aboutsummaryrefslogtreecommitdiff
path: root/security/smack/smack.h
blob: 5e031a2e4c363aa44b10af6e90300149c3eb8c00 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
/*
 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
 *
 *      This program is free software; you can redistribute it and/or modify
 *      it under the terms of the GNU General Public License as published by
 *      the Free Software Foundation, version 2.
 *
 * Author:
 *      Casey Schaufler <casey@schaufler-ca.com>
 *
 */

#ifndef _SECURITY_SMACK_H
#define _SECURITY_SMACK_H

#include <linux/capability.h>
#include <linux/spinlock.h>
#include <linux/security.h>
#include <linux/in.h>
#include <net/netlabel.h>
#include <linux/list.h>
#include <linux/rculist.h>
#include <linux/lsm_audit.h>

/*
 * Smack labels were limited to 23 characters for a long time.
 */
#define SMK_LABELLEN	24
#define SMK_LONGLABEL	256

/*
 * Maximum number of bytes for the levels in a CIPSO IP option.
 * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is
 * bigger than can be used, and 24 is the next lower multiple
 * of 8, and there are too many issues if there isn't space set
 * aside for the terminating null byte.
 */
#define SMK_CIPSOLEN	24

struct superblock_smack {
	char		*smk_root;
	char		*smk_floor;
	char		*smk_hat;
	char		*smk_default;
	int		smk_initialized;
	spinlock_t	smk_sblock;	/* for initialization */
};

struct socket_smack {
	char		*smk_out;	/* outbound label */
	char		*smk_in;	/* inbound label */
	char		*smk_packet;	/* TCP peer label */
};

/*
 * Inode smack data
 */
struct inode_smack {
	char		*smk_inode;	/* label of the fso */
	char		*smk_task;	/* label of the task */
	char		*smk_mmap;	/* label of the mmap domain */
	struct mutex	smk_lock;	/* initialization lock */
	int		smk_flags;	/* smack inode flags */
};

struct task_smack {
	char			*smk_task;	/* label for access control */
	char			*smk_forked;	/* label when forked */
	struct list_head	smk_rules;	/* per task access rules */
	struct mutex		smk_rules_lock;	/* lock for the rules */
};

#define	SMK_INODE_INSTANT	0x01	/* inode is instantiated */
#define	SMK_INODE_TRANSMUTE	0x02	/* directory is transmuting */
#define	SMK_INODE_CHANGED	0x04	/* smack was transmuted */

/*
 * A label access rule.
 */
struct smack_rule {
	struct list_head	list;
	char			*smk_subject;
	char			*smk_object;
	int			smk_access;
};

/*
 * An entry in the table identifying hosts.
 */
struct smk_netlbladdr {
	struct list_head	list;
	struct sockaddr_in	smk_host;	/* network address */
	struct in_addr		smk_mask;	/* network mask */
	char			*smk_label;	/* label */
};

/*
 * This is the repository for labels seen so that it is
 * not necessary to keep allocating tiny chuncks of memory
 * and so that they can be shared.
 *
 * Labels are never modified in place. Anytime a label
 * is imported (e.g. xattrset on a file) the list is checked
 * for it and it is added if it doesn't exist. The address
 * is passed out in either case. Entries are added, but
 * never deleted.
 *
 * Since labels are hanging around anyway it doesn't
 * hurt to maintain a secid for those awkward situations
 * where kernel components that ought to use LSM independent
 * interfaces don't. The secid should go away when all of
 * these components have been repaired.
 *
 * The cipso value associated with the label gets stored here, too.
 *
 * Keep the access rules for this subject label here so that
 * the entire set of rules does not need to be examined every
 * time.
 */
struct smack_known {
	struct list_head		list;
	char				*smk_known;
	u32				smk_secid;
	struct netlbl_lsm_secattr	smk_netlabel;	/* on wire labels */
	struct list_head		smk_rules;	/* access rules */
	struct mutex			smk_rules_lock;	/* lock for rules */
};

/*
 * Mount options
 */
#define SMK_FSDEFAULT	"smackfsdef="
#define SMK_FSFLOOR	"smackfsfloor="
#define SMK_FSHAT	"smackfshat="
#define SMK_FSROOT	"smackfsroot="

#define SMACK_CIPSO_OPTION 	"-CIPSO"

/*
 * How communications on this socket are treated.
 * Usually it's determined by the underlying netlabel code
 * but there are certain cases, including single label hosts
 * and potentially single label interfaces for which the
 * treatment can not be known in advance.
 *
 * The possibility of additional labeling schemes being
 * introduced in the future exists as well.
 */
#define SMACK_UNLABELED_SOCKET	0
#define SMACK_CIPSO_SOCKET	1

/*
 * smackfs magic number
 */
#define SMACK_MAGIC	0x43415d53 /* "SMAC" */

/*
 * CIPSO defaults.
 */
#define SMACK_CIPSO_DOI_DEFAULT		3	/* Historical */
#define SMACK_CIPSO_DOI_INVALID		-1	/* Not a DOI */
#define SMACK_CIPSO_DIRECT_DEFAULT	250	/* Arbitrary */
#define SMACK_CIPSO_MAPPED_DEFAULT	251	/* Also arbitrary */
#define SMACK_CIPSO_MAXCATVAL		63	/* Bigger gets harder */
#define SMACK_CIPSO_MAXLEVEL            255     /* CIPSO 2.2 standard */
#define SMACK_CIPSO_MAXCATNUM           239     /* CIPSO 2.2 standard */

