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.com

Gabriel Vasile

   FhG FOKUS

Juha Heinanen

   TutPro Inc.

Edited by

Jan Janak

Edited by

Bogdan-Andrei Iancu

Edited by

Gabriel Vasile

   Copyright © 2008, 2005, 2003 1&1 Internet AG, FhG Fokus, Voice Sistem
   SRL
     __________________________________________________________________

   Table of Contents

   1. Admin Guide

        1. Overview
        2. Dependencies

              2.1. Kamailio Modules
              2.2. External Libraries or Applications

        3. Parameters

              3.1. ring_timeout (int)
              3.2. options_accept (string)
              3.3. options_accept_encoding (string)
              3.4. contact_flds_separator (string)
              3.5. options_accept_language (string)
              3.6. options_support (string)
              3.7. rpid_prefix (string)
              3.8. rpid_suffix (string)
              3.9. rpid_avp (string)

        4. Functions

              4.1. ring_insert_callid()
              4.2. options_reply()
              4.3. is_user(username)
              4.4. has_totag()
              4.5. uri_param(param)
              4.6. uri_param(param,value)
              4.7. add_uri_param(param)
              4.8. get_uri_param(name, var)
              4.9. tel2sip(uri, hostpart, result)
              4.10. is_e164(pseudo-variable)
              4.11. is_uri_user_e164(pseudo-variable)
              4.12. encode_contact(encoding_prefix,hostpart)
              4.13. decode_contact()
              4.14. decode_contact_header()
              4.15. cmp_uri(str1, str2)
              4.16. cmp_aor(str1, str2)
              4.17. append_rpid_hf()
              4.18. append_rpid_hf(prefix, suffix)
              4.19. is_rpid_user_e164()
              4.20. set_uri_user(uri, user)
              4.21. set_uri_host(uri, host)
              4.22. is_request()
              4.23. is_reply()
              4.24. is_gruu([uri])
              4.25. is_supported(option)
              4.26. is_first_hop()

   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 contact_flds_separator parameter
   1.5. Set options_accept_language parameter
   1.6. Set options_support parameter
   1.7. rpid_prefix parameter example
   1.8. rpid_suffix parameter example
   1.9. rpid_avp parameter example
   1.10. ring_insert_callid() usage
   1.11. options_reply usage
   1.12. is_user usage
   1.13. has_totag usage
   1.14. uri_param usage
   1.15. uri_param usage
   1.16. add_uri_param usage
   1.17. add_uri_param usage
   1.18. tel2sip usage
   1.19. is_e164 usage
   1.20. is_uri_user_e164 usage
   1.21. encode_contact usage
   1.22. decode_contact usage
   1.23. decode_contact_header usage
   1.24. cmp_uri usage
   1.25. cmp_aor usage
   1.26. append_rpid_hf usage
   1.27. append_rpid_hf(prefix, suffix) usage
   1.28. is_rpid_user_e164 usage
   1.29. set_uri_user usage
   1.30. set_uri_host usage
   1.31. is_request usage
   1.32. is_reply usage
   1.33. is_gruu() usage
   1.34. is_supported() usage
   1.35. is_first_hop() usage

Chapter 1. Admin Guide

   Table of Contents

   1. Overview
   2. Dependencies

        2.1. Kamailio Modules
        2.2. External Libraries or Applications

   3. Parameters

        3.1. ring_timeout (int)
        3.2. options_accept (string)
        3.3. options_accept_encoding (string)
        3.4. contact_flds_separator (string)
        3.5. options_accept_language (string)
        3.6. options_support (string)
        3.7. rpid_prefix (string)
        3.8. rpid_suffix (string)
        3.9. rpid_avp (string)

