Commit 4fee5242 authored by Huw Davies's avatar Huw Davies Committed by Paul Moore

calipso: Add a label cache.

This works in exactly the same way as the CIPSO label cache.
The idea is to allow the lsm to cache the result of a secattr
lookup so that it doesn't need to perform the lookup for
every skbuff.

It introduces two sysctl controls:
 calipso_cache_enable - enables/disables the cache.
 calipso_cache_bucket_size - sets the size of a cache bucket.
Signed-off-by: default avatarHuw Davies <huw@codeweavers.com>
Signed-off-by: default avatarPaul Moore <paul@paul-moore.com>
parent 2e532b70
......@@ -62,6 +62,12 @@ struct calipso_doi {
struct rcu_head rcu;
};
/*
* Sysctl Variables
*/
extern int calipso_cache_enabled;
extern int calipso_cache_bucketsize;
#ifdef CONFIG_NETLABEL
int __init calipso_init(void);
void calipso_exit(void);
......
......@@ -235,6 +235,8 @@ struct netlbl_lsm_secattr {
* @skbuff_optptr: find option in packet
* @skbuff_setattr: set the skbuff's attr
* @skbuff_delattr: remove the skbuff's attr
* @cache_invalidate: invalidate cache
* @cache_add: add cache entry
*
* Description:
* This structure is filled out by the CALIPSO engine and passed
......@@ -269,6 +271,9 @@ struct netlbl_calipso_ops {
const struct calipso_doi *doi_def,
const struct netlbl_lsm_secattr *secattr);
int (*skbuff_delattr)(struct sk_buff *skb);
void (*cache_invalidate)(void);
int (*cache_add)(const unsigned char *calipso_ptr,
const struct netlbl_lsm_secattr *secattr);
};
/*
......@@ -494,7 +499,7 @@ void netlbl_skbuff_err(struct sk_buff *skb, u16 family, int error, int gateway);
* LSM label mapping cache operations
*/
void netlbl_cache_invalidate(void);
int netlbl_cache_add(const struct sk_buff *skb,
int netlbl_cache_add(const struct sk_buff *skb, u16 family,
const struct netlbl_lsm_secattr *secattr);
/*
......@@ -647,7 +652,7 @@ static inline void netlbl_cache_invalidate(void)
{
return;
}
static inline int netlbl_cache_add(const struct sk_buff *skb,
static inline int netlbl_cache_add(const struct sk_buff *skb, u16 family,
const struct netlbl_lsm_secattr *secattr)
{
return 0;
......
......@@ -72,6 +72,255 @@
static DEFINE_SPINLOCK(calipso_doi_list_lock);
static LIST_HEAD(calipso_doi_list);
/* Label mapping cache */
int calipso_cache_enabled = 1;
int calipso_cache_bucketsize = 10;
#define CALIPSO_CACHE_BUCKETBITS 7
#define CALIPSO_CACHE_BUCKETS BIT(CALIPSO_CACHE_BUCKETBITS)
#define CALIPSO_CACHE_REORDERLIMIT 10
struct calipso_map_cache_bkt {
spinlock_t lock;
u32 size;
struct list_head list;
};
struct calipso_map_cache_entry {
u32 hash;
unsigned char *key;
size_t key_len;
struct netlbl_lsm_cache *lsm_data;
u32 activity;
struct list_head list;
};
static struct calipso_map_cache_bkt *calipso_cache;
/* Label Mapping Cache Functions
*/
/**
* calipso_cache_entry_free - Frees a cache entry
* @entry: the entry to free
*
* Description:
* This function frees the memory associated with a cache entry including the
* LSM cache data if there are no longer any users, i.e. reference count == 0.
*
*/
static void calipso_cache_entry_free(struct calipso_map_cache_entry *entry)
{
if (entry->lsm_data)
netlbl_secattr_cache_free(entry->lsm_data);
kfree(entry->key);
kfree(entry);
}
/**
* calipso_map_cache_hash - Hashing function for the CALIPSO cache
* @key: the hash key
* @key_len: the length of the key in bytes
*
* Description:
* The CALIPSO tag hashing function. Returns a 32-bit hash value.
*
*/
static u32 calipso_map_cache_hash(const unsigned char *key, u32 key_len)
{
return jhash(key, key_len, 0);
}
/**
* calipso_cache_init - Initialize the CALIPSO cache
*
* Description:
* Initializes the CALIPSO label mapping cache, this function should be called
* before any of the other functions defined in this file. Returns zero on
* success, negative values on error.
