summaryrefslogtreecommitdiffhomepage
path: root/tun/wintun/wintun_windows.go
blob: 14b0260cadc93d29615fb9e99eb1e368ddb17b93 (plain)
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
/* SPDX-License-Identifier: MIT
 *
 * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
 */

package wintun

import (
	"errors"
	"log"
	"runtime"
	"syscall"
	"unsafe"

	"golang.org/x/sys/windows"
)

type loggerLevel int

const (
	logInfo loggerLevel = iota
	logWarn
	logErr
)

const (
	PoolNameMax    = 256
	AdapterNameMax = 128
)

type Pool [PoolNameMax]uint16
type Adapter struct {
	handle uintptr
}

var (
	modwintun = windows.NewLazyDLL("wintun.dll")

	procWintunCreateAdapter           = modwintun.NewProc("WintunCreateAdapter")
	procWintunDeleteAdapter           = modwintun.NewProc("WintunDeleteAdapter")
	procWintunDeletePoolDriver        = modwintun.NewProc("WintunDeletePoolDriver")
	procWintunEnumAdapters            = modwintun.NewProc("WintunEnumAdapters")
	procWintunFreeAdapter             = modwintun.NewProc("WintunFreeAdapter")
	procWintunOpenAdapter             = modwintun.NewProc("WintunOpenAdapter")
	procWintunGetAdapterLUID          = modwintun.NewProc("WintunGetAdapterLUID")
	procWintunGetAdapterName          = modwintun.NewProc("WintunGetAdapterName")
	procWintunGetRunningDriverVersion = modwintun.NewProc("WintunGetRunningDriverVersion")
	procWintunOpenAdapterDeviceObject = modwintun.NewProc("WintunOpenAdapterDeviceObject")
	procWintunSetAdapterName          = modwintun.NewProc("WintunSetAdapterName")
	procWintunSetLogger               = modwintun.NewProc("WintunSetLogger")
)

func init() {
	syscall.Syscall(procWintunSetLogger.Addr(), 1, windows.NewCallback(func(level loggerLevel, msg *uint16) int {
		log.Println("[Wintun]", windows.UTF16PtrToString(msg))
		return 0
	}), 0, 0)
}

func MakePool(poolName string) (pool *Pool, err error) {
	poolName16, err := windows.UTF16FromString(poolName)
	if err != nil {
		return
	}
	if len(poolName16) > PoolNameMax {
		err = errors.New("Pool name too long")
		return
	}
	pool = &Pool{}
	copy(pool[:], poolName16)
	return
}

func (pool *Pool) String() string {
	return windows.UTF16ToString(pool[:])
}

func freeAdapter(wintun *Adapter) {
	syscall.Syscall(procWintunFreeAdapter.Addr(), 1, uintptr(wintun.handle), 0, 0)
}

// OpenAdapter finds a Wintun adapter by its name. This function returns the adapter if found, or
// windows.ERROR_FILE_NOT_FOUND otherwise. If the adapter is found but not a Wintun-class or a
// member of the pool, this function returns windows.ERROR_ALREADY_EXISTS. The adapter must be
// released after use.
func (pool *Pool) OpenAdapter(ifname string) (wintun *Adapter, err error) {
	ifname16, err := windows.UTF16PtrFromString(ifname)
	if err != nil {
		return nil, err
	}
	r0, _, e1 := syscall.Syscall(procWintunOpenAdapter.Addr(), 2, uintptr(unsafe.Pointer(pool)), uintptr(unsafe.Pointer(ifname16)), 0)
	if r0 == 0 {
		err = e1
		return
	}
	wintun = &Adapter{r0}
	runtime.SetFinalizer(wintun, freeAdapter)
	return
}

// CreateAdapter creates a Wintun adapter. ifname is the requested name of the adapter, while
// requestedGUID is the GUID of the created network adapter, which then influences NLA generation
// deterministically. If it is set to nil, the GUID is chosen by the system at random, and hence a
// new NLA entry is created for each new adapter. It is called "requested" GUID because the API it
// uses is completely undocumented, and so there could be minor interesting complications with its
// usage. This function returns the network adapter ID and a flag if reboot is required.
func (pool *Pool) CreateAdapter(ifname string, requestedGUID *windows.GUID) (wintun *Adapter, rebootRequired bool, err error) {
	var ifname16 *uint16
	ifname16, err = windows.UTF16PtrFromString(ifname)
	if err != nil {
		return
	}
	var _p0 uint32
	r0, _, e1 := syscall.Syscall6(procWintunCreateAdapter.Addr(), 4, uintptr(unsafe.Pointer(pool)), uintptr(unsafe.Pointer(ifname16)), uintptr(unsafe.Pointer(requestedGUID)), uintptr(unsafe.Pointer(&_p0)), 0, 0)
	rebootRequired = _p0 != 0
	if r0 == 0 {
		err = e1
		return
	}
	wintun = &Adapter{r0}
	runtime.SetFinalizer(wintun, freeAdapter)
	return
}

