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 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 /* 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 }; 165 166 /* 167 * An entry in the table identifying ports. 168 */ 169 struct smk_port_label { 170 struct list_head list; 171 struct sock *smk_sock; /* socket initialized on */ 172 unsigned short smk_port; /* the port number */ 173 struct smack_known *smk_in; /* inbound label */ 174 struct smack_known *smk_out; /* outgoing label */ 175 short smk_sock_type; /* Socket type */ 176 short smk_can_reuse; 177 }; 178 179 struct smack_known_list_elem { 180 struct list_head list; 181 struct smack_known *smk_label; 182 }; 183 184 enum { 185 Opt_error = -1, 186 Opt_fsdefault = 0, 187 Opt_fsfloor = 1, 188 Opt_fshat = 2, 189 Opt_fsroot = 3, 190 Opt_fstransmute = 4, 191 }; 192 193 #define SMACK_DELETE_OPTION "-DELETE" 194 #define SMACK_CIPSO_OPTION "-CIPSO" 195 196 /* 197 * CIPSO defaults. 198 */ 199 #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ 200 #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ 201 #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ 202 #define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */ 203 #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ 204 /* 205 * CIPSO 2.2 standard is 239, but Smack wants to use the 206 * categories in a structured way that limits the value to 207 * the bits in 23 bytes, hence the unusual number. 208 */ 209 #define SMACK_CIPSO_MAXCATNUM 184 /* 23 * 8 */ 210 211 /* 212 * Ptrace rules 213 */ 214 #define SMACK_PTRACE_DEFAULT 0 215 #define SMACK_PTRACE_EXACT 1 216 #define SMACK_PTRACE_DRACONIAN 2 217 #define SMACK_PTRACE_MAX SMACK_PTRACE_DRACONIAN 218 219 /* 220 * Flags for untraditional access modes. 221 * It shouldn't be necessary to avoid conflicts with definitions 222 * in fs.h, but do so anyway. 223 */ 224 #define MAY_TRANSMUTE 0x00001000 /* Controls directory labeling */ 225 #define MAY_LOCK 0x00002000 /* Locks should be writes, but ... */ 226 #define MAY_BRINGUP 0x00004000 /* Report use of this rule */ 227 228 /* 229 * The policy for delivering signals is configurable. 230 * It is usually "write", but can be "append". 231 */ 232 #ifdef CONFIG_SECURITY_SMACK_APPEND_SIGNALS 233 #define MAY_DELIVER MAY_APPEND /* Signal delivery requires append */ 234 #else 235 #define MAY_DELIVER MAY_WRITE /* Signal delivery requires write */ 236 #endif 237 238 #define SMACK_BRINGUP_ALLOW 1 /* Allow bringup mode */ 239 #define SMACK_UNCONFINED_SUBJECT 2 /* Allow unconfined label */ 240 #define SMACK_UNCONFINED_OBJECT 3 /* Allow unconfined label */ 241 242 /* 243 * Just to make the common cases easier to deal with 244 */ 245 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 246 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 247 #define MAY_NOT 0 248 249 /* 250 * Number of access types used by Smack (rwxatlb) 251 */ 252 #define SMK_NUM_ACCESS_TYPE 7 253 254 /* SMACK data */ 255 struct smack_audit_data { 256 const char *function; 257 char *subject; 258 char *object; 259 char *request; 260 int result; 261 }; 262 263 /* 264 * Smack audit data; is empty if CONFIG_AUDIT not set 265 * to save some stack 266 */ 267 struct smk_audit_info { 268 #ifdef CONFIG_AUDIT 269 struct common_audit_data a; 270 struct smack_audit_data sad; 271 #endif 272 }; 273 274 /* 275 * These functions are in smack_access.c 276 */ 277 int smk_access_entry(char *, char *, struct list_head *); 278 int smk_access(struct smack_known *, struct smack_known *, 279 int, struct smk_audit_info *); 280 int smk_tskacc(struct task_smack *, struct smack_known *, 281 u32, struct smk_audit_info *); 282 int smk_curacc(struct smack_known *, u32, struct smk_audit_info *); 283 struct smack_known *smack_from_secid(const u32); 284 char *smk_parse_smack(const char *string, int len); 285 int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); 286 struct smack_known *smk_import_entry(const char *, int); 287 void smk_insert_entry(struct smack_known *skp); 288 struct smack_known *smk_find_entry(const char *); 289 bool smack_privileged(int cap); 290 bool smack_privileged_cred(int cap, const struct cred *cred); 291 void smk_destroy_label_list(struct list_head *list); 292 int smack_populate_secattr(struct smack_known *skp); 293 294 /* 295 * Shared data. 296 */ 297 extern int smack_enabled __initdata; 298 extern int smack_cipso_direct; 299 extern int smack_cipso_mapped; 300 extern struct smack_known *smack_net_ambient; 301 extern struct smack_known *smack_syslog_label; 302 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 303 extern struct smack_known *smack_unconfined; 304 #endif 305 extern int smack_ptrace_rule; 306 extern struct lsm_blob_sizes smack_blob_sizes; 307 308 extern struct smack_known smack_known_floor; 309 extern struct smack_known smack_known_hat; 310 extern struct smack_known smack_known_huh; 311 extern struct smack_known smack_known_star; 312 extern struct