gtsocial-umbx

Unnamed repository; edit this file 'description' to name the repository.
Log | Files | Refs | README | LICENSE

connection.go (3413B)

      1 // Copyright 2013 The Go Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style
      3 // license that can be found in the LICENSE file.
      4 
      5 package ssh
      6 
      7 import (
      8 	"fmt"
      9 	"net"
     10 )
     11 
     12 // OpenChannelError is returned if the other side rejects an
     13 // OpenChannel request.
     14 type OpenChannelError struct {
     15 	Reason  RejectionReason
     16 	Message string
     17 }
     18 
     19 func (e *OpenChannelError) Error() string {
     20 	return fmt.Sprintf("ssh: rejected: %s (%s)", e.Reason, e.Message)
     21 }
     22 
     23 // ConnMetadata holds metadata for the connection.
     24 type ConnMetadata interface {
     25 	// User returns the user ID for this connection.
     26 	User() string
     27 
     28 	// SessionID returns the session hash, also denoted by H.
     29 	SessionID() []byte
     30 
     31 	// ClientVersion returns the client's version string as hashed
     32 	// into the session ID.
     33 	ClientVersion() []byte
     34 
     35 	// ServerVersion returns the server's version string as hashed
     36 	// into the session ID.
     37 	ServerVersion() []byte
     38 
     39 	// RemoteAddr returns the remote address for this connection.
     40 	RemoteAddr() net.Addr
     41 
     42 	// LocalAddr returns the local address for this connection.
     43 	LocalAddr() net.Addr
     44 }
     45 
     46 // Conn represents an SSH connection for both server and client roles.
     47 // Conn is the basis for implementing an application layer, such
     48 // as ClientConn, which implements the traditional shell access for
     49 // clients.
     50 type Conn interface {
     51 	ConnMetadata
     52 
     53 	// SendRequest sends a global request, and returns the
     54 	// reply. If wantReply is true, it returns the response status
     55 	// and payload. See also RFC 4254, section 4.
     56 	SendRequest(name string, wantReply bool, payload []byte) (bool, []byte, error)
     57 
     58 	// OpenChannel tries to open an channel. If the request is
     59 	// rejected, it returns *OpenChannelError. On success it returns
     60 	// the SSH Channel and a Go channel for incoming, out-of-band
     61 	// requests. The Go channel must be serviced, or the
     62 	// connection will hang.
     63 	OpenChannel(name string, data []byte) (Channel, <-chan *Request, error)
     64 
     65 	// Close closes the underlying network connection
     66 	Close() error
     67 
     68 	// Wait blocks until the connection has shut down, and returns the
     69 	// error causing the shutdown.
     70 	Wait() error
     71 
     72 	// TODO(hanwen): consider exposing:
     73 	//   RequestKeyChange
     74 	//   Disconnect
     75 }
     76 
     77 // DiscardRequests consumes and rejects all requests from the
     78 // passed-in channel.
     79 func DiscardRequests(in <-chan *Request) {
     80 	for req := range in {
     81 		if req.WantReply {
     82 			req.Reply(false, nil)
     83 		}
     84 	}
     85 }
     86 
     87 // A connection represents an incoming connection.
     88 type connection struct {
     89 	transport *handshakeTransport
     90 	sshConn
     91 
     92 	// The connection protocol.
     93 	*mux
     94 }
     95 
     96 func (c *connection) Close() error {
     97 	return c.sshConn.conn.Close()
     98 }
     99 
    100 // sshConn provides net.Conn metadata, but disallows direct reads and
    101 // writes.
    102 type sshConn struct {
    103 	conn net.Conn
    104 
    105 	user          string
    106 	sessionID     []byte
    107 	clientVersion []byte
    108 	serverVersion []byte
    109 }
    110 
    111 func dup(src []byte) []byte {
    112 	dst := make([]byte, len(src))
    113 	copy(dst, src)
    114 	return dst
    115 }
    116 
    117 func (c *sshConn) User() string {
    118 	return c.user
    119 }
    120 
    121 func (c *sshConn) RemoteAddr() net.Addr {
    122 	return c.conn.RemoteAddr()
    123 }
    124 
    125 func (c *sshConn) Close() error {
    126 	return c.conn.Close()
    127 }
    128 
    129 func (c *sshConn) LocalAddr() net.Addr {
    130 	return c.conn.LocalAddr()
    131 }
    132 
    133 func (c *sshConn) SessionID() []byte {
    134 	return dup(c.sessionID)
    135 }
    136 
    137 func (c *sshConn) ClientVersion() []byte {
    138 	return dup(c.clientVersion)
    139 }
    140 
    141 func (c *sshConn) ServerVersion() []byte {
    142 	return dup(c.serverVersion)
    143 }