Skip to content
Permalink
Branch: master
Find file Copy path
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
476 lines (415 sloc) 8.36 KB
package readline
import (
"bufio"
"bytes"
"encoding/binary"
"fmt"
"io"
"net"
"os"
"sync"
"sync/atomic"
)
type MsgType int16
const (
T_DATA = MsgType(iota)
T_WIDTH
T_WIDTH_REPORT
T_ISTTY_REPORT
T_RAW
T_ERAW // exit raw
T_EOF
)
type RemoteSvr struct {
eof int32
closed int32
width int32
reciveChan chan struct{}
writeChan chan *writeCtx
conn net.Conn
isTerminal bool
funcWidthChan func()
stopChan chan struct{}
dataBufM sync.Mutex
dataBuf bytes.Buffer
}
type writeReply struct {
n int
err error
}
type writeCtx struct {
msg *Message
reply chan *writeReply
}
func newWriteCtx(msg *Message) *writeCtx {
return &writeCtx{
msg: msg,
reply: make(chan *writeReply),
}
}
func NewRemoteSvr(conn net.Conn) (*RemoteSvr, error) {
rs := &RemoteSvr{
width: -1,
conn: conn,
writeChan: make(chan *writeCtx),
reciveChan: make(chan struct{}),
stopChan: make(chan struct{}),
}
buf := bufio.NewReader(rs.conn)
if err := rs.init(buf); err != nil {
return nil, err
}
go rs.readLoop(buf)
go rs.writeLoop()
return rs, nil
}
func (r *RemoteSvr) init(buf *bufio.Reader) error {
m, err := ReadMessage(buf)
if err != nil {
return err
}
// receive isTerminal
if m.Type != T_ISTTY_REPORT {
return fmt.Errorf("unexpected init message")
}
r.GotIsTerminal(m.Data)
// receive width
m, err = ReadMessage(buf)
if err != nil {
return err
}
if m.Type != T_WIDTH_REPORT {
return fmt.Errorf("unexpected init message")
}
r.GotReportWidth(m.Data)
return nil
}
func (r *RemoteSvr) HandleConfig(cfg *Config) {
cfg.Stderr = r
cfg.Stdout = r
cfg.Stdin = r
cfg.FuncExitRaw = r.ExitRawMode
cfg.FuncIsTerminal = r.IsTerminal
cfg.FuncMakeRaw = r.EnterRawMode
cfg.FuncExitRaw = r.ExitRawMode
cfg.FuncGetWidth = r.GetWidth
cfg.FuncOnWidthChanged = func(f func()) {
r.funcWidthChan = f
}
}
func (r *RemoteSvr) IsTerminal() bool {
return r.isTerminal
}
func (r *RemoteSvr) checkEOF() error {
if atomic.LoadInt32(&r.eof) == 1 {
return io.EOF
}
return nil
}
func (r *RemoteSvr) Read(b []byte) (int, error) {
r.dataBufM.Lock()
n, err := r.dataBuf.Read(b)
r.dataBufM.Unlock()
if n == 0 {
if err := r.checkEOF(); err != nil {
return 0, err
}
}
if n == 0 && err == io.EOF {
<-r.reciveChan
r.dataBufM.Lock()
n, err = r.dataBuf.Read(b)
r.dataBufM.Unlock()
}
if n == 0 {
if err := r.checkEOF(); err != nil {
return 0, err
}
}
return n, err
}
func (r *RemoteSvr) writeMsg(m *Message) error {
ctx := newWriteCtx(m)
r.writeChan <- ctx
reply := <-ctx.reply
return reply.err
}
func (r *RemoteSvr) Write(b []byte) (int, error) {
ctx := newWriteCtx(NewMessage(T_DATA, b))
r.writeChan <- ctx
reply := <-ctx.reply
return reply.n, reply.err
}
func (r *RemoteSvr) EnterRawMode() error {
return r.writeMsg(NewMessage(T_RAW, nil))
}
func (r *RemoteSvr) ExitRawMode() error {
return r.writeMsg(NewMessage(T_ERAW, nil))
}
func (r *RemoteSvr) writeLoop() {
defer r.Close()
loop:
for {
select {
case ctx, ok := <-r.writeChan:
if !ok {
break
}
n, err := ctx.msg.WriteTo(r.conn)
ctx.reply <- &writeReply{n, err}
case <-r.stopChan:
break loop
}
}
}
func (r *RemoteSvr) Close() error {
if atomic.CompareAndSwapInt32(&r.closed, 0, 1) {
close(r.stopChan)
r.conn.Close()
}
return nil
}
func (r *RemoteSvr) readLoop(buf *bufio.Reader) {
defer r.Close()
for {
m, err := ReadMessage(buf)
if err != nil {
break
}
switch m.Type {
case T_EOF:
atomic.StoreInt32(&r.eof, 1)
select {
case r.reciveChan <- struct{}{}:
default:
}
case T_DATA:
r.dataBufM.Lock()
r.dataBuf.Write(m.Data)
r.dataBufM.Unlock()
select {
case r.reciveChan <- struct{}{}:
default:
}
case T_WIDTH_REPORT:
r.GotReportWidth(m.Data)
case T_ISTTY_REPORT:
r.GotIsTerminal(m.Data)
}
}
}
func (r *RemoteSvr) GotIsTerminal(data []byte) {
if binary.BigEndian.Uint16(data) == 0 {
r.isTerminal = false
} else {
r.isTerminal = true
}
}
func (r *RemoteSvr) GotReportWidth(data []byte) {
atomic.StoreInt32(&r.width, int32(binary.BigEndian.Uint16(data)))
if r.funcWidthChan != nil {
r.funcWidthChan()
}
}
func (r *RemoteSvr) GetWidth() int {
