A bridge to make it appear that a real host process is connected to an ns-3 net device. More...

#include "tap-bridge.h"

Inheritance diagram for ns3::TapBridge:

Collaboration diagram for ns3::TapBridge:

Public Types
enum	Mode { ILLEGAL , CONFIGURE_LOCAL , USE_LOCAL , USE_BRIDGE }
	Enumeration of the operating modes supported in the class. More...

Public Types inherited from ns3::NetDevice
typedef void(*	LinkChangeTracedCallback) ()
	TracedCallback signature for link changed event.

enum	PacketType { PACKET_HOST = 1 , NS3_PACKET_HOST = PACKET_HOST , PACKET_BROADCAST , NS3_PACKET_BROADCAST = PACKET_BROADCAST , PACKET_MULTICAST , NS3_PACKET_MULTICAST = PACKET_MULTICAST , PACKET_OTHERHOST , NS3_PACKET_OTHERHOST = PACKET_OTHERHOST }
	Packet types are used as they are in Linux. More...

typedef Callback< bool, Ptr< NetDevice >, Ptr< const Packet >, uint16_t, const Address &, const Address &, PacketType >	PromiscReceiveCallback

typedef Callback< bool, Ptr< NetDevice >, Ptr< const Packet >, uint16_t, const Address & >	ReceiveCallback

Public Member Functions
	TapBridge ()

	~TapBridge () override

void	AddLinkChangeCallback (Callback< void > callback) override

Address	GetAddress () const override

Ptr< NetDevice >	GetBridgedNetDevice ()
	Get the bridged net device.

Address	GetBroadcast () const override

Ptr< Channel >	GetChannel () const override

uint32_t	GetIfIndex () const override

TapBridge::Mode	GetMode ()
	Get the operating mode of this device.

uint16_t	GetMtu () const override

Address	GetMulticast (Ipv4Address multicastGroup) const override
	Make and return a MAC multicast address using the provided multicast group.

Address	GetMulticast (Ipv6Address addr) const override
	Get the MAC multicast address corresponding to the IPv6 address provided.

Ptr< Node >	GetNode () const override

bool	IsBridge () const override
	Return true if the net device is acting as a bridge.

bool	IsBroadcast () const override

bool	IsLinkUp () const override

bool	IsMulticast () const override

bool	IsPointToPoint () const override
	Return true if the net device is on a point-to-point link.

bool	NeedsArp () const override

bool	Send (Ptr< Packet > packet, const Address &dest, uint16_t protocolNumber) override

bool	SendFrom (Ptr< Packet > packet, const Address &source, const Address &dest, uint16_t protocolNumber) override

void	SetAddress (Address address) override
	Set the address of this interface.

void	SetBridgedNetDevice (Ptr< NetDevice > bridgedDevice)
	Set the ns-3 net device to bridge.

void	SetIfIndex (const uint32_t index) override

void	SetMode (TapBridge::Mode mode)
	Set the operating mode of this device.

bool	SetMtu (const uint16_t mtu) override

void	SetNode (Ptr< Node > node) override

void	SetPromiscReceiveCallback (NetDevice::PromiscReceiveCallback cb) override

void	SetReceiveCallback (NetDevice::ReceiveCallback cb) override

void	Start (Time tStart)
	Set a start time for the device.

void	Stop (Time tStop)
	Set a stop time for the device.

bool	SupportsSendFrom () const override

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

Public Member Functions inherited from ns3::Object
	Object ()
	Constructor.

	~Object () override
	Destructor.

void	AggregateObject (Ptr< Object > other)
	Aggregate two Objects together.

void	Dispose ()
	Dispose of this Object.

AggregateIterator	GetAggregateIterator () const
	Get an iterator to the Objects aggregated to this one.

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

template<typename T >
Ptr< T >	GetObject () const
	Get a pointer to the requested aggregated Object.

template<>
Ptr< Object >	GetObject () const
	Specialization of () for objects of type ns3::Object.

template<typename T >
Ptr< T >	GetObject (TypeId tid) const
	Get a pointer to the requested aggregated Object by TypeId.

template<>
Ptr< Object >	GetObject (TypeId tid) const
	Specialization of (TypeId tid) for objects of type ns3::Object.

void	Initialize ()
	Invoke DoInitialize on all Objects aggregated to this one.

bool	IsInitialized () const
	Check if the object has been initialized.

void	UnidirectionalAggregateObject (Ptr< Object > other)
	Aggregate an Object to another Object.

Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter >
	SimpleRefCount ()
	Default constructor.

	SimpleRefCount (const SimpleRefCount &o)
	Copy constructor.

uint32_t	GetReferenceCount () const
	Get the reference count of the object.

SimpleRefCount &	operator= (const SimpleRefCount &o)
	Assignment operator.

void	Ref () const
	Increment the reference count.

void	Unref () const
	Decrement the reference count.

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::NetDevice
static TypeId	GetTypeId ()
	Get the type ID.

Static Public Member Functions inherited from ns3::Object
static TypeId	GetTypeId ()
	Register this type.

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

Protected Member Functions
bool	DiscardFromBridgedDevice (Ptr< NetDevice > device, Ptr< const Packet > packet, uint16_t protocol, const Address &src)
	Receives a packet from a bridged Device.

void	DoDispose () override
	Call out to a separate process running as suid root in order to get our tap device created.

bool	ReceiveFromBridgedDevice (Ptr< NetDevice > device, Ptr< const Packet > packet, uint16_t protocol, const Address &src, const Address &dst, PacketType packetType)
	Receives a packet from a bridged Device.

