-
Notifications
You must be signed in to change notification settings - Fork 0
/
server.go
244 lines (212 loc) · 5.73 KB
/
server.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
package tun
import (
"bytes"
"context"
"io"
"net"
"net/netip"
"time"
"github.com/go-gost/core/common/bufpool"
"github.com/go-gost/core/logger"
tun_util "github.com/goxpx/x/internal/util/tun"
"github.com/songgao/water/waterutil"
"golang.org/x/net/ipv4"
"golang.org/x/net/ipv6"
)
func (h *tunHandler) handleServer(ctx context.Context, conn net.Conn, config *tun_util.Config, log logger.Logger) error {
for {
err := func() error {
pc, err := net.ListenPacket(conn.LocalAddr().Network(), conn.LocalAddr().String())
if err != nil {
return err
}
defer pc.Close()
return h.transportServer(ctx, conn, pc, config, log)
}()
if err == ErrTun {
return err
}
log.Error(err)
time.Sleep(time.Second)
}
}
func (h *tunHandler) transportServer(ctx context.Context, tun io.ReadWriter, conn net.PacketConn, config *tun_util.Config, log logger.Logger) error {
errc := make(chan error, 1)
go func() {
for {
err := func() error {
b := bufpool.Get(h.md.bufferSize)
defer bufpool.Put(b)
n, err := tun.Read(b)
if err != nil {
return ErrTun
}
if n == 0 {
return nil
}
var src, dst net.IP
if waterutil.IsIPv4(b[:n]) {
header, err := ipv4.ParseHeader(b[:n])
if err != nil {
log.Warnf("parse ipv4 packet header: %v", err)
return nil
}
src, dst = header.Src, header.Dst
log.Tracef("%s >> %s %-4s %d/%-4d %-4x %d",
src, dst, ipProtocol(waterutil.IPv4Protocol(b[:n])),
header.Len, header.TotalLen, header.ID, header.Flags)
} else if waterutil.IsIPv6(b[:n]) {
header, err := ipv6.ParseHeader(b[:n])
if err != nil {
log.Warnf("parse ipv6 packet header: %v", err)
return nil
}
src, dst = header.Src, header.Dst
log.Tracef("%s >> %s %s %d %d",
src, dst,
ipProtocol(waterutil.IPProtocol(header.NextHeader)),
header.PayloadLen, header.TrafficClass)
} else {
log.Warnf("unknown packet, discarded(%d)", n)
return nil
}
addr := h.findRouteFor(ctx, dst, config.Router)
if addr == nil {
log.Debugf("no route for %s -> %s, packet discarded", src, dst)
return nil
}
log.Debugf("find route: %s -> %s", dst, addr)
if _, err := conn.WriteTo(b[:n], addr); err != nil {
return err
}
return nil
}()
if err != nil {
errc <- err
return
}
}
}()
go func() {
for {
err := func() error {
b := bufpool.Get(h.md.bufferSize)
defer bufpool.Put(b)
n, addr, err := conn.ReadFrom(b)
if err != nil {
return err
}
if n == 0 {
return nil
}
if n > keepAliveHeaderLength && bytes.Equal(b[:4], magicHeader) {
var peerIPs []net.IP
data := b[keepAliveHeaderLength:n]
if len(data)%net.IPv6len == 0 {
for len(data) > 0 {
peerIPs = append(peerIPs, net.IP(data[:net.IPv6len]))
data = data[net.IPv6len:]
}
}
if len(peerIPs) == 0 {
return nil
}
for _, net := range config.Net {
for _, ip := range peerIPs {
if ip.Equal(net.IP.To16()) {
return nil
}
}
}
if auther := h.options.Auther; auther != nil {
ok := true
key := bytes.TrimRight(b[4:20], "\x00")
for _, ip := range peerIPs {
if _, ok = auther.Authenticate(ctx, ip.String(), string(key)); !ok {
break
}
}
if !ok {
log.Debugf("keepalive from %v => %v, auth FAILED", addr, peerIPs)
return nil
}
}
log.Debugf("keepalive from %v => %v", addr, peerIPs)
addrPort, err := netip.ParseAddrPort(addr.String())
if err != nil {
log.Warnf("keepalive from %v: %v", addr, err)
return nil
}
var keepAliveData [keepAliveHeaderLength]byte
copy(keepAliveData[:4], magicHeader) // magic header
a16 := addrPort.Addr().As16()
copy(keepAliveData[4:], a16[:])
if _, err := conn.WriteTo(keepAliveData[:], addr); err != nil {
log.Warnf("keepalive to %v: %v", addr, err)
return nil
}
for _, ip := range peerIPs {
h.updateRoute(ip, addr, log)
}
return nil
}
var src, dst net.IP
if waterutil.IsIPv4(b[:n]) {
header, err := ipv4.ParseHeader(b[:n])
if err != nil {
log.Warnf("parse ipv4 packet header: %v", err)
return nil
}
src, dst = header.Src, header.Dst
log.Tracef("%s >> %s %-4s %d/%-4d %-4x %d",
src, dst, ipProtocol(waterutil.IPv4Protocol(b[:n])),
header.Len, header.TotalLen, header.ID, header.Flags)
} else if waterutil.IsIPv6(b[:n]) {
header, err := ipv6.ParseHeader(b[:n])
if err != nil {
log.Warnf("parse ipv6 packet header: %v", err)
return nil
}
src, dst = header.Src, header.Dst
log.Tracef("%s > %s %s %d %d",
src, dst,
ipProtocol(waterutil.IPProtocol(header.NextHeader)),
header.PayloadLen, header.TrafficClass)
} else {
log.Warnf("unknown packet, discarded(%d): % x", n, b[:n])
return nil
}
if addr := h.findRouteFor(ctx, dst, config.Router); addr != nil {
log.Debugf("find route: %s -> %s", dst, addr)
_, err := conn.WriteTo(b[:n], addr)
return err
}
if _, err := tun.Write(b[:n]); err != nil {
return ErrTun
}
return nil
}()
if err != nil {
errc <- err
return
}
}
}()
err := <-errc
if err != nil && err == io.EOF {
err = nil
}
return err
}
func (h *tunHandler) updateRoute(ip net.IP, addr net.Addr, log logger.Logger) {
rkey := ipToTunRouteKey(ip)
if actual, loaded := h.routes.LoadOrStore(rkey, addr); loaded {
if actual.(net.Addr).String() != addr.String() {
h.routes.Store(rkey, addr)
log.Debugf("update route: %s -> %s (old %s)",
ip, addr, actual.(net.Addr))
}
} else {
log.Debugf("new route: %s -> %s", ip, addr)
}
}