satcat5::ptp::Client Class Reference

Detailed Description

Client for the IEEE 1588-2019 Precision Time Protocol (PTP)

This file implements a simple "Client" endpoint for the Precision Time Protocol, which may act as either master or slave depending on mode. It uses a single network port and acts as an "Ordinary Clock" as defined in IEEE 1588-2019 Section 9. Other modes such as boundary clocks may be added in a future release.

This client also supports Meta's proposed "Simple Precision Time Protocol" (SPTP) extention, which reduces overhead for unicast PTP exchanges. https://engineering.fb.com/2024/02/07/production-engineering/simple-precision-time-protocol-sptp-meta/ https://ieeexplore.ieee.org/document/10296989

Long-term feature wishlist:

• Support for automatic configuration and master/grandmaster selection.
• Support for asymmetric handshakes (i.e., many SYNC, few DELAY_REQ).

Definition at line 64 of file ptp_client.h.

#include <ptp_client.h>

Inheritance diagram for satcat5::ptp::Client:

Collaboration diagram for satcat5::ptp::Client:

Public Member Functions
	Client (satcat5::ptp::Interface *ptp_iface, satcat5::ip::Dispatch *ip_dispatch, satcat5::ptp::ClientMode mode=ClientMode::DISABLED)
	Set the network interface for this client.
void	set_clock (const satcat5::ptp::ClockInfo &clk)
	Set clock information for outgoing ANNOUNCE messages.
satcat5::ptp::ClockInfo	get_clock () const
	Get local clock information.
satcat5::ptp::ClockInfo	get_remote () const
	Get grandmaster clock information.
satcat5::ptp::Time	get_time_now ()
	Read the current time from the network interface.
s16	get_utc_offset () const
	Query the current UTC vs. More...
void	set_utc_offset (s16 offset)
	Immediately adjust the UTC vs. More...
void	set_announce_rate (int rate)
	Set the ANNOUNCE message rate to 2^N / sec. More...
void	set_sync_rate (int rate)
	Set the SYNC message rate to 2^N / sec. More...
void	set_pdelay_rate (int rate)
	Set the pdelay message rate to 0.9 x 2^N / sec. More...
bool	send_sync_unicast (const satcat5::eth::MacAddr &mac, const satcat5::ip::Addr &ip=satcat5::ip::ADDR_NONE, const satcat5::eth::VlanTag &vtag=satcat5::eth::VTAG_NONE)
	Send a unicast SYNC message to the designated address. More...
void	ptp_rcvd (satcat5::io::LimitedRead &rd)
	Dispatch calls this method for each incoming packet.
void	timer_once (unsigned msec)
	Configure a one-time notification after X milliseconds.
void	timer_every (unsigned msec)
	Configure a repeating notification every X milliseconds.
void	timer_stop ()
	Stop all future notifications.
unsigned	timer_interval () const
	Accessor for recurring timer interval, if one is set.
unsigned	timer_remaining () const
	Accessor for time to next event, if one is set.
void	add_callback (satcat5::ptp::Callback *callback)
void	remove_callback (satcat5::ptp::Callback *callback)
void	set_mode (satcat5::ptp::ClientMode mode)
	Mode and state accessors.
satcat5::ip::Dispatch *	get_iface () const
	Mode and state accessors.
satcat5::ptp::ClientMode	get_mode () const
	Mode and state accessors.
satcat5::ptp::ClientState	get_state () const
	Mode and state accessors.
satcat5::ptp::PortId	get_source () const
	Mode and state accessors.

Static Public Member Functions
static unsigned	count_timer ()
	Count all objects of this type, including idle timers.

