915 lines
28 KiB
Go
915 lines
28 KiB
Go
package mtprotoedge
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import (
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"context"
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"crypto/sha256"
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"encoding/binary"
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"encoding/hex"
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"errors"
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"fmt"
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"io"
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"math"
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"time"
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"go.uber.org/zap"
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"github.com/gotd/td/bin"
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"github.com/gotd/td/crypto"
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"github.com/gotd/td/mt"
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"github.com/gotd/td/proto"
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"github.com/gotd/td/tgerr"
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"github.com/gotd/td/transport"
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"telesrv/internal/compat/layerwire"
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"telesrv/internal/observability/dbtrace"
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"telesrv/internal/postresponse"
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"telesrv/internal/store"
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)
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// connState 是单连接的 MTProto 运行态。
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type connState struct {
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sentCreated bool
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seen map[int64]clientMsgRecord // 已处理的 client msg_id，用于幂等和 msgs_state_req
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order []int64
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minSeen int64
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maxSeen int64
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}
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type clientMsgRecord struct {
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state byte
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seqNo int32
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content bool
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}
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func newConnState() *connState {
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return &connState{
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seen: make(map[int64]clientMsgRecord),
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minSeen: math.MaxInt64,
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}
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}
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func (cs *connState) reset() {
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next := newConnState()
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*cs = *next
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}
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const (
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maxTrackedClientMsgIDs = 400
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msgStateUnknown byte = 1
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msgStateNotReceived byte = 2
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msgStateNotReceivedHigh byte = 3
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msgStateReceived byte = 4
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badMsgIDTooLow = 16
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badMsgIDTooHigh = 17
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badMsgIDInvalidBits = 18
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badMsgSeqTooLow = 32
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badMsgSeqTooHigh = 33
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badMsgSeqNotEven = 34
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badMsgSeqNotOdd = 35
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badMsgContainer = 64
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)
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// handleEncrypted 解密加密消息，按需注册连接，处理服务消息并分发明文 payload。
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// 返回（可能新建/更新的）当前连接对象，供 serveConn 维护生命周期。
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// fetchedKey 非 nil 表示本帧的 auth key 是刚从 AuthKeyStore 查出的（首帧/换 auth key/被销毁
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// 后回落）；为 nil 表示走快路径——serveConn 判定 current 仍持同一未销毁的 auth key，直接复用
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// current.key/current.salt 解密，既不回查 AuthKeyStore 也不重建 store.AuthKeyData。
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func (s *Server) handleEncrypted(ctx context.Context, tc transport.Conn, cs *connState, current *Conn, fetchedKey *store.AuthKeyData, b *bin.Buffer) (*Conn, error) {
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var key crypto.AuthKey
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var serverSalt int64
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if fetchedKey != nil {
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key = crypto.AuthKey{Value: crypto.Key(fetchedKey.Value), ID: fetchedKey.ID}
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serverSalt = fetchedKey.ServerSalt
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} else {
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// 快路径：复用已建立连接缓存的密钥与盐（同一 auth key 的后续帧，含同连接换 session）。
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key = current.key
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serverSalt = current.salt
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}
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data, err := s.cipher.DecryptFromBuffer(key, b)
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if err != nil {
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return current, fmt.Errorf("decrypt: %w", err)
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}
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if data.Salt != serverSalt {
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c := current
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temp := false
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if c == nil || c.sessionID != data.SessionID {
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c = s.newConn(tc, key, data.SessionID, serverSalt)
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temp = true
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}
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err := s.sendBadServerSalt(ctx, c, data.MessageID, data.SeqNo, serverSalt)
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if temp {
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c.Close()
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}
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return current, err
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}
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// 首个加密消息或 session 变化时（重新）注册连接到 SessionManager。
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if current == nil || current.sessionID != data.SessionID {
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if current != nil {
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cs.reset()
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}
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if current != nil {
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s.conns.Unregister(current)
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current.Close()
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}
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current = s.newConn(tc, key, data.SessionID, serverSalt)
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s.conns.Register(current)
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}
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s.maybePersistSession(ctx, current, data.SessionID, key.ID, serverSalt)
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body := data.Data()
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typeID, err := (&bin.Buffer{Buf: body}).PeekID()
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if err != nil {