*
*/
static int __init calipso_cache_init(void)
{
u32 iter;
calipso_cache = kcalloc(CALIPSO_CACHE_BUCKETS,
sizeof(struct calipso_map_cache_bkt),
GFP_KERNEL);
if (!calipso_cache)
return -ENOMEM;
for (iter = 0; iter < CALIPSO_CACHE_BUCKETS; iter++) {
spin_lock_init(&calipso_cache[iter].lock);
calipso_cache[iter].size = 0;
INIT_LIST_HEAD(&calipso_cache[iter].list);
}
return 0;
}
/**
* calipso_cache_invalidate - Invalidates the current CALIPSO cache
*
* Description:
* Invalidates and frees any entries in the CALIPSO cache. Returns zero on
* success and negative values on failure.
*
*/
static void calipso_cache_invalidate(void)
{
struct calipso_map_cache_entry *entry, *tmp_entry;
u32 iter;
for (iter = 0; iter < CALIPSO_CACHE_BUCKETS; iter++) {
spin_lock_bh(&calipso_cache[iter].lock);
list_for_each_entry_safe(entry,
tmp_entry,
&calipso_cache[iter].list, list) {
list_del(&entry->list);
calipso_cache_entry_free(entry);
}
calipso_cache[iter].size = 0;
spin_unlock_bh(&calipso_cache[iter].lock);
}
}
/**
* calipso_cache_check - Check the CALIPSO cache for a label mapping
* @key: the buffer to check
* @key_len: buffer length in bytes
* @secattr: the security attribute struct to use
*
* Description:
* This function checks the cache to see if a label mapping already exists for
* the given key. If there is a match then the cache is adjusted and the
* @secattr struct is populated with the correct LSM security attributes. The
* cache is adjusted in the following manner if the entry is not already the
* first in the cache bucket:
*
* 1. The cache entry's activity counter is incremented
* 2. The previous (higher ranking) entry's activity counter is decremented
* 3. If the difference between the two activity counters is geater than
* CALIPSO_CACHE_REORDERLIMIT the two entries are swapped
*
* Returns zero on success, -ENOENT for a cache miss, and other negative values
* on error.
*
*/
static int calipso_cache_check(const unsigned char *key,
u32 key_len,
struct netlbl_lsm_secattr *secattr)
{
u32 bkt;
struct calipso_map_cache_entry *entry;
struct calipso_map_cache_entry *prev_entry = NULL;
u32 hash;
if (!calipso_cache_enabled)
return -ENOENT;
hash = calipso_map_cache_hash(key, key_len);
bkt = hash & (CALIPSO_CACHE_BUCKETS - 1);
spin_lock_bh(&calipso_cache[bkt].lock);
list_for_each_entry(entry, &calipso_cache[bkt].list, list) {
if (entry->hash == hash &&
entry->key_len == key_len &&
memcmp(entry->key, key, key_len) == 0) {
entry->activity += 1;
atomic_inc(&entry->lsm_data->refcount);
secattr->cache = entry->lsm_data;
secattr->flags |= NETLBL_SECATTR_CACHE;
secattr->type = NETLBL_NLTYPE_CALIPSO;
if (!prev_entry) {
spin_unlock_bh(&calipso_cache[bkt].lock);
return 0;
}
if (prev_entry->activity > 0)
prev_entry->activity -= 1;
if (entry->activity > prev_entry->activity &&
entry->activity - prev_entry->activity >
CALIPSO_CACHE_REORDERLIMIT) {
__list_del(entry->list.prev, entry->list.next);
__list_add(&entry->list,
prev_entry->list.prev,
&prev_entry->list);
}
spin_unlock_bh(&calipso_cache[bkt].lock);
return 0;
}
prev_entry = entry;
}
spin_unlock_bh(&calipso_cache[bkt].lock);
return -ENOENT;
}
/**
* calipso_cache_add - Add an entry to the CALIPSO cache
* @calipso_ptr: the CALIPSO option
* @secattr: the packet's security attributes
*
* Description:
* Add a new entry into the CALIPSO label mapping cache. Add the new entry to
* head of the cache bucket's list, if the cache bucket is out of room remove
* the last entry in the list first. It is important to note that there is
* currently no checking for duplicate keys. Returns zero on success,
* negative values on failure. The key stored starts at calipso_ptr + 2,
* i.e. the type and length bytes are not stored, this corresponds to
* calipso_ptr[1] bytes of data.
