Update last seen on sync requests (#1593)

* Update last seen on sync requests

* Fix MSC2836 unit tests

* Only update once per minute

* Remove debug logging

* Configurable option

* Simplify updateLastSeen/cleanLastSeen

14 files changed, 127 insertions, 14 deletions

diff --git a/dendrite-config.yaml b/dendrite-config.yaml
index 25503692..2a8650db 100644
--- a/dendrite-config.yaml
+++ b/dendrite-config.yaml
@@ -300,6 +300,11 @@ sync_api:
     max_idle_conns: 2
     conn_max_lifetime: -1
 
+  # This option controls which HTTP header to inspect to find the real remote IP
+  # address of the client. This is likely required if Dendrite is running behind
+  # a reverse proxy server.
+  # real_ip_header: X-Real-IP
+
 # Configuration for the User API.
 user_api:
   internal_api:
diff --git a/internal/config/config_syncapi.go b/internal/config/config_syncapi.go
index 0a96e41c..fc08f738 100644
--- a/internal/config/config_syncapi.go
+++ b/internal/config/config_syncapi.go
@@ -7,6 +7,8 @@ type SyncAPI struct {
 	ExternalAPI ExternalAPIOptions `yaml:"external_api"`
 
 	Database DatabaseOptions `yaml:"database"`
+
+	RealIPHeader string `yaml:"real_ip_header"`
 }
 
 func (c *SyncAPI) Defaults() {
diff --git a/internal/mscs/msc2836/msc2836_test.go b/internal/mscs/msc2836/msc2836_test.go
index cbf8b726..265d6ee6 100644
--- a/internal/mscs/msc2836/msc2836_test.go
+++ b/internal/mscs/msc2836/msc2836_test.go
@@ -457,6 +457,9 @@ func (u *testUserAPI) PerformDeviceDeletion(ctx context.Context, req *userapi.Pe
 func (u *testUserAPI) PerformDeviceUpdate(ctx context.Context, req *userapi.PerformDeviceUpdateRequest, res *userapi.PerformDeviceUpdateResponse) error {
 	return nil
 }
+func (u *testUserAPI) PerformLastSeenUpdate(ctx context.Context, req *userapi.PerformLastSeenUpdateRequest, res *userapi.PerformLastSeenUpdateResponse) error {
+	return nil
+}
 func (u *testUserAPI) PerformAccountDeactivation(ctx context.Context, req *userapi.PerformAccountDeactivationRequest, res *userapi.PerformAccountDeactivationResponse) error {
 	return nil
 }
diff --git a/syncapi/sync/requestpool.go b/syncapi/sync/requestpool.go
index 8a79737a..61f8c46f 100644
--- a/syncapi/sync/requestpool.go
+++ b/syncapi/sync/requestpool.go
@@ -19,10 +19,14 @@ package sync
 import (
 	"context"
 	"fmt"
+	"net"
 	"net/http"
+	"strings"
+	"sync"
 	"time"
 
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
+	"github.com/matrix-org/dendrite/internal/config"
 	keyapi "github.com/matrix-org/dendrite/keyserver/api"
 	roomserverAPI "github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/dendrite/syncapi/internal"
@@ -37,18 +41,62 @@ import (
 // RequestPool manages HTTP long-poll connections for /sync
 type RequestPool struct {
 	db       storage.Database
+	cfg      *config.SyncAPI
 	userAPI  userapi.UserInternalAPI
 	notifier *Notifier
 	keyAPI   keyapi.KeyInternalAPI
 	rsAPI    roomserverAPI.RoomserverInternalAPI
+	lastseen sync.Map
 }
 
