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 smack_known *smk_transmuted;/* label when transmuted */ |
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 (unused) */ |
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 | /* |
156 | * An entry in the table identifying IPv6 hosts. |
157 | */ |
158 | struct smk_net6addr { |
159 | struct list_head list; |
160 | struct in6_addr smk_host; /* network address */ |
161 | struct in6_addr smk_mask; /* network mask */ |
162 | int smk_masks; /* mask size */ |
163 | struct smack_known *smk_label; /* label */ |
164 | }; |
165 | |
166 | /* |
167 | * An entry in the table identifying ports. |
168 | */ |
169 | struct smk_port_label { |
170 | struct list_head list; |
171 | struct sock *smk_sock; /* socket initialized on */ |
172 | unsigned short smk_port; /* the port number */ |
173 | struct smack_known *smk_in; /* inbound label */ |
174 | struct smack_known *smk_out; /* outgoing label */ |
175 | short smk_sock_type; /* Socket type */ |
176 | short smk_can_reuse; |
177 | }; |
178 | |
179 | struct smack_known_list_elem { |
180 | struct list_head list; |
181 | struct smack_known *smk_label; |
182 | }; |
183 | |
184 | enum { |
185 | Opt_error = -1, |
186 | Opt_fsdefault = 0, |
187 | Opt_fsfloor = 1, |
188 | Opt_fshat = 2, |
189 | Opt_fsroot = 3, |
190 | Opt_fstransmute = 4, |
191 | }; |
192 | |
193 | #define SMACK_DELETE_OPTION "-DELETE" |
194 | #define SMACK_CIPSO_OPTION "-CIPSO" |
195 | |
196 | /* |
197 | * CIPSO defaults. |
198 | */ |
199 | #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ |
200 | #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ |
201 | #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ |
202 | #define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */ |
203 | #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ |
204 | /* |
205 | * CIPSO 2.2 standard is 239, but Smack wants to use the |
206 | * categories in a structured way that limits the value to |
207 | * the bits in 23 bytes, hence the unusual number. |
208 | */ |
209 | #define SMACK_CIPSO_MAXCATNUM 184 /* 23 * 8 */ |
210 | |
211 | /* |
212 | * Ptrace rules |
213 | */ |
214 | #define SMACK_PTRACE_DEFAULT 0 |
215 | #define SMACK_PTRACE_EXACT 1 |
216 | #define SMACK_PTRACE_DRACONIAN 2 |
217 | #define SMACK_PTRACE_MAX SMACK_PTRACE_DRACONIAN |
218 | |
219 | /* |
220 | * Flags for untraditional access modes. |
221 | * It shouldn't be necessary to avoid conflicts with definitions |
222 | * in fs.h, but do so anyway. |
223 | */ |
224 | #define MAY_TRANSMUTE 0x00001000 /* Controls directory labeling */ |
225 | #define MAY_LOCK 0x00002000 /* Locks should be writes, but ... */ |
226 | #define MAY_BRINGUP 0x00004000 /* Report use of this rule */ |
227 | |
228 | /* |
229 | * The policy for delivering signals is configurable. |
230 | * It is usually "write", but can be "append". |
231 | */ |
232 | #ifdef CONFIG_SECURITY_SMACK_APPEND_SIGNALS |
233 | #define MAY_DELIVER MAY_APPEND /* Signal delivery requires append */ |
234 | #else |
235 | #define MAY_DELIVER MAY_WRITE /* Signal delivery requires write */ |
236 | #endif |
237 | |
238 | #define SMACK_BRINGUP_ALLOW 1 /* Allow bringup mode */ |
239 | #define SMACK_UNCONFINED_SUBJECT 2 /* Allow unconfined label */ |
240 | #define SMACK_UNCONFINED_OBJECT 3 /* Allow unconfined label */ |
241 | |
242 | /* |
243 | * Just to make the common cases easier to deal with |
244 | */ |
245 | #define MAY_ANYREAD (MAY_READ | MAY_EXEC) |
246 | #define MAY_READWRITE (MAY_READ | MAY_WRITE) |
247 | #define MAY_NOT 0 |
248 | |
249 | /* |
250 | * Number of access types used by Smack (rwxatlb) |
251 | */ |
252 | #define SMK_NUM_ACCESS_TYPE 7 |
253 | |
254 | /* SMACK data */ |
255 | struct smack_audit_data { |
256 | const char *function; |
257 | char *subject; |
258 | char *object; |
259 | char *request; |
260 | int result; |
261 | }; |
262 | |
263 | /* |
264 | * Smack audit data; is empty if CONFIG_AUDIT not set |
