Renamed asio web socket impl.

1 files changed, 683 insertions, 0 deletions

diff --git a/zenhttp/websocketasio.cpp b/zenhttp/websocketasio.cpp
new file mode 100644
index 000000000..bb3999780
--- /dev/null
+++ b/zenhttp/websocketasio.cpp
@@ -0,0 +1,683 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#include <zenhttp/websocketserver.h>
+
+#include <zencore/base64.h>
+#include <zencore/iobuffer.h>
+#include <zencore/logging.h>
+#include <zencore/sha1.h>
+#include <zencore/string.h>
+
+#include <chrono>
+#include <compare>
+#include <optional>
+#include <shared_mutex>
+#include <span>
+#include <system_error>
+#include <thread>
+
+ZEN_THIRD_PARTY_INCLUDES_START
+#include <fmt/format.h>
+#include <http_parser.h>
+#include <asio.hpp>
+ZEN_THIRD_PARTY_INCLUDES_END
+
+namespace zen::asio_ws {
+
+using namespace std::literals;
+
+ZEN_DEFINE_LOG_CATEGORY_STATIC(WsLog, "websocket"sv);
+
+using Clock		= std::chrono::steady_clock;
+using TimePoint = Clock::time_point;
+
+///////////////////////////////////////////////////////////////////////////////
+namespace http_header {
+	static constexpr std::string_view SecWebSocketKey	   = "Sec-WebSocket-Key"sv;
+	static constexpr std::string_view SecWebSocketOrigin   = "Sec-WebSocket-Origin"sv;
+	static constexpr std::string_view SecWebSocketProtocol = "Sec-WebSocket-Protocol"sv;
+	static constexpr std::string_view SecWebSocketVersion  = "Sec-WebSocket-Version"sv;
+	static constexpr std::string_view SecWebSocketAccept   = "Sec-WebSocket-Accept"sv;
+	static constexpr std::string_view Upgrade			   = "Upgrade"sv;
+}  // namespace http_header
+
+///////////////////////////////////////////////////////////////////////////////
+struct HttpParser
+{
+	HttpParser()
+	{
+		http_parser_init(&Parser, HTTP_REQUEST);
+		Parser.data = this;
+	}
+
+	size_t Parse(asio::const_buffer Buffer)
+	{
+		return http_parser_execute(&Parser, &ParserSettings, reinterpret_cast<const char*>(Buffer.data()), Buffer.size());
+	}
+
+	void GetHeaders(std::unordered_map<std::string_view, std::string_view>& OutHeaders)
+	{
+		OutHeaders.reserve(HeaderEntries.size());
+
+		for (const auto& E : HeaderEntries)
+		{
+			auto Name  = std::string_view(HeaderStream.Data() + E.Name.Offset, E.Name.Size);
+			auto Value = std::string_view(HeaderStream.Data() + E.Value.Offset, E.Value.Size);
+
+			OutHeaders[Name] = Value;
+		}
+	}
+
+	std::string ValidateWebSocketHandshake(std::unordered_map<std::string_view, std::string_view>& Headers, std::string& OutReason)
+	{
+		static constexpr std::string_view WebSocketGuid = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"sv;
+
+		std::string AcceptHash;
+
+		if (Headers.contains(http_header::SecWebSocketKey) == false)
+		{
+			OutReason = "Missing header Sec-WebSocket-Key";
+			return AcceptHash;
+		}
+
+		if (Headers.contains(http_header::Upgrade) == false)
+		{
+			OutReason = "Missing header Upgrade";
+			return AcceptHash;
+		}
+
+		ExtendableStringBuilder<128> Sb;
+		Sb << Headers[http_header::SecWebSocketKey] << WebSocketGuid;
+
+		SHA1Stream HashStream;
+		HashStream.Append(Sb.Data(), Sb.Size());
+
+		SHA1 Hash = HashStream.GetHash();
