I am confused

p4app/controller.py

@@ -8,7 +8,7 @@ from p4utils.utils.sswitch_API import SimpleSwitchAPI
 
 from scapy.all import sniff, get_if_list, Ether, get_if_hwaddr, sendp
 from scapy.all import IP, Raw, IPv6, TCP, TCP_client
-from scapy.all import Ether, sniff, Packet, BitField
+from scapy.all import Ether, sniff, Packet, BitField, IntEnumField, ShortField
 from scapy.all import ICMPv6ND_NS
 
 import sys
@@ -24,12 +24,18 @@ logging.basicConfig()
 log = logging.getLogger("main")
 
 
+cpu_fields = {
+    1: 'ICMP6_NS',
+    2: 'ICMP6_GENERAL',
+    3: 'DEBUG'
+}
+
 
 class CpuHeader(Packet):
     name = 'CpuPacket'
     fields_desc = [
-        BitField('task',0,8),
-        BitField('ingress_port', 0, 16)
+        IntEnumField('task', 1, cpu_fields ),
+        ShortField('ingress_port', 0)
     ]
 
 
@@ -38,11 +44,8 @@ class L2Controller(object):
         # Command line mapping
         self.modes = ['base', 'router']
 
-        self.task = {
-            'ICMP6_NS': 1,
-            'ICMP6_GENERAL': 2,
-            'DEBUG': 3
-        }
+        # Reverse maps the cpu header
+        self.task = dict(reversed(item) for item in cpu_fields.items())
 
         self.info={}
         self.info['ndp_multicast'] = ipaddress.ip_network("ff02::1:ff00:0/104")
@@ -227,6 +230,7 @@ class L2Controller(object):
         packet = Ether(str(pkg))
 
         self.debug_print_pkg(pkg)
+        print("p={}".format(pkg.__repr__()))
 
         if packet.type == 0x0800:
             pass
@@ -235,8 +239,31 @@ class L2Controller(object):
         elif packet.type == 0x4242:
             print("Special handling needed")
             cpu_header = CpuHeader(packet.payload)
-            print("cpu = {}".format(cpu_header.__repr__()))
-            print("orig = {}".format(pkg))
+
+            print("cpu = {} {}".format(cpu_header.__repr__(), len(cpu_header)))
+
+            ether_part = pkg[Ether]
+            # read from cpu header
+            ether_part.type = 0x86dd
+
+            ether_orig = Ether(src=packet.src, dst=packet.dst, type=0x86dd)
+
+            # used to find correct offset = 3
+
+            # for i in range(1, 32):
+            #     content_orig  = packet.load[i:]
+            #     try:
+            #         orig_packet = ether_orig / IPv6(content_orig)
+            #         print("{}: {}".format(i, orig_packet.__repr__()))
+
+            #     except Exception as e:
+            #         pass
+
+            orig_packet = ether_orig / IPv6(packet.load[3:])
+            self.debug_print_pkg(orig_packet)
+            print("o={}".format(orig_packet.__repr__()))
+
+
         else:
             print("Broken pkg: {}".format(pkg.__repr__()))
             return