libs/beast/example/advanced/server-flex/advanced_server_flex.cpp
//
// Copyright (c) 2016-2017 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// Official repository: https://github.com/boostorg/beast
//
//------------------------------------------------------------------------------
//
// Example: Advanced server, flex (plain + SSL)
//
//------------------------------------------------------------------------------
#include "example/common/detect_ssl.hpp"
#include "example/common/server_certificate.hpp"
#include "example/common/ssl_stream.hpp"
#include <boost/beast/core.hpp>
#include <boost/beast/http.hpp>
#include <boost/beast/websocket.hpp>
#include <boost/beast/version.hpp>
#include <boost/asio/bind_executor.hpp>
#include <boost/asio/ip/tcp.hpp>
#include <boost/asio/signal_set.hpp>
#include <boost/asio/ssl/stream.hpp>
#include <boost/asio/strand.hpp>
#include <boost/asio/steady_timer.hpp>
#include <boost/make_unique.hpp>
#include <boost/config.hpp>
#include <algorithm>
#include <cstdlib>
#include <functional>
#include <iostream>
#include <memory>
#include <string>
#include <thread>
#include <vector>
using tcp = boost::asio::ip::tcp; // from <boost/asio/ip/tcp.hpp>
namespace ssl = boost::asio::ssl; // from <boost/asio/ssl.hpp>
namespace http = boost::beast::http; // from <boost/beast/http.hpp>
namespace websocket = boost::beast::websocket; // from <boost/beast/websocket.hpp>
// Return a reasonable mime type based on the extension of a file.
boost::beast::string_view
mime_type(boost::beast::string_view path)
{
using boost::beast::iequals;
auto const ext = [&path]
{
auto const pos = path.rfind(".");
if(pos == boost::beast::string_view::npos)
return boost::beast::string_view{};
return path.substr(pos);
}();
if(iequals(ext, ".htm")) return "text/html";
if(iequals(ext, ".html")) return "text/html";
if(iequals(ext, ".php")) return "text/html";
if(iequals(ext, ".css")) return "text/css";
if(iequals(ext, ".txt")) return "text/plain";
if(iequals(ext, ".js")) return "application/javascript";
if(iequals(ext, ".json")) return "application/json";
if(iequals(ext, ".xml")) return "application/xml";
if(iequals(ext, ".swf")) return "application/x-shockwave-flash";
if(iequals(ext, ".flv")) return "video/x-flv";
if(iequals(ext, ".png")) return "image/png";
if(iequals(ext, ".jpe")) return "image/jpeg";
if(iequals(ext, ".jpeg")) return "image/jpeg";
if(iequals(ext, ".jpg")) return "image/jpeg";
if(iequals(ext, ".gif")) return "image/gif";
if(iequals(ext, ".bmp")) return "image/bmp";
if(iequals(ext, ".ico")) return "image/vnd.microsoft.icon";
if(iequals(ext, ".tiff")) return "image/tiff";
if(iequals(ext, ".tif")) return "image/tiff";
if(iequals(ext, ".svg")) return "image/svg+xml";
if(iequals(ext, ".svgz")) return "image/svg+xml";
return "application/text";
}
// Append an HTTP rel-path to a local filesystem path.
// The returned path is normalized for the platform.
std::string
path_cat(
boost::beast::string_view base,
boost::beast::string_view path)
{
if(base.empty())
return path.to_string();
std::string result = base.to_string();
#if BOOST_MSVC
char constexpr path_separator = '\\';
if(result.back() == path_separator)
result.resize(result.size() - 1);
result.append(path.data(), path.size());
for(auto& c : result)
if(c == '/')
c = path_separator;
#else
char constexpr path_separator = '/';
if(result.back() == path_separator)
result.resize(result.size() - 1);
result.append(path.data(), path.size());
#endif
return result;
}
// This function produces an HTTP response for the given
// request. The type of the response object depends on the
// contents of the request, so the interface requires the
// caller to pass a generic lambda for receiving the response.
