- * The following fields in it shall be filled in by x->type->output:
- * payload_len
- *
- * On exit, skb->h will be set to the start of the encapsulation header to be
- * filled in by x->type->output and skb->nh will be set to the nextheader field
- * of the extension header directly preceding the encapsulation header, or in
- * its absence, that of the top IP header. The value of skb->data will always
- * point to the top IP header.