Add file mode-awareness to selabel_lookup

[joshcooper]

Fixes #9431
Supersedes #9437

This PR reproduces much of the mode-related functionality of the now-deprecated matchpathcon codepath. This is important because without this, Puppet determines an incorrect SELinux label to apply to files -- i.e. it does not match what restorecon would do -- which is important because correct SELinux labelling is a necessity in order to ensure that policy is applied correctly.

Author: Dave Baxter davejbax@gmail.com

[joshcooper]

given

# ruby --version
ruby 3.2.5 (2024-07-26 revision 31d0f1a2e7) [aarch64-linux]
# rpm -q httpd
httpd-2.4.57-11.el9_4.1.aarch64
# semanage fcontext -l | grep /etc/httpd | grep -v alias | grep -v keytab
/etc/httpd(/.*)?                                   all files          system_u:object_r:httpd_config_t:s0 
/etc/httpd/.*                                      symbolic link      system_u:object_r:etc_t:s0 

file

# rm -f /etc/httpd/conf.d/foo.conf
# bundle exec puppet apply -e "file { '/etc/httpd/conf.d/foo.conf': ensure => file, content => 'test' }"
Notice: Compiled catalog for XXX in environment production in 0.03 seconds
Notice: /Stage[main]/Main/File[/etc/httpd/conf.d/foo.conf]/ensure: defined content as '{sha256}9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08'
Notice: Applied catalog in 0.05 seconds
# ls -laZ /etc/httpd/conf.d/foo.conf
-rw-r--r--. 1 root root system_u:object_r:httpd_config_t:s0 4 Aug 13 01:33 /etc/httpd/conf.d/foo.conf

directory

# bundle exec puppet apply -e "file { '/etc/httpd/conf.d/more.d': ensure => directory }"
Notice: Compiled catalog for XXX in environment production in 0.03 seconds
Notice: /Stage[main]/Main/File[/etc/httpd/conf.d/more.d]/ensure: created
Notice: Applied catalog in 0.02 seconds
# ls -ladZ /etc/httpd/conf.d/more.d/
drwxr-xr-x. 2 root root system_u:object_r:httpd_config_t:s0 6 Aug 13 01:33 /etc/httpd/conf.d/more.d/

symlink

# touch /etc/foo.conf
# bundle exec puppet apply -e "file { '/etc/httpd/conf.d/link': ensure => link, target => '/etc/foo.conf' }"
Notice: Compiled catalog for XXX in environment production in 0.03 seconds
Notice: /Stage[main]/Main/File[/etc/httpd/conf.d/link]/ensure: created
Notice: Applied catalog in 0.02 seconds
# ls -laZ /etc/httpd/conf.d/link 
lrwxrwxrwx. 1 root root system_u:object_r:etc_t:s0 13 Aug 13 01:36 /etc/httpd/conf.d/link -> /etc/foo.conf