klehr@sun.soe.clarkson.edu (Thomas J. Klehr) (12/15/90)
The following are patches to src/fs/link.c, that allow sticky
directories.
For those who aren't familiar with them, sticky directories
restrict who may delete/rename a file in the directory.
Only the owner of the file or the owner of the directory
can delete/rename files in my implementation, as long as
they have write-permission on the directory. root can also,
of course.
The definition of ALL_MODES in /usr/include/minix/const.h
should be changed from 06777 to 07777 also.
Sticky directories aren't really necessary for a single-user
system, but sometimes they're a nice feature, as in /tmp,
/usr/spool/mail, /usr/spool/at, or any other directory that
you wish to leave world-writable, and yet keep some
protection over what other users can delete. These directories
can help limit the number of set-uid root files needed; `mail'
and `at' no longer need to be set-uid root, since anyone
can write to these directories, and nobody can delete anyone
else's files.
Tom (klehr@sun.soe.clarkson.edu)
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begin 600 link.c.cdif
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end
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Thomas J. Klehr