template<
class Body, class Allocator,
class Send>
void
handle_request(
boost::beast::string_view doc_root,
http::request<Body, http::basic_fields<Allocator>>&& req,
Send&& send)
{
// Returns a bad request response
auto const bad_request =
[&req](boost::beast::string_view why)
{
http::response<http::string_body> res{http::status::bad_request, req.version()};
res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
res.set(http::field::content_type, "text/html");
res.keep_alive(req.keep_alive());
res.body() = why.to_string();
res.prepare_payload();
return res;
};
// Returns a not found response
auto const not_found =
[&req](boost::beast::string_view target)
{
http::response<http::string_body> res{http::status::not_found, req.version()};
res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
res.set(http::field::content_type, "text/html");
res.keep_alive(req.keep_alive());
res.body() = "The resource '" + target.to_string() + "' was not found.";
res.prepare_payload();
return res;
};
// Returns a server error response
auto const server_error =
[&req](boost::beast::string_view what)
{
http::response<http::string_body> res{http::status::internal_server_error, req.version()};
res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
res.set(http::field::content_type, "text/html");
res.keep_alive(req.keep_alive());
res.body() = "An error occurred: '" + what.to_string() + "'";
res.prepare_payload();
return res;
};
// Make sure we can handle the method
if( req.method() != http::verb::get &&
req.method() != http::verb::head)
return send(bad_request("Unknown HTTP-method"));
// Request path must be absolute and not contain "..".
if( req.target().empty() ||
req.target()[0] != '/' ||
req.target().find("..") != boost::beast::string_view::npos)
return send(bad_request("Illegal request-target"));
// Build the path to the requested file
std::string path = path_cat(doc_root, req.target());
if(req.target().back() == '/')
path.append("index.html");
// Attempt to open the file
boost::beast::error_code ec;
http::file_body::value_type body;
body.open(path.c_str(), boost::beast::file_mode::scan, ec);
// Handle the case where the file doesn't exist
if(ec == boost::system::errc::no_such_file_or_directory)
return send(not_found(req.target()));
// Handle an unknown error
if(ec)
return send(server_error(ec.message()));
// Cache the size since we need it after the move
auto const size = body.size();
// Respond to HEAD request
if(req.method() == http::verb::head)
{
http::response<http::empty_body> res{http::status::ok, req.version()};
res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
res.set(http::field::content_type, mime_type(path));
res.content_length(size);
res.keep_alive(req.keep_alive());
return send(std::move(res));
}
// Respond to GET request
http::response<http::file_body> res{
std::piecewise_construct,
std::make_tuple(std::move(body)),
std::make_tuple(http::status::ok, req.version())};
res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
res.set(http::field::content_type, mime_type(path));
res.content_length(size);
res.keep_alive(req.keep_alive());
return send(std::move(res));
}
//------------------------------------------------------------------------------
// Report a failure
void
fail(boost::system::error_code ec, char const* what)
{
std::cerr << what << ": " << ec.message() << "\n";
}
//------------------------------------------------------------------------------
// Echoes back all received WebSocket messages.
// This uses the Curiously Recurring Template Pattern so that
// the same code works with both SSL streams and regular sockets.
template<class Derived>
class websocket_session
{
// Access the derived class, this is part of
// the Curiously Recurring Template Pattern idiom.
Derived&
derived()
{
return static_cast<Derived&>(*this);
}
boost::beast::multi_buffer buffer_;
char ping_state_ = 0;
protected:
boost::asio::strand<
boost::asio::io_context::executor_type> strand_;
boost::asio::steady_timer timer_;
public:
// Construct the session
explicit
websocket_session(boost::asio::io_context& ioc)
: strand_(ioc.get_executor())
, timer_(ioc,
(std::chrono::steady_clock::time_point::max)())
{
}
// Start the asynchronous operation
template<class Body, class Allocator>
void
do_accept(http::request<Body, http::basic_fields<Allocator>> req)
{
// Set the control callback. This will be called
// on every incoming ping, pong, and close frame.
derived().ws().control_callback(
std::bind(
&websocket_session::on_control_callback,
this,
std::placeholders::_1,
std::placeholders::_2));
// Set the timer
timer_.expires_after(std::chrono::seconds(15));
// Accept the websocket handshake
derived().ws().async_accept(
req,
boost::asio::bind_executor(
strand_,
std::bind(
&websocket_session::on_accept,
derived().shared_from_this(),
std::placeholders::_1)));
}
void
on_accept(boost::system::error_code ec)
{
// Happens when the timer closes the socket
if(ec == boost::asio::error::operation_aborted)
return;
if(ec)
return fail(ec, "accept");
// Read a message
do_read();
}
// Called when the timer expires.
