#!/usr/bin/env python3 import sys from scapy.all import ( FieldLenField, IntField, IPOption, Packet, PacketListField, ShortField, get_if_list, sniff ) from scapy.layers.inet import _IPOption_HDR def get_if(): ifs=get_if_list() iface=None for i in get_if_list(): if "eth0" in i: iface=i break; if not iface: print("Cannot find eth0 interface") exit(1) return iface class SwitchTrace(Packet): fields_desc = [ IntField("swid", 0), IntField("qdepth", 0)] def extract_padding(self, p): return "", p class IPOption_MRI(IPOption): name = "MRI" option = 31 fields_desc = [ _IPOption_HDR, FieldLenField("length", None, fmt="B", length_of="swtraces", adjust=lambda pkt,l:l*2+4), ShortField("count", 0), PacketListField("swtraces", [], SwitchTrace, count_from=lambda pkt:(pkt.count*1)) ] def handle_pkt(pkt): print("got a packet") pkt.show2() # hexdump(pkt) sys.stdout.flush() def main(): iface = 'eth0' print("sniffing on %s" % iface) sys.stdout.flush() sniff(filter="udp and port 4321", iface = iface, prn = lambda x: handle_pkt(x)) if __name__ == '__main__': main()