hostetherfilter.cc

COPE the first practical network coding scheme which is developped on click

/*
 * hostetherfilter.{cc,hh} -- Discard packets not for this host.
 * Robert Morris
 *
 * Copyright (c) 1999-2000 Massachusetts Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, subject to the conditions
 * listed in the Click LICENSE file. These conditions include: you must
 * preserve this copyright notice, and you cannot mention the copyright
 * holders in advertising related to the Software without their permission.
 * The Software is provided WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED. This
 * notice is a summary of the Click LICENSE file; the license in that file is
 * legally binding.
 */

#include <click/config.h>
#include "hostetherfilter.hh"
#include <click/confparse.hh>
#include <click/error.hh>
#include <click/glue.hh>
#include <click/etheraddress.hh>
#include <clicknet/ether.h>
CLICK_DECLS

HostEtherFilter::HostEtherFilter()
  : Element(1, 1)
{
}

HostEtherFilter::~HostEtherFilter()
{
}

void
HostEtherFilter::notify_noutputs(int n)
{
  set_noutputs(n < 2 ? 1 : 2);
}

int
HostEtherFilter::configure(Vector<String> &conf, ErrorHandler *errh)
{
  bool drop_own = false, drop_other = true;
  _offset = 0;
  if (cp_va_parse(conf, this, errh,
		  cpEthernetAddress, "Ethernet address", &_addr,
		  cpOptional,
		  cpBool, "Drop packets from us?", &drop_own,
		  cpBool, "Drop packets to others?", &drop_other,
		  cpKeywords,
		  "DROP_OWN", cpBool, "Drop packets from us?", &drop_own,
		  "DROP_OTHER", cpBool, "Drop packets to others?", &drop_other,
		  "OFFSET", cpUnsigned, "offset to IP header", &_offset,
		  cpEnd) < 0)
    return -1;
  _drop_own = drop_own;
  _drop_other = drop_other;
  return 0;
}

Packet *
HostEtherFilter::drop(Packet *p)
{
  if (noutputs() == 2)
    output(1).push(p);
  else
    p->kill();
  return 0;
}

Packet *
HostEtherFilter::simple_action(Packet *p)
{
  const click_ether *e = (const click_ether *) (p->data() + _offset);
  const unsigned short *daddr = (const unsigned short *)e->ether_dhost;

  if (_drop_own && memcmp(e->ether_shost, _addr, 6) == 0)
    return drop(p);
  else if (memcmp(e->ether_dhost, _addr, 6) == 0) {
    p->set_packet_type_anno(Packet::HOST);
    return p;
  } else if (daddr[0] == 0xFFFF && daddr[1] == 0xFFFF && daddr[2] == 0xFFFF) {
    p->set_packet_type_anno(Packet::BROADCAST);
    return p;
  } else if (e->ether_dhost[0] & 0x80) {
    p->set_packet_type_anno(Packet::MULTICAST);
    return p;
  } else {
    p->set_packet_type_anno(Packet::OTHERHOST);
    return (_drop_other ? drop(p) : p);
  }
}

CLICK_ENDDECLS
EXPORT_ELEMENT(HostEtherFilter)