fix bug del chksum pkt

ubuntu_base/opportunistic_node.py

@@ -58,6 +58,8 @@ def process_packet(new_packet):
             else:
                 pkt.options[index_custom_option].add_entry(my_id, inter_num, Cmd.REGISTER)
 
+            del pkt.len
+            del pkt.ihl
             del pkt[IP].chksum  # Invalidate the checksum
             new_packet.set_payload(bytes(pkt))
             pkt.show()  # Now this will work correctly
@@ -77,7 +79,7 @@ def main():
 
             for i in range(MIN_INTER_NUMBER, MAX_INTER_NUMBER):
                 inter_name = MARK_TO_INTERFACE[i]
-                rule_2 = f"sudo iptables -t mangle -A PREROUTING -i {inter_name} -j MARK --set-mark {i}"
+                rule_2 = f"sudo iptables -t mangle -A FORWARD -i br0 -m physdev --physdev-in {inter_name} -j MARK --set-mark {i}"
                 subprocess.run(rule_2, shell=True, check=True)
 
             print("Rule added successfully.")