/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */

 /*

  * Copyright (c) 2005,2006 INRIA

  *

  * 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: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>

  */

 #include "packet.h"

 #include "ns3/assert.h"

 #include "ns3/log.h"

 #include "ns3/test.h"

 #include <string>

 #include <stdarg.h>

 NS_LOG_COMPONENT_DEFINE ("Packet");

 namespace ns3 {

 uint32_t Packet::m_globalUid = 0;

 TypeId 

 ByteTagIterator::Item::GetTypeId (void) const

 {

   return m_tid;

 }

 uint32_t 

 ByteTagIterator::Item::GetStart (void) const

 {

   return m_start;

 }

 uint32_t 

 ByteTagIterator::Item::GetEnd (void) const

 {

   return m_end;

 }

 void 

 ByteTagIterator::Item::GetTag (Tag &tag) const

 {

   if (tag.GetInstanceTypeId () != GetTypeId ())

     {

       NS_FATAL_ERROR ("The tag you provided is not of the right type.");

     }

   tag.Deserialize (m_buffer);

 }

 ByteTagIterator::Item::Item (TypeId tid, uint32_t start, uint32_t end, TagBuffer buffer)

   : m_tid (tid),

     m_start (start),

     m_end (end),

     m_buffer (buffer)

 {}

 bool 

 ByteTagIterator::HasNext (void) const

 {

   return m_current.HasNext ();

 }

 ByteTagIterator::Item 

 ByteTagIterator::Next (void)

 {

   ByteTagList::Iterator::Item i = m_current.Next ();

   return ByteTagIterator::Item (i.tid, 

                                 i.start-m_current.GetOffsetStart (), 

                                 i.end-m_current.GetOffsetStart (), 

                                 i.buf);

 }

 ByteTagIterator::ByteTagIterator (ByteTagList::Iterator i)

   : m_current (i)

 {}

 PacketTagIterator::PacketTagIterator (const struct PacketTagList::TagData *head)

   : m_current (head)

 {}

 bool 

 PacketTagIterator::HasNext (void) const

 {

   return m_current != 0;

 }

 PacketTagIterator::Item 

 PacketTagIterator::Next (void)

 {

   NS_ASSERT (HasNext ());

   const struct PacketTagList::TagData *prev = m_current;

   m_current = m_current->next;

   return PacketTagIterator::Item (prev);

 }

 PacketTagIterator::Item::Item (const struct PacketTagList::TagData *data)

   : m_data (data)

 {}

 TypeId 

 PacketTagIterator::Item::GetTypeId (void) const

 {

   return m_data->tid;

 }

 void 

 PacketTagIterator::Item::GetTag (Tag &tag) const

 {

   NS_ASSERT (tag.GetInstanceTypeId () == m_data->tid);

   tag.Deserialize (TagBuffer ((uint8_t*)m_data->data, (uint8_t*)m_data->data+PACKET_TAG_MAX_SIZE));

 }

 Ptr<Packet> 

 Packet::Copy (void) const

 {

   // we need to invoke the copy constructor directly

   // rather than calling Create because the copy constructor

   // is private.

   return Ptr<Packet> (new Packet (*this), false);

 }

 Packet::Packet ()

   : m_buffer (),

     m_byteTagList (),

     m_packetTagList (),

     m_metadata (m_globalUid, 0),

     m_nixVector (0)

 {

   m_globalUid++;

 }

 Packet::Packet (const Packet &o)

   : m_buffer (o.m_buffer),

     m_byteTagList (o.m_byteTagList),

     m_packetTagList (o.m_packetTagList),

     m_metadata (o.m_metadata)

 {

   o.m_nixVector ? m_nixVector = o.m_nixVector->Copy () 

                 : m_nixVector = 0;

 }

 Packet &

 Packet::operator = (const Packet &o)

 {

   if (this == &o)

     {

       return *this;

     }

   m_buffer = o.m_buffer;

   m_byteTagList = o.m_byteTagList;

   m_packetTagList = o.m_packetTagList;

   m_metadata = o.m_metadata;

   o.m_nixVector ? m_nixVector = o.m_nixVector->Copy () 

                 : m_nixVector = 0;

   return *this;

 }

 Packet::Packet (uint32_t size)

   : m_buffer (size),

     m_byteTagList (),

     m_packetTagList (),

     m_metadata (m_globalUid, size),

     m_nixVector (0)

 {

   m_globalUid++;

 }

 Packet::Packet (uint8_t const*buffer, uint32_t size)

   : m_buffer (),

     m_byteTagList (),

     m_packetTagList (),

     m_metadata (m_globalUid, size),

     m_nixVector (0)

 {

   m_globalUid++;

   m_buffer.AddAtStart (size);

   Buffer::Iterator i = m_buffer.Begin ();

   i.Write (buffer, size);

