/
snell.go
164 lines (142 loc) · 4.3 KB
/
snell.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
package outbound
import (
"context"
"fmt"
"net"
"strconv"
"github.com/MysticalDevil/clash/common/structure"
"github.com/MysticalDevil/clash/component/dialer"
C "github.com/MysticalDevil/clash/constant"
obfs "github.com/MysticalDevil/clash/transport/simple-obfs"
"github.com/MysticalDevil/clash/transport/snell"
)
type Snell struct {
*Base
psk []byte
pool *snell.Pool
obfsOption *simpleObfsOption
version int
}
type SnellOption struct {
BasicOption
Name string `proxy:"name"`
Server string `proxy:"server"`
Port int `proxy:"port"`
Psk string `proxy:"psk"`
UDP bool `proxy:"udp,omitempty"`
Version int `proxy:"version,omitempty"`
ObfsOpts map[string]any `proxy:"obfs-opts,omitempty"`
}
type streamOption struct {
psk []byte
version int
addr string
obfsOption *simpleObfsOption
}
func streamConn(c net.Conn, option streamOption) *snell.Snell {
switch option.obfsOption.Mode {
case "tls":
c = obfs.NewTLSObfs(c, option.obfsOption.Host)
case "http":
_, port, _ := net.SplitHostPort(option.addr)
c = obfs.NewHTTPObfs(c, option.obfsOption.Host, port)
}
return snell.StreamConn(c, option.psk, option.version)
}
// StreamConn implements C.ProxyAdapter
func (s *Snell) StreamConn(c net.Conn, metadata *C.Metadata) (net.Conn, error) {
c = streamConn(c, streamOption{s.psk, s.version, s.addr, s.obfsOption})
err := snell.WriteHeader(c, metadata.String(), uint(metadata.DstPort), s.version)
return c, err
}
// DialContext implements C.ProxyAdapter
func (s *Snell) DialContext(ctx context.Context, metadata *C.Metadata, opts ...dialer.Option) (_ C.Conn, err error) {
if s.version == snell.Version2 && len(opts) == 0 {
c, err := s.pool.Get()
if err != nil {
return nil, err
}
if err = snell.WriteHeader(c, metadata.String(), uint(metadata.DstPort), s.version); err != nil {
c.Close()
return nil, err
}
return NewConn(c, s), err
}
c, err := dialer.DialContext(ctx, "tcp", s.addr, s.Base.DialOptions(opts...)...)
if err != nil {
return nil, fmt.Errorf("%s connect error: %w", s.addr, err)
}
tcpKeepAlive(c)
defer func(c net.Conn) {
safeConnClose(c, err)
}(c)
c, err = s.StreamConn(c, metadata)
return NewConn(c, s), err
}
// ListenPacketContext implements C.ProxyAdapter
func (s *Snell) ListenPacketContext(ctx context.Context, metadata *C.Metadata, opts ...dialer.Option) (C.PacketConn, error) {
c, err := dialer.DialContext(ctx, "tcp", s.addr, s.Base.DialOptions(opts...)...)
if err != nil {
return nil, err
}
tcpKeepAlive(c)
c = streamConn(c, streamOption{s.psk, s.version, s.addr, s.obfsOption})
err = snell.WriteUDPHeader(c, s.version)
if err != nil {
return nil, err
}
pc := snell.PacketConn(c)
return newPacketConn(pc, s), nil
}
func NewSnell(option SnellOption) (*Snell, error) {
addr := net.JoinHostPort(option.Server, strconv.Itoa(option.Port))
psk := []byte(option.Psk)
decoder := structure.NewDecoder(structure.Option{TagName: "obfs", WeaklyTypedInput: true})
obfsOption := &simpleObfsOption{Host: "bing.com"}
if err := decoder.Decode(option.ObfsOpts, obfsOption); err != nil {
return nil, fmt.Errorf("snell %s initialize obfs error: %w", addr, err)
}
switch obfsOption.Mode {
case "tls", "http", "":
break
default:
return nil, fmt.Errorf("snell %s obfs mode error: %s", addr, obfsOption.Mode)
}
// backward compatible
if option.Version == 0 {
option.Version = snell.DefaultSnellVersion
}
switch option.Version {
case snell.Version1, snell.Version2:
if option.UDP {
return nil, fmt.Errorf("snell version %d not support UDP", option.Version)
}
case snell.Version3:
default:
return nil, fmt.Errorf("snell version error: %d", option.Version)
}
s := &Snell{
Base: &Base{
name: option.Name,
addr: addr,
tp: C.Snell,
udp: option.UDP,
iface: option.Interface,
rmark: option.RoutingMark,
},
psk: psk,
obfsOption: obfsOption,
version: option.Version,
}
if option.Version == snell.Version2 {
s.pool = snell.NewPool(func(ctx context.Context) (*snell.Snell, error) {
c, err := dialer.DialContext(ctx, "tcp", addr, s.Base.DialOptions()...)
if err != nil {
return nil, err
}
tcpKeepAlive(c)
return streamConn(c, streamOption{psk, option.Version, addr, obfsOption}), nil
})
}
return s, nil
}