Files
clio/src/server/HttpBase.h
2021-06-24 18:29:19 +00:00

351 lines
10 KiB
C++

//------------------------------------------------------------------------------
/*
This file is part of rippled: https://github.com/ripple/rippled
Copyright (c) 2021 Ripple Labs Inc.
Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL , DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================
#ifndef RIPPLE_REPORTING_HTTP_BASE_SESSION_H
#define RIPPLE_REPORTING_HTTP_BASE_SESSION_H
#include <boost/asio/dispatch.hpp>
#include <boost/asio/strand.hpp>
#include <boost/beast/core.hpp>
#include <boost/beast/http.hpp>
#include <boost/beast/ssl.hpp>
#include <boost/beast/version.hpp>
#include <boost/config.hpp>
#include <boost/json.hpp>
#include <algorithm>
#include <cstdlib>
#include <functional>
#include <iostream>
#include <memory>
#include <string>
#include <thread>
#include <server/DOSGuard.h>
#include <server/Handlers.h>
#include <vector>
namespace http = boost::beast::http;
namespace net = boost::asio;
namespace ssl = boost::asio::ssl;
using tcp = boost::asio::ip::tcp;
static std::string defaultResponse =
"<!DOCTYPE html><html><head><title>"
" Test page for reporting mode</title></head><body><h1>"
" Test</h1><p>This page shows xrpl reporting http(s) "
"connectivity is working.</p></body></html>";
inline void
httpFail(boost::beast::error_code ec, char const* what)
{
// ssl::error::stream_truncated, also known as an SSL "short read",
// indicates the peer closed the connection without performing the
// required closing handshake (for example, Google does this to
// improve performance). Generally this can be a security issue,
// but if your communication protocol is self-terminated (as
// it is with both HTTP and WebSocket) then you may simply
// ignore the lack of close_notify.
//
// https://github.com/boostorg/beast/issues/38
//
// https://security.stackexchange.com/questions/91435/how-to-handle-a-malicious-ssl-tls-shutdown
//
// When a short read would cut off the end of an HTTP message,
// Beast returns the error boost::beast::http::error::partial_message.
// Therefore, if we see a short read here, it has occurred
// after the message has been completed, so it is safe to ignore it.
if (ec == net::ssl::error::stream_truncated)
return;
std::cerr << what << ": " << ec.message() << "\n";
}
bool
validRequest(boost::json::object const& req)
{
if (!req.contains("method") || !req.at("method").is_string())
return false;
if (!req.contains("params"))
return true;
if (!req.at("params").is_array())
return false;
auto array = req.at("params").as_array();
if (array.size() != 1)
return false;
if (!array.at(0).is_object())
return false;
return true;
}
// 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::http::
request<Body, boost::beast::http::basic_fields<Allocator>>&& req,
Send&& send,
std::shared_ptr<BackendInterface> backend,
std::shared_ptr<ETLLoadBalancer> balancer,
DOSGuard& dosGuard)
{
auto const response = [&req](
http::status status,
std::string content_type,
std::string message) {
http::response<http::string_body> res{status, req.version()};
res.set(http::field::server, "xrpl-reporting-server-v0.0.0");
res.set(http::field::content_type, content_type);
res.keep_alive(req.keep_alive());
res.body() = std::string(message);
res.prepare_payload();
return res;
};
if (req.method() == http::verb::get && req.body() == "")
{
send(response(http::status::ok, "text/html", defaultResponse));
return;
}
if (req.method() != http::verb::post)
{
send(response(
http::status::bad_request, "text/html", "Expected a POST request"));
return;
}
try
{
BOOST_LOG_TRIVIAL(info) << "Received request: " << req.body();
boost::json::object request;
try
{
request = boost::json::parse(req.body()).as_object();
}
catch (std::runtime_error const& e)
{
send(response(
http::status::bad_request,
"text/html",
"Cannot parse json in body"));
return;
}
if (!validRequest(request))
{
send(response(
http::status::bad_request, "text/html", "Malformed request"));
return;
}
boost::json::object wsStyleRequest = request.contains("params")
? request.at("params").as_array().at(0).as_object()
: boost::json::object{};
wsStyleRequest["command"] = request["method"];
auto [builtResponse, cost] =
buildResponse(wsStyleRequest, backend, nullptr, balancer, nullptr);
send(response(
http::status::ok,
"application/json",
boost::json::serialize(builtResponse)));
return;
}
catch (std::exception const& e)
{
std::cout << e.what() << std::endl;
send(response(
http::status::internal_server_error,
"text/html",
"Internal server error occurred"));
return;
}
}
// From Boost Beast examples http_server_flex.cpp
template <class Derived>
class HttpBase
{
// Access the derived class, this is part of
// the Curiously Recurring Template Pattern idiom.