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return current, fmt.Errorf("peek encrypted payload type id: %w", err)
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}
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if code := validateClientEnvelope(s.clock.Now(), data.MessageID, data.SeqNo, typeID); code != 0 {
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s.log.Debug("Sending bad_msg_notification",
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zap.Int64("msg_id", data.MessageID),
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zap.Int32("seq_no", data.SeqNo),
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zap.Uint32("type_id", typeID),
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zap.Int("code", code),
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)
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return current, s.sendBadMsg(ctx, current, data.MessageID, data.SeqNo, code)
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}
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if err := sendQuickAckIfRequested(ctx, tc, key, data); err != nil {
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return current, err
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}
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content := clientMessageNeedsAck(typeID)
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if record, ok := cs.seenRecord(data.MessageID); ok {
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s.log.Debug("Duplicate msg_id; replay cached result if available", zap.Int64("msg_id", data.MessageID))
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if err := s.replayRPCResultByRequest(ctx, current, data.MessageID); err != nil {
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return current, err
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}
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if !record.content {
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return current, nil
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}
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return current, s.sendAck(ctx, current, data.MessageID)
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}
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if code := cs.validateSeq(data.MessageID, data.SeqNo, content); code != 0 {
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s.log.Debug("Sending bad_msg_notification",
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zap.Int64("msg_id", data.MessageID),
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zap.Int32("seq_no", data.SeqNo),
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zap.Uint32("type_id", typeID),
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zap.Int("code", code),
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)
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return current, s.sendBadMsg(ctx, current, data.MessageID, data.SeqNo, code)
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}
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cs.track(data.MessageID, data.SeqNo, content, msgStateReceived)
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if !cs.sentCreated {
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cs.sentCreated = true
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s.log.Debug("Sending new_session_created", zap.Int64("msg_id", data.MessageID), zap.Int32("seq_no", data.SeqNo))
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if err := s.sendNewSessionCreated(ctx, current, data.MessageID); err != nil {
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return current, err
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}
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}
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var acks []int64
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if err := s.dispatch(ctx, cs, current, data.MessageID, data.SeqNo, &bin.Buffer{Buf: body}, &acks); err != nil {
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return current, err
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}
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if len(acks) > 0 {
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if err := s.sendAck(ctx, current, acks...); err != nil {
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return current, err
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}
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}
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return current, nil
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}
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// sessionSaveMinInterval 是单连接持久化 session 记录的最小间隔。把原本「每帧一次 Redis SET」
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// 去抖到固定间隔——session 是软状态（生产无热读路径），只需周期刷新 last_seen/续 TTL。
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const sessionSaveMinInterval = 30 * time.Second
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// maybePersistSession 按 sessionSaveMinInterval 去抖持久化 session，失败只告警不断连。
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// 原实现每帧同步 Save 且失败即断连：N 连接×帧率的 Redis 写放大 + Redis 抖动级联断连。
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func (s *Server) maybePersistSession(ctx context.Context, c *Conn, sessionID int64, authKeyID [8]byte, salt int64) {
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if c == nil {
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return
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}
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now := s.clock.Now().Unix()
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if last := c.lastSessionSaveUnix.Load(); last != 0 && now-last < int64(sessionSaveMinInterval/time.Second) {
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return
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}
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c.lastSessionSaveUnix.Store(now)
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if err := s.sessions.Save(ctx, store.SessionData{
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ID: sessionID,
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AuthKeyID: authKeyID,
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Salt: salt,
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LastSeen: now,
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}); err != nil {
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s.log.Warn("Persist session failed (non-fatal)",
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zap.Int64("session_id", sessionID),
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zap.Error(err),
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)
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}
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}
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func sendQuickAckIfRequested(ctx context.Context, tc transport.Conn, key crypto.AuthKey, data *crypto.EncryptedMessageData) error {
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q, ok := tc.(quickAckTransport)
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if !ok || !q.ConsumeQuickAckRequested() {
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return nil
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}
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token, err := clientQuickAckToken(key, data)
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if err != nil {
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return err
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}
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return q.SendQuickAck(ctx, token)
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}
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func clientQuickAckToken(key crypto.AuthKey, data *crypto.EncryptedMessageData) (uint32, error) {
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var plain bin.Buffer
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if err := data.Encode(&plain); err != nil {
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return 0, err
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}
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h := sha256.New()
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_, _ = h.Write(key.Value[88:120])
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_, _ = h.Write(plain.Raw())
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sum := h.Sum(nil)
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return binary.LittleEndian.Uint32(sum[:4]) &^ quickAckResponseFlag, nil
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}
