http.py

#coding:utf-8
import random
from scapy.all import *


HOST = 'www.example.com'
PORT = 80


if __name__=='__main__':
	sport = random.randint(50000,60000)
	seq = random.randint(0,1000000)

	#SYN
	ip = IP(dst=HOST)
	tcp = TCP(sport=sport,dport=PORT,seq=seq,flags='S')
	recv = sr1(ip/tcp)

	#ACK
	seq = seq+1
	ack = recv.seq+1
	tcp = TCP(sport=sport,dport=PORT,seq=seq,ack=ack,flags='A')
	send(ip/tcp)

	#HTTP Request
	req = b'GET / HTTP/1.1\r\nHost: www.example.com\r\n\r\n'
	res = sr(ip/tcp/req,multi=1,timeout=0.1)

	##res[0] : scapy.plist.PacketList
	for packet in res[0]:
		recv = packet[1]
		if 'Raw' in recv:
			break
			
	#ACK	
	seq = seq+len(req)
	ack = recv.seq+len(recv.load)
	tcp = TCP(sport=sport,dport=PORT,seq=seq,ack=ack,flags='A')
	recv = sr1(ip/tcp)

	#ACK
	ack = recv.seq+1
	tcp = TCP(sport=sport,dport=PORT,seq=seq,ack=ack,flags='A')
	send(ip/tcp)

	#FIN
	tcp = TCP(sport=sport,dport=PORT,seq=seq,ack=ack,flags='FA')
	recv = sr1(ip/tcp)