[PATCH bpf-next v9 00/12] bpf: More sock_ops callbacks

[Lawrence Brakmo <brakmo@fb.com>]

This patchset adds support for:

- direct R or R/W access to many tcp_sock fields
- passing up to 4 arguments to sock_ops BPF functions
- tcp_sock field bpf_sock_ops_cb_flags for controlling callbacks
- optionally calling sock_ops BPF program when RTO fires
- optionally calling sock_ops BPF program when packet is retransmitted
- optionally calling sock_ops BPF program when TCP state changes
- access to tclass and sk_txhash
- new selftest

v2: Fixed commit message 0/11. The commit is to "bpf-next" but the patch
    below used "bpf" and Patchwork didn't work correctly.
v3: Cleaned RTO callback as per  Yuchung's comment
    Added BPF enum for TCP states as per  Alexei's comment
v4: Fixed compile warnings related to detecting changes between TCP
    internal states and the BPF defined states.
v5: Fixed comment issues in some selftest files
    Fixed accesss issue with u64 fields in bpf_sock_ops struct
v6: Made fixes based on comments form Eric Dumazet:
    The field bpf_sock_ops_cb_flags was addded in a hole on 64bit kernels
    Field bpf_sock_ops_cb_flags is now set through a helper function
    which returns an error when a BPF program tries to set bits for
    callbacks that are not supported in the current kernel.
    Added a comment indicating that when adding fields to bpf_sock_ops_kern
    they should be added before the field named "temp" if they need to be
    cleared before calling the BPF function.  
v7: Enfornced fields "op" and "replylong[1] .. replylong[3]" not be writable
    based on comments form Eric Dumazet and Alexei Starovoitov.
    Filled 32 bit hole in bpf_sock_ops struct with sk_txhash based on
    comments from Daniel Borkmann.
    Removed unused functions (tcp_call_bpf_1arg, tcp_call_bpf_4arg) based
    on comments from Daniel Borkmann.
v8: Add commit message 00/12
    Add Acked-by as appropriate
v9: Moved the bug fix to the front of the patchset
    Changed RETRANS_CB so it is always called (before it was only called if
    the retransmit succeeded). It is now called with an extra argument, the
    return value of tcp_transmit_skb (0 => success). Based on comments
    from Yuchung Cheng.
    Added support for reading 2 new fields, sacked_out and lost_out, based on
    comments from Yuchung Cheng.

Consists of the following patches:
[PATCH bpf-next v9 01/12] bpf: Only reply field should be writeable
[PATCH bpf-next v9 02/12] bpf: Make SOCK_OPS_GET_TCP size independent
[PATCH bpf-next v9 03/12] bpf: Make SOCK_OPS_GET_TCP struct
[PATCH bpf-next v9 04/12] bpf: Add write access to tcp_sock and sock
[PATCH bpf-next v9 05/12] bpf: Support passing args to sock_ops bpf
[PATCH bpf-next v9 06/12] bpf: Adds field bpf_sock_ops_cb_flags to
[PATCH bpf-next v9 07/12] bpf: Add sock_ops RTO callback
[PATCH bpf-next v9 08/12] bpf: Add support for reading sk_state and
[PATCH bpf-next v9 09/12] bpf: Add sock_ops R/W access to tclass
[PATCH bpf-next v9 10/12] bpf: Add BPF_SOCK_OPS_RETRANS_CB
[PATCH bpf-next v9 11/12] bpf: Add BPF_SOCK_OPS_STATE_CB
[PATCH bpf-next v9 12/12] bpf: add selftest for tcpbpf

 include/linux/filter.h                         |  10 ++
 include/linux/tcp.h                            |  11 ++
 include/net/tcp.h                              |  42 ++++-
 include/uapi/linux/bpf.h                       |  76 +++++++-
 include/uapi/linux/tcp.h                       |   8 +
 net/core/filter.c                              | 290 ++++++++++++++++++++++++++++---
 net/ipv4/tcp.c                                 |  26 ++-
 net/ipv4/tcp_nv.c                              |   2 +-
 net/ipv4/tcp_output.c                          |   6 +-
 net/ipv4/tcp_timer.c                           |   7 +
 tools/include/uapi/linux/bpf.h                 |  78 ++++++++-
 tools/testing/selftests/bpf/Makefile           |   4 +-
 tools/testing/selftests/bpf/bpf_helpers.h      |   2 +
 tools/testing/selftests/bpf/tcp_client.py      |  52 ++++++
 tools/testing/selftests/bpf/tcp_server.py      |  79 +++++++++
 tools/testing/selftests/bpf/test_tcpbpf.h      |  16 ++
 tools/testing/selftests/bpf/test_tcpbpf_kern.c | 131 ++++++++++++++
 tools/testing/selftests/bpf/test_tcpbpf_user.c | 126 ++++++++++++++
 18 files changed, 927 insertions(+), 39 deletions(-)