1. Permissions Module

Miklos Tirpak

Juha Heinanen

   Copyright © 2003, 2006 Miklos Tirpak, Juha Heinanen, iptelorg GmbH
     __________________________________________________________________

   1.1. Overview

        1.1.1. Call Routing
        1.1.2. Registration Permissions
        1.1.3. Refer-To Permissions
        1.1.4. Messages catching

   1.2. Parameters

        1.2.1. default_allow_file (string)
        1.2.2. default_deny_file (string)
        1.2.3. check_all_branches (integer)
        1.2.4. allow_suffix (string)
        1.2.5. deny_suffix (string)
        1.2.6. max_rule_files (int)
        1.2.7. safe_file_load (int)
        1.2.8. db_url (string)
        1.2.9. db_mode (int)
        1.2.10. ipmatch_table (string)
        1.2.11. declare_ipset (string)

   1.3. Functions

        1.3.1. allow_routing()
        1.3.2. allow_routing(basename)
        1.3.3. allow_routing(allow_file, deny_file)
        1.3.4. allow_register(basename)
        1.3.5. allow_register(allow_file, deny_file)
        1.3.6. allow_refer_to(basename)
        1.3.7. allow_refer_to(allow_file, deny_file)
        1.3.8. ipmatch (string/AVP/select, [avp])
        1.3.9. ipmatch_onsend (string)
        1.3.10. ipmatch_filter (unsigned int)
        1.3.11. ip_is_trusted(ip_set, ip)

   1.4. XMLRPC Interface

1.1. Overview

1.1.1. Call Routing

   The module can be used to determine if a call has appropriate
   permission to be established. Permission rules are stored in plaintext
   configuration files similar to hosts.allow and hosts.deny files used by
   tcpd.

   When allow_routing function is called it tries to find a rule that
   matches selected fields of the message.

   SER is a forking proxy and therefore a single message can be sent to
   different destinations simultaneously. When checking permissions all
   the destinations must be checked and if one of them fails, the
   forwarding will fail.

   The matching algorithm is as follows, first match wins:
     * Create a set of pairs of form (From, R-URI of branch 1), (From,
       R-URI of branch 2), etc.
     * Routing will be allowed when all pairs match an entry in the allow
       file.
     * Otherwise routing will be denied when one of pairs matches an entry
       in the deny file.
     * Otherwise, routing will be allowed.

   A non-existing permission control file is treated as if it were an
   empty file. Thus, permission control can be turned off by providing no
   permission control files.

   From header field and Request-URIs are always compared with regular
   expressions! For the syntax see the sample file:
   config/permissions.allow.

1.1.2. Registration Permissions

   In addition to call routing it is also possible to check REGISTER
   messages and decide--based on the configuration files--whether the
   message should be allowed and the registration accepted or not.

   Main purpose of the function is to prevent registration of "prohibited"
   IP addresses. One example, when a malicious user registers a contact
   containing IP address of a PSTN gateway, he might be able to bypass
   authorization checks performed by the SIP proxy. That is undesirable
   and therefore attempts to register IP address of a PSTN gateway should
   be rejected. Files config/register.allow and config/register.deny
   contain an example configuration.

   Function for registration checking is called allow_register and the
   algorithm is very similar to the algorithm described in Section 1.1.1,
   “Call Routing”. The only difference is in the way how pairs are
   created.

   Instead of From header field the function uses To header field because
   To header field in REGISTER messages contains the URI of the person
   being registered. Instead of the Request-URI of branches the function
   uses Contact header field.

   Thus, pairs used in matching will look like this: (To, Contact 1), (To,
   Contact 2), (To, Contact 3), and so on..

   The algorithm of matching is same as described in Section 1.1.1, “Call
   Routing”.

1.1.3. Refer-To Permissions

   In addition to call routing and REGISTER it is also possible to check
   REFER messages and decide--based on the configuration files-- whether
   or not the message should be accepted for forwarding.

   Main purpose of the function is to prevent referring a SIP UA to
   "prohibited" IP addresses. One example is user sending a REFER request
   to PSTN gateway trying to refer it to an expensive phone number.

   Function for Refer-To checking is called allow_refer_to and the
   algorithm is very similar to the algorithm described in Section 1.1.1.
   The only difference is in the way how pairs are created.

   Instead of Request-URI the function uses Refer-To header field because
   Refer-To header field in REFER messages contains the URI to which the
   UA is being referred to. The algorithm of matching is same as described
   in Section 1.1.1.

