-# Copyright (c) 2016 Cisco and/or its affiliates.
+# Copyright (c) 2019 Cisco and/or its affiliates.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at:
"""PacketVerifier module.
- :Example:
-
- >>> from scapy.all import *
- >>> from PacketVerifier import *
- >>> rxq = RxQueue('eth1')
- >>> txq = TxQueue('eth1')
- >>> src_mac = "AA:BB:CC:DD:EE:FF"
- >>> dst_mac = "52:54:00:ca:5d:0b"
- >>> src_ip = "11.11.11.10"
- >>> dst_ip = "11.11.11.11"
- >>> sent_packets = []
- >>> pkt_send = Ether(src=src_mac, dst=dst_mac) /
- ... IP(src=src_ip, dst=dst_ip) /
- ... ICMP()
- >>> sent_packets.append(pkt_send)
- >>> txq.send(pkt_send)
- >>> pkt_send = Ether(src=src_mac, dst=dst_mac) /
- ... ARP(hwsrc=src_mac, psrc=src_ip, hwdst=dst_mac, pdst=dst_ip, op=2)
- >>> sent_packets.append(pkt_send)
- >>> txq.send(pkt_send)
- >>> rxq.recv(100, sent_packets).show()
- ###[ Ethernet ]###
- dst = aa:bb:cc:dd:ee:ff
- src = 52:54:00:ca:5d:0b
- type = 0x800
- ###[ IP ]###
- version = 4L
- ihl = 5L
- tos = 0x0
- len = 28
- id = 43183
- flags =
- frag = 0L
- ttl = 64
- proto = icmp
- chksum = 0xa607
- src = 11.11.11.11
- dst = 11.11.11.10
- options
- ###[ ICMP ]###
- type = echo-reply
- code = 0
- chksum = 0xffff
- id = 0x0
- seq = 0x0
- ###[ Padding ]###
- load = 'RT\x00\xca]\x0b\xaa\xbb\xcc\xdd\xee\xff\x08\x06\x00\x01\x08\x00'
+ Example. ::
+
+ | >>> from scapy.all import *
+ | >>> from PacketVerifier import *
+ | >>> rxq = RxQueue('eth1')
+ | >>> txq = TxQueue('eth1')
+ | >>> src_mac = "AA:BB:CC:DD:EE:FF"
+ | >>> dst_mac = "52:54:00:ca:5d:0b"
+ | >>> src_ip = "11.11.11.10"
+ | >>> dst_ip = "11.11.11.11"
+ | >>> sent_packets = []
+ | >>> pkt_send = Ether(src=src_mac, dst=dst_mac) /
+ | ... IP(src=src_ip, dst=dst_ip) /
+ | ... ICMP()
+ | >>> sent_packets.append(pkt_send)
+ | >>> txq.send(pkt_send)
+ | >>> pkt_send = Ether(src=src_mac, dst=dst_mac) /
+ | ... ARP(hwsrc=src_mac, psrc=src_ip, hwdst=dst_mac, pdst=dst_ip, op=2)
+ | >>> sent_packets.append(pkt_send)
+ | >>> txq.send(pkt_send)
+ | >>> rxq.recv(100, sent_packets).show()
+ | ###[ Ethernet ]###
+ | dst = aa:bb:cc:dd:ee:ff
+ | src = 52:54:00:ca:5d:0b
+ | type = 0x800
+ | ###[ IP ]###
+ | version = 4L
+ | ihl = 5L
+ | tos = 0x0
+ | len = 28
+ | id = 43183
+ | flags =
+ | frag = 0L
+ | ttl = 64
+ | proto = icmp
+ | chksum = 0xa607
+ | src = 11.11.11.11
+ | dst = 11.11.11.10
+ | options
+ | ###[ ICMP ]###
+ | type = echo-reply
+ | code = 0
+ | chksum = 0xffff
+ | id = 0x0
+ | seq = 0x0
+ | ###[ Padding ]###
+ | load = 'RT\x00\xca]\x0b\xaa\xbb\xcc\xdd\xee\xff\x08\x06\x00\x01\x08\x00'
+
+ Example end.
