add locking for stop crash

.github/workflows/gofmt.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
 
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v4
 
     - uses: actions/setup-go@v6
       with:

.github/workflows/release.yml

@@ -10,7 +10,7 @@ jobs:
     name: Build Linux/BSD All
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v4
 
       - uses: actions/setup-go@v6
         with:
@@ -24,7 +24,7 @@ jobs:
           mv build/*.tar.gz release
 
       - name: Upload artifacts
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v4
         with:
           name: linux-latest
           path: release
@@ -33,7 +33,7 @@ jobs:
     name: Build Windows
     runs-on: windows-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v4
 
       - uses: actions/setup-go@v6
         with:
@@ -55,7 +55,7 @@ jobs:
           mv dist\windows\wintun build\dist\windows\
 
       - name: Upload artifacts
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v4
         with:
           name: windows-latest
           path: build
@@ -66,7 +66,7 @@ jobs:
       HAS_SIGNING_CREDS: ${{ secrets.AC_USERNAME != '' }}
     runs-on: macos-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v4
 
       - uses: actions/setup-go@v6
         with:
@@ -104,7 +104,7 @@ jobs:
           fi
 
       - name: Upload artifacts
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v4
         with:
           name: darwin-latest
           path: ./release/*
@@ -124,11 +124,11 @@ jobs:
       # be overwritten
       - name: Checkout code
         if: ${{ env.HAS_DOCKER_CREDS == 'true' }}
-        uses: actions/checkout@v5
+        uses: actions/checkout@v4
 
       - name: Download artifacts
         if: ${{ env.HAS_DOCKER_CREDS == 'true' }}
-        uses: actions/download-artifact@v6
+        uses: actions/download-artifact@v4
         with:
           name: linux-latest
           path: artifacts
@@ -160,10 +160,10 @@ jobs:
     needs: [build-linux, build-darwin, build-windows]
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v4
 
       - name: Download artifacts
-        uses: actions/download-artifact@v6
+        uses: actions/download-artifact@v4
         with:
           path: artifacts
 

.github/workflows/smoke-extra.yml

@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
 
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v4
 
     - uses: actions/setup-go@v6
       with:

.github/workflows/smoke.yml

@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
 
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v4
 
     - uses: actions/setup-go@v6
       with:

.github/workflows/test.yml

@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
 
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v4
 
     - uses: actions/setup-go@v6
       with:
@@ -32,7 +32,7 @@ jobs:
       run: make vet
 
     - name: golangci-lint
-      uses: golangci/golangci-lint-action@v9
+      uses: golangci/golangci-lint-action@v8
       with:
         version: v2.5
 
@@ -45,7 +45,7 @@ jobs:
     - name: Build test mobile
       run: make build-test-mobile
 
-    - uses: actions/upload-artifact@v5
+    - uses: actions/upload-artifact@v4
       with:
         name: e2e packet flow linux-latest
         path: e2e/mermaid/linux-latest
@@ -56,7 +56,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
 
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v4
 
     - uses: actions/setup-go@v6
       with:
@@ -77,7 +77,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
 
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v4
 
     - uses: actions/setup-go@v6
       with:
@@ -98,7 +98,7 @@ jobs:
         os: [windows-latest, macos-latest]
     steps:
 
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v4
 
     - uses: actions/setup-go@v6
       with:
@@ -115,7 +115,7 @@ jobs:
       run: make vet
 
     - name: golangci-lint
-      uses: golangci/golangci-lint-action@v9
+      uses: golangci/golangci-lint-action@v8
       with:
         version: v2.5
 
@@ -125,7 +125,7 @@ jobs:
     - name: End 2 end
       run: make e2evv
 
-    - uses: actions/upload-artifact@v5
+    - uses: actions/upload-artifact@v4
       with:
         name: e2e packet flow ${{ matrix.os }}
         path: e2e/mermaid/${{ matrix.os }}

batch_pipeline.go

@@ -0,0 +1,164 @@
+package nebula
+
+import (
+	"net/netip"
+
+	"github.com/slackhq/nebula/overlay"
+	"github.com/slackhq/nebula/udp"
+)
+
+// batchPipelines tracks whether the inside device can operate on packet batches
+// and, if so, holds the shared packet pool sized for the virtio headroom and
+// payload limits advertised by the device. It also owns the fan-in/fan-out
+// queues between the TUN readers, encrypt/decrypt workers, and the UDP writers.
+type batchPipelines struct {
+	enabled    bool
+	inside     overlay.BatchCapableDevice
+	headroom   int
+	payloadCap int
+	pool       *overlay.PacketPool
+	batchSize  int
+	routines   int
+	rxQueues   []chan *overlay.Packet
+	txQueues   []chan queuedDatagram
+	tunQueues  []chan *overlay.Packet
+}
+
+type queuedDatagram struct {
+	packet *overlay.Packet
+	addr   netip.AddrPort
+}
+
+func (bp *batchPipelines) init(device overlay.Device, routines int, queueDepth int, maxSegments int) {
+	if device == nil || routines <= 0 {
+		return
+	}
+	bcap, ok := device.(overlay.BatchCapableDevice)
+	if !ok {
+		return
+	}
+	headroom := bcap.BatchHeadroom()
+	payload := bcap.BatchPayloadCap()
+	if maxSegments < 1 {
+		maxSegments = 1
+	}
+	requiredPayload := udp.MTU * maxSegments
+	if payload < requiredPayload {
+		payload = requiredPayload
+	}
+	batchSize := bcap.BatchSize()
+	if headroom <= 0 || payload <= 0 || batchSize <= 0 {
+		return
+	}
+	bp.enabled = true
+	bp.inside = bcap
+	bp.headroom = headroom
+	bp.payloadCap = payload
+	bp.batchSize = batchSize
+	bp.routines = routines
+	bp.pool = overlay.NewPacketPool(headroom, payload)
+	queueCap := batchSize * defaultBatchQueueDepthFactor
+	if queueDepth > 0 {
+		queueCap = queueDepth
+	}
+	if queueCap < batchSize {
+		queueCap = batchSize
+	}
+	bp.rxQueues = make([]chan *overlay.Packet, routines)
+	bp.txQueues = make([]chan queuedDatagram, routines)
+	bp.tunQueues = make([]chan *overlay.Packet, routines)
+	for i := 0; i < routines; i++ {
+		bp.rxQueues[i] = make(chan *overlay.Packet, queueCap)
+		bp.txQueues[i] = make(chan queuedDatagram, queueCap)
+		bp.tunQueues[i] = make(chan *overlay.Packet, queueCap)
+	}
+}
+
+func (bp *batchPipelines) Pool() *overlay.PacketPool {
+	if bp == nil || !bp.enabled {
+		return nil
+	}
+	return bp.pool
+}
+
+func (bp *batchPipelines) Enabled() bool {
+	return bp != nil && bp.enabled
+}
+
+func (bp *batchPipelines) batchSizeHint() int {
+	if bp == nil || bp.batchSize <= 0 {
+		return 1
+	}
+	return bp.batchSize
+}
+
+func (bp *batchPipelines) rxQueue(i int) chan *overlay.Packet {
+	if bp == nil || !bp.enabled || i < 0 || i >= len(bp.rxQueues) {
+		return nil
+	}
+	return bp.rxQueues[i]
+}
+
+func (bp *batchPipelines) txQueue(i int) chan queuedDatagram {
+	if bp == nil || !bp.enabled || i < 0 || i >= len(bp.txQueues) {
+		return nil
+	}
+	return bp.txQueues[i]
+}
+
+func (bp *batchPipelines) tunQueue(i int) chan *overlay.Packet {
+	if bp == nil || !bp.enabled || i < 0 || i >= len(bp.tunQueues) {
+		return nil
+	}
+	return bp.tunQueues[i]
+}
+
+func (bp *batchPipelines) txQueueLen(i int) int {
+	q := bp.txQueue(i)
+	if q == nil {
+		return 0
+	}
+	return len(q)
+}
+
+func (bp *batchPipelines) tunQueueLen(i int) int {
+	q := bp.tunQueue(i)
+	if q == nil {
+		return 0
+	}
+	return len(q)
+}
+
+func (bp *batchPipelines) enqueueRx(i int, pkt *overlay.Packet) bool {
+	q := bp.rxQueue(i)
+	if q == nil {
+		return false
+	}
+	q <- pkt
+	return true
+}
+
+func (bp *batchPipelines) enqueueTx(i int, pkt *overlay.Packet, addr netip.AddrPort) bool {
+	q := bp.txQueue(i)
+	if q == nil {
+		return false
+	}
+	q <- queuedDatagram{packet: pkt, addr: addr}
+	return true
+}
+
+func (bp *batchPipelines) enqueueTun(i int, pkt *overlay.Packet) bool {
+	q := bp.tunQueue(i)
+	if q == nil {
+		return false
+	}
+	q <- pkt
+	return true
+}
+
+func (bp *batchPipelines) newPacket() *overlay.Packet {
+	if bp == nil || !bp.enabled || bp.pool == nil {
+		return nil
+	}
+	return bp.pool.Get()
+}

bits.go

@@ -9,13 +9,14 @@ type Bits struct {
 	length             uint64
 	current            uint64
 	bits               []bool
+	firstSeen          bool
 	lostCounter        metrics.Counter
 	dupeCounter        metrics.Counter
 	outOfWindowCounter metrics.Counter
 }
 
 func NewBits(bits uint64) *Bits {
-	b := &Bits{
+	return &Bits{
 		length:             bits,
 		bits:               make([]bool, bits, bits),
 		current:            0,
@@ -23,37 +24,34 @@ func NewBits(bits uint64) *Bits {
 		dupeCounter:        metrics.GetOrRegisterCounter("network.packets.duplicate", nil),
 		outOfWindowCounter: metrics.GetOrRegisterCounter("network.packets.out_of_window", nil),
 	}
-
-	// There is no counter value 0, mark it to avoid counting a lost packet later.
-	b.bits[0] = true
-	b.current = 0
-	return b
 }
 
-func (b *Bits) Check(l *logrus.Logger, i uint64) bool {
+func (b *Bits) Check(l logrus.FieldLogger, i uint64) bool {
 	// If i is the next number, return true.
-	if i > b.current {
+	if i > b.current || (i == 0 && b.firstSeen == false && b.current < b.length) {
 		return true
 	}
 
-	// If i is within the window, check if it's been set already.
+	// If i is within the window, check if it's been set already. The first window will fail this check
-	if i > b.current-b.length || i < b.length && b.current < b.length {
+	if i > b.current-b.length {
+		return !b.bits[i%b.length]
+	}
+
+	// If i is within the first window
+	if i < b.length {
 		return !b.bits[i%b.length]
 	}
 
 	// Not within the window
-	if l.Level >= logrus.DebugLevel {
+	l.Debugf("rejected a packet (top) %d %d\n", b.current, i)
-		l.Debugf("rejected a packet (top) %d %d\n", b.current, i)
-	}
 	return false
 }
 
 func (b *Bits) Update(l *logrus.Logger, i uint64) bool {
 	// If i is the next number, return true and update current.
 	if i == b.current+1 {
-		// Check if the oldest bit was lost since we are shifting the window by 1 and occupying it with this counter
+		// Report missed packets, we can only understand what was missed after the first window has been gone through
-		// The very first window can only be tracked as lost once we are on the 2nd window or greater
+		if i > b.length && b.bits[i%b.length] == false {
-		if b.bits[i%b.length] == false && i > b.length {
 			b.lostCounter.Inc(1)
 		}
 		b.bits[i%b.length] = true
@@ -61,32 +59,61 @@ func (b *Bits) Update(l *logrus.Logger, i uint64) bool {
 		return true
 	}
 
-	// If i is a jump, adjust the window, record lost, update current, and return true
+	// If i packet is greater than current but less than the maximum length of our bitmap,
-	if i > b.current {
+	// flip everything in between to false and move ahead.
-		lost := int64(0)
+	if i > b.current && i < b.current+b.length {
-		// Zero out the bits between the current and the new counter value, limited by the window size,
+		// In between current and i need to be zero'd to allow those packets to come in later
-		// since the window is shifting
+		for n := b.current + 1; n < i; n++ {
-		for n := b.current + 1; n <= min(i, b.current+b.length); n++ {
-			if b.bits[n%b.length] == false && n > b.length {
-				lost++
-			}
 			b.bits[n%b.length] = false
 		}
 
-		// Only record any skipped packets as a result of the window moving further than the window length
+		b.bits[i%b.length] = true
-		// Any loss within the new window will be accounted for in future calls
+		b.current = i
-		lost += max(0, int64(i-b.current-b.length))
+		//l.Debugf("missed %d packets between %d and %d\n", i-b.current, i, b.current)
+		return true
+	}
+
+	// If i is greater than the delta between current and the total length of our bitmap,
+	// just flip everything in the map and move ahead.
+	if i >= b.current+b.length {
+		// The current window loss will be accounted for later, only record the jump as loss up until then
+		lost := maxInt64(0, int64(i-b.current-b.length))
+		//TODO: explain this
+		if b.current == 0 {
+			lost++
+		}
+
+		for n := range b.bits {
+			// Don't want to count the first window as a loss
+			//TODO: this is likely wrong, we are wanting to track only the bit slots that we aren't going to track anymore and this is marking everything as missed
+			//if b.bits[n] == false {
+			//	lost++
+			//}
+			b.bits[n] = false
+		}
+
 		b.lostCounter.Inc(lost)
 
+		if l.Level >= logrus.DebugLevel {
+			l.WithField("receiveWindow", m{"accepted": true, "currentCounter": b.current, "incomingCounter": i, "reason": "window shifting"}).
+				Debug("Receive window")
+		}
 		b.bits[i%b.length] = true
 		b.current = i
 		return true
 	}
 
-	// If i is within the current window but below the current counter,
+	// Allow for the 0 packet to come in within the first window
-	// Check to see if it's a duplicate
+	if i == 0 && b.firstSeen == false && b.current < b.length {
-	if i > b.current-b.length || i < b.length && b.current < b.length {
+		b.firstSeen = true
-		if b.current == i || b.bits[i%b.length] == true {
+		b.bits[i%b.length] = true
+		return true
+	}
+
+	// If i is within the window of current minus length (the total pat window size),
+	// allow it and flip to true but to NOT change current. We also have to account for the first window
+	if ((b.current >= b.length && i > b.current-b.length) || (b.current < b.length && i < b.length)) && i <= b.current {
+		if b.current == i {
 			if l.Level >= logrus.DebugLevel {
 				l.WithField("receiveWindow", m{"accepted": false, "currentCounter": b.current, "incomingCounter": i, "reason": "duplicate"}).
 					Debug("Receive window")
@@ -95,8 +122,18 @@ func (b *Bits) Update(l *logrus.Logger, i uint64) bool {
 			return false
 		}
 
+		if b.bits[i%b.length] == true {
+			if l.Level >= logrus.DebugLevel {
+				l.WithField("receiveWindow", m{"accepted": false, "currentCounter": b.current, "incomingCounter": i, "reason": "old duplicate"}).
+					Debug("Receive window")
+			}
+			b.dupeCounter.Inc(1)
+			return false
+		}
+
 		b.bits[i%b.length] = true
 		return true
+
 	}
 
 	// In all other cases, fail and don't change current.
@@ -110,3 +147,11 @@ func (b *Bits) Update(l *logrus.Logger, i uint64) bool {
 	}
 	return false
 }
+
+func maxInt64(a, b int64) int64 {
+	if a > b {
+		return a
+	}
+
+	return b
+}

bits_test.go

@@ -15,41 +15,48 @@ func TestBits(t *testing.T) {
 	assert.Len(t, b.bits, 10)
 
 	// This is initialized to zero - receive one. This should work.
+
 	assert.True(t, b.Check(l, 1))
-	assert.True(t, b.Update(l, 1))
+	u := b.Update(l, 1)
+	assert.True(t, u)
 	assert.EqualValues(t, 1, b.current)
-	g := []bool{true, true, false, false, false, false, false, false, false, false}
+	g := []bool{false, true, false, false, false, false, false, false, false, false}
 	assert.Equal(t, g, b.bits)
 
 	// Receive two
 	assert.True(t, b.Check(l, 2))
-	assert.True(t, b.Update(l, 2))
+	u = b.Update(l, 2)
+	assert.True(t, u)
 	assert.EqualValues(t, 2, b.current)
-	g = []bool{true, true, true, false, false, false, false, false, false, false}
+	g = []bool{false, true, true, false, false, false, false, false, false, false}
 	assert.Equal(t, g, b.bits)
 
 	// Receive two again - it will fail
 	assert.False(t, b.Check(l, 2))
-	assert.False(t, b.Update(l, 2))
+	u = b.Update(l, 2)
+	assert.False(t, u)
 	assert.EqualValues(t, 2, b.current)
 
 	// Jump ahead to 15, which should clear everything and set the 6th element
 	assert.True(t, b.Check(l, 15))
-	assert.True(t, b.Update(l, 15))
+	u = b.Update(l, 15)
+	assert.True(t, u)
 	assert.EqualValues(t, 15, b.current)
 	g = []bool{false, false, false, false, false, true, false, false, false, false}
 	assert.Equal(t, g, b.bits)
 
 	// Mark 14, which is allowed because it is in the window
 	assert.True(t, b.Check(l, 14))
-	assert.True(t, b.Update(l, 14))
+	u = b.Update(l, 14)
+	assert.True(t, u)
 	assert.EqualValues(t, 15, b.current)
 	g = []bool{false, false, false, false, true, true, false, false, false, false}
 	assert.Equal(t, g, b.bits)
 
 	// Mark 5, which is not allowed because it is not in the window
 	assert.False(t, b.Check(l, 5))
-	assert.False(t, b.Update(l, 5))
+	u = b.Update(l, 5)
+	assert.False(t, u)
 	assert.EqualValues(t, 15, b.current)
 	g = []bool{false, false, false, false, true, true, false, false, false, false}
 	assert.Equal(t, g, b.bits)
@@ -62,29 +69,10 @@ func TestBits(t *testing.T) {
 
 	// Walk through a few windows in order
 	b = NewBits(10)
-	for i := uint64(1); i <= 100; i++ {
+	for i := uint64(0); i <= 100; i++ {
 		assert.True(t, b.Check(l, i), "Error while checking %v", i)
 		assert.True(t, b.Update(l, i), "Error while updating %v", i)
 	}
-
-	assert.False(t, b.Check(l, 1), "Out of window check")
-}
-
-func TestBitsLargeJumps(t *testing.T) {
-	l := test.NewLogger()
-	b := NewBits(10)
-	b.lostCounter.Clear()
-
-	b = NewBits(10)
-	b.lostCounter.Clear()
-	assert.True(t, b.Update(l, 55)) // We saw packet 55 and can still track 45,46,47,48,49,50,51,52,53,54
-	assert.Equal(t, int64(45), b.lostCounter.Count())
-
-	assert.True(t, b.Update(l, 100)) // We saw packet 55 and 100 and can still track 90,91,92,93,94,95,96,97,98,99
-	assert.Equal(t, int64(89), b.lostCounter.Count())
-
-	assert.True(t, b.Update(l, 200)) // We saw packet 55, 100, and 200 and can still track 190,191,192,193,194,195,196,197,198,199
-	assert.Equal(t, int64(188), b.lostCounter.Count())
 }
 
 func TestBitsDupeCounter(t *testing.T) {
@@ -136,7 +124,8 @@ func TestBitsOutOfWindowCounter(t *testing.T) {
 	assert.False(t, b.Update(l, 0))
 	assert.Equal(t, int64(1), b.outOfWindowCounter.Count())
 
-	assert.Equal(t, int64(19), b.lostCounter.Count()) // packet 0 wasn't lost
+	//tODO: make sure lostcounter doesn't increase in orderly increment
+	assert.Equal(t, int64(20), b.lostCounter.Count())
 	assert.Equal(t, int64(0), b.dupeCounter.Count())
 	assert.Equal(t, int64(1), b.outOfWindowCounter.Count())
 }
@@ -148,6 +137,8 @@ func TestBitsLostCounter(t *testing.T) {
 	b.dupeCounter.Clear()
 	b.outOfWindowCounter.Clear()
 
+	//assert.True(t, b.Update(0))
+	assert.True(t, b.Update(l, 0))
 	assert.True(t, b.Update(l, 20))
 	assert.True(t, b.Update(l, 21))
 	assert.True(t, b.Update(l, 22))
@@ -158,7 +149,7 @@ func TestBitsLostCounter(t *testing.T) {
 	assert.True(t, b.Update(l, 27))
 	assert.True(t, b.Update(l, 28))
 	assert.True(t, b.Update(l, 29))
-	assert.Equal(t, int64(19), b.lostCounter.Count()) // packet 0 wasn't lost
+	assert.Equal(t, int64(20), b.lostCounter.Count())
 	assert.Equal(t, int64(0), b.dupeCounter.Count())
 	assert.Equal(t, int64(0), b.outOfWindowCounter.Count())
 
@@ -167,6 +158,8 @@ func TestBitsLostCounter(t *testing.T) {
 	b.dupeCounter.Clear()
 	b.outOfWindowCounter.Clear()
 
+	assert.True(t, b.Update(l, 0))
+	assert.Equal(t, int64(0), b.lostCounter.Count())
 	assert.True(t, b.Update(l, 9))
 	assert.Equal(t, int64(0), b.lostCounter.Count())
 	// 10 will set 0 index, 0 was already set, no lost packets
@@ -221,62 +214,6 @@ func TestBitsLostCounter(t *testing.T) {
 	assert.Equal(t, int64(0), b.outOfWindowCounter.Count())
 }
 
-func TestBitsLostCounterIssue1(t *testing.T) {
-	l := test.NewLogger()
-	b := NewBits(10)
-	b.lostCounter.Clear()
-	b.dupeCounter.Clear()
-	b.outOfWindowCounter.Clear()
-
-	assert.True(t, b.Update(l, 4))
-	assert.Equal(t, int64(0), b.lostCounter.Count())
-	assert.True(t, b.Update(l, 1))
-	assert.Equal(t, int64(0), b.lostCounter.Count())
-	assert.True(t, b.Update(l, 9))
-	assert.Equal(t, int64(0), b.lostCounter.Count())
-	assert.True(t, b.Update(l, 2))
-	assert.Equal(t, int64(0), b.lostCounter.Count())
-	assert.True(t, b.Update(l, 3))
-	assert.Equal(t, int64(0), b.lostCounter.Count())
-	assert.True(t, b.Update(l, 5))
-	assert.Equal(t, int64(0), b.lostCounter.Count())
-	assert.True(t, b.Update(l, 6))
-	assert.Equal(t, int64(0), b.lostCounter.Count())
-	assert.True(t, b.Update(l, 7))
-	assert.Equal(t, int64(0), b.lostCounter.Count())
-	// assert.True(t, b.Update(l, 8))
-	assert.True(t, b.Update(l, 10))
-	assert.Equal(t, int64(0), b.lostCounter.Count())
-	assert.True(t, b.Update(l, 11))
-	assert.Equal(t, int64(0), b.lostCounter.Count())
-
-	assert.True(t, b.Update(l, 14))
-	assert.Equal(t, int64(0), b.lostCounter.Count())
-	// Issue seems to be here, we reset missing packet 8 to false here and don't increment the lost counter
-	assert.True(t, b.Update(l, 19))
-	assert.Equal(t, int64(1), b.lostCounter.Count())
-	assert.True(t, b.Update(l, 12))
-	assert.Equal(t, int64(1), b.lostCounter.Count())
-	assert.True(t, b.Update(l, 13))
-	assert.Equal(t, int64(1), b.lostCounter.Count())
-	assert.True(t, b.Update(l, 15))
-	assert.Equal(t, int64(1), b.lostCounter.Count())
-	assert.True(t, b.Update(l, 16))
-	assert.Equal(t, int64(1), b.lostCounter.Count())
-	assert.True(t, b.Update(l, 17))
-	assert.Equal(t, int64(1), b.lostCounter.Count())
-	assert.True(t, b.Update(l, 18))
-	assert.Equal(t, int64(1), b.lostCounter.Count())
-	assert.True(t, b.Update(l, 20))
-	assert.Equal(t, int64(1), b.lostCounter.Count())
-	assert.True(t, b.Update(l, 21))
-
-	// We missed packet 8 above
-	assert.Equal(t, int64(1), b.lostCounter.Count())
-	assert.Equal(t, int64(0), b.dupeCounter.Count())
-	assert.Equal(t, int64(0), b.outOfWindowCounter.Count())
-}
-
 func BenchmarkBits(b *testing.B) {
 	z := NewBits(10)
 	for n := 0; n < b.N; n++ {

cert/pem.go

@@ -1,8 +1,10 @@
 package cert
 
 import (
+	"encoding/hex"
 	"encoding/pem"
 	"fmt"
+	"time"
 
 	"golang.org/x/crypto/ed25519"
 )
@@ -138,6 +140,101 @@ func MarshalSigningPrivateKeyToPEM(curve Curve, b []byte) []byte {
 	}
 }
 
+// Backward compatibility functions for older API
+func MarshalX25519PublicKey(b []byte) []byte {
+	return MarshalPublicKeyToPEM(Curve_CURVE25519, b)
+}
+
+func MarshalX25519PrivateKey(b []byte) []byte {
+	return MarshalPrivateKeyToPEM(Curve_CURVE25519, b)
+}
+
+func MarshalPublicKey(curve Curve, b []byte) []byte {
+	return MarshalPublicKeyToPEM(curve, b)
+}
+
+func MarshalPrivateKey(curve Curve, b []byte) []byte {
+	return MarshalPrivateKeyToPEM(curve, b)
+}
+
+// NebulaCertificate is a compatibility wrapper for the old API
+type NebulaCertificate struct {
+	Details   NebulaCertificateDetails
+	Signature []byte
+	cert      Certificate
+}
+
+// NebulaCertificateDetails is a compatibility wrapper for certificate details
+type NebulaCertificateDetails struct {
+	Name      string
+	NotBefore time.Time
+	NotAfter  time.Time
+	PublicKey []byte
+	IsCA      bool
+	Issuer    []byte
+	Curve     Curve
+}
+
+// UnmarshalNebulaCertificateFromPEM provides backward compatibility with the old API
+func UnmarshalNebulaCertificateFromPEM(b []byte) (*NebulaCertificate, []byte, error) {
+	c, rest, err := UnmarshalCertificateFromPEM(b)
+	if err != nil {
+		return nil, rest, err
+	}
+
+	issuerBytes, err := func() ([]byte, error) {
+		issuer := c.Issuer()
+		if issuer == "" {
+			return nil, nil
+		}
+		decoded, err := hex.DecodeString(issuer)
+		if err != nil {
+			return nil, fmt.Errorf("failed to decode issuer fingerprint: %w", err)
+		}
+		return decoded, nil
+	}()
+	if err != nil {
+		return nil, rest, err
+	}
+
+	pubKey := c.PublicKey()
+	if pubKey != nil {
+		pubKey = append([]byte(nil), pubKey...)
+	}
+
+	sig := c.Signature()
+	if sig != nil {
+		sig = append([]byte(nil), sig...)
+	}
+
+	return &NebulaCertificate{
+		Details: NebulaCertificateDetails{
+			Name:      c.Name(),
+			NotBefore: c.NotBefore(),
+			NotAfter:  c.NotAfter(),
+			PublicKey: pubKey,
+			IsCA:      c.IsCA(),
+			Issuer:    issuerBytes,
+			Curve:     c.Curve(),
+		},
+		Signature: sig,
+		cert:      c,
+	}, rest, nil
+}
+
+// IssuerString returns the issuer in hex format for compatibility
+func (n *NebulaCertificate) IssuerString() string {
+	if n.Details.Issuer == nil {
+		return ""
+	}
+	return hex.EncodeToString(n.Details.Issuer)
+}
+
+// Certificate returns the underlying certificate (read-only)
+func (n *NebulaCertificate) Certificate() Certificate {
+	return n.cert
+}
+
 // UnmarshalPrivateKeyFromPEM will try to unmarshal the first pem block in a byte array, returning any non
 // consumed data or an error on failure
 func UnmarshalPrivateKeyFromPEM(b []byte) ([]byte, []byte, Curve, error) {

cmd/nebula-cert/ca.go

@@ -173,26 +173,23 @@ func ca(args []string, out io.Writer, errOut io.Writer, pr PasswordReader) error
 
 	var passphrase []byte
 	if !isP11 && *cf.encryption {
-		passphrase = []byte(os.Getenv("NEBULA_CA_PASSPHRASE"))
+		for i := 0; i < 5; i++ {
+			out.Write([]byte("Enter passphrase: "))
+			passphrase, err = pr.ReadPassword()
+
+			if err == ErrNoTerminal {
+				return fmt.Errorf("out-key must be encrypted interactively")
+			} else if err != nil {
+				return fmt.Errorf("error reading passphrase: %s", err)
+			}
+
+			if len(passphrase) > 0 {
+				break
+			}
+		}
+
 		if len(passphrase) == 0 {
-			for i := 0; i < 5; i++ {
+			return fmt.Errorf("no passphrase specified, remove -encrypt flag to write out-key in plaintext")
-				out.Write([]byte("Enter passphrase: "))
-				passphrase, err = pr.ReadPassword()
-
-				if err == ErrNoTerminal {
-					return fmt.Errorf("out-key must be encrypted interactively")
-				} else if err != nil {
-					return fmt.Errorf("error reading passphrase: %s", err)
-				}
-
-				if len(passphrase) > 0 {
-					break
-				}
-			}
-
-			if len(passphrase) == 0 {
-				return fmt.Errorf("no passphrase specified, remove -encrypt flag to write out-key in plaintext")
-			}
 		}
 	}
 

cmd/nebula-cert/ca_test.go

@@ -171,17 +171,6 @@ func Test_ca(t *testing.T) {
 	assert.Equal(t, pwPromptOb, ob.String())
 	assert.Empty(t, eb.String())
 
-	// test encrypted key with passphrase environment variable
-	os.Remove(keyF.Name())
-	os.Remove(crtF.Name())
-	ob.Reset()
-	eb.Reset()
-	args = []string{"-version", "1", "-encrypt", "-name", "test", "-duration", "100m", "-groups", "1,2,3,4,5", "-out-crt", crtF.Name(), "-out-key", keyF.Name()}
-	os.Setenv("NEBULA_CA_PASSPHRASE", string(passphrase))
-	require.NoError(t, ca(args, ob, eb, testpw))
-	assert.Empty(t, eb.String())
-	os.Setenv("NEBULA_CA_PASSPHRASE", "")
-
 	// read encrypted key file and verify default params
 	rb, _ = os.ReadFile(keyF.Name())
 	k, _ := pem.Decode(rb)

cmd/nebula-cert/main.go

@@ -5,28 +5,10 @@ import (
 	"fmt"
 	"io"
 	"os"
-	"runtime/debug"
-	"strings"
 )
 
-// A version string that can be set with
-//
-//	-ldflags "-X main.Build=SOMEVERSION"
-//
-// at compile-time.
 var Build string
 
-func init() {
-	if Build == "" {
-		info, ok := debug.ReadBuildInfo()
-		if !ok {
-			return
-		}
-
-		Build = strings.TrimPrefix(info.Main.Version, "v")
-	}
-}
-
 type helpError struct {
 	s string
 }

cmd/nebula-cert/sign.go

@@ -43,7 +43,7 @@ type signFlags struct {
 func newSignFlags() *signFlags {
 	sf := signFlags{set: flag.NewFlagSet("sign", flag.ContinueOnError)}
 	sf.set.Usage = func() {}
-	sf.version = sf.set.Uint("version", 0, "Optional: version of the certificate format to use. The default is to match the version of the signing CA")
+	sf.version = sf.set.Uint("version", 0, "Optional: version of the certificate format to use, the default is to create both v1 and v2 certificates.")
 	sf.caKeyPath = sf.set.String("ca-key", "ca.key", "Optional: path to the signing CA key")
 	sf.caCertPath = sf.set.String("ca-crt", "ca.crt", "Optional: path to the signing CA cert")
 	sf.name = sf.set.String("name", "", "Required: name of the cert, usually a hostname")
@@ -116,28 +116,26 @@ func signCert(args []string, out io.Writer, errOut io.Writer, pr PasswordReader)
 		// naively attempt to decode the private key as though it is not encrypted
 		caKey, _, curve, err = cert.UnmarshalSigningPrivateKeyFromPEM(rawCAKey)
 		if errors.Is(err, cert.ErrPrivateKeyEncrypted) {
+			// ask for a passphrase until we get one
 			var passphrase []byte
-			passphrase = []byte(os.Getenv("NEBULA_CA_PASSPHRASE"))
+			for i := 0; i < 5; i++ {
-			if len(passphrase) == 0 {
+				out.Write([]byte("Enter passphrase: "))
-				// ask for a passphrase until we get one
+				passphrase, err = pr.ReadPassword()
-				for i := 0; i < 5; i++ {
-					out.Write([]byte("Enter passphrase: "))
-					passphrase, err = pr.ReadPassword()
 
-					if errors.Is(err, ErrNoTerminal) {
+				if errors.Is(err, ErrNoTerminal) {
-						return fmt.Errorf("ca-key is encrypted and must be decrypted interactively")
+					return fmt.Errorf("ca-key is encrypted and must be decrypted interactively")
-					} else if err != nil {
+				} else if err != nil {
-						return fmt.Errorf("error reading password: %s", err)
+					return fmt.Errorf("error reading password: %s", err)
-					}
-
-					if len(passphrase) > 0 {
-						break
-					}
 				}
-				if len(passphrase) == 0 {
+
-					return fmt.Errorf("cannot open encrypted ca-key without passphrase")
+				if len(passphrase) > 0 {
+					break
 				}
 			}
+			if len(passphrase) == 0 {
+				return fmt.Errorf("cannot open encrypted ca-key without passphrase")
+			}
+
 			curve, caKey, _, err = cert.DecryptAndUnmarshalSigningPrivateKey(passphrase, rawCAKey)
 			if err != nil {
 				return fmt.Errorf("error while parsing encrypted ca-key: %s", err)
@@ -167,10 +165,6 @@ func signCert(args []string, out io.Writer, errOut io.Writer, pr PasswordReader)
 		return fmt.Errorf("ca certificate is expired")
 	}
 
-	if version == 0 {
-		version = caCert.Version()
-	}
-
 	// if no duration is given, expire one second before the root expires
 	if *sf.duration <= 0 {
 		*sf.duration = time.Until(caCert.NotAfter()) - time.Second*1
@@ -283,19 +277,21 @@ func signCert(args []string, out io.Writer, errOut io.Writer, pr PasswordReader)
 	notBefore := time.Now()
 	notAfter := notBefore.Add(*sf.duration)
 
-	switch version {
+	if version == 0 || version == cert.Version1 {
-	case cert.Version1:
+		// Make sure we at least have an ip
-		// Make sure we have only one ipv4 address
 		if len(v4Networks) != 1 {
 			return newHelpErrorf("invalid -networks definition: v1 certificates can only have a single ipv4 address")
 		}
 
-		if len(v6Networks) > 0 {
+		if version == cert.Version1 {
-			return newHelpErrorf("invalid -networks definition: v1 certificates can only contain ipv4 addresses")
+			// If we are asked to mint a v1 certificate only then we cant just ignore any v6 addresses
-		}
+			if len(v6Networks) > 0 {
+				return newHelpErrorf("invalid -networks definition: v1 certificates can only be ipv4")
+			}
 
