remove unused code

common/net/dns.go

@@ -1,44 +0,0 @@
-package net
-
-import (
-	"net"
-	"sync/atomic"
-	"unsafe"
-)
-
-// IPResolver is the interface to resolve host name to IPs.
-type IPResolver interface {
-	LookupIP(host string) ([]net.IP, error)
-}
-
-type systemIPResolver int
-
-func (s systemIPResolver) LookupIP(host string) ([]net.IP, error) {
-	return net.LookupIP(host)
-}
-
-const (
-	systemIPResolverInstance = systemIPResolver(0)
-)
-
-// SystemIPResolver returns an IPResolver that resolves IP through underlying system.
-func SystemIPResolver() IPResolver {
-	return systemIPResolverInstance
-}
-
-var (
-	ipResolver unsafe.Pointer
-)
-
-func LookupIP(host string) ([]net.IP, error) {
-	r := (*IPResolver)(atomic.LoadPointer(&ipResolver))
-	return (*r).LookupIP(host)
-}
-
-func RegisterIPResolver(resolver IPResolver) {
-	atomic.StorePointer(&ipResolver, unsafe.Pointer(&resolver))
-}
-
-func init() {
-	RegisterIPResolver(systemIPResolverInstance)
-}

common/net/system.go

@@ -11,6 +11,8 @@ var Listen = net.Listen
 var ListenTCP = net.ListenTCP
 var ListenUDP = net.ListenUDP
 
+var LookupIP = net.LookupIP
+
 var FileConn = net.FileConn
 
 var ParseIP = net.ParseIP