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- //
- // Copyright (c) 2016-2019 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/vinniefalco/CppCon2018
- //
- #include "http_session.hpp"
- #include "websocket_session.hpp"
- #include <boost/config.hpp>
- #include <iostream>
- #define BOOST_NO_CXX14_GENERIC_LAMBDAS
- //------------------------------------------------------------------------------
- // Return a reasonable mime type based on the extension of a file.
- beast::string_view
- mime_type(beast::string_view path)
- {
- using beast::iequals;
- auto const ext = [&path]
- {
- auto const pos = path.rfind(".");
- if(pos == beast::string_view::npos)
- return 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(
- beast::string_view base,
- beast::string_view path)
- {
- if(base.empty())
- return std::string(path);
- std::string result(base);
- #ifdef 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(
- 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](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() = std::string(why);
- res.prepare_payload();
- return res;
- };
- // Returns a not found response
- auto const not_found =
- [&req](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 '" + std::string(target) + "' was not found.";
- res.prepare_payload();
- return res;
- };
- // Returns a server error response
- auto const server_error =
- [&req](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: '" + std::string(what) + "'";
- 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("..") != 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
- beast::error_code ec;
- http::file_body::value_type body;
- body.open(path.c_str(), 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));
- }
- //------------------------------------------------------------------------------
- struct http_session::send_lambda
- {
- http_session& self_;
- explicit
- send_lambda(http_session& self)
- : self_(self)
- {
- }
- template<bool isRequest, class Body, class Fields>
- void
- operator()(http::message<isRequest, Body, Fields>&& msg) const
- {
- // The lifetime of the message has to extend
- // for the duration of the async operation so
- // we use a shared_ptr to manage it.
- auto sp = boost::make_shared<
- http::message<isRequest, Body, Fields>>(std::move(msg));
- // Write the response
- auto self = self_.shared_from_this();
- http::async_write(
- self_.stream_,
- *sp,
- [self, sp](beast::error_code ec, std::size_t bytes)
- {
- self->on_write(ec, bytes, sp->need_eof());
- });
- }
- };
- //------------------------------------------------------------------------------
- http_session::
- http_session(
- tcp::socket&& socket,
- boost::shared_ptr<shared_state> const& state)
- : stream_(std::move(socket))
- , state_(state)
- {
- }
- void
- http_session::
- run()
- {
- do_read();
- }
- // Report a failure
- void
- http_session::
- fail(beast::error_code ec, char const* what)
- {
- // Don't report on canceled operations
- if(ec == net::error::operation_aborted)
- return;
- std::cerr << what << ": " << ec.message() << "\n";
- }
- void
- http_session::
- do_read()
- {
- // Construct a new parser for each message
- parser_.emplace();
- // Apply a reasonable limit to the allowed size
- // of the body in bytes to prevent abuse.
- parser_->body_limit(10000);
- // Set the timeout.
- stream_.expires_after(std::chrono::seconds(30));
- // Read a request
- http::async_read(
- stream_,
- buffer_,
- parser_->get(),
- beast::bind_front_handler(
- &http_session::on_read,
- shared_from_this()));
- }
- void
- http_session::
- on_read(beast::error_code ec, std::size_t)
- {
- // This means they closed the connection
- if(ec == http::error::end_of_stream)
- {
- stream_.socket().shutdown(tcp::socket::shutdown_send, ec);
- return;
- }
- // Handle the error, if any
- if(ec)
- return fail(ec, "read");
- // See if it is a WebSocket Upgrade
- if(websocket::is_upgrade(parser_->get()))
- {
- // Create a websocket session, transferring ownership
- // of both the socket and the HTTP request.
- boost::make_shared<websocket_session>(
- stream_.release_socket(),
- state_)->run(parser_->release());
- return;
- }
- // Send the response
- #ifndef BOOST_NO_CXX14_GENERIC_LAMBDAS
- //
- // The following code requires generic
- // lambdas, available in C++14 and later.
- //
- handle_request(
- state_->doc_root(),
- std::move(req_),
- [this](auto&& response)
- {
- // The lifetime of the message has to extend
- // for the duration of the async operation so
- // we use a shared_ptr to manage it.
- using response_type = typename std::decay<decltype(response)>::type;
- auto sp = boost::make_shared<response_type>(std::forward<decltype(response)>(response));
- #if 0
- // NOTE This causes an ICE in gcc 7.3
- // Write the response
- http::async_write(this->stream_, *sp,
- [self = shared_from_this(), sp](
- beast::error_code ec, std::size_t bytes)
- {
- self->on_write(ec, bytes, sp->need_eof());
- });
- #else
- // Write the response
- auto self = shared_from_this();
- http::async_write(stream_, *sp,
- [self, sp](
- beast::error_code ec, std::size_t bytes)
- {
- self->on_write(ec, bytes, sp->need_eof());
- });
- #endif
- });
- #else
- //
- // This code uses the function object type send_lambda in
- // place of a generic lambda which is not available in C++11
- //
- handle_request(
- state_->doc_root(),
- parser_->release(),
- send_lambda(*this));
- #endif
- }
- void
- http_session::
- on_write(beast::error_code ec, std::size_t, bool close)
- {
- // Handle the error, if any
- if(ec)
- return fail(ec, "write");
- if(close)
- {
- // This means we should close the connection, usually because
- // the response indicated the "Connection: close" semantic.
- stream_.socket().shutdown(tcp::socket::shutdown_send, ec);
- return;
- }
- // Read another request
- do_read();
- }
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