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// dispatch 处理一条明文消息：解包 container/gzip，处理服务消息，其余转 RPC 路由。
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// content-related 消息（ping、RPC）的 msg_id 会收集到 acks 以便统一确认。
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func (s *Server) dispatch(ctx context.Context, cs *connState, c *Conn, msgID int64, seqNo int32, b *bin.Buffer, acks *[]int64) error {
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id, err := b.PeekID()
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if err != nil {
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return fmt.Errorf("peek type id: %w", err)
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}
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ackContent := func() {
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if clientMessageNeedsAck(id) {
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*acks = append(*acks, msgID)
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}
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}
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switch id {
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case proto.GZIPTypeID:
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var gz proto.GZIP
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if err := gz.Decode(b); err != nil {
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return fmt.Errorf("decode gzip: %w", err)
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}
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return s.dispatch(ctx, cs, c, msgID, seqNo, &bin.Buffer{Buf: gz.Data}, acks)
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case proto.MessageContainerTypeID:
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var container proto.MessageContainer
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if err := container.Decode(b); err != nil {
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return fmt.Errorf("decode container: %w", err)
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}
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if code := validateClientContainer(msgID, seqNo, container); code != 0 {
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return s.sendBadMsg(ctx, c, msgID, seqNo, code)
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}
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for i := range container.Messages {
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m := container.Messages[i]
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typeID, err := (&bin.Buffer{Buf: m.Body}).PeekID()
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if err != nil {
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return fmt.Errorf("peek container message type id: %w", err)
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}
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content := clientMessageNeedsAck(typeID)
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if record, ok := cs.seenRecord(m.ID); ok {
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if err := s.replayRPCResultByRequest(ctx, c, m.ID); err != nil {
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return err
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}
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if record.content {
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*acks = append(*acks, m.ID)
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}
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continue
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}
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if code := cs.validateSeq(m.ID, int32(m.SeqNo), content); code != 0 {
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return s.sendBadMsg(ctx, c, m.ID, int32(m.SeqNo), code)
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}
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cs.track(m.ID, int32(m.SeqNo), content, msgStateReceived)
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if err := s.dispatch(ctx, cs, c, m.ID, int32(m.SeqNo), &bin.Buffer{Buf: m.Body}, acks); err != nil {
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return err
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}
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}
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return nil
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case mt.PingRequestTypeID:
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var ping mt.PingRequest
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if err := ping.Decode(b); err != nil {
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return fmt.Errorf("decode ping: %w", err)
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}
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ackContent()
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return s.sendPong(ctx, c, msgID, ping.PingID)
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case mt.PingDelayDisconnectRequestTypeID:
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var ping mt.PingDelayDisconnectRequest
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if err := ping.Decode(b); err != nil {
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return fmt.Errorf("decode ping_delay_disconnect: %w", err)
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}
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ackContent()
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return s.sendPong(ctx, c, msgID, ping.PingID)
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case mt.GetFutureSaltsRequestTypeID:
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var req mt.GetFutureSaltsRequest
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if err := req.Decode(b); err != nil {
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return fmt.Errorf("decode get_future_salts: %w", err)
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}
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ackContent()
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return s.sendFutureSalts(ctx, c, msgID, req.Num)
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case mt.MsgsAckTypeID:
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var ack mt.MsgsAck
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if err := ack.Decode(b); err != nil {
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return fmt.Errorf("decode msgs_ack: %w", err)
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}
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c.AckServerMessages(ack.MsgIDs)
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s.log.Debug("Received msgs_ack", zap.Int64s("msg_ids", ack.MsgIDs))
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return nil
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case mt.MsgsStateReqTypeID:
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var req mt.MsgsStateReq
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if err := req.Decode(b); err != nil {
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return fmt.Errorf("decode msgs_state_req: %w", err)
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}
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ackContent()
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outgoing, err := c.OutgoingStateInfo(ctx, req.MsgIDs)
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if err != nil {
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return err
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}
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return s.sendMsgsStateInfo(ctx, c, msgID, mergeStateInfo(outgoing, cs.stateInfo(req.MsgIDs)))
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case mt.MsgResendReqTypeID:
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var req mt.MsgResendReq
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if err := req.Decode(b); err != nil {
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return fmt.Errorf("decode msg_resend_req: %w", err)
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}
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ackContent()
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outgoing, err := c.ResendMessages(ctx, req.MsgIDs)
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if err != nil {
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return err
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}
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return s.sendMsgsStateInfo(ctx, c, msgID, mergeStateInfo(outgoing, cs.stateInfo(req.MsgIDs)))