Protected Member Functions inherited from ns3::Object
	Object (const Object &o)
	Copy an Object.

virtual void	DoInitialize ()
	Initialize() implementation.

virtual void	NotifyNewAggregate ()
	Notify all Objects aggregated to this one of a new Object being aggregated.

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.

Private Member Functions
void	CreateTap ()
	Call out to a separate process running as suid root in order to get our tap device created.

Ptr< Packet >	Filter (Ptr< Packet > packet, Address src, Address dst, uint16_t *type)
	The host we are bridged to is in the evil real world.

void	ForwardToBridgedDevice (uint8_t *buf, ssize_t len)
	Forward a packet received from the tap device to the bridged ns-3 device.

void	NotifyLinkUp ()
	Notifies that the link is up and ready.

void	ReadCallback (uint8_t *buf, ssize_t len)
	Callback to process packets that are read.

void	StartTapDevice ()
	Spin up the device.

void	StopTapDevice ()
	Tear down the device.

Private Attributes
Mac48Address	m_address
	The (unused) MAC address of the TapBridge net device.

Ptr< NetDevice >	m_bridgedDevice
	The ns-3 net device to which we are bridging.

Ptr< TapBridgeFdReader >	m_fdReader
	Includes the ns-3 read thread used to do blocking reads on the fd corresponding to the host device.

uint32_t	m_ifIndex
	The ns-3 interface index of this TapBridge net device.

TracedCallback	m_linkChangeCallbacks
	Callbacks to fire if the link changes state (up or down).

bool	m_linkUp {false}
	Flag indicating whether or not the link is up.

Mode	m_mode
	The operating mode of the bridge.

uint16_t	m_mtu
	The common mtu to use for the net devices.

Ptr< Node >	m_node
	Pointer to the (ghost) Node to which we are connected.

uint32_t	m_nodeId
	a copy of the node id so the read thread doesn't have to GetNode() in in order to find the node ID.

bool	m_ns3AddressRewritten
	Whether the MAC address of the underlying ns-3 device has already been rewritten is stored in this variable (for UseLocal/UseBridge mode only).

uint8_t *	m_packetBuffer
	A 64K buffer to hold packet data while it is being sent.

NetDevice::PromiscReceiveCallback	m_promiscRxCallback
	Callback used to hook the promiscuous packet receive callback of the TapBridge ns-3 net device.

NetDevice::ReceiveCallback	m_rxCallback
	Callback used to hook the standard packet receive callback of the TapBridge ns-3 net device.

int	m_sock
	The socket (actually interpreted as fd) to use to talk to the Tap device on the real internet host.

EventId	m_startEvent
	The ID of the ns-3 event used to schedule the start up of the underlying host Tap device and ns-3 read thread.

EventId	m_stopEvent
	The ID of the ns-3 event used to schedule the tear down of the underlying host Tap device and ns-3 read thread.

std::string	m_tapDeviceName
	The name of the device to create on the host.

Ipv4Address	m_tapGateway
	The IP address to use as the device default gateway on the host.

Ipv4Address	m_tapIp
	The IP address to use as the device IP on the host.

Mac48Address	m_tapMac
	The MAC address to use as the hardware address on the host; only used in UseLocal mode.

Ipv4Mask	m_tapNetmask
	The network mask to assign to the device created on the host.

Time	m_tStart
	Time to start spinning up the device.

Time	m_tStop
	Time to start tearing down the device.

bool	m_verbose
	Flag indicating whether or not the link is up.

Additional Inherited Members
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

A bridge to make it appear that a real host process is connected to an ns-3 net device.

The Tap Bridge lives in a kind of a gray world somewhere between a Linux host and an ns-3 bridge device. From the Linux perspective, this code appears as the user mode handler for a Tap net device. That is, when the Linux host writes to a /dev/tap device (that is either manually or automatically created depending on basic operating mode – more on this later), the write is redirected into the TapBridge that lives in the ns-3 world; and from this perspective, becomes a read. In other words, a Linux process writes a packet to a tap device and this packet is redirected to an ns-3 process where it is received by the TapBridge as a result of a read operation there. The TapBridge then sends the packet to the ns-3 net device to which it is bridged. In the other direction, a packet received by an ns-3 net device is bridged to the TapBridge (it appears via a callback from that net device. The TapBridge then takes that packet and writes it back to the host using the Linux TAP mechanism. This write to the device will then appear to the Linux host as if a packet has arrived on its device.

The upshot is that the Tap Bridge appears to bridge a tap device on a Linux host in the "real world" to an ns-3 net device in the simulation and make is appear that a ns-3 net device is actually installed in the Linux host. In order to do this on the ns-3 side, we need a "ghost node" in the simulation to hold the bridged ns-3 net device and the TapBridge. This node should not actually do anything else in the simulation since its job is simply to make the net device appear in Linux. This is not just arbitrary policy, it is because:

Bits sent to the Tap Bridge from higher layers in the ghost node (using the TapBridge Send() method) are completely ignored. The Tap Bridge is not, itself, connected to any network, neither in Linux nor in ns-3;
The bridged ns-3 net device is has had its receive callback disconnected from the ns-3 node and reconnected to the Tap Bridge. All data received by a bridged device will be sent to the Linux host and will not be received by the node. From the perspective of the ghost node, you can send over this device but you cannot ever receive.

Of course, if you understand all of the issues you can take control of your own destiny and do whatever you want – we do not actively prevent you from using the ghost node for anything you decide. You will be able to perform typical ns-3 operations on the ghost node if you so desire. The internet stack, for example, must be there and functional on that node in order to participate in IP address assignment and global routing. However, as mentioned above, interfaces talking any Tap Bridge or associated bridged net devices will not work completely. If you understand exactly what you are doing, you can set up other interfaces and devices on the ghost node and use them; or take advantage of the operational send side of the bridged devices to create traffic generators. We generally recommend that you treat this node as a ghost of the Linux host and leave it to itself, though.

