feat: ssh client implement (#3671)

* feat: frps support ssh

* fix: comments

* fix: update pkg

* fix: remove useless change

---------

Co-authored-by: int7 <int7@gmail.com>

pkg/ssh/vclient.go

@@ -0,0 +1,185 @@
+package ssh
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"sync/atomic"
+	"time"
+
+	"golang.org/x/crypto/ssh"
+
+	"github.com/fatedier/frp/pkg/config"
+	v1 "github.com/fatedier/frp/pkg/config/v1"
+	"github.com/fatedier/frp/pkg/msg"
+	plugin "github.com/fatedier/frp/pkg/plugin/server"
+	"github.com/fatedier/frp/pkg/util/log"
+	frp_net "github.com/fatedier/frp/pkg/util/net"
+	"github.com/fatedier/frp/pkg/util/util"
+	"github.com/fatedier/frp/pkg/util/xlog"
+	"github.com/fatedier/frp/server/controller"
+	"github.com/fatedier/frp/server/proxy"
+)
+
+// VirtualService is a client VirtualService run in frps
+type VirtualService struct {
+	clientCfg v1.ClientCommonConfig
+	pxyCfg    v1.ProxyConfigurer
+	serverCfg v1.ServerConfig
+
+	sshSvc *Service
+
+	// uniq id got from frps, attach it in loginMsg
+	runID    string
+	loginMsg *msg.Login
+
+	// All resource managers and controllers
+	rc *controller.ResourceController
+
+	exit uint32 // 0 means not exit
+	// SSHService context
+	ctx context.Context
+	// call cancel to stop SSHService
+	cancel context.CancelFunc
+
+	replyCh chan interface{}
+	pxy     proxy.Proxy
+}
+
+func NewVirtualService(
+	ctx context.Context,
+	clientCfg v1.ClientCommonConfig,
+	serverCfg v1.ServerConfig,
+	logMsg msg.Login,
+	rc *controller.ResourceController,
+	pxyCfg v1.ProxyConfigurer,
+	sshSvc *Service,
+	replyCh chan interface{},
+) (svr *VirtualService, err error) {
+	svr = &VirtualService{
+		clientCfg: clientCfg,
+		serverCfg: serverCfg,
+		rc:        rc,
+
+		loginMsg: &logMsg,
+
+		sshSvc: sshSvc,
+		pxyCfg: pxyCfg,
+
+		ctx:  ctx,
+		exit: 0,
+
+		replyCh: replyCh,
+	}
+
+	svr.runID, err = util.RandID()
+	if err != nil {
+		return nil, err
+	}
+
+	go svr.loopCheck()
+
+	return
+}
+
+func (svr *VirtualService) Run(ctx context.Context) (err error) {
+	ctx, cancel := context.WithCancel(ctx)
+	svr.ctx = xlog.NewContext(ctx, xlog.New())
+	svr.cancel = cancel
+
+	remoteAddr, err := svr.RegisterProxy(&msg.NewProxy{
+		ProxyName:  svr.pxyCfg.(*v1.TCPProxyConfig).Name,
+		ProxyType:  svr.pxyCfg.(*v1.TCPProxyConfig).Type,
+		RemotePort: svr.pxyCfg.(*v1.TCPProxyConfig).RemotePort,
+	})
+	if err != nil {
+		return err
+	}
+
+	log.Info("run a reverse proxy on port: %v", remoteAddr)
+
+	return nil
+}
+
+func (svr *VirtualService) Close() {
+	svr.GracefulClose(time.Duration(0))
+}
+
+func (svr *VirtualService) GracefulClose(d time.Duration) {
+	atomic.StoreUint32(&svr.exit, 1)
+	svr.pxy.Close()
+
+	if svr.cancel != nil {
+		svr.cancel()
+	}
+
+	svr.replyCh <- &VProxyError{}
+}
+
+func (svr *VirtualService) loopCheck() {
+	<-svr.sshSvc.Exit()
+	svr.pxy.Close()
+	log.Info("virtual client service close")
+}
+
+func (svr *VirtualService) RegisterProxy(pxyMsg *msg.NewProxy) (remoteAddr string, err error) {
+	var pxyConf v1.ProxyConfigurer
+	pxyConf, err = config.NewProxyConfigurerFromMsg(pxyMsg, &svr.serverCfg)
+	if err != nil {
+		return
+	}
+
+	// User info
+	userInfo := plugin.UserInfo{
+		User:  svr.loginMsg.User,
+		Metas: svr.loginMsg.Metas,
+		RunID: svr.runID,
+	}
+
+	svr.pxy, err = proxy.NewProxy(svr.ctx, &proxy.Options{
+		LoginMsg:           svr.loginMsg,
+		UserInfo:           userInfo,
+		Configurer:         pxyConf,
+		ResourceController: svr.rc,
+
+		GetWorkConnFn: svr.GetWorkConn,
+		PoolCount:     10,
+
+		ServerCfg: &svr.serverCfg,
+	})
+	if err != nil {
+		return remoteAddr, err
+	}
+
+	remoteAddr, err = svr.pxy.Run()
+	if err != nil {
+		log.Warn("proxy run error: %v", err)
+		return
+	}
+
+	defer func() {
+		if err != nil {
+			log.Warn("proxy close")
+			svr.pxy.Close()
+		}
+	}()
+
+	return
+}
+
+func (svr *VirtualService) GetWorkConn() (workConn net.Conn, err error) {
+	// tell ssh client open a new stream for work
+	payload := forwardedTCPPayload{
+		Addr: svr.serverCfg.BindAddr, // TODO refine
+		Port: uint32(svr.pxyCfg.(*v1.TCPProxyConfig).RemotePort),
+	}
+
+	channel, reqs, err := svr.sshSvc.SSHConn().OpenChannel(ChannelTypeServerOpenChannel, ssh.Marshal(payload))
+	if err != nil {
+		return nil, fmt.Errorf("open ssh channel error: %v", err)
+	}
+	go ssh.DiscardRequests(reqs)
+
+	workConn = frp_net.WrapReadWriteCloserToConn(channel, svr.sshSvc.tcpConn)
+	return workConn, nil
+}