# &adminguide;

## Overview

The userblacklist module allows &kamailio; to handle blacklists on a per user basis. This information is stored in a database table, which is queried to decide if the number (more exactly, the request URI user) is blacklisted or not.

An additional functionality that this module provides is the ability to handle global blacklists. This lists are loaded on startup into memory, thus providing a better performance then in the userblacklist case. This global blacklists are useful to only allow calls to certain international destinations, i.e. block all not whitelisted numbers. They could also used to prevent the blacklisting of important numbers, as whitelisting is supported too. This is useful for example to prevent the customer from blocking emergency call number or service hotlines.

The module exports three functions, check_blacklist check_user_blacklist and check_user_whitelist for usage in the config file. Furthermore its provide a FIFO function to reload the global blacklist cache.

Please note that only numerical strings for matching are supported at the moment (the used library supports this already, but its not yet implemented in the module). Non-digits on the beginning of the matched string are skipped, any later non-digits will stop the matching on this position.

## Dependencies

### &kamailio; Modules

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

- database -- Any database module

### External Libraries or Applications

The following libraries or applications must be installed before running &kamailio; with this module loaded:

- none

## Parameters

### `use_domain` (integer)

If set to non-zero value, the domain column in the userblacklist is used.

Default value is 0.

#### Set `use_domain` parameter

    ...
    modparam("userblacklist", "use_domain", 0)
    ...

### `match_mode` (integer)

The number of individual characters that are used for matching. Valid values are 10 or 128. When you specifiy 10, only digits will be used for matching, this operation mode is equivalent to the old behaviour. When configured with 128, all standard ascii chars are available for matching. Please be aware that memory requirements for storing the routing tree in shared memory will also increase by a factor of 12.8.

Default value is 10.

#### Set `match_mode` parameter

    ...
    modparam("userblacklist", "match_mode", 128)
    ...

## Functions

### `check_user_blacklist (string user, string domain, string number, string table)`

Finds the longest prefix that matches the request URI user (or the number parameter) for the given user and domain name in the database. If a match is found and it is not set to whitelist, false is returned. Otherwise, true is returned. Pseudo-variables or AVPs can be used for the user, domain and number parameters. The number and table variables are optional, the defaults are used if they are ommited. The number parameter can be used to check for example against the from URI user.

#### `check_user_blacklist` usage

    ...
    $avp(i:80) = $rU;
    # rewrite the R-URI
    if (!check_user_blacklist("$avp(i:80)", "$avp(i:82)")) {
    	sl_send_reply("403", "Forbidden");
    	exit;
    }
    ...

### `check_user_whitelist (string user, string domain, string number, string table)`

Finds the longest prefix that matches the request URI user (or the number parameter) for the given user and domain name in the database. If a match is found and it is set to whitelist, true is returned. Otherwise, false is returned. Pseudo-variables or AVPs can be used for the user, domain and number parameters. The number and table variables are optional, the defaults are used if they are ommited. The number parameter can be used to check for example against the from URI user.

#### `check_user_blacklist` usage

    ...
    $avp(i:80) = $rU;
    # rewrite the R-URI
    if (!check_user_whitelist("$avp(i:80)", "$avp(i:82)")) {
    	# process request
    	exit;
    }
    ...

### `check_blacklist ([string table])`

Finds the longest prefix that matches the request URI for the given table. If a match is found and it is not set to whitelist, false is returned. Otherwise, true is returned. If no table is given, then globalblacklist_table is used.

#### `check_blacklist` usage

    ...
    if (!check_blacklist("globalblacklist")) {
    	sl_send_reply("403", "Forbidden");
    	exit;
    }
    ...

## MI Commands

### `reload_blacklist`

Reload the internal global blacklist cache. This is necessary after the database tables for the global blacklist have been changed.

#### `reload_blacklists` usage

    ...
    &ctltool; fifo reload_blacklist
    ...

## Installation and Running

### Database setup

Before running &kamailio; with userblacklist, you have to setup the database table where the module will read the blacklist data. For that, if the table was not created by the installation script or you choose to install everything by yourself you can use the userblacklist-create.sql SQL script in the database directories in the kamailio/scripts folder as template. Database and table name can be set with module parameters so they can be changed, but the name of the columns must be as they are in the SQL script. You can also find the complete database documentation on the project webpage, &kamailiodbdocs;.

#### Example database content - globalblacklist table

    ...
    +----+-----------+-----------+
    | id | prefix    | whitelist |
    +----+-----------+-----------+
    |  1 |           |         0 |
    |  2 | 1         |         1 |
    |  3 | 123456    |         0 |
    |  4 | 123455787 |         0 |
    +----+-----------+-----------+
    ...

This table will setup a global blacklist for all numbers, only allowing calls starting with 1. Numbers that starting with 123456 and 123455787 are also blacklisted, because the longest prefix will be matched.

#### Example database content - userblacklist table

    ...
    +----+----------------+-------------+-----------+-----------+
    | id | username       | domain      | prefix    | whitelist |
    +----+----------------+-------------+-----------+-----------+
    | 23 | 49721123456788 |             | 1234      |         0 |
    | 22 | 49721123456788 |             | 123456788 |         1 |
    | 21 | 49721123456789 |             | 12345     |         0 |
    | 20 | 494675231      |             | 499034133 |         1 |
    | 19 | 494675231      | test        | 499034132 |         0 |
    | 18 | 494675453      | test.domain | 49901     |         0 |
    | 17 | 494675454      |             | 49900     |         0 |
    +----+----------------+-------------+-----------+-----------+
    ...

This table will setup user specific blacklists for certain usernames. For example for user 49721123456788 the prefix 1234 will be not allowed, but the number 123456788 is allowed. Additionally a domain could be specified that is used for username matching if the use_domain parameter is set.