siputils

Hardy Kahl

1&1 Internet AG

Henning Westerholt

1&1 Internet AG

Nils Ohlmeier

FhG Fokus

Jan Janak

FhG FOKUS

Daniel-Constantin Mierla

Asipto SRL

Gabriel Vasile

FhG FOKUS

Edited by

Jan Janak

Edited by

Bogdan-Andrei Iancu

Edited by

Gabriel Vasile

Revision History
Revision $Revision: 4872 $	$Date: 2008-09-09 17:39:38 +0200 (Di, 09 Sep 2008) $

List of Examples

1.1. Set ring_timeout parameter
1.2. Set options_accept parameter
1.3. Set options_accept_encoding parameter
1.4. Set db_url parameter
1.5. Set options_accept_language parameter
1.6. Set options_support parameter
1.7. ring_insert_callid() usage
1.8. options_reply usage
1.9. is_user usage
1.10. has_totag usage
1.11. uri_param usage
1.12. uri_param usage
1.13. add_uri_param usage
1.14. tel2sip usage
1.15. is_uri_user_e164 usage
1.16. encode_contact usage
1.17. decode_contact usage
1.18. decode_contact_header usage
1.19. cmp_uri usage
1.20. cmp_aor usage

Chapter 1. Admin Guide

1.1. Overview

This module implement various functions and checks related to SIP message handling and URI handling.

It offers some functions related to handle ringing. In a parallel forking scenario you get several 183s with SDP. You don't want that your customers hear more than one ringtone or answer machine in parallel on the phone. So its necessary to drop the 183 in this cases and send a 180 instead.

This module provides a function to answer OPTIONS requests which are directed to the server itself. This means an OPTIONS request which has the address of the server in the request URI, and no username in the URI. The request will be answered with a 200 OK which the capabilities of the server.

To answer OPTIONS request directed to your server is the easiest way for is-alive-tests on the SIP (application) layer from remote (similar to ICMP echo requests, also known as “ping”, on the network layer).

1.2. Dependencies

1.2.1. Kamailio Modules

The following modules must be loaded before this module:

sl -- Stateless replies.

1.2.2. External Libraries or Applications

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

None.

1.3. Exported Parameters

1.3.1. `ring_timeout` (int)

Timeout value in seconds, define how long the call-id is stored in the internal list. A reasonable value is “30”.

Default value is “0”.

Example 1.1. Set ring_timeout parameter

...
modparam("siputils", "ring_timeout", 30)
...

1.3.2. `options_accept` (string)

This parameter is the content of the Accept header field. Note: it is not clearly written in RFC3261 if a proxy should accept any content (the default “*/*”) because it does not care about content. Or if it does not accept any content, which is “”.

Default value is “*/*”.

Example 1.2. Set options_accept parameter

...
modparam("siputils", "options_accept", "application/*")
...

1.3.3. `options_accept_encoding` (string)

This parameter is the content of the Accept-Encoding header field. Please do not change the default value because Kamailio does not support any encodings yet.

Default value is “”.

Example 1.3. Set options_accept_encoding parameter

...
modparam("siputils", "options_accept_encoding", "gzip")
...

1.3.4. `contact_flds_separator` (string)

First char of this parameter is used as separator for encoding/decoding Contact header.

Warning

First char of this field must be set to a value which is not used inside username,password or other fields of contact. Otherwise it is possible for the decoding step to fail/produce wrong results.

Default value is “*”.

Example 1.4. Set db_url parameter

...
modparam("siputils", "contact_flds_separator", "-")
...

then an encoded uri might look sip:user-password-ip-port-protocol@PublicIP

1.3.5. `options_accept_language` (string)

This parameter is the content of the Accept-Language header field. You can set any language code which you prefer for error descriptions from other devices, but presumably there are not much devices around which support other languages then the default English.

Default value is “en”.

Example 1.5. Set options_accept_language parameter

...
modparam("siputils", "options_accept_language", "de")
...

1.3.6. `options_support` (string)

This parameter is the content of the Support header field. Please do not change the default value, because Kamailio currently does not support any of the SIP extensions registered at the IANA.

