1package ssh
  2
  3import (
  4	"errors"
  5	"io"
  6	"net"
  7)
  8
  9// streamLocalChannelOpenDirectMsg is a struct used for SSH_MSG_CHANNEL_OPEN message
 10// with "direct-streamlocal@openssh.com" string.
 11//
 12// See openssh-portable/PROTOCOL, section 2.4. connection: Unix domain socket forwarding
 13// https://github.com/openssh/openssh-portable/blob/master/PROTOCOL#L235
 14type streamLocalChannelOpenDirectMsg struct {
 15	socketPath string
 16	reserved0  string
 17	reserved1  uint32
 18}
 19
 20// forwardedStreamLocalPayload is a struct used for SSH_MSG_CHANNEL_OPEN message
 21// with "forwarded-streamlocal@openssh.com" string.
 22type forwardedStreamLocalPayload struct {
 23	SocketPath string
 24	Reserved0  string
 25}
 26
 27// streamLocalChannelForwardMsg is a struct used for SSH2_MSG_GLOBAL_REQUEST message
 28// with "streamlocal-forward@openssh.com"/"cancel-streamlocal-forward@openssh.com" string.
 29type streamLocalChannelForwardMsg struct {
 30	socketPath string
 31}
 32
 33// ListenUnix is similar to ListenTCP but uses a Unix domain socket.
 34func (c *Client) ListenUnix(socketPath string) (net.Listener, error) {
 35	c.handleForwardsOnce.Do(c.handleForwards)
 36	m := streamLocalChannelForwardMsg{
 37		socketPath,
 38	}
 39	// send message
 40	ok, _, err := c.SendRequest("streamlocal-forward@openssh.com", true, Marshal(&m))
 41	if err != nil {
 42		return nil, err
 43	}
 44	if !ok {
 45		return nil, errors.New("ssh: streamlocal-forward@openssh.com request denied by peer")
 46	}
 47	ch := c.forwards.add(&net.UnixAddr{Name: socketPath, Net: "unix"})
 48
 49	return &unixListener{socketPath, c, ch}, nil
 50}
 51
 52func (c *Client) dialStreamLocal(socketPath string) (Channel, error) {
 53	msg := streamLocalChannelOpenDirectMsg{
 54		socketPath: socketPath,
 55	}
 56	ch, in, err := c.OpenChannel("direct-streamlocal@openssh.com", Marshal(&msg))
 57	if err != nil {
 58		return nil, err
 59	}
 60	go DiscardRequests(in)
 61	return ch, err
 62}
 63
 64type unixListener struct {
 65	socketPath string
 66
 67	conn *Client
 68	in   <-chan forward
 69}
 70
 71// Accept waits for and returns the next connection to the listener.
 72func (l *unixListener) Accept() (net.Conn, error) {
 73	s, ok := <-l.in
 74	if !ok {
 75		return nil, io.EOF
 76	}
 77	ch, incoming, err := s.newCh.Accept()
 78	if err != nil {
 79		return nil, err
 80	}
 81	go DiscardRequests(incoming)
 82
 83	return &chanConn{
 84		Channel: ch,
 85		laddr: &net.UnixAddr{
 86			Name: l.socketPath,
 87			Net:  "unix",
 88		},
 89		raddr: &net.UnixAddr{
 90			Name: "@",
 91			Net:  "unix",
 92		},
 93	}, nil
 94}
 95
 96// Close closes the listener.
 97func (l *unixListener) Close() error {
 98	// this also closes the listener.
 99	l.conn.forwards.remove(&net.UnixAddr{Name: l.socketPath, Net: "unix"})
100	m := streamLocalChannelForwardMsg{
101		l.socketPath,
102	}
103	ok, _, err := l.conn.SendRequest("cancel-streamlocal-forward@openssh.com", true, Marshal(&m))
104	if err == nil && !ok {
105		err = errors.New("ssh: cancel-streamlocal-forward@openssh.com failed")
106	}
107	return err
108}
109
110// Addr returns the listener's network address.
111func (l *unixListener) Addr() net.Addr {
112	return &net.UnixAddr{
113		Name: l.socketPath,
114		Net:  "unix",
115	}
116}