Domain Module

Juha Heinanen

   <jh@tutpro.com>

Edited by

Juha Heinanen

   <jh@tutpro.com>

   Copyright © 2002-2008 Juha Heinanen
     __________________________________________________________________

   Table of Contents

   1. Admin Guide

        1. Overview
        2. Dependencies
        3. Exported Parameters

              3.1. db_url (string)
              3.2. db_mode (integer)
              3.3. domain_table (string)
              3.4. domain_col (string)
              3.5. register_myself (integer)

        4. Exported Functions

              4.1. is_from_local()
              4.2. is_uri_host_local()
              4.3. is_domain_local(pseudo_variable)

        5. Exported MI Functions

              5.1. domain_reload
              5.2. domain_dump

        6. Exported RPC Commands

              6.1. domain.reload
              6.2. domain.dump

        7. Known Limitations

   2. Developer Guide

        1. Available Functions

              1.1. is_domain_local(domain)

   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. register_myself example
   1.6. is_from_local usage
   1.7. is_uri_host_local usage
   1.8. is_domain_local usage

Chapter 1. Admin Guide

   Table of Contents

   1. Overview
   2. Dependencies
   3. Exported Parameters

        3.1. db_url (string)
        3.2. db_mode (integer)
        3.3. domain_table (string)
        3.4. domain_col (string)
        3.5. register_myself (integer)

   4. Exported Functions

        4.1. is_from_local()
        4.2. is_uri_host_local()
        4.3. is_domain_local(pseudo_variable)

   5. Exported MI Functions

        5.1. domain_reload
        5.2. domain_dump

   6. Exported RPC Commands

        6.1. domain.reload
        6.2. domain.dump

   7. Known Limitations

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.

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

3. Exported Parameters

   3.1. db_url (string)
   3.2. db_mode (integer)
   3.3. domain_table (string)
   3.4. domain_col (string)
   3.5. register_myself (integer)

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")

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

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")

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")

3.5. register_myself (integer)

   Register the list of domains to match 'myself' check: 0 means no myself
   registration, 1 means enable myself registration.

   Default value is 0 (disable).

   Example 1.5. register_myself example
modparam("domain", "register_myself", 1)

4. Exported Functions

   4.1. is_from_local()
   4.2. is_uri_host_local()
   4.3. is_domain_local(pseudo_variable)

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

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

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 1.8. 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)")) {
        ...
};
...

5. Exported MI Functions

   5.1. domain_reload
   5.2. domain_dump

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_

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_

6. Exported RPC Commands

   6.1. domain.reload
   6.2. domain.dump

6.1. domain.reload

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

   Name: domain.reload

   Parameters: none

   Example:
                sercmd domain.reload

6.2. domain.dump

   Causes domain module to dump domain names in its cache memory.

   Name: domain.dump

   Parameters: none

   Example:
                sercmd domain.dump

7. 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 Guide

   Table of Contents

   1. Available Functions

        1.1. is_domain_local(domain)

   The module provides is_domain_local API function for use by other
   Kamailio modules.

1. Available Functions

   1.1. is_domain_local(domain)

1.1.  is_domain_local(domain)

   Checks if domain given in str* parameter is local.

   The function returns 1 if domain is local and -1 if domain is not local
   or if an error occurred.