1 files changed, 29 insertions, 0 deletions
diff --git a/net/ipv4/gre.c b/net/ipv4/gre.c
index 1cbc465..5ecc9c4 100644
--- a/net/ipv4/gre.c
+++ b/net/ipv4/gre.c
@@ -93,6 +93,35 @@ void gre_build_header(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
 }
 EXPORT_SYMBOL_GPL(gre_build_header);
 
+struct sk_buff *gre_handle_offloads(struct sk_buff *skb, bool gre_csum)
+{
+	int err;
+
+	if (likely(!skb->encapsulation)) {
+		skb_reset_inner_headers(skb);
+		skb->encapsulation = 1;
+	}
+
+	if (skb_is_gso(skb)) {
+		err = skb_unclone(skb, GFP_ATOMIC);
+		if (unlikely(err))
+			goto error;
+		skb_shinfo(skb)->gso_type |= SKB_GSO_GRE;
+		return skb;
+	} else if (skb->ip_summed == CHECKSUM_PARTIAL && gre_csum) {
+		err = skb_checksum_help(skb);
+		if (unlikely(err))
+			goto error;
+	} else if (skb->ip_summed != CHECKSUM_PARTIAL)
+		skb->ip_summed = CHECKSUM_NONE;
+
+	return skb;
+error:
+	kfree_skb(skb);
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(gre_handle_offloads);
+
 static __sum16 check_checksum(struct sk_buff *skb)
 {
 	__sum16 csum = 0;