1.1.4. Messages catching

   The module can be also used for catching messages coming from or going
   to specific network elements, for example gateways or peering partners.

   Users can register or forward the calls to the address of a gateway
   resulting unauthorized access to them. Such calls must be catched and
   dropped, see ipmatch functions for details.

1.2. Parameters

1.2.1. default_allow_file (string)

   Default allow file used by functions without parameters. If you don't
   specify full pathname then the directory in which is the main config
   file is located will be used.

   Default value is “permissions.allow”.

   Example 1. Set default_allow_file parameter
...
modparam("permissions", "default_allow_file", "/etc/permissions.allow")
...

1.2.2. default_deny_file (string)

   Default file containing deny rules. The file is used by functions
   without parameters. If you don't specify full pathname then the
   directory in which the main config file is located will be used.

   Default value is “permissions.deny”.

   Example 2. Set default_deny_file parameter
...
modparam("permissions", "default_deny_file", "/etc/permissions.deny")
...

   If both of the default file parameters are set to "" the module does
   not try to load them.

1.2.3. check_all_branches (integer)

   If set then allow_routing functions will check Request-URI of all
   branches (default). If disabled then only Request-URI of the first
   branch will be checked.

Warning

   Do not disable this parameter unless you really know what you are
   doing.

   Default value is 1.

   Example 3. Set check_all_branches parameter
...
modparam("permissions", "check_all_branches", 0)
...

1.2.4. allow_suffix (string)

   Suffix to be appended to basename to create filename of the allow file
   when version with one parameter of either allow_routing or
   allow_register is used.

Note

   Including leading dot.

   Default value is ".allow".

   Example 4. Set allow_suffix parameter
...
modparam("permissions", "allow_suffix", ".allow")
...

1.2.5. deny_suffix (string)

   Suffix to be appended to basename to create filename of the deny file
   when version with one parameter of either allow_routing or
   allow_register is used.

Note

   Including leading dot.

   Default value is ".deny".

   Example 5. Set deny_suffix parameter
...
modparam("permissions", "deny_suffix", ".deny")
...

1.2.6. max_rule_files (int)

   Maximum number of allow/deny file pairs.

   Default value is 64.

1.2.7. safe_file_load (int)

   Module initialization fails in case of a missing config file if
   safe_file_load is true.

   Default value is 0 (false).

1.2.8. db_url (string)

   URL of the database to be used.

1.2.9. db_mode (int)

   Disables/enables database cache.

   Default value is 0 (cache is disabled)

   NOTE: ipmatch functions can operate only in cache mode, set db_mode to
   1 if you want to use them.

1.2.10. ipmatch_table (string)

   Name of the table containing ipmatch entries.

   Default value is "ipmatch".

1.2.11. declare_ipset (string)

   Declares name of ip set which can be manipulated via RPC commands and
   tested using ip_is_trusted. Identifier must start with letter or
   underscore.

   IP mask may follow equal sign to initialize ipset on startup.

1.3. Functions

1.3.1.  allow_routing()

   Returns true if all pairs constructed as described in Section 1.1.1,
   “Call Routing” have appropriate permissions according to the
   configuration files. This function uses default configuration files
   specified in default_allow_file and default_deny_file.

   Example 6. allow_routing usage
...
if (allow_routing()) {
    t_relay();
};
...

1.3.2.  allow_routing(basename)

   Returns true if all pairs constructed as described in Section 1.1.1,
   “Call Routing” have appropriate permissions according to the
   configuration files given as parameters.

   Meaning of the parameters is as follows:
     * basename - Basename from which allow and deny filenames will be
       created by appending contents of allow_suffix and deny_suffix
       parameters.
       If the parameter doesn't contain full pathname then the function
       expects the file to be located in the same directory as the main
       configuration file of the server.

   Example 7. allow_routing(basename) usage
...
if (allow_routing("basename")) {
    t_relay();
};
...

1.3.3.  allow_routing(allow_file, deny_file)

   Returns true if all pairs constructed as described in Section 1.1.1,
   “Call Routing” have appropriate permissions according to the
   configuration files given as parameters.

   Meaning of the parameters is as follows:
     * allow_file - File containing allow rules.
       If the parameter doesn't contain full pathname then the function
       expects the file to be located in the same directory as the main
       configuration file of the server.
     * deny_file - File containing deny rules.
       If the parameter doesn't contain full pathname then the function
       expects the file to be located in the same directory as the main
       configuration file of the server.

