Public Member Functions | Static Public Member Functions

ns3::EthernetTrailer Class Reference
[Node]

Packet trailer for Ethernet. More...

#include <ethernet-trailer.h>

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List of all members.

Public Member Functions

 EthernetTrailer ()
 Construct a null ethernet trailer.
void EnableFcs (bool enable)
 Enable or disable FCS checking and calculations.
void CalcFcs (Ptr< const Packet > p)
 Updates the Fcs Field to the correct FCS.
void SetFcs (uint32_t fcs)
 Sets the FCS to a new value.
uint32_t GetFcs ()
bool CheckFcs (Ptr< const Packet > p) const
uint32_t GetTrailerSize () const
virtual TypeId GetInstanceTypeId (void) const
virtual void Print (std::ostream &os) const
virtual uint32_t GetSerializedSize (void) const
virtual void Serialize (Buffer::Iterator end) const
virtual uint32_t Deserialize (Buffer::Iterator end)

Static Public Member Functions

static TypeId GetTypeId (void)
 This method returns the TypeId associated to ns3::EthernetTrailer.

Detailed Description

Packet trailer for Ethernet.

This class can be used to add and verify the FCS at the end of an Ethernet packet.


Member Function Documentation

void ns3::EthernetTrailer::CalcFcs ( Ptr< const Packet p  ) 

Updates the Fcs Field to the correct FCS.

Parameters:
p Reference to a packet on which the FCS should be calculated. The packet should not currently contain an EthernetTrailer.
bool ns3::EthernetTrailer::CheckFcs ( Ptr< const Packet p  )  const

Calculate an FCS on the provided packet and check this value against the FCS found when the trailer was deserialized (the one in the transmitted packet).

If FCS checking is disabled, this method will always return true.

Parameters:
p Reference to the packet on which the FCS should be calculated. The packet should not contain an EthernetTrailer.
Returns:
Returns true if the Packet FCS matches the FCS in the trailer, false otherwise.
virtual uint32_t ns3::EthernetTrailer::Deserialize ( Buffer::Iterator  end  )  [virtual]
Parameters:
end an iterator which points to the end of the buffer where the trailer should be read from.
Returns:
the number of bytes read.

This method is used by Packet::RemoveTrailer to re-create a trailer from the byte buffer of a packet. The data read is expected to match bit-for-bit the representation of this trailer in real networks. The input iterator points to the end of the area where the data shall be written. This method is thus expected to call Buffer::Iterator::Prev prio to actually reading any data.

Implements ns3::Trailer.

void ns3::EthernetTrailer::EnableFcs ( bool  enable  ) 

Enable or disable FCS checking and calculations.

Parameters:
enable If true, enables FCS calculations.
uint32_t ns3::EthernetTrailer::GetFcs (  ) 
Returns:
the FCS contained in this trailer
virtual TypeId ns3::EthernetTrailer::GetInstanceTypeId ( void   )  const [virtual]
Returns:
the TypeId associated to the most-derived type of this instance.

This method is typically implemented by ns3::Object::GetInstanceTypeId but some classes which derive from ns3::ObjectBase directly have to implement it themselves.

Implements ns3::ObjectBase.

virtual uint32_t ns3::EthernetTrailer::GetSerializedSize ( void   )  const [virtual]
Returns:
the expected size of the trailer.

This method is used by Packet::AddTrailer to store a trailer into the byte buffer of a packet. This method should return the number of bytes which are needed to store the full trailer data by Serialize.

Implements ns3::Trailer.

uint32_t ns3::EthernetTrailer::GetTrailerSize (  )  const
Returns:
Returns the size of the trailer
static TypeId ns3::EthernetTrailer::GetTypeId ( void   )  [static]

This method returns the TypeId associated to ns3::EthernetTrailer.

No Attributes defined for this type.
No TraceSources defined for this type.

Reimplemented from ns3::Trailer.

virtual void ns3::EthernetTrailer::Print ( std::ostream &  os  )  const [virtual]
Parameters:
os output stream This method is used by Packet::Print to print the content of a trailer as ascii data to a c++ output stream. Although the trailer is free to format its output as it wishes, it is recommended to follow a few rules to integrate with the packet pretty printer: start with flags, small field values located between a pair of parens. Values should be separated by whitespace. Follow the parens with the important fields, separated by whitespace. i.e.: (field1 val1 field2 val2 field3 val3) field4 val4 field5 val5

Implements ns3::Trailer.

virtual void ns3::EthernetTrailer::Serialize ( Buffer::Iterator  start  )  const [virtual]
Parameters:
start an iterator which points to where the trailer should be written.

This method is used by Packet::AddTrailer to store a header into the byte buffer of a packet. The data written is expected to match bit-for-bit the representation of this trailer in real networks. The input iterator points to the end of the area where the data shall be written. This method is thus expected to call Buffer::Iterator::Prev prior to actually writing any data.

Implements ns3::Trailer.

void ns3::EthernetTrailer::SetFcs ( uint32_t  fcs  ) 

Sets the FCS to a new value.

Parameters:
fcs New FCS value

The documentation for this class was generated from the following files: