diff --git a/build-ndk.sh b/build-ndk.sh
index c127ad7f..6678ff04 100755
--- a/build-ndk.sh
+++ b/build-ndk.sh
@@ -4,7 +4,7 @@ ndk-build
 mkdir -p src/main/assets/armeabi
 mkdir -p src/main/assets/armeabi-v7a
 mkdir -p src/main/assets/x86
-for app in ip6tables iptables pdnsd redsocks ss-local ss-tunnel tun2socks
+for app in ip6tables iptables pdnsd redsocks ss-tunnel
 do
     mv libs/armeabi/$app src/main/assets/armeabi/
     mv libs/armeabi-v7a/$app src/main/assets/armeabi-v7a/
diff --git a/jni/Android.mk b/jni/Android.mk
index 2d4feca0..39af4ce1 100755
--- a/jni/Android.mk
+++ b/jni/Android.mk
@@ -143,16 +143,30 @@ LOCAL_CFLAGS    := -Wall -O2 -I$(LOCAL_PATH)/pdnsd
 include $(BUILD_EXECUTABLE)
 
 ########################################################
-## shadowsocks local
+## pdnsd library
+########################################################
+
+include $(CLEAR_VARS)
+
+PDNSD_SOURCES  := $(wildcard $(LOCAL_PATH)/pdnsd/src/*.c) main-jni.cpp
+
+LOCAL_MODULE    := pdnsd-jni
+LOCAL_SRC_FILES := $(PDNSD_SOURCES:$(LOCAL_PATH)/%=%)
+LOCAL_CFLAGS    := -Wall -O2 -DPDNSD_JNI -I$(LOCAL_PATH)/pdnsd
+
+include $(BUILD_SHARED_LIBRARY)
+
+########################################################
+## shadowsocks local library
 ########################################################
 
 include $(CLEAR_VARS)
 
 SHADOWSOCKS_SOURCES := local.c cache.c udprelay.c encrypt.c utils.c json.c jconf.c acl.c 
 
-LOCAL_MODULE    := ss-local
-LOCAL_SRC_FILES := $(addprefix shadowsocks/src/, $(SHADOWSOCKS_SOURCES))
-LOCAL_CFLAGS    := -Wall -O2 -fno-strict-aliasing -DUDPRELAY_LOCAL \
+LOCAL_MODULE    := ss-local-jni
+LOCAL_SRC_FILES := $(addprefix shadowsocks/src/, $(SHADOWSOCKS_SOURCES)) main-jni.cpp
+LOCAL_CFLAGS    := -Wall -O2 -fno-strict-aliasing -DUDPRELAY_LOCAL -DSSLOCAL_JNI \
 					-DUSE_CRYPTO_OPENSSL -DANDROID -DHAVE_CONFIG_H \
 					-I$(LOCAL_PATH)/libev/ \
 					-I$(LOCAL_PATH)/openssl/include  \
@@ -163,7 +177,7 @@ LOCAL_STATIC_LIBRARIES := libev libcrypto libipset libcork
 
 LOCAL_LDLIBS := -llog
 
-include $(BUILD_EXECUTABLE)
+include $(BUILD_SHARED_LIBRARY)
 
 ########################################################
 ## shadowsocks tunnel
@@ -204,7 +218,7 @@ LOCAL_STATIC_LIBRARIES := cpufeatures
 include $(BUILD_SHARED_LIBRARY)
 
 ########################################################
-## tun2socks
+## tun2socks-library
 ########################################################
 
 include $(CLEAR_VARS)
@@ -214,6 +228,7 @@ LOCAL_CFLAGS += -DBADVPN_THREADWORK_USE_PTHREAD -DBADVPN_LINUX -DBADVPN_BREACTOR
 LOCAL_CFLAGS += -DBADVPN_USE_SELFPIPE -DBADVPN_USE_EPOLL
 LOCAL_CFLAGS += -DBADVPN_LITTLE_ENDIAN -DBADVPN_THREAD_SAFE
 LOCAL_CFLAGS += -DNDEBUG -DANDROID
+LOCAL_CFLAGS += -DTUN2SOCKS_JNI
 
 LOCAL_C_INCLUDES:= \
         $(LOCAL_PATH)/badvpn/lwip/src/include/ipv4 \
@@ -283,13 +298,13 @@ TUN2SOCKS_SOURCES := \
         tun2socks/SocksUdpGwClient.c \
         udpgw_client/UdpGwClient.c
 
