1 files changed, 27 insertions, 6 deletions

diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index 229544bc70c2..9a5e79a38c67 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -273,6 +273,7 @@ static int xfrm4_beet_encap_add(struct xfrm_state *x, struct sk_buff *skb)
  */
 static int xfrm4_tunnel_encap_add(struct xfrm_state *x, struct sk_buff *skb)
 {
+	bool small_ipv6 = (skb->protocol == htons(ETH_P_IPV6)) && (skb->len <= IPV6_MIN_MTU);
 	struct dst_entry *dst = skb_dst(skb);
 	struct iphdr *top_iph;
 	int flags;
@@ -303,7 +304,7 @@ static int xfrm4_tunnel_encap_add(struct xfrm_state *x, struct sk_buff *skb)
 	if (flags & XFRM_STATE_NOECN)
 		IP_ECN_clear(top_iph);
 
-	top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
+	top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) || small_ipv6 ?
 		0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF));
 
 	top_iph->ttl = ip4_dst_hoplimit(xfrm_dst_child(dst));
@@ -647,10 +648,12 @@ static int xfrm_output_gso(struct net *net, struct sock *sk, struct sk_buff *skb
  * This requires hardware to know the inner packet type to calculate
  * the inner header checksum. Save inner ip protocol here to avoid
  * traversing the packet in the vendor's xmit code.
- * If the encap type is IPIP, just save skb->inner_ipproto. Otherwise,
- * get the ip protocol from the IP header.
+ * For IPsec tunnel mode save the ip protocol from the IP header of the
+ * plain text packet. Otherwise If the encap type is IPIP, just save
+ * skb->inner_ipproto in any other case get the ip protocol from the IP
+ * header.
  */
-static void xfrm_get_inner_ipproto(struct sk_buff *skb)
+static void xfrm_get_inner_ipproto(struct sk_buff *skb, struct xfrm_state *x)
 {
 	struct xfrm_offload *xo = xfrm_offload(skb);
 	const struct ethhdr *eth;
@@ -658,6 +661,25 @@ static void xfrm_get_inner_ipproto(struct sk_buff *skb)
 	if (!xo)
 		return;
 
+	if (x->outer_mode.encap == XFRM_MODE_TUNNEL) {
+		switch (x->outer_mode.family) {
+		case AF_INET:
+			xo->inner_ipproto = ip_hdr(skb)->protocol;
+			break;
+		case AF_INET6:
+			xo->inner_ipproto = ipv6_hdr(skb)->nexthdr;
+			break;
+		default:
+			break;
+		}
+
+		return;
+	}
+
+	/* non-Tunnel Mode */
+	if (!skb->encapsulation)
+		return;
+
 	if (skb->inner_protocol_type == ENCAP_TYPE_IPPROTO) {
 		xo->inner_ipproto = skb->inner_ipproto;
 		return;
@@ -712,8 +734,7 @@ int xfrm_output(struct sock *sk, struct sk_buff *skb)
 		sp->xvec[sp->len++] = x;
 		xfrm_state_hold(x);
 
-		if (skb->encapsulation)
-			xfrm_get_inner_ipproto(skb);
+		xfrm_get_inner_ipproto(skb, x);
 		skb->encapsulation = 1;
 
 		if (skb_is_gso(skb)) {