"""
-
import os
-import socket
import select
from scapy.all import ETH_P_IP, ETH_P_IPV6, ETH_P_ALL, ETH_P_ARP
-from scapy.all import Ether, ARP
+from scapy.config import conf
from scapy.layers.inet6 import IPv6
+from scapy.layers.l2 import Ether, ARP
+from scapy.packet import Raw
+
+# Enable libpcap's L2listen
+conf.use_pcap = True
-__all__ = ['RxQueue', 'TxQueue', 'Interface', 'create_gratuitous_arp_request',
- 'auto_pad', 'checksum_equal']
+__all__ = [
+ u"RxQueue", u"TxQueue", u"Interface", u"create_gratuitous_arp_request",
+ u"auto_pad", u"checksum_equal"
+]
# TODO: http://stackoverflow.com/questions/320232/
# ensuring-subprocesses-are-dead-on-exiting-python-program
-class PacketVerifier(object):
+class PacketVerifier:
"""Base class for TX and RX queue objects for packet verifier."""
def __init__(self, interface_name):
- os.system('sudo echo 1 > /proc/sys/net/ipv6/conf/{0}/disable_ipv6'
- .format(interface_name))
- os.system('sudo ip link set {0} up promisc on'.format(interface_name))
- self._sock = socket.socket(socket.AF_PACKET, socket.SOCK_RAW,
- ETH_P_ALL)
- self._sock.bind((interface_name, ETH_P_ALL))
+ os.system(
+ f"sudo echo 1 > /proc/sys/net/ipv6/conf/{interface_name}/"
+ f"disable_ipv6"
+ )
+ os.system(f"sudo ip link set {interface_name} up promisc on")
self._ifname = interface_name
try:
ether_type = Ether(buf[0:14]).type
except AttributeError:
- raise RuntimeError(
- 'No EtherType in packet {0}'.format(buf.__repr__()))
+ raise RuntimeError(f"No EtherType in packet {buf!r}")
if ether_type == ETH_P_IP:
# 14 is Ethernet fame header size.
return None
elif ether_type == ETH_P_IPV6:
if not Ether(buf[0:14+6]).haslayer(IPv6):
- raise RuntimeError(
- 'Invalid IPv6 packet {0}'.format(buf.__repr__()))
+ raise RuntimeError(f"Invalid IPv6 packet {buf!r}")
# ... to add to the above, 40 bytes is the length of IPV6 header.
# The ipv6.len only contains length of the payload and not the header
- pkt_len = Ether(buf)['IPv6'].plen + 14 + 40
+ pkt_len = Ether(buf)[u"IPv6"].plen + 14 + 40
if len(buf) < 60:
return None
elif ether_type == ETH_P_ARP:
pkt = Ether(buf[:20])
if not pkt.haslayer(ARP):
- raise RuntimeError('Incomplete ARP packet')
+ raise RuntimeError(u"Incomplete ARP packet")
# len(eth) + arp(2 hw addr type + 2 proto addr type
# + 1b len + 1b len + 2b operation)
elif ether_type == 32821: # RARP (Reverse ARP)
pkt = Ether(buf[:20])
pkt.type = ETH_P_ARP # Change to ARP so it works with scapy
- pkt = Ether(str(pkt))
+ pkt = Ether(pkt)
if not pkt.haslayer(ARP):
pkt.show()
- raise RuntimeError('Incomplete RARP packet')
+ raise RuntimeError(u"Incomplete RARP packet")
# len(eth) + arp(2 hw addr type + 2 proto addr type
# + 1b len + 1b len + 2b operation)
del pkt
else:
- raise RuntimeError('Unknown protocol {0}'.format(ether_type))
+ raise RuntimeError(f"Unknown protocol {ether_type}")
if pkt_len < 60:
pkt_len = 60
:param queue: Queue in which this function will push incoming packets.
