Fix Read, update sample

cmd/yggdrasil/main.go

@@ -283,7 +283,7 @@ func main() {
 			}
 			logger.Println("Accepted")
 			for {
-				b := []byte{}
+				b := make([]byte, 100)
 				if n, err := conn.Read(b); err != nil {
 					logger.Errorln("Read failed:", err)
 					time.Sleep(time.Second * 2)
@@ -319,7 +319,7 @@ func main() {
 					logger.Errorln("Write failed:", err)
 				} else {
 					logger.Println("Wrote", n, "bytes:", b)
-					b = b[:0]
+					b = make([]byte, 100)
 					if n, err := conn.Read(b); err != nil {
 						logger.Errorln("Read failed:", err)
 					} else {

src/yggdrasil/conn.go

@@ -88,8 +88,10 @@ func (c *Conn) Read(b []byte) (int, error) {
 				util.PutBytes(bs)
 				return errors.New("packet dropped due to decryption failure")
 			}
-			b = b[:0]
-			b = append(b, bs...)
+			copy(b, bs)
+			if len(bs) < len(b) {
+				b = b[:len(bs)]
+			}
 			c.session.updateNonce(&p.Nonce)
 			c.session.time = time.Now()
 			return nil