 // NewRequestPool makes a new RequestPool
 func NewRequestPool(
-	db storage.Database, n *Notifier, userAPI userapi.UserInternalAPI, keyAPI keyapi.KeyInternalAPI,
+	db storage.Database, cfg *config.SyncAPI, n *Notifier,
+	userAPI userapi.UserInternalAPI, keyAPI keyapi.KeyInternalAPI,
 	rsAPI roomserverAPI.RoomserverInternalAPI,
 ) *RequestPool {
-	return &RequestPool{db, userAPI, n, keyAPI, rsAPI}
+	rp := &RequestPool{db, cfg, userAPI, n, keyAPI, rsAPI, sync.Map{}}
+	go rp.cleanLastSeen()
+	return rp
+}
+
+func (rp *RequestPool) cleanLastSeen() {
+	for {
+		rp.lastseen.Range(func(key interface{}, _ interface{}) bool {
+			rp.lastseen.Delete(key)
+			return true
+		})
+		time.Sleep(time.Minute)
+	}
+}
+
+func (rp *RequestPool) updateLastSeen(req *http.Request, device *userapi.Device) {
+	if _, ok := rp.lastseen.LoadOrStore(device.UserID+device.ID, struct{}{}); ok {
+		return
+	}
+
+	remoteAddr := req.RemoteAddr
+	if rp.cfg.RealIPHeader != "" {
+		if header := req.Header.Get(rp.cfg.RealIPHeader); header != "" {
+			// TODO: Maybe this isn't great but it will satisfy both X-Real-IP
+			// and X-Forwarded-For (which can be a list where the real client
+			// address is the first listed address). Make more intelligent?
+			addresses := strings.Split(header, ",")
+			if ip := net.ParseIP(addresses[0]); ip != nil {
+				remoteAddr = addresses[0]
+			}
+		}
+	}
+
+	lsreq := &userapi.PerformLastSeenUpdateRequest{
+		UserID:     device.UserID,
+		DeviceID:   device.ID,
+		RemoteAddr: remoteAddr,
+	}
+	lsres := &userapi.PerformLastSeenUpdateResponse{}
+	go rp.userAPI.PerformLastSeenUpdate(req.Context(), lsreq, lsres) // nolint:errcheck
+
+	rp.lastseen.Store(device.UserID+device.ID, time.Now())
 }
 
 // OnIncomingSyncRequest is called when a client makes a /sync request. This function MUST be
@@ -74,6 +122,8 @@ func (rp *RequestPool) OnIncomingSyncRequest(req *http.Request, device *userapi.
 		"limit":     syncReq.limit,
 	})
 
+	rp.updateLastSeen(req, device)
+
 	currPos := rp.notifier.CurrentPosition()
 
 	if rp.shouldReturnImmediately(syncReq) {
diff --git a/syncapi/syncapi.go b/syncapi/syncapi.go
index 393a7aa5..7e277ba1 100644
--- a/syncapi/syncapi.go
+++ b/syncapi/syncapi.go
@@ -61,7 +61,7 @@ func AddPublicRoutes(
 		logrus.WithError(err).Panicf("failed to start notifier")
 	}
 
-	requestPool := sync.NewRequestPool(syncDB, notifier, userAPI, keyAPI, rsAPI)
+	requestPool := sync.NewRequestPool(syncDB, cfg, notifier, userAPI, keyAPI, rsAPI)
 
 	keyChangeConsumer := consumers.NewOutputKeyChangeEventConsumer(
 		cfg.Matrix.ServerName, string(cfg.Matrix.Kafka.TopicFor(config.TopicOutputKeyChangeEvent)),
diff --git a/userapi/api/api.go b/userapi/api/api.go
index 6c3f3c69..809ba047 100644
--- a/userapi/api/api.go
+++ b/userapi/api/api.go
@@ -29,6 +29,7 @@ type UserInternalAPI interface {
 	PerformPasswordUpdate(ctx context.Context, req *PerformPasswordUpdateRequest, res *PerformPasswordUpdateResponse) error
 	PerformDeviceCreation(ctx context.Context, req *PerformDeviceCreationRequest, res *PerformDeviceCreationResponse) error
 	PerformDeviceDeletion(ctx context.Context, req *PerformDeviceDeletionRequest, res *PerformDeviceDeletionResponse) error
+	PerformLastSeenUpdate(ctx context.Context, req *PerformLastSeenUpdateRequest, res *PerformLastSeenUpdateResponse) error
 	PerformDeviceUpdate(ctx context.Context, req *PerformDeviceUpdateRequest, res *PerformDeviceUpdateResponse) error
 	PerformAccountDeactivation(ctx context.Context, req *PerformAccountDeactivationRequest, res *PerformAccountDeactivationResponse) error
 	QueryProfile(ctx context.Context, req *QueryProfileRequest, res *QueryProfileResponse) error
@@ -183,6 +184,17 @@ type PerformPasswordUpdateResponse struct {
 	Account         *Account
 }
 
