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 static inline struct socket_smack *smack_sock(const struct sock *sock)
359 {
360 return sock->sk_security + smack_blob_sizes.lbs_sock;
361 }
362
363 /*
364 * Is the directory transmuting?
365 */
366 static inline int smk_inode_transmutable(const struct inode *isp)
367 {
368 struct inode_smack *sip = smack_inode(isp);
369 return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0;
370 }
371
372 /*
373 * Present a pointer to the smack label entry in an inode blob.
374 */
375 static inline struct smack_known *smk_of_inode(const struct inode *isp)
376 {
377 struct inode_smack *sip = smack_inode(isp);
378 return sip->smk_inode;
379 }
380
381 /*
382 * Present a pointer to the smack label entry in an task blob.
383 */
384 static inline struct smack_known *smk_of_task(const struct task_smack *tsp)
385 {
386 return tsp->smk_task;
387 }
388
389 static inline struct smack_known *smk_of_task_struct_obj(
390 const struct task_struct *t)
391 {
392 struct smack_known *skp;
393 const struct cred *cred;
394
395 rcu_read_lock();
396
397 cred = __task_cred(t);
398 skp = smk_of_task(smack_cred(cred));
399
400 rcu_read_unlock();
401
402 return skp;
403 }
404
405 /*
406 * Present a pointer to the forked smack label entry in an task blob.
407 */
408 static inline struct smack_known *smk_of_forked(const struct task_smack *tsp)
409 {
410 return tsp->smk_forked;
411 }
412
413 /*
414 * Present a pointer to the smack label in the current task blob.
415 */
416 static inline struct smack_known *smk_of_current(void)
417 {
418 return smk_of_task(smack_cred(current_cred()));
419 }
420
421 /*
422 * logging functions
423 */
424 #define SMACK_AUDIT_DENIED 0x1
425 #define SMACK_AUDIT_ACCEPT 0x2
426 extern int log_policy;
427
428 void smack_log(char *subject_label, char *object_label,
429 int request,
430 int result, struct smk_audit_info *auditdata);
431
432 #ifdef CONFIG_AUDIT
433
434 /*
435 * some inline functions to set up audit data
436 * they do nothing if CONFIG_AUDIT is not set
437 *
438 */
439 static inline void smk_ad_init(struct smk_audit_info *a, const char *func,
440 char type)
441 {
442 memset(&a->sad, 0, sizeof(a->sad));
443 a->a.type = type;
444 a->a.smack_audit_data = &a->sad;
445 a->a.smack_audit_data->function = func;
446 }
447
448 static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func,
449 char type, struct lsm_network_audit *net)
450 {
451 smk_ad_init(a, func, type);
452 memset(net, 0, sizeof(*net));
453 a->a.u.net = net;
454 }
455
456 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a,
457 struct task_struct *t)
458 {
459 a->a.u.tsk = t;
460 }
461 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a,
462 struct dentry *d)
463 {
464 a->a.u.dentry = d;
465 }
466 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a,
467 struct inode *i)
468 {
469 a->a.u.inode = i;
470 }
471 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a,
472 struct path p)
473 {
474 a->a.u.path = p;
475 }
476 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a,
477 struct sock *sk)
478 {
479 a->a.u.net->sk = sk;
480 }
481
482 #else /* no AUDIT */
483
484 static inline void smk_ad_init(struct smk_audit_info *a, const char *func,
485 char type)
486 {
487 }
488 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a,
489 struct task_struct *t)
490 {
491 }
492 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a,
493 struct dentry *d)
494 {
495 }
496 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a,
497 struct inode *i)
498 {
499 }
500 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a,
501 struct path p)
502 {
503 }
504 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a,
505 struct sock *sk)
506 {
507 }
508 #endif
509
510 #endif /* _SECURITY_SMACK_H */
511
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