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 }; 104 105 /* 106 * Inode smack data 107 */ 108 struct inode_smack { 109 struct smack_known *smk_inode; /* label of the fso */ 110 struct smack_known *smk_task; /* label of the task */ 111 struct smack_known *smk_mmap; /* label of the mmap domain */ 112 int smk_flags; /* smack inode flags */ 113 }; 114 115 struct task_smack { 116 struct smack_known *smk_task; /* label for access control */ 117 struct smack_known *smk_forked; /* label when forked */ 118 struct list_head smk_rules; /* per task access rules */ 119 struct mutex smk_rules_lock; /* lock for the rules */ 120 struct list_head smk_relabel; /* transit allowed labels */ 121 }; 122 123 #define SMK_INODE_INSTANT 0x01 /* inode is instantiated */ 124 #define SMK_INODE_TRANSMUTE 0x02 /* directory is transmuting */ 125 #define SMK_INODE_CHANGED 0x04 /* smack was transmuted */ 126 #define SMK_INODE_IMPURE 0x08 /* involved in an impure transaction */ 127 128 /* 129 * A label access rule. 130 */ 131 struct smack_rule { 132 struct list_head list; 133 struct smack_known *smk_subject; 134 struct smack_known *smk_object; 135 int smk_access; 136 }; 137 138 /* 139 * An entry in the table identifying IPv4 hosts. 140 */ 141 struct smk_net4addr { 142 struct list_head list; 143 struct in_addr smk_host; /* network address */ 144 struct in_addr smk_mask; /* network mask */ 145 int smk_masks; /* mask size */ 146 struct smack_known *smk_label; /* label */ 147 }; 148 149 /* 150 * An entry in the table identifying IPv6 hosts. 151 */ 152 struct smk_net6addr { 153 struct list_head list; 154 struct in6_addr smk_host; /* network address */ 155 struct in6_addr smk_mask; /* network mask */ 156 int smk_masks; /* mask size */ 157 struct smack_known *smk_label; /* label */ 158 }; 159 160 /* 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 short smk_sock_type; /* Socket type */ 170 short smk_can_reuse; 171 }; 172 173 struct smack_known_list_elem { 174 struct list_head list; 175 struct smack_known *smk_label; 176 }; 177 178 /* Super block security struct flags for mount options */ 179 #define FSDEFAULT_MNT 0x01 180 #define FSFLOOR_MNT 0x02 181 #define FSHAT_MNT 0x04 182 #define FSROOT_MNT 0x08 183 #define FSTRANS_MNT 0x10 184 185 #define NUM_SMK_MNT_OPTS 5 186 187 enum { 188 Opt_error = -1, 189 Opt_fsdefault = 0, 190 Opt_fsfloor = 1, 191 Opt_fshat = 2, 192 Opt_fsroot = 3, 193 Opt_fstransmute = 4, 194 }; 195 196 #define SMACK_DELETE_OPTION "-DELETE" 197 #define SMACK_CIPSO_OPTION "-CIPSO" 198 199 /* 200 * How communications on this socket are treated. 201 * Usually it's determined by the underlying netlabel code 202 * but there are certain cases, including single label hosts 203 * and potentially single label interfaces for which the 204 * treatment can not be known in advance. 205 * 206 * The possibility of additional labeling schemes being 207 * introduced in the future exists as well. 208 */ 209 #define SMACK_UNLABELED_SOCKET 0 210 #define SMACK_CIPSO_SOCKET 1 211 212 /* 213 * CIPSO defaults. 214 */ 215 #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ 216 #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ 217 #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ 218 #define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */ 219 #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ 220 /* 221 * CIPSO 2.2 standard is 239, but Smack wants to use the 222 * categories in a structured way that limits the value to 223 * the bits in 23 bytes, hence the unusual number. 224 */ 225 #define SMACK_CIPSO_MAXCATNUM 184 /* 23 * 8 */ 226 227 /* 228 * Ptrace rules 229 */ 230 #define SMACK_PTRACE_DEFAULT 0 231 #define SMACK_PTRACE_EXACT 1 232 #define SMACK_PTRACE_DRACONIAN 2 233 #define SMACK_PTRACE_MAX SMACK_PTRACE_DRACONIAN 234 235 /* 236 * Flags for untraditional access modes. 237 * It shouldn't be necessary to avoid conflicts with definitions 238 * in fs.h, but do so anyway. 