1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> 4 * 5 * Author: 6 * Casey Schaufler <casey@schaufler-ca.com> 7 */ 8 9 #ifndef _SECURITY_SMACK_H 10 #define _SECURITY_SMACK_H 11 12 #include <linux/capability.h> 13 #include <linux/spinlock.h> 14 #include <linux/lsm_hooks.h> 15 #include <linux/in.h> 16 #if IS_ENABLED(CONFIG_IPV6) 17 #include <linux/in6.h> 18 #endif /* CONFIG_IPV6 */ 19 #include <net/netlabel.h> 20 #include <linux/list.h> 21 #include <linux/rculist.h> 22 #include <linux/lsm_audit.h> 23 #include <linux/msg.h> 24 25 /* 26 * Use IPv6 port labeling if IPv6 is enabled and secmarks 27 * are not being used. 28 */ 29 #if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER) 30 #define SMACK_IPV6_PORT_LABELING 1 31 #endif 32 33 #if IS_ENABLED(CONFIG_IPV6) && defined(CONFIG_SECURITY_SMACK_NETFILTER) 34 #define SMACK_IPV6_SECMARK_LABELING 1 35 #endif 36 37 /* 38 * Smack labels were limited to 23 characters for a long time. 39 */ 40 #define SMK_LABELLEN 24 41 #define SMK_LONGLABEL 256 42 43 /* 44 * This is the repository for labels seen so that it is 45 * not necessary to keep allocating tiny chunks of memory 46 * and so that they can be shared. 47 * 48 * Labels are never modified in place. Anytime a label 49 * is imported (e.g. xattrset on a file) the list is checked 50 * for it and it is added if it doesn't exist. The address 51 * is passed out in either case. Entries are added, but 52 * never deleted. 53 * 54 * Since labels are hanging around anyway it doesn't 55 * hurt to maintain a secid for those awkward situations 56 * where kernel components that ought to use LSM independent 57 * interfaces don't. The secid should go away when all of 58 * these components have been repaired. 59 * 60 * The cipso value associated with the label gets stored here, too. 61 * 62 * Keep the access rules for this subject label here so that 63 * the entire set of rules does not need to be examined every 64 * time. 65 */ 66 struct smack_known { 67 struct list_head list; 68 struct hlist_node smk_hashed; 69 char *smk_known; 70 u32 smk_secid; 71 struct netlbl_lsm_secattr smk_netlabel; /* on wire labels */ 72 struct list_head smk_rules; /* access rules */ 73 struct mutex smk_rules_lock; /* lock for rules */ 74 }; 75 76 /* 77 * Maximum number of bytes for the levels in a CIPSO IP option. 78 * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is 79 * bigger than can be used, and 24 is the next lower multiple 80 * of 8, and there are too many issues if there isn't space set 81 * aside for the terminating null byte. 82 */ 83 #define SMK_CIPSOLEN 24 84 85 struct superblock_smack { 86 struct smack_known *smk_root; 87 struct smack_known *smk_floor; 88 struct smack_known *smk_hat; 89 struct smack_known *smk_default; 90 int smk_flags; 91 }; 92 93 /* 94 * Superblock flags 95 */ 96 #define SMK_SB_INITIALIZED 0x01 97 #define SMK_SB_UNTRUSTED 0x02 98 99 struct socket_smack { 100 struct smack_known *smk_out; /* outbound label */ 101 struct smack_known *smk_in; /* inbound label */ 102 struct smack_known *smk_packet; /* TCP peer label */ 103 int smk_state; /* netlabel socket states */ 104 }; 105 #define SMK_NETLBL_UNSET 0 106 #define SMK_NETLBL_UNLABELED 1 107 #define SMK_NETLBL_LABELED 2 108 #define SMK_NETLBL_REQSKB 3 109 110 /* 111 * Inode smack data 112 */ 113 struct inode_smack { 114 struct smack_known *smk_inode; /* label of the fso */ 115 struct smack_known *smk_task; /* label of the task */ 116 struct smack_known *smk_mmap; /* label of the mmap domain */ 117 int smk_flags; /* smack inode flags */ 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 smack_known *smk_transmuted;/* label when transmuted */ 124 struct list_head smk_rules; /* per task access rules */ 125 struct mutex smk_rules_lock; /* lock for the rules */ 126 struct list_head smk_relabel; /* transit allowed labels */ 127 }; 128 129 #define SMK_INODE_INSTANT 0x01 /* inode is instantiated */ 130 #define SMK_INODE_TRANSMUTE 0x02 /* directory is transmuting */ 131 #define SMK_INODE_CHANGED 0x04 /* smack was transmuted (unused) */ 132 #define SMK_INODE_IMPURE 0x08 /* involved in an impure transaction */ 133 134 /* 135 * A label access rule. 136 */ 137 struct smack_rule { 138 struct list_head list; 139 struct smack_known *smk_subject; 140 struct smack_known *smk_object; 141 int smk_access; 142 }; 143 144 /* 145 * An entry in the table identifying IPv4 hosts. 