 }

 Packet::Packet (const Buffer &buffer,  const ByteTagList &byteTagList, 

                 const PacketTagList &packetTagList, const PacketMetadata &metadata)

   : m_buffer (buffer),

     m_byteTagList (byteTagList),

     m_packetTagList (packetTagList),

     m_metadata (metadata),

     m_nixVector (0)

 {}

 Ptr<Packet>

 Packet::CreateFragment (uint32_t start, uint32_t length) const

 {

   NS_LOG_FUNCTION (this << start << length);

   Buffer buffer = m_buffer.CreateFragment (start, length);

   NS_ASSERT (m_buffer.GetSize () >= start + length);

   uint32_t end = m_buffer.GetSize () - (start + length);

   PacketMetadata metadata = m_metadata.CreateFragment (start, end);

   // again, call the constructor directly rather than

   // through Create because it is private.

   return Ptr<Packet> (new Packet (buffer, m_byteTagList, m_packetTagList, metadata), false);

 }

 void

 Packet::SetNixVector (Ptr<NixVector> nixVector)

 {

   m_nixVector = nixVector;

 }

 Ptr<NixVector>

 Packet::GetNixVector (void) const

 {

   return m_nixVector;

 } 

 uint32_t 

 Packet::GetSize (void) const

 {

   return m_buffer.GetSize ();

 }

 void

 Packet::AddHeader (const Header &header)

 {

   uint32_t size = header.GetSerializedSize ();

   NS_LOG_FUNCTION (this << header.GetInstanceTypeId ().GetName () << size);

   uint32_t orgStart = m_buffer.GetCurrentStartOffset ();

   bool resized = m_buffer.AddAtStart (size);

   if (resized)

     {

       m_byteTagList.AddAtStart (m_buffer.GetCurrentStartOffset () + size - orgStart,

                                 m_buffer.GetCurrentStartOffset () + size);

     }

   header.Serialize (m_buffer.Begin ());

   m_metadata.AddHeader (header, size);

 }

 uint32_t

 Packet::RemoveHeader (Header &header)

 {

   uint32_t deserialized = header.Deserialize (m_buffer.Begin ());

   NS_LOG_FUNCTION (this << header.GetInstanceTypeId ().GetName () << deserialized);

   m_buffer.RemoveAtStart (deserialized);

   m_metadata.RemoveHeader (header, deserialized);

   return deserialized;

 }

 uint32_t

 Packet::PeekHeader (Header &header) const

 {

   uint32_t deserialized = header.Deserialize (m_buffer.Begin ());

   NS_LOG_FUNCTION (this << header.GetInstanceTypeId ().GetName () << deserialized);

   return deserialized;

 }

 void

 Packet::AddTrailer (const Trailer &trailer)

 {

   uint32_t size = trailer.GetSerializedSize ();

   NS_LOG_FUNCTION (this << trailer.GetInstanceTypeId ().GetName () << size);

   uint32_t orgStart = m_buffer.GetCurrentStartOffset ();

   bool resized = m_buffer.AddAtEnd (size);

   if (resized)

     {

       m_byteTagList.AddAtEnd (m_buffer.GetCurrentStartOffset () - orgStart,

                               m_buffer.GetCurrentEndOffset () - size);

     }

   Buffer::Iterator end = m_buffer.End ();

   trailer.Serialize (end);

   m_metadata.AddTrailer (trailer, size);

 }

 uint32_t

 Packet::RemoveTrailer (Trailer &trailer)

 {

   uint32_t deserialized = trailer.Deserialize (m_buffer.End ());

   NS_LOG_FUNCTION (this << trailer.GetInstanceTypeId ().GetName () << deserialized);

   m_buffer.RemoveAtEnd (deserialized);

   m_metadata.RemoveTrailer (trailer, deserialized);

   return deserialized;

 }

 uint32_t

 Packet::PeekTrailer (Trailer &trailer)

 {

   uint32_t deserialized = trailer.Deserialize (m_buffer.End ());

   NS_LOG_FUNCTION (this << trailer.GetInstanceTypeId ().GetName () << deserialized);

   return deserialized;

 }

 void 

 Packet::AddAtEnd (Ptr<const Packet> packet)

 {

   NS_LOG_FUNCTION (this << packet << packet->GetSize ());

   uint32_t aStart = m_buffer.GetCurrentStartOffset ();

   uint32_t bEnd = packet->m_buffer.GetCurrentEndOffset ();

   m_buffer.AddAtEnd (packet->m_buffer);

   uint32_t appendPrependOffset = m_buffer.GetCurrentEndOffset () - packet->m_buffer.GetSize ();

   m_byteTagList.AddAtEnd (m_buffer.GetCurrentStartOffset () - aStart, 

                           appendPrependOffset);

