry(struct smack_known *skp); 322 struct smack_known *smk_find_entry(const char *); 323 bool smack_privileged(int cap); 324 bool smack_privileged_cred(int cap, const struct cred *cred); 325 void smk_destroy_label_list(struct list_head *list); 326 327 /* 328 * Shared data. 329 */ 330 extern int smack_enabled; 331 extern int smack_cipso_direct; 332 extern int smack_cipso_mapped; 333 extern struct smack_known *smack_net_ambient; 334 extern struct smack_known *smack_syslog_label; 335 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 336 extern struct smack_known *smack_unconfined; 337 #endif 338 extern int smack_ptrace_rule; 339 340 extern struct smack_known smack_known_floor; 341 extern struct smack_known smack_known_hat; 342 extern struct smack_known smack_known_huh; 343 extern struct smack_known smack_known_star; 344 extern struct smack_known smack_known_web; 345 346 extern struct mutex smack_known_lock; 347 extern struct list_head smack_known_list; 348 extern struct list_head smk_net4addr_list; 349 #if IS_ENABLED(CONFIG_IPV6) 350 extern struct list_head smk_net6addr_list; 351 #endif /* CONFIG_IPV6 */ 352 353 extern struct mutex smack_onlycap_lock; 354 extern struct list_head smack_onlycap_list; 355 356 #define SMACK_HASH_SLOTS 16 357 extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; 358 359 /* 360 * Is the directory transmuting? 361 */ 362 static inline int smk_inode_transmutable(const struct inode *isp) 363 { 364 struct inode_smack *sip = isp->i_security; 365 return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; 366 } 367 368 /* 369 * Present a pointer to the smack label entry in an inode blob. 370 */ 371 static inline struct smack_known *smk_of_inode(const struct inode *isp) 372 { 373 struct inode_smack *sip = isp->i_security; 374 return sip->smk_inode; 375 } 376 377 /* 378 * Present a pointer to the smack label entry in an task blob. 379 */ 380 static inline struct smack_known *smk_of_task(const struct task_smack *tsp) 381 { 382 return tsp->smk_task; 383 } 384 385 static inline struct smack_known *smk_of_task_struct(const struct task_struct *t) 386 { 387 struct smack_known *skp; 388 389 rcu_read_lock(); 390 skp = smk_of_task(__task_cred(t)->security); 391 rcu_read_unlock(); 392 return skp; 393 } 394 395 /* 396 * Present a pointer to the forked smack label entry in an task blob. 397 */ 398 static inline struct smack_known *smk_of_forked(const struct task_smack *tsp) 399 { 400 return tsp->smk_forked; 401 } 402 403 /* 404 * Present a pointer to the smack label in the current task blob. 405 */ 406 static inline struct smack_known *smk_of_current(void) 407 { 408 return smk_of_task(current_security()); 409 } 410 411 /* 412 * logging functions 413 */ 414 #define SMACK_AUDIT_DENIED 0x1 415 #define SMACK_AUDIT_ACCEPT 0x2 416 extern int log_policy; 417 418 void smack_log(char *subject_label, char *object_label, 419 int request, 420 int result, struct smk_audit_info *auditdata); 421 422 #ifdef CONFIG_AUDIT 423 424 /* 425 * some inline functions to set up audit data 426 * they do nothing if CONFIG_AUDIT is not set 427 * 428 */ 429 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 430 char type) 431 { 432 memset(&a->sad, 0, sizeof(a->sad)); 433 a->a.type = type; 434 a->a.smack_audit_data = &a->sad; 435 a->a.smack_audit_data->function = func; 436 } 437 438 static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func, 439 char type, struct lsm_network_audit *net) 440 { 441 smk_ad_init(a, func, type); 442 memset(net, 0, sizeof(*net)); 443 a->a.u.net = net; 444 } 445 446 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 447 struct task_struct *t) 448 { 449 a->a.u.tsk = t; 450 } 451 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 452 struct dentry *d) 453 { 454 a->a.u.dentry = d; 455 } 456 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 457 struct inode *i) 458 { 459 a->a.u.inode = i; 460 } 461 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 462 struct path p) 463 { 464 a->a.u.path = p; 465 } 466 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 467 struct sock *sk) 468 { 469 a->a.u.net->sk = sk; 470 } 471 472 #else /* no AUDIT */ 473 474 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 475 char type) 476 { 477 } 478 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 479 struct task_struct *t) 480 { 481 } 482 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 483 struct dentry *d) 484 { 485 } 486 static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a, 487 struct vfsmount *m) 488 { 489 } 490 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 491 struct inode *i) 492 { 493 } 494 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 495 struct path p) 496 { 497 } 498 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 499 struct sock *sk) 500 { 501 } 502 #endif 503 504 #endif /* _SECURITY_SMACK_H */ 505