   Example 8. allow_routing(allow_file, deny_file) usage
...
if (allow_routing("rules.allow", "rules.deny")) {
    t_relay();
};
...

1.3.4.  allow_register(basename)

   The function returns true if all pairs constructed as described in
   Section 1.1.2, “Registration Permissions” have appropriate permissions
   according to the configuration files given as parameters.

   Meaning of the parameters is as follows:
     * basename - Basename from which allow and deny filenames will be
       created by appending contents of allow_suffix and deny_suffix
       parameters.
       If the parameter doesn't contain full pathname then the function
       expects the file to be located in the same directory as the main
       configuration file of the server.

   Example 9. allow_register(basename) usage
...
if (method=="REGISTER") {
    if (allow_register("register")) {
        save("location");
        break;
    } else {
        sl_send_reply("403", "Forbidden");
    };
};
...

1.3.5.  allow_register(allow_file, deny_file)

   The function returns true if all pairs constructed as described in
   Section 1.1.2, “Registration Permissions” have appropriate permissions
   according to the configuration files given as parameters.

   Meaning of the parameters is as follows:
     * allow_file - File containing allow rules.
       If the parameter doesn't contain full pathname then the function
       expects the file to be located in the same directory as the main
       configuration file of the server.
     * deny_file - File containing deny rules.
       If the parameter doesn't contain full pathname then the function
       expects the file to be located in the same directory as the main
       configuration file of the server.

   Example 10. allow_register(allow_file, deny_file) usage
...
if (method=="REGISTER") {
    if (allow_register("register.allow", "register.deny")) {
        save("location");
        break;
    } else {
        sl_send_reply("403", "Forbidden");
    };
};
...

1.3.6.  allow_refer_to(basename)

   The function returns true if all pairs constructed as described in
   Section 1.1.2, “Registration Permissions” have appropriate permissions
   according to the configuration files given as parameters.

   Meaning of the parameters is as follows:
     * basename - Basename from which allow and deny filenames will be
       created by appending contents of allow_suffix and deny_suffix
       parameters.
       If the parameter doesn't contain full pathname then the function
       expects the file to be located in the same directory as the main
       configuration file of the server.

   Example 11. allow_register(basename) usage
...
if (method=="REGISTER") {
    if (allow_register("register")) {
        save("location");
        break;
    } else {
        sl_send_reply("403", "Forbidden");
    };
};
...

1.3.7.  allow_refer_to(allow_file, deny_file)

   The function returns true if all pairs constructed as described in
   Section 1.1.2 have appropriate permissions according to the
   configuration files given as parameters.

   Meaning of the parameters is as follows:
     * allow_file - File containing allow rules.
       If the parameter doesn't contain full pathname then the function
       expects the file to be located in the same directory as the main
       configuration file of the server.
     * deny_file - File containing deny rules.
       If the parameter doesn't contain full pathname then the function
       expects the file to be located in the same directory as the main
       configuration file of the server.

   Example 12. allow_register(allow_file, deny_file) usage
...
if (method=="REFER") {
    if (allow_register("refer.allow", "refer.deny")) {
       ...
    } else {
        sl_send_reply("403", "Forbidden");
    };
};
...

1.3.8.  ipmatch (string/AVP/select, [avp])

   The function tries to find an IP address and port pair (defined by the
   first function parameter) in the cached database table. Port is
   optional, it is compared only if both the function parameter and the
   database entry contain it.

   Meaning of the parameters is as follows:
     * string/AVP/select - File containing allow rules.
          + string:
            "src": the source address of the packet is used "via2": the ip
            address of the 2nd via line is used other values are not
            defined currently
          + AVP:
            e.g. "$myavp"
          + select call:
            e.g. "@via[0].host"
     * The second parameter is optional, it is used to set an AVP value
       from the database. Suitable for assigning logical identifiers to
       gateways.

   Note that IPv6 addresses must be enclosed in square brackets in case of
   port is defined: [1111:2222::3333]:5060

1.3.9.  ipmatch_onsend (string)

   ipmatch() function replacement for onsend_route block.

   The function accepts only string parameter, because even AVP reading is
   unsafe in onsend_route.

   Meaning of the parameter:
     * "dst":
       the destination address is used
     * "ruri":
       the ip:port pair is extracted from the Request URI

   The function can be used for example to catch unauthorized requests
   going to gateways: Use a flag to mark the call as PSTN either in
   request or in failure_route, and do not touch it in onreply_route. See
   the examples below.

