--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/devices/csma-cd/csma-cd-net-device.cc Fri Jul 27 21:17:14 2007 +0200
@@ -0,0 +1,504 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2007 Emmanuelle Laprise
+ * 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: Emmanuelle Laprise <emmanuelle.laprise@bluekazoo.ca>
+ */
+
+#include <iostream>
+#include <cassert>
+#include "ns3/debug.h"
+#include "ns3/queue.h"
+#include "ns3/simulator.h"
+#include "ns3/composite-trace-resolver.h"
+#include "csma-cd-net-device.h"
+#include "csma-cd-channel.h"
+#include "ns3/ethernet-header.h"
+#include "ns3/ethernet-trailer.h"
+#include "ns3/llc-snap-header.h"
+
+NS_DEBUG_COMPONENT_DEFINE ("CsmaCdNetDevice");
+
+namespace ns3 {
+
+CsmaCdNetDevice::CsmaCdNetDevice (Ptr<Node> node, MacAddress addr,
+ CsmaCdEncapsulationMode pktType)
+ : NetDevice(node, addr), m_bps (DataRate (0xffffffff))
+{
+ NS_DEBUG ("CsmaCdNetDevice::CsmaCdNetDevice (" << node << ")");
+ m_pktType = pktType;
+
+ Init(true, true);
+}
+
+CsmaCdNetDevice::CsmaCdNetDevice (Ptr<Node> node, MacAddress addr,
+ CsmaCdEncapsulationMode pktType,
+ bool sendEnable, bool receiveEnable)
+ : NetDevice(node, addr), m_bps (DataRate (0xffffffff))
+{
+ NS_DEBUG ("CsmaCdNetDevice::CsmaCdNetDevice (" << node << ")");
+ m_pktType = pktType;
+
+ Init(sendEnable, receiveEnable);
+}
+
+CsmaCdNetDevice::~CsmaCdNetDevice()
+{
+ NS_DEBUG ("CsmaCdNetDevice::~CsmaCdNetDevice ()");
+ m_queue = 0;
+}
+
+//
+// Copy constructor for CsmaCdNetDevice.
+//
+// We use the underlying NetDevice copy constructor to get the base class
+// copied. These just remain as is (e.g. you get the same name, the same
+// MAC address). If you need to fix them up, YOU, the copier need to do
+// that.
+//
+// The things we need to be careful of are the channel, the queue and the
+// trace callback. If the channel pointer is non-zero, we copy the pointer
+// and add a reference. If the queue is non-zero, we copy it using the queue
+// assignment operator. We don't mess with the trace -- we just reset it.
+// We're assuming that the tracing will be set up after the topology creation
+// phase and this won't actually matter.
+//
+
+CsmaCdNetDevice::CsmaCdNetDevice (const CsmaCdNetDevice& nd)
+ : NetDevice(nd), m_bps (nd.m_bps)
+{
+ NS_DEBUG ("CsmaCdNetDevice::CsmaCdNetDevice (" << &nd << ")");
+
+ m_txMachineState = READY;
+ m_tInterframeGap = nd.m_tInterframeGap;
+ m_backoff = nd.m_backoff;
+ m_channel = nd.m_channel;
+ m_queue = 0;
+ m_pktType = nd.m_pktType;
+ m_sendEnable = nd.m_sendEnable;
+ m_receiveEnable = nd.m_receiveEnable;
+
+ if (nd.m_queue)
+ {
+ m_queue = nd.m_queue;
+ }
+
+}
+
+void
+CsmaCdNetDevice::DoDispose ()
+{
+ m_channel = 0;
+ NetDevice::DoDispose ();
+}
+
+//
+// Assignment operator for CsmaCdNetDevice.
+//
+// This uses the non-obvious trick of taking the source net device passed by
+// value instead of by reference. This causes the copy constructor to be
+// invoked (where the real work is done -- see above). All we have to do
+// here is to return the newly constructed net device.
