1 files changed, 67 insertions, 0 deletions
diff --git a/src/conntrack/stack.c b/src/conntrack/stack.c
new file mode 100644
index 0000000..404e38b
--- /dev/null
+++ b/src/conntrack/stack.c
@@ -0,0 +1,67 @@
+/*
+ * (C) 2008 by Pablo Neira Ayuso <pablo@netfilter.org>
+ *
+ * This software may be used and distributed according to the terms
+ * of the GNU General Public License, incorporated herein by reference.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include "internal/stack.h"
+
+struct stack {
+	int num_elems;
+	int max_elems;
+	size_t elem_size;
+	char *data;
+};
+
+struct stack *stack_create(size_t elem_size, int max_elems)
+{
+	struct stack *s;
+
+	s = calloc(sizeof(struct stack), 1);
+	if (s == NULL)
+		return NULL;
+
+	s->data = calloc(elem_size * max_elems, 1);
+	if (s->data == NULL) {
+		free(s);
+		return NULL;
+	}
+	s->elem_size = elem_size;
+	s->max_elems = max_elems;
+
+	return s;
+}
+
+void stack_destroy(struct stack *s)
+{
+	free(s->data);
+	free(s);
+}
+
+int stack_push(struct stack *s, void *data)
+{
+	if (s->num_elems >= s->max_elems) {
+		errno = ENOSPC;
+		return -1;
+	}
+	memcpy(s->data + (s->elem_size * s->num_elems), data, s->elem_size);
+	s->num_elems++;
+	return 0;
+}
+
+int stack_pop(struct stack *s, void *data)
+{
+	if (s->num_elems <= 0) {
+		errno = EINVAL;
+		return -1;
+	}
+	s->num_elems--;
+	memcpy(data, s->data + (s->elem_size * s->num_elems), s->elem_size);
+	return 0;
+}