1.3.10.  ipmatch_filter (unsigned int)

   Entries in the database can be marked to group the different kind of
   network elements. The function sets the filter which is used on the
   mark while comparing the IP addresses. The mark must be the power of 2
   in the database!

   Note that ipmatch() and ipmatch_onsend() functions reset the filter!

   Example 13. ipmatch_filter (unsigned int) usage
+-----------------+-------------------+------+------+
| ip              | avp_val           | mark | flag |
+-----------------+-------------------+------+------+
| 1111:2222::1001 | first_gw          |    1 |    1 |
| 10.38.2.10:5060 | second_gw         |    1 |    1 |
| 10.0.0.10       | first_peering     |    2 |    1 |
+-----------------+-------------------+------+------+


route[0] {
  # is this a request from a GW?
  ipmatch_filter("1");
  if (ipmatch("src", "$gw_id")) {
    # yes, it is from a GW
    ...
  } else {
    # is this a request from a peering partner?
    ipmatch_filter("2");
    if (ipmatch("src", "$peering_id")) {
       # yes, it is from a peering partner
       ...
    };
  }
  ...
  # request goes to PSTN
  setflag(PSTN);
}

onsend_route[0] {
  if (method == "INVITE" && (!isflagset(PSTN))) {
     # is this a request to a GW?
     ipmatch_filter("1");
     if (ipmatch_onsend("dst")) {
        # request is not marked with PSTN flag, but it goes to a gateway
        drop;
     }
  }
  ...
}

1.3.11.  ip_is_trusted(ip_set, ip)

   The function returns true if ip is contained in ip_set. Both IPv4 and
   IPv6 are supported.

   Meaning of the parameters is as follows:
     * ip_set is identified by comma/space/semicolon delimited list of IP
       addresses or subnet masks. The subnet mask is written in
       IP_slash_number form or as IP. If the mask is not mentioned then
       default value is taken, the default value is number of bits of
       particular IP address, i.e. 32 in case of IPv4, 128 in case of
       IPv6.
       Besides list also ip set identifier declared by declare_ipset may
       be provided. In this case ip is checked against set maintainded by
       RPC commands.
     * ip to test. Besides direct address in string form there are extra
       identifiers to force IP related to current message: Source,
       Destination, Received. Note that only the first character is
       essential.

   Example 14. ip_is_trusted usage
modparam("permissions", "declare_ipset", "my_ipset1");
modparam("permissions", "declare_ipset", "my_ipset2=127.0.0.0/24;10.0.0.0/255.25
5.255.0");

route[TT2] {
        if (ip_is_trusted("$net", "$ip")) {
                xlog("L_E", "'%$ip' - TRUE\n");
        } else {
                xlog("L_E", "'%$ip' - FALSE\n");
        }
}

route[TT1] {
        xlog("L_E", "Testing netmask '%$net'\n");

        $ip = "s";   # source address
        route(TT2);

        $ip = "127.0.0.1";
        route(TT2);

        $ip = "127.0.0.2";
        route(TT2);

        $ip = "10.0.0.1";
        route(TT2);

        $ip = "11.0.0.1";
        route(TT2);

        $ip = "172.1.8.1";
        route(TT2);

        $ip = "192.168.1.1";
        route(TT2);

        $ip = "192.168.1.255";
        route(TT2);

        $ip = "192.168.2.1";
        route(TT2);

        $ip = "192.168.3.1";
        route(TT2);

        $ip = "192.168.4.97";
        route(TT2);

        $ip = "192.168.4.100";
        route(TT2);

        $ip = "[0:2:4:A:B:D:E:F301]";
        route(TT2);

        $ip = "[0:2:4:A:B:D:E:F401]";
        route(TT2);

        $ip = "[0:0:0:0:0:0:0:0]";
        route(TT2);
}

route[TEST] {
        $net = "0.0.0.0 128.2.3.4/1 127.0.128.16 [0:2:4:A:B:D:E:F301]";
        route(TT1);

        $net = "255.255.255.255/0"; # all IPv4 addresses, dentical to 0.0.0.0/0
        route(TT1);

        $net = "127.0.0.1/255.255.255.0";
        route(TT1);

        $net = "10.0.0.0/8";  # All type A addresses
        route(TT1);

        $net = "192.168.1.0/24";
        route(TT1);

        $net = "192.168.4.96/27";
        route(TT1);

        $net = "192.168.1.1/32"; # only one IP matches
        route(TT1);

