gomemif: introduce gomemif

golang native memif driver

Type: feature

Signed-off-by: Jakub Grajciar <jgrajcia@cisco.com>
Change-Id: I693156a44011c80025245d25134f5bf5db6eba82
Signed-off-by: Jakub Grajciar <jgrajcia@cisco.com>

9 files changed, 2175 insertions, 0 deletions

diff --git a/extras/gomemif/memif/BUILD.bazel b/extras/gomemif/memif/BUILD.bazel
new file mode 100644
index 00000000000..e6539ff59bd
--- /dev/null
+++ b/extras/gomemif/memif/BUILD.bazel
@@ -0,0 +1,17 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "memif",
+    srcs = [
+        "interface.go",
+        "interface_unsafe.go",
+        "control_channel.go",
+        "control_channel_unsafe.go",
+        "memif.go",
+        "memif_unsafe.go",
+        "packet_writer.go",
+        "packet_reader.go",
+    ],
+    importpath = "memif",
+    visibility = ["//visibility:public",],
+)
diff --git a/extras/gomemif/memif/control_channel.go b/extras/gomemif/memif/control_channel.go
new file mode 100644
index 00000000000..32e34933ab4
--- /dev/null
+++ b/extras/gomemif/memif/control_channel.go
@@ -0,0 +1,965 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2020 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *------------------------------------------------------------------
+ */
+
+package memif
+
+import (
+	"bytes"
+	"container/list"
+	"encoding/binary"
+	"fmt"
+	"os"
+	"sync"
+	"syscall"
+)
+
+const maxEpollEvents = 1
+const maxControlLen = 256
+
+const errorFdNotFound = "fd not found"
+
+// controlMsg represents a message used in communication between memif peers
+type controlMsg struct {
+	Buffer *bytes.Buffer
+	Fd     int
+}
+
+// listener represents a listener functionality of UNIX domain socket
+type listener struct {
+	socket *Socket
+	event  syscall.EpollEvent
+}
+
+// controlChannel represents a communication channel between memif peers
+// backed by UNIX domain socket
+type controlChannel struct {
+	listRef     *list.Element
+	socket      *Socket
+	i           *Interface
+	event       syscall.EpollEvent
+	data        [msgSize]byte
+	control     [maxControlLen]byte
+	controlLen  int
+	msgQueue    []controlMsg
+	isConnected bool
+}
+
+// Socket represents a UNIX domain socket used for communication
+// between memif peers
+type Socket struct {
+	appName       string
+	filename      string
+	listener      *listener
+	interfaceList *list.List
+	ccList        *list.List
+	epfd          int
+	wakeEvent     syscall.EpollEvent
+	stopPollChan  chan struct{}
+	wg            sync.WaitGroup
+}
+
+// StopPolling stops polling events on the socket
+func (socket *Socket) StopPolling() error {
+	if socket.stopPollChan != nil {
+		// stop polling msg
+		close(socket.stopPollChan)
+		// wake epoll
+		buf := make([]byte, 8)
+		binary.PutUvarint(buf, 1)
+		n, err := syscall.Write(int(socket.wakeEvent.Fd), buf[:])
+		if err != nil {
+			return err
+		}
+		if n != 8 {
+			return fmt.Errorf("Faild to write to eventfd")
+		}
+		// wait until polling is stopped
+		socket.wg.Wait()
+	}
+
+	return nil
+}
+
+// StartPolling starts polling and handling events on the socket,
+// enabling communication between memif peers
+func (socket *Socket) StartPolling(errChan chan<- error) {
+	socket.stopPollChan = make(chan struct{})
+	socket.wg.Add(1)
+	go func() {
+		var events [maxEpollEvents]syscall.EpollEvent
+		defer socket.wg.Done()
+
+		for {
+			select {
+			case <-socket.stopPollChan:
+				return
+			default:
+				num, err := syscall.EpollWait(socket.epfd, events[:], -1)
+				if err != nil {
+					errChan <- fmt.Errorf("EpollWait: ", err)
+					return
+				}
+
+				for ev := 0; ev < num; ev++ {
+					if events[0].Fd == socket.wakeEvent.Fd {
+						continue
+					}
+					err = socket.handleEvent(&events[0])
+					if err != nil {
+						errChan <- fmt.Errorf("handleEvent: ", err)
+					}
+				}
+			}
+		}
+	}()
+}
+
+// addEvent adds event to epoll instance associated with the socket
+func (socket *Socket) addEvent(event *syscall.EpollEvent) error {
+	err := syscall.EpollCtl(socket.epfd, syscall.EPOLL_CTL_ADD, int(event.Fd), event)
+	if err != nil {
+		return fmt.Errorf("EpollCtl: %s", err)
+	}
+	return nil
+}
+
+// addEvent deletes event to epoll instance associated with the socket
+func (socket *Socket) delEvent(event *syscall.EpollEvent) error {
+	err := syscall.EpollCtl(socket.epfd, syscall.EPOLL_CTL_DEL, int(event.Fd), event)
+	if err != nil {
+		return fmt.Errorf("EpollCtl: %s", err)
+	}
+	return nil
+}
+
+// Delete deletes the socket
+func (socket *Socket) Delete() (err error) {
+	for elt := socket.ccList.Front(); elt != nil; elt = elt.Next() {
+		cc, ok := elt.Value.(*controlChannel)
+		if ok {
+			err = cc.close(true, "Socket deleted")
+			if err != nil {
+				return nil
+			}
+		}
+	}
+	for elt := socket.interfaceList.Front(); elt != nil; elt = elt.Next() {
+		i, ok := elt.Value.(*Interface)
+		if ok {
+			err = i.Delete()
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	if socket.listener != nil {
+		err = socket.listener.close()
+		if err != nil {
+			return err
+		}
+		err = os.Remove(socket.filename)
+		if err != nil {
+			return nil
+		}
+	}
+
+	err = socket.delEvent(&socket.wakeEvent)
+	if err != nil {
+		return fmt.Errorf("Failed to delete event: ", err)
+	}
+
+	syscall.Close(socket.epfd)
+
+	return nil
+}
+
+// NewSocket returns a new Socket
+func NewSocket(appName string, filename string) (socket *Socket, err error) {
+	socket = &Socket{
+		appName:       appName,
+		filename:      filename,
+		interfaceList: list.New(),
+		ccList:        list.New(),
+	}
+	if socket.filename == "" {
+		socket.filename = DefaultSocketFilename
+	}
+
+	socket.epfd, _ = syscall.EpollCreate1(0)
+
+	efd, err := eventFd()
+	socket.wakeEvent = syscall.EpollEvent{
+		Events: syscall.EPOLLIN | syscall.EPOLLERR | syscall.EPOLLHUP,
+		Fd:     int32(efd),
+	}
+	err = socket.addEvent(&socket.wakeEvent)
+	if err != nil {
+		return nil, fmt.Errorf("Failed to add event: ", err)
+	}
+
+	return socket, nil
+}
+
+// handleEvent handles epoll event
+func (socket *Socket) handleEvent(event *syscall.EpollEvent) error {
+	if socket.listener != nil && socket.listener.event.Fd == event.Fd {
+		return socket.listener.handleEvent(event)
+	}
+
+	for elt := socket.ccList.Front(); elt != nil; elt = elt.Next() {
+		cc, ok := elt.Value.(*controlChannel)
+		if ok {
+			if cc.event.Fd == event.Fd {
+				return cc.handleEvent(event)
+			}
+		}
+	}
+
+	return fmt.Errorf(errorFdNotFound)
+}
+
+// handleEvent handles epoll event for listener
