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 000000000000..4cc85816a718
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+++ 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, void *key);
+                                        /* hash function */
+        int (*keycmp)(struct hashtab *h, void *key1, 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, void *key),
+                               int (*keycmp)(struct hashtab *h, void *key1, 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, 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 */