265 | * to save some stack |
266 | */ |
267 | struct smk_audit_info { |
268 | #ifdef CONFIG_AUDIT |
269 | struct common_audit_data a; |
270 | struct smack_audit_data sad; |
271 | #endif |
272 | }; |
273 | |
274 | /* |
275 | * These functions are in smack_access.c |
276 | */ |
277 | int smk_access_entry(char *, char *, struct list_head *); |
278 | int smk_access(struct smack_known *, struct smack_known *, |
279 | int, struct smk_audit_info *); |
280 | int smk_tskacc(struct task_smack *, struct smack_known *, |
281 | u32, struct smk_audit_info *); |
282 | int smk_curacc(struct smack_known *, u32, struct smk_audit_info *); |
283 | struct smack_known *smack_from_secid(const u32); |
284 | char *smk_parse_smack(const char *string, int len); |
285 | int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); |
286 | struct smack_known *smk_import_entry(const char *, int); |
287 | void smk_insert_entry(struct smack_known *skp); |
288 | struct smack_known *smk_find_entry(const char *); |
289 | bool smack_privileged(int cap); |
290 | bool smack_privileged_cred(int cap, const struct cred *cred); |
291 | void smk_destroy_label_list(struct list_head *list); |
292 | int smack_populate_secattr(struct smack_known *skp); |
293 | |
294 | /* |
295 | * Shared data. |
296 | */ |
297 | extern int smack_enabled __initdata; |
298 | extern int smack_cipso_direct; |
299 | extern int smack_cipso_mapped; |
300 | extern struct smack_known *smack_net_ambient; |
301 | extern struct smack_known *smack_syslog_label; |
302 | #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
303 | extern struct smack_known *smack_unconfined; |
304 | #endif |
305 | extern int smack_ptrace_rule; |
306 | extern struct lsm_blob_sizes smack_blob_sizes; |
307 | |
308 | extern struct smack_known smack_known_floor; |
309 | extern struct smack_known smack_known_hat; |
310 | extern struct smack_known smack_known_huh; |
311 | extern struct smack_known smack_known_star; |
312 | extern struct smack_known smack_known_web; |
313 | |
314 | extern struct mutex smack_known_lock; |
315 | extern struct list_head smack_known_list; |
316 | extern struct list_head smk_net4addr_list; |
317 | extern struct list_head smk_net6addr_list; |
318 | |
319 | extern struct mutex smack_onlycap_lock; |
320 | extern struct list_head smack_onlycap_list; |
321 | |
322 | #define SMACK_HASH_SLOTS 16 |
323 | extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; |
324 | extern struct kmem_cache *smack_rule_cache; |
325 | |
326 | static inline struct task_smack *smack_cred(const struct cred *cred) |
327 | { |
328 | return cred->security + smack_blob_sizes.lbs_cred; |
329 | } |
330 | |
331 | static inline struct smack_known **smack_file(const struct file *file) |
332 | { |
333 | return (struct smack_known **)(file->f_security + |
334 | smack_blob_sizes.lbs_file); |
335 | } |
336 | |
337 | static inline struct inode_smack *smack_inode(const struct inode *inode) |
338 | { |
339 | return inode->i_security + smack_blob_sizes.lbs_inode; |
340 | } |
341 | |
342 | static inline struct smack_known **smack_msg_msg(const struct msg_msg *msg) |
343 | { |
344 | return msg->security + smack_blob_sizes.lbs_msg_msg; |
345 | } |
346 | |
347 | static inline struct smack_known **smack_ipc(const struct kern_ipc_perm *ipc) |
348 | { |
349 | return ipc->security + smack_blob_sizes.lbs_ipc; |
350 | } |
351 | |
352 | static inline struct superblock_smack *smack_superblock( |
353 | const struct super_block *superblock) |
354 | { |
355 | return superblock->s_security + smack_blob_sizes.lbs_superblock; |
356 | } |
357 | |
358 | /* |
359 | * Is the directory transmuting? |
360 | */ |
361 | static inline int smk_inode_transmutable(const struct inode *isp) |
362 | { |
363 | struct inode_smack *sip = smack_inode(inode: isp); |
364 | return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; |
365 | } |
366 | |
367 | /* |
