row socket 网络监听

【核心代码】

        unsafe private void Receive(byte[] buf, int len)
        {
            byte temp_protocol = 0;
            uint temp_version = 0;
            uint temp_ip_srcaddr = 0;
            uint temp_ip_destaddr = 0;
            short temp_srcport = 0;
            short temp_dstport = 0;

            IPAddress temp_ip;

            PacketArrivedEventArgs e = new PacketArrivedEventArgs();

            fixed (byte* fixed_buf = buf)
            {
                IPHeader* head = (IPHeader*)fixed_buf;//把数据流整合为IPHeader结构
                e.HeaderLength = (uint)(head->ip_verlen & 0x0F) << 2;

                temp_protocol = head->ip_protocol;
                switch (temp_protocol)
                {
                    case 1: e.Protocol = "ICMP"; break;
                    case 2: e.Protocol = "IGMP"; break;
                    case 6: e.Protocol = "TCP"; break;
                    case 17: e.Protocol = "UDP"; break;
                    default: e.Protocol = "UNKNOWN"; break;
                }

                temp_version = (uint)(head->ip_verlen & 0xF0) >> 4;//提取IP协议版本
                e.IPVersion = temp_version.ToString();
                temp_ip_srcaddr = head->ip_srcaddr;
                temp_ip_destaddr = head->ip_destaddr;
                temp_ip = new IPAddress(temp_ip_srcaddr);
                e.OriginationAddress = temp_ip.ToString();
                temp_ip = new IPAddress(temp_ip_destaddr);
                e.DestinationAddress = temp_ip.ToString();
                
                temp_srcport = *(short*)&fixed_buf[e.HeaderLength];
                temp_dstport = *(short*)&fixed_buf[e.HeaderLength   2];
                e.OriginationPort = IPAddress.NetworkToHostOrder(temp_srcport).ToString();
                e.DestinationPort = IPAddress.NetworkToHostOrder(temp_dstport).ToString();

                e.PacketLength = (uint)len;
                e.MessageLength = (uint)len-e.HeaderLength;

                e.ReceiveBuffer = buf;
                Array.Copy(buf, 0, e.IPHeaderBuffer, 0, (int)e.HeaderLength);
                Array.Copy(buf, (int)e.HeaderLength, e.MessageBuffer, 0, (int)e.MessageLength);
            }

            OnPacketArrival(e);
        }