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case mt.MsgsStateInfoTypeID:
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var info mt.MsgsStateInfo
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if err := info.Decode(b); err != nil {
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return fmt.Errorf("decode msgs_state_info: %w", err)
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}
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s.log.Debug("Received msgs_state_info", zap.Int64("req_msg_id", info.ReqMsgID), zap.Int("len", len(info.Info)))
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return nil
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case mt.MsgsAllInfoTypeID:
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var info mt.MsgsAllInfo
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if err := info.Decode(b); err != nil {
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return fmt.Errorf("decode msgs_all_info: %w", err)
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}
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s.log.Debug("Received msgs_all_info", zap.Int("msg_ids", len(info.MsgIDs)), zap.Int("len", len(info.Info)))
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return nil
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case mt.DestroySessionRequestTypeID:
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var req mt.DestroySessionRequest
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if err := req.Decode(b); err != nil {
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return fmt.Errorf("decode destroy_session: %w", err)
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}
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ackContent()
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return s.sendDestroySession(ctx, c, req.SessionID)
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case mt.HTTPWaitRequestTypeID:
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var req mt.HTTPWaitRequest
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if err := req.Decode(b); err != nil {
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return fmt.Errorf("decode http_wait: %w", err)
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}
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s.log.Debug("Received http_wait",
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zap.Int("max_delay", req.MaxDelay),
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zap.Int("wait_after", req.WaitAfter),
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zap.Int("max_wait", req.MaxWait),
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)
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return nil
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case mt.RPCDropAnswerRequestTypeID:
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var req mt.RPCDropAnswerRequest
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if err := req.Decode(b); err != nil {
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return fmt.Errorf("decode rpc_drop_answer: %w", err)
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}
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ackContent()
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s.log.Debug("Received rpc_drop_answer", zap.Int64("req_msg_id", req.ReqMsgID))
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return s.sendResult(ctx, c, msgID, &mt.RPCAnswerUnknown{})
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case destroyAuthKeyRequestTypeID:
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var req destroyAuthKeyRequest
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if err := req.Decode(b); err != nil {
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return err
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}
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ackContent()
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s.log.Debug("Received destroy_auth_key", zap.String("auth_key_id", hex.EncodeToString(c.authKeyID[:])))
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// 真正销毁：删密钥库记录（每帧回查，删除后该 key 的入站帧立即失效）并主动
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// 断开同 key 的其他连接——出站推送用连接持有的密钥副本加密、不回查密钥库，
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// 不断开的话被销毁 key 的空闲连接仍能持续收到推送。发起连接除外：响应要
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// 先送达，它的下一帧会因密钥缺失自然断开。授权（authorizations）不在此清理，
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// destroy_auth_key 是 PFS 密钥轮换的清理动作，不等于登出。
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if err := s.authKeys.Delete(ctx, c.authKeyID); err != nil {
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s.log.Warn("Delete auth key failed", zap.String("auth_key_id", hex.EncodeToString(c.authKeyID[:])), zap.Error(err))
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return c.SendAsync(ctx, proto.MessageServerResponse, &destroyAuthKeyFail{})
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}
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// 标记密钥已销毁：发起连接被 CloseSessionsForRawAuthKeyExcept 排除（响应需先送达），
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// 它下一帧不能再走 serveConn 的密钥复用快路径，须回落到 Get→AuthKeyNotFound 自然失效。
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c.keyDestroyed.Store(true)
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s.conns.CloseSessionsForRawAuthKeyExcept(c.authKeyID, c.sessionID)
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return c.SendAsync(ctx, proto.MessageServerResponse, &destroyAuthKeyOk{})
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default:
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ackContent()
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body := b.Copy()
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return s.enqueueRPC(ctx, c, msgID, body)
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}
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}
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func mergeStateInfo(primary, fallback []byte) []byte {
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if len(primary) == 0 {
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return fallback
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}
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info := make([]byte, len(fallback))
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copy(info, fallback)
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for i, state := range primary {
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if i >= len(info) {
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break
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}
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if state != 0 {
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info[i] = state
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}
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}
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return info
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}
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func (s *Server) enqueueRPC(ctx context.Context, c *Conn, msgID int64, body []byte) error {
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id, _ := (&bin.Buffer{Buf: body}).PeekID()
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method := s.typeName(id)
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if cached, ok := s.cachedRPCResult(c, msgID); ok {
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s.log.Info("RPC duplicate replay from session cache",
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zap.String("method", method),
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zap.Int64("msg_id", msgID),
|
||
zap.String("auth_key_id", hex.EncodeToString(c.authKeyID[:])),
|
||
zap.Int64("session_id", c.sessionID),
|
||
)
|
||
return c.SendEncoded(ctx, proto.MessageServerResponse, cached)
|
||
}
|
||
err := c.enqueueInboundRPC(ctx, inboundRPC{
|
||
method: method,
|
||
size: len(body),
|
||
run: func(taskCtx context.Context) error {
|
||
// body 已是 enqueueRPC 入参的独立副本（dispatch 里 b.Copy()），且每个任务只 run 一次，
|
||
// 无需再 append 拷贝；直接复用，省掉一份 inbound 在途内存。
|
||
if err := s.handleRPC(taskCtx, c, msgID, &bin.Buffer{Buf: body}); err != nil {
|
||
fields := []zap.Field{
|
||
zap.Int64("msg_id", msgID),
|
||
zap.String("auth_key_id", hex.EncodeToString(c.authKeyID[:])),
|
||
zap.Int64("session_id", c.sessionID),
|
||
zap.Error(err),
|
||
}
|
||
if isClientDisconnect(err) {
|
||
s.log.Debug("RPC async handler canceled", fields...)
|
||
} else {
|
||
s.log.Info("RPC async handler failed", fields...)
