github.com/technosophos/deis@v1.7.1-0.20150915173815-f9005256004b/Godeps/_workspace/src/golang.org/x/crypto/ssh/connection.go (about)

     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  	// It is empty if no authentication is used.
    27  	User() string
    28  
    29  	// SessionID returns the sesson hash, also denoted by H.
    30  	SessionID() []byte
    31  
    32  	// ClientVersion returns the client's version string as hashed
    33  	// into the session ID.
    34  	ClientVersion() []byte
    35  
    36  	// ServerVersion returns the client's version string as hashed
    37  	// into the session ID.
    38  	ServerVersion() []byte
    39  
    40  	// RemoteAddr returns the remote address for this connection.
    41  	RemoteAddr() net.Addr
    42  
    43  	// LocalAddr returns the local address for this connection.
    44  	LocalAddr() net.Addr
    45  }
    46  
    47  // Conn represents an SSH connection for both server and client roles.
    48  // Conn is the basis for implementing an application layer, such
    49  // as ClientConn, which implements the traditional shell access for
    50  // clients.
    51  type Conn interface {
    52  	ConnMetadata
    53  
    54  	// SendRequest sends a global request, and returns the
    55  	// reply. If wantReply is true, it returns the response status
    56  	// and payload. See also RFC4254, section 4.
    57  	SendRequest(name string, wantReply bool, payload []byte) (bool, []byte, error)
    58  
    59  	// OpenChannel tries to open an channel. If the request is
    60  	// rejected, it returns *OpenChannelError. On success it returns
    61  	// the SSH Channel and a Go channel for incoming, out-of-band
    62  	// requests. The Go channel must be serviced, or the
    63  	// connection will hang.
    64  	OpenChannel(name string, data []byte) (Channel, <-chan *Request, error)
    65  
    66  	// Close closes the underlying network connection
    67  	Close() error
    68  
    69  	// Wait blocks until the connection has shut down, and returns the
    70  	// error causing the shutdown.
    71  	Wait() error
    72  
    73  	// TODO(hanwen): consider exposing:
    74  	//   RequestKeyChange
    75  	//   Disconnect
    76  }
    77  
    78  // DiscardRequests consumes and rejects all requests from the
    79  // passed-in channel.
    80  func DiscardRequests(in <-chan *Request) {
    81  	for req := range in {
    82  		if req.WantReply {
    83  			req.Reply(false, nil)
    84  		}
    85  	}
    86  }
    87  
    88  // A connection represents an incoming connection.
    89  type connection struct {
    90  	transport *handshakeTransport
    91  	sshConn
    92  
    93  	// The connection protocol.
    94  	*mux
    95  }
    96  
    97  func (c *connection) Close() error {
    98  	return c.sshConn.conn.Close()
    99  }
   100  
   101  // sshconn provides net.Conn metadata, but disallows direct reads and
   102  // writes.
   103  type sshConn struct {
   104  	conn net.Conn
   105  
   106  	user          string
   107  	sessionID     []byte
   108  	clientVersion []byte
   109  	serverVersion []byte
   110  }
   111  
   112  func dup(src []byte) []byte {
   113  	dst := make([]byte, len(src))
   114  	copy(dst, src)
   115  	return dst
   116  }
   117  
   118  func (c *sshConn) User() string {
   119  	return c.user
   120  }
   121  
   122  func (c *sshConn) RemoteAddr() net.Addr {
   123  	return c.conn.RemoteAddr()
   124  }
   125  
   126  func (c *sshConn) Close() error {
   127  	return c.conn.Close()
   128  }
   129  
   130  func (c *sshConn) LocalAddr() net.Addr {
   131  	return c.conn.LocalAddr()
   132  }
   133  
   134  func (c *sshConn) SessionID() []byte {
   135  	return dup(c.sessionID)
   136  }
   137  
   138  func (c *sshConn) ClientVersion() []byte {
   139  	return dup(c.clientVersion)
   140  }
   141  
   142  func (c *sshConn) ServerVersion() []byte {
   143  	return dup(c.serverVersion)
   144  }