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_initialized; 94 }; 95 96 struct socket_smack { 97 struct smack_known *smk_out; /* outbound label */ 98 struct smack_known *smk_in; /* inbound label */ 99 struct smack_known *smk_packet; /* TCP peer label */ 100 }; 101 102 /* 103 * Inode smack data 104 */ 105 struct inode_smack { 106 struct smack_known *smk_inode; /* label of the fso */ 107 struct smack_known *smk_task; /* label of the task */ 108 struct smack_known *smk_mmap; /* label of the mmap domain */ 109 struct mutex smk_lock; /* initialization lock */ 110 int smk_flags; /* smack inode flags */ 111 }; 112 113 struct task_smack { 114 struct smack_known *smk_task; /* label for access control */ 115 struct smack_known *smk_forked; /* label when forked */ 116 struct list_head smk_rules; /* per task access rules */ 117 struct mutex smk_rules_lock; /* lock for the rules */ 118 }; 119 120 #define SMK_INODE_INSTANT 0x01 /* inode is instantiated */ 121 #define SMK_INODE_TRANSMUTE 0x02 /* directory is transmuting */ 122 #define SMK_INODE_CHANGED 0x04 /* smack was transmuted */ 123 #define SMK_INODE_IMPURE 0x08 /* involved in an impure transaction */ 124 125 /* 126 * A label access rule. 127 */ 128 struct smack_rule { 129 struct list_head list; 130 struct smack_known *smk_subject; 131 struct smack_known *smk_object; 132 int smk_access; 133 }; 134 135 /* 136 * An entry in the table identifying IPv4 hosts. 137 */ 138 struct smk_net4addr { 139 struct list_head list; 140 struct in_addr smk_host; /* network address */ 141 struct in_addr smk_mask; /* network mask */ 142 int smk_masks; /* mask size */ 143 struct smack_known *smk_label; /* label */ 144 }; 145 146 #if IS_ENABLED(CONFIG_IPV6) 147 /* 148 * An entry in the table identifying IPv6 hosts. 149 */ 150 struct smk_net6addr { 151 struct list_head list; 152 struct in6_addr smk_host; /* network address */ 153 struct in6_addr smk_mask; /* network mask */ 154 int smk_masks; /* mask size */ 155 struct smack_known *smk_label; /* label */ 156 }; 157 #endif /* CONFIG_IPV6 */ 158 159 #ifdef SMACK_IPV6_PORT_LABELING 160 /* 161 * An entry in the table identifying ports. 162 */ 163 struct smk_port_label { 164 struct list_head list; 165 struct sock *smk_sock; /* socket initialized on */ 166 unsigned short smk_port; /* the port number */ 167 struct smack_known *smk_in; /* inbound label */ 168 struct smack_known *smk_out; /* outgoing label */ 169 }; 170 #endif /* SMACK_IPV6_PORT_LABELING */ 171 172 struct smack_onlycap { 173 struct list_head list; 174 struct smack_known *smk_label; 175 }; 176 177 /* Super block security struct flags for mount options */ 178 #define FSDEFAULT_MNT 0x01 179 #define FSFLOOR_MNT 0x02 180 #define FSHAT_MNT 0x04 181 #define FSROOT_MNT 0x08 182 #define FSTRANS_MNT 0x10 183 184 #define NUM_SMK_MNT_OPTS 5 185 186 enum { 187 Opt_error = -1, 188 Opt_fsdefault = 1, 189 Opt_fsfloor = 2, 190 Opt_fshat = 3, 191 Opt_fsroot = 4, 192 Opt_fstransmute = 5, 193 }; 194 195 /* 196 * Mount options 197 */ 198 #define SMK_FSDEFAULT "smackfsdef=" 199 #define SMK_FSFLOOR "smackfsfloor=" 200 #define SMK_FSHAT "smackfshat=" 201 #define SMK_FSROOT "smackfsroot=" 202 #define SMK_FSTRANS "smackfstransmute=" 203 204 #define SMACK_DELETE_OPTION "-DELETE" 205 #define SMACK_CIPSO_OPTION "-CIPSO" 206 207 /* 208 * How communications on this socket are treated. 209 * Usually it's determined by the underlying netlabel code 210 * but there are certain cases, including single label hosts 211 * and potentially single label interfaces for which the 212 * treatment can not be known in advance. 213 * 214 * The possibility of additional labeling schemes being 215 * introduced in the future exists as well. 216 */ 217 #define SMACK_UNLABELED_SOCKET 0 218 #define SMACK_CIPSO_SOCKET 1 219 220 /* 221 * CIPSO defaults. 