-		if len(v6UnsafeNetworks) > 0 {
+			if len(v6UnsafeNetworks) > 0 {
-			return newHelpErrorf("invalid -unsafe-networks definition: v1 certificates can only contain ipv4 addresses")
+				return newHelpErrorf("invalid -unsafe-networks definition: v1 certificates can only be ipv4")
+			}
 		}
 
 		t := &cert.TBSCertificate{
@@ -325,8 +321,9 @@ func signCert(args []string, out io.Writer, errOut io.Writer, pr PasswordReader)
 		}
 
 		crts = append(crts, nc)
+	}
 
-	case cert.Version2:
+	if version == 0 || version == cert.Version2 {
 		t := &cert.TBSCertificate{
 			Version:        cert.Version2,
 			Name:           *sf.name,
@@ -354,9 +351,6 @@ func signCert(args []string, out io.Writer, errOut io.Writer, pr PasswordReader)
 		}
 
 		crts = append(crts, nc)
-	default:
-		// this should be unreachable
-		return fmt.Errorf("invalid version: %d", version)
 	}
 
 	if !isP11 && *sf.inPubPath == "" {

cmd/nebula-cert/sign_test.go

@@ -55,7 +55,7 @@ func Test_signHelp(t *testing.T) {
 			"  -unsafe-networks string\n"+
 			"    \tOptional: comma separated list of ip address and network in CIDR notation. Unsafe networks this cert can route for\n"+
 			"  -version uint\n"+
-			"    \tOptional: version of the certificate format to use. The default is to match the version of the signing CA\n",
+			"    \tOptional: version of the certificate format to use, the default is to create both v1 and v2 certificates.\n",
 		ob.String(),
 	)
 }
@@ -204,7 +204,7 @@ func Test_signCert(t *testing.T) {
 	ob.Reset()
 	eb.Reset()
 	args = []string{"-version", "1", "-ca-crt", caCrtF.Name(), "-ca-key", caKeyF.Name(), "-name", "test", "-ip", "1.1.1.1/24", "-out-crt", "nope", "-out-key", "nope", "-duration", "100m", "-subnets", "100::100/100"}
-	assertHelpError(t, signCert(args, ob, eb, nopw), "invalid -unsafe-networks definition: v1 certificates can only contain ipv4 addresses")
+	assertHelpError(t, signCert(args, ob, eb, nopw), "invalid -unsafe-networks definition: v1 certificates can only be ipv4")
 	assert.Empty(t, ob.String())
 	assert.Empty(t, eb.String())
 
@@ -379,15 +379,6 @@ func Test_signCert(t *testing.T) {
 	assert.Equal(t, "Enter passphrase: ", ob.String())
 	assert.Empty(t, eb.String())
 
-	// test with the proper password in the environment
-	os.Remove(crtF.Name())
-	os.Remove(keyF.Name())
-	args = []string{"-version", "1", "-ca-crt", caCrtF.Name(), "-ca-key", caKeyF.Name(), "-name", "test", "-ip", "1.1.1.1/24", "-out-crt", crtF.Name(), "-out-key", keyF.Name(), "-duration", "100m", "-subnets", "10.1.1.1/32, ,   10.2.2.2/32   ,   ,  ,, 10.5.5.5/32", "-groups", "1,,   2    ,        ,,,3,4,5"}
-	os.Setenv("NEBULA_CA_PASSPHRASE", string(passphrase))
-	require.NoError(t, signCert(args, ob, eb, testpw))
-	assert.Empty(t, eb.String())
-	os.Setenv("NEBULA_CA_PASSPHRASE", "")
-
 	// test with the wrong password
 	ob.Reset()
 	eb.Reset()
@@ -398,17 +389,6 @@ func Test_signCert(t *testing.T) {
 	assert.Equal(t, "Enter passphrase: ", ob.String())
 	assert.Empty(t, eb.String())
 
-	// test with the wrong password in environment
-	ob.Reset()
-	eb.Reset()
-
-	os.Setenv("NEBULA_CA_PASSPHRASE", "invalid password")
-	args = []string{"-version", "1", "-ca-crt", caCrtF.Name(), "-ca-key", caKeyF.Name(), "-name", "test", "-ip", "1.1.1.1/24", "-out-crt", crtF.Name(), "-out-key", keyF.Name(), "-duration", "100m", "-subnets", "10.1.1.1/32, ,   10.2.2.2/32   ,   ,  ,, 10.5.5.5/32", "-groups", "1,,   2    ,        ,,,3,4,5"}
-	require.EqualError(t, signCert(args, ob, eb, nopw), "error while parsing encrypted ca-key: invalid passphrase or corrupt private key")
-	assert.Empty(t, ob.String())
-	assert.Empty(t, eb.String())
-	os.Setenv("NEBULA_CA_PASSPHRASE", "")
-
 	// test with the user not entering a password
 	ob.Reset()
 	eb.Reset()

cmd/nebula-service/main.go

@@ -4,8 +4,6 @@ import (
 	"flag"
 	"fmt"
 	"os"
-	"runtime/debug"
-	"strings"
 
 	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula"
@@ -20,17 +18,6 @@ import (
 // at compile-time.
 var Build string
 
-func init() {
-	if Build == "" {
-		info, ok := debug.ReadBuildInfo()
-		if !ok {
-			return
-		}
-
-		Build = strings.TrimPrefix(info.Main.Version, "v")
-	}
-}
-
 func main() {
 	serviceFlag := flag.String("service", "", "Control the system service.")
 	configPath := flag.String("config", "", "Path to either a file or directory to load configuration from")

cmd/nebula/main.go

@@ -4,8 +4,6 @@ import (
 	"flag"
 	"fmt"
 	"os"
-	"runtime/debug"
-	"strings"
 
 	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula"
@@ -20,17 +18,6 @@ import (
 // at compile-time.
 var Build string
 
-func init() {
-	if Build == "" {
-		info, ok := debug.ReadBuildInfo()
-		if !ok {
-			return
-		}
-
-		Build = strings.TrimPrefix(info.Main.Version, "v")
-	}
-}
-
 func main() {
 	configPath := flag.String("config", "", "Path to either a file or directory to load configuration from")
 	configTest := flag.Bool("test", false, "Test the config and print the end result. Non zero exit indicates a faulty config")

config/config.go

@@ -17,7 +17,7 @@ import (
 
 	"dario.cat/mergo"
 	"github.com/sirupsen/logrus"
-	"go.yaml.in/yaml/v3"
+	"gopkg.in/yaml.v3"
 )
 
 type C struct {

config/config_test.go

@@ -10,7 +10,7 @@ import (
 	"github.com/slackhq/nebula/test"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
-	"go.yaml.in/yaml/v3"
+	"gopkg.in/yaml.v3"
 )
 
 func TestConfig_Load(t *testing.T) {

connection_state.go

@@ -50,6 +50,11 @@ func NewConnectionState(l *logrus.Logger, cs *CertState, crt cert.Certificate, i
 	}
 
 	static := noise.DHKey{Private: cs.privateKey, Public: crt.PublicKey()}
+
+	b := NewBits(ReplayWindow)
+	// Clear out bit 0, we never transmit it, and we don't want it showing as packet loss
+	b.Update(l, 0)
+
 	hs, err := noise.NewHandshakeState(noise.Config{
 		CipherSuite:   ncs,
 		Random:        rand.Reader,
@@ -69,7 +74,7 @@ func NewConnectionState(l *logrus.Logger, cs *CertState, crt cert.Certificate, i
 	ci := &ConnectionState{
 		H:         hs,
 		initiator: initiator,
-		window:    NewBits(ReplayWindow),
+		window:    b,
 		myCert:    crt,
 	}
 	// always start the counter from 2, as packet 1 and packet 2 are handshake packets.

control_tester.go

@@ -174,10 +174,6 @@ func (c *Control) GetHostmap() *HostMap {
 	return c.f.hostMap
 }
 
-func (c *Control) GetF() *Interface {
-	return c.f
-}
-
 func (c *Control) GetCertState() *CertState {
 	return c.f.pki.getCertState()
 }

e2e/handshakes_test.go

@@ -20,7 +20,7 @@ import (
 	"github.com/slackhq/nebula/udp"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
-	"go.yaml.in/yaml/v3"
+	"gopkg.in/yaml.v3"
 )
 
 func BenchmarkHotPath(b *testing.B) {
@@ -97,41 +97,6 @@ func TestGoodHandshake(t *testing.T) {
 	theirControl.Stop()
 }
 
-func TestGoodHandshakeNoOverlap(t *testing.T) {
-	ca, _, caKey, _ := cert_test.NewTestCaCert(cert.Version2, cert.Curve_CURVE25519, time.Now(), time.Now().Add(10*time.Minute), nil, nil, []string{})
-	myControl, myVpnIpNet, myUdpAddr, _ := newSimpleServer(cert.Version2, ca, caKey, "me", "10.128.0.1/24", nil)
-	theirControl, theirVpnIpNet, theirUdpAddr, _ := newSimpleServer(cert.Version2, ca, caKey, "them", "2001::69/24", nil) //look ma, cross-stack!
-
-	// Put their info in our lighthouse
-	myControl.InjectLightHouseAddr(theirVpnIpNet[0].Addr(), theirUdpAddr)
-
-	// Start the servers
-	myControl.Start()
-	theirControl.Start()
-
-	empty := []byte{}
-	t.Log("do something to cause a handshake")
-	myControl.GetF().SendMessageToVpnAddr(header.Test, header.MessageNone, theirVpnIpNet[0].Addr(), empty, empty, empty)
-
-	t.Log("Have them consume my stage 0 packet. They have a tunnel now")
-	theirControl.InjectUDPPacket(myControl.GetFromUDP(true))
-
-	t.Log("Get their stage 1 packet")
-	stage1Packet := theirControl.GetFromUDP(true)
-
-	t.Log("Have me consume their stage 1 packet. I have a tunnel now")
-	myControl.InjectUDPPacket(stage1Packet)
-
-	t.Log("Wait until we see a test packet come through to make sure we give the tunnel time to complete")
-	myControl.WaitForType(header.Test, 0, theirControl)
-
-	t.Log("Make sure our host infos are correct")
-	assertHostInfoPair(t, myUdpAddr, theirUdpAddr, myVpnIpNet, theirVpnIpNet, myControl, theirControl)
-
-	myControl.Stop()
-	theirControl.Stop()
-}
-
 func TestWrongResponderHandshake(t *testing.T) {
 	ca, _, caKey, _ := cert_test.NewTestCaCert(cert.Version1, cert.Curve_CURVE25519, time.Now(), time.Now().Add(10*time.Minute), nil, nil, []string{})
 
@@ -499,35 +464,6 @@ func TestRelays(t *testing.T) {
 	r.RenderHostmaps("Final hostmaps", myControl, relayControl, theirControl)
 }
 
-func TestRelaysDontCareAboutIps(t *testing.T) {
-	ca, _, caKey, _ := cert_test.NewTestCaCert(cert.Version2, cert.Curve_CURVE25519, time.Now(), time.Now().Add(10*time.Minute), nil, nil, []string{})
-	myControl, myVpnIpNet, _, _ := newSimpleServer(cert.Version2, ca, caKey, "me     ", "10.128.0.1/24", m{"relay": m{"use_relays": true}})
-	relayControl, relayVpnIpNet, relayUdpAddr, _ := newSimpleServer(cert.Version2, ca, caKey, "relay  ", "2001::9999/24", m{"relay": m{"am_relay": true}})
-	theirControl, theirVpnIpNet, theirUdpAddr, _ := newSimpleServer(cert.Version2, ca, caKey, "them   ", "10.128.0.2/24", m{"relay": m{"use_relays": true}})
-
-	// Teach my how to get to the relay and that their can be reached via the relay
-	myControl.InjectLightHouseAddr(relayVpnIpNet[0].Addr(), relayUdpAddr)
-	myControl.InjectRelays(theirVpnIpNet[0].Addr(), []netip.Addr{relayVpnIpNet[0].Addr()})
-	relayControl.InjectLightHouseAddr(theirVpnIpNet[0].Addr(), theirUdpAddr)
-
-	// Build a router so we don't have to reason who gets which packet
-	r := router.NewR(t, myControl, relayControl, theirControl)
-	defer r.RenderFlow()
-
-	// Start the servers
-	myControl.Start()
-	relayControl.Start()
-	theirControl.Start()
-
-	t.Log("Trigger a handshake from me to them via the relay")
-	myControl.InjectTunUDPPacket(theirVpnIpNet[0].Addr(), 80, myVpnIpNet[0].Addr(), 80, []byte("Hi from me"))
-
-	p := r.RouteForAllUntilTxTun(theirControl)
-	r.Log("Assert the tunnel works")
-	assertUdpPacket(t, []byte("Hi from me"), p, myVpnIpNet[0].Addr(), theirVpnIpNet[0].Addr(), 80, 80)
-	r.RenderHostmaps("Final hostmaps", myControl, relayControl, theirControl)
-}
-
 func TestReestablishRelays(t *testing.T) {
 	ca, _, caKey, _ := cert_test.NewTestCaCert(cert.Version1, cert.Curve_CURVE25519, time.Now(), time.Now().Add(10*time.Minute), nil, nil, []string{})
 	myControl, myVpnIpNet, _, _ := newSimpleServer(cert.Version1, ca, caKey, "me     ", "10.128.0.1/24", m{"relay": m{"use_relays": true}})
@@ -1291,109 +1227,3 @@ func TestV2NonPrimaryWithLighthouse(t *testing.T) {
 	myControl.Stop()
 	theirControl.Stop()
 }
-
-func TestV2NonPrimaryWithOffNetLighthouse(t *testing.T) {
-	ca, _, caKey, _ := cert_test.NewTestCaCert(cert.Version2, cert.Curve_CURVE25519, time.Now(), time.Now().Add(10*time.Minute), nil, nil, []string{})
-	lhControl, lhVpnIpNet, lhUdpAddr, _ := newSimpleServer(cert.Version2, ca, caKey, "lh  ", "2001::1/64", m{"lighthouse": m{"am_lighthouse": true}})
-
-	o := m{
-		"static_host_map": m{
-			lhVpnIpNet[0].Addr().String(): []string{lhUdpAddr.String()},
-		},
-		"lighthouse": m{
-			"hosts": []string{lhVpnIpNet[0].Addr().String()},
-			"local_allow_list": m{
-				// Try and block our lighthouse updates from using the actual addresses assigned to this computer
-				// If we start discovering addresses the test router doesn't know about then test traffic cant flow
-				"10.0.0.0/24": true,
-				"::/0":        false,
-			},
-		},
-	}
-	myControl, myVpnIpNet, _, _ := newSimpleServer(cert.Version2, ca, caKey, "me  ", "10.128.0.2/24, ff::2/64", o)
-	theirControl, theirVpnIpNet, _, _ := newSimpleServer(cert.Version2, ca, caKey, "them", "10.128.0.3/24, ff::3/64", o)
-
-	// Build a router so we don't have to reason who gets which packet
-	r := router.NewR(t, lhControl, myControl, theirControl)
-	defer r.RenderFlow()
-
-	// Start the servers
-	lhControl.Start()
-	myControl.Start()
-	theirControl.Start()
-
-	t.Log("Stand up an ipv6 tunnel between me and them")
-	assert.True(t, myVpnIpNet[1].Addr().Is6())
-	assert.True(t, theirVpnIpNet[1].Addr().Is6())
-	assertTunnel(t, myVpnIpNet[1].Addr(), theirVpnIpNet[1].Addr(), myControl, theirControl, r)
-
-	lhControl.Stop()
-	myControl.Stop()
-	theirControl.Stop()
-}
-
-func TestGoodHandshakeUnsafeDest(t *testing.T) {
-	unsafePrefix := "192.168.6.0/24"
-	ca, _, caKey, _ := cert_test.NewTestCaCert(cert.Version2, cert.Curve_CURVE25519, time.Now(), time.Now().Add(10*time.Minute), nil, nil, []string{})
-	theirControl, theirVpnIpNet, theirUdpAddr, _ := newSimpleServerWithUdpAndUnsafeNetworks(cert.Version2, ca, caKey, "spooky", "10.128.0.2/24", netip.MustParseAddrPort("10.64.0.2:4242"), unsafePrefix, nil)
-	route := m{"route": unsafePrefix, "via": theirVpnIpNet[0].Addr().String()}
-	myCfg := m{
-		"tun": m{
-			"unsafe_routes": []m{route},
-		},
-	}
-	myControl, myVpnIpNet, myUdpAddr, myConfig := newSimpleServer(cert.Version2, ca, caKey, "me", "10.128.0.1/24", myCfg)
-	t.Logf("my config %v", myConfig)
-	// Put their info in our lighthouse
-	myControl.InjectLightHouseAddr(theirVpnIpNet[0].Addr(), theirUdpAddr)
-
-	spookyDest := netip.MustParseAddr("192.168.6.4")
-
-	// Start the servers
-	myControl.Start()
-	theirControl.Start()
-
-	t.Log("Send a udp packet through to begin standing up the tunnel, this should come out the other side")
-	myControl.InjectTunUDPPacket(spookyDest, 80, myVpnIpNet[0].Addr(), 80, []byte("Hi from me"))
-
-	t.Log("Have them consume my stage 0 packet. They have a tunnel now")
-	theirControl.InjectUDPPacket(myControl.GetFromUDP(true))
-
-	t.Log("Get their stage 1 packet so that we can play with it")
-	stage1Packet := theirControl.GetFromUDP(true)
-
-	t.Log("I consume a garbage packet with a proper nebula header for our tunnel")
-	// this should log a statement and get ignored, allowing the real handshake packet to complete the tunnel
-	badPacket := stage1Packet.Copy()
-	badPacket.Data = badPacket.Data[:len(badPacket.Data)-header.Len]
-	myControl.InjectUDPPacket(badPacket)
-
-	t.Log("Have me consume their real stage 1 packet. I have a tunnel now")
-	myControl.InjectUDPPacket(stage1Packet)
-
-	t.Log("Wait until we see my cached packet come through")
-	myControl.WaitForType(1, 0, theirControl)
-
-	t.Log("Make sure our host infos are correct")
-	assertHostInfoPair(t, myUdpAddr, theirUdpAddr, myVpnIpNet, theirVpnIpNet, myControl, theirControl)
-
-	t.Log("Get that cached packet and make sure it looks right")
-	myCachedPacket := theirControl.GetFromTun(true)
-	assertUdpPacket(t, []byte("Hi from me"), myCachedPacket, myVpnIpNet[0].Addr(), spookyDest, 80, 80)
-
-	//reply
-	theirControl.InjectTunUDPPacket(myVpnIpNet[0].Addr(), 80, spookyDest, 80, []byte("Hi from the spookyman"))
-	//wait for reply
-	theirControl.WaitForType(1, 0, myControl)
-	theirCachedPacket := myControl.GetFromTun(true)
-	assertUdpPacket(t, []byte("Hi from the spookyman"), theirCachedPacket, spookyDest, myVpnIpNet[0].Addr(), 80, 80)
-
-	t.Log("Do a bidirectional tunnel test")
-	r := router.NewR(t, myControl, theirControl)
-	defer r.RenderFlow()
-	assertTunnel(t, myVpnIpNet[0].Addr(), theirVpnIpNet[0].Addr(), myControl, theirControl, r)
-
-	r.RenderHostmaps("Final hostmaps", myControl, theirControl)
-	myControl.Stop()
-	theirControl.Stop()
-}

e2e/helpers_test.go

@@ -22,14 +22,15 @@ import (
 	"github.com/slackhq/nebula/config"
 	"github.com/slackhq/nebula/e2e/router"
 	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
+	"gopkg.in/yaml.v3"
-	"go.yaml.in/yaml/v3"
 )
 
 type m = map[string]any
 
 // newSimpleServer creates a nebula instance with many assumptions
 func newSimpleServer(v cert.Version, caCrt cert.Certificate, caKey []byte, name string, sVpnNetworks string, overrides m) (*nebula.Control, []netip.Prefix, netip.AddrPort, *config.C) {
+	l := NewTestLogger()
+
 	var vpnNetworks []netip.Prefix
 	for _, sn := range strings.Split(sVpnNetworks, ",") {
 		vpnIpNet, err := netip.ParsePrefix(strings.TrimSpace(sn))
@@ -55,54 +56,7 @@ func newSimpleServer(v cert.Version, caCrt cert.Certificate, caKey []byte, name
 		budpIp[3] = 239
 		udpAddr = netip.AddrPortFrom(netip.AddrFrom16(budpIp), 4242)
 	}
-	return newSimpleServerWithUdp(v, caCrt, caKey, name, sVpnNetworks, udpAddr, overrides)
+	_, _, myPrivKey, myPEM := cert_test.NewTestCert(v, cert.Curve_CURVE25519, caCrt, caKey, name, time.Now(), time.Now().Add(5*time.Minute), vpnNetworks, nil, []string{})
-}
-
-func newSimpleServerWithUdp(v cert.Version, caCrt cert.Certificate, caKey []byte, name string, sVpnNetworks string, udpAddr netip.AddrPort, overrides m) (*nebula.Control, []netip.Prefix, netip.AddrPort, *config.C) {
-	return newSimpleServerWithUdpAndUnsafeNetworks(v, caCrt, caKey, name, sVpnNetworks, udpAddr, "", overrides)
-}
-
-func newSimpleServerWithUdpAndUnsafeNetworks(v cert.Version, caCrt cert.Certificate, caKey []byte, name string, sVpnNetworks string, udpAddr netip.AddrPort, sUnsafeNetworks string, overrides m) (*nebula.Control, []netip.Prefix, netip.AddrPort, *config.C) {
-	l := NewTestLogger()
-
-	var vpnNetworks []netip.Prefix
-	for _, sn := range strings.Split(sVpnNetworks, ",") {
-		vpnIpNet, err := netip.ParsePrefix(strings.TrimSpace(sn))
-		if err != nil {
-			panic(err)
-		}
-		vpnNetworks = append(vpnNetworks, vpnIpNet)
-	}
-
-	if len(vpnNetworks) == 0 {
-		panic("no vpn networks")
-	}
-
-	firewallInbound := []m{{
-		"proto": "any",
-		"port":  "any",
-		"host":  "any",
-	}}
-
-	var unsafeNetworks []netip.Prefix
-	if sUnsafeNetworks != "" {
-		firewallInbound = []m{{
-			"proto":      "any",
-			"port":       "any",
-			"host":       "any",
-			"local_cidr": "0.0.0.0/0",
-		}}
-
-		for _, sn := range strings.Split(sUnsafeNetworks, ",") {
-			x, err := netip.ParsePrefix(strings.TrimSpace(sn))
-			if err != nil {
-				panic(err)
-			}
-			unsafeNetworks = append(unsafeNetworks, x)
-		}
-	}
-
-	_, _, myPrivKey, myPEM := cert_test.NewTestCert(v, cert.Curve_CURVE25519, caCrt, caKey, name, time.Now(), time.Now().Add(5*time.Minute), vpnNetworks, unsafeNetworks, []string{})
 
 	caB, err := caCrt.MarshalPEM()
 	if err != nil {
@@ -122,7 +76,11 @@ func newSimpleServerWithUdpAndUnsafeNetworks(v cert.Version, caCrt cert.Certific
 				"port":  "any",
 				"host":  "any",
 			}},
-			"inbound": firewallInbound,
+			"inbound": []m{{
+				"proto": "any",
+				"port":  "any",
+				"host":  "any",
+			}},
 		},
 		//"handshakes": m{
 		//	"try_interval": "1s",
@@ -308,10 +266,10 @@ func assertHostInfoPair(t *testing.T, addrA, addrB netip.AddrPort, vpnNetsA, vpn
 	// Get both host infos
 	//TODO: CERT-V2 we may want to loop over each vpnAddr and assert all the things
 	hBinA := controlA.GetHostInfoByVpnAddr(vpnNetsB[0].Addr(), false)
-	require.NotNil(t, hBinA, "Host B was not found by vpnAddr in controlA")
+	assert.NotNil(t, hBinA, "Host B was not found by vpnAddr in controlA")
 
 	hAinB := controlB.GetHostInfoByVpnAddr(vpnNetsA[0].Addr(), false)
-	require.NotNil(t, hAinB, "Host A was not found by vpnAddr in controlB")
+	assert.NotNil(t, hAinB, "Host A was not found by vpnAddr in controlB")
 
 	// Check that both vpn and real addr are correct
 	assert.EqualValues(t, getAddrs(vpnNetsB), hBinA.VpnAddrs, "Host B VpnIp is wrong in control A")

e2e/tunnels_test.go

@@ -318,50 +318,3 @@ func TestCertMismatchCorrection(t *testing.T) {
 	myControl.Stop()
 	theirControl.Stop()
 }
-
-func TestCrossStackRelaysWork(t *testing.T) {
-	ca, _, caKey, _ := cert_test.NewTestCaCert(cert.Version2, cert.Curve_CURVE25519, time.Now(), time.Now().Add(10*time.Minute), nil, nil, []string{})
-	myControl, myVpnIpNet, _, _ := newSimpleServer(cert.Version2, ca, caKey, "me     ", "10.128.0.1/24,fc00::1/64", m{"relay": m{"use_relays": true}})
-	relayControl, relayVpnIpNet, relayUdpAddr, _ := newSimpleServer(cert.Version2, ca, caKey, "relay  ", "10.128.0.128/24,fc00::128/64", m{"relay": m{"am_relay": true}})
-	theirUdp := netip.MustParseAddrPort("10.0.0.2:4242")
-	theirControl, theirVpnIpNet, theirUdpAddr, _ := newSimpleServerWithUdp(cert.Version2, ca, caKey, "them   ", "fc00::2/64", theirUdp, m{"relay": m{"use_relays": true}})
-
-	//myVpnV4 := myVpnIpNet[0]
-	myVpnV6 := myVpnIpNet[1]
-	relayVpnV4 := relayVpnIpNet[0]
-	relayVpnV6 := relayVpnIpNet[1]
-	theirVpnV6 := theirVpnIpNet[0]
-
-	// Teach my how to get to the relay and that their can be reached via the relay
-	myControl.InjectLightHouseAddr(relayVpnV4.Addr(), relayUdpAddr)
-	myControl.InjectLightHouseAddr(relayVpnV6.Addr(), relayUdpAddr)
-	myControl.InjectRelays(theirVpnV6.Addr(), []netip.Addr{relayVpnV6.Addr()})
-	relayControl.InjectLightHouseAddr(theirVpnV6.Addr(), theirUdpAddr)
-
-	// Build a router so we don't have to reason who gets which packet
-	r := router.NewR(t, myControl, relayControl, theirControl)
-	defer r.RenderFlow()
-
-	// Start the servers
-	myControl.Start()
-	relayControl.Start()
-	theirControl.Start()
-
-	t.Log("Trigger a handshake from me to them via the relay")
-	myControl.InjectTunUDPPacket(theirVpnV6.Addr(), 80, myVpnV6.Addr(), 80, []byte("Hi from me"))
-
-	p := r.RouteForAllUntilTxTun(theirControl)
-	r.Log("Assert the tunnel works")
-	assertUdpPacket(t, []byte("Hi from me"), p, myVpnV6.Addr(), theirVpnV6.Addr(), 80, 80)
-
-	t.Log("reply?")
-	theirControl.InjectTunUDPPacket(myVpnV6.Addr(), 80, theirVpnV6.Addr(), 80, []byte("Hi from them"))
-	p = r.RouteForAllUntilTxTun(myControl)
-	assertUdpPacket(t, []byte("Hi from them"), p, theirVpnV6.Addr(), myVpnV6.Addr(), 80, 80)
-
-	r.RenderHostmaps("Final hostmaps", myControl, relayControl, theirControl)
-	//t.Log("finish up")
-	//myControl.Stop()
-	//theirControl.Stop()
-	//relayControl.Stop()
-}

examples/config.yml

@@ -383,9 +383,8 @@ firewall:
   #   host: `any` or a literal hostname, ie `test-host`
   #   group: `any` or a literal group name, ie `default-group`
   #   groups: Same as group but accepts a list of values. Multiple values are AND'd together and a certificate would have to contain all groups to pass
-  #   cidr: a remote CIDR, `0.0.0.0/0` is any ipv4 and `::/0` is any ipv6. `any` means any ip family and address.
+  #   cidr: a remote CIDR, `0.0.0.0/0` is any ipv4 and `::/0` is any ipv6.
-  #   local_cidr: a local CIDR, `0.0.0.0/0` is any ipv4 and `::/0` is any ipv6. `any` means any ip family and address.
+  #   local_cidr: a local CIDR, `0.0.0.0/0` is any ipv4 and `::/0` is any ipv6. This can be used to filter destinations when using unsafe_routes.
-  #     This can be used to filter destinations when using unsafe_routes.
   #     By default, this is set to only the VPN (overlay) networks assigned via the certificate networks field unless `default_local_cidr_any` is set to true.
   #     If there are unsafe_routes present in this config file, `local_cidr` should be set appropriately for the intended us case.
   #   ca_name: An issuing CA name

firewall.go

@@ -8,7 +8,6 @@ import (
 	"hash/fnv"
 	"net/netip"
 	"reflect"
-	"slices"
 	"strconv"
 	"strings"
 	"sync"
@@ -23,7 +22,7 @@ import (
 )
 
 type FirewallInterface interface {
-	AddRule(incoming bool, proto uint8, startPort int32, endPort int32, groups []string, host string, cidr, localCidr string, caName string, caSha string) error
+	AddRule(incoming bool, proto uint8, startPort int32, endPort int32, groups []string, host string, addr, localAddr netip.Prefix, caName string, caSha string) error
 }
 
 type conn struct {
@@ -248,11 +247,22 @@ func NewFirewallFromConfig(l *logrus.Logger, cs *CertState, c *config.C) (*Firew
 }
 
 // AddRule properly creates the in memory rule structure for a firewall table.
-func (f *Firewall) AddRule(incoming bool, proto uint8, startPort int32, endPort int32, groups []string, host string, cidr, localCidr, caName string, caSha string) error {
+func (f *Firewall) AddRule(incoming bool, proto uint8, startPort int32, endPort int32, groups []string, host string, ip, localIp netip.Prefix, caName string, caSha string) error {
+	// Under gomobile, stringing a nil pointer with fmt causes an abort in debug mode for iOS
+	// https://github.com/golang/go/issues/14131
+	sIp := ""
+	if ip.IsValid() {
+		sIp = ip.String()
+	}
+	lIp := ""
+	if localIp.IsValid() {
+		lIp = localIp.String()
+	}
+
 	// We need this rule string because we generate a hash. Removing this will break firewall reload.
 	ruleString := fmt.Sprintf(
 		"incoming: %v, proto: %v, startPort: %v, endPort: %v, groups: %v, host: %v, ip: %v, localIp: %v, caName: %v, caSha: %s",
-		incoming, proto, startPort, endPort, groups, host, cidr, localCidr, caName, caSha,
+		incoming, proto, startPort, endPort, groups, host, sIp, lIp, caName, caSha,
 	)
 	f.rules += ruleString + "\n"
 
@@ -260,7 +270,7 @@ func (f *Firewall) AddRule(incoming bool, proto uint8, startPort int32, endPort
 	if !incoming {
 		direction = "outgoing"
 	}
-	f.l.WithField("firewallRule", m{"direction": direction, "proto": proto, "startPort": startPort, "endPort": endPort, "groups": groups, "host": host, "cidr": cidr, "localCidr": localCidr, "caName": caName, "caSha": caSha}).
+	f.l.WithField("firewallRule", m{"direction": direction, "proto": proto, "startPort": startPort, "endPort": endPort, "groups": groups, "host": host, "ip": sIp, "localIp": lIp, "caName": caName, "caSha": caSha}).
 		Info("Firewall rule added")
 
 	var (
@@ -287,7 +297,7 @@ func (f *Firewall) AddRule(incoming bool, proto uint8, startPort int32, endPort
 		return fmt.Errorf("unknown protocol %v", proto)
 	}
 
-	return fp.addRule(f, startPort, endPort, groups, host, cidr, localCidr, caName, caSha)
+	return fp.addRule(f, startPort, endPort, groups, host, ip, localIp, caName, caSha)
 }
 
 // GetRuleHash returns a hash representation of all inbound and outbound rules
@@ -327,6 +337,7 @@ func AddFirewallRulesFromConfig(l *logrus.Logger, inbound bool, c *config.C, fw
 	}
 
 	for i, t := range rs {
+		var groups []string
 		r, err := convertRule(l, t, table, i)
 		if err != nil {
 			return fmt.Errorf("%s rule #%v; %s", table, i, err)
@@ -336,10 +347,23 @@ func AddFirewallRulesFromConfig(l *logrus.Logger, inbound bool, c *config.C, fw
 			return fmt.Errorf("%s rule #%v; only one of port or code should be provided", table, i)
 		}
 
-		if r.Host == "" && len(r.Groups) == 0 && r.Cidr == "" && r.LocalCidr == "" && r.CAName == "" && r.CASha == "" {
+		if r.Host == "" && len(r.Groups) == 0 && r.Group == "" && r.Cidr == "" && r.LocalCidr == "" && r.CAName == "" && r.CASha == "" {
 			return fmt.Errorf("%s rule #%v; at least one of host, group, cidr, local_cidr, ca_name, or ca_sha must be provided", table, i)
 		}
 
+		if len(r.Groups) > 0 {
+			groups = r.Groups
+		}
+
+		if r.Group != "" {
+			// Check if we have both groups and group provided in the rule config
+			if len(groups) > 0 {
+				return fmt.Errorf("%s rule #%v; only one of group or groups should be defined, both provided", table, i)
+			}
+
+			groups = []string{r.Group}
+		}
+
 		var sPort, errPort string
 		if r.Code != "" {
 			errPort = "code"
@@ -368,25 +392,23 @@ func AddFirewallRulesFromConfig(l *logrus.Logger, inbound bool, c *config.C, fw
 			return fmt.Errorf("%s rule #%v; proto was not understood; `%s`", table, i, r.Proto)
 		}
 
-		if r.Cidr != "" && r.Cidr != "any" {
+		var cidr netip.Prefix
-			_, err = netip.ParsePrefix(r.Cidr)
+		if r.Cidr != "" {
+			cidr, err = netip.ParsePrefix(r.Cidr)
 			if err != nil {
 				return fmt.Errorf("%s rule #%v; cidr did not parse; %s", table, i, err)
 			}
 		}
 
-		if r.LocalCidr != "" && r.LocalCidr != "any" {
+		var localCidr netip.Prefix
-			_, err = netip.ParsePrefix(r.LocalCidr)
+		if r.LocalCidr != "" {
+			localCidr, err = netip.ParsePrefix(r.LocalCidr)
 			if err != nil {
 				return fmt.Errorf("%s rule #%v; local_cidr did not parse; %s", table, i, err)
 			}
 		}
 
-		if warning := r.sanity(); warning != nil {
+		err = fw.AddRule(inbound, proto, startPort, endPort, groups, r.Host, cidr, localCidr, r.CAName, r.CASha)
-			l.Warnf("%s rule #%v; %s", table, i, warning)
-		}
-
-		err = fw.AddRule(inbound, proto, startPort, endPort, r.Groups, r.Host, r.Cidr, r.LocalCidr, r.CAName, r.CASha)
 		if err != nil {
 			return fmt.Errorf("%s rule #%v; `%s`", table, i, err)
 		}
@@ -395,45 +417,30 @@ func AddFirewallRulesFromConfig(l *logrus.Logger, inbound bool, c *config.C, fw
 	return nil
 }
 
-var ErrUnknownNetworkType = errors.New("unknown network type")
+var ErrInvalidRemoteIP = errors.New("remote IP is not in remote certificate subnets")
-var ErrPeerRejected = errors.New("remote address is not within a network that we handle")
+var ErrInvalidLocalIP = errors.New("local IP is not in list of handled local IPs")
-var ErrInvalidRemoteIP = errors.New("remote address is not in remote certificate networks")
-var ErrInvalidLocalIP = errors.New("local address is not in list of handled local addresses")
 var ErrNoMatchingRule = errors.New("no matching rule in firewall table")
 
