+/*
+ * Handle IPV6_RECVPATHMTU
+ */
+int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len)
+{
+ struct ipv6_pinfo *np = inet6_sk(sk);
+ struct sk_buff *skb;
+ struct sockaddr_in6 *sin;
+ struct ip6_mtuinfo mtu_info;
+ int err;
+ int copied;
+
+ err = -EAGAIN;
+ skb = xchg(&np->rxpmtu, NULL);
+ if (skb == NULL)
+ goto out;
+
+ copied = skb->len;
+ if (copied > len) {
+ msg->msg_flags |= MSG_TRUNC;
+ copied = len;
+ }
+ err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+ if (err)
+ goto out_free_skb;
+
+ sock_recv_timestamp(msg, sk, skb);
+
+ memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
+
+ sin = (struct sockaddr_in6 *)msg->msg_name;
+ if (sin) {
+ sin->sin6_family = AF_INET6;
+ sin->sin6_flowinfo = 0;
+ sin->sin6_port = 0;
+ sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
+ ipv6_addr_copy(&sin->sin6_addr, &mtu_info.ip6m_addr.sin6_addr);
+ }
+
+ put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
+
+ err = copied;
+
+out_free_skb:
+ kfree_skb(skb);
+out:
+ return err;
+}