Websocket proxy

1 files changed, 204 insertions, 95 deletions

diff --git a/websocket.h b/websocket.h
index d8d0262..1611c45 100644
--- a/websocket.h
+++ b/websocket.h
@@ -9,6 +9,7 @@
 #include <boost/beast/websocket/ssl.hpp>
 #include <boost/beast/ssl/ssl_stream.hpp>
 #include <boost/asio/buffers_iterator.hpp>
+#include <boost/asio/connect.hpp>
 #include <boost/asio/dispatch.hpp>
 #include <boost/asio/ssl/context.hpp>
 #include <boost/beast/ssl.hpp>
@@ -33,109 +34,217 @@ namespace net = boost::asio;            // from <boost/asio.hpp>
 namespace ssl = boost::asio::ssl;       // from <boost/asio/ssl.hpp>
 namespace websocket = beast::websocket;
 using tcp = boost::asio::ip::tcp;       // from <boost/asio/ip/tcp.hpp>
+using namespace std::placeholders;
 
+// Server session, asynchronous, proxying
 class websocket_session: public std::enable_shared_from_this<websocket_session>
 {
- websocket::stream<beast::ssl_stream<beast::tcp_stream>> ws_;
- beast::flat_buffer buffer_;
+ boost::asio::io_context& ioc_;
+ boost::asio::ip::tcp::resolver resolver_;
+ boost::beast::websocket::stream<beast::ssl_stream<beast::tcp_stream>> ws_in_;
+ boost::beast::flat_buffer buffer_in_;
+ boost::beast::websocket::stream<beast::tcp_stream> ws_app_;
+ boost::beast::flat_buffer buffer_out_;
+ std::string host_;
+ std::string port_;
 
 public:
- explicit websocket_session(beast::ssl_stream<beast::tcp_stream>&& stream) :
-  ws_(std::move(stream))
+ explicit websocket_session(boost::asio::io_context& ioc, beast::ssl_stream<beast::tcp_stream>&& stream):
+  ioc_(ioc),
+  resolver_(boost::asio::make_strand(ioc_)),
+  ws_in_(std::move(stream)),
+  ws_app_(boost::asio::make_strand(ioc_)),
+  host_{"::1"},
+  port_{"9876"}
  {
  }
 
-    // Start the asynchronous accept operation
-    template<class Body, class Allocator>
-    void
-    do_accept(http::request<Body, http::basic_fields<Allocator>> req)
-    {
-        // Set suggested timeout settings for the websocket
-        ws_.set_option(
-            websocket::stream_base::timeout::suggested(
-                beast::role_type::server));
-
-        // Set a decorator to change the Server of the handshake
-        ws_.set_option(websocket::stream_base::decorator(
-            [](websocket::response_type& res)
-            {
-                res.set(http::field::server,
-                    std::string{"Reichwein.IT Webserver"});
-            }));
-
-        // Accept the websocket handshake
-        ws_.async_accept(
-            req,
-            beast::bind_front_handler(
-                &websocket_session::on_accept,
-                shared_from_this()));
-    }
+ //
+ // The initial setup path
+ //
+ 
+ // Start the asynchronous accept operation
+ template<class Body, class Allocator>
+ void do_accept_in(http::request<Body, http::basic_fields<Allocator>> req)
+ {
+  // Set suggested timeout settings for the websocket
+  ws_in_.set_option(
+      websocket::stream_base::timeout::suggested(
+          beast::role_type::server));
+
+  // Set a decorator to change the Server of the handshake
+  ws_in_.set_option(websocket::stream_base::decorator(
+      [](websocket::response_type& res)
+      {
+          res.set(http::field::server,
+              std::string{"Reichwein.IT Webserver"});
+      }));
+
+  // Accept the websocket handshake
+  ws_in_.async_accept(
+      req,
+      beast::bind_front_handler(
+          &websocket_session::on_accept_in,
+          shared_from_this()));
+ }
 
