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Commit dd47a0a2 authored by Adam Langley's avatar Adam Langley
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exp/ssh: remove duplicated terminal code. 

The terminal code in exp/terminal was forked from the code in exp/ssh.
This change removes the duplicated code from exp/ssh in favour of
using exp/terminal.

R=rsc
CC=golang-dev
https://golang.org/cl/5375064
parent 4dda23a1
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Inline Side-by-side
Showing with 112 additions and 416 deletions
src/pkg/exp/ssh/Makefile
View file @ dd47a0a2
......@@ -13,7 +13,7 @@ GOFILES=\
common.go\
messages.go\
server.go\
server_shell.go\
server_terminal.go\
session.go\
tcpip.go\
transport.go\
......
src/pkg/exp/ssh/doc.go
View file @ dd47a0a2
......@@ -14,7 +14,7 @@ others.
An SSH server is represented by a ServerConfig, which holds certificate
details and handles authentication of ServerConns.
config := new(ServerConfig)
config := new(ssh.ServerConfig)
config.PubKeyCallback = pubKeyAuth
config.PasswordCallback = passwordAuth
......@@ -34,8 +34,7 @@ Once a ServerConfig has been configured, connections can be accepted.
if err != nil {
panic("failed to accept incoming connection")
}
err = sConn.Handshake(conn)
if err != nil {
if err := sConn.Handshake(conn); err != nil {
panic("failed to handshake")
}
......@@ -60,16 +59,20 @@ the case of a shell, the type is "session" and ServerShell may be used to
present a simple terminal interface.
if channel.ChannelType() != "session" {
c.Reject(UnknownChannelType, "unknown channel type")
channel.Reject(UnknownChannelType, "unknown channel type")
return
}
channel.Accept()
shell := NewServerShell(channel, "> ")
term := terminal.NewTerminal(channel, "> ")
serverTerm := &ssh.ServerTerminal{
Term: term,
Channel: channel,
}
go func() {
defer channel.Close()
for {
line, err := shell.ReadLine()
line, err := serverTerm.ReadLine()
if err != nil {
break
}
......@@ -97,7 +100,8 @@ ClientAuth via the Auth field in ClientConfig.
}
}
An SSH client is represented with a ClientConn.
An SSH client is represented with a ClientConn. Currently only the "password"
authentication method is supported.
config := &ClientConfig{
User: "username",
......@@ -105,12 +109,12 @@ An SSH client is represented with a ClientConn.
}
client, err := Dial("yourserver.com:22", config)
Each ClientConn can support multiple interactive sessions, represented by a Session.
Each ClientConn can support multiple interactive sessions, represented by a Session.
session, err := client.NewSession()
Once a Session is created, you can execute a single command on the remote side
using the Run method.
Once a Session is created, you can execute a single command on the remote side
using the Exec method.
b := bytes.NewBuffer()
session.Stdin = b
......
src/pkg/exp/ssh/server_shell.go deleted 100644 → 0
View file @ 4dda23a1
// 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
import "io"
// ServerShell contains the state for running a VT100 terminal that is capable
// of reading lines of input.
type ServerShell struct {
c Channel
prompt string
// line is the current line being entered.
line []byte
// pos is the logical position of the cursor in line
pos int
// cursorX contains the current X value of the cursor where the left
// edge is 0. cursorY contains the row number where the first row of
// the current line is 0.
cursorX, cursorY int
// maxLine is the greatest value of cursorY so far.
maxLine int
termWidth, termHeight int
// outBuf contains the terminal data to be sent.
outBuf []byte
// remainder contains the remainder of any partial key sequences after
// a read. It aliases into inBuf.
remainder []byte
inBuf [256]byte
}
// NewServerShell runs a VT100 terminal on the given channel. prompt is a
// string that is written at the start of each input line. For example: "> ".
func NewServerShell(c Channel, prompt string) *ServerShell {
return &ServerShell{
c: c,
prompt: prompt,
termWidth: 80,
termHeight: 24,
}
}
const (
keyCtrlD = 4
keyEnter = '\r'
keyEscape = 27
keyBackspace = 127
keyUnknown = 256 + iota
keyUp
keyDown
keyLeft
keyRight
keyAltLeft
keyAltRight
)
// bytesToKey tries to parse a key sequence from b. If successful, it returns
// the key and the remainder of the input. Otherwise it returns -1.
