esp: Add a software GRO codepath
This patch adds GRO ifrastructure and callbacks for ESP on
ipv4 and ipv6.
In case the GRO layer detects an ESP packet, the
esp{4,6}_gro_receive() function does a xfrm state lookup
and calls the xfrm input layer if it finds a matching state.
The packet will be decapsulated and reinjected it into layer 2.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/ipv4/xfrm4_input.c b/net/ipv4/xfrm4_input.c
index 62e1e72..1fc6841 100644
--- a/net/ipv4/xfrm4_input.c
+++ b/net/ipv4/xfrm4_input.c
@@ -40,6 +40,7 @@ static inline int xfrm4_rcv_encap_finish(struct net *net, struct sock *sk,
int xfrm4_transport_finish(struct sk_buff *skb, int async)
{
+ struct xfrm_offload *xo = xfrm_offload(skb);
struct iphdr *iph = ip_hdr(skb);
iph->protocol = XFRM_MODE_SKB_CB(skb)->protocol;
@@ -53,6 +54,11 @@ int xfrm4_transport_finish(struct sk_buff *skb, int async)
iph->tot_len = htons(skb->len);
ip_send_check(iph);
+ if (xo && (xo->flags & XFRM_GRO)) {
+ skb_mac_header_rebuild(skb);
+ return 0;
+ }
+
NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING,
dev_net(skb->dev), NULL, skb, skb->dev, NULL,
xfrm4_rcv_encap_finish);
