Files
unison/src/internet/test/tcp-tx-buffer-test.cc
2021-05-01 18:53:56 +02:00

415 lines
16 KiB
C++

/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* 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
*
*/
#include <limits>
#include "ns3/test.h"
#include "ns3/tcp-tx-buffer.h"
#include "ns3/packet.h"
#include "ns3/simulator.h"
#include "ns3/log.h"
using namespace ns3;
NS_LOG_COMPONENT_DEFINE ("TcpTxBufferTestSuite");
/**
* \ingroup internet-tests
* \ingroup tests
*
* \brief The TcpTxBuffer Test
*/
class TcpTxBufferTestCase : public TestCase
{
public:
/** \brief Constructor */
TcpTxBufferTestCase ();
private:
virtual void DoRun (void);
virtual void DoTeardown (void);
/** \brief Test if a segment is really set as lost */
void TestIsLost ();
/** \brief Test the generation of an unsent block */
void TestNewBlock ();
/** \brief Test the generation of a previously sent block */
void TestTransmittedBlock ();
/** \brief Test the generation of the "next" block */
void TestNextSeg ();
/** \brief Test the logic of merging items in GetTransmittedSegment()
* which is triggered by CopyFromSequence()*/
void TestMergeItemsWhenGetTransmittedSegment ();
/**
* \brief Callback to provide a value of receiver window
* \returns the receiver window size
*/
uint32_t GetRWnd (void) const;
};
TcpTxBufferTestCase::TcpTxBufferTestCase ()
: TestCase ("TcpTxBuffer Test")
{
}
void
TcpTxBufferTestCase::DoRun ()
{
Simulator::Schedule (Seconds (0.0), &TcpTxBufferTestCase::TestIsLost, this);
/*
* Cases for new block:
* -> is exactly the same as stored
* -> starts over the boundary, but ends earlier
* -> starts over the boundary, but ends after
*/
Simulator::Schedule (Seconds (0.0), &TcpTxBufferTestCase::TestNewBlock, this);
/*
* Cases for transmitted block:
* -> is exactly the same as previous
* -> starts over the boundary, but ends earlier
* -> starts over the boundary, but ends after
* -> starts inside a packet, ends right
* -> starts inside a packet, ends earlier in the same packet
* -> starts inside a packet, ends in another packet
*/
Simulator::Schedule (Seconds (0.0),
&TcpTxBufferTestCase::TestTransmittedBlock, this);
Simulator::Schedule (Seconds (0.0),
&TcpTxBufferTestCase::TestNextSeg, this);
/*
* Case for transmitted block:
* -> transmitted packets are marked differently for m_lost under some scenarios
* -> packets could be small than MSS when socket buffer is not a multiple of MSS.
* -> during retransmission, the sender tries to send a full segment but it
* should stop to merge items when they have different values for m_lost.
*/
Simulator::Schedule (Seconds (0.0),
&TcpTxBufferTestCase::TestMergeItemsWhenGetTransmittedSegment, this);
Simulator::Run ();
Simulator::Destroy ();
}
void
TcpTxBufferTestCase::TestIsLost ()
{
Ptr<TcpTxBuffer> txBuf = CreateObject<TcpTxBuffer> ();
txBuf->SetRWndCallback (MakeCallback (&TcpTxBufferTestCase::GetRWnd, this));
SequenceNumber32 head (1);
txBuf->SetHeadSequence (head);
SequenceNumber32 ret;
Ptr<TcpOptionSack> sack = CreateObject<TcpOptionSack> ();
txBuf->SetSegmentSize (1000);
txBuf->SetDupAckThresh (3);
txBuf->Add(Create<Packet> (10000));
for (uint8_t i = 0; i <10 ; ++i)
txBuf->CopyFromSequence (1000, SequenceNumber32((i*1000)+1));
for (uint8_t i = 0; i < 10 ; ++i)
NS_TEST_ASSERT_MSG_EQ (txBuf->IsLost(SequenceNumber32((i*1000)+1)), false,
"Lost is true, but it's not");
