rpc: Make sure conn object is always cleaned up

Make sure conn object always gets cleaned up by using a
`boost::shared_ptr`.

This makes valgrind happy - before this commit, one connection object
always leaked at shutdown, as well as can avoid other leaks, when
for example an exception happens.

Also add an explicit Close() to the !ClientAllowed path to make it similar
to the normal path (I'm not sure whether it is needed, but it
can't hurt).

src/rpcserver.cpp

@@ -444,7 +444,7 @@ template <typename Protocol, typename SocketAcceptorService>
 static void RPCAcceptHandler(boost::shared_ptr< basic_socket_acceptor<Protocol, SocketAcceptorService> > acceptor,
                              ssl::context& context,
                              bool fUseSSL,
-                             AcceptedConnection* conn,
+                             boost::shared_ptr< AcceptedConnection > conn,
                              const boost::system::error_code& error);
 
 /**
@@ -456,7 +456,7 @@ static void RPCListen(boost::shared_ptr< basic_socket_acceptor<Protocol, SocketA
                    const bool fUseSSL)
 {
     // Accept connection
-    AcceptedConnectionImpl<Protocol>* conn = new AcceptedConnectionImpl<Protocol>(acceptor->get_io_service(), context, fUseSSL);
+    boost::shared_ptr< AcceptedConnectionImpl<Protocol> > conn(new AcceptedConnectionImpl<Protocol>(acceptor->get_io_service(), context, fUseSSL));
 
     acceptor->async_accept(
             conn->sslStream.lowest_layer(),
@@ -477,23 +477,20 @@ template <typename Protocol, typename SocketAcceptorService>
 static void RPCAcceptHandler(boost::shared_ptr< basic_socket_acceptor<Protocol, SocketAcceptorService> > acceptor,
                              ssl::context& context,
                              const bool fUseSSL,
-                             AcceptedConnection* conn,
+                             boost::shared_ptr< AcceptedConnection > conn,
                              const boost::system::error_code& error)
 {
     // Immediately start accepting new connections, except when we're cancelled or our socket is closed.
     if (error != asio::error::operation_aborted && acceptor->is_open())
         RPCListen(acceptor, context, fUseSSL);
 
-    AcceptedConnectionImpl<ip::tcp>* tcp_conn = dynamic_cast< AcceptedConnectionImpl<ip::tcp>* >(conn);
+    AcceptedConnectionImpl<ip::tcp>* tcp_conn = dynamic_cast< AcceptedConnectionImpl<ip::tcp>* >(conn.get());
 
-    // TODO: Actually handle errors
     if (error)
     {
-        delete conn;
         // TODO: Actually handle errors
         LogPrintf("%s: Error: %s\n", __func__, error.message());
     }
-
     // Restrict callers by IP.  It is important to
     // do this before starting client thread, to filter out
     // certain DoS and misbehaving clients.
@@ -502,12 +499,11 @@ static void RPCAcceptHandler(boost::shared_ptr< basic_socket_acceptor<Protocol,
         // Only send a 403 if we're not using SSL to prevent a DoS during the SSL handshake.
         if (!fUseSSL)
             conn->stream() << HTTPReply(HTTP_FORBIDDEN, "", false) << std::flush;
-        delete conn;
+        conn->close();
     }
     else {
-        ServiceConnection(conn);
+        ServiceConnection(conn.get());
         conn->close();
-        delete conn;
     }
 }