setretry.cc

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

/*
 * setretry.{cc,hh} -- (re)sets wifi max retries annotation on a packet
 * Wenjun Hu
 *
 * Copyright (c) 2005 University of Cambridge
 * Copyright (c) 2005 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 <click/confparse.hh>
#include <click/error.hh>
#include <click/glue.hh>
#include <click/packet_anno.hh>
#include "setretry.hh"
//#include <clicknet/ether.h>
//#include <click/etheraddress.hh>
#include <clicknet/wifi.h>
CLICK_DECLS

SetRetry::SetRetry()
  : Element(1, 1), _retries(WIFI_MAX_RETRIES)
{
}

SetRetry::~SetRetry()
{
}

int
SetRetry::configure(Vector<String> &conf, ErrorHandler *errh)
{
  if (cp_va_parse(conf, this, errh,
		  cpOptional,
		  cpUnsigned, "retries", &_retries, 
		  cpKeywords, 
		  "RETRIES", cpUnsigned, "retries", &_retries, 
		  cpEnd) < 0) {
    return -1;
  }

  if (_retries < 0) {
    return errh->error("RETRIES must be >= 0");
    _retries = WIFI_MAX_RETRIES;
  }

  return 0;
}

Packet *
SetRetry::simple_action(Packet *p_in)
{
  struct click_wifi_extra *ceh = (struct click_wifi_extra *) p_in->all_user_anno();

  if (_retries == 0) {
    ceh->max_tries = 1;
    ceh->max_tries1 = 0;
    ceh->max_tries2 = 0;
    ceh->max_tries3 = 0;
  } else {
    if (_retries <= WIFI_MAX_RETRIES)  
      ceh->max_tries = _retries + 1;
  }

  return p_in;
}

String
SetRetry::max_retries(Element *e, void *thunk)
{
  SetRetry *setretry = (SetRetry *)e;
  return String(setretry->_retries) + "\n";
}

int
SetRetry::update_retries(const String &arg, Element *e,
			 void *vparam, ErrorHandler *errh) 
{
  SetRetry *f = (SetRetry *) e;
  String s = cp_uncomment(arg);

  unsigned m;

  if (!cp_unsigned(s, &m)) 
    return errh->error("retry parameter must be unsigned");

  f->_retries = m;
  
  if (m > WIFI_MAX_RETRIES)
    click_chatter("Max number of retries is %d ; this new value %d will be ignored", WIFI_MAX_RETRIES, m);

  return 0;
}

void
SetRetry::add_handlers()
{
  add_default_handlers(true);
  add_read_handler("retries", max_retries, 0);
  add_write_handler("retries", update_retries, 0);
}

CLICK_ENDDECLS
EXPORT_ELEMENT(SetRetry)