xfrm: remove eth_proto value from xfrm_state_afinfo

xfrm_prepare_input needs to lookup the state afinfo backend again to fetch
the address family ethernet protocol value.

There are only two address families, so a switch statement is simpler.
While at it, use u8 for family and proto and remove the owner member --
its not used anywhere.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

include/net/xfrm.h

@@ -346,10 +346,8 @@ void km_state_expired(struct xfrm_state *x, int hard, u32 portid);
 int __xfrm_state_delete(struct xfrm_state *x);
 
 struct xfrm_state_afinfo {
-	unsigned int			family;
-	unsigned int			proto;
-	__be16				eth_proto;
-	struct module			*owner;
+	u8				family;
+	u8				proto;
 	const struct xfrm_type		*type_map[IPPROTO_MAX];
 	const struct xfrm_type_offload	*type_offload_map[IPPROTO_MAX];
 

net/ipv4/xfrm4_state.c

@@ -34,8 +34,6 @@ int xfrm4_extract_header(struct sk_buff *skb)
 static struct xfrm_state_afinfo xfrm4_state_afinfo = {
 	.family			= AF_INET,
 	.proto			= IPPROTO_IPIP,
-	.eth_proto		= htons(ETH_P_IP),
-	.owner			= THIS_MODULE,
 	.output			= xfrm4_output,
 	.output_finish		= xfrm4_output_finish,
 	.extract_input		= xfrm4_extract_input,

net/ipv6/xfrm6_state.c

@@ -40,8 +40,6 @@ int xfrm6_extract_header(struct sk_buff *skb)
 static struct xfrm_state_afinfo xfrm6_state_afinfo = {
 	.family			= AF_INET6,
 	.proto			= IPPROTO_IPV6,
-	.eth_proto		= htons(ETH_P_IPV6),
-	.owner			= THIS_MODULE,
 	.output			= xfrm6_output,
 	.output_finish		= xfrm6_output_finish,
 	.extract_input		= xfrm6_extract_input,

net/xfrm/xfrm_input.c

@@ -359,28 +359,28 @@ static int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb)
 	afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode.family);
 	if (likely(afinfo))
 		err = afinfo->extract_input(x, skb);
+	rcu_read_unlock();
 
-	if (err) {
-		rcu_read_unlock();
+	if (err)
 		return err;
-	}
 
 	if (x->sel.family == AF_UNSPEC) {
 		inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
-		if (!inner_mode) {
-			rcu_read_unlock();
+		if (!inner_mode)
 			return -EAFNOSUPPORT;
-		}
 	}
 
-	afinfo = xfrm_state_afinfo_get_rcu(inner_mode->family);
-	if (unlikely(!afinfo)) {
-		rcu_read_unlock();
-		return -EAFNOSUPPORT;
+	switch (inner_mode->family) {
+	case AF_INET:
+		skb->protocol = htons(ETH_P_IP);
+		break;
+	case AF_INET6:
+		skb->protocol = htons(ETH_P_IPV6);
+	default:
+		WARN_ON_ONCE(1);
+		break;
 	}
 
-	skb->protocol = afinfo->eth_proto;
-	rcu_read_unlock();
 	return xfrm_inner_mode_encap_remove(x, inner_mode, skb);
 }