Support VPN over any native tethering

First big refactoring of this app.
2018-01-13 00:41:55 +08:00
parent f341bf409e
commit eb165db86c
31 changed files with 1068 additions and 874 deletions
--- a/mobile/src/main/java/be/mygod/vpnhotspot/TetheringService.kt
+++ b/mobile/src/main/java/be/mygod/vpnhotspot/TetheringService.kt
@@ -0,0 +1,87 @@
+package be.mygod.vpnhotspot
+
+import android.app.Service
+import android.content.Intent
+import android.support.v4.content.LocalBroadcastManager
+import be.mygod.vpnhotspot.App.Companion.app
+import be.mygod.vpnhotspot.NetUtils.tetheredIfaces
+
+class TetheringService : Service(), VpnListener.Callback {
+    companion object {
+        const val ACTION_ACTIVE_INTERFACES_CHANGED = "be.mygod.vpnhotspot.TetheringService.ACTIVE_INTERFACES_CHANGED"
+        const val EXTRA_ADD_INTERFACE = "interface.add"
+        const val EXTRA_REMOVE_INTERFACE = "interface.remove"
+        private const val KEY_ACTIVE = "persist.service.tether.active"
+
+        var active: Set<String>?
+            get() = app.pref.getStringSet(KEY_ACTIVE, null)
+            private set(value) {
+                app.pref.edit().putStringSet(KEY_ACTIVE, value).apply()
+                LocalBroadcastManager.getInstance(app).sendBroadcast(Intent(ACTION_ACTIVE_INTERFACES_CHANGED))
+            }
+    }
+
+    private val routings = HashMap<String, Routing?>()
+    private var upstream: String? = null
+    private var receiverRegistered = false
+    private val receiver = broadcastReceiver { _, intent ->
+        val remove = routings - intent.extras.getStringArrayList(NetUtils.EXTRA_ACTIVE_TETHER).toSet()
+        if (remove.isEmpty()) return@broadcastReceiver
+        for ((iface, routing) in remove) {
+            routing?.stop()
+            routings.remove(iface)
+        }
+        val upstream = upstream
+        if (upstream == null) onLost("") else onAvailable(upstream)
+        active = routings.keys
+        if (routings.isEmpty()) terminate()
+    }
+
+    override fun onBind(intent: Intent?) = null
+
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        if (intent != null) {   // otw service is recreated after being killed
+            var iface = intent.getStringExtra(EXTRA_ADD_INTERFACE)
+            if (iface != null && VpnListener.connectivityManager.tetheredIfaces.contains(iface))
+                routings.put(iface, null)
+            iface = intent.getStringExtra(EXTRA_REMOVE_INTERFACE)
+            if (iface != null) routings.remove(iface)?.stop()
+            active = routings.keys
+        } else active?.forEach { routings.put(it, null) }
+        if (routings.isEmpty()) terminate() else {
+            if (!receiverRegistered) {
+                registerReceiver(receiver, intentFilter(NetUtils.ACTION_TETHER_STATE_CHANGED))
+                VpnListener.registerCallback(this)
+                receiverRegistered = true
+            }
+        }
+        return START_STICKY
+    }
+
+    override fun onAvailable(ifname: String) {
+        assert(upstream == null || upstream == ifname)
+        upstream = ifname
+        for ((downstream, value) in routings) if (value == null) {
+            val routing = Routing(ifname, downstream).rule().forward().dnsRedirect(app.dns)
+            if (routing.start()) routings[downstream] = routing else routing.stop()
+        }
+    }
+
+    override fun onLost(ifname: String) {
+        assert(upstream == null || upstream == ifname)
+        upstream = null
+        for ((iface, routing) in routings) {
+            routing?.stop()
+            routings[iface] = null
+        }
+    }
+
+    private fun terminate() {
+        if (receiverRegistered) {
+            unregisterReceiver(receiver)
+            VpnListener.unregisterCallback(this)
+            receiverRegistered = false
+        }
+        stopSelf()
+    }
+}