/* * pingpong.{cc,hh} -- ping-pong link quality/strength stats back to link sender * Douglas S. J. De Couto * * Copyright (c) 1999-2002 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 <clicknet/ether.h>#include "pingpong.hh"#include <click/glue.hh>#include "grid.hh"#include "linkstat.hh"CLICK_DECLSPingPong::PingPong(){  add_input();  add_output();}PingPong::~PingPong(){}intPingPong::configure(Vector<String> &conf, ErrorHandler *errh){  int res = cp_va_parse(conf, this, errh,			cpElement, "LinkStat element", &_ls,			cpEnd);  if (res < 0)    return res;    return res;}intPingPong::initialize(ErrorHandler *){  return 0;}Packet *PingPong::simple_action(Packet *p){  click_ether *eh = (click_ether *) p->data();  grid_hdr *gh = (grid_hdr *) (eh + 1);  switch (gh->type) {  case grid_hdr::GRID_NBR_ENCAP:   case grid_hdr::GRID_LOC_REPLY:  case grid_hdr::GRID_ROUTE_PROBE:   case grid_hdr::GRID_ROUTE_REPLY: {#ifndef SMALL_GRID_HEADERS    grid_nbr_encap *nb = (grid_nbr_encap *) (gh + 1);    nb->link_qual = 0;    nb->link_sig = 0;    nb->measurement_time.tv_sec = nb->measurement_time.tv_usec = 0;    EtherAddress eth(eh->ether_dhost);    LinkStat::stat_t *s = _ls->_stats.findp(eth);    if (s) {      nb->link_qual = htonl(s->qual);      nb->link_sig = htonl(s->sig);      nb->measurement_time.tv_sec = htonl(s->when.tv_sec);      nb->measurement_time.tv_usec = htonl(s->when.tv_usec);          }    else      click_chatter("PingPong: error!  unable to get signal strength or quality info for one-hop neighbor %s\n",		    IPAddress(nb->dst_ip).s().cc());        nb->num_rx = 0;    nb->num_expected = 0;    nb->last_bcast.tv_sec = nb->last_bcast.tv_usec = 0;    unsigned int window = 0;    unsigned int num_rx = 0;    unsigned int num_expected = 0;    bool res = _ls->get_bcast_stats(eth, nb->last_bcast, window, num_rx, num_expected);    if (res) {      if (num_rx > 255 || num_expected > 255) {	click_chatter("PingPong: error! overflow on broadcast loss stats for one-hop neighbor %s",		      IPAddress(nb->dst_ip).s().cc());	num_rx = num_expected = 255;      }      nb->num_rx = num_rx;      nb->num_expected = num_expected;      nb->last_bcast = hton(nb->last_bcast);    }#endif  }  break;  default:    ;  }    return p;}CLICK_ENDDECLSEXPORT_ELEMENT(PingPong)