-LOCAL_MODULE := tun2socks
+LOCAL_MODULE := tun2socks-jni
 
 LOCAL_LDLIBS := -ldl -llog
 
-LOCAL_SRC_FILES := $(addprefix badvpn/, $(TUN2SOCKS_SOURCES))
+LOCAL_SRC_FILES := $(addprefix badvpn/, $(TUN2SOCKS_SOURCES)) main-jni.cpp
 
-include $(BUILD_EXECUTABLE)
+include $(BUILD_SHARED_LIBRARY)
 
 # OpenSSL
 openssl_subdirs := $(addprefix $(LOCAL_PATH)/openssl/,$(addsuffix /Android.mk, \
diff --git a/src/main/scala/com/github/shadowsocks/ShadowsocksNatService.scala b/src/main/scala/com/github/shadowsocks/ShadowsocksNatService.scala
index 39137b75..93163739 100644
--- a/src/main/scala/com/github/shadowsocks/ShadowsocksNatService.scala
+++ b/src/main/scala/com/github/shadowsocks/ShadowsocksNatService.scala
@@ -119,12 +119,13 @@ class ShadowsocksNatService extends Service with BaseService {
     }
 
     val args = (Path.BASE +
-      "ss-local -b 127.0.0.1 -s '%s' -p '%d' -l '%d' -k ''%s' -m '%s' -f " +
+      "ss-local -b 127.0.0.1 -s %s -p %d -l %d -k %s -m %s -f " +
       Path.BASE + "ss-local.pid")
       .format(config.proxy, config.remotePort, config.localPort, config.sitekey, config.encMethod)
     val cmd =  if (config.isGFWList && isACLEnabled) args + " --acl " + Path.BASE + "chn.acl" else args
     if (BuildConfig.DEBUG) Log.d(TAG, cmd)
-    Console.runCommand(cmd)
+
+    Core.sslocal(cmd.split(" "))
   }
 
   def startDnsDaemon() {
diff --git a/src/main/scala/com/github/shadowsocks/ShadowsocksVpnService.scala b/src/main/scala/com/github/shadowsocks/ShadowsocksVpnService.scala
index 96195592..32b0fc3e 100644
--- a/src/main/scala/com/github/shadowsocks/ShadowsocksVpnService.scala
+++ b/src/main/scala/com/github/shadowsocks/ShadowsocksVpnService.scala
@@ -82,11 +82,11 @@ class ShadowsocksVpnService extends VpnService with BaseService {
 
   def startShadowsocksDaemon() {
     val cmd: String = (Path.BASE +
-      "ss-local -b 127.0.0.1 -s '%s' -p '%d' -l '%d' -k '%s' -m '%s' -u -f " +
+      "ss-local -b 127.0.0.1 -s %s -p %d -l %d -k %s -m %s -u -f " +
       Path.BASE + "ss-local.pid")
       .format(config.proxy, config.remotePort, config.localPort, config.sitekey, config.encMethod)
     if (BuildConfig.DEBUG) Log.d(TAG, cmd)
-    System.exec(cmd)
+    Core.sslocal(cmd.split(" "))
   }
 
   def startDnsDaemon() {
@@ -101,7 +101,7 @@ class ShadowsocksVpnService extends VpnService with BaseService {
     })
     val cmd = Path.BASE + "pdnsd -c " + Path.BASE + "pdnsd.conf"
     if (BuildConfig.DEBUG) Log.d(TAG, cmd)
-    System.exec(cmd)
+    Core.pdnsd(cmd.split(" "))
   }
 
   def getVersionName: String = {
@@ -202,10 +202,9 @@ class ShadowsocksVpnService extends VpnService with BaseService {
     else
       cmd += " --dnsgw %s:8153".format(PRIVATE_VLAN.format("1"))
 
-    if (BuildConfig.DEBUG)
-      Log.d(TAG, cmd)
+    if (BuildConfig.DEBUG) Log.d(TAG, cmd)
 
-    System.exec(cmd)
+    Core.tun2socks(cmd.split(" "))
   }
 
   /** Called when the activity is first created. */
@@ -260,11 +259,8 @@ class ShadowsocksVpnService extends VpnService with BaseService {
     val ab = new ArrayBuffer[String]
 
     ab.append("kill -9 `cat " + Path.BASE + "ss-local.pid`")
-    ab.append("killall -9 ss-local")
     ab.append("kill -9 `cat " + Path.BASE + "tun2socks.pid`")
-    ab.append("killall -9 tun2socks")
     ab.append("kill -15 `cat " + Path.BASE + "pdnsd.pid`")
-    ab.append("killall -15 pdnsd")
 
     Console.runCommand(ab.toArray)
   }