feat: add param DoublePacket

config/cfg.go

@@ -33,6 +33,7 @@ type Peer struct {
 	QuerySeconds     int64    `yaml:"QuerySeconds"`
 	AllowTrans       bool     `yaml:"AllowTrans"`
 	UseZstd          bool     `yaml:"UseZstd"`
+	DoublePacket     bool     `yaml:"DoublePacket"`
 	MTU              int64    `yaml:"MTU"`
 	MTURandomRange   int64    `yaml:"MTURandomRange"`
 }

gold/head/packet.go

@@ -155,14 +155,15 @@ func (p *Packet) Unmarshal(data []byte) (complete bool, err error) {
 	return
 }
 
+// DecreaseAndGetTTL TTL 自减后返回
+func (p *Packet) DecreaseAndGetTTL() uint8 {
+	p.TTL--
+	return p.TTL
+}
+
 // Marshal 将自身数据编码为 []byte
 // offset 必须为 8 的倍数，表示偏移的 8 位
 func (p *Packet) Marshal(src net.IP, teatype uint8, additional uint16, datasz uint32, offset uint16, dontfrag, hasmore bool) ([]byte, func()) {
-	p.TTL--
-	if p.TTL == 0 {
-		return nil, nil
-	}
-
 	if src != nil {
 		p.Src = src
 		p.idxdatsz = (uint32(teatype) << 27) | (uint32(additional&0x07ff) << 16) | datasz&0xffff
@@ -175,14 +176,13 @@ func (p *Packet) Marshal(src net.IP, teatype uint8, additional uint16, datasz ui
 	if hasmore {
 		offset |= 0x2000
 	}
-	p.Flags = PacketFlags(offset)
 
 	return helper.OpenWriterF(func(w *helper.Writer) {
 		w.WriteUInt32(p.idxdatsz)
 		w.WriteUInt16((uint16(p.TTL) << 8) | uint16(p.Proto))
 		w.WriteUInt16(p.SrcPort)
 		w.WriteUInt16(p.DstPort)
-		w.WriteUInt16(uint16(p.Flags))
+		w.WriteUInt16(uint16(PacketFlags(offset)))
 		w.Write(p.Src.To4())
 		w.Write(p.Dst.To4())
 		w.Write(p.Hash[:])

gold/link/crypto.go

@@ -125,25 +125,30 @@ func (m *Me) xorenc(data []byte) []byte {
 	batchsz := len(data) / 8
 	remain := len(data) % 8
 	sum := m.mask
+	newdat := helper.MakeBytes(len(data) + 8)
+	_, _ = rand.Read(newdat[:8])
 	if remain > 0 {
 		var buf [8]byte
 		p := batchsz * 8
 		copy(buf[:], data[p:])
 		sum ^= binary.LittleEndian.Uint64(buf[:])
 		binary.LittleEndian.PutUint64(buf[:], sum)
-		copy(data[p:], buf[:])
+		copy(newdat[8+p:], buf[:])
 	}
 	for i := batchsz - 1; i >= 0; i-- {
 		a := i * 8
 		b := (i + 1) * 8
 		sum ^= binary.LittleEndian.Uint64(data[a:b])
-		binary.LittleEndian.PutUint64(data[a:b], sum)
+		binary.LittleEndian.PutUint64(newdat[a+8:b+8], sum)
 	}
-	return data
+	return newdat
 }
 
 // xordec 按 8 字节, 以初始 m.mask 循环异或解码 data
 func (m *Me) xordec(data []byte) []byte {
+	if len(data) <= 8 {
+		return nil
+	}
 	batchsz := len(data) / 8
 	remain := len(data) % 8
 	this := uint64(0)
@@ -173,5 +178,5 @@ func (m *Me) xordec(data []byte) []byte {
 	} else {
 		binary.LittleEndian.PutUint64(data[len(data)-8:], next^m.mask)
 	}
-	return data
+	return data[8:]
 }

gold/link/link.go

@@ -44,6 +44,8 @@ type Link struct {
 	allowtrans bool
 	// 是否对数据进行 zstd 压缩
 	usezstd bool
+	// 是否采用双倍发包对抗强丢包
+	doublepacket bool
 	// udp 数据包的最大大小
 	mtu uint16
 	// 随机放缩 mtu 范围 (只减不增)

gold/link/peer.go

@@ -22,6 +22,7 @@ type PeerConfig struct {
 	MTURandomRange          uint16
 	AllowTrans, NoPipe      bool
 	UseZstd                 bool
+	DoublePacket            bool
 }
 
