How to handle CommandGroupLength in worklist/findscu?

[qarmin]

Recently someone found, that my application freeze sometimes, because gets unknown status
Code is very similar to

dicom-rs/findscu/src/main.rs

Lines 297 to 333 in 5b03b7e

	} else if status == 0xFF00 || status == 0xFF01 {
	if verbose {
	debug!("Operation pending: {:x}", status);
	}
	// fetch DICOM data
	let dcm = {
	let mut rsp = scu.receive_pdata();
	let mut response_data = Vec::new();
	rsp.read_to_end(&mut response_data)
	.whatever_context("Failed to read response data")?;
	InMemDicomObject::read_dataset_with_ts(&response_data[..], ts)
	.whatever_context("Could not read response data set")?
	};
	println!(
	"------------------------ Match #{} ------------------------",
	i
	);
	DumpOptions::new()
	.dump_object(&dcm)
	.context(DumpOutputSnafu)?;
	// check DICOM status in response data,
	// as some implementations might report status code 0
	// upon sending the response data
	if let Some(status) = dcm.get(tags::STATUS) {
	let status = status.to_int::<u16>().ok();
	if status == Some(0) {
	if verbose {
	debug!("Matching is complete");
	}
	break;
	}
	}

but with added code to get from item, data about patient name, birth date etc.

Logs from without unsupported response

2024-03-25 11:15:23.157 :192 - Establishing dicom association with '192.168.1.1:30001'...
2024-03-25 11:15:23.163 :221 - Established association with 192.168.1.1:30001
2024-03-25 11:15:23.163 :239 - Transfer Syntax: Explicit VR Little Endian
2024-03-25 11:15:23.163 :263 - Sending pdu query (166 B)...
2024-03-25 11:15:23.163 :287 - Awaiting response...
2024-03-25 11:15:23.400 :314 - Received PData response (status code: 65280 (hex FF00))
2024-03-25 11:15:23.401 :314 - Received PData response (status code: 0 (hex 0000))
2024-03-25 11:15:23.402 :58 - Get 1 patients from worklist from 192.168.1.1:30001, 0 are in database(basing on ID)

Logs with unsupported CommandGroupLength item

2024-03-25 13:25:41.606 :221 - Established association with 192.168.1.1:30001
2024-03-25 13:25:41.607 :239 - Transfer Syntax: Explicit VR Little Endian
2024-03-25 13:25:41.607 :263 - Sending pdu query (166 B)...
2024-03-25 13:25:41.607 :287 - Awaiting response...
2024-03-25 13:25:41.865 :314 - Received PData response (status code: 65280 (hex FF00))
2024-03-25 13:25:41.865 :314 - Received PData response (status code: 65280 (hex FF00))
2024-03-25 13:25:41.868 :336 - Failed to get patient data from items "(0000,0000) CommandGroupLength           UN (1, 70 bytes): [00, 00, 02, 00, 16, 00, 00, 00, 31, 2E, 32, 2E, 38, 3...\n", error - Failed to get required patient name skipping... 
--------- FREEZE when trying to again use "receive()"

is there a way to handle this? Or maybe this is a bug in worklist and this message should never be send?

[Enet4]

It is hard to make a proper assessment without the concrete example of what you have. Still my educated guess is that some of the responses do not have the data that you are testing against.

The logs do not suggest that this is a problem with Command Group Length, this one just happens to be the first one on the DICOM data set. The output of dicom-dump looks best printed directly on a user-facing text stream rather than debug-printed as a string.