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authorSimon Rozman <simon@rozman.si>2020-10-24 22:40:46 +0200
committerJason A. Donenfeld <Jason@zx2c4.com>2020-11-07 15:20:49 +0100
commita3b231b31eb58da7cef097b6633bcc97484b550d (patch)
tree5c65dfe2a84948093d4f75ea4ba2c5ea55c1e2f1 /tun/wintun/ring_windows.go
parent65e03a918274534015ca189bfadc33cbba9e3ec8 (diff)
wintun: ring management moved to wintun.dll
Signed-off-by: Simon Rozman <simon@rozman.si> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Diffstat (limited to 'tun/wintun/ring_windows.go')
-rw-r--r--tun/wintun/ring_windows.go117
1 files changed, 0 insertions, 117 deletions
diff --git a/tun/wintun/ring_windows.go b/tun/wintun/ring_windows.go
deleted file mode 100644
index ed460fb..0000000
--- a/tun/wintun/ring_windows.go
+++ /dev/null
@@ -1,117 +0,0 @@
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
- */
-
-package wintun
-
-import (
- "runtime"
- "unsafe"
-
- "golang.org/x/sys/windows"
-)
-
-const (
- PacketAlignment = 4 // Number of bytes packets are aligned to in rings
- PacketSizeMax = 0xffff // Maximum packet size
- PacketCapacity = 0x800000 // Ring capacity, 8MiB
- PacketTrailingSize = uint32(unsafe.Sizeof(PacketHeader{})) + ((PacketSizeMax + (PacketAlignment - 1)) &^ (PacketAlignment - 1)) - PacketAlignment
- ioctlRegisterRings = (51820 << 16) | (0x970 << 2) | 0 /*METHOD_BUFFERED*/ | (0x3 /*FILE_READ_DATA | FILE_WRITE_DATA*/ << 14)
-)
-
-type PacketHeader struct {
- Size uint32
-}
-
-type Packet struct {
- PacketHeader
- Data [PacketSizeMax]byte
-}
-
-type Ring struct {
- Head uint32
- Tail uint32
- Alertable int32
- Data [PacketCapacity + PacketTrailingSize]byte
-}
-
-type RingDescriptor struct {
- Send, Receive struct {
- Size uint32
- Ring *Ring
- TailMoved windows.Handle
- }
-}
-
-// Wrap returns value modulo ring capacity
-func (rb *Ring) Wrap(value uint32) uint32 {
- return value & (PacketCapacity - 1)
-}
-
-// Aligns a packet size to PacketAlignment
-func PacketAlign(size uint32) uint32 {
- return (size + (PacketAlignment - 1)) &^ (PacketAlignment - 1)
-}
-
-func NewRingDescriptor() (descriptor *RingDescriptor, err error) {
- descriptor = new(RingDescriptor)
- allocatedRegion, err := windows.VirtualAlloc(0, unsafe.Sizeof(Ring{})*2, windows.MEM_COMMIT|windows.MEM_RESERVE, windows.PAGE_READWRITE)
- if err != nil {
- return
- }
- defer func() {
- if err != nil {
- descriptor.free()
- descriptor = nil
- }
- }()
- descriptor.Send.Size = uint32(unsafe.Sizeof(Ring{}))
- descriptor.Send.Ring = (*Ring)(unsafe.Pointer(allocatedRegion))
- descriptor.Send.TailMoved, err = windows.CreateEvent(nil, 0, 0, nil)
- if err != nil {
- return
- }
-
- descriptor.Receive.Size = uint32(unsafe.Sizeof(Ring{}))
- descriptor.Receive.Ring = (*Ring)(unsafe.Pointer(allocatedRegion + unsafe.Sizeof(Ring{})))
- descriptor.Receive.TailMoved, err = windows.CreateEvent(nil, 0, 0, nil)
- if err != nil {
- windows.CloseHandle(descriptor.Send.TailMoved)
- return
- }
- runtime.SetFinalizer(descriptor, func(d *RingDescriptor) { d.free() })
- return
-}
-
-func (descriptor *RingDescriptor) free() {
- if descriptor.Send.Ring != nil {
- windows.VirtualFree(uintptr(unsafe.Pointer(descriptor.Send.Ring)), 0, windows.MEM_RELEASE)
- descriptor.Send.Ring = nil
- descriptor.Receive.Ring = nil
- }
-}
-
-func (descriptor *RingDescriptor) Close() {
- if descriptor.Send.TailMoved != 0 {
- windows.CloseHandle(descriptor.Send.TailMoved)
- descriptor.Send.TailMoved = 0
- }
- if descriptor.Send.TailMoved != 0 {
- windows.CloseHandle(descriptor.Receive.TailMoved)
- descriptor.Receive.TailMoved = 0
- }
-}
-
-func (wintun *Adapter) Register(descriptor *RingDescriptor) (windows.Handle, error) {
- handle, err := wintun.OpenAdapterDeviceObject()
- if err != nil {
- return 0, err
- }
- var bytesReturned uint32
- err = windows.DeviceIoControl(handle, ioctlRegisterRings, (*byte)(unsafe.Pointer(descriptor)), uint32(unsafe.Sizeof(*descriptor)), nil, 0, &bytesReturned, nil)
- if err != nil {
- return 0, err
- }
- return handle, nil
-}