i wrote this program to sniff icmp packets in the network and print there source address. The code is as follows:
from scapy.all import *
def fun_callback(pkt):
print str(pkt.payload.src)
sniff(prn = fun_callback, filter = 'icmp', timeout =5)
After running this program, I am getting this error.
[root@localhost icmp]# python test.py
WARNING: Failed to execute tcpdump. Check it is installed and in the PATH
WARNING: No route found for IPv6 destination :: (no default route?)
192.168.134.131
192.168.134.131
192.168.134.2
192.168.134.2
fe80::20c:29ff:fee4:a130
134.160.38.1
192.168.134.131
Traceback (most recent call last):
File "test.py", line 5, in <module>
sniff(prn = fun_callback, filter = 'icmp', timeout =5)
File "/usr/lib/python2.7/site-packages/scapy/sendrecv.py", line 586, in sniff
r = prn(p)
File "test.py", line 4, in fun_callback
print str(pkt.payload.src)
File "/usr/lib/python2.7/site-packages/scapy/packet.py", line 176, in __getattr__
fld,v = self.getfield_and_val(attr)
File "/usr/lib/python2.7/site-packages/scapy/packet.py", line 172, in getfield_and_val
return self.payload.getfield_and_val(attr)
File "/usr/lib/python2.7/site-packages/scapy/packet.py", line 172, in getfield_and_val
return self.payload.getfield_and_val(attr)
File "/usr/lib/python2.7/site-packages/scapy/packet.py", line 1057, in getfield_and_val
raise AttributeError(attr)
AttributeError: src
[root@localhost icmp]#
Why this exception is occurring?
You have sniffed a packet with a payload without src
attribute. If you want a quick fix for your code, write:
def fun_callback(pkt):
if hasattr(pkt.payload, "src"):
print str(pkt.payload.src)
The problem is, you don't really known what pkt.payload
will be. If you want a better fix, try something like:
def fun_callback(pkt):
if IP in pkt: print pkt[IP].src
elif IPv6 in pkt: print pkt[IPv6].src
Or better, with .sprintf()
:
sniff(prn=lambda pkt: pkt.sprintf("{IP:%IP.src%}{IPv6:%IPv6.src%}"),
filter='icmp', timeout=5))