blob: da5905d5491aa6960cf7070b210e5939ff0d03e8 (
plain) (
blame)
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
|
package main
import (
"encoding/binary"
"golang.org/x/crypto/chacha20poly1305"
"net"
"sync"
"time"
)
/* Handles outbound flow
*
* 1. TUN queue
* 2. Routing
* 3. Per peer queuing
* 4. (work queuing)
*
*/
type OutboundWorkQueueElement struct {
wg sync.WaitGroup
packet []byte
nonce uint64
keyPair *KeyPair
}
func (device *Device) SendPacket(packet []byte) {
// lookup peer
var peer *Peer
switch packet[0] >> 4 {
case IPv4version:
dst := packet[IPv4offsetDst : IPv4offsetDst+net.IPv4len]
peer = device.routingTable.LookupIPv4(dst)
case IPv6version:
dst := packet[IPv6offsetDst : IPv6offsetDst+net.IPv6len]
peer = device.routingTable.LookupIPv6(dst)
default:
device.logger.Println("unknown IP version")
return
}
if peer == nil {
return
}
// insert into peer queue
for {
select {
case peer.queueOutboundRouting <- packet:
default:
select {
case <-peer.queueOutboundRouting:
default:
}
continue
}
break
}
}
/* Go routine
*
*
* 1. waits for handshake.
* 2. assigns key pair & nonce
* 3. inserts to working queue
*
* TODO: avoid dynamic allocation of work queue elements
*/
func (peer *Peer) RoutineOutboundNonceWorker() {
var packet []byte
var keyPair *KeyPair
var flushTimer time.Timer
for {
// wait for packet
if packet == nil {
packet = <-peer.queueOutboundRouting
}
// wait for key pair
for keyPair == nil {
flushTimer.Reset(time.Second * 10)
// TODO: Handshake or NOP
select {
case <-peer.keyPairs.newKeyPair:
keyPair = peer.keyPairs.Current()
continue
case <-flushTimer.C:
size := len(peer.queueOutboundRouting)
for i := 0; i < size; i += 1 {
<-peer.queueOutboundRouting
}
packet = nil
}
break
}
// process current packet
if packet != nil {
// create work element
work := new(OutboundWorkQueueElement)
work.wg.Add(1)
work.keyPair = keyPair
work.packet = packet
work.nonce = keyPair.sendNonce
packet = nil
peer.queueOutbound <- work
keyPair.sendNonce += 1
// drop packets until there is space
func() {
for {
select {
case peer.device.queueWorkOutbound <- work:
return
default:
drop := <-peer.device.queueWorkOutbound
drop.packet = nil
drop.wg.Done()
}
}
}()
}
}
}
/* Go routine
*
* sequentially reads packets from queue and sends to endpoint
*
*/
func (peer *Peer) RoutineSequential() {
for work := range peer.queueOutbound {
work.wg.Wait()
// check if dropped ("ghost packet")
if work.packet == nil {
continue
}
//
}
}
func (device *Device) RoutineEncryptionWorker() {
var nonce [chacha20poly1305.NonceSize]byte
for work := range device.queueWorkOutbound {
// pad packet
padding := device.mtu - len(work.packet)
if padding < 0 {
work.packet = nil
work.wg.Done()
}
for n := 0; n < padding; n += 1 {
work.packet = append(work.packet, 0)
}
// encrypt
binary.LittleEndian.PutUint64(nonce[4:], work.nonce)
work.packet = work.keyPair.send.Seal(
work.packet[:0],
nonce[:],
work.packet,
nil,
)
work.wg.Done()
}
}
|