void
on_timer(boost::system::error_code ec)
{
if(ec && ec != boost::asio::error::operation_aborted)
return fail(ec, "timer");
// See if the timer really expired since the deadline may have moved.
if(timer_.expiry() <= std::chrono::steady_clock::now())
{
// If this is the first time the timer expired,
// send a ping to see if the other end is there.
if(derived().ws().is_open() && ping_state_ == 0)
{
// Note that we are sending a ping
ping_state_ = 1;
// Set the timer
timer_.expires_after(std::chrono::seconds(15));
// Now send the ping
derived().ws().async_ping({},
boost::asio::bind_executor(
strand_,
std::bind(
&websocket_session::on_ping,
derived().shared_from_this(),
std::placeholders::_1)));
}
else
{
// The timer expired while trying to handshake,
// or we sent a ping and it never completed or
// we never got back a control frame, so close.
derived().do_timeout();
return;
}
}
// Wait on the timer
timer_.async_wait(
boost::asio::bind_executor(
strand_,
std::bind(
&websocket_session::on_timer,
derived().shared_from_this(),
std::placeholders::_1)));
}
// Called to indicate activity from the remote peer
void
activity()
{
// Note that the connection is alive
ping_state_ = 0;
// Set the timer
timer_.expires_after(std::chrono::seconds(15));
}
// Called after a ping is sent.
void
on_ping(boost::system::error_code ec)
{
// Happens when the timer closes the socket
if(ec == boost::asio::error::operation_aborted)
return;
if(ec)
return fail(ec, "ping");
// Note that the ping was sent.
if(ping_state_ == 1)
{
ping_state_ = 2;
}
else
{
// ping_state_ could have been set to 0
// if an incoming control frame was received
// at exactly the same time we sent a ping.
BOOST_ASSERT(ping_state_ == 0);
}
}
void
on_control_callback(
websocket::frame_type kind,
boost::beast::string_view payload)
{
boost::ignore_unused(kind, payload);
// Note that there is activity
activity();
}
void
do_read()
{
// Read a message into our buffer
derived().ws().async_read(
buffer_,
boost::asio::bind_executor(
strand_,
std::bind(
&websocket_session::on_read,
derived().shared_from_this(),
std::placeholders::_1,
std::placeholders::_2)));
}
void
on_read(
boost::system::error_code ec,
std::size_t bytes_transferred)
{
boost::ignore_unused(bytes_transferred);
// Happens when the timer closes the socket
if(ec == boost::asio::error::operation_aborted)
return;
// This indicates that the websocket_session was closed
if(ec == websocket::error::closed)
return;
if(ec)
fail(ec, "read");
// Note that there is activity
activity();
// Echo the message
derived().ws().text(derived().ws().got_text());
derived().ws().async_write(
buffer_.data(),
boost::asio::bind_executor(
strand_,
std::bind(
&websocket_session::on_write,
derived().shared_from_this(),
std::placeholders::_1,
std::placeholders::_2)));
}
void
on_write(
boost::system::error_code ec,
std::size_t bytes_transferred)
{
boost::ignore_unused(bytes_transferred);
// Happens when the timer closes the socket
if(ec == boost::asio::error::operation_aborted)
return;
if(ec)
return fail(ec, "write");
// Clear the buffer
buffer_.consume(buffer_.size());
// Do another read
do_read();
}
};
// Handles a plain WebSocket connection
class plain_websocket_session
: public websocket_session<plain_websocket_session>
, public std::enable_shared_from_this<plain_websocket_session>
{
websocket::stream<tcp::socket> ws_;
bool close_ = false;
public:
// Create the session
explicit
plain_websocket_session(tcp::socket socket)
: websocket_session<plain_websocket_session>(
socket.get_executor().context())
, ws_(std::move(socket))
{
}
// Called by the base class
websocket::stream<tcp::socket>&
ws()
{
return ws_;
}
// Start the asynchronous operation
template<class Body, class Allocator>
void
run(http::request<Body, http::basic_fields<Allocator>> req)
{
// Run the timer. The timer is operated
// continuously, this simplifies the code.