Derived&
derived()
{
return static_cast<Derived&>(*this);
}
struct send_lambda
{
HttpBase& self_;
explicit send_lambda(HttpBase& 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 = std::make_shared<http::message<isRequest, Body, Fields>>(
std::move(msg));
// Store a type-erased version of the shared
// pointer in the class to keep it alive.
self_.res_ = sp;
// Write the response
http::async_write(
self_.derived().stream(),
*sp,
boost::beast::bind_front_handler(
&HttpBase::on_write,
self_.derived().shared_from_this(),
sp->need_eof()));
}
};
http::request<http::string_body> req_;
std::shared_ptr<void> res_;
std::shared_ptr<BackendInterface> backend_;
std::shared_ptr<SubscriptionManager> subscriptions_;
std::shared_ptr<ETLLoadBalancer> balancer_;
DOSGuard& dosGuard_;
send_lambda lambda_;
protected:
boost::beast::flat_buffer buffer_;
public:
HttpBase(
std::shared_ptr<BackendInterface> backend,
std::shared_ptr<SubscriptionManager> subscriptions,
std::shared_ptr<ETLLoadBalancer> balancer,
DOSGuard& dosGuard,
boost::beast::flat_buffer buffer)
: backend_(backend)
, subscriptions_(subscriptions)
, balancer_(balancer)
, dosGuard_(dosGuard)
, lambda_(*this)
, buffer_(std::move(buffer))
{
}
void
do_read()
{
// Make the request empty before reading,
// otherwise the operation behavior is undefined.
req_ = {};
// Set the timeout.
boost::beast::get_lowest_layer(derived().stream())
.expires_after(std::chrono::seconds(30));
// Read a request
http::async_read(
derived().stream(),
buffer_,
req_,
boost::beast::bind_front_handler(
&HttpBase::on_read, derived().shared_from_this()));
}
void
on_read(boost::beast::error_code ec, std::size_t bytes_transferred)
{
boost::ignore_unused(bytes_transferred);
// This means they closed the connection
if (ec == http::error::end_of_stream)
return derived().do_close();
if (ec)
return httpFail(ec, "read");
auto ip = derived().ip();
if (boost::beast::websocket::is_upgrade(req_))
{
// Disable the timeout.
// The websocket::stream uses its own timeout settings.
boost::beast::get_lowest_layer(derived().stream()).expires_never();
return make_websocket_session(
derived().release_stream(),
std::move(req_),
std::move(buffer_),
backend_,
subscriptions_,
balancer_,
dosGuard_);
}
// Send the response
handle_request(
std::move(req_), lambda_, backend_, balancer_, dosGuard_);
}
void
on_write(
bool close,
boost::beast::error_code ec,
std::size_t bytes_transferred)
{
boost::ignore_unused(bytes_transferred);
if (ec)
return httpFail(ec, "write");
if (close)
{
// This means we should close the connection, usually because
// the response indicated the "Connection: close" semantic.
return derived().do_close();
}
// We're done with the response so delete it
res_ = nullptr;
// Read another request
do_read();
}
};
#endif // RIPPLE_REPORTING_HTTP_BASE_SESSION_H