+func (l *listener) handleEvent(event *syscall.EpollEvent) error {
+	// hang up
+	if (event.Events & syscall.EPOLLHUP) == syscall.EPOLLHUP {
+		err := l.close()
+		if err != nil {
+			return fmt.Errorf("Failed to close listener after hang up event: ", err)
+		}
+		return fmt.Errorf("Hang up: ", l.socket.filename)
+	}
+
+	// error
+	if (event.Events & syscall.EPOLLERR) == syscall.EPOLLERR {
+		err := l.close()
+		if err != nil {
+			return fmt.Errorf("Failed to close listener after receiving an error event: ", err)
+		}
+		return fmt.Errorf("Received error event on listener ", l.socket.filename)
+	}
+
+	// read message
+	if (event.Events & syscall.EPOLLIN) == syscall.EPOLLIN {
+		newFd, _, err := syscall.Accept(int(l.event.Fd))
+		if err != nil {
+			return fmt.Errorf("Accept: %s", err)
+		}
+
+		cc, err := l.socket.addControlChannel(newFd, nil)
+		if err != nil {
+			return fmt.Errorf("Failed to add control channel: %s", err)
+		}
+
+		err = cc.msgEnqHello()
+		if err != nil {
+			return fmt.Errorf("msgEnqHello: %s", err)
+		}
+
+		err = cc.sendMsg()
+		if err != nil {
+			return err
+		}
+
+		return nil
+	}
+
+	return fmt.Errorf("Unexpected event: ", event.Events)
+}
+
+// handleEvent handles epoll event for control channel
+func (cc *controlChannel) handleEvent(event *syscall.EpollEvent) error {
+	var size int
+	var err error
+
+	// hang up
+	if (event.Events & syscall.EPOLLHUP) == syscall.EPOLLHUP {
+		// close cc, don't send msg
+		err := cc.close(false, "")
+		if err != nil {
+			return fmt.Errorf("Failed to close control channel after hang up event: ", err)
+		}
+		return fmt.Errorf("Hang up: ", cc.i.GetName())
+	}
+
+	if (event.Events & syscall.EPOLLERR) == syscall.EPOLLERR {
+		// close cc, don't send msg
+		err := cc.close(false, "")
+		if err != nil {
+			return fmt.Errorf("Failed to close control channel after receiving an error event: ", err)
+		}
+		return fmt.Errorf("Received error event on control channel ", cc.i.GetName())
+	}
+
+	if (event.Events & syscall.EPOLLIN) == syscall.EPOLLIN {
+		size, cc.controlLen, _, _, err = syscall.Recvmsg(int(cc.event.Fd), cc.data[:], cc.control[:], 0)
+		if err != nil {
+			return fmt.Errorf("recvmsg: %s", err)
+		}
+		if size != msgSize {
+			return fmt.Errorf("invalid message size %d", size)
+		}
+
+		err = cc.parseMsg()
+		if err != nil {
+			return err
+		}
+
+		err = cc.sendMsg()
+		if err != nil {
+			return err
+		}
+
+		return nil
+	}
+
+	return fmt.Errorf("Unexpected event: ", event.Events)
+}
+
+// close closes the listener
+func (l *listener) close() error {
+	err := l.socket.delEvent(&l.event)
+	if err != nil {
+		return fmt.Errorf("Failed to del event: ", err)
+	}
+	err = syscall.Close(int(l.event.Fd))
+	if err != nil {
+		return fmt.Errorf("Failed to close socket: ", err)
+	}
+	return nil
+}
+
+// AddListener adds a lisntener to the socket. The fd must describe a
+// UNIX domain socket already bound to a UNIX domain filename and
+// marked as listener
+func (socket *Socket) AddListener(fd int) (err error) {
+	l := &listener{
+		// we will need this to look up master interface by id
+		socket: socket,
+	}
+
+	l.event = syscall.EpollEvent{
+		Events: syscall.EPOLLIN | syscall.EPOLLERR | syscall.EPOLLHUP,
+		Fd:     int32(fd),
+	}
+	err = socket.addEvent(&l.event)
+	if err != nil {
+		return fmt.Errorf("Failed to add event: ", err)
+	}
+
+	socket.listener = l
+
+	return nil
+}
+
+// addListener creates new UNIX domain socket, binds it to the address
+// and marks it as listener
+func (socket *Socket) addListener() (err error) {
+	// create socket
+	fd, err := syscall.Socket(syscall.AF_UNIX, syscall.SOCK_SEQPACKET, 0)
+	if err != nil {
+		return fmt.Errorf("Failed to create UNIX domain socket")
+	}
+	usa := &syscall.SockaddrUnix{Name: socket.filename}
+
+	// Bind to address and start listening
+	err = syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_PASSCRED, 1)
+	if err != nil {
+		return fmt.Errorf("Failed to set socket option %s : %v", socket.filename, err)
+	}
+	err = syscall.Bind(fd, usa)
+	if err != nil {
+		return fmt.Errorf("Failed to bind socket %s : %v", socket.filename, err)
+	}
+	err = syscall.Listen(fd, syscall.SOMAXCONN)
+	if err != nil {
+		return fmt.Errorf("Failed to listen on socket %s : %v", socket.filename, err)
+	}
+
+	return socket.AddListener(fd)
+}
+
+// close closes a control channel, if the control channel is assigned an
+// interface, the interface is disconnected
+func (cc *controlChannel) close(sendMsg bool, str string) (err error) {
+	if sendMsg == true {
+		// first clear message queue so that the disconnect
+		// message is the only message in queue
+		cc.msgQueue = []controlMsg{}
+		cc.msgEnqDisconnect(str)
+
+		err = cc.sendMsg()
+		if err != nil {
+			return err
+		}
+	}
+
+	err = cc.socket.delEvent(&cc.event)
+	if err != nil {
+		return fmt.Errorf("Failed to del event: ", err)
+	}
+
+	// remove referance form socket
+	cc.socket.ccList.Remove(cc.listRef)
+
+	if cc.i != nil {
+		err = cc.i.disconnect()
+		if err != nil {
+			return fmt.Errorf("Interface Disconnect: ", err)
+		}
+	}
+
+	return nil
+}
+
+//addControlChannel returns a new controlChannel and adds it to the socket
+func (socket *Socket) addControlChannel(fd int, i *Interface) (*controlChannel, error) {
+	cc := &controlChannel{
+		socket:      socket,
+		i:           i,
+		isConnected: false,
+	}
+
+	var err error
+
+	cc.event = syscall.EpollEvent{
+		Events: syscall.EPOLLIN | syscall.EPOLLERR | syscall.EPOLLHUP,
+		Fd:     int32(fd),
+	}
+	err = socket.addEvent(&cc.event)
+	if err != nil {
+		return nil, fmt.Errorf("Failed to add event: ", err)
+	}
+
+	cc.listRef = socket.ccList.PushBack(cc)
+
+	return cc, nil
+}
+
+func (cc *controlChannel) msgEnqAck() (err error) {
+	buf := new(bytes.Buffer)
+	err = binary.Write(buf, binary.LittleEndian, msgTypeAck)
+
+	msg := controlMsg{
+		Buffer: buf,
+		Fd:     -1,
+	}
+
+	cc.msgQueue = append(cc.msgQueue, msg)
+
+	return nil
+}
+
+func (cc *controlChannel) msgEnqHello() (err error) {
+	hello := MsgHello{
+		VersionMin:      Version,
+		VersionMax:      Version,
+		MaxRegion:       255,
+		MaxRingM2S:      255,
+		MaxRingS2M:      255,
+		MaxLog2RingSize: 14,
+	}
+
+	copy(hello.Name[:], []byte(cc.socket.appName))
+
+	buf := new(bytes.Buffer)
+	err = binary.Write(buf, binary.LittleEndian, msgTypeHello)
+	err = binary.Write(buf, binary.LittleEndian, hello)
+
+	msg := controlMsg{
+		Buffer: buf,
+		Fd:     -1,
+	}
+
+	cc.msgQueue = append(cc.msgQueue, msg)
+
+	return nil
+}
+
+func (cc *controlChannel) parseHello() (err error) {
