Contributed Logic: opensips/modules/enum/README@8ec65b8f6e2c (annotated)

opensips/modules/enum/README@8ec65b8f6e2c (annotated)

opensips/modules/enum/README

Wed, 10 Feb 2010 21:25:01 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 10 Feb 2010 21:25:01 +0100
changeset 18: 8ec65b8f6e2c
parent 13: b63f281afe6b
permissions: -rw-r--r--

Extend uac_auth() of the UAC module to workaround CSEQ problems.
This logic is meant to complement that of changeset 17, which
added rich authentication credentials to the gw table and its
associated logic in the LCR module.

 Enum Module
 Juha Heinanen
    <jh@song.fi>
 Otmar Lendl
    <lendl@nic.at>
    Copyright © 2002, 2003 Juha Heinanen
    Revision History
    Revision $Revision: 5907 $ $Date: 2010-01-18 10:45:05 +0100
                               (Mon, 18 Jan 2010) $
      __________________________________________________________
    Table of Contents
 . Admin Guide
 .1. Overview
 .2. Dependencies
 .3. Exported Parameters
 .3.1. domain_suffix (string)
 .3.2. tel_uri_params (string)
 .3.3. i_enum_suffix (string)
 .3.4. isn_suffix (string)
 .3.5. branchlabel (string)
 .3.6. bl_algorithm (string)
 .4. Exported Functions
 .4.1. enum_query(["suffix"[,"service"]])
 .4.2. enum_pv_query("pvar"[,"suffix"[,"service"]])
 .4.3. i_enum_query(["suffix"[,"service"]])
 .4.4. isn_query(["suffix"[,"service"]])
 .4.5. is_from_user_enum()
    List of Examples
 .1. Setting domain_suffix module parameter
 .2. Setting tel_uri_params module parameter
 .3. Setting i_enum_suffix module parameter
 .4. Setting isn_query usage module parameter
 .5. Setting branchlabel module parameter
 .6. Zone file example
 .7. Zone file example
 .8. Setting the bl_algorithm module parameter
 .9. enum_query usage
 .10. enum_pv_query usage
 .11. isn_query usage
 .12. is_from_user_enum usage
 Chapter 1. Admin Guide
 .1. Overview
    Enum module implements [i_]enum_query functions that make an
    enum query based on the user part of the current Request-URI.
    These functions assume that the user part consists of an
    international phone number of the form +decimal-digits, where
    the number of digits is at least 2 and at most 15. Out of this
    number enum_query forms a domain name, where the digits are in
    reverse order and separated by dots followed by domain suffix
    that by default is "e164.arpa.". For example, if the user part
    is +35831234567, the domain name will be
    "7.6.5.4.3.2.1.3.8.5.3.e164.arpa.". i_enum_query operates in a
    similar fashion. The only difference is that it adds a label
    (default "i") to branch off from the default, user-ENUM tree to
    an infrastructure ENUM tree.
    After forming the domain name, enum_query queries DNS for its
    NAPTR records. From the possible response enum_query chooses
    those records, whose flags field has string value "u", and
    whose services field has string value "e2u+[service:]sip" or
    "e2u+type[:subtype][+type[:subtype]...]" (case is ignored in
    both cases), and whose regexp field is of the form
    !pattern!replacement!.
    Then enum_query sorts the chosen NAPTR records based on their
    <order, preference>. After sorting, enum_query replaces the
    current Request URI by applying regexp of the most preferred
    NAPTR record its user part and appends to the request new
    branches by applying regexp of each remaining NAPTR record to
    the user part of the current Request URI. If a new URI is a tel
    URI, enum_query appends to it as tel URI parameters the value
    of tel_uri_params module parameter. Finally, enum_query
    associates a q value with each new URI based on the <order,
    preference> of the corresponding NAPTR record.
    When using enum_query without any parameters, it searches for
    NAPTRs with service type "e2u+sip" in the default enum tree.
    When using enum_query with a single parameter, this parameter
    will be used as enum tree. When using enum_query with two
    parameters, the functionality depends on the first letter in
    the second parameter. When the first letter is not a '+' sign,
    the second parameter will be used to search for NAPTRs with
    service type "e2u+parameter:sip". When the second parameter
    starts with a '+' sign, the ENUM lookup also supports compound
    NAPTRs (e.g. "e2u+voice:sip+video:sip") and searching for
    multiple service types within one lookup. Multiple service
    types must be separeted by a '+' sign.
