Feature: add dhcp type dns client (#1509)

component/dialer/reuse_unix.go

@@ -0,0 +1,28 @@
+//go:build darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris
+// +build darwin dragonfly freebsd linux netbsd openbsd solaris
+
+package dialer
+
+import (
+	"net"
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+func addrReuseToListenConfig(lc *net.ListenConfig) {
+	chain := lc.Control
+
+	lc.Control = func(network, address string, c syscall.RawConn) (err error) {
+		defer func() {
+			if err == nil && chain != nil {
+				err = chain(network, address, c)
+			}
+		}()
+
+		return c.Control(func(fd uintptr) {
+			unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEADDR, 1)
+			unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEPORT, 1)
+		})
+	}
+}