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
*/
memcpy(new, hop, start);
ret_val = calipso_genopt((unsigned char *)new, start, buf_len, doi_def,
secattr);
- if (ret_val < 0)
+ if (ret_val < 0) {
+ kfree(new);
return ERR_PTR(ret_val);
+ }
buf_len = start + ret_val;
/* At this point buf_len aligns to 4n, so (buf_len & 4) pads to 8n */
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);
.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
};
/**
*/
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);
}
projects / cascardo / linux.git / blobdiff