Definition at line 97 of file tap-bridge.h.

Member Enumeration Documentation

◆ Mode

enum ns3::TapBridge::Mode

Enumeration of the operating modes supported in the class.

Enumerator
ILLEGAL	mode not set
CONFIGURE_LOCAL	ns-3 creates and configures tap device
USE_LOCAL	ns-3 uses a pre-created tap, without configuring it
USE_BRIDGE	ns-3 uses a pre-created tap, and bridges to a bridging net device

Definition at line 110 of file tap-bridge.h.

Constructor & Destructor Documentation

◆ TapBridge()

ns3::TapBridge::TapBridge ( )

Definition at line 142 of file tap-bridge.cc.

References m_packetBuffer, m_tStart, NS_LOG_FUNCTION, and Start().

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◆ ~TapBridge()

ns3::TapBridge::~TapBridge ( )

override

Definition at line 156 of file tap-bridge.cc.

References m_bridgedDevice, m_packetBuffer, NS_LOG_FUNCTION, and StopTapDevice().

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Member Function Documentation

◆ AddLinkChangeCallback()

void ns3::TapBridge::AddLinkChangeCallback ( Callback< void > callback )

overridevirtual

Parameters

callback the callback to invoke

Add a callback invoked whenever the link status changes to UP. This callback is typically used by the IP/ARP layer to flush the ARP cache and by IPv6 stack to flush NDISC cache whenever the link goes up.

Implements ns3::NetDevice.

Definition at line 1131 of file tap-bridge.cc.

References ns3::TracedCallback< Ts >::ConnectWithoutContext(), m_linkChangeCallbacks, and NS_LOG_FUNCTION.

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◆ CreateTap()

void ns3::TapBridge::CreateTap ( )

private

Call out to a separate process running as suid root in order to get our tap device created.

We do this to avoid having the entire simulation running as root. If this method returns, we'll have a socket waiting for us in m_sock that we can use to talk to the tap device.

Definition at line 259 of file tap-bridge.cc.

References CONFIGURE_LOCAL, ns3::Mac48Address::ConvertFrom(), ns3::Mac48Address::CopyFrom(), GetBridgedNetDevice(), ns3::Ipv4Mask::GetOnes(), ns3::Ipv4Address::IsBroadcast(), ns3::Mac48Address::IsBroadcast(), m_bridgedDevice, m_mode, m_ns3AddressRewritten, m_sock, m_tapDeviceName, m_tapGateway, m_tapIp, m_tapMac, m_tapNetmask, m_verbose, NS_ABORT_MSG_IF, NS_ASSERT_MSG, NS_FATAL_ERROR, NS_LOG_DEBUG, NS_LOG_FUNCTION, NS_LOG_INFO, NS_LOG_WARN, TAP_MAGIC, ns3::TapBufferToString(), USE_BRIDGE, and USE_LOCAL.

Referenced by StartTapDevice().

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◆ DiscardFromBridgedDevice()

bool ns3::TapBridge::DiscardFromBridgedDevice	(	Ptr< NetDevice >	device,
		Ptr< const Packet >	packet,
		uint16_t	protocol,
		const Address &	src )

protected

Receives a packet from a bridged Device.

Parameters

device	the originating port
packet	the received packet
protocol	the packet protocol (e.g., Ethertype)
src	the packet source

Returns: true on success

Definition at line 964 of file tap-bridge.cc.

References NS_LOG_FUNCTION, and NS_LOG_LOGIC.

Referenced by SetBridgedNetDevice().

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◆ DoDispose()

void ns3::TapBridge::DoDispose ( )

overrideprotectedvirtual

Call out to a separate process running as suid root in order to get our tap device created.

We do this to avoid having the entire simulation running as root. If this method returns, we'll have a socket waiting for us in m_sock that we can use to talk to the tap device.

Reimplemented from ns3::Object.

Definition at line 169 of file tap-bridge.cc.

References ns3::Object::DoDispose(), and NS_LOG_FUNCTION.

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◆ Filter()

Ptr< Packet > ns3::TapBridge::Filter	(	Ptr< Packet >	packet,
		Address *	src,
		Address *	dst,
		uint16_t *	type )

private

The host we are bridged to is in the evil real world.

Do some sanity checking on a received packet to make sure it isn't too evil for our poor naive virginal simulator to handle.

Parameters

packet	The packet we received from the host, and which we need to check.
src	A pointer to the data structure that will get the source MAC address of the packet (extracted from the packet Ethernet header).
dst	A pointer to the data structure that will get the destination MAC address of the packet (extracted from the packet Ethernet header).
type	A pointer to the variable that will get the packet type from either the Ethernet header in the case of type interpretation (DIX framing) or from the 802.2 LLC header in the case of length interpretation (802.3 framing).

Returns: the packet, or null if the packet has been filtered.

Definition at line 859 of file tap-bridge.cc.

References ns3::EthernetHeader::GetDestination(), ns3::EthernetHeader::GetLengthType(), ns3::EthernetHeader::GetSerializedSize(), ns3::LlcSnapHeader::GetSerializedSize(), ns3::EthernetHeader::GetSource(), ns3::LlcSnapHeader::GetType(), NS_LOG_FUNCTION, NS_LOG_LOGIC, and pktSize.

Referenced by ForwardToBridgedDevice().

