Ip wrapper

This module wraps raw IP sockets

  • pkt : packet type (array of integer traits)
  • protocol : IP protocol number

Because of limitations on Unix raw sockets, this module can only send and receive with a single IP protocol number

module ip_wrapper(pkt,protocol) = {

    object rdr = {}

    <<< header
    class ip_reader;
    >>>

    <<< impl
    class ip_reader : public reader {
        int sock;
        %`handle_recv` rcb;
        ivy_class *ivy;
        bool bound;
      public:
        ip_reader(%`handle_recv` rcb, ivy_class *ivy)
            : rcb(rcb), ivy(ivy), bound(false) {
        sock = socket(PF_INET, SOCK_RAW, `protocol`);
        if (sock < 0)
            { perror("cannot create socket"); exit(1); }
                int one = 1;
                if (setsockopt (sock, IPPROTO_IP, IP_HDRINCL, &one, sizeof (one)) < 0)
            { perror("cannot set socket option"); exit(1); }
            }
        virtual ~ip_reader() {
ifdef _WIN32 
            closesocket(sock);
else 
            close(sock);
endif 
        }
        virtual int fdes() {
        return sock;
        }
        virtual void read() {
        //std::cerr << "RECEIVING\n";
            int len=0;
                socklen_t lenlen=4;
ifdef _WIN32 
            if (getsockopt(sock,SOL_SOCKET,SO_RCVBUF,(char *)&len,&lenlen))
else 
            if (getsockopt(sock,SOL_SOCKET,SO_RCVBUF,&len,&lenlen))
endif 
                { perror("getsockopt failed"); exit(1); }
            std::vector<unsigned char> buf(len);
            int bytes;
        if ((bytes = recv(sock,&buf[0],len,0)) < 0)
            { std::cerr << "recv failed\n"; exit(1); }
            buf.resize(bytes);
            `pkt` pkt;
            pkt.resize(bytes);
            std::copy(buf.begin(),buf.end(),pkt.begin());
            ivy->__lock();
            rcb(pkt);
            ivy->__unlock();
        }
        virtual void write(`pkt` pkt) {
            std::vector<char> buf;
                buf.resize(pkt.size());
                std::copy(pkt.begin(),pkt.end(),buf.begin());
//                std::cerr << "sending to: " << (int)buf[16] << "." << (int)buf[17] << "." << (int)buf[18] << "." << (int)buf[19] << std::endl;
        //std::cerr << "SENDING\n";
        struct sockaddr_in dstaddr;
        memset((char *)&dstaddr, 0, sizeof(dstaddr));
        dstaddr.sin_family = AF_INET;
        dstaddr.sin_addr.s_addr = *(in_addr_t *)&buf[16];
        dstaddr.sin_port = htons(0);
            if (sendto(sock,&buf[0],buf.size(),0,(sockaddr *)&dstaddr,sizeof(sockaddr_in)) < 0)
            // if (send(sock,&buf[0],buf.size(),0) < 0)
ifdef _WIN32 
             { std::cerr << "send failed " << WSAGetLastError() << "\n"; exit(1); }
else 
             { perror("send failed"); exit(1); }
endif 
        }
    };
    >>>
    <<< member
    ip_reader *`rdr`;
    >>>
    <<< init
    install_reader(`rdr` = new ip_reader(`handle_recv`, this));
    >>>

    action handle_recv(x:pkt) = {
    call recv(x)
    }

    implement send(x:pkt) {
    <<<
        `rdr`->write(`x`);
    >>>
    }
}