fixed struct alignment && refactor linter

util/dns/cache.go

@@ -35,7 +35,7 @@ func NewNetDialer(parent DialFunc, opts ...Option) DialFunc {
 	if cache.opts.MaxCacheEntries == 0 {
 		cache.opts.MaxCacheEntries = DefaultMaxCacheEntries
 	}
-	return func(ctx context.Context, network, address string) (net.Conn, error) {
+	return func(_ context.Context, network, address string) (net.Conn, error) {
 		conn := &dnsConn{}
 		conn.roundTrip = cachingRoundTrip(&cache, network, address)
 		return conn, nil
@@ -116,12 +116,12 @@ func PreferIPV6(b bool) Option {
 }
 
 type cache struct {
-	sync.RWMutex
-
-	dial    DialFunc
 	entries map[string]cacheEntry
+	dial    DialFunc
 
 	opts Options
+
+	sync.RWMutex
 }
 
 type cacheEntry struct {
@@ -283,7 +283,7 @@ func getNameLen(msg string) int {
 	for i < len(msg) {
 		if msg[i] == 0 {
 			// end of name
-			i += 1
+			i++
 			break
 		}
 		if msg[i] >= 0xc0 {
@@ -311,7 +311,7 @@ func getUint32(s string) int {
 func cachingRoundTrip(cache *cache, network, address string) roundTripper {
 	return func(ctx context.Context, req string) (res string, err error) {
 		// check cache
-		if res := cache.get(req); res != "" {
+		if res = cache.get(req); res != "" {
 			return res, nil
 		}
 

util/dns/conn.go

@@ -11,15 +11,16 @@ import (
 )
 
 type dnsConn struct {
-	sync.Mutex
+	ctx       context.Context
+	cancel    context.CancelFunc
+	roundTrip roundTripper
+
+	deadline time.Time
 
 	ibuf bytes.Buffer
 	obuf bytes.Buffer
 
-	ctx       context.Context
-	cancel    context.CancelFunc
-	deadline  time.Time
-	roundTrip roundTripper
+	sync.Mutex
 }
 
 type roundTripper func(ctx context.Context, req string) (res string, err error)
@@ -66,8 +67,8 @@ func (c *dnsConn) RemoteAddr() net.Addr {
 }
 
 func (c *dnsConn) SetDeadline(t time.Time) error {
-	c.SetReadDeadline(t)
-	c.SetWriteDeadline(t)
+	_ = c.SetReadDeadline(t)
+	_ = c.SetWriteDeadline(t)
 	return nil
 }
 
@@ -78,7 +79,7 @@ func (c *dnsConn) SetReadDeadline(t time.Time) error {
 	return nil
 }
 
-func (c *dnsConn) SetWriteDeadline(t time.Time) error {
+func (c *dnsConn) SetWriteDeadline(_ time.Time) error {
 	// writes do not timeout
 	return nil
 }
@@ -156,23 +157,22 @@ func readMessage(c net.Conn) (string, error) {
 			return "", err
 		}
 		return string(b[:n]), nil
-	} else {
-		var sz [2]byte
-		_, err := io.ReadFull(c, sz[:])
-		if err != nil {
-			return "", err
-		}
-
-		size := int64(sz[0])<<8 | int64(sz[1])
-
-		var str strings.Builder
-		_, err = io.CopyN(&str, c, size)
-		if err == io.EOF {
-			return "", io.ErrUnexpectedEOF
-		}
-		if err != nil {
-			return "", err
-		}
-		return str.String(), nil
 	}
+	var sz [2]byte
+	_, err := io.ReadFull(c, sz[:])
+	if err != nil {
+		return "", err
+	}
+
+	size := int64(sz[0])<<8 | int64(sz[1])
+
+	var str strings.Builder
+	_, err = io.CopyN(&str, c, size)
+	if err == io.EOF {
+		return "", io.ErrUnexpectedEOF
+	}
+	if err != nil {
+		return "", err
+	}
+	return str.String(), nil
 }