diff mbox series

[v4,net-next,2/2] udp: allow forwarding of plain (non-fraglisted) UDP GRO packets

Message ID 20210122181909.36340-3-alobakin@pm.me (mailing list archive)
State Accepted
Commit 36707061d6bafc254b3dfc23a8bb95451812b233
Delegated to: Netdev Maintainers
Headers show
Series udp: allow forwarding of plain (non-fraglisted) UDP GRO packets | expand

Checks

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 success CCed 4 of 4 maintainers
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: 8 this patch: 8
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 9 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 8 this patch: 8
netdev/header_inline success Link
netdev/stable success Stable not CCed

Commit Message

Alexander Lobakin Jan. 22, 2021, 6:20 p.m. UTC
Commit 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") actually
not only added a support for fraglisted UDP GRO, but also tweaked
some logics the way that non-fraglisted UDP GRO started to work for
forwarding too.
Commit 2e4ef10f5850 ("net: add GSO UDP L4 and GSO fraglists to the
list of software-backed types") added GSO UDP L4 to the list of
software GSO to allow virtual netdevs to forward them as is up to
the real drivers.

Tests showed that currently forwarding and NATing of plain UDP GRO
packets are performed fully correctly, regardless if the target
netdevice has a support for hardware/driver GSO UDP L4 or not.
Add the last element and allow to form plain UDP GRO packets if
we are on forwarding path, and the new NETIF_F_GRO_UDP_FWD is
enabled on a receiving netdevice.

If both NETIF_F_GRO_FRAGLIST and NETIF_F_GRO_UDP_FWD are set,
fraglisted GRO takes precedence. This keeps the current behaviour
and is generally more optimal for now, as the number of NICs with
hardware USO offload is relatively small.

Signed-off-by: Alexander Lobakin <alobakin@pm.me>
---
 net/ipv4/udp_offload.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index 1168d186cc43..41249705d9e9 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -460,7 +460,8 @@  struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb,
 	if (skb->dev->features & NETIF_F_GRO_FRAGLIST)
 		NAPI_GRO_CB(skb)->is_flist = sk ? !udp_sk(sk)->gro_enabled: 1;
 
-	if ((sk && udp_sk(sk)->gro_enabled) || NAPI_GRO_CB(skb)->is_flist) {
+	if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) ||
+	    (sk && udp_sk(sk)->gro_enabled) || NAPI_GRO_CB(skb)->is_flist) {
 		pp = call_gro_receive(udp_gro_receive_segment, head, skb);
 		return pp;
 	}