diff --git a/Android.mk b/Android.mk
index a640e06..819c86f 100644
--- a/Android.mk
+++ b/Android.mk
@@ -1,7 +1,7 @@
 LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 
-LOCAL_SRC_FILES:=clatd.c dump.c checksum.c translate.c icmp.c ipv4.c ipv6.c config.c dns64.c logging.c getaddr.c netlink_callbacks.c netlink_msg.c setif.c mtu.c
+LOCAL_SRC_FILES:=clatd.c dump.c checksum.c translate.c icmp.c ipv4.c ipv6.c config.c dns64.c logging.c getaddr.c netlink_callbacks.c netlink_msg.c setif.c mtu.c tun.c
 
 LOCAL_CFLAGS := -Wall -Werror -Wunused-parameter
 LOCAL_C_INCLUDES := external/libnl/include bionic/libc/dns/include
diff --git a/clatd.c b/clatd.c
index dbf725b..e2c96e6 100644
--- a/clatd.c
+++ b/clatd.c
@@ -50,6 +50,7 @@
 #include "mtu.h"
 #include "getaddr.h"
 #include "dump.h"
+#include "tun.h"
 
 #define DEVICENAME4 "clat4"
 
@@ -65,44 +66,6 @@
   running = 0;
 }
 
-/* function: tun_open
- * tries to open the tunnel device
- */
-int tun_open() {
-  int fd;
-
-  fd = open("/dev/tun", O_RDWR);
-  if(fd < 0) {
-    fd = open("/dev/net/tun", O_RDWR);
-  }
-
-  return fd;
-}
-
-/* function: tun_alloc
- * creates a tun interface and names it
- * dev - the name for the new tun device
- */
-int tun_alloc(char *dev, int fd) {
-  struct ifreq ifr;
-  int err;
-
-  memset(&ifr, 0, sizeof(ifr));
-
-  ifr.ifr_flags = IFF_TUN;
-  if( *dev ) {
-    strncpy(ifr.ifr_name, dev, IFNAMSIZ);
-    ifr.ifr_name[IFNAMSIZ-1] = '\0';
-  }
-
-  if( (err = ioctl(fd, TUNSETIFF, (void *) &ifr)) < 0 ){
-    close(fd);
-    return err;
-  }
-  strcpy(dev, ifr.ifr_name);
-  return 0;
-}
-
 /* function: configure_packet_socket
  * Binds the packet socket and attaches the receive filter to it.
  * sock - the socket to configure
diff --git a/clatd.h b/clatd.h
index ca7369b..6368a09 100644
--- a/clatd.h
+++ b/clatd.h
@@ -18,9 +18,6 @@
 #ifndef __CLATD_H__
 #define __CLATD_H__
 
-#include <linux/if.h>
-#include <linux/if_tun.h>
-
 #define MAXMTU 1500
 #define PACKETLEN (MAXMTU+sizeof(struct tun_pi))
 #define CLATD_VERSION "1.3"
@@ -33,9 +30,4 @@
 // how frequently (in seconds) to poll for an address change while there is no traffic
 #define NO_TRAFFIC_INTERFACE_POLL_FREQUENCY 90
 
-struct tun_data {
-  char device4[IFNAMSIZ];
-  int read_fd6, write_fd6, fd4;
-};
-
 #endif /* __CLATD_H__ */
diff --git a/tun.c b/tun.c
new file mode 100644
index 0000000..ef6b111
--- /dev/null
+++ b/tun.c
@@ -0,0 +1,62 @@
+/*
+ * Copyright 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * tun.c - tun device functions
+ */
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <linux/if.h>
+#include <linux/if_tun.h>
+#include <sys/ioctl.h>
+
+/* function: tun_open
+ * tries to open the tunnel device
+ */
+int tun_open() {
+  int fd;
+
+  fd = open("/dev/tun", O_RDWR);
+  if(fd < 0) {
+    fd = open("/dev/net/tun", O_RDWR);
+  }
+
+  return fd;
+}
+
+/* function: tun_alloc
+ * creates a tun interface and names it
+ * dev - the name for the new tun device
+ */
+int tun_alloc(char *dev, int fd) {
+  struct ifreq ifr;
+  int err;
+
+  memset(&ifr, 0, sizeof(ifr));
+
+  ifr.ifr_flags = IFF_TUN;
+  if( *dev ) {
+    strncpy(ifr.ifr_name, dev, IFNAMSIZ);
+    ifr.ifr_name[IFNAMSIZ-1] = '\0';
+  }
+
+  if( (err = ioctl(fd, TUNSETIFF, (void *) &ifr)) < 0 ){
+    close(fd);
+    return err;
+  }
+  strcpy(dev, ifr.ifr_name);
+  return 0;
+}
diff --git a/tun.h b/tun.h
new file mode 100644
index 0000000..9ccb037
--- /dev/null
+++ b/tun.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * tun.h - tun device functions
+ */
+#ifndef __TUN_H__
+#define __TUN_H__
+
+struct tun_data {
+  char device4[IFNAMSIZ];
+  int read_fd6, write_fd6, fd4;
+};
+
+int set_nonblocking(int fd);
+int tun_open();
+int tun_alloc(char *dev, int fd);
+
+#endif