Add UDP socket class

src/openrct2/network/UdpSocket.cpp

@@ -0,0 +1,322 @@
+/*****************************************************************************
+ * Copyright (c) 2014-2019 OpenRCT2 developers
+ *
+ * For a complete list of all authors, please refer to contributors.md
+ * Interested in contributing? Visit https://github.com/OpenRCT2/OpenRCT2
+ *
+ * OpenRCT2 is licensed under the GNU General Public License version 3.
+ *****************************************************************************/
+
+#ifndef DISABLE_NETWORK
+
+#    include <chrono>
+#    include <cmath>
+#    include <cstring>
+#    include <future>
+#    include <string>
+#    include <thread>
+
+// clang-format off
+// MSVC: include <math.h> here otherwise PI gets defined twice
+#include <cmath>
+
+#ifdef _WIN32
+    // winsock2 must be included before windows.h
+    #include <winsock2.h>
+    #include <ws2tcpip.h>
+
+    #define LAST_SOCKET_ERROR() WSAGetLastError()
+    #undef EWOULDBLOCK
+    #define EWOULDBLOCK WSAEWOULDBLOCK
+    #ifndef SHUT_RD
+        #define SHUT_RD SD_RECEIVE
+    #endif
+    #ifndef SHUT_RDWR
+        #define SHUT_RDWR SD_BOTH
+    #endif
+    #define FLAG_NO_PIPE 0
+#else
+    #include <cerrno>
+    #include <arpa/inet.h>
+    #include <netdb.h>
+    #include <netinet/tcp.h>
+    #include <netinet/in.h>
+    #include <sys/socket.h>
+    #include <fcntl.h>
+    #include "../common.h"
+    using SOCKET = int32_t;
+    #define SOCKET_ERROR -1
+    #define INVALID_SOCKET -1
+    #define LAST_SOCKET_ERROR() errno
+    #define closesocket close
+    #define ioctlsocket ioctl
+    #if defined(__linux__)
+        #define FLAG_NO_PIPE MSG_NOSIGNAL
+    #else
+        #define FLAG_NO_PIPE 0
+    #endif // defined(__linux__)
+#endif // _WIN32
+// clang-format on
+
+#    include "UdpSocket.h"
+
+constexpr auto CONNECT_TIMEOUT = std::chrono::milliseconds(3000);
+
+#    ifdef _WIN32
+static bool _wsaInitialised = false;
+#    endif
+
+class UdpSocket;
+
+class SocketException : public std::runtime_error
+{
+public:
+    explicit SocketException(const std::string& message)
+        : std::runtime_error(message)
+    {
+    }
+};
+
+class UdpSocket final : public IUdpSocket
+{
+private:
+    SOCKET_STATUS _status = SOCKET_STATUS_CLOSED;
+    uint16_t _listeningPort = 0;
+    SOCKET _socket = INVALID_SOCKET;
+
+    std::string _hostName;
+    std::string _error;
+
+public:
+    UdpSocket() = default;
+
+    ~UdpSocket() override
+    {
+        CloseSocket();
+    }
+
+    SOCKET_STATUS GetStatus() override
+    {
+        return _status;
+    }
+
+    const char* GetError() override
+    {
+        return _error.empty() ? nullptr : _error.c_str();
+    }
+
+    void Listen(uint16_t port) override
+    {
+        Listen("", port);
+    }
+
+    void Listen(const std::string& address, uint16_t port) override
+    {
+        if (_status != SOCKET_STATUS_CLOSED)
+        {
+            throw std::runtime_error("Socket not closed.");
+        }
+
+        sockaddr_storage ss{};
+        int32_t ss_len;
+        if (!ResolveAddress(address, port, &ss, &ss_len))
+        {
+            throw SocketException("Unable to resolve address.");
+        }
+
+        // Create the listening socket
+        _socket = socket(ss.ss_family, SOCK_STREAM, IPPROTO_TCP);
+        if (_socket == INVALID_SOCKET)
+        {
+            throw SocketException("Unable to create socket.");
+        }
+
+        // Turn off IPV6_V6ONLY so we can accept both v4 and v6 connections
+        int32_t value = 0;
+        if (setsockopt(_socket, IPPROTO_IPV6, IPV6_V6ONLY, (const char*)&value, sizeof(value)) != 0)
+        {
+            log_error("IPV6_V6ONLY failed. %d", LAST_SOCKET_ERROR());
