--- a/src/devices/wifi/mac-low.cc Wed Feb 03 20:34:50 2010 +0100
+++ b/src/devices/wifi/mac-low.cc Wed Feb 03 20:34:51 2010 +0100
@@ -1,6 +1,7 @@
/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2005,2006 INRIA
+ * Copyright (c) 2009 MIRKO BANCHI
*
* 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
@@ -16,6 +17,7 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
+ * Author: Mirko Banchi <mk.banchi@gmail.com>
*/
#include "ns3/assert.h"
@@ -28,6 +30,7 @@
#include "mac-low.h"
#include "wifi-phy.h"
#include "wifi-mac-trailer.h"
+#include "qos-utils.h"
NS_LOG_COMPONENT_DEFINE ("MacLow");
@@ -1298,4 +1301,138 @@
ForwardDown (packet, &ack, ackTxMode);
}
+bool
+MacLow::StoreMpduIfNeeded (Ptr<Packet> packet, WifiMacHeader hdr)
+{
+ AgreementsI it = m_bAckAgreements.find (std::make_pair (hdr.GetAddr2 (), hdr.GetQosTid ()));
+ if (it != m_bAckAgreements.end ())
+ {
+ WifiMacTrailer fcs;
+ packet->RemoveTrailer (fcs);
+ BufferedPacket bufferedPacket (packet, hdr);
+
+ uint16_t endSequence = ((*it).second.first.GetStartingSequence () + 2047) % 4096;
+ uint16_t mappedSeqControl = QosUtilsMapSeqControlToUniqueInteger (hdr.GetSequenceControl () ,endSequence);
+
+ BufferedPacketI i = (*it).second.second.begin ();
+ for (; i != (*it).second.second.end () &&
+ QosUtilsMapSeqControlToUniqueInteger ((*i).second.GetSequenceControl (), endSequence) < mappedSeqControl; i++);
+ (*it).second.second.insert (i, bufferedPacket);
+ return true;
+ }
+ return false;
+}
+
+void
+MacLow::CreateBlockAckAgreement (const MgtAddBaResponseHeader *respHdr, Mac48Address originator,
+ uint16_t startingSeq)
+{
+ BlockAckAgreement agreement (originator, respHdr->GetTid ());
+ if (respHdr->IsImmediateBlockAck ())
+ {
+ agreement.SetImmediateBlockAck ();
+ }
+ else
+ {
+ agreement.SetDelayedBlockAck ();
+ }
+ agreement.SetAmsduSupport (respHdr->IsAmsduSupported ());
+ agreement.SetBufferSize (respHdr->GetBufferSize ());
+ agreement.SetTimeout (respHdr->GetTimeout ());
+ agreement.SetStartingSequence (startingSeq);
+
+ std::list<BufferedPacket> buffer (0);
+ AgreementKey key (originator, respHdr->GetTid ());
+ AgreementValue value (agreement, buffer);
+ m_bAckAgreements.insert (std::make_pair (key, value));
+}
+
+void
+MacLow::DestroyBlockAckAgreement (Mac48Address originator, uint8_t tid)
+{
+ AgreementsI it = m_bAckAgreements.find (std::make_pair (originator, tid));
+ if (it != m_bAckAgreements.end ())
+ {
+ RxCompleteBufferedPacketsWithSmallerSequence (it->second.first.GetStartingSequence (), originator, tid);
+ RxCompleteBufferedPackets (originator, tid);
+ m_bAckAgreements.erase (it);
+ }
+}
+
+void
+MacLow::RxCompleteBufferedPacketsWithSmallerSequence (uint16_t seq, Mac48Address originator, uint8_t tid)
+{
+ AgreementsI it = m_bAckAgreements.find (std::make_pair (originator, tid));
+ if (it != m_bAckAgreements.end ())
+ {
+ BufferedPacketI i = (*it).second.second.begin ();
+ uint16_t endSequence = ((*it).second.first.GetStartingSequence () + 2047) % 4096;
+ uint16_t mappedStart = QosUtilsMapSeqControlToUniqueInteger (seq, endSequence);
