dendrite/syncapi/types/types.go
Neil Alexander 353168a9e9
Fix potential panic in NewStreamTokenFromString caused by off-by-one error (#2196)
Line 291 could panic when trying to set `positions[i]` if `i == len(positions)`.
2022-02-17 13:25:41 +00:00

465 lines
15 KiB
Go

// Copyright 2017 Vector Creations Ltd
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package types
import (
"encoding/json"
"errors"
"fmt"
"strconv"
"strings"
"github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/gomatrixserverlib"
"github.com/tidwall/gjson"
)
var (
// This error is returned when parsing sync tokens if the token is invalid. Callers can use this
// error to detect whether to 400 or 401 the client. It is recommended to 401 them to force a
// logout.
ErrMalformedSyncToken = errors.New("malformed sync token")
)
type StateDelta struct {
RoomID string
StateEvents []*gomatrixserverlib.HeaderedEvent
Membership string
// The PDU stream position of the latest membership event for this user, if applicable.
// Can be 0 if there is no membership event in this delta.
MembershipPos StreamPosition
}
// StreamPosition represents the offset in the sync stream a client is at.
type StreamPosition int64
// StreamEvent is the same as gomatrixserverlib.Event but also has the PDU stream position for this event.
type StreamEvent struct {
*gomatrixserverlib.HeaderedEvent
StreamPosition StreamPosition
TransactionID *api.TransactionID
ExcludeFromSync bool
}
// Range represents a range between two stream positions.
type Range struct {
// From is the position the client has already received.
From StreamPosition
// To is the position the client is going towards.
To StreamPosition
// True if the client is going backwards
Backwards bool
}
// Low returns the low number of the range.
// This represents the position the client already has and hence is exclusive.
func (r *Range) Low() StreamPosition {
if !r.Backwards {
return r.From
}
return r.To
}
// High returns the high number of the range
// This represents the position the client is going towards and hence is inclusive.
func (r *Range) High() StreamPosition {
if !r.Backwards {
return r.To
}
return r.From
}
// SyncTokenType represents the type of a sync token.
// It can be either "s" (representing a position in the whole stream of events)
// or "t" (representing a position in a room's topology/depth).
type SyncTokenType string
const (
// SyncTokenTypeStream represents a position in the server's whole
// stream of events
SyncTokenTypeStream SyncTokenType = "s"
// SyncTokenTypeTopology represents a position in a room's topology.
SyncTokenTypeTopology SyncTokenType = "t"
)
type StreamingToken struct {
PDUPosition StreamPosition
TypingPosition StreamPosition
ReceiptPosition StreamPosition
SendToDevicePosition StreamPosition
InvitePosition StreamPosition
AccountDataPosition StreamPosition
DeviceListPosition StreamPosition
}
// This will be used as a fallback by json.Marshal.
func (s StreamingToken) MarshalText() ([]byte, error) {
return []byte(s.String()), nil
}
// This will be used as a fallback by json.Unmarshal.
func (s *StreamingToken) UnmarshalText(text []byte) (err error) {
*s, err = NewStreamTokenFromString(string(text))
return err
}
func (t StreamingToken) String() string {
posStr := fmt.Sprintf(
"s%d_%d_%d_%d_%d_%d_%d",
t.PDUPosition, t.TypingPosition,
t.ReceiptPosition, t.SendToDevicePosition,
t.InvitePosition, t.AccountDataPosition, t.DeviceListPosition,
)
return posStr
}
// IsAfter returns true if ANY position in this token is greater than `other`.
func (t *StreamingToken) IsAfter(other StreamingToken) bool {
switch {
case t.PDUPosition > other.PDUPosition:
return true
case t.TypingPosition > other.TypingPosition:
return true
case t.ReceiptPosition > other.ReceiptPosition:
return true
case t.SendToDevicePosition > other.SendToDevicePosition:
return true
case t.InvitePosition > other.InvitePosition:
return true
case t.AccountDataPosition > other.AccountDataPosition:
return true
case t.DeviceListPosition > other.DeviceListPosition:
return true
}
return false
}
func (t *StreamingToken) IsEmpty() bool {
return t == nil || t.PDUPosition+t.TypingPosition+t.ReceiptPosition+t.SendToDevicePosition+t.InvitePosition+t.AccountDataPosition+t.DeviceListPosition == 0
}
// WithUpdates returns a copy of the StreamingToken with updates applied from another StreamingToken.
// If the latter StreamingToken contains a field that is not 0, it is considered an update,
// and its value will replace the corresponding value in the StreamingToken on which WithUpdates is called.