+//
+/*
+CsmaCdNetDevice&
+CsmaCdNetDevice::operator= (const CsmaCdNetDevice nd)
+{
+ NS_DEBUG ("CsmaCdNetDevice::operator= (" << &nd << ")");
+ return *this;
+}
+*/
+
+void
+CsmaCdNetDevice::Init(bool sendEnable, bool receiveEnable)
+{
+ m_txMachineState = READY;
+ m_tInterframeGap = Seconds(0);
+ m_channel = 0;
+ m_queue = 0;
+
+ EnableBroadcast (MacAddress ("ff:ff:ff:ff:ff:ff"));
+ EnableMulticast();
+ EnablePointToPoint();
+
+ SetSendEnable (sendEnable);
+ SetReceiveEnable (receiveEnable);
+}
+
+void
+CsmaCdNetDevice::SetSendEnable (bool sendEnable)
+{
+ m_sendEnable = sendEnable;
+}
+
+void
+CsmaCdNetDevice::SetReceiveEnable (bool receiveEnable)
+{
+ m_receiveEnable = receiveEnable;
+}
+bool
+CsmaCdNetDevice::IsSendEnabled (void)
+{
+ return (m_sendEnable);
+}
+
+bool
+CsmaCdNetDevice::IsReceiveEnabled (void)
+{
+ return (m_receiveEnable);
+}
+
+void
+CsmaCdNetDevice::SetDataRate (DataRate bps)
+{
+ m_bps = bps;
+}
+
+void
+CsmaCdNetDevice::SetInterframeGap (Time t)
+{
+ m_tInterframeGap = t;
+}
+
+void
+CsmaCdNetDevice::SetBackoffParams (Time slotTime, uint32_t minSlots,
+ uint32_t maxSlots, uint32_t ceiling,
+ uint32_t maxRetries)
+{
+ m_backoff.m_slotTime = slotTime;
+ m_backoff.m_minSlots = minSlots;
+ m_backoff.m_maxSlots = maxSlots;
+ m_backoff.m_ceiling = ceiling;
+ m_backoff.m_maxRetries = maxRetries;
+}
+void
+CsmaCdNetDevice::AddHeader (Packet& p, const MacAddress& dest,
+ uint16_t protocolNumber)
+{
+ if ((m_pktType == ETHERNET_V1) || (m_pktType == IP_ARP))
+ {
+ EthernetHeader header;
+ EthernetTrailer trailer;
+
+ header.SetSource(this->GetAddress());
+ header.SetDestination(dest);
+ switch (m_pktType)
+ {
+ case IP_ARP:
+ header.SetLengthType(protocolNumber);
+ break;
+ default:
+ header.SetLengthType(p.GetSize() + header.GetSize() + trailer.GetSize());
+ break;
+ }
+ p.AddHeader(header);
+ trailer.CalcFcs(p);
+ p.AddTrailer(trailer);
+ }
+ else if (m_pktType == LLC)
+ {
+ LlcSnapHeader llc;
+ llc.SetType (protocolNumber);
+ p.AddHeader (llc);
+ }
+}
+bool
+CsmaCdNetDevice::ProcessHeader(Packet& p, int& param)
+{
+ bool retVal = true;
+
+ if ((m_pktType == ETHERNET_V1) || (m_pktType == IP_ARP))
+ {
+ EthernetHeader header;
+ EthernetTrailer trailer;
+
+ p.RemoveTrailer(trailer);
+ trailer.CheckFcs(p);
+ p.RemoveHeader(header);
+
+ param = header.GetLengthType();
+ if ((header.GetDestination() != this->GetBroadcast()) &&
+ (header.GetDestination() != this->GetAddress()))
+ {
+ retVal = false;
+ }
+ }
+ else if (m_pktType == LLC)
+ {
+ LlcSnapHeader llc;
+ p.RemoveHeader (llc);
+
+ param = llc.GetType ();
+ }
+
+ return retVal;
+}
+
+bool
+CsmaCdNetDevice::DoNeedsArp (void) const
+{
+ if ((m_pktType == IP_ARP) || (m_pktType == LLC))
+ {
+ return true;
+ } else {
+ return false;
+ }
+}
+
+bool
+CsmaCdNetDevice::SendTo (Packet& p, const MacAddress& dest, uint16_t protocolNumber)
+{
+ NS_DEBUG ("CsmaCdNetDevice::SendTo (" << &p << ")");
+ NS_DEBUG ("CsmaCdNetDevice::SendTo (): UID is " << p.GetUid () << ")");
+
+ NS_ASSERT (IsLinkUp ());
+
+ // Only transmit if send side of net device is enabled
