| Message ID | 7fa75957409a3f5d14198261a7eddb2bf1bff8e1.1616692794.git.pabeni@redhat.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | udp: GRO L4 improvements | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for net-next |
| netdev/subject_prefix | success | Link |
| netdev/cc_maintainers | warning | 2 maintainers not CCed: yoshfuji@linux-ipv6.org dsahern@kernel.org |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 3175 this patch: 3175 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | warning | WARNING: line length of 85 exceeds 80 columns WARNING: line length of 93 exceeds 80 columns |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 3406 this patch: 3406 |
| netdev/header_inline | success | Link |
On Thu, Mar 25, 2021 at 1:24 PM Paolo Abeni <pabeni@redhat.com> wrote: > > Currently the UDP protocol delivers GSO_FRAGLIST packets to > the sockets without the expected segmentation. > > This change addresses the issue introducing and maintaining > a couple of new fields to explicitly accept SKB_GSO_UDP_L4 > or GSO_FRAGLIST packets. Additionally updates udp_unexpected_gso() > accordingly. > > UDP sockets enabling UDP_GRO stil keep accept_udp_fraglist > zeroed. > > v1 -> v2: > - use 2 bits instead of a whole GSO bitmask (Willem) > > Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") > Signed-off-by: Paolo Abeni <pabeni@redhat.com> This looks good to me in principle, thanks for the revision. I hadn't fully appreciated that gro_enabled implies accept_udp_l4, but not necessarily vice versa. It is equivalent to (accept_udp_l4 && !up->gro_receive), right? Could the extra bit be avoided with " + /* Prefer fraglist GRO unless target is a socket with UDP_GRO, + * which requires all but last segments to be of same gso_size, passed in cmsg */ if (skb->dev->features & NETIF_F_GRO_FRAGLIST) - NAPI_GRO_CB(skb)->is_flist = sk ? !udp_sk(sk)->gro_enabled: 1; + NAPI_GRO_CB(skb)->is_flist = sk ? (!udp_sk(sk)->gro_enabled || udp_sk(sk)->accept_udp_fraglist) : 1; + /* Apply transport layer GRO if forwarding is enabled or the flow lands at a local socket */ if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) || (sk && udp_sk(sk)->gro_enabled && !up->encap_rcv) || NAPI_GRO_CB(skb)->is_flist) { pp = call_gro_receive(udp_gro_receive_segment, head, skb); return pp; } + /* Continue with tunnel GRO */ " .. not that the extra bit matters a lot. And these two conditions with gro_enabled are not very obvious. Just a thought.
On Fri, 2021-03-26 at 14:15 -0400, Willem de Bruijn wrote: > On Thu, Mar 25, 2021 at 1:24 PM Paolo Abeni <pabeni@redhat.com> wrote: > > Currently the UDP protocol delivers GSO_FRAGLIST packets to > > the sockets without the expected segmentation. > > > > This change addresses the issue introducing and maintaining > > a couple of new fields to explicitly accept SKB_GSO_UDP_L4 > > or GSO_FRAGLIST packets. Additionally updates udp_unexpected_gso() > > accordingly. > > > > UDP sockets enabling UDP_GRO stil keep accept_udp_fraglist > > zeroed. > > > > v1 -> v2: > > - use 2 bits instead of a whole GSO bitmask (Willem) > > > > Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") > > Signed-off-by: Paolo Abeni <pabeni@redhat.com> > > This looks good to me in principle, thanks for the revision. > > I hadn't fully appreciated that gro_enabled implies accept_udp_l4, but > not necessarily vice versa. > > It is equivalent to (accept_udp_l4 && !up->gro_receive), right? In this series, yes. > Could the extra bit be avoided with > > " > + /* Prefer fraglist GRO unless target is a socket with UDP_GRO, > + * which requires all but last segments to be of same gso_size, > passed in cmsg */ > if (skb->dev->features & NETIF_F_GRO_FRAGLIST) > - NAPI_GRO_CB(skb)->is_flist = sk ? !udp_sk(sk)->gro_enabled: 1; > + NAPI_GRO_CB(skb)->is_flist = sk ? > (!udp_sk(sk)->gro_enabled || udp_sk(sk)->accept_udp_fraglist) : 1; This is not ovious at all to me. > + /* Apply transport layer GRO if forwarding is enabled or the > flow lands at a local socket */ > if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) || > (sk && udp_sk(sk)->gro_enabled && !up->encap_rcv) || > NAPI_GRO_CB(skb)->is_flist) { > pp = call_gro_receive(udp_gro_receive_segment, head, skb); > return pp; > } > > + /* Continue with tunnel GRO */ > " > > .. not that the extra bit matters a lot. And these two conditions with > gro_enabled are not very obvious. > > Just a thought. Overall looks more complex to me. I would keep the extra bit, unless you have strong opinion. Side note: I was wondering about a follow-up to simplify the condition: if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) || (sk && udp_sk(sk)->gro_enabled && !up->encap_rcv) || NAPI_GRO_CB(skb)->is_flist) { Since UDP sockets could process (segmenting as needed) unexpected GSO packets, we could always do 'NETIF_F_GRO_UDP_FWD', when enabled on the device level. The above becomes: if (skb->dev->features & NETIF_F_GRO_UDP_FWD) || (sk && udp_sk(sk)->gro_enabled && !up->encap_rcv) || NAPI_GRO_CB(skb)->is_flist) { which is hopefully more clear (and simpler). As said, non for this series anyhow. Thanks, Paolo
On Mon, Mar 29, 2021 at 4:14 AM Paolo Abeni <pabeni@redhat.com> wrote: > > On Fri, 2021-03-26 at 14:15 -0400, Willem de Bruijn wrote: > > On Thu, Mar 25, 2021 at 1:24 PM Paolo Abeni <pabeni@redhat.com> wrote: > > > Currently the UDP protocol delivers GSO_FRAGLIST packets to > > > the sockets without the expected segmentation. > > > > > > This change addresses the issue introducing and maintaining > > > a couple of new fields to explicitly accept SKB_GSO_UDP_L4 > > > or GSO_FRAGLIST packets. Additionally updates udp_unexpected_gso() > > > accordingly. > > > > > > UDP sockets enabling UDP_GRO stil keep accept_udp_fraglist > > > zeroed. > > > > > > v1 -> v2: > > > - use 2 bits instead of a whole GSO bitmask (Willem) > > > > > > Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") > > > Signed-off-by: Paolo Abeni <pabeni@redhat.com> > > > > This looks good to me in principle, thanks for the revision. > > > > I hadn't fully appreciated that gro_enabled implies accept_udp_l4, but > > not necessarily vice versa. > > > > It is equivalent to (accept_udp_l4 && !up->gro_receive), right? > > In this series, yes. > > > Could the extra bit be avoided with > > > > " > > + /* Prefer fraglist GRO unless target is a socket with UDP_GRO, > > + * which requires all but last segments to be of same gso_size, > > passed in cmsg */ > > if (skb->dev->features & NETIF_F_GRO_FRAGLIST) > > - NAPI_GRO_CB(skb)->is_flist = sk ? !udp_sk(sk)->gro_enabled: 1; > > + NAPI_GRO_CB(skb)->is_flist = sk ? > > (!udp_sk(sk)->gro_enabled || udp_sk(sk)->accept_udp_fraglist) : 1; > > This is not ovious at all to me. > > > + /* Apply transport layer GRO if forwarding is enabled or the > > flow lands at a local socket */ > > if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) || > > (sk && udp_sk(sk)->gro_enabled && !up->encap_rcv) || > > NAPI_GRO_CB(skb)->is_flist) { > > pp = call_gro_receive(udp_gro_receive_segment, head, skb); > > return pp; > > } > > > > + /* Continue with tunnel GRO */ > > " > > > > .. not that the extra bit matters a lot. And these two conditions with > > gro_enabled are not very obvious. > > > > Just a thought. > > Overall looks more complex to me. I would keep the extra bit, unless > you have strong opinion. Sounds good. > Side note: I was wondering about a follow-up to simplify the condition: > > if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) || > (sk && udp_sk(sk)->gro_enabled && !up->encap_rcv) || NAPI_GRO_CB(skb)->is_flist) { > > Since UDP sockets could process (segmenting as needed) unexpected GSO > packets, we could always do 'NETIF_F_GRO_UDP_FWD', when enabled on the > device level. The above becomes: > > if (skb->dev->features & NETIF_F_GRO_UDP_FWD) || > (sk && udp_sk(sk)->gro_enabled && !up->encap_rcv) || > NAPI_GRO_CB(skb)->is_flist) { > > which is hopefully more clear (and simpler). As said, non for this > series anyhow. UDP sockets can segment, but it is expensive. In this case I think the simplification is not worth the possible regression.
