Hi, In the kernel, I added some customized options to the ip_options struct, and I send the ip packet with these option fields set. After I receive the packet, I extract these options and try to remove them from the ip packet because I don't want these options be delivered to upper layer. In the method ip_rcv_finish of the file ip_input.c, I added following code: /*********My code to process the options****/ process_my_options(skb); /*********My code to remove the options ****/ //skb_pull(skb, sizeof(struct iphdr) + 12); //skb_push(skb, sizeof(struct iphdr)); //skb_reset_network_header(skb); //iph->ihl -= 3; /*********Normal process of the ip packet.****/ if (iph->ihl > 5 && ip_rcv_options(skb)) goto drop; The question is at how to remove the options. I tried some code but none of them works correctly. Can anybody give me some suggestion? Thanks.