        $net = "192.168.1.0/24,192.168.2.0/24";
        route(TT1);

        $net = "192.168.1.0/24,192.168.2.0/24,127.0.0.1/31";
        route(TT1);

        $net = "[0:0:0:0:0:0:0:0]/0";  # all IPv6 addresses
        route(TT1);

        $net = "[0:2:4:A:B:D:E:f300]/120";
        route(TT1);

        $net = "my_ipset1";
        route(TT1);

}
# the result is:

Testing netmask '0.0.0.0 128.2.3.4/1 127.0.128.16 [0:2:4:A:B:D:E:F301]'
's' - FALSE
'127.0.0.1' - FALSE
'127.0.0.2' - FALSE
'10.0.0.1' - FALSE
'11.0.0.1' - FALSE
'172.1.8.1' - TRUE
'192.168.1.1' - TRUE
'192.168.1.255' - TRUE
'192.168.2.1' - TRUE
'192.168.3.1' - TRUE
'192.168.4.97' - TRUE
'192.168.4.100' - TRUE
'[0:2:4:A:B:D:E:F301]' - TRUE
'[0:2:4:A:B:D:E:F401]' - FALSE
'[0:0:0:0:0:0:0:0]' - FALSE
Testing netmask '255.255.255.255/0'
's' - TRUE
'127.0.0.1' - TRUE
'127.0.0.2' - TRUE
'10.0.0.1' - TRUE
'11.0.0.1' - TRUE
'172.1.8.1' - TRUE
'192.168.1.1' - TRUE
'192.168.1.255' - TRUE
'192.168.2.1' - TRUE
'192.168.3.1' - TRUE
'192.168.4.97' - TRUE
'192.168.4.100' - TRUE
'[0:2:4:A:B:D:E:F301]' - FALSE
'[0:2:4:A:B:D:E:F401]' - FALSE
'[0:0:0:0:0:0:0:0]' - FALSE
Testing netmask '127.0.0.1/24'
's' - FALSE
'127.0.0.1' - TRUE
'127.0.0.2' - TRUE
'10.0.0.1' - FALSE
'11.0.0.1' - FALSE
'172.1.8.1' - FALSE
'192.168.1.1' - FALSE
'192.168.1.255' - FALSE
'192.168.2.1' - FALSE
'192.168.3.1' - FALSE
'192.168.4.97' - FALSE
'192.168.4.100' - FALSE
'[0:2:4:A:B:D:E:F301]' - FALSE
'[0:2:4:A:B:D:E:F401]' - FALSE
'[0:0:0:0:0:0:0:0]' - FALSE
Testing netmask '10.0.0.0/8'
's' - FALSE
'127.0.0.1' - FALSE
'127.0.0.2' - FALSE
'10.0.0.1' - TRUE
'11.0.0.1' - FALSE
'172.1.8.1' - FALSE
'192.168.1.1' - FALSE
'192.168.1.255' - FALSE
'192.168.2.1' - FALSE
'192.168.3.1' - FALSE
'192.168.4.97' - FALSE
'192.168.4.100' - FALSE
'[0:2:4:A:B:D:E:F301]' - FALSE
'[0:2:4:A:B:D:E:F401]' - FALSE
'[0:0:0:0:0:0:0:0]' - FALSE
Testing netmask '192.168.1.0/24'
's' - FALSE
'127.0.0.1' - FALSE
'127.0.0.2' - FALSE
'10.0.0.1' - FALSE
'11.0.0.1' - FALSE
'172.1.8.1' - FALSE
'192.168.1.1' - TRUE
'192.168.1.255' - TRUE
'192.168.2.1' - FALSE
'192.168.3.1' - FALSE
'192.168.4.97' - FALSE
'192.168.4.100' - FALSE
'[0:2:4:A:B:D:E:F301]' - FALSE
'[0:2:4:A:B:D:E:F401]' - FALSE
'[0:0:0:0:0:0:0:0]' - FALSE
Testing netmask '192.168.4.96/27'
's' - FALSE
'127.0.0.1' - FALSE
'127.0.0.2' - FALSE
'10.0.0.1' - FALSE
'11.0.0.1' - FALSE
'172.1.8.1' - FALSE
'192.168.1.1' - FALSE
'192.168.1.255' - FALSE
'192.168.2.1' - FALSE
'192.168.3.1' - FALSE
'192.168.4.97' - TRUE
'192.168.4.100' - TRUE
'[0:2:4:A:B:D:E:F301]' - FALSE
'[0:2:4:A:B:D:E:F401]' - FALSE
'[0:0:0:0:0:0:0:0]' - FALSE
Testing netmask '192.168.1.1/32'
's' - FALSE
'127.0.0.1' - FALSE
