/*
    UDP Server
*/

#include <stdio.h>
#include <stdlib.h>

#ifdef __linux__
// gcc udp_main.c -w -o udp_main && ./udp_main
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <unistd.h>
#elif _WIN32
// compile with linker settings: "gcc udp_main.c -lws2_32"
g++ main.cpp - lws2_32
#define _WIN32_WINNT 0x0A00
#include <winsock2.h>
#include <ws2tcpip.h>
#endif

int main()
{
#ifdef _WIN32 // Win Only: Treiber Starten
    WSADATA wsaData;
    int iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
    if (iResult != 0)
    {
        printf("WSAStartup failed: %d\n", iResult);
        return 1;
    }
#endif

    // socket()
    int s = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
    printf("socket: %i\n", s);

    // bind()
    struct sockaddr_in srvAddr;
    srvAddr.sin_family = AF_INET;
    srvAddr.sin_port = htons(51234); // port
    srvAddr.sin_addr.s_addr = htonl(INADDR_ANY);

    int b = bind(s, &srvAddr, sizeof(srvAddr));
    printf("bind: %i\n", b);

    // listen()
    struct sockaddr_in cliAddr;
    int size = sizeof(cliAddr);
    char str[128];
    int r = recvfrom(s, str, 100, 0, (struct sockaddr *)&cliAddr, &size);
    printf("receive: %i\n", r);
    printf("data: %s\n", str);

#ifdef __linux__
    close(s);
#elif _WIN32 // Win Only: Treiber Beenden
    closesocket(s);
    int iReuslt = WSACleanup();
#endif
    return 0;
}