|Filenames||File Types (all executable)||chmod command to type|
|pppd||binary||chmod u+s pppd|
|ppp-on||shell script||chmod 555 ppp-on|
|ppp-on-dialer||chat script||chmod 555 ppp-on-dialer|
|ppp-off||shell script||chmod 555 ppp-off|
Where "chmod u+s pppd" sets the file permission for pppd to suid root. But this still doesn't make pppd universal to the desired groups of users. Assuming that you have edited /etc/groups to include several accounts under a group called ppp, you must change the file's ownership. When you installed the file as root, the ownership was likely to be the default "root.root" That is, root is both the group and owner of the file.To change the group to ppp, issue the command:
chown root.ppp pppd
root::0: users::100:john,paul,george,ringo,aretha,tina,alanis,courtney beatles::150:john,paul,george,ringoTo give root, john, paul, george, ringo, and tina ppp access, one could add the line:
ppp::200:root,beatles,tinaNote that as in this example, you can add groups to groups if you want all users in a group to have access. Above, the group beatles have been added to the group ppp, which by implication include users john, paul, george and ringo. In addition, the group number (200) that I have assigned is an arbitrary number. The only requirement placed on it is that it uniquely identifies this group.
You need not concern yourself with why you would need a password field for a group. Just leave it blank like the rest of the default groups in that file. If you have a need to know about group passwords and how such groups are managed, Running Linux by Welsh and Kaufman gives an extensive explanation on this beginning on page 132.
root, john, paul, george, ringo, alanis and courtney are assumed to be users that don't have "200" set as the default group-id in /etc/passwd. Again, see Running Linux, pages 129-131 for details on the /etc/passwd file if you are not familiar with password files.
since Apr 1 2007