+ iph->tot_len=htons(iph->ihl*4+tlen);
+
+ /*Compute IPv4 Checksum*/
+ iph->check=0;
+ iph->check=ipv4_chksum(data,iph->ihl*4);
+
+ /*Compute TCP Checksum*/
+ data+=iph->ihl*4;
+ tcph=(struct tcphdr*)data;
+ tcph->check=0;
+ tcph->check=ipv4_pseudohdr_chksum(data, tlen, (u_char*)&iph->daddr, (u_char*)&iph->saddr, iph->protocol);