Read a TCP/IP session from a pcap or pcapng file. More...

#include <tsPcapStream.h>

Inheritance diagram for ts::PcapStream:

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Collaboration diagram for ts::PcapStream:

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Public Member Functions
	PcapStream ()=default
	Default constructor.

bool	addressFilterIsSet () const
	Check if the address filter is precisely set.

const IPv4SocketAddress &	clientPeer () const
	Get the address of the client peer.

virtual void	close ()
	Close the file.

void	defineArgs (Args &args)
	Add command line option definitions in an Args.

const IPv4SocketAddress &	destinationFilter () const
	Get the current destination filter.

bool	endOfFile () const
	Check if the end of file (or other error) has been reached.

bool	endOfSession (Report &report)
	Check if the TCP session is fully terminated on both sides.

bool	endOfStream (const IPv4SocketAddress &source, Report &report)
	Check if the next data to read is at end of TCP session.

fs::path	fileName () const
	Get the file name.

uint64_t	fileSize () const
	Get the total file size in bytes so far.

cn::microseconds	firstTimestamp () const
	Get the capture timestamp of the first packet in the file.

uint64_t	ipv4PacketCount () const
	Get the number of valid captured IPv4 packets so far.

bool	isOpen () const
	Check if the file is open.

cn::microseconds	lastTimestamp () const
	Get the capture timestamp of the last packet which was read from the file.

bool	loadArgs (DuckContext &duck, Args &args)
	Load arguments from command line.

size_t	maxReassemblyQueueSize () const
	Get the maximum number of queued data blocks to reassemble TCP streams.

bool	nextSession (Report &report)
	Skip the end of the current TCP session and prepare for next session.

virtual bool	open (const fs::path &filename, Report &report) override
	Open the file for read.

const IPv4SocketAddress &	otherFilter (const IPv4SocketAddress &addr) const
	Get the "other" filter (source or destination) based on the other one.

uint64_t	packetCount () const
	Get the number of captured packets so far.

virtual bool	readIPv4 (IPv4Packet &packet, cn::microseconds &timestamp, Report &report) override
	Read the next IPv4 packet (headers included).

bool	readTCP (IPv4SocketAddress &source, ByteBlock &data, size_t &size, cn::microseconds &timestamp, Report &report)
	Read data from the TCP session either in one specific direction or any direction.

const IPv4SocketAddress &	serverPeer () const
	Get the address of the server peer.

virtual void	setBidirectionalFilter (const IPv4SocketAddress &addr1, const IPv4SocketAddress &addr2) override
	Set a bidirectional address filter.

void	setFirstPacketFilter (size_t count)
	Filter packets starting at the specified number.

void	setFirstTimeOffset (cn::microseconds time)
	Filter packets starting at the specified time offset from the beginning of the file.

void	setFirstTimestamp (cn::microseconds time)
	Filter packets starting at the specified timestamp.

void	setLastPacketFilter (size_t count)
	Filter packets up to the specified number.

void	setLastTimeOffset (cn::microseconds time)
	Filter packets up to the specified time offset from the beginning of the file.

void	setLastTimestamp (cn::microseconds time)
	Filter packets up to the specified timestamp.

void	setReportAddressesFilterSeverity (int level)
	Specify the severity to report the filtered addresses once (in non-wildcard mode).

const IPv4SocketAddress &	sourceFilter () const
	Get the current source filter.

bool	startOfStream (const IPv4SocketAddress &source, Report &report)
	Check if the next data to read is at start of TCP session.

bool	startOfStream (Report &report)
	Check if the next data to read is at start of TCP session.

cn::microseconds	timeOffset (cn::microseconds timestamp) const
	Compute the time offset from the beginning of the file of a packet timestamp.

uint64_t	totalIPv4PacketsSize () const
	Get the total size in bytes of valid captured IPv4 packets so far.

uint64_t	totalPacketsSize () const
	Get the total size in bytes of captured packets so far.

Static Public Member Functions
static Time	ToTime (cn::microseconds timestamp)
	Compute the date and time from a packet timestamp.

Detailed Description

Read a TCP/IP session from a pcap or pcapng file.

A TCP session uses two continuous streams, one in each direction, between two socket addresses.

Filtering a specified TCP stream shall be set using setBidirectionalFilter(). If not set, the first TCP packet defines the TCP session to follow.

Setting a new filter clears the current state of the previous filter but does not change the current position inside the pcap file. If any IPv4 address or TCP port is unspecified in filtered addresses, then the first TCP/IP packet matching the specified fields is used to determine the unspecified field.

Once the peers are defined, either because they were fully specified using setBidirectionalFilter() or the first packet resolved them, use sourceFilter() and destinationFilter() to get the peers addresses. In that case, "source" and "destination" are interchangeable since a TCP session is bidirectional.

