1 files changed, 313 insertions, 0 deletions
diff --git a/drivers/staging/batman-adv/hash.c b/drivers/staging/batman-adv/hash.c
new file mode 100644
index 000000000000..61cb4a20ebca
--- /dev/null
+++ b/drivers/staging/batman-adv/hash.c
@@ -0,0 +1,313 @@
+/*
+ * Copyright (C) 2006-2009 B.A.T.M.A.N. contributors:
+ *
+ * Simon Wunderlich, Marek Lindner
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA
+ *
+ */
+
+#include "main.h"
+#include "hash.h"
+
+/* clears the hash */
+void hash_init(struct hashtable_t *hash)
+{
+	int i;
+
+	hash->elements = 0;
+
+	for (i = 0 ; i < hash->size; i++)
+		hash->table[i] = NULL;
+}
+
+/* remove the hash structure. if hashdata_free_cb != NULL, this function will be
+ * called to remove the elements inside of the hash.  if you don't remove the
+ * elements, memory might be leaked. */
+void hash_delete(struct hashtable_t *hash, hashdata_free_cb free_cb)
+{
+	struct element_t *bucket, *last_bucket;
+	int i;
+
+	for (i = 0; i < hash->size; i++) {
+		bucket = hash->table[i];
+
+		while (bucket != NULL) {
+			if (free_cb != NULL)
+				free_cb(bucket->data);
+
+			last_bucket = bucket;
+			bucket = bucket->next;
+			kfree(last_bucket);
+		}
+	}
+
+	hash_destroy(hash);
+}
+
+/* free only the hashtable and the hash itself. */
+void hash_destroy(struct hashtable_t *hash)
+{
+	kfree(hash->table);
+	kfree(hash);
+}
+
+/* iterate though the hash. first element is selected with iter_in NULL.  use
+ * the returned iterator to access the elements until hash_it_t returns NULL. */
+struct hash_it_t *hash_iterate(struct hashtable_t *hash,
+			       struct hash_it_t *iter_in)
+{
+	struct hash_it_t *iter;
+
+	if (!hash)
+		return NULL;
+
+	if (iter_in == NULL) {
+		iter = kmalloc(sizeof(struct hash_it_t), GFP_ATOMIC);
+		iter->index = -1;
+		iter->bucket = NULL;
+		iter->prev_bucket = NULL;
+	} else {
+		iter = iter_in;
+	}
+
+	/* sanity checks first (if our bucket got deleted in the last
+	 * iteration): */
+	if (iter->bucket != NULL) {
+		if (iter->first_bucket != NULL) {
+			/* we're on the first element and it got removed after
+			 * the last iteration. */
+			if ((*iter->first_bucket) != iter->bucket) {
+				/* there are still other elements in the list */
+				if ((*iter->first_bucket) != NULL) {
+					iter->prev_bucket = NULL;
+					iter->bucket = (*iter->first_bucket);
+					iter->first_bucket =
+						&hash->table[iter->index];
+					return iter;
+				} else {
+					iter->bucket = NULL;
+				}
+			}
+		} else if (iter->prev_bucket != NULL) {
+			/*
+			* we're not on the first element, and the bucket got
+			* removed after the last iteration.  the last bucket's
+			* next pointer is not pointing to our actual bucket
+			* anymore.  select the next.
+			*/
+			if (iter->prev_bucket->next != iter->bucket)
+				iter->bucket = iter->prev_bucket;
+		}
+	}
+
+	/* now as we are sane, select the next one if there is some */
+	if (iter->bucket != NULL) {
+		if (iter->bucket->next != NULL) {
+			iter->prev_bucket = iter->bucket;
+			iter->bucket = iter->bucket->next;
+			iter->first_bucket = NULL;
+			return iter;
+		}
+	}
+
+	/* if not returned yet, we've reached the last one on the index and have
+	 * to search forward */
+	iter->index++;
+	/* go through the entries of the hash table */
+	while (iter->index < hash->size) {
+		if ((hash->table[iter->index]) != NULL) {
+			iter->prev_bucket = NULL;
+			iter->bucket = hash->table[iter->index];
+			iter->first_bucket = &hash->table[iter->index];
+			return iter;
+		} else {
+			iter->index++;
+		}
+	}
+
+	/* nothing to iterate over anymore */
+	kfree(iter);
+	return NULL;
+}
+
+/* allocates and clears the hash */
+struct hashtable_t *hash_new(int size, hashdata_compare_cb compare,
+			     hashdata_choose_cb choose)
+{
+	struct hashtable_t *hash;
+
+	hash = kmalloc(sizeof(struct hashtable_t) , GFP_ATOMIC);
+
+	if (hash == NULL)