|
||
}
|
||
return err
|
||
}
|
||
return nil
|
||
},
|
||
})
|
||
if errors.Is(err, ErrInboundRPCQueueFull) {
|
||
s.log.Debug("Inbound RPC queue full",
|
||
zap.String("method", method),
|
||
zap.Int64("msg_id", msgID),
|
||
zap.String("auth_key_id", hex.EncodeToString(c.authKeyID[:])),
|
||
zap.Int64("session_id", c.sessionID),
|
||
)
|
||
return s.sendResult(ctx, c, msgID, &mt.RPCError{
|
||
ErrorCode: 420,
|
||
ErrorMessage: "FLOOD_WAIT_1",
|
||
})
|
||
}
|
||
return err
|
||
}
|
||
|
||
// handleRPC 把明文 RPC 请求交给 RPC 路由，并将结果或错误包成 rpc_result 回发。
|
||
func (s *Server) handleRPC(ctx context.Context, c *Conn, msgID int64, b *bin.Buffer) error {
|
||
id, _ := b.PeekID()
|
||
method := s.typeName(id)
|
||
if s.rpc == nil {
|
||
s.log.Warn("No RPC handler configured; dropping request", zap.String("method", method))
|
||
return nil
|
||
}
|
||
|
||
ctx = postresponse.WithCallbacks(ctx)
|
||
ctx, dbStats := dbtrace.WithStats(ctx)
|
||
start := s.clock.Now()
|
||
result, err := s.rpc.Dispatch(ctx, c.authKeyID, c.sessionID, b)
|
||
dur := s.clock.Now().Sub(start)
|
||
s.metrics.RPCHandled(method, dur, err)
|
||
// 刷新本连接协商 layer（invokeWithLayer/initConnection 已被 Dispatch 处理并登记），
|
||
// 供 rpc_result 与后续 push 出站降级使用。仅在确实观测到 layer 时更新——缓存被驱逐
|
||
// 时 NegotiatedLayer 返回 ok=false，此时必须保留连接已记住的 layer，绝不覆盖成默认值，
|
||
// 否则长连接老客户端的条目被驱逐后会被误降回 227。
|
||
if layer, ok := s.rpc.NegotiatedLayer(c.authKeyID, c.sessionID); ok {
|
||
c.SetClientLayer(layer)
|
||
}
|
||
|
||
fields := []zap.Field{
|
||
zap.String("method", method),
|
||
zap.String("auth_key_id", hex.EncodeToString(c.authKeyID[:])),
|
||
zap.Int64("session_id", c.sessionID),
|
||
zap.Int64("msg_id", msgID),
|
||
zap.Duration("dur", dur),
|
||
}
|
||
if businessAuthKeyID, ok := c.BusinessAuthKeyID(); ok {
|
||
fields = append(fields, zap.String("business_auth_key_id", hex.EncodeToString(businessAuthKeyID[:])))
|
||
}
|
||
if userID := c.UserID(); userID != 0 {
|
||
fields = append(fields, zap.Int64("user_id", userID))
|
||
}
|
||
fields = dbtrace.AppendZapFields(fields, "", dbStats.Snapshot())
|
||
|
||
if ctxErr := ctx.Err(); ctxErr != nil && err != nil {
|
||
// A canceled request context means the result cannot be delivered. Do not
|
||
// turn cancellation-derived handler errors into cacheable rpc_error replies.
|
||
s.log.Info("RPC canceled", append(fields, zap.NamedError("dispatch_error", err), zap.NamedError("context_error", ctxErr))...)
|
||
return ctxErr
|
||
}
|
||
|
||
if err != nil {
|
||
var rpcErr *tgerr.Error
|
||
if errors.As(err, &rpcErr) {
|
||
s.log.Info("RPC error", append(fields, zap.Int("code", rpcErr.Code), zap.String("error", rpcErr.Message))...)
|
||
return s.sendResult(ctx, c, msgID, &mt.RPCError{
|
||
ErrorCode: rpcErr.Code,
|
||
ErrorMessage: rpcErr.Message,
|
||
})
|
||
}
|
||
s.log.Info("RPC internal error", append(fields, zap.Error(err))...)
|
||
return s.sendResult(ctx, c, msgID, &mt.RPCError{
|
||
ErrorCode: 500,
|
||
ErrorMessage: "INTERNAL",
|
||
})
|
||
}
|
||
|
||
s.log.Info("RPC handled", fields...)
|
||
if err := s.sendResult(ctx, c, msgID, result); err != nil {
|
||
return err
|
||
}
|
||
postresponse.Run(ctx)
|
||
return nil
|
||
}
|
||
|
||
// sendResult 把 RPC 结果包成 rpc_result 并加密回发。
|
||
func (s *Server) sendResult(ctx context.Context, c *Conn, reqMsgID int64, result bin.Encoder) error {
|
||
encoded, err := s.encodeRPCResult(c, reqMsgID, result)
|
||
if err != nil {
|
||
return err
|
||
}
|
||
s.storeRPCResult(c, reqMsgID, encoded)
|
||
return c.SendEncoded(ctx, proto.MessageServerResponse, encoded)
|
||
}
|
||
|
||
// encodeRPCResult 编码 rpc_result。proto.Result.Result 是裸 boxed 对象字节，故在包入
