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 #include <linux/msg.h> 28 29 /* 30 * Use IPv6 port labeling if IPv6 is enabled and secmarks 31 * are not being used. 32 */ 33 #if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER) 34 #define SMACK_IPV6_PORT_LABELING 1 35 #endif 36 37 #if IS_ENABLED(CONFIG_IPV6) && defined(CONFIG_SECURITY_SMACK_NETFILTER) 38 #define SMACK_IPV6_SECMARK_LABELING 1 39 #endif 40 41 /* 42 * Smack labels were limited to 23 characters for a long time. 43 */ 44 #define SMK_LABELLEN 24 45 #define SMK_LONGLABEL 256 46 47 /* 48 * This is the repository for labels seen so that it is 49 * not necessary to keep allocating tiny chuncks of memory 50 * and so that they can be shared. 51 * 52 * Labels are never modified in place. Anytime a label 53 * is imported (e.g. xattrset on a file) the list is checked 54 * for it and it is added if it doesn't exist. The address 55 * is passed out in either case. Entries are added, but 56 * never deleted. 57 * 58 * Since labels are hanging around anyway it doesn't 59 * hurt to maintain a secid for those awkward situations 60 * where kernel components that ought to use LSM independent 61 * interfaces don't. The secid should go away when all of 62 * these components have been repaired. 63 * 64 * The cipso value associated with the label gets stored here, too. 65 * 66 * Keep the access rules for this subject label here so that 67 * the entire set of rules does not need to be examined every 68 * time. 69 */ 70 struct smack_known { 71 struct list_head list; 72 struct hlist_node smk_hashed; 73 char *smk_known; 74 u32 smk_secid; 75 struct netlbl_lsm_secattr smk_netlabel; /* on wire labels */ 76 struct list_head smk_rules; /* access rules */ 77 struct mutex smk_rules_lock; /* lock for rules */ 78 }; 79 80 /* 81 * Maximum number of bytes for the levels in a CIPSO IP option. 82 * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is 83 * bigger than can be used, and 24 is the next lower multiple 84 * of 8, and there are too many issues if there isn't space set 85 * aside for the terminating null byte. 86 */ 87 #define SMK_CIPSOLEN 24 88 89 struct superblock_smack { 90 struct smack_known *smk_root; 91 struct smack_known *smk_floor; 92 struct smack_known *smk_hat; 93 struct smack_known *smk_default; 94 int smk_flags; 95 }; 96 97 /* 98 * Superblock flags 99 */ 100 #define SMK_SB_INITIALIZED 0x01 101 #define SMK_SB_UNTRUSTED 0x02 102 103 struct socket_smack { 104 struct smack_known *smk_out; /* outbound label */ 105 struct smack_known *smk_in; /* inbound label */ 106 struct smack_known *smk_packet; /* TCP peer label */ 107 }; 108 109 /* 110 * Inode smack data 111 */ 112 struct inode_smack { 113 struct smack_known *smk_inode; /* label of the fso */ 114 struct smack_known *smk_task; /* label of the task */ 115 struct smack_known *smk_mmap; /* label of the mmap domain */ 116 struct mutex smk_lock; /* initialization lock */ 117 int smk_flags; /* smack inode flags */ 118 struct rcu_head smk_rcu; /* for freeing inode_smack */ 119 }; 120 121 struct task_smack { 122 struct smack_known *smk_task; /* label for access control */ 123 struct smack_known *smk_forked; /* label when forked */ 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 */ 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 #if IS_ENABLED(CONFIG_IPV6) 156 /* 157 * An entry in the table identifying IPv6 hosts. 158 */ 159 struct smk_net6addr { 160 struct list_head list; 161 struct in6_addr smk_host; /* network address */ 162 struct in6_addr smk_mask; /* network mask */ 163 int smk_masks; /* mask size */ 164 struct smack_known *smk_label; /* label */ 165 }; 166 #endif /* CONFIG_IPV6 */ 167 168 #ifdef SMACK_IPV6_PORT_LABELING 169 /* 170 * An entry in the table identifying ports. 171 */ 172 struct smk_port_label { 173 struct list_head list; 174 struct sock *smk_sock; /* socket initialized on */ 175 unsigned short smk_port; /* the port number */ 176 struct smack_known *smk_in; /* inbound label */ 177 struct smack_known *smk_out; /* outgoing label */ 178 short smk_sock_type; /* Socket type */ 179 short smk_can_reuse; 180 }; 181 #endif /* SMACK_IPV6_PORT_LABELING */ 182 183 struct smack_known_list_elem { 184 struct list_head list; 185 struct smack_known *smk_label; 186 }; 187 188 /* Super block security struct flags for mount options */ 189 #define FSDEFAULT_MNT 0x01 190 #define FSFLOOR_MNT 0x02 191 #define FSHAT_MNT 0x04 192 #define FSROOT_MNT 0x08 193 #define FSTRANS_MNT 0x10 194 195 #define NUM_SMK_MNT_OPTS 5 196 197 enum { 198 Opt_error = -1, 199 Opt_fsdefault = 1, 200 Opt_fsfloor = 2, 201 Opt_fshat = 3, 202 Opt_fsroot = 4, 203 Opt_fstransmute = 5, 204 }; 205 206 /* 207 * Mount options 208 */ 209 #define SMK_FSDEFAULT "smackfsdef=" 210 #define SMK_FSFLOOR "smackfsfloor=" 211 #define SMK_FSHAT "smackfshat=" 212 #define SMK_FSROOT "smackfsroot=" 213 #define SMK_FSTRANS "smackfstransmute=" 214 215 #define SMACK_DELETE_OPTION "-DELETE" 216 #define SMACK_CIPSO_OPTION "-CIPSO" 217 218 /* 219 * How communications on this socket are treated. 