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◆ ForwardToBridgedDevice()

void ns3::TapBridge::ForwardToBridgedDevice	(	uint8_t *	buf,
		ssize_t	len )

private

Forward a packet received from the tap device to the bridged ns-3 device.

Parameters

buf	A character buffer containing the actual packet bits that were received from the host.
len	The length of the buffer.

Definition at line 728 of file tap-bridge.cc.

References CONFIGURE_LOCAL, ns3::Mac48Address::ConvertFrom(), ns3::Create(), Filter(), ns3::Mac48Address::GetBroadcast(), m_bridgedDevice, m_mode, m_ns3AddressRewritten, NS_ASSERT_MSG, NS_LOG_FUNCTION, NS_LOG_LOGIC, USE_BRIDGE, and USE_LOCAL.

Referenced by ReadCallback().

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◆ GetAddress()

Address ns3::TapBridge::GetAddress ( ) const

overridevirtual

Returns: the current Address of this interface.

Implements ns3::NetDevice.

Definition at line 1077 of file tap-bridge.cc.

References m_address, and NS_LOG_FUNCTION.

◆ GetBridgedNetDevice()

Ptr< NetDevice > ns3::TapBridge::GetBridgedNetDevice ( )

Get the bridged net device.

The bridged net device is the ns-3 device to which this bridge is connected,

Returns: the bridged net device.

Definition at line 921 of file tap-bridge.cc.

References m_bridgedDevice, and NS_LOG_FUNCTION.

Referenced by CreateTap().

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◆ GetBroadcast()

Address ns3::TapBridge::GetBroadcast ( ) const

overridevirtual

Returns: the broadcast address supported by this netdevice.

Calling this method is invalid if IsBroadcast returns not true.

Implements ns3::NetDevice.

Definition at line 1145 of file tap-bridge.cc.

References ns3::Mac48Address::GetBroadcast(), and NS_LOG_FUNCTION.

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◆ GetChannel()

Ptr< Channel > ns3::TapBridge::GetChannel ( ) const

overridevirtual

Returns: the channel this NetDevice is connected to. The value returned can be zero if the NetDevice is not yet connected to any channel or if the underlying NetDevice has no concept of a channel. i.e., callers must check for zero and be ready to handle it.

Implements ns3::NetDevice.

Definition at line 1063 of file tap-bridge.cc.

References NS_LOG_FUNCTION.

◆ GetIfIndex()

uint32_t ns3::TapBridge::GetIfIndex ( ) const

overridevirtual

Returns: index ifIndex of the device

Implements ns3::NetDevice.

Definition at line 1056 of file tap-bridge.cc.

References m_ifIndex, and NS_LOG_FUNCTION.

◆ GetMode()

TapBridge::Mode ns3::TapBridge::GetMode ( )

Get the operating mode of this device.

Returns: The operating mode of this device.

Definition at line 1091 of file tap-bridge.cc.

References m_mode, and NS_LOG_FUNCTION.

◆ GetMtu()

uint16_t ns3::TapBridge::GetMtu ( ) const

overridevirtual

Returns: the link-level MTU in bytes for this interface.

This value is typically used by the IP layer to perform IP fragmentation when needed.

Implements ns3::NetDevice.

Definition at line 1106 of file tap-bridge.cc.

References m_mtu, and NS_LOG_FUNCTION.

Referenced by GetTypeId().

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◆ GetMulticast() [1/2]

Address ns3::TapBridge::GetMulticast ( Ipv4Address multicastGroup ) const

overridevirtual

Make and return a MAC multicast address using the provided multicast group.

RFC 1112 says that an Ipv4 host group address is mapped to an Ethernet multicast address by placing the low-order 23-bits of the IP address into the low-order 23 bits of the Ethernet multicast address 01-00-5E-00-00-00 (hex). Similar RFCs exist for Ipv6 and Eui64 mappings. This method performs the multicast address creation function appropriate to the underlying MAC address of the device. This MAC address is encapsulated in an abstract Address to avoid dependencies on the exact MAC address format.

In the case of net devices that do not support multicast, clients are expected to test NetDevice::IsMulticast and avoid attempting to map multicast packets. Subclasses of NetDevice that do support multicasting are expected to override this method and provide an implementation appropriate to the particular device.

Parameters

multicastGroup The IP address for the multicast group destination of the packet.

Returns: The MAC multicast Address used to send packets to the provided multicast group.

Warning: Calling this method is invalid if IsMulticast returns not true.

See also: IsMulticast()

Implements ns3::NetDevice.

Definition at line 1159 of file tap-bridge.cc.

References ns3::Mac48Address::GetMulticast(), and NS_LOG_FUNCTION.

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◆ GetMulticast() [2/2]

Address ns3::TapBridge::GetMulticast ( Ipv6Address addr ) const

overridevirtual

Get the MAC multicast address corresponding to the IPv6 address provided.

Parameters

addr	IPv6 address

Returns: the MAC multicast address

Warning: Calling this method is invalid if IsMulticast returns not true.

Implements ns3::NetDevice.

Definition at line 1245 of file tap-bridge.cc.

References ns3::Mac48Address::GetMulticast(), and NS_LOG_FUNCTION.

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◆ GetNode()

Ptr< Node > ns3::TapBridge::GetNode ( ) const

overridevirtual

Returns: the node base class which contains this network interface.

When a subclass needs to get access to the underlying node base class to print the nodeid for example, it can invoke this method.

Implements ns3::NetDevice.

Definition at line 1203 of file tap-bridge.cc.

References m_node, and NS_LOG_FUNCTION.

Referenced by StartTapDevice().

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◆ GetTypeId()

TypeId ns3::TapBridge::GetTypeId ( )

static

Get the type ID.

