From f3c20333b03f41cecdf093ef5f2d63e23b15f35f Mon Sep 17 00:00:00 2001
From: Torsten Grote <t@grobox.de>
Date: Thu, 21 Oct 2021 15:16:42 -0300
Subject: [PATCH] Don't teardown things after sockets have been closed

Before, the call to closeAll() in McsService#connect() would trigger a SocketException (Socket closed) in McsOutputStream and/or McsInputStream. This would send a teardown message causing McsService to take the new connection down right away. In unlucky situations, this could cause small connect/teardown loops. This commit hopes to prevent those.

Change-Id: Id347d598e028bdd1ba2622cd6a5c6b07874335d6
---
 .../main/java/org/microg/gms/gcm/McsInputStream.java  | 11 +++++++----
 .../main/java/org/microg/gms/gcm/McsOutputStream.java | 10 +++++++---
 .../src/main/java/org/microg/gms/gcm/McsService.java  |  4 +++-
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/play-services-core/src/main/java/org/microg/gms/gcm/McsInputStream.java b/play-services-core/src/main/java/org/microg/gms/gcm/McsInputStream.java
index c1913ba3..2e7f2b36 100644
--- a/play-services-core/src/main/java/org/microg/gms/gcm/McsInputStream.java
+++ b/play-services-core/src/main/java/org/microg/gms/gcm/McsInputStream.java
@@ -20,7 +20,6 @@ import android.os.Handler;
 import android.util.Log;
 
 import com.squareup.wire.Message;
-import com.squareup.wire.Wire;
 
 import org.microg.gms.gcm.mcs.Close;
 import org.microg.gms.gcm.mcs.DataMessageStanza;
@@ -57,7 +56,7 @@ public class McsInputStream extends Thread implements Closeable {
     private int streamId = 0;
     private long lastMsgTime = 0;
 
-    private boolean closed = false;
+    private volatile boolean closed = false;
 
     public McsInputStream(InputStream is, Handler mainHandler) {
         this(is, mainHandler, false);
@@ -83,7 +82,11 @@ public class McsInputStream extends Thread implements Closeable {
                 }
             }
         } catch (IOException e) {
-            mainHandler.dispatchMessage(mainHandler.obtainMessage(MSG_INPUT_ERROR, e));
+            if (closed) {
+                Log.d(TAG, "We were closed already. Ignoring IOException");
+            } else {
+                mainHandler.dispatchMessage(mainHandler.obtainMessage(MSG_INPUT_ERROR, e));
+            }
         }
         try {
             is.close();
@@ -120,7 +123,7 @@ public class McsInputStream extends Thread implements Closeable {
                 Log.d(TAG, "Reading from MCS version: " + version);
                 initialized = true;
             } catch (IOException e) {
-                Log.w(TAG, e);
+                Log.w(TAG, "Error reading version", e);
             }
         }
     }
diff --git a/play-services-core/src/main/java/org/microg/gms/gcm/McsOutputStream.java b/play-services-core/src/main/java/org/microg/gms/gcm/McsOutputStream.java
index a4867b6d..5448adef 100644
--- a/play-services-core/src/main/java/org/microg/gms/gcm/McsOutputStream.java
+++ b/play-services-core/src/main/java/org/microg/gms/gcm/McsOutputStream.java
@@ -41,10 +41,10 @@ public class McsOutputStream extends Thread implements Handler.Callback, Closeab
     private int version = MCS_VERSION_CODE;
     private int streamId = 0;
 
-    private Handler mainHandler;
+    private final Handler mainHandler;
     private Handler myHandler;
 
-    private boolean closed = false;
+    private volatile boolean closed = false;
 
     public McsOutputStream(OutputStream os, Handler mainHandler) {
         this(os, mainHandler, false);
@@ -78,7 +78,11 @@ public class McsOutputStream extends Thread implements Handler.Callback, Closeab
                     writeInternal((Message) msg.obj, msg.arg1);
                     mainHandler.dispatchMessage(mainHandler.obtainMessage(MSG_OUTPUT_DONE, msg.arg1, msg.arg2, msg.obj));
                 } catch (IOException e) {
-                    mainHandler.dispatchMessage(mainHandler.obtainMessage(MSG_OUTPUT_ERROR, e));
+                    if (closed) {
+                        Log.d(TAG, "We were closed already. Ignoring IOException");
+                    } else {
+                        mainHandler.dispatchMessage(mainHandler.obtainMessage(MSG_OUTPUT_ERROR, e));
+                    }
                 }
                 return true;
             case MSG_TEARDOWN:
diff --git a/play-services-core/src/main/java/org/microg/gms/gcm/McsService.java b/play-services-core/src/main/java/org/microg/gms/gcm/McsService.java
index 600b24ba..5a9eb534 100644
--- a/play-services-core/src/main/java/org/microg/gms/gcm/McsService.java
+++ b/play-services-core/src/main/java/org/microg/gms/gcm/McsService.java
@@ -441,7 +441,6 @@ public class McsService extends Service implements Handler.Callback {
     }
 
     private synchronized void connect() {
-        wasTornDown = false;
         try {
             closeAll();
             ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
@@ -452,6 +451,7 @@ public class McsService extends Service implements Handler.Callback {
                 scheduleReconnect(this);
                 return;
             }
+            wasTornDown = false;
 
             logd(this, "Starting MCS connection...");
             Socket socket = new Socket(SERVICE_HOST, SERVICE_PORT);
@@ -744,6 +744,7 @@ public class McsService extends Service implements Handler.Callback {
             resetCurrentDelay();
             lastIncomingNetworkRealtime = SystemClock.elapsedRealtime();
         } catch (Exception e) {
+            Log.w(TAG, "Exception when handling input: " + message, e);
             rootHandler.sendMessage(rootHandler.obtainMessage(MSG_TEARDOWN, e));
         }
     }
@@ -758,6 +759,7 @@ public class McsService extends Service implements Handler.Callback {
     }
 
     private static void closeAll() {
+        logd(null, "Closing all sockets...");
         tryClose(inputStream);
         tryClose(outputStream);
         if (sslSocket != null) {