   ByteTagList copy = packet->m_byteTagList;

   copy.AddAtStart (m_buffer.GetCurrentEndOffset () - bEnd,

                    appendPrependOffset);

   m_byteTagList.Add (copy);

   m_metadata.AddAtEnd (packet->m_metadata);

 }

 void

 Packet::AddPaddingAtEnd (uint32_t size)

 {

   NS_LOG_FUNCTION (this << size);

   uint32_t orgEnd = m_buffer.GetCurrentEndOffset ();

   bool resized = m_buffer.AddAtEnd (size);

   if (resized)

     {

       m_byteTagList.AddAtEnd (m_buffer.GetCurrentEndOffset () - orgEnd,

                               m_buffer.GetCurrentEndOffset () - size);

     }

   m_metadata.AddPaddingAtEnd (size);

 }

 void 

 Packet::RemoveAtEnd (uint32_t size)

 {

   NS_LOG_FUNCTION (this << size);

   m_buffer.RemoveAtEnd (size);

   m_metadata.RemoveAtEnd (size);

 }

 void 

 Packet::RemoveAtStart (uint32_t size)

 {

   NS_LOG_FUNCTION (this << size);

   m_buffer.RemoveAtStart (size);

   m_metadata.RemoveAtStart (size);

 }

 void 

 Packet::RemoveAllByteTags (void)

 {

   NS_LOG_FUNCTION (this);

   m_byteTagList.RemoveAll ();

 }

 uint8_t const *

 Packet::PeekData (void) const

 {

   NS_LOG_FUNCTION (this);

   uint32_t oldStart = m_buffer.GetCurrentStartOffset ();

   uint8_t const * data = m_buffer.PeekData ();

   uint32_t newStart = m_buffer.GetCurrentStartOffset ();

   // Update tag offsets if buffer offsets were changed

   const_cast<ByteTagList &>(m_byteTagList).AddAtStart (newStart - oldStart, newStart);

   return data;

 }

 uint32_t 

 Packet::CopyData (uint8_t *buffer, uint32_t size) const

 {

   Buffer::Iterator i = m_buffer.Begin ();

   uint32_t cur = 0;

   while (!i.IsEnd () && cur < size)

     {

       buffer[cur] = i.ReadU8 ();

       cur++;

     }

   return cur;

 }

 void

 Packet::CopyData(std::ostream *os, uint32_t size) const

 {

   return m_buffer.CopyData (os, size);

 }

 uint32_t 

 Packet::GetUid (void) const

 {

   return m_metadata.GetUid ();

 }

 void 

 Packet::PrintByteTags (std::ostream &os) const

 {

   ByteTagIterator i = GetByteTagIterator ();

   while (i.HasNext ())

     {

       ByteTagIterator::Item item = i.Next ();

       os << item.GetTypeId ().GetName () << " [" << item.GetStart () << "-" << item.GetEnd () << "]";

       Callback<ObjectBase *> constructor = item.GetTypeId ().GetConstructor ();

       if (constructor.IsNull ())

         {

           if (i.HasNext ())

             {

               os << " ";

             }

           continue;

         }

       Tag *tag = dynamic_cast<Tag *> (constructor ());

       NS_ASSERT (tag != 0);

       os << " ";

       item.GetTag (*tag);

       tag->Print (os);

       if (i.HasNext ())

         {

           os << " ";

         }

       delete tag;

     }

 }

 void 

 Packet::Print (std::ostream &os) const

 {

   PacketMetadata::ItemIterator i = m_metadata.BeginItem (m_buffer);

   while (i.HasNext ())

     {

       PacketMetadata::Item item = i.Next ();

       if (item.isFragment)

         {

           switch (item.type) {

           case PacketMetadata::Item::PAYLOAD:

             os << "Payload";

             break;

           case PacketMetadata::Item::HEADER:

           case PacketMetadata::Item::TRAILER:

             os << item.tid.GetName ();

             break;

           }

           os << " Fragment [" << item.currentTrimedFromStart<<":"

              << (item.currentTrimedFromStart + item.currentSize) << "]";

         }

       else

         {

           switch (item.type) {

           case PacketMetadata::Item::PAYLOAD:

             os << "Payload (size=" << item.currentSize << ")";

             break;

           case PacketMetadata::Item::HEADER:

           case PacketMetadata::Item::TRAILER:

             os << item.tid.GetName () << " (";

             {

               NS_ASSERT (item.tid.HasConstructor ());

               Callback<ObjectBase *> constructor = item.tid.GetConstructor ();

               NS_ASSERT (!constructor.IsNull ());

               ObjectBase *instance = constructor ();

               NS_ASSERT (instance != 0);

               Chunk *chunk = dynamic_cast<Chunk *> (instance);

               NS_ASSERT (chunk != 0);

               chunk->Deserialize (item.current);

               chunk->Print (os);

               delete chunk;

             }

             os << ")";

             break;

           }          

         }

       if (i.HasNext ())

         {

           os << " ";

         }

     }

 #if 0

   // The code below will work only if headers and trailers

   // define the right attributes which is not the case for

   // now. So, as a temporary measure, we use the 

   // headers' and trailers' Print method as shown above.

