-
Notifications
You must be signed in to change notification settings - Fork 32
/
client.go
275 lines (234 loc) · 5.98 KB
/
client.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
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
/*
* This file is part of open-snell.
* open-snell is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
* open-snell is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with open-snell. If not, see <https://www.gnu.org/licenses/>.
*/
package snell
import (
"bytes"
"encoding/binary"
"errors"
"fmt"
"io"
"net"
"strconv"
"sync"
"time"
log "github.com/golang/glog"
"github.com/icpz/open-snell/components/aead"
obfs "github.com/icpz/open-snell/components/simple-obfs"
"github.com/icpz/open-snell/components/socks5"
"github.com/icpz/open-snell/components/utils"
p "github.com/icpz/open-snell/components/utils/pool"
)
const (
MaxPoolCap = 10
PoolTimeoutMS = 150000
)
var (
bufferPool = sync.Pool{New: func() interface{} { return &bytes.Buffer{} }}
)
type clientSession struct {
net.Conn
buffer [1]byte
reply bool
}
func (s *clientSession) Read(b []byte) (int, error) {
if s.reply {
return s.Conn.Read(b)
}
s.reply = true
if _, err := io.ReadFull(s.Conn, s.buffer[:]); err != nil {
return 0, err
}
if s.buffer[0] == ResponseTunnel {
return s.Conn.Read(b)
} else if s.buffer[0] != ResponseError {
return 0, errors.New("Command not support")
}
// ResponseError
if _, err := io.ReadFull(s.Conn, s.buffer[:]); err != nil {
return 0, err
}
if _, err := io.ReadFull(s.Conn, s.buffer[:]); err != nil {
return 0, err
}
length := int(s.buffer[0])
msg := make([]byte, length)
if _, err := io.ReadFull(s.Conn, msg); err != nil {
return 0, err
}
return 0, NewAppError(0, string(msg))
}
func WriteHeader(conn net.Conn, host string, port uint, v2 bool) error {
buf := bufferPool.Get().(*bytes.Buffer)
buf.Reset()
defer bufferPool.Put(buf)
buf.WriteByte(Version)
if v2 {
buf.WriteByte(CommandConnectV2)
} else {
buf.WriteByte(CommandConnect)
}
// clientID length & id
buf.WriteByte(0)
// host & port
buf.WriteByte(uint8(len(host)))
buf.WriteString(host)
binary.Write(buf, binary.BigEndian, uint16(port))
if _, err := conn.Write(buf.Bytes()); err != nil {
return err
}
return nil
}
type SnellClient struct {
server string
obfs string
obfsHost string
cipher aead.Cipher
socks5 *socks5.SockListener
isV2 bool
pool *snellPool
}
func (s *SnellClient) StreamConn(c net.Conn, target string) (net.Conn, error) {
host, port, _ := net.SplitHostPort(target)
iport, _ := strconv.Atoi(port)
err := WriteHeader(c, host, uint(iport), s.isV2)
return c, err
}
func (s *SnellClient) newSession() (net.Conn, error) {
c, err := net.Dial("tcp", s.server)
if err != nil {
return nil, err
}
if tc, ok := c.(*net.TCPConn); ok {
tc.SetKeepAlive(true)
}
_, port, _ := net.SplitHostPort(s.server)
c, _ = obfs.NewObfsClient(c, s.obfsHost, port, s.obfs)
c = &clientSession{
Conn: aead.NewConn(c, s.cipher),
}
return c, nil
}
func (s *SnellClient) GetSession(target string) (net.Conn, error) {
c, err := s.pool.Get()
if err != nil {
return nil, err
}
log.V(1).Infof("Using conn %s\n", c.LocalAddr().String())
c, err = s.StreamConn(c, target)
if err != nil {
s.DropSession(c)
return nil, err
}
return c, nil
}
func (s *SnellClient) PutSession(c net.Conn) {
if pc, ok := c.(*snellPoolConn); ok {
pc.Conn.(*clientSession).reply = false
} else {
log.Fatalf("Invalid session type!")
}
if !s.isV2 {
s.DropSession(c)
} else {
log.V(1).Infof("Cache conn %s\n", c.LocalAddr().String())
c.Close()
}
}
func (s *SnellClient) DropSession(c net.Conn) {
if sess, ok := c.(*snellPoolConn); ok {
sess.MarkUnusable()
sess.Close()
} else {
log.Fatalf("Invalid session type!")
}
}
func (s *SnellClient) Close() {
s.socks5.Close()
s.pool.Close()
}
func NewSnellClient(listen, server, obfs, obfsHost, psk string, isV2 bool) (*SnellClient, error) {
if obfs != "tls" && obfs != "http" && obfs != "" {
return nil, fmt.Errorf("invalid snell obfs type %s", obfs)
}
if obfsHost == "" {
obfsHost = "www.bing.com"
}
var cipher aead.Cipher = nil
if isV2 {
cipher = aead.NewAES128GCM([]byte(psk))
} else {
cipher = aead.NewChacha20Poly1305([]byte(psk))
}
sc := &SnellClient{
server: server,
obfs: obfs,
obfsHost: obfsHost,
cipher: cipher,
isV2: isV2,
}
p, err := newSnellPool(MaxPoolCap, PoolTimeoutMS, sc.newSession)
if err != nil {
return nil, err
}
sc.pool = p
sl, err := socks5.NewSocksProxy(listen, sc.handleSnell)
if err != nil {
return nil, err
}
sc.socks5 = sl
return sc, nil
}
func (s *SnellClient) handleSnell(client net.Conn, addr socks5.Addr) {
target, err := s.GetSession(addr.String())
log.V(1).Infof("New target from %s to %s\n", client.RemoteAddr().String(), addr.String())
if err != nil {
log.Warningf("Failed to connect to target %s, error %v\n", addr.String(), err)
client.Close()
return
}
_, er := utils.Relay(client, target)
client.Close()
if s.isV2 {
target.SetReadDeadline(time.Time{})
_, err := target.Write([]byte{}) // write zero chunk back
if err != nil {
log.Errorf("Unexpected write error %v\n", err)
s.DropSession(target)
return
}
switch e := er.(type) {
case *net.OpError:
if e.Op == "write" {
log.V(1).Infof("Ignored write error %v\n", e)
er = nil
} else if ae, ok := e.Unwrap().(*AppError); ok {
log.Errorf("Server reported error: %v\n", ae)
er = nil
}
}
buf := p.Get(p.RelayBufferSize)
for er == nil {
_, err := target.Read(buf)
er = err
}
p.Put(buf)
if !errors.Is(er, aead.ErrZeroChunk) {
log.Warningf("Unexpected error %v, ZERO CHUNK wanted\n", er)
s.DropSession(target)
return
}
}
s.PutSession(target)
log.V(1).Infof("Session from %s done\n", client.RemoteAddr().String())
}