/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2005,2006 INRIA
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation;
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Author: Craig Dowell <craigdo@ee.washington.edu>
* Revised: George Riley <riley@ece.gatech.edu>
*/
#include <iostream>
#include <cassert>
#include "ns3/debug.h"
#include "ns3/queue.h"
#include "ns3/simulator.h"
#include "ns3/composite-trace-resolver.h"
#include "ns3/eui48-address.h"
#include "ns3/llc-snap-header.h"
#include "point-to-point-net-device.h"
#include "point-to-point-channel.h"
NS_DEBUG_COMPONENT_DEFINE ("PointToPointNetDevice");
namespace ns3 {
DataRateDefaultValue PointToPointNetDevice::g_defaultRate(
"PointToPointLinkDataRate",
"The default data rate for point to point links",
DataRate ("10Mb/s"));
PointToPointTraceType::PointToPointTraceType ()
{}
void
PointToPointTraceType::Print (std::ostream &os) const
{
os << "dev-rx";
}
uint16_t
PointToPointTraceType::GetUid (void)
{
static uint16_t uid = AllocateUid<PointToPointTraceType> ("PointToPointTraceType");
return uid;
}
std::string
PointToPointTraceType::GetTypeName (void) const
{
return "ns3::PointToPointTraceType";
}
PointToPointNetDevice::PointToPointNetDevice (Ptr<Node> node,
const DataRate& rate)
:
NetDevice(node, Eui48Address::Allocate ()),
m_txMachineState (READY),
m_bps (rate),
m_tInterframeGap (Seconds(0)),
m_channel (0),
m_queue (0),
m_rxTrace ()
{
NS_DEBUG ("PointToPointNetDevice::PointToPointNetDevice (" << node << ")");
// BUGBUG FIXME
//
// You _must_ support broadcast to get any sort of packet from the ARP layer.
EnableBroadcast (Eui48Address ("ff:ff:ff:ff:ff:ff"));
EnableMulticast();
EnablePointToPoint();
}
PointToPointNetDevice::~PointToPointNetDevice()
{
NS_DEBUG ("PointToPointNetDevice::~PointToPointNetDevice ()");
m_queue = 0;
}
void
PointToPointNetDevice::AddHeader(Packet& p, uint16_t protocolNumber)
{
LlcSnapHeader llc;
llc.SetType (protocolNumber);
p.AddHeader (llc);
}
bool
PointToPointNetDevice::ProcessHeader(Packet& p, uint16_t& param)
{
LlcSnapHeader llc;
p.RemoveHeader (llc);
param = llc.GetType ();
return true;
}
void PointToPointNetDevice::DoDispose()
{
m_channel = 0;
NetDevice::DoDispose ();
}
void PointToPointNetDevice::SetDataRate(const DataRate& bps)
{
m_bps = bps;
}
void PointToPointNetDevice::SetInterframeGap(const Time& t)
{
m_tInterframeGap = t;
}
bool PointToPointNetDevice::SendTo (const Packet& packet, const Address& dest,
uint16_t protocolNumber)
{
Packet p = packet;
NS_DEBUG ("PointToPointNetDevice::SendTo (" << &p << ", " << &dest << ")");
NS_DEBUG ("PointToPointNetDevice::SendTo (): UID is " << p.GetUid () << ")");
// GFR Comment. Why is this an assertion? Can't a link legitimately
// "go down" during the simulation? Shouldn't we just wait for it
// to come back up?
NS_ASSERT (IsLinkUp ());
AddHeader(p, protocolNumber);
//
// This class simulates a point to point device. In the case of a serial
// link, this means that we're simulating something like a UART.
//
//
// If there's a transmission in progress, we enque the packet for later
// trnsmission; otherwise we send it now.
if (m_txMachineState == READY)
{
return TransmitStart (p);
}
else
{
return m_queue->Enqueue(p);
}
}
bool
PointToPointNetDevice::TransmitStart (Packet &p)
{
NS_DEBUG ("PointToPointNetDevice::TransmitStart (" << &p << ")");
NS_DEBUG (
"PointToPointNetDevice::TransmitStart (): UID is " << p.GetUid () << ")");
//
// This function is called to start the process of transmitting a packet.
// We need to tell the channel that we've started wiggling the wire and
// schedule an event that will be executed when the transmission is complete.
//
NS_ASSERT_MSG(m_txMachineState == READY, "Must be READY to transmit");
m_txMachineState = BUSY;
Time txTime = Seconds (m_bps.CalculateTxTime(p.GetSize()));
Time txCompleteTime = txTime + m_tInterframeGap;
NS_DEBUG ("PointToPointNetDevice::TransmitStart (): " <<
"Schedule TransmitCompleteEvent in " <<
txCompleteTime.GetSeconds () << "sec");
// Schedule the tx complete event
Simulator::Schedule (txCompleteTime,
&PointToPointNetDevice::TransmitComplete,
this);
return m_channel->TransmitStart(p, this, txTime);
}
void PointToPointNetDevice::TransmitComplete (void)
{
NS_DEBUG ("PointToPointNetDevice::TransmitCompleteEvent ()");
//
// This function is called to finish the process of transmitting a packet.
// We need to tell the channel that we've stopped wiggling the wire and
// get the next packet from the queue. If the queue is empty, we are
// done, otherwise transmit the next packet.
//
NS_ASSERT_MSG(m_txMachineState == BUSY, "Must be BUSY if transmitting");
m_txMachineState = READY;
Packet p;
if (!m_queue->Dequeue(p)) return; // Nothing to do at this point
TransmitStart(p);
}
Ptr<TraceResolver>
PointToPointNetDevice::GetTraceResolver (void) const
{
Ptr<CompositeTraceResolver> resolver = Create<CompositeTraceResolver> ();
resolver->AddComposite ("queue", m_queue);
resolver->AddSource ("rx",
TraceDoc ("receive MAC packet",
"const Packet &", "packet received"),
m_rxTrace,
PointToPointTraceType ());
resolver->SetParentResolver (NetDevice::GetTraceResolver ());
return resolver;
}
bool PointToPointNetDevice::Attach (Ptr<PointToPointChannel> ch)
{
NS_DEBUG ("PointToPointNetDevice::Attach (" << &ch << ")");
m_channel = ch;
m_channel->Attach(this);
m_bps = m_channel->GetDataRate ();
// GFR Comment. Below is definitely wrong. Interframe gap
// is unrelated to channel delay.
//m_tInterframeGap = m_channel->GetDelay ();
/*
* For now, this device is up whenever a channel is attached to it.
* In fact, it should become up only when the second device
* is attached to the channel. So, there should be a way for
* a PointToPointChannel to notify both of its attached devices
* that the channel is 'complete', hence that the devices are
* up, hence that they can call NotifyLinkUp.
*/
NotifyLinkUp ();
return true;
}
void PointToPointNetDevice::AddQueue (Ptr<Queue> q)
{
NS_DEBUG ("PointToPointNetDevice::AddQueue (" << q << ")");
m_queue = q;
}
void PointToPointNetDevice::Receive (Packet& p)
{
NS_DEBUG ("PointToPointNetDevice::Receive (" << &p << ")");
uint16_t protocol = 0;
Packet packet = p;
m_rxTrace (packet);
ProcessHeader(packet, protocol);
ForwardUp (packet, protocol, GetBroadcast ());
}
Ptr<Queue> PointToPointNetDevice::GetQueue(void) const
{
return m_queue;
}
Ptr<Channel> PointToPointNetDevice::DoGetChannel(void) const
{
return m_channel;
}
bool PointToPointNetDevice::DoNeedsArp (void) const
{
return false;
}
} // namespace ns3