146 */ 147 struct smk_net4addr { 148 struct list_head list; 149 struct in_addr smk_host; /* network address */ 150 struct in_addr smk_mask; /* network mask */ 151 int smk_masks; /* mask size */ 152 struct smack_known *smk_label; /* label */ 153 }; 154 155 #if IS_ENABLED(CONFIG_IPV6) 156 /* 157 * An entry in the table identifying IPv6 hosts. 158 */ 159 struct smk_net6addr { 160 struct list_head list; 161 struct in6_addr smk_host; /* network address */ 162 struct in6_addr smk_mask; /* network mask */ 163 int smk_masks; /* mask size */ 164 struct smack_known *smk_label; /* label */ 165 }; 166 #endif /* CONFIG_IPV6 */ 167 168 #ifdef SMACK_IPV6_PORT_LABELING 169 /* 170 * An entry in the table identifying ports. 171 */ 172 struct smk_port_label { 173 struct list_head list; 174 struct sock *smk_sock; /* socket initialized on */ 175 unsigned short smk_port; /* the port number */ 176 struct smack_known *smk_in; /* inbound label */ 177 struct smack_known *smk_out; /* outgoing label */ 178 short smk_sock_type; /* Socket type */ 179 short smk_can_reuse; 180 }; 181 #endif /* SMACK_IPV6_PORT_LABELING */ 182 183 struct smack_known_list_elem { 184 struct list_head list; 185 struct smack_known *smk_label; 186 }; 187 188 enum { 189 Opt_error = -1, 190 Opt_fsdefault = 0, 191 Opt_fsfloor = 1, 192 Opt_fshat = 2, 193 Opt_fsroot = 3, 194 Opt_fstransmute = 4, 195 }; 196 197 #define SMACK_DELETE_OPTION "-DELETE" 198 #define SMACK_CIPSO_OPTION "-CIPSO" 199 200 /* 201 * CIPSO defaults. 202 */ 203 #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ 204 #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ 205 #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ 206 #define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */ 207 #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ 208 /* 209 * CIPSO 2.2 standard is 239, but Smack wants to use the 210 * categories in a structured way that limits the value to 211 * the bits in 23 bytes, hence the unusual number. 212 */ 213 #define SMACK_CIPSO_MAXCATNUM 184 /* 23 * 8 */ 214 215 /* 216 * Ptrace rules 217 */ 218 #define SMACK_PTRACE_DEFAULT 0 219 #define SMACK_PTRACE_EXACT 1 220 #define SMACK_PTRACE_DRACONIAN 2 221 #define SMACK_PTRACE_MAX SMACK_PTRACE_DRACONIAN 222 223 /* 224 * Flags for untraditional access modes. 225 * It shouldn't be necessary to avoid conflicts with definitions 226 * in fs.h, but do so anyway. 227 */ 228 #define MAY_TRANSMUTE 0x00001000 /* Controls directory labeling */ 229 #define MAY_LOCK 0x00002000 /* Locks should be writes, but ... */ 230 #define MAY_BRINGUP 0x00004000 /* Report use of this rule */ 231 232 /* 233 * The policy for delivering signals is configurable. 234 * It is usually "write", but can be "append". 235 */ 236 #ifdef CONFIG_SECURITY_SMACK_APPEND_SIGNALS 237 #define MAY_DELIVER MAY_APPEND /* Signal delivery requires append */ 238 #else 239 #define MAY_DELIVER MAY_WRITE /* Signal delivery requires write */ 240 #endif 241 242 #define SMACK_BRINGUP_ALLOW 1 /* Allow bringup mode */ 243 #define SMACK_UNCONFINED_SUBJECT 2 /* Allow unconfined label */ 244 #define SMACK_UNCONFINED_OBJECT 3 /* Allow unconfined label */ 245 246 /* 247 * Just to make the common cases easier to deal with 248 */ 249 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 250 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 