// SPDX-License-Identifier: GPL-2.0-only
/*
* Implementation of the kernel access vector cache (AVC).
*
* Authors: Stephen Smalley, <sds@tycho.nsa.gov>
* James Morris <jmorris@redhat.com>
*
* Update: KaiGai, Kohei <kaigai@ak.jp.nec.com>
* Replaced the avc_lock spinlock by RCU.
*
* Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
*/
#include <linux/types.h>
#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/dcache.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/percpu.h>
#include <linux/list.h>
#include <net/sock.h>
#include <linux/un.h>
#include <net/af_unix.h>
#include <linux/ip.h>
#include <linux/audit.h>
#include <linux/ipv6.h>
#include <net/ipv6.h>
#include "avc.h"
#include "avc_ss.h"
#include "classmap.h"
#define AVC_CACHE_SLOTS 512
#define AVC_DEF_CACHE_THRESHOLD 512
#define AVC_CACHE_RECLAIM 16
#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
#define avc_cache_stats_incr(field) this_cpu_inc(avc_cache_stats.field)
#else
#define avc_cache_stats_incr(field) do {} while (0)
#endif
struct avc_entry {
u32 ssid;
u32 tsid;
u16 tclass;
struct av_decision avd;
struct avc_xperms_node *xp_node;
};
struct avc_node {
struct avc_entry ae;
struct hlist_node list; /* anchored in avc_cache->slots[i] */
struct rcu_head rhead;
};
struct avc_xperms_decision_node {
struct extended_perms_decision xpd;
struct list_head xpd_list; /* list of extended_perms_decision */
};
struct avc_xperms_node {
struct extended_perms xp;
struct list_head xpd_head; /* list head of extended_perms_decision */
};
struct avc_cache {
struct hlist_head slots[AVC_CACHE_SLOTS]; /* head for avc_node->list */
spinlock_t slots_lock[AVC_CACHE_SLOTS]; /* lock for writes */
atomic_t lru_hint; /* LRU hint for reclaim scan */
atomic_t active_nodes;
u32 latest_notif; /* latest revocation notification */
};
struct avc_callback_node {
int (*callback) (u32 event);
u32 events;
struct avc_callback_node *next;
};
#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
DEFINE_PER_CPU(struct avc_cache_stats, avc_cache_stats) = { 0 };
#endif
struct selinux_avc {
unsigned int avc_cache_threshold;
struct avc_cache avc_cache;
};
static struct selinux_avc selinux_avc;
void selinux_avc_init(struct selinux_avc **avc)
{
int i;
selinux_avc.avc_cache_threshold = AVC_DEF_CACHE_THRESHOLD;
for (i = 0; i < AVC_CACHE_SLOTS; i++) {
INIT_HLIST_HEAD(&selinux_avc.avc_cache.slots[i]);
spin_lock_init(&selinux_avc.avc_cache.slots_lock[i]);
}
atomic_set(&selinux_avc.avc_cache.active_nodes, 0);
atomic_set(&selinux_avc.avc_cache.lru_hint, 0);
*avc = &selinux_avc;
}
unsigned int avc_get_cache_threshold(struct selinux_avc *avc)
{
return avc->avc_cache_threshold;
}
void avc_set_cache_threshold(struct selinux_avc *avc,
unsigned int cache_threshold)
{
avc->avc_cache_threshold = cache_threshold;
}
static struct avc_callback_node *avc_callbacks;
static struct kmem_cache