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