+ if (!IsSendEnabled())
+ return false;
+
+ AddHeader(p, dest, protocolNumber);
+
+ // Place the packet to be sent on the send queue
+ if (m_queue->Enqueue(p) == false )
+ {
+ return false;
+ }
+ // If the device is idle, we need to start a transmission. Otherwise,
+ // the transmission will be started when the current packet finished
+ // transmission (see TransmitCompleteEvent)
+ if (m_txMachineState == READY)
+ {
+ // Store the next packet to be transmitted
+ if (m_queue->Dequeue (m_currentPkt))
+ {
+ TransmitStart();
+ }
+ }
+ return true;
+}
+
+void
+CsmaCdNetDevice::TransmitStart ()
+{
+ NS_DEBUG ("CsmaCdNetDevice::TransmitStart (" << &m_currentPkt << ")");
+ NS_DEBUG ("CsmaCdNetDevice::TransmitStart (): UID is "
+ << m_currentPkt.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 it's time to tell the
+// channel that we're done wiggling the wire.
+//
+ NS_ASSERT_MSG((m_txMachineState == READY) || (m_txMachineState == BACKOFF),
+ "Must be READY to transmit. Tx state is: "
+ << m_txMachineState);
+
+ // Only transmit if send side of net device is enabled
+ if (!IsSendEnabled())
+ return;
+
+ if (m_channel->GetState() != IDLE)
+ { // Channel busy, backoff and rechedule TransmitStart()
+ m_txMachineState = BACKOFF;
+ if (m_backoff.MaxRetriesReached())
+ { // Too many retries reached, abort transmission of packet
+ TransmitAbort();
+ } else {
+ m_backoff.IncrNumRetries();
+ Time backoffTime = m_backoff.GetBackoffTime();
+
+ NS_DEBUG ("CsmaCdNetDevice::TransmitStart (): "
+ << "Channel busy, backing off for "
+ << backoffTime.GetSeconds () << "sec");
+
+ Simulator::Schedule (backoffTime,
+ &CsmaCdNetDevice::TransmitStart,
+ this);
+ }
+ } else {
+ // Channel is free, transmit packet
+ m_txMachineState = BUSY;
+ Time tEvent = Seconds (m_bps.CalculateTxTime(m_currentPkt.GetSize()));
+
+ NS_DEBUG ("CsmaCdNetDevice::TransmitStart (): " <<
+ "Schedule TransmitCompleteEvent in " <<
+ tEvent.GetSeconds () << "sec");
+
+ Simulator::Schedule (tEvent,
+ &CsmaCdNetDevice::TransmitCompleteEvent,
+ this);
+ if (!m_channel->TransmitStart (m_currentPkt, m_deviceId))
+ {
+ NS_DEBUG ("CsmaCdNetDevice::TransmitStart (): " <<
+ "Channel transmit start did not work at " <<
+ tEvent.GetSeconds () << "sec");
+ m_txMachineState = READY;
+ } else {
+ // Transmission success, reset backoff time parameters.
+ m_backoff.ResetBackoffTime();
+ }
+ }
+}
+
+
+void
+CsmaCdNetDevice::TransmitAbort (void)
+{
+ NS_DEBUG ("CsmaCdNetDevice::TransmitAbort ()");
+
+ NS_DEBUG ("CsmaCdNetDevice::TransmitAbort (): Pkt UID is " <<
+ m_currentPkt.GetUid () << ")");
+
+ // Try to transmit a new packet
+ bool found;
+ found = m_queue->Dequeue (m_currentPkt);
+ NS_ASSERT_MSG(found, "IsEmpty false but no Packet on queue?");
+ m_backoff.ResetBackoffTime();
+ m_txMachineState = READY;
+ TransmitStart ();
+}
+
+void
+CsmaCdNetDevice::TransmitCompleteEvent (void)
+{
+ NS_DEBUG ("CsmaCdNetDevice::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
+// schedule an event that will be executed when it's time to re-enable
+// the transmitter after the interframe gap.