Default value is “”.

Example 1.6. Set options_support parameter

...
modparam("siputils", "options_support", "100rel")
...

1.4. Exported Functions

1.4.1. `ring_insert_callid()`

Inserting the call-id in the internal list, which is checked when further replies arrive. Any 183 reply that is received during the timeout value will be converted to a 180 message, the SDP body is removed as well. Please not that you need to set a positive timeout value in order to use this function.

The function returns TRUE on success, and FALSE during processing failures.

This function can be used from REQUEST_ROUTE and FAILURE_ROUTE.

Example 1.7. ring_insert_callid() usage

...
ring_insert_callid();
...

1.4.2. `options_reply()`

This function checks if the request method is OPTIONS and if the request URI does not contain an username. If both is true the request will be answered stateless with “200 OK” and the capabilities from the modules parameters.

It sends “500 Server Internal Error” for some errors and returns false if it is called for a wrong request.

The check for the request method and the missing username is optional because it is also done by the function itself. But you should not call this function outside the myself check because in this case the function could answer OPTIONS requests which are sent to you as outbound proxy but with an other destination then your proxy (this check is currently missing in the function).

This function can be used from REQUEST_ROUTE.

Example 1.8. options_reply usage

...
if (uri==myself) {
	if ((method==OPTIONS) && (! uri=~"sip:.*[@]+.*")) {
		options_reply();
	}
}
...

1.4.3. `is_user(username)`

Check if the username in credentials matches the given username.

Meaning of the parameters is as follows:

username - Username string.

This function can be used from REQUEST_ROUTE.

Example 1.9. is_user usage

...
if (is_user("john")) {
	...
};
...

1.4.4. `has_totag()`

Check if To header field uri contains tag parameter.

This function can be used from REQUEST_ROUTE.

Example 1.10. has_totag usage

...
if (has_totag()) {
	...
};
...

1.4.5. `uri_param(param)`

Find if Request URI has a given parameter with no value

Meaning of the parameters is as follows:

param - parameter name to look for.

This function can be used from REQUEST_ROUTE.

Example 1.11. uri_param usage

...
if (uri_param("param1")) {
	...
};
...

1.4.6. `uri_param(param,value)`

Find if Request URI has a given parameter with matching value

Meaning of the parameters is as follows:

param - parameter name to look for.
value - parameter value to match.

This function can be used from REQUEST_ROUTE.

Example 1.12. uri_param usage

...
if (uri_param("param1","value1")) {
	...
};
...

1.4.7. `add_uri_param(param)`

Add to RURI a parameter (name=value);

Meaning of the parameters is as follows:

param - parameter to be appended in “name=value” format.

This function can be used from REQUEST_ROUTE.

Example 1.13. add_uri_param usage

...
add_uri_param("nat=yes");
...

1.4.8. `tel2sip()`

Converts RURI, if it is tel URI, to SIP URI. Returns true, only if conversion succeeded or if no conversion was needed (like RURI was not tel URI.

This function can be used from REQUEST_ROUTE.

Example 1.14. tel2sip usage

...
tel2sip();
...

1.4.9. `is_uri_user_e164(pseudo-variable)`

Checks if userpart of URI stored in pseudo variable is E164 number.

This function can be used from REQUEST_ROUTE and FAILURE_ROUTE.

Example 1.15. is_uri_user_e164 usage

...
if (is_uri_user_e164("$fu")) {  # Check From header URI user part
   ...
}
if (is_uri_user_e164("$avp(i:705)") {
   # Check user part of URI stored in avp i:705
   ...
};
...

1.4.10. `encode_contact(encoding_prefix)`

This function will encode uri-s inside Contact header in the following manner sip:username:password@ip:port;transport=protocol goes sip:enc_pref*username*ip*port*protocol@public_ip * is the default separator.

The function returns negative on error, 1 on success.

Meaning of the parameters is as follows:

encoding_prefix - Something to allow us to determine that a contact is encoded publicip--a routable IP, most probably you should put your external IP of your NAT box.