+// PerformLastSeenUpdateRequest is the request for PerformLastSeenUpdate.
+type PerformLastSeenUpdateRequest struct {
+	UserID     string
+	DeviceID   string
+	RemoteAddr string
+}
+
+// PerformLastSeenUpdateResponse is the response for PerformLastSeenUpdate.
+type PerformLastSeenUpdateResponse struct {
+}
+
 // PerformDeviceCreationRequest is the request for PerformDeviceCreation
 type PerformDeviceCreationRequest struct {
 	Localpart   string
diff --git a/userapi/internal/api.go b/userapi/internal/api.go
index 81d00241..3b5f4978 100644
--- a/userapi/internal/api.go
+++ b/userapi/internal/api.go
@@ -172,6 +172,21 @@ func (a *UserInternalAPI) deviceListUpdate(userID string, deviceIDs []string) er
 	return nil
 }
 
+func (a *UserInternalAPI) PerformLastSeenUpdate(
+	ctx context.Context,
+	req *api.PerformLastSeenUpdateRequest,
+	res *api.PerformLastSeenUpdateResponse,
+) error {
+	localpart, _, err := gomatrixserverlib.SplitID('@', req.UserID)
+	if err != nil {
+		return fmt.Errorf("gomatrixserverlib.SplitID: %w", err)
+	}
+	if err := a.DeviceDB.UpdateDeviceLastSeen(ctx, localpart, req.DeviceID, req.RemoteAddr); err != nil {
+		return fmt.Errorf("a.DeviceDB.UpdateDeviceLastSeen: %w", err)
+	}
+	return nil
+}
+
 func (a *UserInternalAPI) PerformDeviceUpdate(ctx context.Context, req *api.PerformDeviceUpdateRequest, res *api.PerformDeviceUpdateResponse) error {
 	localpart, _, err := gomatrixserverlib.SplitID('@', req.RequestingUserID)
 	if err != nil {
diff --git a/userapi/inthttp/client.go b/userapi/inthttp/client.go
index 4d9dcc41..680e4cb5 100644
--- a/userapi/inthttp/client.go
+++ b/userapi/inthttp/client.go
@@ -32,6 +32,7 @@ const (
 	PerformAccountCreationPath     = "/userapi/performAccountCreation"
 	PerformPasswordUpdatePath      = "/userapi/performPasswordUpdate"
 	PerformDeviceDeletionPath      = "/userapi/performDeviceDeletion"
+	PerformLastSeenUpdatePath      = "/userapi/performLastSeenUpdate"
 	PerformDeviceUpdatePath        = "/userapi/performDeviceUpdate"
 	PerformAccountDeactivationPath = "/userapi/performAccountDeactivation"
 
@@ -119,6 +120,18 @@ func (h *httpUserInternalAPI) PerformDeviceDeletion(
 	return httputil.PostJSON(ctx, span, h.httpClient, apiURL, request, response)
 }
 
