def cksum(self):
# must take IP header into account: in pseud...
mem = self.cs.Val
self.cs.Val = 0
icmpstr = str(self)
self.cs.Val = mem
return checksum(icmpstr)
def cksum(self):
# must take IPv4 options into account...
mem = self.cs.Val
self.cs.Val = 0
s = str(self)
self.cs.Val = mem
# big thanks to scapy /p.biondy:
return checksum(s)
def cksum(self):
# must take IP header into account: in pseud...
mem = self.cs.Val
self.cs.Val = 0
tcpstr = str(self)
hdrstr = str(self.get_header())
paystr = str(self.get_payload())
self.cs.Val = mem
ln = len(tcpstr) + len(paystr)
if len(hdrstr)>=20 and ord(hdrstr[0])>>4 == 4 :
pseudstr = ''.join((hdrstr[12:20], '\0', hdrstr[9:10], pack('!H', ln)))
elif len(hdrstr)>=40 and ord(hdrstr[0])>>4 == 6 :
# TODO: do it correctly!
# warning, not considering IPv6 options when selecting proto field
# double warning, not sure its the right way to do...
# and anyway, IPv6 is has-been
pseudstr = ''.join((hdrstr[8:40], '\0' , hdrstr[6:7], pack('!H', ln)))
else:
pseudstr = ''.join(('\0\0', pack('!H', ln)))
return checksum(''.join((pseudstr, tcpstr, paystr)))