sack->AddSackBlock (TcpOptionSack::SackBlock (SequenceNumber32 (1001), SequenceNumber32 (2001)));
txBuf->Update(sack->GetSackList());
for (uint8_t i = 0; i < 10 ; ++i)
NS_TEST_ASSERT_MSG_EQ (txBuf->IsLost(SequenceNumber32((i*1000)+1)), false,
"Lost is true, but it's not");
sack->AddSackBlock (TcpOptionSack::SackBlock (SequenceNumber32 (2001), SequenceNumber32 (3001)));
txBuf->Update(sack->GetSackList());
for (uint8_t i = 0; i < 10 ; ++i)
NS_TEST_ASSERT_MSG_EQ (txBuf->IsLost(SequenceNumber32((i*1000)+1)), false,
"Lost is true, but it's not");
sack->AddSackBlock (TcpOptionSack::SackBlock (SequenceNumber32 (3001), SequenceNumber32 (4001)));
txBuf->Update(sack->GetSackList());
NS_TEST_ASSERT_MSG_EQ (txBuf->IsLost(SequenceNumber32(1)), true,
"Lost is true, but it's not");
for (uint8_t i = 1; i < 10 ; ++i)
NS_TEST_ASSERT_MSG_EQ (txBuf->IsLost(SequenceNumber32((i*1000)+1)), false,
"Lost is true, but it's not");
}
uint32_t
TcpTxBufferTestCase::GetRWnd (void) const
{
// Assume unlimited receiver window
return std::numeric_limits<uint32_t>::max ();
}
void
TcpTxBufferTestCase::TestNextSeg ()
{
Ptr<TcpTxBuffer> txBuf = CreateObject<TcpTxBuffer> ();;
txBuf->SetRWndCallback (MakeCallback (&TcpTxBufferTestCase::GetRWnd, this));
SequenceNumber32 head (1);
SequenceNumber32 ret;
SequenceNumber32 retHigh;
txBuf->SetSegmentSize (150);
txBuf->SetDupAckThresh (3);
uint32_t dupThresh = 3;
uint32_t segmentSize = 150;
Ptr<TcpOptionSack> sack = CreateObject<TcpOptionSack> ();
// At the beginning the values of dupThresh and segmentSize don't matter
NS_TEST_ASSERT_MSG_EQ (txBuf->NextSeg (&ret, &retHigh, false), false,
"NextSeq should not be returned at the beginning");
txBuf->SetHeadSequence (head);
NS_TEST_ASSERT_MSG_EQ (txBuf->NextSeg (&ret, &retHigh, false), false,
"NextSeq should not be returned with no data");
// Add a single, 30000-bytes long, packet
txBuf->Add (Create<Packet> (30000));
NS_TEST_ASSERT_MSG_EQ (txBuf->NextSeg (&ret, &retHigh, false), true,
"No NextSeq with data at beginning");
NS_TEST_ASSERT_MSG_EQ (ret.GetValue (), head.GetValue (),
"Different NextSeq than expected at the beginning");
// Simulate sending 100 packets, 150 bytes long each, from seq 1
for (uint32_t i=0; i<100; ++i)
{
NS_TEST_ASSERT_MSG_EQ (txBuf->NextSeg (&ret, &retHigh, false), true,
"No NextSeq with data while \"transmitting\"");
NS_TEST_ASSERT_MSG_EQ (ret, head + (segmentSize * i),
"Different NextSeq than expected while \"transmitting\"");
txBuf->CopyFromSequence (segmentSize, ret);
}
// Ok, now simulate we lost the first segment [1;151], and that we have
// limited transmit. NextSeg should return (up to dupThresh-1) new pieces of data
SequenceNumber32 lastRet = ret; // This is like m_highTx
for (uint32_t i=1; i<dupThresh; ++i) // iterate dupThresh-1 times (limited transmit)
{
SequenceNumber32 begin = head + (segmentSize * i);
SequenceNumber32 end = begin + segmentSize;
sack->AddSackBlock (TcpOptionSack::SackBlock (begin, end));
txBuf->Update (sack->GetSackList ());
// new data expected and sent
NS_TEST_ASSERT_MSG_EQ (txBuf->NextSeg (&ret, &retHigh, false), true,
"No NextSeq with SACK block while \"transmitting\"");
NS_TEST_ASSERT_MSG_EQ (ret, lastRet + segmentSize,
"Different NextSeq than expected in limited transmit");
txBuf->CopyFromSequence (segmentSize, ret);
sack->ClearSackList ();
lastRet = ret;
}
// Limited transmit was ok; now there is the dupThresh-th dupack.
// Now we need to retransmit the first block..
sack->AddSackBlock (TcpOptionSack::SackBlock (head + (segmentSize * (dupThresh)),
head + (segmentSize * (dupThresh)) + segmentSize));
txBuf->Update (sack->GetSackList ());
NS_TEST_ASSERT_MSG_EQ (txBuf->NextSeg (&ret, &retHigh, false), true,
"No NextSeq with SACK block for Fast Recovery");
NS_TEST_ASSERT_MSG_EQ (ret, head,
"Different NextSeq than expected for Fast Recovery");
txBuf->CopyFromSequence (segmentSize, ret);
sack->ClearSackList ();
// Fast Retransmission was ok; now check some additional dupacks.
for (uint32_t i=1; i<=4; ++i)
{
sack->AddSackBlock (TcpOptionSack::SackBlock (head + (segmentSize * (dupThresh+i)),
head + (segmentSize * (dupThresh+i)) + segmentSize));
txBuf->Update (sack->GetSackList ());
NS_TEST_ASSERT_MSG_EQ (txBuf->NextSeg (&ret, &retHigh, false), true,
"No NextSeq with SACK block after recv dupacks in FR");
NS_TEST_ASSERT_MSG_EQ (ret, lastRet + segmentSize,
"Different NextSeq than expected after recv dupacks in FR");
txBuf->CopyFromSequence (segmentSize, ret);
sack->ClearSackList ();
lastRet = ret;
}
// Well now we receive a partial ACK, corresponding to the segment we retransmitted.
// Unfortunately, the next one is lost as well; but NextSeg should be smart enough
// to give us the next segment (head + segmentSize) to retransmit.
/* In this particular case, we are checking the fact that we have badly crafted
* the SACK blocks. Talking in segment, we transmitted 1,2,3,4,5 ... and then
* received dupack for 1. While receiving these, we crafted SACK block in the
* way that 2,3,4,... were correctly received. Now, if we receive an ACK for 2,
* we clearly crafted the corresponding ACK wrongly. TcpTxBuffer should be able
* to "backoff" that flag on its HEAD (segment 2). We still don't know for segment
* 3,4 .. so keep them.
*/
head = head + segmentSize;
txBuf->DiscardUpTo (head);
NS_TEST_ASSERT_MSG_EQ (txBuf->NextSeg (&ret, &retHigh, false), true,
"No NextSeq with SACK block after receiving partial ACK");
NS_TEST_ASSERT_MSG_EQ (ret, head,
"Different NextSeq than expected after receiving partial ACK ");
txBuf->CopyFromSequence (segmentSize, ret);
// Now, check for one more dupack...
sack->AddSackBlock (TcpOptionSack::SackBlock (head + (segmentSize * (dupThresh+6)),
head + (segmentSize * (dupThresh+6)) + segmentSize));
txBuf->Update (sack->GetSackList ());
NS_TEST_ASSERT_MSG_EQ (txBuf->NextSeg (&ret, &retHigh, false), true,
"No NextSeq with SACK block after recv dupacks after partial ack");
NS_TEST_ASSERT_MSG_EQ (ret, lastRet + segmentSize,
"Different NextSeq than expected after recv dupacks after partial ack");
txBuf->CopyFromSequence (segmentSize, ret);
sack->ClearSackList ();
head = lastRet = ret + segmentSize;
// And now ack everything we sent to date!
txBuf->DiscardUpTo (head);
// And continue normally until the end
for (uint32_t i=0; i<93; ++i)
{
NS_TEST_ASSERT_MSG_EQ (txBuf->NextSeg (&ret, &retHigh, false), true,
"No NextSeq with data while \"transmitting\"");
NS_TEST_ASSERT_MSG_EQ (ret, head + (segmentSize * i),
"Different NextSeq than expected while \"transmitting\"");
txBuf->CopyFromSequence (segmentSize, ret);
}
txBuf->DiscardUpTo (ret+segmentSize);
NS_TEST_ASSERT_MSG_EQ (txBuf->Size (), 0,
"Data inside the buffer");
}
void
TcpTxBufferTestCase::TestNewBlock ()
{
// Manually recreating all the conditions
Ptr<TcpTxBuffer> txBuf = CreateObject<TcpTxBuffer> ();
txBuf->SetRWndCallback (MakeCallback (&TcpTxBufferTestCase::GetRWnd, this));
txBuf->SetHeadSequence (SequenceNumber32 (1));