 // AddPeer 添加一个 peer
@@ -41,6 +42,7 @@ func (m *Me) AddPeer(cfg *PeerConfig) (l *Link) {
 		rawep:          cfg.EndPoint,
 		allowtrans:     cfg.AllowTrans,
 		usezstd:        cfg.UseZstd,
+		doublepacket:   cfg.DoublePacket,
 		me:             m,
 		mtu:            cfg.MTU,
 		mturandomrange: cfg.MTURandomRange,

gold/link/recv.go

@@ -34,6 +34,7 @@ func (m *Me) wait(data []byte) *head.Packet {
 		return nil
 	}
 	crc := binary.LittleEndian.Uint64(data[52:head.PacketHeadLen])
+	logrus.Debugf("[recv] packet crc %016x", crc)
 	if m.recved.Get(crc) { // 是重放攻击
 		logrus.Warnln("[recv] ignore duplicated crc packet", strconv.FormatUint(crc, 16))
 		return nil
@@ -78,5 +79,6 @@ func (m *Me) wait(data []byte) *head.Packet {
 		return nil
 	}
 	m.recving.Set(hsh, h)
+	m.recved.Set(crc, true)
 	return nil
 }

gold/link/send.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"io"
 	"math/rand"
+	"time"
 
 	"github.com/fumiama/WireGold/gold/head"
 	"github.com/fumiama/WireGold/helper"
@@ -88,8 +89,23 @@ func (l *Link) encrypt(p *head.Packet, sndcnt uint16, teatype uint8) {
 	logrus.Debugln("[send] data len after xchacha20:", p.BodyLen(), "addt:", sndcnt)
 }
 
-// write 向 peer 发一个包
+// write 向 peer 发包
 func (l *Link) write(p *head.Packet, teatype uint8, additional uint16, datasz uint32, offset uint16, istransfer, hasmore bool) (int, error) {
+	if p.DecreaseAndGetTTL() <= 0 {
+		return 0, ErrTTL
+	}
+	if l.doublepacket {
+		cpp := p.Copy()
+		time.AfterFunc(time.Millisecond*(10+time.Duration(rand.Intn(10))), func() {
+			defer cpp.Put()
+			_, _ = l.writeonce(cpp, teatype, additional, datasz, offset, istransfer, hasmore)
+		})
+	}
+	return l.writeonce(p, teatype, additional, datasz, offset, istransfer, hasmore)
+}
+
+// write 向 peer 发一个包
+func (l *Link) writeonce(p *head.Packet, teatype uint8, additional uint16, datasz uint32, offset uint16, istransfer, hasmore bool) (int, error) {
 	peerep := l.endpoint
 	if peerep == nil {
 		return 0, errors.New("nil endpoint of " + p.Dst.String())
@@ -103,9 +119,6 @@ func (l *Link) write(p *head.Packet, teatype uint8, additional uint16, datasz ui
 	} else {
 		d, cl = p.Marshal(l.me.me, teatype, additional, datasz, offset, false, hasmore)
 	}
-	if d == nil {
-		return 0, ErrTTL
-	}
 	defer cl()
 
 	bound := 64
@@ -118,5 +131,6 @@ func (l *Link) write(p *head.Packet, teatype uint8, additional uint16, datasz ui
 	logrus.Debugln("[send] data bytes", hex.EncodeToString(d[:bound]), endl)
 	d = l.me.xorenc(d)
 	logrus.Debugln("[send] data xored", hex.EncodeToString(d[:bound]), endl)
+	defer helper.PutBytes(d)
 	return l.me.conn.WriteToPeer(d, peerep)
 }

upper/services/tunnel/tunnel_test.go

@@ -81,6 +81,7 @@ func testTunnel(t *testing.T, nw string, isplain bool, pshk *[32]byte, mtu uint1
 		MTU:            mtu,
 		MTURandomRange: mtu / 2,
 		UseZstd:        true,
+		DoublePacket:   true,
 	})
 	p.AddPeer(&link.PeerConfig{
 		PeerIP:         "192.168.1.2",

upper/services/wg/wg.go

@@ -154,6 +154,7 @@ func (wg *WG) init(srcport, dstport uint16) {
 			AllowTrans:     peer.AllowTrans,
 			NoPipe:         true,
 			UseZstd:        peer.UseZstd,
+			DoublePacket:   peer.DoublePacket,
 		})
 	}
 }