def post_build(self, pkt, pay):
# calculating checksum if requested
pdu = pkt + pay
checksumInfo = self[1].checksum_info(self.hdrlen)
if checksumInfo is not None:
(cbegin, cpos) = checksumInfo
checkbytes = fletcher16_checkbytes(pdu[cbegin:], (cpos - cbegin))
pdu = pdu[:cpos] + checkbytes + pdu[cpos + 2:]
return pdu
def post_build(self, pkt, pay):
# calculating checksum if requested
pdu = pkt + pay
checksumInfo = self[1].checksum_info(self.hdrlen)
if checksumInfo is not None:
(cbegin, cpos) = checksumInfo
checkbytes = fletcher16_checkbytes(pdu[cbegin:], (cpos - cbegin))
pdu = pdu[:cpos] + checkbytes + pdu[cpos+2:]
return pdu
def ospf_lsa_checksum(lsa):
return fletcher16_checkbytes(b"\x00\x00" + lsa[2:], 16) # leave out age
def ospf_lsa_checksum(lsa):
return fletcher16_checkbytes(b"\x00\x00" + lsa[2:], 16) # leave out age