+ uint16_t guard = (*it).second.first.GetStartingSequence ();
+ BufferedPacketI last = (*it).second.second.begin ();
+
+ for (; i != (*it).second.second.end () &&
+ QosUtilsMapSeqControlToUniqueInteger ((*i).second.GetSequenceNumber (), endSequence) < mappedStart;)
+ {
+ while (i != (*it).second.second.end () && guard == (*i).second.GetSequenceControl ())
+ {
+ if (!(*i).second.IsMoreFragments ())
+ {
+ while (last != i)
+ {
+ m_rxCallback ((*last).first, &(*last).second);
+ last++;
+ }
+ m_rxCallback ((*last).first, &(*last).second);
+ last++;
+ }
+ guard = (*i).second.IsMoreFragments () ? (guard + 1) : ((guard + 16) & 0xfff0);
+ }
+ /* go to next packet */
+ while (i != (*it).second.second.end () && ((guard >> 4) & 0x0fff) == (*i).second.GetSequenceNumber ())
+ {
+ i++;
+ }
+ if (i != (*it).second.second.end ())
+ {
+ guard = (*i).second.GetSequenceControl () & 0xfff0;
+ last = i;
+ }
+ }
+ (*it).second.second.erase ((*it).second.second.begin (), i);
+ }
+}
+
+void
+MacLow::RxCompleteBufferedPackets (Mac48Address originator, uint8_t tid)
+{
+ AgreementsI it = m_bAckAgreements.find (std::make_pair (originator, tid));
+ if (it != m_bAckAgreements.end ())
+ {
+ uint16_t startingSeqCtrl = ((*it).second.first.GetStartingSequence ()<<4) & 0xfff0;
+ uint16_t guard = startingSeqCtrl;
+
+ BufferedPacketI lastComplete = (*it).second.second.begin ();
+ BufferedPacketI i = (*it).second.second.begin ();
+ for (;i != (*it).second.second.end() && guard == (*i).second.GetSequenceControl (); i++)
+ {
+ if (!(*i).second.IsMoreFragments ())
+ {
+ while (lastComplete != i)
+ {
+ m_rxCallback ((*lastComplete).first, &(*lastComplete).second);
+ lastComplete++;
+ }
+ m_rxCallback ((*lastComplete).first, &(*lastComplete).second);
+ lastComplete++;
+ }
+ guard = (*i).second.IsMoreFragments () ? (guard + 1) : ((guard + 16) & 0xfff0);
+ }
+ (*it).second.first.SetStartingSequence ((guard>>4)&0x0fff);
+ /* All packets already forwarded to WifiMac must be removed from buffer:
+ [begin (), lastComplete) */
+ (*it).second.second.erase ((*it).second.second.begin (), lastComplete);
+ }
+}
+
} // namespace ns3
--- a/src/devices/wifi/mac-low.h Wed Feb 03 20:34:50 2010 +0100
+++ b/src/devices/wifi/mac-low.h Wed Feb 03 20:34:51 2010 +0100
@@ -1,6 +1,7 @@
/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2005, 2006 INRIA
+ * Copyright (c) 2009 MIRKO BANCHI
*
* 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
@@ -16,6 +17,7 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
+ * Author: Mirko Banchi <mk.banchi@gmail.com>
*/
#ifndef MAC_LOW_H
#define MAC_LOW_H
@@ -23,12 +25,15 @@
#include <vector>
#include <stdint.h>
#include <ostream>
+#include <map>
#include "wifi-mac-header.h"
#include "wifi-mode.h"
#include "wifi-preamble.h"
#include "wifi-remote-station-manager.h"
#include "ctrl-headers.h"
+#include "mgt-headers.h"
+#include "block-ack-agreement.h"
#include "ns3/mac48-address.h"
#include "ns3/callback.h"
#include "ns3/event-id.h"
@@ -411,6 +416,27 @@
* occurs, pending MAC transmissions (RTS, CTS, DATA and ACK) are cancelled.