|
||
// rpc_result 之前对其按连接协商 layer 降级（layer==227 直通，零开销）。降级失败 fail-safe：
|
||
// 记日志并发送 canonical 字节——宁可老客户端对个别长尾对象渲染异常，也不让连接/流崩。
|
||
func (s *Server) encodeRPCResult(c *Conn, reqMsgID int64, result bin.Encoder) (*encodedOutboundMessage, error) {
|
||
var buf bin.Buffer
|
||
if err := result.Encode(&buf); err != nil {
|
||
return nil, fmt.Errorf("encode rpc result: %w", err)
|
||
}
|
||
inner := buf.Raw()
|
||
if layer := c.ClientLayer(); layer < layerwire.CanonicalLayer {
|
||
if down, err := layerwire.Transcode(inner, layer); err != nil {
|
||
s.log.Warn("layerwire downgrade failed; sending canonical rpc_result",
|
||
zap.Int("layer", layer), zap.Int64("req_msg_id", reqMsgID), zap.Error(err))
|
||
} else {
|
||
inner = down
|
||
}
|
||
}
|
||
encoded, err := encodeOutboundMessage(&proto.Result{
|
||
RequestMessageID: reqMsgID,
|
||
Result: inner,
|
||
})
|
||
if err != nil {
|
||
return nil, err
|
||
}
|
||
return encoded, nil
|
||
}
|
||
|
||
func (s *Server) cachedRPCResult(c *Conn, reqMsgID int64) (*encodedOutboundMessage, bool) {
|
||
if s == nil || s.rpcResults == nil || c == nil {
|
||
return nil, false
|
||
}
|
||
return s.rpcResults.Get(c.authKeyID, c.sessionID, reqMsgID)
|
||
}
|
||
|
||
func (s *Server) replayRPCResultByRequest(ctx context.Context, c *Conn, reqMsgID int64) error {
|
||
if c == nil {
|
||
return nil
|
||
}
|
||
if resent, err := c.ResendByRequest(ctx, reqMsgID); err != nil {
|
||
return err
|
||
} else if resent {
|
||
s.log.Debug("Resent connection cached rpc_result for duplicate msg_id", zap.Int64("msg_id", reqMsgID))
|
||
return nil
|
||
}
|
||
if cached, ok := s.cachedRPCResult(c, reqMsgID); ok {
|
||
if err := c.SendEncoded(ctx, proto.MessageServerResponse, cached); err != nil {
|
||
return err
|
||
}
|
||
s.log.Debug("Resent session cached rpc_result for duplicate msg_id", zap.Int64("msg_id", reqMsgID))
|
||
}
|
||
return nil
|
||
}
|
||
|
||
func (s *Server) storeRPCResult(c *Conn, reqMsgID int64, encoded *encodedOutboundMessage) {
|
||
if s == nil || s.rpcResults == nil || c == nil {
|
||
return
|
||
}
|
||
s.rpcResults.Put(c.authKeyID, c.sessionID, reqMsgID, encoded)
|
||
}
|
||
|
||
// sendPong 回复 mt.PingRequest / mt.PingDelayDisconnectRequest。
|
||
func (s *Server) sendPong(ctx context.Context, c *Conn, reqMsgID, pingID int64) error {
|
||
return c.SendAsync(ctx, proto.MessageServerResponse, &mt.Pong{MsgID: reqMsgID, PingID: pingID})
|
||
}
|
||
|
||
// sendFutureSalts 回复 MTProto get_future_salts。
|
||
//
|
||
// 第一阶段只维护当前 auth key 的权威 server_salt，因此返回当前 salt 的有效窗口。
|
||
// 后续如引入 salt rotation，可在这里扩展为多条未来 salt。
|
||
func (s *Server) sendFutureSalts(ctx context.Context, c *Conn, reqMsgID int64, num int) error {
|
||
if num < 0 {
|
||
num = 0
|
||
}
|
||
if num > 1 {
|
||
num = 1
|
||
}
|
||
now := int(s.clock.Now().Unix())
|
||
salts := make([]mt.FutureSalt, 0, num)
|
||
if num == 1 {
|
||
salts = append(salts, mt.FutureSalt{
|
||
ValidSince: now - 300,
|
||
ValidUntil: now + 24*60*60,
|
||
Salt: c.salt,
|
||
})
|
||
}
|
||
return c.SendAsync(ctx, proto.MessageServerResponse, &mt.FutureSalts{
|
||
ReqMsgID: reqMsgID,
|
||
Now: now,
|
||
Salts: salts,
|
||
})
|
||
}
|
||
|
||
// sendNewSessionCreated 在连接首个加密消息后通知客户端新 session 已建立。
|
||
// unique_id 必须每个 server session 实例独立：客户端按 unique_id 去重，
|
||
// 复用同一值会让断线重连后的 new_session_created 被吞掉，错过的差分补拉
|
||
// （Android 收到后才调 getDifference）随之丢失。
|
||
func (s *Server) sendNewSessionCreated(ctx context.Context, c *Conn, firstMsgID int64) error {
|
||
return c.SendAsync(ctx, proto.MessageFromServer, &mt.NewSessionCreated{
|
||
FirstMsgID: firstMsgID,
|
||