func bytesToKey(b []byte) (int, []byte) {
if len(b) == 0 {
return -1, nil
}
if b[0] != keyEscape {
return int(b[0]), b[1:]
}
if len(b) >= 3 && b[0] == keyEscape && b[1] == '[' {
switch b[2] {
case 'A':
return keyUp, b[3:]
case 'B':
return keyDown, b[3:]
case 'C':
return keyRight, b[3:]
case 'D':
return keyLeft, b[3:]
}
}
if len(b) >= 6 && b[0] == keyEscape && b[1] == '[' && b[2] == '1' && b[3] == ';' && b[4] == '3' {
switch b[5] {
case 'C':
return keyAltRight, b[6:]
case 'D':
return keyAltLeft, b[6:]
}
}
// If we get here then we have a key that we don't recognise, or a
// partial sequence. It's not clear how one should find the end of a
// sequence without knowing them all, but it seems that [a-zA-Z] only
// appears at the end of a sequence.
for i, c := range b[0:] {
if c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z' {
return keyUnknown, b[i+1:]
}
}
return -1, b
}
// queue appends data to the end of ss.outBuf
func (ss *ServerShell) queue(data []byte) {
if len(ss.outBuf)+len(data) > cap(ss.outBuf) {
newOutBuf := make([]byte, len(ss.outBuf), 2*(len(ss.outBuf)+len(data)))
copy(newOutBuf, ss.outBuf)
ss.outBuf = newOutBuf
}
oldLen := len(ss.outBuf)
ss.outBuf = ss.outBuf[:len(ss.outBuf)+len(data)]
copy(ss.outBuf[oldLen:], data)
}
var eraseUnderCursor = []byte{' ', keyEscape, '[', 'D'}
func isPrintable(key int) bool {
return key >= 32 && key < 127
}
// moveCursorToPos appends data to ss.outBuf which will move the cursor to the
// given, logical position in the text.
func (ss *ServerShell) moveCursorToPos(pos int) {
x := len(ss.prompt) + pos
y := x / ss.termWidth
x = x % ss.termWidth
up := 0
if y < ss.cursorY {
up = ss.cursorY - y
}
down := 0
if y > ss.cursorY {
down = y - ss.cursorY
}
left := 0
if x < ss.cursorX {
left = ss.cursorX - x
}
right := 0
if x > ss.cursorX {
right = x - ss.cursorX
}
movement := make([]byte, 3*(up+down+left+right))
m := movement
for i := 0; i < up; i++ {
m[0] = keyEscape
m[1] = '['
m[2] = 'A'
m = m[3:]
}
for i := 0; i < down; i++ {
m[0] = keyEscape
m[1] = '['
m[2] = 'B'
m = m[3:]
}
for i := 0; i < left; i++ {
m[0] = keyEscape
m[1] = '['
m[2] = 'D'
m = m[3:]
}
for i := 0; i < right; i++ {
m[0] = keyEscape
m[1] = '['
m[2] = 'C'
m = m[3:]
}
ss.cursorX = x
ss.cursorY = y
ss.queue(movement)
}
const maxLineLength = 4096
// handleKey processes the given key and, optionally, returns a line of text
// that the user has entered.
func (ss *ServerShell) handleKey(key int) (line string, ok bool) {
switch key {
case keyBackspace:
if ss.pos == 0 {
return
}
ss.pos--
copy(ss.line[ss.pos:], ss.line[1+ss.pos:])
ss.line = ss.line[:len(ss.line)-1]
ss.writeLine(ss.line[ss.pos:])
ss.moveCursorToPos(ss.pos)
ss.queue(eraseUnderCursor)
case keyAltLeft:
// move left by a word.
if ss.pos == 0 {
return
}
ss.pos--
for ss.pos > 0 {
if ss.line[ss.pos] != ' ' {
break
}
ss.pos--
}
for ss.pos > 0 {
if ss.line[ss.pos] == ' ' {
ss.pos++
break
}
ss.pos--
}
ss.moveCursorToPos(ss.pos)
case keyAltRight:
// move right by a word.
for ss.pos < len(ss.line) {
if ss.line[ss.pos] == ' ' {
break
}
ss.pos++
}
for ss.pos < len(ss.line) {
if ss.line[ss.pos] != ' ' {
break
}
ss.pos++
}
ss.moveCursorToPos(ss.pos)
case keyLeft:
if ss.pos == 0 {
return
}
ss.pos--
ss.moveCursorToPos(ss.pos)
case keyRight:
if ss.pos == len(ss.line) {
return
}
ss.pos++
ss.moveCursorToPos(ss.pos)
case keyEnter:
ss.moveCursorToPos(len(ss.line))
ss.queue([]byte("\r\n"))
line = string(ss.line)
ok = true
ss.line = ss.line[:0]
ss.pos = 0
ss.cursorX = 0
ss.cursorY = 0
ss.maxLine = 0
default:
if !isPrintable(key) {
return
}
if len(ss.line) == maxLineLength {
return
}
if len(ss.line) == cap(ss.line) {
newLine := make([]byte, len(ss.line), 2*(1+len(ss.line)))
copy(newLine, ss.line)
ss.line = newLine
}
ss.line = ss.line[:len(ss.line)+1]
copy(ss.line[ss.pos+1:], ss.line[ss.pos:])
ss.line[ss.pos] = byte(key)
ss.writeLine(ss.line[ss.pos:])
ss.pos++
ss.moveCursorToPos(ss.pos)
}
return
}
func (ss *ServerShell) writeLine(line []byte) {
for len(line) != 0 {
if ss.cursorX == ss.termWidth {
ss.queue([]byte("\r\n"))
ss.cursorX = 0
ss.cursorY++
if ss.cursorY > ss.maxLine {
ss.maxLine = ss.cursorY
}
}
remainingOnLine := ss.termWidth - ss.cursorX
todo := len(line)
if todo > remainingOnLine {
todo = remainingOnLine
}
ss.queue(line[:todo])
ss.cursorX += todo
line = line[todo:]
}
}
// 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 *ServerShell) Write(buf []byte) (n int, err error) {
return ss.c.Write(buf)
}
// ReadLine returns a line of input from the terminal.
