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_col (string)
1.4. Exported Functions
1.4.1. is_from_local()
1.4.2. is_uri_host_local()
1.4.3. is_domain_local(pseudo_variable)
1.5. Exported MI Functions
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. db_mode example
1-3. Setting domain_table parameter
1-4. Setting domain_col parameter
1-5. is_from_local usage
1-6. is_uri_host_local usage
1-7. is_domain_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 "mysql://openserro:openserro@localhost/openser"

Example 1-1. Setting db_url parameter

modparam("domain", "db_url", "mysql://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. db_mode example

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

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_col (string)

Name of column containing domains in domain table.

Default value is "domain".

Example 1-4. Setting domain_col parameter

modparam("domain", "domain_col", "domain_name")

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

This function can be used from REQUEST_ROUTE.

Example 1-5. is_from_local usage

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

1.4.2. is_uri_host_local()

If called from route or failure route block, checks based on domain table if host part of Request-URI is one of the local domains that the proxy is responsible for. If called from branch route, the test is made on host part of URI of first branch, which thus must have been appended to the transaction before is_uri_host_local() is called.

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, BRANCH_ROUTE.

Example 1-6. is_uri_host_local usage

...
if (is_uri_host_local()) {
	...
};
...
		

1.4.3. is_domain_local(pseudo_variable)

This function checks if the domain contained in the pseudo_variable is local.

This function is a generalized form of the is_from_local() and is_uri_host_local() functions, being able to completely replace them and also extends them by allowing the domain to be taken from any of the above mentioned sources. The following equivalences exist:

  • is_domain_local("$rd") is same as is_uri_host_local()

  • is_domain_local("$fd") is same as is_from_local()

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, BRANCH_ROUTE.

Example 1-7. is_domain_local usage

...
if (is_domain_local("$rd")) {
	...
};
if (is_domain_local("$fd")) {
	...
};
if (is_domain_local("$avp(some_avp_alias)")) {
	...
};
if (is_domain_local("$avp(i:850)")) {
	...
};
if (is_domain_local("$avp(s:some_avp)")) {
	...
};
...
		

1.5. Exported MI Functions

1.5.1. domain_reload

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

Name: domain_reload

Parameters: none

MI FIFO Command Format:

		:domain_reload:_reply_fifo_file_
		_empty_line_
		

1.5.2. domain_dump

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

Name: domain_dump

Parameters: none

MI FIFO Command Format:

		:domain_dump:_reply_fifo_file_
		_empty_line_
		

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

The module does not provide any API to use in other OpenSER modules.


Chapter 3. Frequently Asked Questions

3.1. Where can I find more about OpenSER?
3.2. Where can I post a question about this module?
3.3. How can I report a bug?

3.1. Where can I find more about OpenSER?

3.2. Where can I post a question about this module?

First at all check if your question was already answered on one of our mailing lists:

E-mails regarding any stable OpenSER release should be sent to and e-mails regarding development versions should be sent to .

If you want to keep the mail private, send it to .

3.3. How can I report a bug?

Please follow the guidelines provided at: http://sourceforge.net/tracker/?group_id=139143.