xfrm: Fix GSO for IPsec with GRE tunnel.
We reset the encapsulation field of the skb too early
in xfrm_output. As a result, the GRE GSO handler does
not segment the packets. This leads to a performance
drop down. We fix this by resetting the encapsulation
field right before we do the transformation, when
the inner headers become invalid.
Fixes: f1bd7d659ef0 ("xfrm: Add encapsulation header offsets while SKB is not encrypted")
Reported-by: Vicente De Luca <vdeluca@zendesk.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index 31a2e6d..73ad8c8 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -105,6 +105,9 @@ static int xfrm_output_one(struct sk_buff *skb, int err)
if (xfrm_offload(skb)) {
x->type_offload->encap(x, skb);
} else {
+ /* Inner headers are invalid now. */
+ skb->encapsulation = 0;
+
err = x->type->output(x, skb);
if (err == -EINPROGRESS)
goto out;
@@ -208,7 +211,6 @@ int xfrm_output(struct sock *sk, struct sk_buff *skb)
int err;
secpath_reset(skb);
- skb->encapsulation = 0;
if (xfrm_dev_offload_ok(skb, x)) {
struct sec_path *sp;