/*
 * SPDX-License-Identifier: GPL-2.0-only
 *
 * Author:  Craig Dowell (craigdo@ee.washington.edu)
 */

#include "ns3/log.h"
#include "ns3/pcap-file.h"
#include "ns3/test.h"

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <sstream>

using namespace ns3;

NS_LOG_COMPONENT_DEFINE("pcap-file-test-suite");

// ===========================================================================
// Some utility functions for the tests.
// ===========================================================================

static uint16_t
Swap(uint16_t val)
{
    return ((val >> 8) & 0x00ff) | ((val << 8) & 0xff00);
}

static uint32_t
Swap(uint32_t val)
{
    return ((val >> 24) & 0x000000ff) | ((val >> 8) & 0x0000ff00) | ((val << 8) & 0x00ff0000) |
           ((val << 24) & 0xff000000);
}

static bool
CheckFileExists(std::string filename)
{
    FILE* p = std::fopen(filename.c_str(), "rb");
    if (p == nullptr)
    {
        return false;
    }

    std::fclose(p);
    return true;
}

static bool
CheckFileLength(std::string filename, long sizeExpected)
{
    FILE* p = std::fopen(filename.c_str(), "rb");
    if (p == nullptr)
    {
        return false;
    }

    std::fseek(p, 0, SEEK_END);

    auto sizeActual = std::ftell(p);
    std::fclose(p);

    return sizeActual == sizeExpected;
}

/**
 * \ingroup network-test
 * \ingroup tests
 *
 * \brief Test case to make sure that the Pcap File Object can do its
 * most basic job and create an empty pcap file.
 */
class WriteModeCreateTestCase : public TestCase
{
  public:
    WriteModeCreateTestCase();
    ~WriteModeCreateTestCase() override;

  private:
    void DoSetup() override;
    void DoRun() override;
    void DoTeardown() override;

    std::string m_testFilename; //!< File name
};

WriteModeCreateTestCase::WriteModeCreateTestCase()
    : TestCase("Check to see that PcapFile::Open with mode std::ios::out works")
{
}

WriteModeCreateTestCase::~WriteModeCreateTestCase()
{
}

void
WriteModeCreateTestCase::DoSetup()
{
    std::stringstream filename;
    uint32_t n = rand();
    filename << n;
    m_testFilename = CreateTempDirFilename(filename.str() + ".pcap");
}

void
WriteModeCreateTestCase::DoTeardown()
{
    if (remove(m_testFilename.c_str()))
    {
        NS_LOG_ERROR("Failed to delete file " << m_testFilename);
    }
}

void
WriteModeCreateTestCase::DoRun()
{
    PcapFile f;

    //
    // Opening a new file in write mode should result in an empty file of the
    // given name.
    //
    f.Open(m_testFilename, std::ios::out);

    NS_TEST_ASSERT_MSG_EQ(f.Fail(), false, "Open (" << m_testFilename << ", \"w\") returns error");
    f.Close();

    NS_TEST_ASSERT_MSG_EQ(CheckFileExists(m_testFilename),
                          true,
                          "Open (" << m_testFilename
                                   << ", \"std::ios::out\") does not create file");
    NS_TEST_ASSERT_MSG_EQ(CheckFileLength(m_testFilename, 0),
                          true,
                          "Open (" << m_testFilename
                                   << ", \"std::ios::out\") does not result in an empty file");

    //
    // Calling Init() on a file created with "std::ios::out" should result in a file just
    // long enough to contain the pcap file header.
    //
    f.Open(m_testFilename, std::ios::out);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          false,
                          "Open (" << m_testFilename << ", \"std::ios::out\") returns error");

    f.Init(1234, 5678, 7);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(), false, "Init (1234, 5678, 7) returns error");

    f.Close();

    NS_TEST_ASSERT_MSG_EQ(CheckFileLength(m_testFilename, 24),
                          true,
                          "Init () does not result in a file with a pcap file header");

    //
    // Opening an existing file in write mode should result in that file being
    // emptied.
    //
    f.Open(m_testFilename, std::ios::out);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          false,
                          "Open (" << m_testFilename << ", \"std::ios::out\") returns error");

    f.Close();

    NS_TEST_ASSERT_MSG_EQ(CheckFileLength(m_testFilename, 0),
                          true,
                          "Open (" << m_testFilename
                                   << ", \"w\") does not result in an empty file");

    //
    // Initialize the file again.
    //
    f.Open(m_testFilename, std::ios::out);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(), false, "Open (" << m_testFilename << ", \"w\") returns error");

    f.Init(1234, 5678, 7);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(), false, "Init (1234, 5678, 7) returns error");

    //
    // Now we should be able to write to it since it was opened in std::ios::out mode.
    // This is just a permissions check so we don't actually look at the
    // data.
    //
    uint8_t buffer[128];
    memset(buffer, 0, sizeof(buffer));
    f.Write(0, 0, buffer, 128);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          false,
                          "Write (write-only-file " << m_testFilename << ") returns error");
}

/**
 * \ingroup network-test
 * \ingroup tests
 *
 * \brief Test case to make sure that the Pcap File Object can open an
 * existing pcap file.
 */
class ReadModeCreateTestCase : public TestCase
{
  public:
    ReadModeCreateTestCase();
    ~ReadModeCreateTestCase() override;

  private:
    void DoSetup() override;
    void DoRun() override;
    void DoTeardown() override;

    std::string m_testFilename; //!< File name
};

