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
|
/* SPDX-License-Identifier: GPL-2.0
*
* Copyright (C) 2017-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
package main
import (
"errors"
"golang.org/x/net/ipv4"
"golang.org/x/net/ipv6"
"net"
)
/* A Bind handles listening on a port for both IPv6 and IPv4 UDP traffic
*/
type Bind interface {
SetMark(value uint32) error
ReceiveIPv6(buff []byte) (int, Endpoint, error)
ReceiveIPv4(buff []byte) (int, Endpoint, error)
Send(buff []byte, end Endpoint) error
Close() error
}
/* An Endpoint maintains the source/destination caching for a peer
*
* dst : the remote address of a peer ("endpoint" in uapi terminology)
* src : the local address from which datagrams originate going to the peer
*/
type Endpoint interface {
ClearSrc() // clears the source address
SrcToString() string // returns the local source address (ip:port)
DstToString() string // returns the destination address (ip:port)
DstToBytes() []byte // used for mac2 cookie calculations
DstIP() net.IP
SrcIP() net.IP
}
func parseEndpoint(s string) (*net.UDPAddr, error) {
// ensure that the host is an IP address
host, _, err := net.SplitHostPort(s)
if err != nil {
return nil, err
}
if ip := net.ParseIP(host); ip == nil {
return nil, errors.New("Failed to parse IP address: " + host)
}
// parse address and port
addr, err := net.ResolveUDPAddr("udp", s)
if err != nil {
return nil, err
}
return addr, err
}
/* Must hold device and net lock
*/
func unsafeCloseBind(device *Device) error {
var err error
netc := &device.net
if netc.bind != nil {
err = netc.bind.Close()
netc.bind = nil
}
return err
}
func (device *Device) BindSetMark(mark uint32) error {
device.net.mutex.Lock()
defer device.net.mutex.Unlock()
// check if modified
if device.net.fwmark == mark {
return nil
}
// update fwmark on existing bind
device.net.fwmark = mark
if device.isUp.Get() && device.net.bind != nil {
if err := device.net.bind.SetMark(mark); err != nil {
return err
}
}
// clear cached source addresses
device.peers.mutex.RLock()
for _, peer := range device.peers.keyMap {
peer.mutex.Lock()
defer peer.mutex.Unlock()
if peer.endpoint != nil {
peer.endpoint.ClearSrc()
}
}
device.peers.mutex.RUnlock()
return nil
}
func (device *Device) BindUpdate() error {
device.net.mutex.Lock()
defer device.net.mutex.Unlock()
// close existing sockets
if err := unsafeCloseBind(device); err != nil {
return err
}
// open new sockets
if device.isUp.Get() {
// bind to new port
var err error
netc := &device.net
netc.bind, netc.port, err = CreateBind(netc.port, device)
if err != nil {
netc.bind = nil
netc.port = 0
return err
}
// set fwmark
if netc.fwmark != 0 {
err = netc.bind.SetMark(netc.fwmark)
if err != nil {
return err
}
}
// clear cached source addresses
device.peers.mutex.RLock()
for _, peer := range device.peers.keyMap {
peer.mutex.Lock()
defer peer.mutex.Unlock()
if peer.endpoint != nil {
peer.endpoint.ClearSrc()
}
}
device.peers.mutex.RUnlock()
// start receiving routines
go device.RoutineReceiveIncoming(ipv4.Version, netc.bind)
go device.RoutineReceiveIncoming(ipv6.Version, netc.bind)
device.log.Debug.Println("UDP bind has been updated")
}
return nil
}
func (device *Device) BindClose() error {
device.net.mutex.Lock()
err := unsafeCloseBind(device)
device.net.mutex.Unlock()
return err
}
|