    Most of the time you want to route based on the RURI. On rare
    occasions you may wish to route based on something else. The
    function enum_pv_query mimics the behavior of the enum_query
    function except the E.164 number in its pseudo variable
    argument is used for the enum lookup instead of the user part
    of the RURI. Obviously the user part of the RURI is still used
    in the NAPTR regexp.
    Enum query returns 1 if the current Request URI was replaced
    and -1 if not.
    Enum module also implements is_from_user_enum function. This
    function does an enum lookup on the from user and returns true
    if found, false otherwise.
    In addition to standard ENUM, support for ISN (ITAD Subscriber
    Numbers) is provided as well. To allow ISN lookups to resolve,
    a different formatting algorithm is expected by the DNS server.
    Whereas a ENUM NAPTR record expects a DNS query of the form
 .8.7.6.5.4.3.2.1.<suffix>, ISN method expects a DNS query of
    the form 6.5.1212.<suffix>. That is, a valid ISN number includes
    a prefix of '56' in the example. The rest of the number is a
    ITAD (Internet Telephony Administrative Domain) as defined
    in RFCs 3872 and 2871, and as allocated by the IANA in
    http://www.iana.org/assignments/trip-parameters. The ITAD is
    left intact and not refersed as ENUM requires. To learn more
    about ISN please refer to documents at www.freenum.org.
    To complete a ISN lookup on the user part of the Request-URI,
    isn_query() is used instead of enum_query().
 .2. Dependencies
    The module depends on the following modules (in the other words
    the listed modules must be loaded before this module):
      * No dependencies.
 .3. Exported Parameters
 .3.1. domain_suffix (string)
    The domain suffix to be added to the domain name obtained from
    the digits of an E164 number. Can be overridden by a parameter
    to enum_query.
    Default value is "e164.arpa."
    Example 1.1. Setting domain_suffix module parameter
 modparam("enum", "domain_suffix", "e1234.arpa.")
 .3.2. tel_uri_params (string)
    A string whose contents is appended to each new tel URI in the
    request as tel URI parameters.
 Note
    Currently OpenSIPS does not support tel URIs. This means that
    at present tel_uri_params is appended as URI parameters to
    every URI.
    Default value is ""
    Example 1.2. Setting tel_uri_params module parameter
 modparam("enum", "tel_uri_params", ";npdi")
 .3.3. i_enum_suffix (string)
    The domain suffix to be used for i_enum_query() lookups. Can be
    overridden by a parameter to i_enum_query.
    Default value is "e164.arpa."
    Example 1.3. Setting i_enum_suffix module parameter
 modparam("enum", "i_enum_suffix", "e1234.arpa.")
 .3.4. isn_suffix (string)
    The domain suffix to be used for isn_query() lookups. Can be
    overridden by a parameter to isn_query.
    Default value is "freenum.org."
    Example 1.4. Setting isn_suffix module parameter
 modparam("enum", "isn_suffix", "freenum.org.")
 .3.5. branchlabel (string)
    This parameter determines which label i_enum_query() will use
    to branch off to the infrastructure ENUM tree.
    Default value is ""i""
    Example 1.5. Setting branchlabel module parameter
 modparam("enum", "branchlabel", "i")
 .3.6. bl_algorithm (string)
    This parameter determines which algorithm i_enum_query() will
    use to select the position in the DNS tree where the
    infrastructure tree branches off the user ENUM tree.
    If set to "cc", i_enum_query() will always inserts the label at
    the country-code level. Examples: i.1.e164.arpa,
    i.3.4.e164.arpa, i.2.5.3.e164.arpa
    If set to "txt", i_enum_query() will look for a TXT record at
    [branchlabel].[reverse-country-code].[i_enum_suffix] to
    indicate after how many digits the label should in inserted.
    Example 1.6. Zone file example
 i.1.e164.arpa.                     IN TXT   "4"
 .9.9.8.7.6.5.i.4.3.2.1.e164.arpa. IN NAPTR "NAPTR content for  +1 234 5
 999"
    If set to "ebl", i_enum_query() will look for an EBL (ENUM
    Branch Label) record at
    [branchlabel].[reverse-country-code].[i_enum_suffix]. See
    http://www.ietf.org/internet-drafts/draft-lendl-enum-branch-loc
    ation-record-00.txt for a description of that record and the
    meaning of the fields. The RR type for the EBL has not been
    allocated yet. This version of the code uses 65300. See
    resolve.h.
    Example 1.7. Zone file example
