From cdf416cb730ad4e51d02bdb289691fa5adb2fb2f Mon Sep 17 00:00:00 2001
From: Kevin Hester <kevinh@geeksville.com>
Date: Thu, 31 Dec 2020 09:52:08 +0800
Subject: [PATCH] partial fix for #608 - when a new TCP API connection arrives,
 close old one completely

---
 src/esp32/WiFiServerAPI.cpp | 33 ++++++++++++++++++++++-----------
 src/esp32/WiFiServerAPI.h   |  6 +++++-
 src/mesh/PhoneAPI.cpp       |  8 +++++++-
 src/mesh/PhoneAPI.h         |  7 +++++--
 4 files changed, 39 insertions(+), 15 deletions(-)

diff --git a/src/esp32/WiFiServerAPI.cpp b/src/esp32/WiFiServerAPI.cpp
index 3b11c2ae..fac955cc 100644
--- a/src/esp32/WiFiServerAPI.cpp
+++ b/src/esp32/WiFiServerAPI.cpp
@@ -28,18 +28,19 @@ void WiFiServerAPI::onConnectionChanged(bool connected)
     }
 }
 
-void WiFiServerAPI::loop()
+/// override close to also shutdown the TCP link
+void WiFiServerAPI::close() {
+    client.stop(); // drop tcp connection
+    StreamAPI::close();
+}
+
+bool WiFiServerAPI::loop()
 {
     if (client.connected()) {
         StreamAPI::loop();
-    } else if(isConnected) {
-        // If our API link was up, shut it down
-
-        DEBUG_MSG("Client dropped connection, closing API client\n");
-        // Note: we can't call delete here because this object includes other state
-        // besides the stream API.  Instead kill it later when we start a new instance
-        // delete this;
-        close();
+        return true;
+    } else {
+        return false;       
     }
 }
 
@@ -58,15 +59,25 @@ int32_t WiFiServerPort::runOnce()
     auto client = available();
     if (client) {
         // Close any previous connection (see FIXME in header file)
-        if (openAPI)
+        if (openAPI) {
+            DEBUG_MSG("Force closing previous TCP connection\n");
             delete openAPI;
+        }
 
         openAPI = new WiFiServerAPI(client);
     }
 
     if (openAPI) {
         // Allow idle processing so the API can read from its incoming stream
-        openAPI->loop();
+        if(!openAPI->loop()) {
+            // If our API link was up, shut it down
+
+            DEBUG_MSG("Client dropped connection, closing API client\n");
+            // Note: we can't call delete here because this object includes other state
+            // besides the stream API.  Instead kill it later when we start a new instance
+            delete openAPI;
+            openAPI = NULL;
+        }
         return 0; // run fast while our API server is running
     } else
         return 100; // only check occasionally for incoming connections
diff --git a/src/esp32/WiFiServerAPI.h b/src/esp32/WiFiServerAPI.h
index 19f99cbc..96380020 100644
--- a/src/esp32/WiFiServerAPI.h
+++ b/src/esp32/WiFiServerAPI.h
@@ -18,7 +18,11 @@ class WiFiServerAPI : public StreamAPI
 
     virtual ~WiFiServerAPI();
 
-    virtual void loop(); // Check for dropped client connections
+    /// @return true if we want to keep running, or false if we are ready to be destroyed
+    virtual bool loop(); // Check for dropped client connections
+
+    /// override close to also shutdown the TCP link
+    virtual void close();
 
   protected:
     /// Hookable to find out when connection changes
diff --git a/src/mesh/PhoneAPI.cpp b/src/mesh/PhoneAPI.cpp
index a0cad427..545ef2b9 100644
--- a/src/mesh/PhoneAPI.cpp
+++ b/src/mesh/PhoneAPI.cpp
@@ -21,11 +21,17 @@ void PhoneAPI::init()
     observe(&service.fromNumChanged);
 }
 
+PhoneAPI::~PhoneAPI() {
+    close();
+}
+
 void PhoneAPI::close() {
     unobserve();
     state = STATE_SEND_NOTHING;
+    bool oldConnected = isConnected;
     isConnected = false;
-    onConnectionChanged(isConnected);
+    if(oldConnected != isConnected)
+        onConnectionChanged(isConnected);
 }
 
 void PhoneAPI::checkConnectionTimeout()
diff --git a/src/mesh/PhoneAPI.h b/src/mesh/PhoneAPI.h
index 202f7fa2..3cfd9744 100644
--- a/src/mesh/PhoneAPI.h
+++ b/src/mesh/PhoneAPI.h
@@ -55,12 +55,15 @@ class PhoneAPI
   public:
     PhoneAPI();
 
+    /// Destructor - calls close()
+    virtual ~PhoneAPI();
+
     /// Do late init that can't happen at constructor time
     virtual void init();
 
     // Call this when the client drops the connection, resets the state to STATE_SEND_NOTHING
-    // Unregisters our observer
-    void close();
+    // Unregisters our observer.  A closed connection **can** be reopened by calling init again.
+    virtual void close();
 
     /**
      * Handle a ToRadio protobuf