Crafting a DNS Query Message in Python

Question

I've been using Scapy to craft packets and test my network, but the programmer inside me is itching to know how to do this without Scapy.

For example, how do I craft a DNS Query using sockets (I assume it's sockets that would be used).

Thanks

Answer 1

To open a UDP socket you'd use:

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM, socket.IPPROTO_UDP

To send use:

query = craft_dns_query() # you do this part s.sendto(query,(socket.inet_aton("8.8.8.8",53))

To receive the response use: response = s.recv(1024)

You'll have to refer to documentation on DNS for actually crafting the messages and handling the responses.