 // Drop returns an error if the packet should be dropped, explaining why. It
 // returns nil if the packet should not be dropped.
-func (f *Firewall) Drop(fp firewall.Packet, incoming bool, h *HostInfo, caPool *cert.CAPool, localCache firewall.ConntrackCache) error {
+func (f *Firewall) Drop(fp firewall.Packet, incoming bool, h *HostInfo, caPool *cert.CAPool, localCache *firewall.ConntrackCache) error {
 	// Check if we spoke to this tuple, if we did then allow this packet
 	if f.inConns(fp, h, caPool, localCache) {
 		return nil
 	}
 
-	// Make sure remote address matches nebula certificate, and determine how to treat it
+	// Make sure remote address matches nebula certificate
-	if h.networks == nil {
+	if h.networks != nil {
-		// Simple case: Certificate has one address and no unsafe networks
+		if !h.networks.Contains(fp.RemoteAddr) {
-		if h.vpnAddrs[0] != fp.RemoteAddr {
 			f.metrics(incoming).droppedRemoteAddr.Inc(1)
 			return ErrInvalidRemoteIP
 		}
 	} else {
-		nwType, ok := h.networks.Lookup(fp.RemoteAddr)
+		// Simple case: Certificate has one address and no unsafe networks
-		if !ok {
+		if h.vpnAddrs[0] != fp.RemoteAddr {
 			f.metrics(incoming).droppedRemoteAddr.Inc(1)
 			return ErrInvalidRemoteIP
 		}
-		switch nwType {
-		case NetworkTypeVPN:
-			break // nothing special
-		case NetworkTypeVPNPeer:
-			f.metrics(incoming).droppedRemoteAddr.Inc(1)
-			return ErrPeerRejected // reject for now, one day this may have different FW rules
-		case NetworkTypeUnsafe:
-			break // nothing special, one day this may have different FW rules
-		default:
-			f.metrics(incoming).droppedRemoteAddr.Inc(1)
-			return ErrUnknownNetworkType //should never happen
-		}
 	}
 
 	// Make sure we are supposed to be handling this local ip address
@@ -483,11 +490,9 @@ func (f *Firewall) EmitStats() {
 	metrics.GetOrRegisterGauge("firewall.rules.hash", nil).Update(int64(f.GetRuleHashFNV()))
 }
 
-func (f *Firewall) inConns(fp firewall.Packet, h *HostInfo, caPool *cert.CAPool, localCache firewall.ConntrackCache) bool {
+func (f *Firewall) inConns(fp firewall.Packet, h *HostInfo, caPool *cert.CAPool, localCache *firewall.ConntrackCache) bool {
-	if localCache != nil {
+	if localCache != nil && localCache.Has(fp) {
-		if _, ok := localCache[fp]; ok {
+		return true
-			return true
-		}
 	}
 	conntrack := f.Conntrack
 	conntrack.Lock()
@@ -552,7 +557,7 @@ func (f *Firewall) inConns(fp firewall.Packet, h *HostInfo, caPool *cert.CAPool,
 	conntrack.Unlock()
 
 	if localCache != nil {
-		localCache[fp] = struct{}{}
+		localCache.Add(fp)
 	}
 
 	return true
@@ -633,7 +638,7 @@ func (ft *FirewallTable) match(p firewall.Packet, incoming bool, c *cert.CachedC
 	return false
 }
 
-func (fp firewallPort) addRule(f *Firewall, startPort int32, endPort int32, groups []string, host string, cidr, localCidr, caName string, caSha string) error {
+func (fp firewallPort) addRule(f *Firewall, startPort int32, endPort int32, groups []string, host string, ip, localIp netip.Prefix, caName string, caSha string) error {
 	if startPort > endPort {
 		return fmt.Errorf("start port was lower than end port")
 	}
@@ -646,7 +651,7 @@ func (fp firewallPort) addRule(f *Firewall, startPort int32, endPort int32, grou
 			}
 		}
 
-		if err := fp[i].addRule(f, groups, host, cidr, localCidr, caName, caSha); err != nil {
+		if err := fp[i].addRule(f, groups, host, ip, localIp, caName, caSha); err != nil {
 			return err
 		}
 	}
@@ -677,7 +682,7 @@ func (fp firewallPort) match(p firewall.Packet, incoming bool, c *cert.CachedCer
 	return fp[firewall.PortAny].match(p, c, caPool)
 }
 
-func (fc *FirewallCA) addRule(f *Firewall, groups []string, host string, cidr, localCidr, caName, caSha string) error {
+func (fc *FirewallCA) addRule(f *Firewall, groups []string, host string, ip, localIp netip.Prefix, caName, caSha string) error {
 	fr := func() *FirewallRule {
 		return &FirewallRule{
 			Hosts:  make(map[string]*firewallLocalCIDR),
@@ -691,14 +696,14 @@ func (fc *FirewallCA) addRule(f *Firewall, groups []string, host string, cidr, l
 			fc.Any = fr()
 		}
 
-		return fc.Any.addRule(f, groups, host, cidr, localCidr)
+		return fc.Any.addRule(f, groups, host, ip, localIp)
 	}
 
 	if caSha != "" {
 		if _, ok := fc.CAShas[caSha]; !ok {
 			fc.CAShas[caSha] = fr()
 		}
-		err := fc.CAShas[caSha].addRule(f, groups, host, cidr, localCidr)
+		err := fc.CAShas[caSha].addRule(f, groups, host, ip, localIp)
 		if err != nil {
 			return err
 		}
@@ -708,7 +713,7 @@ func (fc *FirewallCA) addRule(f *Firewall, groups []string, host string, cidr, l
 		if _, ok := fc.CANames[caName]; !ok {
 			fc.CANames[caName] = fr()
 		}
-		err := fc.CANames[caName].addRule(f, groups, host, cidr, localCidr)
+		err := fc.CANames[caName].addRule(f, groups, host, ip, localIp)
 		if err != nil {
 			return err
 		}
@@ -740,24 +745,24 @@ func (fc *FirewallCA) match(p firewall.Packet, c *cert.CachedCertificate, caPool
 	return fc.CANames[s.Certificate.Name()].match(p, c)
 }
 
-func (fr *FirewallRule) addRule(f *Firewall, groups []string, host, cidr, localCidr string) error {
+func (fr *FirewallRule) addRule(f *Firewall, groups []string, host string, ip, localCIDR netip.Prefix) error {
 	flc := func() *firewallLocalCIDR {
 		return &firewallLocalCIDR{
 			LocalCIDR: new(bart.Lite),
 		}
 	}
 
-	if fr.isAny(groups, host, cidr) {
+	if fr.isAny(groups, host, ip) {
 		if fr.Any == nil {
 			fr.Any = flc()
 		}
 
-		return fr.Any.addRule(f, localCidr)
+		return fr.Any.addRule(f, localCIDR)
 	}
 
 	if len(groups) > 0 {
 		nlc := flc()
-		err := nlc.addRule(f, localCidr)
+		err := nlc.addRule(f, localCIDR)
 		if err != nil {
 			return err
 		}
@@ -773,34 +778,30 @@ func (fr *FirewallRule) addRule(f *Firewall, groups []string, host, cidr, localC
 		if nlc == nil {
 			nlc = flc()
 		}
-		err := nlc.addRule(f, localCidr)
+		err := nlc.addRule(f, localCIDR)
 		if err != nil {
 			return err
 		}
 		fr.Hosts[host] = nlc
 	}
 
-	if cidr != "" {
+	if ip.IsValid() {
-		c, err := netip.ParsePrefix(cidr)
+		nlc, _ := fr.CIDR.Get(ip)
-		if err != nil {
-			return err
-		}
-		nlc, _ := fr.CIDR.Get(c)
 		if nlc == nil {
 			nlc = flc()
 		}
-		err = nlc.addRule(f, localCidr)
+		err := nlc.addRule(f, localCIDR)
 		if err != nil {
 			return err
 		}
-		fr.CIDR.Insert(c, nlc)
+		fr.CIDR.Insert(ip, nlc)
 	}
 
 	return nil
 }
 
-func (fr *FirewallRule) isAny(groups []string, host string, cidr string) bool {
+func (fr *FirewallRule) isAny(groups []string, host string, ip netip.Prefix) bool {
-	if len(groups) == 0 && host == "" && cidr == "" {
+	if len(groups) == 0 && host == "" && !ip.IsValid() {
 		return true
 	}
 
@@ -814,7 +815,7 @@ func (fr *FirewallRule) isAny(groups []string, host string, cidr string) bool {
 		return true
 	}
 
-	if cidr == "any" {
+	if ip.IsValid() && ip.Bits() == 0 {
 		return true
 	}
 
@@ -866,13 +867,8 @@ func (fr *FirewallRule) match(p firewall.Packet, c *cert.CachedCertificate) bool
 	return false
 }
 
-func (flc *firewallLocalCIDR) addRule(f *Firewall, localCidr string) error {
+func (flc *firewallLocalCIDR) addRule(f *Firewall, localIp netip.Prefix) error {
-	if localCidr == "any" {
+	if !localIp.IsValid() {
-		flc.Any = true
-		return nil
-	}
-
-	if localCidr == "" {
 		if !f.hasUnsafeNetworks || f.defaultLocalCIDRAny {
 			flc.Any = true
 			return nil
@@ -883,13 +879,12 @@ func (flc *firewallLocalCIDR) addRule(f *Firewall, localCidr string) error {
 		}
 		return nil
 
+	} else if localIp.Bits() == 0 {
+		flc.Any = true
+		return nil
 	}
 
-	c, err := netip.ParsePrefix(localCidr)
+	flc.LocalCIDR.Insert(localIp)
-	if err != nil {
-		return err
-	}
-	flc.LocalCIDR.Insert(c)
 	return nil
 }
 
@@ -910,6 +905,7 @@ type rule struct {
 	Code      string
 	Proto     string
 	Host      string
+	Group     string
 	Groups    []string
 	Cidr      string
 	LocalCidr string
@@ -951,8 +947,7 @@ func convertRule(l *logrus.Logger, p any, table string, i int) (rule, error) {
 		l.Warnf("%s rule #%v; group was an array with a single value, converting to simple value", table, i)
 		m["group"] = v[0]
 	}
-
+	r.Group = toString("group", m)
-	singleGroup := toString("group", m)
 
 	if rg, ok := m["groups"]; ok {
 		switch reflect.TypeOf(rg).Kind() {
@@ -969,60 +964,9 @@ func convertRule(l *logrus.Logger, p any, table string, i int) (rule, error) {
 		}
 	}
 
-	//flatten group vs groups
-	if singleGroup != "" {
-		// Check if we have both groups and group provided in the rule config
-		if len(r.Groups) > 0 {
-			return r, fmt.Errorf("only one of group or groups should be defined, both provided")
-		}
-		r.Groups = []string{singleGroup}
-	}
-
 	return r, nil
 }
 
-// sanity returns an error if the rule would be evaluated in a way that would short-circuit a configured check on a wildcard value
-// rules are evaluated as "port AND proto AND (ca_sha OR ca_name) AND (host OR group OR groups OR cidr) AND local_cidr"
-func (r *rule) sanity() error {
-	//port, proto, local_cidr are AND, no need to check here
-	//ca_sha and ca_name don't have a wildcard value, no need to check here
-	groupsEmpty := len(r.Groups) == 0
-	hostEmpty := r.Host == ""
-	cidrEmpty := r.Cidr == ""
-
-	if (groupsEmpty && hostEmpty && cidrEmpty) == true {
-		return nil //no content!
-	}
-
-	groupsHasAny := slices.Contains(r.Groups, "any")
-	if groupsHasAny && len(r.Groups) > 1 {
-		return fmt.Errorf("groups spec [%s] contains the group '\"any\". This rule will ignore the other groups specified", r.Groups)
-	}
-
-	if r.Host == "any" {
-		if !groupsEmpty {
-			return fmt.Errorf("groups specified as %s, but host=any will match any host, regardless of groups", r.Groups)
-		}
-
-		if !cidrEmpty {
-			return fmt.Errorf("cidr specified as %s, but host=any will match any host, regardless of cidr", r.Cidr)
-		}
-	}
-
-	if groupsHasAny {
-		if !hostEmpty && r.Host != "any" {
-			return fmt.Errorf("groups spec [%s] contains the group '\"any\". This rule will ignore the specified host %s", r.Groups, r.Host)
-		}
-		if !cidrEmpty {
-			return fmt.Errorf("groups spec [%s] contains the group '\"any\". This rule will ignore the specified cidr %s", r.Groups, r.Cidr)
-		}
-	}
-
-	//todo alert on cidr-any
-
-	return nil
-}
-
 func parsePort(s string) (startPort, endPort int32, err error) {
 	if s == "any" {
 		startPort = firewall.PortAny

firewall/cache.go

@@ -1,6 +1,7 @@
 package firewall
 
 import (
+	"sync"
 	"sync/atomic"
 	"time"
 
@@ -9,13 +10,58 @@ import (
 
 // ConntrackCache is used as a local routine cache to know if a given flow
 // has been seen in the conntrack table.
-type ConntrackCache map[Packet]struct{}
+type ConntrackCache struct {
+	mu      sync.Mutex
+	entries map[Packet]struct{}
+}
+
+func newConntrackCache() *ConntrackCache {
+	return &ConntrackCache{entries: make(map[Packet]struct{})}
+}
+
+func (c *ConntrackCache) Has(p Packet) bool {
+	if c == nil {
+		return false
+	}
+	c.mu.Lock()
+	_, ok := c.entries[p]
+	c.mu.Unlock()
+	return ok
+}
+
+func (c *ConntrackCache) Add(p Packet) {
+	if c == nil {
+		return
+	}
+	c.mu.Lock()
+	c.entries[p] = struct{}{}
+	c.mu.Unlock()
+}
+
+func (c *ConntrackCache) Len() int {
+	if c == nil {
+		return 0
+	}
+	c.mu.Lock()
+	l := len(c.entries)
+	c.mu.Unlock()
+	return l
+}
+
+func (c *ConntrackCache) Reset(capHint int) {
+	if c == nil {
+		return
+	}
+	c.mu.Lock()
+	c.entries = make(map[Packet]struct{}, capHint)
+	c.mu.Unlock()
+}
 
 type ConntrackCacheTicker struct {
 	cacheV    uint64
 	cacheTick atomic.Uint64
 
-	cache ConntrackCache
+	cache *ConntrackCache
 }
 
 func NewConntrackCacheTicker(d time.Duration) *ConntrackCacheTicker {
@@ -23,9 +69,7 @@ func NewConntrackCacheTicker(d time.Duration) *ConntrackCacheTicker {
 		return nil
 	}
 
-	c := &ConntrackCacheTicker{
+	c := &ConntrackCacheTicker{cache: newConntrackCache()}
-		cache: ConntrackCache{},
-	}
 
 	go c.tick(d)
 
@@ -41,17 +85,17 @@ func (c *ConntrackCacheTicker) tick(d time.Duration) {
 
 // Get checks if the cache ticker has moved to the next version before returning
 // the map. If it has moved, we reset the map.
-func (c *ConntrackCacheTicker) Get(l *logrus.Logger) ConntrackCache {
+func (c *ConntrackCacheTicker) Get(l *logrus.Logger) *ConntrackCache {
 	if c == nil {
 		return nil
 	}
 	if tick := c.cacheTick.Load(); tick != c.cacheV {
 		c.cacheV = tick
-		if ll := len(c.cache); ll > 0 {
+		if ll := c.cache.Len(); ll > 0 {
 			if l.Level == logrus.DebugLevel {
 				l.WithField("len", ll).Debug("resetting conntrack cache")
 			}
-			c.cache = make(ConntrackCache, ll)
+			c.cache.Reset(ll)
 		}
 	}
 

firewall_test.go

@@ -8,8 +8,6 @@ import (
 	"testing"
 	"time"
 
-	"github.com/gaissmai/bart"
-	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula/cert"
 	"github.com/slackhq/nebula/config"
 	"github.com/slackhq/nebula/firewall"
@@ -73,114 +71,85 @@ func TestFirewall_AddRule(t *testing.T) {
 	ti6, err := netip.ParsePrefix("fd12::34/128")
 	require.NoError(t, err)
 
-	require.NoError(t, fw.AddRule(true, firewall.ProtoTCP, 1, 1, []string{}, "", "", "", "", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoTCP, 1, 1, []string{}, "", netip.Prefix{}, netip.Prefix{}, "", ""))
 	// An empty rule is any
 	assert.True(t, fw.InRules.TCP[1].Any.Any.Any)
 	assert.Empty(t, fw.InRules.TCP[1].Any.Groups)
 	assert.Empty(t, fw.InRules.TCP[1].Any.Hosts)
 
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoUDP, 1, 1, []string{"g1"}, "", "", "", "", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoUDP, 1, 1, []string{"g1"}, "", netip.Prefix{}, netip.Prefix{}, "", ""))
 	assert.Nil(t, fw.InRules.UDP[1].Any.Any)
 	assert.Contains(t, fw.InRules.UDP[1].Any.Groups[0].Groups, "g1")
 	assert.Empty(t, fw.InRules.UDP[1].Any.Hosts)
 
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoICMP, 1, 1, []string{}, "h1", "", "", "", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoICMP, 1, 1, []string{}, "h1", netip.Prefix{}, netip.Prefix{}, "", ""))
 	assert.Nil(t, fw.InRules.ICMP[1].Any.Any)
 	assert.Empty(t, fw.InRules.ICMP[1].Any.Groups)
 	assert.Contains(t, fw.InRules.ICMP[1].Any.Hosts, "h1")
 
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c)
-	require.NoError(t, fw.AddRule(false, firewall.ProtoAny, 1, 1, []string{}, "", ti.String(), "", "", ""))
+	require.NoError(t, fw.AddRule(false, firewall.ProtoAny, 1, 1, []string{}, "", ti, netip.Prefix{}, "", ""))
 	assert.Nil(t, fw.OutRules.AnyProto[1].Any.Any)
 	_, ok := fw.OutRules.AnyProto[1].Any.CIDR.Get(ti)
 	assert.True(t, ok)
 
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c)
-	require.NoError(t, fw.AddRule(false, firewall.ProtoAny, 1, 1, []string{}, "", ti6.String(), "", "", ""))
+	require.NoError(t, fw.AddRule(false, firewall.ProtoAny, 1, 1, []string{}, "", ti6, netip.Prefix{}, "", ""))
 	assert.Nil(t, fw.OutRules.AnyProto[1].Any.Any)
 	_, ok = fw.OutRules.AnyProto[1].Any.CIDR.Get(ti6)
 	assert.True(t, ok)
 
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c)
-	require.NoError(t, fw.AddRule(false, firewall.ProtoAny, 1, 1, []string{}, "", "", ti.String(), "", ""))
+	require.NoError(t, fw.AddRule(false, firewall.ProtoAny, 1, 1, []string{}, "", netip.Prefix{}, ti, "", ""))
 	assert.NotNil(t, fw.OutRules.AnyProto[1].Any.Any)
-	ok = fw.OutRules.AnyProto[1].Any.Any.LocalCIDR.Get(ti)
+	_, ok = fw.OutRules.AnyProto[1].Any.Any.LocalCIDR.Get(ti)
 	assert.True(t, ok)
 
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c)
-	require.NoError(t, fw.AddRule(false, firewall.ProtoAny, 1, 1, []string{}, "", "", ti6.String(), "", ""))
+	require.NoError(t, fw.AddRule(false, firewall.ProtoAny, 1, 1, []string{}, "", netip.Prefix{}, ti6, "", ""))
 	assert.NotNil(t, fw.OutRules.AnyProto[1].Any.Any)
-	ok = fw.OutRules.AnyProto[1].Any.Any.LocalCIDR.Get(ti6)
+	_, ok = fw.OutRules.AnyProto[1].Any.Any.LocalCIDR.Get(ti6)
 	assert.True(t, ok)
 
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoUDP, 1, 1, []string{"g1"}, "", "", "", "ca-name", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoUDP, 1, 1, []string{"g1"}, "", netip.Prefix{}, netip.Prefix{}, "ca-name", ""))
 	assert.Contains(t, fw.InRules.UDP[1].CANames, "ca-name")
 
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoUDP, 1, 1, []string{"g1"}, "", "", "", "", "ca-sha"))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoUDP, 1, 1, []string{"g1"}, "", netip.Prefix{}, netip.Prefix{}, "", "ca-sha"))
 	assert.Contains(t, fw.InRules.UDP[1].CAShas, "ca-sha")
 
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c)
-	require.NoError(t, fw.AddRule(false, firewall.ProtoAny, 0, 0, []string{}, "any", "", "", "", ""))
+	require.NoError(t, fw.AddRule(false, firewall.ProtoAny, 0, 0, []string{}, "any", netip.Prefix{}, netip.Prefix{}, "", ""))
 	assert.True(t, fw.OutRules.AnyProto[0].Any.Any.Any)
 
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c)
 	anyIp, err := netip.ParsePrefix("0.0.0.0/0")
 	require.NoError(t, err)
 
-	require.NoError(t, fw.AddRule(false, firewall.ProtoAny, 0, 0, []string{}, "", anyIp.String(), "", "", ""))
+	require.NoError(t, fw.AddRule(false, firewall.ProtoAny, 0, 0, []string{}, "", anyIp, netip.Prefix{}, "", ""))
-	assert.Nil(t, fw.OutRules.AnyProto[0].Any.Any)
+	assert.True(t, fw.OutRules.AnyProto[0].Any.Any.Any)
-	table, ok := fw.OutRules.AnyProto[0].Any.CIDR.Lookup(netip.MustParseAddr("1.1.1.1"))
-	assert.True(t, table.Any)
-	table, ok = fw.OutRules.AnyProto[0].Any.CIDR.Lookup(netip.MustParseAddr("9::9"))
-	assert.False(t, ok)
 
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c)
 	anyIp6, err := netip.ParsePrefix("::/0")
 	require.NoError(t, err)
 
-	require.NoError(t, fw.AddRule(false, firewall.ProtoAny, 0, 0, []string{}, "", anyIp6.String(), "", "", ""))
+	require.NoError(t, fw.AddRule(false, firewall.ProtoAny, 0, 0, []string{}, "", anyIp6, netip.Prefix{}, "", ""))
-	assert.Nil(t, fw.OutRules.AnyProto[0].Any.Any)
-	table, ok = fw.OutRules.AnyProto[0].Any.CIDR.Lookup(netip.MustParseAddr("9::9"))
-	assert.True(t, table.Any)
-	table, ok = fw.OutRules.AnyProto[0].Any.CIDR.Lookup(netip.MustParseAddr("1.1.1.1"))
-	assert.False(t, ok)
-
-	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c)
-	require.NoError(t, fw.AddRule(false, firewall.ProtoAny, 0, 0, []string{}, "", "any", "", "", ""))
-	assert.True(t, fw.OutRules.AnyProto[0].Any.Any.Any)
-
-	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c)
-	require.NoError(t, fw.AddRule(false, firewall.ProtoAny, 0, 0, []string{}, "", "", anyIp.String(), "", ""))
-	assert.False(t, fw.OutRules.AnyProto[0].Any.Any.Any)
-	assert.True(t, fw.OutRules.AnyProto[0].Any.Any.LocalCIDR.Lookup(netip.MustParseAddr("1.1.1.1")))
-	assert.False(t, fw.OutRules.AnyProto[0].Any.Any.LocalCIDR.Lookup(netip.MustParseAddr("9::9")))
-
-	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c)
-	require.NoError(t, fw.AddRule(false, firewall.ProtoAny, 0, 0, []string{}, "", "", anyIp6.String(), "", ""))
-	assert.False(t, fw.OutRules.AnyProto[0].Any.Any.Any)
-	assert.True(t, fw.OutRules.AnyProto[0].Any.Any.LocalCIDR.Lookup(netip.MustParseAddr("9::9")))
-	assert.False(t, fw.OutRules.AnyProto[0].Any.Any.LocalCIDR.Lookup(netip.MustParseAddr("1.1.1.1")))
-
-	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c)
-	require.NoError(t, fw.AddRule(false, firewall.ProtoAny, 0, 0, []string{}, "", "", "any", "", ""))
 	assert.True(t, fw.OutRules.AnyProto[0].Any.Any.Any)
 
 	// Test error conditions
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c)
-	require.Error(t, fw.AddRule(true, math.MaxUint8, 0, 0, []string{}, "", "", "", "", ""))
+	require.Error(t, fw.AddRule(true, math.MaxUint8, 0, 0, []string{}, "", netip.Prefix{}, netip.Prefix{}, "", ""))
-	require.Error(t, fw.AddRule(true, firewall.ProtoAny, 10, 0, []string{}, "", "", "", "", ""))
+	require.Error(t, fw.AddRule(true, firewall.ProtoAny, 10, 0, []string{}, "", netip.Prefix{}, netip.Prefix{}, "", ""))
 }
 
 func TestFirewall_Drop(t *testing.T) {
 	l := test.NewLogger()
 	ob := &bytes.Buffer{}
 	l.SetOutput(ob)
-	myVpnNetworksTable := new(bart.Lite)
+
-	myVpnNetworksTable.Insert(netip.MustParsePrefix("1.1.1.1/8"))
 	p := firewall.Packet{
 		LocalAddr:  netip.MustParseAddr("1.2.3.4"),
 		RemoteAddr: netip.MustParseAddr("1.2.3.4"),
@@ -205,10 +174,10 @@ func TestFirewall_Drop(t *testing.T) {
 		},
 		vpnAddrs: []netip.Addr{netip.MustParseAddr("1.2.3.4")},
 	}
-	h.buildNetworks(myVpnNetworksTable, &c)
+	h.buildNetworks(c.networks, c.unsafeNetworks)
 
 	fw := NewFirewall(l, time.Second, time.Minute, time.Hour, &c)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"any"}, "", "", "", "", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"any"}, "", netip.Prefix{}, netip.Prefix{}, "", ""))
 	cp := cert.NewCAPool()
 
 	// Drop outbound
@@ -227,28 +196,28 @@ func TestFirewall_Drop(t *testing.T) {
 
 	// ensure signer doesn't get in the way of group checks
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, &c)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"nope"}, "", "", "", "", "signer-shasum"))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"nope"}, "", netip.Prefix{}, netip.Prefix{}, "", "signer-shasum"))
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"default-group"}, "", "", "", "", "signer-shasum-bad"))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"default-group"}, "", netip.Prefix{}, netip.Prefix{}, "", "signer-shasum-bad"))
 	assert.Equal(t, fw.Drop(p, true, &h, cp, nil), ErrNoMatchingRule)
 
 	// test caSha doesn't drop on match
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, &c)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"nope"}, "", "", "", "", "signer-shasum-bad"))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"nope"}, "", netip.Prefix{}, netip.Prefix{}, "", "signer-shasum-bad"))
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"default-group"}, "", "", "", "", "signer-shasum"))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"default-group"}, "", netip.Prefix{}, netip.Prefix{}, "", "signer-shasum"))
 	require.NoError(t, fw.Drop(p, true, &h, cp, nil))
 
 	// ensure ca name doesn't get in the way of group checks
 	cp.CAs["signer-shasum"] = &cert.CachedCertificate{Certificate: &dummyCert{name: "ca-good"}}
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, &c)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"nope"}, "", "", "", "ca-good", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"nope"}, "", netip.Prefix{}, netip.Prefix{}, "ca-good", ""))
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"default-group"}, "", "", "", "ca-good-bad", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"default-group"}, "", netip.Prefix{}, netip.Prefix{}, "ca-good-bad", ""))
 	assert.Equal(t, fw.Drop(p, true, &h, cp, nil), ErrNoMatchingRule)
 
 	// test caName doesn't drop on match
 	cp.CAs["signer-shasum"] = &cert.CachedCertificate{Certificate: &dummyCert{name: "ca-good"}}
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, &c)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"nope"}, "", "", "", "ca-good-bad", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"nope"}, "", netip.Prefix{}, netip.Prefix{}, "ca-good-bad", ""))
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"default-group"}, "", "", "", "ca-good", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"default-group"}, "", netip.Prefix{}, netip.Prefix{}, "ca-good", ""))
 	require.NoError(t, fw.Drop(p, true, &h, cp, nil))
 }
 
@@ -257,9 +226,6 @@ func TestFirewall_DropV6(t *testing.T) {
 	ob := &bytes.Buffer{}
 	l.SetOutput(ob)
 
-	myVpnNetworksTable := new(bart.Lite)
-	myVpnNetworksTable.Insert(netip.MustParsePrefix("fd00::/7"))
-
 	p := firewall.Packet{
 		LocalAddr:  netip.MustParseAddr("fd12::34"),
 		RemoteAddr: netip.MustParseAddr("fd12::34"),
@@ -284,10 +250,10 @@ func TestFirewall_DropV6(t *testing.T) {
 		},
 		vpnAddrs: []netip.Addr{netip.MustParseAddr("fd12::34")},
 	}
-	h.buildNetworks(myVpnNetworksTable, &c)
+	h.buildNetworks(c.networks, c.unsafeNetworks)
 
 	fw := NewFirewall(l, time.Second, time.Minute, time.Hour, &c)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"any"}, "", "", "", "", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"any"}, "", netip.Prefix{}, netip.Prefix{}, "", ""))
 	cp := cert.NewCAPool()
 
 	// Drop outbound
@@ -306,28 +272,28 @@ func TestFirewall_DropV6(t *testing.T) {
 
 	// ensure signer doesn't get in the way of group checks
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, &c)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"nope"}, "", "", "", "", "signer-shasum"))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"nope"}, "", netip.Prefix{}, netip.Prefix{}, "", "signer-shasum"))
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"default-group"}, "", "", "", "", "signer-shasum-bad"))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"default-group"}, "", netip.Prefix{}, netip.Prefix{}, "", "signer-shasum-bad"))
 	assert.Equal(t, fw.Drop(p, true, &h, cp, nil), ErrNoMatchingRule)
 
 	// test caSha doesn't drop on match
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, &c)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"nope"}, "", "", "", "", "signer-shasum-bad"))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"nope"}, "", netip.Prefix{}, netip.Prefix{}, "", "signer-shasum-bad"))
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"default-group"}, "", "", "", "", "signer-shasum"))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"default-group"}, "", netip.Prefix{}, netip.Prefix{}, "", "signer-shasum"))
 	require.NoError(t, fw.Drop(p, true, &h, cp, nil))
 
 	// ensure ca name doesn't get in the way of group checks
 	cp.CAs["signer-shasum"] = &cert.CachedCertificate{Certificate: &dummyCert{name: "ca-good"}}
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, &c)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"nope"}, "", "", "", "ca-good", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"nope"}, "", netip.Prefix{}, netip.Prefix{}, "ca-good", ""))
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"default-group"}, "", "", "", "ca-good-bad", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"default-group"}, "", netip.Prefix{}, netip.Prefix{}, "ca-good-bad", ""))
 	assert.Equal(t, fw.Drop(p, true, &h, cp, nil), ErrNoMatchingRule)
 
 	// test caName doesn't drop on match
 	cp.CAs["signer-shasum"] = &cert.CachedCertificate{Certificate: &dummyCert{name: "ca-good"}}
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, &c)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"nope"}, "", "", "", "ca-good-bad", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"nope"}, "", netip.Prefix{}, netip.Prefix{}, "ca-good-bad", ""))
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"default-group"}, "", "", "", "ca-good", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"default-group"}, "", netip.Prefix{}, netip.Prefix{}, "ca-good", ""))
 	require.NoError(t, fw.Drop(p, true, &h, cp, nil))
 }
 
@@ -338,12 +304,12 @@ func BenchmarkFirewallTable_match(b *testing.B) {
 	}
 
 	pfix := netip.MustParsePrefix("172.1.1.1/32")
-	_ = ft.TCP.addRule(f, 10, 10, []string{"good-group"}, "good-host", pfix.String(), "", "", "")
+	_ = ft.TCP.addRule(f, 10, 10, []string{"good-group"}, "good-host", pfix, netip.Prefix{}, "", "")
-	_ = ft.TCP.addRule(f, 100, 100, []string{"good-group"}, "good-host", "", pfix.String(), "", "")
+	_ = ft.TCP.addRule(f, 100, 100, []string{"good-group"}, "good-host", netip.Prefix{}, pfix, "", "")
 
 	pfix6 := netip.MustParsePrefix("fd11::11/128")
-	_ = ft.TCP.addRule(f, 10, 10, []string{"good-group"}, "good-host", pfix6.String(), "", "", "")
+	_ = ft.TCP.addRule(f, 10, 10, []string{"good-group"}, "good-host", pfix6, netip.Prefix{}, "", "")
-	_ = ft.TCP.addRule(f, 100, 100, []string{"good-group"}, "good-host", "", pfix6.String(), "", "")
+	_ = ft.TCP.addRule(f, 100, 100, []string{"good-group"}, "good-host", netip.Prefix{}, pfix6, "", "")
 	cp := cert.NewCAPool()
 
 	b.Run("fail on proto", func(b *testing.B) {
@@ -487,8 +453,6 @@ func TestFirewall_Drop2(t *testing.T) {
 	l := test.NewLogger()
 	ob := &bytes.Buffer{}
 	l.SetOutput(ob)
-	myVpnNetworksTable := new(bart.Lite)
-	myVpnNetworksTable.Insert(netip.MustParsePrefix("1.1.1.1/8"))
 
 	p := firewall.Packet{
 		LocalAddr:  netip.MustParseAddr("1.2.3.4"),
@@ -514,7 +478,7 @@ func TestFirewall_Drop2(t *testing.T) {
 		},
 		vpnAddrs: []netip.Addr{network.Addr()},
 	}
-	h.buildNetworks(myVpnNetworksTable, c.Certificate)
+	h.buildNetworks(c.Certificate.Networks(), c.Certificate.UnsafeNetworks())
 
 	c1 := cert.CachedCertificate{
 		Certificate: &dummyCert{
@@ -529,10 +493,10 @@ func TestFirewall_Drop2(t *testing.T) {
 			peerCert: &c1,
 		},
 	}
-	h1.buildNetworks(myVpnNetworksTable, c1.Certificate)
+	h1.buildNetworks(c1.Certificate.Networks(), c1.Certificate.UnsafeNetworks())
 
 	fw := NewFirewall(l, time.Second, time.Minute, time.Hour, c.Certificate)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"default-group", "test-group"}, "", "", "", "", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"default-group", "test-group"}, "", netip.Prefix{}, netip.Prefix{}, "", ""))
 	cp := cert.NewCAPool()
 
 	// h1/c1 lacks the proper groups
@@ -546,8 +510,6 @@ func TestFirewall_Drop3(t *testing.T) {
 	l := test.NewLogger()
 	ob := &bytes.Buffer{}
 	l.SetOutput(ob)
-	myVpnNetworksTable := new(bart.Lite)
-	myVpnNetworksTable.Insert(netip.MustParsePrefix("1.1.1.1/8"))
 
 	p := firewall.Packet{
 		LocalAddr:  netip.MustParseAddr("1.2.3.4"),
@@ -579,7 +541,7 @@ func TestFirewall_Drop3(t *testing.T) {
 		},
 		vpnAddrs: []netip.Addr{network.Addr()},
 	}
-	h1.buildNetworks(myVpnNetworksTable, c1.Certificate)
+	h1.buildNetworks(c1.Certificate.Networks(), c1.Certificate.UnsafeNetworks())
 
 	c2 := cert.CachedCertificate{
 		Certificate: &dummyCert{
@@ -594,7 +556,7 @@ func TestFirewall_Drop3(t *testing.T) {
 		},
 		vpnAddrs: []netip.Addr{network.Addr()},
 	}
-	h2.buildNetworks(myVpnNetworksTable, c2.Certificate)
+	h2.buildNetworks(c2.Certificate.Networks(), c2.Certificate.UnsafeNetworks())
 
 	c3 := cert.CachedCertificate{
 		Certificate: &dummyCert{
@@ -609,11 +571,11 @@ func TestFirewall_Drop3(t *testing.T) {
 		},
 		vpnAddrs: []netip.Addr{network.Addr()},
 	}
-	h3.buildNetworks(myVpnNetworksTable, c3.Certificate)
+	h3.buildNetworks(c3.Certificate.Networks(), c3.Certificate.UnsafeNetworks())
 
 	fw := NewFirewall(l, time.Second, time.Minute, time.Hour, c.Certificate)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 1, 1, []string{}, "host1", "", "", "", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 1, 1, []string{}, "host1", netip.Prefix{}, netip.Prefix{}, "", ""))
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 1, 1, []string{}, "", "", "", "", "signer-sha"))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 1, 1, []string{}, "", netip.Prefix{}, netip.Prefix{}, "", "signer-sha"))
 	cp := cert.NewCAPool()
 