 private:
-    void
-    on_accept(beast::error_code ec)
-    {
-        if(ec)
-            return fail(ec, "accept");
-
-        // Read a message
-        do_read();
-    }
-
-    void
-    do_read()
-    {
-        // Read a message into our buffer
-        ws_.async_read(
-            buffer_,
-            beast::bind_front_handler(
-                &websocket_session::on_read,
-                shared_from_this()));
-    }
-
-    void
-    on_read(
-        beast::error_code ec,
-        std::size_t bytes_transferred)
-    {
-        boost::ignore_unused(bytes_transferred);
-
-        // This indicates that the websocket_session was closed
-        if(ec == websocket::error::closed)
-            return;
-
-        if(ec)
-            fail(ec, "read");
-
-        // Echo the message
-        ws_.text(ws_.got_text());
-        std::string data(boost::asio::buffers_begin(buffer_.data()), boost::asio::buffers_end(buffer_.data()));
-        static int count{};
-        data += ": " + std::to_string(count++);
-        buffer_.consume(buffer_.size());
-        boost::beast::ostream(buffer_) << data;
-        ws_.async_write(
-            buffer_.data(),
-            beast::bind_front_handler(
-                &websocket_session::on_write,
-                shared_from_this()));
-    }
-
-    void
-    on_write(
-        beast::error_code ec,
-        std::size_t bytes_transferred)
-    {
-        boost::ignore_unused(bytes_transferred);
-
-        if(ec)
-            return fail(ec, "write");
-
-        // Clear the buffer
-        buffer_.consume(buffer_.size());
-
-        // Do another read
-        do_read();
-    }
-};
+ void on_accept_in(beast::error_code ec)
+ {
+  if (ec)
+   return fail(ec, "accept in");
+
+  resolver_.async_resolve(host_, port_,
+                          beast::bind_front_handler(&websocket_session::on_resolve_app, shared_from_this()));
+ }
+ 
+ void on_resolve_app(beast::error_code ec, tcp::resolver::results_type results)
+ {
+  if (ec)
+   return fail(ec, "resolve app");
+
+  beast::get_lowest_layer(ws_app_).async_connect(results,
+                          beast::bind_front_handler(&websocket_session::on_connect_app, shared_from_this()));
+ }
+
+ void on_connect_app(beast::error_code ec, tcp::resolver::results_type::endpoint_type endpoint)
+ {
+  if (ec)
+   return fail(ec, "connect app");
+
+  beast::get_lowest_layer(ws_app_).expires_never();
+
+  host_ += ':' + std::to_string(endpoint.port());
+
+  // Set suggested timeout settings for the websocket
+  ws_app_.set_option(
+      websocket::stream_base::timeout::suggested(
+	  beast::role_type::client));
+
+  ws_app_.set_option(boost::beast::websocket::stream_base::decorator(
+   [](boost::beast::websocket::request_type& req)
+   {
+    req.set(boost::beast::http::field::user_agent, "Reichwein.IT Webserver Websocket client");
+   }));
+
+  ws_app_.async_handshake(host_, "/",
+                          beast::bind_front_handler(&websocket_session::on_handshake_app, shared_from_this()));
+ }
+
+ void on_handshake_app(beast::error_code ec)
+ {
+  if (ec)
+   return fail(ec, "handshake app");
+
+  // Start reading messages from both sides, asynchronously
+  do_read_in();
+  do_read_app();
+ }
+
+ //
+ // The input path (client,ws_in_ -> app,ws_app_) via
+ //
+ 
+ void
+ do_read_in()
+ {
+  // Read a message into our buffer
+  ws_in_.async_read(
+      buffer_in_,
+      beast::bind_front_handler(
+          &websocket_session::on_read_in,
+          shared_from_this()));
+ }
+
+ void
+ on_read_in(
+     beast::error_code ec,
+     std::size_t bytes_transferred)
+ {
+  boost::ignore_unused(bytes_transferred);
+
+  // This indicates that the websocket_session was closed
+  if (ec == websocket::error::closed)
+   return;
+
+  if (ec)
+   fail(ec, "read in");
+
+  ws_app_.text(ws_in_.got_text());
+  
+  do_write_app();
+ }
+ 
+ void do_write_app()
+ {
+  ws_app_.async_write(buffer_in_.data(),
+      beast::bind_front_handler(
+          &websocket_session::on_write_app,
+          shared_from_this()));
+ }
+
+ void on_write_app(beast::error_code ec, std::size_t bytes_transferred)
+ {
+  boost::ignore_unused(bytes_transferred);
+
+  if (ec)
+   fail(ec, "write app");
+
+  buffer_in_.consume(buffer_in_.size());
+
+  // Do another read
+  do_read_in();
+ }
+
+ //
+ // The output path (app,ws_app_ -> client,ws_in_)
+ //
+ 
+ void do_read_app()
+ {
+  // Read a message into our buffer
+  ws_app_.async_read(
+      buffer_out_,
+      beast::bind_front_handler(
+          &websocket_session::on_read_app,
+          shared_from_this()));
+ }
+
+ void on_read_app(beast::error_code ec, std::size_t bytes_transferred)
+ {
+  boost::ignore_unused(bytes_transferred);
+
+  if (ec == websocket::error::closed)
+   return;
+
+  if (ec)
+   fail(ec, "read app");
+
+  do_write_out();
+ }
+
+ void do_write_out()
+ {
+  ws_in_.async_write(buffer_out_.data(),
+      beast::bind_front_handler(
+          &websocket_session::on_write_out,
+          shared_from_this()));
+ }
+
+ void on_write_out(
+     beast::error_code ec,
+     std::size_t bytes_transferred)
+ {
+  boost::ignore_unused(bytes_transferred);
+
+  if(ec)
+   return fail(ec, "write out");
+
+  // Clear the buffer
+  buffer_out_.consume(buffer_out_.size());
+
+  // Do another read
+  do_read_app();
+ }
 
+}; // class