14#include "ns3/packet.h"
15#include "ns3/simulator.h"
31 .SetGroupName(
"Internet")
33 .AddTraceSource(
"UnackSequence",
34 "First unacknowledged sequence number (SND.UNA)",
36 "ns3::SequenceNumber32TracedValueCallback");
172 NS_LOG_LOGIC(
"Try to append " << p->GetSize() <<
" bytes to window starting at "
176 if (p->GetSize() > 0)
179 item->m_packet = p->Copy();
188 NS_LOG_LOGIC(
"Rejected. Not enough room to buffer packet.");
201 return static_cast<uint32_t>(lastSeq - seq);
204 NS_LOG_ERROR(
"Requested a sequence beyond our space (" << seq <<
" > " << lastSeq
205 <<
"). Returning 0 for convenience.");
215 "Requested a sequence number which is not in the buffer anymore");
235 NS_LOG_DEBUG(
"Returning already sent item " << *outItem <<
" from " << *
this);
240 "Requesting a piece of new data with an hole");
247 NS_LOG_DEBUG(
"Returning new item " << *outItem <<
" from " << *
this);
263 "Returning an item " << *outItem <<
" with SND.UNA as " <<
m_firstByteSeq);
301 bool listEdited =
false;
308 if ((*it)->m_startSeq == seq)
316 if ((!(*next)->m_sacked) && ((*it)->m_lost == (*next)->m_lost))
318 s = std::min(s, (*it)->m_packet->GetSize() + (*next)->m_packet->GetSize());
323 s = std::min(s, (*it)->m_packet->GetSize());
328 s = std::min(s, (*it)->m_packet->GetSize());
345std::pair<TcpTxBuffer::PacketList::const_iterator, SequenceNumber32>
359 ret = std::make_pair(it, beginOfCurrentPacket);
370 NS_ASSERT(t1 !=
nullptr && t2 !=
nullptr);
384 NS_LOG_INFO(
"Split of size " << size <<
" result: t1 " << *t1 <<
" t2 " << *t2);
392 bool* listEdited)
const
426 auto it = list.begin();
429 while (it != list.end())
432 currentPacket = currentItem->
m_packet;
435 <<
" currentItem start: " << currentItem->
m_startSeq);
440 if (seq < beginOfCurrentPacket + currentPacket->
GetSize())
443 if (seq == beginOfCurrentPacket)
446 outItem = currentItem;
447 NS_LOG_INFO(
"Current packet starts at seq " << seq <<
" ends at "
448 << seq + currentPacket->GetSize());
450 else if (seq > beginOfCurrentPacket)
455 NS_LOG_INFO(
"we are at " << beginOfCurrentPacket <<
" searching for " << seq
456 <<
" and now we recurse because packet ends at "
457 << beginOfCurrentPacket + currentPacket->GetSize());
459 SplitItems(firstPart, currentItem, seq - beginOfCurrentPacket);
462 list.insert(it, firstPart);
478 beginOfCurrentPacket += currentPacket->GetSize();
489 if (seq + numBytes <= beginOfCurrentPacket + currentPacket->
GetSize())
492 if (numBytes == currentPacket->GetSize())
520 else if (numBytes < currentPacket->
GetSize())
528 list.insert(it, firstPart);
541 if (++it == list.end())
545 NS_LOG_WARN(
"Cannot reach the end, but this case is covered "
546 "with conditional statements inside CopyFromSequence."
547 "Something has gone wrong, report a bug");
577 NS_ASSERT(t1 !=
nullptr && t2 !=
nullptr);
582 "Merging one sacked and another not sacked. Impossible");
632 "Trying to remove " << size <<
" bytes from " <<
m_lostOut);
671 while (
m_size > 0 && offset > 0)
686 "Item starts at " << item->
m_startSeq <<
" while SND.UNA is "
702 if (!beforeDelCb.