+	var hello MsgHello
+
+	buf := bytes.NewReader(cc.data[msgTypeSize:])
+	err = binary.Read(buf, binary.LittleEndian, &hello)
+	if err != nil {
+		return
+	}
+
+	if hello.VersionMin > Version || hello.VersionMax < Version {
+		return fmt.Errorf("Incompatible memif version")
+	}
+
+	cc.i.run = cc.i.args.MemoryConfig
+
+	cc.i.run.NumQueuePairs = min16(cc.i.args.MemoryConfig.NumQueuePairs, hello.MaxRingS2M)
+	cc.i.run.NumQueuePairs = min16(cc.i.args.MemoryConfig.NumQueuePairs, hello.MaxRingM2S)
+	cc.i.run.Log2RingSize = min8(cc.i.args.MemoryConfig.Log2RingSize, hello.MaxLog2RingSize)
+
+	cc.i.remoteName = string(hello.Name[:])
+
+	return nil
+}
+
+func (cc *controlChannel) msgEnqInit() (err error) {
+	init := MsgInit{
+		Version: Version,
+		Id:      cc.i.args.Id,
+		Mode:    interfaceModeEthernet,
+	}
+
+	copy(init.Name[:], []byte(cc.socket.appName))
+
+	buf := new(bytes.Buffer)
+	err = binary.Write(buf, binary.LittleEndian, msgTypeInit)
+	err = binary.Write(buf, binary.LittleEndian, init)
+
+	msg := controlMsg{
+		Buffer: buf,
+		Fd:     -1,
+	}
+
+	cc.msgQueue = append(cc.msgQueue, msg)
+
+	return nil
+}
+
+func (cc *controlChannel) parseInit() (err error) {
+	var init MsgInit
+
+	buf := bytes.NewReader(cc.data[msgTypeSize:])
+	err = binary.Read(buf, binary.LittleEndian, &init)
+	if err != nil {
+		return
+	}
+
+	if init.Version != Version {
+		return fmt.Errorf("Incompatible memif driver version")
+	}
+
+	// find peer interface
+	for elt := cc.socket.interfaceList.Front(); elt != nil; elt = elt.Next() {
+		i, ok := elt.Value.(*Interface)
+		if ok {
+			if i.args.Id == init.Id && i.args.IsMaster && i.cc == nil {
+				// verify secret
+				if i.args.Secret != init.Secret {
+					return fmt.Errorf("Invalid secret")
+				}
+				// interface is assigned to control channel
+				i.cc = cc
+				cc.i = i
+				cc.i.run = cc.i.args.MemoryConfig
+				cc.i.remoteName = string(init.Name[:])
+
+				return nil
+			}
+		}
+	}
+
+	return fmt.Errorf("Invalid interface id")
+}
+
+func (cc *controlChannel) msgEnqAddRegion(regionIndex uint16) (err error) {
+	if len(cc.i.regions) <= int(regionIndex) {
+		return fmt.Errorf("Invalid region index")
+	}
+
+	addRegion := MsgAddRegion{
+		Index: regionIndex,
+		Size:  cc.i.regions[regionIndex].size,
+	}
+
+	buf := new(bytes.Buffer)
+	err = binary.Write(buf, binary.LittleEndian, msgTypeAddRegion)
+	err = binary.Write(buf, binary.LittleEndian, addRegion)
+
+	msg := controlMsg{
+		Buffer: buf,
+		Fd:     cc.i.regions[regionIndex].fd,
+	}
+
+	cc.msgQueue = append(cc.msgQueue, msg)
+
+	return nil
+}
+
+func (cc *controlChannel) parseAddRegion() (err error) {
+	var addRegion MsgAddRegion
+
+	buf := bytes.NewReader(cc.data[msgTypeSize:])
+	err = binary.Read(buf, binary.LittleEndian, &addRegion)
+	if err != nil {
+		return
+	}
+
+	fd, err := cc.parseControlMsg()
+	if err != nil {
+		return fmt.Errorf("parseControlMsg: %s", err)
+	}
+
+	if addRegion.Index > 255 {
+		return fmt.Errorf("Invalid memory region index")
+	}
+
+	region := memoryRegion{
+		size: addRegion.Size,
+		fd:   fd,
+	}
+
+	cc.i.regions = append(cc.i.regions, region)
+
+	return nil
+}
+
+func (cc *controlChannel) msgEnqAddRing(ringType ringType, ringIndex uint16) (err error) {
+	var q Queue
+	var flags uint16 = 0
+
+	if ringType == ringTypeS2M {
+		q = cc.i.txQueues[ringIndex]
+		flags = msgAddRingFlagS2M
+	} else {
+		q = cc.i.rxQueues[ringIndex]
+	}
+
+	addRing := MsgAddRing{
+		Index:          ringIndex,
+		Offset:         uint32(q.ring.offset),
+		Region:         uint16(q.ring.region),
+		RingSizeLog2:   uint8(q.ring.log2Size),
+		Flags:          flags,
+		PrivateHdrSize: 0,
+	}
+
+	buf := new(bytes.Buffer)
+	err = binary.Write(buf, binary.LittleEndian, msgTypeAddRing)
+	err = binary.Write(buf, binary.LittleEndian, addRing)
+
+	msg := controlMsg{
+		Buffer: buf,
+		Fd:     q.interruptFd,
+	}
+
+	cc.msgQueue = append(cc.msgQueue, msg)
+
+	return nil
+}
+
+func (cc *controlChannel) parseAddRing() (err error) {
+	var addRing MsgAddRing
+
+	buf := bytes.NewReader(cc.data[msgTypeSize:])
+	err = binary.Read(buf, binary.LittleEndian, &addRing)
+	if err != nil {
+		return
+	}
+
+	fd, err := cc.parseControlMsg()
+	if err != nil {
+		return err
+	}
+
+	if addRing.Index >= cc.i.run.NumQueuePairs {
+		return fmt.Errorf("invalid ring index")
+	}
+
+	q := Queue{
+		i:           cc.i,
+		interruptFd: fd,
+	}
+
+	if (addRing.Flags & msgAddRingFlagS2M) == msgAddRingFlagS2M {
+		q.ring = newRing(int(addRing.Region), ringTypeS2M, int(addRing.Offset), int(addRing.RingSizeLog2))
+		cc.i.rxQueues = append(cc.i.rxQueues, q)
+	} else {
+		q.ring = newRing(int(addRing.Region), ringTypeM2S, int(addRing.Offset), int(addRing.RingSizeLog2))
+		cc.i.txQueues = append(cc.i.txQueues, q)
+	}
+
+	return nil
+}
+
+func (cc *controlChannel) msgEnqConnect() (err error) {
+	var connect MsgConnect
+	copy(connect.Name[:], []byte(cc.i.args.Name))
+
+	buf := new(bytes.Buffer)
+	err = binary.Write(buf, binary.LittleEndian, msgTypeConnect)
+	err = binary.Write(buf, binary.LittleEndian, connect)
+
+	msg := controlMsg{
+		Buffer: buf,
+		Fd:     -1,
+	}
+
+	cc.msgQueue = append(cc.msgQueue, msg)
+
+	return nil
+}
+
+func (cc *controlChannel) parseConnect() (err error) {
+	var connect MsgConnect
+
+	buf := bytes.NewReader(cc.data[msgTypeSize:])
+	err = binary.Read(buf, binary.LittleEndian, &connect)
+	if err != nil {
+		return
+	}
+
+	cc.i.peerName = string(connect.Name[:])
+
+	err = cc.i.connect()
+	if err != nil {
+		return err
+	}
+
+	cc.isConnected = true
+
+	return nil
+}
+
+func (cc *controlChannel) msgEnqConnected() (err error) {
+	var connected MsgConnected
+	copy(connected.Name[:], []byte(cc.i.args.Name))
+
+	buf := new(bytes.Buffer)
+	err = binary.Write(buf, binary.LittleEndian, msgTypeConnected)
+	err = binary.Write(buf, binary.LittleEndian, connected)
+
+	msg := controlMsg{
+		Buffer: buf,
+		Fd:     -1,
+	}
+
+	cc.msgQueue = append(cc.msgQueue, msg)
+
+	return nil
+}
+
+func (cc *controlChannel) parseConnected() (err error) {
+	var conn MsgConnected
+
+	buf := bytes.NewReader(cc.data[msgTypeSize:])
+	err = binary.Read(buf, binary.LittleEndian, &conn)
+	if err != nil {
+		return
+	}
+
+	cc.i.peerName = string(conn.Name[:])
+
+	err = cc.i.connect()
+	if err != nil {
+		return err
+	}
+
+	cc.isConnected = true
+
+	return nil
+}
+
+func (cc *controlChannel) msgEnqDisconnect(str string) (err error) {
+	dc := MsgDisconnect{
+		// not implemented
+		Code: 0,
+	}
+	copy(dc.String[:], str)
+
+	buf := new(bytes.Buffer)
