ackreceiver.cc

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

#include <click/config.h>
#include <click/confparse.hh>
#include <click/error.hh>
#include <click/glue.hh>

#include <clicknet/ether.h>
#include <click/etheraddress.hh>
#include <click/ipaddress.hh>

#include "ackheader.hh"
#include "sendmanager.hh"
#include "ackreceiver.hh"

AckReceiver::AckReceiver()
  : Element(1, 0), 
    _aliases(0), _sendmgr(0), _myalias(0)
  //, _scrambleq(0)
{
}

AckReceiver::~AckReceiver()
{
}

int
AckReceiver::configure(Vector<String> &conf, ErrorHandler *errh)
{
  int res = cp_va_parse(conf, this, errh, 
			cpKeywords, 
			"ETH", cpEtherAddress, "Ethernet address", &_myea,
			"ALIASTABLE", cpElement, "Alias table", &_aliases,
			"SENDMGR", cpElement, "Send Manager", &_sendmgr,
			//"SCRAMBLEQUEUE", cpElement, "ScrambleQueue element", &_scrambleq,
			cpEnd);

  if (!_myea) {
    return errh->error("ETH not specified");
  }

  if (!_aliases) {
    return errh->error("ALIASTABLE not specified");
  }
  if (_aliases->cast("AliasTable") == 0) {
    return errh->error("ALIASTABLE element is not an AliasTable");
  }
    
  if (!_sendmgr) {
    return errh->error("SENDMGR not specified");
  }
  if (_sendmgr->cast("SendManager") == 0) {
    return errh->error("SENDMGR element is not a SendManager");
  }
    
  /*
  if (!_scrambleq) {
    return errh->error("SCRAMBLEQUEUE not specified");
  }
  if (_scrambleq->cast("ScrambleQueue") == 0) {
    return errh->error("SCRAMBLEQUEUE element is not a ScrambleQueue");
  }
  */
  
  _myalias = _aliases->lookup(_myea);
  click_chatter("%s: my alias is %u", id().cc(), _myalias);

  return res;
}

void
AckReceiver::push(int, Packet *p)
{
  click_ether *eth = (click_ether *)p->data();
  click_enc_ack *ackh = (struct click_enc_ack *)(eth+1);

  click_chatter("%s: push() called", id().cc());

  int idx = -1;
  for (uint16_t i = 0; i < ackh->nentries(); i++) {
    click_chatter("%s: push() looking for alias index %u", id().cc(), i);
    if (ackh->get_entry_nb(i) == _myalias) {
      idx = i;
      click_chatter("%s: push() matched entry %d of %d", id().cc(), idx, ackh->nentries());
      break;
    }
  }

  if (idx >= 0) {
    EtherAddress nbr = EtherAddress(eth->ether_shost);
    uint16_t seq = ackh->get_entry_seq(idx);
    uint8_t bmap = ackh->get_entry_bmap(idx);
    StringAccum sa;
    sa << "push() matched ack for nbr " << nbr << ", seq " << seq;
    click_chatter("%s: %s, bmap %x at %u", id().cc(), sa.c_str(), (uint32_t)bmap, Timestamp::now().msec1());
    register_acks(nbr, seq, bmap);
  }
  p->kill();

 // _scrambleq->register_next_rexmit_wakeup(_sendmgr->get_next_rexmit_time());

}

void
AckReceiver::register_acks(const EtherAddress &ea, uint16_t seq, uint8_t bmap)
{
  PacketID pid(ea, seq);
  _sendmgr->register_ack(pid);
  click_chatter("%s: register_acks called for packet with seq %d at %u", id().cc(), pid._seq, Timestamp::now().msec1());
  
  for (uint32_t i = 1; i <=8; i++) {
    if (bmap & (0x01 << (i-1))) {
      pid._seq = ((uint32_t)seq + i) % (1 << 15);
      click_chatter("%s: register_acks called for packet with seq %d at %u", id().cc(), pid._seq, Timestamp::now().msec1());
      _sendmgr->register_ack(pid);
    }
  }
}

  
EXPORT_ELEMENT(AckReceiver)