Returns: the object TypeId

Definition at line 70 of file tap-bridge.cc.

References CONFIGURE_LOCAL, GetMtu(), m_tapDeviceName, m_tapGateway, m_tapIp, m_tapMac, m_tapNetmask, m_tStart, m_tStop, m_verbose, ns3::MakeBooleanAccessor(), ns3::MakeBooleanChecker(), ns3::MakeEnumAccessor(), ns3::MakeEnumChecker(), ns3::MakeIpv4AddressAccessor(), ns3::MakeIpv4AddressChecker(), ns3::MakeIpv4MaskAccessor(), ns3::MakeIpv4MaskChecker(), ns3::MakeMac48AddressAccessor(), ns3::MakeMac48AddressChecker(), ns3::MakeStringAccessor(), ns3::MakeStringChecker(), ns3::MakeTimeAccessor(), ns3::MakeTimeChecker(), ns3::MakeUintegerAccessor(), ns3::MakeUintegerChecker(), ns3::Seconds(), SetMode(), SetMtu(), ns3::TypeId::SetParent(), USE_BRIDGE, and USE_LOCAL.

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◆ IsBridge()

bool ns3::TapBridge::IsBridge ( ) const

overridevirtual

Return true if the net device is acting as a bridge.

Returns: value of m_isBridge flag

Implements ns3::NetDevice.

Definition at line 1174 of file tap-bridge.cc.

References NS_LOG_FUNCTION.

◆ IsBroadcast()

bool ns3::TapBridge::IsBroadcast ( ) const

overridevirtual

Returns: true if this interface supports a broadcast address, false otherwise.

Implements ns3::NetDevice.

Definition at line 1138 of file tap-bridge.cc.

References NS_LOG_FUNCTION.

◆ IsLinkUp()

bool ns3::TapBridge::IsLinkUp ( ) const

overridevirtual

Returns: true if link is up; false otherwise

Implements ns3::NetDevice.

Definition at line 1124 of file tap-bridge.cc.

References m_linkUp, and NS_LOG_FUNCTION.

◆ IsMulticast()

bool ns3::TapBridge::IsMulticast ( ) const

overridevirtual

Returns: value of m_isMulticast flag

Implements ns3::NetDevice.

Definition at line 1152 of file tap-bridge.cc.

References NS_LOG_FUNCTION.

◆ IsPointToPoint()

bool ns3::TapBridge::IsPointToPoint ( ) const

overridevirtual

Return true if the net device is on a point-to-point link.

Returns: value of m_isPointToPoint flag

Implements ns3::NetDevice.

Definition at line 1167 of file tap-bridge.cc.

References NS_LOG_FUNCTION.

◆ NeedsArp()

bool ns3::TapBridge::NeedsArp ( ) const

overridevirtual

Returns: true if ARP is needed, false otherwise.

Called by higher-layers to check if this NetDevice requires ARP to be used.

Implements ns3::NetDevice.

Definition at line 1217 of file tap-bridge.cc.

References NS_LOG_FUNCTION.

◆ NotifyLinkUp()

void ns3::TapBridge::NotifyLinkUp ( )

private

Notifies that the link is up and ready.

Definition at line 1113 of file tap-bridge.cc.

References m_linkChangeCallbacks, m_linkUp, and NS_LOG_FUNCTION.

Referenced by StartTapDevice().

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◆ ReadCallback()

void ns3::TapBridge::ReadCallback	(	uint8_t *	buf,
		ssize_t	len )

private

Callback to process packets that are read.

Parameters

buf	input buffer
len	input buffer length

Definition at line 701 of file tap-bridge.cc.

References ForwardToBridgedDevice(), m_nodeId, ns3::MakeEvent(), NS_ASSERT_MSG, NS_LOG_FUNCTION, NS_LOG_INFO, ns3::Simulator::ScheduleWithContext(), and ns3::Seconds().

Referenced by StartTapDevice().

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◆ ReceiveFromBridgedDevice()

bool ns3::TapBridge::ReceiveFromBridgedDevice	(	Ptr< NetDevice >	device,
		Ptr< const Packet >	packet,
		uint16_t	protocol,
		const Address &	src,
		const Address &	dst,
		PacketType	packetType )

protected

Receives a packet from a bridged Device.

Parameters

device	the originating port
packet	the received packet
protocol	the packet protocol (e.g., Ethertype)
src	the packet source
dst	the packet destination
packetType	the packet type (e.g., host, broadcast, etc.)

Returns: true on success

Definition at line 975 of file tap-bridge.cc.

References CONFIGURE_LOCAL, ns3::Mac48Address::ConvertFrom(), ns3::EthernetHeader::GetDestination(), ns3::Node::GetId(), ns3::EthernetHeader::GetLengthType(), ns3::EthernetHeader::GetSource(), m_bridgedDevice, m_mode, m_node, m_packetBuffer, m_sock, NS_ABORT_MSG_IF, NS_ASSERT_MSG, NS_LOG_DEBUG, NS_LOG_FUNCTION, NS_LOG_LOGIC, ns3::NetDevice::PACKET_OTHERHOST, ns3::EthernetHeader::SetDestination(), ns3::EthernetHeader::SetLengthType(), and ns3::EthernetHeader::SetSource().

Referenced by SetBridgedNetDevice().

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◆ Send()

bool ns3::TapBridge::Send	(	Ptr< Packet >	packet,
		const Address &	dest,
		uint16_t	protocolNumber )

overridevirtual

Parameters

packet	packet sent from above down to Network Device
dest	mac address of the destination (already resolved)
protocolNumber	identifies the type of payload contained in this packet. Used to call the right L3Protocol when the packet is received.