+		return NULL;
+
+	hash->size = size;
+	hash->table = kmalloc(sizeof(struct element_t *) * size, GFP_ATOMIC);
+
+	if (hash->table == NULL) {
+		kfree(hash);
+		return NULL;
+	}
+
+	hash_init(hash);
+
+	hash->compare = compare;
+	hash->choose = choose;
+
+	return hash;
+}
+
+/* adds data to the hashtable. returns 0 on success, -1 on error */
+int hash_add(struct hashtable_t *hash, void *data)
+{
+	int index;
+	struct element_t *bucket, *prev_bucket = NULL;
+
+	if (!hash)
+		return -1;
+
+	index = hash->choose(data, hash->size);
+	bucket = hash->table[index];
+
+	while (bucket != NULL) {
+		if (hash->compare(bucket->data, data))
+			return -1;
+
+		prev_bucket = bucket;
+		bucket = bucket->next;
+	}
+
+	/* found the tail of the list, add new element */
+	bucket = kmalloc(sizeof(struct element_t), GFP_ATOMIC);
+
+	if (bucket == NULL)
+		return -1;
+
+	bucket->data = data;
+	bucket->next = NULL;
+
+	/* and link it */
+	if (prev_bucket == NULL)
+		hash->table[index] = bucket;
+	else
+		prev_bucket->next = bucket;
+
+	hash->elements++;
+	return 0;
+}
+
+/* finds data, based on the key in keydata. returns the found data on success,
+ * or NULL on error */
+void *hash_find(struct hashtable_t *hash, void *keydata)
+{
+	int index;
+	struct element_t *bucket;
+
+	if (!hash)
+		return NULL;
+
+	index = hash->choose(keydata , hash->size);
+	bucket = hash->table[index];
+
+	while (bucket != NULL) {
+		if (hash->compare(bucket->data, keydata))
+			return bucket->data;
+
+		bucket = bucket->next;
+	}
+
+	return NULL;
+}
+
+/* remove bucket (this might be used in hash_iterate() if you already found the
+ * bucket you want to delete and don't need the overhead to find it again with
+ * hash_remove(). But usually, you don't want to use this function, as it
+ * fiddles with hash-internals. */
+void *hash_remove_bucket(struct hashtable_t *hash, struct hash_it_t *hash_it_t)
+{
+	void *data_save;
+
+	data_save = hash_it_t->bucket->data;
+
+	if (hash_it_t->prev_bucket != NULL)
+		hash_it_t->prev_bucket->next = hash_it_t->bucket->next;
+	else if (hash_it_t->first_bucket != NULL)
+		(*hash_it_t->first_bucket) = hash_it_t->bucket->next;
+
+	kfree(hash_it_t->bucket);
+	hash->elements--;
+
+	return data_save;
+}
+
+/* removes data from hash, if found. returns pointer do data on success, so you
+ * can remove the used structure yourself, or NULL on error .  data could be the
+ * structure you use with just the key filled, we just need the key for
+ * comparing. */
+void *hash_remove(struct hashtable_t *hash, void *data)
+{
+	struct hash_it_t hash_it_t;
+
+	hash_it_t.index = hash->choose(data, hash->size);
+	hash_it_t.bucket = hash->table[hash_it_t.index];
+	hash_it_t.prev_bucket = NULL;
+
+	while (hash_it_t.bucket != NULL) {
+		if (hash->compare(hash_it_t.bucket->data, data)) {
+			hash_it_t.first_bucket =
+				(hash_it_t.bucket ==
+				 hash->table[hash_it_t.index] ?
+				 &hash->table[hash_it_t.index] : NULL);
+			return hash_remove_bucket(hash, &hash_it_t);
+		}
+
+		hash_it_t.prev_bucket = hash_it_t.bucket;
+		hash_it_t.bucket = hash_it_t.bucket->next;
+	}
+
+	return NULL;
+}
+
+/* resize the hash, returns the pointer to the new hash or NULL on
+ * error. removes the old hash on success. */
+struct hashtable_t *hash_resize(struct hashtable_t *hash, int size)
+{
+	struct hashtable_t *new_hash;
+	struct element_t *bucket;
+	int i;
+
+	/* initialize a new hash with the new size */
+	new_hash = hash_new(size, hash->compare, hash->choose);
+
+	if (new_hash == NULL)
+		return NULL;
+
+	/* copy the elements */
+	for (i = 0; i < hash->size; i++) {
+		bucket = hash->table[i];
+
+		while (bucket != NULL) {
+			hash_add(new_hash, bucket->data);
+			bucket = bucket->next;
+		}
+	}
+
+	/* remove hash and eventual overflow buckets but not the content
+	 * itself. */
+	hash_delete(hash, NULL);
+
+	return new_hash;
+}