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
|
/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2017-2021 WireGuard LLC. All Rights Reserved.
*/
package wintun
import (
"syscall"
"unsafe"
"golang.org/x/sys/windows"
)
type Session struct {
handle uintptr
}
const (
PacketSizeMax = 0xffff // Maximum packet size
RingCapacityMin = 0x20000 // Minimum ring capacity (128 kiB)
RingCapacityMax = 0x4000000 // Maximum ring capacity (64 MiB)
)
// Packet with data
type Packet struct {
Next *Packet // Pointer to next packet in queue
Size uint32 // Size of packet (max WINTUN_MAX_IP_PACKET_SIZE)
Data *[PacketSizeMax]byte // Pointer to layer 3 IPv4 or IPv6 packet
}
var (
procWintunAllocateSendPacket = modwintun.NewProc("WintunAllocateSendPacket")
procWintunEndSession = modwintun.NewProc("WintunEndSession")
procWintunGetReadWaitEvent = modwintun.NewProc("WintunGetReadWaitEvent")
procWintunReceivePacket = modwintun.NewProc("WintunReceivePacket")
procWintunReleaseReceivePacket = modwintun.NewProc("WintunReleaseReceivePacket")
procWintunSendPacket = modwintun.NewProc("WintunSendPacket")
procWintunStartSession = modwintun.NewProc("WintunStartSession")
)
func (wintun *Adapter) StartSession(capacity uint32) (session Session, err error) {
r0, _, e1 := syscall.Syscall(procWintunStartSession.Addr(), 2, uintptr(wintun.handle), uintptr(capacity), 0)
if r0 == 0 {
err = e1
} else {
session = Session{r0}
}
return
}
func (session Session) End() {
syscall.Syscall(procWintunEndSession.Addr(), 1, session.handle, 0, 0)
session.handle = 0
}
func (session Session) ReadWaitEvent() (handle windows.Handle) {
r0, _, _ := syscall.Syscall(procWintunGetReadWaitEvent.Addr(), 1, session.handle, 0, 0)
handle = windows.Handle(r0)
return
}
func (session Session) ReceivePacket() (packet []byte, err error) {
var packetSize uint32
r0, _, e1 := syscall.Syscall(procWintunReceivePacket.Addr(), 2, session.handle, uintptr(unsafe.Pointer(&packetSize)), 0)
if r0 == 0 {
err = e1
return
}
unsafeSlice(unsafe.Pointer(&packet), unsafe.Pointer(r0), int(packetSize))
return
}
func (session Session) ReleaseReceivePacket(packet []byte) {
syscall.Syscall(procWintunReleaseReceivePacket.Addr(), 2, session.handle, uintptr(unsafe.Pointer(&packet[0])), 0)
}
func (session Session) AllocateSendPacket(packetSize int) (packet []byte, err error) {
r0, _, e1 := syscall.Syscall(procWintunAllocateSendPacket.Addr(), 2, session.handle, uintptr(packetSize), 0)
if r0 == 0 {
err = e1
return
}
unsafeSlice(unsafe.Pointer(&packet), unsafe.Pointer(r0), int(packetSize))
return
}
func (session Session) SendPacket(packet []byte) {
syscall.Syscall(procWintunSendPacket.Addr(), 2, session.handle, uintptr(unsafe.Pointer(&packet[0])), 0)
}
// unsafeSlice updates the slice slicePtr to be a slice
// referencing the provided data with its length & capacity set to
// lenCap.
//
// TODO: when Go 1.16 or Go 1.17 is the minimum supported version,
// update callers to use unsafe.Slice instead of this.
func unsafeSlice(slicePtr, data unsafe.Pointer, lenCap int) {
type sliceHeader struct {
Data unsafe.Pointer
Len int
Cap int
}
h := (*sliceHeader)(slicePtr)
h.Data = data
h.Len = lenCap
h.Cap = lenCap
}
|
