prefix_route Module

Alfred E. Heggestad

Telio Telecom

List of Examples

1. Setting db_url parameter
2. Setting db_table parameter
3. Setting exit parameter
4. prefix_route() usage
5. Sample data

1. Overview

The prefix_route module does routing based on a set of prefixes from the database. The prefix rule-set is loaded from the database into a binary tree in memory, either on startup or when issuing the "prefix_route.reload" RPC command. When calling the "prefix_route()" function from the ser.cfg configuration script, it will try to match the user part of the request URI with the best matching route. If a route is found, it will be used for further processing. If not found normal processing will continue.

Development was sponsored by Telio Telecom.

2. Parameters

2.1. db_url (string)

This is URL of the database to be used.

Default value is "mysql://ser@localhost/ser"

Example 1. Setting db_url parameter

modparam("prefix_route", "db_url", "mysql://ser:pass@db_host/ser")

2.2. db_table (string)

The name of table where to read prefix route set.

Default value is "prefix_route".

Example 2. Setting db_table parameter

modparam("prefix_route", "db_table", "new_prefix_route")

2.3. exit (int)

If set, exit the execution of the configuration file when a route block is executed upon matching a prefix. Otherwise return 1 (true).

Default value is 1 (on).

Example 3. Setting exit parameter

modparam("prefix_route", "exit", 0)

3. Functions

3.1. prefix_route([user])

This function tries to find a route from the user part of the request URI (if no parameter is provided), or from the value of the parameter. The parameter can contain config variables.

If a route is found, it will be used for further processing. Otherwise the function will return false.

Example 4. prefix_route() usage

  if (!prefix_route()) {
      xlog("L_ERR", "prefix_route(): no matching routes\n");
  if (!prefix_route("$fU")) {
      xlog("L_ERR", "prefix_route(): no matching routes\n");


4. RPC Commands

4.1. prefix_route.reload

Reload prefix route tree from the database. Validation is done and the prefix route tree will only be reloaded if there are no errors.

4.2. prefix_route.dump

Dump the current prefix route tree.

5. Database Structure

A prefix route set consists of three fields:

  • prefix - varchar(64) - Prefix rule

  • route - varchar(64) - Route name

  • comment - varchar(64) - Free-form comment

Example 5. Sample data

   | prefix | route | comment       |
   | 46     | SE    | Sweden        | 
   | 47     | NO    | Norway        | 
   | 479    | NOMOB | Norway mobile | 
   | 49     | DE    | Deutschland   | 
   | 39     | IT    | Italy         |