[PATCH v1 bpf-next/net 0/5] bpf: Support RX/TX HW timestamp proxy.

[Kuniyuki Iwashima <kuniyu@google.com>]

We have some hosts where packets come from special hardware
and are provided directly to userspace, bypassing the kernel
networking stack.

When standard socket applications are run on these hosts,
a userspace proxy is required to mediate traffic between the
hardware and the applications.

            +---------+                 +----------------------+
            |  proxy  |                 |  socket application  |
            +---------+                 +----------------------+
              ^     ^                               ^
  userspace   |     |                               |
  -----------| |-----------------------------------------------
             | |    |    +---------------------+    | skb
             | |    `--->|  virtual interface  |<---'
  kernel     | |   skb   +---------------------+
  -----------| |-----------------------------------------------
              |
              v
       +------------+
       |  hardware  |
       +------------+

However, even though the hardware fully supports timestamping,
the HW timestamps are not directly accessible to the socket
applications because the skb is consumed/injected by the proxy.

This series extends ethtool and adds BPF kfuncs to transparently
support HW timestamp on such a setup.

Patch 1 is pure net-next patch to advertise fake timestamping
capability on virtual interfaces (e.g. ipvlan, geneve, etc).

Patch 2 is misc cleanup.

Patch 3 & 4 add kfunc to proxy RX/TX hwtstamp.

Patch 5 is selftest to demonstrate how it works.

Note the test requires this iproute2 commit:
https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/commit/?id=c9a9f12aa619288fd3d4e16bc4b3c73b655a4efe


Kuniyuki Iwashima (5):
  ethtool: Introduce ETHTOOL_MSG_TSINFO_SET for virtual interfaces.
  bpf: Rename bpf_kfunc_set_tcp_reqsk to bpf_kfunc_set_sched_cls.
  bpf: Add bpf_skb_set_hwtstamp().
  bpf: Add kfunc to proxy TX HW Timestamp.
  selftest: bpf: Add test for hwtstamp proxy.

 Documentation/netlink/specs/ethtool.yaml      |  13 +
 include/linux/filter.h                        |   2 +
 include/linux/netdevice.h                     |  11 +
 include/linux/skbuff.h                        |  13 +
 include/net/tcx.h                             |   1 +
 include/uapi/linux/bpf.h                      |   1 +
 .../uapi/linux/ethtool_netlink_generated.h    |   1 +
 include/uapi/linux/pkt_cls.h                  |   3 +-
 kernel/bpf/verifier.c                         |  13 +-
 net/core/dev.c                                |  39 ++
 net/core/dev_ioctl.c                          |  31 +-
 net/core/filter.c                             |  91 ++-
 net/ethtool/common.c                          |   4 +
 net/ethtool/netlink.c                         |   8 +
 net/ethtool/netlink.h                         |   1 +
 net/ethtool/tsconfig.c                        |   7 +-
 net/ethtool/tsinfo.c                          | 123 +++-
 tools/testing/selftests/bpf/bpf_kfuncs.h      |  10 +
 .../selftests/bpf/prog_tests/proxy_hwtstamp.c | 580 ++++++++++++++++++
 .../selftests/bpf/progs/bpf_tracing_net.h     |   1 +
 .../selftests/bpf/progs/proxy_hwtstamp.c      | 234 +++++++
 21 files changed, 1169 insertions(+), 18 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/proxy_hwtstamp.c
 create mode 100644 tools/testing/selftests/bpf/progs/proxy_hwtstamp.c

-- 
2.54.0.1136.gdb2ca164c4-goog