 	// c1 should pass because host match
@@ -627,7 +589,7 @@ func TestFirewall_Drop3(t *testing.T) {
 
 	// Test a remote address match
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c.Certificate)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 1, 1, []string{}, "", "1.2.3.4/24", "", "", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 1, 1, []string{}, "", netip.MustParsePrefix("1.2.3.4/24"), netip.Prefix{}, "", ""))
 	require.NoError(t, fw.Drop(p, true, &h1, cp, nil))
 }
 
@@ -635,8 +597,6 @@ func TestFirewall_Drop3V6(t *testing.T) {
 	l := test.NewLogger()
 	ob := &bytes.Buffer{}
 	l.SetOutput(ob)
-	myVpnNetworksTable := new(bart.Lite)
-	myVpnNetworksTable.Insert(netip.MustParsePrefix("fd00::/7"))
 
 	p := firewall.Packet{
 		LocalAddr:  netip.MustParseAddr("fd12::34"),
@@ -660,12 +620,12 @@ func TestFirewall_Drop3V6(t *testing.T) {
 		},
 		vpnAddrs: []netip.Addr{network.Addr()},
 	}
-	h.buildNetworks(myVpnNetworksTable, c.Certificate)
+	h.buildNetworks(c.Certificate.Networks(), c.Certificate.UnsafeNetworks())
 
 	// Test a remote address match
 	fw := NewFirewall(l, time.Second, time.Minute, time.Hour, c.Certificate)
 	cp := cert.NewCAPool()
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 1, 1, []string{}, "", "fd12::34/120", "", "", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 1, 1, []string{}, "", netip.MustParsePrefix("fd12::34/120"), netip.Prefix{}, "", ""))
 	require.NoError(t, fw.Drop(p, true, &h, cp, nil))
 }
 
@@ -673,8 +633,6 @@ func TestFirewall_DropConntrackReload(t *testing.T) {
 	l := test.NewLogger()
 	ob := &bytes.Buffer{}
 	l.SetOutput(ob)
-	myVpnNetworksTable := new(bart.Lite)
-	myVpnNetworksTable.Insert(netip.MustParsePrefix("1.1.1.1/8"))
 
 	p := firewall.Packet{
 		LocalAddr:  netip.MustParseAddr("1.2.3.4"),
@@ -701,10 +659,10 @@ func TestFirewall_DropConntrackReload(t *testing.T) {
 		},
 		vpnAddrs: []netip.Addr{network.Addr()},
 	}
-	h.buildNetworks(myVpnNetworksTable, c.Certificate)
+	h.buildNetworks(c.Certificate.Networks(), c.Certificate.UnsafeNetworks())
 
 	fw := NewFirewall(l, time.Second, time.Minute, time.Hour, c.Certificate)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"any"}, "", "", "", "", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"any"}, "", netip.Prefix{}, netip.Prefix{}, "", ""))
 	cp := cert.NewCAPool()
 
 	// Drop outbound
@@ -717,7 +675,7 @@ func TestFirewall_DropConntrackReload(t *testing.T) {
 
 	oldFw := fw
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c.Certificate)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 10, 10, []string{"any"}, "", "", "", "", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 10, 10, []string{"any"}, "", netip.Prefix{}, netip.Prefix{}, "", ""))
 	fw.Conntrack = oldFw.Conntrack
 	fw.rulesVersion = oldFw.rulesVersion + 1
 
@@ -726,7 +684,7 @@ func TestFirewall_DropConntrackReload(t *testing.T) {
 
 	oldFw = fw
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c.Certificate)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 11, 11, []string{"any"}, "", "", "", "", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 11, 11, []string{"any"}, "", netip.Prefix{}, netip.Prefix{}, "", ""))
 	fw.Conntrack = oldFw.Conntrack
 	fw.rulesVersion = oldFw.rulesVersion + 1
 
@@ -738,8 +696,6 @@ func TestFirewall_DropIPSpoofing(t *testing.T) {
 	l := test.NewLogger()
 	ob := &bytes.Buffer{}
 	l.SetOutput(ob)
-	myVpnNetworksTable := new(bart.Lite)
-	myVpnNetworksTable.Insert(netip.MustParsePrefix("192.0.2.1/24"))
 
 	c := cert.CachedCertificate{
 		Certificate: &dummyCert{
@@ -761,11 +717,11 @@ func TestFirewall_DropIPSpoofing(t *testing.T) {
 		},
 		vpnAddrs: []netip.Addr{c1.Certificate.Networks()[0].Addr()},
 	}
-	h1.buildNetworks(myVpnNetworksTable, c1.Certificate)
+	h1.buildNetworks(c1.Certificate.Networks(), c1.Certificate.UnsafeNetworks())
 
 	fw := NewFirewall(l, time.Second, time.Minute, time.Hour, c.Certificate)
 
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 1, 1, []string{}, "", "", "", "", ""))
+	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 1, 1, []string{}, "", netip.Prefix{}, netip.Prefix{}, "", ""))
 	cp := cert.NewCAPool()
 
 	// Packet spoofed by `c1`. Note that the remote addr is not a valid one.
@@ -959,28 +915,28 @@ func TestAddFirewallRulesFromConfig(t *testing.T) {
 	mf := &mockFirewall{}
 	conf.Settings["firewall"] = map[string]any{"outbound": []any{map[string]any{"port": "1", "proto": "tcp", "host": "a"}}}
 	require.NoError(t, AddFirewallRulesFromConfig(l, false, conf, mf))
-	assert.Equal(t, addRuleCall{incoming: false, proto: firewall.ProtoTCP, startPort: 1, endPort: 1, groups: nil, host: "a", ip: "", localIp: ""}, mf.lastCall)
+	assert.Equal(t, addRuleCall{incoming: false, proto: firewall.ProtoTCP, startPort: 1, endPort: 1, groups: nil, host: "a", ip: netip.Prefix{}, localIp: netip.Prefix{}}, mf.lastCall)
 
 	// Test adding udp rule
 	conf = config.NewC(l)
 	mf = &mockFirewall{}
 	conf.Settings["firewall"] = map[string]any{"outbound": []any{map[string]any{"port": "1", "proto": "udp", "host": "a"}}}
 	require.NoError(t, AddFirewallRulesFromConfig(l, false, conf, mf))
-	assert.Equal(t, addRuleCall{incoming: false, proto: firewall.ProtoUDP, startPort: 1, endPort: 1, groups: nil, host: "a", ip: "", localIp: ""}, mf.lastCall)
+	assert.Equal(t, addRuleCall{incoming: false, proto: firewall.ProtoUDP, startPort: 1, endPort: 1, groups: nil, host: "a", ip: netip.Prefix{}, localIp: netip.Prefix{}}, mf.lastCall)
 
 	// Test adding icmp rule
 	conf = config.NewC(l)
 	mf = &mockFirewall{}
 	conf.Settings["firewall"] = map[string]any{"outbound": []any{map[string]any{"port": "1", "proto": "icmp", "host": "a"}}}
 	require.NoError(t, AddFirewallRulesFromConfig(l, false, conf, mf))
-	assert.Equal(t, addRuleCall{incoming: false, proto: firewall.ProtoICMP, startPort: 1, endPort: 1, groups: nil, host: "a", ip: "", localIp: ""}, mf.lastCall)
+	assert.Equal(t, addRuleCall{incoming: false, proto: firewall.ProtoICMP, startPort: 1, endPort: 1, groups: nil, host: "a", ip: netip.Prefix{}, localIp: netip.Prefix{}}, mf.lastCall)
 
 	// Test adding any rule
 	conf = config.NewC(l)
 	mf = &mockFirewall{}
 	conf.Settings["firewall"] = map[string]any{"inbound": []any{map[string]any{"port": "1", "proto": "any", "host": "a"}}}
 	require.NoError(t, AddFirewallRulesFromConfig(l, true, conf, mf))
-	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: nil, host: "a", ip: "", localIp: ""}, mf.lastCall)
+	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: nil, host: "a", ip: netip.Prefix{}, localIp: netip.Prefix{}}, mf.lastCall)
 
 	// Test adding rule with cidr
 	cidr := netip.MustParsePrefix("10.0.0.0/8")
@@ -988,14 +944,14 @@ func TestAddFirewallRulesFromConfig(t *testing.T) {
 	mf = &mockFirewall{}
 	conf.Settings["firewall"] = map[string]any{"inbound": []any{map[string]any{"port": "1", "proto": "any", "cidr": cidr.String()}}}
 	require.NoError(t, AddFirewallRulesFromConfig(l, true, conf, mf))
-	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: nil, ip: cidr.String(), localIp: ""}, mf.lastCall)
+	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: nil, ip: cidr, localIp: netip.Prefix{}}, mf.lastCall)
 
 	// Test adding rule with local_cidr
 	conf = config.NewC(l)
 	mf = &mockFirewall{}
 	conf.Settings["firewall"] = map[string]any{"inbound": []any{map[string]any{"port": "1", "proto": "any", "local_cidr": cidr.String()}}}
 	require.NoError(t, AddFirewallRulesFromConfig(l, true, conf, mf))
-	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: nil, ip: "", localIp: cidr.String()}, mf.lastCall)
+	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: nil, ip: netip.Prefix{}, localIp: cidr}, mf.lastCall)
 
 	// Test adding rule with cidr ipv6
 	cidr6 := netip.MustParsePrefix("fd00::/8")
@@ -1003,75 +959,49 @@ func TestAddFirewallRulesFromConfig(t *testing.T) {
 	mf = &mockFirewall{}
 	conf.Settings["firewall"] = map[string]any{"inbound": []any{map[string]any{"port": "1", "proto": "any", "cidr": cidr6.String()}}}
 	require.NoError(t, AddFirewallRulesFromConfig(l, true, conf, mf))
-	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: nil, ip: cidr6.String(), localIp: ""}, mf.lastCall)
+	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: nil, ip: cidr6, localIp: netip.Prefix{}}, mf.lastCall)
-
-	// Test adding rule with any cidr
-	conf = config.NewC(l)
-	mf = &mockFirewall{}
-	conf.Settings["firewall"] = map[string]any{"inbound": []any{map[string]any{"port": "1", "proto": "any", "cidr": "any"}}}
-	require.NoError(t, AddFirewallRulesFromConfig(l, true, conf, mf))
-	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: nil, ip: "any", localIp: ""}, mf.lastCall)
-
-	// Test adding rule with junk cidr
-	conf = config.NewC(l)
-	mf = &mockFirewall{}
-	conf.Settings["firewall"] = map[string]any{"inbound": []any{map[string]any{"port": "1", "proto": "any", "cidr": "junk/junk"}}}
-	require.EqualError(t, AddFirewallRulesFromConfig(l, true, conf, mf), "firewall.inbound rule #0; cidr did not parse; netip.ParsePrefix(\"junk/junk\"): ParseAddr(\"junk\"): unable to parse IP")
 
 	// Test adding rule with local_cidr ipv6
 	conf = config.NewC(l)
 	mf = &mockFirewall{}
 	conf.Settings["firewall"] = map[string]any{"inbound": []any{map[string]any{"port": "1", "proto": "any", "local_cidr": cidr6.String()}}}
 	require.NoError(t, AddFirewallRulesFromConfig(l, true, conf, mf))
-	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: nil, ip: "", localIp: cidr6.String()}, mf.lastCall)
+	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: nil, ip: netip.Prefix{}, localIp: cidr6}, mf.lastCall)
-
-	// Test adding rule with any local_cidr
-	conf = config.NewC(l)
-	mf = &mockFirewall{}
-	conf.Settings["firewall"] = map[string]any{"inbound": []any{map[string]any{"port": "1", "proto": "any", "local_cidr": "any"}}}
-	require.NoError(t, AddFirewallRulesFromConfig(l, true, conf, mf))
-	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: nil, localIp: "any"}, mf.lastCall)
-
-	// Test adding rule with junk local_cidr
-	conf = config.NewC(l)
-	mf = &mockFirewall{}
-	conf.Settings["firewall"] = map[string]any{"inbound": []any{map[string]any{"port": "1", "proto": "any", "local_cidr": "junk/junk"}}}
-	require.EqualError(t, AddFirewallRulesFromConfig(l, true, conf, mf), "firewall.inbound rule #0; local_cidr did not parse; netip.ParsePrefix(\"junk/junk\"): ParseAddr(\"junk\"): unable to parse IP")
 
 	// Test adding rule with ca_sha
 	conf = config.NewC(l)
 	mf = &mockFirewall{}
 	conf.Settings["firewall"] = map[string]any{"inbound": []any{map[string]any{"port": "1", "proto": "any", "ca_sha": "12312313123"}}}
 	require.NoError(t, AddFirewallRulesFromConfig(l, true, conf, mf))
-	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: nil, ip: "", localIp: "", caSha: "12312313123"}, mf.lastCall)
+	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: nil, ip: netip.Prefix{}, localIp: netip.Prefix{}, caSha: "12312313123"}, mf.lastCall)
 
 	// Test adding rule with ca_name
 	conf = config.NewC(l)
 	mf = &mockFirewall{}
 	conf.Settings["firewall"] = map[string]any{"inbound": []any{map[string]any{"port": "1", "proto": "any", "ca_name": "root01"}}}
 	require.NoError(t, AddFirewallRulesFromConfig(l, true, conf, mf))
-	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: nil, ip: "", localIp: "", caName: "root01"}, mf.lastCall)
+	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: nil, ip: netip.Prefix{}, localIp: netip.Prefix{}, caName: "root01"}, mf.lastCall)
 
 	// Test single group
 	conf = config.NewC(l)
 	mf = &mockFirewall{}
 	conf.Settings["firewall"] = map[string]any{"inbound": []any{map[string]any{"port": "1", "proto": "any", "group": "a"}}}
 	require.NoError(t, AddFirewallRulesFromConfig(l, true, conf, mf))
-	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: []string{"a"}, ip: "", localIp: ""}, mf.lastCall)
+	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: []string{"a"}, ip: netip.Prefix{}, localIp: netip.Prefix{}}, mf.lastCall)
 
 	// Test single groups
 	conf = config.NewC(l)
 	mf = &mockFirewall{}
 	conf.Settings["firewall"] = map[string]any{"inbound": []any{map[string]any{"port": "1", "proto": "any", "groups": "a"}}}
 	require.NoError(t, AddFirewallRulesFromConfig(l, true, conf, mf))
-	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: []string{"a"}, ip: "", localIp: ""}, mf.lastCall)
+	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: []string{"a"}, ip: netip.Prefix{}, localIp: netip.Prefix{}}, mf.lastCall)
 
 	// Test multiple AND groups
 	conf = config.NewC(l)
 	mf = &mockFirewall{}
 	conf.Settings["firewall"] = map[string]any{"inbound": []any{map[string]any{"port": "1", "proto": "any", "groups": []string{"a", "b"}}}}
 	require.NoError(t, AddFirewallRulesFromConfig(l, true, conf, mf))
-	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: []string{"a", "b"}, ip: "", localIp: ""}, mf.lastCall)
+	assert.Equal(t, addRuleCall{incoming: true, proto: firewall.ProtoAny, startPort: 1, endPort: 1, groups: []string{"a", "b"}, ip: netip.Prefix{}, localIp: netip.Prefix{}}, mf.lastCall)
 
 	// Test Add error
 	conf = config.NewC(l)
@@ -1094,7 +1024,7 @@ func TestFirewall_convertRule(t *testing.T) {
 	r, err := convertRule(l, c, "test", 1)
 	assert.Contains(t, ob.String(), "test rule #1; group was an array with a single value, converting to simple value")
 	require.NoError(t, err)
-	assert.Equal(t, []string{"group1"}, r.Groups)
+	assert.Equal(t, "group1", r.Group)
 
 	// Ensure group array of > 1 is errord
 	ob.Reset()
@@ -1114,228 +1044,7 @@ func TestFirewall_convertRule(t *testing.T) {
 
 	r, err = convertRule(l, c, "test", 1)
 	require.NoError(t, err)
-	assert.Equal(t, []string{"group1"}, r.Groups)
+	assert.Equal(t, "group1", r.Group)
-}
-
-func TestFirewall_convertRuleSanity(t *testing.T) {
-	l := test.NewLogger()
-	ob := &bytes.Buffer{}
-	l.SetOutput(ob)
-
-	noWarningPlease := []map[string]any{
-		{"group": "group1"},
-		{"groups": []any{"group2"}},
-		{"host": "bob"},
-		{"cidr": "1.1.1.1/1"},
-		{"groups": []any{"group2"}, "host": "bob"},
-		{"cidr": "1.1.1.1/1", "host": "bob"},
-		{"groups": []any{"group2"}, "cidr": "1.1.1.1/1"},
-		{"groups": []any{"group2"}, "cidr": "1.1.1.1/1", "host": "bob"},
-	}
-	for _, c := range noWarningPlease {
-		r, err := convertRule(l, c, "test", 1)
-		require.NoError(t, err)
-		require.NoError(t, r.sanity(), "should not generate a sanity warning, %+v", c)
-	}
-
-	yesWarningPlease := []map[string]any{
-		{"group": "group1"},
-		{"groups": []any{"group2"}},
-		{"cidr": "1.1.1.1/1"},
-		{"groups": []any{"group2"}, "host": "bob"},
-		{"cidr": "1.1.1.1/1", "host": "bob"},
-		{"groups": []any{"group2"}, "cidr": "1.1.1.1/1"},
-		{"groups": []any{"group2"}, "cidr": "1.1.1.1/1", "host": "bob"},
-	}
-	for _, c := range yesWarningPlease {
-		c["host"] = "any"
-		r, err := convertRule(l, c, "test", 1)
-		require.NoError(t, err)
-		err = r.sanity()
-		require.Error(t, err, "I wanted a warning: %+v", c)
-	}
-	//reset the list
-	yesWarningPlease = []map[string]any{
-		{"group": "group1"},
-		{"groups": []any{"group2"}},
-		{"cidr": "1.1.1.1/1"},
-		{"groups": []any{"group2"}, "host": "bob"},
-		{"cidr": "1.1.1.1/1", "host": "bob"},
-		{"groups": []any{"group2"}, "cidr": "1.1.1.1/1"},
-		{"groups": []any{"group2"}, "cidr": "1.1.1.1/1", "host": "bob"},
-	}
-	for _, c := range yesWarningPlease {
-		r, err := convertRule(l, c, "test", 1)
-		require.NoError(t, err)
-		r.Groups = append(r.Groups, "any")
-		err = r.sanity()
-		require.Error(t, err, "I wanted a warning: %+v", c)
-	}
-}
-
-type testcase struct {
-	h   *HostInfo
-	p   firewall.Packet
-	c   cert.Certificate
-	err error
-}
-
-func (c *testcase) Test(t *testing.T, fw *Firewall) {
-	t.Helper()
-	cp := cert.NewCAPool()
-	resetConntrack(fw)
-	err := fw.Drop(c.p, true, c.h, cp, nil)
-	if c.err == nil {
-		require.NoError(t, err, "failed to not drop remote address %s", c.p.RemoteAddr)
-	} else {
-		require.ErrorIs(t, c.err, err, "failed to drop remote address %s", c.p.RemoteAddr)
-	}
-}
-
-func buildTestCase(setup testsetup, err error, theirPrefixes ...netip.Prefix) testcase {
-	c1 := dummyCert{
-		name:     "host1",
-		networks: theirPrefixes,
-		groups:   []string{"default-group"},
-		issuer:   "signer-shasum",
-	}
-	h := HostInfo{
-		ConnectionState: &ConnectionState{
-			peerCert: &cert.CachedCertificate{
-				Certificate:    &c1,
-				InvertedGroups: map[string]struct{}{"default-group": {}},
-			},
-		},
-		vpnAddrs: make([]netip.Addr, len(theirPrefixes)),
-	}
-	for i := range theirPrefixes {
-		h.vpnAddrs[i] = theirPrefixes[i].Addr()
-	}
-	h.buildNetworks(setup.myVpnNetworksTable, &c1)
-	p := firewall.Packet{
-		LocalAddr:  setup.c.Networks()[0].Addr(), //todo?
-		RemoteAddr: theirPrefixes[0].Addr(),
-		LocalPort:  10,
-		RemotePort: 90,
-		Protocol:   firewall.ProtoUDP,
-		Fragment:   false,
-	}
-	return testcase{
-		h:   &h,
-		p:   p,
-		c:   &c1,
-		err: err,
-	}
-}
-
-type testsetup struct {
-	c                  dummyCert
-	myVpnNetworksTable *bart.Lite
-	fw                 *Firewall
-}
-
-func newSetup(t *testing.T, l *logrus.Logger, myPrefixes ...netip.Prefix) testsetup {
-	c := dummyCert{
-		name:     "me",
-		networks: myPrefixes,
-		groups:   []string{"default-group"},
-		issuer:   "signer-shasum",
-	}
-
-	return newSetupFromCert(t, l, c)
-}
-
-func newSetupFromCert(t *testing.T, l *logrus.Logger, c dummyCert) testsetup {
-	myVpnNetworksTable := new(bart.Lite)
-	for _, prefix := range c.Networks() {
-		myVpnNetworksTable.Insert(prefix)
-	}
-	fw := NewFirewall(l, time.Second, time.Minute, time.Hour, &c)
-	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"any"}, "", "", "", "", ""))
-
-	return testsetup{
-		c:                  c,
-		fw:                 fw,
-		myVpnNetworksTable: myVpnNetworksTable,
-	}
-}
-
-func TestFirewall_Drop_EnforceIPMatch(t *testing.T) {
-	t.Parallel()
-	l := test.NewLogger()
-	ob := &bytes.Buffer{}
-	l.SetOutput(ob)
-
-	myPrefix := netip.MustParsePrefix("1.1.1.1/8")
-	// for now, it's okay that these are all "incoming", the logic this test tries to check doesn't care about in/out
-	t.Run("allow inbound all matching", func(t *testing.T) {
-		t.Parallel()
-		setup := newSetup(t, l, myPrefix)
-		tc := buildTestCase(setup, nil, netip.MustParsePrefix("1.2.3.4/24"))
-		tc.Test(t, setup.fw)
-	})
-	t.Run("allow inbound local matching", func(t *testing.T) {
-		t.Parallel()
-		setup := newSetup(t, l, myPrefix)
-		tc := buildTestCase(setup, ErrInvalidLocalIP, netip.MustParsePrefix("1.2.3.4/24"))
-		tc.p.LocalAddr = netip.MustParseAddr("1.2.3.8")
-		tc.Test(t, setup.fw)
-	})
-	t.Run("block inbound remote mismatched", func(t *testing.T) {
-		t.Parallel()
-		setup := newSetup(t, l, myPrefix)
-		tc := buildTestCase(setup, ErrInvalidRemoteIP, netip.MustParsePrefix("1.2.3.4/24"))
-		tc.p.RemoteAddr = netip.MustParseAddr("9.9.9.9")
-		tc.Test(t, setup.fw)
-	})
-	t.Run("Block a vpn peer packet", func(t *testing.T) {
-		t.Parallel()
-		setup := newSetup(t, l, myPrefix)
-		tc := buildTestCase(setup, ErrPeerRejected, netip.MustParsePrefix("2.2.2.2/24"))
-		tc.Test(t, setup.fw)
-	})
-	twoPrefixes := []netip.Prefix{
-		netip.MustParsePrefix("1.2.3.4/24"), netip.MustParsePrefix("2.2.2.2/24"),
-	}
-	t.Run("allow inbound one matching", func(t *testing.T) {
-		t.Parallel()
-		setup := newSetup(t, l, myPrefix)
-		tc := buildTestCase(setup, nil, twoPrefixes...)
-		tc.Test(t, setup.fw)
-	})
-	t.Run("block inbound multimismatch", func(t *testing.T) {
-		t.Parallel()
-		setup := newSetup(t, l, myPrefix)
-		tc := buildTestCase(setup, ErrInvalidRemoteIP, twoPrefixes...)
-		tc.p.RemoteAddr = netip.MustParseAddr("9.9.9.9")
-		tc.Test(t, setup.fw)
-	})
-	t.Run("allow inbound 2nd one matching", func(t *testing.T) {
-		t.Parallel()
-		setup2 := newSetup(t, l, netip.MustParsePrefix("2.2.2.1/24"))
-		tc := buildTestCase(setup2, nil, twoPrefixes...)
-		tc.p.RemoteAddr = twoPrefixes[1].Addr()
-		tc.Test(t, setup2.fw)
-	})
-	t.Run("allow inbound unsafe route", func(t *testing.T) {
-		t.Parallel()
-		unsafePrefix := netip.MustParsePrefix("192.168.0.0/24")
-		c := dummyCert{
-			name:           "me",
-			networks:       []netip.Prefix{myPrefix},
-			unsafeNetworks: []netip.Prefix{unsafePrefix},
-			groups:         []string{"default-group"},
-			issuer:         "signer-shasum",
-		}
-		unsafeSetup := newSetupFromCert(t, l, c)
-		tc := buildTestCase(unsafeSetup, nil, twoPrefixes...)
-		tc.p.LocalAddr = netip.MustParseAddr("192.168.0.3")
-		tc.err = ErrNoMatchingRule
-		tc.Test(t, unsafeSetup.fw) //should hit firewall and bounce off
-		require.NoError(t, unsafeSetup.fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"any"}, "", "", unsafePrefix.String(), "", ""))
-		tc.err = nil
-		tc.Test(t, unsafeSetup.fw) //should pass
-	})
 }
 
 type addRuleCall struct {
@@ -1345,8 +1054,8 @@ type addRuleCall struct {
 	endPort   int32
 	groups    []string
 	host      string
-	ip        string
+	ip        netip.Prefix
-	localIp   string
+	localIp   netip.Prefix
 	caName    string
 	caSha     string
 }
@@ -1356,7 +1065,7 @@ type mockFirewall struct {
 	nextCallReturn error
 }
 
-func (mf *mockFirewall) AddRule(incoming bool, proto uint8, startPort int32, endPort int32, groups []string, host string, ip, localIp, caName string, caSha string) error {
+func (mf *mockFirewall) AddRule(incoming bool, proto uint8, startPort int32, endPort int32, groups []string, host string, ip netip.Prefix, localIp netip.Prefix, caName string, caSha string) error {
 	mf.lastCall = addRuleCall{
 		incoming:  incoming,
 		proto:     proto,

go.mod

@@ -8,7 +8,7 @@ require (
 	github.com/armon/go-radix v1.0.0
 	github.com/cyberdelia/go-metrics-graphite v0.0.0-20161219230853-39f87cc3b432
 	github.com/flynn/noise v1.1.0
-	github.com/gaissmai/bart v0.26.0
+	github.com/gaissmai/bart v0.25.0
 	github.com/gogo/protobuf v1.3.2
 	github.com/google/gopacket v1.1.19
 	github.com/kardianos/service v1.2.4
@@ -22,17 +22,16 @@ require (
 	github.com/stefanberger/go-pkcs11uri v0.0.0-20230803200340-78284954bff6
 	github.com/stretchr/testify v1.11.1
 	github.com/vishvananda/netlink v1.3.1
-	go.yaml.in/yaml/v3 v3.0.4
+	golang.org/x/crypto v0.43.0
-	golang.org/x/crypto v0.45.0
 	golang.org/x/exp v0.0.0-20230725093048-515e97ebf090
-	golang.org/x/net v0.47.0
+	golang.org/x/net v0.45.0
-	golang.org/x/sync v0.18.0
+	golang.org/x/sync v0.17.0
-	golang.org/x/sys v0.38.0
+	golang.org/x/sys v0.37.0
-	golang.org/x/term v0.37.0
+	golang.org/x/term v0.36.0
 	golang.zx2c4.com/wintun v0.0.0-20230126152724-0fa3db229ce2
 	golang.zx2c4.com/wireguard v0.0.0-20230325221338-052af4a8072b
 	golang.zx2c4.com/wireguard/windows v0.5.3
-	google.golang.org/protobuf v1.36.10
+	google.golang.org/protobuf v1.36.8
 	gopkg.in/yaml.v3 v3.0.1
 	gvisor.dev/gvisor v0.0.0-20240423190808-9d7a357edefe
 )

go.sum

@@ -24,8 +24,8 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/flynn/noise v1.1.0 h1:KjPQoQCEFdZDiP03phOvGi11+SVVhBG2wOWAorLsstg=
 github.com/flynn/noise v1.1.0/go.mod h1:xbMo+0i6+IGbYdJhF31t2eR1BIU0CYc12+BNAKwUTag=
-github.com/gaissmai/bart v0.26.0 h1:xOZ57E9hJLBiQaSyeZa9wgWhGuzfGACgqp4BE77OkO0=
+github.com/gaissmai/bart v0.25.0 h1:eqiokVPqM3F94vJ0bTHXHtH91S8zkKL+bKh+BsGOsJM=
-github.com/gaissmai/bart v0.26.0/go.mod h1:GREWQfTLRWz/c5FTOsIw+KkscuFkIV5t8Rp7Nd1Td5c=
+github.com/gaissmai/bart v0.25.0/go.mod h1:GREWQfTLRWz/c5FTOsIw+KkscuFkIV5t8Rp7Nd1Td5c=
 github.com/go-kit/kit v0.8.0/go.mod h1:xBxKIO96dXMWWy0MnWVtmwkA9/13aqxPnvrjFYMA2as=
 github.com/go-kit/kit v0.9.0/go.mod h1:xBxKIO96dXMWWy0MnWVtmwkA9/13aqxPnvrjFYMA2as=
 github.com/go-kit/log v0.1.0/go.mod h1:zbhenjAZHb184qTLMA9ZjW7ThYL0H2mk7Q6pNt4vbaY=
@@ -155,15 +155,13 @@ go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
 go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
 go.yaml.in/yaml/v2 v2.4.2 h1:DzmwEr2rDGHl7lsFgAHxmNz/1NlQ7xLIrlN2h5d1eGI=
 go.yaml.in/yaml/v2 v2.4.2/go.mod h1:081UH+NErpNdqlCXm3TtEran0rJZGxAYx9hb/ELlsPU=
-go.yaml.in/yaml/v3 v3.0.4 h1:tfq32ie2Jv2UxXFdLJdh3jXuOzWiL1fo0bu/FbuKpbc=
-go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20210322153248-0c34fe9e7dc2/go.mod h1:T9bdIzuCu7OtxOm1hfPfRQxPLYneinmdGuTeoZ9dtd4=
-golang.org/x/crypto v0.45.0 h1:jMBrvKuj23MTlT0bQEOBcAE0mjg8mK9RXFhRH6nyF3Q=
+golang.org/x/crypto v0.43.0 h1:dduJYIi3A3KOfdGOHX8AVZ/jGiyPa3IbBozJ5kNuE04=
-golang.org/x/crypto v0.45.0/go.mod h1:XTGrrkGJve7CYK7J8PEww4aY7gM3qMCElcJQ8n8JdX4=
+golang.org/x/crypto v0.43.0/go.mod h1:BFbav4mRNlXJL4wNeejLpWxB7wMbc79PdRGhWKncxR0=
 golang.org/x/exp v0.0.0-20230725093048-515e97ebf090 h1:Di6/M8l0O2lCLc6VVRWhgCiApHV8MnQurBnFSHsQtNY=
 golang.org/x/exp v0.0.0-20230725093048-515e97ebf090/go.mod h1:FXUEEKJgO7OQYeo8N01OfiKP8RXMtf6e8aTskBGqWdc=
 golang.org/x/lint v0.0.0-20200302205851-738671d3881b/go.mod h1:3xt1FjdF8hUf6vQPIChWIBhFzV8gjjsPE/fR3IyQdNY=
@@ -182,8 +180,8 @@ golang.org/x/net v0.0.0-20200226121028-0de0cce0169b/go.mod h1:z5CRVTTTmAJ677TzLL
 golang.org/x/net v0.0.0-20200625001655-4c5254603344/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
 golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
-golang.org/x/net v0.47.0 h1:Mx+4dIFzqraBXUugkia1OOvlD6LemFo1ALMHjrXDOhY=
+golang.org/x/net v0.45.0 h1:RLBg5JKixCy82FtLJpeNlVM0nrSqpCRYzVU1n8kj0tM=
-golang.org/x/net v0.47.0/go.mod h1:/jNxtkgq5yWUGYkaZGqo27cfGZ1c5Nen03aYrrKpVRU=
+golang.org/x/net v0.45.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
@@ -191,8 +189,8 @@ golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201207232520-09787c993a3a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.18.0 h1:kr88TuHDroi+UVf+0hZnirlk8o8T+4MrK6mr60WkH/I=
+golang.org/x/sync v0.17.0 h1:l60nONMj9l5drqw6jlhIELNv9I0A4OFgRsG9k2oT9Ug=
-golang.org/x/sync v0.18.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
+golang.org/x/sync v0.17.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
 golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20181116152217-5ac8a444bdc5/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -209,11 +207,11 @@ golang.org/x/sys v0.0.0-20210603081109-ebe580a85c40/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.2.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.10.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.38.0 h1:3yZWxaJjBmCWXqhN1qh02AkOnCQ1poK6oF+a7xWL6Gc=
+golang.org/x/sys v0.37.0 h1:fdNQudmxPjkdUTPnLn5mdQv7Zwvbvpaxqs831goi9kQ=
-golang.org/x/sys v0.38.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/sys v0.37.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
-golang.org/x/term v0.37.0 h1:8EGAD0qCmHYZg6J17DvsMy9/wJ7/D/4pV/wfnld5lTU=
+golang.org/x/term v0.36.0 h1:zMPR+aF8gfksFprF/Nc/rd1wRS1EI6nDBGyWAvDzx2Q=
-golang.org/x/term v0.37.0/go.mod h1:5pB4lxRNYYVZuTLmy8oR2BH8dflOR+IbTYFD8fi3254=
+golang.org/x/term v0.36.0/go.mod h1:Qu394IJq6V6dCBRgwqshf3mPF85AqzYEzofzRdZkWss=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
@@ -244,8 +242,8 @@ google.golang.org/protobuf v1.20.1-0.20200309200217-e05f789c0967/go.mod h1:A+miE
 google.golang.org/protobuf v1.21.0/go.mod h1:47Nbq4nVaFHyn7ilMalzfO3qCViNmqZ2kzikPIcrTAo=
 google.golang.org/protobuf v1.23.0/go.mod h1:EGpADcykh3NcUnDUJcl1+ZksZNG86OlYog2l/sGQquU=
 google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
-google.golang.org/protobuf v1.36.10 h1:AYd7cD/uASjIL6Q9LiTjz8JLcrh/88q5UObnmY3aOOE=
+google.golang.org/protobuf v1.36.8 h1:xHScyCOEuuwZEc6UtSOvPbAT4zRh0xcNRYekJwfqyMc=
-google.golang.org/protobuf v1.36.10/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
+google.golang.org/protobuf v1.36.8/go.mod h1:fuxRtAxBytpl4zzqUh6/eyUujkJdNiuEkXntxiD/uRU=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

handshake_ix.go

@@ -2,6 +2,7 @@ package nebula
 
 import (
 	"net/netip"
+	"slices"
 	"time"
 