   PacketMetadata::ItemIterator i = m_metadata.BeginItem (m_buffer);

   while (i.HasNext ())

     {

       PacketMetadata::Item item = i.Next ();

       if (item.isFragment)

         {

           switch (item.type) {

           case PacketMetadata::Item::PAYLOAD:

             os << "Payload";

             break;

           case PacketMetadata::Item::HEADER:

           case PacketMetadata::Item::TRAILER:

             os << item.tid.GetName ();

             break;

           }

           os << " Fragment [" << item.currentTrimedFromStart<<":"

              << (item.currentTrimedFromStart + item.currentSize) << "]";

         }

       else

         {

           switch (item.type) {

           case PacketMetadata::Item::PAYLOAD:

             os << "Payload (size=" << item.currentSize << ")";

             break;

           case PacketMetadata::Item::HEADER:

           case PacketMetadata::Item::TRAILER:

             os << item.tid.GetName () << "(";

             {

               NS_ASSERT (item.tid.HasConstructor ());

               Callback<ObjectBase *> constructor = item.tid.GetConstructor ();

               NS_ASSERT (constructor.IsNull ());

               ObjectBase *instance = constructor ();

               NS_ASSERT (instance != 0);

               Chunk *chunk = dynamic_cast<Chunk *> (instance);

               NS_ASSERT (chunk != 0);

               chunk->Deserialize (item.current);

               for (uint32_t j = 0; j < item.tid.GetAttributeN (); j++)

                 {

                   std::string attrName = item.tid.GetAttributeName (j);

                   std::string value;

                   bool ok = chunk->GetAttribute (attrName, value);

                   NS_ASSERT (ok);

                   os << attrName << "=" << value;

                   if ((j + 1) < item.tid.GetAttributeN ())

                     {

                       os << ",";

                     }

                 }

             }

             os << ")";

             break;

           }          

         }

       if (i.HasNext ())

         {

           os << " ";

         }

     }

 #endif   

 }

 PacketMetadata::ItemIterator 

 Packet::BeginItem (void) const

 {

   return m_metadata.BeginItem (m_buffer);

 }

 void

 Packet::EnablePrinting (void)

 {

   NS_LOG_FUNCTION_NOARGS ();

   PacketMetadata::Enable ();

 }

 void

 Packet::EnableChecking (void)

 {

   NS_LOG_FUNCTION_NOARGS ();

   PacketMetadata::EnableChecking ();

 }

 Buffer 

 Packet::Serialize (void) const

 {

   NS_LOG_FUNCTION (this);

   Buffer buffer;

   uint32_t reserve;

   // write metadata

   reserve = m_metadata.GetSerializedSize ();

   buffer.AddAtStart (reserve);

   m_metadata.Serialize (buffer.Begin (), reserve);

   // write tags

   //XXX

   //reserve = m_tags.GetSerializedSize ();

   //buffer.AddAtStart (reserve);

   //m_tags.Serialize (buffer.Begin (), reserve);

   // aggregate byte buffer, metadata, and tags

   Buffer tmp = m_buffer.CreateFullCopy ();

   tmp.AddAtEnd (buffer);

   // write byte buffer size.

   tmp.AddAtStart (4);

   tmp.Begin ().WriteU32 (m_buffer.GetSize ());

   return tmp;

 }

 void 

 Packet::Deserialize (Buffer buffer)

 {

   NS_LOG_FUNCTION (this);

   Buffer buf = buffer;

   // read size

   uint32_t packetSize = buf.Begin ().ReadU32 ();

   buf.RemoveAtStart (4);

   // read buffer.

   buf.RemoveAtEnd (buf.GetSize () - packetSize);

   m_buffer = buf;

   buffer.RemoveAtStart (4 + packetSize);

   // read tags

   //XXX

   //uint32_t tagsDeserialized = m_tags.Deserialize (buffer.Begin ());

   //buffer.RemoveAtStart (tagsDeserialized);

   // read metadata

   uint32_t metadataDeserialized = 

     m_metadata.Deserialize (buffer.Begin ());

   buffer.RemoveAtStart (metadataDeserialized);

 }

 void 

 Packet::AddByteTag (const Tag &tag) const

 {

   NS_LOG_FUNCTION (this << tag.GetInstanceTypeId ().GetName () << tag.GetSerializedSize ());