+
+		AcceptHash.resize(Base64::GetEncodedDataSize(sizeof(SHA1::Hash)));
+		Base64::Encode(Hash.Hash, sizeof(SHA1::Hash), AcceptHash.data());
+
+		return AcceptHash;
+	}
+
+	static void Initialize()
+	{
+		ParserSettings = {.on_message_begin =
+							  [](http_parser* P) {
+								  HttpParser& Parser = *reinterpret_cast<HttpParser*>(P->data);
+
+								  Parser.Url		   = UrlEntry{};
+								  Parser.CurrentHeader = HeaderEntry{};
+								  Parser.IsUpgrade	   = false;
+								  Parser.IsComplete	   = false;
+
+								  Parser.HeaderStream.Clear();
+								  Parser.HeaderEntries.clear();
+
+								  return 0;
+							  },
+						  .on_url =
+							  [](http_parser* P, const char* Data, size_t Size) {
+								  HttpParser& Parser = *reinterpret_cast<HttpParser*>(P->data);
+
+								  Parser.Url.Offset = Parser.HeaderStream.Pos();
+								  Parser.Url.Size	= Size;
+
+								  Parser.HeaderStream.Append(Data, uint32_t(Size));
+
+								  return 0;
+							  },
+						  .on_header_field =
+							  [](http_parser* P, const char* Data, size_t Size) {
+								  HttpParser& Parser = *reinterpret_cast<HttpParser*>(P->data);
+
+								  if (Parser.CurrentHeader.Value.Size > 0)
+								  {
+									  Parser.HeaderEntries.push_back(Parser.CurrentHeader);
+									  Parser.CurrentHeader = HeaderEntry{};
+								  }
+
+								  if (Parser.CurrentHeader.Name.Size == 0)
+								  {
+									  Parser.CurrentHeader.Name.Offset = Parser.HeaderStream.Pos();
+								  }
+
+								  Parser.CurrentHeader.Name.Size += Size;
+
+								  Parser.HeaderStream.Append(Data, Size);
+
+								  return 0;
+							  },
+						  .on_header_value =
+							  [](http_parser* P, const char* Data, size_t Size) {
+								  HttpParser& Parser = *reinterpret_cast<HttpParser*>(P->data);
+
+								  if (Parser.CurrentHeader.Value.Size == 0)
+								  {
+									  Parser.CurrentHeader.Value.Offset = Parser.HeaderStream.Pos();
+								  }
+
+								  Parser.CurrentHeader.Value.Size += Size;
+
+								  Parser.HeaderStream.Append(Data, Size);
+
+								  return 0;
+							  },
+						  .on_headers_complete =
+							  [](http_parser* P) {
+								  HttpParser& Parser = *reinterpret_cast<HttpParser*>(P->data);
+
+								  if (Parser.CurrentHeader.Value.Size > 0)
+								  {
+									  Parser.HeaderEntries.push_back(Parser.CurrentHeader);
+									  Parser.CurrentHeader = HeaderEntry{};
+								  }
+
+								  Parser.IsUpgrade = P->upgrade > 0;
+
+								  return 0;
+							  },
+						  .on_message_complete =
+							  [](http_parser* P) {
+								  HttpParser& Parser = *reinterpret_cast<HttpParser*>(P->data);
+								  Parser.IsComplete	 = true;
+								  Parser.IsUpgrade	 = P->upgrade > 0;
+								  return 0;
+							  }};
+	}
+
+	struct MemStreamEntry
+	{
+		size_t Offset{};
+		size_t Size{};
+	};
+
+	class MemStream
+	{
+	public:
+		MemStream(size_t BlockSize = 1024) : m_BlockSize(BlockSize) {}
+
+		void Append(const char* Data, size_t Size)
+		{
+			const size_t NewSize = m_Size + Size;
+
+			if (NewSize > m_Buf.size())
+			{
+				m_Buf.resize(m_Buf.size() + m_BlockSize);