 	"github.com/flynn/noise"
@@ -191,17 +192,17 @@ func ixHandshakeStage1(f *Interface, addr netip.AddrPort, via *ViaSender, packet
 		return
 	}
 
+	var vpnAddrs []netip.Addr
+	var filteredNetworks []netip.Prefix
 	certName := remoteCert.Certificate.Name()
 	certVersion := remoteCert.Certificate.Version()
 	fingerprint := remoteCert.Fingerprint
 	issuer := remoteCert.Certificate.Issuer()
-	vpnNetworks := remoteCert.Certificate.Networks()
 
-	anyVpnAddrsInCommon := false
+	for _, network := range remoteCert.Certificate.Networks() {
-	vpnAddrs := make([]netip.Addr, len(vpnNetworks))
+		vpnAddr := network.Addr()
-	for i, network := range vpnNetworks {
+		if f.myVpnAddrsTable.Contains(vpnAddr) {
-		if f.myVpnAddrsTable.Contains(network.Addr()) {
+			f.l.WithField("vpnAddr", vpnAddr).WithField("udpAddr", addr).
-			f.l.WithField("vpnNetworks", vpnNetworks).WithField("udpAddr", addr).
 				WithField("certName", certName).
 				WithField("certVersion", certVersion).
 				WithField("fingerprint", fingerprint).
@@ -209,10 +210,24 @@ func ixHandshakeStage1(f *Interface, addr netip.AddrPort, via *ViaSender, packet
 				WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).Error("Refusing to handshake with myself")
 			return
 		}
-		vpnAddrs[i] = network.Addr()
+
-		if f.myVpnNetworksTable.Contains(network.Addr()) {
+		// vpnAddrs outside our vpn networks are of no use to us, filter them out
-			anyVpnAddrsInCommon = true
+		if !f.myVpnNetworksTable.Contains(vpnAddr) {
+			continue
 		}
+
+		filteredNetworks = append(filteredNetworks, network)
+		vpnAddrs = append(vpnAddrs, vpnAddr)
+	}
+
+	if len(vpnAddrs) == 0 {
+		f.l.WithError(err).WithField("udpAddr", addr).
+			WithField("certName", certName).
+			WithField("certVersion", certVersion).
+			WithField("fingerprint", fingerprint).
+			WithField("issuer", issuer).
+			WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).Error("No usable vpn addresses from host, refusing handshake")
+		return
 	}
 
 	if addr.IsValid() {
@@ -249,30 +264,26 @@ func ixHandshakeStage1(f *Interface, addr netip.AddrPort, via *ViaSender, packet
 		},
 	}
 
-	msgRxL := f.l.WithFields(m{
+	f.l.WithField("vpnAddrs", vpnAddrs).WithField("udpAddr", addr).
-		"vpnAddrs":       vpnAddrs,
+		WithField("certName", certName).
-		"udpAddr":        addr,
+		WithField("certVersion", certVersion).
-		"certName":       certName,
+		WithField("fingerprint", fingerprint).
-		"certVersion":    certVersion,
+		WithField("issuer", issuer).
-		"fingerprint":    fingerprint,
+		WithField("initiatorIndex", hs.Details.InitiatorIndex).WithField("responderIndex", hs.Details.ResponderIndex).
-		"issuer":         issuer,
+		WithField("remoteIndex", h.RemoteIndex).WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).
-		"initiatorIndex": hs.Details.InitiatorIndex,
+		Info("Handshake message received")
-		"responderIndex": hs.Details.ResponderIndex,
-		"remoteIndex":    h.RemoteIndex,
-		"handshake":      m{"stage": 1, "style": "ix_psk0"},
-	})
-
-	if anyVpnAddrsInCommon {
-		msgRxL.Info("Handshake message received")
-	} else {
-		//todo warn if not lighthouse or relay?
-		msgRxL.Info("Handshake message received, but no vpnNetworks in common.")
-	}
 
 	hs.Details.ResponderIndex = myIndex
 	hs.Details.Cert = cs.getHandshakeBytes(ci.myCert.Version())
 	if hs.Details.Cert == nil {
-		msgRxL.WithField("myCertVersion", ci.myCert.Version()).
+		f.l.WithField("vpnAddrs", vpnAddrs).WithField("udpAddr", addr).
+			WithField("certName", certName).
+			WithField("certVersion", certVersion).
+			WithField("fingerprint", fingerprint).
+			WithField("issuer", issuer).
+			WithField("initiatorIndex", hs.Details.InitiatorIndex).WithField("responderIndex", hs.Details.ResponderIndex).
+			WithField("remoteIndex", h.RemoteIndex).WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).
+			WithField("certVersion", ci.myCert.Version()).
 			Error("Unable to handshake with host because no certificate handshake bytes is available")
 		return
 	}
@@ -330,7 +341,7 @@ func ixHandshakeStage1(f *Interface, addr netip.AddrPort, via *ViaSender, packet
 
 	hostinfo.remotes = f.lightHouse.QueryCache(vpnAddrs)
 	hostinfo.SetRemote(addr)
-	hostinfo.buildNetworks(f.myVpnNetworksTable, remoteCert.Certificate)
+	hostinfo.buildNetworks(filteredNetworks, remoteCert.Certificate.UnsafeNetworks())
 
 	existing, err := f.handshakeManager.CheckAndComplete(hostinfo, 0, f)
 	if err != nil {
@@ -571,22 +582,31 @@ func ixHandshakeStage2(f *Interface, addr netip.AddrPort, via *ViaSender, hh *Ha
 		hostinfo.relayState.InsertRelayTo(via.relayHI.vpnAddrs[0])
 	}
 
-	correctHostResponded := false
+	var vpnAddrs []netip.Addr
-	anyVpnAddrsInCommon := false
+	var filteredNetworks []netip.Prefix
-	vpnAddrs := make([]netip.Addr, len(vpnNetworks))
+	for _, network := range vpnNetworks {
-	for i, network := range vpnNetworks {
+		// vpnAddrs outside our vpn networks are of no use to us, filter them out
-		vpnAddrs[i] = network.Addr()
+		vpnAddr := network.Addr()
-		if f.myVpnNetworksTable.Contains(network.Addr()) {
+		if !f.myVpnNetworksTable.Contains(vpnAddr) {
-			anyVpnAddrsInCommon = true
+			continue
-		}
-		if hostinfo.vpnAddrs[0] == network.Addr() {
-			// todo is it more correct to see if any of hostinfo.vpnAddrs are in the cert? it should have len==1, but one day it might not?
-			correctHostResponded = true
 		}
+
+		filteredNetworks = append(filteredNetworks, network)
+		vpnAddrs = append(vpnAddrs, vpnAddr)
+	}
+
+	if len(vpnAddrs) == 0 {
+		f.l.WithError(err).WithField("udpAddr", addr).
+			WithField("certName", certName).
+			WithField("certVersion", certVersion).
+			WithField("fingerprint", fingerprint).
+			WithField("issuer", issuer).
+			WithField("handshake", m{"stage": 2, "style": "ix_psk0"}).Error("No usable vpn addresses from host, refusing handshake")
+		return true
 	}
 
 	// Ensure the right host responded
-	if !correctHostResponded {
+	if !slices.Contains(vpnAddrs, hostinfo.vpnAddrs[0]) {
 		f.l.WithField("intendedVpnAddrs", hostinfo.vpnAddrs).WithField("haveVpnNetworks", vpnNetworks).
 			WithField("udpAddr", addr).
 			WithField("certName", certName).
@@ -598,7 +618,6 @@ func ixHandshakeStage2(f *Interface, addr netip.AddrPort, via *ViaSender, hh *Ha
 		f.handshakeManager.DeleteHostInfo(hostinfo)
 
 		// Create a new hostinfo/handshake for the intended vpn ip
-		//TODO is hostinfo.vpnAddrs[0] always the address to use?
 		f.handshakeManager.StartHandshake(hostinfo.vpnAddrs[0], func(newHH *HandshakeHostInfo) {
 			// Block the current used address
 			newHH.hostinfo.remotes = hostinfo.remotes
@@ -625,7 +644,7 @@ func ixHandshakeStage2(f *Interface, addr netip.AddrPort, via *ViaSender, hh *Ha
 	ci.window.Update(f.l, 2)
 
 	duration := time.Since(hh.startTime).Nanoseconds()
-	msgRxL := f.l.WithField("vpnAddrs", vpnAddrs).WithField("udpAddr", addr).
+	f.l.WithField("vpnAddrs", vpnAddrs).WithField("udpAddr", addr).
 		WithField("certName", certName).
 		WithField("certVersion", certVersion).
 		WithField("fingerprint", fingerprint).
@@ -633,17 +652,12 @@ func ixHandshakeStage2(f *Interface, addr netip.AddrPort, via *ViaSender, hh *Ha
 		WithField("initiatorIndex", hs.Details.InitiatorIndex).WithField("responderIndex", hs.Details.ResponderIndex).
 		WithField("remoteIndex", h.RemoteIndex).WithField("handshake", m{"stage": 2, "style": "ix_psk0"}).
 		WithField("durationNs", duration).
-		WithField("sentCachedPackets", len(hh.packetStore))
+		WithField("sentCachedPackets", len(hh.packetStore)).
-	if anyVpnAddrsInCommon {
+		Info("Handshake message received")
-		msgRxL.Info("Handshake message received")
-	} else {
-		//todo warn if not lighthouse or relay?
-		msgRxL.Info("Handshake message received, but no vpnNetworks in common.")
-	}
 
 	// Build up the radix for the firewall if we have subnets in the cert
 	hostinfo.vpnAddrs = vpnAddrs
-	hostinfo.buildNetworks(f.myVpnNetworksTable, remoteCert.Certificate)
+	hostinfo.buildNetworks(filteredNetworks, remoteCert.Certificate.UnsafeNetworks())
 
 	// Complete our handshake and update metrics, this will replace any existing tunnels for the vpnAddrs here
 	f.handshakeManager.Complete(hostinfo, f)

handshake_manager.go

@@ -269,12 +269,12 @@ func (hm *HandshakeManager) handleOutbound(vpnIp netip.Addr, lighthouseTriggered
 		hostinfo.logger(hm.l).WithField("relays", hostinfo.remotes.relays).Info("Attempt to relay through hosts")
 		// Send a RelayRequest to all known Relay IP's
 		for _, relay := range hostinfo.remotes.relays {
-			// Don't relay through the host I'm trying to connect to
+			// Don't relay to myself
 			if relay == vpnIp {
 				continue
 			}
 
-			// Don't relay to myself
+			// Don't relay through the host I'm trying to connect to
 			if hm.f.myVpnAddrsTable.Contains(relay) {
 				continue
 			}

hostmap.go

@@ -212,18 +212,6 @@ func (rs *RelayState) InsertRelay(ip netip.Addr, idx uint32, r *Relay) {
 	rs.relayForByIdx[idx] = r
 }
 
-type NetworkType uint8
-
-const (
-	NetworkTypeUnknown NetworkType = iota
-	// NetworkTypeVPN is a network that overlaps one or more of the vpnNetworks in our certificate
-	NetworkTypeVPN
-	// NetworkTypeVPNPeer is a network that does not overlap one of our networks
-	NetworkTypeVPNPeer
-	// NetworkTypeUnsafe is a network from Certificate.UnsafeNetworks()
-	NetworkTypeUnsafe
-)
-
 type HostInfo struct {
 	remote          netip.AddrPort
 	remotes         *RemoteList
@@ -237,8 +225,8 @@ type HostInfo struct {
 	// vpn networks but were removed because they are not usable
 	vpnAddrs []netip.Addr
 
-	// networks is a combination of specific vpn addresses (not prefixes!) and full unsafe networks assigned to this host.
+	// networks are both all vpn and unsafe networks assigned to this host
-	networks   *bart.Table[NetworkType]
+	networks   *bart.Lite
 	relayState RelayState
 
 	// HandshakePacket records the packets used to create this hostinfo
@@ -742,26 +730,20 @@ func (i *HostInfo) SetRemoteIfPreferred(hm *HostMap, newRemote netip.AddrPort) b
 	return false
 }
 
-// buildNetworks fills in the networks field of HostInfo. It accepts a cert.Certificate so you never ever mix the network types up.
+func (i *HostInfo) buildNetworks(networks, unsafeNetworks []netip.Prefix) {
-func (i *HostInfo) buildNetworks(myVpnNetworksTable *bart.Lite, c cert.Certificate) {
+	if len(networks) == 1 && len(unsafeNetworks) == 0 {
-	if len(c.Networks()) == 1 && len(c.UnsafeNetworks()) == 0 {
+		// Simple case, no CIDRTree needed
-		if myVpnNetworksTable.Contains(c.Networks()[0].Addr()) {
+		return
-			return // Simple case, no BART needed
-		}
 	}
 
-	i.networks = new(bart.Table[NetworkType])
+	i.networks = new(bart.Lite)
-	for _, network := range c.Networks() {
+	for _, network := range networks {
 		nprefix := netip.PrefixFrom(network.Addr(), network.Addr().BitLen())
-		if myVpnNetworksTable.Contains(network.Addr()) {
+		i.networks.Insert(nprefix)
-			i.networks.Insert(nprefix, NetworkTypeVPN)
-		} else {
-			i.networks.Insert(nprefix, NetworkTypeVPNPeer)
-		}
 	}
 
-	for _, network := range c.UnsafeNetworks() {
+	for _, network := range unsafeNetworks {
-		i.networks.Insert(network, NetworkTypeUnsafe)
+		i.networks.Insert(network)
 	}
 }
 

inside.go

@@ -2,16 +2,18 @@ package nebula
 
 import (
 	"net/netip"
+	"unsafe"
 
 	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula/firewall"
 	"github.com/slackhq/nebula/header"
 	"github.com/slackhq/nebula/iputil"
 	"github.com/slackhq/nebula/noiseutil"
+	"github.com/slackhq/nebula/overlay"
 	"github.com/slackhq/nebula/routing"
 )
 
-func (f *Interface) consumeInsidePacket(packet []byte, fwPacket *firewall.Packet, nb, out []byte, q int, localCache firewall.ConntrackCache) {
+func (f *Interface) consumeInsidePacket(packet []byte, fwPacket *firewall.Packet, nb, out []byte, q int, localCache *firewall.ConntrackCache) {
 	err := newPacket(packet, false, fwPacket)
 	if err != nil {
 		if f.l.Level >= logrus.DebugLevel {
@@ -120,10 +122,9 @@ func (f *Interface) rejectOutside(packet []byte, ci *ConnectionState, hostinfo *
 	f.sendNoMetrics(header.Message, 0, ci, hostinfo, netip.AddrPort{}, out, nb, packet, q)
 }
 
-// Handshake will attempt to initiate a tunnel with the provided vpn address. This is a no-op if the tunnel is already established or being established
+// Handshake will attempt to initiate a tunnel with the provided vpn address if it is within our vpn networks. This is a no-op if the tunnel is already established or being established
-// it does not check if it is within our vpn networks!
 func (f *Interface) Handshake(vpnAddr netip.Addr) {
-	f.handshakeManager.GetOrHandshake(vpnAddr, nil)
+	f.getOrHandshakeNoRouting(vpnAddr, nil)
 }
 
 // getOrHandshakeNoRouting returns nil if the vpnAddr is not routable.
@@ -139,6 +140,7 @@ func (f *Interface) getOrHandshakeNoRouting(vpnAddr netip.Addr, cacheCallback fu
 // getOrHandshakeConsiderRouting will try to find the HostInfo to handle this packet, starting a handshake if necessary.
 // If the 2nd return var is false then the hostinfo is not ready to be used in a tunnel.
 func (f *Interface) getOrHandshakeConsiderRouting(fwPacket *firewall.Packet, cacheCallback func(*HandshakeHostInfo)) (*HostInfo, bool) {
+
 	destinationAddr := fwPacket.RemoteAddr
 
 	hostinfo, ready := f.getOrHandshakeNoRouting(destinationAddr, cacheCallback)
@@ -231,10 +233,9 @@ func (f *Interface) sendMessageNow(t header.MessageType, st header.MessageSubTyp
 	f.sendNoMetrics(header.Message, st, hostinfo.ConnectionState, hostinfo, netip.AddrPort{}, p, nb, out, 0)
 }
 
-// SendMessageToVpnAddr handles real addr:port lookup and sends to the current best known address for vpnAddr.
+// SendMessageToVpnAddr handles real addr:port lookup and sends to the current best known address for vpnAddr
-// This function ignores myVpnNetworksTable, and will always attempt to treat the address as a vpnAddr
 func (f *Interface) SendMessageToVpnAddr(t header.MessageType, st header.MessageSubType, vpnAddr netip.Addr, p, nb, out []byte) {
-	hostInfo, ready := f.handshakeManager.GetOrHandshake(vpnAddr, func(hh *HandshakeHostInfo) {
+	hostInfo, ready := f.getOrHandshakeNoRouting(vpnAddr, func(hh *HandshakeHostInfo) {
 		hh.cachePacket(f.l, t, st, p, f.SendMessageToHostInfo, f.cachedPacketMetrics)
 	})
 
@@ -336,9 +337,21 @@ func (f *Interface) sendNoMetrics(t header.MessageType, st header.MessageSubType
 	if ci.eKey == nil {
 		return
 	}
-	useRelay := !remote.IsValid() && !hostinfo.remote.IsValid()
+	target := remote
+	if !target.IsValid() {
+		target = hostinfo.remote
+	}
+	useRelay := !target.IsValid()
 	fullOut := out
 
+	var pkt *overlay.Packet
+	if !useRelay && f.batches.Enabled() {
+		pkt = f.batches.newPacket()
+		if pkt != nil {
+			out = pkt.Payload()[:0]
+		}
+	}
+
 	if useRelay {
 		if len(out) < header.Len {
 			// out always has a capacity of mtu, but not always a length greater than the header.Len.
@@ -372,41 +385,85 @@ func (f *Interface) sendNoMetrics(t header.MessageType, st header.MessageSubType
 	}
 
 	var err error
+	if len(p) > 0 && slicesOverlap(out, p) {
+		tmp := make([]byte, len(p))
+		copy(tmp, p)
+		p = tmp
+	}
 	out, err = ci.eKey.EncryptDanger(out, out, p, c, nb)
 	if noiseutil.EncryptLockNeeded {
 		ci.writeLock.Unlock()
 	}
 	if err != nil {
+		if pkt != nil {
+			pkt.Release()
+		}
 		hostinfo.logger(f.l).WithError(err).
-			WithField("udpAddr", remote).WithField("counter", c).
+			WithField("udpAddr", target).WithField("counter", c).
 			WithField("attemptedCounter", c).
 			Error("Failed to encrypt outgoing packet")
 		return
 	}
 
-	if remote.IsValid() {
+	if target.IsValid() {
-		err = f.writers[q].WriteTo(out, remote)
+		if pkt != nil {
-		if err != nil {
+			pkt.Len = len(out)
-			hostinfo.logger(f.l).WithError(err).
+			if f.l.Level >= logrus.DebugLevel {
-				WithField("udpAddr", remote).Error("Failed to write outgoing packet")
+				f.l.WithFields(logrus.Fields{
-		}
+					"queue":        q,
-	} else if hostinfo.remote.IsValid() {
+					"dest":         target,
-		err = f.writers[q].WriteTo(out, hostinfo.remote)
+					"payload_len":  pkt.Len,
-		if err != nil {
+					"use_batches":  true,
-			hostinfo.logger(f.l).WithError(err).
+					"remote_index": hostinfo.remoteIndexId,
-				WithField("udpAddr", remote).Error("Failed to write outgoing packet")
+				}).Debug("enqueueing packet to UDP batch queue")
-		}
-	} else {
-		// Try to send via a relay
-		for _, relayIP := range hostinfo.relayState.CopyRelayIps() {
-			relayHostInfo, relay, err := f.hostMap.QueryVpnAddrsRelayFor(hostinfo.vpnAddrs, relayIP)
-			if err != nil {
-				hostinfo.relayState.DeleteRelay(relayIP)
-				hostinfo.logger(f.l).WithField("relay", relayIP).WithError(err).Info("sendNoMetrics failed to find HostInfo")
-				continue
 			}
-			f.SendVia(relayHostInfo, relay, out, nb, fullOut[:header.Len+len(out)], true)
+			if f.tryQueuePacket(q, pkt, target) {
-			break
+				return
+			}
+			if f.l.Level >= logrus.DebugLevel {
+				f.l.WithFields(logrus.Fields{
+					"queue": q,
+					"dest":  target,
+				}).Debug("failed to enqueue packet; falling back to immediate send")
+			}
+			f.writeImmediatePacket(q, pkt, target, hostinfo)
+			return
 		}
+		if f.tryQueueDatagram(q, out, target) {
+			return
+		}
+		f.writeImmediate(q, out, target, hostinfo)
+		return
+	}
+
+	// fall back to relay path
+	if pkt != nil {
+		pkt.Release()
+	}
+
+	// Try to send via a relay
+	for _, relayIP := range hostinfo.relayState.CopyRelayIps() {
+		relayHostInfo, relay, err := f.hostMap.QueryVpnAddrsRelayFor(hostinfo.vpnAddrs, relayIP)
+		if err != nil {
+			hostinfo.relayState.DeleteRelay(relayIP)
+			hostinfo.logger(f.l).WithField("relay", relayIP).WithError(err).Info("sendNoMetrics failed to find HostInfo")
+			continue
+		}
+		f.SendVia(relayHostInfo, relay, out, nb, fullOut[:header.Len+len(out)], true)
+		break
 	}
 }
+
+// slicesOverlap reports whether the two byte slices share any portion of memory.
+// cipher.AEAD.Seal requires plaintext and dst to live in disjoint regions.
+func slicesOverlap(a, b []byte) bool {
+	if len(a) == 0 || len(b) == 0 {
+		return false
+	}
+
+	aStart := uintptr(unsafe.Pointer(&a[0]))
+	aEnd := aStart + uintptr(len(a))
+	bStart := uintptr(unsafe.Pointer(&b[0]))
+	bEnd := bStart + uintptr(len(b))
+	return aStart < bEnd && bStart < aEnd
+}

interface.go

@@ -8,6 +8,7 @@ import (
 	"net/netip"
 	"os"
 	"runtime"
+	"strings"
 	"sync/atomic"
 	"time"
 
@@ -21,7 +22,13 @@ import (
 	"github.com/slackhq/nebula/udp"
 )
 
-const mtu = 9001
+const (
+	mtu                          = 9001
+	defaultGSOFlushInterval      = 150 * time.Microsecond
+	defaultBatchQueueDepthFactor = 4
+	defaultGSOMaxSegments        = 8
+	maxKernelGSOSegments         = 64
+)
 
 type InterfaceConfig struct {
 	HostMap            *HostMap
@@ -36,6 +43,9 @@ type InterfaceConfig struct {
 	connectionManager  *connectionManager
 	DropLocalBroadcast bool
 	DropMulticast      bool
+	EnableGSO          bool
+	EnableGRO          bool
+	GSOMaxSegments     int
 	routines           int
 	MessageMetrics     *MessageMetrics
 	version            string
@@ -47,6 +57,8 @@ type InterfaceConfig struct {
 	reQueryWait     time.Duration
 
 	ConntrackCacheTimeout time.Duration
+	BatchFlushInterval    time.Duration
+	BatchQueueDepth       int
 	l                     *logrus.Logger
 }
 
@@ -84,9 +96,20 @@ type Interface struct {
 	version     string
 
 	conntrackCacheTimeout time.Duration
+	batchQueueDepth       int
+	enableGSO             bool
+	enableGRO             bool
+	gsoMaxSegments        int
+	batchUDPQueueGauge    metrics.Gauge
+	batchUDPFlushCounter  metrics.Counter
+	batchTunQueueGauge    metrics.Gauge
+	batchTunFlushCounter  metrics.Counter
+	batchFlushInterval    atomic.Int64
+	sendSem               chan struct{}
 
 	writers []udp.Conn
 	readers []io.ReadWriteCloser
+	batches batchPipelines
 
 	metricHandshakes    metrics.Histogram
 	messageMetrics      *MessageMetrics
@@ -161,6 +184,22 @@ func NewInterface(ctx context.Context, c *InterfaceConfig) (*Interface, error) {
 		return nil, errors.New("no connection manager")
 	}
 
+	if c.GSOMaxSegments <= 0 {
+		c.GSOMaxSegments = defaultGSOMaxSegments
+	}
+	if c.GSOMaxSegments > maxKernelGSOSegments {
+		c.GSOMaxSegments = maxKernelGSOSegments
+	}
+	if c.BatchQueueDepth <= 0 {
+		c.BatchQueueDepth = c.routines * defaultBatchQueueDepthFactor
+	}
+	if c.BatchFlushInterval < 0 {
+		c.BatchFlushInterval = 0
+	}
+	if c.BatchFlushInterval == 0 && c.EnableGSO {
+		c.BatchFlushInterval = defaultGSOFlushInterval
+	}
+
 	cs := c.pki.getCertState()
 	ifce := &Interface{
 		pki:                   c.pki,
@@ -186,6 +225,10 @@ func NewInterface(ctx context.Context, c *InterfaceConfig) (*Interface, error) {
 		relayManager:          c.relayManager,
 		connectionManager:     c.connectionManager,
 		conntrackCacheTimeout: c.ConntrackCacheTimeout,
+		batchQueueDepth:       c.BatchQueueDepth,
+		enableGSO:             c.EnableGSO,
+		enableGRO:             c.EnableGRO,
+		gsoMaxSegments:        c.GSOMaxSegments,
 
 		metricHandshakes: metrics.GetOrRegisterHistogram("handshakes", nil, metrics.NewExpDecaySample(1028, 0.015)),
 		messageMetrics:   c.MessageMetrics,
@@ -198,8 +241,25 @@ func NewInterface(ctx context.Context, c *InterfaceConfig) (*Interface, error) {
 	}
 
 	ifce.tryPromoteEvery.Store(c.tryPromoteEvery)
+	ifce.batchUDPQueueGauge = metrics.GetOrRegisterGauge("batch.udp.queue_depth", nil)
+	ifce.batchUDPFlushCounter = metrics.GetOrRegisterCounter("batch.udp.flushes", nil)
+	ifce.batchTunQueueGauge = metrics.GetOrRegisterGauge("batch.tun.queue_depth", nil)
+	ifce.batchTunFlushCounter = metrics.GetOrRegisterCounter("batch.tun.flushes", nil)
+	ifce.batchFlushInterval.Store(int64(c.BatchFlushInterval))
+	ifce.sendSem = make(chan struct{}, c.routines)
+	ifce.batches.init(c.Inside, c.routines, c.BatchQueueDepth, c.GSOMaxSegments)
 	ifce.reQueryEvery.Store(c.reQueryEvery)
 	ifce.reQueryWait.Store(int64(c.reQueryWait))
+	if c.l.Level >= logrus.DebugLevel {
+		c.l.WithFields(logrus.Fields{
+			"enableGSO":       c.EnableGSO,
+			"enableGRO":       c.EnableGRO,
+			"gsoMaxSegments":  c.GSOMaxSegments,
+			"batchQueueDepth": c.BatchQueueDepth,
+			"batchFlush":      c.BatchFlushInterval,
+			"batching":        ifce.batches.Enabled(),
+		}).Debug("initialized batch pipelines")
+	}
 
 	ifce.connectionManager.intf = ifce
 
@@ -222,13 +282,6 @@ func (f *Interface) activate() {
 		WithField("boringcrypto", boringEnabled()).
 		Info("Nebula interface is active")
 
-	if f.routines > 1 {
-		if !f.inside.SupportsMultiqueue() || !f.outside.SupportsMultipleReaders() {
-			f.routines = 1
-			f.l.Warn("routines is not supported on this platform, falling back to a single routine")
-		}
-	}
-
 	metrics.GetOrRegisterGauge("routines", nil).Update(int64(f.routines))
 
 	// Prepare n tun queues
@@ -255,6 +308,18 @@ func (f *Interface) run() {
 		go f.listenOut(i)
 	}
 
+	if f.l.Level >= logrus.DebugLevel {
+		f.l.WithField("batching", f.batches.Enabled()).Debug("starting interface run loops")
+	}
+
+	if f.batches.Enabled() {
+		for i := 0; i < f.routines; i++ {
+			go f.runInsideBatchWorker(i)
+			go f.runTunWriteQueue(i)
+			go f.runSendQueue(i)
+		}
+	}
+
 	// Launch n queues to read packets from tun dev
 	for i := 0; i < f.routines; i++ {
 		go f.listenIn(f.readers[i], i)
@@ -286,6 +351,17 @@ func (f *Interface) listenOut(i int) {
 func (f *Interface) listenIn(reader io.ReadWriteCloser, i int) {
 	runtime.LockOSThread()
 
+	if f.batches.Enabled() {
+		if br, ok := reader.(overlay.BatchReader); ok {
+			f.listenInBatchLocked(reader, br, i)
+			return
+		}
+	}
+
+	f.listenInLegacyLocked(reader, i)
+}
+
+func (f *Interface) listenInLegacyLocked(reader io.ReadWriteCloser, i int) {
 	packet := make([]byte, mtu)
 	out := make([]byte, mtu)
 	fwPacket := &firewall.Packet{}
@@ -309,6 +385,581 @@ func (f *Interface) listenIn(reader io.ReadWriteCloser, i int) {
 	}
 }
 
