1 /*
2 * Access vector cache interface for object managers.
3 *
4 * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
5 */
6 #ifndef _SELINUX_AVC_H_
7 #define _SELINUX_AVC_H_
8
9 #include <linux/stddef.h>
10 #include <linux/errno.h>
11 #include <linux/kernel.h>
12 #include <linux/kdev_t.h>
13 #include <linux/spinlock.h>
14 #include <linux/init.h>
15 #include <linux/audit.h>
16 #include <linux/lsm_audit.h>
17 #include <linux/in6.h>
18 #include "flask.h"
19 #include "av_permissions.h"
20 #include "security.h"
21
22 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
23 extern int selinux_enforcing;
24 #else
25 #define selinux_enforcing 1
26 #endif
27
28 /*
29 * An entry in the AVC.
30 */
31 struct avc_entry;
32
33 struct task_struct;
34 struct inode;
35 struct sock;
36 struct sk_buff;
37
38 /*
39 * AVC statistics
40 */
41 struct avc_cache_stats {
42 unsigned int lookups;
43 unsigned int misses;
44 unsigned int allocations;
45 unsigned int reclaims;
46 unsigned int frees;
47 };
48
49 /*
50 * We only need this data after we have decided to send an audit message.
51 */
52 struct selinux_audit_data {
53 u32 ssid;
54 u32 tsid;
55 u16 tclass;
56 u32 requested;
57 u32 audited;
58 u32 denied;
59 int result;
60 };
61
62 /*
63 * AVC operations
64 */
65
66 void __init avc_init(void);
67
avc_audit_required(u32 requested,struct av_decision * avd,int result,u32 auditdeny,u32 * deniedp)68 static inline u32 avc_audit_required(u32 requested,
69 struct av_decision *avd,
70 int result,
71 u32 auditdeny,
72 u32 *deniedp)
73 {
74 u32 denied, audited;
75 denied = requested & ~avd->allowed;
76 if (unlikely(denied)) {
77 audited = denied & avd->auditdeny;
78 /*
79 * auditdeny is TRICKY! Setting a bit in
80 * this field means that ANY denials should NOT be audited if
81 * the policy contains an explicit dontaudit rule for that
82 * permission. Take notice that this is unrelated to the
83 * actual permissions that were denied. As an example lets
84 * assume:
85 *
86 * denied == READ
87 * avd.auditdeny & ACCESS == 0 (not set means explicit rule)
88 * auditdeny & ACCESS == 1
89 *
90 * We will NOT audit the denial even though the denied
91 * permission was READ and the auditdeny checks were for
92 * ACCESS
93 */
94 if (auditdeny && !(auditdeny & avd->auditdeny))
95 audited = 0;
96 } else if (result)
97 audited = denied = requested;
98 else
99 audited = requested & avd->auditallow;
100 *deniedp = denied;
101 return audited;
102 }
103
104 int slow_avc_audit(u32 ssid, u32 tsid, u16 tclass,
105 u32 requested, u32 audited, u32 denied, int result,
106 struct common_audit_data *a,
107 unsigned flags);
108
109 /**
110 * avc_audit - Audit the granting or denial of permissions.
111 * @ssid: source security identifier
112 * @tsid: target security identifier
113 * @tclass: target security class
114 * @requested: requested permissions
115 * @avd: access vector decisions
116 * @result: result from avc_has_perm_noaudit
117 * @a: auxiliary audit data
118 * @flags: VFS walk flags
119 *
120 * Audit the granting or denial of permissions in accordance
121 * with the policy. This function is typically called by
122 * avc_has_perm() after a permission check, but can also be
123 * called directly by callers who use avc_has_perm_noaudit()
124 * in order to separate the permission check from the auditing.
125 * For example, this separation is useful when the permission check must
126 * be performed under a lock, to allow the lock to be released
127 * before calling the auditing code.
128 */
avc_audit(u32 ssid,u32 tsid,u16 tclass,u32 requested,struct av_decision * avd,int result,struct common_audit_data * a,int flags)129 static inline int avc_audit(u32 ssid, u32 tsid,
130 u16 tclass, u32 requested,
131 struct av_decision *avd,
132 int result,
133 struct common_audit_data *a,
134 int flags)
135 {
136 u32 audited, denied;
137 audited = avc_audit_required(requested, avd, result, 0, &denied);
138 if (likely(!audited))
139 return 0;
140 return slow_avc_audit(ssid, tsid, tclass,
141 requested, audited, denied, result,
142 a, flags);
143 }
144
145 #define AVC_STRICT 1 /* Ignore permissive mode. */
146 #define AVC_EXTENDED_PERMS 2 /* update extended permissions */
147 int avc_has_perm_noaudit(u32 ssid, u32 tsid,
148 u16 tclass, u32 requested,
149 unsigned flags,
150 struct av_decision *avd);
151
152 int avc_has_perm(u32 ssid, u32 tsid,
153 u16 tclass, u32 requested,
154 struct common_audit_data *auditdata);
155 int avc_has_perm_flags(u32 ssid, u32 tsid,
156 u16 tclass, u32 requested,
157 struct common_audit_data *auditdata,
158 int flags);
159
160 int avc_has_extended_perms(u32 ssid, u32 tsid, u16 tclass, u32 requested,
161 u8 driver, u8 perm, struct common_audit_data *ad);
162
163
164 u32 avc_policy_seqno(void);
165
166 #define AVC_CALLBACK_GRANT 1
167 #define AVC_CALLBACK_TRY_REVOKE 2
168 #define AVC_CALLBACK_REVOKE 4
169 #define AVC_CALLBACK_RESET 8
170 #define AVC_CALLBACK_AUDITALLOW_ENABLE 16
171 #define AVC_CALLBACK_AUDITALLOW_DISABLE 32
172 #define AVC_CALLBACK_AUDITDENY_ENABLE 64
173 #define AVC_CALLBACK_AUDITDENY_DISABLE 128
174 #define AVC_CALLBACK_ADD_XPERMS 256
175
176 int avc_add_callback(int (*callback)(u32 event), u32 events);
177
178 /* Exported to selinuxfs */
179 int avc_get_hash_stats(char *page);
180 extern unsigned int avc_cache_threshold;
181
182 /* Attempt to free avc node cache */
183 void avc_disable(void);
184
185 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
186 DECLARE_PER_CPU(struct avc_cache_stats, avc_cache_stats);
187 #endif
188
189 #endif /* _SELINUX_AVC_H_ */
190
191