+			}
+
+			memcpy(m_Buf.data() + m_Size, Data, Size);
+			m_Size += Size;
+		}
+
+		const char* Data() const { return m_Buf.data(); }
+		size_t		Pos() const { return m_Size; }
+		void		Clear() { m_Size = 0; }
+
+	private:
+		std::vector<char> m_Buf;
+		size_t			  m_Size{};
+		size_t			  m_BlockSize{};
+	};
+
+	using UrlEntry = MemStreamEntry;
+
+	struct HeaderEntry
+	{
+		MemStreamEntry Name;
+		MemStreamEntry Value;
+	};
+
+	static http_parser_settings ParserSettings;
+
+	http_parser				 Parser;
+	MemStream				 HeaderStream;
+	std::vector<HeaderEntry> HeaderEntries;
+	HeaderEntry				 CurrentHeader{};
+	UrlEntry				 Url{};
+	bool					 IsUpgrade	= false;
+	bool					 IsComplete = false;
+};
+
+http_parser_settings HttpParser::ParserSettings;
+
+///////////////////////////////////////////////////////////////////////////////
+enum class WsConnectionState : uint32_t
+{
+	kDisconnected,
+	kHandshaking,
+	kConnected
+};
+
+///////////////////////////////////////////////////////////////////////////////
+class WsConnectionId
+{
+	static std::atomic_uint32_t WsConnectionCounter;
+
+public:
+	WsConnectionId() = default;
+
+	uint32_t Value() const { return m_Value; }
+
+	auto operator<=>(const WsConnectionId& RHS) const = default;
+
+	static WsConnectionId New() { return WsConnectionId(WsConnectionCounter.fetch_add(1)); }
+
+private:
+	WsConnectionId(uint32_t Value) : m_Value(Value) {}
+
+	uint32_t m_Value{};
+};
+
+std::atomic_uint32_t WsConnectionId::WsConnectionCounter{1};
+
+class WsServer;
+
+///////////////////////////////////////////////////////////////////////////////
+class WsConnection : public std::enable_shared_from_this<WsConnection>
+{
+public:
+	WsConnection(WsServer& Server, WsConnectionId Id, std::unique_ptr<asio::ip::tcp::socket> Socket)
+	: m_Server(Server)
+	, m_Id(Id)
+	, m_Socket(std::move(Socket))
+	, m_StartTime(Clock::now())
+	, m_Status()
+	{
+	}
+
+	~WsConnection();
+
+	WsConnectionId				  Id() const { return m_Id; }
+	asio::ip::tcp::socket&		  Socket() { return *m_Socket; }
+	TimePoint					  StartTime() const { return m_StartTime; }
+	std::shared_ptr<WsConnection> AsShared() { return shared_from_this(); }
+	asio::streambuf&			  ReadBuffer() { return m_ReadBuffer; }
+	HttpParser&					  ParserHttp() { return *m_HttpParser; }
+	WsConnectionState			  Close();
+	WsConnectionState			  State() const { return static_cast<WsConnectionState>(m_Status.load(std::memory_order_relaxed)); }
+
+	WsConnectionState SetState(WsConnectionState NewState) { return static_cast<WsConnectionState>(m_Status.exchange(uint32_t(NewState))); }
+
+	void InitializeHttpParser() { m_HttpParser = std::make_unique<HttpParser>(); }
+	void ReleaseHttpParser() { m_HttpParser.reset(); }
+
+private:
+	WsServer&							   m_Server;
+	WsConnectionId						   m_Id;
+	std::unique_ptr<asio::ip::tcp::socket> m_Socket;
+	std::unique_ptr<HttpParser>			   m_HttpParser;
+	TimePoint							   m_StartTime;
+	std::atomic_uint32_t				   m_Status;
+	asio::streambuf						   m_ReadBuffer;
+};
+
+WsConnectionState
+WsConnection::Close()
+{
+	using enum WsConnectionState;
+
+	const auto PrevState = SetState(kDisconnected);