This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE.

Example 1.16. encode_contact usage

...
if (src_ip == 10.0.0.0/8) encode_contact("enc_prefix","193.175.135.38"); 
...

1.4.11. `decode_contact()`

This function will decode the URI in first line in packets which come with encoded URI in the following manner sip:enc_pref*username*ip*port*protocol@public_ip goes to sip:username:password@ip:port;transport=protocol It uses the default set parameter for contact encoding separator.

The function returns negative on error, 1 on success.

Meaning of the parameters is as follows:

This function can be used from REQUEST_ROUTE.

Example 1.17. decode_contact usage

...
if (uri =~ "^enc*") { decode_contact(); }
...

1.4.12. `decode_contact_header()`

This function will decode URIs inside Contact header in the following manner sip:enc_pref*username*ip*port*protocol@public_ip goes to sip:username:password@ip:port;transport=protocol. It uses the default set parameter for contact encoding separator.

The function returns negative on error, 1 on success.

Meaning of the parameters is as follows:

This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE.

Example 1.18. decode_contact_header usage

...
if (uri =~ "^enc*") { decode_contact_header(); }
...

1.4.13. `cmp_uri(str1, str2)`

The function returns true if the two parameters matches as SIP URI.

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

Example 1.19. cmp_uri usage

...
if(cmp_uri("$ru", "sip:kamailio@kamailio.org"))
{
    # do interesting stuff here
}
...

1.4.14. `cmp_aor(str1, str2)`

The function returns true if the two parameters matches as AoR. The parameters have to be SIP URIs.

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

Example 1.20. cmp_aor usage

...
if(cmp_aor("$rU@KaMaIlIo.org", "sip:kamailio@$fd"))
{
    # do interesting stuff here
}
...

siputils

Hardy Kahl

Henning Westerholt

Nils Ohlmeier

Jan Janak

Daniel-Constantin Mierla

Gabriel Vasile

Edited by

Jan Janak

Edited by

Bogdan-Andrei Iancu

Edited by

Gabriel Vasile

Chapter 1. Admin Guide

1.1. Overview

1.2. Dependencies

1.2.1. Kamailio Modules

1.2.2. External Libraries or Applications

1.3. Exported Parameters

1.3.1. ring_timeout (int)

1.3.2. options_accept (string)

1.3.3. options_accept_encoding (string)

1.3.4. contact_flds_separator (string)

Warning

1.3.5. options_accept_language (string)

1.3.6. options_support (string)

1.4. Exported Functions

1.4.1. ring_insert_callid()

1.4.2. options_reply()

1.4.3. is_user(username)

1.4.4. has_totag()

1.4.5. uri_param(param)

1.4.6. uri_param(param,value)

1.4.7. add_uri_param(param)

1.4.8. tel2sip()

1.4.9. is_uri_user_e164(pseudo-variable)

1.4.10. encode_contact(encoding_prefix)

1.4.11. decode_contact()

1.4.12. decode_contact_header()

1.4.13. cmp_uri(str1, str2)

1.4.14. cmp_aor(str1, str2)

1.3.1. `ring_timeout` (int)

1.3.2. `options_accept` (string)

1.3.3. `options_accept_encoding` (string)

1.3.4. `contact_flds_separator` (string)

1.3.5. `options_accept_language` (string)

1.3.6. `options_support` (string)

1.4.1. `ring_insert_callid()`

1.4.2. `options_reply()`

1.4.3. `is_user(username)`

1.4.4. `has_totag()`

1.4.5. `uri_param(param)`

1.4.6. `uri_param(param,value)`

1.4.7. `add_uri_param(param)`

1.4.8. `tel2sip()`

1.4.9. `is_uri_user_e164(pseudo-variable)`

1.4.10. `encode_contact(encoding_prefix)`

1.4.11. `decode_contact()`

1.4.12. `decode_contact_header()`

1.4.13. `cmp_uri(str1, str2)`

1.4.14. `cmp_aor(str1, str2)`