220 * Usually it's determined by the underlying netlabel code 221 * but there are certain cases, including single label hosts 222 * and potentially single label interfaces for which the 223 * treatment can not be known in advance. 224 * 225 * The possibility of additional labeling schemes being 226 * introduced in the future exists as well. 227 */ 228 #define SMACK_UNLABELED_SOCKET 0 229 #define SMACK_CIPSO_SOCKET 1 230 231 /* 232 * CIPSO defaults. 233 */ 234 #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ 235 #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ 236 #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ 237 #define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */ 238 #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ 239 /* 240 * CIPSO 2.2 standard is 239, but Smack wants to use the 241 * categories in a structured way that limits the value to 242 * the bits in 23 bytes, hence the unusual number. 243 */ 244 #define SMACK_CIPSO_MAXCATNUM 184 /* 23 * 8 */ 245 246 /* 247 * Ptrace rules 248 */ 249 #define SMACK_PTRACE_DEFAULT 0 250 #define SMACK_PTRACE_EXACT 1 251 #define SMACK_PTRACE_DRACONIAN 2 252 #define SMACK_PTRACE_MAX SMACK_PTRACE_DRACONIAN 253 254 /* 255 * Flags for untraditional access modes. 256 * It shouldn't be necessary to avoid conflicts with definitions 257 * in fs.h, but do so anyway. 258 */ 259 #define MAY_TRANSMUTE 0x00001000 /* Controls directory labeling */ 260 #define MAY_LOCK 0x00002000 /* Locks should be writes, but ... */ 261 #define MAY_BRINGUP 0x00004000 /* Report use of this rule */ 262 263 /* 264 * The policy for delivering signals is configurable. 265 * It is usually "write", but can be "append". 266 */ 267 #ifdef CONFIG_SECURITY_SMACK_APPEND_SIGNALS 268 #define MAY_DELIVER MAY_APPEND /* Signal delivery requires append */ 269 #else 270 #define MAY_DELIVER MAY_WRITE /* Signal delivery requires write */ 271 #endif 272 273 #define SMACK_BRINGUP_ALLOW 1 /* Allow bringup mode */ 274 #define SMACK_UNCONFINED_SUBJECT 2 /* Allow unconfined label */ 275 #define SMACK_UNCONFINED_OBJECT 3 /* Allow unconfined label */ 276 277 /* 278 * Just to make the common cases easier to deal with 279 */ 280 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 281 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 282 #define MAY_NOT 0 283 284 /* 285 * Number of access types used by Smack (rwxatlb) 286 */ 287 #define SMK_NUM_ACCESS_TYPE 7 288 289 /* SMACK data */ 290 struct smack_audit_data { 291 const char *function; 292 char *subject; 293 char *object; 294 char *request; 295 int result; 296 }; 297 298 /* 299 * Smack audit data; is empty if CONFIG_AUDIT not set 300 * to save some stack 301 */ 302 struct smk_audit_info { 303 #ifdef CONFIG_AUDIT 304 struct common_audit_data a; 305 struct smack_audit_data sad; 306 #endif 307 }; 308 309 /* 310 * These functions are in smack_access.c 311 */ 312 int smk_access_entry(char *, char *, struct list_head *); 313 int smk_access(struct smack_known *, struct smack_known *, 314 int, struct smk_audit_info *); 315 int smk_tskacc(struct task_smack *, struct smack_known *, 316 u32, struct smk_audit_info *); 317 int smk_curacc(struct smack_known *, u32, struct smk_audit_info *); 318 struct smack_known *smack_from_secid(const u32); 319 char *smk_parse_smack(const char *string, int len); 320 int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); 321 struct smack_known *smk_import_entry(const char *, int); 322 void smk_insert_entry(struct smack_known *skp); 323 struct smack_known *smk_find_entry(const char *); 324 bool smack_privileged(int cap); 325 bool smack_privileged_cred(int cap, const struct cred *cred); 326 void smk_destroy_label_list(struct list_head *list); 327 328 /* 329 * Shared data. 330 */ 331 extern int smack_enabled; 332 extern int smack_cipso_direct; 333 extern int smack_cipso_mapped; 334 extern struct smack_known *smack_net_ambient; 335 extern struct smack_known *smack_syslog_label; 336 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 337 extern struct smack_known *smack_unconfined; 338 #endif 339 extern int smack_ptrace_rule; 340 extern struct lsm_blob_sizes smack_blob_sizes; 341 342 extern struct smack_known smack_known_floor; 343 extern struct smack_known smack_known_hat; 344 extern struct smack_known smack_known_huh; 345 extern struct smack_known smack_known_star; 346 extern struct smack_known smack_known_web; 347 348 extern struct mutex smack_known_lock; 349 extern struct list_head