fix bug

ubuntu_intermediate/inter_op_ebpf.c

@@ -277,6 +277,7 @@ int inter_op_ebpf(struct xdp_md *ctx)
     {
         ip->daddr = *saved_daddr;
 //         bpf_trace_printk("Change dest");
+        asm volatile("" ::: "memory");
         ip->check = iph_csum(ip, data_end);
         tcp->check = tcp_checksum(ip, tcp, data_end);
     }
@@ -284,6 +285,7 @@ int inter_op_ebpf(struct xdp_md *ctx)
     {
         ip->saddr = *saved_saddr;
 //         bpf_trace_printk("Change src");
+        asm volatile("" ::: "memory");
         ip->check = iph_csum(ip, data_end);
         tcp->check = tcp_checksum(ip, tcp, data_end);
     }