*/
void NotifySwitchingStartNow (Time duration);
+ /**
+ * \param respHdr Add block ack response from originator (action frame).
+ * \param originator Address of peer station involved in block ack mechanism.
+ * \param startingSeq Sequence number of the first MPDU of all packets for which block ack was negotiated.
+ *
+ * This function is typically invoked only by ns3::QapWifiMac and ns3::QstaWifiMac.
+ * If we are transmitting an Add block ack response, MacLow must allocate buffers to collect
+ * all correctly received packets belonging to category for which block ack was negotiated.
+ * It's needed in order to send a Block ack after corresponding originator's Block ack request.
+ */
+ void CreateBlockAckAgreement (const MgtAddBaResponseHeader *respHdr, Mac48Address originator,
+ uint16_t startingSeq);
+ /**
+ * \param originator Address of peer partecipating in Block Ack mechanism.
+ * \param tid TID for which Block Ack was created.
+ *
+ * Checks if exists an established block ack agreement with <i>originator</i>
+ * for tid <i>tid</i>. If the agreement exists, tears down it. This function is typically
+ * invoked when a DELBA frame is received from <i>originator</i>.
+ */
+ void DestroyBlockAckAgreement (Mac48Address originator, uint8_t tid);
private:
void CancelAllEvents (void);
uint32_t GetAckSize (void) const;
@@ -456,6 +482,35 @@
void SendCurrentTxPacket (void);
void StartDataTxTimers (void);
virtual void DoDispose (void);
+ /**
+ * \param originator Address of peer partecipating in Block Ack mechanism.
+ * \param tid TID for which Block Ack was created.
+ * \param seq Starting sequence
+ *
+ * This function forward up all completed "old" packets with sequence number
+ * smaller than <i>seq</i>. All comparison are performed circularly mod 4096.
+ */
+ void RxCompleteBufferedPacketsWithSmallerSequence (uint16_t seq, Mac48Address originator, uint8_t tid);
+ /**
+ * \param originator Address of peer partecipating in Block Ack mechanism.
+ * \param tid TID for which Block Ack was created.
+ *
+ * This method is typically invoked when a MPDU with ack policy
+ * subfield set to Normal Ack is received and a block ack agreement
+ * for that packet exists.
+ * This happens when the originator of block ack has only few MPDUs to send.
+ * All completed MSDUs starting with starting sequence number of block ack
+ * agreement are forward up to WifiMac until there is an incomplete MSDU.
+ * See section 9.10.4 in IEEE802.11 standard for more details.
+ */
+ void RxCompleteBufferedPackets (Mac48Address originator, uint8_t tid);
+ /*
+ * This method checks if exists a valid established block ack agreement.
+ * If there is, store the packet without pass it up to WifiMac. The packet is buffered
+ * in order of increasing sequence control field. All comparison are performed
+ * circularly modulo 2^12.
+ */
+ bool StoreMpduIfNeeded (Ptr<Packet> packet, WifiMacHeader hdr);
void SetupPhyMacLowListener (Ptr<WifiPhy> phy);
@@ -494,6 +549,20 @@
// Listerner needed to monitor when a channel switching occurs.
class PhyMacLowListener *m_phyMacLowListener;
+
+ /*
+ * BlockAck data structures.
+ */
+ typedef std::pair<Ptr<Packet>, WifiMacHeader> BufferedPacket;
+ typedef std::list<BufferedPacket>::iterator BufferedPacketI;
+
+ typedef std::pair<Mac48Address, uint8_t> AgreementKey;
+ typedef std::pair<BlockAckAgreement, std::list<BufferedPacket> > AgreementValue;
+
+ typedef std::map<AgreementKey, AgreementValue> Agreements;
+ typedef std::map<AgreementKey, AgreementValue>::iterator AgreementsI;
+
+ Agreements m_bAckAgreements;
};
} // namespace ns3
--- a/src/devices/wifi/qadhoc-wifi-mac.cc Wed Feb 03 20:34:50 2010 +0100
+++ b/src/devices/wifi/qadhoc-wifi-mac.cc Wed Feb 03 20:34:51 2010 +0100
@@ -528,7 +528,7 @@
packet->AddHeader (actionHdr);
/* ns3::MacLow have to buffer all correctly received packet for this block ack session */
- //m_low->CreateIngoingAgreement (&respHdr, originator, reqHdr->GetStartingSequence ());
+ m_low->CreateBlockAckAgreement (&respHdr, originator, reqHdr->GetStartingSequence ());
//Better a management queue?
