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References: <20191204.165528.1483577978366613524.davem@davemloft.net>
 <20191205064118.8299-1-vvidic@valentin-vidic.from.hr> <20191205113411.5e672807@cakuba.netronome.com>
In-Reply-To: <20191205113411.5e672807@cakuba.netronome.com>
From:   Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Date:   Thu, 5 Dec 2019 15:06:55 -0500
Message-ID: <CA+FuTSe=GSP41GG+QYKEmQ0eDUEoFeQ+oGAsgGJEZTe=hJq4Tw@mail.gmail.com>
Subject: Re: [PATCH v3] net/tls: Fix return values to avoid ENOTSUPP
To:     Jakub Kicinski <jakub.kicinski@netronome.com>
Cc:     Valentin Vidic <vvidic@valentin-vidic.from.hr>,
        Willem de Bruijn <willemdebruijn.kernel@gmail.com>,
        Boris Pismenny <borisp@mellanox.com>,
        Aviad Yehezkel <aviadye@mellanox.com>,
        John Fastabend <john.fastabend@gmail.com>,
        Daniel Borkmann <daniel@iogearbox.net>,
        "David S. Miller" <davem@davemloft.net>,
        Network Development <netdev@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>
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Sender: linux-kernel-owner@vger.kernel.org
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On Thu, Dec 5, 2019 at 2:34 PM Jakub Kicinski
<jakub.kicinski@netronome.com> wrote:
>
> On Thu,  5 Dec 2019 07:41:18 +0100, Valentin Vidic wrote:
> > ENOTSUPP is not available in userspace, for example:
> >
> >   setsockopt failed, 524, Unknown error 524
> >
> > Signed-off-by: Valentin Vidic <vvidic@valentin-vidic.from.hr>
>
> > diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
> > index 0683788bbef0..cd91ad812291 100644
> > --- a/net/tls/tls_device.c
> > +++ b/net/tls/tls_device.c
> > @@ -429,7 +429,7 @@ static int tls_push_data(struct sock *sk,
> >
> >       if (flags &
> >           ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL | MSG_SENDPAGE_NOTLAST))
> > -             return -ENOTSUPP;
> > +             return -EOPNOTSUPP;
> >
> >       if (unlikely(sk->sk_err))
> >               return -sk->sk_err;
> > @@ -571,7 +571,7 @@ int tls_device_sendpage(struct sock *sk, struct page *page,
> >       lock_sock(sk);
> >
> >       if (flags & MSG_OOB) {
> > -             rc = -ENOTSUPP;
> > +             rc = -EOPNOTSUPP;
>
> Perhaps the flag checks should return EINVAL? Willem any opinions?

No strong opinion. Judging from do_tcp_sendpages MSG_OOB is a
supported flag in general for sendpage, so signaling that the TLS
variant cannot support that otherwise valid request sounds fine to me.

>
> >               goto out;
> >       }
> >
> > @@ -1023,7 +1023,7 @@ int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
> >       }
> >
> >       if (!(netdev->features & NETIF_F_HW_TLS_TX)) {
> > -             rc = -ENOTSUPP;
> > +             rc = -EOPNOTSUPP;
> >               goto release_netdev;
> >       }
> >
> > @@ -1098,7 +1098,7 @@ int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
> >       }
> >
> >       if (!(netdev->features & NETIF_F_HW_TLS_RX)) {
> > -             rc = -ENOTSUPP;
> > +             rc = -EOPNOTSUPP;
> >               goto release_netdev;
> >       }
> >
> > diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
> > index bdca31ffe6da..5830b8e02a36 100644
> > --- a/net/tls/tls_main.c
> > +++ b/net/tls/tls_main.c
> > @@ -496,7 +496,7 @@ static int do_tls_setsockopt_conf(struct sock *sk, char __user *optval,
> >       /* check version */
> >       if (crypto_info->version != TLS_1_2_VERSION &&
> >           crypto_info->version != TLS_1_3_VERSION) {
> > -             rc = -ENOTSUPP;
> > +             rc = -EINVAL;
>
> This one I think Willem asked to be EOPNOTSUPP OTOH.

Indeed (assuming no one disagrees). Based on the same rationale: the
request may be valid, it just cannot be accommodated (yet).