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 }; 104 105 /* 106 * Inode smack data 107 */ 108 struct inode_smack { 109 struct smack_known *smk_inode; /* label of the fso */ 110 struct smack_known *smk_task; /* label of the task */ 111 struct smack_known *smk_mmap; /* label of the mmap domain */ 112 struct mutex smk_lock; /* initialization lock */ 113 int smk_flags; /* smack inode flags */ 114 struct rcu_head smk_rcu; /* for freeing inode_smack */ 115 }; 116 117 struct task_smack { 118 struct smack_known *smk_task; /* label for access control */ 119 struct smack_known *smk_forked; /* label when forked */ 120 struct list_head smk_rules; /* per task access rules */ 121 struct mutex smk_rules_lock; /* lock for the rules */ 122 struct list_head smk_relabel; /* transit allowed labels */ 123 }; 124 125 #define SMK_INODE_INSTANT 0x01 /* inode is instantiated */ 126 #define SMK_INODE_TRANSMUTE 0x02 /* directory is transmuting */ 127 #define SMK_INODE_CHANGED 0x04 /* smack was transmuted */ 128 #define SMK_INODE_IMPURE 0x08 /* involved in an impure transaction */ 129 130 /* 131 * A label access rule. 132 */ 133 struct smack_rule { 134 struct list_head list; 135 struct smack_known *smk_subject; 136 struct smack_known *smk_object; 137 int smk_access; 138 }; 139 140 /* 141 * An entry in the table identifying IPv4 hosts. 142 */ 143 struct smk_net4addr { 144 struct list_head list; 145 struct in_addr smk_host; /* network address */ 146 struct in_addr smk_mask; /* network mask */ 147 int smk_masks; /* mask size */ 148 struct smack_known *smk_label; /* label */ 149 }; 150 151 #if IS_ENABLED(CONFIG_IPV6) 152 /* 153 * An entry in the table identifying IPv6 hosts. 154 */ 155 struct smk_net6addr { 156 struct list_head list; 157 struct in6_addr smk_host; /* network address */ 158 struct in6_addr smk_mask; /* network mask */ 159 int smk_masks; /* mask size */ 160 struct smack_known *smk_label; /* label */ 161 }; 162 #endif /* CONFIG_IPV6 */ 163 164 #ifdef SMACK_IPV6_PORT_LABELING 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 #endif /* SMACK_IPV6_PORT_LABELING */ 178 179 struct smack_known_list_elem { 180 struct list_head list; 181 struct smack_known *smk_label; 182 }; 183 184 /* Super block security struct flags for mount options */ 185 #define FSDEFAULT_MNT 0x01 186 #define FSFLOOR_MNT 0x02 187 #define FSHAT_MNT 0x04 188 #define FSROOT_MNT 0x08 189 #define FSTRANS_MNT 0x10 190 191 #define NUM_SMK_MNT_OPTS 5 192 193 enum { 194 Opt_error = -1, 195 Opt_fsdefault = 0, 196 Opt_fsfloor = 1, 197 Opt_fshat = 2, 198 Opt_fsroot = 3, 199 Opt_fstransmute = 4, 200 }; 201 202 #define SMACK_DELETE_OPTION "-DELETE" 203 #define SMACK_CIPSO_OPTION "-CIPSO" 204 205 /* 206 * How communications on this socket are treated. 207 * Usually it's determined by the underlying netlabel code 208 * but there are certain cases, including single label hosts 209 * and potentially single label interfaces for which the 210 * treatment can not be known in advance. 211 * 212 * The possibility of additional labeling schemes being 213 * introduced in the future exists as well. 214 */ 215 #define SMACK_UNLABELED_SOCKET 0 216 #define SMACK_CIPSO_SOCKET 1 217 218 /* 219 * CIPSO defaults. 220 */ 221 #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ 222 #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ 223 #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ 224 #define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */ 225 #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ 226 /* 227 * CIPSO 2.2 standard is 239, but Smack wants to use the 228 * categories in a structured way that limits the value to 229 * the bits in 23 bytes, hence the unusual number. 230 */ 231 #define SMACK_CIPSO_MAXCATNUM 184 /* 23 * 8 */ 232 233 /* 234 * Ptrace rules 235 */ 236 #define SMACK_PTRACE_DEFAULT 0 237 #define SMACK_PTRACE_EXACT 1 238 #define SMACK_PTRACE_DRACONIAN 2 239 #define SMACK_PTRACE_MAX SMACK_PTRACE_DRACONIAN 240 241 /* 242 * Flags for untraditional access modes. 