Re: [PATCH net-next v2 1/2] net: add missing syncookie statistics for BPF custom syncookies

[Kuniyuki Iwashima]

On Fri, Apr 10, 2026 at 6:32 PM Jiayuan Chen <jiayuan.chen@xxxxxxxxx> wrote:
>
> 1. Replace IS_ENABLED(CONFIG_BPF) with CONFIG_BPF_SYSCALL for
>    cookie_bpf_ok() and cookie_bpf_check(). CONFIG_BPF is selected by
>    CONFIG_NET unconditionally, so IS_ENABLED(CONFIG_BPF) is always
>    true and provides no real guard. CONFIG_BPF_SYSCALL is the correct
>    config for BPF program functionality.
>
> 2. Remove the CONFIG_BPF_SYSCALL guard around struct bpf_tcp_req_attrs.
>    This struct is referenced by bpf_sk_assign_tcp_reqsk() in
>    net/core/filter.c which is compiled unconditionally, so wrapping
>    the definition in a config guard could cause build failures when
>    CONFIG_BPF_SYSCALL=n.
>
> 3. Fix mismatched declaration of cookie_bpf_check() between the
>    CONFIG_BPF_SYSCALL and stub paths: the real definition takes
>    'struct net *net' but the declaration in the header did not.
>    Add the net parameter to the declaration and all call sites.
>
> 4. Add missing LINUX_MIB_SYNCOOKIESRECV and LINUX_MIB_SYNCOOKIESFAILED
>    statistics in cookie_bpf_check(), so that BPF custom syncookie
>    validation is accounted for in SNMP counters just like the
>    non-BPF path.
>
> Compile-tested with CONFIG_BPF_SYSCALL=y and CONFIG_BPF_SYSCALL
> not set.
>
> Signed-off-by: Jiayuan Chen <jiayuan.chen@xxxxxxxxx>

Reviewed-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>