chksum = 0xa607
src = 11.11.11.11
dst = 11.11.11.10
- \options \
+ options
###[ ICMP ]###
type = echo-reply
code = 0
seq = 0x0
###[ Padding ]###
load = 'RT\x00\xca]\x0b\xaa\xbb\xcc\xdd\xee\xff\x08\x06\x00\x01\x08\x00'
- >>> rxq._proc.terminate()
"""
-
-import socket
import os
-import time
-from multiprocessing import Queue, Process
+import select
+
+import interruptingcow
+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
def extract_one_packet(buf):
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)
- buf = ""
while True:
- recvd = sock.recv(1500)
- buf = buf + recvd
-
- pkt = extract_one_packet(buf)
- while pkt is not None:
- if pkt is None:
- break
- queue.put(pkt)
- buf = buf[len(pkt):]
- pkt = extract_one_packet(buf)
+ pkt = sock.recv(0x7fff)
+ queue.put(pkt)
class RxQueue(PacketVerifier):
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)
-
- 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:
- # 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)
+ (rlist, _, _) = select.select([self._sock], [], [], timeout)
+ if self._sock not in rlist:
+ return None
+ try:
+ with interruptingcow.timeout(timeout,
+ exception=RuntimeError('Timeout')):
+ ignore_list = list()
+ if ignore is not None:
+ for ig_pkt in ignore:
+ # Auto pad all packets in ignore list
+ ignore_list.append(auto_pad(ig_pkt))
+ while True:
+ 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
+ except RuntimeError:
+ return None
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
"""
- if isinstance(pkt, Packet):
- pkt = str(pkt)
- pkt = auto_pad(pkt)
+ print 'Sending packet out of {0} of len {1}'.format(self._ifname,
+ len(pkt))
+ 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.txq = TxQueue(if_name)
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):
- while True:
- pkt = self.rxq.recv(timeout, self.sent_packets)
- # TODO: FIX FOLLOWING: DO NOT SKIP RARP IN ALL TESTS!!!
- if pkt.type != 32821: # Skip RARP packets
- return pkt
+ """Read one packet from the interface's receive queue.
- def close(self):
- self.rxq._proc.terminate()
+ :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