Called from higher layer to send packet into Network Device to the specified destination Address

Returns: whether the Send operation succeeded

Implements ns3::NetDevice.

Definition at line 1187 of file tap-bridge.cc.

References NS_FATAL_ERROR, and NS_LOG_FUNCTION.

◆ SendFrom()

bool ns3::TapBridge::SendFrom	(	Ptr< Packet >	packet,
		const Address &	source,
		const Address &	dest,
		uint16_t	protocolNumber )

overridevirtual

Parameters

packet	packet sent from above down to Network Device
source	source mac address (so called "MAC spoofing")
dest	mac address of the destination (already resolved)
protocolNumber	identifies the type of payload contained in this packet. Used to call the right L3Protocol when the packet is received.

Called from higher layer to send packet into Network Device with the specified source and destination Addresses.

Returns: whether the Send operation succeeded

Implements ns3::NetDevice.

Definition at line 1195 of file tap-bridge.cc.

References NS_FATAL_ERROR, and NS_LOG_FUNCTION.

◆ SetAddress()

void ns3::TapBridge::SetAddress ( Address address )

overridevirtual

Set the address of this interface.

Parameters

address address to set

Implements ns3::NetDevice.

Definition at line 1070 of file tap-bridge.cc.

References ns3::Mac48Address::ConvertFrom(), m_address, and NS_LOG_FUNCTION.

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◆ SetBridgedNetDevice()

void ns3::TapBridge::SetBridgedNetDevice ( Ptr< NetDevice > bridgedDevice )

Set the ns-3 net device to bridge.

This method tells the bridge which ns-3 net device it should use to connect the simulation side of the bridge.

Parameters

bridgedDevice device to set

Attention: The ns-3 net device that is being set as the device must have an an IP address assigned to it before the simulation is run. This address will be used to set the hardware address of the host Linux device.

Definition at line 928 of file tap-bridge.cc.

References DiscardFromBridgedDevice(), ns3::Mac48Address::IsMatchingType(), m_bridgedDevice, m_mode, m_node, ns3::MakeCallback(), NS_ASSERT_MSG, NS_FATAL_ERROR, NS_LOG_FUNCTION, ReceiveFromBridgedDevice(), and USE_BRIDGE.

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◆ SetIfIndex()

void ns3::TapBridge::SetIfIndex ( const uint32_t index )

overridevirtual

Parameters

index ifIndex of the device

Implements ns3::NetDevice.

Definition at line 1049 of file tap-bridge.cc.

References m_ifIndex, and NS_LOG_FUNCTION.

◆ SetMode()

void ns3::TapBridge::SetMode ( TapBridge::Mode mode )

Set the operating mode of this device.

Parameters

mode	The operating mode of this device.

Definition at line 1084 of file tap-bridge.cc.

References m_mode, and NS_LOG_FUNCTION.

Referenced by GetTypeId().

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◆ SetMtu()

bool ns3::TapBridge::SetMtu ( const uint16_t mtu )

overridevirtual

Parameters

mtu	MTU value, in bytes, to set for the device

Returns: whether the MTU value was within legal bounds

Override for default MTU defined on a per-type basis.

Implements ns3::NetDevice.

Definition at line 1098 of file tap-bridge.cc.

References m_mtu, and NS_LOG_FUNCTION.

Referenced by GetTypeId().

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◆ SetNode()

void ns3::TapBridge::SetNode ( Ptr< Node > node )

overridevirtual

Parameters

node	the node associated to this netdevice.

This method is called from ns3::Node::AddDevice.

Implements ns3::NetDevice.

Definition at line 1210 of file tap-bridge.cc.

References m_node, and NS_LOG_FUNCTION.

◆ SetPromiscReceiveCallback()

void ns3::TapBridge::SetPromiscReceiveCallback ( NetDevice::PromiscReceiveCallback cb )

overridevirtual

Parameters

cb	callback to invoke whenever a packet has been received in promiscuous mode and must be forwarded to the higher layers.

Enables netdevice promiscuous mode and sets the callback that will handle promiscuous mode packets. Note, promiscuous mode packets means all packets, including those packets that can be sensed by the netdevice but which are intended to be received by other hosts.

Implements ns3::NetDevice.

Definition at line 1231 of file tap-bridge.cc.

References m_promiscRxCallback, and NS_LOG_FUNCTION.

◆ SetReceiveCallback()

void ns3::TapBridge::SetReceiveCallback ( NetDevice::ReceiveCallback cb )

overridevirtual

Parameters

cb	callback to invoke whenever a packet has been received and must be forwarded to the higher layers.

Set the callback to be used to notify higher layers when a packet has been received.

Implements ns3::NetDevice.

Definition at line 1224 of file tap-bridge.cc.

References m_rxCallback, and NS_LOG_FUNCTION.

◆ Start()

void ns3::TapBridge::Start ( Time tStart )

Set a start time for the device.

The tap bridge consumes a non-trivial amount of time to start. It starts up in the context of a scheduled event to ensure that all configuration has been completed before extracting the configuration (IP addresses, etc.) In order to allow a more reasonable start-up sequence than a thundering herd of devices, the time at which each device starts is also configurable bot via the Attribute system and via this call.

Parameters

tStart the start time

Definition at line 176 of file tap-bridge.cc.

References ns3::Simulator::Cancel(), m_startEvent, NS_LOG_FUNCTION, ns3::Simulator::Schedule(), and StartTapDevice().

Referenced by TapBridge().

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◆ StartTapDevice()

void ns3::TapBridge::StartTapDevice ( )

private

Spin up the device.

