All of lore.kernel.org
 help / color / mirror / Atom feed
* [RFC v1 0/4] introduce PTP protocol library and software relay example
@ 2026-04-28  1:01 Rajesh Kumar
  2026-04-27 23:42 ` Stephen Hemminger
                   ` (11 more replies)
  0 siblings, 12 replies; 60+ messages in thread
From: Rajesh Kumar @ 2026-04-28  1:01 UTC (permalink / raw)
  To: dev; +Cc: bruce.richardson, aman.deep.singh, rajesh3.kumar

This series introduces a new DPDK library (lib/ptp) for IEEE 1588-2019
PTP protocol packet processing and a companion example application
(ptp_tap_relay_sw) that demonstrates its usage.

Motivation
----------
Several DPDK applications need to classify and manipulate PTP packets
(e.g. ptpclient, ptp_tap_relay, custom Transparent Clocks). Today each
application re-implements its own PTP header parsing and correctionField
handling. A shared library avoids duplication and provides a tested,
standards-compliant foundation.

Library: lib/ptp
----------------
The library provides:
  - PTP header structures (IEEE 1588-2019 common header, timestamp,
    port identity)
  - Packet classification: rte_ptp_classify() detects PTP over L2
    (EtherType 0x88F7), VLAN-tagged L2, and UDP/IPv4 (ports 319/320)
  - Header access: rte_ptp_hdr_get() returns a pointer to the PTP
    header inside an mbuf
  - Inline helpers: correctionField manipulation (48.16 fixed-point),
    message type extraction, two-step flag check, timestamp conversion
  - Debug: rte_ptp_msg_type_str() for human-readable message names

The API is experimental (targeted for 26.07). Dependencies are minimal:
mbuf and net libraries only.

Example: ptp_tap_relay_sw
-------------------------
A minimal PTP Transparent Clock relay between a DPDK-bound physical NIC
and a kernel TAP interface using software timestamps only. No patched
kernel modules, custom TAP PMD, or hardware timestamp support is
required.

The relay:
  1. Receives packets on the physical NIC via DPDK
  2. Classifies PTP packets using rte_ptp_classify()
  3. For event messages, records software timestamps
     (CLOCK_MONOTONIC_RAW) at ingress and egress
  4. Adds residence time to correctionField via rte_ptp_add_correction()
     (IEEE 1588-2019 §10.2 Transparent Clock)
  5. Forwards bidirectionally: PHY <-> TAP

A two-pass design takes the TX timestamp as close to rte_eth_tx_burst()
as possible, minimising untracked delay.

Test Results
------------
Test setup: Intel E610 10GbE NIC (vfio-pci), ptp4l master with HW
timestamps on physical port, ptp4l slave with SW timestamps (-S) on TAP
interface, logSyncInterval=-4 (16 Sync/sec), 120s duration.

  Post-convergence (60s of locked data):
    Average RMS offset:   929 ns
    Worst max offset:     11615 ns (single transient)
    Steady-state range:   489 - 1055 ns RMS
    Corrections applied:  3635

linuxptp's PI servo uses relaxed gains for software timestamps
(kp=0.1, ki=0.001 vs kp=0.7, ki=0.3 for HW), expecting ~5-50 µs
jitter. Sub-microsecond RMS is achieved here because the master uses
HW timestamps and DPDK's poll-mode relay provides deterministic
low-latency forwarding.

Rajesh Kumar (4):
  ptp: introduce PTP protocol library
  doc: add PTP library programmer's guide
  examples/ptp_tap_relay_sw: add software PTP relay example
  doc: add PTP software relay sample app guide

