Packet trailer for Ethernet. More...

#include "ethernet-trailer.h"

Inheritance diagram for ns3::EthernetTrailer:

Collaboration diagram for ns3::EthernetTrailer:

Public Member Functions
	EthernetTrailer ()
	Construct a null ethernet trailer.

void	CalcFcs (Ptr< const Packet > p)
	Updates the Fcs Field to the correct FCS.

bool	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).

uint32_t	Deserialize (Buffer::Iterator end) override

void	EnableFcs (bool enable)
	Enable or disable FCS checking and calculations.

uint32_t	GetFcs () const

TypeId	GetInstanceTypeId () const override
	Get the most derived TypeId for this Object.

uint32_t	GetSerializedSize () const override

uint32_t	GetTrailerSize () const

void	Print (std::ostream &os) const override

void	Serialize (Buffer::Iterator end) const override

void	SetFcs (uint32_t fcs)
	Sets the FCS to a new value.

Public Member Functions inherited from ns3::Trailer
	~Trailer () override

uint32_t	Deserialize (Buffer::Iterator start, Buffer::Iterator end) override

Public Member Functions inherited from ns3::ObjectBase
virtual	~ObjectBase ()
	Virtual destructor.

void	GetAttribute (std::string name, AttributeValue &value, bool permissive=false) const
	Get the value of an attribute, raising fatal errors if unsuccessful.

bool	GetAttributeFailSafe (std::string name, AttributeValue &value) const
	Get the value of an attribute without raising errors.

void	SetAttribute (std::string name, const AttributeValue &value)
	Set a single attribute, raising fatal errors if unsuccessful.

bool	SetAttributeFailSafe (std::string name, const AttributeValue &value)
	Set a single attribute without raising errors.

bool	TraceConnect (std::string name, std::string context, const CallbackBase &cb)
	Connect a TraceSource to a Callback with a context.

bool	TraceConnectWithoutContext (std::string name, const CallbackBase &cb)
	Connect a TraceSource to a Callback without a context.

bool	TraceDisconnect (std::string name, std::string context, const CallbackBase &cb)
	Disconnect from a TraceSource a Callback previously connected with a context.

bool	TraceDisconnectWithoutContext (std::string name, const CallbackBase &cb)
	Disconnect from a TraceSource a Callback previously connected without a context.

Static Public Member Functions
static TypeId	GetTypeId ()
	Get the type ID.

Static Public Member Functions inherited from ns3::Trailer
static TypeId	GetTypeId ()
	Get the type ID.

Static Public Member Functions inherited from ns3::Chunk
static TypeId	GetTypeId ()
	Get the type ID.

Static Public Member Functions inherited from ns3::ObjectBase
static TypeId	GetTypeId ()
	Get the type ID.

Private Attributes
bool	m_calcFcs
	Enabled FCS calculations.

uint32_t	m_fcs
	Value of the fcs contained in the trailer.

Additional Inherited Members
Protected Member Functions inherited from ns3::ObjectBase
void	ConstructSelf (const AttributeConstructionList &attributes)
	Complete construction of ObjectBase; invoked by derived classes.

virtual void	NotifyConstructionCompleted ()
	Notifier called once the ObjectBase is fully constructed.

Related Symbols inherited from ns3::ObjectBase
static TypeId	GetObjectIid ()
	Ensure the TypeId for ObjectBase gets fully configured to anchor the inheritance tree properly.

Detailed Description

Packet trailer for Ethernet.

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

Definition at line 28 of file ethernet-trailer.h.

Constructor & Destructor Documentation

◆ EthernetTrailer()

ns3::EthernetTrailer::EthernetTrailer ( )

Construct a null ethernet trailer.

Definition at line 24 of file ethernet-trailer.cc.

References NS_LOG_FUNCTION.

Member Function Documentation

◆ CalcFcs()

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.

Definition at line 59 of file ethernet-trailer.cc.

References ns3::CRC32Calculate(), m_calcFcs, m_fcs, and NS_LOG_FUNCTION.

Referenced by ns3::CsmaNetDevice::AddHeader().

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◆ CheckFcs()

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.

Definition at line 39 of file ethernet-trailer.cc.

References ns3::CRC32Calculate(), m_calcFcs, m_fcs, and NS_LOG_FUNCTION.

Referenced by ns3::CsmaNetDevice::Receive().