+	err = binary.Write(buf, binary.LittleEndian, msgTypeDisconnect)
+	err = binary.Write(buf, binary.LittleEndian, dc)
+
+	msg := controlMsg{
+		Buffer: buf,
+		Fd:     -1,
+	}
+
+	cc.msgQueue = append(cc.msgQueue, msg)
+
+	return nil
+}
+
+func (cc *controlChannel) parseDisconnect() (err error) {
+	var dc MsgDisconnect
+
+	buf := bytes.NewReader(cc.data[msgTypeSize:])
+	err = binary.Read(buf, binary.LittleEndian, &dc)
+	if err != nil {
+		return
+	}
+
+	err = cc.close(false, string(dc.String[:]))
+	if err != nil {
+		return fmt.Errorf("Failed to disconnect control channel: ", err)
+	}
+
+	return nil
+}
+
+func (cc *controlChannel) parseMsg() error {
+	var msgType msgType
+	var err error
+
+	buf := bytes.NewReader(cc.data[:])
+	err = binary.Read(buf, binary.LittleEndian, &msgType)
+
+	if msgType == msgTypeAck {
+		return nil
+	} else if msgType == msgTypeHello {
+		// Configure
+		err = cc.parseHello()
+		if err != nil {
+			goto error
+		}
+		// Initialize slave memif
+		err = cc.i.initializeRegions()
+		if err != nil {
+			goto error
+		}
+		err = cc.i.initializeQueues()
+		if err != nil {
+			goto error
+		}
+		// Enqueue messages
+		err = cc.msgEnqInit()
+		if err != nil {
+			goto error
+		}
+		for i := 0; i < len(cc.i.regions); i++ {
+			err = cc.msgEnqAddRegion(uint16(i))
+			if err != nil {
+				goto error
+			}
+		}
+		for i := 0; uint16(i) < cc.i.run.NumQueuePairs; i++ {
+			err = cc.msgEnqAddRing(ringTypeS2M, uint16(i))
+			if err != nil {
+				goto error
+			}
+		}
+		for i := 0; uint16(i) < cc.i.run.NumQueuePairs; i++ {
+			err = cc.msgEnqAddRing(ringTypeM2S, uint16(i))
+			if err != nil {
+				goto error
+			}
+		}
+		err = cc.msgEnqConnect()
+		if err != nil {
+			goto error
+		}
+	} else if msgType == msgTypeInit {
+		err = cc.parseInit()
+		if err != nil {
+			goto error
+		}
+
+		err = cc.msgEnqAck()
+		if err != nil {
+			goto error
+		}
+	} else if msgType == msgTypeAddRegion {
+		err = cc.parseAddRegion()
+		if err != nil {
+			goto error
+		}
+
+		err = cc.msgEnqAck()
+		if err != nil {
+			goto error
+		}
+	} else if msgType == msgTypeAddRing {
+		err = cc.parseAddRing()
+		if err != nil {
+			goto error
+		}
+
+		err = cc.msgEnqAck()
+		if err != nil {
+			goto error
+		}
+	} else if msgType == msgTypeConnect {
+		err = cc.parseConnect()
+		if err != nil {
+			goto error
+		}
+
+		err = cc.msgEnqConnected()
+		if err != nil {
+			goto error
+		}
+	} else if msgType == msgTypeConnected {
+		err = cc.parseConnected()
+		if err != nil {
+			goto error
+		}
+	} else if msgType == msgTypeDisconnect {
+		err = cc.parseDisconnect()
+		if err != nil {
+			goto error
+		}
+	} else {
+		err = fmt.Errorf("unknown message %d", msgType)
+		goto error
+	}
+
+	return nil
+
+error:
+	err1 := cc.close(true, err.Error())
+	if err1 != nil {
+		return fmt.Errorf(err.Error(), ": Failed to close control channel: ", err1)
+	}
+
+	return err
+}
+
+// parseControlMsg parses control message and returns file descriptor
+// if any
+func (cc *controlChannel) parseControlMsg() (fd int, err error) {
+	// Assert only called when we require FD
+	fd = -1
+
+	controlMsgs, err := syscall.ParseSocketControlMessage(cc.control[:cc.controlLen])
+	if err != nil {
+		return -1, fmt.Errorf("syscall.ParseSocketControlMessage: %s", err)
+	}
+
+	if len(controlMsgs) == 0 {
+		return -1, fmt.Errorf("Missing control message")
+	}
+
+	for _, cmsg := range controlMsgs {
+		if cmsg.Header.Level == syscall.SOL_SOCKET {
+			if cmsg.Header.Type == syscall.SCM_RIGHTS {
+				FDs, err := syscall.ParseUnixRights(&cmsg)
+				if err != nil {
+					return -1, fmt.Errorf("syscall.ParseUnixRights: %s", err)
+				}
+				if len(FDs) == 0 {
+					continue
+				}
+				// Only expect single FD
+				fd = FDs[0]
+			}
+		}
+	}
+
+	if fd == -1 {
+		return -1, fmt.Errorf("Missing file descriptor")
+	}
+
+	return fd, nil
+}
diff --git a/extras/gomemif/memif/control_channel_unsafe.go b/extras/gomemif/memif/control_channel_unsafe.go
new file mode 100644
index 00000000000..9e91297b160
--- /dev/null
+++ b/extras/gomemif/memif/control_channel_unsafe.go
@@ -0,0 +1,60 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2020 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *------------------------------------------------------------------
+ */
+
+package memif
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+// sendMsg sends a control message from contorl channels message queue
+func (cc *controlChannel) sendMsg() (err error) {
+	if len(cc.msgQueue) < 1 {
+		return nil
+	}
+	// Get message buffer
+	msg := cc.msgQueue[0]
+	// Dequeue
+	cc.msgQueue = cc.msgQueue[1:]
+
+	iov := &syscall.Iovec{
+		Base: &msg.Buffer.Bytes()[0],
+		Len:  msgSize,
+	}
+
+	msgh := syscall.Msghdr{
+		Iov:    iov,
+		Iovlen: 1,
+	}
+
+	if msg.Fd > 0 {
+		oob := syscall.UnixRights(msg.Fd)
+		msgh.Control = &oob[0]
+		msgh.Controllen = uint64(syscall.CmsgSpace(4))
+	}
+
+	_, _, errno := syscall.Syscall(syscall.SYS_SENDMSG, uintptr(cc.event.Fd), uintptr(unsafe.Pointer(&msgh)), uintptr(0))
+	if errno != 0 {
+		err = os.NewSyscallError("sendmsg", errno)
+		return fmt.Errorf("SYS_SENDMSG: %s", errno)
+	}
+
+	return nil
+}
diff --git a/extras/gomemif/memif/interface.go b/extras/gomemif/memif/interface.go
new file mode 100644
index 00000000000..a571deb43c9
--- /dev/null
+++ b/extras/gomemif/memif/interface.go
@@ -0,0 +1,507 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2020 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *------------------------------------------------------------------
+ */
+
+// Package memif provides the implementation of shared memory interface (memif).
+//
+// Memif network interfaces communicate using UNIX domain socket. This socket
+// must be first created using NewSocket(). Then interfaces can be added
+// to this socket using NewInterface(). To start communication on each socket
+// socket.StartPolling() must be called. socket.StopPolling() will stop
+// the communication. When the interface changes link status Connected and
+// Disconencted callbacks set in Arguments for each interface are called
+// respectively. Once the interface is connected rx and tx queues can be
+// aquired using interface.GetRxQueue() and interface.GetTxQueue().
+// Packets can be transmitted by calling queue.ReadPacket() on rx queues and
+// queue.WritePacket() on tx queues. If the interface is disconnected
+// queue.ReadPacket() and queue.WritePacket() MUST not be called.
+//
+// Data transmission is backed by shared memory. The driver works in
+// promiscuous mode only.
