1 files changed, 32 insertions, 4 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 0096349ee38..4d2b5167d7f 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1162,9 +1162,17 @@ int skb_checksum_help(struct sk_buff *skb, int inward)
         unsigned int csum;
         int ret = 0, offset = skb->h.raw - skb->data;
 
-        if (inward) {
-                skb->ip_summed = CHECKSUM_NONE;
-                goto out;
+        if (inward)
+                goto out_set_summed;
+
+        if (unlikely(skb_shinfo(skb)->gso_size)) {
+                static int warned;
+
+                WARN_ON(!warned);
+                warned = 1;
+
+                /* Let GSO fix up the checksum. */
+                goto out_set_summed;
         }
 
         if (skb_cloned(skb)) {
@@ -1181,6 +1189,8 @@ int skb_checksum_help(struct sk_buff *skb, int inward)
         BUG_ON(skb->csum + 2 > offset);
 
         *(u16*)(skb->h.raw + skb->csum) = csum_fold(csum);
+
+out_set_summed:
         skb->ip_summed = CHECKSUM_NONE;
 out:    
         return ret;
@@ -1201,17 +1211,35 @@ struct sk_buff *skb_gso_segment(struct sk_buff *skb, int features)
         struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
         struct packet_type *ptype;
         int type = skb->protocol;
+        int err;
 
         BUG_ON(skb_shinfo(skb)->frag_list);
-        BUG_ON(skb->ip_summed != CHECKSUM_HW);
 
         skb->mac.raw = skb->data;
         skb->mac_len = skb->nh.raw - skb->data;
         __skb_pull(skb, skb->mac_len);
 
+        if (unlikely(skb->ip_summed != CHECKSUM_HW)) {
+                static int warned;
+
+                WARN_ON(!warned);
+                warned = 1;
+
+                if (skb_header_cloned(skb) &&
+                    (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
+                        return ERR_PTR(err);
+        }
+
         rcu_read_lock();
         list_for_each_entry_rcu(ptype, &ptype_base[ntohs(type) & 15], list) {
                 if (ptype->type == type && !ptype->dev && ptype->gso_segment) {
+                        if (unlikely(skb->ip_summed != CHECKSUM_HW)) {
+                                err = ptype->gso_send_check(skb);
+                                segs = ERR_PTR(err);
+                                if (err || skb_gso_ok(skb, features))
+                                        break;
+                                __skb_push(skb, skb->data - skb->nh.raw);
+                        }
                         segs = ptype->gso_segment(skb, features);
                         break;
                 }