ReadModeCreateTestCase::ReadModeCreateTestCase()
    : TestCase("Check to see that PcapFile::Open with mode std::ios::in works")
{
}

ReadModeCreateTestCase::~ReadModeCreateTestCase()
{
}

void
ReadModeCreateTestCase::DoSetup()
{
    std::stringstream filename;
    uint32_t n = rand();
    filename << n;
    m_testFilename = CreateTempDirFilename(filename.str() + ".pcap");
}

void
ReadModeCreateTestCase::DoTeardown()
{
    if (remove(m_testFilename.c_str()))
    {
        NS_LOG_ERROR("Failed to delete file " << m_testFilename);
    }
}

void
ReadModeCreateTestCase::DoRun()
{
    PcapFile f;

    //
    // Opening a non-existing file in read mode should result in an error.
    //
    f.Open(m_testFilename, std::ios::in);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          true,
                          "Open (non-existing-filename "
                              << m_testFilename << ", \"std::ios::in\") does not return error");
    f.Close();
    f.Clear();
    NS_TEST_ASSERT_MSG_EQ(CheckFileExists(m_testFilename),
                          false,
                          "Open (" << m_testFilename
                                   << ", \"std::ios::in\") unexpectedly created a file");

    //
    // Okay, now create an uninitialized file using previously tested operations
    //
    f.Open(m_testFilename, std::ios::out);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(), false, "Open (filename, \"std::ios::out\") returns error");
    f.Close();

    //
    // Opening this file should result in an error since it has no pcap file header.
    //
    f.Open(m_testFilename, std::ios::in);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          true,
                          "Open (non-initialized-filename "
                              << m_testFilename << ", \"std::ios::in\") does not return error");
    f.Close();
    f.Clear();

    //
    // Okay, now open that non-initialized file in write mode and initialize it
    // Note that we open it in write mode to initialize it.
    //
    f.Open(m_testFilename, std::ios::out);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          false,
                          "Open (" << m_testFilename << ", \"std::ios::out\") returns error");

    f.Init(1234, 5678, 7);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(), false, "Init (1234, 5678, 7) returns error");
    f.Close();

    //
    // Opening this file should now work since it has a pcap file header.
    //
    f.Open(m_testFilename, std::ios::in);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          false,
                          "Open (initialized-filename " << m_testFilename
                                                        << ", \"std::ios::in\") returns error");

    //
    // Now we should not be able to write to it since it was opened in "r" mode
    // even if it has been initialized..
    //
    uint8_t buffer[128];
    f.Write(0, 0, buffer, 128);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          true,
                          "Write (read-only-file " << m_testFilename << ") does not return error");
    f.Close();
    f.Clear();
}

#if 0
// ===========================================================================
// Test case to make sure that the Pcap File Object can open an existing pcap
// file for appending.
// ===========================================================================
class AppendModeCreateTestCase : public TestCase
{
public:
  AppendModeCreateTestCase ();
  virtual ~AppendModeCreateTestCase ();

private:
  virtual void DoSetup ();
  virtual void DoRun ();
  virtual void DoTeardown ();

  std::string m_testFilename;
};

AppendModeCreateTestCase::AppendModeCreateTestCase ()
  : TestCase ("Check to see that PcapFile::Open with mode std::ios::app works")
{
}

AppendModeCreateTestCase::~AppendModeCreateTestCase ()
{
}

void
AppendModeCreateTestCase::DoSetup ()
{
  std::stringstream filename;
  uint32_t n = rand ();
  filename << n;
  m_testFilename = CreateTempDirFilename (filename.str () + ".pcap");
}

void
AppendModeCreateTestCase::DoTeardown ()
{
  if (remove (m_testFilename.c_str ()))
    {
      NS_LOG_ERROR ("Failed to delete file " << m_testFilename);
    }
}

void
AppendModeCreateTestCase::DoRun ()
{
  PcapFile f;

  //
  // Opening a non-existing file in append mode should result in an error.
  //
  f.Open (m_testFilename, std::ios::out | std::ios::app);
  NS_TEST_ASSERT_MSG_EQ (f.Fail (), true, "Open (non-existing-filename " << m_testFilename <<
                         ", \"std::ios::app\") does not return error");
  f.Close ();
  f.Clear ();

  NS_TEST_ASSERT_MSG_EQ (CheckFileExists (m_testFilename), false,
                         "Open (" << m_testFilename << ", \"std::ios::app\") unexpectedly created a file");

  //
  // Okay, now create an uninitialized file using previously tested operations
  //
  f.Open (m_testFilename, std::ios::out);
  NS_TEST_ASSERT_MSG_EQ (f.Fail (), false, "Open (" << m_testFilename <<
                         ", \"std::ios::out\") returns error");
  f.Close ();

  //
  // Opening this file should result in an error since it has no pcap file header.
  //
  f.Open (m_testFilename, std::ios::out | std::ios::app);
  NS_TEST_ASSERT_MSG_EQ (f.Fail (), true, "Open (non-initialized-filename " << m_testFilename <<
                         ", \"std::ios::app\") does not return error");
  f.Close ();
  f.Clear ();

