Wireshark mailing list archives
Re: Subdissector with multiple selection fields needed?
From: Guy Harris <guy () alum mit edu>
Date: Mon, 12 Jul 2010 22:19:07 -0700
On Jul 12, 2010, at 7:11 PM, Weston Schmidt wrote:
I've got a protocol that I'm dissecting that has 3 fields that define which subdissector should be called. How should I enable the selection in a 'Wireshark' friendly way?
There's no mechanism for using anything other than an up-to-32-bit integer, or a string, to directly select a subdissector.
3 Fields I need to merge into 1 for sub-dissector selection purposes: EISS
An "ETV integrated signaling stream", as per CableLabs spec OC-SP-ETV-AM1.0-I04-070921? If so, then an EISS section contains an application_identifier, which "identifies the application according to DVB-MHP section 10.5". DVB-MHP is ETSI TS 101 812, which says that an application identifier has:
org_id (4 bytes)
organisation_id: This 32 bit field is a globally unique value identifying the organisation that is responsible for the application. These values are registered in ETSI TR 101 162 [10]. Values of zero shall not be encoded.
app_id (2 bytes)
application_id: This 16 bit field uniquely identifies the application function. This is allocated by the organisation registered with the organisation_id who decides the policy for allocation within the organisation. Values of zero shall not be encoded.
trigger_table_id (2 bytes)
So which field is that? The ETSI spec doesn't seem to have anything of that sort, and the only 16-bit field in an EISS section, according to the CableLabs spec, is the application_type field. Is this from some other spec? At least for the organization ID/application ID pair, that's somewhat similar to an OID and protocol ID in the SNAP protocol, which we handle by having the OID select a dissector table from a table-of-dissector-tables, and using the protocol ID to select a dissector from the dissector table in question. I don't know whether that would work here or not. However, I'm not sure how the trigger table ID would fit in there, other than just adding another layer to the tables-of-tables. ___________________________________________________________________________ Sent via: Wireshark-dev mailing list <wireshark-dev () wireshark org> Archives: http://www.wireshark.org/lists/wireshark-dev Unsubscribe: https://wireshark.org/mailman/options/wireshark-dev mailto:wireshark-dev-request () wireshark org?subject=unsubscribe
Current thread:
- Subdissector with multiple selection fields needed? Weston Schmidt (Jul 12)
- Re: Subdissector with multiple selection fields needed? Guy Harris (Jul 12)
- Re: Subdissector with multiple selection fields needed? Weston Schmidt (Jul 13)
- Re: Subdissector with multiple selection fields needed? Guy Harris (Jul 13)
- Re: Subdissector with multiple selection fields needed? Weston Schmidt (Jul 13)
- Re: Subdissector with multiple selection fields needed? Guy Harris (Jul 12)