   ByteTagList *list = const_cast<ByteTagList *> (&m_byteTagList);

   TagBuffer buffer = list->Add (tag.GetInstanceTypeId (), tag.GetSerializedSize (), 

                                 m_buffer.GetCurrentStartOffset (),

                                 m_buffer.GetCurrentEndOffset ());

   tag.Serialize (buffer);

 }

 ByteTagIterator 

 Packet::GetByteTagIterator (void) const

 {

   return ByteTagIterator (m_byteTagList.Begin (m_buffer.GetCurrentStartOffset (), m_buffer.GetCurrentEndOffset ()));

 }

 bool 

 Packet::FindFirstMatchingByteTag (Tag &tag) const

 {

   TypeId tid = tag.GetInstanceTypeId ();

   ByteTagIterator i = GetByteTagIterator ();

   while (i.HasNext ())

     {

       ByteTagIterator::Item item = i.Next ();

       if (tid == item.GetTypeId ())

         {

           item.GetTag (tag);

           return true;

         }

     }

   return false;

 }

 void 

 Packet::AddPacketTag (const Tag &tag) const

 {

   NS_LOG_FUNCTION (this << tag.GetInstanceTypeId ().GetName () << tag.GetSerializedSize ());

   m_packetTagList.Add (tag);

 }

 bool 

 Packet::RemovePacketTag (Tag &tag)

 {

   NS_LOG_FUNCTION (this << tag.GetInstanceTypeId ().GetName () << tag.GetSerializedSize ());

   bool found = m_packetTagList.Remove (tag);

   return found;

 }

 bool 

 Packet::PeekPacketTag (Tag &tag) const

 {

   bool found = m_packetTagList.Peek (tag);

   return found;

 }

 void 

 Packet::RemoveAllPacketTags (void)

 {

   NS_LOG_FUNCTION (this);

   m_packetTagList.RemoveAll ();

 }

 void 

 Packet::PrintPacketTags (std::ostream &os) const

 {

   PacketTagIterator i = GetPacketTagIterator ();

   while (i.HasNext ())

     {

       PacketTagIterator::Item item = i.Next ();

       NS_ASSERT (item.GetTypeId ().HasConstructor ());

       Callback<ObjectBase *> constructor = item.GetTypeId ().GetConstructor ();

       NS_ASSERT (!constructor.IsNull ());

       ObjectBase *instance = constructor ();

       Tag *tag = dynamic_cast<Tag *> (instance);

       NS_ASSERT (tag != 0);

       item.GetTag (*tag);

       tag->Print (os);

       delete tag;

       if (i.HasNext ())

         {

           os << " ";

         }

     }

 }

 PacketTagIterator 

 Packet::GetPacketTagIterator (void) const

 {

   return PacketTagIterator (m_packetTagList.Head ());

 }

 std::ostream& operator<< (std::ostream& os, const Packet &packet)

 {

   packet.Print (os);

   return os;

 }

 //-----------------------------------------------------------------------------

 // Unit tests

 //-----------------------------------------------------------------------------

 namespace {

 class ATestTagBase : public Tag

 {

 public:

   ATestTagBase () : m_error (false) {}

   bool m_error;

 };

 template <int N>

 class ATestTag : public ATestTagBase

 {

 public:

   static TypeId GetTypeId (void) {

     std::ostringstream oss;

     oss << "anon::ATestTag<" << N << ">";

     static TypeId tid = TypeId (oss.str ().c_str ())

       .SetParent<Tag> ()

       .AddConstructor<ATestTag<N> > ()

       .HideFromDocumentation ()

       ;

     return tid;

   }

   virtual TypeId GetInstanceTypeId (void) const {

     return GetTypeId ();

   }

   virtual uint32_t GetSerializedSize (void) const {

     return N;

   }

   virtual void Serialize (TagBuffer buf) const {

     for (uint32_t i = 0; i < N; ++i)

       {

         buf.WriteU8 (N);

       }

   }

   virtual void Deserialize (TagBuffer buf) {

     for (uint32_t i = 0; i < N; ++i)

       {

         uint8_t v = buf.ReadU8 ();

         if (v != N)

           {

             m_error = true;

           }

       }

   }

   virtual void Print (std::ostream &os) const {

     os << N;

   }

   ATestTag ()

     : ATestTagBase () {}

 };

 class ATestHeaderBase : public Header

 {

 public:

   ATestHeaderBase () : Header (), m_error (false) {}

   bool m_error;

 };

 template <int N>

 class ATestHeader : public ATestHeaderBase

 {

 public:

   static TypeId GetTypeId (void) {

     std::ostringstream oss;

     oss << "anon::ATestHeader<" << N << ">";

     static TypeId tid = TypeId (oss.str ().c_str ())

       .SetParent<Header> ()

