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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Access vector cache interface for object managers.
*
* Author : Stephen Smalley, <sds@tycho.nsa.gov>
*/
#ifndef _SELINUX_AVC_H_
#define _SELINUX_AVC_H_
#include <linux/stddef.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/kdev_t.h>
#include <linux/spinlock.h>
#include <linux/init.h>
#include <linux/audit.h>
#include <linux/lsm_audit.h>
#include <linux/in6.h>
#include "flask.h"
#include "av_permissions.h"
#include "security.h"
/*
* An entry in the AVC.
*/
struct avc_entry;
struct task_struct;
struct inode;
struct sock;
struct sk_buff;
/*
* AVC statistics
*/
struct avc_cache_stats {
unsigned int lookups;
unsigned int misses;
unsigned int allocations;
unsigned int reclaims;
unsigned int frees;
};
/*
* We only need this data after we have decided to send an audit message.
*/
struct selinux_audit_data {
u32 ssid;
u32 tsid;
u16 tclass;
u32 requested;
u32 audited;
u32 denied;
int result;
struct selinux_state *state;
};
/*
* AVC operations
*/
void __init avc_init(void);
static inline u32 avc_audit_required(u32 requested,
struct av_decision *avd,
int result,
u32 auditdeny,
u32 *deniedp)
{
u32 denied, audited;
denied = requested & ~avd->allowed;
if (unlikely(denied)) {
audited = denied & avd->auditdeny;
/*
* auditdeny is TRICKY! Setting a bit in
* this field means that ANY denials should NOT be audited if
* the policy contains an explicit dontaudit rule for that
* permission. Take notice that this is unrelated to the
* actual permissions that were denied. As an example lets
* assume:
*
* denied == READ
* avd.auditdeny & ACCESS == 0 (not set means explicit rule)
* auditdeny & ACCESS == 1
*
* We will NOT audit the denial even though the denied
* permission was READ and the auditdeny checks were for
* ACCESS
*/
if (auditdeny && !(auditdeny & avd->auditdeny))
audited = 0;
} else if (result)
audited = denied = requested;
else
audited = requested & avd->auditallow;
*deniedp = denied;
return audited;
}
int slow_avc_audit(struct selinux_state *state,
u32 ssid, u32 tsid, u16 tclass,
u32 requested, u32 audited, u32 denied, int result,
struct common_audit_data *a);
/**
* avc_audit - Audit the granting or denial of permissions.
* @ssid: source security identifier
* @tsid: target security identifier
* @tclass: target security class
* @requested: requested permissions
* @avd: access vector decisions
* @result: result from avc_has_perm_noaudit
* @a: auxiliary audit data
* @flags: VFS walk flags
*
* Audit the granting or denial of permissions in accordance
* with the policy. This function is typically called by
* avc_has_perm() after a permission check, but can also be
* called directly by callers who use avc_has_perm_noaudit()
* in order to separate the permission check from the auditing.
* For example, this separation is useful when the permission check must
* be performed under a lock, to allow the lock to be released
* before calling the auditing code.
*/
static inline int avc_audit(struct selinux_state *state,
u32 ssid, u32 tsid,
u16 tclass, u32 requested,
struct av_decision *avd,
int result,
struct common_audit_data *a,
int flags)
{
u32 audited, denied;
audited = avc_audit_required(requested, avd, result, 0, &denied);
if (likely(!audited))
return 0;
return slow_avc_audit(state, ssid, tsid, tclass,
requested, audited, denied, result,
a);
}
#define AVC_STRICT 1 /* Ignore permissive mode. */
#define AVC_EXTENDED_PERMS 2 /* update extended permissions */
int avc_has_perm_noaudit(struct selinux_state *state,
u32 ssid, u32 tsid,
u16 tclass, u32 requested,
unsigned flags,
struct av_decision *avd);
int avc_has_perm(struct selinux_state *state,
u32 ssid, u32 tsid,
u16 tclass, u32 requested,
struct common_audit_data *auditdata);
int avc_has_perm_flags(struct selinux_state *state,
u32 ssid, u32 tsid,
u16 tclass, u32 requested,
struct common_audit_data *auditdata,
int flags);
int avc_has_extended_perms(struct selinux_state *state,
u32 ssid, u32 tsid, u16 tclass, u32 requested,
u8 driver, u8 perm, struct common_audit_data *ad);
u32 avc_policy_seqno(struct selinux_state *state);
#define AVC_CALLBACK_GRANT 1
#define AVC_CALLBACK_TRY_REVOKE 2
#define AVC_CALLBACK_REVOKE 4
#define AVC_CALLBACK_RESET 8
#define AVC_CALLBACK_AUDITALLOW_ENABLE 16
#define AVC_CALLBACK_AUDITALLOW_DISABLE 32
#define AVC_CALLBACK_AUDITDENY_ENABLE 64
#define AVC_CALLBACK_AUDITDENY_DISABLE 128
#define AVC_CALLBACK_ADD_XPERMS 256
int avc_add_callback(int (*callback)(u32 event), u32 events);
/* Exported to selinuxfs */
struct selinux_avc;
int avc_get_hash_stats(struct selinux_avc *avc, char *page);
unsigned int avc_get_cache_threshold(struct selinux_avc *avc);
void avc_set_cache_threshold(struct selinux_avc *avc,
unsigned int cache_threshold);
/* Attempt to free avc node cache */
void avc_disable(void);
#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
DECLARE_PER_CPU(struct avc_cache_stats, avc_cache_stats);
#endif
#endif /* _SELINUX_AVC_H_ */
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