fix: check if opus created (#1166)

* fix: check is opus created

* fix: careful concurrency fixes

voice.go

@@ -120,9 +120,9 @@ func (v *VoiceConnection) ChangeChannel(channelID string, mute, deaf bool) (err
 	v.log(LogInformational, "called")
 
 	data := voiceChannelJoinOp{4, voiceChannelJoinData{&v.GuildID, &channelID, mute, deaf}}
-	v.wsMutex.Lock()
+	v.session.wsMutex.Lock()
 	err = v.session.wsConn.WriteJSON(data)
-	v.wsMutex.Unlock()
+	v.session.wsMutex.Unlock()
 	if err != nil {
 		return
 	}
@@ -323,7 +323,9 @@ func (v *VoiceConnection) open() (err error) {
 	}
 	data := voiceHandshakeOp{0, voiceHandshakeData{v.GuildID, v.UserID, v.sessionID, v.token}}
 
+	v.wsMutex.Lock()
 	err = v.wsConn.WriteJSON(data)
+	v.wsMutex.Unlock()
 	if err != nil {
 		v.log(LogWarning, "error sending init packet, %s", err)
 		return
@@ -829,7 +831,12 @@ func (v *VoiceConnection) opusReceiver(udpConn *net.UDPConn, close <-chan struct
 		p.SSRC = binary.BigEndian.Uint32(recvbuf[8:12])
 		// decrypt opus data
 		copy(nonce[:], recvbuf[0:12])
-		p.Opus, _ = secretbox.Open(nil, recvbuf[12:rlen], &nonce, &v.op4.SecretKey)
+
+		if opus, ok := secretbox.Open(nil, recvbuf[12:rlen], &nonce, &v.op4.SecretKey); ok {
+			p.Opus = opus
+		} else {
+			return
+		}
 
 		// extension bit set, and not a RTCP packet
 		if ((recvbuf[0] & 0x10) == 0x10) && ((recvbuf[1] & 0x80) == 0) {
@@ -870,7 +877,11 @@ func (v *VoiceConnection) reconnect() {
 	v.reconnecting = true
 	v.Unlock()
 
-	defer func() { v.reconnecting = false }()
+	defer func() {
+		v.Lock()
+		v.reconnecting = false
+		v.Unlock()
+	}()
 
 	// Close any currently open connections
 	v.Close()