+func (f *Interface) listenInBatchLocked(raw io.ReadWriteCloser, reader overlay.BatchReader, i int) {
+	pool := f.batches.Pool()
+	if pool == nil {
+		f.l.Warn("batch pipeline enabled without an allocated pool; falling back to single-packet reads")
+		f.listenInLegacyLocked(raw, i)
+		return
+	}
+
+	for {
+		packets, err := reader.ReadIntoBatch(pool)
+		if err != nil {
+			if errors.Is(err, os.ErrClosed) && f.closed.Load() {
+				return
+			}
+
+			if isVirtioHeadroomError(err) {
+				f.l.WithError(err).Warn("Batch reader fell back due to tun headroom issue")
+				f.listenInLegacyLocked(raw, i)
+				return
+			}
+
+			f.l.WithError(err).Error("Error while reading outbound packet batch")
+			os.Exit(2)
+		}
+
+		if len(packets) == 0 {
+			continue
+		}
+
+		for _, pkt := range packets {
+			if pkt == nil {
+				continue
+			}
+			if !f.batches.enqueueRx(i, pkt) {
+				pkt.Release()
+			}
+		}
+	}
+}
+
+func (f *Interface) runInsideBatchWorker(i int) {
+	queue := f.batches.rxQueue(i)
+	if queue == nil {
+		return
+	}
+
+	out := make([]byte, mtu)
+	fwPacket := &firewall.Packet{}
+	nb := make([]byte, 12, 12)
+	conntrackCache := firewall.NewConntrackCacheTicker(f.conntrackCacheTimeout)
+
+	for pkt := range queue {
+		if pkt == nil {
+			continue
+		}
+		f.consumeInsidePacket(pkt.Payload(), fwPacket, nb, out, i, conntrackCache.Get(f.l))
+		pkt.Release()
+	}
+}
+
+func (f *Interface) runSendQueue(i int) {
+	queue := f.batches.txQueue(i)
+	if queue == nil {
+		if f.l.Level >= logrus.DebugLevel {
+			f.l.WithField("queue", i).Debug("tx queue not initialized; batching disabled for writer")
+		}
+		return
+	}
+	writer := f.writerForIndex(i)
+	if writer == nil {
+		if f.l.Level >= logrus.DebugLevel {
+			f.l.WithField("queue", i).Debug("no UDP writer for batch queue")
+		}
+		return
+	}
+	if f.l.Level >= logrus.DebugLevel {
+		f.l.WithField("queue", i).Debug("send queue worker started")
+	}
+	defer func() {
+		if f.l.Level >= logrus.WarnLevel {
+			f.l.WithField("queue", i).Warn("send queue worker exited")
+		}
+	}()
+
+	batchCap := f.batches.batchSizeHint()
+	if batchCap <= 0 {
+		batchCap = 1
+	}
+	gsoLimit := f.effectiveGSOMaxSegments()
+	if gsoLimit > batchCap {
+		batchCap = gsoLimit
+	}
+	pending := make([]queuedDatagram, 0, batchCap)
+	var (
+		flushTimer *time.Timer
+		flushC     <-chan time.Time
+	)
+	dispatch := func(reason string, timerFired bool) {
+		if len(pending) == 0 {
+			return
+		}
+		batch := pending
+		f.flushAndReleaseBatch(i, writer, batch, reason)
+		for idx := range batch {
+			batch[idx] = queuedDatagram{}
+		}
+		pending = pending[:0]
+		if flushTimer != nil {
+			if !timerFired {
+				if !flushTimer.Stop() {
+					select {
+					case <-flushTimer.C:
+					default:
+					}
+				}
+			}
+			flushTimer = nil
+			flushC = nil
+		}
+	}
+	armTimer := func() {
+		delay := f.currentBatchFlushInterval()
+		if delay <= 0 {
+			dispatch("nogso", false)
+			return
+		}
+		if flushTimer == nil {
+			flushTimer = time.NewTimer(delay)
+			flushC = flushTimer.C
+		}
+	}
+
+	for {
+		select {
+		case d := <-queue:
+			if d.packet == nil {
+				continue
+			}
+			if f.l.Level >= logrus.DebugLevel {
+				f.l.WithFields(logrus.Fields{
+					"queue":       i,
+					"payload_len": d.packet.Len,
+					"dest":        d.addr,
+				}).Debug("send queue received packet")
+			}
+			pending = append(pending, d)
+			if gsoLimit > 0 && len(pending) >= gsoLimit {
+				dispatch("gso", false)
+				continue
+			}
+			if len(pending) >= cap(pending) {
+				dispatch("cap", false)
+				continue
+			}
+			armTimer()
+			f.observeUDPQueueLen(i)
+		case <-flushC:
+			dispatch("timer", true)
+		}
+	}
+}
+
+func (f *Interface) runTunWriteQueue(i int) {
+	queue := f.batches.tunQueue(i)
+	if queue == nil {
+		return
+	}
+	writer := f.batches.inside
+	if writer == nil {
+		return
+	}
+	requiredHeadroom := writer.BatchHeadroom()
+
+	batchCap := f.batches.batchSizeHint()
+	if batchCap <= 0 {
+		batchCap = 1
+	}
+	pending := make([]*overlay.Packet, 0, batchCap)
+	var (
+		flushTimer *time.Timer
+		flushC     <-chan time.Time
+	)
+	flush := func(reason string, timerFired bool) {
+		if len(pending) == 0 {
+			return
+		}
+		valid := pending[:0]
+		for idx := range pending {
+			if !f.ensurePacketHeadroom(&pending[idx], requiredHeadroom, i, reason) {
+				pending[idx] = nil
+				continue
+			}
+			if pending[idx] != nil {
+				valid = append(valid, pending[idx])
+			}
+		}
+		if len(valid) > 0 {
+			if _, err := writer.WriteBatch(valid); err != nil {
+				f.l.WithError(err).
+					WithField("queue", i).
+					WithField("reason", reason).
+					Warn("Failed to write tun batch")
+				for _, pkt := range valid {
+					if pkt != nil {
+						f.writePacketToTun(i, pkt)
+					}
+				}
+			}
+		}
+		pending = pending[:0]
+		if flushTimer != nil {
+			if !timerFired {
+				if !flushTimer.Stop() {
+					select {
+					case <-flushTimer.C:
+					default:
+					}
+				}
+			}
+			flushTimer = nil
+			flushC = nil
+		}
+	}
+	armTimer := func() {
+		delay := f.currentBatchFlushInterval()
+		if delay <= 0 {
+			return
+		}
+		if flushTimer == nil {
+			flushTimer = time.NewTimer(delay)
+			flushC = flushTimer.C
+		}
+	}
+
+	for {
+		select {
+		case pkt := <-queue:
+			if pkt == nil {
+				continue
+			}
+			if f.ensurePacketHeadroom(&pkt, requiredHeadroom, i, "queue") {
+				pending = append(pending, pkt)
+			}
+			if len(pending) >= cap(pending) {
+				flush("cap", false)
+				continue
+			}
+			armTimer()
+			f.observeTunQueueLen(i)
+		case <-flushC:
+			flush("timer", true)
+		}
+	}
+}
+
+func (f *Interface) flushAndReleaseBatch(index int, writer udp.Conn, batch []queuedDatagram, reason string) {
+	if len(batch) == 0 {
+		return
+	}
+	f.flushDatagrams(index, writer, batch, reason)
+	for idx := range batch {
+		if batch[idx].packet != nil {
+			batch[idx].packet.Release()
+			batch[idx].packet = nil
+		}
+	}
+	if f.batchUDPFlushCounter != nil {
+		f.batchUDPFlushCounter.Inc(int64(len(batch)))
+	}
+}
+
+func (f *Interface) flushDatagrams(index int, writer udp.Conn, batch []queuedDatagram, reason string) {
+	if len(batch) == 0 {
+		return
+	}
+	if f.l.Level >= logrus.DebugLevel {
+		f.l.WithFields(logrus.Fields{
+			"writer":  index,
+			"reason":  reason,
+			"pending": len(batch),
+		}).Debug("udp batch flush summary")
+	}
+	maxSeg := f.effectiveGSOMaxSegments()
+	if bw, ok := writer.(udp.BatchConn); ok {
+		chunkCap := maxSeg
+		if chunkCap <= 0 {
+			chunkCap = len(batch)
+		}
+		chunk := make([]udp.Datagram, 0, chunkCap)
+		var (
+			currentAddr netip.AddrPort
+			segments    int
+		)
+		flushChunk := func() {
+			if len(chunk) == 0 {
+				return
+			}
+			if f.l.Level >= logrus.DebugLevel {
+				f.l.WithFields(logrus.Fields{
+					"writer":        index,
+					"segments":      len(chunk),
+					"dest":          chunk[0].Addr,
+					"reason":        reason,
+					"pending_total": len(batch),
+				}).Debug("flushing UDP batch")
+			}
+			if err := bw.WriteBatch(chunk); err != nil {
+				f.l.WithError(err).
+					WithField("writer", index).
+					WithField("reason", reason).
+					Warn("Failed to write UDP batch")
+			}
+			chunk = chunk[:0]
+			segments = 0
+		}
+		for _, item := range batch {
+			if item.packet == nil || !item.addr.IsValid() {
+				continue
+			}
+			payload := item.packet.Payload()[:item.packet.Len]
+			if segments == 0 {
+				currentAddr = item.addr
+			}
+			if item.addr != currentAddr || (maxSeg > 0 && segments >= maxSeg) {
+				flushChunk()
+				currentAddr = item.addr
+			}
+			chunk = append(chunk, udp.Datagram{Payload: payload, Addr: item.addr})
+			segments++
+		}
+		flushChunk()
+		return
+	}
+	for _, item := range batch {
+		if item.packet == nil || !item.addr.IsValid() {
+			continue
+		}
+		if f.l.Level >= logrus.DebugLevel {
+			f.l.WithFields(logrus.Fields{
+				"writer":   index,
+				"reason":   reason,
+				"dest":     item.addr,
+				"segments": 1,
+			}).Debug("flushing UDP batch")
+		}
+		if err := writer.WriteTo(item.packet.Payload()[:item.packet.Len], item.addr); err != nil {
+			f.l.WithError(err).
+				WithField("writer", index).
+				WithField("udpAddr", item.addr).
+				WithField("reason", reason).
+				Warn("Failed to write UDP packet")
+		}
+	}
+}
+
+func (f *Interface) tryQueueDatagram(q int, buf []byte, addr netip.AddrPort) bool {
+	if !addr.IsValid() || !f.batches.Enabled() {
+		return false
+	}
+	pkt := f.batches.newPacket()
+	if pkt == nil {
+		return false
+	}
+	payload := pkt.Payload()
+	if len(payload) < len(buf) {
+		pkt.Release()
+		return false
+	}
+	copy(payload, buf)
+	pkt.Len = len(buf)
+	if f.batches.enqueueTx(q, pkt, addr) {
+		f.observeUDPQueueLen(q)
+		return true
+	}
+	pkt.Release()
+	return false
+}
+
+func (f *Interface) writerForIndex(i int) udp.Conn {
+	if i < 0 || i >= len(f.writers) {
+		return nil
+	}
+	return f.writers[i]
+}
+
+func (f *Interface) writeImmediate(q int, buf []byte, addr netip.AddrPort, hostinfo *HostInfo) {
+	writer := f.writerForIndex(q)
+	if writer == nil {
+		f.l.WithField("udpAddr", addr).
+			WithField("writer", q).
+			Error("Failed to write outgoing packet: no writer available")
+		return
+	}
+	if err := writer.WriteTo(buf, addr); err != nil {
+		hostinfo.logger(f.l).
+			WithError(err).
+			WithField("udpAddr", addr).
+			Error("Failed to write outgoing packet")
+	}
+}
+
+func (f *Interface) tryQueuePacket(q int, pkt *overlay.Packet, addr netip.AddrPort) bool {
+	if pkt == nil || !addr.IsValid() || !f.batches.Enabled() {
+		return false
+	}
+	if f.batches.enqueueTx(q, pkt, addr) {
+		f.observeUDPQueueLen(q)
+		return true
+	}
+	return false
+}
+
+func (f *Interface) writeImmediatePacket(q int, pkt *overlay.Packet, addr netip.AddrPort, hostinfo *HostInfo) {
+	if pkt == nil {
+		return
+	}
+	writer := f.writerForIndex(q)
+	if writer == nil {
+		f.l.WithField("udpAddr", addr).
+			WithField("writer", q).
+			Error("Failed to write outgoing packet: no writer available")
+		pkt.Release()
+		return
+	}
+	if err := writer.WriteTo(pkt.Payload()[:pkt.Len], addr); err != nil {
+		hostinfo.logger(f.l).
+			WithError(err).
+			WithField("udpAddr", addr).
+			Error("Failed to write outgoing packet")
+	}
+	pkt.Release()
+}
+
+func (f *Interface) writePacketToTun(q int, pkt *overlay.Packet) {
+	if pkt == nil {
+		return
+	}
+	writer := f.readers[q]
+	if writer == nil {
+		pkt.Release()
+		return
+	}
+	if bw, ok := writer.(interface {
+		WriteBatch([]*overlay.Packet) (int, error)
+	}); ok {
+		if _, err := bw.WriteBatch([]*overlay.Packet{pkt}); err != nil {
+			f.l.WithError(err).WithField("queue", q).Warn("Failed to write tun packet via batch writer")
+			pkt.Release()
+		}
+		return
+	}
+	if _, err := writer.Write(pkt.Payload()[:pkt.Len]); err != nil {
+		f.l.WithError(err).Error("Failed to write to tun")
+	}
+	pkt.Release()
+}
+
+func (f *Interface) clonePacketWithHeadroom(pkt *overlay.Packet, required int) *overlay.Packet {
+	if pkt == nil {
+		return nil
+	}
+	payload := pkt.Payload()[:pkt.Len]
+	if len(payload) == 0 && required <= 0 {
+		return pkt
+	}
+
+	pool := f.batches.Pool()
+	if pool != nil {
+		if clone := pool.Get(); clone != nil {
+			if len(clone.Payload()) >= len(payload) {
+				clone.Len = copy(clone.Payload(), payload)
+				pkt.Release()
+				return clone
+			}
+			clone.Release()
+		}
+	}
+
+	if required < 0 {
+		required = 0
+	}
+	buf := make([]byte, required+len(payload))
+	n := copy(buf[required:], payload)
+	pkt.Release()
+	return &overlay.Packet{
+		Buf:    buf,
+		Offset: required,
+		Len:    n,
+	}
+}
+
+func (f *Interface) observeUDPQueueLen(i int) {
+	if f.batchUDPQueueGauge == nil {
+		return
+	}
+	f.batchUDPQueueGauge.Update(int64(f.batches.txQueueLen(i)))
+}
+
+func (f *Interface) observeTunQueueLen(i int) {
+	if f.batchTunQueueGauge == nil {
+		return
+	}
+	f.batchTunQueueGauge.Update(int64(f.batches.tunQueueLen(i)))
+}
+
+func (f *Interface) currentBatchFlushInterval() time.Duration {
+	if v := f.batchFlushInterval.Load(); v > 0 {
+		return time.Duration(v)
+	}
+	return 0
+}
+
+func (f *Interface) ensurePacketHeadroom(pkt **overlay.Packet, required int, queue int, reason string) bool {
+	p := *pkt
+	if p == nil {
+		return false
+	}
+	if required <= 0 || p.Offset >= required {
+		return true
+	}
+	clone := f.clonePacketWithHeadroom(p, required)
+	if clone == nil {
+		f.l.WithFields(logrus.Fields{
+			"queue":  queue,
+			"reason": reason,
+		}).Warn("dropping packet lacking tun headroom")
+		return false
+	}
+	*pkt = clone
+	return true
+}
+
+func isVirtioHeadroomError(err error) bool {
+	if err == nil {
+		return false
+	}
+	msg := err.Error()
+	return strings.Contains(msg, "headroom") || strings.Contains(msg, "virtio")
+}
+
+func (f *Interface) effectiveGSOMaxSegments() int {
+	max := f.gsoMaxSegments
+	if max <= 0 {
+		max = defaultGSOMaxSegments
+	}
+	if max > maxKernelGSOSegments {
+		max = maxKernelGSOSegments
+	}
+	if !f.enableGSO {
+		return 1
+	}
+	return max
+}
+
+type udpOffloadConfigurator interface {
+	ConfigureOffload(enableGSO, enableGRO bool, maxSegments int)
+}
+
+func (f *Interface) applyOffloadConfig(enableGSO, enableGRO bool, maxSegments int) {
+	if maxSegments <= 0 {
+		maxSegments = defaultGSOMaxSegments
+	}
+	if maxSegments > maxKernelGSOSegments {
+		maxSegments = maxKernelGSOSegments
+	}
+	f.enableGSO = enableGSO
+	f.enableGRO = enableGRO
+	f.gsoMaxSegments = maxSegments
+	for _, writer := range f.writers {
+		if cfg, ok := writer.(udpOffloadConfigurator); ok {
+			cfg.ConfigureOffload(enableGSO, enableGRO, maxSegments)
+		}
+	}
+}
+
 func (f *Interface) RegisterConfigChangeCallbacks(c *config.C) {
 	c.RegisterReloadCallback(f.reloadFirewall)
 	c.RegisterReloadCallback(f.reloadSendRecvError)
@@ -411,6 +1062,42 @@ func (f *Interface) reloadMisc(c *config.C) {
 		f.reQueryWait.Store(int64(n))
 		f.l.Info("timers.requery_wait_duration has changed")
 	}
+
+	if c.HasChanged("listen.gso_flush_timeout") {
+		d := c.GetDuration("listen.gso_flush_timeout", defaultGSOFlushInterval)
+		if d < 0 {
+			d = 0
+		}
+		f.batchFlushInterval.Store(int64(d))
+		f.l.WithField("duration", d).Info("listen.gso_flush_timeout has changed")
+	} else if c.HasChanged("batch.flush_interval") {
+		d := c.GetDuration("batch.flush_interval", defaultGSOFlushInterval)
+		if d < 0 {
+			d = 0
+		}
+		f.batchFlushInterval.Store(int64(d))
+		f.l.WithField("duration", d).Warn("batch.flush_interval is deprecated; use listen.gso_flush_timeout")
+	}
+
+	if c.HasChanged("batch.queue_depth") {
+		n := c.GetInt("batch.queue_depth", f.batchQueueDepth)
+		if n != f.batchQueueDepth {
+			f.batchQueueDepth = n
+			f.l.Warn("batch.queue_depth changes require a restart to take effect")
+		}
+	}
+
+	if c.HasChanged("listen.enable_gso") || c.HasChanged("listen.enable_gro") || c.HasChanged("listen.gso_max_segments") {
+		enableGSO := c.GetBool("listen.enable_gso", f.enableGSO)
+		enableGRO := c.GetBool("listen.enable_gro", f.enableGRO)
+		maxSeg := c.GetInt("listen.gso_max_segments", f.gsoMaxSegments)
+		f.applyOffloadConfig(enableGSO, enableGRO, maxSeg)
+		f.l.WithFields(logrus.Fields{
+			"enableGSO":      enableGSO,
+			"enableGRO":      enableGRO,
+			"gsoMaxSegments": maxSeg,
+		}).Info("listen GSO/GRO configuration updated")
+	}
 }
 
 func (f *Interface) emitStats(ctx context.Context, i time.Duration) {

lighthouse.go

@@ -360,8 +360,7 @@ func (lh *LightHouse) parseLighthouses(c *config.C) ([]netip.Addr, error) {
 		}
 
 		if !lh.myVpnNetworksTable.Contains(addr) {
-			lh.l.WithFields(m{"vpnAddr": addr, "networks": lh.myVpnNetworks}).
+			return nil, util.NewContextualError("lighthouse host is not in our networks, invalid", m{"vpnAddr": addr, "networks": lh.myVpnNetworks}, nil)
-				Warn("lighthouse host is not within our networks, lighthouse functionality will work but layer 3 network traffic to the lighthouse will not")
 		}
 		out[i] = addr
 	}
@@ -432,8 +431,7 @@ func (lh *LightHouse) loadStaticMap(c *config.C, staticList map[netip.Addr]struc
 		}
 
 		if !lh.myVpnNetworksTable.Contains(vpnAddr) {
-			lh.l.WithFields(m{"vpnAddr": vpnAddr, "networks": lh.myVpnNetworks, "entry": i + 1}).
+			return util.NewContextualError("static_host_map key is not in our network, invalid", m{"vpnAddr": vpnAddr, "networks": lh.myVpnNetworks, "entry": i + 1}, nil)
-				Warn("static_host_map key is not within our networks, layer 3 network traffic to this host will not work")
 		}
 
 		vals, ok := v.([]any)
@@ -1339,19 +1337,12 @@ func (lhh *LightHouseHandler) handleHostPunchNotification(n *NebulaMeta, fromVpn
 		}
 	}
 
-	remoteAllowList := lhh.lh.GetRemoteAllowList()
 	for _, a := range n.Details.V4AddrPorts {
-		b := protoV4AddrPortToNetAddrPort(a)
+		punch(protoV4AddrPortToNetAddrPort(a), detailsVpnAddr)
-		if remoteAllowList.Allow(detailsVpnAddr, b.Addr()) {
-			punch(b, detailsVpnAddr)
-		}
 	}
 
 	for _, a := range n.Details.V6AddrPorts {
-		b := protoV6AddrPortToNetAddrPort(a)
+		punch(protoV6AddrPortToNetAddrPort(a), detailsVpnAddr)
-		if remoteAllowList.Allow(detailsVpnAddr, b.Addr()) {
-			punch(b, detailsVpnAddr)
-		}
 	}
 
 	// This sends a nebula test packet to the host trying to contact us. In the case

lighthouse_test.go

@@ -14,7 +14,7 @@ import (
 	"github.com/slackhq/nebula/test"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
-	"go.yaml.in/yaml/v3"
+	"gopkg.in/yaml.v3"
 )
 
 func TestOldIPv4Only(t *testing.T) {

main.go

@@ -5,8 +5,7 @@ import (
 	"fmt"
 	"net"
 	"net/netip"
-	"runtime/debug"
+	"runtime"
-	"strings"
 	"time"
 
 	"github.com/sirupsen/logrus"
@@ -15,7 +14,7 @@ import (
 	"github.com/slackhq/nebula/sshd"
 	"github.com/slackhq/nebula/udp"
 	"github.com/slackhq/nebula/util"
-	"go.yaml.in/yaml/v3"
+	"gopkg.in/yaml.v3"
 )
 
 type m = map[string]any
@@ -29,10 +28,6 @@ func Main(c *config.C, configTest bool, buildVersion string, logger *logrus.Logg
 		}
 	}()
 
-	if buildVersion == "" {
-		buildVersion = moduleVersion()
-	}
-
 	l := logger
 	l.Formatter = &logrus.TextFormatter{
 		FullTimestamp: true,
@@ -81,8 +76,7 @@ func Main(c *config.C, configTest bool, buildVersion string, logger *logrus.Logg
 	if c.GetBool("sshd.enabled", false) {
 		sshStart, err = configSSH(l, ssh, c)
 		if err != nil {
-			l.WithError(err).Warn("Failed to configure sshd, ssh debugging will not be available")
+			return nil, util.ContextualizeIfNeeded("Error while configuring the sshd", err)
-			sshStart = nil
 		}
 	}
 
@@ -150,6 +144,20 @@ func Main(c *config.C, configTest bool, buildVersion string, logger *logrus.Logg
 	// set up our UDP listener
 	udpConns := make([]udp.Conn, routines)
 	port := c.GetInt("listen.port", 0)
+	enableGSO := c.GetBool("listen.enable_gso", true)
+	enableGRO := c.GetBool("listen.enable_gro", true)
+	gsoMaxSegments := c.GetInt("listen.gso_max_segments", defaultGSOMaxSegments)
+	if gsoMaxSegments <= 0 {
+		gsoMaxSegments = defaultGSOMaxSegments
+	}
+	if gsoMaxSegments > maxKernelGSOSegments {
+		gsoMaxSegments = maxKernelGSOSegments
+	}
+	gsoFlushTimeout := c.GetDuration("listen.gso_flush_timeout", defaultGSOFlushInterval)
+	if gsoFlushTimeout < 0 {
+		gsoFlushTimeout = 0
+	}
+	batchQueueDepth := c.GetInt("batch.queue_depth", 0)
 
 	if !configTest {
 		rawListenHost := c.GetString("listen.host", "0.0.0.0")
@@ -169,13 +177,27 @@ func Main(c *config.C, configTest bool, buildVersion string, logger *logrus.Logg
 			listenHost = ips[0].Unmap()
 		}
 
+		useWGDefault := runtime.GOOS == "linux"
+		useWG := c.GetBool("listen.use_wireguard_stack", useWGDefault)
+		var mkListener func(*logrus.Logger, netip.Addr, int, bool, int) (udp.Conn, error)
+		if useWG {
+			mkListener = udp.NewWireguardListener
+		} else {
+			mkListener = udp.NewListener
+		}
+
 		for i := 0; i < routines; i++ {
 			l.Infof("listening on %v", netip.AddrPortFrom(listenHost, uint16(port)))
-			udpServer, err := udp.NewListener(l, listenHost, port, routines > 1, c.GetInt("listen.batch", 64))
+			udpServer, err := mkListener(l, listenHost, port, routines > 1, c.GetInt("listen.batch", 64))
 			if err != nil {
 				return nil, util.NewContextualError("Failed to open udp listener", m{"queue": i}, err)
 			}
 			udpServer.ReloadConfig(c)
+			if cfg, ok := udpServer.(interface {
+				ConfigureOffload(bool, bool, int)
+			}); ok {
+				cfg.ConfigureOffload(enableGSO, enableGRO, gsoMaxSegments)
+			}
 			udpConns[i] = udpServer
 
 			// If port is dynamic, discover it before the next pass through the for loop
@@ -243,12 +265,17 @@ func Main(c *config.C, configTest bool, buildVersion string, logger *logrus.Logg
 		reQueryWait:           c.GetDuration("timers.requery_wait_duration", defaultReQueryWait),
 		DropLocalBroadcast:    c.GetBool("tun.drop_local_broadcast", false),
 		DropMulticast:         c.GetBool("tun.drop_multicast", false),
+		EnableGSO:             enableGSO,
+		EnableGRO:             enableGRO,
+		GSOMaxSegments:        gsoMaxSegments,
 		routines:              routines,
 		MessageMetrics:        messageMetrics,
 		version:               buildVersion,
 		relayManager:          NewRelayManager(ctx, l, hostMap, c),
 		punchy:                punchy,
 		ConntrackCacheTimeout: conntrackCacheTimeout,
+		BatchFlushInterval:    gsoFlushTimeout,
+		BatchQueueDepth:       batchQueueDepth,
 		l:                     l,
 	}
 
@@ -260,6 +287,7 @@ func Main(c *config.C, configTest bool, buildVersion string, logger *logrus.Logg
 		}
 
 		ifce.writers = udpConns
+		ifce.applyOffloadConfig(enableGSO, enableGRO, gsoMaxSegments)
 		lightHouse.ifce = ifce
 
 		ifce.RegisterConfigChangeCallbacks(c)
@@ -302,18 +330,3 @@ func Main(c *config.C, configTest bool, buildVersion string, logger *logrus.Logg
 		connManager.Start,
 	}, nil
 }
-
-func moduleVersion() string {
-	info, ok := debug.ReadBuildInfo()
-	if !ok {
-		return ""
-	}
-
-	for _, dep := range info.Deps {
-		if dep.Path == "github.com/slackhq/nebula" {
-			return strings.TrimPrefix(dep.Version, "v")
-		}
-	}
-
-	return ""
-}

outside.go

@@ -12,6 +12,7 @@ import (
 	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula/firewall"
 	"github.com/slackhq/nebula/header"
+	"github.com/slackhq/nebula/overlay"
 	"golang.org/x/net/ipv4"
 )
 
@@ -19,7 +20,7 @@ const (
 	minFwPacketLen = 4
 )
 
-func (f *Interface) readOutsidePackets(ip netip.AddrPort, via *ViaSender, out []byte, packet []byte, h *header.H, fwPacket *firewall.Packet, lhf *LightHouseHandler, nb []byte, q int, localCache firewall.ConntrackCache) {
+func (f *Interface) readOutsidePackets(ip netip.AddrPort, via *ViaSender, out []byte, packet []byte, h *header.H, fwPacket *firewall.Packet, lhf *LightHouseHandler, nb []byte, q int, localCache *firewall.ConntrackCache) {
 	err := h.Parse(packet)
 	if err != nil {
 		// Hole punch packets are 0 or 1 byte big, so lets ignore printing those errors
@@ -61,7 +62,7 @@ func (f *Interface) readOutsidePackets(ip netip.AddrPort, via *ViaSender, out []
 
 		switch h.Subtype {
 		case header.MessageNone:
-			if !f.decryptToTun(hostinfo, h.MessageCounter, out, packet, fwPacket, nb, q, localCache) {
+			if !f.decryptToTun(hostinfo, h.MessageCounter, out, packet, fwPacket, nb, q, localCache, ip, h.RemoteIndex) {
 				return
 			}
 		case header.MessageRelay:
@@ -465,23 +466,45 @@ func (f *Interface) decrypt(hostinfo *HostInfo, mc uint64, out []byte, packet []
 	return out, nil
 }
 
-func (f *Interface) decryptToTun(hostinfo *HostInfo, messageCounter uint64, out []byte, packet []byte, fwPacket *firewall.Packet, nb []byte, q int, localCache firewall.ConntrackCache) bool {
+func (f *Interface) decryptToTun(hostinfo *HostInfo, messageCounter uint64, out []byte, packet []byte, fwPacket *firewall.Packet, nb []byte, q int, localCache *firewall.ConntrackCache, addr netip.AddrPort, recvIndex uint32) bool {
-	var err error
+	var (
+		err error
+		pkt *overlay.Packet
+	)
+
+	if f.batches.tunQueue(q) != nil {
+		pkt = f.batches.newPacket()
+		if pkt != nil {
+			out = pkt.Payload()[:0]
+		}
+	}
 
 	out, err = hostinfo.ConnectionState.dKey.DecryptDanger(out, packet[:header.Len], packet[header.Len:], messageCounter, nb)
 	if err != nil {
+		if pkt != nil {
+			pkt.Release()
+		}
 		hostinfo.logger(f.l).WithError(err).Error("Failed to decrypt packet")
+		if addr.IsValid() {
+			f.maybeSendRecvError(addr, recvIndex)
+		}
 		return false
 	}
 
 	err = newPacket(out, true, fwPacket)
 	if err != nil {
+		if pkt != nil {
+			pkt.Release()
+		}
 		hostinfo.logger(f.l).WithError(err).WithField("packet", out).
 			Warnf("Error while validating inbound packet")
 		return false
 	}
 
 	if !hostinfo.ConnectionState.window.Update(f.l, messageCounter) {
+		if pkt != nil {
+			pkt.Release()
+		}
 		hostinfo.logger(f.l).WithField("fwPacket", fwPacket).
 			Debugln("dropping out of window packet")
 		return false
@@ -489,6 +512,9 @@ func (f *Interface) decryptToTun(hostinfo *HostInfo, messageCounter uint64, out
 
 	dropReason := f.firewall.Drop(*fwPacket, true, hostinfo, f.pki.GetCAPool(), localCache)
 	if dropReason != nil {
+		if pkt != nil {
+			pkt.Release()
+		}
 		// NOTE: We give `packet` as the `out` here since we already decrypted from it and we don't need it anymore
 		// This gives us a buffer to build the reject packet in
 		f.rejectOutside(out, hostinfo.ConnectionState, hostinfo, nb, packet, q)
@@ -501,8 +527,17 @@ func (f *Interface) decryptToTun(hostinfo *HostInfo, messageCounter uint64, out
 	}
 
 	f.connectionManager.In(hostinfo)
-	_, err = f.readers[q].Write(out)
+	if pkt != nil {
-	if err != nil {
+		pkt.Len = len(out)
+		if f.batches.enqueueTun(q, pkt) {
+			f.observeTunQueueLen(q)
+			return true
+		}
+		f.writePacketToTun(q, pkt)
+		return true
+	}
+
+	if _, err = f.readers[q].Write(out); err != nil {
 		f.l.WithError(err).Error("Failed to write to tun")
 	}
 	return true

overlay/device.go

@@ -3,6 +3,7 @@ package overlay
 import (
 	"io"
 	"net/netip"
+	"sync"
 
 	"github.com/slackhq/nebula/routing"
 )
@@ -13,6 +14,86 @@ type Device interface {
 	Networks() []netip.Prefix
 	Name() string
 	RoutesFor(netip.Addr) routing.Gateways
-	SupportsMultiqueue() bool
 	NewMultiQueueReader() (io.ReadWriteCloser, error)
 }
+
+// Packet represents a single packet buffer with optional headroom to carry
+// metadata (for example virtio-net headers).
+type Packet struct {
+	Buf     []byte
+	Offset  int
+	Len     int
+	release func()
+}
+
+func (p *Packet) Payload() []byte {
+	return p.Buf[p.Offset : p.Offset+p.Len]
+}
+
+func (p *Packet) Reset() {
+	p.Len = 0
+	p.Offset = 0
+	p.release = nil
+}
+
+func (p *Packet) Release() {
+	if p.release != nil {
+		p.release()
+		p.release = nil
+	}
+}
+
+func (p *Packet) Capacity() int {
+	return len(p.Buf) - p.Offset
+}
+
+// PacketPool manages reusable buffers with headroom.
+type PacketPool struct {
+	headroom int
+	blksz    int
+	pool     sync.Pool
+}
+
+func NewPacketPool(headroom, payload int) *PacketPool {
+	p := &PacketPool{headroom: headroom, blksz: headroom + payload}
+	p.pool.New = func() any {
+		buf := make([]byte, p.blksz)
+		return &Packet{Buf: buf, Offset: headroom}
+	}
+	return p
+}
+
+func (p *PacketPool) Get() *Packet {
+	pkt := p.pool.Get().(*Packet)
+	pkt.Offset = p.headroom
+	pkt.Len = 0
+	pkt.release = func() { p.put(pkt) }
+	return pkt
+}
+
+func (p *PacketPool) put(pkt *Packet) {
+	pkt.Reset()
+	p.pool.Put(pkt)
+}
+
+// BatchReader allows reading multiple packets into a shared pool with
+// preallocated headroom (e.g. virtio-net headers).
+type BatchReader interface {
+	ReadIntoBatch(pool *PacketPool) ([]*Packet, error)
+}
+
+// BatchWriter writes a slice of packets that carry their own metadata.
+type BatchWriter interface {
+	WriteBatch(packets []*Packet) (int, error)
+}
+
+// BatchCapableDevice describes a device that can efficiently read and write
+// batches of packets with virtio headroom.
+type BatchCapableDevice interface {
+	Device
+	BatchReader
+	BatchWriter
+	BatchHeadroom() int
+	BatchPayloadCap() int
+	BatchSize() int
+}

overlay/tun_android.go

@@ -95,10 +95,6 @@ func (t *tun) Name() string {
 	return "android"
 }
 
-func (t *tun) SupportsMultiqueue() bool {
-	return false
-}
-
 func (t *tun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
 	return nil, fmt.Errorf("TODO: multiqueue not implemented for android")
 }

overlay/tun_darwin.go

@@ -549,10 +549,6 @@ func (t *tun) Name() string {
 	return t.Device
 }
 
-func (t *tun) SupportsMultiqueue() bool {
-	return false
-}
-
 func (t *tun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
 	return nil, fmt.Errorf("TODO: multiqueue not implemented for darwin")
 }

overlay/tun_disabled.go

@@ -105,10 +105,6 @@ func (t *disabledTun) Write(b []byte) (int, error) {
 	return len(b), nil
 }
 
-func (t *disabledTun) SupportsMultiqueue() bool {
-	return true
-}
-
 func (t *disabledTun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
 	return t, nil
 }

overlay/tun_freebsd.go

@@ -450,10 +450,6 @@ func (t *tun) Name() string {
 	return t.Device
 }
 
-func (t *tun) SupportsMultiqueue() bool {
-	return false
-}
-
 func (t *tun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
 	return nil, fmt.Errorf("TODO: multiqueue not implemented for freebsd")
 }

overlay/tun_ios.go

@@ -151,10 +151,6 @@ func (t *tun) Name() string {
 	return "iOS"
 }
 
-func (t *tun) SupportsMultiqueue() bool {
-	return false
-}
-
 func (t *tun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
 	return nil, fmt.Errorf("TODO: multiqueue not implemented for ios")
 }

overlay/tun_linux.go

@@ -9,6 +9,7 @@ import (
 	"net"
 	"net/netip"
 	"os"
+	"runtime"
 	"strings"
 	"sync/atomic"
 	"time"
@@ -19,6 +20,7 @@ import (
 	"github.com/slackhq/nebula/config"
 	"github.com/slackhq/nebula/routing"
 	"github.com/slackhq/nebula/util"
+	wgtun "github.com/slackhq/nebula/wgstack/tun"
 	"github.com/vishvananda/netlink"
 	"golang.org/x/sys/unix"
 )
@@ -33,6 +35,7 @@ type tun struct {
 	TXQueueLen  int
 	deviceIndex int
 	ioctlFd     uintptr
+	wgDevice    wgtun.Device
 
 	Routes                    atomic.Pointer[[]Route]
 	routeTree                 atomic.Pointer[bart.Table[routing.Gateways]]
@@ -68,7 +71,9 @@ type ifreqQLEN struct {
 func newTunFromFd(c *config.C, l *logrus.Logger, deviceFd int, vpnNetworks []netip.Prefix) (*tun, error) {
 	file := os.NewFile(uintptr(deviceFd), "/dev/net/tun")
 
-	t, err := newTunGeneric(c, l, file, vpnNetworks)
+	useWGDefault := runtime.GOOS == "linux"
+	useWG := c.GetBool("tun.use_wireguard_stack", c.GetBool("listen.use_wireguard_stack", useWGDefault))
+	t, err := newTunGeneric(c, l, file, vpnNetworks, useWG)
 	if err != nil {
 		return nil, err
 	}
@@ -113,7 +118,9 @@ func newTun(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, multiqueu
 	name := strings.Trim(string(req.Name[:]), "\x00")
 
 	file := os.NewFile(uintptr(fd), "/dev/net/tun")
-	t, err := newTunGeneric(c, l, file, vpnNetworks)
+	useWGDefault := runtime.GOOS == "linux"
+	useWG := c.GetBool("tun.use_wireguard_stack", c.GetBool("listen.use_wireguard_stack", useWGDefault))
+	t, err := newTunGeneric(c, l, file, vpnNetworks, useWG)
 	if err != nil {
 		return nil, err
 	}
@@ -123,16 +130,45 @@ func newTun(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, multiqueu
 	return t, nil
 }
 
-func newTunGeneric(c *config.C, l *logrus.Logger, file *os.File, vpnNetworks []netip.Prefix) (*tun, error) {
+func newTunGeneric(c *config.C, l *logrus.Logger, file *os.File, vpnNetworks []netip.Prefix, useWireguard bool) (*tun, error) {
+	var (
+		rw    io.ReadWriteCloser = file
+		fd                       = int(file.Fd())
+		wgDev wgtun.Device
+	)
+
+	if useWireguard {
+		dev, err := wgtun.CreateTUNFromFile(file, c.GetInt("tun.mtu", DefaultMTU))
+		if err != nil {
+			return nil, fmt.Errorf("failed to initialize wireguard tun device: %w", err)
+		}
+		wgDev = dev
+		rw = newWireguardTunIO(dev, c.GetInt("tun.mtu", DefaultMTU))
+		fd = int(dev.File().Fd())
+	}
+
 	t := &tun{
-		ReadWriteCloser:           file,
+		ReadWriteCloser:           rw,
-		fd:                        int(file.Fd()),
+		fd:                        fd,
 		vpnNetworks:               vpnNetworks,
 		TXQueueLen:                c.GetInt("tun.tx_queue", 500),
 		useSystemRoutes:           c.GetBool("tun.use_system_route_table", false),
 		useSystemRoutesBufferSize: c.GetInt("tun.use_system_route_table_buffer_size", 0),
 		l:                         l,
 	}
+	if wgDev != nil {
+		t.wgDevice = wgDev
+	}
+	if wgDev != nil {
+		// replace ioctl fd with device file descriptor to keep route management working
+		file = wgDev.File()
+		t.fd = int(file.Fd())
+		t.ioctlFd = file.Fd()
+	}
+
+	if t.ioctlFd == 0 {
+		t.ioctlFd = file.Fd()
+	}
 
 	err := t.reload(c, true)
 	if err != nil {
@@ -216,10 +252,6 @@ func (t *tun) reload(c *config.C, initial bool) error {
 	return nil
 }
 
-func (t *tun) SupportsMultiqueue() bool {
-	return true
-}
-
 func (t *tun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
 	fd, err := unix.Open("/dev/net/tun", os.O_RDWR, 0)
 	if err != nil {
@@ -586,42 +618,48 @@ func (t *tun) isGatewayInVpnNetworks(gwAddr netip.Addr) bool {
 }
 
 func (t *tun) getGatewaysFromRoute(r *netlink.Route) routing.Gateways {
+
 	var gateways routing.Gateways
 
 	link, err := netlink.LinkByName(t.Device)
 	if err != nil {
-		t.l.WithField("deviceName", t.Device).Error("Ignoring route update: failed to get link by name")
+		t.l.WithField("Devicename", t.Device).Error("Ignoring route update: failed to get link by name")
 		return gateways
 	}
 