  //
  // Okay, now open that non-initialized file in write mode and initialize it.
  //
  f.Open (m_testFilename, std::ios::out);
  NS_TEST_ASSERT_MSG_EQ (f.Fail (), false, "Open (non-initialized-filename " << m_testFilename <<
                         ", \"std::ios::out\") returns error");

  f.Init (1234, 5678, 7);
  NS_TEST_ASSERT_MSG_EQ (f.Fail (), false, "Init (1234, 5678, 7) returns error");
  f.Close ();

  //
  // Opening this file should now work since it has a pcap file header.
  //
  f.Open (m_testFilename, std::ios::out | std::ios::app);
  NS_TEST_ASSERT_MSG_EQ (f.Fail (), false, "Open (initialized-filename " << m_testFilename <<
                         ", \"std::ios::app\") returns error");

  //
  // We should be able to write to it since it was opened in "std::ios::app" mode.
  //
  uint8_t buffer[128];
  memset (buffer, 0, sizeof(buffer));
  f.Write (0, 0, buffer, 128);
  NS_TEST_ASSERT_MSG_EQ (f.Fail (), false, "Write (append-mode-file " << m_testFilename << ") returns error");

  f.Close ();
}
#endif

/**
 * \ingroup network-test
 * \ingroup tests
 *
 * \brief Test case to make sure that the Pcap File Object can
 * write out correct pcap file headers in both endian cases,
 * and then read them in correctly.
 */
class FileHeaderTestCase : public TestCase
{
  public:
    FileHeaderTestCase();
    ~FileHeaderTestCase() override;

  private:
    void DoSetup() override;
    void DoRun() override;
    void DoTeardown() override;

    std::string m_testFilename; //!< File name
};

FileHeaderTestCase::FileHeaderTestCase()
    : TestCase("Check to see that PcapFileHeader is managed correctly")
{
}

FileHeaderTestCase::~FileHeaderTestCase()
{
}

void
FileHeaderTestCase::DoSetup()
{
    std::stringstream filename;
    uint32_t n = rand();
    filename << n;
    m_testFilename = CreateTempDirFilename(filename.str() + ".pcap");
}

void
FileHeaderTestCase::DoTeardown()
{
    if (remove(m_testFilename.c_str()))
    {
        NS_LOG_ERROR("Failed to delete file " << m_testFilename);
    }
}

void
FileHeaderTestCase::DoRun()
{
    PcapFile f;

    //
    // Create an uninitialized file using previously tested operations
    //
    f.Open(m_testFilename, std::ios::out);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          false,
                          "Open (" << m_testFilename << ", \"std::ios::out\") returns error");

    //
    // Initialize the pcap file header.
    //
    f.Init(1234, 5678, 7);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(), false, "Init (1234, 5678, 7) returns error");
    f.Close();

    //
    // Take a look and see what was done to the file
    //
    FILE* p = std::fopen(m_testFilename.c_str(), "r+b");
    NS_TEST_ASSERT_MSG_NE(p,
                          nullptr,
                          "fopen("
                              << m_testFilename
                              << ") should have been able to open a correctly created pcap file");

    uint32_t val32;
    uint16_t val16;

    //
    // Because the regression tests require that pcap file output be compared
    // byte-by-byte, we had to decide on a single format for written pcap files.
    // This was little endian.  So we have to do something special with big-
    // endian machines here.
    //
    // When a big endian machine writes a pcap file, it is forced into swap
    // mode and actually writes little endian files.  This is automagically
    // fixed up when using a PcapFile to read the values, but when a big-
    // endian machine reads these values directly, they will be swapped.
    //
    // We can remove this nonsense when we get rid of the pcap-file-comparison
    // regression tests.
    //
    // So, determine the endian-ness of the running system, and if we're on
    // a big-endian machine, swap all of the results below before checking.
    //
    union {
        uint32_t a;
        uint8_t b[4];
    } u;

    u.a = 1;
    bool bigEndian = u.b[3];

    size_t result = std::fread(&val32, sizeof(val32), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() magic number");
    if (bigEndian)
    {
        val32 = Swap(val32);
    }
    NS_TEST_ASSERT_MSG_EQ(val32, 0xa1b2c3d4, "Magic number written incorrectly");

    result = std::fread(&val16, sizeof(val16), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() version major");
    if (bigEndian)
    {
        val16 = Swap(val16);
    }
    NS_TEST_ASSERT_MSG_EQ(val16, 2, "Version major written incorrectly");

    result = std::fread(&val16, sizeof(val16), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() version minor");
    if (bigEndian)
    {
        val16 = Swap(val16);
    }
    NS_TEST_ASSERT_MSG_EQ(val16, 4, "Version minor written incorrectly");

    result = std::fread(&val32, sizeof(val32), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() time zone correction");
    if (bigEndian)
    {
        val32 = Swap(val32);
    }
    NS_TEST_ASSERT_MSG_EQ(val32, 7, "Version minor written incorrectly");

    result = std::fread(&val32, sizeof(val32), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() sig figs");
    if (bigEndian)
    {
        val32 = Swap(val32);
    }
    NS_TEST_ASSERT_MSG_EQ(val32, 0, "Sig figs written incorrectly");

    result = std::fread(&val32, sizeof(val32), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() snap length");
    if (bigEndian)
    {
        val32 = Swap(val32);
    }
    NS_TEST_ASSERT_MSG_EQ(val32, 5678, "Snap length written incorrectly");

    result = std::fread(&val32, sizeof(val32), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() data link type");
    if (bigEndian)
    {
        val32 = Swap(val32);
    }
    NS_TEST_ASSERT_MSG_EQ(val32, 1234, "Data length type written incorrectly");

    std::fclose(p);
    p = nullptr;

