userver.cpp

#include "userver.h"




UDPServer::UDPServer(unsigned short port)
    : m_sock{ AF_INET, SOCK_DGRAM, IPPROTO_UDP }, m_client_address{ 0 }, m_client_address_len{ sizeof(sockaddr_in) }, m_port(port), m_recv_len{ 0 } {}

void UDPServer::listenUDP()
{
    std::cout << "Starting echo server on the port " << m_port << "...\n";

    if (!m_sock)
    {
        std::cerr << m_sock_wrap.get_last_error_string() << std::endl;
        exit(EXIT_FAILURE);
    }



    sockaddr_in addr
    {
        .sin_family = PF_INET,
        .sin_port = htons(m_port),
    };

    addr.sin_addr.s_addr = INADDR_ANY;

    if (bind(m_sock, reinterpret_cast<const sockaddr*>(&addr), sizeof(addr)) != 0)
    {
        std::cerr << m_sock_wrap.get_last_error_string() << std::endl;
        // Socket will be closed in the Socket destructor.
        exit(EXIT_FAILURE);
    }

    std::cout << "Running echo server(Enter 'exit' to exit)...\n" << std::endl;
    const int len = 256;
    char buffer[len];
    char client_address_buf[INET_ADDRSTRLEN];
    char hbuf[NI_MAXHOST];
    bool run = true;

    while (run)
    {
        // Read content into buffer from an incoming client.
        m_recv_len = recvfrom(m_sock, buffer, sizeof(buffer) - 1, 0,
            reinterpret_cast<sockaddr*>(&m_client_address),
            &m_client_address_len);



        int x = 0;
        if (m_recv_len > 0)
        {
            buffer[m_recv_len] = '\0';
            std::cout
                << "Client with address: "
                << inet_ntop(AF_INET, &m_client_address.sin_addr, client_address_buf, sizeof(client_address_buf) / sizeof(client_address_buf[0]))
                << ":" << ntohs(m_client_address.sin_port)
                << " and host name: ";
            if (x = getnameinfo(reinterpret_cast<sockaddr*>(&m_client_address), m_client_address_len,
                hbuf, sizeof(hbuf), nullptr, 0, NI_NAMEREQD) != 0)
            {
                std::cerr << "could not resolve hostname" << std::endl;
            }
            else
            {
                std::cout << "host" << hbuf << std::endl;
            }
            std::cout << " sent datagram "
                << "[length = "
                << m_recv_len
                << "]:\n'''\n"
                << buffer
                << "\n'''"
                << std::endl;
            std::string command_string = { buffer, 0, len };
            rtrim(command_string);
            if ("exit" == command_string)
            {
                std::cout << "See you!" << std::endl;
                run = false;
            }



         // Send same content back to the client ("echo").
            sendto(m_sock, buffer, m_recv_len, 0, reinterpret_cast<const sockaddr*>(&m_client_address),
                m_client_address_len);
        }

        std::cout << std::endl;
    }
}

UDPServer::~UDPServer() {}