on_timer({});
// Accept the WebSocket upgrade request
do_accept(std::move(req));
}
void
do_timeout()
{
// This is so the close can have a timeout
if(close_)
return;
close_ = true;
// Set the timer
timer_.expires_after(std::chrono::seconds(15));
// Close the WebSocket Connection
ws_.async_close(
websocket::close_code::normal,
boost::asio::bind_executor(
strand_,
std::bind(
&plain_websocket_session::on_close,
shared_from_this(),
std::placeholders::_1)));
}
void
on_close(boost::system::error_code ec)
{
// Happens when close times out
if(ec == boost::asio::error::operation_aborted)
return;
if(ec)
return fail(ec, "close");
// At this point the connection is gracefully closed
}
};
// Handles an SSL WebSocket connection
class ssl_websocket_session
: public websocket_session<ssl_websocket_session>
, public std::enable_shared_from_this<ssl_websocket_session>
{
websocket::stream<ssl_stream<tcp::socket>> ws_;
boost::asio::strand<
boost::asio::io_context::executor_type> strand_;
bool eof_ = false;
public:
// Create the http_session
explicit
ssl_websocket_session(ssl_stream<tcp::socket> stream)
: websocket_session<ssl_websocket_session>(
stream.get_executor().context())
, ws_(std::move(stream))
, strand_(ws_.get_executor())
{
}
// Called by the base class
websocket::stream<ssl_stream<tcp::socket>>&
ws()
{
return ws_;
}
// Start the asynchronous operation
template<class Body, class Allocator>
void
run(http::request<Body, http::basic_fields<Allocator>> req)
{
// Run the timer. The timer is operated
// continuously, this simplifies the code.
on_timer({});
// Accept the WebSocket upgrade request
do_accept(std::move(req));
}
void
do_eof()
{
eof_ = true;
// Set the timer
timer_.expires_after(std::chrono::seconds(15));
// Perform the SSL shutdown
ws_.next_layer().async_shutdown(
boost::asio::bind_executor(
strand_,
std::bind(
&ssl_websocket_session::on_shutdown,
shared_from_this(),
std::placeholders::_1)));
}
void
on_shutdown(boost::system::error_code ec)
{
// Happens when the shutdown times out
if(ec == boost::asio::error::operation_aborted)
return;
if(ec)
return fail(ec, "shutdown");
// At this point the connection is closed gracefully
}
void
do_timeout()
{
// If this is true it means we timed out performing the shutdown
if(eof_)
return;
// Start the timer again
timer_.expires_at(
(std::chrono::steady_clock::time_point::max)());
on_timer({});
do_eof();
}
};
template<class Body, class Allocator>
void
make_websocket_session(
tcp::socket socket,
http::request<Body, http::basic_fields<Allocator>> req)
{
std::make_shared<plain_websocket_session>(
std::move(socket))->run(std::move(req));
}
template<class Body, class Allocator>
void
make_websocket_session(
ssl_stream<tcp::socket> stream,
http::request<Body, http::basic_fields<Allocator>> req)
{
std::make_shared<ssl_websocket_session>(
std::move(stream))->run(std::move(req));
}
//------------------------------------------------------------------------------
// Handles an HTTP server connection.
// This uses the Curiously Recurring Template Pattern so that
// the same code works with both SSL streams and regular sockets.
template<class Derived>
class http_session
{
// Access the derived class, this is part of
// the Curiously Recurring Template Pattern idiom.
Derived&
derived()
{
return static_cast<Derived&>(*this);
}
// This queue is used for HTTP pipelining.
class queue
{
enum
{
// Maximum number of responses we will queue
limit = 8
};
// The type-erased, saved work item
struct work
{
virtual ~work() = default;
virtual void operator()() = 0;
};
http_session& self_;
std::vector<std::unique_ptr<work>> items_;
public:
explicit
queue(http_session& self)
: self_(self)
{
static_assert(limit > 0, "queue limit must be positive");
items_.reserve(limit);
}
// Returns `true` if we have reached the queue limit
bool
is_full() const
{
return items_.size() >= limit;
}
// Called when a message finishes sending
// Returns `true` if the caller should initiate a read
bool
on_write()
{
BOOST_ASSERT(! items_.empty());
auto const was_full = is_full();
items_.erase(items_.begin());
if(! items_.empty())
(*items_.front())();
return was_full;
}
// Called by the HTTP handler to send a response.