 	// If this route is relevant to our interface and there is a gateway then add it
-	if r.LinkIndex == link.Attrs().Index {
+	if r.LinkIndex == link.Attrs().Index && len(r.Gw) > 0 {
-		gwAddr, ok := getGatewayAddr(r.Gw, r.Via)
+		gwAddr, ok := netip.AddrFromSlice(r.Gw)
-		if ok {
+		if !ok {
-			if t.isGatewayInVpnNetworks(gwAddr) {
+			t.l.WithField("route", r).Debug("Ignoring route update, invalid gateway address")
-				gateways = append(gateways, routing.NewGateway(gwAddr, 1))
-			} else {
-				// Gateway isn't in our overlay network, ignore
-				t.l.WithField("route", r).Debug("Ignoring route update, gateway is not in our network")
-			}
 		} else {
-			t.l.WithField("route", r).Debug("Ignoring route update, invalid gateway or via address")
+			gwAddr = gwAddr.Unmap()
+
+			if !t.isGatewayInVpnNetworks(gwAddr) {
+				// Gateway isn't in our overlay network, ignore
+				t.l.WithField("route", r).Debug("Ignoring route update, not in our network")
+			} else {
+				gateways = append(gateways, routing.NewGateway(gwAddr, 1))
+			}
 		}
 	}
 
 	for _, p := range r.MultiPath {
 		// If this route is relevant to our interface and there is a gateway then add it
-		if p.LinkIndex == link.Attrs().Index {
+		if p.LinkIndex == link.Attrs().Index && len(p.Gw) > 0 {
-			gwAddr, ok := getGatewayAddr(p.Gw, p.Via)
+			gwAddr, ok := netip.AddrFromSlice(p.Gw)
-			if ok {
+			if !ok {
-				if t.isGatewayInVpnNetworks(gwAddr) {
+				t.l.WithField("route", r).Debug("Ignoring multipath route update, invalid gateway address")
-					gateways = append(gateways, routing.NewGateway(gwAddr, p.Hops+1))
-				} else {
-					// Gateway isn't in our overlay network, ignore
-					t.l.WithField("route", r).Debug("Ignoring route update, gateway is not in our network")
-				}
 			} else {
-				t.l.WithField("route", r).Debug("Ignoring route update, invalid gateway or via address")
+				gwAddr = gwAddr.Unmap()
+
+				if !t.isGatewayInVpnNetworks(gwAddr) {
+					// Gateway isn't in our overlay network, ignore
+					t.l.WithField("route", r).Debug("Ignoring route update, not in our network")
+				} else {
+					// p.Hops+1 = weight of the route
+					gateways = append(gateways, routing.NewGateway(gwAddr, p.Hops+1))
+				}
 			}
 		}
 	}
@@ -630,27 +668,10 @@ func (t *tun) getGatewaysFromRoute(r *netlink.Route) routing.Gateways {
 	return gateways
 }
 
-func getGatewayAddr(gw net.IP, via netlink.Destination) (netip.Addr, bool) {
-	// Try to use the old RTA_GATEWAY first
-	gwAddr, ok := netip.AddrFromSlice(gw)
-	if !ok {
-		// Fallback to the new RTA_VIA
-		rVia, ok := via.(*netlink.Via)
-		if ok {
-			gwAddr, ok = netip.AddrFromSlice(rVia.Addr)
-		}
-	}
-
-	if gwAddr.IsValid() {
-		gwAddr = gwAddr.Unmap()
-		return gwAddr, true
-	}
-
-	return netip.Addr{}, false
-}
-
 func (t *tun) updateRoutes(r netlink.RouteUpdate) {
+
 	gateways := t.getGatewaysFromRoute(&r.Route)
+
 	if len(gateways) == 0 {
 		// No gateways relevant to our network, no routing changes required.
 		t.l.WithField("route", r).Debug("Ignoring route update, no gateways")
@@ -693,6 +714,14 @@ func (t *tun) Close() error {
 		_ = t.ReadWriteCloser.Close()
 	}
 
+	if t.wgDevice != nil {
+		_ = t.wgDevice.Close()
+		if t.ioctlFd > 0 {
+			// underlying fd already closed by the device
+			t.ioctlFd = 0
+		}
+	}
+
 	if t.ioctlFd > 0 {
 		_ = os.NewFile(t.ioctlFd, "ioctlFd").Close()
 	}

overlay/tun_linux_batch.go

@@ -0,0 +1,56 @@
+//go:build linux && !android && !e2e_testing
+
+package overlay
+
+import "fmt"
+
+func (t *tun) batchIO() (*wireguardTunIO, bool) {
+	io, ok := t.ReadWriteCloser.(*wireguardTunIO)
+	return io, ok
+}
+
+func (t *tun) ReadIntoBatch(pool *PacketPool) ([]*Packet, error) {
+	io, ok := t.batchIO()
+	if !ok {
+		return nil, fmt.Errorf("wireguard batch I/O not enabled")
+	}
+	return io.ReadIntoBatch(pool)
+}
+
+func (t *tun) WriteBatch(packets []*Packet) (int, error) {
+	io, ok := t.batchIO()
+	if ok {
+		return io.WriteBatch(packets)
+	}
+	for _, pkt := range packets {
+		if pkt == nil {
+			continue
+		}
+		if _, err := t.Write(pkt.Payload()[:pkt.Len]); err != nil {
+			return 0, err
+		}
+		pkt.Release()
+	}
+	return len(packets), nil
+}
+
+func (t *tun) BatchHeadroom() int {
+	if io, ok := t.batchIO(); ok {
+		return io.BatchHeadroom()
+	}
+	return 0
+}
+
+func (t *tun) BatchPayloadCap() int {
+	if io, ok := t.batchIO(); ok {
+		return io.BatchPayloadCap()
+	}
+	return 0
+}
+
+func (t *tun) BatchSize() int {
+	if io, ok := t.batchIO(); ok {
+		return io.BatchSize()
+	}
+	return 1
+}

overlay/tun_netbsd.go

@@ -390,10 +390,6 @@ func (t *tun) Name() string {
 	return t.Device
 }
 
-func (t *tun) SupportsMultiqueue() bool {
-	return false
-}
-
 func (t *tun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
 	return nil, fmt.Errorf("TODO: multiqueue not implemented for netbsd")
 }

overlay/tun_openbsd.go

@@ -310,10 +310,6 @@ func (t *tun) Name() string {
 	return t.Device
 }
 
-func (t *tun) SupportsMultiqueue() bool {
-	return false
-}
-
 func (t *tun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
 	return nil, fmt.Errorf("TODO: multiqueue not implemented for openbsd")
 }

overlay/tun_tester.go

@@ -132,10 +132,6 @@ func (t *TestTun) Read(b []byte) (int, error) {
 	return len(p), nil
 }
 
-func (t *TestTun) SupportsMultiqueue() bool {
-	return false
-}
-
 func (t *TestTun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
 	return nil, fmt.Errorf("TODO: multiqueue not implemented")
 }

overlay/tun_windows.go

@@ -234,10 +234,6 @@ func (t *winTun) Write(b []byte) (int, error) {
 	return t.tun.Write(b, 0)
 }
 
-func (t *winTun) SupportsMultiqueue() bool {
-	return false
-}
-
 func (t *winTun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
 	return nil, fmt.Errorf("TODO: multiqueue not implemented for windows")
 }

overlay/user.go

@@ -46,10 +46,6 @@ func (d *UserDevice) RoutesFor(ip netip.Addr) routing.Gateways {
 	return routing.Gateways{routing.NewGateway(ip, 1)}
 }
 
-func (d *UserDevice) SupportsMultiqueue() bool {
-	return true
-}
-
 func (d *UserDevice) NewMultiQueueReader() (io.ReadWriteCloser, error) {
 	return d, nil
 }

overlay/wireguard_tun_linux.go

@@ -0,0 +1,220 @@
+//go:build linux && !android && !e2e_testing
+
+package overlay
+
+import (
+	"fmt"
+	"sync"
+
+	wgtun "github.com/slackhq/nebula/wgstack/tun"
+)
+
+type wireguardTunIO struct {
+	dev       wgtun.Device
+	mtu       int
+	batchSize int
+
+	readMu      sync.Mutex
+	readBuffers [][]byte
+	readLens    []int
+	legacyBuf   []byte
+
+	writeMu      sync.Mutex
+	writeBuf     []byte
+	writeWrap    [][]byte
+	writeBuffers [][]byte
+}
+
+func newWireguardTunIO(dev wgtun.Device, mtu int) *wireguardTunIO {
+	batch := dev.BatchSize()
+	if batch <= 0 {
+		batch = 1
+	}
+	if mtu <= 0 {
+		mtu = DefaultMTU
+	}
+	return &wireguardTunIO{
+		dev:       dev,
+		mtu:       mtu,
+		batchSize: batch,
+		readLens:  make([]int, batch),
+		legacyBuf: make([]byte, wgtun.VirtioNetHdrLen+mtu),
+		writeBuf:  make([]byte, wgtun.VirtioNetHdrLen+mtu),
+		writeWrap: make([][]byte, 1),
+	}
+}
+
+func (w *wireguardTunIO) Read(p []byte) (int, error) {
+	w.readMu.Lock()
+	defer w.readMu.Unlock()
+
+	bufs := w.readBuffers
+	if len(bufs) == 0 {
+		bufs = [][]byte{w.legacyBuf}
+		w.readBuffers = bufs
+	}
+	n, err := w.dev.Read(bufs[:1], w.readLens[:1], wgtun.VirtioNetHdrLen)
+	if err != nil {
+		return 0, err
+	}
+	if n == 0 {
+		return 0, nil
+	}
+	length := w.readLens[0]
+	copy(p, w.legacyBuf[wgtun.VirtioNetHdrLen:wgtun.VirtioNetHdrLen+length])
+	return length, nil
+}
+
+func (w *wireguardTunIO) Write(p []byte) (int, error) {
+	if len(p) > w.mtu {
+		return 0, fmt.Errorf("wireguard tun: payload exceeds MTU (%d > %d)", len(p), w.mtu)
+	}
+	w.writeMu.Lock()
+	defer w.writeMu.Unlock()
+	buf := w.writeBuf[:wgtun.VirtioNetHdrLen+len(p)]
+	for i := 0; i < wgtun.VirtioNetHdrLen; i++ {
+		buf[i] = 0
+	}
+	copy(buf[wgtun.VirtioNetHdrLen:], p)
+	w.writeWrap[0] = buf
+	n, err := w.dev.Write(w.writeWrap, wgtun.VirtioNetHdrLen)
+	if err != nil {
+		return n, err
+	}
+	return len(p), nil
+}
+
+func (w *wireguardTunIO) ReadIntoBatch(pool *PacketPool) ([]*Packet, error) {
+	if pool == nil {
+		return nil, fmt.Errorf("wireguard tun: packet pool is nil")
+	}
+
+	w.readMu.Lock()
+	defer w.readMu.Unlock()
+
+	if len(w.readBuffers) < w.batchSize {
+		w.readBuffers = make([][]byte, w.batchSize)
+	}
+	if len(w.readLens) < w.batchSize {
+		w.readLens = make([]int, w.batchSize)
+	}
+
+	packets := make([]*Packet, w.batchSize)
+	requiredHeadroom := w.BatchHeadroom()
+	requiredPayload := w.BatchPayloadCap()
+	headroom := 0
+	for i := 0; i < w.batchSize; i++ {
+		pkt := pool.Get()
+		if pkt == nil {
+			releasePackets(packets[:i])
+			return nil, fmt.Errorf("wireguard tun: packet pool returned nil packet")
+		}
+		if pkt.Capacity() < requiredPayload {
+			pkt.Release()
+			releasePackets(packets[:i])
+			return nil, fmt.Errorf("wireguard tun: packet capacity %d below required %d", pkt.Capacity(), requiredPayload)
+		}
+		if i == 0 {
+			headroom = pkt.Offset
+			if headroom < requiredHeadroom {
+				pkt.Release()
+				releasePackets(packets[:i])
+				return nil, fmt.Errorf("wireguard tun: packet headroom %d below virtio requirement %d", headroom, requiredHeadroom)
+			}
+		} else if pkt.Offset != headroom {
+			pkt.Release()
+			releasePackets(packets[:i])
+			return nil, fmt.Errorf("wireguard tun: inconsistent packet headroom (%d != %d)", pkt.Offset, headroom)
+		}
+		packets[i] = pkt
+		w.readBuffers[i] = pkt.Buf
+	}
+
+	n, err := w.dev.Read(w.readBuffers[:w.batchSize], w.readLens[:w.batchSize], headroom)
+	if err != nil {
+		releasePackets(packets)
+		return nil, err
+	}
+	if n == 0 {
+		releasePackets(packets)
+		return nil, nil
+	}
+	for i := 0; i < n; i++ {
+		packets[i].Len = w.readLens[i]
+	}
+	for i := n; i < w.batchSize; i++ {
+		packets[i].Release()
+		packets[i] = nil
+	}
+	return packets[:n], nil
+}
+
+func (w *wireguardTunIO) WriteBatch(packets []*Packet) (int, error) {
+	if len(packets) == 0 {
+		return 0, nil
+	}
+	requiredHeadroom := w.BatchHeadroom()
+	offset := packets[0].Offset
+	if offset < requiredHeadroom {
+		releasePackets(packets)
+		return 0, fmt.Errorf("wireguard tun: packet offset %d smaller than required headroom %d", offset, requiredHeadroom)
+	}
+	for _, pkt := range packets {
+		if pkt == nil {
+			continue
+		}
+		if pkt.Offset != offset {
+			releasePackets(packets)
+			return 0, fmt.Errorf("wireguard tun: mixed packet offsets not supported")
+		}
+		limit := pkt.Offset + pkt.Len
+		if limit > len(pkt.Buf) {
+			releasePackets(packets)
+			return 0, fmt.Errorf("wireguard tun: packet length %d exceeds buffer capacity %d", pkt.Len, len(pkt.Buf)-pkt.Offset)
+		}
+	}
+	w.writeMu.Lock()
+	defer w.writeMu.Unlock()
+
+	if len(w.writeBuffers) < len(packets) {
+		w.writeBuffers = make([][]byte, len(packets))
+	}
+	for i, pkt := range packets {
+		if pkt == nil {
+			w.writeBuffers[i] = nil
+			continue
+		}
+		limit := pkt.Offset + pkt.Len
+		w.writeBuffers[i] = pkt.Buf[:limit]
+	}
+	n, err := w.dev.Write(w.writeBuffers[:len(packets)], offset)
+	if err != nil {
+		return n, err
+	}
+	releasePackets(packets)
+	return n, nil
+}
+
+func (w *wireguardTunIO) BatchHeadroom() int {
+	return wgtun.VirtioNetHdrLen
+}
+
+func (w *wireguardTunIO) BatchPayloadCap() int {
+	return w.mtu
+}
+
+func (w *wireguardTunIO) BatchSize() int {
+	return w.batchSize
+}
+
+func (w *wireguardTunIO) Close() error {
+	return nil
+}
+
+func releasePackets(pkts []*Packet) {
+	for _, pkt := range pkts {
+		if pkt != nil {
+			pkt.Release()
+		}
+	}
+}

pki.go

@@ -523,13 +523,9 @@ func loadCAPoolFromConfig(l *logrus.Logger, c *config.C) (*cert.CAPool, error) {
 		return nil, fmt.Errorf("error while adding CA certificate to CA trust store: %s", err)
 	}
 
-	bl := c.GetStringSlice("pki.blocklist", []string{})
+	for _, fp := range c.GetStringSlice("pki.blocklist", []string{}) {
-	if len(bl) > 0 {
+		l.WithField("fingerprint", fp).Info("Blocklisting cert")
-		for _, fp := range bl {
+		caPool.BlocklistFingerprint(fp)
-			caPool.BlocklistFingerprint(fp)
-		}
-
-		l.WithField("fingerprintCount", len(bl)).Info("Blocklisted certificates")
 	}
 
 	return caPool, nil

service/service_test.go

@@ -16,8 +16,8 @@ import (
 	"github.com/slackhq/nebula/cert_test"
 	"github.com/slackhq/nebula/config"
 	"github.com/slackhq/nebula/overlay"
-	"go.yaml.in/yaml/v3"
 	"golang.org/x/sync/errgroup"
+	"gopkg.in/yaml.v3"
 )
 
 type m = map[string]any

test/tun.go

@@ -34,10 +34,6 @@ func (NoopTun) Write([]byte) (int, error) {
 	return 0, nil
 }
 
-func (NoopTun) SupportsMultiqueue() bool {
-	return false
-}
-
 func (NoopTun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
 	return nil, errors.New("unsupported")
 }

udp/conn.go

@@ -19,10 +19,21 @@ type Conn interface {
 	ListenOut(r EncReader)
 	WriteTo(b []byte, addr netip.AddrPort) error
 	ReloadConfig(c *config.C)
-	SupportsMultipleReaders() bool
 	Close() error
 }
 
+// Datagram represents a UDP payload destined to a specific address.
+type Datagram struct {
+	Payload []byte
+	Addr    netip.AddrPort
+}
+
+// BatchConn can send multiple datagrams in one syscall.
+type BatchConn interface {
+	Conn
+	WriteBatch(pkts []Datagram) error
+}
+
 type NoopConn struct{}
 
 func (NoopConn) Rebind() error {
@@ -34,9 +45,6 @@ func (NoopConn) LocalAddr() (netip.AddrPort, error) {
 func (NoopConn) ListenOut(_ EncReader) {
 	return
 }
-func (NoopConn) SupportsMultipleReaders() bool {
-	return false
-}
 func (NoopConn) WriteTo(_ []byte, _ netip.AddrPort) error {
 	return nil
 }

udp/udp_darwin.go

@@ -98,9 +98,9 @@ func (u *StdConn) WriteTo(b []byte, ap netip.AddrPort) error {
 			return ErrInvalidIPv6RemoteForSocket
 		}
 
-		var rsa unix.RawSockaddrInet4
+		var rsa unix.RawSockaddrInet6
-		rsa.Family = unix.AF_INET
+		rsa.Family = unix.AF_INET6
-		rsa.Addr = ap.Addr().As4()
+		rsa.Addr = ap.Addr().As16()
 		binary.BigEndian.PutUint16((*[2]byte)(unsafe.Pointer(&rsa.Port))[:], ap.Port())
 		sa = unsafe.Pointer(&rsa)
 		addrLen = syscall.SizeofSockaddrInet4
@@ -184,10 +184,6 @@ func (u *StdConn) ListenOut(r EncReader) {
 	}
 }
 
-func (u *StdConn) SupportsMultipleReaders() bool {
-	return false
-}
-
 func (u *StdConn) Rebind() error {
 	var err error
 	if u.isV4 {

udp/udp_generic.go

@@ -85,7 +85,3 @@ func (u *GenericConn) ListenOut(r EncReader) {
 		r(netip.AddrPortFrom(rua.Addr().Unmap(), rua.Port()), buffer[:n])
 	}
 }
-
-func (u *GenericConn) SupportsMultipleReaders() bool {
-	return false
-}

udp/udp_linux.go

@@ -72,10 +72,6 @@ func NewListener(l *logrus.Logger, ip netip.Addr, port int, multi bool, batch in
 	return &StdConn{sysFd: fd, isV4: ip.Is4(), l: l, batch: batch}, err
 }
 
-func (u *StdConn) SupportsMultipleReaders() bool {
-	return true
-}
-
 func (u *StdConn) Rebind() error {
 	return nil
 }
@@ -314,31 +310,51 @@ func (u *StdConn) Close() error {
 }
 
 func NewUDPStatsEmitter(udpConns []Conn) func() {
-	// Check if our kernel supports SO_MEMINFO before registering the gauges
+	if len(udpConns) == 0 {
-	var udpGauges [][unix.SK_MEMINFO_VARS]metrics.Gauge
+		return func() {}
+	}
+
+	type statsProvider struct {
+		index int
+		conn  *StdConn
+	}
+
+	providers := make([]statsProvider, 0, len(udpConns))
+	for i, c := range udpConns {
+		if sc, ok := c.(*StdConn); ok {
+			providers = append(providers, statsProvider{index: i, conn: sc})
+		}
+	}
+
+	if len(providers) == 0 {
+		return func() {}
+	}
+
 	var meminfo [unix.SK_MEMINFO_VARS]uint32
-	if err := udpConns[0].(*StdConn).getMemInfo(&meminfo); err == nil {
+	if err := providers[0].conn.getMemInfo(&meminfo); err != nil {
-		udpGauges = make([][unix.SK_MEMINFO_VARS]metrics.Gauge, len(udpConns))
+		return func() {}
-		for i := range udpConns {
+	}
-			udpGauges[i] = [unix.SK_MEMINFO_VARS]metrics.Gauge{
+
-				metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.rmem_alloc", i), nil),
+	udpGauges := make([][unix.SK_MEMINFO_VARS]metrics.Gauge, len(providers))
-				metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.rcvbuf", i), nil),
+	for i, provider := range providers {
-				metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.wmem_alloc", i), nil),
+		udpGauges[i] = [unix.SK_MEMINFO_VARS]metrics.Gauge{
-				metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.sndbuf", i), nil),
+			metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.rmem_alloc", provider.index), nil),
-				metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.fwd_alloc", i), nil),
+			metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.rcvbuf", provider.index), nil),
-				metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.wmem_queued", i), nil),
+			metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.wmem_alloc", provider.index), nil),
-				metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.optmem", i), nil),
+			metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.sndbuf", provider.index), nil),
-				metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.backlog", i), nil),
+			metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.fwd_alloc", provider.index), nil),
-				metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.drops", i), nil),
+			metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.wmem_queued", provider.index), nil),
-			}
+			metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.optmem", provider.index), nil),
+			metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.backlog", provider.index), nil),
+			metrics.GetOrRegisterGauge(fmt.Sprintf("udp.%d.drops", provider.index), nil),
 		}
 	}
 
 	return func() {
-		for i, gauges := range udpGauges {
+		for i, provider := range providers {
-			if err := udpConns[i].(*StdConn).getMemInfo(&meminfo); err == nil {
+			if err := provider.conn.getMemInfo(&meminfo); err == nil {
 				for j := 0; j < unix.SK_MEMINFO_VARS; j++ {
-					gauges[j].Update(int64(meminfo[j]))
+					udpGauges[i][j].Update(int64(meminfo[j]))
 				}
 			}
 		}

udp/udp_rio_windows.go

@@ -315,10 +315,6 @@ func (u *RIOConn) LocalAddr() (netip.AddrPort, error) {
 
 }
 
-func (u *RIOConn) SupportsMultipleReaders() bool {
-	return false
-}
-
 func (u *RIOConn) Rebind() error {
 	return nil
 }

udp/udp_tester.go

@@ -127,10 +127,6 @@ func (u *TesterConn) LocalAddr() (netip.AddrPort, error) {
 	return u.Addr, nil
 }
 
-func (u *TesterConn) SupportsMultipleReaders() bool {
-	return false
-}
-
 func (u *TesterConn) Rebind() error {
 	return nil
 }

udp/wireguard_conn_linux.go

@@ -0,0 +1,225 @@
+//go:build linux && !android && !e2e_testing
+
+package udp
+
+import (
+	"errors"
+	"net"
+	"net/netip"
+	"sync"
+	"sync/atomic"
+
+	"github.com/sirupsen/logrus"
+	"github.com/slackhq/nebula/config"
+	wgconn "github.com/slackhq/nebula/wgstack/conn"
+)
+
+// WGConn adapts WireGuard's batched UDP bind implementation to Nebula's udp.Conn interface.
+type WGConn struct {
+	l         *logrus.Logger
+	bind      *wgconn.StdNetBind
+	recvers   []wgconn.ReceiveFunc
+	batch     int
+	reqBatch  int
+	localIP   netip.Addr
+	localPort uint16
+	enableGSO bool
+	enableGRO bool
+	gsoMaxSeg int
+	closed    atomic.Bool
+
+	closeOnce sync.Once
+}
+
+// NewWireguardListener creates a UDP listener backed by WireGuard's StdNetBind.
+func NewWireguardListener(l *logrus.Logger, ip netip.Addr, port int, multi bool, batch int) (Conn, error) {
+	bind := wgconn.NewStdNetBindForAddr(ip, multi)
+	recvers, actualPort, err := bind.Open(uint16(port))
+	if err != nil {
+		return nil, err
+	}
+	if batch <= 0 {
+		batch = bind.BatchSize()
+	} else if batch > bind.BatchSize() {
+		batch = bind.BatchSize()
+	}
+	return &WGConn{
+		l:         l,
+		bind:      bind,
+		recvers:   recvers,
+		batch:     batch,
+		reqBatch:  batch,
+		localIP:   ip,
+		localPort: actualPort,
+	}, nil
+}
+
+func (c *WGConn) Rebind() error {
+	// WireGuard's bind does not support rebinding in place.
+	return nil
+}
+
+func (c *WGConn) LocalAddr() (netip.AddrPort, error) {
+	if !c.localIP.IsValid() || c.localIP.IsUnspecified() {
+		// Fallback to wildcard IPv4 for display purposes.
+		return netip.AddrPortFrom(netip.IPv4Unspecified(), c.localPort), nil
+	}
+	return netip.AddrPortFrom(c.localIP, c.localPort), nil
+}
+
+func (c *WGConn) listen(fn wgconn.ReceiveFunc, r EncReader) {
+	batchSize := c.batch
+	packets := make([][]byte, batchSize)
+	for i := range packets {
+		packets[i] = make([]byte, MTU)
+	}
+	sizes := make([]int, batchSize)
+	endpoints := make([]wgconn.Endpoint, batchSize)
+
+	for {
+		if c.closed.Load() {
+			return
+		}
+		n, err := fn(packets, sizes, endpoints)
+		if err != nil {
+			if errors.Is(err, net.ErrClosed) {
+				return
+			}
+			if c.l != nil {
+				c.l.WithError(err).Debug("wireguard UDP listener receive error")
+			}
+			continue
+		}
+		for i := 0; i < n; i++ {
+			if sizes[i] == 0 {
+				continue
+			}
+			stdEp, ok := endpoints[i].(*wgconn.StdNetEndpoint)
+			if !ok {
+				if c.l != nil {
+					c.l.Warn("wireguard UDP listener received unexpected endpoint type")
+				}
+				continue
+			}
+			addr := stdEp.AddrPort
+			r(addr, packets[i][:sizes[i]])
+			endpoints[i] = nil
+		}
+	}
+}
+
+func (c *WGConn) ListenOut(r EncReader) {
+	for _, fn := range c.recvers {
+		go c.listen(fn, r)
+	}
+}
+
+func (c *WGConn) WriteTo(b []byte, addr netip.AddrPort) error {
+	if len(b) == 0 {
+		return nil
+	}
+	if c.closed.Load() {
+		return net.ErrClosed
+	}
+	ep := &wgconn.StdNetEndpoint{AddrPort: addr}
+	return c.bind.Send([][]byte{b}, ep)
+}
+
+func (c *WGConn) WriteBatch(datagrams []Datagram) error {
+	if len(datagrams) == 0 {
+		return nil
+	}
+	if c.closed.Load() {
+		return net.ErrClosed
+	}
+	max := c.batch
+	if max <= 0 {
+		max = len(datagrams)
+		if max == 0 {
+			max = 1
+		}
+	}
+	bufs := make([][]byte, 0, max)
+	var (
+		current  netip.AddrPort
+		endpoint *wgconn.StdNetEndpoint
+		haveAddr bool
+	)
+	flush := func() error {
+		if len(bufs) == 0 || endpoint == nil {
+			bufs = bufs[:0]
+			return nil
+		}
+		err := c.bind.Send(bufs, endpoint)
+		bufs = bufs[:0]
+		return err
+	}
+
+	for _, d := range datagrams {
+		if len(d.Payload) == 0 || !d.Addr.IsValid() {
+			continue
+		}
+		if !haveAddr || d.Addr != current {
+			if err := flush(); err != nil {
+				return err
+			}
+			current = d.Addr
+			endpoint = &wgconn.StdNetEndpoint{AddrPort: current}
+			haveAddr = true
+		}
+		bufs = append(bufs, d.Payload)
+		if len(bufs) >= max {
+			if err := flush(); err != nil {
+				return err
+			}
+		}
+	}
+	return flush()
+}
+
+func (c *WGConn) ConfigureOffload(enableGSO, enableGRO bool, maxSegments int) {
+	c.enableGSO = enableGSO
+	c.enableGRO = enableGRO
+	if maxSegments <= 0 {
+		maxSegments = 1
+	} else if maxSegments > wgconn.IdealBatchSize {
+		maxSegments = wgconn.IdealBatchSize
+	}
+	c.gsoMaxSeg = maxSegments
+
+	effectiveBatch := c.reqBatch
+	if enableGSO && c.bind != nil {
+		bindBatch := c.bind.BatchSize()
+		if effectiveBatch < bindBatch {
+			if c.l != nil {
+				c.l.WithFields(logrus.Fields{
+					"requested": c.reqBatch,
+					"effective": bindBatch,
+				}).Warn("listen.batch below wireguard minimum; using bind batch size for UDP GSO support")
+			}
+			effectiveBatch = bindBatch
+		}
+	}
+	c.batch = effectiveBatch
+
+	if c.l != nil {
+		c.l.WithFields(logrus.Fields{
+			"enableGSO":      enableGSO,
+			"enableGRO":      enableGRO,
+			"gsoMaxSegments": maxSegments,
+		}).Debug("configured wireguard UDP offload")
+	}
+}
+
+func (c *WGConn) ReloadConfig(*config.C) {
+	// WireGuard bind currently does not expose runtime configuration knobs.
+}
+
+func (c *WGConn) Close() error {
+	var err error
+	c.closeOnce.Do(func() {
+		c.closed.Store(true)
+		err = c.bind.Close()
+	})
+	return err
+}

udp/wireguard_conn_unsupported.go

@@ -0,0 +1,15 @@
+//go:build !linux || android || e2e_testing
+
+package udp
+
+import (
+	"fmt"
+	"net/netip"
+
+	"github.com/sirupsen/logrus"
+)
+
+// NewWireguardListener is only available on Linux builds.
+func NewWireguardListener(*logrus.Logger, netip.Addr, int, bool, int) (Conn, error) {
+	return nil, fmt.Errorf("wireguard experimental UDP listener is only supported on Linux")
+}

