1 files changed, 21 insertions, 13 deletions

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index ef02b26ccf81..64d6073731d3 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -342,6 +342,20 @@ static unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst)
         return mtu;
 }
 
+static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
+{
+        if (skb->len <= mtu || skb->local_df)
+                return false;
+
+        if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)
+                return true;
+
+        if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu)
+                return false;
+
+        return true;
+}
+
 int ip6_forward(struct sk_buff *skb)
 {
         struct dst_entry *dst = skb_dst(skb);
@@ -466,8 +480,7 @@ int ip6_forward(struct sk_buff *skb)
         if (mtu < IPV6_MIN_MTU)
                 mtu = IPV6_MIN_MTU;
 
-        if ((!skb->local_df && skb->len > mtu && !skb_is_gso(skb)) ||
-            (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)) {
+        if (ip6_pkt_too_big(skb, mtu)) {
                 /* Again, force OUTPUT device used as source address */
                 skb->dev = dst->dev;
                 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
@@ -517,9 +530,6 @@ static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
         to->tc_index = from->tc_index;
 #endif
         nf_copy(to, from);
-#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
-        to->nf_trace = from->nf_trace;
-#endif
         skb_copy_secmark(to, from);
 }
 
@@ -1091,21 +1101,19 @@ static void ip6_append_data_mtu(unsigned int *mtu,
                                 unsigned int fragheaderlen,
                                 struct sk_buff *skb,
                                 struct rt6_info *rt,
-                                bool pmtuprobe)
+                                unsigned int orig_mtu)
 {
         if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
                 if (skb == NULL) {
                         /* first fragment, reserve header_len */
-                        *mtu = *mtu - rt->dst.header_len;
+                        *mtu = orig_mtu - rt->dst.header_len;
 
                 } else {
                         /*
                          * this fragment is not first, the headers
                          * space is regarded as data space.
                          */
-                        *mtu = min(*mtu, pmtuprobe ?
-                                   rt->dst.dev->mtu :
-                                   dst_mtu(rt->dst.path));
+                        *mtu = orig_mtu;
                 }
                 *maxfraglen = ((*mtu - fragheaderlen) & ~7)
                               + fragheaderlen - sizeof(struct frag_hdr);
@@ -1122,7 +1130,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
         struct ipv6_pinfo *np = inet6_sk(sk);
         struct inet_cork *cork;
         struct sk_buff *skb, *skb_prev = NULL;
-        unsigned int maxfraglen, fragheaderlen, mtu;
+        unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu;
         int exthdrlen;
         int dst_exthdrlen;
         int hh_len;
@@ -1204,6 +1212,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
                 dst_exthdrlen = 0;
                 mtu = cork->fragsize;
         }
+        orig_mtu = mtu;
 
         hh_len = LL_RESERVED_SPACE(rt->dst.dev);
 
@@ -1301,8 +1310,7 @@ alloc_new_skb:
                         if (skb == NULL || skb_prev == NULL)
                                 ip6_append_data_mtu(&mtu, &maxfraglen,
                                                     fragheaderlen, skb, rt,
-                                                    np->pmtudisc >=
-                                                    IPV6_PMTUDISC_PROBE);
+                                                    orig_mtu);
 
                         skb_prev = skb;