template<bool isRequest, class Body, class Fields>
void
operator()(http::message<isRequest, Body, Fields>&& msg)
{
// This holds a work item
struct work_impl : work
{
http_session& self_;
http::message<isRequest, Body, Fields> msg_;
work_impl(
http_session& self,
http::message<isRequest, Body, Fields>&& msg)
: self_(self)
, msg_(std::move(msg))
{
}
void
operator()()
{
http::async_write(
self_.derived().stream(),
msg_,
boost::asio::bind_executor(
self_.strand_,
std::bind(
&http_session::on_write,
self_.derived().shared_from_this(),
std::placeholders::_1,
msg_.need_eof())));
}
};
// Allocate and store the work
items_.push_back(
boost::make_unique<work_impl>(self_, std::move(msg)));
// If there was no previous work, start this one
if(items_.size() == 1)
(*items_.front())();
}
};
std::string const& doc_root_;
http::request<http::string_body> req_;
queue queue_;
protected:
boost::asio::steady_timer timer_;
boost::asio::strand<
boost::asio::io_context::executor_type> strand_;
boost::beast::flat_buffer buffer_;
public:
// Construct the session
http_session(
boost::asio::io_context& ioc,
boost::beast::flat_buffer buffer,
std::string const& doc_root)
: doc_root_(doc_root)
, queue_(*this)
, timer_(ioc,
(std::chrono::steady_clock::time_point::max)())
, strand_(ioc.get_executor())
, buffer_(std::move(buffer))
{
}
void
do_read()
{
// Set the timer
timer_.expires_after(std::chrono::seconds(15));
// Make the request empty before reading,
// otherwise the operation behavior is undefined.
req_ = {};
// Read a request
http::async_read(
derived().stream(),
buffer_,
req_,
boost::asio::bind_executor(
strand_,
std::bind(
&http_session::on_read,
derived().shared_from_this(),
std::placeholders::_1)));
}
// Called when the timer expires.
void
on_timer(boost::system::error_code ec)
{
if(ec && ec != boost::asio::error::operation_aborted)
return fail(ec, "timer");
// Verify that the timer really expired since the deadline may have moved.
if(timer_.expiry() <= std::chrono::steady_clock::now())
return derived().do_timeout();
// Wait on the timer
timer_.async_wait(
boost::asio::bind_executor(
strand_,
std::bind(
&http_session::on_timer,
derived().shared_from_this(),
std::placeholders::_1)));
}
void
on_read(boost::system::error_code ec)
{
// Happens when the timer closes the socket
if(ec == boost::asio::error::operation_aborted)
return;
// This means they closed the connection
if(ec == http::error::end_of_stream)
return derived().do_eof();
if(ec)
return fail(ec, "read");
// See if it is a WebSocket Upgrade
if(websocket::is_upgrade(req_))
{
// Transfer the stream to a new WebSocket session
return make_websocket_session(
derived().release_stream(),
std::move(req_));
}
// Send the response
handle_request(doc_root_, std::move(req_), queue_);
// If we aren't at the queue limit, try to pipeline another request
if(! queue_.is_full())
do_read();
}
void
on_write(boost::system::error_code ec, bool close)
{
// Happens when the timer closes the socket
if(ec == boost::asio::error::operation_aborted)
return;
if(ec)
return fail(ec, "write");
if(close)
{
// This means we should close the connection, usually because
// the response indicated the "Connection: close" semantic.
