Move all the connect() logic from TCPSocketHandler into a subclass

This way, TCPSocketHandler only deal with the message sending/receiving, not
the connect() or anything else.  This will be used for implementing servers
(because when a client is accepted, we don’t need all the connect() and dns
resolution stuff).

louloulibs/network/tcp_socket_handler.hpp

@@ -20,10 +20,8 @@
 #include <list>
 
 /**
- * An interface, with a series of callbacks that should be implemented in
- * subclasses that deal with a socket. These callbacks are called on various events
- * (read/write/timeout, etc) when they are notified to a poller
- * (select/poll/epoll etc)
+ * Does all the read/write, buffering etc. With optional tls.
+ * But doesn’t do any connect() or accept() or anything else.
  */
 class TCPSocketHandler: public SocketHandler
 {
@@ -36,13 +34,6 @@ public:
   TCPSocketHandler& operator=(const TCPSocketHandler&) = delete;
   TCPSocketHandler& operator=(TCPSocketHandler&&) = delete;
 
-  /**
-   * Connect to the remote server, and call on_connected() if this
-   * succeeds. If tls is true, we set use_tls to true and will also call
-   * start_tls() when the connection succeeds.
-   */
-  void connect(const std::string& address, const std::string& port, const bool tls);
-  void connect() override final;
   /**
    * Reads raw data from the socket. And pass it to parse_in_buffer()
    * If we are using TLS on this connection, we call tls_recv()
@@ -67,25 +58,7 @@ public:
   /**
    * Close the connection, remove us from the poller
    */
-  void close();
-  /**
-   * Called by a TimedEvent, when the connection did not succeed or fail
-   * after a given time.
-   */
-  void on_connection_timeout();
-  /**
-   * Called when the connection is successful.
-   */
-  virtual void on_connected() = 0;
-  /**
-   * Called when the connection fails. Not when it is closed later, just at
-   * the connect() call.
-   */
-  virtual void on_connection_failed(const std::string& reason) = 0;
-  /**
-   * Called when we detect a disconnection from the remote host.
-   */
-  virtual void on_connection_close(const std::string& error) = 0;
+  virtual void close();
   /**
    * Handle/consume (some of) the data received so far.  The data to handle
    * may be in the in_buf buffer, or somewhere else, depending on what
@@ -93,6 +66,9 @@ public:
    * should be truncated, only the unused data should be left untouched.
    *
    * The size argument is the size of the last chunk of data that was added to the buffer.
+   *
+   * The function should call consume_in_buffer, with the size that was consumed by the
+   * “parsing”, and thus to be removed from the input buffer.
    */
   virtual void parse_in_buffer(const size_t size) = 0;
 #ifdef BOTAN_FOUND
@@ -105,18 +81,9 @@ public:
     return true;
   }
 #endif
-  bool is_connected() const override final;
-  bool is_connecting() const;
   bool is_using_tls() const;
-  std::string get_port() const;
-  std::chrono::system_clock::time_point connection_date;
 
 private:
-  /**
-   * Initialize the socket with the parameters contained in the given
-   * addrinfo structure.
-   */
-  void init_socket(const struct addrinfo* rp);
   /**
    * Reads from the socket into the provided buffer.  If an error occurs
    * (read returns <= 0), the handling of the error is done here (close the
@@ -137,12 +104,14 @@ private:
   void raw_send(std::string&& data);
 
 #ifdef BOTAN_FOUND
+ protected:
   /**
    * Create the TLS::Client object, with all the callbacks etc. This must be
    * called only when we know we are able to send TLS-encrypted data over
    * the socket.
    */
-  void start_tls();
+  void start_tls(const std::string& address, const std::string& port);
+ private:
   /**
    * An additional step to pass the data into our tls object to decrypt it
    * before passing it to parse_in_buffer.
@@ -185,20 +154,11 @@ private:
    * Where data is added, when we want to send something to the client.
    */
   std::vector<std::string> out_buf;
-  /**
-   * DNS resolver
-   */
-  Resolver resolver;
-  /**
-   * Keep the details of the addrinfo returned by the resolver that
-   * triggered a EINPROGRESS error when connect()ing to it, to reuse it
-   * directly when connect() is called again.
-   */
-  struct addrinfo addrinfo;
-  struct sockaddr_in6 ai_addr;
-  socklen_t ai_addrlen;
-
 protected:
+  /**
+   * Whether we are using TLS on this connection or not.
+   */
+  bool use_tls;
   /**
    * Where data read from the socket is added until we can extract a full
    * and meaningful “message” from it.
@@ -207,9 +167,9 @@ protected:
    */
   std::string in_buf;
   /**
-   * Whether we are using TLS on this connection or not.
+   * Remove the given “size” first bytes from our in_buf.
    */
-  bool use_tls;
+  void consume_in_buffer(const std::size_t size);
   /**
    * Provide a buffer in which data can be directly received. This can be
    * used to avoid copying data into in_buf before using it. If no buffer
@@ -219,31 +179,12 @@ protected:
    */
   virtual void* get_receive_buffer(const size_t size) const;
   /**
-   * Hostname we are connected/connecting to
+   * Called when we detect a disconnection from the remote host.
    */
-  std::string address;
-  /**
-   * Port we are connected/connecting to
-   */
-  std::string port;
-
-  bool connected;
-  bool connecting;
-
-  bool hostname_resolution_failed;
-
-  /**
-   * Address to bind the socket to, before calling connect().
-   * If empty, it’s equivalent to binding to INADDR_ANY.
-   */
-  std::string bind_addr;
+  virtual void on_connection_close(const std::string& error) = 0;
+  virtual void on_connection_failed(const std::string& error) = 0;
 
 private:
-  /**
-   * Display the resolved IP, just for information purpose.
-   */
-  void display_resolved_ip(struct addrinfo* rp) const;
-
 #ifdef BOTAN_FOUND
   /**
    * Botan stuff to manipulate a TLS session.