239 */ 240 #define MAY_TRANSMUTE 0x00001000 /* Controls directory labeling */ 241 #define MAY_LOCK 0x00002000 /* Locks should be writes, but ... */ 242 #define MAY_BRINGUP 0x00004000 /* Report use of this rule */ 243 244 /* 245 * The policy for delivering signals is configurable. 246 * It is usually "write", but can be "append". 247 */ 248 #ifdef CONFIG_SECURITY_SMACK_APPEND_SIGNALS 249 #define MAY_DELIVER MAY_APPEND /* Signal delivery requires append */ 250 #else 251 #define MAY_DELIVER MAY_WRITE /* Signal delivery requires write */ 252 #endif 253 254 #define SMACK_BRINGUP_ALLOW 1 /* Allow bringup mode */ 255 #define SMACK_UNCONFINED_SUBJECT 2 /* Allow unconfined label */ 256 #define SMACK_UNCONFINED_OBJECT 3 /* Allow unconfined label */ 257 258 /* 259 * Just to make the common cases easier to deal with 260 */ 261 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 262 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 263 #define MAY_NOT 0 264 265 /* 266 * Number of access types used by Smack (rwxatlb) 267 */ 268 #define SMK_NUM_ACCESS_TYPE 7 269 270 /* SMACK data */ 271 struct smack_audit_data { 272 const char *function; 273 char *subject; 274 char *object; 275 char *request; 276 int result; 277 }; 278 279 /* 280 * Smack audit data; is empty if CONFIG_AUDIT not set 281 * to save some stack 282 */ 283 struct smk_audit_info { 284 #ifdef CONFIG_AUDIT 285 struct common_audit_data a; 286 struct smack_audit_data sad; 287 #endif 288 }; 289 290 /* 291 * These functions are in smack_access.c 292 */ 293 int smk_access_entry(char *, char *, struct list_head *); 294 int smk_access(struct smack_known *, struct smack_known *, 295 int, struct smk_audit_info *); 296 int smk_tskacc(struct task_smack *, struct smack_known *, 297 u32, struct smk_audit_info *); 298 int smk_curacc(struct smack_known *, u32, struct smk_audit_info *); 299 struct smack_known *smack_from_secid(const u32); 300 char *smk_parse_smack(const char *string, int len); 301 int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); 302 struct smack_known *smk_import_entry(const char *, int); 303 void smk_insert_entry(struct smack_known *skp); 304 struct smack_known *smk_find_entry(const char *); 305 bool smack_privileged(int cap); 306 bool smack_privileged_cred(int cap, const struct cred *cred); 307 void smk_destroy_label_list(struct list_head *list); 308 309 /* 310 * Shared data. 311 */ 312 extern int smack_enabled; 313 extern int smack_cipso_direct; 314 extern int smack_cipso_mapped; 315 extern struct smack_known *smack_net_ambient; 316 extern struct smack_known *smack_syslog_label; 317 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 318 extern struct smack_known *smack_unconfined; 319 #endif 320 extern int smack_ptrace_rule; 321 extern struct lsm_blob_sizes smack_blob_sizes; 322 323 extern struct smack_known smack_known_floor; 324 extern struct smack_known smack_known_hat; 325 extern struct smack_known smack_known_huh; 326 extern struct smack_known smack_known_star; 327 extern struct smack_known smack_known_web; 328 329 extern struct mutex smack_known_lock; 330 extern struct list_head smack_known_list; 331 extern struct list_head smk_net4addr_list; 332 extern struct list_head smk_net6addr_list; 333 334 extern struct mutex smack_onlycap_lock; 335 extern struct list_head smack_onlycap_list; 336 337 #define SMACK_HASH_SLOTS 16 338 extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; 339 extern struct kmem_cache *smack_rule_cache; 340 341 static inline struct task_smack *smack_cred(const struct cred *cred) 342 { 343 return cred->security + smack_blob_sizes.lbs_cred; 344 } 345 346 static inline struct smack_known **smack_file(const struct file *file) 347 { 348 return (struct smack_known **)(file->f_security + 349 smack_blob_sizes.lbs_file); 350 } 351 352 static inline struct inode_smack *smack_inode(const struct inode *inode) 353 { 354 return inode->i_security + smack_blob_sizes.lbs_inode; 355 } 356 357 static inline struct smack_known **smack_msg_msg(const struct msg_msg *msg) 358 { 359 return msg->security + smack_blob_sizes.lbs_msg_msg; 360 } 361 362 static inline struct smack_known **smack_ipc(const struct kern_ipc_perm *ipc) 363 { 364 return ipc->security + smack_blob_sizes.lbs_ipc; 365 } 366 367 /* 368 * Is the directory transmuting? 