group Module

Jan Janak


Daniel-Constantin Mierla

Edited by

Jan Janak

Revision History
Revision $Revision$ $Date$

Table of Contents

1. Admin Guide
1. Overview
1.1. Strict membership checking
1.2. Regular Expression based checking
2. Dependencies
2.1. Kamailio Modules
2.2. External Libraries or Applications
3. Exported Parameters
3.1. db_url (string)
3.2. table (string)
3.3. user_column (string)
3.4. domain_column (string)
3.5. group_column (string)
3.6. use_domain (integer)
3.7. re_table (string)
3.8. re_exp_column (string)
3.9. re_gid_column (string)
3.10. multiple_gid (integer)
4. Exported Functions
4.1. is_user_in(URI, group)
4.2. get_user_group(URI, AVP)

List of Examples

1.1. Set db_url parameter
1.2. Set table parameter
1.3. Set user_column parameter
1.4. Set domain_column parameter
1.5. Set group_column parameter
1.6. Set use_domain parameter
1.7. Set re_table parameter
1.8. Set reg_exp_column parameter
1.9. Set re_gid_column parameter
1.10. Set multiple_gid parameter
1.11. is_user_in usage
1.12. get_user_group usage

Chapter 1. Admin Guide

1. Overview

This module provides functionalities for different methods of group membership checking.

1.1. Strict membership checking

There is a database table that contains list of users and groups they belong to. The module provides the possibility to check if a specific user belongs to a specific group.

There is no DB caching support, each check involving a DB query.

1.2. Regular Expression based checking

Another database table contains list of regular expressions and group IDs. A matching occurs if the user URI match the regular expression. This type of matching may be used to fetch the group ID(s) the user belongs to (via RE matching) .

Due performance reasons (regular expression evaluation), DB cache support is available: the table content is loaded into memory at startup and all regular expressions are compiled.

2. Dependencies

2.1. Kamailio Modules

The following modules must be loaded before this module:

  • A database module, like mysql, postgres or dbtext

2.2. External Libraries or Applications

The following libraries or applications must be installed before running Kamailio with this module loaded:

  • None.

3. Exported Parameters

3.1. db_url (string)

URL of the database table to be used.

Default value is “mysql://openserro:openserro@localhost/openser”.

Example 1.1. Set db_url parameter

modparam("group", "db_url", "mysql://username:password@dbhost/openser")

3.2. table (string)

Name of the table holding strict definitions of groups and their members.

Default value is “grp”.

Example 1.2. Set table parameter

modparam("group", "table", "grp_table")

3.3. user_column (string)

Name of the “table” column holding usernames.

Default value is “username”.

Example 1.3. Set user_column parameter

modparam("group", "user_column", "user")

3.4. domain_column (string)

Name of the “table” column holding domains.

Default value is “domain”.

Example 1.4. Set domain_column parameter

modparam("group", "domain_column", "realm")

3.5. group_column (string)

Name of the “table” column holding groups.

Default value is “grp”.

Example 1.5. Set group_column parameter

modparam("group", "group_column", "grp")

3.6. use_domain (integer)

If enabled (set to non zero value) then domain will be used also used for strict group matching; otherwise only the username part will be used.

Default value is 0 (no).

Example 1.6. Set use_domain parameter

modparam("group", "use_domain", 1)

3.7. re_table (string)

Name of the table holding definitions for regular-expression based groups. If no table is defined, the regular-expression support is disabled.

Default value is “NULL”.

Example 1.7. Set re_table parameter

modparam("group", "re_table", "re_grp")

3.8. re_exp_column (string)

Name of the “re_table” column holding the regular expression used for user matching.

Default value is “reg_exp”.

Example 1.8. Set reg_exp_column parameter

modparam("group", "reg_exp_column", "re")

3.9. re_gid_column (string)

Name of the “re_table” column holding the group IDs.

Default value is “group_id”.

Example 1.9. Set re_gid_column parameter

modparam("group", "re_gid_column", "grp_id")

3.10. multiple_gid (integer)

If enabled (non zero value) the regular-expression matching will return all group IDs that match the user; otherwise only the first will be returned.

Default value is “1”.

Example 1.10. Set multiple_gid parameter

modparam("group", "multiple_gid", 0)

4. Exported Functions

4.1.  is_user_in(URI, group)

This function is to be used for script group membership. The function returns true if username in the given URI is member of the given group and false if not.

Meaning of the parameters is as follows:

  • URI - URI whose username and optionally domain to be used, this can be one of:

    • Request-URI - Use Request-URI username and (optionally) domain.

    • To - Use To username and (optionally) domain.

    • From - Use From username and (optionally) domain.

    • Credentials - Use digest credentials username.

    • $avp(name) - Use the URI from the AVP specified by this pseudo-variable.

  • group - Name of the group to check.

This function can be used from REQUEST_ROUTE and FAILURE_ROUTE.

Example 1.11. is_user_in usage

if (is_user_in("Request-URI", "ld")) {

4.2.  get_user_group(URI, AVP)

This function is to be used for regular expression based group membership. The function returns true if username in the given URI belongs to at least one group; the group ID(s) are returned as AVPs.

Meaning of the parameters is as follows:

  • URI - URI to be matched against the regular expressions:

    • Request-URI - Use Request-URI

    • To - Use To URI.

    • From - Use From URI

    • Credentials - Use digest credentials username and realm.

    • $avp(name) - Use the URI from the AVP specified by this pseudo-variable.

  • AVP - $avp(name) - the matched group IDs are returned in this AVP.

This function can be used from REQUEST_ROUTE and FAILURE_ROUTE.

Example 1.12. get_user_group usage

if (get_user_group("Request-URI", "$avp(i:10)")) {
    xgdb("User $ru belongs to $(avp(i:10)[*]) group(s)\n");