+package memif
+
+import (
+	"container/list"
+	"fmt"
+	"os"
+	"syscall"
+)
+
+const (
+	DefaultSocketFilename   = "/run/vpp/memif.sock"
+	DefaultNumQueuePairs    = 1
+	DefaultLog2RingSize     = 10
+	DefaultPacketBufferSize = 2048
+)
+
+const mfd_allow_sealing = 2
+const sys_memfd_create = 319
+const f_add_seals = 1033
+const f_seal_shrink = 0x0002
+
+const efd_nonblock = 04000
+
+// ConnectedFunc is a callback called when an interface is connected
+type ConnectedFunc func(i *Interface) error
+
+// DisconnectedFunc is a callback called when an interface is disconnected
+type DisconnectedFunc func(i *Interface) error
+
+// MemoryConfig represents shared memory configuration
+type MemoryConfig struct {
+	NumQueuePairs    uint16 // number of queue pairs
+	Log2RingSize     uint8  // ring size as log2
+	PacketBufferSize uint32 // size of single packet buffer
+}
+
+// Arguments represent interface configuration
+type Arguments struct {
+	Id               uint32 // Interface identifier unique across socket. Used to identify peer interface when connecting
+	IsMaster         bool   // Interface role master/slave
+	Name             string
+	Secret           [24]byte // optional parameter, secrets of the interfaces must match if they are to connect
+	MemoryConfig     MemoryConfig
+	ConnectedFunc    ConnectedFunc    // callback called when interface changes status to connected
+	DisconnectedFunc DisconnectedFunc // callback called when interface changes status to disconnected
+	PrivateData      interface{}      // private data used by client program
+}
+
+// memoryRegion represents a shared memory mapped file
+type memoryRegion struct {
+	data               []byte
+	size               uint64
+	fd                 int
+	packetBufferOffset uint32
+}
+
+// Queue represents rx or tx queue
+type Queue struct {
+	ring        *ring
+	i           *Interface
+	lastHead    uint16
+	lastTail    uint16
+	interruptFd int
+}
+
+// Interface represents memif network interface
+type Interface struct {
+	args        Arguments
+	run         MemoryConfig
+	privateData interface{}
+	listRef     *list.Element
+	socket      *Socket
+	cc          *controlChannel
+	remoteName  string
+	peerName    string
+	regions     []memoryRegion
+	txQueues    []Queue
+	rxQueues    []Queue
+}
+
+// IsMaster returns true if the interfaces role is master, else returns false
+func (i *Interface) IsMaster() bool {
+	return i.args.IsMaster
+}
+
+// GetRemoteName returns the name of the application on which the peer
+// interface exists
+func (i *Interface) GetRemoteName() string {
+	return i.remoteName
+}
+
+// GetPeerName returns peer interfaces name
+func (i *Interface) GetPeerName() string {
+	return i.peerName
+}
+
+// GetName returens interfaces name
+func (i *Interface) GetName() string {
+	return i.args.Name
+}
+
+// GetMemoryConfig returns interfaces active memory config.
+// If interface is not connected the config is invalid.
+func (i *Interface) GetMemoryConfig() MemoryConfig {
+	return i.run
+}
+
+// GetRxQueue returns an rx queue specified by queue index
+func (i *Interface) GetRxQueue(qid int) (*Queue, error) {
+	if qid >= len(i.rxQueues) {
+		return nil, fmt.Errorf("Invalid Queue index")
+	}
+	return &i.rxQueues[qid], nil
+}
+
+// GetRxQueue returns a tx queue specified by queue index
+func (i *Interface) GetTxQueue(qid int) (*Queue, error) {
+	if qid >= len(i.txQueues) {
+		return nil, fmt.Errorf("Invalid Queue index")
+	}
+	return &i.txQueues[qid], nil
+}
+
+// GetEventFd returns queues interrupt event fd
+func (q *Queue) GetEventFd() (int, error) {
+	return q.interruptFd, nil
+}
+
+// GetFilename returns sockets filename
+func (socket *Socket) GetFilename() string {
+	return socket.filename
+}
+
+// close closes the queue
+func (q *Queue) close() {
+	syscall.Close(q.interruptFd)
+}
+
+// IsConnecting returns true if the interface is connecting
+func (i *Interface) IsConnecting() bool {
+	if i.cc != nil {
+		return true
+	}
+	return false
+}
+
+// IsConnected returns true if the interface is connected
+func (i *Interface) IsConnected() bool {
+	if i.cc != nil && i.cc.isConnected {
+		return true
+	}
+	return false
+}
+
+// Disconnect disconnects the interface
+func (i *Interface) Disconnect() (err error) {
+	if i.cc != nil {
+		// close control and disconenct interface
+		return i.cc.close(true, "Interface disconnected")
+	}
+	return nil
+}
+
+// disconnect finalizes interface disconnection
+func (i *Interface) disconnect() (err error) {
+	if i.cc == nil { // disconnected
+		return nil
+	}
+
+	err = i.args.DisconnectedFunc(i)
+	if err != nil {
+		return fmt.Errorf("DisconnectedFunc: ", err)
+	}
+
+	for _, q := range i.txQueues {
+		q.close()
+	}
+	i.txQueues = []Queue{}
+
+	for _, q := range i.rxQueues {
+		q.close()
+	}
+	i.rxQueues = []Queue{}
+
+	// unmap regions
+	for _, r := range i.regions {
+		err = syscall.Munmap(r.data)
+		if err != nil {
+			return err
+		}
+		err = syscall.Close(r.fd)
+		if err != nil {
+			return err
+		}
+	}
+	i.regions = nil
+	i.cc = nil
+
+	i.peerName = ""
+	i.remoteName = ""
+
+	return nil
+}
+
+// Delete deletes the interface
+func (i *Interface) Delete() (err error) {
+	i.Disconnect()
+
+	// remove referance on socket
+	i.socket.interfaceList.Remove(i.listRef)
+	i = nil
+
+	return nil
+}
+
+// GetSocket returns the socket the interface belongs to
+func (i *Interface) GetSocket() *Socket {
+	return i.socket
+}
+
+// GetPrivateDate returns interfaces private data
+func (i *Interface) GetPrivateData() interface{} {
+	return i.args.PrivateData
+}
+
+// GetId returns interfaces id
+func (i *Interface) GetId() uint32 {
+	return i.args.Id
+}
+
+// RoleToString returns 'Master' if isMaster os true, else returns 'Slave'
+func RoleToString(isMaster bool) string {
+	if isMaster {
+		return "Master"
+	}
+	return "Slave"
+}
+
+// RequestConnection is used by slave interface to connect to a socket and
+// create a control channel
+func (i *Interface) RequestConnection() error {
+	if i.IsMaster() {
+		return fmt.Errorf("Only slave can request connection")
+	}
+	// create socket
+	fd, err := syscall.Socket(syscall.AF_UNIX, syscall.SOCK_SEQPACKET, 0)
+	if err != nil {
+		return fmt.Errorf("Failed to create UNIX domain socket: %v", err)
+	}
+	usa := &syscall.SockaddrUnix{Name: i.socket.filename}
+
+	// Connect to listener socket
+	err = syscall.Connect(fd, usa)
+	if err != nil {
+		return fmt.Errorf("Failed to connect socket %s : %v", i.socket.filename, err)
+	}
+
+	// Create control channel
+	i.cc, err = i.socket.addControlChannel(fd, i)
+	if err != nil {
+		return fmt.Errorf("Failed to create control channel: %v", err)
+	}
+
+	return nil
+}
+
+// NewInterface returns a new memif network interface. When creating an interface
+// it's id must be unique across socket with the exception of loopback interface
