1 /* 2 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation, version 2. 7 * 8 * Author: 9 * Casey Schaufler <casey@schaufler-ca.com> 10 * 11 */ 12 13 #ifndef _SECURITY_SMACK_H 14 #define _SECURITY_SMACK_H 15 16 #include <linux/capability.h> 17 #include <linux/spinlock.h> 18 #include <linux/lsm_hooks.h> 19 #include <linux/in.h> 20 #if IS_ENABLED(CONFIG_IPV6) 21 #include <linux/in6.h> 22 #endif /* CONFIG_IPV6 */ 23 #include <net/netlabel.h> 24 #include <linux/list.h> 25 #include <linux/rculist.h> 26 #include <linux/lsm_audit.h> 27 28 /* 29 * Use IPv6 port labeling if IPv6 is enabled and secmarks 30 * are not being used. 31 */ 32 #if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER) 33 #define SMACK_IPV6_PORT_LABELING 1 34 #endif 35 36 #if IS_ENABLED(CONFIG_IPV6) && defined(CONFIG_SECURITY_SMACK_NETFILTER) 37 #define SMACK_IPV6_SECMARK_LABELING 1 38 #endif 39 40 /* 41 * Smack labels were limited to 23 characters for a long time. 42 */ 43 #define SMK_LABELLEN 24 44 #define SMK_LONGLABEL 256 45 46 /* 47 * This is the repository for labels seen so that it is 48 * not necessary to keep allocating tiny chuncks of memory 49 * and so that they can be shared. 50 * 51 * Labels are never modified in place. Anytime a label 52 * is imported (e.g. xattrset on a file) the list is checked 53 * for it and it is added if it doesn't exist. The address 54 * is passed out in either case. Entries are added, but 55 * never deleted. 56 * 57 * Since labels are hanging around anyway it doesn't 58 * hurt to maintain a secid for those awkward situations 59 * where kernel components that ought to use LSM independent 60 * interfaces don't. The secid should go away when all of 61 * these components have been repaired. 62 * 63 * The cipso value associated with the label gets stored here, too. 64 * 65 * Keep the access rules for this subject label here so that 66 * the entire set of rules does not need to be examined every 67 * time. 68 */ 69 struct smack_known { 70 struct list_head list; 71 struct hlist_node smk_hashed; 72 char *smk_known; 73 u32 smk_secid; 74 struct netlbl_lsm_secattr smk_netlabel; /* on wire labels */ 75 struct list_head smk_rules; /* access rules */ 76 struct mutex smk_rules_lock; /* lock for rules */ 77 }; 78 79 /* 80 * Maximum number of bytes for the levels in a CIPSO IP option. 81 * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is 82 * bigger than can be used, and 24 is the next lower multiple 83 * of 8, and there are too many issues if there isn't space set 84 * aside for the terminating null byte. 85 */ 86 #define SMK_CIPSOLEN 24 87 88 struct superblock_smack { 89 struct smack_known *smk_root; 90 struct smack_known *smk_floor; 91 struct smack_known *smk_hat; 92 struct smack_known *smk_default; 93 int smk_flags; 94 }; 95 96 /* 97 * Superblock flags 98 */ 99 #define SMK_SB_INITIALIZED 0x01 100 #define SMK_SB_UNTRUSTED 0x02 101 102 struct socket_smack { 103 struct smack_known *smk_out; /* outbound label */ 104 struct smack_known *smk_in; /* inbound label */ 105 struct smack_known *smk_packet; /* TCP peer label */ 106 }; 107 108 /* 109 * Inode smack data 110 */ 111 struct inode_smack { 112 struct smack_known *smk_inode; /* label of the fso */ 113 struct smack_known *smk_task; /* label of the task */ 114 struct smack_known *smk_mmap; /* label of the mmap domain */ 115 struct mutex smk_lock; /* initialization lock */ 116 int smk_flags; /* smack inode flags */ 117 }; 118 119 struct task_smack { 120 struct smack_known *smk_task; /* label for access control */ 121 struct smack_known *smk_forked; /* label when forked */ 122 struct list_head smk_rules; /* per task access rules */ 123 struct mutex smk_rules_lock; /* lock for the rules */ 124 struct list_head smk_relabel; /* transit allowed labels */ 125 }; 126 127 #define SMK_INODE_INSTANT 0x01 /* inode is instantiated */ 128 #define SMK_INODE_TRANSMUTE 0x02 /* directory is transmuting */ 129 #define SMK_INODE_CHANGED 0x04 /* smack was transmuted */ 130 #define SMK_INODE_IMPURE 0x08 /* involved in an impure transaction */ 131 132 /* 133 * A label access rule. 134 */ 135 struct smack_rule { 136 struct list_head list; 137 struct smack_known *smk_subject; 138 struct smack_known *smk_object; 139 int smk_access; 140 }; 141 142 /* 143 * An entry in the table identifying IPv4 hosts. 144 */ 145 struct smk_net4addr { 146 struct list_head list; 147 struct in_addr smk_host; /* network address */ 148 struct in_addr smk_mask; /* network mask */ 149 int smk_masks; /* mask size */ 150 struct smack_known *smk_label; /* label */ 151 }; 152 153 #if IS_ENABLED(CONFIG_IPV6) 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 #endif /* CONFIG_IPV6 */ 165 166 #ifdef SMACK_IPV6_PORT_LABELING 167 /* 168 * An entry in the table identifying ports. 