harness-drone/vendor/code.google.com/p/go.crypto/ssh/server_terminal.go
2015-09-29 18:21:17 -07:00

81 lines
1.7 KiB
Go

// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package ssh
// A Terminal is capable of parsing and generating virtual terminal
// data from an SSH client.
type Terminal interface {
ReadLine() (line string, err error)
SetSize(x, y int)
Write([]byte) (int, error)
}
// ServerTerminal contains the state for running a terminal that is capable of
// reading lines of input.
type ServerTerminal struct {
Term Terminal
Channel Channel
}
// parsePtyRequest parses the payload of the pty-req message and extracts the
// dimensions of the terminal. See RFC 4254, section 6.2.
func parsePtyRequest(s []byte) (width, height int, ok bool) {
_, s, ok = parseString(s)
if !ok {
return
}
width32, s, ok := parseUint32(s)
if !ok {
return
}
height32, _, ok := parseUint32(s)
width = int(width32)
height = int(height32)
if width < 1 {
ok = false
}
if height < 1 {
ok = false
}
return
}
func (ss *ServerTerminal) Write(buf []byte) (n int, err error) {
return ss.Term.Write(buf)
}
// ReadLine returns a line of input from the terminal.
func (ss *ServerTerminal) ReadLine() (line string, err error) {
for {
if line, err = ss.Term.ReadLine(); err == nil {
return
}
req, ok := err.(ChannelRequest)
if !ok {
return
}
ok = false
switch req.Request {
case "pty-req":
var width, height int
width, height, ok = parsePtyRequest(req.Payload)
ss.Term.SetSize(width, height)
case "shell":
ok = true
if len(req.Payload) > 0 {
// We don't accept any commands, only the default shell.
ok = false
}
case "env":
ok = true
}
if req.WantReply {
ss.Channel.AckRequest(ok)
}
}
panic("unreachable")
}