Enhancement: Log more Infos on Filtering (JoinEui Filter, DevAddr Filter)

[sil-zh]

Hallo,

When Chirpstack MQTT Forwarder is configured to filter packages (based on devAddr or JoinEUI), packages that not match the filter will be ignored.
This leads to the debug message

Ignoring uplink frame because of dev_addr and join_eui filters, uplink_id: 2233143934

To have a better overview whats going on on the gateway, what is blocked and also why, it would be nice to have a output like this:

for devAddr:
Ignoring uplink frame because of dev_addr filters: devAddr: 016b204b, devAddr Filter: 0000ff00/24, uplink_id: 2233143934

for JoinEui:
Ignoring uplink frame because of join_eui filters: JoinEui: E13D29FA81000123/64, devAddr Filter: A13B29EF81000123/64, uplink_id: 2233143935

So basicly, every message has the information about the JoinEui/DevAddr and the configured filter(s). If the configured Filter is needed, i dont know. But maybe it's helpfull, if some people have different filters on different gateways.

I do not know, how time consuming it is to do this - but as far as i see the code, there is the chance to get this information out from uf.phy_payload

for uf in &uplink_frames {
    if let Some(rx_info) = &uf.rx_info
        && !((rx_info.crc_status() == gw::CrcStatus::CrcOk && state.forward_crc_ok)
            || (rx_info.crc_status() == gw::CrcStatus::BadCrc && state.forward_crc_invalid)
            || (rx_info.crc_status() == gw::CrcStatus::NoCrc && state.forward_crc_missing))
        {
            debug!(
                "Ignoring uplink frame because of forward_crc_ flags, uplink_id: {}",
                uf.rx_info.as_ref().map(|v| v.uplink_id).unwrap_or_default(),
            );

            continue;
        }

    if lrwn_filters::matches(&uf.phy_payload, &state.filters) {
        state.count_uplink(uf).await?;
        send_uplink_frame(uf).await?;
    } else {
        debug!(
            "Ignoring uplink frame because of dev_addr and join_eui filters, uplink_id: {}",
            uf.rx_info.as_ref().map(|v| v.uplink_id).unwrap_or_default()
        );
    }
}`

Edit, Aditional Infos:

Based on thel lrwn_filters::matches part of this code from the chirpstack repository could be used.
Chirsptack Repo - lrwn_filters

As it extracts the devAddr or JoinEui from the pyh_payload

[sil-zh]

i started something on the weekend - it's working on gateways with semtech backend.

https://github.com/sil-zh/chirpstack-mqtt-forwarder/blob/c70d25b170f07cea408b940a60cc1c038619094d/src/backend/semtech_udp/mod.rs#L362

this gives debug logs for

• uplinks which matches filters (devAddr and join eui)
• uplinks which does not match filters (devAddr and join eui)

as a example:
Ignoring uplink frame because of dev_addr filters, dev_addr: 006083C3 uplink_id: 2611854420

[brocaar]

I think it might be better to add this to:
https://github.com/chirpstack/chirpstack/blob/master/lrwn-filters/src/lib.rs

That is the crate that handles the filtering and which already parses the DevAddr / JoinEUI values. The advantage is also that all components using the filters will benefit from this logging.