diff options
Diffstat (limited to 'resources/libraries/python/PacketVerifier.py')
| -rw-r--r-- | resources/libraries/python/PacketVerifier.py | 79 |
1 files changed, 40 insertions, 39 deletions
diff --git a/resources/libraries/python/PacketVerifier.py b/resources/libraries/python/PacketVerifier.py index 978babf7ce..397ce76f49 100644 --- a/resources/libraries/python/PacketVerifier.py +++ b/resources/libraries/python/PacketVerifier.py @@ -1,4 +1,4 @@ -# Copyright (c) 2018 Cisco and/or its affiliates. +# Copyright (c) 2019 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: @@ -67,28 +67,33 @@ import os 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.config import conf from scapy.layers.inet6 import IPv6 from scapy.layers.l2 import Ether, ARP +from scapy.packet import Raw # 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', 'checksum_equal'] +__all__ = [ + u"RxQueue", u"TxQueue", u"Interface", u"create_gratuitous_arp_request", + u"auto_pad", u"checksum_equal" +] # TODO: http://stackoverflow.com/questions/320232/ # ensuring-subprocesses-are-dead-on-exiting-python-program -class PacketVerifier(object): +class PacketVerifier: """Base class for TX and RX queue objects for packet verifier.""" def __init__(self, interface_name): - 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)) + os.system( + f"sudo echo 1 > /proc/sys/net/ipv6/conf/{interface_name}/" + f"disable_ipv6" + ) + os.system(f"sudo ip link set {interface_name} up promisc on") self._ifname = interface_name @@ -111,8 +116,7 @@ def extract_one_packet(buf): try: ether_type = Ether(buf[0:14]).type except AttributeError: - raise RuntimeError( - 'No EtherType in packet {0}'.format(buf.__repr__())) + raise RuntimeError(f"No EtherType in packet {buf!r}") if ether_type == ETH_P_IP: # 14 is Ethernet fame header size. @@ -124,17 +128,16 @@ def extract_one_packet(buf): return None elif ether_type == ETH_P_IPV6: if not Ether(buf[0:14+6]).haslayer(IPv6): - raise RuntimeError( - 'Invalid IPv6 packet {0}'.format(buf.__repr__())) + raise RuntimeError(f"Invalid IPv6 packet {buf!r}") # ... to add to the above, 40 bytes is the length of IPV6 header. # The ipv6.len only contains length of the payload and not the header - pkt_len = Ether(buf)['IPv6'].plen + 14 + 40 + pkt_len = Ether(buf)[u"IPv6"].plen + 14 + 40 if len(buf) < 60: return None elif ether_type == ETH_P_ARP: pkt = Ether(buf[:20]) if not pkt.haslayer(ARP): - raise RuntimeError('Incomplete ARP packet') + raise RuntimeError(u"Incomplete ARP packet") # len(eth) + arp(2 hw addr type + 2 proto addr type # + 1b len + 1b len + 2b operation) @@ -146,10 +149,10 @@ def extract_one_packet(buf): elif ether_type == 32821: # RARP (Reverse ARP) pkt = Ether(buf[:20]) pkt.type = ETH_P_ARP # Change to ARP so it works with scapy - pkt = Ether(str(pkt)) + pkt = Ether(pkt) if not pkt.haslayer(ARP): pkt.show() - raise RuntimeError('Incomplete RARP packet') + raise RuntimeError(u"Incomplete RARP packet") # len(eth) + arp(2 hw addr type + 2 proto addr type # + 1b len + 1b len + 2b operation) @@ -159,7 +162,7 @@ def extract_one_packet(buf): del pkt else: - raise RuntimeError('Unknown protocol {0}'.format(ether_type)) + raise RuntimeError(f"Unknown protocol {ether_type}") if pkt_len < 60: pkt_len = 60 @@ -222,25 +225,23 @@ class RxQueue(PacketVerifier): if ignore is not None: for ig_pkt in ignore: # Auto pad all packets in ignore list - ignore_list.append(auto_pad(ig_pkt)) + ignore_list.append(str(auto_pad(ig_pkt))) while True: - (rlist, _, _) = select.select([self._sock], [], [], 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)) + pkt_pad = str(auto_pad(pkt)) + print(f"Received packet on {self._ifname} of len {len(pkt)}") if verbose: pkt.show2() # pylint: disable=no-member - print + print() if pkt_pad in ignore_list: ignore_list.remove(pkt_pad) - print 'Received packet ignored.' + print(u"Received packet ignored.") continue - else: - return pkt + return pkt class TxQueue(PacketVerifier): @@ -259,21 +260,20 @@ class TxQueue(PacketVerifier): """Send packet out of the bound interface. :param pkt: Packet to send. - :param verbose: Used to supress detailed logging of sent packets. + :param verbose: Used to suppress 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)) + pkt = auto_pad(pkt) + print(f"Sending packet out of {self._ifname} of len {len(pkt)}") if verbose: - Ether(str(pkt)).show2() - print + pkt.show2() + print() - pkt = auto_pad(str(pkt)) self._sock.send(pkt) -class Interface(object): +class Interface: """Class for network interfaces. Contains methods for sending and receiving packets.""" def __init__(self, if_name): @@ -305,16 +305,17 @@ class Interface(object): def create_gratuitous_arp_request(src_mac, src_ip): """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)) + return (Ether(src=src_mac, dst=u"ff:ff:ff:ff:ff:ff") / + ARP(psrc=src_ip, hwsrc=src_mac, pdst=src_ip) + ) def auto_pad(packet): """Pads zeroes at the end of the packet if the total len < 60 bytes.""" - padded = str(packet) - if len(padded) < 60: - padded += ('\0' * (60 - len(padded))) - return padded + # padded = str(packet) + if len(packet) < 60: + packet[Raw].load += (b"\0" * (60 - len(packet))) + return packet def checksum_equal(chksum1, chksum2): |