1 files changed, 154 insertions, 0 deletions
diff --git a/khm/khm.c b/khm/khm.c
new file mode 100644
index 0000000..a0a4c74
--- /dev/null
+++ b/khm/khm.c
@@ -0,0 +1,154 @@
+/*
+ *   khm - (Linux) kernel hash map implementation
+ *
+ *   Copyright (c) 2011 Guillermo Ramos <0xwille@gmail.com>
+ *
+ * This file is part of khm
+ *
+ * khm is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * khm 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 khm.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/errno.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include "khm.h"
+
+/*
+ * Returns the node with the value passed, or NULL in case it does not exist
+ */
+static inline struct khashmap *khm_search(struct khashmap *head, int value)
+{
+	struct list_head *list;
+	struct khashmap *node;
+
+	list_for_each(list, &head->l) {
+		node = list_entry(list, struct khashmap, l);
+		if (node->value == value)
+			return node;
+	}
+
+	return NULL;
+}
+
+/*
+ * Prints in klog a representation of all the nodes in the hashmap
+ */
+void khm_display(struct khashmap *head)
+{
+	struct khashmap *node;
+	struct list_head *list;
+
+	printk(KERN_ALERT "Displaying...");
+	list_for_each(list, &head->l) {
+		node = list_entry(list, struct khashmap, l);
+		printk(KERN_ALERT "  %p: v=%d d=%s\n",
+				node, node->value, (char*)node->data);
+	}
+}
+
+/*
+ * Creates and returns a new head node
+ */
+inline struct khashmap *khm_create(void)
+{
+	struct khashmap *head;
+
+	head = kmalloc(sizeof(struct khashmap), GFP_KERNEL);
+	if (!head)
+		return NULL;
+
+	INIT_LIST_HEAD(&head->l);
+
+	return head;
+}
+
+/*
+ * Deletes the hashmap and frees the memory used by its nodes
+ */
+void khm_destroy(struct khashmap *head)
+{
+	struct khashmap *node;
+	struct list_head *list = head->l.next;
+
+	while (list != &head->l) {
+		node = list_entry(list, struct khashmap, l);
+		list = list->next;
+		kfree(node);
+	}
+
+	kfree(head);
+}
+
+/*
+ * Creates a new node with the given value and data, and adds it to the hm head
+ */
+int khm_insert(struct khashmap *head, int value, void *data)
+{
+	struct khashmap *new;
+
+	// Key already exists
+	if (khm_search(head, value))
+		return -EINVAL;
+
+	new = khm_create();
+	if (!new)
+		return -ENOMEM;
+
+	new->value = value;
+	new->data = data;
+	list_add_tail(&new->l, &head->l);
+
+	return 0;
+}
+
+/*
+ * Removes from the hashmap the node with the given value.
+ */
+int khm_delete(struct khashmap *head, int value)
+{
+	struct khashmap *node = khm_search(head, value);
+
+	if (node) {
+		list_del(&node->l);
+		kfree(node);
+		return 0;
+	} else {
+		return -EINVAL;
+	}
+}
+
+/*
+ * Returns the data mapped to the given value, or NULL if that value has no data
+ * associated to it
+ */
+void *khm_get(struct khashmap *head, int value)
+{
+	struct khashmap *node = khm_search(head, value);
+
+	if (node)
+		return node->data;
+	else
+		return NULL;
+}
+
+/*
+ * Associates the given value with new data, if the value was already in the hm
+ */
+void khm_set(struct khashmap *head, int value, void *data)
+{
+	struct khashmap *node = khm_search(head, value);
+
+	if (node)
+		node->data = data;
+}