xfrm: remove hdr_offset indirection

After previous patches all remaining users set the function pointer to
the same function: xfrm6_find_1stfragopt.

So remove this function pointer and call ip6_find_1stfragopt directly.

Reduces size of xfrm_type to 64 bytes on 64bit platforms.

Signed-off-by: Florian Westphal <[e-mail]>
Signed-off-by: Steffen Klassert <[e-mail]>

include/net/xfrm.h

···
 	int			(*output)(struct xfrm_state *, struct sk_buff *pskb);
 	int			(*reject)(struct xfrm_state *, struct sk_buff *,
 					  const struct flowi *);
-	int			(*hdr_offset)(struct xfrm_state *, struct sk_buff *, u8 **);
 };
 
 int xfrm_register_type(const struct xfrm_type *type, unsigned short family);
···
 __be32 xfrm6_tunnel_spi_lookup(struct net *net, const xfrm_address_t *saddr);
 int xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 int xfrm6_output_finish(struct sock *sk, struct sk_buff *skb);
-int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
-			  u8 **prevhdr);
 
 #ifdef CONFIG_XFRM
 void xfrm6_local_rxpmtu(struct sk_buff *skb, u32 mtu);

net/ipv6/ah6.c

···
 	.destructor	= ah6_destroy,
 	.input		= ah6_input,
 	.output		= ah6_output,
-	.hdr_offset	= xfrm6_find_1stfragopt,
 };
 
 static struct xfrm6_protocol ah6_protocol = {

net/ipv6/esp6.c

···
 	.destructor	= esp6_destroy,
 	.input		= esp6_input,
 	.output		= esp6_output,
-	.hdr_offset	= xfrm6_find_1stfragopt,
 };
 
 static struct xfrm6_protocol esp6_protocol = {

net/ipv6/ipcomp6.c

···
 	.destructor	= ipcomp_destroy,
 	.input		= ipcomp_input,
 	.output		= ipcomp_output,
-	.hdr_offset	= xfrm6_find_1stfragopt,
 };
 
 static struct xfrm6_protocol ipcomp6_protocol = {

net/ipv6/xfrm6_output.c

···
 #include <net/ip6_route.h>
 #include <net/xfrm.h>
 
-int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
-			  u8 **prevhdr)
-{
-	return ip6_find_1stfragopt(skb, prevhdr);
-}
-EXPORT_SYMBOL(xfrm6_find_1stfragopt);
-
 void xfrm6_local_rxpmtu(struct sk_buff *skb, u32 mtu)
 {
 	struct flowi6 fl6;

net/xfrm/xfrm_output.c

···
 		break;
 	}
 
-	return x->type->hdr_offset(x, skb, prevhdr);
+	return ip6_find_1stfragopt(skb, prevhdr);
 }
 
 /* Add encapsulation header.