/*
 * Flag for transmute access
 */
#define MAY_TRANSMUTE	64
/*
 * Just to make the common cases easier to deal with
 */
#define MAY_ANYREAD	(MAY_READ | MAY_EXEC)
#define MAY_READWRITE	(MAY_READ | MAY_WRITE)
#define MAY_NOT		0

/*
 * Number of access types used by Smack (rwxat)
 */
#define SMK_NUM_ACCESS_TYPE 5

/* SMACK data */
struct smack_audit_data {
	const char *function;
	char *subject;
	char *object;
	char *request;
	int result;
};

/*
 * Smack audit data; is empty if CONFIG_AUDIT not set
 * to save some stack
 */
struct smk_audit_info {
#ifdef CONFIG_AUDIT
	struct common_audit_data a;
	struct smack_audit_data sad;
#endif
};
/*
 * These functions are in smack_lsm.c
 */
struct inode_smack *new_inode_smack(char *);

/*
 * These functions are in smack_access.c
 */
int smk_access_entry(char *, char *, struct list_head *);
int smk_access(char *, char *, int, struct smk_audit_info *);
int smk_curacc(char *, u32, struct smk_audit_info *);
char *smack_from_secid(const u32);
char *smk_parse_smack(const char *string, int len);
int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int);
char *smk_import(const char *, int);
struct smack_known *smk_import_entry(const char *, int);
struct smack_known *smk_find_entry(const char *);
u32 smack_to_secid(const char *);

/*
 * Shared data.
 */
extern int smack_cipso_direct;
extern int smack_cipso_mapped;
extern char *smack_net_ambient;
extern char *smack_onlycap;
extern const char *smack_cipso_option;

extern struct smack_known smack_known_floor;
extern struct smack_known smack_known_hat;
extern struct smack_known smack_known_huh;
extern struct smack_known smack_known_invalid;
extern struct smack_known smack_known_star;
extern struct smack_known smack_known_web;

extern struct mutex	smack_known_lock;
extern struct list_head smack_known_list;
extern struct list_head smk_netlbladdr_list;

extern struct security_operations smack_ops;

/*
 * Is the directory transmuting?
 */
static inline int smk_inode_transmutable(const struct inode *isp)
{
	struct inode_smack *sip = isp->i_security;
	return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0;
}

/*
 * Present a pointer to the smack label in an inode blob.
 */
static inline char *smk_of_inode(const struct inode *isp)
{
	struct inode_smack *sip = isp->i_security;
	return sip->smk_inode;
}

/*
 * Present a pointer to the smack label in an task blob.
 */
static inline char *smk_of_task(const struct task_smack *tsp)
{
	return tsp->smk_task;
}

/*
 * Present a pointer to the forked smack label in an task blob.
 */
static inline char *smk_of_forked(const struct task_smack *tsp)
{
	return tsp->smk_forked;
}

/*
 * Present a pointer to the smack label in the current task blob.
 */
static inline char *smk_of_current(void)
{
	return smk_of_task(current_security());
}

/*
 * logging functions
 */
#define SMACK_AUDIT_DENIED 0x1
#define SMACK_AUDIT_ACCEPT 0x2
extern int log_policy;

void smack_log(char *subject_label, char *object_label,
		int request,
		int result, struct smk_audit_info *auditdata);

#ifdef CONFIG_AUDIT

/*
 * some inline functions to set up audit data
 * they do nothing if CONFIG_AUDIT is not set
 *
 */
static inline void smk_ad_init(struct smk_audit_info *a, const char *func,
			       char type)
{
	memset(a, 0, sizeof(*a));
	a->a.type = type;
	a->a.smack_audit_data = &a->sad;
	a->a.smack_audit_data->function = func;
}

static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func,
				   char type, struct lsm_network_audit *net)
{
	smk_ad_init(a, func, type);
	memset(net, 0, sizeof(*net));
	a->a.u.net = net;
}

static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a,
					 struct task_struct *t)
{
	a->a.u.tsk = t;
}
static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a,
						    struct dentry *d)
{
	a->a.u.dentry = d;
}
static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a,
					      struct inode *i)
{
	a->a.u.inode = i;
}
static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a,
					     struct path p)
{
	a->a.u.path = p;
}
static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a,
					    struct sock *sk)
{
	a->a.u.net->sk = sk;
}

#else /* no AUDIT */

static inline void smk_ad_init(struct smk_audit_info *a, const char *func,
			       char type)
{
}
static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a,
					 struct task_struct *t)
{
}
static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a,
						    struct dentry *d)
{
}
static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a,
						 struct vfsmount *m)
{
}
static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a,
					      struct inode *i)
{
}
static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a,
					     struct path p)
{
}
static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a,
					    struct sock *sk)
{
}
#endif

#endif  /* _SECURITY_SMACK_H */