Protected Member Functions
void	timer_event () override
	Child class MUST override this method.
void	timer_reset ()
void	cache_miss ()
void	client_timeout ()
unsigned	tlv_send (const satcat5::ptp::Header &hdr, satcat5::io::Writeable *wr)
void	notify_if_complete (const satcat5::ptp::Measurement *meas)
void	rcvd_announce (const satcat5::ptp::Header &hdr, satcat5::io::ArrayRead &rd)
void	rcvd_delay_req (const satcat5::ptp::Header &hdr, satcat5::io::ArrayRead &rd)
void	rcvd_pdelay_req (const Header &hdr, satcat5::io::ArrayRead &rd)
void	rcvd_delay_resp (const satcat5::ptp::Header &hdr, satcat5::io::ArrayRead &rd)
void	rcvd_pdelay_resp (const satcat5::ptp::Header &hdr, satcat5::io::ArrayRead &rd)
void	rcvd_follow_up (const satcat5::ptp::Header &hdr, satcat5::io::ArrayRead &rd)
void	rcvd_pdelay_follow_up (const satcat5::ptp::Header &hdr, satcat5::io::ArrayRead &rd)
void	rcvd_sync (const satcat5::ptp::Header &hdr, satcat5::io::ArrayRead &rd)
void	rcvd_unexpected (const satcat5::ptp::Header &hdr)
satcat5::ptp::Header	make_header (u8 type, u16 seq_id)
bool	send_announce ()
bool	send_sync (satcat5::ptp::DispatchTo addr, u16 seq_id, u16 flags=0, u64 tref=0)
bool	send_sync_bcast ()
bool	send_follow_up (satcat5::ptp::DispatchTo addr, u16 seq_id, u16 flags=0, u64 tref=0)
void	send_delay_req_sptp ()
bool	send_delay_req (u16 seq_id, u16 flags=0)
bool	send_delay_resp (const satcat5::ptp::Header &ref)
bool	send_pdelay_req ()
bool	send_pdelay_resp (const satcat5::ptp::Header &ref)
bool	send_pdelay_follow_up (const satcat5::ptp::Header &ref)
void	notify_callbacks (const satcat5::ptp::Measurement &meas)
	Notify all Callback objects of a new Measurement.

Protected Attributes
satcat5::ptp::Dispatch	m_iface
satcat5::igmp::Address	m_mcast_primary
satcat5::igmp::Address	m_mcast_pdelay
satcat5::util::List< satcat5::ptp::TlvHandler >	m_tlv_list
satcat5::ptp::ClientMode	m_mode
satcat5::ptp::ClientState	m_state
satcat5::ptp::MeasurementCache	m_cache
satcat5::ptp::ClockInfo	m_clock_local
satcat5::ptp::ClockInfo	m_clock_remote
satcat5::ptp::PortId	m_current_source
unsigned	m_announce_count
unsigned	m_announce_every
unsigned	m_sync_count
unsigned	m_sync_every
unsigned	m_cache_wdog
unsigned	m_request_wdog
int	m_announce_rate
int	m_sync_rate
int	m_pdelay_rate
u16	m_announce_id
u16	m_sync_id
u16	m_pdelay_id
s16	m_utc_offset
satcat5::util::List< satcat5::ptp::Callback >	m_callbacks
	Linked list of registered callback objects.

Private Member Functions
void	query (unsigned elapsed_msec)

Private Attributes
satcat5::poll::Timer *	m_next
unsigned	m_trem
unsigned	m_tnext

Member Function Documentation

get_utc_offset()

s16 satcat5::ptp::Client::get_utc_offset ( ) const

inline

Query the current UTC vs.

TAI offset (currentUtcOffset). This is the offset (TAI - UTC), equal to the cumulative number of UTC leap seconds, which is +37 as of 2017. See IEEE1588 Section 7.2.4 for details.

Definition at line 93 of file ptp_client.h.

send_sync_unicast()

bool Client::send_sync_unicast	(	const satcat5::eth::MacAddr &	mac,
		const satcat5::ip::Addr &	ip = satcat5::ip::ADDR_NONE,
		const satcat5::eth::VlanTag &	vtag = satcat5::eth::VTAG_NONE
	)

Send a unicast SYNC message to the designated address.

Unicast allows higher message rates than broadcast mode, and ignores the rate parameter from set_sync_rate.

Definition at line 209 of file ptp_client.cc.

set_announce_rate()

void Client::set_announce_rate

(

int

rate

)

Set the ANNOUNCE message rate to 2^N / sec.

Range -8 to +8. INT_MIN disables outgoing ANNOUNCE messages. This setting applies to master mode only.

Definition at line 187 of file ptp_client.cc.

set_pdelay_rate()

void Client::set_pdelay_rate

(

int

rate

)

Set the pdelay message rate to 0.9 x 2^N / sec.

Range -8 to +8. INT_MIN disables outgoing PDELAY_REQ messages. This setting applies to passive mode only.

Definition at line 199 of file ptp_client.cc.

set_sync_rate()

void Client::set_sync_rate

(

int

rate

)

Set the SYNC message rate to 2^N / sec.

Range -8 to +8. INT_MIN disables outgoing SYNC messages. This setting applies to master mode and to SPTP slaves.

Definition at line 193 of file ptp_client.cc.

set_utc_offset()

void satcat5::ptp::Client::set_utc_offset ( s16  offset )

inline

Immediately adjust the UTC vs.

TAI offset (currentUtcOffset). This has no effect on the client itself, except to change the "currentUtcOffset" reported in each ANNOUNCE message. Changes take effect immediately, without setting the pending-change flags (i.e., "leap59" and "leap61"), which are not supported. See IEEE1588 Section 7.2.4 for details.

Definition at line 102 of file ptp_client.h.

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

• ptp_client.h
• ptp_client.cc