On Wed, Dec 16, 2020 at 5:56 PM Victor Stewart <v@nametag.social> wrote: > > This patch adds PROTO_CMSG_DATA_ONLY to inet_dgram_ops and inet6_dgram_ops so that UDP_SEGMENT (GSO) and UDP_GRO can be used through io_uring. > > GSO and GRO are vital to bring QUIC servers on par with TCP throughputs, and together offer a higher > throughput gain than io_uring alone (rate of data transit > considering), thus io_uring is presently the lesser performance choice. > > RE http://vger.kernel.org/lpc_net2018_talks/willemdebruijn-lpc2018-udpgso-paper-DRAFT-1.pdf, > GSO is about +~63% and GRO +~82%. > > this patch closes that loophole. > > Signed-off-by: Victor Stewart <v@nametag.social> Acked-by: Soheil Hassas Yeganeh <soheil@xxxxxxxxxx> Thanks for adding this! I audied the code and couldn't find an escalation path. +Jann could you please double check? > --- > net/ipv4/af_inet.c | 1 + > net/ipv6/af_inet6.c | 1 + > net/socket.c | 8 +++++--- > 3 files changed, 7 insertions(+), 3 deletions(-) > > diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c > index b7260c8cef2e..c9fd5e7cfd6e 100644 > --- a/net/ipv4/af_inet.c > +++ b/net/ipv4/af_inet.c > @@ -1052,6 +1052,7 @@ EXPORT_SYMBOL(inet_stream_ops); > > const struct proto_ops inet_dgram_ops = { > .family = PF_INET, > + .flags = PROTO_CMSG_DATA_ONLY, > .owner = THIS_MODULE, > .release = inet_release, > .bind = inet_bind, > diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c > index e648fbebb167..560f45009d06 100644 > --- a/net/ipv6/af_inet6.c > +++ b/net/ipv6/af_inet6.c > @@ -695,6 +695,7 @@ const struct proto_ops inet6_stream_ops = { > > const struct proto_ops inet6_dgram_ops = { > .family = PF_INET6, > + .flags = PROTO_CMSG_DATA_ONLY, > .owner = THIS_MODULE, > .release = inet6_release, > .bind = inet6_bind, > diff --git a/net/socket.c b/net/socket.c > index 6e6cccc2104f..6995835d6355 100644 > --- a/net/socket.c > +++ b/net/socket.c > @@ -2416,9 +2416,11 @@ static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg, > long __sys_sendmsg_sock(struct socket *sock, struct msghdr *msg, > unsigned int flags) > { > - /* disallow ancillary data requests from this path */ > - if (msg->msg_control || msg->msg_controllen) > - return -EINVAL; > + if (msg->msg_control || msg->msg_controllen) { > + /* disallow ancillary data reqs unless cmsg is plain data */ > + if (!(sock->ops->flags & PROTO_CMSG_DATA_ONLY)) > + return -EINVAL; > + } > > return ____sys_sendmsg(sock, msg, flags, NULL, 0); > } > -- > 2.26.2 >