+
+	if (PrevState != kDisconnected && m_Socket->is_open())
+	{
+		m_Socket->close();
+	}
+
+	return PrevState;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+class WsThreadPool
+{
+public:
+	WsThreadPool(asio::io_service& IoSvc) : m_IoSvc(IoSvc) {}
+	void Start(uint32_t ThreadCount);
+	void Stop();
+
+private:
+	asio::io_service&		 m_IoSvc;
+	std::vector<std::thread> m_Threads;
+};
+
+void
+WsThreadPool::Start(uint32_t ThreadCount)
+{
+	ZEN_ASSERT(m_Threads.empty());
+
+	ZEN_LOG_DEBUG(WsLog, "starting '{}' websocket I/O thread(s)", ThreadCount);
+
+	for (uint32_t Idx = 0; Idx < ThreadCount; Idx++)
+	{
+		m_Threads.emplace_back([this, ThreadId = Idx + 1] {
+			try
+			{
+				m_IoSvc.run();
+			}
+			catch (std::exception& Err)
+			{
+				ZEN_LOG_ERROR(WsLog, "process websocket I/O FAILED, reason '{}'", Err.what());
+			}
+
+			ZEN_DEBUG("websocket I/O thread '{}' exiting", ThreadId);
+		});
+	}
+}
+
+void
+WsThreadPool::Stop()
+{
+	for (std::thread& Thread : m_Threads)
+	{
+		if (Thread.joinable())
+		{
+			Thread.join();
+		}
+	}
+
+	m_Threads.clear();
+}
+
+///////////////////////////////////////////////////////////////////////////////
+class WsServer final : public WebSocketServer
+{
+public:
+	WsServer() = default;
+	virtual ~WsServer() { Shutdown(); }
+
+	virtual bool Run(const WebSocketServerOptions& Options) override;
+	virtual void Shutdown() override;
+
+private:
+	friend class WsConnection;
+
+	void AcceptConnection();
+	void CloseConnection(WsConnection& Connection, const std::error_code& Ec);
+	void RemoveConnection(WsConnection& Connection);
+	void ReadConnection(WsConnection& Connection);
+
+	struct IdHasher
+	{
+		size_t operator()(WsConnectionId Id) const { return size_t(Id.Value()); }
+	};
+
+	using ConnectionMap = std::unordered_map<WsConnectionId, std::shared_ptr<WsConnection>, IdHasher>;
+
+	asio::io_service						 m_IoSvc;
+	std::unique_ptr<asio::ip::tcp::acceptor> m_Acceptor;
+	std::unique_ptr<WsThreadPool>			 m_ThreadPool;
+	ConnectionMap							 m_Connections;
+	std::shared_mutex						 m_ConnMutex;
+	std::atomic_bool						 m_Running{};
+};
+
+WsConnection::~WsConnection()
+{
+	m_Server.RemoveConnection(*this);
+}
+
+bool
+WsServer::Run(const WebSocketServerOptions& Options)
+{
+	HttpParser::Initialize();
+
+	m_Acceptor = std::make_unique<asio::ip::tcp::acceptor>(m_IoSvc, asio::ip::tcp::v6());
+
+	m_Acceptor->set_option(asio::ip::v6_only(false));
+	m_Acceptor->set_option(asio::socket_base::reuse_address(true));
+	m_Acceptor->set_option(asio::ip::tcp::no_delay(true));
+	m_Acceptor->set_option(asio::socket_base::receive_buffer_size(128 * 1024));
+	m_Acceptor->set_option(asio::socket_base::send_buffer_size(256 * 1024));
+
+	asio::error_code Ec;
+	m_Acceptor->bind(asio::ip::tcp::endpoint(asio::ip::address_v6::any(), Options.Port), Ec);
+
+	if (Ec)
+	{
+		ZEN_LOG_ERROR(WsLog, "failed to bind websocket endpoint, error code '{}'", Ec.value());
+
+		return false;
+	}
+
+	m_Acceptor->listen();
+	m_Running = true;
+
+	ZEN_LOG_INFO(WsLog, "web socket server running on port '{}'", Options.Port);
+
+	AcceptConnection();
+