UniqueID: s.newServerSessionUID(),
|
||
ServerSalt: c.salt,
|
||
})
|
||
}
|
||
|
||
func (s *Server) newServerSessionUID() int64 {
|
||
var b [8]byte
|
||
if _, err := io.ReadFull(s.rand, b[:]); err == nil {
|
||
return int64(binary.LittleEndian.Uint64(b[:]))
|
||
}
|
||
return s.clock.Now().UnixNano()
|
||
}
|
||
|
||
// sendAck 确认收到客户端 content-related 消息。
|
||
func (s *Server) sendAck(ctx context.Context, c *Conn, ids ...int64) error {
|
||
return c.SendAsync(ctx, proto.MessageFromServer, &mt.MsgsAck{MsgIDs: ids})
|
||
}
|
||
|
||
// sendMsgsStateInfo 回复 msgs_state_req/msg_resend_req。
|
||
func (s *Server) sendMsgsStateInfo(ctx context.Context, c *Conn, reqMsgID int64, info []byte) error {
|
||
return c.SendAsync(ctx, proto.MessageServerResponse, &mt.MsgsStateInfo{ReqMsgID: reqMsgID, Info: info})
|
||
}
|
||
|
||
func (s *Server) sendDestroySession(ctx context.Context, c *Conn, sessionID int64) error {
|
||
removed := false
|
||
if sessionID != c.sessionID {
|
||
removed = s.conns.DestroySessionForAuthKey(c.authKeyID, sessionID)
|
||
if err := s.sessions.Delete(ctx, sessionID); err != nil {
|
||
s.log.Debug("Delete session record failed",
|
||
zap.String("auth_key_id", hex.EncodeToString(c.authKeyID[:])),
|
||
zap.Int64("session_id", sessionID),
|
||
zap.Error(err),
|
||
)
|
||
}
|
||
}
|
||
if removed {
|
||
return c.Send(ctx, proto.MessageServerResponse, &mt.DestroySessionOk{SessionID: sessionID})
|
||
}
|
||
return c.Send(ctx, proto.MessageServerResponse, &mt.DestroySessionNone{SessionID: sessionID})
|
||
}
|
||
|
||
// sendBadMsg 通知客户端消息存在协议层错误（msg_id/seqno 非法）。
|
||
func (s *Server) sendBadMsg(ctx context.Context, c *Conn, badMsgID int64, badSeqno int32, code int) error {
|
||
return c.SendAsync(ctx, proto.MessageFromServer, &mt.BadMsgNotification{
|
||
BadMsgID: badMsgID,
|
||
BadMsgSeqno: int(badSeqno),
|
||
ErrorCode: code,
|
||
})
|
||
}
|
||
|
||
// sendBadServerSalt 通知客户端修正 server_salt（error_code 48）。
|
||
func (s *Server) sendBadServerSalt(ctx context.Context, c *Conn, badMsgID int64, badSeqno int32, newSalt int64) error {
|
||
return c.SendPriority(ctx, proto.MessageFromServer, &mt.BadServerSalt{
|
||
BadMsgID: badMsgID,
|
||
BadMsgSeqno: int(badSeqno),
|
||
ErrorCode: 48,
|
||
NewServerSalt: newSalt,
|
||
})
|
||
}
|
||
|
||
// typeName 返回 TL TypeID 的可读名称，未知时回退到 hex。
|
||
func (s *Server) typeName(id uint32) string {
|
||
if name := s.types.Get(id); name != "" {
|
||
return name
|
||
}
|
||
return fmt.Sprintf("%#x", id)
|
||
}
|
||
|
||
func validateClientEnvelope(now time.Time, msgID int64, seqNo int32, typeID uint32) int {
|
||
if msgID == 0 || proto.MessageID(msgID).Type() != proto.MessageFromClient {
|
||
return badMsgIDInvalidBits
|
||
}
|
||
msgTime := proto.MessageID(msgID).Time()
|
||
if msgTime.Before(now.Add(-300 * time.Second)) {
|
||
return badMsgIDTooLow
|
||
}
|
||
if msgTime.After(now.Add(30 * time.Second)) {
|
||
return badMsgIDTooHigh
|
||
}
|
||
if clientMessageAllowsEitherSeqParity(typeID) {
|
||
return 0
|
||
}
|
||
if clientMessageNeedsAck(typeID) {
|
||
if seqNo%2 == 0 {
|
||
return badMsgSeqNotOdd
|
||
}
|
||
} else if seqNo%2 != 0 {
|
||
return badMsgSeqNotEven
|
||
}
|
||
return 0
|
||
}
|
||
|
||
func validateClientContainer(containerMsgID int64, containerSeqNo int32, container proto.MessageContainer) int {
|
||
for _, m := range container.Messages {
|
||
if m.ID >= containerMsgID || int32(m.SeqNo) > containerSeqNo {
|
||
return badMsgContainer
|
||
}
|
||
typeID, err := (&bin.Buffer{Buf: m.Body}).PeekID()
|
||
if err != nil {
|
||
return badMsgContainer
|
||
}
|
||
if typeID == proto.MessageContainerTypeID {
|
||
return badMsgContainer