+        }
+
+        value = 1;
+        if (setsockopt(_socket, SOL_SOCKET, SO_REUSEADDR, (const char*)&value, sizeof(value)) != 0)
+        {
+            log_error("SO_REUSEADDR failed. %d", LAST_SOCKET_ERROR());
+        }
+
+        try
+        {
+            // Bind to address:port and listen
+            if (bind(_socket, (sockaddr*)&ss, ss_len) != 0)
+            {
+                throw SocketException("Unable to bind to socket.");
+            }
+            if (listen(_socket, SOMAXCONN) != 0)
+            {
+                throw SocketException("Unable to listen on socket.");
+            }
+
+            if (!SetNonBlocking(_socket, true))
+            {
+                throw SocketException("Failed to set non-blocking mode.");
+            }
+        }
+        catch (const std::exception&)
+        {
+            CloseSocket();
+            throw;
+        }
+
+        _listeningPort = port;
+        _status = SOCKET_STATUS_LISTENING;
+    }
+
+    size_t SendData(const std::string& address, uint16_t port, const void* buffer, size_t size) override
+    {
+        if (_status != SOCKET_STATUS_CONNECTED)
+        {
+            throw std::runtime_error("Socket not connected.");
+        }
+
+        size_t totalSent = 0;
+        do
+        {
+            const char* bufferStart = (const char*)buffer + totalSent;
+            size_t remainingSize = size - totalSent;
+            int32_t sentBytes = send(_socket, bufferStart, (int32_t)remainingSize, FLAG_NO_PIPE);
+            if (sentBytes == SOCKET_ERROR)
+            {
+                return totalSent;
+            }
+            totalSent += sentBytes;
+        } while (totalSent < size);
+        return totalSent;
+    }
+
+    NETWORK_READPACKET ReceiveData(void* buffer, size_t size, size_t* sizeReceived) override
+    {
+        if (_status != SOCKET_STATUS_CONNECTED)
+        {
+            throw std::runtime_error("Socket not connected.");
+        }
+
+        int32_t readBytes = recv(_socket, (char*)buffer, (int32_t)size, 0);
+        if (readBytes == 0)
+        {
+            *sizeReceived = 0;
+            return NETWORK_READPACKET_DISCONNECTED;
+        }
+        else if (readBytes == SOCKET_ERROR)
+        {
+            *sizeReceived = 0;
+#    ifndef _WIN32
+            // Removing the check for EAGAIN and instead relying on the values being the same allows turning on of
+            // -Wlogical-op warning.
+            // This is not true on Windows, see:
+            // * https://msdn.microsoft.com/en-us/library/windows/desktop/ms737828(v=vs.85).aspx
+            // * https://msdn.microsoft.com/en-us/library/windows/desktop/ms741580(v=vs.85).aspx
+            // * https://msdn.microsoft.com/en-us/library/windows/desktop/ms740668(v=vs.85).aspx
+            static_assert(
+                EWOULDBLOCK == EAGAIN,
+                "Portability note: your system has different values for EWOULDBLOCK "
+                "and EAGAIN, please extend the condition below");
+#    endif // _WIN32
+            if (LAST_SOCKET_ERROR() != EWOULDBLOCK)
+            {
+                return NETWORK_READPACKET_DISCONNECTED;
+            }
+            else
+            {
+                return NETWORK_READPACKET_NO_DATA;
+            }
+        }
+        else
+        {
+            *sizeReceived = readBytes;
+            return NETWORK_READPACKET_SUCCESS;
+        }
+    }
+
+    void Close() override
+    {
+        CloseSocket();
+    }
+
+    const char* GetHostName() const override
+    {
+        return _hostName.empty() ? nullptr : _hostName.c_str();
+    }
+
+private:
+    explicit UdpSocket(SOCKET socket, const std::string& hostName)
