[PATCH] [NETFILTER] xt_TCPMSS: combine nearly identical reverse_mtu4/6

["Ilpo Järvinen" <ilpo.jarvinen@xxxxxxxxxxx>]

Added tcpmss_reverse_mtu, only flowi setup and family differ

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxx>
---
 net/netfilter/xt_TCPMSS.c |   34 ++++++++++++++--------------------
 1 files changed, 14 insertions(+), 20 deletions(-)

diff --git a/net/netfilter/xt_TCPMSS.c b/net/netfilter/xt_TCPMSS.c
index 217e2b6..1619166 100644
--- a/net/netfilter/xt_TCPMSS.c
+++ b/net/netfilter/xt_TCPMSS.c
@@ -147,28 +147,35 @@ tcpmss_mangle_packet(struct sk_buff *skb,
 	return TCPOLEN_MSS;
 }
 
-static u_int32_t tcpmss_reverse_mtu4(const struct iphdr *iph)
+static u_int32_t tcpmss_reverse_mtu(struct flowi *fl, unsigned short family)
 {
-	struct flowi fl = {
-		.fl4_dst = iph->saddr,
-	};
 	const struct nf_afinfo *ai;
 	struct rtable *rt = NULL;
 	u_int32_t mtu     = ~0U;
 
 	rcu_read_lock();
-	ai = nf_get_afinfo(AF_INET);
+	ai = nf_get_afinfo(family);
 	if (ai != NULL)
-		ai->route((struct dst_entry **)&rt, &fl);
+		ai->route((struct dst_entry **)&rt, fl);
 	rcu_read_unlock();
 
 	if (rt != NULL) {
 		mtu = dst_mtu(&rt->u.dst);
 		dst_release(&rt->u.dst);
 	}
+
 	return mtu;
 }
 
+static u_int32_t tcpmss_reverse_mtu4(const struct iphdr *iph)
+{
+	struct flowi fl = {
+		.fl4_dst = iph->saddr,
+	};
+
+	return tcpmss_reverse_mtu(&fl, AF_INET);
+}
+
 static unsigned int
 tcpmss_tg4(struct sk_buff *skb, const struct net_device *in,
            const struct net_device *out, unsigned int hooknum,
@@ -198,21 +205,8 @@ static u_int32_t tcpmss_reverse_mtu6(const struct ipv6hdr *iph)
 	struct flowi fl = {
 		.fl6_dst = iph->saddr,
 	};
-	const struct nf_afinfo *ai;
-	struct rtable *rt = NULL;
-	u_int32_t mtu     = ~0U;
-
-	rcu_read_lock();
-	ai = nf_get_afinfo(AF_INET6);
-	if (ai != NULL)
-		ai->route((struct dst_entry **)&rt, &fl);
-	rcu_read_unlock();
 
-	if (rt != NULL) {
-		mtu = dst_mtu(&rt->u.dst);
-		dst_release(&rt->u.dst);
-	}
-	return mtu;
+	return tcpmss_reverse_mtu(&fl, AF_INET6);
 }
 
 static unsigned int
-- 
1.5.2.2