| Message ID | 88b8993a835f87440fd875bcbb080d8b7f6ab1bb.1616692794.git.pabeni@redhat.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | udp: GRO L4 improvements | expand |
On Thu, Mar 25, 2021 at 1:24 PM Paolo Abeni <pabeni@redhat.com> wrote: > > After the previous patch, the stack can do L4 UDP aggregation > on top of a UDP tunnel. > > In such scenario, udp{4,6}_gro_complete will be called twice. This function > will enter its is_flist branch immediately, even though that is only > correct on the second call, as GSO_FRAGLIST is only relevant for the > inner packet. > > Instead, we need to try first UDP tunnel-based aggregation, if the GRO > packet requires that. > > This patch changes udp{4,6}_gro_complete to skip the frag list processing > when while encap_mark == 1, identifying processing of the outer tunnel > header. > Additionally, clears the field in udp_gro_complete() so that we can enter > the frag list path on the next round, for the inner header. > > v1 -> v2: > - hopefully clarified the commit message > > Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Willem de Bruijn <willemb@google.com>
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index 25134a3548e99..54e06b88af69a 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -642,6 +642,11 @@ int udp_gro_complete(struct sk_buff *skb, int nhoff, skb_shinfo(skb)->gso_type = uh->check ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL; + /* clear the encap mark, so that inner frag_list gro_complete + * can take place + */ + NAPI_GRO_CB(skb)->encap_mark = 0; + /* Set encapsulation before calling into inner gro_complete() * functions to make them set up the inner offsets. */ @@ -665,7 +670,8 @@ INDIRECT_CALLABLE_SCOPE int udp4_gro_complete(struct sk_buff *skb, int nhoff) const struct iphdr *iph = ip_hdr(skb); struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); - if (NAPI_GRO_CB(skb)->is_flist) { + /* do fraglist only if there is no outer UDP encap (or we already processed it) */ + if (NAPI_GRO_CB(skb)->is_flist && !NAPI_GRO_CB(skb)->encap_mark) { uh->len = htons(skb->len - nhoff); skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4); diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c index faa823c242923..b3d9ed96e5ea5 100644 --- a/net/ipv6/udp_offload.c +++ b/net/ipv6/udp_offload.c @@ -163,7 +163,8 @@ INDIRECT_CALLABLE_SCOPE int udp6_gro_complete(struct sk_buff *skb, int nhoff) const struct ipv6hdr *ipv6h = ipv6_hdr(skb); struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); - if (NAPI_GRO_CB(skb)->is_flist) { + /* do fraglist only if there is no outer UDP encap (or we already processed it) */ + if (NAPI_GRO_CB(skb)->is_flist && !NAPI_GRO_CB(skb)->encap_mark) { uh->len = htons(skb->len - nhoff); skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4);
After the previous patch, the stack can do L4 UDP aggregation on top of a UDP tunnel. In such scenario, udp{4,6}_gro_complete will be called twice. This function will enter its is_flist branch immediately, even though that is only correct on the second call, as GSO_FRAGLIST is only relevant for the inner packet. Instead, we need to try first UDP tunnel-based aggregation, if the GRO packet requires that. This patch changes udp{4,6}_gro_complete to skip the frag list processing when while encap_mark == 1, identifying processing of the outer tunnel header. Additionally, clears the field in udp_gro_complete() so that we can enter the frag list path on the next round, for the inner header. v1 -> v2: - hopefully clarified the commit message Signed-off-by: Paolo Abeni <pabeni@redhat.com> --- net/ipv4/udp_offload.c | 8 +++++++- net/ipv6/udp_offload.c | 3 ++- 2 files changed, 9 insertions(+), 2 deletions(-)