Code review fixes

psiphon/common/dsl/relay.go

@@ -307,7 +307,10 @@ func (r *Relay) HandleRequest(
 			r.config.Logger.WithTraceFields(common.LogFields{
 				"error": err.Error(),
 			}).Warning("DSL: serve cached response failed")
-			// Proceed with relaying request
+			// Proceed with relaying request, even if the failure was due to
+			// an error in DecodePackedAPIParameters or APIParameterValidator.
+			// This allows the DSL backend to make the authoritative decision
+			// and also log all failure cases.
 		}
 		cachedResponse = err == nil && response != nil
 	}

psiphon/common/inproxy/broker.go

@@ -1662,9 +1662,6 @@ func (b *Broker) handleClientDSL(
 		logFields["broker_event"] = "client-dsl"
 		logFields["broker_id"] = b.brokerID
 		logFields["elapsed_time"] = time.Since(startTime) / time.Millisecond
-		if retErr != nil {
-			logFields["error"] = retErr.Error()
-		}
 		logFields["request_size"] = requestSize
 		logFields["response_size"] = responseSize
 		if retErr != nil {

psiphon/common/inproxy/brokerClient.go

@@ -232,8 +232,7 @@ func (b *BrokerClient) ClientRelayedPacket(
 	return response, nil
 }
 
-// ClientRelayedPacket sends a ClientRelayedPacket request and returns the
-// response.
+// ClientDSL sends a DSL request to be relayed by the broker.
 func (b *BrokerClient) ClientDSL(
 	ctx context.Context,
 	request *ClientDSLRequest) (*ClientDSLResponse, error) {