    //
    // We wrote a little-endian file out correctly, now let's see if we can read
    // it back in correctly.
    //
    // As mentioned above, when a big endian machine writes a pcap file, it is
    // forced into swap mode and actually writes little endian files.  This is
    // automagically fixed up when using a PcapFile to read the values, so we
    // don't have to do anything special here.
    //
    f.Open(m_testFilename, std::ios::in);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          false,
                          "Open (existing-initialized-file "
                              << m_testFilename << ", \"std::ios::in\") returns error");

    NS_TEST_ASSERT_MSG_EQ(f.GetMagic(), 0xa1b2c3d4, "Read back magic number incorrectly");
    NS_TEST_ASSERT_MSG_EQ(f.GetVersionMajor(), 2, "Read back version major incorrectly");
    NS_TEST_ASSERT_MSG_EQ(f.GetVersionMinor(), 4, "Read back version minor incorrectly");
    NS_TEST_ASSERT_MSG_EQ(f.GetTimeZoneOffset(), 7, "Read back time zone offset incorrectly");
    NS_TEST_ASSERT_MSG_EQ(f.GetSigFigs(), 0, "Read back sig figs incorrectly");
    NS_TEST_ASSERT_MSG_EQ(f.GetSnapLen(), 5678, "Read back snap len incorrectly");
    NS_TEST_ASSERT_MSG_EQ(f.GetDataLinkType(), 1234, "Read back data link type incorrectly");
    f.Close();

    //
    // Re-open the file to erase its contents.
    //
    f.Open(m_testFilename, std::ios::out);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          false,
                          "Open (" << m_testFilename << ", \"std::ios::out\") returns error");

    //
    // Initialize the pcap file header, turning on swap mode manually to force
    // the pcap file header to be written out in foreign-endian form, whichever
    // endian-ness that might be.  Since big-endian machines are automatically
    // forced into swap mode, the <true> parameter to f.Init() below is actually
    // a no-op and we're always writing foreign-endian files.  In that case,
    // this test case is really just a duplicate of the previous.
    //
    f.Init(1234, 5678, 7, true);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(), false, "Init (1234, 5678, 7) returns error");
    f.Close();

    //
    // Take a look and see what was done to the file.  Everything should now
    // appear byte-swapped.
    //
    p = std::fopen(m_testFilename.c_str(), "r+b");
    NS_TEST_ASSERT_MSG_NE(p,
                          nullptr,
                          "fopen("
                              << m_testFilename
                              << ") should have been able to open a correctly created pcap file");

    result = std::fread(&val32, sizeof(val32), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() magic number");
    NS_TEST_ASSERT_MSG_EQ(val32, Swap(uint32_t(0xa1b2c3d4)), "Magic number written incorrectly");

    result = std::fread(&val16, sizeof(val16), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() version major");
    NS_TEST_ASSERT_MSG_EQ(val16, Swap(uint16_t(2)), "Version major written incorrectly");

    result = std::fread(&val16, sizeof(val16), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() version minor");
    NS_TEST_ASSERT_MSG_EQ(val16, Swap(uint16_t(4)), "Version minor written incorrectly");

    result = std::fread(&val32, sizeof(val32), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() time zone correction");
    NS_TEST_ASSERT_MSG_EQ(val32, Swap(uint32_t(7)), "Version minor written incorrectly");

    result = std::fread(&val32, sizeof(val32), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() sig figs");
    NS_TEST_ASSERT_MSG_EQ(val32, 0, "Sig figs written incorrectly");

    result = std::fread(&val32, sizeof(val32), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() snap length");
    NS_TEST_ASSERT_MSG_EQ(val32, Swap(uint32_t(5678)), "Snap length written incorrectly");

    result = std::fread(&val32, sizeof(val32), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() data link type");
    NS_TEST_ASSERT_MSG_EQ(val32, Swap(uint32_t(1234)), "Data length type written incorrectly");

    std::fclose(p);
    p = nullptr;

    //
    // We wrote an opposite-endian file out correctly, now let's see if we can read
    // it back in correctly.  Again, in the case of a big-endian machine, we already
    // did this test and it is just a duplicate.  What we don't test on a big endian
    // machine is writing out a big-endian file by default, but we can't do that
    // since it breaks regression testing.
    //
    f.Open(m_testFilename, std::ios::in);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          false,
                          "Open (existing-initialized-file "
                              << m_testFilename << ", \"std::ios::in\") returns error");

    NS_TEST_ASSERT_MSG_EQ(f.GetSwapMode(), true, "Byte-swapped file not correctly indicated");

