-# Copyright (c) 2016 Cisco and/or its affiliates.
+# Copyright (c) 2018 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 socket
-import select
import os
-import time
-from multiprocessing import Queue, Process
+import select
+
+from scapy.config import conf
from scapy.all import ETH_P_IP, ETH_P_IPV6, ETH_P_ALL, ETH_P_ARP
-from scapy.all import Ether, ARP, Packet
from scapy.layers.inet6 import IPv6
+from scapy.layers.l2 import Ether, ARP
+
+# Enable libpcap's L2listen
+conf.use_pcap = True
+import scapy.arch.pcapdnet # pylint: disable=C0413, unused-import
__all__ = ['RxQueue', 'TxQueue', 'Interface', 'create_gratuitous_arp_request',
- 'auto_pad']
+ 'auto_pad', 'checksum_equal']
+
+# TODO: http://stackoverflow.com/questions/320232/
+# ensuring-subprocesses-are-dead-on-exiting-python-program
-# TODO: http://stackoverflow.com/questions/320232/ensuring-subprocesses-are-dead-on-exiting-python-program
class PacketVerifier(object):
"""Base class for TX and RX queue objects for packet verifier."""
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))
self._ifname = interface_name
Takes string as input and looks for first whole packet in it.
If it finds one, it returns substring from the buf parameter.
- :param buf: string representation of incoming packet buffer.
- :type buf: string
- :return: String representation of first packet in buf.
- :rtype: string
+ :param buf: String representation of incoming packet buffer.
+ :type buf: str
+ :returns: String representation of first packet in buf.
+ :rtype: str
"""
pkt_len = 0
if len(buf) < 60:
return None
- # print
- # print buf.__repr__()
- # print Ether(buf).__repr__()
- # print len(Ether(buf))
- # print
try:
ether_type = Ether(buf[0:14]).type
except AttributeError:
This function is meant to be run in separate subprocess and is in tight
loop reading raw packets from interface passed as parameter.
- :param interace_name: Name of interface to read packets from.
+ :param interface_name: Name of interface to read packets from.
:param queue: Queue in which this function will push incoming packets.
- :type interface_name: string
+ :type interface_name: str
:type queue: multiprocessing.Queue
- :return: None
+ :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)
function to access them.
:param interface_name: Which interface to bind to.
- :type interface_name: string
+ :type interface_name: str
"""
-
def __init__(self, interface_name):
PacketVerifier.__init__(self, interface_name)
+ self._sock = conf.L2listen(iface=interface_name, type=ETH_P_ALL)
- #self._queue = Queue()
- #self._proc = Process(target=packet_reader, args=(interface_name,
- # self._queue))
- #self._proc.daemon = True
- #self._proc.start()
- #time.sleep(2)
-
- def recv(self, timeout=3, ignore=None):
+ def recv(self, timeout=3, ignore=None, verbose=True):
"""Read next received packet.
Returns scapy's Ether() object created from next packet in the queue.
arrives in given timeout queue.Empty exception will be risen.
:param timeout: How many seconds to wait for next packet.
+ :param ignore: List of packets that should be ignored.
+ :param verbose: Used to suppress detailed logging of received packets.
:type timeout: int
+ :type ignore: list
+ :type verbose: bool
- :return: Ether() initialized object from packet data.
+ :returns: Ether() initialized object from packet data.
:rtype: scapy.Ether
"""
-
- #pkt = self._queue.get(True, timeout=timeout)
- (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))
- 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)
-
- return Ether(pkt)
+ # Auto pad all packets in ignore list
+ ignore_list.append(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 = auto_pad(pkt)
+ print 'Received packet on {0} of len {1}'\
+ .format(self._ifname, len(pkt))
+ if verbose:
+ pkt.show2() # pylint: disable=no-member
+ print
+ if pkt_pad in ignore_list:
+ ignore_list.remove(pkt_pad)
+ print 'Received packet ignored.'
+ continue
+ else:
+ return pkt
class TxQueue(PacketVerifier):
This object is used to send packets over RAW socket on a interface.
:param interface_name: Which interface to send packets from.
- :type interface_name: string
+ :type interface_name: str
"""
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):
+ 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.
:type pkt: string or scapy Packet derivative.
+ :type verbose: bool
"""
print 'Sending packet out of {0} of len {1}'.format(self._ifname,
len(pkt))
- Ether(str(pkt)).show2()
- print
+ if verbose:
+ Ether(str(pkt)).show2()
+ print
pkt = auto_pad(str(pkt))
self._sock.send(pkt)
class Interface(object):
+ """Class for network interfaces. Contains methods for sending and receiving
+ packets."""
def __init__(self, if_name):
+ """Initialize the interface class.
+
+ :param if_name: Name of the interface.
+ :type if_name: str
+ """
self.if_name = if_name
self.sent_packets = []
self.rxq = RxQueue(if_name)
self.txq = TxQueue(if_name)
def send_pkt(self, pkt):
+ """Send the provided packet out the interface."""
self.sent_packets.append(pkt)
self.txq.send(pkt)
def recv_pkt(self, timeout=3):
+ """Read one packet from the interface's receive queue.
+
+ :param timeout: Timeout value in seconds.
+ :type timeout: int
+ :returns: Ether() initialized object from packet data.
+ :rtype: scapy.Ether
+ """
return self.rxq.recv(timeout, self.sent_packets)
def create_gratuitous_arp_request(src_mac, src_ip):
- """Creates scapy representation of gratuitous ARP request"""
+ """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))
padded += ('\0' * (60 - len(padded)))
return padded
+
+def checksum_equal(chksum1, chksum2):
+ """Compares two checksums in one's complement notation.
+
+ Checksums to be compared are calculated as 16 bit one's complement of the
+ one's complement sum of 16 bit words of some buffer.
+ In one's complement notation 0x0000 (positive zero) and 0xFFFF
+ (negative zero) are equivalent.
+
+ :param chksum1: First checksum.
+ :param chksum2: Second checksum.
+ :type chksum1: uint16
+ :type chksum2: uint16
+
+ :returns: True if checksums are equivalent, False otherwise.
+ :rtype: boolean
+ """
+ if chksum1 == 0xFFFF:
+ chksum1 = 0
+ if chksum2 == 0xFFFF:
+ chksum2 = 0
+ return chksum1 == chksum2
Code Review / csit.git / blobdiff