251 #define MAY_NOT 0 252 253 /* 254 * Number of access types used by Smack (rwxatlb) 255 */ 256 #define SMK_NUM_ACCESS_TYPE 7 257 258 /* SMACK data */ 259 struct smack_audit_data { 260 const char *function; 261 char *subject; 262 char *object; 263 char *request; 264 int result; 265 }; 266 267 /* 268 * Smack audit data; is empty if CONFIG_AUDIT not set 269 * to save some stack 270 */ 271 struct smk_audit_info { 272 #ifdef CONFIG_AUDIT 273 struct common_audit_data a; 274 struct smack_audit_data sad; 275 #endif 276 }; 277 278 /* 279 * These functions are in smack_access.c 280 */ 281 int smk_access_entry(char *, char *, struct list_head *); 282 int smk_access(struct smack_known *, struct smack_known *, 283 int, struct smk_audit_info *); 284 int smk_tskacc(struct task_smack *, struct smack_known *, 285 u32, struct smk_audit_info *); 286 int smk_curacc(struct smack_known *, u32, struct smk_audit_info *); 287 int smack_str_from_perm(char *string, int access); 288 struct smack_known *smack_from_secid(const u32); 289 int smk_parse_label_len(const char *string, int len); 290 char *smk_parse_smack(const char *string, int len); 291 int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); 292 struct smack_known *smk_import_entry(const char *, int); 293 struct smack_known *smk_import_valid_label(const char *label, int label_len, 294 gfp_t gfp); 295 void smk_insert_entry(struct smack_known *skp); 296 struct smack_known *smk_find_entry(const char *); 297 bool smack_privileged(int cap); 298 bool smack_privileged_cred(int cap, const struct cred *cred); 299 void smk_destroy_label_list(struct list_head *list); 300 int smack_populate_secattr(struct smack_known *skp); 301 302 /* 303 * Shared data. 304 */ 305 extern int smack_enabled __initdata; 306 extern int smack_cipso_direct; 307 extern int smack_cipso_mapped; 308 extern struct smack_known *smack_net_ambient; 309 extern struct smack_known *smack_syslog_label; 310 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 311 extern struct smack_known *smack_unconfined; 312 #endif 313 extern int smack_ptrace_rule; 314 extern struct lsm_blob_sizes smack_blob_sizes; 315 316 extern struct smack_known smack_known_floor; 317 extern struct smack_known smack_known_hat; 318 extern struct smack_known smack_known_huh; 319 extern struct smack_known smack_known_star; 320 extern struct smack_known smack_known_web; 321 322 extern struct mutex smack_known_lock; 323 extern struct list_head smack_known_list; 324 extern struct list_head smk_net4addr_list; 325 #if IS_ENABLED(CONFIG_IPV6) 326 extern struct list_head smk_net6addr_list; 327 #endif /* CONFIG_IPV6 */ 328 329 extern struct mutex smack_onlycap_lock; 330 extern struct list_head smack_onlycap_list; 331 332 #define SMACK_HASH_SLOTS 16 333 extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; 334 extern struct kmem_cache *smack_rule_cache; 335 336 static inline struct task_smack *smack_cred(const struct cred *cred) 337 { 338 return cred->security + smack_blob_sizes.lbs_cred; 339 } 340 341 static inline struct smack_known **smack_file(const struct file *file) 342 { 343 return (struct smack_known **)(file->f_security + 344 smack_blob_sizes.lbs_file); 345 } 346 347 static inline struct inode_smack *smack_inode(const struct inode *inode) 348 { 349 return inode->i_security + smack_blob_sizes.lbs_inode; 350 } 351 352 static inline struct smack_known **smack_msg_msg(const struct msg_msg *msg) 353 { 354 return msg->security + smack_blob_sizes.lbs_msg_msg; 355 } 356 357 static inline struct smack_known **smack_ipc(const struct kern_ipc_perm *ipc) 358 { 359 return ipc->security + smack_blob_sizes.lbs_ipc; 360 } 361 362 static inline struct superblock_smack *smack_superblock( 363 const struct super_block *superblock) 364 { 365 return superblock->s_security + smack_blob_sizes.lbs_superblock; 366 } 367 368 static inline struct socket_smack *smack_sock(const struct sock *sock) 369 { 370 return sock->sk_security + smack_blob_sizes.lbs_sock; 371 } 372 373 #ifdef CONFIG_KEYS 374 static inline struct smack_known **smack_key(const struct key *key) 375 { 376 return key->security + smack_blob_sizes.lbs_key; 377 } 378 #endif /* CONFIG_KEYS */ 379 380 /* 381 * Is the directory transmuting? 