summaryrefslogtreecommitdiffhomepage
path: root/websocket.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'websocket.cpp')
-rw-r--r--websocket.cpp302
1 files changed, 302 insertions, 0 deletions
diff --git a/websocket.cpp b/websocket.cpp
index 37d4b59..68ff194 100644
--- a/websocket.cpp
+++ b/websocket.cpp
@@ -1,5 +1,307 @@
+//
+// Websocket, implemented via CRTP for both plain and ssl websockets
+//
#include "websocket.h"
+namespace beast = boost::beast; // from <boost/beast.hpp>
+namespace http = beast::http; // from <boost/beast/http.hpp>
+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, implemented w/ CRTP for plain+ssl variants
+template<class Derived>
+class websocket_session
+{
+private:
+ Derived& derived()
+ {
+ return static_cast<Derived&>(*this);
+ }
+
+ boost::asio::io_context& ioc_;
+ boost::asio::ip::tcp::resolver resolver_;
+ 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_;
+ std::string subprotocol_;
+ std::string relative_target_;
+
+public:
+ explicit websocket_session(boost::asio::io_context& ioc, std::string&& websocket_address):
+ ioc_(ioc),
+ resolver_(boost::asio::make_strand(ioc_)),
+ ws_app_(boost::asio::make_strand(ioc_)),
+ host_{},
+ port_{},
+ subprotocol_{},
+ relative_target_{}
+ {
+ // Parse websocket address host:port :
+
+ auto colon_pos{websocket_address.find_last_of(':')};
+
+ if (colon_pos == std::string::npos) {
+ std::cerr << "Warning: Bad websocket address (colon missing): " << websocket_address << std::endl;
+ return;
+ }
+
+ auto slash_pos{websocket_address.find('/')};
+ if (slash_pos == std::string::npos) {
+ std::cerr << "Warning: Bad websocket address (slash missing): " << websocket_address << std::endl;
+ return;
+ }
+ if (slash_pos <= colon_pos) {
+ std::cerr << "Warning: Bad websocket address: " << websocket_address << std::endl;
+ return;
+ }
+
+ host_ = websocket_address.substr(0, colon_pos);
+ port_ = websocket_address.substr(colon_pos + 1, slash_pos - (colon_pos + 1));
+ relative_target_ = websocket_address.substr(slash_pos);
+ }
+
+ //
+ // The initial setup path
+ //
+
+ // Start the asynchronous accept operation
+ void do_accept_in(request_type req)
+ {
+ // Set suggested timeout settings for the websocket
+ derived().ws_in().set_option(
+ websocket::stream_base::timeout::suggested(
+ beast::role_type::server));
+
+ // Set a decorator to change the Server of the handshake
+ derived().ws_in().set_option(websocket::stream_base::decorator(
+ [](websocket::response_type& res)
+ {
+ res.set(http::field::server,
+ std::string{"Reichwein.IT Webserver"});
+ }));
+
+ // Forward subprotocol from request to target websocket
+ subprotocol_ = std::string{req[http::field::sec_websocket_protocol]};
+
+ // Accept the websocket handshake
+ derived().ws_in().async_accept(
+ req,
+ beast::bind_front_handler(
+ &websocket_session::on_accept_in,
+ derived().shared_from_this()));
+ }
+
+private:
+ 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, derived().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, derived().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_.set_option(boost::beast::websocket::stream_base::decorator(
+ [this](boost::beast::websocket::request_type& req)
+ {
+ req.set(boost::beast::http::field::sec_websocket_protocol, subprotocol_);
+ }));
+
+ ws_app_.async_handshake(host_, relative_target_,
+ beast::bind_front_handler(&websocket_session::on_handshake_app, derived().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
+ derived().ws_in().async_read(
+ buffer_in_,
+ beast::bind_front_handler(
+ &websocket_session::on_read_in,
+ derived().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(derived().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,
+ derived().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,
+ derived().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()
+ {
+ derived().ws_in().async_write(buffer_out_.data(),
+ beast::bind_front_handler(
+ &websocket_session::on_write_out,
+ derived().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
+
+class plain_websocket_session:
+ public websocket_session<plain_websocket_session>,
+ public std::enable_shared_from_this<plain_websocket_session>
+{
+ boost::beast::websocket::stream<beast::tcp_stream> ws_in_;
+
+public:
+
+ explicit plain_websocket_session(boost::asio::io_context& ioc, beast::tcp_stream&& stream, std::string&& websocket_address):
+ websocket_session(ioc, std::move(websocket_address)),
+ ws_in_(std::move(stream))
+ {
+ }
+
+ boost::beast::websocket::stream<beast::tcp_stream>& ws_in()
+ {
+ return ws_in_;
+ }
+}; // class
+
+class ssl_websocket_session:
+ public websocket_session<ssl_websocket_session>,
+ public std::enable_shared_from_this<ssl_websocket_session>
+{
+ boost::beast::websocket::stream<beast::ssl_stream<beast::tcp_stream>> ws_in_;
+
+public:
+
+ explicit ssl_websocket_session(boost::asio::io_context& ioc, beast::ssl_stream<beast::tcp_stream>&& stream, std::string&& websocket_address):
+ websocket_session(ioc, std::move(websocket_address)),
+ ws_in_(std::move(stream))
+ {
+ }
+
+ boost::beast::websocket::stream<beast::ssl_stream<beast::tcp_stream>>& ws_in()
+ {
+ return ws_in_;
+ }
+}; // class
void make_websocket_session(boost::asio::io_context& ioc, beast::tcp_stream&& stream, std::string websocket_address, request_type&& req)
{