       .AddConstructor<ATestHeader<N> > ()

       .HideFromDocumentation ()

       ;

     return tid;

   }

   virtual TypeId GetInstanceTypeId (void) const {

     return GetTypeId ();

   }

   virtual uint32_t GetSerializedSize (void) const {

     return N;

   }

   virtual void Serialize (Buffer::Iterator iter) const {

     for (uint32_t i = 0; i < N; ++i)

       {

         iter.WriteU8 (N);

       }

   }

   virtual uint32_t Deserialize (Buffer::Iterator iter) {

     for (uint32_t i = 0; i < N; ++i)

       {

         uint8_t v = iter.ReadU8 ();

         if (v != N)

           {

             m_error = true;

           }

       }

     return N;

   }

   virtual void Print (std::ostream &os) const {

   }

   ATestHeader ()

     : ATestHeaderBase () {}

 };

 class ATestTrailerBase : public Trailer

 {

 public:

   ATestTrailerBase () : Trailer (), m_error (false) {}

   bool m_error;

 };

 template <int N>

 class ATestTrailer : public ATestTrailerBase

 {

 public:

   static TypeId GetTypeId (void) {

     std::ostringstream oss;

     oss << "anon::ATestTrailer<" << N << ">";

     static TypeId tid = TypeId (oss.str ().c_str ())

       .SetParent<Header> ()

       .AddConstructor<ATestTrailer<N> > ()

       .HideFromDocumentation ()

       ;

     return tid;

   }

   virtual TypeId GetInstanceTypeId (void) const {

     return GetTypeId ();

   }

   virtual uint32_t GetSerializedSize (void) const {

     return N;

   }

   virtual void Serialize (Buffer::Iterator iter) const {

     iter.Prev (N);

     for (uint32_t i = 0; i < N; ++i)

       {

         iter.WriteU8 (N);

       }

   }

   virtual uint32_t Deserialize (Buffer::Iterator iter) {

     iter.Prev (N);

     for (uint32_t i = 0; i < N; ++i)

       {

         uint8_t v = iter.ReadU8 ();

         if (v != N)

           {

             m_error = true;

           }

       }

     return N;

   }

   virtual void Print (std::ostream &os) const {

   }

   ATestTrailer ()

     : ATestTrailerBase () {}

 };

 struct Expected

 {

   Expected (uint32_t n_, uint32_t start_, uint32_t end_)

     : n (n_), start (start_), end (end_) {}

   uint32_t n;

   uint32_t start;

   uint32_t end;

 };

 }

 // tag name, start, end

 #define E(a,b,c) a,b,c

 #define CHECK(p, n, ...)                                \

   DoCheck (p, __FILE__, __LINE__, n, __VA_ARGS__)

 class PacketTest: public TestCase 

 {

 public:

   PacketTest ();

   virtual bool DoRun (void);

 private:

   void DoCheck (Ptr<const Packet> p, const char *file, int line, uint32_t n, ...);

 };

 PacketTest::PacketTest ()

   : TestCase ("Packet") {}

 void

 PacketTest::DoCheck (Ptr<const Packet> p, const char *file, int line, uint32_t n, ...)

 {

   std::vector<struct Expected> expected;

   va_list ap;

   va_start (ap, n);

   for (uint32_t k = 0; k < n; ++k)

     {

       uint32_t N = va_arg (ap, uint32_t);

       uint32_t start = va_arg (ap, uint32_t);

       uint32_t end = va_arg (ap, uint32_t);

       expected.push_back (Expected (N, start, end));

     }

   va_end (ap);

   ByteTagIterator i = p->GetByteTagIterator ();

   uint32_t j = 0;

   while (i.HasNext () && j < expected.size ())

     {

       ByteTagIterator::Item item = i.Next ();

       struct Expected e = expected[j];

       std::ostringstream oss;

       oss << "anon::ATestTag<" << e.n << ">";

       NS_TEST_EXPECT_MSG_EQ_INTERNAL (item.GetTypeId ().GetName (), oss.str (), "trivial", file, line);

       NS_TEST_EXPECT_MSG_EQ_INTERNAL (item.GetStart (), e.start, "trivial", file, line);

       NS_TEST_EXPECT_MSG_EQ_INTERNAL (item.GetEnd (), e.end, "trivial", file, line);

       ATestTagBase *tag = dynamic_cast<ATestTagBase *> (item.GetTypeId ().GetConstructor () ());

       NS_TEST_EXPECT_MSG_NE (tag, 0, "trivial");

       item.GetTag (*tag);

       NS_TEST_EXPECT_MSG_EQ (tag->m_error, false, "trivial");

       delete tag;

       j++;

     }

   NS_TEST_EXPECT_MSG_EQ (i.HasNext (), false, "Nothing left");

