[PATCH mptcp-next v17 00/15] BPF redundant scheduler

[Geliang Tang <geliang.tang@suse.com>]

v17:
 - address to Mat's comments in v16
 - rebase to export/20221108T055508.

v16:
- keep last_snd and snd_burst in struct mptcp_sock.
- drop "mptcp: register default scheduler".
- drop "mptcp: add scheduler wrappers", move it into "mptcp: use
get_send wrapper" and "mptcp: use get_retrans wrapper".
- depends on 'v2, Revert "mptcp: add get_subflow wrappers" - fix
divide error in mptcp_subflow_get_send'

v15:
 1: "refactor push pending" v10
 2-11: "register default scheduler" v3
  - move last_snd and snd_burst into struct mptcp_sched_ops
 12-19: "BPF redundant scheduler" v15
  - split "use get_send wrapper" into two patches
 - rebase to export/20221021T061837.

v14:
- add "mptcp: refactor push_pending logic" v10 as patch 1
- drop update_first_pending in patch 4
- drop update_already_sent in patch 5

v13:
- deponds on "refactor push pending" v9.
- Simply 'goto out' after invoking mptcp_subflow_delegate in patch 1.
- All selftests (mptcp_connect.sh, mptcp_join.sh and simult_flows.sh) passed.

v12:
 - fix WARN_ON_ONCE(reuse_skb) and WARN_ON_ONCE(!msk->recovery) errors
   in kernel logs.

v11:
 - address to Mat's comments in v10.
 - rebase to export/20220908T063452

v10:
 - send multiple dfrags in __mptcp_push_pending().

v9:
 - drop the extra *err paramenter of mptcp_sched_get_send() as Florian
   suggested.

v8:
 - update __mptcp_push_pending(), send the same data on each subflow.
 - update __mptcp_retrans, track the max sent data.
 = add a new patch.

v7:
 - drop redundant flag in v6
 - drop __mptcp_subflows_push_pending in v6
 - update redundant subflows support in __mptcp_push_pending
 - update redundant subflows support in __mptcp_retrans

v6:
 - Add redundant flag for struct mptcp_sched_ops.
 - add a dedicated function __mptcp_subflows_push_pending() to deal with
   redundat subflows push pending.

v5:
 - address to Paolo's comment, keep the optimization to
mptcp_subflow_get_send() for the non eBPF case.
 - merge mptcp_sched_get_send() and __mptcp_sched_get_send() in v4 into one.
 - depends on "cleanups for bpf sched selftests".

v4:
 - small cleanups in patch 1, 2.
 - add TODO in patch 3.
 - rebase patch 5 on 'cleanups for bpf sched selftests'.

v3:
 - use new API.
 - fix the link failure tests issue mentioned in ("https://patchwork.kernel.org/project/mptcp/cover/cover.1653033459.git.geliang.tang@suse.com/").

v2:
 - add MPTCP_SUBFLOWS_MAX limit to avoid infinite loops when the
   scheduler always sets call_again to true.
 - track the largest copied amount.
 - deal with __mptcp_subflow_push_pending() and the retransmit loop.
 - depends on "BPF round-robin scheduler" v14.

v1:

Implements the redundant BPF MPTCP scheduler, which sends all packets
redundantly on all available subflows.

Geliang Tang (15):
  mptcp: refactor push_pending logic
  mptcp: drop last_snd and MPTCP_RESET_SCHEDULER
  mptcp: add sched_data_set_contexts helper
  Squash to "mptcp: add struct mptcp_sched_ops"
  Squash to "bpf: Add bpf_mptcp_sched_ops"
  Squash to "bpf: Add bpf_mptcp_sched_kfunc_set"
  Squash to "selftests/bpf: Add bpf_first scheduler"
  Squash to "selftests/bpf: Add bpf_bkup scheduler"
  Squash to "selftests/bpf: Add bpf_rr scheduler"
  mptcp: use get_send wrapper
  mptcp: use get_retrans wrapper
  mptcp: delay updating first_pending
  mptcp: delay updating already_sent
  selftests/bpf: Add bpf_red scheduler
  selftests/bpf: Add bpf_red test

 include/net/mptcp.h                           |   6 +-
 net/mptcp/bpf.c                               |   1 +
 net/mptcp/pm.c                                |   9 +-
 net/mptcp/pm_netlink.c                        |   3 -
 net/mptcp/protocol.c                          | 333 +++++++++++-------
 net/mptcp/protocol.h                          |  19 +-
 net/mptcp/sched.c                             |  88 ++++-
 tools/testing/selftests/bpf/bpf_tcp_helpers.h |   8 +-
 .../testing/selftests/bpf/prog_tests/mptcp.c  |  34 ++
 .../selftests/bpf/progs/mptcp_bpf_bkup.c      |  10 +-
 .../selftests/bpf/progs/mptcp_bpf_first.c     |  10 +-
 .../selftests/bpf/progs/mptcp_bpf_red.c       |  45 +++
 .../selftests/bpf/progs/mptcp_bpf_rr.c        |  10 +-
 13 files changed, 433 insertions(+), 143 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/progs/mptcp_bpf_red.c

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2.35.3