[mirror_ubuntu-bionic-kernel.git] / security / selinux / include / avc.h

/*
 * 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_audit_data {
	u32 ssid;
	u32 tsid;
	u16 tclass;
	u32 requested;
	u32 audited;
	u32 denied;
	int result;
};

/*
 * 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, int result,
		   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)
{
	u32 audited, denied;
	audited = avc_audit_required(requested, avd, result, 0, &denied);
	if (likely(!audited))
		return 0;
	return slow_avc_audit(ssid, tsid, tclass,
			      requested, audited, denied, result,
			      a, 0);
}

#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(u32 ssid, u32 tsid,
		 u16 tclass, u32 requested,
		 struct common_audit_data *auditdata);

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 events);

/* 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_ */
Commit	Line	Data
1da177e4 LT	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>
d9250dea	15	#include <linux/audit.h>
2bf49690	16	#include <linux/lsm_audit.h>
1da177e4	17	#include <linux/in6.h>
1da177e4 LT	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;
1da177e4 LT	34	struct inode;
	35	struct sock;
	36	struct sk_buff;
	37
1da177e4 LT	38	/*
	39	* AVC statistics
	40	*/
f5269710	41	struct avc_cache_stats {
1da177e4	42	unsigned int lookups;
1da177e4 LT	43	unsigned int misses;
	44	unsigned int allocations;
	45	unsigned int reclaims;
	46	unsigned int frees;
	47	};
	48
3f0882c4 EP	49	/*
	50	* We only need this data after we have decided to send an audit message.
	51	*/
899838b2	52	struct selinux_audit_data {
3b3b0e4f EP	53	u32 ssid;
	54	u32 tsid;
	55	u16 tclass;
	56	u32 requested;
	57	u32 audited;
	58	u32 denied;
3f0882c4 EP	59	int result;
	60	};
	61
1da177e4 LT	62	/*
	63	* AVC operations
	64	*/
	65
	66	void __init avc_init(void);
	67
2e334057 EP	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,
626b9740	105	u32 requested, u32 audited, u32 denied, int result,
2e334057 EP	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	*/
	129	static inline int avc_audit(u32 ssid, u32 tsid,
	130	u16 tclass, u32 requested,
	131	struct av_decision *avd,
	132	int result,
ab354062	133	struct common_audit_data *a)
2e334057 EP	134	{
2e334057 EP	135	u32 audited, denied;
1d349292	136	audited = avc_audit_required(requested, avd, result, 0, &denied);
2e334057 EP	137	if (likely(!audited))
	138	return 0;
	139	return slow_avc_audit(ssid, tsid, tclass,
626b9740	140	requested, audited, denied, result,
ab354062	141	a, 0);
2e334057	142	}
1da177e4	143
2c3c05db	144	#define AVC_STRICT 1 /* Ignore permissive mode. */
1da177e4	145	int avc_has_perm_noaudit(u32 ssid, u32 tsid,
2c3c05db SS	146	u16 tclass, u32 requested,
	147	unsigned flags,
	148	struct av_decision *avd);
1da177e4	149
cb4fbe57 LT	150	int avc_has_perm(u32 ssid, u32 tsid,
	151	u16 tclass, u32 requested,
	152	struct common_audit_data *auditdata);
1da177e4	153
788e7dd4 YN	154	u32 avc_policy_seqno(void);
788e7dd4 YN	155
1da177e4 LT	156	#define AVC_CALLBACK_GRANT 1
	157	#define AVC_CALLBACK_TRY_REVOKE 2
	158	#define AVC_CALLBACK_REVOKE 4
	159	#define AVC_CALLBACK_RESET 8
	160	#define AVC_CALLBACK_AUDITALLOW_ENABLE 16
	161	#define AVC_CALLBACK_AUDITALLOW_DISABLE 32
	162	#define AVC_CALLBACK_AUDITDENY_ENABLE 64
	163	#define AVC_CALLBACK_AUDITDENY_DISABLE 128
	164
562c99f2	165	int avc_add_callback(int (*callback)(u32 event), u32 events);
1da177e4 LT	166
	167	/* Exported to selinuxfs */
	168	int avc_get_hash_stats(char *page);
	169	extern unsigned int avc_cache_threshold;
	170
89c86576 TL	171	/* Attempt to free avc node cache */
	172	void avc_disable(void);
	173
1da177e4 LT	174	#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
	175	DECLARE_PER_CPU(struct avc_cache_stats, avc_cache_stats);
	176	#endif
	177
	178	#endif /* _SELINUX_AVC_H_ */
	179