func (ss *ServerShell) ReadLine() (line string, err error) {
ss.writeLine([]byte(ss.prompt))
ss.c.Write(ss.outBuf)
ss.outBuf = ss.outBuf[:0]
for {
// ss.remainder is a slice at the beginning of ss.inBuf
// containing a partial key sequence
readBuf := ss.inBuf[len(ss.remainder):]
var n int
n, err = ss.c.Read(readBuf)
if err == nil {
ss.remainder = ss.inBuf[:n+len(ss.remainder)]
rest := ss.remainder
lineOk := false
for !lineOk {
var key int
key, rest = bytesToKey(rest)
if key < 0 {
break
}
if key == keyCtrlD {
return "", io.EOF
}
line, lineOk = ss.handleKey(key)
}
if len(rest) > 0 {
n := copy(ss.inBuf[:], rest)
ss.remainder = ss.inBuf[:n]
} else {
ss.remainder = nil
}
ss.c.Write(ss.outBuf)
ss.outBuf = ss.outBuf[:0]
if lineOk {
return
}
continue
}
if req, ok := err.(ChannelRequest); ok {
ok := false
switch req.Request {
case "pty-req":
ss.termWidth, ss.termHeight, ok = parsePtyRequest(req.Payload)
if !ok {
ss.termWidth = 80
ss.termHeight = 24
}
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.c.AckRequest(ok)
}
} else {
return "", err
}
}
panic("unreachable")
}
src/pkg/exp/ssh/server_terminal.go 0 → 100644
View file @ dd47a0a2
// 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")
}
src/pkg/exp/ssh/session_test.go
View file @ dd47a0a2
......@@ -8,6 +8,7 @@ package ssh
import (
"bytes"
"exp/terminal"
"io"
"testing"
)
......@@ -290,24 +291,32 @@ type exitSignalMsg struct {
Lang string
}
func newServerShell(ch *channel, prompt string) *ServerTerminal {
term := terminal.NewTerminal(ch, prompt)
return &ServerTerminal{
Term: term,
Channel: ch,
}
}
func exitStatusZeroHandler(ch *channel) {
defer ch.Close()
// this string is returned to stdout
shell := NewServerShell(ch, "> ")
shell := newServerShell(ch, "> ")
shell.ReadLine()
sendStatus(0, ch)
}
func exitStatusNonZeroHandler(ch *channel) {
defer ch.Close()
shell := NewServerShell(ch, "> ")
shell := newServerShell(ch, "> ")
shell.ReadLine()
sendStatus(15, ch)
}
func exitSignalAndStatusHandler(ch *channel) {
defer ch.Close()
shell := NewServerShell(ch, "> ")
shell := newServerShell(ch, "> ")
shell.ReadLine()
sendStatus(15, ch)
sendSignal("TERM", ch)
......@@ -315,28 +324,28 @@ func exitSignalAndStatusHandler(ch *channel) {
func exitSignalHandler(ch *channel) {
defer ch.Close()
shell := NewServerShell(ch, "> ")
shell := newServerShell(ch, "> ")
shell.ReadLine()
sendSignal("TERM", ch)
}
func exitSignalUnknownHandler(ch *channel) {
defer ch.Close()
shell := NewServerShell(ch, "> ")
shell := newServerShell(ch, "> ")
shell.ReadLine()
sendSignal("SYS", ch)
}
func exitWithoutSignalOrStatus(ch *channel) {
defer ch.Close()
shell := NewServerShell(ch, "> ")
shell := newServerShell(ch, "> ")
shell.ReadLine()
}
func shellHandler(ch *channel) {
defer ch.Close()
// this string is returned to stdout
shell := NewServerShell(ch, "golang")
shell := newServerShell(ch, "golang")
shell.ReadLine()
sendStatus(0, ch)
}
......
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