+// in which case the id is the same but role differs
+func (socket *Socket) NewInterface(args *Arguments) (*Interface, error) {
+	var err error
+	// make sure the ID is unique on this socket
+	for elt := socket.interfaceList.Front(); elt != nil; elt = elt.Next() {
+		i, ok := elt.Value.(*Interface)
+		if ok {
+			if i.args.Id == args.Id && i.args.IsMaster == args.IsMaster {
+				return nil, fmt.Errorf("Interface with id %u role %s already exists on this socket", args.Id, RoleToString(args.IsMaster))
+			}
+		}
+	}
+
+	// copy interface configuration
+	i := Interface{
+		args: *args,
+	}
+	// set default values
+	if i.args.MemoryConfig.NumQueuePairs == 0 {
+		i.args.MemoryConfig.NumQueuePairs = DefaultNumQueuePairs
+	}
+	if i.args.MemoryConfig.Log2RingSize == 0 {
+		i.args.MemoryConfig.Log2RingSize = DefaultLog2RingSize
+	}
+	if i.args.MemoryConfig.PacketBufferSize == 0 {
+		i.args.MemoryConfig.PacketBufferSize = DefaultPacketBufferSize
+	}
+
+	i.socket = socket
+
+	// append interface to the list
+	i.listRef = socket.interfaceList.PushBack(&i)
+
+	if i.args.IsMaster {
+		if socket.listener == nil {
+			err = socket.addListener()
+			if err != nil {
+				return nil, fmt.Errorf("Failed to create listener channel: %s", err)
+			}
+		}
+	}
+
+	return &i, nil
+}
+
+// eventFd returns an eventfd (SYS_EVENTFD2)
+func eventFd() (efd int, err error) {
+	u_efd, _, errno := syscall.Syscall(syscall.SYS_EVENTFD2, uintptr(0), uintptr(efd_nonblock), 0)
+	if errno != 0 {
+		return -1, os.NewSyscallError("eventfd", errno)
+	}
+	return int(u_efd), nil
+}
+
+// addRegions creates and adds a new memory region to the interface (slave only)
+func (i *Interface) addRegion(hasPacketBuffers bool, hasRings bool) (err error) {
+	var r memoryRegion
+
+	if hasRings {
+		r.packetBufferOffset = uint32((i.run.NumQueuePairs + i.run.NumQueuePairs) * (ringSize + descSize*(1<<i.run.Log2RingSize)))
+	} else {
+		r.packetBufferOffset = 0
+	}
+
+	if hasPacketBuffers {
+		r.size = uint64(r.packetBufferOffset + i.run.PacketBufferSize*uint32(1<<i.run.Log2RingSize)*uint32(i.run.NumQueuePairs+i.run.NumQueuePairs))
+	} else {
+		r.size = uint64(r.packetBufferOffset)
+	}
+
+	r.fd, err = memfdCreate()
+	if err != nil {
+		return err
+	}
+
+	_, _, errno := syscall.Syscall(syscall.SYS_FCNTL, uintptr(r.fd), uintptr(f_add_seals), uintptr(f_seal_shrink))
+	if errno != 0 {
+		syscall.Close(r.fd)
+		return fmt.Errorf("memfdCreate: %s", os.NewSyscallError("fcntl", errno))
+	}
+
+	err = syscall.Ftruncate(r.fd, int64(r.size))
+	if err != nil {
+		syscall.Close(r.fd)
+		r.fd = -1
+		return fmt.Errorf("memfdCreate: %s", err)
+	}
+
+	r.data, err = syscall.Mmap(r.fd, 0, int(r.size), syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_SHARED)
+	if err != nil {
+		return fmt.Errorf("addRegion: %s", err)
+	}
+
+	i.regions = append(i.regions, r)
+
+	return nil
+}
+
+// initializeRegions initializes interfaces regions (slave only)
+func (i *Interface) initializeRegions() (err error) {
+
+	err = i.addRegion(true, true)
+	if err != nil {
+		return fmt.Errorf("initializeRegions: %s", err)
+	}
+
+	return nil
+}
+
+// initializeQueues initializes interfaces queues (slave only)
+func (i *Interface) initializeQueues() (err error) {
+	var q *Queue
+	var desc descBuf
+	var slot int
+
+	desc = newDescBuf()
+	desc.setFlags(0)
+	desc.setRegion(0)
+	desc.setLength(int(i.run.PacketBufferSize))
+
+	for qid := 0; qid < int(i.run.NumQueuePairs); qid++ {
+		/* TX */
+		q = &Queue{
+			ring:     i.newRing(0, ringTypeS2M, qid),
+			lastHead: 0,
+			lastTail: 0,
+			i:        i,
+		}
+		q.ring.setCookie(cookie)
+		q.ring.setFlags(1)
+		q.interruptFd, err = eventFd()
+		if err != nil {
+			return err
+		}
+		q.putRing()
+		i.txQueues = append(i.txQueues, *q)
+
+		for j := 0; j < q.ring.size; j++ {
+			slot = qid*q.ring.size + j
+			desc.setOffset(int(i.regions[0].packetBufferOffset + uint32(slot)*i.run.PacketBufferSize))
+			q.putDescBuf(slot, desc)
+		}
+	}
+	for qid := 0; qid < int(i.run.NumQueuePairs); qid++ {
+		/* RX */
+		q = &Queue{
+			ring:     i.newRing(0, ringTypeM2S, qid),
+			lastHead: 0,
+			lastTail: 0,
+			i:        i,
+		}
+		q.ring.setCookie(cookie)
+		q.ring.setFlags(1)
+		q.interruptFd, err = eventFd()
+		if err != nil {
+			return err
+		}
+		q.putRing()
+		i.rxQueues = append(i.rxQueues, *q)
+
+		for j := 0; j < q.ring.size; j++ {
+			slot = qid*q.ring.size + j
+			desc.setOffset(int(i.regions[0].packetBufferOffset + uint32(slot)*i.run.PacketBufferSize))
+			q.putDescBuf(slot, desc)
+		}
+	}
+
+	return nil
+}
+
+// connect finalizes interface connection
+func (i *Interface) connect() (err error) {
+	for rid, _ := range i.regions {
+		r := &i.regions[rid]
+		if r.data == nil {
+			r.data, err = syscall.Mmap(r.fd, 0, int(r.size), syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_SHARED)
+			if err != nil {
+				return fmt.Errorf("Mmap: %s", err)
+			}
+		}
+	}
+
+	for _, q := range i.txQueues {
+		q.updateRing()
+
+		if q.ring.getCookie() != cookie {
+			return fmt.Errorf("Wrong cookie")
+		}
+
+		q.lastHead = 0
+		q.lastTail = 0
+	}
+
+	for _, q := range i.rxQueues {
+		q.updateRing()
+
+		if q.ring.getCookie() != cookie {
+			return fmt.Errorf("Wrong cookie")
+		}
+
+		q.lastHead = 0
+		q.lastTail = 0
+	}
+
+	return i.args.ConnectedFunc(i)
+}
diff --git a/extras/gomemif/memif/interface_unsafe.go b/extras/gomemif/memif/interface_unsafe.go
new file mode 100644
index 00000000000..f5cbc2ed207
--- /dev/null
+++ b/extras/gomemif/memif/interface_unsafe.go
@@ -0,0 +1,40 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2020 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *------------------------------------------------------------------
+ */
+
+package memif
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+// memfdCreate returns memory file file descriptor (memif.sys_memfd_create)
+func memfdCreate() (mfd int, err error) {
+	p0, err := syscall.BytePtrFromString("memif_region_0")
+	if err != nil {
+		return -1, fmt.Errorf("memfdCreate: %s", err)
+	}
+
+	u_mfd, _, errno := syscall.Syscall(sys_memfd_create, uintptr(unsafe.Pointer(p0)), uintptr(mfd_allow_sealing), uintptr(0))
+	if errno != 0 {
+		return -1, fmt.Errorf("memfdCreate: %s", os.NewSyscallError("memfd_create", errno))
+	}
+
+	return int(u_mfd), nil
+}
diff --git a/extras/gomemif/memif/memif.go b/extras/gomemif/memif/memif.go
new file mode 100644
index 00000000000..1a7857de03e
--- /dev/null
+++ b/extras/gomemif/memif/memif.go
@@ -0,0 +1,345 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2020 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *------------------------------------------------------------------
+ */
+
+package memif
+
+import (
+	"encoding/binary"
+	"fmt"
+	"syscall"
+)
+
+const cookie = 0x3E31F20
+
+// VersionMajor is memif protocols major version