    NS_TEST_ASSERT_MSG_EQ(f.GetMagic(), 0xa1b2c3d4, "Read back magic number incorrectly");
    NS_TEST_ASSERT_MSG_EQ(f.GetVersionMajor(), 2, "Read back version major incorrectly");
    NS_TEST_ASSERT_MSG_EQ(f.GetVersionMinor(), 4, "Read back version minor incorrectly");
    NS_TEST_ASSERT_MSG_EQ(f.GetTimeZoneOffset(), 7, "Read back time zone offset incorrectly");
    NS_TEST_ASSERT_MSG_EQ(f.GetSigFigs(), 0, "Read back sig figs incorrectly");
    NS_TEST_ASSERT_MSG_EQ(f.GetSnapLen(), 5678, "Read back snap len incorrectly");
    NS_TEST_ASSERT_MSG_EQ(f.GetDataLinkType(), 1234, "Read back data link type incorrectly");

    f.Close();
}

/**
 * \ingroup network-test
 * \ingroup tests
 *
 * \brief Test case to make sure that the Pcap File Object can
 * write pcap packet records in both endian cases, and then read
 * them in correctly.
 */
class RecordHeaderTestCase : public TestCase
{
  public:
    RecordHeaderTestCase();
    ~RecordHeaderTestCase() override;

  private:
    void DoSetup() override;
    void DoRun() override;
    void DoTeardown() override;

    std::string m_testFilename; //!< File name
};

RecordHeaderTestCase::RecordHeaderTestCase()
    : TestCase("Check to see that PcapRecordHeader is managed correctly")
{
}

RecordHeaderTestCase::~RecordHeaderTestCase()
{
}

void
RecordHeaderTestCase::DoSetup()
{
    std::stringstream filename;
    uint32_t n = rand();
    filename << n;
    m_testFilename = CreateTempDirFilename(filename.str() + ".pcap");
}

void
RecordHeaderTestCase::DoTeardown()
{
    if (remove(m_testFilename.c_str()))
    {
        NS_LOG_ERROR("Failed to delete file " << m_testFilename);
    }
}

void
RecordHeaderTestCase::DoRun()
{
    PcapFile f;

    //
    // Create an uninitialized file using previously tested operations
    //
    f.Open(m_testFilename, std::ios::out);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          false,
                          "Open (" << m_testFilename << ", \"std::ios::out\") returns error");

    //
    // Initialize the pcap file header.
    //
    f.Init(37, 43, -7);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(), false, "Init (37, 43, -7) returns error");

    //
    // Initialize a buffer with a counting pattern to check the data later.
    //
    uint8_t bufferOut[128];
    for (uint32_t i = 0; i < 128; ++i)
    {
        bufferOut[i] = i;
    }

    //
    // Now we should be able to write a packet to it since it was opened in "w"
    // mode.  The packet data written should be limited to 43 bytes in length
    // by the Init() call above.
    //
    f.Write(1234, 5678, bufferOut, 128);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          false,
                          "Write (write-only-file " << m_testFilename << ") returns error");
    f.Close();

    //
    // Let's peek into the file and see what actually went out for that
    // packet.
    //
    FILE* p = std::fopen(m_testFilename.c_str(), "r+b");
    NS_TEST_ASSERT_MSG_NE(p,
                          nullptr,
                          "fopen() should have been able to open a correctly created pcap file");

    //
    // A pcap file header takes up 24 bytes, a pcap record header takes up 16 bytes
    // and we wrote in 43 bytes, so the file must be 83 bytes long.  Let's just
    // double check that this is exactly what happened.
    //
    std::fseek(p, 0, SEEK_END);
    auto size = std::ftell(p);
    NS_TEST_ASSERT_MSG_EQ(size, 83, "Pcap file with one 43 byte packet is incorrect size");

    //
    // A pcap file header takes up 24 bytes, so we should see a pcap record header
    // starting there in the file.  We've tested this all before so we just assume
    // it's all right and just seek to just past that point..
    //
    std::fseek(p, 24, SEEK_SET);

    uint32_t val32;

    //
    // Because the regression tests require that pcap file output be compared
    // byte-by-byte, we had to decide on a single format for written pcap files.
    // This was little endian.  So we have to do something special with big-
    // endian machines here.
    //
    // When a big endian machine writes a pcap file, it is forced into swap
    // mode and actually writes little endian files.  This is automagically
    // fixed up when using a PcapFile to read the values, but when a big-
    // endian machine reads these values directly, they will be swapped.
    //
    // We can remove this nonsense when we get rid of the pcap-file-comparison
    // regression tests.
    //
    // So, determine the endian-ness of the running system, and if we're on
    // a big-endian machine, swap all of the results below before checking.
    //
    union {
        uint32_t a;
        uint8_t b[4];
    } u;

    u.a = 1;
    bool bigEndian = u.b[3];

    size_t result = std::fread(&val32, sizeof(val32), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() seconds timestamp");
    if (bigEndian)
    {
        val32 = Swap(val32);
    }
    NS_TEST_ASSERT_MSG_EQ(val32, 1234, "Seconds timestamp written incorrectly");

    result = std::fread(&val32, sizeof(val32), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() microseconds timestamp");
    if (bigEndian)
    {
        val32 = Swap(val32);
    }
    NS_TEST_ASSERT_MSG_EQ(val32, 5678, "Microseconds timestamp written incorrectly");

    result = std::fread(&val32, sizeof(val32), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() included length");
    if (bigEndian)
    {
        val32 = Swap(val32);
    }
    NS_TEST_ASSERT_MSG_EQ(val32, 43, "Included length written incorrectly");

    result = std::fread(&val32, sizeof(val32), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() actual length");
    if (bigEndian)
    {
        val32 = Swap(val32);
    }
    NS_TEST_ASSERT_MSG_EQ(val32, 128, "Actual length written incorrectly");