Use addressFilterIsSet() to check if the peers are fully specified.

Some effort is made to reassemble repeated or re-ordered TCP packets. Fragmented IP packets are ignored. It is not possible to rebuild a TCP session with fragmented packets.

Member Function Documentation

◆ clientPeer()

const IPv4SocketAddress & ts::PcapStream::clientPeer ( ) const

inline

Get the address of the client peer.

Returns: A constant reference to the client socket address if the client is known, no addres/port if the client is unknown. When the pcap capture starts when the TCP connection is already established, the SYN/ACK sequence is not present and we do not know which peer is the client.

◆ serverPeer()

const IPv4SocketAddress & ts::PcapStream::serverPeer ( ) const

inline

Get the address of the server peer.

Returns: A constant reference to the server socket address if the server is known, no addres/port if the server is unknown. When the pcap capture starts when the TCP connection is already established, the SYN/ACK sequence is not present and we do not know which peer is the client.

◆ readTCP()

bool ts::PcapStream::readTCP	(	IPv4SocketAddress &	source,
		ByteBlock &	data,
		size_t &	size,
		cn::microseconds &	timestamp,
		Report &	report
	)

Read data from the TCP session either in one specific direction or any direction.

Reading stops at end of TCP session or end of pcap file. To move to next TCP session, use nextSession().

Parameters

[in,out]	source	Source address of the TCP stream to extract data from. If, on input, the value is unset (no address, no port), then data from any direction are read. On output, source contains the address of the peer from which data were read.
[in,out]	data	Byte block into which data is read. The byte block is not reinitialized, input data are appended to it.
[in,out]	size	On input, this is the data size to read in bytes. In absence of error, that exact number of bytes is read. Reading can stop earlier in case of end of TCP stream or end of pcap file. On output, it contains the actual number of read bytes.
[out]	timestamp	Capture timestamp in microseconds since Unix epoch or -1 if none is available. If the data has been reassembled from several IP packets, this is the timestamp of the last part.
[in,out]	report	Where to report errors.

Returns: True on success, false on error or end of file.

◆ startOfStream() [1/2]

bool ts::PcapStream::startOfStream ( Report & report )

Check if the next data to read is at start of TCP session.

Parameters

[in,out] report Where to report errors.

Returns: True on success and if the next data to read is at start of TCP session, false otherwise.

◆ startOfStream() [2/2]

bool ts::PcapStream::startOfStream	(	const IPv4SocketAddress &	source,
		Report &	report
	)

Check if the next data to read is at start of TCP session.

Parameters

[in]	source	Source address of the TCP stream. It must match one of the peers of the TCP session.
[in,out]	report	Where to report errors.

Returns: True on success and if the next data to read is at start of TCP session, false otherwise.

◆ endOfStream()

bool ts::PcapStream::endOfStream	(	const IPv4SocketAddress &	source,
		Report &	report
	)

Check if the next data to read is at end of TCP session.

Parameters

[in]	source	Source address of the TCP stream. It must match one of the peers of the TCP session.
[in,out]	report	Where to report errors.

Returns: True if the next data to read is at end of TCP session or on error, false otherwise.

◆ endOfSession()

bool ts::PcapStream::endOfSession ( Report & report )

inline

Check if the TCP session is fully terminated on both sides.

Parameters

[in,out] report Where to report errors.

Returns: True if the TCP session is fully terminated on both sides or on error, false otherwise.

◆ nextSession()

bool ts::PcapStream::nextSession ( Report & report )

Skip the end of the current TCP session and prepare for next session.

Parameters

[in,out] report Where to report errors.

Returns: True on success, false on error or end of file before an explicit end of current session.

◆ maxReassemblyQueueSize()

size_t ts::PcapStream::maxReassemblyQueueSize ( ) const

inline

Get the maximum number of queued data blocks to reassemble TCP streams.

This value gives an idea of how packets were reordered during transmission.

Returns: The maximum number of queued data blocks to reassemble TCP streams.

◆ open()

virtual bool ts::PcapStream::open	(	const fs::path &	filename,
		Report &	report
	)

overridevirtual

Open the file for read.

Parameters

[in]	filename	File name. If empty or "-", use standard input.
[in,out]	report	Where to report errors.

Returns: True on success, false on error.

Reimplemented from ts::PcapFilter.

◆ setBidirectionalFilter()

virtual void ts::PcapStream::setBidirectionalFilter	(	const IPv4SocketAddress &	addr1,
		const IPv4SocketAddress &	addr2
	)

overridevirtual

Set a bidirectional address filter.

Select packets where the source and destination addresses match the pair of filtered address, in any direction.

Parameters

[in]	addr1	First address to filter, either source or destination. The port is meaningful only with TCP and UDP.
[in]	addr2	Second address to filter, either source or destination. The port is meaningful only with TCP and UDP.