243 * It shouldn't be necessary to avoid conflicts with definitions 244 * in fs.h, but do so anyway. 245 */ 246 #define MAY_TRANSMUTE 0x00001000 /* Controls directory labeling */ 247 #define MAY_LOCK 0x00002000 /* Locks should be writes, but ... */ 248 #define MAY_BRINGUP 0x00004000 /* Report use of this rule */ 249 250 /* 251 * The policy for delivering signals is configurable. 252 * It is usually "write", but can be "append". 253 */ 254 #ifdef CONFIG_SECURITY_SMACK_APPEND_SIGNALS 255 #define MAY_DELIVER MAY_APPEND /* Signal delivery requires append */ 256 #else 257 #define MAY_DELIVER MAY_WRITE /* Signal delivery requires write */ 258 #endif 259 260 #define SMACK_BRINGUP_ALLOW 1 /* Allow bringup mode */ 261 #define SMACK_UNCONFINED_SUBJECT 2 /* Allow unconfined label */ 262 #define SMACK_UNCONFINED_OBJECT 3 /* Allow unconfined label */ 263 264 /* 265 * Just to make the common cases easier to deal with 266 */ 267 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 268 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 269 #define MAY_NOT 0 270 271 /* 272 * Number of access types used by Smack (rwxatlb) 273 */ 274 #define SMK_NUM_ACCESS_TYPE 7 275 276 /* SMACK data */ 277 struct smack_audit_data { 278 const char *function; 279 char *subject; 280 char *object; 281 char *request; 282 int result; 283 }; 284 285 /* 286 * Smack audit data; is empty if CONFIG_AUDIT not set 287 * to save some stack 288 */ 289 struct smk_audit_info { 290 #ifdef CONFIG_AUDIT 291 struct common_audit_data a; 292 struct smack_audit_data sad; 293 #endif 294 }; 295 296 /* 297 * These functions are in smack_access.c 298 */ 299 int smk_access_entry(char *, char *, struct list_head *); 300 int smk_access(struct smack_known *, struct smack_known *, 301 int, struct smk_audit_info *); 302 int smk_tskacc(struct task_smack *, struct smack_known *, 303 u32, struct smk_audit_info *); 304 int smk_curacc(struct smack_known *, u32, struct smk_audit_info *); 305 struct smack_known *smack_from_secid(const u32); 306 char *smk_parse_smack(const char *string, int len); 307 int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); 308 struct smack_known *smk_import_entry(const char *, int); 309 void smk_insert_entry(struct smack_known *skp); 310 struct smack_known *smk_find_entry(const char *); 311 bool smack_privileged(int cap); 312 bool smack_privileged_cred(int cap, const struct cred *cred); 313 void smk_destroy_label_list(struct list_head *list); 314 315 /* 316 * Shared data. 317 */ 318 extern int smack_enabled; 319 extern int smack_cipso_direct; 320 extern int smack_cipso_mapped; 321 extern struct smack_known *smack_net_ambient; 322 extern struct smack_known *smack_syslog_label; 323 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 324 extern struct smack_known *smack_unconfined; 325 #endif 326 extern int smack_ptrace_rule; 327 extern struct lsm_blob_sizes smack_blob_sizes; 328 329 extern struct smack_known smack_known_floor; 330 extern struct smack_known smack_known_hat; 331 extern struct smack_known smack_known_huh; 332 extern struct smack_known smack_known_star; 333 extern struct smack_known smack_known_web; 334 335 extern struct mutex smack_known_lock; 336 extern struct list_head smack_known_list; 337 extern struct list_head smk_net4addr_list; 338 #if IS_ENABLED(CONFIG_IPV6) 339 extern struct list_head smk_net6addr_list; 340 #endif /* CONFIG_IPV6 */ 341 342 extern struct mutex smack_onlycap_lock; 343 extern struct list_head smack_onlycap_list; 344 345 #define SMACK_HASH_SLOTS 16 346 extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; 347 extern struct kmem_cache *smack_rule_cache; 348 349 static inline struct task_smack *smack_cred(const struct cred *cred) 350 { 351 return cred->security + smack_blob_sizes.lbs_cred; 352 } 353 354 static inline struct smack_known **smack_file(const struct file *file) 355 { 356 return (struct smack_known **)(file->f_security + 357 smack_blob_sizes.lbs_file); 358 } 359 360 static inline struct inode_smack *smack_inode(const struct inode *inode) 361 { 362 return inode->i_security + smack_blob_sizes.lbs_inode; 363 } 364 365 static inline struct smack_known **smack_msg_msg(const struct msg_msg *msg) 366 { 367 return msg->security + smack_blob_sizes.lbs_msg_msg; 368 } 369 370 static inline struct smack_known **smack_ipc(const struct kern_ipc_perm *ipc) 371 { 372 return ipc->security + smack_blob_sizes.lbs_ipc; 373 } 374 375 /* 376 * Is the directory transmuting? 