nfd::face::PcapHelper Class Reference

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

#include <daemon/face/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 ()
	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
	Get last error message. More...
size_t	getNDropped () const
	Get the number of packets dropped by the kernel, as reported by libpcap. More...
	operator pcap_t * () const
std::tuple< const uint8_t *, size_t, std::string >	readNextPacket () const
	Read the next packet captured on the interface. More...
void	setPacketFilter (const char *filter) const
	Install a BPF filter on the receiving socket. More...

Detailed Description

Helper class for dealing with libpcap handles.

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

Constructor & Destructor Documentation

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 38 of file pcap-helper.cpp.

nfd::face::PcapHelper::~PcapHelper

(

)

Definition at line 56 of file pcap-helper.cpp.

Member Function Documentation

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 62 of file pcap-helper.cpp.

void nfd::face::PcapHelper::close

(

)

Stop capturing and close the handle.

See also

pcap_close(3pcap)

Definition at line 76 of file pcap-helper.cpp.

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 85 of file pcap-helper.cpp.

std::string nfd::face::PcapHelper::getLastError

(

)

const

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 97 of file pcap-helper.cpp.

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 103 of file pcap-helper.cpp.

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

inline

Definition at line 134 of file pcap-helper.hpp.

std::tuple< const uint8_t *, size_t, std::string > nfd::face::PcapHelper::readNextPacket

(

)

const

Read the next packet captured on the interface.

Returns

If successful, returns a tuple containing a pointer to the received packet (including the link-layer header) and the size of the packet; the third element must be ignored. On failure, returns a tuple containing nullptr, 0, and the reason for the failure.

Warning

The returned pointer must not be freed by the caller, and is valid only until the next call to this function.

See also

pcap_next_ex(3pcap)

Definition at line 126 of file pcap-helper.cpp.

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 113 of file pcap-helper.cpp.