+	m_ThreadPool = std::make_unique<WsThreadPool>(m_IoSvc);
+	m_ThreadPool->Start(Options.ThreadCount);
+
+	return true;
+}
+
+void
+WsServer::Shutdown()
+{
+	if (m_Running)
+	{
+		ZEN_LOG_INFO(WsLog, "websocket server shutting down");
+
+		m_Running = false;
+
+		m_Acceptor->close();
+		m_Acceptor.reset();
+		m_IoSvc.stop();
+
+		m_ThreadPool->Stop();
+	}
+}
+
+void
+WsServer::AcceptConnection()
+{
+	auto				   Socket	 = std::make_unique<asio::ip::tcp::socket>(m_IoSvc);
+	asio::ip::tcp::socket& SocketRef = *Socket.get();
+
+	m_Acceptor->async_accept(SocketRef, [this, ConnectedSocket = std::move(Socket)](const asio::error_code& Ec) mutable {
+		if (Ec)
+		{
+			ZEN_LOG_WARN(WsLog, "accept connection FAILED, error code '{}'", Ec.value());
+		}
+		else
+		{
+			auto ConnId = WsConnectionId::New();
+
+			ZEN_LOG_DEBUG(WsLog, "accept connection OK, ID '{}'", ConnId.Value());
+
+			auto Connection = std::make_shared<WsConnection>(*this, ConnId, std::move(ConnectedSocket));
+
+			{
+				std::unique_lock _(m_ConnMutex);
+				m_Connections[ConnId] = Connection;
+			}
+
+			Connection->InitializeHttpParser();
+			Connection->SetState(WsConnectionState::kHandshaking);
+
+			ReadConnection(*Connection);
+		}
+
+		if (m_Running)
+		{
+			AcceptConnection();
+		}
+	});
+}
+
+void
+WsServer::CloseConnection(WsConnection& Connection, const std::error_code& Ec)
+{
+	if (const auto State = Connection.Close(); State != WsConnectionState::kDisconnected)
+	{
+		if (Ec)
+		{
+			ZEN_LOG_INFO(WsLog,
+						 "closing connection '{}' ERROR, reason '{}' error code '{}'",
+						 Connection.Id().Value(),
+						 Ec.message(),
+						 Ec.value());
+		}
+		else
+		{
+			ZEN_LOG_INFO(WsLog, "closing connection '{}'", Connection.Id().Value());
+		}
+	}
+}
+
+void
+WsServer::RemoveConnection(WsConnection& Connection)
+{
+	ZEN_LOG_INFO(WsLog, "removing connection '{}'", Connection.Id().Value());
+}
+
+void
+WsServer::ReadConnection(WsConnection& Connection)
+{
+	Connection.ReadBuffer().prepare(64 << 10);
+
+	asio::async_read(
+		Connection.Socket(),
+		Connection.ReadBuffer(),
+		asio::transfer_at_least(1),
+		[this, &Connection](const asio::error_code& ReadEc, std::size_t ByteCount) mutable {
+			if (ReadEc)
+			{
+				return CloseConnection(Connection, ReadEc);
+			}
+
+			ZEN_LOG_DEBUG(WsLog, "reading {}B from connection '{}'", ByteCount, Connection.Id().Value());
+
+			using enum WsConnectionState;
+
+			switch (Connection.State())
+			{
+				case kHandshaking:
+					{
+						HttpParser&	 Parser	  = Connection.ParserHttp();
+						const size_t Consumed = Parser.Parse(Connection.ReadBuffer().data());
+						Connection.ReadBuffer().consume(Consumed);
+
+						if (Parser.IsComplete == false)
+						{
+							return ReadConnection(Connection);
+						}
+
+						if (Parser.IsUpgrade == false)
+						{
+							ZEN_LOG_DEBUG(WsLog,
+										  "handshake with connection '{}' FAILED, reason 'not an upgrade request'",
+										  Connection.Id().Value());
+
+							constexpr auto UpgradeRequiredResponse = "HTTP/1.1 426 Upgrade Required\n\r\n\r"sv;
+
+							return async_write(Connection.Socket(),
+											   asio::buffer(UpgradeRequiredResponse),
