Define Parameters for a TC to be read by the CommandPostProcessor

[Patrick Dohmen]

Hello group,

Is there a way to define parameters inside a TC to be used by the CommandPostProcessor?

I am currently trying to configure a "flag" if a TC needs authorisation or not, as we have a few commands that should be used by the amateur radio community. Of course there needs to be some protection for sensitive commands.

What I am trying now is:

<MetaCommand name="generic_cmd_hmac"

shortDescription="Send a generic TC with HMAC">

<LongDescription>

Sends a generic command to the S/C using HMAC authentication and verification

</LongDescription>

<AncillaryDataSet>

<AncillaryData name="HMAC">true</AncillaryData>

</AncillaryDataSet>

<BaseMetaCommand metaCommandRef="base_packet">

</BaseMetaCommand>

<ArgumentList>

<Argument argumentTypeRef="custom_cmd_payload_type" name="custom_cmd_payload"

shortDescription="Sends an HMAC signed Telecommand" />

</ArgumentList>

<CommandContainer name="generic_cmd_hmac">

<EntryList>

<ArgumentRefEntry argumentRef="custom_cmd_payload" />

</EntryList>

<BaseContainer containerRef="base_packet" />

</CommandContainer>

</MetaCommand>

<MetaCommand name="deploy_antenna" shortDescription="TC to deploy antenna">

<LongDescription>

To be defined...

</LongDescription>

<AncillaryDataSet>

<AncillaryData name="Yamcs:CcsdsMapId">3</AncillaryData>

</AncillaryDataSet>

<BaseMetaCommand metaCommandRef="generic_cmd_hmac">

<ArgumentAssignmentList>

<ArgumentAssignment argumentName="ccsds_apid" argumentValue="100" />

</ArgumentAssignmentList>

</BaseMetaCommand>

<CommandContainer name="deploy_antenna">

<EntryList />

<BaseContainer containerRef="generic_cmd_hmac" />

</CommandContainer>

</MetaCommand>

Then read in the processor:

/**

* Checks if a command requires HMAC protection based on ancillary data in the MDB.

*

* @param pc The prepared command

* @return true if the command should be protected with HMAC

*/

private boolean commandRequiresHmac(PreparedCommand pc) {

// Check for ancillary data flag in the command definition

String ancillaryValue = pc.getMetaCommand().getAncillaryData("HMAC");

if (ancillaryValue != null) {

// If the flag exists, check if it's set to true

return "true".equalsIgnoreCase(ancillaryValue) ||

"yes".equalsIgnoreCase(ancillaryValue) ||

"1".equals(ancillaryValue);

}

// If no flag is specified, default behavior (can be configured)

// Return false to require explicit opt-in, or true for opt-out behavior

return false;

}

This doesn't seem to work, at least, the expected value (here: true) does never appear .

Any help would be gratefully appreciated!

Best regards,

Patrick, DL4PD

[fabia...@spaceapplications.com]

deploy_antenna is extending the (abstract) base command generic_cmd_hmac. So the following is likely what you need: pc.getMetaCommand().getBaseMetaCommand().getAncillaryData("HMAC")

[Patrick Dohmen]

Thanks for that hint!

It wasn't the full solution but it lead me to the following (maybe overcomplicated) implementation.

I am not a java expert - just for the records ;-)

/**

* Checks if a command requires HMAC protection based on ancillary data in the MDB.

*

* @param pc The prepared command

* @return true if the command should be protected with HMAC

*/

private boolean commandRequiresHmac(PreparedCommand pc) {

// Get the list of ancillary data from the command definition

List<org.yamcs.xtce.AncillaryData> ancillaryDataList = pc.getMetaCommand().getBaseMetaCommand().getAncillaryData();

if (ancillaryDataList != null) {

// Search for the "HMAC" ancillary data entry

for (org.yamcs.xtce.AncillaryData data : ancillaryDataList) {

if ("HMAC".equals(data.getName())) {

String value = data.getValue();

// Check if it's set to true

return "true".equalsIgnoreCase(value) ||

"yes".equalsIgnoreCase(value) ||

"1".equals(value);