+const VersionMajor = 2
+
+// VersionMinor is memif protocols minor version
+const VersionMinor = 0
+
+// Version is memif protocols version as uint16
+// (M-Major m-minor: MMMMMMMMmmmmmmmm)
+const Version = ((VersionMajor << 8) | VersionMinor)
+
+type msgType uint16
+
+const (
+	msgTypeNone msgType = iota
+	msgTypeAck
+	msgTypeHello
+	msgTypeInit
+	msgTypeAddRegion
+	msgTypeAddRing
+	msgTypeConnect
+	msgTypeConnected
+	msgTypeDisconnect
+)
+
+type interfaceMode uint8
+
+const (
+	interfaceModeEthernet interfaceMode = iota
+	interfaceModeIp
+	interfaceModePuntInject
+)
+
+const msgSize = 128
+const msgTypeSize = 2
+
+const msgAddRingFlagS2M = (1 << 0)
+
+// Descriptor flags
+//
+// next buffer present
+const descFlagNext = (1 << 0)
+
+// Ring flags
+//
+// Interrupt
+const ringFlagInterrupt = 1
+
+func min16(a uint16, b uint16) uint16 {
+	if a < b {
+		return a
+	}
+	return b
+}
+
+func min8(a uint8, b uint8) uint8 {
+	if a < b {
+		return a
+	}
+	return b
+}
+
+type MsgHello struct {
+	// app name
+	Name            [32]byte
+	VersionMin      uint16
+	VersionMax      uint16
+	MaxRegion       uint16
+	MaxRingM2S      uint16
+	MaxRingS2M      uint16
+	MaxLog2RingSize uint8
+}
+
+type MsgInit struct {
+	Version uint16
+	Id      uint32
+	Mode    interfaceMode
+	Secret  [24]byte
+	// app name
+	Name [32]byte
+}
+
+type MsgAddRegion struct {
+	Index uint16
+	Size  uint64
+}
+
+type MsgAddRing struct {
+	Flags          uint16
+	Index          uint16
+	Region         uint16
+	Offset         uint32
+	RingSizeLog2   uint8
+	PrivateHdrSize uint16
+}
+
+type MsgConnect struct {
+	// interface name
+	Name [32]byte
+}
+
+type MsgConnected struct {
+	// interface name
+	Name [32]byte
+}
+
+type MsgDisconnect struct {
+	Code   uint32
+	String [96]byte
+}
+
+/* DESCRIPTOR BEGIN */
+
+const descSize = 16
+
+// desc field offsets
+const descFlagsOffset = 0
+const descRegionOffset = 2
+const descLengthOffset = 4
+const descOffsetOffset = 8
+const descMetadataOffset = 12
+
+// descBuf represents a memif descriptor as array of bytes
+type descBuf []byte
+
+// newDescBuf returns new descriptor buffer
+func newDescBuf() descBuf {
+	return make(descBuf, descSize)
+}
+
+// getDescBuff copies descriptor from shared memory to descBuf
+func (q *Queue) getDescBuf(slot int, db descBuf) {
+	copy(db, q.i.regions[q.ring.region].data[q.ring.offset+ringSize+slot*descSize:])
+}
+
+// putDescBuf copies contents of descriptor buffer into shared memory
+func (q *Queue) putDescBuf(slot int, db descBuf) {
+	copy(q.i.regions[q.ring.region].data[q.ring.offset+ringSize+slot*descSize:], db)
+}
+
+func (db descBuf) getFlags() int {
+	return (int)(binary.LittleEndian.Uint16((db)[descFlagsOffset:]))
+}
+
+func (db descBuf) getRegion() int {
+	return (int)(binary.LittleEndian.Uint16((db)[descRegionOffset:]))
+}
+
+func (db descBuf) getLength() int {
+	return (int)(binary.LittleEndian.Uint32((db)[descLengthOffset:]))
+}
+
+func (db descBuf) getOffset() int {
+	return (int)(binary.LittleEndian.Uint32((db)[descOffsetOffset:]))
+}
+
+func (db descBuf) getMetadata() int {
+	return (int)(binary.LittleEndian.Uint32((db)[descMetadataOffset:]))
+}
+
+func (db descBuf) setFlags(val int) {
+	binary.LittleEndian.PutUint16((db)[descFlagsOffset:], uint16(val))
+}
+
+func (db descBuf) setRegion(val int) {
+	binary.LittleEndian.PutUint16((db)[descRegionOffset:], uint16(val))
+}
+
+func (db descBuf) setLength(val int) {
+	binary.LittleEndian.PutUint32((db)[descLengthOffset:], uint32(val))
+}
+
+func (db descBuf) setOffset(val int) {
+	binary.LittleEndian.PutUint32((db)[descOffsetOffset:], uint32(val))
+}
+
+func (db descBuf) setMetadata(val int) {
+	binary.LittleEndian.PutUint32((db)[descMetadataOffset:], uint32(val))
+}
+
+/* DESCRIPTOR END */
+
+/* RING BEGIN */
+
+type ringType uint8
+
+const (
+	ringTypeS2M ringType = iota
+	ringTypeM2S
+)
+
+const ringSize = 128
+
+// ring field offsets
+const ringCookieOffset = 0
+const ringFlagsOffset = 4
+const ringHeadOffset = 6
+const ringTailOffset = 64
+
+// ringBuf represents a memif ring as array of bytes
+type ringBuf []byte
+
+type ring struct {
+	ringType ringType
+	size     int
+	log2Size int
+	region   int
+	rb       ringBuf
+	offset   int
+}
+
+// newRing returns new memif ring based on data received in msgAddRing (master only)
+func newRing(regionIndex int, ringType ringType, ringOffset int, log2RingSize int) *ring {
+	r := &ring{
+		ringType: ringType,
+		size:     (1 << log2RingSize),
+		log2Size: log2RingSize,
+		rb:       make(ringBuf, ringSize),
+		offset:   ringOffset,
+	}
+
+	return r
+}
+
+// newRing returns a new memif ring
+func (i *Interface) newRing(regionIndex int, ringType ringType, ringIndex int) *ring {
+	r := &ring{
+		ringType: ringType,
+		size:     (1 << i.run.Log2RingSize),
+		log2Size: int(i.run.Log2RingSize),
+		rb:       make(ringBuf, ringSize),
+	}
+
+	rSize := ringSize + descSize*r.size
+	if r.ringType == ringTypeS2M {
+		r.offset = 0
+	} else {
+		r.offset = int(i.run.NumQueuePairs) * rSize
+	}
+	r.offset += ringIndex * rSize
+
+	return r
+}
+
+// putRing put the ring to the shared memory
+func (q *Queue) putRing() {
+	copy(q.i.regions[q.ring.region].data[q.ring.offset:], q.ring.rb)
+}
+
+// updateRing updates ring with data from shared memory
+func (q *Queue) updateRing() {
+	copy(q.ring.rb, q.i.regions[q.ring.region].data[q.ring.offset:])
+}
+
+func (r *ring) getCookie() int {
+	return (int)(binary.LittleEndian.Uint32((r.rb)[ringCookieOffset:]))
+}
+
+// getFlags returns the flags value from ring buffer
+// Use Queue.getFlags in fast-path to avoid updating the whole ring.
+func (r *ring) getFlags() int {
+	return (int)(binary.LittleEndian.Uint16((r.rb)[ringFlagsOffset:]))
+}
+
+// getHead returns the head pointer value from ring buffer.
+// Use readHead in fast-path to avoid updating the whole ring.
+func (r *ring) getHead() int {
+	return (int)(binary.LittleEndian.Uint16((r.rb)[ringHeadOffset:]))
+}
+
+// getTail returns the tail pointer value from ring buffer.
+// Use readTail in fast-path to avoid updating the whole ring.
+func (r *ring) getTail() int {
+	return (int)(binary.LittleEndian.Uint16((r.rb)[ringTailOffset:]))
+}
+
+func (r *ring) setCookie(val int) {
+	binary.LittleEndian.PutUint32((r.rb)[ringCookieOffset:], uint32(val))
+}
+
+func (r *ring) setFlags(val int) {
+	binary.LittleEndian.PutUint16((r.rb)[ringFlagsOffset:], uint16(val))
+}
+
+// setHead set the head pointer value int the ring buffer.
+// Use writeHead in fast-path to avoid putting the whole ring into shared memory.
+func (r *ring) setHead(val int) {
+	binary.LittleEndian.PutUint16((r.rb)[ringHeadOffset:], uint16(val))
+}
+
+// setTail set the tail pointer value int the ring buffer.
+// Use writeTail in fast-path to avoid putting the whole ring into shared memory.
