Add pypcap python requirement

Using pypcap's L2listen instead of standard AF_PACKET scapy can
see received Dot1Q tag.

Change-Id: Icb3dcb272a9611158a26a83fede7550bba3f367e
Signed-off-by: Matej Klotton <mklotton@cisco.com>

1 files changed, 34 insertions, 28 deletions

diff --git a/resources/libraries/python/PacketVerifier.py b/resources/libraries/python/PacketVerifier.py
index 793a8feb4b..4500961151 100644
--- a/resources/libraries/python/PacketVerifier.py
+++ b/resources/libraries/python/PacketVerifier.py
@@ -62,14 +62,18 @@
       load = 'RT\x00\xca]\x0b\xaa\xbb\xcc\xdd\xee\xff\x08\x06\x00\x01\x08\x00'
 """
 
-
 import os
-import socket
 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
 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', 'checksum_equal']
@@ -84,9 +88,6 @@ 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
 
 
@@ -180,8 +181,7 @@ def packet_reader(interface_name, queue):
     :type queue: multiprocessing.Queue
     :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)
@@ -199,6 +199,7 @@ class RxQueue(PacketVerifier):
     """
     def __init__(self, interface_name):
         PacketVerifier.__init__(self, interface_name)
+        self._sock = conf.L2listen(iface=interface_name, type=ETH_P_ALL)
 
     def recv(self, timeout=3, ignore=None, verbose=True):
         """Read next received packet.
@@ -220,26 +221,30 @@ class RxQueue(PacketVerifier):
         (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:
-            Ether(pkt).show2()
-            print
-
-        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, verbose)
-
-        return Ether(pkt)
+        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):
@@ -252,6 +257,7 @@ class TxQueue(PacketVerifier):
     """
     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, verbose=True):
         """Send packet out of the bound interface.