Controlling Login Access by Time….

As part of continuing to control computer access by my kids (they are good kids, but kids are kids after all), I set about to restrict access by time.  I also wanted a means to automatically log them out, as well as a notification telling them their time was almost up.

Links that helped:

• http://articles.techrepublic.com.com/5100-10878_11-1055269.html
• http://ubuntuforums.org/archive/index.php/t-505876.html
• http://skindley.wordpress.com/2006/12/11/fedora-core-6-controlling-logins-by-time/

It took a little tinkering, but in the end, I added the following line to /etc/pam.d/common-account:

• account requisite pam_time.so

Because the /etc/pam.d/login and KDM files reference common-account, I did not have to modify them.  I placed it below the existing unix.so entry.

Next, I edited /etc/security/time.conf and added several lines at the bottom:

• *;*;root|parent-user1|parent-user2;Al0000-2400 #This ensures root and our parent accounts are not restricted.
• *;*;child1:Al0900-2130 # Child1 is restricted for all services and logins on all days for access between 9 am and 9:30 pm.
• *;*;child2:Al0900-2130 #Child2 restrictions…

Syntax is described in the man page for time.conf….  Be careful with the logic – piping the two child accounts together on one line did not work.  Separating them into two lines did.

For notification and logoff, I thought about kdialog (zenity if using GNOME), but went for festival instead.  Since there is no GUI notification, I do not have to point it to the right display variable and it gets a little easier.  Plus, there is a definite geek factor here with a talking computer.

I installed festival and the English festvox packages, and then added the lines to /etc/crontab:

• 28 21 * * * root echo "It is now `date +\%r` .  Time for bed.  Log off now.  You will be rudely ejected in two minutes.  Good night." | festival --tts
• 30 21 * * * root /usr/bin/skill -KILL -u child1
• 30 21 * * * root /usr/bin/skill -KILL -u child2

The syntax for cron is found in the man page for crontab, and is also summarized in the crontab itself.

I chose not to use crontab -e and have user-based crontab files – this one is system-wide and is a little easier to work with.  No special editor (I use vi), and when I am done, I restart the cron service:

• sudo /etc/init.d/cron restart

I tested each step, and it all works on Kubuntu 8.04 just fine.  Now, before 9 am and after 9:30 pm, the kids cannot log in.  At 9:28 pm each night, a Steven Hawking voice will tell them they have two minutes.  At 9:30 pm each night, their sessions are killed.  If they are not on, nothing happens.

Some improvements I can make later is to check and see if they are on before running the festival notification.  I will also play around with more realistic voices for festival.

I also think I will add birthday and holiday notifications in the crontab.  I have already added in a wake-up call to the crontab using festival, and a .wav file will play (you don’t wanna know, trust me – it is very juvenile).  To play files from the command line, I installed sox and all the suggested and recommended packages.  But you probably only need sox.

And of course, there is the mischief factor – SSH, festival, and sox.  Think of the possibilities!   ^__________^