Merge branch 'bpf-more-sock_ops-callbacks'

Lawrence Brakmo says:

====================
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.
v10: Moved the callback flags from include/uapi/linux/tcp.h to
     include/uapi/linux/bpf.h
     Cleaned up the test in selftest. Added a timeout so it always completes,
     even if the client is not communicating with the server. Made it faster
     by removing the sleeps. Made sure it works even when called back-to-back
     20 times.

Consists of the following patches:
[PATCH bpf-next v10 01/12] bpf: Only reply field should be writeable
[PATCH bpf-next v10 02/12] bpf: Make SOCK_OPS_GET_TCP size
[PATCH bpf-next v10 03/12] bpf: Make SOCK_OPS_GET_TCP struct
[PATCH bpf-next v10 04/12] bpf: Add write access to tcp_sock and sock
[PATCH bpf-next v10 05/12] bpf: Support passing args to sock_ops bpf
[PATCH bpf-next v10 06/12] bpf: Adds field bpf_sock_ops_cb_flags to
[PATCH bpf-next v10 07/12] bpf: Add sock_ops RTO callback
[PATCH bpf-next v10 08/12] bpf: Add support for reading sk_state and
[PATCH bpf-next v10 09/12] bpf: Add sock_ops R/W access to tclass
[PATCH bpf-next v10 10/12] bpf: Add BPF_SOCK_OPS_RETRANS_CB
[PATCH bpf-next v10 11/12] bpf: Add BPF_SOCK_OPS_STATE_CB
[PATCH bpf-next v10 12/12] bpf: add selftest for tcpbpf
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>