"""
+import os
import socket
import select
-import os
-import time
-from multiprocessing import Queue, Process
+
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
__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
+
class PacketVerifier(object):
"""Base class for TX and RX queue objects for packet verifier."""
def __init__(self, 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
+ :param buf: String representation of incoming packet buffer.
+ :type buf: str
:return: String representation of first packet in buf.
- :rtype: string
+ :rtype: str
"""
pkt_len = 0
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
"""
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._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):
"""Read next received packet.
arrives in given timeout queue.Empty exception will be risen.
:param timeout: How many seconds to wait for next packet.
+ :param ignore: Packet list that should be ignored.
:type timeout: int
+ :type ignore: list
:return: 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
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)
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
+
+ :return: True if checksums are equivalent, False otherwise.
+ :rtype: boolean
+ """
+ if chksum1 == 0xFFFF:
+ chksum1 = 0
+ if chksum2 == 0xFFFF:
+ chksum2 = 0
+ return chksum1 == chksum2