sockets-cpp

A header-only library with socket classes:

• TcpClient - template class for a TCP client socket
• TcpServer - template class for a TCP Server supporting multiple client connections
• UdpSocket - template class for a UDP Multicast/Unicast

Dependencies

• Optional dependency on fmt for error string formatting
• C++14 or later
• CMake
• gtest and gmock for unit tests. Enable unit tests by specifying -DBUILD_TESTS=ON when running CMake

Socket Options

struct SocketOpt {
    /**
     * @brief Value passed to setsockopt(SO_SNDBUF)
     * 
     */
    int m_txBufSize = TX_BUFFER_SIZE;

    /**
     * @brief Value passed to setsockopt(SO_RCVBUF)
     * 
     */
    int m_rxBufSize = RX_BUFFER_SIZE;

    /**
     * @brief Socket listen address
     * 
     */
    std::string m_listenAddr = "0.0.0.0";

};

UdpSocket

The UdpSocket class is templated on the "callback" class which receives data via UDP.

The template argument type must support the following interface:

   void onReceiveData(const char *data, size_t size) ;

The UdpSocket class has the following interface for managing the UDP socket:

// Constructor
UdpSocket(CallbackImpl &callback, SocketOpt *options = nullptr);

// Start a multicast socket
SocketRet startMcast(const char *mcastAddr, uint16_t port);

// Start a unicast client/server socket
SocketRet startUnicast(const char *remoteAddr, uint16_t localPort, uint16_t port)

// Start a unicast server-only socket
SocketRet startUnicast(uint16_t localPort);

// Send data via UDP
SocketRet sendMsg(const char *msg, size_t size);

// Shutdown the UDP socket
void finish();

TcpClient

The TcpClient class is templated on the "callback" class which receives data via TCP.

The template argument type must support the following interface:

    void onReceiveData(const char *data, size_t size);

    void onDisconnect(const sockets::SocketRet &ret);

The TcpClient class has the following interface for managing the TCP client connection:

// Constructor
TcpClient(CallbackImpl &callback, SocketOpt *options = nullptr);

// Connect to a TCP server
SocketRet connectTo(const char *remoteIp, uint16_t remotePort);

// Send data to the TCP server
SocketRet sendMsg(const char *msg, size_t size);

// Shutdown the TCP client socket
void finish();

TcpServer

The TcpServer class is templated on the "callback" class which manages the TCP server.

The template argument must support the following interface:

    void onClientConnect(const sockets::ClientHandle &client);

    void onReceiveClientData(const sockets::ClientHandle &client, const char *data, size_t size);

    void onClientDisconnect(const sockets::ClientHandle &client, const sockets::SocketRet &ret);

The TcpServer class has the following interfaces:

// Create a TCP server socket
TcpServer(CallbackImpl &callback, SocketOpt *options = nullptr);

// Start the server listening on the specified port
SocketRet start(uint16_t port);

// Send a message to all connected clients
SocketRet sendBcast(const char *msg, size_t size);

// Send a message to a specific client connection
SocketRet sendClientMessage(ClientHandle &clientId, const char *msg, size_t size);

// Shutdown the TCP server socket
void finish();

Sample socket apps using these classes:

Enable building sample apps by specifying -DBUILD_EXAMPLES=ON when running CMake.

TCP Client

$ ./clientApp -a <ipAddr> -p <port>

TCP Server

$ ./serverApp -p <port> -L <listenAddr>

UDP Multicast

$ ./mcastApp -m <multicastAddr> -p <port>

UDP Unicast

$ ./unicastApp -a <ipAddr> -l <localPort> -p <remotePort> -L <listenAddr>