+func (r *ring) setTail(val int) {
+	binary.LittleEndian.PutUint16((r.rb)[ringTailOffset:], uint16(val))
+}
+
+/* RING END */
+
+// isInterrupt returns true if the queue is in interrupt mode
+func (q *Queue) isInterrupt() bool {
+	return (q.getFlags() & ringFlagInterrupt) == 0
+}
+
+// interrupt performs an interrupt if the queue is in interrupt mode
+func (q *Queue) interrupt() error {
+	if q.isInterrupt() {
+		buf := make([]byte, 8)
+		binary.PutUvarint(buf, 1)
+		n, err := syscall.Write(q.interruptFd, buf[:])
+		if err != nil {
+			return err
+		}
+		if n != 8 {
+			return fmt.Errorf("Faild to write to eventfd")
+		}
+	}
+
+	return nil
+}
diff --git a/extras/gomemif/memif/memif_unsafe.go b/extras/gomemif/memif/memif_unsafe.go
new file mode 100644
index 00000000000..4469d26e982
--- /dev/null
+++ b/extras/gomemif/memif/memif_unsafe.go
@@ -0,0 +1,55 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2020 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *------------------------------------------------------------------
+ */
+
+package memif
+
+import (
+	"unsafe"
+)
+
+// readHead reads ring head directly form the shared memory
+func (q *Queue) readHead() (head int) {
+	return (int)(*(*uint16)(unsafe.Pointer(&q.i.regions[q.ring.region].data[q.ring.offset+ringHeadOffset])))
+	// return atomicload16(&q.i.regions[q.region].data[q.offset + descHeadOffset])
+}
+
+// readTail reads ring tail directly form the shared memory
+func (q *Queue) readTail() (tail int) {
+	return (int)(*(*uint16)(unsafe.Pointer(&q.i.regions[q.ring.region].data[q.ring.offset+ringTailOffset])))
+	// return atomicload16(&q.i.regions[q.region].data[q.offset + descTailOffset])
+}
+
+// writeHead writes ring head directly to the shared memory
+func (q *Queue) writeHead(value int) {
+	*(*uint16)(unsafe.Pointer(&q.i.regions[q.ring.region].data[q.ring.offset+ringHeadOffset])) = *(*uint16)(unsafe.Pointer(&value))
+	//atomicstore16(&q.i.regions[q.region].data[q.offset + descHeadOffset], value)
+}
+
+// writeTail writes ring tail directly to the shared memory
+func (q *Queue) writeTail(value int) {
+	*(*uint16)(unsafe.Pointer(&q.i.regions[q.ring.region].data[q.ring.offset+ringTailOffset])) = *(*uint16)(unsafe.Pointer(&value))
+	//atomicstore16(&q.i.regions[q.region].data[q.offset + descTailOffset], value)
+}
+
+func (q *Queue) setDescLength(slot int, length int) {
+	*(*uint16)(unsafe.Pointer(&q.i.regions[q.ring.region].data[q.ring.offset+ringSize+slot*descSize+descLengthOffset])) = *(*uint16)(unsafe.Pointer(&length))
+}
+
+// getFlags reads ring flags directly from the shared memory
+func (q *Queue) getFlags() int {
+	return (int)(*(*uint16)(unsafe.Pointer(&q.i.regions[q.ring.region].data[q.ring.offset+ringFlagsOffset])))
+}
diff --git a/extras/gomemif/memif/packet_reader.go b/extras/gomemif/memif/packet_reader.go
new file mode 100644
index 00000000000..58338f6f2ab
--- /dev/null
+++ b/extras/gomemif/memif/packet_reader.go
@@ -0,0 +1,91 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2020 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *------------------------------------------------------------------
+ */
+
+package memif
+
+import "fmt"
+
+// ReadPacket reads one packet form the shared memory and
+// returns the number of bytes read
+func (q *Queue) ReadPacket(pkt []byte) (int, error) {
+	var mask int = q.ring.size - 1
+	var slot int
+	var lastSlot int
+	var length int
+	var offset int
+	var pktOffset int = 0
+	var nSlots uint16
+	var desc descBuf = newDescBuf()
+
+	if q.i.args.IsMaster {
+		slot = int(q.lastHead)
+		lastSlot = q.readHead()
+	} else {
+		slot = int(q.lastTail)
+		lastSlot = q.readTail()
+	}
+
+	nSlots = uint16(lastSlot - slot)
+	if nSlots == 0 {
+		goto refill
+	}
+
+	// copy descriptor from shm
+	q.getDescBuf(slot&mask, desc)
+	length = desc.getLength()
+	offset = desc.getOffset()
+
+	copy(pkt[:], q.i.regions[desc.getRegion()].data[offset:offset+length])
+	pktOffset += length
+
+	slot++
+	nSlots--
+
+	for (desc.getFlags() & descFlagNext) == descFlagNext {
+		if nSlots == 0 {
+			return 0, fmt.Errorf("Incomplete chained buffer, may suggest peer error.")
+		}
+
+		q.getDescBuf(slot&mask, desc)
+		length = desc.getLength()
+		offset = desc.getOffset()
+
+		copy(pkt[pktOffset:], q.i.regions[desc.getRegion()].data[offset:offset+length])
+		pktOffset += length
+
+		slot++
+		nSlots--
+	}
+
+refill:
+	if q.i.args.IsMaster {
+		q.lastHead = uint16(slot)
+		q.writeTail(slot)
+	} else {
+		q.lastTail = uint16(slot)
+
+		head := q.readHead()
+
+		for nSlots := uint16(q.ring.size - head + int(q.lastTail)); nSlots > 0; nSlots-- {
+			q.setDescLength(head&mask, int(q.i.run.PacketBufferSize))
+			head++
+		}
+		q.writeHead(head)
+	}
+
+	return pktOffset, nil
+}
diff --git a/extras/gomemif/memif/packet_writer.go b/extras/gomemif/memif/packet_writer.go
new file mode 100644
index 00000000000..702044f4b49
--- /dev/null
+++ b/extras/gomemif/memif/packet_writer.go
@@ -0,0 +1,95 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2020 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *------------------------------------------------------------------
+ */
+
+package memif
+
+// WritePacket writes one packet to the shared memory and
+// returns the number of bytes written
+func (q *Queue) WritePacket(pkt []byte) int {
+	var mask int = q.ring.size - 1
+	var slot int
+	var nFree uint16
+	var packetBufferSize int = int(q.i.run.PacketBufferSize)
+
+	if q.i.args.IsMaster {
+		slot = q.readTail()
+		nFree = uint16(q.readHead() - slot)
+	} else {
+		slot = q.readHead()
+		nFree = uint16(q.ring.size - slot + q.readTail())
+	}
+
+	if nFree == 0 {
+		q.interrupt()
+		return 0
+	}
+
+	// copy descriptor from shm
+	desc := newDescBuf()
+	q.getDescBuf(slot&mask, desc)
+	// reset flags
+	desc.setFlags(0)
+	// reset length
+	if q.i.args.IsMaster {
+		packetBufferSize = desc.getLength()
+	}
+	desc.setLength(0)
+	offset := desc.getOffset()
+
+	// write packet into memif buffer
+	n := copy(q.i.regions[desc.getRegion()].data[offset:offset+packetBufferSize], pkt[:])
+	desc.setLength(n)
+	for n < len(pkt) {
+		nFree--
+		if nFree == 0 {
+			q.interrupt()
+			return 0
+		}
+		desc.setFlags(descFlagNext)
+		q.putDescBuf(slot&mask, desc)
+		slot++
+
+		// copy descriptor from shm
+		q.getDescBuf(slot&mask, desc)
+		// reset flags
+		desc.setFlags(0)
+		// reset length
+		if q.i.args.IsMaster {
+			packetBufferSize = desc.getLength()
+		}
+		desc.setLength(0)
+		offset := desc.getOffset()
+
+		tmp := copy(q.i.regions[desc.getRegion()].data[offset:offset+packetBufferSize], pkt[:])
+		desc.setLength(tmp)
+		n += tmp
+	}
+
+	// copy descriptor to shm
+	q.putDescBuf(slot&mask, desc)
+	slot++
+
+	if q.i.args.IsMaster {
+		q.writeTail(slot)
+	} else {
+		q.writeHead(slot)
+	}
+
+	q.interrupt()
+
+	return n
+}