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◆ Deserialize()

uint32_t ns3::EthernetTrailer::Deserialize ( Buffer::Iterator end )

overridevirtual

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 read from. This method is thus expected to call Buffer::Iterator::Prev prior to actually reading any data.

Implements ns3::Trailer.

Definition at line 138 of file ethernet-trailer.cc.

References GetSerializedSize(), m_fcs, NS_LOG_FUNCTION, ns3::Buffer::Iterator::Prev(), and ns3::Buffer::Iterator::ReadU32().

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◆ EnableFcs()

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

Enable or disable FCS checking and calculations.

Parameters

enable If true, enables FCS calculations.

Definition at line 32 of file ethernet-trailer.cc.

References m_calcFcs, and NS_LOG_FUNCTION.

Referenced by ns3::CsmaNetDevice::AddHeader(), and ns3::CsmaNetDevice::Receive().

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◆ GetFcs()

uint32_t ns3::EthernetTrailer::GetFcs ( ) const

Returns: the FCS contained in this trailer

Definition at line 84 of file ethernet-trailer.cc.

References m_fcs, and NS_LOG_FUNCTION.

◆ GetInstanceTypeId()

TypeId ns3::EthernetTrailer::GetInstanceTypeId ( ) const

overridevirtual

Get the most derived TypeId for this Object.

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

Returns: The TypeId associated to the most-derived type of this instance.

Implements ns3::ObjectBase.

Definition at line 108 of file ethernet-trailer.cc.

References GetTypeId().

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◆ GetSerializedSize()

uint32_t ns3::EthernetTrailer::GetSerializedSize ( ) const

overridevirtual

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.

Definition at line 121 of file ethernet-trailer.cc.

References NS_LOG_FUNCTION.

Referenced by Deserialize(), GetTrailerSize(), and Serialize().

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◆ GetTrailerSize()

uint32_t ns3::EthernetTrailer::GetTrailerSize ( ) const

Returns: Returns the size of the trailer

Definition at line 91 of file ethernet-trailer.cc.

References GetSerializedSize(), and NS_LOG_FUNCTION.

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◆ GetTypeId()

TypeId ns3::EthernetTrailer::GetTypeId ( )

static

Get the type ID.

Returns: the object TypeId

Definition at line 98 of file ethernet-trailer.cc.

References ns3::TypeId::SetParent().

Referenced by GetInstanceTypeId().

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◆ Print()

void ns3::EthernetTrailer::Print ( std::ostream & os ) const

overridevirtual

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.

Definition at line 114 of file ethernet-trailer.cc.

References m_fcs, and NS_LOG_FUNCTION.

◆ Serialize()

void ns3::EthernetTrailer::Serialize ( Buffer::Iterator start ) const

overridevirtual

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.

Definition at line 128 of file ethernet-trailer.cc.

References GetSerializedSize(), m_fcs, NS_LOG_FUNCTION, ns3::Buffer::Iterator::Prev(), and ns3::Buffer::Iterator::WriteU32().

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◆ SetFcs()

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

Sets the FCS to a new value.

Parameters

fcs	New FCS value

Definition at line 77 of file ethernet-trailer.cc.

References m_fcs, and NS_LOG_FUNCTION.

Member Data Documentation

◆ m_calcFcs

bool ns3::EthernetTrailer::m_calcFcs

private

Enabled FCS calculations.

If false, m_fcs is set to 0 and CheckFcs returns true.

Definition at line 98 of file ethernet-trailer.h.

Referenced by CalcFcs(), CheckFcs(), and EnableFcs().

◆ m_fcs

uint32_t ns3::EthernetTrailer::m_fcs

private

Value of the fcs contained in the trailer.

Definition at line 99 of file ethernet-trailer.h.

Referenced by CalcFcs(), CheckFcs(), Deserialize(), GetFcs(), Print(), Serialize(), and SetFcs().

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

src/network/utils/ethernet-trailer.h
src/network/utils/ethernet-trailer.cc

Public Member Functions

Static Public Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ EthernetTrailer()

Member Function Documentation

◆ CalcFcs()

◆ CheckFcs()

◆ Deserialize()

◆ EnableFcs()

◆ GetFcs()

◆ GetInstanceTypeId()

◆ GetSerializedSize()

◆ GetTrailerSize()

◆ GetTypeId()

◆ Print()

◆ Serialize()

◆ SetFcs()

Member Data Documentation

◆ m_calcFcs

◆ m_fcs