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
|
package sshd
import (
"context"
"errors"
"testing"
"github.com/stretchr/testify/require"
"golang.org/x/crypto/ssh"
)
type rejectCall struct {
reason ssh.RejectionReason
message string
}
type fakeNewChannel struct {
channelType string
extraData []byte
acceptErr error
acceptCh chan struct{}
rejectCh chan rejectCall
}
func (f *fakeNewChannel) Accept() (ssh.Channel, <-chan *ssh.Request, error) {
if f.acceptCh != nil {
f.acceptCh <- struct{}{}
}
return nil, nil, f.acceptErr
}
func (f *fakeNewChannel) Reject(reason ssh.RejectionReason, message string) error {
if f.rejectCh != nil {
f.rejectCh <- rejectCall{reason: reason, message: message}
}
return nil
}
func (f *fakeNewChannel) ChannelType() string {
return f.channelType
}
func (f *fakeNewChannel) ExtraData() []byte {
return f.extraData
}
func setup(sessionsNum int64, newChannel *fakeNewChannel) (*connection, chan ssh.NewChannel) {
conn := newConnection(sessionsNum, "127.0.0.1:50000")
chans := make(chan ssh.NewChannel, 1)
chans <- newChannel
return conn, chans
}
func TestPanicDuringSessionIsRecovered(t *testing.T) {
newChannel := &fakeNewChannel{channelType: "session"}
conn, chans := setup(1, newChannel)
numSessions := 0
require.NotPanics(t, func() {
conn.handle(context.Background(), chans, func(context.Context, ssh.Channel, <-chan *ssh.Request) {
numSessions += 1
close(chans)
panic("This is a panic")
})
})
require.Equal(t, numSessions, 1)
}
func TestUnknownChannelType(t *testing.T) {
rejectCh := make(chan rejectCall)
defer close(rejectCh)
newChannel := &fakeNewChannel{channelType: "unknown session", rejectCh: rejectCh}
conn, chans := setup(1, newChannel)
go func() {
conn.handle(context.Background(), chans, nil)
}()
rejectionData := <-rejectCh
expectedRejection := rejectCall{reason: ssh.UnknownChannelType, message: "unknown channel type"}
require.Equal(t, expectedRejection, rejectionData)
}
func TestTooManySessions(t *testing.T) {
rejectCh := make(chan rejectCall)
defer close(rejectCh)
newChannel := &fakeNewChannel{channelType: "session", rejectCh: rejectCh}
conn, chans := setup(1, newChannel)
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
go func() {
conn.handle(context.Background(), chans, func(context.Context, ssh.Channel, <-chan *ssh.Request) {
<-ctx.Done() // Keep the accepted channel open until the end of the test
})
}()
chans <- newChannel
require.Equal(t, <-rejectCh, rejectCall{reason: ssh.ResourceShortage, message: "too many concurrent sessions"})
}
func TestAcceptSessionSucceeds(t *testing.T) {
newChannel := &fakeNewChannel{channelType: "session"}
conn, chans := setup(1, newChannel)
channelHandled := false
conn.handle(context.Background(), chans, func(context.Context, ssh.Channel, <-chan *ssh.Request) {
channelHandled = true
close(chans)
})
require.True(t, channelHandled)
}
func TestAcceptSessionFails(t *testing.T) {
acceptCh := make(chan struct{})
defer close(acceptCh)
acceptErr := errors.New("some failure")
newChannel := &fakeNewChannel{channelType: "session", acceptCh: acceptCh, acceptErr: acceptErr}
conn, chans := setup(1, newChannel)
channelHandled := false
go func() {
conn.handle(context.Background(), chans, func(context.Context, ssh.Channel, <-chan *ssh.Request) {
channelHandled = true
})
}()
require.Equal(t, <-acceptCh, struct{}{})
// Waits until the number of sessions is back to 0, since we can only have 1
conn.concurrentSessions.Acquire(context.Background(), 1)
defer conn.concurrentSessions.Release(1)
require.False(t, channelHandled)
}
|
