Re: [bpf PATCH v2 2/6] bpf: tls fix transition through disconnect with close

Jakub Kicinski
2019-07-10T19:34:27Z

On Tue, 09 Jul 2019 20:39:24 -0700, John Fastabend wrote:
> Jakub Kicinski wrote:
> > On Mon, 08 Jul 2019 19:14:05 +0000, John Fastabend wrote:
> > > @@ -287,6 +313,27 @@ static void tls_sk_proto_cleanup(struct sock *sk,
> > > #endif
> > > }
> > >
> > > +static void tls_sk_proto_unhash(struct sock *sk)
> > > +{
> > > + struct inet_connection_sock *icsk = inet_csk(sk);
> > > + long timeo = sock_sndtimeo(sk, 0);
> > > + struct tls_context *ctx;
> > > +
> > > + if (unlikely(!icsk->icsk_ulp_data)) {
> >
> > Is this for when sockmap is stacked on top of TLS and TLS got removed
> > without letting sockmap know?
>
> Right its a pattern I used on the sockmap side and put here. But
> I dropped the patch to let sockmap stack on top of TLS because
> it was more than a fix IMO. We could probably drop this check on
> the other hand its harmless.

I feel like this code is pretty complex I struggle to follow all the
paths, so perhaps it'd be better to drop stuff that's not necessary
to have a clearer picture.

> > > + if (sk->sk_prot->unhash)
> > > + sk->sk_prot->unhash(sk);
> > > + }
> > > +
> > > + ctx = tls_get_ctx(sk);
> > > + if (ctx->tx_conf == TLS_SW || ctx->rx_conf == TLS_SW)
> > > + tls_sk_proto_cleanup(sk, ctx, timeo);
> > > + icsk->icsk_ulp_data = NULL;
> >
> > I think close only starts checking if ctx is NULL in patch 6.
> > Looks like some chunks of ctx checking/clearing got spread to
> > patch 1 and some to patch 6.
>
> Yeah, I thought the patches were easier to read this way but
> maybe not. Could add something in the commit log.

Ack! Let me try to get a full grip of patches 2 and 6 and come back
to this.

> > > + tls_ctx_free_wq(ctx);
> > > +
> > > + if (ctx->unhash)
> > > + ctx->unhash(sk);
> > > +}
> > > +
> > > static void tls_sk_proto_close(struct sock *sk, long timeout)
> > > {
> > > struct tls_context *ctx = tls_get_ctx(sk);