xfrm: replay: avoid replay indirection

Add and use xfrm_replay_check helper instead of indirection.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

include/net/xfrm.h

@@ -306,9 +306,6 @@ struct km_event {
 };
 
 struct xfrm_replay {
-	int	(*check)(struct xfrm_state *x,
-			 struct sk_buff *skb,
-			 __be32 net_seq);
 	int	(*overflow)(struct xfrm_state *x, struct sk_buff *skb);
 };
 
@@ -1719,6 +1716,7 @@ static inline int xfrm_policy_id2dir(u32 index)
 
 #ifdef CONFIG_XFRM
 void xfrm_replay_advance(struct xfrm_state *x, __be32 net_seq);
+int xfrm_replay_check(struct xfrm_state *x, struct sk_buff *skb, __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);
 

net/xfrm/xfrm_input.c

@@ -612,7 +612,7 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
 			goto drop_unlock;
 		}
 
-		if (x->repl->check(x, skb, seq)) {
+		if (xfrm_replay_check(x, skb, seq)) {
 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
 			goto drop_unlock;
 		}

net/xfrm/xfrm_replay.c

@@ -118,7 +118,7 @@ static int xfrm_replay_overflow(struct xfrm_state *x, struct sk_buff *skb)
 	return err;
 }
 
-static int xfrm_replay_check(struct xfrm_state *x,
+static int xfrm_replay_check_legacy(struct xfrm_state *x,
 				    struct sk_buff *skb, __be32 net_seq)
 {
 	u32 diff;
@@ -507,6 +507,21 @@ static int xfrm_replay_check_esn(struct xfrm_state *x,
 	return -EINVAL;
 }
 
+int xfrm_replay_check(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:
+		return xfrm_replay_check_bmp(x, skb, net_seq);
+	case XFRM_REPLAY_MODE_ESN:
+		return xfrm_replay_check_esn(x, skb, net_seq);
+	}
+
+	return xfrm_replay_check_legacy(x, skb, net_seq);
+}
+
 static int xfrm_replay_recheck_esn(struct xfrm_state *x,
 				   struct sk_buff *skb, __be32 net_seq)
 {
@@ -532,7 +547,7 @@ int xfrm_replay_recheck(struct xfrm_state *x,
 		return xfrm_replay_recheck_esn(x, skb, net_seq);
 	}
 
-	return xfrm_replay_check(x, skb, net_seq);
+	return xfrm_replay_check_legacy(x, skb, net_seq);
 }
 
 static void xfrm_replay_advance_esn(struct xfrm_state *x, __be32 net_seq)
@@ -723,32 +738,26 @@ 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,
 	.overflow	= xfrm_replay_overflow_offload,
 };
 
 static const struct xfrm_replay xfrm_replay_bmp = {
-	.check		= xfrm_replay_check_bmp,
 	.overflow	= xfrm_replay_overflow_offload_bmp,
 };
 
 static const struct xfrm_replay xfrm_replay_esn = {
-	.check		= xfrm_replay_check_esn,
 	.overflow	= xfrm_replay_overflow_offload_esn,
 };
 #else
 static const struct xfrm_replay xfrm_replay_legacy = {
-	.check		= xfrm_replay_check,
 	.overflow	= xfrm_replay_overflow,
 };
 
 static const struct xfrm_replay xfrm_replay_bmp = {
-	.check		= xfrm_replay_check_bmp,
 	.overflow	= xfrm_replay_overflow_bmp,
 };
 
 static const struct xfrm_replay xfrm_replay_esn = {
-	.check		= xfrm_replay_check_esn,
 	.overflow	= xfrm_replay_overflow_esn,
 };
 #endif