[sr-dev] [SR-Users] topoh, angle brackets and Contact URI params interpretation

[Daniel-Constantin Mierla]

Hello,

I added the code for enclosing contact uri between angle brackets. I 
committed on git master branch, but have no way to test it for now due 
to traveling. If you can test it and report back would be great. When 
all is working fine, I will backport to 3.x branches.

Thanks,
Daniel

On 2/3/11 8:18 PM, Libor Chocholaty wrote:
> On 02/03/2011 09:26 AM, Andrew Pogrebennyk wrote:
>> I'm having an issue with topoh module in Kamailio 3.1.0. When Contact
>> header is formed like this:
>>         Contact: 0991
>> <sip:192.168.0.107;line=sr-N6IAzBysz.tyz.D4M.VLOBMfOBFuWxvfMxV4>
>> The other party responds properly. But when there is no angle brackets
>> in Contact:
>>         Contact:
>> sip:192.168.0.107;line=sr-N6IAzB3AWxyfz.stM.quOBFZMJZfWxj7W.y-MljAWBy*
>>
>> Really, many parsers implement "prefer shift to reduce" principle,
>> which means if something can be interpreted in more enclosed
>> expression, it will be interpreted this way and no as part of less
>> enclosed expression so ;line is interpreted as header parameter but
>> not URI parameter.
>>
>> RFC 3261 section 20 suggests that any URI parameters be contained
>> within angle brackets:
>> ===
>>     The Contact, From, and To header fields contain a URI.  If the URI
>>     contains a comma, question mark or semicolon, the URI MUST be
>>     enclosed in angle brackets (<  and>).  Any URI parameters are
>>     contained within these brackets.  If the URI is not enclosed in angle
>>     brackets, any semicolon-delimited parameters are header-parameters,
>>     not URI parameters.
>> ===
>> I think the topoh module should force the angle brackets.
> Why? What about regular Contact params?
>
> RFC3261 section 20.10 Contact:
>
>     ...
>     ... If no "<"
>     and ">" are present, all parameters after the URI are header
>     parameters, not URI parameters.  The display name can be tokens, or a
>     quoted string, if a larger character set is desired.
>
>
> I think that it is clean enough, you should ask why the proxy sends
> Contact URI without "<" and">" when there is an URI param.
>
> Libor
>
>
>> BTW it seems that parameter needs to be urlencoded, see rule
>> 'other-param' in RFC 3261 section 25.1:
>>
>> other-param       =  pname [ "=" pvalue ]
>> pname             =  1*paramchar
>> pvalue            =  1*paramchar
>> paramchar         =  param-unreserved / unreserved / escaped
>> param-unreserved  =  "[" / "]" / "/" / ":" / "&" / "+" / "$"
>>
>> No .-* characters are allowed in the paramchar. But at least that's
>> not causing me any problems.
>>
>
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-- 
Daniel-Constantin Mierla
http://www.asipto.com