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 chuncks 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 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 /* 155 * An entry in the table identifying IPv6 hosts. 156 */ 157 struct smk_net6addr { 158 struct list_head list; 159 struct in6_addr smk_host; /* network address */ 160 struct in6_addr smk_mask; /* network mask */ 161 int smk_masks; /* mask size */ 162 struct smack_known *smk_label; /* label */ 163 }; 164 165 /* 166 * An entry in the table identifying ports. 167 */ 168 struct smk_port_label { 169 struct list_head list; 170 struct sock *smk_sock; /* socket initialized on */ 171 unsigned short smk_port; /* the port number */ 172 struct smack_known *smk_in; /* inbound label */ 173 struct smack_known *smk_out; /* outgoing label */ 174 short smk_sock_type; /* Socket type */ 175 short smk_can_reuse; 176 }; 177 178 struct smack_known_list_elem { 179 struct list_head list; 180 struct smack_known *smk_label; 181 }; 182 183 /* Super block security struct flags for mount options */ 184 #define FSDEFAULT_MNT 0x01 185 #define FSFLOOR_MNT 0x02 186 #define FSHAT_MNT 0x04 187 #define FSROOT_MNT 0x08 188 #define FSTRANS_MNT 0x10 189 190 #define NUM_SMK_MNT_OPTS 5 191 192 enum { 193 Opt_error = -1, 194 Opt_fsdefault = 0, 195 Opt_fsfloor = 1, 196 Opt_fshat = 2, 197 Opt_fsroot = 3, 198 Opt_fstransmute = 4, 199 }; 200 201 #define SMACK_DELETE_OPTION "-DELETE" 202 #define SMACK_CIPSO_OPTION "-CIPSO" 203 204 /* 205 * CIPSO defaults. 206 */ 207 #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ 208 #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ 209 #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ 210 #define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */ 211 #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ 212 /* 213 * CIPSO 2.2 standard is 239, but Smack wants to use the 214 * categories in a structured way that limits the value to 215 * the bits in 23 bytes, hence the unusual number. 216 */ 217 #define SMACK_CIPSO_MAXCATNUM 184 /* 23 * 8 */ 218 219 /* 220 * Ptrace rules 221 */ 222 #define SMACK_PTRACE_DEFAULT 0 223 #define SMACK_PTRACE_EXACT 1 224 #define SMACK_PTRACE_DRACONIAN 2 225 #define SMACK_PTRACE_MAX SMACK_PTRACE_DRACONIAN 226 227 /* 228 * Flags for untraditional access modes. 229 * It shouldn't be necessary to avoid conflicts with definitions 230 * in fs.h, but do so anyway. 231 */ 232 #define MAY_TRANSMUTE 0x00001000 /* Controls directory labeling */ 233 #define MAY_LOCK 0x00002000 /* Locks should be writes, but ... */ 234 #define MAY_BRINGUP 0x00004000 /* Report use of this rule */ 235 236 /* 237 * The policy for delivering signals is configurable. 238 * It is usually "write", but can be "append". 239 */ 240 #ifdef CONFIG_SECURITY_SMACK_APPEND_SIGNALS 241 #define MAY_DELIVER MAY_APPEND /* Signal delivery requires append */ 242 #else 243 #define MAY_DELIVER MAY_WRITE /* Signal delivery requires write */ 244 #endif 245 246 #define SMACK_BRINGUP_ALLOW 1 /* Allow bringup mode */ 247 #define SMACK_UNCONFINED_SUBJECT 2 /* Allow unconfined label */ 248 #define SMACK_UNCONFINED_OBJECT 3 /* Allow unconfined label */ 249 250 /* 251 * Just to make the common cases easier to deal with 252 */ 253 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 254 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 255 #define MAY_NOT 0 256 257 /* 258 * Number of access types used by Smack (rwxatlb) 259 */ 260 #define SMK_NUM_ACCESS_TYPE 7 261 262 /* SMACK data */ 263 struct smack_audit_data { 264 const char *function; 265 char *subject; 266 char *object; 267 char *request; 268 int result; 269 }; 270 271 /* 272 * Smack audit data; is empty if CONFIG_AUDIT not set 273 * to save some stack 274 */ 275 struct smk_audit_info { 276 #ifdef CONFIG_AUDIT 277 struct common_audit_data a; 278 struct smack_audit_data sad; 279 #endif 280 }; 281 282 /* 283 * These functions are in smack_access.c 284 */ 285 int smk_access_entry(char *, char *, struct list_head *); 286 int smk_access(struct smack_known *, struct smack_known *, 287 int, struct smk_audit_info *); 288 int smk_tskacc(struct task_smack *, struct smack_known *, 289 u32, struct smk_audit_info *); 290 int smk_curacc(struct smack_known *, u32, struct smk_audit_info *); 291 struct smack_known *smack_from_secid(const u32); 292 char *smk_parse_smack(const char *string, int len); 293 int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); 294 struct smack_known *smk_import_entry(const char *, int); 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; 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 extern struct list_head smk_net6addr_list; 326 327 extern struct mutex smack_onlycap_lock; 328 extern struct list_head smack_onlycap_list; 329 330 #define SMACK_HASH_SLOTS 16 331 extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; 332 extern struct kmem_cache *smack_rule_cache; 333 334 static inline struct task_smack *smack_cred(const struct cred *cred) 335 { 336 return cred->security + smack_blob_sizes.lbs_cred; 337 } 338 339 static inline struct smack_known **smack_file(const struct file *file) 340 { 341 return (struct smack_known **)(file->f_security + 342 smack_blob_sizes.lbs_file); 343 } 344 345 static inline struct inode_smack *smack_inode(const struct inode *inode) 346 { 347 return inode->i_security + smack_blob_sizes.lbs_inode; 348 } 349 350 static inline struct smack_known **smack_msg_msg(const struct msg_msg *msg) 351 { 352 return msg->security + smack_blob_sizes.lbs_msg_msg; 353 } 354 355 static inline struct smack_known **smack_ipc(const struct kern_ipc_perm *ipc) 356 { 357 return ipc->security + smack_blob_sizes.lbs_ipc; 358 } 359 360 /* 361 * Is the directory transmuting? 362 */ 363 static inline int smk_inode_transmutable(const struct inode *isp) 364 { 365 struct inode_smack *sip = smack_inode(isp); 366 return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; 367 } 368 369 /* 370 * Present a pointer to the smack label entry in an inode blob. 371 */ 372 static inline struct smack_known *smk_of_inode(const struct inode *isp) 373 { 374 struct inode_smack *sip = smack_inode(isp); 375 return sip->smk_inode; 376 } 377 378 /* 379 * Present a pointer to the smack label entry in an task blob. 380 */ 381 static inline struct smack_known *smk_of_task(const struct task_smack *tsp) 382 { 383 return tsp->smk_task; 384 } 385 386 static inline struct smack_known *smk_of_task_struct_subj( 387 const struct task_struct *t) 388 { 389 struct smack_known *skp; 390 const struct cred *cred; 391 392 rcu_read_lock(); 393 394 cred = rcu_dereference(t->cred); 395 skp = smk_of_task(smack_cred(cred)); 396 397 rcu_read_unlock(); 398 399 return skp; 400 } 401 402 static inline struct smack_known *smk_of_task_struct_obj( 403 const struct task_struct *t) 404 { 405 struct smack_known *skp; 406 const struct cred *cred; 407 408 rcu_read_lock(); 409 410 cred = __task_cred(t); 411 skp = smk_of_task(smack_cred(cred)); 412 413 rcu_read_unlock(); 414 415 return skp; 416 } 417 418 /* 419 * Present a pointer to the forked smack label entry in an task blob. 420 */ 421 static inline struct smack_known *smk_of_forked(const struct task_smack *tsp) 422 { 423 return tsp->smk_forked; 424 } 425 426 /* 427 * Present a pointer to the smack label in the current task blob. 428 */ 429 static inline struct smack_known *smk_of_current(void) 430 { 431 return smk_of_task(smack_cred(current_cred())); 432 } 433 434 /* 435 * logging functions 436 */ 437 #define SMACK_AUDIT_DENIED 0x1 438 #define SMACK_AUDIT_ACCEPT 0x2 439 extern int log_policy; 440 441 void smack_log(char *subject_label, char *object_label, 442 int request, 443 int result, struct smk_audit_info *auditdata); 444 445 #ifdef CONFIG_AUDIT 446 447 /* 448 * some inline functions to set up audit data 449 * they do nothing if CONFIG_AUDIT is not set 450 * 451 */ 452 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 453 char type) 454 { 455 memset(&a->sad, 0, sizeof(a->sad)); 456 a->a.type = type; 457 a->a.smack_audit_data = &a->sad; 458 a->a.smack_audit_data->function = func; 459 } 460 461 static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func, 462 char type, struct lsm_network_audit *net) 463 { 464 smk_ad_init(a, func, type); 465 memset(net, 0, sizeof(*net)); 466 a->a.u.net = net; 467 } 468 469 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 470 struct task_struct *t) 471 { 472 a->a.u.tsk = t; 473 } 474 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 475 struct dentry *d) 476 { 477 a->a.u.dentry = d; 478 } 479 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 480 struct inode *i) 481 { 482 a->a.u.inode = i; 483 } 484 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 485 struct path p) 486 { 487 a->a.u.path = p; 488 } 489 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 490 struct sock *sk) 491 { 492 a->a.u.net->sk = sk; 493 } 494 495 #else /* no AUDIT */ 496 497 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 498 char type) 499 { 500 } 501 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 502 struct task_struct *t) 503 { 504 } 505 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 506 struct dentry *d) 507 { 508 } 509 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 510 struct inode *i) 511 { 512 } 513 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 514 struct path p) 515 { 516 } 517 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 518 struct sock *sk) 519 { 520 } 521 #endif 522 523 #endif /* _SECURITY_SMACK_H */ 524