    //
    // Take a look and see what went out into the file.  The packet data
    // should be unchanged (unswapped).
    //
    uint8_t bufferIn[128];

    result = std::fread(bufferIn, 1, 43, p);
    NS_TEST_ASSERT_MSG_EQ(result, 43, "Unable to fread() packet data of expected length");

    for (uint32_t i = 0; i < 43; ++i)
    {
        NS_TEST_ASSERT_MSG_EQ(bufferIn[i], bufferOut[i], "Incorrect packet data written");
    }

    std::fclose(p);
    p = nullptr;

    //
    // Let's see if the PcapFile object can figure out how to do the same thing and
    // correctly read in a packet.
    //
    f.Open(m_testFilename, std::ios::in);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          false,
                          "Open (" << m_testFilename
                                   << ", \"std::ios::in\") of existing good file returns error");

    uint32_t tsSec;
    uint32_t tsUsec;
    uint32_t inclLen;
    uint32_t origLen;
    uint32_t readLen;

    f.Read(bufferIn, sizeof(bufferIn), tsSec, tsUsec, inclLen, origLen, readLen);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(), false, "Read() of known good packet returns error");
    NS_TEST_ASSERT_MSG_EQ(tsSec, 1234, "Incorrectly read seconds timestamp from known good packet");
    NS_TEST_ASSERT_MSG_EQ(tsUsec,
                          5678,
                          "Incorrectly read microseconds timestamp from known good packet");
    NS_TEST_ASSERT_MSG_EQ(inclLen, 43, "Incorrectly read included length from known good packet");
    NS_TEST_ASSERT_MSG_EQ(origLen, 128, "Incorrectly read original length from known good packet");
    NS_TEST_ASSERT_MSG_EQ(
        readLen,
        43,
        "Incorrectly constructed actual read length from known good packet given buffer size");
    f.Close();

    //
    // Did the data come back correctly?
    //
    for (uint32_t i = 0; i < 43; ++i)
    {
        NS_TEST_ASSERT_MSG_EQ(bufferIn[i],
                              bufferOut[i],
                              "Incorrect packet data read from known good packet");
    }

    //
    // We have to check to make sure that the pcap record header is swapped
    // correctly.  Since big-endian machines are automatically forced into
    // swap mode, the <true> parameter to f.Init() below is actually
    // a no-op and we're always writing foreign-endian files.  In that case,
    // this test case is really just a duplicate of the previous.
    //
    // Open the file in write mode to clear the data.
    //
    f.Open(m_testFilename, std::ios::out);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          false,
                          "Open (" << m_testFilename << ", \"std::ios::out\") returns error");

    //
    // Initialize the pcap file header, forcing the object into swap mode.
    //
    f.Init(37, 43, -7, true);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(), false, "Init (37, 43, -7) returns error");

    //
    // Now we should be able to write a packet to it since it was opened in "w"
    // mode.  The packet data written should be limited to 43 bytes in length
    // by the Init() call above.
    //
    f.Write(1234, 5678, bufferOut, 128);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          false,
                          "Write (write-only-file " << m_testFilename << ") returns error");
    f.Close();

    //
    // Let's peek into the file and see what actually went out for that
    // packet.
    //
    p = std::fopen(m_testFilename.c_str(), "r+b");
    NS_TEST_ASSERT_MSG_NE(p,
                          nullptr,
                          "fopen() should have been able to open a correctly created pcap file");

    //
    // A pcap file header takes up 24 bytes, a pcap record header takes up 16 bytes
    // and we wrote in 43 bytes, so the file must be 83 bytes long.  Let's just
    // double check that this is exactly what happened.
    //
    std::fseek(p, 0, SEEK_END);
    size = std::ftell(p);
    NS_TEST_ASSERT_MSG_EQ(size, 83, "Pcap file with one 43 byte packet is incorrect size");

    //
    // A pcap file header takes up 24 bytes, so we should see a pcap record header
    // starting there in the file.  We've tested this all before so we just assume
    // it's all right and just seek past it.
    //
    result = std::fseek(p, 24, SEEK_SET);
    NS_TEST_ASSERT_MSG_EQ(result, 0, "Failed seeking past pcap header");

    result = std::fread(&val32, sizeof(val32), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() seconds timestamp");
    NS_TEST_ASSERT_MSG_EQ(val32,
                          Swap(uint32_t(1234)),
                          "Swapped seconds timestamp written incorrectly");

    result = std::fread(&val32, sizeof(val32), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() microseconds timestamp");
    NS_TEST_ASSERT_MSG_EQ(val32,
                          Swap(uint32_t(5678)),
                          "Swapped microseconds timestamp written incorrectly");

    result = std::fread(&val32, sizeof(val32), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() included length");
    NS_TEST_ASSERT_MSG_EQ(val32, Swap(uint32_t(43)), "Swapped included length written incorrectly");

    result = std::fread(&val32, sizeof(val32), 1, p);
    NS_TEST_ASSERT_MSG_EQ(result, 1, "Unable to fread() actual length");
    NS_TEST_ASSERT_MSG_EQ(val32, Swap(uint32_t(128)), "Swapped Actual length written incorrectly");

    //
    // Take a look and see what went out into the file.  The packet data
    // should be unchanged (unswapped).
    //
    result = std::fread(bufferIn, 1, 43, p);
    NS_TEST_ASSERT_MSG_EQ(result, 43, "Unable to fread() packet data of expected length");

    for (uint32_t i = 0; i < 43; ++i)
    {
        NS_TEST_ASSERT_MSG_EQ(bufferIn[i], bufferOut[i], "Incorrect packet data written");
    }

    std::fclose(p);
    p = nullptr;

