Fix profiler path validation

[tparchambault]

Support for validating relative executable paths by using the existing PATH from the users environment. This also supports evaluating a custom PATH provided through the profiler GUI.

This fixes the issue from #655 where users are forced to use absolute paths to avoid a validation error reporting that the file cannot be found.

Closes #655

[tparchambault]

Target executables specified with relative paths are now supported, whether the PATH environment variable is acquired from the pkexec runtime environment (On RHEL8.6: /usr/sbin:/usr/bin:/sbin:/bin:/root/bin) or provided by the user in the enironment variable entry in the Profiler Page UI.

If the PATH env var provided by the user on the Profiler Page, the below syntax is supported and expanded in the following order::

• $PATH or ${PATH} are expanded to the pkexec runtime environment's PATH value.
• Single periods, lone leading colons, lone trailing colons, and internal double colons in the PATH variable are expanded to the user-specified Profiler Page Working Directory entry. If not specified uses the directory where fapolicy-analyzer was invoked.
• Double periods are expanded to the parent of the user-specified Profiler Page Working Directory entry otherwise the parent of the directory where invoked.

This new expanded PATH variable is used to determine the absolute path of a relatively specified target executable and also passed into the target executable's runtime environment, in the event it or any spawned processes or shells use the PATH variable.

[tparchambault]

If you aren't running as root you can activate the Profiler Page menu item by creating a file, /tmp/prof_ui_enable. Alternatively, you can extract the attached tarball within your /tmp directory as it contains the above mentioned file and a trivial shell script, Now.sh the prints out a teletype test, and the environment variables WEINER and PATH.

Also, if not running as root the fapolicyd daemon can not be started/stopped by the fapolicy-analyzer, so only the execution of the specified target will occur.

FaProfilerTestCode.zip

[jw3]

Is this ready?

[tparchambault]

No. Worked it yesterday; As requested in review, added dict key checking for robustness, and adding requested unit-tests. Have not pushed latest work. Hopefully today.

[tparchambault]

Opened #670 related to the Profiler's default pwd given that within the pkexec environment where /root is the default pwd.`

[jw3]

@tparchambault conflicts in the main .pot

[jw3]

Works as expected 👍

[jw3]

Resoled the conflict, was just the file info date/time conflicting.