I'm trying to write a simple judge that will compile and execute user submitted c files. I found libsandbox and a question here on stackoverflow.
I have installed the python module and as per the instructions I'm trying to run a hello world program written in C
➜ sandbox git:(V_0_3_x) ✗ ./hello
Hello World%
➜ sandbox git:(V_0_3_x) ✗ python sample2.py hello
result: RF
cpu: 2ms
mem: 288kB
As you can see, when I run the program in the sandbox I don't get any output. It'd be great if someone could tell me how to correctly use it.
The sample code of libsandbox forbids system calls for file operations, such as open(), stat(), close(). That said, you'll need to either (1) link the hello world program statically to avoid opening files such as shared libraries (i.e. libc.so), or (2) write a customized sandbox policy that permits relevant system calls. Some examples on customizing sandbox policies can be found at https://github.com/liuyu81/TR-OJA-201209A.
DISCLAIMER: I am the author of libsandbox.