smack_known_list; 350 extern struct list_head smk_net4addr_list; 351 #if IS_ENABLED(CONFIG_IPV6) 352 extern struct list_head smk_net6addr_list; 353 #endif /* CONFIG_IPV6 */ 354 355 extern struct mutex smack_onlycap_lock; 356 extern struct list_head smack_onlycap_list; 357 358 #define SMACK_HASH_SLOTS 16 359 extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; 360 361 static inline struct task_smack *smack_cred(const struct cred *cred) 362 { 363 return cred->security + smack_blob_sizes.lbs_cred; 364 } 365 366 static inline struct smack_known **smack_file(const struct file *file) 367 { 368 return (struct smack_known **)(file->f_security + 369 smack_blob_sizes.lbs_file); 370 } 371 372 static inline struct inode_smack *smack_inode(const struct inode *inode) 373 { 374 return inode->i_security + smack_blob_sizes.lbs_inode; 375 } 376 377 static inline struct smack_known **smack_msg_msg(const struct msg_msg *msg) 378 { 379 return msg->security + smack_blob_sizes.lbs_msg_msg; 380 } 381 382 static inline struct smack_known **smack_ipc(const struct kern_ipc_perm *ipc) 383 { 384 return ipc->security + smack_blob_sizes.lbs_ipc; 385 } 386 387 /* 388 * Is the directory transmuting? 389 */ 390 static inline int smk_inode_transmutable(const struct inode *isp) 391 { 392 struct inode_smack *sip = smack_inode(isp); 393 return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; 394 } 395 396 /* 397 * Present a pointer to the smack label entry in an inode blob. 398 */ 399 static inline struct smack_known *smk_of_inode(const struct inode *isp) 400 { 401 struct inode_smack *sip = smack_inode(isp); 402 return sip->smk_inode; 403 } 404 405 /* 406 * Present a pointer to the smack label entry in an task blob. 407 */ 408 static inline struct smack_known *smk_of_task(const struct task_smack *tsp) 409 { 410 return tsp->smk_task; 411 } 412 413 static inline struct smack_known *smk_of_task_struct( 414 const struct task_struct *t) 415 { 416 struct smack_known *skp; 417 const struct cred *cred; 418 419 rcu_read_lock(); 420 421 cred = __task_cred(t); 422 skp = smk_of_task(smack_cred(cred)); 423 424 rcu_read_unlock(); 425 426 return skp; 427 } 428 429 /* 430 * Present a pointer to the forked smack label entry in an task blob. 431 */ 432 static inline struct smack_known *smk_of_forked(const struct task_smack *tsp) 433 { 434 return tsp->smk_forked; 435 } 436 437 /* 438 * Present a pointer to the smack label in the current task blob. 439 */ 440 static inline struct smack_known *smk_of_current(void) 441 { 442 return smk_of_task(smack_cred(current_cred())); 443 } 444 445 /* 446 * logging functions 447 */ 448 #define SMACK_AUDIT_DENIED 0x1 449 #define SMACK_AUDIT_ACCEPT 0x2 450 extern int log_policy; 451 452 void smack_log(char *subject_label, char *object_label, 453 int request, 454 int result, struct smk_audit_info *auditdata); 455 456 #ifdef CONFIG_AUDIT 457 458 /* 459 * some inline functions to set up audit data 460 * they do nothing if CONFIG_AUDIT is not set 461 * 462 */ 463 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 464 char type) 465 { 466 memset(&a->sad, 0, sizeof(a->sad)); 467 a->a.type = type; 468 a->a.smack_audit_data = &a->sad; 469 a->a.smack_audit_data->function = func; 470 } 471 472 static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func, 473 char type, struct lsm_network_audit *net) 474 { 475 smk_ad_init(a, func, type); 476 memset(net, 0, sizeof(*net)); 477 a->a.u.net = net; 478 } 479 480 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 481 struct task_struct *t) 482 { 483 a->a.u.tsk = t; 484 } 485 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 486 struct dentry *d) 487 { 488 a->a.u.dentry = d; 489 } 490 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 491 struct inode *i) 492 { 493 a->a.u.inode = i; 494 } 495 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 496 struct path p) 497 { 498 a->a.u.path = p; 499 } 500 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 501 struct sock *sk) 502 { 503 a->a.u.net->sk = sk; 504 } 505 506 #else /* no AUDIT */ 507 508 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 509 char type) 510 { 511 } 512 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 513 struct task_struct *t) 514 { 515 } 516 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 517 struct dentry *d) 518 { 519 } 520 static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a, 521 struct vfsmount *m) 522 { 523 } 524 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 525 struct inode *i) 526 { 527 } 528 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 529 struct path p) 530 { 531 } 532 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 533 struct sock *sk) 534 { 535 } 536 #endif 537 538 #endif /* _SECURITY_SMACK_H */ 539