Add WORKAROUND_IGNORE_RX_TIME to disable rxtime parsing.

Author: brocaar

internal/backend/basicstation/structs/radio_meta_data.go

@@ -3,6 +3,7 @@ package structs
 import (
 	"encoding/binary"
 	"math"
+	"os"
 	"time"
 
 	"github.com/brocaar/chirpstack-api/go/v3/common"
@@ -87,7 +88,9 @@ func SetRadioMetaDataToProto(loraBand band.Band, gatewayID lorawan.EUI64, rmd Ra
 
 	}
 
-	if rxTime := rmd.UpInfo.RxTime; rxTime != 0 {
+	// The WORKAROUND_IGNORE_RX_TIME flag is a workaround in case the reported
+	// rxtime from the Basics Station must be ignored (e.g. it is not accurate).
+	if rxTime := rmd.UpInfo.RxTime; rxTime != 0 && os.Getenv("WORKAROUND_IGNORE_RX_TIME") == "" {
 		sec, nsec := math.Modf(rmd.UpInfo.RxTime)
 		if sec != 0 {
 			val := time.Unix(int64(sec), int64(nsec))