SER CVS head, new select identifiers info - was - Re: [Serusers]Textops with AVPs?

Greger V. Teigre greger at teigre.com
Fri Jul 14 11:57:03 CEST 2006 

Hi Luis, you forgot to copy the list :-)
I'm not the right person to ask these questions. I stay a bit behind the 
bleeding edge as I focus mostly on documentation from a "what everybody 
needs" perspective (i.e. ONsip.org best practice configurations).
There has been several threads lately addressing some of these. Maybe 
some of the developers can help out?!
g-)

Luis Silva wrote:
> Hi!
> can I just ask you 4 more things?
>
> 1 - What is the difference between $ and % ?
> 2 - is it possible to concatenate avps or strings?
> 3 - is there another way for doing the same thing as avp_subst but 
> without using the avp module?
> 4 - is it possible for doing this: @contact[1].uri = "sip:"; ?
>
> Tks for the answer. these are all my questions. please help me.  Tks 
> in advance
> Regards
>
>
>> From: "Greger V. Teigre" <greger at teigre.com>
>> To: Luis Silva <lfs12 at hotmail.com>
>> CC: serusers at iptel.org, jan at iptel.org
>> Subject: Re: SER CVS head, new select identifiers info - was - Re: 
>> [Serusers]Textops with AVPs?
>> Date: Wed, 12 Jul 2006 13:41:36 +0200
>>
>> AFAIK, there is no single place to find all the @vars. It's still on 
>> the to-do...
>> Jan: Could you provide some quick pointers?
>> g-)
>>
>> Luis Silva wrote:
>>>
>>> Hi Greger, where can I find the complete list of all the @vars?
>>>
>>> @from, @from.uri, @to, @to.uri, @from.tag, @from.name, @to.tag.
>>>  @to.name, @from.params, @to.params, @contact, @contact.uri,
>>>  @contact.params, @contact.expires, @contact.q, @via, and so on.  <---
>>>
>>> Regards,Luis Silva
>>>
>>>
>>>
>>>
>>>> From: "Greger V. Teigre" <greger at teigre.com>
>>>> To: sip <sip at arcdiv.com>
>>>> CC: serusers at lists.iptel.org
>>>> Subject: Re: SER CVS head, new select identifiers info - was - Re: 
>>>> [Serusers]Textops with AVPs?
>>>> Date: Wed, 12 Jul 2006 08:47:11 +0200
>>>>
>>>> It's in head only (0.10.x track)
>>>> g-)
>>>>
>>>> sip wrote:
>>>>> Greger,
>>>>>
>>>>> Sounds incredibly handy. Is this available only in SER head or is 
>>>>> it something
>>>>> that's been around for a little while (i.e. do I have any hope of 
>>>>> using it in
>>>>> ser 0.9.6) ?
>>>>>
>>>>>
>>>>> N.
>>>>>
>>>>>
>>>>> On Tue, 11 Jul 2006 21:18:38 +0200, Greger V. Teigre wrote
>>>>>
>>>>>> I repost Jan's original description of the "select identifier"
>>>>>>
>>>>> functionality. Since then, more select identifiers have been 
>>>>> added, both from
>>>>> core and modules.
>>>>> g-)
>>>>>
>>>>> SER core can parse select identifiers using the configuration parser.
>>>>>  A select identifiers begins with @ characters and contains several
>>>>>  components/tokens delimited by . (unless it is integer component).
>>>>>  Integer components are enclosed in [], for example:
>>>>>
>>>>> @contact[1].uri
>>>>>
>>>>> This identifier is converted into binary structure which contains the
>>>>>  array of components. After that the parser tries to lookup function
>>>>>  that matches the identifier.
>>>>>
>>>>> Available functions are arranged in a tree-like structure. When
>>>>>  looking up a function the tree is traversed (starting at the root)
>>>>>  until the parser finds corresponding function. The part of the tree
>>>>>  containing TLS functions looks like:
>>>>>
>>>>> "tls"-+-"peer"-+-"subj"-+-"name" (select_peer_name())
>>>>>  | \
>>>>>  | "state" (select_peer_state())
>>>>>  |
>>>>>  +-"issuer"-+-"name" (select_peer_issuer_name())
>>>>>  \
>>>>>  "state" (select_peer_issuer_state())
>>>>>
>>>>> Thus when you write @tls.peer.subj.state in the configuration file
>>>>>  then the parser will traverse the tree until it reaches
>>>>>  select_peer_state() function and then it would remember that this
>>>>>  function should be called.
>>>>>
>>>>> The tree of identifiers and functions is built dynamically at 
>>>>> runtime.
>>>>>  This is a nice feature becase this way modules can register their 
>>>>> own
