tailscale: Add tailssh server

experimental/libbox/config.go

@@ -167,6 +167,30 @@ func (s *platformInterfaceStub) CloseNeighborMonitor(listener adapter.NeighborUp
 	return nil
 }
 
+func (s *platformInterfaceStub) UsePlatformShell() bool {
+	return false
+}
+
+func (s *platformInterfaceStub) CheckPlatformShell() error {
+	return nil
+}
+
+func (s *platformInterfaceStub) OpenShellSession(user *adapter.PlatformUser, command string, env []string, term string, rows int32, cols int32) (adapter.ShellSession, error) {
+	return nil, os.ErrInvalid
+}
+
+func (s *platformInterfaceStub) LookupSFTPServer() (string, error) {
+	return "", os.ErrInvalid
+}
+
+func (s *platformInterfaceStub) ReadSystemSSHHostKey() ([]byte, error) {
+	return nil, os.ErrInvalid
+}
+
+func (s *platformInterfaceStub) LookupUser(username string) (*adapter.PlatformUser, error) {
+	return nil, os.ErrInvalid
+}
+
 func (s *platformInterfaceStub) UsePlatformLocalDNSTransport() bool {
 	return false
 }

experimental/libbox/native_shell_session.go

@@ -0,0 +1,78 @@
+//go:build linux || android || (darwin && !ios)
+
+package libbox
+
+import (
+	"github.com/sagernet/sing-box/protocol/tailscale/tailssh"
+	"github.com/sagernet/sing/common"
+)
+
+type nativeShellSession struct {
+	shell *tailssh.Shell
+}
+
+func OpenNativeShellSession(
+	shell, cwd string,
+	args, environ StringIterator,
+	term string,
+	rows, cols, uid, gid int32,
+	groups Int32Iterator,
+) (ShellSession, error) {
+	sh, err := tailssh.OpenPtyShell(
+		shell,
+		iteratorToArray[string](args),
+		iteratorToArray[string](environ),
+		cwd,
+		int(uid), int(gid),
+		common.Map(iteratorToArray[int32](groups), func(g int32) int { return int(g) }),
+		uint16(rows), uint16(cols),
+	)
+	if err != nil {
+		return nil, err
+	}
+	return &nativeShellSession{shell: sh}, nil
+}
+
+func OpenNativePipeSession(
+	shell, cwd string,
+	args, environ StringIterator,
+	uid, gid int32,
+	groups Int32Iterator,
+) (ShellSession, error) {
+	sh, err := tailssh.OpenSocketpairShell(
+		shell,
+		iteratorToArray[string](args),
+		iteratorToArray[string](environ),
+		cwd,
+		int(uid), int(gid),
+		common.Map(iteratorToArray[int32](groups), func(g int32) int { return int(g) }),
+	)
+	if err != nil {
+		return nil, err
+	}
+	return &nativeShellSession{shell: sh}, nil
+}
+
+func (s *nativeShellSession) MasterFD() int32 {
+	return int32(s.shell.MasterFD())
+}
+
+func (s *nativeShellSession) Resize(rows, cols int32) error {
+	return s.shell.Resize(uint16(rows), uint16(cols))
+}
+
+func (s *nativeShellSession) Signal(sig int32) error {
+	return s.shell.Signal(int(sig))
+}
+
+func (s *nativeShellSession) WaitExit() (int32, error) {
+	status, err := s.shell.Wait()
+	if err != nil {
+		return 0, err
+	}
+	return int32(status), nil
+}
+
+func (s *nativeShellSession) Close() error {
+	return s.shell.Close()
+}

experimental/libbox/native_shell_session_stub.go

@@ -0,0 +1,26 @@
+//go:build !linux && !android && (!darwin || ios)
+
+package libbox
+
+import (
+	E "github.com/sagernet/sing/common/exceptions"
+)
+
+func OpenNativeShellSession(
+	shell, cwd string,
+	args, environ StringIterator,
+	term string,
+	rows, cols, uid, gid int32,
+	groups Int32Iterator,
+) (ShellSession, error) {
+	return nil, E.New("native shell session not supported on this platform")
+}
+
+func OpenNativePipeSession(
+	shell, cwd string,
+	args, environ StringIterator,
+	uid, gid int32,
+	groups Int32Iterator,
+) (ShellSession, error) {
+	return nil, E.New("native pipe session not supported on this platform")
+}