+    {
+        _socket = socket;
+        _hostName = hostName;
+        _status = SOCKET_STATUS_CONNECTED;
+    }
+
+    void CloseSocket()
+    {
+        if (_socket != INVALID_SOCKET)
+        {
+            closesocket(_socket);
+            _socket = INVALID_SOCKET;
+        }
+        _status = SOCKET_STATUS_CLOSED;
+    }
+
+    bool ResolveAddress(const std::string& address, uint16_t port, sockaddr_storage* ss, int32_t* ss_len)
+    {
+        std::string serviceName = std::to_string(port);
+
+        addrinfo hints = {};
+        hints.ai_family = AF_UNSPEC;
+        if (address.empty())
+        {
+            hints.ai_flags = AI_PASSIVE;
+        }
+
+        addrinfo* result = nullptr;
+        int errorcode = getaddrinfo(address.empty() ? nullptr : address.c_str(), serviceName.c_str(), &hints, &result);
+        if (errorcode != 0)
+        {
+            log_error("Resolving address failed: Code %d.", errorcode);
+            log_error("Resolution error message: %s.", gai_strerror(errorcode));
+            return false;
+        }
+        if (result == nullptr)
+        {
+            return false;
+        }
+        else
+        {
+            std::memcpy(ss, result->ai_addr, result->ai_addrlen);
+            *ss_len = (int32_t)result->ai_addrlen;
+            freeaddrinfo(result);
+            return true;
+        }
+    }
+
+    static bool SetNonBlocking(SOCKET socket, bool on)
+    {
+#    ifdef _WIN32
+        u_long nonBlocking = on;
+        return ioctlsocket(socket, FIONBIO, &nonBlocking) == 0;
+#    else
+        int32_t flags = fcntl(socket, F_GETFL, 0);
+        return fcntl(socket, F_SETFL, on ? (flags | O_NONBLOCK) : (flags & ~O_NONBLOCK)) == 0;
+#    endif
+    }
+
+    static bool SetSOBroadcast(SOCKET socket, bool enabled)
+    {
+        return setsockopt(socket, SOL_SOCKET, SO_BROADCAST, (const char*)&enabled, sizeof(enabled)) == 0;
+    }
+};
+
+std::unique_ptr<IUdpSocket> CreateUdpSocket()
+{
+    return std::make_unique<UdpSocket>();
+}
+
+#endif

src/openrct2/network/UdpSocket.h

@@ -0,0 +1,57 @@
+/*****************************************************************************
+ * Copyright (c) 2014-2019 OpenRCT2 developers
+ *
+ * For a complete list of all authors, please refer to contributors.md
+ * Interested in contributing? Visit https://github.com/OpenRCT2/OpenRCT2
+ *
+ * OpenRCT2 is licensed under the GNU General Public License version 3.
+ *****************************************************************************/
+
+#pragma once
+
+#include "../common.h"
+
+#include <memory>
+#include <string>
+
+enum SOCKET_STATUS
+{
+    SOCKET_STATUS_CLOSED,
+    SOCKET_STATUS_RESOLVING,
+    SOCKET_STATUS_CONNECTING,
+    SOCKET_STATUS_CONNECTED,
+    SOCKET_STATUS_LISTENING,
+};
+
+enum NETWORK_READPACKET
+{
+    NETWORK_READPACKET_SUCCESS,
+    NETWORK_READPACKET_NO_DATA,
+    NETWORK_READPACKET_MORE_DATA,
+    NETWORK_READPACKET_DISCONNECTED
+};
+
+/**
+ * Represents a UDP socket / listener.
+ */
+interface IUdpSocket
+{
+public:
+    virtual ~IUdpSocket()
+    {
+    }
+
+    virtual SOCKET_STATUS GetStatus() abstract;
+    virtual const char* GetError() abstract;
+    virtual const char* GetHostName() const abstract;
+
+    virtual void Listen(uint16_t port) abstract;
+    virtual void Listen(const std::string& address, uint16_t port) abstract;
+
+    virtual size_t SendData(const std::string& address, uint16_t port, const void* buffer, size_t size) abstract;
+    virtual NETWORK_READPACKET ReceiveData(void* buffer, size_t size, size_t* sizeReceived) abstract;
+
+    virtual void Close() abstract;
+};
+
+std::unique_ptr<IUdpSocket> CreateUdpSocket();