|
||
}
|
||
if code := validateClientContainerEnvelope(m.ID, int32(m.SeqNo), typeID); code != 0 {
|
||
return badMsgContainer
|
||
}
|
||
}
|
||
return 0
|
||
}
|
||
|
||
func validateClientContainerEnvelope(msgID int64, seqNo int32, typeID uint32) int {
|
||
if msgID == 0 || proto.MessageID(msgID).Type() != proto.MessageFromClient {
|
||
return badMsgIDInvalidBits
|
||
}
|
||
if clientMessageAllowsEitherSeqParity(typeID) {
|
||
return 0
|
||
}
|
||
if clientMessageNeedsAck(typeID) {
|
||
if seqNo%2 == 0 {
|
||
return badMsgSeqNotOdd
|
||
}
|
||
} else if seqNo%2 != 0 {
|
||
return badMsgSeqNotEven
|
||
}
|
||
return 0
|
||
}
|
||
|
||
func clientMessageAllowsEitherSeqParity(typeID uint32) bool {
|
||
switch typeID {
|
||
case mt.PingDelayDisconnectRequestTypeID,
|
||
// get_future_salts 的 seqno 奇偶在客户端间不一致：部分客户端按内容消息发奇数，
|
||
// gotd 按服务消息发偶数。两者都合法（官方服务器都接受），故不在此卡奇偶，避免
|
||
// 误判 bad_msg 触发客户端重连风暴。ack/content 行为仍由 clientMessageNeedsAck 决定。
|
||
mt.GetFutureSaltsRequestTypeID:
|
||
return true
|
||
default:
|
||
return false
|
||
}
|
||
}
|
||
|
||
func clientMessageNeedsAck(typeID uint32) bool {
|
||
switch typeID {
|
||
case proto.MessageContainerTypeID,
|
||
mt.MsgsAckTypeID,
|
||
mt.PingDelayDisconnectRequestTypeID,
|
||
mt.DestroySessionRequestTypeID,
|
||
mt.HTTPWaitRequestTypeID,
|
||
mt.BadMsgNotificationTypeID,
|
||
mt.BadServerSaltTypeID,
|
||
mt.MsgsAllInfoTypeID,
|
||
mt.MsgsStateInfoTypeID,
|
||
mt.MsgDetailedInfoTypeID,
|
||
mt.MsgNewDetailedInfoTypeID:
|
||
return false
|
||
default:
|
||
return true
|
||
}
|
||
}
|
||
|
||
func (cs *connState) seenRecord(msgID int64) (clientMsgRecord, bool) {
|
||
record, ok := cs.seen[msgID]
|
||
return record, ok
|
||
}
|
||
|
||
func (cs *connState) validateSeq(msgID int64, seqNo int32, content bool) int {
|
||
if !content {
|
||
return 0
|
||
}
|
||
for seenMsgID, record := range cs.seen {
|
||
if !record.content {
|
||
continue
|
||
}
|
||
if seenMsgID < msgID && record.seqNo >= seqNo {
|
||
return badMsgSeqTooLow
|
||
}
|
||
if seenMsgID > msgID && record.seqNo <= seqNo {
|
||
return badMsgSeqTooHigh
|
||
}
|
||
}
|
||
return 0
|
||
}
|
||
|
||
func (cs *connState) track(msgID int64, seqNo int32, content bool, state byte) {
|
||
cs.seen[msgID] = clientMsgRecord{
|
||
state: state,
|
||
seqNo: seqNo,
|
||
content: content,
|
||
}
|
||
cs.order = append(cs.order, msgID)
|
||
if msgID < cs.minSeen {
|
||
cs.minSeen = msgID
|
||
}
|
||
if msgID > cs.maxSeen {
|
||
cs.maxSeen = msgID
|
||
}
|
||
if len(cs.order) > maxTrackedClientMsgIDs {
|
||
oldest := cs.order[0]
|
||
cs.order = cs.order[1:]
|
||
delete(cs.seen, oldest)
|
||
if oldest == cs.minSeen || oldest == cs.maxSeen {
|
||
cs.recomputeRange()
|
||
}
|
||
}
|
||
}
|
||
|
||
func (cs *connState) stateInfo(msgIDs []int64) []byte {
|
||
info := make([]byte, len(msgIDs))
|
||
if len(cs.seen) == 0 {
|
||
for i := range info {
|
||
info[i] = msgStateUnknown
|
||
}
|
||
return info
|
||
}
|
||
for i, id := range msgIDs {
|
||
if id < cs.minSeen {
|
||
info[i] = msgStateUnknown
|
||
continue
|
||
}
|
||
if id > cs.maxSeen {
|
||
info[i] = msgStateNotReceivedHigh
|
||
continue
|
||
}
|
||
record, ok := cs.seen[id]
|
||
if !ok {
|
||
info[i] = msgStateNotReceived
|
||
continue
|
||
}
|
||
info[i] = record.state
|
||
}
|
||
return info
|
||
}
|
||
|
||
func (cs *connState) recomputeRange() {
|
||
cs.minSeen = math.MaxInt64
|
||
cs.maxSeen = 0
|
||
for id := range cs.seen {
|
||
if id < cs.minSeen {
|
||
cs.minSeen = id
|
||
}
|
||
if id > cs.maxSeen {
|
||
cs.maxSeen = id
|
||
}
|
||
}
|
||
if len(cs.seen) == 0 {
|
||
cs.minSeen = math.MaxInt64
|
||
}
|
||
}
|