3.3 Compiling OpenLDAP 2

Once the necessary software libraries have been installed and correctly configured, compiling and installing OpenLDAP becomes a matter defining the appropriate options for the configure script and executing the make command. For the sake of simplicity, all examples in this book assume that the root directory for the OpenLDAP installation is /usr/local, which is the default.

Most of the configuration options are set to reasonable defaults or will be set appropriately by the configure script itself. I've already mentioned the �disable-threads option, which you can use if you don't want thread support. You should also be aware of the �enable-wrappers option, which uses the tcp_wrappers libraries for restricting access via the standard /etc/hosts.allow and /etc/hosts.deny. In order to use this option, the tcpd.h header file and libwrap.a library must be installed on a local system.

For more information on tcp_wrappers, refer to the hosts_access(5) manpage or Wietse Venema's tcp_wrappers web page, which is located at ftp://ftp.porcupine.org/pub/security/index.html.

After extracting the source files using the command:

$ gzip -dc openldap-2.1.8.tar.gz | tar xvf -

go into the newly created directory and execute the ./configure script, defining any options you wish to enable or disable. For example:

$ cd openldap-2.1.8/
$ ./configure --enable-wrappers

Be sure to examine the output that follows this command to verify that the correct DBM libraries were located and any other options you defined were correctly configured. Once you are satisfied with the configuration process, building the OpenLDAP clients and servers is a four-step process:

$ make depend 
$ make
$ make test
$ /bin/su -c "make install"

Here are some things to check if you have any problems:

• On systems that support it, the ldd tool can be used to verify that the LDAP server binary, slapd, is linked with the correct shared libraries. For example, if libsasl.so cannot be located but is installed in /usr/local/lib/, check your system's documentation for adding directories to the library search path. Under Linux, add the directory to /etc/ld.so.conf and rerun ldconfig -v; under Solaris (or Linux), set the LD_LIBRARY_PATH environment variable.

• Verify that DNS resolution for your host is configured correctly. In particular, reverse DNS resolution is important. Problems with DNS resolution can make it appear that the OpenLDAP server is not responding.

• Verify that the network interface on the host is configured and functioning properly. I experience this problem quite often when using my laptop as a test server.