return derived().do_eof();
}
// Inform the queue that a write completed
if(queue_.on_write())
{
// Read another request
do_read();
}
}
};
// Handles a plain HTTP connection
class plain_http_session
: public http_session<plain_http_session>
, public std::enable_shared_from_this<plain_http_session>
{
tcp::socket socket_;
boost::asio::strand<
boost::asio::io_context::executor_type> strand_;
public:
// Create the http_session
plain_http_session(
tcp::socket socket,
boost::beast::flat_buffer buffer,
std::string const& doc_root)
: http_session<plain_http_session>(
socket.get_executor().context(),
std::move(buffer),
doc_root)
, socket_(std::move(socket))
, strand_(socket_.get_executor())
{
}
// Called by the base class
tcp::socket&
stream()
{
return socket_;
}
// Called by the base class
tcp::socket
release_stream()
{
return std::move(socket_);
}
// Start the asynchronous operation
void
run()
{
// Run the timer. The timer is operated
// continuously, this simplifies the code.
on_timer({});
do_read();
}
void
do_eof()
{
// Send a TCP shutdown
boost::system::error_code ec;
socket_.shutdown(tcp::socket::shutdown_send, ec);
// At this point the connection is closed gracefully
}
void
do_timeout()
{
// Closing the socket cancels all outstanding operations. They
// will complete with boost::asio::error::operation_aborted
boost::system::error_code ec;
socket_.shutdown(tcp::socket::shutdown_both, ec);
socket_.close(ec);
}
};
// Handles an SSL HTTP connection
class ssl_http_session
: public http_session<ssl_http_session>
, public std::enable_shared_from_this<ssl_http_session>
{
ssl_stream<tcp::socket> stream_;
boost::asio::strand<
boost::asio::io_context::executor_type> strand_;
bool eof_ = false;
public:
// Create the http_session
ssl_http_session(
tcp::socket socket,
ssl::context& ctx,
boost::beast::flat_buffer buffer,
std::string const& doc_root)
: http_session<ssl_http_session>(
socket.get_executor().context(),
std::move(buffer),
doc_root)
, stream_(std::move(socket), ctx)
, strand_(stream_.get_executor())
{
}
// Called by the base class
ssl_stream<tcp::socket>&
stream()
{
return stream_;
}
// Called by the base class
ssl_stream<tcp::socket>
release_stream()
{
return std::move(stream_);
}
// Start the asynchronous operation
void
run()
{
// Run the timer. The timer is operated
// continuously, this simplifies the code.
on_timer({});
// Set the timer
timer_.expires_after(std::chrono::seconds(15));
// Perform the SSL handshake
// Note, this is the buffered version of the handshake.
stream_.async_handshake(
ssl::stream_base::server,
buffer_.data(),
boost::asio::bind_executor(
strand_,
std::bind(
&ssl_http_session::on_handshake,
shared_from_this(),
std::placeholders::_1,
std::placeholders::_2)));
}
void
on_handshake(
boost::system::error_code ec,
std::size_t bytes_used)
{
// Happens when the handshake times out
if(ec == boost::asio::error::operation_aborted)
return;
if(ec)
return fail(ec, "handshake");
// Consume the portion of the buffer used by the handshake
buffer_.consume(bytes_used);
do_read();
}
void
do_eof()
{
eof_ = true;
// Set the timer
timer_.expires_after(std::chrono::seconds(15));
// Perform the SSL shutdown
stream_.async_shutdown(
boost::asio::bind_executor(
strand_,
std::bind(
&ssl_http_session::on_shutdown,
shared_from_this(),
std::placeholders::_1)));
}
void
on_shutdown(boost::system::error_code ec)
{
// Happens when the shutdown times out
if(ec == boost::asio::error::operation_aborted)
return;
if(ec)
return fail(ec, "shutdown");
// At this point the connection is closed gracefully
}
void
do_timeout()
{
// If this is true it means we timed out performing the shutdown
if(eof_)
return;
// Start the timer again
timer_.expires_at(
(std::chrono::steady_clock::time_point::max)());
on_timer({});
do_eof();
}
};
//------------------------------------------------------------------------------
// Detects SSL handshakes
class detect_session : public std::enable_shared_from_this<detect_session>
{
tcp::socket socket_;
