go-tunnel/control/control.go

195 lines
3.5 KiB
Go

package control
import (
"context"
"encoding/json"
"github.com/pkg/errors"
"github.com/xtaci/smux"
"gitlab.com/wpetit/goweb/logger"
)
type Control struct {
encoder *json.Encoder
decoder *json.Decoder
stream *smux.Stream
}
func (c *Control) Init(ctx context.Context, sess *smux.Session, serverMode bool) error {
config := smux.DefaultConfig()
config.Version = 2
logger.Debug(ctx, "creating control stream")
var (
stream *smux.Stream
err error
)
if serverMode {
stream, err = sess.AcceptStream()
if err != nil {
return errors.WithStack(err)
}
} else {
stream, err = sess.OpenStream()
if err != nil {
return errors.WithStack(err)
}
}
c.stream = stream
c.decoder = json.NewDecoder(stream)
c.encoder = json.NewEncoder(stream)
return nil
}
func (c *Control) AuthRequest(credentials interface{}) (bool, error) {
req := NewMessage(TypeAuthRequest, &AuthRequestPayload{
Credentials: credentials,
})
res := NewMessage(TypeAuthResponse, nil)
if err := c.reqRes(req, res); err != nil {
return false, errors.WithStack(err)
}
authResPayload, ok := res.Payload.(*AuthResponsePayload)
if !ok {
return false, errors.WithStack(ErrUnexpectedMessage)
}
return authResPayload.Success, nil
}
func (c *Control) ProxyReq(ctx context.Context, network, address string) error {
req := NewMessage(TypeProxyRequest, &ProxyRequestPayload{
Network: network,
Address: address,
})
if err := c.Write(req); err != nil {
return errors.WithStack(err)
}
return nil
}
func (c *Control) Listen(ctx context.Context, handlers Handlers) error {
errChan := make(chan error)
msgChan := make(chan *Message)
dieChan := c.stream.GetDieCh()
go func(msgChan chan *Message, errChan chan error) {
for {
logger.Debug(ctx, "reading next message")
msg, err := c.Read()
if err != nil {
errChan <- errors.WithStack(err)
close(errChan)
close(msgChan)
return
}
msgChan <- msg
}
}(msgChan, errChan)
for {
select {
case <-ctx.Done():
return nil
case <-dieChan:
return errors.WithStack(ErrStreamClosed)
case err := <-errChan:
return errors.WithStack(err)
case msg := <-msgChan:
go func() {
subCtx := logger.With(ctx, logger.F("messageType", msg.Type))
handler, exists := handlers[msg.Type]
if !exists {
logger.Error(subCtx, "no message handler registered")
return
}
res, err := handler(subCtx, msg)
if err != nil {
logger.Error(subCtx, "error while handling message", logger.E(err))
return
}
if res == nil {
return
}
if err := c.Write(res); err != nil {
logger.Error(subCtx, "error while write message response", logger.E(err))
return
}
}()
}
}
}
func (c *Control) Read() (*Message, error) {
message := &Message{}
if err := c.read(message); err != nil {
return nil, errors.WithStack(err)
}
return message, nil
}
func (c *Control) Write(m *Message) error {
if err := c.write(m); err != nil {
return errors.WithStack(err)
}
return nil
}
func (c *Control) reqRes(req *Message, res *Message) error {
if err := c.write(req); err != nil {
return errors.WithStack(err)
}
if err := c.read(res); err != nil {
return errors.WithStack(err)
}
return nil
}
func (c *Control) read(m *Message) error {
if err := c.decoder.Decode(m); err != nil {
return errors.WithStack(err)
}
return nil
}
func (c *Control) write(m *Message) error {
if err := c.encoder.Encode(m); err != nil {
return errors.WithStack(err)
}
return nil
}
func New() *Control {
return &Control{}
}