afp_acls(8) Setup and Usage Howto for ACLs with Netatalk


ACL support for AFP is implemented with NFSv4 ACLs. Few filesystems and fewer OSes support these. At the time of implementation its only provided with ZFS on Solaris, Opensolaris and derived distributions.


In order to be able to support ACLs, the following things have to be configured:

1. ZFS Volumes

You MUST configure two ACL parameters for any volume you want to use with Netatalk:

aclinherit = passthrough
aclmode = passthrough

For an explanation of what these parameters mean and how to apply them see, your hosts ZFS documentation (e.g. man zfs).

2. Authentication Domain

Your server and the clients must be part of a security association where identity data is coming from a common source. ACLs in Darwin are based on UUIDs and so is the ACL specification in AFP 3.2. Therefor your source of identity data has to provide an attribute for every user and group where a UUID is stored as a ASCII string.

In other words:

• you need an Open Directory Server or an LDAP server where you store UUIDs in some attribute

• your clients must be configured to use this server

• your server should be configured to use this server via nsswitch and PAM.

This however is not a strict requirement: if you create duplicates of every LDAP/OD user and group with identic attributes (name, uid, gid) in your local data store (/etc/[passwd|group]) ACLs will work as long as user/group names/ids in the filesystem are equal to their counterparts in the LDAP/OD datastore.

• configure Netatalk via afp_ldap.conf so that Netatalk is able to retrieve the UUID for users and groups via LDAP search queries

3. Netatalk Volumes

Finally you can add options:acls to your volume defintion to add ACL support. In case your volume basedir doesn't grant read permissions via mode (like: 0700 root:adm) but only via ACLs, you MUST add the nostat option to the volume defintion.