On 03/20/2018 08:53 AM, Ursula Braun wrote: > From: Hans Wippel <hwip...@linux.vnet.ibm.com> > > Currently, the SMC experimental TCP option in a SYN packet is lost on > the server side when SYN Cookies are active. However, the corresponding > SYNACK sent back to the client contains the SMC option. This causes an > inconsistent view of the SMC capabilities on the client and server. > > This patch disables the SMC option in the SYNACK when SYN Cookies are > active to avoid this issue. > > Signed-off-by: Hans Wippel <hwip...@linux.vnet.ibm.com> > Signed-off-by: Ursula Braun <ubr...@linux.vnet.ibm.com> > --- > net/ipv4/tcp_output.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c > index 383cac0ff0ec..22894514feae 100644 > --- a/net/ipv4/tcp_output.c > +++ b/net/ipv4/tcp_output.c > @@ -3199,6 +3199,8 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, > struct dst_entry *dst, > /* Under synflood, we do not attach skb to a socket, > * to avoid false sharing. > */ > + if (IS_ENABLED(CONFIG_SMC)) > + ireq->smc_ok = 0; > break; > case TCP_SYNACK_FASTOPEN: > /* sk is a const pointer, because we want to express multiple >
I disagree with net-next qualification. This fixes a bug, so please send it for net tree, and including an appropriate Fixes: tag. Thanks !
