xfrm: replay: remove recheck indirection

Adds new xfrm_replay_recheck() helper and calls it from
xfrm input path instead of the indirection.

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

include/net/xfrm.h

@@ -309,9 +309,6 @@ struct xfrm_replay {
 	int	(*check)(struct xfrm_state *x,
 			 struct sk_buff *skb,
 			 __be32 net_seq);
-	int	(*recheck)(struct xfrm_state *x,
-			   struct sk_buff *skb,
-			   __be32 net_seq);
 	int	(*overflow)(struct xfrm_state *x, struct sk_buff *skb);
 };
 
@@ -1723,6 +1720,7 @@ static inline int xfrm_policy_id2dir(u32 index)
 #ifdef CONFIG_XFRM
 void xfrm_replay_advance(struct xfrm_state *x, __be32 net_seq);
 void xfrm_replay_notify(struct xfrm_state *x, int event);
+int xfrm_replay_recheck(struct xfrm_state *x, struct sk_buff *skb, __be32 net_seq);
 
 static inline int xfrm_aevent_is_on(struct net *net)
 {

net/xfrm/xfrm_input.c

@@ -660,7 +660,7 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
 		/* only the first xfrm gets the encap type */
 		encap_type = 0;
 
-		if (x->repl->recheck(x, skb, seq)) {
+		if (xfrm_replay_recheck(x, skb, seq)) {
 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
 			goto drop_unlock;
 		}

net/xfrm/xfrm_replay.c

@@ -519,6 +519,22 @@ static int xfrm_replay_recheck_esn(struct xfrm_state *x,
 	return xfrm_replay_check_esn(x, skb, net_seq);
 }
 
+int xfrm_replay_recheck(struct xfrm_state *x,
+			struct sk_buff *skb, __be32 net_seq)
+{
+	switch (x->repl_mode) {
+	case XFRM_REPLAY_MODE_LEGACY:
+		break;
+	case XFRM_REPLAY_MODE_BMP:
+		/* no special recheck treatment */
+		return xfrm_replay_check_bmp(x, skb, net_seq);
+	case XFRM_REPLAY_MODE_ESN:
+		return xfrm_replay_recheck_esn(x, skb, net_seq);
+	}
+
+	return xfrm_replay_check(x, skb, net_seq);
+}
+
 static void xfrm_replay_advance_esn(struct xfrm_state *x, __be32 net_seq)
 {
 	unsigned int bitnr, nr, i;
@@ -708,37 +724,31 @@ static int xfrm_replay_overflow_offload_esn(struct xfrm_state *x, struct sk_buff
 
 static const struct xfrm_replay xfrm_replay_legacy = {
 	.check		= xfrm_replay_check,
-	.recheck	= xfrm_replay_check,
 	.overflow	= xfrm_replay_overflow_offload,
 };
 
 static const struct xfrm_replay xfrm_replay_bmp = {
 	.check		= xfrm_replay_check_bmp,
-	.recheck	= xfrm_replay_check_bmp,
 	.overflow	= xfrm_replay_overflow_offload_bmp,
 };
 
 static const struct xfrm_replay xfrm_replay_esn = {
 	.check		= xfrm_replay_check_esn,
-	.recheck	= xfrm_replay_recheck_esn,
 	.overflow	= xfrm_replay_overflow_offload_esn,
 };
 #else
 static const struct xfrm_replay xfrm_replay_legacy = {
 	.check		= xfrm_replay_check,
-	.recheck	= xfrm_replay_check,
 	.overflow	= xfrm_replay_overflow,
 };
 
 static const struct xfrm_replay xfrm_replay_bmp = {
 	.check		= xfrm_replay_check_bmp,
-	.recheck	= xfrm_replay_check_bmp,
 	.overflow	= xfrm_replay_overflow_bmp,
 };
 
 static const struct xfrm_replay xfrm_replay_esn = {
 	.check		= xfrm_replay_check_esn,
-	.recheck	= xfrm_replay_recheck_esn,
 	.overflow	= xfrm_replay_overflow_esn,
 };
 #endif