+ *dst = NULL;
+ return ip6_dst_lookup_tail(sk, dst, fl);
+}
+EXPORT_SYMBOL_GPL(ip6_dst_lookup);
+
+/**
+ * ip6_sk_dst_lookup - perform socket cached route lookup on flow
+ * @sk: socket which provides the dst cache and route info
+ * @dst: pointer to dst_entry * for result
+ * @fl: flow to lookup
+ *
+ * This function performs a route lookup on the given flow with the
+ * possibility of using the cached route in the socket if it is valid.
+ * It will take the socket dst lock when operating on the dst cache.
+ * As a result, this function can only be used in process context.
+ *
+ * It returns zero on success, or a standard errno code on error.
+ */
+int ip6_sk_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
+{
+ *dst = NULL;
+ if (sk) {
+ *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
+ *dst = ip6_sk_dst_check(sk, *dst, fl);
+ }
+
+ return ip6_dst_lookup_tail(sk, dst, fl);
+}
+EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup);
+
+static inline int ip6_ufo_append_data(struct sock *sk,
+ int getfrag(void *from, char *to, int offset, int len,
+ int odd, struct sk_buff *skb),
+ void *from, int length, int hh_len, int fragheaderlen,
+ int transhdrlen, int mtu,unsigned int flags)
+
+{
+ struct sk_buff *skb;
+ int err;
+
+ /* There is support for UDP large send offload by network
+ * device, so create one single skb packet containing complete
+ * udp datagram
+ */
+ if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
+ skb = sock_alloc_send_skb(sk,
+ hh_len + fragheaderlen + transhdrlen + 20,
+ (flags & MSG_DONTWAIT), &err);
+ if (skb == NULL)
+ return -ENOMEM;
+
+ /* reserve space for Hardware header */
+ skb_reserve(skb, hh_len);
+
+ /* create space for UDP/IP header */
+ skb_put(skb,fragheaderlen + transhdrlen);
+
+ /* initialize network header pointer */
+ skb->nh.raw = skb->data;
+
+ /* initialize protocol header pointer */
+ skb->h.raw = skb->data + fragheaderlen;
+
+ skb->ip_summed = CHECKSUM_HW;
+ skb->csum = 0;
+ sk->sk_sndmsg_off = 0;
+ }
+
+ err = skb_append_datato_frags(sk,skb, getfrag, from,
+ (length - transhdrlen));
+ if (!err) {
+ struct frag_hdr fhdr;
+
+ /* specify the length of each IP datagram fragment*/
+ skb_shinfo(skb)->gso_size = mtu - fragheaderlen -
+ sizeof(struct frag_hdr);
+ skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
+ ipv6_select_ident(skb, &fhdr);
+ skb_shinfo(skb)->ip6_frag_id = fhdr.identification;
+ __skb_queue_tail(&sk->sk_write_queue, skb);
+
+ return 0;
+ }
+ /* There is not enough support do UPD LSO,
+ * so follow normal path
+ */
+ kfree_skb(skb);
+
+ return err;
+}
+
+int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
+ int offset, int len, int odd, struct sk_buff *skb),
+ void *from, int length, int transhdrlen,
+ int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi *fl,
+ struct rt6_info *rt, unsigned int flags)
+{
+ struct inet_sock *inet = inet_sk(sk);