return int(atomic.LoadInt32(&r.width))
}
// -----------------------------------------------------------------------------
type Message struct {
Type MsgType
Data []byte
}
func ReadMessage(r io.Reader) (*Message, error) {
m := new(Message)
var length int32
if err := binary.Read(r, binary.BigEndian, &length); err != nil {
return nil, err
}
if err := binary.Read(r, binary.BigEndian, &m.Type); err != nil {
return nil, err
}
m.Data = make([]byte, int(length)-2)
if _, err := io.ReadFull(r, m.Data); err != nil {
return nil, err
}
return m, nil
}
func NewMessage(t MsgType, data []byte) *Message {
return &Message{t, data}
}
func (m *Message) WriteTo(w io.Writer) (int, error) {
buf := bytes.NewBuffer(make([]byte, 0, len(m.Data)+2+4))
binary.Write(buf, binary.BigEndian, int32(len(m.Data)+2))
binary.Write(buf, binary.BigEndian, m.Type)
buf.Write(m.Data)
n, err := buf.WriteTo(w)
return int(n), err
}
// -----------------------------------------------------------------------------
type RemoteCli struct {
conn net.Conn
raw RawMode
receiveChan chan struct{}
inited int32
isTerminal *bool
data bytes.Buffer
dataM sync.Mutex
}
func NewRemoteCli(conn net.Conn) (*RemoteCli, error) {
r := &RemoteCli{
conn: conn,
receiveChan: make(chan struct{}),
}
return r, nil
}
func (r *RemoteCli) MarkIsTerminal(is bool) {
r.isTerminal = &is
}
func (r *RemoteCli) init() error {
if !atomic.CompareAndSwapInt32(&r.inited, 0, 1) {
return nil
}
if err := r.reportIsTerminal(); err != nil {
return err
}
if err := r.reportWidth(); err != nil {
return err
}
// register sig for width changed
DefaultOnWidthChanged(func() {
r.reportWidth()
})
return nil
}
func (r *RemoteCli) writeMsg(m *Message) error {
r.dataM.Lock()
_, err := m.WriteTo(r.conn)
r.dataM.Unlock()
return err
}
func (r *RemoteCli) Write(b []byte) (int, error) {
m := NewMessage(T_DATA, b)
r.dataM.Lock()
_, err := m.WriteTo(r.conn)
r.dataM.Unlock()
return len(b), err
}
func (r *RemoteCli) reportWidth() error {
screenWidth := GetScreenWidth()
data := make([]byte, 2)
binary.BigEndian.PutUint16(data, uint16(screenWidth))
msg := NewMessage(T_WIDTH_REPORT, data)
if err := r.writeMsg(msg); err != nil {
return err
}
return nil
}
func (r *RemoteCli) reportIsTerminal() error {
var isTerminal bool
if r.isTerminal != nil {
isTerminal = *r.isTerminal
} else {
isTerminal = DefaultIsTerminal()
}
data := make([]byte, 2)
if isTerminal {
binary.BigEndian.PutUint16(data, 1)
} else {
binary.BigEndian.PutUint16(data, 0)
}
msg := NewMessage(T_ISTTY_REPORT, data)
if err := r.writeMsg(msg); err != nil {
return err
}
return nil
}
func (r *RemoteCli) readLoop() {
buf := bufio.NewReader(r.conn)
for {
msg, err := ReadMessage(buf)
if err != nil {
break
}
switch msg.Type {
case T_ERAW:
r.raw.Exit()
case T_RAW:
r.raw.Enter()
case T_DATA:
os.Stdout.Write(msg.Data)
}
}
}
func (r *RemoteCli) ServeBy(source io.Reader) error {
if err := r.init(); err != nil {
return err
}
go func() {
defer r.Close()
for {
n, _ := io.Copy(r, source)
if n == 0 {
break
}
}
}()
defer r.raw.Exit()
r.readLoop()
return nil
}
func (r *RemoteCli) Close() {
r.writeMsg(NewMessage(T_EOF, nil))
}
func (r *RemoteCli) Serve() error {
return r.ServeBy(os.Stdin)
}
func ListenRemote(n, addr string, cfg *Config, h func(*Instance), onListen ...func(net.Listener) error) error {
ln, err := net.Listen(n, addr)
if err != nil {
return err
}
if len(onListen) > 0 {
if err := onListen[0](ln); err != nil {
return err
}
}
for {
conn, err := ln.Accept()
if err != nil {
break
}
go func() {
defer conn.Close()
rl, err := HandleConn(*cfg, conn)
if err != nil {
return
}
h(rl)
}()
}
return nil
}
func HandleConn(cfg Config, conn net.Conn) (*Instance, error) {
r, err := NewRemoteSvr(conn)
if err != nil {
return nil, err
}
r.HandleConfig(&cfg)
rl, err := NewEx(&cfg)
if err != nil {
return nil, err
}
return rl, nil
}
func DialRemote(n, addr string) error {
conn, err := net.Dial(n, addr)
if err != nil {
return err
}
defer conn.Close()
cli, err := NewRemoteCli(conn)
if err != nil {
return err
}
return cli.Serve()
}
You can’t perform that action at this time.