perf: disconnect early when an invalid message was received

Signed-off-by: Jianhui Zhao <[email protected]>
zhaojh329 · Sep 8, 2021 · a0c4f76 · a0c4f76
1 parent c4a6406
commit a0c4f76
Showing 1 changed file with 16 additions and 9 deletions.
diff --git a/device.go b/device.go
@@ -19,15 +19,16 @@ import (
 )
 
 const (
- msgTypeRegister = 0x00
- msgTypeLogin = 0x01
- msgTypeLogout = 0x02
- msgTypeTermData = 0x03
- msgTypeWinsize = 0x04
- msgTypeCmd = 0x05
- msgTypeHeartbeat = 0x06
- msgTypeFile = 0x07
- msgTypeWeb = 0x08
+ msgTypeRegister = iota
+ msgTypeLogin
+ msgTypeLogout
+ msgTypeTermData
+ msgTypeWinsize
+ msgTypeCmd
+ msgTypeHeartbeat
+ msgTypeFile
+ msgTypeWeb
+ msgTypeMax = msgTypeWeb
 )
 
 const heartbeatInterval = time.Second * 5
@@ -189,6 +190,12 @@ func (dev *device) readLoop() {
  br.Discard(3)
 
  typ := b[0]
+
+ if typ > msgTypeMax {
+ log.Error().Msgf("invalid msg type: %d", typ)
+ return
+ }
+
  msgLen := binary.BigEndian.Uint16(b[1:])
 
  b = make([]byte, msgLen)