How to create HTTP GET request Scapy?

Question

I need to create HTTP GET request and save the data response. I tried to use this:

    syn = IP(dst=URL) / TCP(dport=80, flags=\'S\')
    syn_ack = sr1(syn)         


        

Answer 1

After setting the rule in your iptables as has been suggested above, you could do the following :

from scapy.all import *

seq = 12345
sport = 1040
dport = 80

ip_packet = IP(dst='192.168.56.107')
syn_packet = TCP(sport=sport, dport=dport, flags='S', seq=seq)

packet = ip_packet/syn_packet
synack_response = sr1(packet)

next_seq = seq + 1
my_ack = synack_response.seq + 1

ack_packet = TCP(sport=sport, dport=dport, flags='A', seq=next_seq, ack=my_ack)

send(ip_packet/ack_packet)

payload_packet = TCP(sport=sport, dport=dport, flags='A', seq=next_seq, ack=my_ack)
payload = "GET / HTTP/1.0\r\nHOST: 192.168.56.107\r\n\r\n"

reply, error = sr(ip_packet/payload_packet/payload, multi=1, timeout=1)
for r in reply:
    r[0].show2()
    r[1].show2()

Hope this helps. Basically, the first response you get back does not really hold the HTTP response data. I tested the script against an INETSIM simulated HTTP server and in that case (at least) the first packet (after the 3-way TCP handshake) that the server responded with was a series of NULL (0x00) bytes. Hence using multi somehow did the stuff in my case.