+//
+ NS_ASSERT_MSG(m_txMachineState == BUSY, "Must be BUSY if transmitting");
+ // Channel should be transmitting
+ NS_ASSERT(m_channel->GetState() == TRANSMITTING);
+ m_txMachineState = GAP;
+
+ NS_DEBUG ("CsmaCdNetDevice::TransmitCompleteEvent (): Pkt UID is " <<
+ m_currentPkt.GetUid () << ")");
+ m_channel->TransmitEnd ();
+
+ NS_DEBUG (
+ "CsmaCdNetDevice::TransmitCompleteEvent (): " <<
+ "Schedule TransmitReadyEvent in "
+ << m_tInterframeGap.GetSeconds () << "sec");
+
+ Simulator::Schedule (m_tInterframeGap,
+ &CsmaCdNetDevice::TransmitReadyEvent,
+ this);
+}
+
+void
+CsmaCdNetDevice::TransmitReadyEvent (void)
+{
+ NS_DEBUG ("CsmaCdNetDevice::TransmitReadyEvent ()");
+//
+// This function is called to enable the transmitter after the interframe
+// gap has passed. If there are pending transmissions, we use this opportunity
+// to start the next transmit.
+//
+ NS_ASSERT_MSG(m_txMachineState == GAP, "Must be in interframe gap");
+ m_txMachineState = READY;
+
+ // Get the next packet from the queue for transmitting
+ if (m_queue->IsEmpty())
+ {
+ return;
+ }
+ else
+ {
+ bool found;
+ found = m_queue->Dequeue (m_currentPkt);
+ NS_ASSERT_MSG(found, "IsEmpty false but no Packet on queue?");
+ TransmitStart ();
+ }
+}
+
+TraceResolver *
+CsmaCdNetDevice::DoCreateTraceResolver (TraceContext const &context)
+{
+ CompositeTraceResolver *resolver = new CompositeTraceResolver (context);
+ resolver->Add ("queue",
+ MakeCallback (&Queue::CreateTraceResolver,
+ PeekPointer (m_queue)),
+ CsmaCdNetDevice::QUEUE);
+ resolver->Add ("rx",
+ m_rxTrace,
+ CsmaCdNetDevice::RX);
+ return resolver;
+}
+
+bool
+CsmaCdNetDevice::Attach (Ptr<CsmaCdChannel> ch)
+{
+ NS_DEBUG ("CsmaCdNetDevice::Attach (" << &ch << ")");
+
+ m_channel = ch;
+
+ m_deviceId = m_channel->Attach(this);
+ m_bps = m_channel->GetDataRate ();
+ m_tInterframeGap = m_channel->GetDelay ();
+
+ /*
+ * For now, this device is up whenever a channel is attached to it.
+ */
+ NotifyLinkUp ();
+ return true;
+}
+
+void
+CsmaCdNetDevice::AddQueue (Ptr<Queue> q)
+{
+ NS_DEBUG ("CsmaCdNetDevice::AddQueue (" << q << ")");
+
+ m_queue = q;
+}
+
+void
+CsmaCdNetDevice::Receive (Packet& p)
+{
+ NS_DEBUG ("CsmaCdNetDevice::Receive UID is (" << p.GetUid() << ")");
+
+ // Only receive if send side of net device is enabled
+ if (!IsReceiveEnabled())
+ return;
+
+ int param = 0;
+ Packet packet = p;
+
+ if (ProcessHeader(packet, param))
+ {
+ m_rxTrace (packet);
+ ForwardUp (packet, param);
+ } else {
+ m_dropTrace (packet);
+ }
+}
+
+Ptr<Queue>
+CsmaCdNetDevice::GetQueue(void) const
+{
+ return m_queue;
+}
+
+Ptr<Channel>
+CsmaCdNetDevice::DoGetChannel(void) const
+{
+ return m_channel;
+}
+
+} // namespace ns3