Beyond Linux® From Scratch - Version 2012-01-16

Chapter 4. Security

acl-2.2.51

Introduction to acl

The acl package contains utilities to administer Access Control Lists, which are used to define more fine-grained discretionary access rights for files and directories.

This package is known to build and work properly using an LFS-7.0 platform.

Package Information

acl Dependencies

Required

attr-2.4.44

User Notes: http://wiki.linuxfromscratch.org/blfs/wiki/acl

Installation of acl

Install acl by running the following commands: 

sed -i -e 's|/@pkg_name@|&-@pkg_version@|' \
       -e 's|@prefix|$(DESTDIR)&|'         \
       -e 's|@libexec|$(DESTDIR)&|'        \
    include/builddefs.in &&

./configure --prefix=/usr --libexecdir=/usr/lib &&
make

For meaningful results, the tests need to be carried out on a file system that supports extended attributes. It is also required that Coreutils is re-installed after acl is installed so that the extra acl bit displays correctly on a ls command.

Now, as the root user: 

make install install-dev install-lib                       &&
install -dv -m755          /usr/share/doc/acl-2.2.51       &&
install -v -m644 doc/*.txt /usr/share/doc/acl-2.2.51       &&
chmod   -v 755             /usr/lib/libacl.{so.1.1.0,la}   &&
chown   -v root.root       /usr/lib/libacl.{so.1.1.0,la,a} &&
chown   -v root.root       /usr/share/man/man*/*acl*

You should now re-install Coreutils and proceed to run the test suite.

There are three sets of tests that come with this package. Issue the following to execute all three: make tests root-tests ext-tests.

Command Explanations

sed -i ... include/builddefs.in: This command changes the documentation directory to a versioned directory and provides for a DESTDIR installation.

chmod ...: This command modifies the permissions of installed library files to standards.

Configuring acl

Configuration Information

There is no configuration to acl itself, but to get any use out of acl, a filesystem needs to support access control lists.

One way to achieve this is to add the acl option to an ext3 filesystem in the /etc/fstab file as shown below: 

# file system  mount-point  type   options                 dump  fsck
#                                                                order

/dev/sda1      /            ext3   defaults,acl,user_xattr 0     2

Contents

Installed Programs: chacl, getfacl, and setfacl
Installed Library: libacl.{so,a}
Installed Directories: /usr/{include/acl,share/doc/acl-2.2.51}

Short Descriptions

chacl

changes the access control list of a file or directory.

getfacl

gets file access control lists.

setfacl

sets file access control lists.

libacl.{so,a}

contains the acl API functions.

Last updated on 2011-10-25 03:31:31 +0000