1. System Concepts
2. Managing Programming Contests
3. Mooshak interfaces
4. Frequently asked questions

FAQ

• Setup and initial testing
• Contest configuration
• Evaluating submissions
• Email registration

Setup and initial testes FAQ

• How do I configure Mooshak with SELinux
Restrictions enforced by SELinux are registered in a log file, suc as /var/log/audit/audit.log. Using the tools audit2why and audit2allow you can analyze and create a module with a security policy that can be added with the command line:

 semodule –i 

Here is a policy file for Mooshak

module mooshak 1.0;

 

require {

    type home_root_t;

    type httpd_sys_script_t;

    class file { setattr read create ioctl write getattr unlink open append };

    class dir { setattr read create write rmdir remove_name open add_name };

}

#============= httpd_sys_script_t ==============

allow httpd_sys_script_t home_root_t:dir { setattr read create write rmdir remove_name open add_name };

allow httpd_sys_script_t home_root_t:file { setattr read create
getattr write ioctl unlink open append };

(Answer contributed by David Carvalho - david@di.ubi.pt)
• I get a server error after accessing Mooshak's initial page
This probably means that your Apache configuration does not support a /cgi-bin/ directory for users. To allow programs to be executed in this directory you should include these lines in the Apache configuration file e restart the server.

<Directory /home/*/public_html/cgi-bin>
     Options +ExecCGI -Includes -Indexes
     SetHandler cgi-script
</Directory>

• When I use the save command in the admin's screen I get an error message
Mooshak's scripts and data files are installed in a certain OS user's home - by default mooshak - and the CGI scripts should run with the same user. The suexec module of Apache runs CGI scripts in users directories as the corresponding and ensures that scripts cannot be invoked by other users. Mooshak expects suexec in order to run properly.

If you have this kind of error then you probably don't have suexec installed. Some distributions install suexec by default when you install Apache. Sometimes you may need to recompile Apache with a certain configuration

Of course that you can just give all permissions to all data files by executing chmod -R 777 data command in Mooshak's home directory but I advise you against it. You will be compromising your contest security.

• I am using Fedora Core 3 and when Mooshak calls gcc to compile C/C++ programs it produces either Internal Error or SegFault, but the programs compile on the shell
People using Mooshak reported that starting Apache in init.d, i.e., httpd start, intead of startssl solved this problem. Apparently this script sets important environment variables

Configuration FAQ

Evaluating submissions FAQ

• I have a submission that Mooshak classifies as ... but when I run it on the shell it works just fine In Mooshak executions are similar to those you launch from the command line, but you have to have in mind that Mooshak uses a safe execution command to execute you program as an underprivileged user. To have exactly the same type of execution you use the following command line

  
  	~mooshak/bin/safeexec --exec $COMMAND_LINE
  
  

  In fact Mooshak invokes safexec with more command line options to enforce limits over system resources (memory, time, etc), but with this command line you may find, for instance, that your program requires certain environment variables that are not available to the safeexec user.

  Also, if you copy data files for the test vectors using the clipboard (CUT-PAST) that were produced in Windows then you should be aware that Mooshak runs in Linux and this system uses a single end-of-file character, instead of the sequence used by Windows.

Registration FAQ

• I want to prevent people from registering in a contest

  After version 1.3 email registering is switched off by default. As admin you can to set the Register field in the contest folder to control email registation.

  In versions before 1.3, you can disable registration by removing the register command from the guest profile. To manage the guest profile open the config/profiles/guest folder in the admin interface, them select the register item in the Authorized selector.

• Registration seams to be working but emails are not being sent To be able to send email the server must have sendmail installed and configured. In the mail_log file in the contests/your_contest/groups folder you should find a pair of lines for each registration, the first written when Mooshak started sending the message and the last when it terminated.

  22.11.2004 18:31:38: sending to zp@ncc.up.pt
  22.11.2004 18:31:38: OK sent to zp@ncc.up.pt.
  

  If an error occurs during this phase then the second line will have the error message generated by the sendmail.