 i.1.e164.arpa.     TYPE65300  \# 14 (
 ; position
 69 ; separator
 65 31 36 34 04 61 72 70 61 00 ; e164.ar
 pa
 ;                               )
 .9.9.8.7.6.5.i.4.3.2.1.e164.arpa. IN NAPTR "NAPTR content for  +1 234 5
 999"
    Default value is "cc"
    Example 1.8. Setting the bl_algorithm module parameter
 modparam("enum", "bl_algorithm", "txt")
 .4. Exported Functions
 .4.1.  enum_query(["suffix"[,"service"]])
    The function performs an enum query and rewrites the
    Request-URI with the result of the query. See Section 1.1,
    "Overview" for more information.
    Meaning of the parameters is as follows:
      * suffix - Suffix to be appended to the domain name.
      * service - Service string to be used in the service field.
    This function can be used from REQUEST_ROUTE.
    Example 1.9. enum_query usage
 ...
 # search for "e2u+sip" in freenum.org
 enum_query("freenum.org.");
 ...
 # search for "e2u+sip" in default tree (configured as parameter)
 enum_query();
 ...
 # search for "e2u+voice:sip" in e164.arpa
 enum_query("e164.arpa.","voice");
 ...
 # search for service type "sip" or "voice:sip" or "video:sip"
 # note the '+' sign in front of the second parameter
 enum_query("e164.arpa.","+sip+voice:sip+video:sip");
 ...
 # quering for service sip and voice:sip
 enum_query("e164.arpa.");
 enum_query("e164.arpa.","voice");
 # or use instead
 enum_query("e164.arpa.","+sip+voice:sip");
 ...
 .4.2.  enum_pv_query("pvar"[,"suffix"[,"service"]])
    The function performs an enum query on E.164 number stored in
    its pseudo variable argument and rewrites the Request-URI with
    the result of the query. See Section 1.1, "Overview" for more
    information.
    Meaning of the parameters is as follows:
      * pvar - Pseudo variable that holds an E.164 number on which
        enum query is performed.
      * suffix - Suffix to be appended to the domain name.
      * service - Service string to be used in the service field.
    This function can be used from REQUEST_ROUTE.
    Example 1.10. enum_pv_query usage
 ...
 # search for "e2u+sip" in freenum.org
 enum_pv_query("$avp(i:100)", "freenum.org.");
 ...
 # search for "e2u+sip" in default tree (configured as parameter)
 enum_pv_query("$fU");
 ...
 # search for "e2u+voice:sip" in e164.arpa
 enum_pv_query("$avp(i:100)","e164.arpa.","voice");
 ...
 # search for service type "sip" or "voice:sip" or "video:sip"
 # note the '+' sign in front of the second parameter
 enum_pv_query("$fU","e164.arpa.","+sip+voice:sip+video:sip");
 ...
 # quering for service sip and voice:sip
 enum_pv_query("$avp(i:100)","e164.arpa.");
 enum_pv_query("$avp(i:100)","e164.arpa.","voice");
 # or use instead
 enum_pv_query("$avp(i:100)","e164.arpa.","+sip+voice:sip");
 ...
 .4.3.  i_enum_query(["suffix"[,"service"]])
    The function performs an enum query and rewrites the
    Request-URI with the result of the query. This the
    Infrastructure-ENUM version of enum_query(). The only
    difference to enum_query() is in the calculation of the FQDN
    where NAPTR records are looked for.
    See
    ftp://ftp.rfc-editor.org/in-notes/internet-drafts/draft-haberle
    r-carrier-enum-01.txt for the rationale behind this function.
 .4.4.  isn_query(["suffix"[,"service"]])
    The function performs a ISN query and rewrites the
    Request-URI with the result of the query. See Section 1.1,
    "Overview" for more information.
    Meaning of the parameters is as follows:
      * suffix - Suffix to be appended to the domain name.
      * service - Service string to be used in the service field.
    This function can be used from REQUEST_ROUTE.
    See ftp://ftp.ietf.org/rfc/rfc3872.txt and
    ftp://ftp.ietf.org/rfc/rfc2871.txt for information
    regarding the ITAD part of the ISN string.
    Example 1.11. isn_query usage
 ...
 # search for "e2u+sip" in freenum.org
 isn_query("freenum.org.");
 ...
 # search for "e2u+sip" in default tree (configured as parameter)
 enum_query();
 ...
 # search for "e2u+voice:sip" in freenum.org
 enum_query("freenum.org.","voice");
 ...
 .4.5. is_from_user_enum()
    Checks if the user part of from URI is found in an enum lookup.
    Returns 1 if yes and -1 if not.
    This function can be used from REQUEST_ROUTE.
    Example 1.12. is_from_user_enum usage
 ...
 if (is_from_user_enum()) {
         ....
 };
 ...

Contributed Logic / annotate

opensips/modules/enum/README@8ec65b8f6e2c (annotated)

opensips/modules/enum/README