def sniff(count=0, store=1, offline=None, prn = None, lfilter=None, L2socket=None, timeout=None, opened_socket=None, *arg, **karg):
"""Sniff packets
sniff([count=0,] [prn=None,] [store=1,] [offline=None,] [lfilter=None,] + L2ListenSocket args) -> list of packets
count: number of packets to capture. 0 means infinity
store: wether to store sniffed packets or discard them
prn: function to apply to each packet. If something is returned,
it is displayed. Ex:
ex: prn = lambda x: x.summary()
lfilter: python function applied to each packet to determine
if further action may be done
ex: lfilter = lambda x: x.haslayer(Padding)
offline: pcap file to read packets from, instead of sniffing them
timeout: stop sniffing after a given time (default: None)
L2socket: use the provided L2socket
opened_socket: provide an object ready to use .recv() on
"""
c = 0
if opened_socket is not None:
s = opened_socket
else:
if offline is None:
if L2socket is None:
L2socket = conf.L2listen
s = L2socket(type=ETH_P_ALL, *arg, **karg)
else:
s = PcapReader(offline)
lst = []
if timeout is not None:
stoptime = time.time()+timeout
remain = None
while 1:
try:
if timeout is not None:
remain = stoptime-time.time()
if remain <= 0:
break
sel = select([s],[],[],remain)
if s in sel[0]:
p = s.recv(MTU)
if p is None:
break
if lfilter and not lfilter(p):
continue
if store:
lst.append(p)
c += 1
if prn:
r = prn(p)
if r is not None:
print r
if count > 0 and c >= count:
break
except KeyboardInterrupt:
break
if opened_socket is None:
s.close()
return plist.PacketList(lst,"Sniffed")