   4. Functions

        4.1. ring_insert_callid()
        4.2. options_reply()
        4.3. is_user(username)
        4.4. has_totag()
        4.5. uri_param(param)
        4.6. uri_param(param,value)
        4.7. add_uri_param(param)
        4.8. get_uri_param(name, var)
        4.9. tel2sip(uri, hostpart, result)
        4.10. is_e164(pseudo-variable)
        4.11. is_uri_user_e164(pseudo-variable)
        4.12. encode_contact(encoding_prefix,hostpart)
        4.13. decode_contact()
        4.14. decode_contact_header()
        4.15. cmp_uri(str1, str2)
        4.16. cmp_aor(str1, str2)
        4.17. append_rpid_hf()
        4.18. append_rpid_hf(prefix, suffix)
        4.19. is_rpid_user_e164()
        4.20. set_uri_user(uri, user)
        4.21. set_uri_host(uri, host)
        4.22. is_request()
        4.23. is_reply()
        4.24. is_gruu([uri])
        4.25. is_supported(option)
        4.26. is_first_hop()

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 also 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 with 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).

2. Dependencies

   2.1. Kamailio Modules
   2.2. External Libraries or Applications

2.1. Kamailio Modules

   The following modules must be loaded before this module:
     * sl -- Stateless replies.

2.2. External Libraries or Applications

   The following libraries or applications must be installed before
   running Kamailio with this module loaded:
     * None.

3. Parameters

   3.1. ring_timeout (int)
   3.2. options_accept (string)
   3.3. options_accept_encoding (string)
   3.4. contact_flds_separator (string)
   3.5. options_accept_language (string)
   3.6. options_support (string)
   3.7. rpid_prefix (string)
   3.8. rpid_suffix (string)
   3.9. rpid_avp (string)

3.1. ring_timeout (int)

   Timeout value in seconds, define how long the call-id is stored in the
   internal list kept for replacing 183 messages with 180. A reasonable
   value is "30".

   Default value is "0". This means functionality is disabled.

   Example 1.1. Set ring_timeout parameter
...
modparam("siputils", "ring_timeout", 30)
...

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/*")
...

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")
...

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

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

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 many devices around which
   support other languages than the default English.

   Default value is "en".

   Example 1.5. Set options_accept_language parameter
...
modparam("siputils", "options_accept_language", "de")
...

3.6. options_support (string)

   This parameter is the content of the Support header field, indicating
   SIP extensions. 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")
...

3.7. rpid_prefix (string)

   Prefix to be added to Remote-Party-ID header field just before the URI
   returned from either radius or database.

   Default value is "".

   Example 1.7. rpid_prefix parameter example
modparam("auth", "rpid_prefix", "Whatever <")

3.8. rpid_suffix (string)

   Suffix to be added to Remote-Party-ID header field after the URI
   returned from either radius or database.

   Default value is ";party=calling;id-type=subscriber;screen=yes".

   Example 1.8. rpid_suffix parameter example
modparam("auth", "rpid_suffix", "@1.2.3.4>")

3.9. rpid_avp (string)

   Full AVP specification for the AVP which stores the RPID value. It used
   to transport the RPID value from authentication backend modules
   (auth_db or auth_radius) or from script to the auth function
   append_rpid_hf and is_rpid_user_e164.

   If defined to NULL string, all RPID functions will fail at runtime.

   Default value is "$avp(s:rpid)".

   Example 1.9. rpid_avp parameter example
modparam("auth", "rpid_avp", "$avp(myrpid)")

4. Functions

   4.1. ring_insert_callid()
   4.2. options_reply()
   4.3. is_user(username)
   4.4. has_totag()
   4.5. uri_param(param)
   4.6. uri_param(param,value)
   4.7. add_uri_param(param)
   4.8. get_uri_param(name, var)
   4.9. tel2sip(uri, hostpart, result)
   4.10. is_e164(pseudo-variable)
   4.11. is_uri_user_e164(pseudo-variable)
   4.12. encode_contact(encoding_prefix,hostpart)
   4.13. decode_contact()
   4.14. decode_contact_header()
   4.15. cmp_uri(str1, str2)
   4.16. cmp_aor(str1, str2)
   4.17. append_rpid_hf()
   4.18. append_rpid_hf(prefix, suffix)
   4.19. is_rpid_user_e164()
   4.20. set_uri_user(uri, user)
   4.21. set_uri_host(uri, host)
   4.22. is_request()
   4.23. is_reply()
   4.24. is_gruu([uri])
   4.25. is_supported(option)
   4.26. is_first_hop()

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. Please note 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 1.10. ring_insert_callid() usage
...
ring_insert_callid();
...