// Delete deletes a Wintun adapter. This function succeeds if the adapter was not found. It returns
// a bool indicating whether a reboot is required.
func (wintun *Adapter) Delete(forceCloseSessions bool) (rebootRequired bool, err error) {
	var _p0 uint32
	if forceCloseSessions {
		_p0 = 1
	}
	var _p1 uint32
	r1, _, e1 := syscall.Syscall(procWintunDeleteAdapter.Addr(), 3, uintptr(wintun.handle), uintptr(_p0), uintptr(unsafe.Pointer(&_p1)))
	rebootRequired = _p1 != 0
	if r1 == 0 {
		err = e1
	}
	return
}

// DeleteMatchingAdapters deletes all Wintun adapters, which match
// given criteria, and returns which ones it deleted, whether a reboot
// is required after, and which errors occurred during the process.
func (pool *Pool) DeleteMatchingAdapters(matches func(adapter *Adapter) bool, forceCloseSessions bool) (rebootRequired bool, errors []error) {
	cb := func(handle uintptr, _ uintptr) int {
		adapter := &Adapter{handle}
		if !matches(adapter) {
			return 1
		}
		rebootRequired2, err := adapter.Delete(forceCloseSessions)
		if err != nil {
			errors = append(errors, err)
			return 1
		}
		rebootRequired = rebootRequired || rebootRequired2
		return 1
	}
	r1, _, e1 := syscall.Syscall(procWintunEnumAdapters.Addr(), 3, uintptr(unsafe.Pointer(pool)), uintptr(windows.NewCallback(cb)), 0)
	if r1 == 0 {
		errors = append(errors, e1)
	}
	return
}

// Name returns the name of the Wintun adapter.
func (wintun *Adapter) Name() (ifname string, err error) {
	var ifname16 [AdapterNameMax]uint16
	r1, _, e1 := syscall.Syscall(procWintunGetAdapterName.Addr(), 2, uintptr(wintun.handle), uintptr(unsafe.Pointer(&ifname16[0])), 0)
	if r1 == 0 {
		err = e1
		return
	}
	ifname = windows.UTF16ToString(ifname16[:])
	return
}

// DeleteDriver deletes all Wintun adapters in a pool and if there are no more adapters in any other
// pools, also removes Wintun from the driver store, usually called by uninstallers.
func (pool *Pool) DeleteDriver() (rebootRequired bool, err error) {
	var _p0 uint32
	r1, _, e1 := syscall.Syscall(procWintunDeletePoolDriver.Addr(), 2, uintptr(unsafe.Pointer(pool)), uintptr(unsafe.Pointer(&_p0)), 0)
	rebootRequired = _p0 != 0
	if r1 == 0 {
		err = e1
	}
	return

}

// SetName sets name of the Wintun adapter.
func (wintun *Adapter) SetName(ifname string) (err error) {
	ifname16, err := windows.UTF16FromString(ifname)
	if err != nil {
		return err
	}
	r1, _, e1 := syscall.Syscall(procWintunSetAdapterName.Addr(), 2, uintptr(wintun.handle), uintptr(unsafe.Pointer(&ifname16[0])), 0)
	if r1 == 0 {
		err = e1
	}
	return
}

// RunningVersion returns the version of the running Wintun driver.
func RunningVersion() (version uint32, err error) {
	r0, _, e1 := syscall.Syscall(procWintunGetRunningDriverVersion.Addr(), 0, 0, 0, 0)
	version = uint32(r0)
	if version == 0 {
		err = e1
	}
	return
}

// handle returns a handle to the adapter device object. Release handle with windows.CloseHandle
func (wintun *Adapter) OpenAdapterDeviceObject() (handle windows.Handle, err error) {
	r0, _, e1 := syscall.Syscall(procWintunOpenAdapterDeviceObject.Addr(), 1, uintptr(wintun.handle), 0, 0)
	handle = windows.Handle(r0)
	if handle == windows.InvalidHandle {
		err = e1
	}
	return
}

// LUID returns the LUID of the adapter.
func (wintun *Adapter) LUID() (luid uint64) {
	syscall.Syscall(procWintunGetAdapterLUID.Addr(), 2, uintptr(wintun.handle), uintptr(unsafe.Pointer(&luid)), 0)
	return
}