>>>>>  functions or whole subtrees and make their functions available in 
>>>>> the
>>>>>  configuration file.
>>>>>
>>>>> Thus if you load TLS module then all @tls.* selects become avaiable,
>>>>>  if you do not load the module they are not available. Only a 
>>>>> couple of
>>>>>  core functions and the framework is built in the core, the rest 
>>>>> can be
>>>>>  in modules.
>>>>>
>>>>> This framework is currently used in tls and xmlrpc modules. XMLRPC
>>>>>  module exports the name of the XML-RPC method to the script. TLS
>>>>>  module exports information from TLS layer.
>>>>>
>>>>> The SER core itself contains a couple of functions that can retrieve
>>>>>  various parts of a SIP message:
>>>>>
>>>>> @from, @from.uri, @to, @to.uri, @from.tag, @from.name, @to.tag.
>>>>>  @to.name, @from.params, @to.params, @contact, @contact.uri,
>>>>>  @contact.params, @contact.expires, @contact.q, @via, and so on.
>>>>>
>>>>> TLS related functions are described in a separate email.
>>>>>
>>>>>> sip wrote: Sounds like something I might look more into. Thanks, 
>>>>>> Greger. Is
>>>>>>
>>>>> there
>>>>> anything written more about @var constructs? I checked the admin 
>>>>> guide (I
>>>>> know... that was kind of silly considering how out of date it is 
>>>>> ;) ), and
>>>>> tried to do a search in Google (it seems to ignore the @, so @var 
>>>>> just gives
>>>>> me every message with the word 'var' in it) and didn't see 
>>>>> anything. Is there
>>>>> anything over at OnSIP discussing it?
>>>>>
>>>>> N.
>>>>>
>>>>> On Tue, 11 Jul 2006 08:35:11 +0200, Greger V. Teigre wrote
>>>>>    If this functionality was added in later openser versions than 
>>>>> 0.9,
>>>>>  it will most likely not be in SER. What you are describing is 
>>>>> hard to do with the avpops version in 0.9. The avpops module was 
>>>>> generic enough to do more than it was designed for; making some 
>>>>> code operations quite dirty in 0.9 (using the ruri as a temporary 
>>>>> storage while manipulating a variable). SER head uses @var to more 
>>>>> directly access data instead of going through a module. You may 
>>>>> want to have a look at it! g-)
>>>>>
>>>>> sip wrote:
>>>>>    Is there a version of textops that can do substs with AVPs that 
>>>>> will work on
>>>>> SER 0.9.6 or is that an openSER-only modification of the code?
>>>>>
>>>>> I'm curious because we're ALSO running into the issues of charging 
>>>>> the
>>>>> call-forwarding user for forwarding a call to the PSTN instead of 
>>>>> charging the
>>>>> calling party. Ideally, I'd like to rewrite the from address 
>>>>> solely for the
>>>>> purpose of authenticating the user who's doing the forwarding and 
>>>>> charging him
>>>>> for the call, but that would likely break things as there'd be no 
>>>>> way to get
>>>>> back to the original user if I just rewrote the from username.
>>>>>
>>>>> SO, I thought, why not let the b2bua handle the details and just 
>>>>> forward a uri
>>>>> with a prefix string that includes the user who's forwarding the 
>>>>> call (the
>>>>> original RURI instead of just the rewritten one).
>>>>>
>>>>> And there's the trick. How do I craft a RURI out of bits and 
>>>>> pieces of things
>>>>> into one long RURI?
>>>>>
>>>>> If it were all the same number, I could use prefix, but it's 
>>>>> dynamic (as is
>>>>> the nature of most things), so prefix won't work.
>>>>>
>>>>> How do I take
>>>>>
>>>>> RURI=1105
>>>>>
>>>>> And add to it:
>>>>>
>>>>> The rewritten RURI from the call forwarding info: 18005551212
>>>>>
>>>>> AND the prefix for the b2bua auth: 9999
>>>>>
>>>>> To make:
>>>>>
>>>>> new ruri: 9999110518005551212
>>>>>
>>>>> N.
>>>>> _______________________________________________
>>>>> Serusers mailing list
>>>>> Serusers at lists.iptel.orghttp://lists.iptel.org/mailman/listinfo/serusers 
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>
>>>
>>>> _______________________________________________
>>>> Serusers mailing list
>>>> Serusers at lists.iptel.org
>>>> http://lists.iptel.org/mailman/listinfo/serusers
>>>
>>>
>>>
>
>
>

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