169 */ 170 struct smk_port_label { 171 struct list_head list; 172 struct sock *smk_sock; /* socket initialized on */ 173 unsigned short smk_port; /* the port number */ 174 struct smack_known *smk_in; /* inbound label */ 175 struct smack_known *smk_out; /* outgoing label */ 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 = 1, 196 Opt_fsfloor = 2, 197 Opt_fshat = 3, 198 Opt_fsroot = 4, 199 Opt_fstransmute = 5, 200 }; 201 202 /* 203 * Mount options 204 */ 205 #define SMK_FSDEFAULT "smackfsdef=" 206 #define SMK_FSFLOOR "smackfsfloor=" 207 #define SMK_FSHAT "smackfshat=" 208 #define SMK_FSROOT "smackfsroot=" 209 #define SMK_FSTRANS "smackfstransmute=" 210 211 #define SMACK_DELETE_OPTION "-DELETE" 212 #define SMACK_CIPSO_OPTION "-CIPSO" 213 214 /* 215 * How communications on this socket are treated. 216 * Usually it's determined by the underlying netlabel code 217 * but there are certain cases, including single label hosts 218 * and potentially single label interfaces for which the 219 * treatment can not be known in advance. 220 * 221 * The possibility of additional labeling schemes being 222 * introduced in the future exists as well. 223 */ 224 #define SMACK_UNLABELED_SOCKET 0 225 #define SMACK_CIPSO_SOCKET 1 226 227 /* 228 * CIPSO defaults. 229 */ 230 #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ 231 #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ 232 #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ 233 #define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */ 234 #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ 235 /* 236 * CIPSO 2.2 standard is 239, but Smack wants to use the 237 * categories in a structured way that limits the value to 238 * the bits in 23 bytes, hence the unusual number. 239 */ 240 #define SMACK_CIPSO_MAXCATNUM 184 /* 23 * 8 */ 241 242 /* 243 * Ptrace rules 244 */ 245 #define SMACK_PTRACE_DEFAULT 0 246 #define SMACK_PTRACE_EXACT 1 247 #define SMACK_PTRACE_DRACONIAN 2 248 #define SMACK_PTRACE_MAX SMACK_PTRACE_DRACONIAN 249 250 /* 251 * Flags for untraditional access modes. 252 * It shouldn't be necessary to avoid conflicts with definitions 253 * in fs.h, but do so anyway. 254 */ 255 #define MAY_TRANSMUTE 0x00001000 /* Controls directory labeling */ 256 #define MAY_LOCK 0x00002000 /* Locks should be writes, but ... */ 257 #define MAY_BRINGUP 0x00004000 /* Report use of this rule */ 258 259 /* 260 * The policy for delivering signals is configurable. 261 * It is usually "write", but can be "append". 262 */ 263 #ifdef CONFIG_SECURITY_SMACK_APPEND_SIGNALS 264 #define MAY_DELIVER MAY_APPEND /* Signal delivery requires append */ 265 #else 266 #define MAY_DELIVER MAY_WRITE /* Signal delivery requires write */ 267 #endif 268 269 #define SMACK_BRINGUP_ALLOW 1 /* Allow bringup mode */ 270 #define SMACK_UNCONFINED_SUBJECT 2 /* Allow unconfined label */ 271 #define SMACK_UNCONFINED_OBJECT 3 /* Allow unconfined label */ 272 273 /* 274 * Just to make the common cases easier to deal with 275 */ 276 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 277 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 278 #define MAY_NOT 0 279 280 /* 281 * Number of access types used by Smack (rwxatlb) 282 */ 283 #define SMK_NUM_ACCESS_TYPE 7 284 285 /* SMACK data */ 286 struct smack_audit_data { 287 const char *function; 288 char *subject; 289 char *object; 290 char *request; 291 int result; 292 }; 293 294 /* 295 * Smack audit data; is empty if CONFIG_AUDIT not set 296 * to save some stack 297 */ 298 struct smk_audit_info { 299 #ifdef CONFIG_AUDIT 300 struct common_audit_data a; 301 struct smack_audit_data sad; 302 #endif 303 }; 304 305 /* 306 * These functions are in smack_access.c 307 */ 308 int smk_access_entry(char *, char *, struct list_head *); 309 int smk_access(struct smack_known *, struct smack_known *, 310 int, struct smk_audit_info *); 311 int smk_tskacc(struct task_smack *, struct smack_known *, 312 u32, struct smk_audit_info *); 313 int smk_curacc(struct smack_known *, u32, struct smk_audit_info *); 314 struct smack_known *smack_from_secid(const u32); 315 char *smk_parse_smack(const char *string, int len); 316 int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); 317 struct smack_known *smk_import_entry(const char *, int); 318 void smk_insert_entry(struct smack_known *skp); 319 struct smack_known *smk_find_entry(const char *); 320 int smack_privileged(int cap); 321 void smk_destroy_label_list(struct list_head *list); 322 323 /* 324 * Shared data. 325 */ 326 extern int smack_enabled; 327 extern int smack_cipso_direct; 328 extern int smack_cipso_mapped; 329 extern struct smack_known *smack_net_ambient; 330 extern struct smack_known *smack_syslog_label; 331 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 332 extern struct smack_known *smack_unconfined; 333 #endif 334 extern int smack_ptrace_rule; 335 336 extern struct smack_known smack_known_floor; 337 extern struct smack_known smack_known_hat; 338 extern struct smack_known smack_known_huh; 339 extern struct smack_known smack_known_invalid; 340 extern struct smack_known smack_known_star; 341 extern struct smack_known smack_known_web; 342 343 extern struct mutex smack_known_lock; 344 extern struct list_head smack_known_list; 345 extern struct list_head smk_net4addr_list; 346 #if IS_ENABLED(CONFIG_IPV6) 347 extern struct list_head smk_net6addr_list; 348 #endif /* CONFIG_IPV6 */ 349 350 extern struct mutex smack_onlycap_lock; 351 extern struct list_head smack_onlycap_list; 352 353 #define SMACK_HASH_SLOTS 16 354 extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; 355 356 /* 357 * Is the directory transmuting? 358 */ 359 static inline int smk_inode_transmutable(const struct inode *isp) 360 { 361 struct inode_smack *sip = isp->i_security; 362 return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; 363 } 364 365 /* 366 * Present a pointer to the smack label entry in an inode blob. 367 */ 368 static inline struct smack_known *smk_of_inode(const struct inode *isp) 369 { 370 struct inode_smack *sip = isp->i_security; 371 return sip->smk_inode; 372 } 373 374 /* 375 * Present a pointer to the smack label entry in an task blob. 376 */ 377 static inline struct smack_known *smk_of_task(const struct task_smack *tsp) 378 { 379 return tsp->smk_task; 380 } 381 382 static inline struct smack_known *smk_of_task_struct(const struct task_struct *t) 383 { 384 struct smack_known *skp; 385 386 rcu_read_lock(); 387 skp = smk_of_task(__task_cred(t)->security); 388 rcu_read_unlock(); 389 return skp; 390 } 391 392 /* 393 * Present a pointer to the forked smack label entry in an task blob. 394 */ 395 static inline struct smack_known *smk_of_forked(const struct task_smack *tsp) 396 { 397 return tsp->smk_forked; 398 } 399 400 /* 401 * Present a pointer to the smack label in the current task blob. 402 */ 403 static inline struct smack_known *smk_of_current(void) 404 { 405 return smk_of_task(current_security()); 406 } 407 408 /* 409 * logging functions 410 */ 411 #define SMACK_AUDIT_DENIED 0x1 412 #define SMACK_AUDIT_ACCEPT 0x2 413 extern int log_policy; 414 415 void smack_log(char *subject_label, char *object_label, 416 int request, 417 int result, struct smk_audit_info *auditdata); 418 419 #ifdef CONFIG_AUDIT 420 421 /* 422 * some inline functions to set up audit data 423 * they do nothing if CONFIG_AUDIT is not set 424 * 425 */ 426 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 427 char type) 428 { 429 memset(&a->sad, 0, sizeof(a->sad)); 430 a->a.type = type; 431 a->a.smack_audit_data = &a->sad; 432 a->a.smack_audit_data->function = func; 433 } 434 435 static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func, 436 char type, struct lsm_network_audit *net) 437 { 438 smk_ad_init(a, func, type); 439 memset(net, 0, sizeof(*net)); 440 a->a.u.net = net; 441 } 442 443 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 444 struct task_struct *t) 445 { 446 a->a.u.tsk = t; 447 } 448 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 449 struct dentry *d) 450 { 451 a->a.u.dentry = d; 452 } 453 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 454 struct inode *i) 455 { 456 a->a.u.inode = i; 457 } 458 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 459 struct path p) 460 { 461 a->a.u.path = p; 462 } 463 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 464 struct sock *sk) 465 { 466 a->a.u.net->sk = sk; 467 } 468 469 #else /* no AUDIT */ 470 471 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 472 char type) 473 { 474 } 475 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 476 struct task_struct *t) 477 { 478 } 479 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 480 struct dentry *d) 481 { 482 } 483 static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a, 484 struct vfsmount *m) 485 { 486 } 487 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 488 struct inode *i) 489 { 490 } 491 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 492 struct path p) 493 { 494 } 495 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 496 struct sock *sk) 497 { 498 } 499 #endif 500 501 #endif /* _SECURITY_SMACK_H */ 502