m_queues[QosUtilsMapTidToAc (reqHdr->GetTid ())]->PushFront (packet, hdr);
--- a/src/devices/wifi/qap-wifi-mac.cc Wed Feb 03 20:34:50 2010 +0100
+++ b/src/devices/wifi/qap-wifi-mac.cc Wed Feb 03 20:34:51 2010 +0100
@@ -881,7 +881,7 @@
packet->AddHeader (actionHdr);
/* ns3::MacLow have to buffer all correctly received packet for this block ack session */
- //m_low->CreateIngoingAgreement (&respHdr, originator, reqHdr->GetStartingSequence ());
+ m_low->CreateBlockAckAgreement (&respHdr, originator, reqHdr->GetStartingSequence ());
//Better a management queue?
m_queues[QosUtilsMapTidToAc (reqHdr->GetTid ())]->PushFront (packet, hdr);
--- a/src/devices/wifi/qos-utils.cc Wed Feb 03 20:34:50 2010 +0100
+++ b/src/devices/wifi/qos-utils.cc Wed Feb 03 20:34:51 2010 +0100
@@ -16,6 +16,7 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Author: Mirko Banchi <mk.banchi@gmail.com>
+ * Author: Cecchi Niccolò <insa@igeek.it>
*/
#include "qos-utils.h"
#include "qos-tag.h"
@@ -69,4 +70,16 @@
return tid;
}
+uint32_t
+QosUtilsMapSeqControlToUniqueInteger (uint16_t seqControl, uint16_t endSequence)
+{
+ uint32_t integer = 0;
+ uint16_t numberSeq = (seqControl>>4) & 0x0fff;
+ integer = (4096 - (endSequence + 1) + numberSeq) % 4096;
+ integer *= 16;
+ integer += (seqControl & 0x000f);
+ return integer;
+}
+
+
} //namespace ns3
--- a/src/devices/wifi/qos-utils.h Wed Feb 03 20:34:50 2010 +0100
+++ b/src/devices/wifi/qos-utils.h Wed Feb 03 20:34:51 2010 +0100
@@ -45,6 +45,13 @@
*/
uint8_t QosUtilsGetTidForPacket (Ptr<const Packet> packet);
+/*
+ * Next function is useful to correctly sort buffered packets under block ack.
+ * When an BAR is received from originator station, completed "old"
+ * (see section 9.10.3 in IEEE802.11e) packets must be forwarded up before "new" packets.
+ */
+uint32_t QosUtilsMapSeqControlToUniqueInteger (uint16_t seqControl, uint16_t endSequence);
+
} //namespace ns3
#endif /* QOS_UTILS_H */
--- a/src/devices/wifi/qsta-wifi-mac.cc Wed Feb 03 20:34:50 2010 +0100
+++ b/src/devices/wifi/qsta-wifi-mac.cc Wed Feb 03 20:34:51 2010 +0100
@@ -857,7 +857,7 @@
packet->AddHeader (actionHdr);
/* ns3::MacLow have to buffer all correctly received packet for this block ack session */
- //m_low->CreateIngoingAgreement (&respHdr, originator, reqHdr->GetStartingSequence ());
+ m_low->CreateBlockAckAgreement (&respHdr, originator, reqHdr->GetStartingSequence ());
//Better a management queue?
m_queues[QosUtilsMapTidToAc (reqHdr->GetTid ())]->PushFront (packet, hdr);