   NS_TEST_EXPECT_MSG_EQ (j, expected.size (), "Size match");

 }

 bool

 PacketTest::DoRun (void)

 {

   Ptr<Packet> pkt1 = Create<Packet> (reinterpret_cast<const uint8_t*> ("hello"), 5);

   Ptr<Packet> pkt2 = Create<Packet> (reinterpret_cast<const uint8_t*> (" world"), 6);

   Ptr<Packet> packet = Create<Packet> ();

   packet->AddAtEnd (pkt1);

   packet->AddAtEnd (pkt2);

   NS_TEST_EXPECT_MSG_EQ (packet->GetSize (), 11, "trivial");

   std::string msg = std::string (reinterpret_cast<const char *>(packet->PeekData ()),

                                  packet->GetSize ());

   NS_TEST_EXPECT_MSG_EQ (msg, "hello world", "trivial");

   Ptr<const Packet> p = Create<Packet> (1000);

   p->AddByteTag (ATestTag<1> ());

   CHECK (p, 1, E (1, 0, 1000));

   Ptr<const Packet> copy = p->Copy ();

   CHECK (copy, 1, E (1, 0, 1000));

   p->AddByteTag (ATestTag<2> ());

   CHECK (p, 2, E (1, 0, 1000), E(2, 0, 1000));

   CHECK (copy, 1, E (1, 0, 1000));

   {

     Packet c0 = *copy;

     Packet c1 = *copy;

     c0 = c1;

     CHECK (&c0, 1, E (1, 0, 1000));

     CHECK (&c1, 1, E (1, 0, 1000));

     CHECK (copy, 1, E (1, 0, 1000));

     c0.AddByteTag (ATestTag<10> ());

     CHECK (&c0, 2, E (1, 0, 1000), E (10, 0, 1000));

     CHECK (&c1, 1, E (1, 0, 1000));

     CHECK (copy, 1, E (1, 0, 1000));

   }

   Ptr<Packet> frag0 = p->CreateFragment (0, 10);

   Ptr<Packet> frag1 = p->CreateFragment (10, 90);

   Ptr<const Packet> frag2 = p->CreateFragment (100, 900);

   frag0->AddByteTag (ATestTag<3> ());

   CHECK (frag0, 3, E (1, 0, 10), E(2, 0, 10), E (3, 0, 10));

   frag1->AddByteTag (ATestTag<4> ());

   CHECK (frag1, 3, E (1, 0, 90), E(2, 0, 90), E (4, 0, 90));

   frag2->AddByteTag (ATestTag<5> ());

   CHECK (frag2, 3, E (1, 0, 900), E(2, 0, 900), E (5, 0, 900));

   frag1->AddAtEnd (frag2);

   CHECK (frag1, 6, E (1, 0, 90), E(2, 0, 90), E (4, 0, 90), E (1, 90, 990), E(2, 90, 990), E (5, 90, 990));

   CHECK (frag0, 3, E (1, 0, 10), E(2, 0, 10), E (3, 0, 10));

   frag0->AddAtEnd (frag1);

   CHECK (frag0, 9, 

          E (1, 0, 10), E(2, 0, 10), E (3, 0, 10),

          E (1, 10, 100), E(2, 10, 100), E (4, 10, 100), 

          E (1, 100, 1000), E(2, 100, 1000), E (5, 100, 1000));

   // force caching a buffer of the right size.

   frag0 = Create<Packet> (1000);

   frag0->AddHeader (ATestHeader<10> ());

   frag0 = 0;

   p = Create<Packet> (1000);

   p->AddByteTag (ATestTag<20> ());

   CHECK (p, 1, E (20, 0, 1000));

   frag0 = p->CreateFragment (10, 90);

   CHECK (p, 1, E (20, 0, 1000));

   CHECK (frag0, 1, E (20, 0, 90));

   p = 0;

   frag0->AddHeader (ATestHeader<10> ());

   CHECK (frag0, 1, E (20, 10, 100));

   {

     Ptr<Packet> tmp = Create<Packet> (100);

     tmp->AddByteTag (ATestTag<20> ());

     CHECK (tmp, 1, E (20, 0, 100));

     tmp->AddHeader (ATestHeader<10> ());

     CHECK (tmp, 1, E (20, 10, 110));

     ATestHeader<10> h;

     tmp->RemoveHeader (h);

     CHECK (tmp, 1, E (20, 0, 100));

     tmp->AddHeader (ATestHeader<10> ());

     CHECK (tmp, 1, E (20, 10, 110));

     tmp = Create<Packet> (100);

     tmp->AddByteTag (ATestTag<20> ());

     CHECK (tmp, 1, E (20, 0, 100));

     tmp->AddTrailer (ATestTrailer<10> ());

     CHECK (tmp, 1, E (20, 0, 100));

