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Commit 95f5c64c authored by Tom Herbert's avatar Tom Herbert Committed by David S. Miller
Browse files

gre: Move utility functions to common headers 



Several of the GRE functions defined in net/ipv4/ip_gre.c are usable
for IPv6 GRE implementation (that is they are protocol agnostic).

These include:
  - GRE flag handling functions are move to gre.h
  - GRE build_header is moved to gre.h and renamed gre_build_header
  - parse_gre_header is moved to gre_demux.c and renamed gre_parse_header
  - iptunnel_pull_header is taken out of gre_parse_header. This is now
    done by caller. The header length is returned from gre_parse_header
    in an int* argument.

Signed-off-by: default avatarTom Herbert <tom@herbertland.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0d3c703a

include/net/gre.h

+60 −0
Original line number Diff line number Diff line
@@ -25,4 +25,64 @@ int gre_del_protocol(const struct gre_protocol *proto, u8 version); 


struct net_device *gretap_fb_dev_create(struct net *net, const char *name,

				       u8 name_assign_type);

int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,

		     bool *csum_err, int *hdr_len);



static inline int gre_calc_hlen(__be16 o_flags)

{

	int addend = 4;



	if (o_flags & TUNNEL_CSUM)

		addend += 4;

	if (o_flags & TUNNEL_KEY)

		addend += 4;

	if (o_flags & TUNNEL_SEQ)

		addend += 4;

	return addend;

}



static inline __be16 gre_flags_to_tnl_flags(__be16 flags)

{

	__be16 tflags = 0;



	if (flags & GRE_CSUM)

		tflags |= TUNNEL_CSUM;

	if (flags & GRE_ROUTING)

		tflags |= TUNNEL_ROUTING;

	if (flags & GRE_KEY)

		tflags |= TUNNEL_KEY;

	if (flags & GRE_SEQ)

		tflags |= TUNNEL_SEQ;

	if (flags & GRE_STRICT)

		tflags |= TUNNEL_STRICT;

	if (flags & GRE_REC)

		tflags |= TUNNEL_REC;

	if (flags & GRE_VERSION)

		tflags |= TUNNEL_VERSION;



	return tflags;

}



static inline __be16 gre_tnl_flags_to_gre_flags(__be16 tflags)

{

	__be16 flags = 0;



	if (tflags & TUNNEL_CSUM)

		flags |= GRE_CSUM;

	if (tflags & TUNNEL_ROUTING)

		flags |= GRE_ROUTING;

	if (tflags & TUNNEL_KEY)

		flags |= GRE_KEY;

	if (tflags & TUNNEL_SEQ)

		flags |= GRE_SEQ;

	if (tflags & TUNNEL_STRICT)

		flags |= GRE_STRICT;

	if (tflags & TUNNEL_REC)

		flags |= GRE_REC;

	if (tflags & TUNNEL_VERSION)

		flags |= GRE_VERSION;



	return flags;

}



#endif

net/ipv4/gre_demux.c

+64 −0
Original line number Diff line number Diff line
@@ -60,6 +60,70 @@ int gre_del_protocol(const struct gre_protocol *proto, u8 version) 
}

EXPORT_SYMBOL_GPL(gre_del_protocol);



int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,

		     bool *csum_err, int *ret_hdr_len)

{

	const struct gre_base_hdr *greh;

	__be32 *options;

	int hdr_len;



	if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr))))

		return -EINVAL;



	greh = (struct gre_base_hdr *)skb_transport_header(skb);

	if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING)))

		return -EINVAL;



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

	hdr_len = gre_calc_hlen(tpi->flags);



	if (!pskb_may_pull(skb, hdr_len))

		return -EINVAL;



	greh = (struct gre_base_hdr *)skb_transport_header(skb);

	tpi->proto = greh->protocol;



	options = (__be32 *)(greh + 1);

	if (greh->flags & GRE_CSUM) {

		if (skb_checksum_simple_validate(skb)) {

			*csum_err = true;

			return -EINVAL;

		}



		skb_checksum_try_convert(skb, IPPROTO_GRE, 0,

					 null_compute_pseudo);

		options++;

	}



	if (greh->flags & GRE_KEY) {

		tpi->key = *options;

		options++;

	} else {

		tpi->key = 0;

	}

	if (unlikely(greh->flags & GRE_SEQ)) {

		tpi->seq = *options;

		options++;

	} else {

		tpi->seq = 0;

	}

	/* WCCP version 1 and 2 protocol decoding.