See also: setWildcardFilter()

Reimplemented from ts::PcapFilter.

◆ setFirstPacketFilter()

void ts::PcapFilter::setFirstPacketFilter ( size_t count )

inlineinherited

Filter packets starting at the specified number.

The packet numbering counts all captured packets from the beginning of the file, starting at 1. This is the same value as seen on Wireshark in the leftmost column.

Parameters

[in] count Number of first captured packet to read.

◆ setLastPacketFilter()

void ts::PcapFilter::setLastPacketFilter ( size_t count )

inlineinherited

Filter packets up to the specified number.

The packet numbering counts all captured packets from the beginning of the file, starting at 1. This is the same value as seen on Wireshark in the leftmost column.

Parameters

[in] count Number of last captured packet to read.

◆ setFirstTimeOffset()

void ts::PcapFilter::setFirstTimeOffset ( cn::microseconds time )

inlineinherited

Filter packets starting at the specified time offset from the beginning of the file.

This is the same value as seen on Wireshark in the "Time" column (in seconds).

Parameters

[in] time First time offset in microseconds from the beginning of the capture.

◆ setLastTimeOffset()

void ts::PcapFilter::setLastTimeOffset ( cn::microseconds time )

inlineinherited

Filter packets up to the specified time offset from the beginning of the file.

This is the same value as seen on Wireshark in the "Time" column (in seconds).

Parameters

[in] time Last time offset in microseconds from the beginning of the capture.

◆ setFirstTimestamp()

void ts::PcapFilter::setFirstTimestamp ( cn::microseconds time )

inlineinherited

Filter packets starting at the specified timestamp.

Parameters

[in] time First timestamp, in microseconds from the UNIX epoch.

See also: ts::Time::UnixEpoch

◆ setLastTimestamp()

void ts::PcapFilter::setLastTimestamp ( cn::microseconds time )

inlineinherited

Filter packets up to the specified timestamp.

Parameters

[in] time Last timestamp, in microseconds from the UNIX epoch.

See also: ts::Time::UnixEpoch

◆ sourceFilter()

const IPv4SocketAddress & ts::PcapFilter::sourceFilter ( ) const

inlineinherited

Get the current source filter.

In the case of non-wildcard filtering, after returning the first packet, this is the actual socket address of the filtered stream.

In the case of bidirectional filtering (for instance a TCP session), there is no real "source" or "destination". They are the two endpoints of the stream.

Returns: A constant reference to the current source filter.

See also: setWildcardFilter()

◆ destinationFilter()

const IPv4SocketAddress & ts::PcapFilter::destinationFilter ( ) const

inlineinherited

Get the current destination filter.

In the case of non-wildcard filtering, after returning the first packet, this is the actual socket address of the filtered stream.

In the case of bidirectional filtering (for instance a TCP session), there is no real "source" or "destination". They are the two endpoints of the stream.

Returns: A constant reference to the current source filter.

See also: setWildcardFilter()

◆ addressFilterIsSet()

bool ts::PcapFilter::addressFilterIsSet ( ) const

inherited

Check if the address filter is precisely set.

Using address filtering, some addresses or port may be unspecified, acting as a wildcard. In non-wildcard mode, the first packet matching this wildcard is selected and the corresponding stream is then exclusively filtered. At this point, the filter is precisely set.

Returns: True if the address filter is precisely set.

◆ otherFilter()

const IPv4SocketAddress & ts::PcapFilter::otherFilter ( const IPv4SocketAddress & addr ) const

inherited

Get the "other" filter (source or destination) based on the other one.

Parameters

[in] addr A socket address, typically matching the source or destination filter.

Returns: A constant reference to the other filter. If addr matches neither the source nor the destination filter, return an empty socket address.

◆ setReportAddressesFilterSeverity()

void ts::PcapFilter::setReportAddressesFilterSeverity ( int level )

inlineinherited

Specify the severity to report the filtered addresses once (in non-wildcard mode).

In non-wildcard mode, when the filtered addresses contain non-specified fields, the first packet which matches the filters define the stream. At this point, the selected stream is displayed (in debug mode by default). This function redefines the severity level (info or verbose for instance).

Parameters

[in] level Severity level to use.

◆ defineArgs()

void ts::PcapFilter::defineArgs ( Args & args )

inherited

Add command line option definitions in an Args.

Parameters

[in,out] args Command line arguments to update.

◆ loadArgs()

bool ts::PcapFilter::loadArgs	(	DuckContext &	duck,
		Args &	args
	)

inherited

Load arguments from command line.

Args error indicator is set in case of incorrect arguments.

Parameters

[in,out]	duck	TSDuck execution context.
[in,out]	args	Command line arguments.

Returns: True on success, false on error in argument line.

