From: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri, 29 Jan 2021 19:10:48 +0000 (+0100)
Subject: device: reduce number of append calls when padding
X-Git-Tag: 0.0.20210212~52
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a9f80d8c587df99c6e8f57704aef3fe1ac62d0db;p=thirdparty%2Fwireguard-go.git

device: reduce number of append calls when padding

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---

diff --git a/device/send.go b/device/send.go
index 5261c2f..9d63c4e 100644
--- a/device/send.go
+++ b/device/send.go
@@ -367,7 +367,7 @@ func calculatePaddingSize(packetSize, mtu int) int {
  * Obs. One instance per core
  */
 func (device *Device) RoutineEncryption() {
-
+	var paddingZeros [PaddingMultiple]byte
 	var nonce [chacha20poly1305.NonceSize]byte
 
 	defer device.log.Verbosef("Routine: encryption worker - stopped")
@@ -386,11 +386,8 @@ func (device *Device) RoutineEncryption() {
 		binary.LittleEndian.PutUint64(fieldNonce, elem.nonce)
 
 		// pad content to multiple of 16
-
 		paddingSize := calculatePaddingSize(len(elem.packet), int(atomic.LoadInt32(&device.tun.mtu)))
-		for i := 0; i < paddingSize; i++ {
-			elem.packet = append(elem.packet, 0)
-		}
+		elem.packet = append(elem.packet, paddingZeros[:paddingSize]...)
 
 		// encrypt content and release to consumer