Definition at line 199 of file tap-bridge.cc.

References ns3::Create(), CreateTap(), ns3::Node::GetId(), GetNode(), m_fdReader, m_nodeId, m_sock, ns3::MakeCallback(), NotifyLinkUp(), NS_ABORT_MSG_IF, NS_LOG_FUNCTION, NS_LOG_LOGIC, and ReadCallback().

Referenced by Start().

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◆ Stop()

void ns3::TapBridge::Stop ( Time tStop )

Set a stop time for the device.

Parameters

tStop the stop time

See also: TapBridge::Start

Definition at line 188 of file tap-bridge.cc.

References ns3::Simulator::Cancel(), m_startEvent, m_stopEvent, NS_LOG_FUNCTION, ns3::Simulator::Schedule(), and StopTapDevice().

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◆ StopTapDevice()

void ns3::TapBridge::StopTapDevice ( )

private

Tear down the device.

Definition at line 241 of file tap-bridge.cc.

References m_fdReader, m_sock, and NS_LOG_FUNCTION.

Referenced by ~TapBridge(), and Stop().

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◆ SupportsSendFrom()

bool ns3::TapBridge::SupportsSendFrom ( ) const

overridevirtual

Returns: true if this interface supports a bridging mode, false otherwise.

Implements ns3::NetDevice.

Definition at line 1238 of file tap-bridge.cc.

References NS_LOG_FUNCTION.

Member Data Documentation

◆ m_address

Mac48Address ns3::TapBridge::m_address

private

The (unused) MAC address of the TapBridge net device.

Since the TapBridge is implemented as a ns-3 net device, it is required to implement certain functionality. In this case, the TapBridge is automatically assigned a MAC address, but it is not used.

Definition at line 383 of file tap-bridge.h.

Referenced by GetAddress(), and SetAddress().

◆ m_bridgedDevice

Ptr<NetDevice> ns3::TapBridge::m_bridgedDevice

private

The ns-3 net device to which we are bridging.

Definition at line 427 of file tap-bridge.h.

Referenced by ~TapBridge(), CreateTap(), ForwardToBridgedDevice(), GetBridgedNetDevice(), ReceiveFromBridgedDevice(), and SetBridgedNetDevice().

◆ m_fdReader

Ptr<TapBridgeFdReader> ns3::TapBridge::m_fdReader

private

Includes the ns-3 read thread used to do blocking reads on the fd corresponding to the host device.

Definition at line 369 of file tap-bridge.h.

Referenced by StartTapDevice(), and StopTapDevice().

◆ m_ifIndex

uint32_t ns3::TapBridge::m_ifIndex

private

The ns-3 interface index of this TapBridge net device.

Definition at line 340 of file tap-bridge.h.

Referenced by GetIfIndex(), and SetIfIndex().

◆ m_linkChangeCallbacks

TracedCallback ns3::TapBridge::m_linkChangeCallbacks

private

Callbacks to fire if the link changes state (up or down).

Definition at line 463 of file tap-bridge.h.

Referenced by AddLinkChangeCallback(), and NotifyLinkUp().

◆ m_linkUp

bool ns3::TapBridge::m_linkUp {false}

private

Flag indicating whether or not the link is up.

In this case, whether or not ns-3 is connected to the underlying TAP device with a file descriptor.

Definition at line 451 of file tap-bridge.h.

Referenced by IsLinkUp(), and NotifyLinkUp().

◆ m_mode

Mode ns3::TapBridge::m_mode

private

The operating mode of the bridge.

Tells basically who creates and configures the underlying network tap.

Definition at line 375 of file tap-bridge.h.

Referenced by CreateTap(), ForwardToBridgedDevice(), GetMode(), ReceiveFromBridgedDevice(), SetBridgedNetDevice(), and SetMode().

◆ m_mtu

uint16_t ns3::TapBridge::m_mtu

private

The common mtu to use for the net devices.

Definition at line 345 of file tap-bridge.h.

Referenced by GetMtu(), and SetMtu().

◆ m_node

Ptr<Node> ns3::TapBridge::m_node

private

Pointer to the (ghost) Node to which we are connected.

Definition at line 335 of file tap-bridge.h.

Referenced by GetNode(), ReceiveFromBridgedDevice(), SetBridgedNetDevice(), and SetNode().

◆ m_nodeId

uint32_t ns3::TapBridge::m_nodeId

private

a copy of the node id so the read thread doesn't have to GetNode() in in order to find the node ID.

Thread unsafe reference counting in multithreaded apps is not a good thing.

Definition at line 444 of file tap-bridge.h.

Referenced by ReadCallback(), and StartTapDevice().

◆ m_ns3AddressRewritten

bool ns3::TapBridge::m_ns3AddressRewritten

private

Whether the MAC address of the underlying ns-3 device has already been rewritten is stored in this variable (for UseLocal/UseBridge mode only).

Definition at line 432 of file tap-bridge.h.

Referenced by CreateTap(), and ForwardToBridgedDevice().

◆ m_packetBuffer

uint8_t* ns3::TapBridge::m_packetBuffer

private

A 64K buffer to hold packet data while it is being sent.

Definition at line 437 of file tap-bridge.h.

Referenced by TapBridge(), ~TapBridge(), and ReceiveFromBridgedDevice().

◆ m_promiscRxCallback

NetDevice::PromiscReceiveCallback ns3::TapBridge::m_promiscRxCallback

private

Callback used to hook the promiscuous packet receive callback of the TapBridge ns-3 net device.

This is never called, and therefore no packets will ever be received forwarded up the IP stack on the ghost node through this device.

