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[[!meta copyright="Copyright © 2024 Free Software Foundation,
Inc."]]
[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
id="license" text="Permission is granted to copy, distribute and/or modify this
document under the terms of the GNU Free Documentation License, Version 1.2 or
any later version published by the Free Software Foundation; with no Invariant
Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license
is included in the section entitled [[GNU Free Documentation
License|/fdl]]."]]"""]]
[[!tag stable_URL]]
A translator for faking privileged access to an underlying filesystem.
This translator appears to give transparent access to the underlying
directory node. However, all accesses are made using the credentials
of the translator regardless of the client and the translator fakes
success for chown and chmod operations that only root could actually
do, reporting the faked IDs and modes in later stat calls, and allows
any user to open nodes regardless of permissions as is done for root.
## A trivial example
Let's demonstrate that chown and chgrp requires root permission.
$ mkdir ~/etc
$ touch ~/etc/this
$ settrans ~/etc/this /hurd/hello
$ ls -lha ~/etc/
total 12K
drwxr-xr-x 2 joshua joshua 4.0K Oct 15 20:12 .
drwxr-xr-x 33 joshua joshua 4.0K Oct 15 20:11 ..
-r--r--r-- 1 joshua joshua 14 Oct 15 20:12 this
$
$ chown root ~/etc/this
chown: changing ownership of '/home/joshua/etc/this': Operation not permitted
Now, let's run through `fakeroot-hurd`:
$ fakeroot
# ls -lha ~/etc/
total 12K
drwxr-xr-x 2 root root 4.0K Oct 15 20:12 .
drwxr-xr-x 33 root root 4.0K Oct 15 20:11 ..
-r--r--r-- 1 root root 14 Oct 15 20:12 this
The shell now believes we are root, and all the owner and group are turned into
root. Now we can chmod, chown, chgrp, ...
# chown daemon ~/etc/this
# ls -lha ~/etc/
total 12K
drwxr-xr-x 2 root root 4.0K Oct 15 20:12 .
drwxr-xr-x 33 root root 4.0K Oct 15 20:11 ..
-r--r--r-- 1 daemon root 14 Oct 15 20:12 this
## A manual example
We can also attach `/hurd/fakeroot` manually to `~/etc`, and we'll be able to
use `chown`, `chgrp`, `chmod`, etc. as a normal user.
$ settrans ~/etc /hurd/fakeroot
$ cd ~/etc
$ cd
$ showtrans ~/etc
/hurd/fakeroot
$ ls -lha ~/etc/
total 16K
drwxr-xr-x 2 joshua joshua 4.0K Oct 15 20:12 .
drwxr-xr-x 33 root root 4.0K Oct 15 20:11 ..
-r--r--r-- 1 root root 14 Oct 15 20:12 this
`fakeroot` turns all the owner and group to root when it starts. Now
we can chmod, chown, and chgrp as a normal user.
$ chown joshua ~/etc/this
$ chgrp joshua ~/etc/this
$ chmod +xr ~/etc/this
$ ls -lha ~/etc/
total 16K
drwxr-xr-x 2 joshua joshua 4.0K Oct 15 20:12 .
drwxr-xr-x 33 root root 4.0K Oct 15 20:11 ..
-rwxr-xr-x 1 joshua joshua 14 Oct 15 20:12 this
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