	 * - Change protocol to IP

	 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header

	 */

	if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) {

		tpi->proto = htons(ETH_P_IP);

		if ((*(u8 *)options & 0xF0) != 0x40) {

			hdr_len += 4;

			if (!pskb_may_pull(skb, hdr_len))

				return -EINVAL;

		}

	}

	*ret_hdr_len = hdr_len;

	return 0;

}

EXPORT_SYMBOL(gre_parse_header);



static int gre_rcv(struct sk_buff *skb)

{

	const struct gre_protocol *proto;

net/ipv4/ip_gre.c

+20 −129
Original line number Diff line number Diff line
@@ -122,125 +122,6 @@ static int ipgre_tunnel_init(struct net_device *dev); 
static int ipgre_net_id __read_mostly;

static int gre_tap_net_id __read_mostly;



static int ip_gre_calc_hlen(__be16 o_flags)

{

	int addend = 4;



	if (o_flags & TUNNEL_CSUM)

		addend += 4;

	if (o_flags & TUNNEL_KEY)

		addend += 4;

	if (o_flags & TUNNEL_SEQ)

		addend += 4;

	return addend;

}



static __be16 gre_flags_to_tnl_flags(__be16 flags)

{

	__be16 tflags = 0;



	if (flags & GRE_CSUM)

		tflags |= TUNNEL_CSUM;

	if (flags & GRE_ROUTING)

		tflags |= TUNNEL_ROUTING;

	if (flags & GRE_KEY)

		tflags |= TUNNEL_KEY;

	if (flags & GRE_SEQ)

		tflags |= TUNNEL_SEQ;

	if (flags & GRE_STRICT)

		tflags |= TUNNEL_STRICT;

	if (flags & GRE_REC)

		tflags |= TUNNEL_REC;

	if (flags & GRE_VERSION)

		tflags |= TUNNEL_VERSION;



	return tflags;

}



static __be16 tnl_flags_to_gre_flags(__be16 tflags)

{

	__be16 flags = 0;



	if (tflags & TUNNEL_CSUM)

		flags |= GRE_CSUM;

	if (tflags & TUNNEL_ROUTING)

		flags |= GRE_ROUTING;

	if (tflags & TUNNEL_KEY)

		flags |= GRE_KEY;

	if (tflags & TUNNEL_SEQ)

		flags |= GRE_SEQ;

	if (tflags & TUNNEL_STRICT)

		flags |= GRE_STRICT;

	if (tflags & TUNNEL_REC)

		flags |= GRE_REC;

	if (tflags & TUNNEL_VERSION)

		flags |= GRE_VERSION;



	return flags;

}



static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,

			    bool *csum_err)

{

	const struct gre_base_hdr *greh;

	__be32 *options;

	int hdr_len;



	if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr))))

		return -EINVAL;



	greh = (struct gre_base_hdr *)skb_transport_header(skb);

	if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING)))

		return -EINVAL;



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

	hdr_len = ip_gre_calc_hlen(tpi->flags);



	if (!pskb_may_pull(skb, hdr_len))

		return -EINVAL;



	greh = (struct gre_base_hdr *)skb_transport_header(skb);

	tpi->proto = greh->protocol;



	options = (__be32 *)(greh + 1);

	if (greh->flags & GRE_CSUM) {

		if (skb_checksum_simple_validate(skb)) {

			*csum_err = true;

			return -EINVAL;

		}



		skb_checksum_try_convert(skb, IPPROTO_GRE, 0,

					 null_compute_pseudo);

		options++;

	}



	if (greh->flags & GRE_KEY) {

		tpi->key = *options;

		options++;

	} else {

		tpi->key = 0;

	}

	if (unlikely(greh->flags & GRE_SEQ)) {

		tpi->seq = *options;

		options++;

	} else {

		tpi->seq = 0;

	}

	/* WCCP version 1 and 2 protocol decoding.

