Refactor socksopts per functionality, not per build flag

network/v2/sockopts_reuseaddr.go

@@ -0,0 +1,30 @@
+//go:build !windows
+
+package network
+
+import (
+	"fmt"
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+func setSocketReuseAddrPort(conn syscall.RawConn) error {
+	var err error
+
+	conn.Control(func(fd uintptr) { //nolint: errcheck
+		err = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEADDR, 1)
+		if err != nil {
+			err = fmt.Errorf("cannot set SO_REUSEADDR: %w", err)
+
+			return
+		}
+
+		err = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEPORT, 1)
+		if err != nil {
+			err = fmt.Errorf("cannot set SO_REUSEPORT: %w", err)
+		}
+	})
+
+	return err
+}