ssl::context& ctx_;
boost::asio::strand<
boost::asio::io_context::executor_type> strand_;
std::string const& doc_root_;
boost::beast::flat_buffer buffer_;
public:
explicit
detect_session(
tcp::socket socket,
ssl::context& ctx,
std::string const& doc_root)
: socket_(std::move(socket))
, ctx_(ctx)
, strand_(socket_.get_executor())
, doc_root_(doc_root)
{
}
// Launch the detector
void
run()
{
async_detect_ssl(
socket_,
buffer_,
boost::asio::bind_executor(
strand_,
std::bind(
&detect_session::on_detect,
shared_from_this(),
std::placeholders::_1,
std::placeholders::_2)));
}
void
on_detect(boost::system::error_code ec, boost::tribool result)
{
if(ec)
return fail(ec, "detect");
if(result)
{
// Launch SSL session
std::make_shared<ssl_http_session>(
std::move(socket_),
ctx_,
std::move(buffer_),
doc_root_)->run();
return;
}
// Launch plain session
std::make_shared<plain_http_session>(
std::move(socket_),
std::move(buffer_),
doc_root_)->run();
}
};
// Accepts incoming connections and launches the sessions
class listener : public std::enable_shared_from_this<listener>
{
ssl::context& ctx_;
tcp::acceptor acceptor_;
tcp::socket socket_;
std::string const& doc_root_;
public:
listener(
boost::asio::io_context& ioc,
ssl::context& ctx,
tcp::endpoint endpoint,
std::string const& doc_root)
: ctx_(ctx)
, acceptor_(ioc)
, socket_(ioc)
, doc_root_(doc_root)
{
boost::system::error_code ec;
// Open the acceptor
acceptor_.open(endpoint.protocol(), ec);
if(ec)
{
fail(ec, "open");
return;
}
// Allow address reuse
acceptor_.set_option(boost::asio::socket_base::reuse_address(true));
if(ec)
{
fail(ec, "set_option");
return;
}
// Bind to the server address
acceptor_.bind(endpoint, ec);
if(ec)
{
fail(ec, "bind");
return;
}
// Start listening for connections
acceptor_.listen(
boost::asio::socket_base::max_listen_connections, ec);
if(ec)
{
fail(ec, "listen");
return;
}
}
// Start accepting incoming connections
void
run()
{
if(! acceptor_.is_open())
return;
do_accept();
}
void
do_accept()
{
acceptor_.async_accept(
socket_,
std::bind(
&listener::on_accept,
shared_from_this(),
std::placeholders::_1));
}
void
on_accept(boost::system::error_code ec)
{
if(ec)
{
fail(ec, "accept");
}
else
{
// Create the detector http_session and run it
std::make_shared<detect_session>(
std::move(socket_),
ctx_,
doc_root_)->run();
}
// Accept another connection
do_accept();
}
};
//------------------------------------------------------------------------------
int main(int argc, char* argv[])
{
// Check command line arguments.
if (argc != 5)
{
std::cerr <<
"Usage: advanced-server-flex <address> <port> <doc_root> <threads>\n" <<
"Example:\n" <<
" advanced-server-flex 0.0.0.0 8080 . 1\n";
return EXIT_FAILURE;
}
auto const address = boost::asio::ip::make_address(argv[1]);
auto const port = static_cast<unsigned short>(std::atoi(argv[2]));
std::string const doc_root = argv[3];
auto const threads = std::max<int>(1, std::atoi(argv[4]));
// The io_context is required for all I/O
boost::asio::io_context ioc{threads};
// The SSL context is required, and holds certificates
ssl::context ctx{ssl::context::sslv23};
// This holds the self-signed certificate used by the server
load_server_certificate(ctx);
// Create and launch a listening port
std::make_shared<listener>(
ioc,
ctx,
tcp::endpoint{address, port},
doc_root)->run();
// Capture SIGINT and SIGTERM to perform a clean shutdown
boost::asio::signal_set signals(ioc, SIGINT, SIGTERM);
signals.async_wait(
[&](boost::system::error_code const&, int)
{
// Stop the `io_context`. This will cause `run()`
// to return immediately, eventually destroying the
// `io_context` and all of the sockets in it.
ioc.stop();
});
// Run the I/O service on the requested number of threads
std::vector<std::thread> v;
v.reserve(threads - 1);
for(auto i = threads - 1; i > 0; --i)
v.emplace_back(
[&ioc]
{
ioc.run();
});
ioc.run();
// (If we get here, it means we got a SIGINT or SIGTERM)
// Block until all the threads exit
for(auto& t : v)
t.join();
return EXIT_SUCCESS;
}