:type interface_name: str
:type queue: multiprocessing.Queue
- :returns: None
"""
- sock = socket.socket(socket.AF_PACKET, socket.SOCK_RAW, ETH_P_ALL)
- sock.bind((interface_name, ETH_P_ALL))
+ sock = conf.L2listen(iface=interface_name, type=ETH_P_ALL)
while True:
pkt = sock.recv(0x7fff)
"""
def __init__(self, interface_name):
PacketVerifier.__init__(self, interface_name)
+ self._sock = conf.L2listen(iface=interface_name, type=ETH_P_ALL)
def recv(self, timeout=3, ignore=None, verbose=True):
"""Read next received packet.
:returns: Ether() initialized object from packet data.
:rtype: scapy.Ether
"""
- (rlist, _, _) = select.select([self._sock], [], [], timeout)
- if self._sock not in rlist:
- return None
-
- pkt = self._sock.recv(0x7fff)
- pkt_pad = auto_pad(pkt)
- print'Received packet on {0} of len {1}'.format(self._ifname, len(pkt))
- if verbose:
- Ether(pkt).show2()
- print
-
+ ignore_list = list()
if ignore is not None:
- for i, ig_pkt in enumerate(ignore):
- # Auto pad all packets in ignore list
- ignore[i] = auto_pad(ig_pkt)
for ig_pkt in ignore:
- if ig_pkt == pkt_pad:
- # Found the packet in ignore list, get another one
- # TODO: subtract timeout - time_spent in here
- ignore.remove(ig_pkt)
- return self.recv(timeout, ignore, verbose)
-
- return Ether(pkt)
+ # Auto pad all packets in ignore list
+ ignore_list.append(str(auto_pad(ig_pkt)))
+ while True:
+ rlist, _, _ = select.select([self._sock], [], [], timeout)
+ if self._sock not in rlist:
+ return None
+
+ pkt = self._sock.recv(0x7fff)
+ pkt_pad = str(auto_pad(pkt))
+ print(f"Received packet on {self._ifname} of len {len(pkt)}")
+ if verbose:
+ if hasattr(pkt, u"show2"):
+ pkt.show2()
+ else:
+ # Never happens in practice, but Pylint does not know that.
+ print(f"Unexpected instance: {pkt!r}")
+ print()
+ if pkt_pad in ignore_list:
+ ignore_list.remove(pkt_pad)
+ print(u"Received packet ignored.")
+ continue
+ return pkt
class TxQueue(PacketVerifier):
"""
def __init__(self, interface_name):
PacketVerifier.__init__(self, interface_name)
+ self._sock = conf.L2socket(iface=interface_name, type=ETH_P_ALL)
def send(self, pkt, verbose=True):
"""Send packet out of the bound interface.
:param pkt: Packet to send.
- :param verbose: Used to supress detailed logging of sent packets.
+ :param verbose: Used to suppress detailed logging of sent packets.
:type pkt: string or scapy Packet derivative.
:type verbose: bool
"""
- print 'Sending packet out of {0} of len {1}'.format(self._ifname,
- len(pkt))
+ pkt = auto_pad(pkt)
+ print(f"Sending packet out of {self._ifname} of len {len(pkt)}")
if verbose:
- Ether(str(pkt)).show2()
- print
+ pkt.show2()
+ print()
- pkt = auto_pad(str(pkt))
self._sock.send(pkt)
-class Interface(object):
+class Interface:
"""Class for network interfaces. Contains methods for sending and receiving
packets."""
def __init__(self, if_name):
def create_gratuitous_arp_request(src_mac, src_ip):
"""Creates scapy representation of gratuitous ARP request."""
- return (Ether(src=src_mac, dst='ff:ff:ff:ff:ff:ff') /
- ARP(psrc=src_ip, hwsrc=src_mac, pdst=src_ip))
+ return (Ether(src=src_mac, dst=u"ff:ff:ff:ff:ff:ff") /
+ ARP(psrc=src_ip, hwsrc=src_mac, pdst=src_ip)
+ )
def auto_pad(packet):
"""Pads zeroes at the end of the packet if the total len < 60 bytes."""
- padded = str(packet)
- if len(padded) < 60:
- padded += ('\0' * (60 - len(padded)))
- return padded
+ # padded = str(packet)
+ if len(packet) < 60:
+ packet[Raw].load += (b"\0" * (60 - len(packet)))
+ return packet
def checksum_equal(chksum1, chksum2):