368 | * Present a pointer to the smack label entry in an inode blob. |
369 | */ |
370 | static inline struct smack_known *smk_of_inode(const struct inode *isp) |
371 | { |
372 | struct inode_smack *sip = smack_inode(inode: isp); |
373 | return sip->smk_inode; |
374 | } |
375 | |
376 | /* |
377 | * Present a pointer to the smack label entry in an task blob. |
378 | */ |
379 | static inline struct smack_known *smk_of_task(const struct task_smack *tsp) |
380 | { |
381 | return tsp->smk_task; |
382 | } |
383 | |
384 | static inline struct smack_known *smk_of_task_struct_obj( |
385 | const struct task_struct *t) |
386 | { |
387 | struct smack_known *skp; |
388 | const struct cred *cred; |
389 | |
390 | rcu_read_lock(); |
391 | |
392 | cred = __task_cred(t); |
393 | skp = smk_of_task(tsp: smack_cred(cred)); |
394 | |
395 | rcu_read_unlock(); |
396 | |
397 | return skp; |
398 | } |
399 | |
400 | /* |
401 | * Present a pointer to the forked smack label entry in an task blob. |
402 | */ |
403 | static inline struct smack_known *smk_of_forked(const struct task_smack *tsp) |
404 | { |
405 | return tsp->smk_forked; |
406 | } |
407 | |
408 | /* |
409 | * Present a pointer to the smack label in the current task blob. |
410 | */ |
411 | static inline struct smack_known *smk_of_current(void) |
412 | { |
413 | return smk_of_task(tsp: smack_cred(current_cred())); |
414 | } |
415 | |
416 | /* |
417 | * logging functions |
418 | */ |
419 | #define SMACK_AUDIT_DENIED 0x1 |
420 | #define SMACK_AUDIT_ACCEPT 0x2 |
421 | extern int log_policy; |
422 | |
423 | void smack_log(char *subject_label, char *object_label, |
424 | int request, |
425 | int result, struct smk_audit_info *auditdata); |
426 | |
427 | #ifdef CONFIG_AUDIT |
428 | |
429 | /* |
430 | * some inline functions to set up audit data |
431 | * they do nothing if CONFIG_AUDIT is not set |
432 | * |
433 | */ |
434 | static inline void smk_ad_init(struct smk_audit_info *a, const char *func, |
435 | char type) |
436 | { |
437 | memset(&a->sad, 0, sizeof(a->sad)); |
438 | a->a.type = type; |
439 | a->a.smack_audit_data = &a->sad; |
440 | a->a.smack_audit_data->function = func; |
441 | } |
442 | |
443 | static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func, |
444 | char type, struct lsm_network_audit *net) |
445 | { |
446 | smk_ad_init(a, func, type); |
447 | memset(net, 0, sizeof(*net)); |
448 | a->a.u.net = net; |
449 | } |
450 | |
451 | static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, |
452 | struct task_struct *t) |
453 | { |
454 | a->a.u.tsk = t; |
455 | } |
456 | static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, |
457 | struct dentry *d) |
458 | { |
459 | a->a.u.dentry = d; |
460 | } |
461 | static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, |
462 | struct inode *i) |
463 | { |
464 | a->a.u.inode = i; |
465 | } |
466 | static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, |
467 | struct path p) |
468 | { |
469 | a->a.u.path = p; |
470 | } |
471 | static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, |
472 | struct sock *sk) |
473 | { |
474 | a->a.u.net->sk = sk; |
475 | } |
476 | |
477 | #else /* no AUDIT */ |
478 | |
479 | static inline void smk_ad_init(struct smk_audit_info *a, const char *func, |
480 | char type) |
481 | { |
482 | } |
483 | static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, |
484 | struct task_struct *t) |
485 | { |
486 | } |
487 | static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, |
488 | struct dentry *d) |
489 | { |
490 | } |
491 | static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, |
492 | struct inode *i) |
493 | { |
494 | } |
495 | static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, |
496 | struct path p) |
497 | { |
498 | } |
499 | static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, |
500 | struct sock *sk) |
501 | { |
502 | } |
503 | #endif |
504 | |
505 | #endif /* _SECURITY_SMACK_H */ |
506 | |