Subject: [PATCH ipsec-next v2 5/6] xfrm: replay: avoid replay indirection

From: Florian Westphal <[email-masked]>
Date: Wed, 24 Jun 2020 10:08:03 +0200

Add and use xfrm_replay_check helper instead of indirection.

Signed-off-by: Florian Westphal <[email-masked]>
---
 include/net/xfrm.h     |  4 +---
 net/xfrm/xfrm_input.c  |  2 +-
 net/xfrm/xfrm_replay.c | 27 ++++++++++++++++++---------
 3 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 7c0b69e00128..008b564cb126 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -304,9 +304,6 @@ 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);
 };
 
@@ -1716,6 +1713,7 @@ 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);
 
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index 005d8e9c5df4..694adc6e9286 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -610,7 +610,7 @@ 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;
 		}
diff --git a/net/xfrm/xfrm_replay.c b/net/xfrm/xfrm_replay.c
index 60608b51b2d9..8c97fcaf17cf 100644
--- a/net/xfrm/xfrm_replay.c
+++ b/net/xfrm/xfrm_replay.c
@@ -119,8 +119,8 @@ static int xfrm_replay_overflow(struct xfrm_state *x, struct sk_buff *skb)
 	return err;
 }
 
-static int xfrm_replay_check(struct xfrm_state *x,
-		      struct sk_buff *skb, __be32 net_seq)
+static int xfrm_replay_check_legacy(struct xfrm_state *x,
+				    struct sk_buff *skb, __be32 net_seq)
 {
 	u32 diff;
 	u32 seq = ntohl(net_seq);
@@ -491,6 +491,21 @@ 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)
 {
@@ -516,7 +531,7 @@ 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)
@@ -705,32 +720,26 @@ 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
-- 
2.26.2