From a3b231b31eb58da7cef097b6633bcc97484b550d Mon Sep 17 00:00:00 2001
From: Simon Rozman <simon@rozman.si>
Date: Sat, 24 Oct 2020 22:40:46 +0200
Subject: wintun: ring management moved to wintun.dll

Signed-off-by: Simon Rozman <simon@rozman.si>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 tun/wintun/ring_windows.go | 117 ---------------------------------------------
 1 file changed, 117 deletions(-)
 delete mode 100644 tun/wintun/ring_windows.go

(limited to 'tun/wintun/ring_windows.go')

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
-}
-- 
cgit v1.2.3