diff --git a/ipv6/control_rfc2292_unix.go b/ipv6/control_rfc2292_unix.go
index 47196c5..54c6a4a 100644
--- a/ipv6/control_rfc2292_unix.go
+++ b/ipv6/control_rfc2292_unix.go
@@ -7,145 +7,47 @@
 package ipv6
 
 import (
-	"net"
-	"os"
 	"syscall"
 	"unsafe"
 )
 
-const pktinfo = FlagDst | FlagInterface
-
-func setControlMessage(fd int, opt *rawOpt, cf ControlFlags, on bool) error {
-	opt.Lock()
-	defer opt.Unlock()
-	if cf&FlagHopLimit != 0 {
-		if err := setIPv6ReceiveHopLimit(fd, on); err != nil {
-			return err
-		}
-		if on {
-			opt.set(FlagHopLimit)
-		} else {
-			opt.clear(FlagHopLimit)
-		}
+func marshal2292HopLimit(b []byte, cm *ControlMessage) []byte {
+	m := (*syscall.Cmsghdr)(unsafe.Pointer(&b[0]))
+	m.Level = ianaProtocolIPv6
+	m.Type = sysIPV6_2292HOPLIMIT
+	m.SetLen(syscall.CmsgLen(4))
+	if cm != nil {
+		data := b[syscall.CmsgLen(0):]
+		*(*int32)(unsafe.Pointer(&data[:4][0])) = int32(cm.HopLimit)
 	}
-	if cf&pktinfo != 0 {
-		if err := setIPv6ReceivePacketInfo(fd, on); err != nil {
-			return err
-		}
-		if on {
-			opt.set(cf & pktinfo)
-		} else {
-			opt.clear(cf & pktinfo)
-		}
-	}
-	return nil
+	return b[syscall.CmsgSpace(4):]
 }
 
-func newControlMessage(opt *rawOpt) (oob []byte) {
-	opt.Lock()
-	defer opt.Unlock()
-	l, off := 0, 0
-	if opt.isset(FlagHopLimit) {
-		l += syscall.CmsgSpace(4)
-	}
-	if opt.isset(pktinfo) {
-		l += syscall.CmsgSpace(sysSizeofPacketInfo)
-	}
-	if l > 0 {
-		oob = make([]byte, l)
-		if opt.isset(FlagHopLimit) {
-			m := (*syscall.Cmsghdr)(unsafe.Pointer(&oob[off]))
-			m.Level = ianaProtocolIPv6
-			m.Type = sysSockopt2292HopLimit
-			m.SetLen(syscall.CmsgLen(4))
-			off += syscall.CmsgSpace(4)
+func marshal2292PacketInfo(b []byte, cm *ControlMessage) []byte {
+	m := (*syscall.Cmsghdr)(unsafe.Pointer(&b[0]))
+	m.Level = ianaProtocolIPv6
+	m.Type = sysIPV6_2292PKTINFO
+	m.SetLen(syscall.CmsgLen(sysSizeofInet6Pktinfo))
+	if cm != nil {
+		pi := (*sysInet6Pktinfo)(unsafe.Pointer(&b[syscall.CmsgLen(0)]))
+		if ip := cm.Src.To16(); ip != nil && ip.To4() == nil {
+			copy(pi.Addr[:], ip)
 		}
-		if opt.isset(pktinfo) {
-			m := (*syscall.Cmsghdr)(unsafe.Pointer(&oob[off]))
-			m.Level = ianaProtocolIPv6
-			m.Type = sysSockopt2292PacketInfo
-			m.SetLen(syscall.CmsgLen(sysSizeofPacketInfo))
-			off += syscall.CmsgSpace(sysSizeofPacketInfo)
+		if cm.IfIndex > 0 {
+			pi.setIfindex(cm.IfIndex)
 		}
 	}
-	return
+	return b[syscall.CmsgSpace(sysSizeofInet6Pktinfo):]
 }
 