Note that we intercept the similar callback in the bridged device in order to do the actual bridging between the bridged ns-3 net device and the Tap device on the host.

Definition at line 330 of file tap-bridge.h.

Referenced by SetPromiscReceiveCallback().

◆ m_rxCallback

NetDevice::ReceiveCallback ns3::TapBridge::m_rxCallback

private

Callback used to hook the standard packet receive callback of the TapBridge ns-3 net device.

This is never called, and therefore no packets will ever be received forwarded up the IP stack on the ghost node through this device.

Definition at line 319 of file tap-bridge.h.

Referenced by SetReceiveCallback().

◆ m_sock

int ns3::TapBridge::m_sock

private

The socket (actually interpreted as fd) to use to talk to the Tap device on the real internet host.

Definition at line 351 of file tap-bridge.h.

Referenced by CreateTap(), ReceiveFromBridgedDevice(), StartTapDevice(), and StopTapDevice().

◆ m_startEvent

EventId ns3::TapBridge::m_startEvent

private

The ID of the ns-3 event used to schedule the start up of the underlying host Tap device and ns-3 read thread.

Definition at line 357 of file tap-bridge.h.

Referenced by Start(), and Stop().

◆ m_stopEvent

EventId ns3::TapBridge::m_stopEvent

private

The ID of the ns-3 event used to schedule the tear down of the underlying host Tap device and ns-3 read thread.

Definition at line 363 of file tap-bridge.h.

Referenced by Stop().

◆ m_tapDeviceName

std::string ns3::TapBridge::m_tapDeviceName

private

The name of the device to create on the host.

If the device name is the empty string, we allow the host kernel to choose a name.

Definition at line 399 of file tap-bridge.h.

Referenced by CreateTap(), and GetTypeId().

◆ m_tapGateway

Ipv4Address ns3::TapBridge::m_tapGateway

private

The IP address to use as the device default gateway on the host.

Definition at line 404 of file tap-bridge.h.

Referenced by CreateTap(), and GetTypeId().

◆ m_tapIp

Ipv4Address ns3::TapBridge::m_tapIp

private

The IP address to use as the device IP on the host.

Definition at line 409 of file tap-bridge.h.

Referenced by CreateTap(), and GetTypeId().

◆ m_tapMac

Mac48Address ns3::TapBridge::m_tapMac

private

The MAC address to use as the hardware address on the host; only used in UseLocal mode.

This value comes from the MAC address assigned to the bridged ns-3 net device and matches the MAC address of the underlying network TAP which we configured to have the same value.

Definition at line 417 of file tap-bridge.h.

Referenced by CreateTap(), and GetTypeId().

◆ m_tapNetmask

Ipv4Mask ns3::TapBridge::m_tapNetmask

private

The network mask to assign to the device created on the host.

Definition at line 422 of file tap-bridge.h.

Referenced by CreateTap(), and GetTypeId().

◆ m_tStart

Time ns3::TapBridge::m_tStart

private

Time to start spinning up the device.

Definition at line 388 of file tap-bridge.h.

Referenced by TapBridge(), and GetTypeId().

◆ m_tStop

Time ns3::TapBridge::m_tStop

private

Time to start tearing down the device.

Definition at line 393 of file tap-bridge.h.

Referenced by GetTypeId().

◆ m_verbose

bool ns3::TapBridge::m_verbose

private

Flag indicating whether or not the link is up.

In this case, whether or not ns-3 is connected to the underlying TAP device with a file descriptor.

Definition at line 458 of file tap-bridge.h.

Referenced by CreateTap(), and GetTypeId().

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

src/tap-bridge/model/tap-bridge.h
src/tap-bridge/model/tap-bridge.cc

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ Mode

Constructor & Destructor Documentation

◆ TapBridge()

◆ ~TapBridge()

Member Function Documentation

◆ AddLinkChangeCallback()

◆ CreateTap()

◆ DiscardFromBridgedDevice()

◆ DoDispose()

◆ Filter()

◆ ForwardToBridgedDevice()

◆ GetAddress()

◆ GetBridgedNetDevice()

◆ GetBroadcast()

◆ GetChannel()

◆ GetIfIndex()

◆ GetMode()

◆ GetMtu()

◆ GetMulticast() [1/2]

◆ GetMulticast() [2/2]

◆ GetNode()

◆ GetTypeId()

◆ IsBridge()

◆ IsBroadcast()

◆ IsLinkUp()

◆ IsMulticast()

◆ IsPointToPoint()

◆ NeedsArp()

◆ NotifyLinkUp()

◆ ReadCallback()

◆ ReceiveFromBridgedDevice()

◆ Send()

◆ SendFrom()

◆ SetAddress()

◆ SetBridgedNetDevice()

◆ SetIfIndex()

◆ SetMode()

◆ SetMtu()

◆ SetNode()

◆ SetPromiscReceiveCallback()

◆ SetReceiveCallback()

◆ Start()

◆ StartTapDevice()

◆ Stop()

◆ StopTapDevice()

◆ SupportsSendFrom()

Member Data Documentation

◆ m_address

◆ m_bridgedDevice

◆ m_fdReader

◆ m_ifIndex

◆ m_linkChangeCallbacks

◆ m_linkUp

◆ m_mode

◆ m_mtu

◆ m_node

◆ m_nodeId

◆ m_ns3AddressRewritten

◆ m_packetBuffer

◆ m_promiscRxCallback

◆ m_rxCallback

◆ m_sock

◆ m_startEvent

◆ m_stopEvent

◆ m_tapDeviceName

◆ m_tapGateway

◆ m_tapIp

◆ m_tapMac

◆ m_tapNetmask

◆ m_tStart

◆ m_tStop