Implements the Peer-to-Peer (P2P) transparent clock delay measurement
mechanism (IEEE 1588-2008 §11.4 / IEEE 802.1AS / IEC/IEEE 61850-9-3)
in apps/netutils/ptpd:
- Add PTP_MSGTYPE_PDELAY_REQ, PTP_MSGTYPE_PDELAY_RESP, and
PTP_MSGTYPE_PDELAY_RESP_FOLLOW_UP definitions and structs in ptpv2.h.
- Define IEEE 1588-2008 Annex F peer delay multicast MAC address
01:80:c2:00:00:0e and Annex D peer delay IP address 224.0.0.107.
- Replace bool delay_e2e with enum ptp_delay_mechanism_e (PTP_DELAY_NONE,
PTP_DELAY_E2E, PTP_DELAY_P2P) in include/netutils/ptpd.h.
- Add -P CLI option in system/ptpd/ptpd_main.c with mutual exclusion
check against -E, and display last_transmitted_pdelayreq in status.
- Implement responder logic in ptp_process_pdelay_req() sending
Pdelay_Resp (t2) and Pdelay_Resp_Follow_Up (t3) regardless of master
or slave state.
- Implement requester logic in ptp_send_pdelay_req() gated on the
physical link without requiring prior BMCA master selection.
- Implement ptp_process_pdelay_resp() and
ptp_process_pdelay_resp_followup() using canonical mean path delay
formula ((t4 - t1) - (t3 - t2)) / 2.
- Refactor path delay bounds checking and moving average filter into
ptp_record_path_delay() shared across E2E and P2P mechanisms.
- Set PTP version 2.0 and controlField 0x05 in Pdelay_Req, Pdelay_Resp
and Pdelay_Resp_Follow_Up, and in the own-identity header, so that
peers such as linuxptp accept the messages.
- Clear pdelay_waiting_followup when a new Pdelay_Req is sent, so an
orphaned Pdelay_Resp_Follow_Up from an abandoned cycle is not paired
with stale timestamps.
- Warn at startup when P2P is selected without CONFIG_SCHED_TICKLESS,
since a tick-driven clock cannot resolve the peer delay.
- Skip IP multicast join/leave handling for AF_PACKET.
Assisted-by: Claude:claude-sonnet-5
Assisted-by: Gemini:gemini-3.8-flash-medium
Signed-off-by: Daniel P. Carvalho <danieloak@gmail.com>
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