From 68c331631143f5f039baac99a650e0b9e1ea02b6 Mon Sep 17 00:00:00 2001 From: Pravin B Shelar Date: Thu, 14 Feb 2013 14:02:41 +0000 Subject: v4 GRE: Add TCP segmentation offload for GRE Following patch adds GRE protocol offload handler so that skb_gso_segment() can segment GRE packets. SKB GSO CB is added to keep track of total header length so that skb_segment can push entire header. e.g. in case of GRE, skb_segment need to push inner and outer headers to every segment. New NETIF_F_GRE_GSO feature is added for devices which support HW GRE TSO offload. Currently none of devices support it therefore GRE GSO always fall backs to software GSO. [ Compute pkt_len before ip_local_out() invocation. -DaveM ] Signed-off-by: Pravin B Shelar Signed-off-by: David S. Miller --- include/linux/skbuff.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'include/linux/skbuff.h') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index ca6ee7d93edb..821c7f45d2a7 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -314,6 +314,8 @@ enum { SKB_GSO_TCPV6 = 1 << 4, SKB_GSO_FCOE = 1 << 5, + + SKB_GSO_GRE = 1 << 6, }; #if BITS_PER_LONG > 32 @@ -2732,6 +2734,21 @@ static inline struct sec_path *skb_sec_path(struct sk_buff *skb) } #endif +/* Keeps track of mac header offset relative to skb->head. + * It is useful for TSO of Tunneling protocol. e.g. GRE. + * For non-tunnel skb it points to skb_mac_header() and for + * tunnel skb it points to outer mac header. */ +struct skb_gso_cb { + int mac_offset; +}; +#define SKB_GSO_CB(skb) ((struct skb_gso_cb *)(skb)->cb) + +static inline int skb_tnl_header_len(const struct sk_buff *inner_skb) +{ + return (skb_mac_header(inner_skb) - inner_skb->head) - + SKB_GSO_CB(inner_skb)->mac_offset; +} + static inline bool skb_is_gso(const struct sk_buff *skb) { return skb_shinfo(skb)->gso_size; -- cgit v1.2.3