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

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

4.4. has_totag()

   Check if To header field uri contains tag parameter.

   This function can be used from ANY_ROUTE.

   Example 1.13. has_totag usage
...
if (has_totag()) {
        ...
};
...

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

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

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

4.8. get_uri_param(name, var)

   Get the value of RURI parameter.

   Meaning of the parameters is as follows:
     * name - the name of R-URI parameter
     * var - the variable where to store the value of the parameter

   This function can be used from REQUEST_ROUTE.

   Example 1.17. add_uri_param usage
...
get_uri_param("nat", "$var(nat)");
...

4.9. tel2sip(uri, hostpart, result)

   Converts URI in first param (pseudo variable or string) to SIP URI, if
   it is a tel URI. If conversion was done, writes resulting SIP URI to
   third param (pseudo variable). Returns 1 if conversion succeeded or if
   no conversion was needed.

   The conversion follows the rules in RFC 3261 section 19.1.6:
     * Visual separators ( "-", ".", "(", ")" ) are removed from tel URI
       number before converting it to SIP URI userinfo.
     * tel URI parameters are downcased before appending them to SIP URI
       userinfo

   The SIP URI hostpart is taken from second param (pseudo variable or
   string).

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

   Example 1.18. tel2sip usage
...
# $ru: tel:+(34)-999-888-777
# $fu: sip:test@foo.com
tel2sip("$ru", $fd", "$ru");
# $ru:  sip:+34999888777@foo.com;user=phone

# $ru: tel:+12-(34)-56-78;Ext=200;ISUB=+123-456
# $fu: sip:test@foo.com
tel2sip("$ru", $fd", "$ru");
# $ru:  sip:+12345678;ext=200;isub=+123-456@foo.com;user=phone
...

4.10. is_e164(pseudo-variable)

   Checks if string value of pseudo variable argument is an E164 number.

   This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, and
   LOCAL_ROUTE.

   Example 1.19. is_e164 usage
...
if (is_164("$fU")) {  # Check From header URI user part
   ...
}
if (is_e164("$avp(i:705)") {
   # Check stgring value stored in avp i:705
   ...
};
...

4.11. is_uri_user_e164(pseudo-variable)

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

   This function can be used from ANY_ROUTE.

   Example 1.20. 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
   ...
};
...

4.12. encode_contact(encoding_prefix,hostpart)

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

   * is the default separator and can be changed by setting the
   contact_flds_separator module parameter.

   Note: This function discards all of the URI parameters. Thus, none of
   the parameters (except the transport parameter which is encoded into
   the userpart) can be restored.

   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.
     * hostpart - An IP address or a hostname.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE.

   Example 1.21. encode_contact usage
...
if (src_ip == 10.0.0.0/8) encode_contact("natted_client","1.2.3.4");
...

4.13. decode_contact()

   This function will decode the request URI. If the RURI is in the format
   sip:encoding_prefix*username*ip*port*protocol@hostpart it will be
   decoded 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 1.22. decode_contact usage
...
if (uri =~ "^sip:natted_client") { decode_contact(); }
...

4.14. decode_contact_header()

   This function will decode URIs inside Contact header. If the URI in the
   format sip:encoding_prefix*username*ip*port*protocol@hostpart it will
   be decoded 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 1.23. decode_contact_header usage
...
reply_route[2] {
        ...
        decode_contact_header();
        ...
}
...

4.15. cmp_uri(str1, str2)

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

   This function can be used from ANY_ROUTE.

   Example 1.24. cmp_uri usage
...
if(cmp_uri("$ru", "sip:kamailio@kamailio.org"))
{
    # do interesting stuff here
}
...

4.16. 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 ANY_ROUTE.

   Example 1.25. cmp_aor usage
...
if(cmp_aor("$rU@KaMaIlIo.org", "sip:kamailio@$fd"))
{
    # do interesting stuff here
}
...