 MAINTAINERS                                   |   7 +
 doc/api/doxy-api-index.md                     |   1 +
 doc/api/doxy-api.conf.in                      |   1 +
 doc/guides/prog_guide/index.rst               |   1 +
 doc/guides/prog_guide/ptp_lib.rst             | 195 ++++++++
 doc/guides/sample_app_ug/index.rst            |   1 +
 doc/guides/sample_app_ug/ptp_tap_relay_sw.rst | 210 +++++++++
 examples/meson.build                          |   1 +
 examples/ptp_tap_relay_sw/Makefile            |  41 ++
 examples/ptp_tap_relay_sw/meson.build         |  14 +
 examples/ptp_tap_relay_sw/ptp_tap_relay_sw.c  | 424 ++++++++++++++++++
 lib/meson.build                               |   1 +
 lib/ptp/meson.build                           |   6 +
 lib/ptp/rte_ptp.c                             | 195 ++++++++
 lib/ptp/rte_ptp.h                             | 328 ++++++++++++++
 15 files changed, 1426 insertions(+)
 create mode 100644 doc/guides/prog_guide/ptp_lib.rst
 create mode 100644 doc/guides/sample_app_ug/ptp_tap_relay_sw.rst
 create mode 100644 examples/ptp_tap_relay_sw/Makefile
 create mode 100644 examples/ptp_tap_relay_sw/meson.build
 create mode 100644 examples/ptp_tap_relay_sw/ptp_tap_relay_sw.c
 create mode 100644 lib/ptp/meson.build
 create mode 100644 lib/ptp/rte_ptp.c
 create mode 100644 lib/ptp/rte_ptp.h

-- 
2.52.0


^ permalink raw reply	[flat|nested] 60+ messages in thread

end of thread, other threads:[~2026-05-09 18:00 UTC | newest]