IsNull())
724 <<
" resulting item is " << *item
725 <<
" status: " << *
this);
746 NS_LOG_INFO(
"Moving the SACK flag from the HEAD to another segment");
752 "While removing up to " << seq <<
" we get SND.UNA to " <<
m_firstByteSeq
753 <<
" this is the result: " << *
this);
764 NS_LOG_LOGIC(
"Buffer status after discarding data " << *
this);
774 NS_LOG_INFO(
"Updating scoreboard, got " << list.size() <<
" blocks to analyze");
778 for (
auto option_it = list.begin(); option_it != list.end(); ++option_it)
785 NS_LOG_INFO(
"Not updating scoreboard, the option block is outside the sent list");
798 if (beginOfCurrentPacket >= (*option_it).first &&
799 beginOfCurrentPacket +
pktSize <= (*option_it).second)
801 if ((*item_it)->m_sacked)
804 NS_LOG_INFO(
"Received block " << *option_it <<
", checking sentList for block "
806 <<
", found in the sackboard already sacked");
810 if ((*item_it)->m_lost)
812 (*item_it)->m_lost =
false;
813 m_lostOut -= (*item_it)->m_packet->GetSize();
816 (*item_it)->m_sacked =
true;
818 bytesSacked += (*item_it)->m_packet->GetSize();
824 m_highestSack = std::make_pair(item_it, beginOfCurrentPacket);
828 << *option_it <<
", checking sentList for block " << *(*item_it)
829 <<
", found in the sackboard, sacking, current highSack: "
838 else if (beginOfCurrentPacket +
pktSize > (*option_it).second)
841 NS_LOG_INFO(
"Received block [" << *option_it <<
", checking sentList for block "
842 << *(*item_it) <<
"], not found, breaking loop");
846 beginOfCurrentPacket +=
pktSize;
874 <<
", will start from the latest sent item");
878 NS_LOG_INFO(
"Status before the update: " << *
this <<
", will start from item "
929 if ((*it)->m_startSeq <= seq && seq < (*it)->m_startSeq + (*it)->m_packet->GetSize())
933 NS_LOG_INFO(
"seq=" << seq <<
" is lost because of lost flag");
939 NS_LOG_INFO(
"seq=" << seq <<
" is not lost because of sacked flag");
968 bool isSeqPerRule3Valid =
false;
981 NS_LOG_INFO(
"IsLost, returning" << beginOfCurrentPkt);
982 *seq = beginOfCurrentPkt;
986 else if (seqPerRule3.
GetValue() == 0 && isRecovery)
988 NS_LOG_INFO(
"Saving for rule 3 the seq " << beginOfCurrentPkt);
989 isSeqPerRule3Valid =
true;
990 seqPerRule3 = beginOfCurrentPkt;
1015 NS_LOG_INFO(
"There is no available receiver window to send");
1030 if (isSeqPerRule3Valid)
1059 <<
" is out of sync with sent list size " <<
m_sentSize <<
" "
1095 bool isLost =
IsLostRFC(beginOfCurrentPkt, it);
1123 "Lost counted: " << lostOut <<
" " <<
m_lostOut <<
"\n"
1126 "Retrans Counted: " << retrans <<
" " <<
m_retrans <<
"\n"
1129 "Sacked counted: " << sackedOut <<
" " <<
m_sackedOut << *
this);
1131 "Sent size counted: " << totalSize <<
" " <<
m_sentSize << *
this);
1142 PacketList::const_iterator it;
1147 if ((*segment)->m_sacked)
1157 for (it = segment; it !=
m_sentList.end(); ++it)
1164 NS_LOG_INFO(
"Segment " << *item <<
" found to be SACKed while checking for " << seq);
1166 bytes += current->GetSize();
1169 NS_LOG_INFO(
"seq=" << seq <<
" is lost because of 3 sacked blocks ahead");
1181 NS_LOG_INFO(
"seq=" << seq <<
" is not lost because there are no sacked segment ahead");
1185 beginOfCurrentPacket += current->GetSize();
1189 NS_LOG_INFO(
"seq=" << seq <<
" is not lost because there are no sacked segment ahead "
1203 (*it)->m_sacked =
false;
1281 (*it)->m_sacked =
false;
1282 (*it)->m_lost =
true;
1289 m_lostOut += (*it)->m_packet->GetSize();
1291 else if (!(*it)->m_sacked)
1294 (*it)->m_lost =
true;
1295 m_lostOut += (*it)->m_packet->GetSize();
1299 (*it)->m_retrans =
false;
1302 NS_LOG_INFO(
"Set sent list lost, status: " << *
this);
1387 while (it !=
m_sentList.end() && (*it)->m_sacked)
1395 (*it)->m_sacked =
true;
1399 NS_LOG_INFO(
"Added a Reno SACK, status: " << *
this);
1403 NS_LOG_INFO(
"Can't add a Reno SACK because we miss segments. This dupack"
1404 " should be arrived from spurious retransmissions");
1413 static const bool enable =
false;
1426 if ((*it)->m_sacked)
1428 sacked += (*it)->m_packet->GetSize();
1432 lost += (*it)->m_packet->GetSize();
1434 if ((*it)->m_retrans)
1436 retrans += (*it)->m_packet->GetSize();
1441 "Counted SACK: " << sacked <<
" stored SACK: " <<
m_sackedOut);
1444 " Counted retrans: " << retrans <<
" stored retrans: " <<
m_retrans);
1457 std::stringstream ss;
1465 p = (*it)->GetPacket();
1469 sentSize += p->GetSize();
1470 beginOfCurrentPacket += p->GetSize();
1475 appSize += (*it)->GetPacket()->GetSize();
1478 os <<
"Sent list: " << ss.str() <<
", size = " << tcpTxBuf.
m_sentList.size()
bool IsNull() const
Check for null implementation.