     ATestTrailer<10> t;

     tmp->RemoveTrailer (t);

     CHECK (tmp, 1, E (20, 0, 100));

     tmp->AddTrailer (ATestTrailer<10> ());

     CHECK (tmp, 1, E (20, 0, 100));

   }

   {

     Ptr<Packet> tmp = Create<Packet> (0);

     tmp->AddHeader (ATestHeader<156> ());

     tmp->AddByteTag (ATestTag<20> ());

     CHECK (tmp, 1, E (20, 0, 156));

     tmp->RemoveAtStart (120);

     CHECK (tmp, 1, E (20, 0, 36));

     Ptr<Packet> a = Create<Packet> (0);

     a->AddAtEnd (tmp);

     CHECK (a, 1, E (20, 0, 36));

   }

   {

     Ptr<Packet> tmp = Create<Packet> (0);

     tmp->AddByteTag (ATestTag<20> ());

     CHECK (tmp, 0, E (20, 0, 0));

   }

   {

     Ptr<Packet> tmp = Create<Packet> (1000);

     tmp->AddByteTag (ATestTag<20> ());

     CHECK (tmp, 1, E (20, 0, 1000));

     tmp->RemoveAtStart (1000);

     CHECK (tmp, 0,  E (0,0,0));

     Ptr<Packet> a = Create<Packet> (10);

     a->AddByteTag (ATestTag<10> ());

     CHECK (a, 1, E (10, 0, 10));

     tmp->AddAtEnd (a);

     CHECK (tmp, 1, E (10, 0, 10));

   }

   {

     Packet p;

     ATestTag<10> a;

     p.AddPacketTag (a);

     NS_TEST_EXPECT_MSG_EQ (p.PeekPacketTag (a), true, "trivial");

     ATestTag<11> b;

     p.AddPacketTag (b);

     NS_TEST_EXPECT_MSG_EQ (p.PeekPacketTag (b), true, "trivial");

     NS_TEST_EXPECT_MSG_EQ (p.PeekPacketTag (a), true, "trivial");

     Packet copy = p;

     NS_TEST_EXPECT_MSG_EQ (copy.PeekPacketTag (b), true, "trivial");

     NS_TEST_EXPECT_MSG_EQ (copy.PeekPacketTag (a), true, "trivial");

     ATestTag<12> c;

     NS_TEST_EXPECT_MSG_EQ (copy.PeekPacketTag (c), false, "trivial");

     copy.AddPacketTag (c);

     NS_TEST_EXPECT_MSG_EQ (copy.PeekPacketTag (c), true, "trivial");

     NS_TEST_EXPECT_MSG_EQ (copy.PeekPacketTag (b), true, "trivial");

     NS_TEST_EXPECT_MSG_EQ (copy.PeekPacketTag (a), true, "trivial");

     NS_TEST_EXPECT_MSG_EQ (p.PeekPacketTag (c), false, "trivial");

     copy.RemovePacketTag (b);

     NS_TEST_EXPECT_MSG_EQ (copy.PeekPacketTag (b), false, "trivial");

     NS_TEST_EXPECT_MSG_EQ (p.PeekPacketTag (b), true, "trivial");

     p.RemovePacketTag (a);

     NS_TEST_EXPECT_MSG_EQ (p.PeekPacketTag (a), false, "trivial");

     NS_TEST_EXPECT_MSG_EQ (copy.PeekPacketTag (a), true, "trivial");

     NS_TEST_EXPECT_MSG_EQ (p.PeekPacketTag (c), false, "trivial");

     NS_TEST_EXPECT_MSG_EQ (copy.PeekPacketTag (c), true, "trivial");

     p.RemoveAllPacketTags ();

     NS_TEST_EXPECT_MSG_EQ (p.PeekPacketTag (b), false, "trivial");

   }

   {

     // bug 572                                                                  

     Ptr<Packet> tmp = Create<Packet> (1000);

     tmp->AddByteTag (ATestTag<20> ());

     CHECK (tmp, 1, E (20, 0, 1000));

     tmp->AddHeader (ATestHeader<2> ());

     CHECK (tmp, 1, E (20, 2, 1002));

     tmp->RemoveAtStart (1);

     CHECK (tmp, 1, E (20, 1, 1001));

     tmp->PeekData ();

     CHECK (tmp, 1, E (20, 1, 1001));

   }

   return GetErrorStatus ();

 }

 //-----------------------------------------------------------------------------

 class PacketTestSuite : public TestSuite

 {

 public:

   PacketTestSuite ();

 };

 PacketTestSuite::PacketTestSuite ()

   : TestSuite ("packet", UNIT)

 {

   AddTestCase (new PacketTest);

 }

 PacketTestSuite g_packetTestSuite;

 } // namespace ns3