Thread overview: 60+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-04-28  1:01 [RFC v1 0/4] introduce PTP protocol library and software relay example Rajesh Kumar
2026-04-27 23:42 ` Stephen Hemminger
2026-04-28 16:52   ` Kumar, Rajesh
2026-04-28  1:01 ` [RFC v1 1/4] ptp: introduce PTP protocol library Rajesh Kumar
2026-04-27 23:01   ` Stephen Hemminger
2026-04-28 16:50     ` Kumar, Rajesh
2026-04-28  1:01 ` [RFC v1 2/4] doc: add PTP library programmer's guide Rajesh Kumar
2026-04-28  1:01 ` [RFC v1 3/4] examples/ptp_tap_relay_sw: add software PTP relay example Rajesh Kumar
2026-04-28  1:01 ` [RFC v1 4/4] doc: add PTP software relay sample app guide Rajesh Kumar
2026-04-28 22:28 ` [RFC v2 0/6] introduce PTP protocol library and software relay Rajesh Kumar
2026-04-28 22:28   ` [RFC v2 1/6] ptp: introduce PTP protocol library Rajesh Kumar
2026-04-28 22:28   ` [RFC v2 2/6] doc: add PTP library programmer's guide Rajesh Kumar
2026-04-28 22:28   ` [RFC v2 3/6] examples/ptp_tap_relay_sw: add software PTP relay example Rajesh Kumar
2026-04-28 22:28   ` [RFC v2 4/6] doc: add PTP software relay sample app guide Rajesh Kumar
2026-04-28 22:28   ` [RFC v2 5/6] app/test: add PTP library unit tests Rajesh Kumar
2026-04-28 22:28   ` [RFC v2 6/6] examples/ptpclient: use shared PTP library definitions Rajesh Kumar
2026-04-29 15:37   ` [RFC v2 0/6] introduce PTP protocol library and software relay Stephen Hemminger
2026-05-04  3:49     ` Kumar, Rajesh3
2026-05-04  9:17 ` [RFC v3 " Rajesh Kumar
2026-05-04  9:17   ` [RFC v3 1/6] ptp: introduce PTP protocol library Rajesh Kumar
2026-05-04  9:17   ` [RFC v3 2/6] doc: add PTP library programmer's guide Rajesh Kumar
2026-05-04  9:17   ` [RFC v3 3/6] examples/ptp_tap_relay_sw: add software PTP relay example Rajesh Kumar
2026-05-04  9:17   ` [RFC v3 4/6] doc: add PTP software relay sample app guide Rajesh Kumar
2026-05-04  9:17   ` [RFC v3 5/6] app/test: add PTP library unit tests Rajesh Kumar
2026-05-04  9:17   ` [RFC v3 6/6] examples/ptpclient: use shared PTP library definitions Rajesh Kumar
2026-05-04 17:56   ` [RFC v3 0/6] introduce PTP protocol library and software relay Stephen Hemminger
2026-05-05 16:38 ` [RFC v4 " Rajesh Kumar
2026-05-05 16:38   ` [RFC v4 1/6] ptp: introduce PTP protocol library Rajesh Kumar
2026-05-05 16:38   ` [RFC v4 2/6] doc: add PTP library programmer's guide Rajesh Kumar
2026-05-05 16:38   ` [RFC v4 3/6] examples/ptp_tap_relay_sw: add software PTP relay example Rajesh Kumar
2026-05-05 16:38   ` [RFC v4 4/6] doc: add PTP software relay sample app guide Rajesh Kumar
2026-05-05 16:38   ` [RFC v4 5/6] app/test: add PTP library unit tests Rajesh Kumar
2026-05-05 16:38   ` [RFC v4 6/6] examples/ptpclient: use shared PTP library definitions Rajesh Kumar
2026-05-06 15:41 ` [RFC v5 0/6] introduce PTP protocol library and software relay Rajesh Kumar
2026-05-06 15:41   ` [RFC v5 1/6] ptp: introduce PTP protocol library Rajesh Kumar
2026-05-06 11:02     ` Morten Brørup
2026-05-07  4:45       ` Kumar, Rajesh
2026-05-06 15:41   ` [RFC v5 2/6] doc: add PTP library programmer's guide Rajesh Kumar
2026-05-06 15:41   ` [RFC v5 3/6] examples/ptp_tap_relay_sw: add software PTP relay example Rajesh Kumar
2026-05-06 15:41   ` [RFC v5 4/6] doc: add PTP software relay sample app guide Rajesh Kumar
2026-05-06 15:41   ` [RFC v5 5/6] app/test: add PTP library unit tests Rajesh Kumar
2026-05-06 15:41   ` [RFC v5 6/6] examples/ptpclient: use shared PTP library definitions Rajesh Kumar
2026-05-06 15:45   ` [RFC v5 0/6] introduce PTP protocol library and software relay Stephen Hemminger
2026-05-07 10:13 ` [PATCH v6 0/4] PTP protocol support in lib/net Rajesh Kumar
2026-05-07 10:13   ` [PATCH v6 1/4] lib/net: add IEEE 1588 PTP v2 protocol header definitions Rajesh Kumar
2026-05-07 10:13   ` [PATCH v6 2/4] examples/ptp_tap_relay_sw: add PTP software transparent clock relay Rajesh Kumar
2026-05-07 10:13   ` [PATCH v6 3/4] doc: update release notes for PTP protocol library Rajesh Kumar
2026-05-07 10:13   ` [PATCH v6 4/4] examples/ptpclient: use shared PTP library definitions Rajesh Kumar
2026-05-07 13:45 ` [PATCH v7 0/4] IEEE 1588 PTP v2 protocol support in lib/net Rajesh Kumar
2026-05-07 13:45   ` [PATCH v7 1/4] lib/net: add IEEE 1588 PTP v2 protocol header definitions Rajesh Kumar
2026-05-07 15:27     ` Morten Brørup
2026-05-09 17:57       ` Kumar, Rajesh
2026-05-07 13:45   ` [PATCH v7 2/4] examples/ptp_tap_relay_sw: add PTP software transparent clock relay Rajesh Kumar
2026-05-07 13:45   ` [PATCH v7 3/4] doc: update release notes for PTP protocol library Rajesh Kumar
2026-05-07 13:45   ` [PATCH v7 4/4] examples/ptpclient: use shared PTP library definitions Rajesh Kumar
2026-05-09 23:25 ` [PATCH v8 0/4] IEEE 1588 PTP v2 protocol support in lib/net Rajesh Kumar
2026-05-09 23:25   ` [PATCH v8 1/4] lib/net: add IEEE 1588 PTP v2 protocol header definitions Rajesh Kumar
2026-05-09 23:25   ` [PATCH v8 2/4] examples/ptp_tap_relay_sw: add PTP software transparent clock relay Rajesh Kumar
2026-05-09 23:25   ` [PATCH v8 3/4] doc: update release notes for PTP protocol library Rajesh Kumar
2026-05-09 23:25   ` [PATCH v8 4/4] examples/ptpclient: use shared PTP library definitions Rajesh Kumar

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.