X-Git-Url: https://gerrit.fd.io/r/gitweb?p=csit.git;a=blobdiff_plain;f=resources%2Flibraries%2Fpython%2FPacketVerifier.py;h=793a8feb4b8dc7d9b94c2f363d5e453e17dbb925;hp=19d6aaf53ff72b3f4f5a7538ee9fe0b5e88e661a;hb=a060d519d0a89574f5e75d4e8d4c142fa5687555;hpb=8f285166faf13156a4f7c70adac9a7e20549268f diff --git a/resources/libraries/python/PacketVerifier.py b/resources/libraries/python/PacketVerifier.py index 19d6aaf53f..793a8feb4b 100644 --- a/resources/libraries/python/PacketVerifier.py +++ b/resources/libraries/python/PacketVerifier.py @@ -51,7 +51,7 @@ chksum = 0xa607 src = 11.11.11.11 dst = 11.11.11.10 - \options \ + options ###[ ICMP ]### type = echo-reply code = 0 @@ -63,19 +63,20 @@ """ +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.all import Ether, ARP 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 -# 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.""" @@ -95,21 +96,16 @@ 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: @@ -178,11 +174,11 @@ 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)) @@ -199,20 +195,12 @@ 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._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. @@ -220,22 +208,25 @@ 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 + print'Received packet on {0} of len {1}'.format(self._ifname, len(pkt)) + if verbose: + Ether(pkt).show2() + print if ignore is not None: for i, ig_pkt in enumerate(ignore): @@ -246,7 +237,7 @@ class RxQueue(PacketVerifier): # 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 self.recv(timeout, ignore, verbose) return Ether(pkt) @@ -257,47 +248,61 @@ 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) - 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): - return self.rxq.recv(timeout, self.sent_packets) + """Read one packet from the interface's receive queue. - def close(self): - #self.rxq._proc.terminate() - pass + :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)) @@ -309,3 +314,25 @@ 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