Resolve server name dynamically always (#2731)

Fixes #2722.

core/src/main/java/com/github/shadowsocks/bg/BaseService.kt

@@ -50,7 +50,6 @@ import timber.log.Timber
 import java.io.File
 import java.io.IOException
 import java.net.URL
-import java.net.UnknownHostException
 
 /**
  * This object uses WeakMap to simulate the effects of multi-inheritance.
@@ -316,7 +315,6 @@ object BaseService {
                 listOfNotNull(data.proxy, data.udpFallback).forEach { it.trafficMonitor?.persistStats(it.profile.id) }
 
         suspend fun preInit() { }
-        suspend fun resolver(host: String) = DnsResolverCompat.resolveOnActiveNetwork(host)
         suspend fun rawResolver(query: ByteArray) = DnsResolverCompat.resolveRawOnActiveNetwork(query)
         suspend fun openConnection(url: URL) = url.openConnection()
 
@@ -355,8 +353,6 @@ object BaseService {
                 try {
                     Executable.killAll()    // clean up old processes
                     preInit()
-                    proxy.init(this@Interface)
-                    data.udpFallback?.init(this@Interface)
                     if (profile.route == Acl.CUSTOM_RULES) try {
                         withContext(Dispatchers.IO) {
                             Acl.customRules.flatten(10, this@Interface::openConnection).also {
@@ -379,8 +375,6 @@ object BaseService {
                     data.changeState(State.Connected)
                 } catch (_: CancellationException) {
                     // if the job was cancelled, it is canceller's responsibility to call stopRunner
-                } catch (_: UnknownHostException) {
-                    stopRunner(false, getString(R.string.invalid_server))
                 } catch (exc: Throwable) {
                     if (exc is ExpectedException) Timber.d(exc) else Timber.w(exc)
                     stopRunner(false, "${getString(R.string.service_failed)}: ${exc.readableMessage}")

core/src/main/java/com/github/shadowsocks/bg/ProxyInstance.kt

@@ -27,15 +27,12 @@ import com.github.shadowsocks.database.Profile
 import com.github.shadowsocks.plugin.PluginConfiguration
 import com.github.shadowsocks.plugin.PluginManager
 import com.github.shadowsocks.preference.DataStore
-import com.github.shadowsocks.utils.parseNumericAddress
 import kotlinx.coroutines.CoroutineScope
 import org.json.JSONArray
 import org.json.JSONObject
 import java.io.File
-import java.io.IOException
 import java.net.URI
 import java.net.URISyntaxException
-import java.net.UnknownHostException
 
 /**
  * This class sets up environment for ss-local.
@@ -51,17 +48,6 @@ class ProxyInstance(val profile: Profile, private val route: String = profile.ro
     var trafficMonitor: TrafficMonitor? = null
     val plugin by lazy { PluginManager.init(PluginConfiguration(profile.plugin ?: "")) }
 
-    suspend fun init(service: BaseService.Interface) {
-        // it's hard to resolve DNS on a specific interface so we'll do it here
-        if (plugin != null && profile.host.parseNumericAddress() == null) {
-            profile.host = try {
-                service.resolver(profile.host).firstOrNull()
-            } catch (e: IOException) {
-                throw UnknownHostException().initCause(e)
-            }?.hostAddress ?: throw UnknownHostException()
-        }
-    }
-
     /**
      * Sensitive shadowsocks configuration file requires extra protection. It may be stored in encrypted storage or
      * device storage, depending on which is currently available.

core/src/main/java/com/github/shadowsocks/bg/VpnService.kt

@@ -146,7 +146,6 @@ class VpnService : BaseVpnService(), BaseService.Interface {
     }
 
     override suspend fun preInit() = DefaultNetworkListener.start(this) { underlyingNetwork = it }
-    override suspend fun resolver(host: String) = DnsResolverCompat.resolve(DefaultNetworkListener.get(), host)
     override suspend fun rawResolver(query: ByteArray) =
             // no need to listen for network here as this is only used for forwarding local DNS queries.
             // retries should be attempted by client.

core/src/main/res/values/strings.xml

@@ -69,7 +69,6 @@
   <string name="service_proxy">Proxy Service</string>
   <string name="service_transproxy">Transproxy Service</string>
   <string name="forward_success">Shadowsocks started.</string>
-  <string name="invalid_server">Invalid server name</string>
   <string name="service_failed">Failed to connect the remote server</string>
   <string name="stop">Stop</string>
   <string name="stopping">Shutting down…</string>