forked from WireGuard/wireguard-go
-
Notifications
You must be signed in to change notification settings - Fork 51
/
sticky_linux.go
224 lines (208 loc) · 5.51 KB
/
sticky_linux.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
/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
*
* This implements userspace semantics of "sticky sockets", modeled after
* WireGuard's kernelspace implementation. This is more or less a straight port
* of the sticky-sockets.c example code:
* https://git.zx2c4.com/WireGuard/tree/contrib/examples/sticky-sockets/sticky-sockets.c
*
* Currently there is no way to achieve this within the net package:
* See e.g. https://github.com/golang/go/issues/17930
* So this code is remains platform dependent.
*/
package device
import (
"sync"
"unsafe"
"golang.org/x/sys/unix"
"github.com/amnezia-vpn/amneziawg-go/conn"
"github.com/amnezia-vpn/amneziawg-go/rwcancel"
)
func (device *Device) startRouteListener(bind conn.Bind) (*rwcancel.RWCancel, error) {
if !conn.StdNetSupportsStickySockets {
return nil, nil
}
if _, ok := bind.(*conn.StdNetBind); !ok {
return nil, nil
}
netlinkSock, err := createNetlinkRouteSocket()
if err != nil {
return nil, err
}
netlinkCancel, err := rwcancel.NewRWCancel(netlinkSock)
if err != nil {
unix.Close(netlinkSock)
return nil, err
}
go device.routineRouteListener(bind, netlinkSock, netlinkCancel)
return netlinkCancel, nil
}
func (device *Device) routineRouteListener(bind conn.Bind, netlinkSock int, netlinkCancel *rwcancel.RWCancel) {
type peerEndpointPtr struct {
peer *Peer
endpoint *conn.Endpoint
}
var reqPeer map[uint32]peerEndpointPtr
var reqPeerLock sync.Mutex
defer netlinkCancel.Close()
defer unix.Close(netlinkSock)
for msg := make([]byte, 1<<16); ; {
var err error
var msgn int
for {
msgn, _, _, _, err = unix.Recvmsg(netlinkSock, msg[:], nil, 0)
if err == nil || !rwcancel.RetryAfterError(err) {
break
}
if !netlinkCancel.ReadyRead() {
return
}
}
if err != nil {
return
}
for remain := msg[:msgn]; len(remain) >= unix.SizeofNlMsghdr; {
hdr := *(*unix.NlMsghdr)(unsafe.Pointer(&remain[0]))
if uint(hdr.Len) > uint(len(remain)) {
break
}
switch hdr.Type {
case unix.RTM_NEWROUTE, unix.RTM_DELROUTE:
if hdr.Seq <= MaxPeers && hdr.Seq > 0 {
if uint(len(remain)) < uint(hdr.Len) {
break
}
if hdr.Len > unix.SizeofNlMsghdr+unix.SizeofRtMsg {
attr := remain[unix.SizeofNlMsghdr+unix.SizeofRtMsg:]
for {
if uint(len(attr)) < uint(unix.SizeofRtAttr) {
break
}
attrhdr := *(*unix.RtAttr)(unsafe.Pointer(&attr[0]))
if attrhdr.Len < unix.SizeofRtAttr || uint(len(attr)) < uint(attrhdr.Len) {
break
}
if attrhdr.Type == unix.RTA_OIF && attrhdr.Len == unix.SizeofRtAttr+4 {
ifidx := *(*uint32)(unsafe.Pointer(&attr[unix.SizeofRtAttr]))
reqPeerLock.Lock()
if reqPeer == nil {
reqPeerLock.Unlock()
break
}
pePtr, ok := reqPeer[hdr.Seq]
reqPeerLock.Unlock()
if !ok {
break
}
pePtr.peer.endpoint.Lock()
if &pePtr.peer.endpoint.val != pePtr.endpoint {
pePtr.peer.endpoint.Unlock()
break
}
if uint32(pePtr.peer.endpoint.val.(*conn.StdNetEndpoint).SrcIfidx()) == ifidx {
pePtr.peer.endpoint.Unlock()
break
}
pePtr.peer.endpoint.clearSrcOnTx = true
pePtr.peer.endpoint.Unlock()
}
attr = attr[attrhdr.Len:]
}
}
break
}
reqPeerLock.Lock()
reqPeer = make(map[uint32]peerEndpointPtr)
reqPeerLock.Unlock()
go func() {
device.peers.RLock()
i := uint32(1)
for _, peer := range device.peers.keyMap {
peer.endpoint.Lock()
if peer.endpoint.val == nil {
peer.endpoint.Unlock()
continue
}
nativeEP, _ := peer.endpoint.val.(*conn.StdNetEndpoint)
if nativeEP == nil {
peer.endpoint.Unlock()
continue
}
if nativeEP.DstIP().Is6() || nativeEP.SrcIfidx() == 0 {
peer.endpoint.Unlock()
break
}
nlmsg := struct {
hdr unix.NlMsghdr
msg unix.RtMsg
dsthdr unix.RtAttr
dst [4]byte
srchdr unix.RtAttr
src [4]byte
markhdr unix.RtAttr
mark uint32
}{
unix.NlMsghdr{
Type: uint16(unix.RTM_GETROUTE),
Flags: unix.NLM_F_REQUEST,
Seq: i,
},
unix.RtMsg{
Family: unix.AF_INET,
Dst_len: 32,
Src_len: 32,
},
unix.RtAttr{
Len: 8,
Type: unix.RTA_DST,
},
nativeEP.DstIP().As4(),
unix.RtAttr{
Len: 8,
Type: unix.RTA_SRC,
},
nativeEP.SrcIP().As4(),
unix.RtAttr{
Len: 8,
Type: unix.RTA_MARK,
},
device.net.fwmark,
}
nlmsg.hdr.Len = uint32(unsafe.Sizeof(nlmsg))
reqPeerLock.Lock()
reqPeer[i] = peerEndpointPtr{
peer: peer,
endpoint: &peer.endpoint.val,
}
reqPeerLock.Unlock()
peer.endpoint.Unlock()
i++
_, err := netlinkCancel.Write((*[unsafe.Sizeof(nlmsg)]byte)(unsafe.Pointer(&nlmsg))[:])
if err != nil {
break
}
}
device.peers.RUnlock()
}()
}
remain = remain[hdr.Len:]
}
}
}
func createNetlinkRouteSocket() (int, error) {
sock, err := unix.Socket(unix.AF_NETLINK, unix.SOCK_RAW|unix.SOCK_CLOEXEC, unix.NETLINK_ROUTE)
if err != nil {
return -1, err
}
saddr := &unix.SockaddrNetlink{
Family: unix.AF_NETLINK,
Groups: unix.RTMGRP_IPV4_ROUTE,
}
err = unix.Bind(sock, saddr)
if err != nil {
unix.Close(sock)
return -1, err
}
return sock, nil
}