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/*
* Access vector cache interface for object managers.
*
* Author : Stephen Smalley, <sds@epoch.ncsc.mil>
*/
#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"
#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
extern int selinux_enforcing;
#else
#define selinux_enforcing 1
#endif
/*
* 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_late_audit_data {
u32 ssid;
u32 tsid;
u16 tclass;
u32 requested;
u32 audited;
u32 denied;
int result;
};
/*
* We collect this at the beginning or during an selinux security operation
*/
struct selinux_audit_data {
/*
* auditdeny is a bit tricky and unintuitive. See the
* comments in avc.c for it's meaning and usage.
*/
u32 auditdeny;
struct selinux_late_audit_data *slad;
};
/*
* 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(u32 ssid, u32 tsid, u16 tclass,
u32 requested, u32 audited, u32 denied,
struct common_audit_data *a,
unsigned flags);
/**
* 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(u32 ssid, u32 tsid,
u16 tclass, u32 requested,
struct av_decision *avd,
int result,
struct common_audit_data *a, unsigned flags)
{
u32 audited, denied;
audited = avc_audit_required(requested, avd, result,
a ? a->selinux_audit_data->auditdeny : 0,
&denied);
if (likely(!audited))
return 0;
return slow_avc_audit(ssid, tsid, tclass,
requested, audited, denied,
a, flags);
}
#define AVC_STRICT 1 /* Ignore permissive mode. */
int avc_has_perm_noaudit(u32 ssid, u32 tsid,
u16 tclass, u32 requested,
unsigned flags,
struct av_decision *avd);
int avc_has_perm_flags(u32 ssid, u32 tsid,
u16 tclass, u32 requested,
struct common_audit_data *auditdata,
unsigned);
static inline int avc_has_perm(u32 ssid, u32 tsid,
u16 tclass, u32 requested,
struct common_audit_data *auditdata)
{
return avc_has_perm_flags(ssid, tsid, tclass, requested, auditdata, 0);
}
u32 avc_policy_seqno(void);
#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
int avc_add_callback(int (*callback)(u32 event, u32 ssid, u32 tsid,
u16 tclass, u32 perms,
u32 *out_retained),
u32 events, u32 ssid, u32 tsid,
u16 tclass, u32 perms);
/* Exported to selinuxfs */
int avc_get_hash_stats(char *page);
extern unsigned int avc_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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