diff options
Diffstat (limited to 'security/selinux/ss/hashtab.h')
-rw-r--r-- | security/selinux/ss/hashtab.h | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/security/selinux/ss/hashtab.h b/security/selinux/ss/hashtab.h new file mode 100644 index 00000000..953872cd --- /dev/null +++ b/security/selinux/ss/hashtab.h @@ -0,0 +1,87 @@ +/* + * A hash table (hashtab) maintains associations between + * key values and datum values. The type of the key values + * and the type of the datum values is arbitrary. The + * functions for hash computation and key comparison are + * provided by the creator of the table. + * + * Author : Stephen Smalley, <sds@epoch.ncsc.mil> + */ +#ifndef _SS_HASHTAB_H_ +#define _SS_HASHTAB_H_ + +#define HASHTAB_MAX_NODES 0xffffffff + +struct hashtab_node { + void *key; + void *datum; + struct hashtab_node *next; +}; + +struct hashtab { + struct hashtab_node **htable; /* hash table */ + u32 size; /* number of slots in hash table */ + u32 nel; /* number of elements in hash table */ + u32 (*hash_value)(struct hashtab *h, const void *key); + /* hash function */ + int (*keycmp)(struct hashtab *h, const void *key1, const void *key2); + /* key comparison function */ +}; + +struct hashtab_info { + u32 slots_used; + u32 max_chain_len; +}; + +/* + * Creates a new hash table with the specified characteristics. + * + * Returns NULL if insufficent space is available or + * the new hash table otherwise. + */ +struct hashtab *hashtab_create(u32 (*hash_value)(struct hashtab *h, const void *key), + int (*keycmp)(struct hashtab *h, const void *key1, const void *key2), + u32 size); + +/* + * Inserts the specified (key, datum) pair into the specified hash table. + * + * Returns -ENOMEM on memory allocation error, + * -EEXIST if there is already an entry with the same key, + * -EINVAL for general errors or + 0 otherwise. + */ +int hashtab_insert(struct hashtab *h, void *k, void *d); + +/* + * Searches for the entry with the specified key in the hash table. + * + * Returns NULL if no entry has the specified key or + * the datum of the entry otherwise. + */ +void *hashtab_search(struct hashtab *h, const void *k); + +/* + * Destroys the specified hash table. + */ +void hashtab_destroy(struct hashtab *h); + +/* + * Applies the specified apply function to (key,datum,args) + * for each entry in the specified hash table. + * + * The order in which the function is applied to the entries + * is dependent upon the internal structure of the hash table. + * + * If apply returns a non-zero status, then hashtab_map will cease + * iterating through the hash table and will propagate the error + * return to its caller. + */ +int hashtab_map(struct hashtab *h, + int (*apply)(void *k, void *d, void *args), + void *args); + +/* Fill info with some hash table statistics */ +void hashtab_stat(struct hashtab *h, struct hashtab_info *info); + +#endif /* _SS_HASHTAB_H */ |