On Mon, 2021-03-29 at 08:31 -0400, Willem de Bruijn wrote: > On Mon, Mar 29, 2021 at 4:14 AM Paolo Abeni <pabeni@redhat.com> wrote: > > On Fri, 2021-03-26 at 14:15 -0400, Willem de Bruijn wrote: > > > On Thu, Mar 25, 2021 at 1:24 PM Paolo Abeni <pabeni@redhat.com> wrote: > > > > Currently the UDP protocol delivers GSO_FRAGLIST packets to > > > > the sockets without the expected segmentation. > > > > > > > > This change addresses the issue introducing and maintaining > > > > a couple of new fields to explicitly accept SKB_GSO_UDP_L4 > > > > or GSO_FRAGLIST packets. Additionally updates udp_unexpected_gso() > > > > accordingly. > > > > > > > > UDP sockets enabling UDP_GRO stil keep accept_udp_fraglist > > > > zeroed. > > > > > > > > v1 -> v2: > > > > - use 2 bits instead of a whole GSO bitmask (Willem) > > > > > > > > Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") > > > > Signed-off-by: Paolo Abeni <pabeni@redhat.com> > > > > > > This looks good to me in principle, thanks for the revision. > > > > > > I hadn't fully appreciated that gro_enabled implies accept_udp_l4, but > > > not necessarily vice versa. > > > > > > It is equivalent to (accept_udp_l4 && !up->gro_receive), right? > > > > In this series, yes. > > > > > Could the extra bit be avoided with > > > > > > " > > > + /* Prefer fraglist GRO unless target is a socket with UDP_GRO, > > > + * which requires all but last segments to be of same gso_size, > > > passed in cmsg */ > > > if (skb->dev->features & NETIF_F_GRO_FRAGLIST) > > > - NAPI_GRO_CB(skb)->is_flist = sk ? !udp_sk(sk)->gro_enabled: 1; > > > + NAPI_GRO_CB(skb)->is_flist = sk ? > > > (!udp_sk(sk)->gro_enabled || udp_sk(sk)->accept_udp_fraglist) : 1; > > > > This is not ovious at all to me. > > > > > + /* Apply transport layer GRO if forwarding is enabled or the > > > flow lands at a local socket */ > > > if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) || > > > (sk && udp_sk(sk)->gro_enabled && !up->encap_rcv) || > > > NAPI_GRO_CB(skb)->is_flist) { > > > pp = call_gro_receive(udp_gro_receive_segment, head, skb); > > > return pp; > > > } > > > > > > + /* Continue with tunnel GRO */ > > > " > > > > > > .. not that the extra bit matters a lot. And these two conditions with > > > gro_enabled are not very obvious. > > > > > > Just a thought. > > > > Overall looks more complex to me. I would keep the extra bit, unless > > you have strong opinion. > > Sounds good. > > > Side note: I was wondering about a follow-up to simplify the condition: > > > > if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) || > > (sk && udp_sk(sk)->gro_enabled && !up->encap_rcv) || NAPI_GRO_CB(skb)->is_flist) { > > > > Since UDP sockets could process (segmenting as needed) unexpected GSO > > packets, we could always do 'NETIF_F_GRO_UDP_FWD', when enabled on the > > device level. The above becomes: > > > > if (skb->dev->features & NETIF_F_GRO_UDP_FWD) || > > (sk && udp_sk(sk)->gro_enabled && !up->encap_rcv) || > > NAPI_GRO_CB(skb)->is_flist) { > > > > which is hopefully more clear (and simpler). As said, non for this > > series anyhow. > > UDP sockets can segment, but it is expensive. In this case I think the > simplification is not worth the possible regression. No strong opinion here, I will not do the thing mentioned above. Thanks! Paolo
diff --git a/include/linux/udp.h b/include/linux/udp.h index aa84597bdc33c..ae58ff3b6b5b8 100644 --- a/include/linux/udp.h +++ b/include/linux/udp.h @@ -51,7 +51,9 @@ struct udp_sock { * different encapsulation layer set * this */ - gro_enabled:1; /* Can accept GRO packets */ + gro_enabled:1, /* Request GRO aggregation */ + accept_udp_l4:1, + accept_udp_fraglist:1; /* * Following member retains the information to create a UDP header * when the socket is uncorked. @@ -131,8 +133,16 @@ static inline void udp_cmsg_recv(struct msghdr *msg, struct sock *sk, static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb) { - return !udp_sk(sk)->gro_enabled && skb_is_gso(skb) && - skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4; + if (!skb_is_gso(skb)) + return false; + + if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && !udp_sk(sk)->accept_udp_l4) + return true; + + if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST && !udp_sk(sk)->accept_udp_fraglist) + return true; + + return false; } #define udp_portaddr_for_each_entry(__sk, list) \ diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index fe85dcf8c0087..c0695ce42dc53 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -2666,9 +2666,12 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname, case UDP_GRO: lock_sock(sk); + + /* when enabling GRO, accept the related GSO packet type */ if (valbool) udp_tunnel_encap_enable(sk->sk_socket); up->gro_enabled = valbool; + up->accept_udp_l4 = valbool; release_sock(sk); break;
Currently the UDP protocol delivers GSO_FRAGLIST packets to the sockets without the expected segmentation. This change addresses the issue introducing and maintaining a couple of new fields to explicitly accept SKB_GSO_UDP_L4 or GSO_FRAGLIST packets. Additionally updates udp_unexpected_gso() accordingly. UDP sockets enabling UDP_GRO stil keep accept_udp_fraglist zeroed. v1 -> v2: - use 2 bits instead of a whole GSO bitmask (Willem) Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") Signed-off-by: Paolo Abeni <pabeni@redhat.com> --- include/linux/udp.h | 16 +++++++++++++--- net/ipv4/udp.c | 3 +++ 2 files changed, 16 insertions(+), 3 deletions(-)