aboutsummaryrefslogtreecommitdiffstats
path: root/security/smack/smack.h
blob: a21a0e907ab34092017e6a67243a1ad93b3be171 (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
/*
 * 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 <net/netlabel.h>

/*
 * 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_MAXLEN	23
#define SMK_LABELLEN	(SMK_MAXLEN+1)

/*
 * How many kinds of access are there?
 * Here's your answer.
 */
#define SMK_ACCESSDASH	'-'
#define SMK_ACCESSLOW	"rwxa"
#define SMK_ACCESSKINDS	(sizeof(SMK_ACCESSLOW) - 1)

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[SMK_LABELLEN];	/* TCP peer label */
};

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

#define	SMK_INODE_INSTANT	0x01	/* inode is instantiated */

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

/*
 * An entry in the table of permitted label accesses.
 */
struct smk_list_entry {
	struct smk_list_entry	*smk_next;
	struct smack_rule	smk_rule;
};

/*
 * An entry in the table mapping smack values to
 * CIPSO level/category-set values.
 */
struct smack_cipso {
	int	smk_level;
	char	smk_catset[SMK_LABELLEN];
};

/*
 * 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.
 *
 * If there is a cipso value associated with the label it
 * gets stored here, too. This will most likely be rare as
 * the cipso direct mapping in used internally.
 */
struct smack_known {
	struct smack_known	*smk_next;
	char			smk_known[SMK_LABELLEN];
	u32			smk_secid;
	struct smack_cipso	*smk_cipso;
	spinlock_t		smk_cipsolock; /* for changing cipso map */
};

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

/*
 * xattr names
 */
#define XATTR_SMACK_SUFFIX	"SMACK64"
#define XATTR_SMACK_IPIN	"SMACK64IPIN"
#define XATTR_SMACK_IPOUT	"SMACK64IPOUT"
#define XATTR_NAME_SMACK	XATTR_SECURITY_PREFIX XATTR_SMACK_SUFFIX
#define XATTR_NAME_SMACKIPIN	XATTR_SECURITY_PREFIX XATTR_SMACK_IPIN
#define XATTR_NAME_SMACKIPOUT	XATTR_SECURITY_PREFIX XATTR_SMACK_IPOUT

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

/*
 * A limit on the number of entries in the lists
 * makes some of the list administration easier.
 */
#define SMACK_LIST_MAX	10000

/*
 * CIPSO defaults.
 */
#define SMACK_CIPSO_DOI_DEFAULT		3	/* Historical */
#define SMACK_CIPSO_DIRECT_DEFAULT	250	/* 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 */

/*
 * Just to make the common cases easier to deal with
 */
#define MAY_ANY		(MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
#define MAY_ANYREAD	(MAY_READ | MAY_EXEC)
#define MAY_ANYWRITE	(MAY_WRITE | MAY_APPEND)
#define MAY_READWRITE	(MAY_READ | MAY_WRITE)
#define MAY_NOT		0

/*
 * These functions are in smack_lsm.c
 */
struct inode_smack *new_inode_smack(char *);

/*
 * These functions are in smack_access.c
 */
int smk_access(char *, char *, int);
int smk_curacc(char *, u32);
int smack_to_cipso(const char *, struct smack_cipso *);
void smack_from_cipso(u32, char *, char *);
char *smack_from_secid(const u32);
char *smk_import(const char *, int);
struct smack_known *smk_import_entry(const char *, int);
u32 smack_to_secid(const char *);

/*
 * Shared data.
 */
extern int smack_cipso_direct;
extern int smack_net_nltype;
extern char *smack_net_ambient;

extern struct smack_known *smack_known;
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_unset;

extern struct smk_list_entry *smack_list;

/*
 * Stricly for CIPSO level manipulation.
 * Set the category bit number in a smack label sized buffer.
 */
static inline void smack_catset_bit(int cat, char *catsetp)
{
	if (cat > SMK_LABELLEN * 8)
		return;

	catsetp[(cat - 1) / 8] |= 0x80 >> ((cat - 1) % 8);
}

/*
 * 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;
}

#endif  /* _SECURITY_SMACK_H */

Privacy Policy