How can I send tcp ip packet via limesdr usb?

I am sorry but my question may be entry-level. I am a programmer who is very interested in SDR. I bought two limesdr borad. I want to get data from tcp ip stack via virtual networking card and send the data through limesdr. I modified the gr-limesdr/examples/GFSK.grc and change the file source and sink block with my costumed block attached with virtual networking cards. My problem is when I blocked for a packet from TCP/IP stack and then resend the content of the received packets, part of the packet will missing. I wonder if there are some simple examples to implement my applications? thanks