1 files changed, 180 insertions, 0 deletions
diff --git a/checkpolicy/queue.c b/checkpolicy/queue.c
new file mode 100644
index 00000000..272079c0
--- /dev/null
+++ b/checkpolicy/queue.c
@@ -0,0 +1,180 @@
+
+/* Author : Stephen Smalley, <sds@epoch.ncsc.mil> */
+
+/* FLASK */
+
+/*
+ * Implementation of the double-ended queue type.
+ */
+
+#include <stdlib.h>
+#include "queue.h"
+
+queue_t queue_create(void)
+{
+	queue_t q;
+
+	q = (queue_t) malloc(sizeof(struct queue_info));
+	if (q == NULL)
+		return NULL;
+
+	q->head = q->tail = NULL;
+
+	return q;
+}
+
+int queue_insert(queue_t q, queue_element_t e)
+{
+	queue_node_ptr_t newnode;
+
+	if (!q)
+		return -1;
+
+	newnode = (queue_node_ptr_t) malloc(sizeof(struct queue_node));
+	if (newnode == NULL)
+		return -1;
+
+	newnode->element = e;
+	newnode->next = NULL;
+
+	if (q->head == NULL) {
+		q->head = q->tail = newnode;
+	} else {
+		q->tail->next = newnode;
+		q->tail = newnode;
+	}
+
+	return 0;
+}
+
+int queue_push(queue_t q, queue_element_t e)
+{
+	queue_node_ptr_t newnode;
+
+	if (!q)
+		return -1;
+
+	newnode = (queue_node_ptr_t) malloc(sizeof(struct queue_node));
+	if (newnode == NULL)
+		return -1;
+
+	newnode->element = e;
+	newnode->next = NULL;
+
+	if (q->head == NULL) {
+		q->head = q->tail = newnode;
+	} else {
+		newnode->next = q->head;
+		q->head = newnode;
+	}
+
+	return 0;
+}
+
+queue_element_t queue_remove(queue_t q)
+{
+	queue_node_ptr_t node;
+	queue_element_t e;
+
+	if (!q)
+		return NULL;
+
+	if (q->head == NULL)
+		return NULL;
+
+	node = q->head;
+	q->head = q->head->next;
+	if (q->head == NULL)
+		q->tail = NULL;
+
+	e = node->element;
+	free(node);
+
+	return e;
+}
+
+queue_element_t queue_head(queue_t q)
+{
+	if (!q)
+		return NULL;
+
+	if (q->head == NULL)
+		return NULL;
+
+	return q->head->element;
+}
+
+void queue_destroy(queue_t q)
+{
+	queue_node_ptr_t p, temp;
+
+	if (!q)
+		return;
+
+	p = q->head;
+	while (p != NULL) {
+		temp = p;
+		p = p->next;
+		free(temp);
+	}
+
+	free(q);
+}
+
+int queue_map(queue_t q, int (*f) (queue_element_t, void *), void *vp)
+{
+	queue_node_ptr_t p;
+	int ret;
+
+	if (!q)
+		return 0;
+
+	p = q->head;
+	while (p != NULL) {
+		ret = f(p->element, vp);
+		if (ret)
+			return ret;
+		p = p->next;
+	}
+	return 0;
+}
+
+void queue_map_remove_on_error(queue_t q,
+			       int (*f) (queue_element_t, void *),
+			       void (*g) (queue_element_t, void *), void *vp)
+{
+	queue_node_ptr_t p, last, temp;
+	int ret;
+
+	if (!q)
+		return;
+
+	last = NULL;
+	p = q->head;
+	while (p != NULL) {
+		ret = f(p->element, vp);
+		if (ret) {
+			if (last) {
+				last->next = p->next;
+				if (last->next == NULL)
+					q->tail = last;
+			} else {
+				q->head = p->next;
+				if (q->head == NULL)
+					q->tail = NULL;
+			}
+
+			temp = p;
+			p = p->next;
+			g(temp->element, vp);
+			free(temp);
+		} else {
+			last = p;
+			p = p->next;
+		}
+	}
+
+	return;
+}
+
+/* FLASK */