A base class which provides memory management and object aggregation.
void AddAtEnd(Ptr< const Packet > packet)
Concatenate the input packet at the end of the current packet.
uint32_t GetSize() const
Returns the the size in bytes of the packet (including the zero-filled initial payload).
void RemoveAtStart(uint32_t size)
Remove size bytes from the start of the current packet.
Ptr< Packet > CreateFragment(uint32_t start, uint32_t length) const
Create a new packet which contains a fragment of the original packet.
Smart pointer class similar to boost::intrusive_ptr.
NUMERIC_TYPE GetValue() const
Extracts the numeric value of the sequence number.
static Time Now()
Return the current simulation virtual time.
std::list< SackBlock > SackList
SACK list definition.
uint32_t m_retrans
Number of retransmitted bytes.
void ResetRenoSack()
Reset the SACKs.
void ConsistencyCheck() const
Check if the values of sacked, lost, retrans, are in sync with the sent list.
bool m_sackEnabled
Indicates if SACK is enabled on this connection.
uint32_t m_lostOut
Number of lost bytes.
bool IsLostRFC(const SequenceNumber32 &seq, const PacketList::const_iterator &segment) const
Decide if a segment is lost based on RFC 6675 algorithm.
std::pair< TcpTxBuffer::PacketList::const_iterator, SequenceNumber32 > FindHighestSacked() const
Find the highest SACK byte.
SequenceNumber32 HeadSequence() const
Get the sequence number of the buffer head.
std::pair< PacketList::const_iterator, SequenceNumber32 > m_highestSack
Highest SACK byte.
bool IsHeadRetransmitted() const
Check if the head is retransmitted.
bool Add(Ptr< Packet > p)
Append a data packet to the end of the buffer.
void SetSegmentSize(uint32_t segmentSize)
Set the segment size.
uint32_t GetRetransmitsCount() const
Return the number of segments in the sent list that have been transmitted more than once,...
bool IsRetransmittedDataAcked(const SequenceNumber32 &ack) const
Checks whether the ack corresponds to retransmitted data.
static TypeId GetTypeId()
Get the type ID.
TcpTxItem * GetPacketFromList(PacketList &list, const SequenceNumber32 &startingSeq, uint32_t numBytes, const SequenceNumber32 &requestedSeq, bool *listEdited=nullptr) const
Get a block (which is returned as Packet) from a list.
uint32_t SizeFromSequence(const SequenceNumber32 &seq) const
Returns the number of bytes from the buffer in the range [seq, tailSequence)
TracedValue< SequenceNumber32 > m_firstByteSeq
Sequence number of the first byte in data (SND.UNA)
std::list< TcpTxItem * > PacketList
container for data stored in the buffer
uint32_t MaxBufferSize() const
Get the maximum buffer size.
TcpTxItem * GetTransmittedSegment(uint32_t numBytes, const SequenceNumber32 &seq)
Get a block of data previously transmitted.
uint32_t m_maxBuffer
Max number of data bytes in buffer (SND.WND)
bool m_renoSack
Indicates if AddRenoSack was called.
bool m_sackSeen
Indicates if a SACK was received.
uint32_t m_dupAckThresh
Duplicate Ack threshold from TcpSocketBase.
uint32_t Size() const
Returns total number of bytes in this buffer.
void SetSackEnabled(bool enabled)
tell tx-buffer whether SACK is used on this TCP socket
uint32_t m_sackedOut
Number of sacked bytes.
void ResetLastSegmentSent()
Take the last segment sent and put it back into the un-sent list (at the beginning)
bool IsLost(const SequenceNumber32 &seq) const
Check if a segment is lost.
bool NextSeg(SequenceNumber32 *seq, SequenceNumber32 *seqHigh, bool isRecovery) const
Get the next sequence number to transmit, according to RFC 6675.
void SetDupAckThresh(uint32_t dupAckThresh)
Set the DupAckThresh.
TcpTxItem * CopyFromSequence(uint32_t numBytes, const SequenceNumber32 &seq)
Copy data from the range [seq, seq+numBytes) into a packet.
bool IsSackEnabled() const
check whether SACK is used on the corresponding TCP socket
TcpTxItem * GetNewSegment(uint32_t numBytes)
Get a block of data not transmitted yet and move it into SentList.
uint32_t Available() const
Returns the available capacity of this buffer.
uint32_t m_segmentSize
Segment size from TcpSocketBase.
uint32_t Update(const TcpOptionSack::SackList &list, const Callback< void, TcpTxItem * > &sackedCb=m_nullCb)
Update the scoreboard.
uint32_t GetLost() const
Get the number of segments that we believe are lost in the network.
void AddRenoSack()
Emulate SACKs for SACKless connection: account for a new dupack.
void MarkHeadAsLost()
Mark the head of the sent list as lost.
void UpdateLostCount()
Update the lost count.