+func (h *httpUserInternalAPI) PerformLastSeenUpdate(
+	ctx context.Context,
+	req *api.PerformLastSeenUpdateRequest,
+	res *api.PerformLastSeenUpdateResponse,
+) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "PerformLastSeen")
+	defer span.Finish()
+
+	apiURL := h.apiURL + PerformLastSeenUpdatePath
+	return httputil.PostJSON(ctx, span, h.httpClient, apiURL, req, res)
+}
+
 func (h *httpUserInternalAPI) PerformDeviceUpdate(ctx context.Context, req *api.PerformDeviceUpdateRequest, res *api.PerformDeviceUpdateResponse) error {
 	span, ctx := opentracing.StartSpanFromContext(ctx, "PerformDeviceUpdate")
 	defer span.Finish()
diff --git a/userapi/inthttp/server.go b/userapi/inthttp/server.go
index 81e936e5..e495e353 100644
--- a/userapi/inthttp/server.go
+++ b/userapi/inthttp/server.go
@@ -65,6 +65,19 @@ func AddRoutes(internalAPIMux *mux.Router, s api.UserInternalAPI) {
 			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
 		}),
 	)
+	internalAPIMux.Handle(PerformLastSeenUpdatePath,
+		httputil.MakeInternalAPI("performLastSeenUpdate", func(req *http.Request) util.JSONResponse {
+			request := api.PerformLastSeenUpdateRequest{}
+			response := api.PerformLastSeenUpdateResponse{}
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			if err := s.PerformLastSeenUpdate(req.Context(), &request, &response); err != nil {
+				return util.ErrorResponse(err)
+			}
+			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
+		}),
+	)
 	internalAPIMux.Handle(PerformDeviceUpdatePath,
 		httputil.MakeInternalAPI("performDeviceUpdate", func(req *http.Request) util.JSONResponse {
 			request := api.PerformDeviceUpdateRequest{}
diff --git a/userapi/storage/devices/interface.go b/userapi/storage/devices/interface.go
index 9953ba06..95fe99f3 100644
--- a/userapi/storage/devices/interface.go
+++ b/userapi/storage/devices/interface.go
@@ -33,9 +33,9 @@ type Database interface {
 	// Returns the device on success.
 	CreateDevice(ctx context.Context, localpart string, deviceID *string, accessToken string, displayName *string, ipAddr, userAgent string) (dev *api.Device, returnErr error)
 	UpdateDevice(ctx context.Context, localpart, deviceID string, displayName *string) error
+	UpdateDeviceLastSeen(ctx context.Context, localpart, deviceID, ipAddr string) error
 	RemoveDevice(ctx context.Context, deviceID, localpart string) error
 	RemoveDevices(ctx context.Context, localpart string, devices []string) error
 	// RemoveAllDevices deleted all devices for this user. Returns the devices deleted.
 	RemoveAllDevices(ctx context.Context, localpart, exceptDeviceID string) (devices []api.Device, err error)
-	UpdateDeviceLastSeen(ctx context.Context, deviceID, ipAddr string) error
 }
diff --git a/userapi/storage/devices/postgres/devices_table.go b/userapi/storage/devices/postgres/devices_table.go
index cc554fe7..7de9f5f9 100644
--- a/userapi/storage/devices/postgres/devices_table.go
+++ b/userapi/storage/devices/postgres/devices_table.go
@@ -95,7 +95,7 @@ const selectDevicesByIDSQL = "" +
 	"SELECT device_id, localpart, display_name FROM device_devices WHERE device_id = ANY($1)"
 
 const updateDeviceLastSeen = "" +
-	"UPDATE device_devices SET last_seen_ts = $1, ip = $2 WHERE device_id = $3"
+	"UPDATE device_devices SET last_seen_ts = $1, ip = $2 WHERE localpart = $3 AND device_id = $4"
 
 type devicesStatements struct {
 	insertDeviceStmt             *sql.Stmt
@@ -310,9 +310,9 @@ func (s *devicesStatements) selectDevicesByLocalpart(
 	return devices, rows.Err()
 }
 
