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

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.