	 * - Change protocol to IP

	 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header

	 */

	if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) {

		tpi->proto = htons(ETH_P_IP);

		if ((*(u8 *)options & 0xF0) != 0x40) {

			hdr_len += 4;

			if (!pskb_may_pull(skb, hdr_len))

				return -EINVAL;

		}

	}

	return iptunnel_pull_header(skb, hdr_len, tpi->proto, false);

}



static void ipgre_err(struct sk_buff *skb, u32 info,

		      const struct tnl_ptk_info *tpi)

{
@@ -340,12 +221,16 @@ static void gre_err(struct sk_buff *skb, u32 info) 
	const int code = icmp_hdr(skb)->code;

	struct tnl_ptk_info tpi;

	bool csum_err = false;

	int hdr_len;



	if (parse_gre_header(skb, &tpi, &csum_err)) {

	if (gre_parse_header(skb, &tpi, &csum_err, &hdr_len)) {

		if (!csum_err)		/* ignore csum errors. */

			return;

	}



	if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))

		return;



	if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {

		ipv4_update_pmtu(skb, dev_net(skb->dev), info,

				 skb->dev->ifindex, 0, IPPROTO_GRE, 0);
@@ -419,6 +304,7 @@ static int gre_rcv(struct sk_buff *skb) 
{

	struct tnl_ptk_info tpi;

	bool csum_err = false;

	int hdr_len;



#ifdef CONFIG_NET_IPGRE_BROADCAST

	if (ipv4_is_multicast(ip_hdr(skb)->daddr)) {
@@ -428,7 +314,10 @@ static int gre_rcv(struct sk_buff *skb) 
	}

#endif



	if (parse_gre_header(skb, &tpi, &csum_err) < 0)

	if (gre_parse_header(skb, &tpi, &csum_err, &hdr_len) < 0)

		goto drop;



	if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))

		goto drop;



	if (ipgre_rcv(skb, &tpi) == PACKET_RCVD)
@@ -460,7 +349,7 @@ static void build_header(struct sk_buff *skb, int hdr_len, __be16 flags, 


	skb_reset_transport_header(skb);

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

	greh->flags = tnl_flags_to_gre_flags(flags);

	greh->flags = gre_tnl_flags_to_gre_flags(flags);

	greh->protocol = proto;



	if (flags & (TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_SEQ)) {
@@ -552,7 +441,7 @@ static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev) 
					  fl.saddr);

	}



	tunnel_hlen = ip_gre_calc_hlen(key->tun_flags);

	tunnel_hlen = gre_calc_hlen(key->tun_flags);



	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len

			+ tunnel_hlen + sizeof(struct iphdr);
@@ -694,8 +583,8 @@ static int ipgre_tunnel_ioctl(struct net_device *dev, 
	if (err)

		return err;



	p.i_flags = tnl_flags_to_gre_flags(p.i_flags);

	p.o_flags = tnl_flags_to_gre_flags(p.o_flags);

	p.i_flags = gre_tnl_flags_to_gre_flags(p.i_flags);

	p.o_flags = gre_tnl_flags_to_gre_flags(p.o_flags);



	if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))

		return -EFAULT;
@@ -739,7 +628,7 @@ static int ipgre_header(struct sk_buff *skb, struct net_device *dev, 


	iph = (struct iphdr *)skb_push(skb, t->hlen + sizeof(*iph));

	greh = (struct gre_base_hdr *)(iph+1);

	greh->flags = tnl_flags_to_gre_flags(t->parms.o_flags);

	greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags);

	greh->protocol = htons(type);



	memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
@@ -840,7 +729,7 @@ static void __gre_tunnel_init(struct net_device *dev) 
	int t_hlen;



	tunnel = netdev_priv(dev);

	tunnel->tun_hlen = ip_gre_calc_hlen(tunnel->parms.o_flags);

	tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);

	tunnel->parms.iph.protocol = IPPROTO_GRE;



	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
@@ -1155,8 +1044,10 @@ static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) 
	struct ip_tunnel_parm *p = &t->parms;



	if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||

	    nla_put_be16(skb, IFLA_GRE_IFLAGS, tnl_flags_to_gre_flags(p->i_flags)) ||

	    nla_put_be16(skb, IFLA_GRE_OFLAGS, tnl_flags_to_gre_flags(p->o_flags)) ||

	    nla_put_be16(skb, IFLA_GRE_IFLAGS,

			 gre_tnl_flags_to_gre_flags(p->i_flags)) ||

	    nla_put_be16(skb, IFLA_GRE_OFLAGS,

			 gre_tnl_flags_to_gre_flags(p->o_flags)) ||

	    nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||

	    nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||

	    nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||