Hi, I have been looking at the networking code of Linux for my Masters thesis. I observed the following: In ip_route_input(), if a route is found in the cache, the skb->dst is setup with the route found by casting the rtable entry to dst_entry: skb->dst = (struct dst_entry*)rth; Later in ip_route_input(), skb->dst->input() is called: return skb->dst->input(skb); In ip_forward(), skb->dst is again casted to rtable: rt = (struct rtable*)skb->dst; I am unable to understand how a rtable structure casted to dst_entry will give a correct pointer to the input() function. I looked at the fields in rtable and dst_entry, the fields in the structures are cannot be lined up (the fourth field in rtable is not the same type as the fourth field in dst_entry). Can anybody help me understand this casting of rtable to dst_entry and then back to rtable? Thanks, Ashok - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
