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Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001/* SPDX-License-Identifier: GPL-2.0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002/*
3 * Access vector cache interface for object managers.
4 *
Stephen Smalley7efbb602017-08-17 13:32:36 -04005 * Author : Stephen Smalley, <sds@tycho.nsa.gov>
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 */
7#ifndef _SELINUX_AVC_H_
8#define _SELINUX_AVC_H_
9
10#include <linux/stddef.h>
11#include <linux/errno.h>
12#include <linux/kernel.h>
13#include <linux/kdev_t.h>
14#include <linux/spinlock.h>
15#include <linux/init.h>
KaiGai Koheid9250de2008-08-28 16:35:57 +090016#include <linux/audit.h>
Thomas Liu2bf49692009-07-14 12:14:09 -040017#include <linux/lsm_audit.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/in6.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include "flask.h"
20#include "av_permissions.h"
21#include "security.h"
22
Linus Torvalds1da177e2005-04-16 15:20:36 -070023/*
24 * An entry in the AVC.
25 */
26struct avc_entry;
27
28struct task_struct;
Linus Torvalds1da177e2005-04-16 15:20:36 -070029struct inode;
30struct sock;
31struct sk_buff;
32
Linus Torvalds1da177e2005-04-16 15:20:36 -070033/*
34 * AVC statistics
35 */
Eric Parisf5269712008-05-14 11:27:45 -040036struct avc_cache_stats {
Linus Torvalds1da177e2005-04-16 15:20:36 -070037 unsigned int lookups;
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 unsigned int misses;
39 unsigned int allocations;
40 unsigned int reclaims;
41 unsigned int frees;
42};
43
Eric Paris3f0882c2012-04-03 09:38:00 -070044/*
45 * We only need this data after we have decided to send an audit message.
46 */
Eric Paris899838b2012-04-04 15:01:43 -040047struct selinux_audit_data {
Eric Paris3b3b0e42012-04-03 09:37:02 -070048 u32 ssid;
49 u32 tsid;
50 u16 tclass;
51 u32 requested;
52 u32 audited;
53 u32 denied;
Eric Paris3f0882c2012-04-03 09:38:00 -070054 int result;
Stephen Smalley6b6bc622018-03-05 11:47:56 -050055 struct selinux_state *state;
Eric Paris3f0882c2012-04-03 09:38:00 -070056};
57
58/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 * AVC operations
60 */
61
62void __init avc_init(void);
63
Eric Paris2e3340572012-04-04 15:01:42 -040064static inline u32 avc_audit_required(u32 requested,
65 struct av_decision *avd,
66 int result,
67 u32 auditdeny,
68 u32 *deniedp)
69{
70 u32 denied, audited;
71 denied = requested & ~avd->allowed;
72 if (unlikely(denied)) {
73 audited = denied & avd->auditdeny;
74 /*
75 * auditdeny is TRICKY! Setting a bit in
76 * this field means that ANY denials should NOT be audited if
77 * the policy contains an explicit dontaudit rule for that
78 * permission. Take notice that this is unrelated to the
79 * actual permissions that were denied. As an example lets
80 * assume:
81 *
82 * denied == READ
83 * avd.auditdeny & ACCESS == 0 (not set means explicit rule)
84 * auditdeny & ACCESS == 1
85 *
86 * We will NOT audit the denial even though the denied
87 * permission was READ and the auditdeny checks were for
88 * ACCESS
89 */
90 if (auditdeny && !(auditdeny & avd->auditdeny))
91 audited = 0;
92 } else if (result)
93 audited = denied = requested;
94 else
95 audited = requested & avd->auditallow;
96 *deniedp = denied;
97 return audited;
98}
99
Stephen Smalley6b6bc622018-03-05 11:47:56 -0500100int slow_avc_audit(struct selinux_state *state,
101 u32 ssid, u32 tsid, u16 tclass,
Stephen Smalleyca7786a2014-04-29 11:29:04 -0700102 u32 requested, u32 audited, u32 denied, int result,
Stephen Smalley0188d5c2019-11-22 12:22:45 -0500103 struct common_audit_data *a);
Eric Paris2e3340572012-04-04 15:01:42 -0400104
105/**
106 * avc_audit - Audit the granting or denial of permissions.
107 * @ssid: source security identifier
108 * @tsid: target security identifier
109 * @tclass: target security class
110 * @requested: requested permissions
111 * @avd: access vector decisions
112 * @result: result from avc_has_perm_noaudit
113 * @a: auxiliary audit data
114 * @flags: VFS walk flags
115 *
116 * Audit the granting or denial of permissions in accordance
117 * with the policy. This function is typically called by
118 * avc_has_perm() after a permission check, but can also be
119 * called directly by callers who use avc_has_perm_noaudit()
120 * in order to separate the permission check from the auditing.
121 * For example, this separation is useful when the permission check must
122 * be performed under a lock, to allow the lock to be released
123 * before calling the auditing code.