SequenceNumber32 TailSequence() const
Get the sequence number of the buffer tail (plus one)
Callback< uint32_t > m_rWndCallback
Callback to obtain RCV.WND value.
void SetRWndCallback(Callback< uint32_t > rWndCallback)
Set callback to obtain receiver window value.
uint32_t BytesInFlight() const
Return total bytes in flight.
void SetSentListLost(bool resetSack=false)
Set the entire sent list as lost (typically after an RTO)
void SplitItems(TcpTxItem *t1, TcpTxItem *t2, uint32_t size) const
Split one TcpTxItem.
void DiscardUpTo(const SequenceNumber32 &seq, const Callback< void, TcpTxItem * > &beforeDelCb=m_nullCb)
Discard data up to but not including this sequence number.
uint32_t BytesInFlightRFC() const
Calculate the number of bytes in flight per RFC 6675.
PacketList m_appList
Buffer for application data.
uint32_t GetSacked() const
Get the number of segments that have been explicitly sacked by the receiver.
void MergeItems(TcpTxItem *t1, TcpTxItem *t2) const
Merge two TcpTxItem.
uint32_t m_size
Size of all data in this buffer.
void ResetSentList()
Reset the sent list.
void DeleteRetransmittedFlagFromHead()
DeleteRetransmittedFlagFromHead.
void SetMaxBufferSize(uint32_t n)
Set the maximum buffer size.
PacketList m_sentList
Buffer for sent (but not acked) data.
uint32_t m_sentSize
Size of sent (and not discarded) segments.
void RemoveFromCounts(TcpTxItem *item, uint32_t size)
Remove the size specified from the lostOut, retrans, sacked count.
void SetHeadSequence(const SequenceNumber32 &seq)
Set the head sequence of the buffer.
TcpTxBuffer(uint32_t n=0)
Constructor.
Item that encloses the application packet and some flags for it.
bool m_sacked
Indicates if the segment has been SACKed.
bool m_retrans
Indicates if the segment is retransmitted.
SequenceNumber32 m_startSeq
Sequence number of the item (if transmitted)
Time m_lastSent
Timestamp of the time at which the segment has been sent last time.
Ptr< Packet > GetPacketCopy() const
Get a copy of the Packet underlying this item.
bool m_lost
Indicates if the segment has been lost (RTO)
Ptr< Packet > m_packet
Application packet (can be null)
void Print(std::ostream &os, Time::Unit unit=Time::S) const
Print the time.
T Get() const
Get the underlying value.
a unique identifier for an interface.
TypeId SetParent(TypeId tid)
Set the parent TypeId.
#define NS_ASSERT(condition)
At runtime, in debugging builds, if this condition is not true, the program prints the source file,...
#define NS_ASSERT_MSG(condition, message)
At runtime, in debugging builds, if this condition is not true, the program prints the message to out...
Callback< R, Args... > MakeNullCallback()
#define NS_ABORT_MSG_UNLESS(cond, msg)
Abnormal program termination if a condition is false, with a message.
#define NS_FATAL_ERROR(msg)
Report a fatal error with a message and terminate.
#define NS_ABORT_MSG_IF(cond, msg)
Abnormal program termination if a condition is true, with a message.
#define NS_LOG_ERROR(msg)
Use NS_LOG to output a message of level LOG_ERROR.
#define NS_LOG_COMPONENT_DEFINE(name)
Define a Log component with a specific name.
#define NS_LOG_DEBUG(msg)
Use NS_LOG to output a message of level LOG_DEBUG.
#define NS_LOG_LOGIC(msg)
Use NS_LOG to output a message of level LOG_LOGIC.
#define NS_LOG_FUNCTION(parameters)
If log level LOG_FUNCTION is enabled, this macro will output all input parameters separated by ",...
#define NS_LOG_WARN(msg)
Use NS_LOG to output a message of level LOG_WARN.
#define NS_LOG_INFO(msg)
Use NS_LOG to output a message of level LOG_INFO.
#define NS_OBJECT_ENSURE_REGISTERED(type)
Register an Object subclass with the TypeId system.
SequenceNumber< uint32_t, int32_t > SequenceNumber32
32 bit Sequence number.
Ptr< const TraceSourceAccessor > MakeTraceSourceAccessor(T a)
Create a TraceSourceAccessor which will control access to the underlying trace source.
Every class exported by the ns3 library is enclosed in the ns3 namespace.
std::ostream & operator<<(std::ostream &os, const Angles &a)
uint32_t GetSize(Ptr< const Packet > packet, const WifiMacHeader *hdr, bool isAmpdu)
Return the total size of the packet after WifiMacHeader and FCS trailer have been added.
uint32_t pktSize
packet size used for the simulation (in bytes)