WebGUI: How to get the users IP-address

Question

Hello.
I have to develop a simple web-application, that will enable users to reset their forgotten passwords or to unlock themselves, if they are locked because of too many failed login-attempts.
As you can imagine, this application must not require a login. For security reasons any action has to be logged.
The username can not be used for logging-purposes, as the application is executed using a default-user defined in transaction SICF. That's why the IP-address of the user's pc has to be written into the log-table.
My problem is, that i do not know how to get it. I have read many articles on help.sap.com, searched in the sap notes, used Google and tried to find usefull functions in our SAP-system, but after two days it still does not work and i do'nt know, what else to try.
At the moment i am able to read the name of the client-pc with my test-coding.
  DATA:    lv_webgui TYPE xfeld.
  STATICS: lv_computer_name TYPE string,
           lv_username TYPE string.
  CLASS: cl_gui_frontend_services DEFINITION LOAD.
  lv_webgui = cl_gui_frontend_services=>www_active.
  IF lv_webgui EQ gc_true.
    " Begin of experimental coding #1
    CALL METHOD cl_gui_frontend_services=>get_computer_name
      CHANGING
        computer_name = lv_computer_name.
    " End of experimental coding #1
    " Begin of experimental coding #2
    CALL FUNCTION 'ITS_ENV_GET_VARIABLE'
      EXPORTING
        variable = 'COMPUTERNAME'
      CHANGING
        value = lv_computer_name.
    " End of experimental coding #2
    MESSAGE s000(38) WITH lv_computer_name.
  ENDIF.
The problem is, that the Internet Explorer 7 (version: 7.0.5730.13CO) shows a warning before the scripts, generated by the ITS, are executed on the client. If the user clicks "abort", the scripts are not executed and the name of the client-pc will not be returned to the server (experimental coding #1 returns the value 'localhost', experimental coding #2 returns an empty string).
That's why the experimental coding is quite useless, because the user is able to avoid it's execution.
In theory i could use experimental coding #2 and stop the execution of the program if an empty string is returned but some users in our company have administrator-privileges and so they can change environment-variables at will. So i am afraid, that this procedure is not an option.
I am quite sure, that there must be a way to read the IP-address directly from the ITS without using the functions in my experimental coding, but i have no clue how this could be done.
Any suggestions would be highly appreciated.
As i do'nt know how to determine the version of our ITS, i have to leave this information out for the moment. If anyone needs this information it would be very kind, if he or she could tell me how to get the required information.
EDIT: As we are using SAP ECC 6.0 and Services are maintained via transaction SICF, it should be ITS 6.40.
Regards
Jörg Neumann
Edited by: Jörg Neumann on Oct 16, 2009 1:27 PM

Answer 1

Hello Wolfgang.
Thanks for your reply.
I can imagine, that the application as described above seems to be very insecure, but the description is not complete - i left some parts out, as they were not relevant for my problem.
1.) The application can only be reached from our intranet.
2.) Unlocking / Resetting password can be done three times per day, which limits the number of attemps for cracking a password to a total of 20 per day.
3.) The owner of the account will receive an email if the acount was changed by the application. So if somebody tries to crack the password, the owner of the account will get a total
20 3 mails per day - which should make him/her at least a litte suspicious. 
I know, that the logged data is quite worthless, as computername and username are read using clientside-scripting and there could be a proxy between the client and the server, but this is exaclty, what i have to develop.
I will keep the logging-problem in mind and talk about it in the next meeting, though i am quite sure, that it wo'nt change anything.
Regards Jörg Neumann
Edited by: Jörg Neumann on Oct 19, 2009 4:57 PM