X-Git-Url: https://gerrit.fd.io/r/gitweb?p=csit.git;a=blobdiff_plain;f=resources%2Flibraries%2Fpython%2FPacketVerifier.py;h=d1e7bbd229a8e479f105c173cfa2ff8ec86c39c0;hp=9af14e3dce302e5fbaf63602ba31d26810f5c39f;hb=4c6fe5602edcbd9857a846e5b13a21d5c671a2c8;hpb=c8d76a16533edac586a98d2842932804709fea30 diff --git a/resources/libraries/python/PacketVerifier.py b/resources/libraries/python/PacketVerifier.py index 9af14e3dce..d1e7bbd229 100644 --- a/resources/libraries/python/PacketVerifier.py +++ b/resources/libraries/python/PacketVerifier.py @@ -1,4 +1,4 @@ -# 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: @@ -13,69 +13,75 @@ """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.""" @@ -83,9 +89,6 @@ class PacketVerifier(object): 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 @@ -95,21 +98,16 @@ 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: @@ -178,14 +176,13 @@ def packet_reader(interface_name, queue): 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) @@ -199,20 +196,13 @@ 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. @@ -220,35 +210,38 @@ class RxQueue(PacketVerifier): 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): @@ -257,43 +250,62 @@ 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)) @@ -305,3 +317,25 @@ def auto_pad(packet): 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