124 */
Stephen Smalley6b6bc622018-03-05 11:47:56 -0500125static inline int avc_audit(struct selinux_state *state,
126 u32 ssid, u32 tsid,
Eric Paris2e3340572012-04-04 15:01:42 -0400127 u16 tclass, u32 requested,
128 struct av_decision *avd,
129 int result,
NeilBrown7b20ea22015-03-23 13:37:39 +1100130 struct common_audit_data *a,
131 int flags)
Eric Paris2e3340572012-04-04 15:01:42 -0400132{
133 u32 audited, denied;
Eric Paris1d349292012-04-04 15:01:43 -0400134 audited = avc_audit_required(requested, avd, result, 0, &denied);
Eric Paris2e3340572012-04-04 15:01:42 -0400135 if (likely(!audited))
136 return 0;
Stephen Smalley0188d5c2019-11-22 12:22:45 -0500137 /* fall back to ref-walk if we have to generate audit */
138 if (flags & MAY_NOT_BLOCK)
139 return -ECHILD;
Stephen Smalley6b6bc622018-03-05 11:47:56 -0500140 return slow_avc_audit(state, ssid, tsid, tclass,
Stephen Smalleyca7786a2014-04-29 11:29:04 -0700141 requested, audited, denied, result,
Stephen Smalley0188d5c2019-11-22 12:22:45 -0500142 a);
Eric Paris2e3340572012-04-04 15:01:42 -0400143}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
Stephen Smalley2c3c05d2007-06-07 15:34:10 -0400145#define AVC_STRICT 1 /* Ignore permissive mode. */
Jeff Vander Stoepfa1aa142015-07-10 17:19:56 -0400146#define AVC_EXTENDED_PERMS 2 /* update extended permissions */
Stephen Smalley3a28cff2018-12-12 10:10:55 -0500147#define AVC_NONBLOCKING 4 /* non blocking */
Stephen Smalley6b6bc622018-03-05 11:47:56 -0500148int avc_has_perm_noaudit(struct selinux_state *state,
149 u32 ssid, u32 tsid,
Stephen Smalley2c3c05d2007-06-07 15:34:10 -0400150 u16 tclass, u32 requested,
151 unsigned flags,
152 struct av_decision *avd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153
Stephen Smalley6b6bc622018-03-05 11:47:56 -0500154int avc_has_perm(struct selinux_state *state,
155 u32 ssid, u32 tsid,
Linus Torvaldscb4fbe52013-10-04 12:57:22 -0700156 u16 tclass, u32 requested,
157 struct common_audit_data *auditdata);
Stephen Smalley1a370792019-11-22 12:22:44 -0500158int avc_has_perm_flags(struct selinux_state *state,
159 u32 ssid, u32 tsid,
160 u16 tclass, u32 requested,
161 struct common_audit_data *auditdata,
162 int flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163
Stephen Smalley6b6bc622018-03-05 11:47:56 -0500164int avc_has_extended_perms(struct selinux_state *state,
165 u32 ssid, u32 tsid, u16 tclass, u32 requested,
166 u8 driver, u8 perm, struct common_audit_data *ad);
Jeff Vander Stoepfa1aa142015-07-10 17:19:56 -0400167
168
Stephen Smalley6b6bc622018-03-05 11:47:56 -0500169u32 avc_policy_seqno(struct selinux_state *state);
Yuichi Nakamura788e7dd2007-09-14 09:27:07 +0900170
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171#define AVC_CALLBACK_GRANT 1
172#define AVC_CALLBACK_TRY_REVOKE 2
173#define AVC_CALLBACK_REVOKE 4
174#define AVC_CALLBACK_RESET 8
175#define AVC_CALLBACK_AUDITALLOW_ENABLE 16
176#define AVC_CALLBACK_AUDITALLOW_DISABLE 32
177#define AVC_CALLBACK_AUDITDENY_ENABLE 64
178#define AVC_CALLBACK_AUDITDENY_DISABLE 128
Jeff Vander Stoepfa1aa142015-07-10 17:19:56 -0400179#define AVC_CALLBACK_ADD_XPERMS 256
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180
Wanlong Gao562c99f2012-03-07 22:17:14 +0800181int avc_add_callback(int (*callback)(u32 event), u32 events);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183/* Exported to selinuxfs */
Stephen Smalley6b6bc622018-03-05 11:47:56 -0500184struct selinux_avc;
185int avc_get_hash_stats(struct selinux_avc *avc, char *page);
186unsigned int avc_get_cache_threshold(struct selinux_avc *avc);
187void avc_set_cache_threshold(struct selinux_avc *avc,
188 unsigned int cache_threshold);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189
Thomas Liu89c86572009-06-24 17:58:05 -0400190/* Attempt to free avc node cache */
191void avc_disable(void);
192
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
194DECLARE_PER_CPU(struct avc_cache_stats, avc_cache_stats);
195#endif
196
197#endif /* _SELINUX_AVC_H_ */
198