*
*/
static int calipso_cache_add(const unsigned char *calipso_ptr,
const struct netlbl_lsm_secattr *secattr)
{
int ret_val = -EPERM;
u32 bkt;
struct calipso_map_cache_entry *entry = NULL;
struct calipso_map_cache_entry *old_entry = NULL;
u32 calipso_ptr_len;
if (!calipso_cache_enabled || calipso_cache_bucketsize <= 0)
return 0;
calipso_ptr_len = calipso_ptr[1];
entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
if (!entry)
return -ENOMEM;
entry->key = kmemdup(calipso_ptr + 2, calipso_ptr_len, GFP_ATOMIC);
if (!entry->key) {
ret_val = -ENOMEM;
goto cache_add_failure;
}
entry->key_len = calipso_ptr_len;
entry->hash = calipso_map_cache_hash(calipso_ptr, calipso_ptr_len);
atomic_inc(&secattr->cache->refcount);
entry->lsm_data = secattr->cache;
bkt = entry->hash & (CALIPSO_CACHE_BUCKETS - 1);
spin_lock_bh(&calipso_cache[bkt].lock);
if (calipso_cache[bkt].size < calipso_cache_bucketsize) {
list_add(&entry->list, &calipso_cache[bkt].list);
calipso_cache[bkt].size += 1;
} else {
old_entry = list_entry(calipso_cache[bkt].list.prev,
struct calipso_map_cache_entry, list);
list_del(&old_entry->list);
list_add(&entry->list, &calipso_cache[bkt].list);
calipso_cache_entry_free(old_entry);
}
spin_unlock_bh(&calipso_cache[bkt].lock);
return 0;
cache_add_failure:
if (entry)
calipso_cache_entry_free(entry);
return ret_val;
}
/* DOI List Functions
*/
......@@ -789,6 +1038,9 @@ static int calipso_opt_getattr(const unsigned char *calipso,
if (cat_len + 8 > len)
return -EINVAL;
if (calipso_cache_check(calipso + 2, calipso[1], secattr) == 0)
return 0;
doi = get_unaligned_be32(calipso + 2);
rcu_read_lock();
doi_def = calipso_doi_search(doi);
......@@ -1191,6 +1443,8 @@ static const struct netlbl_calipso_ops ops = {
.skbuff_optptr = calipso_skbuff_optptr,
.skbuff_setattr = calipso_skbuff_setattr,
.skbuff_delattr = calipso_skbuff_delattr,
.cache_invalidate = calipso_cache_invalidate,
.cache_add = calipso_cache_add
};
/**
......@@ -1203,11 +1457,17 @@ static const struct netlbl_calipso_ops ops = {
*/
int __init calipso_init(void)
{
netlbl_calipso_ops_register(&ops);
return 0;
int ret_val;
ret_val = calipso_cache_init();
if (!ret_val)
netlbl_calipso_ops_register(&ops);
return ret_val;
}
void calipso_exit(void)
{
netlbl_calipso_ops_register(NULL);
calipso_cache_invalidate();
kfree(calipso_cache);
}
......@@ -15,6 +15,9 @@
#include <net/ipv6.h>
#include <net/addrconf.h>
#include <net/inet_frag.h>
#ifdef CONFIG_NETLABEL
#include <net/calipso.h>
#endif
static int one = 1;
static int auto_flowlabels_min;
......@@ -106,6 +109,22 @@ static struct ctl_table ipv6_rotable[] = {
.proc_handler = proc_dointvec_minmax,
.extra1 = &one
},
#ifdef CONFIG_NETLABEL
{
.procname = "calipso_cache_enable",
.data = &calipso_cache_enabled,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "calipso_cache_bucket_size",
.data = &calipso_cache_bucketsize,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
#endif /* CONFIG_NETLABEL */
{ }
};
......
......@@ -700,3 +700,41 @@ int calipso_skbuff_delattr(struct sk_buff *skb)
ret_val = ops->skbuff_delattr(skb);
return ret_val;
}
/**
* calipso_cache_invalidate - Invalidates the current CALIPSO cache
*
* Description:
* Invalidates and frees any entries in the CALIPSO cache. Returns zero on
* success and negative values on failure.