369 */ 370 static inline int smk_inode_transmutable(const struct inode *isp) 371 { 372 struct inode_smack *sip = smack_inode(isp); 373 return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; 374 } 375 376 /* 377 * Present a pointer to the smack label entry in an inode blob. 378 */ 379 static inline struct smack_known *smk_of_inode(const struct inode *isp) 380 { 381 struct inode_smack *sip = smack_inode(isp); 382 return sip->smk_inode; 383 } 384 385 /* 386 * Present a pointer to the smack label entry in an task blob. 387 */ 388 static inline struct smack_known *smk_of_task(const struct task_smack *tsp) 389 { 390 return tsp->smk_task; 391 } 392 393 static inline struct smack_known *smk_of_task_struct( 394 const struct task_struct *t) 395 { 396 struct smack_known *skp; 397 const struct cred *cred; 398 399 rcu_read_lock(); 400 401 cred = __task_cred(t); 402 skp = smk_of_task(smack_cred(cred)); 403 404 rcu_read_unlock(); 405 406 return skp; 407 } 408 409 /* 410 * Present a pointer to the forked smack label entry in an task blob. 411 */ 412 static inline struct smack_known *smk_of_forked(const struct task_smack *tsp) 413 { 414 return tsp->smk_forked; 415 } 416 417 /* 418 * Present a pointer to the smack label in the current task blob. 419 */ 420 static inline struct smack_known *smk_of_current(void) 421 { 422 return smk_of_task(smack_cred(current_cred())); 423 } 424 425 /* 426 * logging functions 427 */ 428 #define SMACK_AUDIT_DENIED 0x1 429 #define SMACK_AUDIT_ACCEPT 0x2 430 extern int log_policy; 431 432 void smack_log(char *subject_label, char *object_label, 433 int request, 434 int result, struct smk_audit_info *auditdata); 435 436 #ifdef CONFIG_AUDIT 437 438 /* 439 * some inline functions to set up audit data 440 * they do nothing if CONFIG_AUDIT is not set 441 * 442 */ 443 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 444 char type) 445 { 446 memset(&a->sad, 0, sizeof(a->sad)); 447 a->a.type = type; 448 a->a.smack_audit_data = &a->sad; 449 a->a.smack_audit_data->function = func; 450 } 451 452 static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func, 453 char type, struct lsm_network_audit *net) 454 { 455 smk_ad_init(a, func, type); 456 memset(net, 0, sizeof(*net)); 457 a->a.u.net = net; 458 } 459 460 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 461 struct task_struct *t) 462 { 463 a->a.u.tsk = t; 464 } 465 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 466 struct dentry *d) 467 { 468 a->a.u.dentry = d; 469 } 470 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 471 struct inode *i) 472 { 473 a->a.u.inode = i; 474 } 475 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 476 struct path p) 477 { 478 a->a.u.path = p; 479 } 480 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 481 struct sock *sk) 482 { 483 a->a.u.net->sk = sk; 484 } 485 486 #else /* no AUDIT */ 487 488 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 489 char type) 490 { 491 } 492 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 493 struct task_struct *t) 494 { 495 } 496 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 497 struct dentry *d) 498 { 499 } 500 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 501 struct inode *i) 502 { 503 } 504 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 505 struct path p) 506 { 507 } 508 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 509 struct sock *sk) 510 { 511 } 512 #endif 513 514 #endif /* _SECURITY_SMACK_H */ 515