Default limit & upper bound (#1411)

We allow the user not to specify an upper bound, in which case it will
default to Time.Now() + 60 seconds, to accomodate for messages with
higher timestamp.

Limit is also defaulted to 2000 if not set.

We removed as well the 24 hours limitation as now all the requests will
come with a limit.

mailserver/mailserver.go

@@ -40,7 +40,10 @@ import (
 
 const (
 	maxQueryRange = 24 * time.Hour
-	noLimits      = 0
+	defaultLimit  = 2000
+	// When we default the upper limit, we want to extend the range a bit
+	// to accommodate for envelopes with slightly higher timestamp, in seconds
+	whisperTTLSafeThreshold = 60
 )
 
 var (
@@ -265,6 +268,10 @@ func (s *WMailServer) DeliverMail(peer *whisper.Peer, request *whisper.Envelope)
 		lower, upper, bloom, limit, cursor, err = s.validateRequest(peer.ID(), request)
 	}
 
+	if limit == 0 {
+		limit = defaultLimit
+	}
+
 	if err != nil {
 		requestValidationErrorsCounter.Inc(1)
 		log.Error("[mailserver:DeliverMail] request failed validaton",
@@ -535,7 +542,7 @@ func (s *WMailServer) processRequestInBundles(
 		lastEnvelopeHash = envelope.Hash()
 		processedEnvelopes++
 		envelopeSize := whisper.EnvelopeHeaderLength + uint32(len(envelope.Data))
-		limitReached := limit != noLimits && processedEnvelopes == limit
+		limitReached := processedEnvelopes == limit
 		newSize := bundleSize + envelopeSize
 
 		// If we still have some room for messages, add and continue
@@ -676,18 +683,15 @@ func (s *WMailServer) decodeRequest(peerID []byte, request *whisper.Envelope) (M
 		return payload, fmt.Errorf("failed to decode data: %v", err)
 	}
 
+	if payload.Upper == 0 {
+		payload.Upper = uint32(time.Now().Unix() + whisperTTLSafeThreshold)
+	}
+
 	if payload.Upper < payload.Lower {
 		log.Error("Query range is invalid: lower > upper", "lower", payload.Lower, "upper", payload.Upper)
 		return payload, errors.New("query range is invalid: lower > upper")
 	}
 
-	lowerTime := time.Unix(int64(payload.Lower), 0)
-	upperTime := time.Unix(int64(payload.Upper), 0)
-	if upperTime.Sub(lowerTime) > maxQueryRange {
-		log.Warn("Query range too long", "peerID", peerIDBytesString(peerID), "length", upperTime.Sub(lowerTime), "max", maxQueryRange)
-		return payload, fmt.Errorf("query range must be shorted than %d", maxQueryRange)
-	}
-
 	return payload, nil
 }
 

mailserver/mailserver_test.go

@@ -467,6 +467,32 @@ func (s *MailserverSuite) TestDecodeRequest() {
 	s.Equal(payload, decodedPayload)
 }
 
+func (s *MailserverSuite) TestDecodeRequestNoUpper() {
+	s.setupServer(s.server)
+	defer s.server.Close()
+
+	payload := MessagesRequestPayload{
+		Lower:  50,
+		Bloom:  []byte{0x01},
+		Limit:  10,
+		Cursor: []byte{},
+		Batch:  true,
+	}
+	data, err := rlp.EncodeToBytes(payload)
+	s.Require().NoError(err)
+
+	id, err := s.shh.NewKeyPair()
+	s.Require().NoError(err)
+	srcKey, err := s.shh.GetPrivateKey(id)
+	s.Require().NoError(err)
+
+	env := s.createEnvelope(whisper.TopicType{0x01}, data, srcKey)
+
+	decodedPayload, err := s.server.decodeRequest(nil, env)
+	s.Require().NoError(err)
+	s.NotEqual(0, decodedPayload.Upper)
+}
+
 func (s *MailserverSuite) TestProcessRequestDeadlockHandling() {
 	s.setupServer(s.server)
 	defer s.server.Close()