Hi Guy
I'm guessing (my first look at the code was yesterday) that the "dissect_per_restricted_character_string()" is designed for something else (of is broken for single character representation)
Basically I modified dissect_h245_signalType to be
static int
dissect_h245_signalType(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
{
offset=dissect_per_IA5String(tvb, offset, pinfo, tree, hf_h245_signalType, 1, 1;
return offset;
}
and the results of the decode were exactly as I expected ( signalType: ! ) but of course without any validity check.
Having some dissect_per_restricted_IA5string() function would be the better overall solution.
Paul
-----Original Message-----
From: Guy Harris [mailto:guy@xxxxxxxxxxxx]
Sent: Wednesday, November 19, 2003 4:24 PM
To: Paul Higgs (CA/EUS)
Cc: 'ethereal-dev@xxxxxxxxxxxx'; 'ethereal-users@xxxxxxxxxxxx' Users
Subject: Re: [Ethereal-users] Problem with h245 dissector
On Nov 19, 2003, at 10:47 AM, Paul Higgs (CA/EUS) wrote:
> I have found a problem with the dissector for H245 in regards to
> displaying the signalType of a UserInputIndication. The signalType
> prints as a ? when it is actually an !
>
> H.225.0 CS
> H323_UserInformation
> H323_UU_PDU
> h323_message_body
> h323_message_body: .... .110 : facility (6)
> FacilityUUIE
> ProtocolIdentifier: 0.0.8.2250.0.4
> FacilityReason
> transportedInformation
> CallIdentifier
> guid: 2AFA51A97C0000102143204166275475
> multipleCalls: 0... .... False
> maintainConnection: 0... .... False
> h245Tunneling: 1... .... True
> h245Control
> Item 0
> Octet String Length: 7
> H.245
> MultimediaSystemControlMessage
> PDU Type: .11. .... : Indication (3)
> IndicationMessage
> Indication Type: .... 1101 :
> UserInputIndication (13)
> UserInputIndication
> signal
>
> UserInputIndication_signal
> signalType: ?
> duration: 400
>
> 0000 00 80 37 84 fb 9c 00 10 b5 75 ac 1d 08 00 45 00
> ..7......u....E.
> 0010 00 6a bb 17 40 00 80 06 93 e7 c0 a8 15 32 c0 a8
> [email protected]..
> 0020 15 0c 75 5a 0f a1 e5 77 18 df 95 c4 e6 f4 50 18
> ..uZ...w......P.
> 0030 43 3a b0 d2 00 00 03 00 00 42 08 02 12 76 62 1c
> C:.......B...vb.
> 0040 00 7e 00 34 05 26 80 06 00 08 91 4a 00 04 86 01
> .~.4.&.....J....
> 0050 00 1f 01 80 11 00 2a fa 51 a9 7c 00 00 10 21 43
> ......*.Q.|...!C
> 0060 20 41 66 27 54 75 01 00 01 00 10 c0 01 80 09 01
> Af'Tu..........
> 0070 07 6d 81 04 44 20 01 8f .m..D ..
>
> I looked in the codebase and it seems that this element is not
> dissceted as an IA5string but with some other method.
It's dissected as a restricted character string - but the set of
characters in that string includes "!".
What does the H.245 spec say that element is? And, if it's a
restricted character string:
1) what's the alphabet for it?
2) what's the numerical value of the first (and only) character in it)?
According to
http://www.packetizer.com/iptel/h245/h245_asn.html
the ASN.1 for it is
signalType
IA5String(SIZE (1) ^ FROM ("0123456789#*ABCD!")),
but the alphabet string passed to
"dissect_per_restricted_character_string()" is "!#*0123456789ABCD".