'127.0.0.2' - FALSE
'10.0.0.1' - FALSE
'11.0.0.1' - FALSE
'172.1.8.1' - FALSE
'192.168.1.1' - TRUE
'192.168.1.255' - FALSE
'192.168.2.1' - FALSE
'192.168.3.1' - FALSE
'192.168.4.97' - FALSE
'192.168.4.100' - FALSE
'[0:2:4:A:B:D:E:F301]' - FALSE
'[0:2:4:A:B:D:E:F401]' - FALSE
'[0:0:0:0:0:0:0:0]' - FALSE
Testing netmask '192.168.1.0/24,192.168.2.0/24'
's' - FALSE
'127.0.0.1' - FALSE
'127.0.0.2' - FALSE
'10.0.0.1' - FALSE
'11.0.0.1' - FALSE
'172.1.8.1' - FALSE
'192.168.1.1' - TRUE
'192.168.1.255' - TRUE
'192.168.2.1' - TRUE
'192.168.3.1' - FALSE
'192.168.4.97' - FALSE
'192.168.4.100' - FALSE
'[0:2:4:A:B:D:E:F301]' - FALSE
'[0:2:4:A:B:D:E:F401]' - FALSE
'[0:0:0:0:0:0:0:0]' - FALSE
Testing netmask '192.168.1.0/24,192.168.2.0/24,127.0.0.1/31'
's' - FALSE
'127.0.0.1' - TRUE
'127.0.0.2' - FALSE
'10.0.0.1' - FALSE
'11.0.0.1' - FALSE
'172.1.8.1' - FALSE
'192.168.1.1' - TRUE
'192.168.1.255' - TRUE
'192.168.2.1' - TRUE
'192.168.3.1' - FALSE
'192.168.4.97' - FALSE
'192.168.4.100' - FALSE
'[0:2:4:A:B:D:E:F301]' - FALSE
'[0:2:4:A:B:D:E:F401]' - FALSE
'[0:0:0:0:0:0:0:0]' - FALSE
Testing netmask '[0:0:0:0:0:0:0:0]/0'
's' - FALSE
'127.0.0.1' - FALSE
'127.0.0.2' - FALSE
'10.0.0.1' - FALSE
'11.0.0.1' - FALSE
'172.1.8.1' - FALSE
'192.168.1.1' - FALSE
'192.168.1.255' - FALSE
'192.168.2.1' - FALSE
'192.168.3.1' - FALSE
'192.168.4.97' - FALSE
'192.168.4.100' - FALSE
'[0:2:4:A:B:D:E:F301]' - TRUE
'[0:2:4:A:B:D:E:F401]' - TRUE
'[0:0:0:0:0:0:0:0]' - TRUE
Testing netmask '[0:2:4:A:B:D:E:f300]/120'
's' - FALSE
'127.0.0.1' - FALSE
'127.0.0.2' - FALSE
'10.0.0.1' - FALSE
'11.0.0.1' - FALSE
'172.1.8.1' - FALSE
'192.168.1.1' - FALSE
'192.168.1.255' - FALSE
'192.168.2.1' - FALSE
'192.168.3.1' - FALSE
'192.168.4.97' - FALSE
'192.168.4.100' - FALSE
'[0:2:4:A:B:D:E:F301]' - TRUE
'[0:2:4:A:B:D:E:F401]' - FALSE
'[0:0:0:0:0:0:0:0]' - FALSE
}

1.4. XMLRPC Interface

   Some functionality may be controled using RPC commands.
     * ipmatch.reload - Reloads the cached ipmatch table. The original
       table remains active in case of any failure.
     * ipset.clean(ipset_name) - Clear all entries in "pending" ipset.
     * ipset.add(ipset_name, ip, netmask) - Add ip and mask into ipset.
       IPv6 should should be enclosed in brackets. Netmask may be
       identified as number or in IP form. Note that number requires
       leading slash, e.g. "/24" or "255.255.255.0".
     * ipset.commit(ipset_name) - Makes pending ip set usable by
       ip_is_trusted. Pending ip set is cleared.
     * ipset.list() - List declared ip sets.
     * ipset.print(ipset_name, pending) - Dump ipset trees. If pending non
       zero then pending ipset is dumped.
