Private read receipts (#2789)

Implement behaviours for `m.read.private` receipts.

6 files changed, 65 insertions, 32 deletions

diff --git a/clientapi/routing/account_data.go b/clientapi/routing/account_data.go
index b28f0bb1..4742b124 100644
--- a/clientapi/routing/account_data.go
+++ b/clientapi/routing/account_data.go
@@ -154,33 +154,31 @@ func SaveReadMarker(
 		return *resErr
 	}
 
-	if r.FullyRead == "" {
-		return util.JSONResponse{
-			Code: http.StatusBadRequest,
-			JSON: jsonerror.BadJSON("Missing m.fully_read mandatory field"),
+	if r.FullyRead != "" {
+		data, err := json.Marshal(fullyReadEvent{EventID: r.FullyRead})
+		if err != nil {
+			return jsonerror.InternalServerError()
 		}
-	}
 
-	data, err := json.Marshal(fullyReadEvent{EventID: r.FullyRead})
-	if err != nil {
-		return jsonerror.InternalServerError()
-	}
-
-	dataReq := api.InputAccountDataRequest{
-		UserID:      device.UserID,
-		DataType:    "m.fully_read",
-		RoomID:      roomID,
-		AccountData: data,
-	}
-	dataRes := api.InputAccountDataResponse{}
-	if err := userAPI.InputAccountData(req.Context(), &dataReq, &dataRes); err != nil {
-		util.GetLogger(req.Context()).WithError(err).Error("userAPI.InputAccountData failed")
-		return util.ErrorResponse(err)
+		dataReq := api.InputAccountDataRequest{
+			UserID:      device.UserID,
+			DataType:    "m.fully_read",
+			RoomID:      roomID,
+			AccountData: data,
+		}
+		dataRes := api.InputAccountDataResponse{}
+		if err := userAPI.InputAccountData(req.Context(), &dataReq, &dataRes); err != nil {
+			util.GetLogger(req.Context()).WithError(err).Error("userAPI.InputAccountData failed")
+			return util.ErrorResponse(err)
+		}
 	}
 
-	// Handle the read receipt that may be included in the read marker
+	// Handle the read receipts that may be included in the read marker.
 	if r.Read != "" {
-		return SetReceipt(req, syncProducer, device, roomID, "m.read", r.Read)
+		return SetReceipt(req, userAPI, syncProducer, device, roomID, "m.read", r.Read)
+	}
+	if r.ReadPrivate != "" {
+		return SetReceipt(req, userAPI, syncProducer, device, roomID, "m.read.private", r.ReadPrivate)
 	}
 
 	return util.JSONResponse{
diff --git a/clientapi/routing/receipt.go b/clientapi/routing/receipt.go
index 0f9b1b4f..99217a78 100644
--- a/clientapi/routing/receipt.go
+++ b/clientapi/routing/receipt.go
@@ -15,19 +15,22 @@
 package routing
 
 import (
+	"encoding/json"
 	"fmt"
 	"net/http"
 	"time"
 
+	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	"github.com/matrix-org/dendrite/clientapi/producers"
 	"github.com/matrix-org/gomatrixserverlib"
 
+	"github.com/matrix-org/dendrite/userapi/api"
 	userapi "github.com/matrix-org/dendrite/userapi/api"
 	"github.com/matrix-org/util"
 	"github.com/sirupsen/logrus"
 )
 
-func SetReceipt(req *http.Request, syncProducer *producers.SyncAPIProducer, device *userapi.Device, roomID, receiptType, eventID string) util.JSONResponse {
+func SetReceipt(req *http.Request, userAPI api.ClientUserAPI, syncProducer *producers.SyncAPIProducer, device *userapi.Device, roomID, receiptType, eventID string) util.JSONResponse {
 	timestamp := gomatrixserverlib.AsTimestamp(time.Now())
 	logrus.WithFields(logrus.Fields{
 		"roomID":      roomID,
@@ -37,13 +40,32 @@ func SetReceipt(req *http.Request, syncProducer *producers.SyncAPIProducer, devi
 		"timestamp":   timestamp,
 	}).Debug("Setting receipt")
 
