Commit e0e3070a authored by Paolo Abeni's avatar Paolo Abeni Committed by David S. Miller
Browse files

udp: properly complete L4 GRO over UDP tunnel packet 



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

Reviewed-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 18f25dc3

net/ipv4/udp_offload.c

+7 −1
Original line number Diff line number Diff line
@@ -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);

net/ipv6/udp_offload.c

+2 −1
Original line number Diff line number Diff line
@@ -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);