+											   [this, &Connection](const asio::error_code& WriteEc, std::size_t) {
+												   if (WriteEc)
+												   {
+													   CloseConnection(Connection, WriteEc);
+												   }
+												   else
+												   {
+													   Connection.InitializeHttpParser();
+													   Connection.SetState(WsConnectionState::kHandshaking);
+
+													   ReadConnection(Connection);
+												   }
+											   });
+						}
+
+						std::unordered_map<std::string_view, std::string_view> Headers;
+						Parser.GetHeaders(Headers);
+
+						std::string Reason;
+						std::string AcceptHash = Parser.ValidateWebSocketHandshake(Headers, Reason);
+
+						if (AcceptHash.empty())
+						{
+							ZEN_LOG_DEBUG(WsLog, "handshake with connection '{}' FAILED, reason '{}'", Connection.Id().Value(), Reason);
+
+							constexpr auto UpgradeRequiredResponse = "HTTP/1.1 400 Bad Request\n\r\n\r"sv;
+
+							return async_write(Connection.Socket(),
+											   asio::buffer(UpgradeRequiredResponse),
+											   [this, &Connection](const asio::error_code& WriteEc, std::size_t) {
+												   if (WriteEc)
+												   {
+													   CloseConnection(Connection, WriteEc);
+												   }
+												   else
+												   {
+													   Connection.InitializeHttpParser();
+													   Connection.SetState(WsConnectionState::kHandshaking);
+
+													   ReadConnection(Connection);
+												   }
+											   });
+						}
+
+						ExtendableStringBuilder<128> Sb;
+
+						Sb << "HTTP/1.1 101 Switching Protocols\r\n"sv;
+						Sb << "Upgrade: websocket\r\n"sv;
+						Sb << "Connection: Upgrade\r\n"sv;
+
+						// TODO: Verify protocol
+						if (Headers.contains(http_header::SecWebSocketProtocol))
+						{
+							Sb << http_header::SecWebSocketProtocol << ": " << Headers[http_header::SecWebSocketProtocol] << "\r\n";
+						}
+
+						Sb << http_header::SecWebSocketAccept << ": " << AcceptHash << "\r\n";
+						Sb << "\r\n"sv;
+
+						std::string		   Response = Sb.ToString();
+						asio::const_buffer Buffer	= asio::buffer(Response);
+
+						ZEN_LOG_DEBUG(WsLog, "accepting handshake from connection '{}'", Connection.Id().Value());
+
+						async_write(Connection.Socket(),
+									Buffer,
+									[this, &Connection, _ = std::move(Response)](const asio::error_code& WriteEc, std::size_t) {
+										if (WriteEc)
+										{
+											CloseConnection(Connection, WriteEc);
+										}
+										else
+										{
+											ZEN_LOG_DEBUG(WsLog, "handshake with connection '{}' OK", Connection.Id().Value());
+
+											Connection.ReleaseHttpParser();
+											Connection.SetState(kConnected);
+
+											ReadConnection(Connection);
+										}
+									});
+					}
+					break;
+
+				case kConnected:
+					{
+						// TODO: Implement RPC API
+					}
+					break;
+
+				default:
+					break;
+			};
+		});
+}
+
+}  // namespace zen::asio_ws
+
+namespace zen {
+
+std::unique_ptr<WebSocketServer>
+WebSocketServer::Create()
+{
+	return std::make_unique<asio_ws::WsServer>();
+}
+
+}  // namespace zen