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Commit 182a352d authored by Tom Herbert's avatar Tom Herbert Committed by David S. Miller
Browse files

gre: Create common functions for transmit 



Create common functions for both IPv4 and IPv6 GRE in transmit. These
are put into gre.h.

Common functions are for:
  - GRE checksum calculation. Move gre_checksum to gre.h.
  - Building a GRE header. Move GRE build_header and rename
    gre_build_header.

Signed-off-by: default avatarTom Herbert <tom@herbertland.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8eb30be0

include/net/gre.h

+44 −0
Original line number Diff line number Diff line
@@ -85,4 +85,48 @@ static inline __be16 gre_tnl_flags_to_gre_flags(__be16 tflags) 
	return flags;

}



static inline __sum16 gre_checksum(struct sk_buff *skb)

{

	__wsum csum;



	if (skb->ip_summed == CHECKSUM_PARTIAL)

		csum = lco_csum(skb);

	else

		csum = skb_checksum(skb, 0, skb->len, 0);

	return csum_fold(csum);

}



static inline void gre_build_header(struct sk_buff *skb, int hdr_len,

				    __be16 flags, __be16 proto,

				    __be32 key, __be32 seq)

{

	struct gre_base_hdr *greh;



	skb_push(skb, hdr_len);



	skb_reset_transport_header(skb);

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

	greh->flags = gre_tnl_flags_to_gre_flags(flags);

	greh->protocol = proto;



	if (flags & (TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_SEQ)) {

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



		if (flags & TUNNEL_SEQ) {

			*ptr = seq;

			ptr--;

		}

		if (flags & TUNNEL_KEY) {

			*ptr = key;

			ptr--;

		}

		if (flags & TUNNEL_CSUM &&

		    !(skb_shinfo(skb)->gso_type &

		      (SKB_GSO_GRE | SKB_GSO_GRE_CSUM))) {

			*ptr = 0;

			*(__sum16 *)ptr = gre_checksum(skb);

		}

	}

}



#endif

net/ipv4/ip_gre.c

+5 −47
Original line number Diff line number Diff line
@@ -329,49 +329,6 @@ static int gre_rcv(struct sk_buff *skb) 
	return 0;

}



static __sum16 gre_checksum(struct sk_buff *skb)

{

	__wsum csum;



	if (skb->ip_summed == CHECKSUM_PARTIAL)

		csum = lco_csum(skb);

	else

		csum = skb_checksum(skb, 0, skb->len, 0);

	return csum_fold(csum);

}



static void build_header(struct sk_buff *skb, int hdr_len, __be16 flags,

			 __be16 proto, __be32 key, __be32 seq)

{

	struct gre_base_hdr *greh;



	skb_push(skb, hdr_len);



	skb_reset_transport_header(skb);

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

	greh->flags = gre_tnl_flags_to_gre_flags(flags);

	greh->protocol = proto;



	if (flags & (TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_SEQ)) {

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



		if (flags & TUNNEL_SEQ) {

			*ptr = seq;

			ptr--;

		}

		if (flags & TUNNEL_KEY) {

			*ptr = key;

			ptr--;

		}

		if (flags & TUNNEL_CSUM &&

		    !(skb_shinfo(skb)->gso_type &

		      (SKB_GSO_GRE | SKB_GSO_GRE_CSUM))) {

			*ptr = 0;

			*(__sum16 *)ptr = gre_checksum(skb);

		}

	}

}



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

		       const struct iphdr *tnl_params,

		       __be16 proto)
@@ -382,8 +339,9 @@ static void __gre_xmit(struct sk_buff *skb, struct net_device *dev, 
		tunnel->o_seqno++;



	/* Push GRE header. */

	build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,

		     proto, tunnel->parms.o_key, htonl(tunnel->o_seqno));

	gre_build_header(skb, tunnel->tun_hlen,

			 tunnel->parms.o_flags, proto, tunnel->parms.o_key,

			 htonl(tunnel->o_seqno));



	skb_set_inner_protocol(skb, proto);

	ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol);
@@ -460,7 +418,7 @@ static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev) 
		goto err_free_rt;



	flags = tun_info->key.tun_flags & (TUNNEL_CSUM | TUNNEL_KEY);

	build_header(skb, tunnel_hlen, flags, htons(ETH_P_TEB),

	gre_build_header(skb, tunnel_hlen, flags, htons(ETH_P_TEB),

			 tunnel_id_to_key(tun_info->key.tun_id), 0);



	df = key->tun_flags & TUNNEL_DONT_FRAGMENT ?  htons(IP_DF) : 0;