// If the other token has a log, they will replace any existing log on this token.
func (t *StreamingToken) WithUpdates(other StreamingToken) StreamingToken {
ret := *t
ret.ApplyUpdates(other)
return ret
}
// ApplyUpdates applies any changes from the supplied StreamingToken. If the supplied
// streaming token contains any positions that are not 0, they are considered updates
// and will overwrite the value in the token.
func (t *StreamingToken) ApplyUpdates(other StreamingToken) {
if other.PDUPosition > t.PDUPosition {
t.PDUPosition = other.PDUPosition
}
if other.TypingPosition > t.TypingPosition {
t.TypingPosition = other.TypingPosition
}
if other.ReceiptPosition > t.ReceiptPosition {
t.ReceiptPosition = other.ReceiptPosition
}
if other.SendToDevicePosition > t.SendToDevicePosition {
t.SendToDevicePosition = other.SendToDevicePosition
}
if other.InvitePosition > t.InvitePosition {
t.InvitePosition = other.InvitePosition
}
if other.AccountDataPosition > t.AccountDataPosition {
t.AccountDataPosition = other.AccountDataPosition
}
if other.DeviceListPosition > t.DeviceListPosition {
t.DeviceListPosition = other.DeviceListPosition
}
}
type TopologyToken struct {
Depth StreamPosition
PDUPosition StreamPosition
}
// This will be used as a fallback by json.Marshal.
func (t TopologyToken) MarshalText() ([]byte, error) {
return []byte(t.String()), nil
}
// This will be used as a fallback by json.Unmarshal.
func (t *TopologyToken) UnmarshalText(text []byte) (err error) {
*t, err = NewTopologyTokenFromString(string(text))
return err
}
func (t *TopologyToken) StreamToken() StreamingToken {
return StreamingToken{
PDUPosition: t.PDUPosition,
}
}
func (t TopologyToken) String() string {
return fmt.Sprintf("t%d_%d", t.Depth, t.PDUPosition)
}
// Decrement the topology token to one event earlier.
func (t *TopologyToken) Decrement() {
depth := t.Depth
pduPos := t.PDUPosition
if depth-1 <= 0 {
// nothing can be lower than this
depth = 1
} else {
// this assumes that we will never have 1000 events all with the same
// depth. TODO: work out what the right PDU position is to use, probably needs a db hit.
depth--
pduPos += 1000
}
// The lowest token value is 1, therefore we need to manually set it to that
// value if we're below it.
if depth < 1 {
depth = 1
}
t.Depth = depth
t.PDUPosition = pduPos
}
func NewTopologyTokenFromString(tok string) (token TopologyToken, err error) {
if len(tok) < 1 {
err = fmt.Errorf("empty topology token")
return
}
if tok[0] != SyncTokenTypeTopology[0] {
err = fmt.Errorf("topology token must start with 't'")
return
}
parts := strings.Split(tok[1:], "_")
var positions [2]StreamPosition
for i, p := range parts {
if i > len(positions) {
break
}
var pos int
pos, err = strconv.Atoi(p)
if err != nil {
return
}
positions[i] = StreamPosition(pos)
}
token = TopologyToken{
Depth: positions[0],
PDUPosition: positions[1],
}
return
}
func NewStreamTokenFromString(tok string) (token StreamingToken, err error) {
if len(tok) < 1 {
err = ErrMalformedSyncToken
return
}
if tok[0] != SyncTokenTypeStream[0] {
err = ErrMalformedSyncToken
return
}
// Migration: Remove everything after and including '.' - we previously had tokens like:
// s478_0_0_0_0_13.dl-0-2 but we have now removed partitioned stream positions
tok = strings.Split(tok, ".")[0]
parts := strings.Split(tok[1:], "_")
var positions [7]StreamPosition
for i, p := range parts {
if i >= len(positions) {
break
}
var pos int
pos, err = strconv.Atoi(p)
if err != nil {
err = ErrMalformedSyncToken
return
}
positions[i] = StreamPosition(pos)
}
token = StreamingToken{
PDUPosition: positions[0],
TypingPosition: positions[1],
ReceiptPosition: positions[2],
SendToDevicePosition: positions[3],
InvitePosition: positions[4],
AccountDataPosition: positions[5],
DeviceListPosition: positions[6],
}
return token, nil
}
// PrevEventRef represents a reference to a previous event in a state event upgrade
type PrevEventRef struct {
PrevContent json.RawMessage `json:"prev_content"`
ReplacesState string `json:"replaces_state"`
PrevSender string `json:"prev_sender"`
}
// Response represents a /sync API response. See https://matrix.org/docs/spec/client_server/r0.2.0.html#get-matrix-client-r0-sync
type Response struct {
NextBatch StreamingToken `json:"next_batch"`
AccountData struct {
Events []gomatrixserverlib.ClientEvent `json:"events,omitempty"`
} `json:"account_data"`
Presence struct {
Events []gomatrixserverlib.ClientEvent `json:"events,omitempty"`
} `json:"presence"`
Rooms struct {
Join map[string]JoinResponse `json:"join"`
Peek map[string]JoinResponse `json:"peek"`
Invite map[string]InviteResponse `json:"invite"`
Leave map[string]LeaveResponse `json:"leave"`
} `json:"rooms"`
ToDevice struct {
Events []gomatrixserverlib.SendToDeviceEvent `json:"events"`
} `json:"to_device"`
DeviceLists struct {
Changed []string `json:"changed,omitempty"`
Left []string `json:"left,omitempty"`
} `json:"device_lists"`
DeviceListsOTKCount map[string]int `json:"device_one_time_keys_count,omitempty"`
}
// NewResponse creates an empty response with initialised maps.
