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From:   Lorenz Bauer <lmb@isovalent.com>
Date:   Mon, 3 Jul 2023 10:45:59 +0100
Message-ID: <CAN+4W8ihqdQnZW5oWxhgmNaEDisdG9UDQYozVw_HpR41HkWL_g@mail.gmail.com>
Subject: Re: [PATCH bpf-next v4 3/7] net: remove duplicate reuseport_lookup functions
To:     Kuniyuki Iwashima <kuniyu@amazon.com>
Cc:     andrii@kernel.org, ast@kernel.org, bpf@vger.kernel.org,
        daniel@iogearbox.net, davem@davemloft.net, dsahern@kernel.org,
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        kpsingh@kernel.org, kuba@kernel.org, linux-kernel@vger.kernel.org,
        linux-kselftest@vger.kernel.org, martin.lau@linux.dev,
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On Wed, Jun 28, 2023 at 7:33=E2=80=AFPM Kuniyuki Iwashima <kuniyu@amazon.co=
m> wrote:

> > +
> > +inet6_ehashfn_t inet6_ehashfn;
> > +
> > +INDIRECT_CALLABLE_DECLARE(inet6_ehashfn_t udp6_ehashfn);
>
> We need not define udp6_ehashfn() here as inet6_hashtables.c has
> the definition.
>
> Only inet6_ehashfn() is needed because sk_ehashfn() uses it.

Without udp6_ehashfn we get the following error, as reported by Simon
against v1:

net/ipv4/udp.c:410:5: error: no previous prototype for =E2=80=98udp_ehashfn=
=E2=80=99
[-Werror=3Dmissing-prototypes]
  410 | u32 udp_ehashfn(const struct net *net, const __be32 laddr,
const __u16 lport,
      |     ^~~~~~~~~~~

> > +inet_ehashfn_t inet_ehashfn;
> > +
> > +INDIRECT_CALLABLE_DECLARE(inet_ehashfn_t udp_ehashfn);
> > +
>
> We don't need inet_ehashfn() and udp_ehashfn() declarations here.

Without inet_ehashfn I get:

./include/net/inet_hashtables.h: In function =E2=80=98__inet_lookup_skb=E2=
=80=99:
./include/net/inet_hashtables.h:501:42: error: =E2=80=98inet_ehashfn=E2=80=
=99
undeclared (first use in this function); did you mean =E2=80=98inet_bhashfn=
=E2=80=99?
  501 |                              refcounted, inet_ehashfn);

Same problem with the warning as above.

I think this needs to stay the way it is.