1 files changed, 36 insertions, 34 deletions

diff --git a/net/netfilter/xt_TCPMSS.c b/net/netfilter/xt_TCPMSS.c
index cd24290f3b2f..62776de8293c 100644
--- a/net/netfilter/xt_TCPMSS.c
+++ b/net/netfilter/xt_TCPMSS.c
@@ -43,10 +43,41 @@ optlen(const u_int8_t *opt, unsigned int offset)
                 return opt[offset+1];
 }
 
+static u_int32_t tcpmss_reverse_mtu(const struct sk_buff *skb,
+                                    unsigned int family)
+{
+        struct flowi fl;
+        const struct nf_afinfo *ai;
+        struct rtable *rt = NULL;
+        u_int32_t mtu     = ~0U;
+
+        if (family == PF_INET) {
+                struct flowi4 *fl4 = &fl.u.ip4;
+                memset(fl4, 0, sizeof(*fl4));
+                fl4->daddr = ip_hdr(skb)->saddr;
+        } else {
+                struct flowi6 *fl6 = &fl.u.ip6;
+
+                memset(fl6, 0, sizeof(*fl6));
+                fl6->daddr = ipv6_hdr(skb)->saddr;
+        }
+        rcu_read_lock();
+        ai = nf_get_afinfo(family);
+        if (ai != NULL)
+                ai->route(&init_net, (struct dst_entry **)&rt, &fl, false);
+        rcu_read_unlock();
+
+        if (rt != NULL) {
+                mtu = dst_mtu(&rt->dst);
+                dst_release(&rt->dst);
+        }
+        return mtu;
+}
+
 static int
 tcpmss_mangle_packet(struct sk_buff *skb,
                      const struct xt_action_param *par,
-                     unsigned int in_mtu,
+                     unsigned int family,
                      unsigned int tcphoff,
                      unsigned int minlen)
 {
@@ -76,6 +107,8 @@ tcpmss_mangle_packet(struct sk_buff *skb,
                 return -1;
 
         if (info->mss == XT_TCPMSS_CLAMP_PMTU) {
+                unsigned int in_mtu = tcpmss_reverse_mtu(skb, family);
+
                 if (dst_mtu(skb_dst(skb)) <= minlen) {
                         net_err_ratelimited("unknown or invalid path-MTU (%u)\n",
                                             dst_mtu(skb_dst(skb)));
@@ -165,37 +198,6 @@ tcpmss_mangle_packet(struct sk_buff *skb,
         return TCPOLEN_MSS;
 }
 
-static u_int32_t tcpmss_reverse_mtu(const struct sk_buff *skb,
-                                    unsigned int family)
-{
-        struct flowi fl;
-        const struct nf_afinfo *ai;
-        struct rtable *rt = NULL;
-        u_int32_t mtu     = ~0U;
-
-        if (family == PF_INET) {
-                struct flowi4 *fl4 = &fl.u.ip4;
-                memset(fl4, 0, sizeof(*fl4));
-                fl4->daddr = ip_hdr(skb)->saddr;
-        } else {
-                struct flowi6 *fl6 = &fl.u.ip6;
-
-                memset(fl6, 0, sizeof(*fl6));
-                fl6->daddr = ipv6_hdr(skb)->saddr;
-        }
-        rcu_read_lock();
-        ai = nf_get_afinfo(family);
-        if (ai != NULL)
-                ai->route(&init_net, (struct dst_entry **)&rt, &fl, false);
-        rcu_read_unlock();
-
-        if (rt != NULL) {
-                mtu = dst_mtu(&rt->dst);
-                dst_release(&rt->dst);
-        }
-        return mtu;
-}
-
 static unsigned int
 tcpmss_tg4(struct sk_buff *skb, const struct xt_action_param *par)
 {
@@ -204,7 +206,7 @@ tcpmss_tg4(struct sk_buff *skb, const struct xt_action_param *par)
         int ret;
 
         ret = tcpmss_mangle_packet(skb, par,
-                                   tcpmss_reverse_mtu(skb, PF_INET),
+                                   PF_INET,
                                    iph->ihl * 4,
                                    sizeof(*iph) + sizeof(struct tcphdr));
         if (ret < 0)
@@ -233,7 +235,7 @@ tcpmss_tg6(struct sk_buff *skb, const struct xt_action_param *par)
         if (tcphoff < 0)
                 return NF_DROP;
         ret = tcpmss_mangle_packet(skb, par,
-                                   tcpmss_reverse_mtu(skb, PF_INET6),
+                                   PF_INET6,
                                    tcphoff,
                                    sizeof(*ipv6h) + sizeof(struct tcphdr));
         if (ret < 0)