222 */ 223 #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ 224 #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ 225 #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ 226 #define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */ 227 #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ 228 /* 229 * CIPSO 2.2 standard is 239, but Smack wants to use the 230 * categories in a structured way that limits the value to 231 * the bits in 23 bytes, hence the unusual number. 232 */ 233 #define SMACK_CIPSO_MAXCATNUM 184 /* 23 * 8 */ 234 235 /* 236 * Ptrace rules 237 */ 238 #define SMACK_PTRACE_DEFAULT 0 239 #define SMACK_PTRACE_EXACT 1 240 #define SMACK_PTRACE_DRACONIAN 2 241 #define SMACK_PTRACE_MAX SMACK_PTRACE_DRACONIAN 242 243 /* 244 * Flags for untraditional access modes. 245 * It shouldn't be necessary to avoid conflicts with definitions 246 * in fs.h, but do so anyway. 247 */ 248 #define MAY_TRANSMUTE 0x00001000 /* Controls directory labeling */ 249 #define MAY_LOCK 0x00002000 /* Locks should be writes, but ... */ 250 #define MAY_BRINGUP 0x00004000 /* Report use of this rule */ 251 252 #define SMACK_BRINGUP_ALLOW 1 /* Allow bringup mode */ 253 #define SMACK_UNCONFINED_SUBJECT 2 /* Allow unconfined label */ 254 #define SMACK_UNCONFINED_OBJECT 3 /* Allow unconfined label */ 255 256 /* 257 * Just to make the common cases easier to deal with 258 */ 259 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 260 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 261 #define MAY_NOT 0 262 263 /* 264 * Number of access types used by Smack (rwxatlb) 265 */ 266 #define SMK_NUM_ACCESS_TYPE 7 267 268 /* SMACK data */ 269 struct smack_audit_data { 270 const char *function; 271 char *subject; 272 char *object; 273 char *request; 274 int result; 275 }; 276 277 /* 278 * Smack audit data; is empty if CONFIG_AUDIT not set 279 * to save some stack 280 */ 281 struct smk_audit_info { 282 #ifdef CONFIG_AUDIT 283 struct common_audit_data a; 284 struct smack_audit_data sad; 285 #endif 286 }; 287 288 /* 289 * These functions are in smack_access.c 290 */ 291 int smk_access_entry(char *, char *, struct list_head *); 292 int smk_access(struct smack_known *, struct smack_known *, 293 int, struct smk_audit_info *); 294 int smk_tskacc(struct task_smack *, struct smack_known *, 295 u32, struct smk_audit_info *); 296 int smk_curacc(struct smack_known *, u32, struct smk_audit_info *); 297 struct smack_known *smack_from_secid(const u32); 298 char *smk_parse_smack(const char *string, int len); 299 int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); 300 struct smack_known *smk_import_entry(const char *, int); 301 void smk_insert_entry(struct smack_known *skp); 302 struct smack_known *smk_find_entry(const char *); 303 int smack_privileged(int cap); 304 305 /* 306 * Shared data. 307 */ 308 extern int smack_enabled; 309 extern int smack_cipso_direct; 310 extern int smack_cipso_mapped; 311 extern struct smack_known *smack_net_ambient; 312 extern struct smack_known *smack_syslog_label; 313 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 314 extern struct smack_known *smack_unconfined; 315 #endif 316 extern int smack_ptrace_rule; 317 318 extern struct smack_known smack_known_floor; 319 extern struct smack_known smack_known_hat; 320 extern struct smack_known smack_known_huh; 321 extern struct smack_known smack_known_invalid; 322 extern struct smack_known smack_known_star; 323 extern struct smack_known smack_known_web; 324 325 extern struct mutex smack_known_lock; 326 extern struct list_head smack_known_list; 327 extern struct list_head smk_net4addr_list; 328 #if IS_ENABLED(CONFIG_IPV6) 329 extern struct list_head smk_net6addr_list; 330 #endif /* CONFIG_IPV6 */ 331 332 extern struct mutex smack_onlycap_lock; 333 extern struct list_head smack_onlycap_list; 334 335 #define SMACK_HASH_SLOTS 16 336 extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; 337 338 /* 339 * Is the directory transmuting? 