ord() expected string of length 1, but int found - python/libpcap [RESOLVIDO]

1. ord() expected string of length 1, but int found - python/libpcap [RESOLVIDO]

Lucas
DcoderLA

(usa Debian)

Enviado em 27/03/2022 - 17:16h

Boa tarde pessoal, bom domingo a todos !

Estou tentando reproduzir um exemplo de código que usa a libpcap para fazer um sniffing básico. O código é em python, como não domino muito fiquei sem saída para o erro que apareceu:

ord() expected string of length 1, but int found

E este é o código:
'''
Packet sniffer in python using the pcapy python library

Project website
http://oss.coresecurity.com/projects/pcapy.html
'''

import socket
from struct import *
import datetime
import pcapy
import sys

def main(argv):
#list all devices
devices = pcapy.findalldevs()
print (devices)

#ask user to enter device name to sniff
print ("Available devices are :")
for d in devices :
print (d)

dev = input("Enter device name to sniff : ")

print ("Sniffing device " + dev)

'''
open device
# Arguments here are:
# device
# snaplen (maximum number of bytes to capture _per_packet_)
# promiscious mode (1 for true)
# timeout (in milliseconds)
'''
cap = pcapy.open_live(dev , 65536 , 1 , 0)

#start sniffing packets
while(1) :
(header, packet) = cap.next()
#print ('%s: captured %d bytes, truncated to %d bytes' %(datetime.datetime.now(), header.getlen(), header.getcaplen()))
parse_packet(packet)

#Convert a string of 6 characters of ethernet address into a dash separated hex string
def eth_addr (a) :
b = "%.2x:%.2x:%.2x:%.2x:%.2x:%.2x" % (ord(a[0]) , ord(a[1]) , ord(a[2]), ord(a[3]), ord(a[4]) , ord(a[5]))
return b

#function to parse a packet
def parse_packet(packet) :

#parse ethernet header
eth_length = 14

eth_header = packet[:eth_length]
eth = unpack('!6s6sH' , eth_header)
eth_protocol = socket.ntohs(eth[2])
print ('Destination MAC : ' + eth_addr(packet[0:6]) + ' Source MAC : ' + eth_addr(packet[6:12]) + ' Protocol : ' + str(eth_protocol))

#Parse IP packets, IP Protocol number = 8
if eth_protocol == 8 :
#Parse IP header
#take first 20 characters for the ip header
ip_header = packet[eth_length:20+eth_length]

#now unpack them :)
iph = unpack('!BBHHHBBH4s4s' , ip_header)

version_ihl = iph[0]
version = version_ihl >> 4
ihl = version_ihl & 0xF

iph_length = ihl * 4

ttl = iph[5]
protocol = iph[6]
s_addr = socket.inet_ntoa(iph[8]);
d_addr = socket.inet_ntoa(iph[9]);

print ('Version : ' + str(version) + ' IP Header Length : ' + str(ihl) + ' TTL : ' + str(ttl) + ' Protocol : ' + str(protocol) + ' Source Address : ' + str(s_addr) + ' Destination Address : ' + str(d_addr))

#TCP protocol
if protocol == 6 :
t = iph_length + eth_length
tcp_header = packet[t:t+20]

#now unpack them :)
tcph = unpack('!HHLLBBHHH' , tcp_header)

source_port = tcph[0]
dest_port = tcph[1]
sequence = tcph[2]
acknowledgement = tcph[3]
doff_reserved = tcph[4]
tcph_length = doff_reserved >> 4

print ('Source Port : ' + str(source_port) + ' Dest Port : ' + str(dest_port) + ' Sequence Number : ' + str(sequence) + ' Acknowledgement : ' + str(acknowledgement) + ' TCP header length : ' + str(tcph_length))

h_size = eth_length + iph_length + tcph_length * 4
data_size = len(packet) - h_size

#get data from the packet
data = packet[h_size:]

print ('Data : ' + data)

#ICMP Packets
elif protocol == 1 :
u = iph_length + eth_length
icmph_length = 4
icmp_header = packet[u:u+4]

#now unpack them :)
icmph = unpack('!BBH' , icmp_header)

icmp_type = icmph[0]
code = icmph[1]
checksum = icmph[2]

print ('Type : ' + str(icmp_type) + ' Code : ' + str(code) + ' Checksum : ' + str(checksum))

h_size = eth_length + iph_length + icmph_length
data_size = len(packet) - h_size

#get data from the packet
data = packet[h_size:]

print ('Data : ' + data)

#UDP packets
elif protocol == 17 :
u = iph_length + eth_length
udph_length = 8
udp_header = packet[u:u+8]

#now unpack them :)
udph = unpack('!HHHH' , udp_header)

source_port = udph[0]
dest_port = udph[1]
length = udph[2]
checksum = udph[3]

print ('Source Port : ' + str(source_port) + ' Dest Port : ' + str(dest_port) + ' Length : ' + str(length) + ' Checksum : ' + str(checksum))

h_size = eth_length + iph_length + udph_length
data_size = len(packet) - h_size

#get data from the packet
data = packet[h_size:]

print ('Data : ' + data)

#some other IP packet like IGMP
else :
print ('Protocol other than TCP/UDP/ICMP')

print

if __name__ == "__main__":
main(sys.argv)


Qualquer dica é bem vinda. Desde já agradeço a todos pela ajuda.