I am using svn+ssh to interact with repositories. I would like to know if there is any mechanism to retrict users to only a set of svn commands, for example, to prevent the use of locks.
In the worst case scenario, if I have to modify the source code, any pointers to which file needs to be modified would also help. I see that there is svnserve.c file but a quick review tells me that that may not be the right file to look at.
You can prevent the use of locks with pre-lock and pre-unlock hook scripts. Make the hook exit with any code besides 0 and users won't be able to lock or unlock files. E.g., add a hook with just one line
exit 1