From 7e9d608530dac8533771c6a9c07b7f3b451cf34f Mon Sep 17 00:00:00 2001
From: Mark Qvist <mark@unsigned.io>
Date: Fri, 24 Sep 2021 16:42:31 +0200
Subject: [PATCH] Improved shutdown handling for local shared instances

---
 RNS/Interfaces/LocalInterface.py | 32 ++++++++++++++++++++++++++++++++
 RNS/Interfaces/TCPInterface.py   | 18 +++++++++++++++---
 RNS/Transport.py                 |  3 +++
 3 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/RNS/Interfaces/LocalInterface.py b/RNS/Interfaces/LocalInterface.py
index b1629f6..e2389f2 100644
--- a/RNS/Interfaces/LocalInterface.py
+++ b/RNS/Interfaces/LocalInterface.py
@@ -36,6 +36,8 @@ class LocalClientInterface(Interface):
             self.target_port = None
             self.socket      = connected_socket
 
+            self.is_connected_to_shared_instance = False
+
         elif target_port != None:
             self.receives    = True
             self.target_ip   = "127.0.0.1"
@@ -116,6 +118,25 @@ class LocalClientInterface(Interface):
             RNS.log("Tearing down "+str(self), RNS.LOG_ERROR)
             self.teardown()
 
+    def detach(self):
+        if self.socket != None:
+            if hasattr(self.socket, "close"):
+                if callable(self.socket.close):
+                    RNS.log("Detaching "+str(self), RNS.LOG_DEBUG)
+                    self.detached = True
+                    
+                    try:
+                        self.socket.shutdown(socket.SHUT_RDWR)
+                    except Exception as e:
+                        RNS.log("Error while shutting down socket for "+str(self)+": "+str(e))
+
+                    try:
+                        self.socket.close()
+                    except Exception as e:
+                        RNS.log("Error while closing socket for "+str(self)+": "+str(e))
+
+                    self.socket = None
+
     def teardown(self, nowarning=False):
         self.online = False
         self.OUT = False
@@ -132,6 +153,15 @@ class LocalClientInterface(Interface):
             if RNS.Reticulum.panic_on_interface_error:
                 RNS.panic()
 
+        if self.is_connected_to_shared_instance:
+            # TODO: Maybe add automatic recovery here.
+            # Needs thinking through, since user needs
+            # to now that all connectivity has been cut
+            # while service is recovering. Better for
+            # now to take down entire stack.
+            RNS.log("Lost connection to local shared RNS instance. Exiting now.", RNS.LOG_CRITICAL)
+            RNS.panic()
+
 
     def __str__(self):
         return "LocalInterface["+str(self.target_port)+"]"
@@ -158,6 +188,8 @@ class LocalServerInterface(Interface):
             self.is_local_shared_instance = True
 
             address = (self.bind_ip, self.bind_port)
+
+            ThreadingTCPServer.allow_reuse_address = True
             self.server = ThreadingTCPServer(address, handlerFactory(self.incoming_connection))
 
             thread = threading.Thread(target=self.server.serve_forever)
diff --git a/RNS/Interfaces/TCPInterface.py b/RNS/Interfaces/TCPInterface.py
index d39b26c..b27183d 100644
--- a/RNS/Interfaces/TCPInterface.py
+++ b/RNS/Interfaces/TCPInterface.py
@@ -45,6 +45,7 @@ class TCPClientInterface(Interface):
         self.owner            = owner
         self.writing          = False
         self.online           = False
+        self.detached         = False
 
         if max_reconnect_tries == None:
             self.max_reconnect_tries = TCPClientInterface.RECONNECT_MAX_TRIES
@@ -101,8 +102,18 @@ class TCPClientInterface(Interface):
             if hasattr(self.socket, "close"):
                 if callable(self.socket.close):
                     RNS.log("Detaching "+str(self), RNS.LOG_DEBUG)
-                    self.socket.shutdown(socket.SHUT_RDWR)
-                    self.socket.close()
+                    self.detached = True
+                    
+                    try:
+                        self.socket.shutdown(socket.SHUT_RDWR)
+                    except Exception as e:
+                        RNS.log("Error while shutting down socket for "+str(self)+": "+str(e))
+
+                    try:
+                        self.socket.close()
+                    except Exception as e:
+                        RNS.log("Error while closing socket for "+str(self)+": "+str(e))
+
                     self.socket = None
 
     def connect(self, initial=False):
@@ -216,7 +227,7 @@ class TCPClientInterface(Interface):
                                 data_buffer = data_buffer+bytes([byte])
                 else:
                     self.online = False
-                    if self.initiator:
+                    if self.initiator and not self.detached:
                         RNS.log("TCP socket for "+str(self)+" was closed, attempting to reconnect...", RNS.LOG_WARNING)
                         self.reconnect()
                     else:
@@ -285,6 +296,7 @@ class TCPServerInterface(Interface):
 
             self.owner = owner
             address = (self.bind_ip, self.bind_port)
+
             ThreadingTCPServer.allow_reuse_address = True
             self.server = ThreadingTCPServer(address, handlerFactory(self.incoming_connection))
 
diff --git a/RNS/Transport.py b/RNS/Transport.py
index 8b7af39..85932ff 100755
--- a/RNS/Transport.py
+++ b/RNS/Transport.py
@@ -1427,6 +1427,9 @@ class Transport:
         for interface in Transport.interfaces:
             interface.detach()
 
+        for interface in Transport.local_client_interfaces:
+            interface.detach()
+
 
     @staticmethod
     def exit_handler():