-	// currently only m.read is accepted
-	if receiptType != "m.read" {
-		return util.MessageResponse(400, fmt.Sprintf("receipt type must be m.read not '%s'", receiptType))
-	}
+	switch receiptType {
+	case "m.read", "m.read.private":
+		if err := syncProducer.SendReceipt(req.Context(), device.UserID, roomID, eventID, receiptType, timestamp); err != nil {
+			return util.ErrorResponse(err)
+		}
+
+	case "m.fully_read":
+		data, err := json.Marshal(fullyReadEvent{EventID: eventID})
+		if err != nil {
+			return jsonerror.InternalServerError()
+		}
+
+		dataReq := api.InputAccountDataRequest{
+			UserID:      device.UserID,
+			DataType:    "m.fully_read",
+			RoomID:      roomID,
+			AccountData: data,
+		}
+		dataRes := api.InputAccountDataResponse{}
+		if err := userAPI.InputAccountData(req.Context(), &dataReq, &dataRes); err != nil {
+			util.GetLogger(req.Context()).WithError(err).Error("userAPI.InputAccountData failed")
+			return util.ErrorResponse(err)
+		}
 
-	if err := syncProducer.SendReceipt(req.Context(), device.UserID, roomID, eventID, receiptType, timestamp); err != nil {
-		return util.ErrorResponse(err)
+	default:
+		return util.MessageResponse(400, fmt.Sprintf("Receipt type '%s' not known", receiptType))
 	}
 
 	return util.JSONResponse{
diff --git a/clientapi/routing/routing.go b/clientapi/routing/routing.go
index f1fa66ca..e72880ec 100644
--- a/clientapi/routing/routing.go
+++ b/clientapi/routing/routing.go
@@ -1343,7 +1343,7 @@ func Setup(
 				return util.ErrorResponse(err)
 			}
 
-			return SetReceipt(req, syncProducer, device, vars["roomId"], vars["receiptType"], vars["eventId"])
+			return SetReceipt(req, userAPI, syncProducer, device, vars["roomId"], vars["receiptType"], vars["eventId"])
 		}),
 	).Methods(http.MethodPost, http.MethodOptions)
 	v3mux.Handle("/presence/{userId}/status",
diff --git a/federationapi/consumers/receipts.go b/federationapi/consumers/receipts.go
index 366cb264..75827cb6 100644
--- a/federationapi/consumers/receipts.go
+++ b/federationapi/consumers/receipts.go
@@ -81,6 +81,14 @@ func (t *OutputReceiptConsumer) onMessage(ctx context.Context, msgs []*nats.Msg)
 		Type:    msg.Header.Get("type"),
 	}
 
+	switch receipt.Type {
+	case "m.read":
+		// These are allowed to be sent over federation
+	case "m.read.private", "m.fully_read":
+		// These must not be sent over federation
+		return true
+	}
+
 	// only send receipt events which originated from us
 	_, receiptServerName, err := gomatrixserverlib.SplitID('@', receipt.UserID)
 	if err != nil {
diff --git a/internal/eventutil/types.go b/internal/eventutil/types.go
index afc62d8c..18175d6a 100644
--- a/internal/eventutil/types.go
+++ b/internal/eventutil/types.go
@@ -35,8 +35,9 @@ type AccountData struct {
 }
 
 type ReadMarkerJSON struct {
-	FullyRead string `json:"m.fully_read"`
-	Read      string `json:"m.read"`
+	FullyRead   string `json:"m.fully_read"`
+	Read        string `json:"m.read"`
+	ReadPrivate string `json:"m.read.private"`
 }
 
 // NotificationData contains statistics about notifications, sent from
diff --git a/syncapi/streams/stream_receipt.go b/syncapi/streams/stream_receipt.go
index bba91102..97781507 100644
--- a/syncapi/streams/stream_receipt.go
+++ b/syncapi/streams/stream_receipt.go
@@ -67,6 +67,10 @@ func (p *ReceiptStreamProvider) IncrementalSync(
 		if _, ok := req.IgnoredUsers.List[receipt.UserID]; ok {
 			continue
 		}
+		// Don't send private read receipts to other users
+		if receipt.Type == "m.read.private" && req.Device.UserID != receipt.UserID {
+			continue
+		}
 		receiptsByRoom[receipt.RoomID] = append(receiptsByRoom[receipt.RoomID], receipt)
 	}