pingback.php

This file implements Pingback for LnBlog, as described by the Pingback specification at http://hixie.ch/specs/pingback/pingback.

Pingback is similar to Trackback in that it is a mechanism for one blog to notify another when the first blog links to it.  However, Pingback uses XML-RPC to send pings rather than HTTP POSTs.  Additionally, the Pingback enables auto-discovery of pingable resources using HTTP headers and HTML link elements, as opposed to the embedded RDF code used by Trackback.

The XML-RPC interface for Pingback consists of a single pingback.ping method which is used to send a ping.  This method takes a source and a target URI parameter.