Hello,
On 8/19/11 2:09 AM, Bucur Marius wrote:
Hi Jijo,
In my opinion, decode_mime_type is broken, and parse_accept_body does not work
as expected.
For example, this is a valid accept header:
accept: text/plain;param=",some value".
but the parse_accept_body will return -1 because the first return value of decode_mime_type is ",some
value\"". The second invocation will think "some value\"" is a mime type, which
obviously isn't.
I must say I never saw such an accept header, but the standard permits it.
Indeed, a quick fix would be to ignore the return code when comma is found.
This must be done for other functions that call decode_mime_type like
has_body(mime) in textops.
This is just my opinion, but I think this solution is a bit hackish since the convention,
the "promise" that decode_mime_type should respect is to return a non-NULL,
non-end pointer ONLY when there are more mime types in the body. And it doesn't.
A lot of functions that call it rely on this. I think it is easier/more elegant
to fix the bug in the decode_mime_type then to change the function convention
in all callers.
Also, this might work for most callers, but parse_accept_body will still be
buggy, as I explained in the example above.
this has to be fixed, the safest way not to forget about this is to open
an issue on bug tracker.
Cheers,
Daniel
Cheers,
Marius
________________________________
From: Jijo<realj...@gmail.com>
To: Bucur Marius<bucur_marius_ovi...@yahoo.com>
Sent: Thursday, August 18, 2011 10:48 AM
Subject: Re: [SR-Users] decode_mime_type error
Hi Marius,
Right, the same function is used for Accept and Content-Type.
I don't think there is any change required for parsing Accept. In case of
Accept the function decode_mime_type is called in a loop until it find all the
media types. On the returning from decode_mime_type(), the main function
parse_accept_xxx() checks the pointer is 'comma' or not. if its comma, then the
function decode_mime_type called again and find the remaining media types. So
i think the existing implementation for Parsing Accept is fine.
The only change required here is not return error for comma while parsing the
Content-Type.
Thanks
Jijo
On Thu, Aug 18, 2011 at 12:32 PM, Bucur Marius<bucur_marius_ovi...@yahoo.com>
wrote:
Hello Jijo,
You are right, multiple mime-types are not allowed. But it seems like
decode_mime_type had the purpose of also parsing the Accept header:
Accept: text/html, image/jpeg, multipart
hence the search for commas :).
The only function that uses this feature and calls decode_mime_type in a loop
is parse_accept_body. The other functions that call decode_mime_type just fail
when returning ret != end, and since multiple mime types in content-type are
not allowed the behavior is fine.
The bad thing is the Accept header can have mime parameters too (which can
contain comma).
Accept = "Accept" HCOLON [ accept-range *(COMMA accept-range) ]
accept-range = media-range *(SEMI accept-param)
media-range = ( "*/*" / ( m-type SLASH "*" ) / ( m-type SLASH m-subtype ) )
*( SEMI m-parameter )
So I think the best thing would be to change decode_mime_type so that it does a
more thorough parsing (e.g. check for parameter) hence a parameter value can
contain commas (only if quoted).
Cheers,
Marius
________________________________
From: Jijo<realj...@gmail.com>
To: Bucur Marius<bucur_marius_ovi...@yahoo.com>; SIP Router - Kamailio (OpenSER) and
SIP Express Router (SER) - Users Mailing List<sr-users@lists.sip-router.org>
Sent: Thursday, August 18, 2011 8:04 AM
Subject: Re: [SR-Users] decode_mime_type error
Hi Marius,
Thanks for the response.. I checked the other functions, but they don't have
the check for ret !=end, but they check the pointer and if it is comma then
loop through again until it find all the media types.
As per the RFC3261 multiple media-types are not supoorted in the Content-Type.
So I'm not sure why the author used comma to determine multiple media types .
Probably just followed like Route or Record-Route headers..??
Content-Type = ( "Content-Type" / "c" ) HCOLON media-type
media-type = m-type SLASH m-subtype *(SEMI m-parameter)
m-type = discrete-type / composite-type
discrete-type = "text" / "image" / "audio" / "video"
/ "application" / extension-token
composite-type = "message" / "multipart" / extension-token
Record-Route = "Record-Route" HCOLON rec-route *(COMMA rec-route)
Thanks
Jijo
On Thu, Aug 18, 2011 at 2:23 AM, Bucur Marius<bucur_marius_ovi...@yahoo.com>
wrote:
Hello Jijo,
It seems like the decode_mime_type is a somehow broken. The comma is very well
allowed in boundary, as you said. The BNF specified in RFC2046 permits it.
But, the decode_mime_type function ignores everything coming after comma. More
than that, it notifies the function caller that this content type has multiple
mime types.
I think the author of the function thought of something like:
Content-Type: text/html, image/jpeg // very weird, though
This is wrong, hence the comma can be in a parameter (like in your case).
I think the best fix, as you said is to remove that check, hence a non-NULL
return value doesn't mean anything (that the content type has multiple mime
types).
Another fix is to write a "good" decode_mime_type, that checks if the comma is
inside a parameter. I don't know if effort is worth it.
One thing we need to do is to check if there are any functions in Kamailio that
call decode_mime_type and also perform this check (ret != end).
Cheers,
Marius
________________________________
From: Jijo<realj...@gmail.com>
To: sr-users@lists.sip-router.org; sr-...@lists.sip-router.org
Sent: Wednesday, August 17, 2011 10:54 AM
Subject: [SR-Users] decode_mime_type error
Hi All,
The function parse_content_type_hdr() is failing in decode_mime_type() when Content-Type parameter
"boundary" has value comma as below. The error message is
"ERROR:parse_content_type_hdr: CONTENT_TYPE hdr contains "
"more then one mime type :-(!
Content Type Header is as below, It works fine if the boundary value is without
comma.
Content-Type: multipart/mixed;boundary=",AW"
The parse_content_type_hdr() is failing in the following code,
ret = decode_mime_type(msg->content_type->body.s, end ,&mime);
if (ret==0)
goto error;
if (ret!=end) {
LOG(L_INFO,"ERROR:parse_content_type_hdr: CONTENT_TYPE hdr contains "
"more then one mime type :-(!\n");
goto error ;
}
I thought of fixing this issue by commenting the code for condition ret !=end.
I'm not sure why we we need that check, as mime variable has the information
to process the content.
Please let me know if you see any impact.
Thanks
Jijo
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--
Daniel-Constantin Mierla -- http://www.asipto.com
Kamailio Advanced Training, Oct 10-13, Berlin: http://asipto.com/u/kat
http://linkedin.com/in/miconda -- http://twitter.com/miconda
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