377 */ 378 static inline int smk_inode_transmutable(const struct inode *isp) 379 { 380 struct inode_smack *sip = smack_inode(isp); 381 return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; 382 } 383 384 /* 385 * Present a pointer to the smack label entry in an inode blob. 386 */ 387 static inline struct smack_known *smk_of_inode(const struct inode *isp) 388 { 389 struct inode_smack *sip = smack_inode(isp); 390 return sip->smk_inode; 391 } 392 393 /* 394 * Present a pointer to the smack label entry in an task blob. 395 */ 396 static inline struct smack_known *smk_of_task(const struct task_smack *tsp) 397 { 398 return tsp->smk_task; 399 } 400 401 static inline struct smack_known *smk_of_task_struct( 402 const struct task_struct *t) 403 { 404 struct smack_known *skp; 405 const struct cred *cred; 406 407 rcu_read_lock(); 408 409 cred = __task_cred(t); 410 skp = smk_of_task(smack_cred(cred)); 411 412 rcu_read_unlock(); 413 414 return skp; 415 } 416 417 /* 418 * Present a pointer to the forked smack label entry in an task blob. 419 */ 420 static inline struct smack_known *smk_of_forked(const struct task_smack *tsp) 421 { 422 return tsp->smk_forked; 423 } 424 425 /* 426 * Present a pointer to the smack label in the current task blob. 427 */ 428 static inline struct smack_known *smk_of_current(void) 429 { 430 return smk_of_task(smack_cred(current_cred())); 431 } 432 433 /* 434 * logging functions 435 */ 436 #define SMACK_AUDIT_DENIED 0x1 437 #define SMACK_AUDIT_ACCEPT 0x2 438 extern int log_policy; 439 440 void smack_log(char *subject_label, char *object_label, 441 int request, 442 int result, struct smk_audit_info *auditdata); 443 444 #ifdef CONFIG_AUDIT 445 446 /* 447 * some inline functions to set up audit data 448 * they do nothing if CONFIG_AUDIT is not set 449 * 450 */ 451 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 452 char type) 453 { 454 memset(&a->sad, 0, sizeof(a->sad)); 455 a->a.type = type; 456 a->a.smack_audit_data = &a->sad; 457 a->a.smack_audit_data->function = func; 458 } 459 460 static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func, 461 char type, struct lsm_network_audit *net) 462 { 463 smk_ad_init(a, func, type); 464 memset(net, 0, sizeof(*net)); 465 a->a.u.net = net; 466 } 467 468 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 469 struct task_struct *t) 470 { 471 a->a.u.tsk = t; 472 } 473 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 474 struct dentry *d) 475 { 476 a->a.u.dentry = d; 477 } 478 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 479 struct inode *i) 480 { 481 a->a.u.inode = i; 482 } 483 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 484 struct path p) 485 { 486 a->a.u.path = p; 487 } 488 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 489 struct sock *sk) 490 { 491 a->a.u.net->sk = sk; 492 } 493 494 #else /* no AUDIT */ 495 496 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 497 char type) 498 { 499 } 500 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 501 struct task_struct *t) 502 { 503 } 504 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 505 struct dentry *d) 506 { 507 } 508 static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a, 509 struct vfsmount *m) 510 { 511 } 512 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 513 struct inode *i) 514 { 515 } 516 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 517 struct path p) 518 { 519 } 520 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 521 struct sock *sk) 522 { 523 } 524 #endif 525 526 #endif /* _SECURITY_SMACK_H */ 527