◆ readIPv4()

virtual bool ts::PcapFilter::readIPv4	(	IPv4Packet &	packet,
		cn::microseconds &	timestamp,
		Report &	report
	)

overridevirtualinherited

Read the next IPv4 packet (headers included).

Skip intermediate metadata and other types of packets.

Parameters

[out]	packet	Received IPv4 packet.
[out]	timestamp	Capture timestamp in microseconds since Unix epoch or -1 if none is available.
[in,out]	report	Where to report error.

Returns: True on success, false on error.

Reimplemented from ts::PcapFile.

◆ isOpen()

bool ts::PcapFile::isOpen ( ) const

inlineinherited

Check if the file is open.

Returns: True if the file is open, false otherwise.

◆ fileName()

fs::path ts::PcapFile::fileName ( ) const

inlineinherited

Get the file name.

Returns: The file name as specified in open(). If the standard input is used, return "standard input".

◆ packetCount()

uint64_t ts::PcapFile::packetCount ( ) const

inlineinherited

Get the number of captured packets so far.

This includes all packets, not only IPv4 packets. This value is the number of the last returned packet, as seen in the left-most column in Wireshark interface.

Returns: The number of captured packets so far.

◆ endOfFile()

bool ts::PcapFile::endOfFile ( ) const

inlineinherited

Check if the end of file (or other error) has been reached.

Returns: True on end of file or error.

◆ ipv4PacketCount()

uint64_t ts::PcapFile::ipv4PacketCount ( ) const

inlineinherited

Get the number of valid captured IPv4 packets so far.

Returns: The number of valid captured IPv4 packets so far.

◆ fileSize()

uint64_t ts::PcapFile::fileSize ( ) const

inlineinherited

Get the total file size in bytes so far.

Returns: The total file size in bytes so far.

◆ totalPacketsSize()

uint64_t ts::PcapFile::totalPacketsSize ( ) const

inlineinherited

Get the total size in bytes of captured packets so far.

This includes all packets, including link-layer headers when present.

Returns: The total size in bytes of captured packets so far.

◆ totalIPv4PacketsSize()

uint64_t ts::PcapFile::totalIPv4PacketsSize ( ) const

inlineinherited

Get the total size in bytes of valid captured IPv4 packets so far.

This includes all IPv4 headers but not link-layer headers when present.

Returns: The total size in bytes of valid captured IPv4 packets so far.

◆ firstTimestamp()

cn::microseconds ts::PcapFile::firstTimestamp ( ) const

inlineinherited

Get the capture timestamp of the first packet in the file.

Returns: Capture timestamp in microseconds since Unix epoch or -1 if none is available.

◆ lastTimestamp()

cn::microseconds ts::PcapFile::lastTimestamp ( ) const

inlineinherited

Get the capture timestamp of the last packet which was read from the file.

Returns: Capture timestamp in microseconds since Unix epoch or -1 if none is available.

◆ timeOffset()

cn::microseconds ts::PcapFile::timeOffset ( cn::microseconds timestamp ) const

inlineinherited

Compute the time offset from the beginning of the file of a packet timestamp.

Parameters

[in] timestamp Capture timestamp of a packet in the file.

Returns: Time offset in microseconds of the packet from the beginning of the file.

◆ ToTime()

static Time ts::PcapFile::ToTime ( cn::microseconds timestamp )

inlinestaticinherited

Compute the date and time from a packet timestamp.

Parameters

[in] timestamp Capture timestamp of a packet in a file.

Returns: Corresponding date or Epoch in case of error.

◆ close()

virtual void ts::PcapFile::close ( )

virtualinherited

Close the file.

Do not reset counters, file names, etc. The last values before close() are still accessible.

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

tsPcapStream.h

Public Member Functions

Static Public Member Functions

Detailed Description

Member Function Documentation

◆ clientPeer()

◆ serverPeer()

◆ readTCP()

◆ startOfStream() [1/2]

◆ startOfStream() [2/2]

◆ endOfStream()

◆ endOfSession()

◆ nextSession()

◆ maxReassemblyQueueSize()

◆ open()

◆ setBidirectionalFilter()

◆ setFirstPacketFilter()

◆ setLastPacketFilter()

◆ setFirstTimeOffset()

◆ setLastTimeOffset()

◆ setFirstTimestamp()

◆ setLastTimestamp()

◆ sourceFilter()

◆ destinationFilter()

◆ addressFilterIsSet()

◆ otherFilter()

◆ setReportAddressesFilterSeverity()

◆ defineArgs()

◆ loadArgs()

◆ readIPv4()

◆ isOpen()

◆ fileName()

◆ packetCount()

◆ endOfFile()

◆ ipv4PacketCount()

◆ fileSize()

◆ totalPacketsSize()

◆ totalIPv4PacketsSize()

◆ firstTimestamp()

◆ lastTimestamp()

◆ timeOffset()

◆ ToTime()

◆ close()