func NewResponse() *Response {
res := Response{}
// Pre-initialise the maps. Synapse will return {} even if there are no rooms under a specific section,
// so let's do the same thing. Bonus: this means we can't get dreaded 'assignment to entry in nil map' errors.
res.Rooms.Join = map[string]JoinResponse{}
res.Rooms.Peek = map[string]JoinResponse{}
res.Rooms.Invite = map[string]InviteResponse{}
res.Rooms.Leave = map[string]LeaveResponse{}
// Also pre-intialise empty slices or else we'll insert 'null' instead of '[]' for the value.
// TODO: We really shouldn't have to do all this to coerce encoding/json to Do The Right Thing. We should
// really be using our own Marshal/Unmarshal implementations otherwise this may prove to be a CPU bottleneck.
// This also applies to NewJoinResponse, NewInviteResponse and NewLeaveResponse.
res.AccountData.Events = []gomatrixserverlib.ClientEvent{}
res.Presence.Events = []gomatrixserverlib.ClientEvent{}
res.ToDevice.Events = []gomatrixserverlib.SendToDeviceEvent{}
res.DeviceListsOTKCount = map[string]int{}
return &res
}
// IsEmpty returns true if the response is empty, i.e. used to decided whether
// to return the response immediately to the client or to wait for more data.
func (r *Response) IsEmpty() bool {
return len(r.Rooms.Join) == 0 &&
len(r.Rooms.Invite) == 0 &&
len(r.Rooms.Leave) == 0 &&
len(r.AccountData.Events) == 0 &&
len(r.Presence.Events) == 0 &&
len(r.ToDevice.Events) == 0
}
// JoinResponse represents a /sync response for a room which is under the 'join' or 'peek' key.
type JoinResponse struct {
State struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
} `json:"state"`
Timeline struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
Limited bool `json:"limited"`
PrevBatch *TopologyToken `json:"prev_batch,omitempty"`
} `json:"timeline"`
Ephemeral struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
} `json:"ephemeral"`
AccountData struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
} `json:"account_data"`
}
// NewJoinResponse creates an empty response with initialised arrays.
func NewJoinResponse() *JoinResponse {
res := JoinResponse{}
res.State.Events = []gomatrixserverlib.ClientEvent{}
res.Timeline.Events = []gomatrixserverlib.ClientEvent{}
res.Ephemeral.Events = []gomatrixserverlib.ClientEvent{}
res.AccountData.Events = []gomatrixserverlib.ClientEvent{}
return &res
}
// InviteResponse represents a /sync response for a room which is under the 'invite' key.
type InviteResponse struct {
InviteState struct {
Events []json.RawMessage `json:"events"`
} `json:"invite_state"`
}
// NewInviteResponse creates an empty response with initialised arrays.
func NewInviteResponse(event *gomatrixserverlib.HeaderedEvent) *InviteResponse {
res := InviteResponse{}
res.InviteState.Events = []json.RawMessage{}
// First see if there's invite_room_state in the unsigned key of the invite.
// If there is then unmarshal it into the response. This will contain the
// partial room state such as join rules, room name etc.
if inviteRoomState := gjson.GetBytes(event.Unsigned(), "invite_room_state"); inviteRoomState.Exists() {
_ = json.Unmarshal([]byte(inviteRoomState.Raw), &res.InviteState.Events)
}
// Then we'll see if we can create a partial of the invite event itself.
// This is needed for clients to work out *who* sent the invite.
inviteEvent := gomatrixserverlib.ToClientEvent(event.Unwrap(), gomatrixserverlib.FormatSync)
inviteEvent.Unsigned = nil
if ev, err := json.Marshal(inviteEvent); err == nil {
res.InviteState.Events = append(res.InviteState.Events, ev)
}
return &res
}
// LeaveResponse represents a /sync response for a room which is under the 'leave' key.
type LeaveResponse struct {
State struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
} `json:"state"`
Timeline struct {
Events []gomatrixserverlib.ClientEvent `json:"events"`
Limited bool `json:"limited"`
PrevBatch *TopologyToken `json:"prev_batch,omitempty"`
} `json:"timeline"`
}
// NewLeaveResponse creates an empty response with initialised arrays.
func NewLeaveResponse() *LeaveResponse {
res := LeaveResponse{}
res.State.Events = []gomatrixserverlib.ClientEvent{}
res.Timeline.Events = []gomatrixserverlib.ClientEvent{}
return &res
}
type SendToDeviceEvent struct {
gomatrixserverlib.SendToDeviceEvent
ID StreamPosition
UserID string
DeviceID string
}
type PeekingDevice struct {
UserID string
DeviceID string
}
type Peek struct {
RoomID string
New bool
Deleted bool
}