PMDF System Manager's Guide

A substitution of the form $]ldap-url[ is handled specially. ldap-url is interpreted as an LDAP query URL and the result of the LDAP query is substituted. Standard LDAP URLs are used, with the host and port omitted; the host and port are instead specified with the LDAP_HOST and LDAP_PORT PMDF options (see Section 7.3.2 for further discussion of this option). That is, the LDAP URL should be specified as

ldap:///dn[?attributes[?scope?filter]]

where the square bracket characters [ and ] shown above indicate optional portions of the URL. The dn is required and is a distinguished name specifying the search base. The optional attributes , scope , and filter portions of the URL further refine what information to return. For a rewrite rule, the desired attributes to specify returning might be a mailRoutingSystem attribute (or some similar attribute). The scope may be any of base (the default), one , or sub . And the desired filter might be to request the return of the object whose mailDomain value matches the domain being rewritten.

For instance, at a site example.com with an LDAP server running on port 389 of the system ldap.example.com, the PMDF option file might have the lines

LDAP_HOST=ldap.example.com LDAP_PORT=389

set, and if the LDAP directory schema includes attributes mailRoutingSystem and mailDomain , then a possible rewrite rule to determine to which system to route a given sort of address might appear as:

.example.com \ $U%$H$D@$]<ldap:///o=example.com?mailRoutingSystem?sub?(mailDomain=$D)[

where here the LDAP URL substitution sequence $D is used to substituted in the current domain name into the LDAP query constructed; for ease in reading, the backslash character, \ , is used to continue the single logical rewrite rule line onto a second physical line. See Table 3-1 for a full list of the LDAP URL substitution sequences available.