-func parseControlMessage(b []byte) (*ControlMessage, error) {
-	if len(b) == 0 {
-		return nil, nil
+func marshal2292NextHop(b []byte, cm *ControlMessage) []byte {
+	m := (*syscall.Cmsghdr)(unsafe.Pointer(&b[0]))
+	m.Level = ianaProtocolIPv6
+	m.Type = sysIPV6_2292NEXTHOP
+	m.SetLen(syscall.CmsgLen(sysSizeofSockaddrInet6))
+	if cm != nil {
+		sa := (*sysSockaddrInet6)(unsafe.Pointer(&b[syscall.CmsgLen(0)]))
+		sa.setSockaddr(cm.NextHop, cm.IfIndex)
 	}
-	cmsgs, err := syscall.ParseSocketControlMessage(b)
-	if err != nil {
-		return nil, os.NewSyscallError("parse socket control message", err)
-	}
-	cm := &ControlMessage{}
-	for _, m := range cmsgs {
-		if m.Header.Level != ianaProtocolIPv6 {
-			continue
-		}
-		switch m.Header.Type {
-		case sysSockopt2292HopLimit:
-			cm.HopLimit = int(*(*byte)(unsafe.Pointer(&m.Data[:1][0])))
-		case sysSockopt2292PacketInfo:
-			pi := (*sysPacketInfo)(unsafe.Pointer(&m.Data[0]))
-			cm.IfIndex = int(pi.IfIndex)
-			cm.Dst = pi.IP[:]
-		}
-	}
-	return cm, nil
-}
-
-func marshalControlMessage(cm *ControlMessage) (oob []byte) {
-	if cm == nil {
-		return
-	}
-	l, off := 0, 0
-	if cm.HopLimit > 0 {
-		l += syscall.CmsgSpace(4)
-	}
-	pion := false
-	if cm.Src.To4() == nil && cm.Src.To16() != nil || cm.IfIndex != 0 {
-		pion = true
-		l += syscall.CmsgSpace(sysSizeofPacketInfo)
-	}
-	if len(cm.NextHop) == net.IPv6len {
-		l += syscall.CmsgSpace(syscall.SizeofSockaddrInet6)
-	}
-	if l > 0 {
-		oob = make([]byte, l)
-		if cm.HopLimit > 0 {
-			m := (*syscall.Cmsghdr)(unsafe.Pointer(&oob[off]))
-			m.Level = ianaProtocolIPv6
-			m.Type = sysSockopt2292HopLimit
-			m.SetLen(syscall.CmsgLen(4))
-			data := oob[off+syscall.CmsgLen(0):]
-			*(*byte)(unsafe.Pointer(&data[:1][0])) = byte(cm.HopLimit)
-			off += syscall.CmsgSpace(4)
-		}
-		if pion {
-			m := (*syscall.Cmsghdr)(unsafe.Pointer(&oob[off]))
-			m.Level = ianaProtocolIPv6
-			m.Type = sysSockopt2292PacketInfo
-			m.SetLen(syscall.CmsgLen(sysSizeofPacketInfo))
-			pi := (*sysPacketInfo)(unsafe.Pointer(&oob[off+syscall.CmsgLen(0)]))
-			if ip := cm.Src.To16(); ip != nil && ip.To4() == nil {
-				copy(pi.IP[:], ip)
-			}
-			if cm.IfIndex != 0 {
-				pi.IfIndex = uint32(cm.IfIndex)
-			}
-			off += syscall.CmsgSpace(sysSizeofPacketInfo)
-		}
-		if len(cm.NextHop) == net.IPv6len {
-			m := (*syscall.Cmsghdr)(unsafe.Pointer(&oob[off]))
-			m.Level = ianaProtocolIPv6
-			m.Type = sysSockopt2292NextHop
-			m.SetLen(syscall.CmsgLen(syscall.SizeofSockaddrInet6))
-			sa := (*syscall.RawSockaddrInet6)(unsafe.Pointer(&oob[off+syscall.CmsgLen(0)]))
-			setSockaddr(sa, cm.NextHop, cm.IfIndex)
-			off += syscall.CmsgSpace(syscall.SizeofSockaddrInet6)
-		}
-	}
-	return
+	return b[syscall.CmsgSpace(sysSizeofSockaddrInet6):]
 }