340 */ 341 static inline int smk_inode_transmutable(const struct inode *isp) 342 { 343 struct inode_smack *sip = isp->i_security; 344 return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; 345 } 346 347 /* 348 * Present a pointer to the smack label entry in an inode blob. 349 */ 350 static inline struct smack_known *smk_of_inode(const struct inode *isp) 351 { 352 struct inode_smack *sip = isp->i_security; 353 return sip->smk_inode; 354 } 355 356 /* 357 * Present a pointer to the smack label entry in an task blob. 358 */ 359 static inline struct smack_known *smk_of_task(const struct task_smack *tsp) 360 { 361 return tsp->smk_task; 362 } 363 364 static inline struct smack_known *smk_of_task_struct(const struct task_struct *t) 365 { 366 struct smack_known *skp; 367 368 rcu_read_lock(); 369 skp = smk_of_task(__task_cred(t)->security); 370 rcu_read_unlock(); 371 return skp; 372 } 373 374 /* 375 * Present a pointer to the forked smack label entry in an task blob. 376 */ 377 static inline struct smack_known *smk_of_forked(const struct task_smack *tsp) 378 { 379 return tsp->smk_forked; 380 } 381 382 /* 383 * Present a pointer to the smack label in the current task blob. 384 */ 385 static inline struct smack_known *smk_of_current(void) 386 { 387 return smk_of_task(current_security()); 388 } 389 390 /* 391 * logging functions 392 */ 393 #define SMACK_AUDIT_DENIED 0x1 394 #define SMACK_AUDIT_ACCEPT 0x2 395 extern int log_policy; 396 397 void smack_log(char *subject_label, char *object_label, 398 int request, 399 int result, struct smk_audit_info *auditdata); 400 401 #ifdef CONFIG_AUDIT 402 403 /* 404 * some inline functions to set up audit data 405 * they do nothing if CONFIG_AUDIT is not set 406 * 407 */ 408 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 409 char type) 410 { 411 memset(&a->sad, 0, sizeof(a->sad)); 412 a->a.type = type; 413 a->a.smack_audit_data = &a->sad; 414 a->a.smack_audit_data->function = func; 415 } 416 417 static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func, 418 char type, struct lsm_network_audit *net) 419 { 420 smk_ad_init(a, func, type); 421 memset(net, 0, sizeof(*net)); 422 a->a.u.net = net; 423 } 424 425 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 426 struct task_struct *t) 427 { 428 a->a.u.tsk = t; 429 } 430 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 431 struct dentry *d) 432 { 433 a->a.u.dentry = d; 434 } 435 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 436 struct inode *i) 437 { 438 a->a.u.inode = i; 439 } 440 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 441 struct path p) 442 { 443 a->a.u.path = p; 444 } 445 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 446 struct sock *sk) 447 { 448 a->a.u.net->sk = sk; 449 } 450 451 #else /* no AUDIT */ 452 453 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 454 char type) 455 { 456 } 457 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 458 struct task_struct *t) 459 { 460 } 461 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 462 struct dentry *d) 463 { 464 } 465 static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a, 466 struct vfsmount *m) 467 { 468 } 469 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 470 struct inode *i) 471 { 472 } 473 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 474 struct path p) 475 { 476 } 477 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 478 struct sock *sk) 479 { 480 } 481 #endif 482 483 #endif /* _SECURITY_SMACK_H */ 484