    //
    // Let's see if the PcapFile object can figure out how to do the same thing and
    // correctly read in a packet.  The record header info should come back to us
    // swapped back into correct form.
    //
    f.Open(m_testFilename, std::ios::in);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          false,
                          "Open (" << m_testFilename
                                   << ", \"std::ios::in\") of existing good file returns error");

    f.Read(bufferIn, sizeof(bufferIn), tsSec, tsUsec, inclLen, origLen, readLen);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(), false, "Read() of known good packet returns error");
    NS_TEST_ASSERT_MSG_EQ(tsSec, 1234, "Incorrectly read seconds timestamp from known good packet");
    NS_TEST_ASSERT_MSG_EQ(tsUsec,
                          5678,
                          "Incorrectly read microseconds timestamp from known good packet");
    NS_TEST_ASSERT_MSG_EQ(inclLen, 43, "Incorrectly read included length from known good packet");
    NS_TEST_ASSERT_MSG_EQ(origLen, 128, "Incorrectly read original length from known good packet");
    NS_TEST_ASSERT_MSG_EQ(
        readLen,
        43,
        "Incorrectly constructed actual read length from known good packet given buffer size");

    //
    // Did the data come back correctly (unchanged / unswapped)?
    //
    for (uint32_t i = 0; i < 43; ++i)
    {
        NS_TEST_ASSERT_MSG_EQ(bufferIn[i],
                              bufferOut[i],
                              "Incorrect packet data read from known good packet");
    }

    f.Close();
}

/**
 * \ingroup network-test
 * \ingroup tests
 *
 * \brief Test case to make sure that the Pcap File Object can read
 * out the contents of a known good pcap file.
 */
class ReadFileTestCase : public TestCase
{
  public:
    ReadFileTestCase();
    ~ReadFileTestCase() override;

  private:
    void DoSetup() override;
    void DoRun() override;
    void DoTeardown() override;

    std::string m_testFilename; //!< File name
};

ReadFileTestCase::ReadFileTestCase()
    : TestCase("Check to see that PcapFile can read out a known good pcap file")
{
}

ReadFileTestCase::~ReadFileTestCase()
{
}

void
ReadFileTestCase::DoSetup()
{
}

void
ReadFileTestCase::DoTeardown()
{
}

static const uint32_t N_KNOWN_PACKETS = 6;
static const uint32_t N_PACKET_BYTES = 16;

/**
 * PCAP Packet structure
 */
struct PacketEntry
{
    uint32_t tsSec;                //!< Time (seconds part)
    uint32_t tsUsec;               //!< Time (micro seconds part)
    uint32_t inclLen;              //!< Length of the entry in the PCAP
    uint32_t origLen;              //!< length of the original packet
    uint16_t data[N_PACKET_BYTES]; //!< Packet data
};

static const PacketEntry knownPackets[] = {
    {2,
     3696,
     46,
     46,
     {0x0001,
      0x0800,
      0x0604,
      0x0001,
      0x0000,
      0x0000,
      0x0003,
      0x0a01,
      0x0201,
      0xffff,
      0xffff,
      0xffff,
      0x0a01,
      0x0204,
      0x0000,
      0x0000}},
    {2,
     3707,
     46,
     46,
     {0x0001,
      0x0800,
      0x0604,
      0x0002,
      0x0000,
      0x0000,
      0x0006,
      0x0a01,
      0x0204,
      0x0000,
      0x0000,
      0x0003,
      0x0a01,
      0x0201,
      0x0000,
      0x0000}},
    {2,
     3801,
     1070,
     1070,
     {0x4500,
      0x041c,
      0x0000,
      0x0000,
      0x3f11,
      0x0000,
      0x0a01,
      0x0101,
      0x0a01,
      0x0204,
      0xc001,
      0x0009,
      0x0408,
      0x0000,
      0x0000,
      0x0000}},
    {2,
     3811,
     46,
     46,
     {0x0001,
      0x0800,
      0x0604,
      0x0001,
      0x0000,
      0x0000,
      0x0006,
      0x0a01,
      0x0204,
      0xffff,
      0xffff,
      0xffff,
      0x0a01,
      0x0201,
      0x0000,
      0x0000}},
    {2,
     3822,
     46,
     46,
     {0x0001,
      0x0800,
      0x0604,
      0x0002,
      0x0000,
      0x0000,
      0x0003,
      0x0a01,
      0x0201,
      0x0000,
      0x0000,
      0x0006,
      0x0a01,
      0x0204,
      0x0000,
      0x0000}},
    {2,
     3915,
     1070,
     1070,
     {0x4500,
      0x041c,
      0x0000,
      0x0000,
      0x4011,
      0x0000,
      0x0a01,
      0x0204,
      0x0a01,
      0x0101,
      0x0009,
      0xc001,
      0x0408,
      0x0000,
      0x0000,
      0x0000}},
};

void
ReadFileTestCase::DoRun()
{
    PcapFile f;

    //
    //
    std::string filename = CreateDataDirFilename("known.pcap");
    f.Open(filename, std::ios::in);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          false,
                          "Open (" << filename << ", \"std::ios::in\") returns error");

