Sendmail with LDAP support in Slackware

The sendmail package that comes with Slackware has no LDAP support. In case that you need it then this article might help. It covers the following topics:

1. Recompile and reinstall sendmail with LDAP support
2. Reconfigure OpenLDAP
3. Reconfigure sendmail and import aliases into LDAP

Before you try to use this description make sure that you know a little about OpenLDAP and sendmail itself! This article was tested on a Slackware environment but should also work for any other Unix/Linux (except for recompiling the sendmail package).

TNS lookup over LDAP

This article describes how to migrate tnsnames.ora into LDAP. My current tnsnames.ora looks like this:

$ cat tnsnames.ora
...
PINK=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.56.100)(PORT=1521)))(CONNECT_DATA=(SERVICE_NAME=PINK)(GLOBAL_NAME=PINK)))
FLOYD=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.56.100)(PORT=1522)))(CONNECT_DATA=(SERVICE_NAME=FLOYD)(GLOBAL_NAME=FLOYD)))
...

LDAP backup with bacula

To backup your LDAP with bacula is very easy. You only need to create a script that exports the DIT in a file. Then create a job that backups this file. To start go into the bacula configuration directory and define a new job:

Creating an LDAP based address book

Imagine you have a small company with one manager, his secretary and a couple of workers. Each of these guys needs their own space to store some contacts, eg. the manager needs to store some manager contacts, the secretary needs to store some secretary contacts and workers need to store some contact about sales guys. At this point you need to create an organizational unit for your address book with more organizational units in it for all workers etc:

LDAP for Solaris 10

With this article I want you to show how to set up OpenLDAP for Solaris 10. I have here a small Sun Fire V100 with 2GB running - perfect for playing around. Using Solaris as a LDAP client is a little bit strange first, but with the time you will enjoy it. Solaris comes with a tool called ldapclient to initiate a Solaris host as a LDAP client. There is a daemon called ldap_cachemgr which will be started when you initialize Solaris as a LDAP client and it runs all the time.

PPPD with PAM/LDAP

This article is an update to the prior released article Setting up a pppd server. In this article I want you to show how to setup PPPD with authentication against LDAP using PAM in Slackware. How to setup LDAP and PAM in Slackware is described here: LDAP for Slackware Linux
Normally pppd looks for users and their passwords that may login via PPP in /etc/ppp/pap-secrets, /etc/passwd and /etc/shadow. But when you are using LDAP for your users then you need to use PPP with PAM and LDAP.

Migrating /etc/protocols into LDAP

The file /etc/protocols contains information about the protocols and their numbers. To be honest, until I tried to put every database into LDAP  that getent can handle I did not recognized or cared about the file /etc/protocols...
Before you continue reading keep in mind that I had serious trouble with my server while looking up for /etc/protocols in my LDAP. Currently I don't use it anymore just like my prior released article about migrating /etc/services into LDAP.

Migrating /etc/services into LDAP

Before you continue reading you should know that migrating /etc/services into LDAP may refuses your system to boot. I had plenty of trouble with /etc/services in LDAP, that is why I don't use it anymore. The next point is that you may use different operating systems. In this case the content of /etc/services may differ. When I take a look at /etc/services in Slackware, I have three entrys for port 1: 

Migrating /etc/rpc into LDAP

If you are using any rpc service like NFS or NIS then you probably know the command rpcinfo. With rpcinfo you can get all rpc servives running on a remote host:

# rpcinfo -p dc01
   program vers proto   port
    100000    2   tcp    111  portmapper
    100000    2   udp    111  portmapper
...

LDAP N-Way Multi-Master Replication

When you are using OpenLDAP for any reason then you should think about replication. With replication you have to setup minimum two LDAP servers. If one of your LDAP servers accidently shuts down then the other will take over. If you add content (or remove content) then you have to do it only once, the other server will get the new content by replication. Before you can use replication you have to setup a ntp server (not shown here). It is very important that both LDAP servers are usingthe same time. Also make sure that both server always know each other by FQDN. My current setup looks like this:

Migrating /etc/networks into LDAP

If you are using /etc/networks than you can move it into your LDAP. First take a look at your /etc/networks:

# cat /etc/networks
loopback        127.0.0.0
example.com     192.168.1.0
example2.com    192.168.2.0

Migrating /etc/ethers into LDAP

If you are using /etc/ethers than you can move it into your LDAP. First take a look at your /etc/ethers:

# cat /etc/ethers
00:1B:21:02:96:56    192.168.1.70
00:30:05:c5:2a:ba    192.168.1.73
98:FC:11:79:37:76    192.168.1.69

Migrating /etc/hosts into LDAP

If you are using /etc/hosts than you can move it into your LDAP. First take a look at your /etc/hosts:

# cat /etc/hosts
127.0.0.1        localhost
192.168.1.70     blog01
192.168.1.73     dc01
192.168.1.69     wlan01

Backing up and restoring your LDAP

If you're using LDAP with BDB backend then you have two chances to backup your LDAP server:

1. from any client via ldapsearch
2. on the LDAP server via slapcat

LDAP for Slackware Linux

When you work with Slackware Linux and try to authenticate with LDAP then you will figure out that it won't work. This has a simple reason: to authenticate with LDAP you need PAM, but Patrick Volkerding refuses to put PAM into Slackware because of security reason - AFAIK. Here is a small description how to setup Slackware for authentication with LDAP. But be aware: I am doing some things here that you shouldn't do under normal circumstances.

xdm, pam & fluxbox

I have configured xdm on my Slackware machine to use pam and authentication against LDAP. I won't show you here howto setup LDAP or pam on Slackware, this is more a quickie for xdm - assuming everything else is already setup!

The first thing that need to be done is to grab a copy from the source Patrick uses for xdm. You can