*
*/
void calipso_cache_invalidate(void)
{
const struct netlbl_calipso_ops *ops = netlbl_calipso_ops_get();
if (ops)
ops->cache_invalidate();
}
/**
* calipso_cache_add - Add an entry to the CALIPSO cache
* @calipso_ptr: the CALIPSO option
* @secattr: the packet's security attributes
*
* Description:
* Add a new entry into the CALIPSO label mapping cache.
* Returns zero on success, negative values on failure.
*
*/
int calipso_cache_add(const unsigned char *calipso_ptr,
const struct netlbl_lsm_secattr *secattr)
{
int ret_val = -ENOMSG;
const struct netlbl_calipso_ops *ops = netlbl_calipso_ops_get();
if (ops)
ret_val = ops->cache_add(calipso_ptr, secattr);
return ret_val;
}
......@@ -144,5 +144,8 @@ int calipso_skbuff_setattr(struct sk_buff *skb,
const struct calipso_doi *doi_def,
const struct netlbl_lsm_secattr *secattr);
int calipso_skbuff_delattr(struct sk_buff *skb);
void calipso_cache_invalidate(void);
int calipso_cache_add(const unsigned char *calipso_ptr,
const struct netlbl_lsm_secattr *secattr);
#endif
......@@ -1281,11 +1281,15 @@ void netlbl_skbuff_err(struct sk_buff *skb, u16 family, int error, int gateway)
void netlbl_cache_invalidate(void)
{
cipso_v4_cache_invalidate();
#if IS_ENABLED(CONFIG_IPV6)
calipso_cache_invalidate();
#endif /* IPv6 */
}
/**
* netlbl_cache_add - Add an entry to a NetLabel protocol cache
* @skb: the packet
* @family: the family
* @secattr: the packet's security attributes
*
* Description:
......@@ -1294,7 +1298,7 @@ void netlbl_cache_invalidate(void)
* values on error.
*
*/
int netlbl_cache_add(const struct sk_buff *skb,
int netlbl_cache_add(const struct sk_buff *skb, u16 family,
const struct netlbl_lsm_secattr *secattr)
{
unsigned char *ptr;
......@@ -1302,10 +1306,20 @@ int netlbl_cache_add(const struct sk_buff *skb,
if ((secattr->flags & NETLBL_SECATTR_CACHE) == 0)
return -ENOMSG;
ptr = cipso_v4_optptr(skb);
if (ptr)
return cipso_v4_cache_add(ptr, secattr);
switch (family) {
case AF_INET:
ptr = cipso_v4_optptr(skb);
if (ptr)
return cipso_v4_cache_add(ptr, secattr);
break;
#if IS_ENABLED(CONFIG_IPV6)
case AF_INET6:
ptr = calipso_optptr(skb);
if (ptr)
return calipso_cache_add(ptr, secattr);
break;
#endif /* IPv6 */
}
return -ENOMSG;
}
......
......@@ -54,6 +54,7 @@
*
*/
static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
u16 family,
struct netlbl_lsm_secattr *secattr,
u32 *sid)
{
......@@ -63,7 +64,7 @@ static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
if (rc == 0 &&
(secattr->flags & NETLBL_SECATTR_CACHEABLE) &&
(secattr->flags & NETLBL_SECATTR_CACHE))
netlbl_cache_add(skb, secattr);
netlbl_cache_add(skb, family, secattr);
return rc;
}
......@@ -214,7 +215,8 @@ int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
netlbl_secattr_init(&secattr);
rc = netlbl_skbuff_getattr(skb, family, &secattr);
if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
rc = selinux_netlbl_sidlookup_cached(skb, &secattr, sid);
rc = selinux_netlbl_sidlookup_cached(skb, family,
&secattr, sid);
else
*sid = SECSID_NULL;
*type = secattr.type;
......@@ -382,7 +384,8 @@ int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
netlbl_secattr_init(&secattr);
rc = netlbl_skbuff_getattr(skb, family, &secattr);
if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
rc = selinux_netlbl_sidlookup_cached(skb, &secattr, &nlbl_sid);
rc = selinux_netlbl_sidlookup_cached(skb, family,
&secattr, &nlbl_sid);
else
nlbl_sid = SECINITSID_UNLABELED;
netlbl_secattr_destroy(&secattr);
......
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