-
Notifications
You must be signed in to change notification settings - Fork 0
/
connect.go
201 lines (180 loc) · 5.35 KB
/
connect.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
/*
Copyright 2015 Gravitational, Inc.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package web
import (
"fmt"
"net/http"
"github.com/gravitational/teleport/lib/reversetunnel"
"github.com/gravitational/teleport/lib/services"
"github.com/gravitational/teleport/lib/session"
"github.com/gravitational/teleport/lib/sshutils"
"github.com/gravitational/teleport/lib/utils"
log "github.com/Sirupsen/logrus"
"github.com/gravitational/trace"
"golang.org/x/crypto/ssh"
"golang.org/x/net/websocket"
)
// connectReq is a request to open interactive SSH
// connection to remote server
type connectReq struct {
// ServerID is a server id to connect to
ServerID string `json:"server_id"`
// User is linux username to connect as
Login string `json:"login"`
// Term sets PTY params like width and height
Term session.TerminalParams `json:"term"`
// SessionID is a teleport session ID to join as
SessionID session.ID `json:"sid"`
}
func newConnectHandler(req connectReq, ctx *SessionContext, site reversetunnel.RemoteSite) (*connectHandler, error) {
clt, err := site.GetClient()
if err != nil {
return nil, trace.Wrap(err)
}
servers, err := clt.GetNodes()
if err != nil {
return nil, trace.Wrap(err)
}
var server *services.Server
for i := range servers {
node := servers[i]
if node.ID == req.ServerID {
server = &node
}
}
if server == nil {
return nil, trace.NotFound("node '%v' not found", req.ServerID)
}
if req.Login == "" {
return nil, trace.BadParameter("login: missing login")
}
if req.Term.W <= 0 || req.Term.H <= 0 {
return nil, trace.BadParameter("term: bad term dimensions")
}
return &connectHandler{
req: req,
ctx: ctx,
site: site,
server: *server,
}, nil
}
// connectHandler is a websocket to SSH proxy handler
type connectHandler struct {
ctx *SessionContext
site reversetunnel.RemoteSite
up *sshutils.Upstream
req connectReq
ws *websocket.Conn
server services.Server
}
func (w *connectHandler) String() string {
return fmt.Sprintf("connectHandler(%#v)", w.req)
}
func (w *connectHandler) Close() error {
if w.ws != nil {
w.ws.Close()
}
if w.up != nil {
return w.up.Close()
}
return nil
}
// connect is called when a web browser wants to start piping an active terminal session
// io/out via the provided websocket
func (w *connectHandler) connect(ws *websocket.Conn) {
// connectUpstream establishes an SSH connection to a requested node
up, err := w.connectUpstream()
if err != nil {
log.Errorf("wsHandler: failed: %v", err)
return
}
w.up = up
w.ws = ws
// PipeShell will be piping inputs/output to/from SSH connection (to the node)
// and the websocket (to a browser)
err = w.up.PipeShell(utils.NewWebSockWrapper(ws, utils.WebSocketTextMode),
&sshutils.PTYReqParams{
W: uint32(w.req.Term.W),
H: uint32(w.req.Term.H),
})
log.Infof("pipe shell finished with: %v", err)
}
// resizePTYWindow is called when a brower resizes its window. Now the node
// needs to be notified via SSH
func (w *connectHandler) resizePTYWindow(params session.TerminalParams) error {
_, err := w.up.GetSession().SendRequest(
// send SSH "window resized" SSH request:
sshutils.WindowChangeReq, false,
ssh.Marshal(sshutils.WinChangeReqParams{
W: uint32(params.W),
H: uint32(params.H),
}))
return trace.Wrap(err)
}
// connectUpstream establishes the SSH connection to a requested SSH server (node)
func (w *connectHandler) connectUpstream() (*sshutils.Upstream, error) {
agent, err := w.ctx.GetAgent()
if err != nil {
return nil, trace.Wrap(err)
}
defer agent.Close()
signers, err := agent.Signers()
if err != nil {
return nil, trace.Wrap(err)
}
client, err := w.site.ConnectToServer(
w.server.Addr, w.req.Login, []ssh.AuthMethod{ssh.PublicKeys(signers...)})
if err != nil {
return nil, trace.Wrap(err)
}
up, err := sshutils.NewUpstream(client)
if err != nil {
return nil, trace.Wrap(err)
}
// this goroutine receives terminal window size changes in real time
// and stores the last size (example: "100:25") as a special "prefix"
// which gets added to future SSH reads by web clients.
go func() {
buff := make([]byte, 16)
sshChan, _, err := up.GetClient().OpenChannel("x-teleport-request-resize-events", nil)
for err == nil {
n, err := sshChan.Read(buff)
if err != nil {
break
}
up.SetPrefix(buff[:n])
}
if err != nil {
log.Error(err)
}
}()
up.GetSession().SendRequest(
sshutils.SetEnvReq, false,
ssh.Marshal(sshutils.EnvReqParams{
Name: sshutils.SessionEnvVar,
Value: string(w.req.SessionID),
}))
return up, nil
}
func (w *connectHandler) Handler() http.Handler {
// TODO(klizhentas)
// we instantiate a server explicitly here instead of using
// websocket.HandlerFunc to set empty origin checker
// make sure we check origin when in prod mode
return &websocket.Server{
Handler: w.connect,
}
}
func newWSHandler(host string, auth []string) *connectHandler {
return &connectHandler{}
}