nfd::face::PcapHelper Class Reference

Helper class for dealing with libpcap handles. More...

#include <pcap-helper.hpp>

Inheritance diagram for nfd::face::PcapHelper:

Collaboration diagram for nfd::face::PcapHelper:

Classes
class	Error

Public Member Functions
	PcapHelper (const std::string &interfaceName)
	Create a libpcap context for live packet capture on a network interface. More...
	~PcapHelper ()
void	activate (int dlt)
	Start capturing packets. More...
void	close () noexcept
	Stop capturing and close the handle. More...
int	getFd () const
	Obtain a file descriptor that can be used in calls such as select(2) and poll(2). More...
std::string	getLastError () const noexcept
	Get last error message. More...
size_t	getNDropped () const
	Get the number of packets dropped by the kernel, as reported by libpcap. More...
void	setPacketFilter (const char *filter) const
	Install a BPF filter on the receiving socket. More...
std::tuple< span< const uint8_t >, std::string >	readNextPacket () const noexcept
	Read the next packet captured on the interface. More...
	operator pcap_t * () const noexcept

Detailed Description

Helper class for dealing with libpcap handles.

Definition at line 45 of file pcap-helper.hpp.

Constructor & Destructor Documentation

PcapHelper()

nfd::face::PcapHelper::PcapHelper ( const std::string &  interfaceName )

explicit

Create a libpcap context for live packet capture on a network interface.

Exceptions

Error

on any error

See also

pcap_create(3pcap)

Definition at line 41 of file pcap-helper.cpp.

References ndn::ethernet::HDR_LEN, ndn::MAX_NDN_PACKET_SIZE, and NDN_THROW.

Referenced by nfd::face::PcapHelper::Error::Error().

~PcapHelper()

nfd::face::PcapHelper::~PcapHelper

(

)

Definition at line 60 of file pcap-helper.cpp.

References close().

Referenced by nfd::face::PcapHelper::Error::Error().

Member Function Documentation

activate()

void nfd::face::PcapHelper::activate

(

int

dlt

)

Start capturing packets.

Parameters

dlt	The link-layer header type to be used.

Exceptions

Error

on any error

See also

pcap_activate(3pcap), pcap_set_datalink(3pcap)

Definition at line 66 of file pcap-helper.cpp.

References getLastError(), NDN_THROW, and nfd::PrivilegeHelper::runElevated().

Referenced by nfd::face::PcapHelper::Error::Error(), nfd::face::EthernetTransport::EthernetTransport(), and nfd::face::EthernetChannel::listen().

close()

void nfd::face::PcapHelper::close ( )

noexcept

Stop capturing and close the handle.

See also

pcap_close(3pcap)

Definition at line 82 of file pcap-helper.cpp.

Referenced by nfd::face::EthernetTransport::doClose(), nfd::face::PcapHelper::Error::Error(), and ~PcapHelper().

getFd()

int nfd::face::PcapHelper::getFd

(

)

const

Obtain a file descriptor that can be used in calls such as select(2) and poll(2).

Precondition

activate() has been called.

Returns

A selectable file descriptor. It is the caller's responsibility to close the fd.

Exceptions

Error

on any error

See also

pcap_get_selectable_fd(3pcap)

Definition at line 91 of file pcap-helper.cpp.

References NDN_THROW.

Referenced by nfd::face::PcapHelper::Error::Error(), nfd::face::EthernetTransport::EthernetTransport(), and nfd::face::EthernetChannel::listen().

getLastError()

std::string nfd::face::PcapHelper::getLastError ( ) const

noexcept

Get last error message.

Returns

Human-readable explanation of the last libpcap error.

Warning

The behavior is undefined if no error occurred.

See also

pcap_geterr(3pcap)

Definition at line 103 of file pcap-helper.cpp.

Referenced by activate(), nfd::face::EthernetTransport::doClose(), nfd::face::PcapHelper::Error::Error(), getNDropped(), readNextPacket(), and setPacketFilter().

getNDropped()

size_t nfd::face::PcapHelper::getNDropped

(

)

const

Get the number of packets dropped by the kernel, as reported by libpcap.

Exceptions

Error

on any error

See also

pcap_stats(3pcap)

Definition at line 109 of file pcap-helper.cpp.

References getLastError(), and NDN_THROW.

Referenced by nfd::face::EthernetTransport::doClose(), nfd::face::PcapHelper::Error::Error(), and nfd::face::EthernetChannel::listen().

setPacketFilter()

void nfd::face::PcapHelper::setPacketFilter

(

const char *

filter

)

const

Install a BPF filter on the receiving socket.

Parameters

filter

Null-terminated string containing the BPF program source.

Precondition

activate() has been called.

Exceptions

Error

on any error

See also

pcap_setfilter(3pcap), pcap-filter(7)

Definition at line 119 of file pcap-helper.cpp.

References getLastError(), NDN_THROW, and PCAP_NETMASK_UNKNOWN.

Referenced by nfd::face::PcapHelper::Error::Error(), nfd::face::EthernetChannel::listen(), nfd::face::MulticastEthernetTransport::MulticastEthernetTransport(), and nfd::face::UnicastEthernetTransport::UnicastEthernetTransport().

readNextPacket()

std::tuple< span< const uint8_t >, std::string > nfd::face::PcapHelper::readNextPacket ( ) const

noexcept

Read the next packet captured on the interface.

Returns

If successful, returns a tuple containing a read-only view of the received packet bytes (including the link-layer header) and a second element that must be ignored. On failure, returns a tuple containing an empty span and the reason for the failure.

Warning

The returned span is valid only until the next call to this function.

See also

pcap_next_ex(3pcap)

Definition at line 132 of file pcap-helper.cpp.

References getLastError().

Referenced by nfd::face::EthernetTransport::doClose(), nfd::face::PcapHelper::Error::Error(), and nfd::face::EthernetChannel::listen().

operator pcap_t *()

nfd::face::PcapHelper::operator pcap_t * ( ) const

inlinenoexcept

Definition at line 133 of file pcap-helper.hpp.

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

• ndnSIM/NFD/daemon/face/pcap-helper.hpp
• ndnSIM/NFD/daemon/face/pcap-helper.cpp