    //
    // We are going to read out the file header and all of the packets to make
    // sure that we read what we know, a priori, to be there.
    //
    // The packet data was gotten using "tcpdump -nn -tt -r known.pcap -x"
    // and the timestamp and first 32 bytes of the resulting dump were
    // duplicated in the structure above.
    //
    uint8_t data[N_PACKET_BYTES];
    uint32_t tsSec;
    uint32_t tsUsec;
    uint32_t inclLen;
    uint32_t origLen;
    uint32_t readLen;

    for (uint32_t i = 0; i < N_KNOWN_PACKETS; ++i)
    {
        const PacketEntry& p = knownPackets[i];

        f.Read(data, sizeof(data), tsSec, tsUsec, inclLen, origLen, readLen);
        NS_TEST_ASSERT_MSG_EQ(f.Fail(), false, "Read() of known good pcap file returns error");
        NS_TEST_ASSERT_MSG_EQ(tsSec,
                              p.tsSec,
                              "Incorrectly read seconds timestamp from known good pcap file");
        NS_TEST_ASSERT_MSG_EQ(tsUsec,
                              p.tsUsec,
                              "Incorrectly read microseconds timestamp from known good pcap file");
        NS_TEST_ASSERT_MSG_EQ(inclLen,
                              p.inclLen,
                              "Incorrectly read included length from known good packet");
        NS_TEST_ASSERT_MSG_EQ(origLen,
                              p.origLen,
                              "Incorrectly read original length from known good packet");
        NS_TEST_ASSERT_MSG_EQ(
            readLen,
            N_PACKET_BYTES,
            "Incorrect actual read length from known good packet given buffer size");
    }

    //
    // The file should now be at EOF since we've read all of the packets.
    // Another packet read should return an error.
    //
    f.Read(data, 1, tsSec, tsUsec, inclLen, origLen, readLen);
    NS_TEST_ASSERT_MSG_EQ(f.Eof(),
                          true,
                          "Read() of known good pcap file at EOF does not return error");

    f.Close();
}

/**
 * \ingroup network-test
 * \ingroup tests
 *
 * \brief Test case to make sure that the Pcap::Diff method works as expected.
 */
class DiffTestCase : public TestCase
{
  public:
    DiffTestCase();

  private:
    void DoRun() override;
};

DiffTestCase::DiffTestCase()
    : TestCase("Check that PcapFile::Diff works as expected")
{
}

void
DiffTestCase::DoRun()
{
    //
    // Check that PcapDiff(file, file) is false
    //
    std::string filename = CreateDataDirFilename("known.pcap");
    uint32_t sec(0);
    uint32_t usec(0);
    uint32_t packets(0);
    bool diff = PcapFile::Diff(filename, filename, sec, usec, packets);
    NS_TEST_EXPECT_MSG_EQ(diff, false, "PcapDiff(file, file) must always be false");

    //
    // Create different PCAP file (with the same timestamps, but different packets) and check that
    // it is indeed different
    //
    std::string filename2 = CreateTempDirFilename("different.pcap");
    PcapFile f;

    f.Open(filename2, std::ios::out);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(),
                          false,
                          "Open (" << filename2 << ", \"std::ios::out\") returns error");
    f.Init(1, N_PACKET_BYTES);
    NS_TEST_ASSERT_MSG_EQ(f.Fail(), false, "Init (1, " << N_PACKET_BYTES << ") returns error");

    for (uint32_t i = 0; i < N_KNOWN_PACKETS; ++i)
    {
        const PacketEntry& p = knownPackets[i];

        f.Write(p.tsSec, p.tsUsec, (const uint8_t*)p.data, p.origLen);
        NS_TEST_EXPECT_MSG_EQ(f.Fail(), false, "Write must not fail");
    }
    f.Close();

    packets = 0;
    diff = PcapFile::Diff(filename, filename2, sec, usec, packets);
    NS_TEST_EXPECT_MSG_EQ(diff, true, "PcapDiff(file, file2) must be true");
    NS_TEST_EXPECT_MSG_EQ(sec, 2, "Files are different from 2.3696 seconds");
    NS_TEST_EXPECT_MSG_EQ(usec, 3696, "Files are different from 2.3696 seconds");
}

/**
 * \ingroup network-test
 * \ingroup tests
 *
 * \brief PCAP file utils TestSuite
 */
class PcapFileTestSuite : public TestSuite
{
  public:
    PcapFileTestSuite();
};

PcapFileTestSuite::PcapFileTestSuite()
    : TestSuite("pcap-file", Type::UNIT)
{
    SetDataDir(NS_TEST_SOURCEDIR);
    AddTestCase(new WriteModeCreateTestCase, TestCase::Duration::QUICK);
    AddTestCase(new ReadModeCreateTestCase, TestCase::Duration::QUICK);
    // AddTestCase (new AppendModeCreateTestCase, TestCase::Duration::QUICK);
    AddTestCase(new FileHeaderTestCase, TestCase::Duration::QUICK);
    AddTestCase(new RecordHeaderTestCase, TestCase::Duration::QUICK);
    AddTestCase(new ReadFileTestCase, TestCase::Duration::QUICK);
    AddTestCase(new DiffTestCase, TestCase::Duration::QUICK);
}

static PcapFileTestSuite pcapFileTestSuite; //!< Static variable for test initialization
