source: Daodan/Flatline/src/Flatline_Net.c@ 1170

#include "Flatline.h"

thread int UDPServer_Socket = 0;

bool NetUDPServer_Listen(uint16_t port, bool (*packet_callback)(char* data, int datalen, int from))
{
        UDPServer_Socket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
        
        if (UDPServer_Socket < 0)
        {
                DDrStartupMessage("could not create socket");
                return false;
        }
        
        sockaddr_in address;
        memset(&address, 0, sizeof(sockaddr_in));
        address.sin_family = AF_INET;
        address.sin_addr.s_addr = htonl(INADDR_ANY);
        address.sin_port = htons(port);
        
        if (bind(UDPServer_Socket, (sockaddr*)&address, sizeof(sockaddr_in)) < 0)
        {
                DDrStartupMessage("could not bind port %d", port);
                closesocket(UDPServer_Socket);
                return false;
        }
        
        char data[65537];
        data[sizeof(data) - 1] = '\0';
        sockaddr_in from;
        int recvlen;
        for (;;)
        {
                int fromlen = sizeof(sockaddr_in);
                memset(&from, 0, sizeof(sockaddr_in));
                recvlen = recvfrom(UDPServer_Socket, data, sizeof(data) - 1, 0, (sockaddr*)&from, (void*)&fromlen);
                if (!packet_callback(data, recvlen, ntohl(from.sin_addr.s_addr)))
                        break;
        }
        closesocket(UDPServer_Socket);
        return true;
}

bool NetUDPServer_Send(sockaddr* address, char* data, int datalen)
{
        return NetUDPSocket_Send(UDPServer_Socket, address, data, datalen);
}

int NetUDPSocket_Create(uint16_t port)
{
        int sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
        
        if (sock < 0)
        {
                DDrStartupMessage("could not create socket");
                return -1;
        }
        
        sockaddr_in address;
        memset(&address, 0, sizeof(sockaddr_in));
        address.sin_family = AF_INET;
        address.sin_addr.s_addr = htonl(INADDR_ANY);
        address.sin_port = htons(port);
        
        if (bind(sock, (sockaddr*)&address, sizeof(sockaddr_in)) < 0)
        {
                DDrStartupMessage("could not bind port %d", port);
                return false;
        }
        
        unsigned long nonBlocking = 1;
        if (ioctlsocket(sock, FIONBIO, &nonBlocking))
        {
                DDrStartupMessage("failed to set non-blocking socket");
                return false;
        }
        
        return sock;
}

void NetUDPSocket_Close(int socket)
{
        closesocket(socket);
}

bool NetUDPSocket_Send(int socket, const sockaddr* address, const char* data, int datalen)
{
        int addr_size;
        switch (address->sa_family)
        {
                case AF_INET:
                        addr_size = sizeof(sockaddr_in);
                        break;
                case AF_INET6:
                        addr_size = sizeof(sockaddr_in6);
                        break;
                default:
                        addr_size = sizeof(sockaddr_storage);
        }
        return sendto(socket, data, datalen, 0, address, addr_size);
}

bool NetUDPSocket_Recieve(int socket, sockaddr_storage* address, char* data, uint16_t* datalen)
{
        int address_size = sizeof(sockaddr_storage);
        uint32_t msg_size = recvfrom(socket, data, 512, 0, (sockaddr*)address, &address_size);
        if (msg_size == 0)
                return false;
        else
        {
                *datalen = msg_size;
                return true;
        }
}