382 */ 383 static inline int smk_inode_transmutable(const struct inode *isp) 384 { 385 struct inode_smack *sip = smack_inode(isp); 386 return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; 387 } 388 389 /* 390 * Present a pointer to the smack label entry in an inode blob. 391 */ 392 static inline struct smack_known *smk_of_inode(const struct inode *isp) 393 { 394 struct inode_smack *sip = smack_inode(isp); 395 return sip->smk_inode; 396 } 397 398 /* 399 * Present a pointer to the smack label entry in an task blob. 400 */ 401 static inline struct smack_known *smk_of_task(const struct task_smack *tsp) 402 { 403 return tsp->smk_task; 404 } 405 406 static inline struct smack_known *smk_of_task_struct_obj( 407 const struct task_struct *t) 408 { 409 struct smack_known *skp; 410 const struct cred *cred; 411 412 rcu_read_lock(); 413 414 cred = __task_cred(t); 415 skp = smk_of_task(smack_cred(cred)); 416 417 rcu_read_unlock(); 418 419 return skp; 420 } 421 422 /* 423 * Present a pointer to the forked smack label entry in an task blob. 424 */ 425 static inline struct smack_known *smk_of_forked(const struct task_smack *tsp) 426 { 427 return tsp->smk_forked; 428 } 429 430 /* 431 * Present a pointer to the smack label in the current task blob. 432 */ 433 static inline struct smack_known *smk_of_current(void) 434 { 435 return smk_of_task(smack_cred(current_cred())); 436 } 437 438 void smack_log(char *subject_label, char *object_label, 439 int request, 440 int result, struct smk_audit_info *auditdata); 441 442 #ifdef CONFIG_AUDIT 443 444 /* 445 * logging functions 446 */ 447 #define SMACK_AUDIT_DENIED 0x1 448 #define SMACK_AUDIT_ACCEPT 0x2 449 extern int log_policy; 450 451 /* 452 * some inline functions to set up audit data 453 * they do nothing if CONFIG_AUDIT is not set 454 * 455 */ 456 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 457 char type) 458 { 459 memset(&a->sad, 0, sizeof(a->sad)); 460 a->a.type = type; 461 a->a.smack_audit_data = &a->sad; 462 a->a.smack_audit_data->function = func; 463 } 464 465 static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func, 466 char type, struct lsm_network_audit *net) 467 { 468 smk_ad_init(a, func, type); 469 memset(net, 0, sizeof(*net)); 470 a->a.u.net = net; 471 } 472 473 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 474 struct task_struct *t) 475 { 476 a->a.u.tsk = t; 477 } 478 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 479 struct dentry *d) 480 { 481 a->a.u.dentry = d; 482 } 483 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 484 struct inode *i) 485 { 486 a->a.u.inode = i; 487 } 488 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 489 struct path p) 490 { 491 a->a.u.path = p; 492 } 493 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 494 struct sock *sk) 495 { 496 a->a.u.net->sk = sk; 497 } 498 499 #else /* no AUDIT */ 500 501 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 502 char type) 503 { 504 } 505 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 506 struct task_struct *t) 507 { 508 } 509 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 510 struct dentry *d) 511 { 512 } 513 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 514 struct inode *i) 515 { 516 } 517 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 518 struct path p) 519 { 520 } 521 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 522 struct sock *sk) 523 { 524 } 525 #endif 526 527 #endif /* _SECURITY_SMACK_H */ 528