txBuf->SetSegmentSize (100);
// get a packet which is exactly the same stored
Ptr<Packet> p1 = Create<Packet> (100);
txBuf->Add (p1);
NS_TEST_ASSERT_MSG_EQ (txBuf->SizeFromSequence (SequenceNumber32 (1)), 100,
"TxBuf miscalculates size");
NS_TEST_ASSERT_MSG_EQ (txBuf->BytesInFlight (), 0,
"TxBuf miscalculates size of in flight segments");
Ptr<Packet> ret = txBuf->CopyFromSequence (100, SequenceNumber32 (1))->GetPacketCopy ();
NS_TEST_ASSERT_MSG_EQ (ret->GetSize (), 100,
"Returned packet has different size than requested");
NS_TEST_ASSERT_MSG_EQ (txBuf->SizeFromSequence (SequenceNumber32 (1)), 100,
"TxBuf miscalculates size");
NS_TEST_ASSERT_MSG_EQ (txBuf->BytesInFlight (), 100,
"TxBuf miscalculates size of in flight segments");
txBuf->DiscardUpTo (SequenceNumber32 (101));
NS_TEST_ASSERT_MSG_EQ (txBuf->SizeFromSequence (SequenceNumber32 (101)), 0,
"TxBuf miscalculates size");
NS_TEST_ASSERT_MSG_EQ (txBuf->BytesInFlight (), 0,
"TxBuf miscalculates size of in flight segments");
// starts over the boundary, but ends earlier
Ptr<Packet> p2 = Create<Packet> (100);
txBuf->Add (p2);
ret = txBuf->CopyFromSequence (50, SequenceNumber32 (101))->GetPacketCopy ();
NS_TEST_ASSERT_MSG_EQ (ret->GetSize (), 50,
"Returned packet has different size than requested");
NS_TEST_ASSERT_MSG_EQ (txBuf->SizeFromSequence (SequenceNumber32 (151)), 50,
"TxBuf miscalculates size");
NS_TEST_ASSERT_MSG_EQ (txBuf->BytesInFlight (), 50,
"TxBuf miscalculates size of in flight segments");
// starts over the boundary, but ends after
Ptr<Packet> p3 = Create<Packet> (100);
txBuf->Add (p3);
ret = txBuf->CopyFromSequence (70, SequenceNumber32 (151))->GetPacketCopy ();
NS_TEST_ASSERT_MSG_EQ (ret->GetSize (), 70,
"Returned packet has different size than requested");
NS_TEST_ASSERT_MSG_EQ (txBuf->SizeFromSequence (SequenceNumber32 (221)), 80,
"TxBuf miscalculates size");
NS_TEST_ASSERT_MSG_EQ (txBuf->BytesInFlight (), 120,
"TxBuf miscalculates size of in flight segments");
ret = txBuf->CopyFromSequence (3000, SequenceNumber32 (221))->GetPacketCopy ();
NS_TEST_ASSERT_MSG_EQ (ret->GetSize (), 80,
"Returned packet has different size than requested");
NS_TEST_ASSERT_MSG_EQ (txBuf->SizeFromSequence (SequenceNumber32 (301)), 0,
"TxBuf miscalculates size");
NS_TEST_ASSERT_MSG_EQ (txBuf->BytesInFlight (), 200,
"TxBuf miscalculates size of in flight segments");
// Clear everything
txBuf->DiscardUpTo (SequenceNumber32 (381));
NS_TEST_ASSERT_MSG_EQ (txBuf->Size (), 0,
"Size is different than expected");
}
void
TcpTxBufferTestCase::TestMergeItemsWhenGetTransmittedSegment ()
{
TcpTxBuffer txBuf;
SequenceNumber32 head (1);
txBuf.SetHeadSequence (head);
txBuf.SetSegmentSize (2000);
txBuf.Add(Create<Packet> (2000));
txBuf.CopyFromSequence (1000, SequenceNumber32(1));
txBuf.CopyFromSequence (1000, SequenceNumber32(1001));
txBuf.MarkHeadAsLost();
// GetTransmittedSegment() will be called and handle the case that two items
// have different m_lost value.
txBuf.CopyFromSequence (2000, SequenceNumber32(1));
}
void
TcpTxBufferTestCase::TestTransmittedBlock ()
{
}
void
TcpTxBufferTestCase::DoTeardown ()
{
}
/**
* \ingroup internet-test
* \ingroup tests
*
* \brief the TestSuite for the TcpTxBuffer test case
*/
class TcpTxBufferTestSuite : public TestSuite
{
public:
TcpTxBufferTestSuite ()
: TestSuite ("tcp-tx-buffer", UNIT)
{
AddTestCase (new TcpTxBufferTestCase, TestCase::QUICK);
}
};
static TcpTxBufferTestSuite g_tcpTxBufferTestSuite; //!< Static variable for test initialization