4.17. append_rpid_hf()

   Appends to the message a Remote-Party-ID header that contains header
   'Remote-Party-ID: ' followed by the saved value of the SIP URI received
   from the database or radius server followed by the value of module
   parameter radius_rpid_suffix. The function does nothing if no saved SIP
   URI exists.

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

   Example 1.26. append_rpid_hf usage
...
append_rpid_hf();  # Append Remote-Party-ID header field
...

4.18. append_rpid_hf(prefix, suffix)

   This function is the same as Section 4.17, " append_rpid_hf()". The
   only difference is that it accepts two parameters--prefix and suffix to
   be added to Remote-Party-ID header field. This function ignores
   rpid_prefix and rpid_suffix parameters, instead of that allows to set
   them in every call.

   Meaning of the parameters is as follows:
     * prefix - Prefix of the Remote-Party-ID URI. The string will be
       added at the begining of body of the header field, just before the
       URI.
     * suffix - Suffix of the Remote-Party-ID header field. The string
       will be appended at the end of the header field. It can be used to
       set various URI parameters, for example.

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

   Example 1.27. append_rpid_hf(prefix, suffix) usage
...
# Append Remote-Party-ID header field
append_rpid_hf("", ";party=calling;id-type=subscriber;screen=yes");
...

4.19. is_rpid_user_e164()

   The function checks if the SIP URI received from the database or radius
   server and will potentially be used in Remote-Party-ID header field
   contains an E164 number (+followed by up to 15 decimal digits) in its
   user part. Check fails, if no such SIP URI exists (i.e. radius server
   or database didn't provide this information).

   This function can be used from REQUEST_ROUTE.

   Example 1.28. is_rpid_user_e164 usage
...
if (is_rpid_user_e164()) {
    # do something here
};
...

4.20. set_uri_user(uri, user)

   Sets userpart of SIP URI stored in writable pseudo variable 'uri' to
   value of pseudo variable 'user'.

   This function can be used from ANY_ROUTE.

   Example 1.29. set_uri_user usage
...
$var(uri) = "sip:user@host";
$var(user) = "new_user";
set_uri_user("$var(uri)", "$var(user)");
...

4.21. set_uri_host(uri, host)

   Sets hostpart of SIP URI stored in writable pseudo variable 'uri' to
   value of pseudo variable 'host'.

   This function can be used from ANY_ROUTE.

   Example 1.30. set_uri_host usage
...
$var(uri) = "sip:user@host";
$var(host) = "new_host";
set_uri_host("$var(uri)", "$var(host)");
...

4.22. is_request()

   Return true if the SIP message is a request.

   This function can be used from ANY_ROUTE.

   Example 1.31. is_request usage
...
if (is_request()) {
        ...
}
...

4.23. is_reply()

   Return true if the SIP message is a reply.

   This function can be used from ANY_ROUTE.

   Example 1.32. is_reply usage
...
if (is_reply()) {
        ...
}
...

4.24. is_gruu([uri])

   The function returns true if the uri is GRUU ('gr' parameter is
   present): 1 - pub-gruu; 2 - temp-gruu.

   Meaning of the parameters is as follows:
     * uri - the SIP URI to check for GRUU parameter. It is optional, when
       missing, the value of R-URI is used.

   This function can be used from ANY_ROUTE.

   Example 1.33. is_gruu() usage
...
if(is_gruu()) { ... }
...

4.25. is_supported(option)

   Function returns true if given option is listed in Supported header(s)
   (if any) of the request. Currently the following options are known:
   path, 100rel, timer, eventlist, gruu, and outbound.

   This function can be used from ANY_ROUTE.

   Example 1.34. is_supported() usage
...
if (is_supported("outbound")) { ... }
...

4.26. is_first_hop()

   The function returns true if the proxy is first hop after the original
   sender. For incoming SIP requests, it means there is only one Via
   header. For incoming SIP replies, it means that top Record-Route URI is
   'myself' and source address is not matching it (to avoid detecting in
   case of local loops). Note that it does not detect spirals, which can
   have the condition for replies true also in the case of additional SIP
   reply receival.

   This function can be used from ANY_ROUTE.

   Example 1.35. is_first_hop() usage
...
if(is_first_hop()) { ... }
...
