Commit 752f36da authored by Pravin B Shelar's avatar Pravin B Shelar Committed by David S. Miller
Browse files

gre: export gre_build_header() function. 



This is required for ovs gre module.

Signed-off-by: default avatarPravin B Shelar <pshelar@nicira.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent bda7bb46

include/net/gre.h

+2 −0
Original line number Diff line number Diff line
@@ -32,6 +32,8 @@ struct gre_cisco_protocol { 


int gre_cisco_register(struct gre_cisco_protocol *proto);

int gre_cisco_unregister(struct gre_cisco_protocol *proto);

void gre_build_header(struct sk_buff *skb, const struct tnl_ptk_info *tpi,

		      int hdr_len);



static inline int ip_gre_calc_hlen(__be16 o_flags)

{

net/ipv4/gre.c

+32 −0
Original line number Diff line number Diff line
@@ -61,6 +61,38 @@ int gre_del_protocol(const struct gre_protocol *proto, u8 version) 
}

EXPORT_SYMBOL_GPL(gre_del_protocol);



void gre_build_header(struct sk_buff *skb, const struct tnl_ptk_info *tpi,

		      int hdr_len)

{

	struct gre_base_hdr *greh;



	skb_push(skb, hdr_len);



	greh = (struct gre_base_hdr *)skb->data;

	greh->flags = tnl_flags_to_gre_flags(tpi->flags);

	greh->protocol = tpi->proto;



	if (tpi->flags&(TUNNEL_KEY|TUNNEL_CSUM|TUNNEL_SEQ)) {

		__be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4);



		if (tpi->flags&TUNNEL_SEQ) {

			*ptr = tpi->seq;

			ptr--;

		}

		if (tpi->flags&TUNNEL_KEY) {

			*ptr = tpi->key;

			ptr--;

		}

		if (tpi->flags&TUNNEL_CSUM &&

		    !(skb_shinfo(skb)->gso_type & SKB_GSO_GRE)) {

			*ptr = 0;

			*(__sum16 *)ptr = csum_fold(skb_checksum(skb, 0,

								 skb->len, 0));

		}

	}

}

EXPORT_SYMBOL_GPL(gre_build_header);



static __sum16 check_checksum(struct sk_buff *skb)

{

	__sum16 csum = 0;

net/ipv4/ip_gre.c

+1 −39
Original line number Diff line number Diff line
@@ -248,40 +248,6 @@ error: 
	return ERR_PTR(err);

}



static struct sk_buff *gre_build_header(struct sk_buff *skb,

					const struct tnl_ptk_info *tpi,

					int hdr_len)

{

	struct gre_base_hdr *greh;



	skb_push(skb, hdr_len);



	greh = (struct gre_base_hdr *)skb->data;

	greh->flags = tnl_flags_to_gre_flags(tpi->flags);

	greh->protocol = tpi->proto;



	if (tpi->flags&(TUNNEL_KEY|TUNNEL_CSUM|TUNNEL_SEQ)) {

		__be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4);



		if (tpi->flags&TUNNEL_SEQ) {

			*ptr = tpi->seq;

			ptr--;

		}

		if (tpi->flags&TUNNEL_KEY) {

			*ptr = tpi->key;

			ptr--;

		}

		if (tpi->flags&TUNNEL_CSUM &&

		    !(skb_shinfo(skb)->gso_type & SKB_GSO_GRE)) {

			*(__sum16 *)ptr = 0;

			*(__sum16 *)ptr = csum_fold(skb_checksum(skb, 0,

								 skb->len, 0));

		}

	}



	return skb;

}



static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,

		       const struct iphdr *tnl_params,

		       __be16 proto)
@@ -302,11 +268,7 @@ static void __gre_xmit(struct sk_buff *skb, struct net_device *dev, 
	tpi.seq = htonl(tunnel->o_seqno);



	/* Push GRE header. */

	skb = gre_build_header(skb, &tpi, tunnel->hlen);

	if (unlikely(!skb)) {

		dev->stats.tx_dropped++;

		return;

	}

	gre_build_header(skb, &tpi, tunnel->hlen);



	ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol);

}