Domain Module

Juha Heinanen

Edited by

Juha Heinanen


Table of Contents
1. User's Guide
1.1. Overview
1.2. Dependencies
1.3. Exported Parameters
1.3.1. db_url (string)
1.3.2. db_mode (integer)
1.3.3. domain_table (string)
1.3.4. domain_column (string)
1.4. Exported Functions
1.4.1. is_from_local()
1.5. FIFO Commands
1.5.1. domain_reload
1.5.2. domain_dump
1.6. Known Limitations
2. Developer's Guide
3. Frequently Asked Questions
List of Examples
1-1. Setting db_url parameter
1-2. nonce_expire example
1-3. Setting domain_table parameter
1-4. Setting domain_column parameter
1-5. is_from_local usage

Chapter 1. User's Guide

1.1. Overview

Domain module implements checks that based on domain table determine if a host part of an URI is "local" or not. A "local" domain is one that the proxy is responsible for.

Domain module operates in caching or non-caching mode depending on value of module parameter db_mode. In caching mode domain module reads the contents of domain table into cache memory when the module is loaded. After that domain table is re-read only when module is given domain_reload fifo command. Any changes in domain table must thus be followed by domain_reload command in order to reflect them in module behavior. In non-caching mode domain module always queries domain table in the database.

Caching is implemented using a hash table. The size of the hash table is given by HASH_SIZE constant defined in domain_mod.h. Its "factory default" value is 128.


1.2. Dependencies

The module depends on the following modules (in the other words the listed modules must be loaded before this module):

  • database -- Any database module


1.3. Exported Parameters

1.3.1. db_url (string)

This is URL of the database to be used.

Default value is "sql://serro:47serro11@localhost/ser"

Example 1-1. Setting db_url parameter

modparam("domain", "db_url", "sql://ser:pass@db_host/ser")

1.3.2. db_mode (integer)

Database mode. 0 means non-caching, 1 means caching.

Default value is 0 (non-caching).

Example 1-2. nonce_expire example

modparam("domain", "db_mode", 1)   # Use chaching

1.3.3. domain_table (string)

Name of table containing names of local domains that the proxy is responsible for. Local users must have in their sip uri a host part that is equal to one of these domains.

Default value is "domain".

Example 1-3. Setting domain_table parameter

modparam("domain", "domain_table", "new_name")

1.3.4. domain_column (string)

Name of column containing domains in domain table.

Default value is "domain".

Example 1-4. Setting domain_column parameter

modparam("domain", "domain_column", "domain_col")

1.4. Exported Functions

1.4.1. is_from_local()

Checks based on domain table if host part of From header uri is one of the local domains that the proxy is responsible for

Example 1-5. is_from_local usage

...
if (is_from_local()) {
    ...
};
...

1.5. FIFO Commands

1.5.1. domain_reload

Causes domain module to re-read the contents of domain table into cache memory.


1.5.2. domain_dump

Causes domain module to dump hash indexes and domain names in its cache memory.


1.6. Known Limitations

There is an unlikely race condition on domain list update. If a process uses a table, which is reloaded at the same time twice through FIFO, the second reload will delete the original table still in use by the process.


Chapter 2. Developer's Guide

To be done.


Chapter 3. Frequently Asked Questions

3.1. What is the meaning of life ?

3.1. What is the meaning of life ?

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