smack_known smack_known_web; 313 314 extern struct mutex smack_known_lock; 315 extern struct list_head smack_known_list; 316 extern struct list_head smk_net4addr_list; 317 extern struct list_head smk_net6addr_list; 318 319 extern struct mutex smack_onlycap_lock; 320 extern struct list_head smack_onlycap_list; 321 322 #define SMACK_HASH_SLOTS 16 323 extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; 324 extern struct kmem_cache *smack_rule_cache; 325 326 static inline struct task_smack *smack_cred(const struct cred *cred) 327 { 328 return cred->security + smack_blob_sizes.lbs_cred; 329 } 330 331 static inline struct smack_known **smack_file(const struct file *file) 332 { 333 return (struct smack_known **)(file->f_security + 334 smack_blob_sizes.lbs_file); 335 } 336 337 static inline struct inode_smack *smack_inode(const struct inode *inode) 338 { 339 return inode->i_security + smack_blob_sizes.lbs_inode; 340 } 341 342 static inline struct smack_known **smack_msg_msg(const struct msg_msg *msg) 343 { 344 return msg->security + smack_blob_sizes.lbs_msg_msg; 345 } 346 347 static inline struct smack_known **smack_ipc(const struct kern_ipc_perm *ipc) 348 { 349 return ipc->security + smack_blob_sizes.lbs_ipc; 350 } 351 352 static inline struct superblock_smack *smack_superblock( 353 const struct super_block *superblock) 354 { 355 return superblock->s_security + smack_blob_sizes.lbs_superblock; 356 } 357 358 /* 359 * Is the directory transmuting? 360 */ 361 static inline int smk_inode_transmutable(const struct inode *isp) 362 { 363 struct inode_smack *sip = smack_inode(isp); 364 return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; 365 } 366 367 /* 368 * Present a pointer to the smack label entry in an inode blob. 369 */ 370 static inline struct smack_known *smk_of_inode(const struct inode *isp) 371 { 372 struct inode_smack *sip = smack_inode(isp); 373 return sip->smk_inode; 374 } 375 376 /* 377 * Present a pointer to the smack label entry in an task blob. 378 */ 379 static inline struct smack_known *smk_of_task(const struct task_smack *tsp) 380 { 381 return tsp->smk_task; 382 } 383 384 static inline struct smack_known *smk_of_task_struct_obj( 385 const struct task_struct *t) 386 { 387 struct smack_known *skp; 388 const struct cred *cred; 389 390 rcu_read_lock(); 391 392 cred = __task_cred(t); 393 skp = smk_of_task(smack_cred(cred)); 394 395 rcu_read_unlock(); 396 397 return skp; 398 } 399 400 /* 401 * Present a pointer to the forked smack label entry in an task blob. 402 */ 403 static inline struct smack_known *smk_of_forked(const struct task_smack *tsp) 404 { 405 return tsp->smk_forked; 406 } 407 408 /* 409 * Present a pointer to the smack label in the current task blob. 410 */ 411 static inline struct smack_known *smk_of_current(void) 412 { 413 return smk_of_task(smack_cred(current_cred())); 414 } 415 416 /* 417 * logging functions 418 */ 419 #define SMACK_AUDIT_DENIED 0x1 420 #define SMACK_AUDIT_ACCEPT 0x2 421 extern int log_policy; 422 423 void smack_log(char *subject_label, char *object_label, 424 int request, 425 int result, struct smk_audit_info *auditdata); 426 427 #ifdef CONFIG_AUDIT 428 429 /* 430 * some inline functions to set up audit data 431 * they do nothing if CONFIG_AUDIT is not set 432 * 433 */ 434 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 435 char type) 436 { 437 memset(&a->sad, 0, sizeof(a->sad)); 438 a->a.type = type; 439 a->a.smack_audit_data = &a->sad; 440 a->a.smack_audit_data->function = func; 441 } 442 443 static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func, 444 char type, struct lsm_network_audit *net) 445 { 446 smk_ad_init(a, func, type); 447 memset(net, 0, sizeof(*net)); 448 a->a.u.net = net; 449 } 450 451 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 452 struct task_struct *t) 453 { 454 a->a.u.tsk = t; 455 } 456 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 457 struct dentry *d) 458 { 459 a->a.u.dentry = d; 460 } 461 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 462 struct inode *i) 463 { 464 a->a.u.inode = i; 465 } 466 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 467 struct path p) 468 { 469 a->a.u.path = p; 470 } 471 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 472 struct sock *sk) 473 { 474 a->a.u.net->sk = sk; 475 } 476 477 #else /* no AUDIT */ 478 479 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 480 char type) 481 { 482 } 483 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 484 struct task_struct *t) 485 { 486 } 487 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 488 struct dentry *d) 489 { 490 } 491 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 492 struct inode *i) 493 { 494 } 495 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 496 struct path p) 497 { 498 } 499 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 500 struct sock *sk) 501 { 502 } 503 #endif 504 505 #endif /* _SECURITY_SMACK_H */ 506