+#endif
+
+static inline int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
+{
+#ifdef CONFIG_HIGHMEM
+ int i;
+
+ if (dev->features & NETIF_F_HIGHDMA)
+ return 0;
+
+ for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
+ if (PageHighMem(skb_shinfo(skb)->frags[i].page))
+ return 1;
+
+#endif
+ return 0;
+}
+
+static u32 harmonize_features(struct sk_buff *skb, __be16 protocol, u32 features)
+{
+ if (!can_checksum_protocol(features, protocol)) {
+ features &= ~NETIF_F_ALL_CSUM;
+ features &= ~NETIF_F_SG;
+ } else if (illegal_highdma(skb->dev, skb)) {
+ features &= ~NETIF_F_SG;
+ }
+
+ return features;
+}
+
+u32 rpl_netif_skb_features(struct sk_buff *skb)
+{
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,26)
+ unsigned long vlan_features = 0;
+#else
+ unsigned long vlan_features = skb->dev->vlan_features;
+#endif /* kernel version < 2.6.26 */
+
+ __be16 protocol = skb->protocol;
+ u32 features = skb->dev->features;
+
+ if (protocol == htons(ETH_P_8021Q)) {
+ struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
+ protocol = veh->h_vlan_encapsulated_proto;
+ } else if (!vlan_tx_tag_present(skb)) {
+ return harmonize_features(skb, protocol, features);
+ }
+
+ features &= (vlan_features | NETIF_F_HW_VLAN_TX);
+
+ if (protocol != htons(ETH_P_8021Q)) {
+ return harmonize_features(skb, protocol, features);
+ } else {
+ features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST |
+ NETIF_F_GEN_CSUM | NETIF_F_HW_VLAN_TX;
+ return harmonize_features(skb, protocol, features);
+ }
+}
+
+struct sk_buff *rpl_skb_gso_segment(struct sk_buff *skb, u32 features)
+{
+ int vlan_depth = ETH_HLEN;
+ __be16 type = skb->protocol;
+ __be16 skb_proto;
+ struct sk_buff *skb_gso;
+
+ while (type == htons(ETH_P_8021Q)) {
+ struct vlan_hdr *vh;
+
+ if (unlikely(!pskb_may_pull(skb, vlan_depth + VLAN_HLEN)))
+ return ERR_PTR(-EINVAL);
+
+ vh = (struct vlan_hdr *)(skb->data + vlan_depth);
+ type = vh->h_vlan_encapsulated_proto;
+ vlan_depth += VLAN_HLEN;
+ }
+
+ /* this hack needed to get regular skb_gso_segment() */
+#undef skb_gso_segment
+ skb_proto = skb->protocol;
+ skb->protocol = type;
+
+ skb_gso = skb_gso_segment(skb, features);
+ skb->protocol = skb_proto;
+ return skb_gso;
+}
+#endif /* kernel version < 2.6.38 */