This plugin implements a buddy lookup using a xml-rpc lookup to a distant server.
The server side implementation isn't available here but it is quite simple to implement.
The format of the xml-rpc request defined below:

The function name is "fp.searchUsers"
 /**
 * Arguments:
 * sip_uri: string, mandatory, the SIP username, ie john.doe@example.net
 * password: string, mandatory, the SIP password
 * criteria: string, mandatory, the key or criteria to search for, multiple keywords should be space separated
 * limit: int, optional default 100, the maximum number of results to get back, -1 for all of them (note that -1 would really be limited by a hard limit at the server, something decent in the style of 100 or similar).
 * offset: int, optional default 0, where to start in the result list for the given criteria
 * domain: string, optional default is the same name as the SIP name, in which domain to search for users
 * 
 * Returns:
 * If sip-uri & password is correct, an array where each element is a struct with the following members:
 * first_name: string, example: "John"
 * last_name: string, example: "Doe"
 * display_name: string, example: "John Doe"
 * street: string, example: "Paradise Avenue"
 * zip: string, example: "7777777"
 * city: string, example: "Heaven"
 * country: string, example: "SKY"
 * email: string, example: "john.doe@example.net"
 * sip: string, example "john.doe@example.net"
 * domain: string, example: "myjoice.com"
 * 
 * If username || password is incorrect an error with a numeric code and a message is returned.
 *
 */

The server uri is configurable in ~/.linphonerc :

[BuddyLookup]
url=https://....