-func (s *devicesStatements) updateDeviceLastSeen(ctx context.Context, txn *sql.Tx, deviceID, ipAddr string) error {
+func (s *devicesStatements) updateDeviceLastSeen(ctx context.Context, txn *sql.Tx, localpart, deviceID, ipAddr string) error {
 	lastSeenTs := time.Now().UnixNano() / 1000000
 	stmt := sqlutil.TxStmt(txn, s.updateDeviceLastSeenStmt)
-	_, err := stmt.ExecContext(ctx, lastSeenTs, ipAddr, deviceID)
+	_, err := stmt.ExecContext(ctx, lastSeenTs, ipAddr, localpart, deviceID)
 	return err
 }
diff --git a/userapi/storage/devices/postgres/storage.go b/userapi/storage/devices/postgres/storage.go
index e318b260..6dd18b09 100644
--- a/userapi/storage/devices/postgres/storage.go
+++ b/userapi/storage/devices/postgres/storage.go
@@ -205,8 +205,8 @@ func (d *Database) RemoveAllDevices(
 }
 
 // UpdateDeviceLastSeen updates a the last seen timestamp and the ip address
-func (d *Database) UpdateDeviceLastSeen(ctx context.Context, deviceID, ipAddr string) error {
+func (d *Database) UpdateDeviceLastSeen(ctx context.Context, localpart, deviceID, ipAddr string) error {
 	return sqlutil.WithTransaction(d.db, func(txn *sql.Tx) error {
-		return d.devices.updateDeviceLastSeen(ctx, txn, deviceID, ipAddr)
+		return d.devices.updateDeviceLastSeen(ctx, txn, localpart, deviceID, ipAddr)
 	})
 }
diff --git a/userapi/storage/devices/sqlite3/devices_table.go b/userapi/storage/devices/sqlite3/devices_table.go
index cdfe2bb9..955d8ac7 100644
--- a/userapi/storage/devices/sqlite3/devices_table.go
+++ b/userapi/storage/devices/sqlite3/devices_table.go
@@ -80,7 +80,7 @@ const selectDevicesByIDSQL = "" +
 	"SELECT device_id, localpart, display_name FROM device_devices WHERE device_id IN ($1)"
 
 const updateDeviceLastSeen = "" +
-	"UPDATE device_devices SET last_seen_ts = $1, ip = $2 WHERE device_id = $3"
+	"UPDATE device_devices SET last_seen_ts = $1, ip = $2 WHERE localpart = $3 AND device_id = $4"
 
 type devicesStatements struct {
 	db                           *sql.DB
@@ -314,9 +314,9 @@ func (s *devicesStatements) selectDevicesByID(ctx context.Context, deviceIDs []s
 	return devices, rows.Err()
 }
 
-func (s *devicesStatements) updateDeviceLastSeen(ctx context.Context, txn *sql.Tx, deviceID, ipAddr string) error {
+func (s *devicesStatements) updateDeviceLastSeen(ctx context.Context, txn *sql.Tx, localpart, deviceID, ipAddr string) error {
 	lastSeenTs := time.Now().UnixNano() / 1000000
 	stmt := sqlutil.TxStmt(txn, s.updateDeviceLastSeenStmt)
-	_, err := stmt.ExecContext(ctx, lastSeenTs, ipAddr, deviceID)
+	_, err := stmt.ExecContext(ctx, lastSeenTs, ipAddr, localpart, deviceID)
 	return err
 }
diff --git a/userapi/storage/devices/sqlite3/storage.go b/userapi/storage/devices/sqlite3/storage.go
index 25888eae..2eefb3f3 100644
--- a/userapi/storage/devices/sqlite3/storage.go
+++ b/userapi/storage/devices/sqlite3/storage.go
@@ -207,8 +207,8 @@ func (d *Database) RemoveAllDevices(
 }
 
 // UpdateDeviceLastSeen updates a the last seen timestamp and the ip address
-func (d *Database) UpdateDeviceLastSeen(ctx context.Context, deviceID, ipAddr string) error {
+func (d *Database) UpdateDeviceLastSeen(ctx context.Context, localpart, deviceID, ipAddr string) error {
 	return d.writer.Do(d.db, nil, func(txn *sql.Tx) error {
-		return d.devices.updateDeviceLastSeen(ctx, txn, deviceID, ipAddr)
+		return d.devices.updateDeviceLastSeen(ctx, txn, localpart, deviceID, ipAddr)
 	})
 }