experimental/libbox/platform.go

@@ -21,6 +21,30 @@ type PlatformInterface interface {
 	StartNeighborMonitor(listener NeighborUpdateListener) error
 	CloseNeighborMonitor(listener NeighborUpdateListener) error
 	RegisterMyInterface(name string)
+	UsePlatformShell() bool
+	CheckPlatformShell() error
+	OpenShellSession(user *PlatformUser, command string, environ StringIterator, term string, rows int32, cols int32) (ShellSession, error)
+	LookupUser(username string) (*PlatformUser, error)
+	LookupSFTPServer() (*StringBox, error)
+	ReadSystemSSHHostKey() (*StringBox, error)
+}
+
+type PlatformUser struct {
+	Username string
+	Uid      int32
+	Gid      int32
+	HomeDir  string
+	Shell    string
+
+	groups []int32
+}
+
+func (u *PlatformUser) SetGroups(groups Int32Iterator) {
+	u.groups = iteratorToArray[int32](groups)
+}
+
+func (u *PlatformUser) Groups() Int32Iterator {
+	return newIterator(u.groups)
 }
 
 type NeighborUpdateListener interface {

experimental/libbox/service.go

@@ -247,6 +247,63 @@ func (w *platformInterfaceWrapper) CloseNeighborMonitor(listener adapter.Neighbo
 	return w.iif.CloseNeighborMonitor(nil)
 }
 
+func (w *platformInterfaceWrapper) UsePlatformShell() bool {
+	return w.iif.UsePlatformShell()
+}
+
+func (w *platformInterfaceWrapper) CheckPlatformShell() error {
+	return w.iif.CheckPlatformShell()
+}
+
+func (w *platformInterfaceWrapper) OpenShellSession(user *adapter.PlatformUser, command string, environ []string, term string, rows int32, cols int32) (adapter.ShellSession, error) {
+	libboxUser := &PlatformUser{
+		Username: user.Username,
+		Uid:      int32(user.Uid),
+		Gid:      int32(user.Gid),
+		HomeDir:  user.HomeDir,
+		Shell:    user.Shell,
+	}
+	if len(user.Groups) > 0 {
+		libboxUser.SetGroups(newIterator(common.Map(user.Groups, func(g int) int32 { return int32(g) })))
+	}
+	session, err := w.iif.OpenShellSession(libboxUser, command, newIterator(environ), term, rows, cols)
+	if err != nil {
+		return nil, err
+	}
+	return session, nil
+}
+
+func (w *platformInterfaceWrapper) LookupSFTPServer() (string, error) {
+	result, err := w.iif.LookupSFTPServer()
+	if err != nil {
+		return "", err
+	}
+	return result.Value, nil
+}
+
+func (w *platformInterfaceWrapper) ReadSystemSSHHostKey() ([]byte, error) {
+	result, err := w.iif.ReadSystemSSHHostKey()
+	if err != nil {
+		return nil, err
+	}
+	return []byte(result.Value), nil
+}
+
+func (w *platformInterfaceWrapper) LookupUser(username string) (*adapter.PlatformUser, error) {
+	platformUser, err := w.iif.LookupUser(username)
+	if err != nil {
+		return nil, err
+	}
+	return &adapter.PlatformUser{
+		Username: platformUser.Username,
+		Uid:      int(platformUser.Uid),
+		Gid:      int(platformUser.Gid),
+		HomeDir:  platformUser.HomeDir,
+		Shell:    platformUser.Shell,
+		Groups:   common.Map(iteratorToArray[int32](platformUser.Groups()), func(g int32) int { return int(g) }),
+	}, nil
+}
+
 type neighborUpdateListenerWrapper struct {
 	listener adapter.NeighborUpdateListener
 }

experimental/libbox/ssh_shell.go

@@ -0,0 +1,9 @@
+package libbox
+
+type ShellSession interface {
+	MasterFD() int32
+	Resize(rows int32, cols int32) error
+	Signal(signal int32) error
+	WaitExit() (int32, error)
+	Close() error
+}