wgstack/conn/bind_std.go

@@ -0,0 +1,539 @@
+// SPDX-License-Identifier: MIT
+//
+// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+
+package conn
+
+import (
+	"context"
+	"errors"
+	"net"
+	"net/netip"
+	"runtime"
+	"strconv"
+	"sync"
+	"syscall"
+
+	"golang.org/x/net/ipv4"
+	"golang.org/x/net/ipv6"
+	"golang.org/x/sys/unix"
+)
+
+var (
+	_ Bind = (*StdNetBind)(nil)
+)
+
+// StdNetBind implements Bind for all platforms. While Windows has its own Bind
+// (see bind_windows.go), it may fall back to StdNetBind.
+// TODO: Remove usage of ipv{4,6}.PacketConn when net.UDPConn has comparable
+// methods for sending and receiving multiple datagrams per-syscall. See the
+// proposal in https://github.com/golang/go/issues/45886#issuecomment-1218301564.
+type StdNetBind struct {
+	mu     sync.Mutex // protects all fields except as specified
+	ipv4   *net.UDPConn
+	ipv6   *net.UDPConn
+	ipv4PC *ipv4.PacketConn // will be nil on non-Linux
+	ipv6PC *ipv6.PacketConn // will be nil on non-Linux
+
+	// these three fields are not guarded by mu
+	udpAddrPool  sync.Pool
+	ipv4MsgsPool sync.Pool
+	ipv6MsgsPool sync.Pool
+
+	blackhole4 bool
+	blackhole6 bool
+
+	listenAddr4 string
+	listenAddr6 string
+	bindV4      bool
+	bindV6      bool
+	reusePort   bool
+}
+
+func newStdNetBind() *StdNetBind {
+	return &StdNetBind{
+		udpAddrPool: sync.Pool{
+			New: func() any {
+				return &net.UDPAddr{
+					IP: make([]byte, 16),
+				}
+			},
+		},
+
+		ipv4MsgsPool: sync.Pool{
+			New: func() any {
+				msgs := make([]ipv4.Message, IdealBatchSize)
+				for i := range msgs {
+					msgs[i].Buffers = make(net.Buffers, 1)
+					msgs[i].OOB = make([]byte, srcControlSize)
+				}
+				return &msgs
+			},
+		},
+
+		ipv6MsgsPool: sync.Pool{
+			New: func() any {
+				msgs := make([]ipv6.Message, IdealBatchSize)
+				for i := range msgs {
+					msgs[i].Buffers = make(net.Buffers, 1)
+					msgs[i].OOB = make([]byte, srcControlSize)
+				}
+				return &msgs
+			},
+		},
+		bindV4:    true,
+		bindV6:    true,
+		reusePort: false,
+	}
+}
+
+// NewStdNetBind creates a bind that listens on all interfaces.
+func NewStdNetBind() *StdNetBind {
+	return newStdNetBind()
+}
+
+// NewStdNetBindForAddr creates a bind that listens on a specific address.
+// If addr is IPv4, only the IPv4 socket will be created. For IPv6, only the
+// IPv6 socket will be created.
+func NewStdNetBindForAddr(addr netip.Addr, reusePort bool) *StdNetBind {
+	b := newStdNetBind()
+	if addr.IsValid() {
+		if addr.IsUnspecified() {
+			// keep dual-stack defaults with empty listen addresses
+		} else if addr.Is4() {
+			b.listenAddr4 = addr.Unmap().String()
+			b.bindV4 = true
+			b.bindV6 = false
+		} else {
+			b.listenAddr6 = addr.Unmap().String()
+			b.bindV6 = true
+			b.bindV4 = false
+		}
+	}
+	b.reusePort = reusePort
+	return b
+}
+
+type StdNetEndpoint struct {
+	// AddrPort is the endpoint destination.
+	netip.AddrPort
+	// src is the current sticky source address and interface index, if supported.
+	src struct {
+		netip.Addr
+		ifidx int32
+	}
+}
+
+var (
+	_ Bind     = (*StdNetBind)(nil)
+	_ Endpoint = &StdNetEndpoint{}
+)
+
+func (*StdNetBind) ParseEndpoint(s string) (Endpoint, error) {
+	e, err := netip.ParseAddrPort(s)
+	if err != nil {
+		return nil, err
+	}
+	return &StdNetEndpoint{
+		AddrPort: e,
+	}, nil
+}
+
+func (e *StdNetEndpoint) ClearSrc() {
+	e.src.ifidx = 0
+	e.src.Addr = netip.Addr{}
+}
+
+func (e *StdNetEndpoint) DstIP() netip.Addr {
+	return e.AddrPort.Addr()
+}
+
+func (e *StdNetEndpoint) SrcIP() netip.Addr {
+	return e.src.Addr
+}
+
+func (e *StdNetEndpoint) SrcIfidx() int32 {
+	return e.src.ifidx
+}
+
+func (e *StdNetEndpoint) DstToBytes() []byte {
+	b, _ := e.AddrPort.MarshalBinary()
+	return b
+}
+
+func (e *StdNetEndpoint) DstToString() string {
+	return e.AddrPort.String()
+}
+
+func (e *StdNetEndpoint) SrcToString() string {
+	return e.src.Addr.String()
+}
+
+func (s *StdNetBind) listenNet(network string, host string, port int) (*net.UDPConn, int, error) {
+	lc := listenConfig()
+	if s.reusePort {
+		base := lc.Control
+		lc.Control = func(network, address string, c syscall.RawConn) error {
+			if base != nil {
+				if err := base(network, address, c); err != nil {
+					return err
+				}
+			}
+			return c.Control(func(fd uintptr) {
+				_ = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEPORT, 1)
+			})
+		}
+	}
+
+	addr := ":" + strconv.Itoa(port)
+	if host != "" {
+		addr = net.JoinHostPort(host, strconv.Itoa(port))
+	}
+
+	conn, err := lc.ListenPacket(context.Background(), network, addr)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	// Retrieve port.
+	laddr := conn.LocalAddr()
+	uaddr, err := net.ResolveUDPAddr(
+		laddr.Network(),
+		laddr.String(),
+	)
+	if err != nil {
+		return nil, 0, err
+	}
+	return conn.(*net.UDPConn), uaddr.Port, nil
+}
+
+func (s *StdNetBind) openIPv4(port int) (*net.UDPConn, *ipv4.PacketConn, int, error) {
+	if !s.bindV4 {
+		return nil, nil, port, nil
+	}
+	host := s.listenAddr4
+	conn, actualPort, err := s.listenNet("udp4", host, port)
+	if err != nil {
+		if errors.Is(err, syscall.EAFNOSUPPORT) {
+			return nil, nil, port, nil
+		}
+		return nil, nil, port, err
+	}
+	if runtime.GOOS != "linux" {
+		return conn, nil, actualPort, nil
+	}
+	pc := ipv4.NewPacketConn(conn)
+	return conn, pc, actualPort, nil
+}
+
+func (s *StdNetBind) openIPv6(port int) (*net.UDPConn, *ipv6.PacketConn, int, error) {
+	if !s.bindV6 {
+		return nil, nil, port, nil
+	}
+	host := s.listenAddr6
+	conn, actualPort, err := s.listenNet("udp6", host, port)
+	if err != nil {
+		if errors.Is(err, syscall.EAFNOSUPPORT) {
+			return nil, nil, port, nil
+		}
+		return nil, nil, port, err
+	}
+	if runtime.GOOS != "linux" {
+		return conn, nil, actualPort, nil
+	}
+	pc := ipv6.NewPacketConn(conn)
+	return conn, pc, actualPort, nil
+}
+
+func (s *StdNetBind) Open(uport uint16) ([]ReceiveFunc, uint16, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	var err error
+	var tries int
+
+	if s.ipv4 != nil || s.ipv6 != nil {
+		return nil, 0, ErrBindAlreadyOpen
+	}
+
+	// Attempt to open ipv4 and ipv6 listeners on the same port.
+	// If uport is 0, we can retry on failure.
+again:
+	port := int(uport)
+	var v4conn *net.UDPConn
+	var v6conn *net.UDPConn
+	var v4pc *ipv4.PacketConn
+	var v6pc *ipv6.PacketConn
+
+	v4conn, v4pc, port, err = s.openIPv4(port)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	// Listen on the same port as we're using for ipv4.
+	v6conn, v6pc, port, err = s.openIPv6(port)
+	if uport == 0 && errors.Is(err, syscall.EADDRINUSE) && tries < 100 {
+		if v4conn != nil {
+			v4conn.Close()
+		}
+		tries++
+		goto again
+	}
+	if err != nil {
+		if v4conn != nil {
+			v4conn.Close()
+		}
+		return nil, 0, err
+	}
+
+	var fns []ReceiveFunc
+	if v4conn != nil {
+		s.ipv4 = v4conn
+		if v4pc != nil {
+			s.ipv4PC = v4pc
+		}
+		fns = append(fns, s.makeReceiveIPv4(v4pc, v4conn))
+	}
+	if v6conn != nil {
+		s.ipv6 = v6conn
+		if v6pc != nil {
+			s.ipv6PC = v6pc
+		}
+		fns = append(fns, s.makeReceiveIPv6(v6pc, v6conn))
+	}
+	if len(fns) == 0 {
+		return nil, 0, syscall.EAFNOSUPPORT
+	}
+
+	return fns, uint16(port), nil
+}
+
+func (s *StdNetBind) makeReceiveIPv4(pc *ipv4.PacketConn, conn *net.UDPConn) ReceiveFunc {
+	return func(bufs [][]byte, sizes []int, eps []Endpoint) (n int, err error) {
+		msgs := s.ipv4MsgsPool.Get().(*[]ipv4.Message)
+		defer s.ipv4MsgsPool.Put(msgs)
+		for i := range bufs {
+			(*msgs)[i].Buffers[0] = bufs[i]
+		}
+		var numMsgs int
+		if runtime.GOOS == "linux" && pc != nil {
+			numMsgs, err = pc.ReadBatch(*msgs, 0)
+			if err != nil {
+				return 0, err
+			}
+		} else {
+			msg := &(*msgs)[0]
+			msg.N, msg.NN, _, msg.Addr, err = conn.ReadMsgUDP(msg.Buffers[0], msg.OOB)
+			if err != nil {
+				return 0, err
+			}
+			numMsgs = 1
+		}
+		for i := 0; i < numMsgs; i++ {
+			msg := &(*msgs)[i]
+			sizes[i] = msg.N
+			addrPort := msg.Addr.(*net.UDPAddr).AddrPort()
+			ep := &StdNetEndpoint{AddrPort: addrPort} // TODO: remove allocation
+			getSrcFromControl(msg.OOB[:msg.NN], ep)
+			eps[i] = ep
+		}
+		return numMsgs, nil
+	}
+}
+
+func (s *StdNetBind) makeReceiveIPv6(pc *ipv6.PacketConn, conn *net.UDPConn) ReceiveFunc {
+	return func(bufs [][]byte, sizes []int, eps []Endpoint) (n int, err error) {
+		msgs := s.ipv6MsgsPool.Get().(*[]ipv6.Message)
+		defer s.ipv6MsgsPool.Put(msgs)
+		for i := range bufs {
+			(*msgs)[i].Buffers[0] = bufs[i]
+		}
+		var numMsgs int
+		if runtime.GOOS == "linux" && pc != nil {
+			numMsgs, err = pc.ReadBatch(*msgs, 0)
+			if err != nil {
+				return 0, err
+			}
+		} else {
+			msg := &(*msgs)[0]
+			msg.N, msg.NN, _, msg.Addr, err = conn.ReadMsgUDP(msg.Buffers[0], msg.OOB)
+			if err != nil {
+				return 0, err
+			}
+			numMsgs = 1
+		}
+		for i := 0; i < numMsgs; i++ {
+			msg := &(*msgs)[i]
+			sizes[i] = msg.N
+			addrPort := msg.Addr.(*net.UDPAddr).AddrPort()
+			ep := &StdNetEndpoint{AddrPort: addrPort} // TODO: remove allocation
+			getSrcFromControl(msg.OOB[:msg.NN], ep)
+			eps[i] = ep
+		}
+		return numMsgs, nil
+	}
+}
+
+// TODO: When all Binds handle IdealBatchSize, remove this dynamic function and
+// rename the IdealBatchSize constant to BatchSize.
+func (s *StdNetBind) BatchSize() int {
+	if runtime.GOOS == "linux" {
+		return IdealBatchSize
+	}
+	return 1
+}
+
+func (s *StdNetBind) Close() error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	var err1, err2 error
+	if s.ipv4 != nil {
+		err1 = s.ipv4.Close()
+		s.ipv4 = nil
+		s.ipv4PC = nil
+	}
+	if s.ipv6 != nil {
+		err2 = s.ipv6.Close()
+		s.ipv6 = nil
+		s.ipv6PC = nil
+	}
+	s.blackhole4 = false
+	s.blackhole6 = false
+	if err1 != nil {
+		return err1
+	}
+	return err2
+}
+
+func (s *StdNetBind) Send(bufs [][]byte, endpoint Endpoint) error {
+	s.mu.Lock()
+	blackhole := s.blackhole4
+	conn := s.ipv4
+	var (
+		pc4 *ipv4.PacketConn
+		pc6 *ipv6.PacketConn
+	)
+	is6 := false
+	if endpoint.DstIP().Is6() {
+		blackhole = s.blackhole6
+		conn = s.ipv6
+		pc6 = s.ipv6PC
+		is6 = true
+	} else {
+		pc4 = s.ipv4PC
+	}
+	s.mu.Unlock()
+
+	if blackhole {
+		return nil
+	}
+	if conn == nil {
+		return syscall.EAFNOSUPPORT
+	}
+	if is6 {
+		return s.send6(conn, pc6, endpoint, bufs)
+	} else {
+		return s.send4(conn, pc4, endpoint, bufs)
+	}
+}
+
+func (s *StdNetBind) send4(conn *net.UDPConn, pc *ipv4.PacketConn, ep Endpoint, bufs [][]byte) error {
+	ua := s.udpAddrPool.Get().(*net.UDPAddr)
+	as4 := ep.DstIP().As4()
+	copy(ua.IP, as4[:])
+	ua.IP = ua.IP[:4]
+	ua.Port = int(ep.(*StdNetEndpoint).Port())
+	msgs := s.ipv4MsgsPool.Get().(*[]ipv4.Message)
+	for i, buf := range bufs {
+		(*msgs)[i].Buffers[0] = buf
+		(*msgs)[i].Addr = ua
+		setSrcControl(&(*msgs)[i].OOB, ep.(*StdNetEndpoint))
+	}
+	var (
+		n     int
+		err   error
+		start int
+	)
+	if runtime.GOOS == "linux" && pc != nil {
+		for {
+			n, err = pc.WriteBatch((*msgs)[start:len(bufs)], 0)
+			if err != nil {
+				if errors.Is(err, syscall.EAFNOSUPPORT) {
+					for j := start; j < len(bufs); j++ {
+						_, _, werr := conn.WriteMsgUDP(bufs[j], (*msgs)[j].OOB, ua)
+						if werr != nil {
+							err = werr
+							break
+						}
+					}
+				}
+				break
+			}
+			if n == len((*msgs)[start:len(bufs)]) {
+				break
+			}
+			start += n
+		}
+	} else {
+		for i, buf := range bufs {
+			_, _, err = conn.WriteMsgUDP(buf, (*msgs)[i].OOB, ua)
+			if err != nil {
+				break
+			}
+		}
+	}
+	s.udpAddrPool.Put(ua)
+	s.ipv4MsgsPool.Put(msgs)
+	return err
+}
+
+func (s *StdNetBind) send6(conn *net.UDPConn, pc *ipv6.PacketConn, ep Endpoint, bufs [][]byte) error {
+	ua := s.udpAddrPool.Get().(*net.UDPAddr)
+	as16 := ep.DstIP().As16()
+	copy(ua.IP, as16[:])
+	ua.IP = ua.IP[:16]
+	ua.Port = int(ep.(*StdNetEndpoint).Port())
+	msgs := s.ipv6MsgsPool.Get().(*[]ipv6.Message)
+	for i, buf := range bufs {
+		(*msgs)[i].Buffers[0] = buf
+		(*msgs)[i].Addr = ua
+		setSrcControl(&(*msgs)[i].OOB, ep.(*StdNetEndpoint))
+	}
+	var (
+		n     int
+		err   error
+		start int
+	)
+	if runtime.GOOS == "linux" && pc != nil {
+		for {
+			n, err = pc.WriteBatch((*msgs)[start:len(bufs)], 0)
+			if err != nil {
+				if errors.Is(err, syscall.EAFNOSUPPORT) {
+					for j := start; j < len(bufs); j++ {
+						_, _, werr := conn.WriteMsgUDP(bufs[j], (*msgs)[j].OOB, ua)
+						if werr != nil {
+							err = werr
+							break
+						}
+					}
+				}
+				break
+			}
+			if n == len((*msgs)[start:len(bufs)]) {
+				break
+			}
+			start += n
+		}
+	} else {
+		for i, buf := range bufs {
+			_, _, err = conn.WriteMsgUDP(buf, (*msgs)[i].OOB, ua)
+			if err != nil {
+				break
+			}
+		}
+	}
+	s.udpAddrPool.Put(ua)
+	s.ipv6MsgsPool.Put(msgs)
+	return err
+}

wgstack/conn/conn.go

@@ -0,0 +1,131 @@
+// SPDX-License-Identifier: MIT
+//
+// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+
+package conn
+
+import (
+	"errors"
+	"fmt"
+	"net/netip"
+	"reflect"
+	"runtime"
+	"strings"
+)
+
+const (
+	IdealBatchSize = 128 // maximum number of packets handled per read and write
+)
+
+// A ReceiveFunc receives at least one packet from the network and writes them
+// into packets. On a successful read it returns the number of elements of
+// sizes, packets, and endpoints that should be evaluated. Some elements of
+// sizes may be zero, and callers should ignore them. Callers must pass a sizes
+// and eps slice with a length greater than or equal to the length of packets.
+// These lengths must not exceed the length of the associated Bind.BatchSize().
+type ReceiveFunc func(packets [][]byte, sizes []int, eps []Endpoint) (n int, err error)
+
+// A Bind listens on a port for both IPv6 and IPv4 UDP traffic.
+//
+// A Bind interface may also be a PeekLookAtSocketFd or BindSocketToInterface,
+// depending on the platform-specific implementation.
+type Bind interface {
+	// Open puts the Bind into a listening state on a given port and reports the actual
+	// port that it bound to. Passing zero results in a random selection.
+	// fns is the set of functions that will be called to receive packets.
+	Open(port uint16) (fns []ReceiveFunc, actualPort uint16, err error)
+
+	// Close closes the Bind listener.
+	// All fns returned by Open must return net.ErrClosed after a call to Close.
+	Close() error
+
+	// SetMark sets the mark for each packet sent through this Bind.
+	// This mark is passed to the kernel as the socket option SO_MARK.
+	SetMark(mark uint32) error
+
+	// Send writes one or more packets in bufs to address ep. The length of
+	// bufs must not exceed BatchSize().
+	Send(bufs [][]byte, ep Endpoint) error
+
+	// ParseEndpoint creates a new endpoint from a string.
+	ParseEndpoint(s string) (Endpoint, error)
+
+	// BatchSize is the number of buffers expected to be passed to
+	// the ReceiveFuncs, and the maximum expected to be passed to SendBatch.
+	BatchSize() int
+}
+
+// BindSocketToInterface is implemented by Bind objects that support being
+// tied to a single network interface. Used by wireguard-windows.
+type BindSocketToInterface interface {
+	BindSocketToInterface4(interfaceIndex uint32, blackhole bool) error
+	BindSocketToInterface6(interfaceIndex uint32, blackhole bool) error
+}
+
+// PeekLookAtSocketFd is implemented by Bind objects that support having their
+// file descriptor peeked at. Used by wireguard-android.
+type PeekLookAtSocketFd interface {
+	PeekLookAtSocketFd4() (fd int, err error)
+	PeekLookAtSocketFd6() (fd int, err error)
+}
+
+// An Endpoint maintains the source/destination caching for a peer.
+//
+//	dst: the remote address of a peer ("endpoint" in uapi terminology)
+//	src: the local address from which datagrams originate going to the peer
+type Endpoint interface {
+	ClearSrc()           // clears the source address
+	SrcToString() string // returns the local source address (ip:port)
+	DstToString() string // returns the destination address (ip:port)
+	DstToBytes() []byte  // used for mac2 cookie calculations
+	DstIP() netip.Addr
+	SrcIP() netip.Addr
+}
+
+var (
+	ErrBindAlreadyOpen   = errors.New("bind is already open")
+	ErrWrongEndpointType = errors.New("endpoint type does not correspond with bind type")
+)
+
+func (fn ReceiveFunc) PrettyName() string {
+	name := runtime.FuncForPC(reflect.ValueOf(fn).Pointer()).Name()
+	// 0. cheese/taco.beansIPv6.func12.func21218-fm
+	name = strings.TrimSuffix(name, "-fm")
+	// 1. cheese/taco.beansIPv6.func12.func21218
+	if idx := strings.LastIndexByte(name, '/'); idx != -1 {
+		name = name[idx+1:]
+		// 2. taco.beansIPv6.func12.func21218
+	}
+	for {
+		var idx int
+		for idx = len(name) - 1; idx >= 0; idx-- {
+			if name[idx] < '0' || name[idx] > '9' {
+				break
+			}
+		}
+		if idx == len(name)-1 {
+			break
+		}
+		const dotFunc = ".func"
+		if !strings.HasSuffix(name[:idx+1], dotFunc) {
+			break
+		}
+		name = name[:idx+1-len(dotFunc)]
+		// 3. taco.beansIPv6.func12
+		// 4. taco.beansIPv6
+	}
+	if idx := strings.LastIndexByte(name, '.'); idx != -1 {
+		name = name[idx+1:]
+		// 5. beansIPv6
+	}
+	if name == "" {
+		return fmt.Sprintf("%p", fn)
+	}
+	if strings.HasSuffix(name, "IPv4") {
+		return "v4"
+	}
+	if strings.HasSuffix(name, "IPv6") {
+		return "v6"
+	}
+	return name
+}

wgstack/conn/controlfns.go

@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: MIT
+//
+// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+
+package conn
+
+import (
+	"net"
+	"syscall"
+)
+
+// UDP socket read/write buffer size (7MB). The value of 7MB is chosen as it is
+// the max supported by a default configuration of macOS. Some platforms will
+// silently clamp the value to other maximums, such as linux clamping to
+// net.core.{r,w}mem_max (see _linux.go for additional implementation that works
+// around this limitation)
+const socketBufferSize = 7 << 20
+
+// controlFn is the callback function signature from net.ListenConfig.Control.
+// It is used to apply platform specific configuration to the socket prior to
+// bind.
+type controlFn func(network, address string, c syscall.RawConn) error
+
+// controlFns is a list of functions that are called from the listen config
+// that can apply socket options.
+var controlFns = []controlFn{}
+
+// listenConfig returns a net.ListenConfig that applies the controlFns to the
+// socket prior to bind. This is used to apply socket buffer sizing and packet
+// information OOB configuration for sticky sockets.
+func listenConfig() *net.ListenConfig {
+	return &net.ListenConfig{
+		Control: func(network, address string, c syscall.RawConn) error {
+			for _, fn := range controlFns {
+				if err := fn(network, address, c); err != nil {
+					return err
+				}
+			}
+			return nil
+		},
+	}
+}

wgstack/conn/controlfns_linux.go

@@ -0,0 +1,62 @@
+//go:build linux
+
+// SPDX-License-Identifier: MIT
+//
+// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+
+package conn
+
+import (
+	"fmt"
+	"runtime"
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+func init() {
+	controlFns = append(controlFns,
+
+		// Attempt to set the socket buffer size beyond net.core.{r,w}mem_max by
+		// using SO_*BUFFORCE. This requires CAP_NET_ADMIN, and is allowed here to
+		// fail silently - the result of failure is lower performance on very fast
+		// links or high latency links.
+		func(network, address string, c syscall.RawConn) error {
+			return c.Control(func(fd uintptr) {
+				// Set up to *mem_max
+				_ = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_RCVBUF, socketBufferSize)
+				_ = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_SNDBUF, socketBufferSize)
+				// Set beyond *mem_max if CAP_NET_ADMIN
+				_ = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_RCVBUFFORCE, socketBufferSize)
+				_ = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_SNDBUFFORCE, socketBufferSize)
+			})
+		},
+
+		// Enable receiving of the packet information (IP_PKTINFO for IPv4,
+		// IPV6_PKTINFO for IPv6) that is used to implement sticky socket support.
+		func(network, address string, c syscall.RawConn) error {
+			var err error
+			switch network {
+			case "udp4":
+				if runtime.GOOS != "android" {
+					c.Control(func(fd uintptr) {
+						err = unix.SetsockoptInt(int(fd), unix.IPPROTO_IP, unix.IP_PKTINFO, 1)
+					})
+				}
+			case "udp6":
+				c.Control(func(fd uintptr) {
+					if runtime.GOOS != "android" {
+						err = unix.SetsockoptInt(int(fd), unix.IPPROTO_IPV6, unix.IPV6_RECVPKTINFO, 1)
+						if err != nil {
+							return
+						}
+					}
+					err = unix.SetsockoptInt(int(fd), unix.IPPROTO_IPV6, unix.IPV6_V6ONLY, 1)
+				})
+			default:
+				err = fmt.Errorf("unhandled network: %s: %w", network, unix.EINVAL)
+			}
+			return err
+		},
+	)
+}

wgstack/conn/default.go

@@ -0,0 +1,9 @@
+//go:build !windows
+
+// SPDX-License-Identifier: MIT
+//
+// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+
+package conn
+
+func NewDefaultBind() Bind { return NewStdNetBind() }

wgstack/conn/errors_default.go

@@ -0,0 +1,12 @@
+//go:build !linux
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+ */
+
+package conn
+
+func errShouldDisableUDPGSO(err error) bool {
+	return false
+}

wgstack/conn/errors_linux.go

@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+ */
+
+package conn
+
+import (
+	"errors"
+	"os"
+
+	"golang.org/x/sys/unix"
+)
+
+func errShouldDisableUDPGSO(err error) bool {
+	var serr *os.SyscallError
+	if errors.As(err, &serr) {
+		// EIO is returned by udp_send_skb() if the device driver does not have
+		// tx checksumming enabled, which is a hard requirement of UDP_SEGMENT.
+		// See:
+		// https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/man7/udp.7?id=806eabd74910447f21005160e90957bde4db0183#n228
+		// https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/net/ipv4/udp.c?h=v6.2&id=c9c3395d5e3dcc6daee66c6908354d47bf98cb0c#n942
+		return serr.Err == unix.EIO
+	}
+	return false
+}

wgstack/conn/features_default.go

@@ -0,0 +1,15 @@
+//go:build !linux
+// +build !linux
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+ */
+
+package conn
+
+import "net"
+
+func supportsUDPOffload(conn *net.UDPConn) (txOffload, rxOffload bool) {
+	return
+}

wgstack/conn/features_linux.go

@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+ */
+
+package conn
+
+import (
+	"net"
+
+	"golang.org/x/sys/unix"
+)
+
+func supportsUDPOffload(conn *net.UDPConn) (txOffload, rxOffload bool) {
+	rc, err := conn.SyscallConn()
+	if err != nil {
+		return
+	}
+	err = rc.Control(func(fd uintptr) {
+		_, errSyscall := unix.GetsockoptInt(int(fd), unix.IPPROTO_UDP, unix.UDP_SEGMENT)
+		txOffload = errSyscall == nil
+		opt, errSyscall := unix.GetsockoptInt(int(fd), unix.IPPROTO_UDP, unix.UDP_GRO)
+		rxOffload = errSyscall == nil && opt == 1
+	})
+	if err != nil {
+		return false, false
+	}
+	return txOffload, rxOffload
+}

wgstack/conn/gso_default.go

@@ -0,0 +1,21 @@
+//go:build !linux
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+ */
+
+package conn
+
+// getGSOSize parses control for UDP_GRO and if found returns its GSO size data.
+func getGSOSize(control []byte) (int, error) {
+	return 0, nil
+}
+
+// setGSOSize sets a UDP_SEGMENT in control based on gsoSize.
+func setGSOSize(control *[]byte, gsoSize uint16) {
+}
+
+// gsoControlSize returns the recommended buffer size for pooling sticky and UDP
+// offloading control data.
+const gsoControlSize = 0

wgstack/conn/gso_linux.go

@@ -0,0 +1,65 @@
+//go:build linux
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+ */
+
+package conn
+
+import (
+	"fmt"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
+
+const (
+	sizeOfGSOData = 2
+)
+
+// getGSOSize parses control for UDP_GRO and if found returns its GSO size data.
+func getGSOSize(control []byte) (int, error) {
+	var (
+		hdr  unix.Cmsghdr
+		data []byte
+		rem  = control
+		err  error
+	)
+
+	for len(rem) > unix.SizeofCmsghdr {
+		hdr, data, rem, err = unix.ParseOneSocketControlMessage(rem)
+		if err != nil {
+			return 0, fmt.Errorf("error parsing socket control message: %w", err)
+		}
+		if hdr.Level == unix.SOL_UDP && hdr.Type == unix.UDP_GRO && len(data) >= sizeOfGSOData {
+			var gso uint16
+			copy(unsafe.Slice((*byte)(unsafe.Pointer(&gso)), sizeOfGSOData), data[:sizeOfGSOData])
+			return int(gso), nil
+		}
+	}
+	return 0, nil
+}
+
+// setGSOSize sets a UDP_SEGMENT in control based on gsoSize. It leaves existing
+// data in control untouched.
+func setGSOSize(control *[]byte, gsoSize uint16) {
+	existingLen := len(*control)
+	avail := cap(*control) - existingLen
+	space := unix.CmsgSpace(sizeOfGSOData)
+	if avail < space {
+		return
+	}
+	*control = (*control)[:cap(*control)]
+	gsoControl := (*control)[existingLen:]
+	hdr := (*unix.Cmsghdr)(unsafe.Pointer(&(gsoControl)[0]))
+	hdr.Level = unix.SOL_UDP
+	hdr.Type = unix.UDP_SEGMENT
+	hdr.SetLen(unix.CmsgLen(sizeOfGSOData))
+	copy((gsoControl)[unix.CmsgLen(0):], unsafe.Slice((*byte)(unsafe.Pointer(&gsoSize)), sizeOfGSOData))
+	*control = (*control)[:existingLen+space]
+}
+
+// gsoControlSize returns the recommended buffer size for pooling UDP
+// offloading control data.
+var gsoControlSize = unix.CmsgSpace(sizeOfGSOData)

wgstack/conn/mark_unix.go

@@ -0,0 +1,64 @@
+//go:build linux || openbsd || freebsd
+
+// SPDX-License-Identifier: MIT
+//
+// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+
+package conn
+
+import (
+	"runtime"
+
+	"golang.org/x/sys/unix"
+)
+
+var fwmarkIoctl int
+
+func init() {
+	switch runtime.GOOS {
+	case "linux", "android":
+		fwmarkIoctl = 36 /* unix.SO_MARK */
+	case "freebsd":
+		fwmarkIoctl = 0x1015 /* unix.SO_USER_COOKIE */
+	case "openbsd":
+		fwmarkIoctl = 0x1021 /* unix.SO_RTABLE */
+	}
+}
+
+func (s *StdNetBind) SetMark(mark uint32) error {
+	var operr error
+	if fwmarkIoctl == 0 {
+		return nil
+	}
+	if s.ipv4 != nil {
+		fd, err := s.ipv4.SyscallConn()
+		if err != nil {
+			return err
+		}
+		err = fd.Control(func(fd uintptr) {
+			operr = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, fwmarkIoctl, int(mark))
+		})
+		if err == nil {
+			err = operr
+		}
+		if err != nil {
+			return err
+		}
+	}
+	if s.ipv6 != nil {
+		fd, err := s.ipv6.SyscallConn()
+		if err != nil {
+			return err
+		}
+		err = fd.Control(func(fd uintptr) {
+			operr = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, fwmarkIoctl, int(mark))
+		})
+		if err == nil {
+			err = operr
+		}
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}

wgstack/conn/sticky_default.go

@@ -0,0 +1,42 @@
+//go:build !linux || android
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+ */
+
+package conn
+
+import "net/netip"
+
+func (e *StdNetEndpoint) SrcIP() netip.Addr {
+	return netip.Addr{}
+}
+
+func (e *StdNetEndpoint) SrcIfidx() int32 {
+	return 0
+}
+
+func (e *StdNetEndpoint) SrcToString() string {
+	return ""
+}
+
+// TODO: macOS, FreeBSD and other BSDs likely do support the sticky sockets
+// {get,set}srcControl feature set, but use alternatively named flags and need
+// ports and require testing.
+
+// getSrcFromControl parses the control for PKTINFO and if found updates ep with
+// the source information found.
+func getSrcFromControl(control []byte, ep *StdNetEndpoint) {
+}
+
+// setSrcControl parses the control for PKTINFO and if found updates ep with
+// the source information found.
+func setSrcControl(control *[]byte, ep *StdNetEndpoint) {
+}
+
+// stickyControlSize returns the recommended buffer size for pooling sticky
+// offloading control data.
+const stickyControlSize = 0
+
+const StdNetSupportsStickySockets = false

wgstack/conn/sticky_linux.go

@@ -0,0 +1,116 @@
+//go:build linux && !android
+
+// SPDX-License-Identifier: MIT
+//
+// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+
+package conn
+
+import (
+	"net/netip"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
+
+// getSrcFromControl parses the control for PKTINFO and if found updates ep with
+// the source information found.
+func getSrcFromControl(control []byte, ep *StdNetEndpoint) {
+	ep.ClearSrc()
+
+	var (
+		hdr  unix.Cmsghdr
+		data []byte
+		rem  []byte = control
+		err  error
+	)
+
+	for len(rem) > unix.SizeofCmsghdr {
+		hdr, data, rem, err = unix.ParseOneSocketControlMessage(rem)
+		if err != nil {
+			return
+		}
+
+		if hdr.Level == unix.IPPROTO_IP &&
+			hdr.Type == unix.IP_PKTINFO {
+
+			info := pktInfoFromBuf[unix.Inet4Pktinfo](data)
+			ep.src.Addr = netip.AddrFrom4(info.Spec_dst)
+			ep.src.ifidx = info.Ifindex
+
+			return
+		}
+
+		if hdr.Level == unix.IPPROTO_IPV6 &&
+			hdr.Type == unix.IPV6_PKTINFO {
+
+			info := pktInfoFromBuf[unix.Inet6Pktinfo](data)
+			ep.src.Addr = netip.AddrFrom16(info.Addr)
+			ep.src.ifidx = int32(info.Ifindex)
+
+			return
+		}
+	}
+}
+
+// pktInfoFromBuf returns type T populated from the provided buf via copy(). It
+// panics if buf is of insufficient size.
+func pktInfoFromBuf[T unix.Inet4Pktinfo | unix.Inet6Pktinfo](buf []byte) (t T) {
+	size := int(unsafe.Sizeof(t))
+	if len(buf) < size {
+		panic("pktInfoFromBuf: buffer too small")
+	}
+	copy(unsafe.Slice((*byte)(unsafe.Pointer(&t)), size), buf)
+	return t
+}
+
+// setSrcControl sets an IP{V6}_PKTINFO in control based on the source address
+// and source ifindex found in ep. control's len will be set to 0 in the event
+// that ep is a default value.
+func setSrcControl(control *[]byte, ep *StdNetEndpoint) {
+	*control = (*control)[:cap(*control)]
+	if len(*control) < int(unsafe.Sizeof(unix.Cmsghdr{})) {
+		*control = (*control)[:0]
+		return
+	}
+
+	if ep.src.ifidx == 0 && !ep.SrcIP().IsValid() {
+		*control = (*control)[:0]
+		return
+	}
+
+	if len(*control) < srcControlSize {
+		*control = (*control)[:0]
+		return
+	}
+
+	hdr := (*unix.Cmsghdr)(unsafe.Pointer(&(*control)[0]))
+	if ep.SrcIP().Is4() {
+		hdr.Level = unix.IPPROTO_IP
+		hdr.Type = unix.IP_PKTINFO
+		hdr.SetLen(unix.CmsgLen(unix.SizeofInet4Pktinfo))
+
+		info := (*unix.Inet4Pktinfo)(unsafe.Pointer(&(*control)[unix.SizeofCmsghdr]))
+		info.Ifindex = ep.src.ifidx
+		if ep.SrcIP().IsValid() {
+			info.Spec_dst = ep.SrcIP().As4()
+		}
+		*control = (*control)[:unix.CmsgSpace(unix.SizeofInet4Pktinfo)]
+	} else {
+		hdr.Level = unix.IPPROTO_IPV6
+		hdr.Type = unix.IPV6_PKTINFO
+		hdr.SetLen(unix.CmsgLen(unix.SizeofInet6Pktinfo))
+
+		info := (*unix.Inet6Pktinfo)(unsafe.Pointer(&(*control)[unix.SizeofCmsghdr]))
+		info.Ifindex = uint32(ep.src.ifidx)
+		if ep.SrcIP().IsValid() {
+			info.Addr = ep.SrcIP().As16()
+		}
+		*control = (*control)[:unix.CmsgSpace(unix.SizeofInet6Pktinfo)]
+	}
+
+}
+
+var srcControlSize = unix.CmsgSpace(unix.SizeofInet6Pktinfo)
+
+const StdNetSupportsStickySockets = true

wgstack/tun/checksum.go

@@ -0,0 +1,42 @@
+package tun
+
+import "encoding/binary"
+
+// TODO: Explore SIMD and/or other assembly optimizations.
+func checksumNoFold(b []byte, initial uint64) uint64 {
+	ac := initial
+	i := 0
+	n := len(b)
+	for n >= 4 {
+		ac += uint64(binary.BigEndian.Uint32(b[i : i+4]))
+		n -= 4
+		i += 4
+	}
+	for n >= 2 {
+		ac += uint64(binary.BigEndian.Uint16(b[i : i+2]))
+		n -= 2
+		i += 2
+	}
+	if n == 1 {
+		ac += uint64(b[i]) << 8
+	}
+	return ac
+}
+
+func checksum(b []byte, initial uint64) uint16 {
+	ac := checksumNoFold(b, initial)
+	ac = (ac >> 16) + (ac & 0xffff)
+	ac = (ac >> 16) + (ac & 0xffff)
+	ac = (ac >> 16) + (ac & 0xffff)
+	ac = (ac >> 16) + (ac & 0xffff)
+	return uint16(ac)
+}
+
+func pseudoHeaderChecksumNoFold(protocol uint8, srcAddr, dstAddr []byte, totalLen uint16) uint64 {
+	sum := checksumNoFold(srcAddr, 0)
+	sum = checksumNoFold(dstAddr, sum)
+	sum = checksumNoFold([]byte{0, protocol}, sum)
+	tmp := make([]byte, 2)
+	binary.BigEndian.PutUint16(tmp, totalLen)
+	return checksumNoFold(tmp, sum)
+}

wgstack/tun/export.go

@@ -0,0 +1,3 @@
+package tun
+
+const VirtioNetHdrLen = virtioNetHdrLen

wgstack/tun/tcp_offload_linux.go

@@ -0,0 +1,630 @@
+//go:build linux
+
+// SPDX-License-Identifier: MIT
+//
+// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+
+package tun
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"io"
+	"unsafe"
+
+	wgconn "github.com/slackhq/nebula/wgstack/conn"
+	"golang.org/x/sys/unix"
+)
+
+var ErrTooManySegments = errors.New("tun: too many segments for TSO")
+
+const tcpFlagsOffset = 13
+
+const (
+	tcpFlagFIN uint8 = 0x01
+	tcpFlagPSH uint8 = 0x08
+	tcpFlagACK uint8 = 0x10
+)
+
+// virtioNetHdr is defined in the kernel in include/uapi/linux/virtio_net.h. The
+// kernel symbol is virtio_net_hdr.
+type virtioNetHdr struct {
+	flags      uint8
+	gsoType    uint8
+	hdrLen     uint16
+	gsoSize    uint16
+	csumStart  uint16
+	csumOffset uint16
+}
+
+func (v *virtioNetHdr) decode(b []byte) error {
+	if len(b) < virtioNetHdrLen {
+		return io.ErrShortBuffer
+	}
+	copy(unsafe.Slice((*byte)(unsafe.Pointer(v)), virtioNetHdrLen), b[:virtioNetHdrLen])
+	return nil
+}
+
+func (v *virtioNetHdr) encode(b []byte) error {
+	if len(b) < virtioNetHdrLen {
+		return io.ErrShortBuffer
+	}
+	copy(b[:virtioNetHdrLen], unsafe.Slice((*byte)(unsafe.Pointer(v)), virtioNetHdrLen))
+	return nil
+}
+
+const (
+	// virtioNetHdrLen is the length in bytes of virtioNetHdr. This matches the
+	// shape of the C ABI for its kernel counterpart -- sizeof(virtio_net_hdr).
+	virtioNetHdrLen = int(unsafe.Sizeof(virtioNetHdr{}))
+)
+
+// flowKey represents the key for a flow.
+type flowKey struct {
+	srcAddr, dstAddr [16]byte
+	srcPort, dstPort uint16
+	rxAck            uint32 // varying ack values should not be coalesced. Treat them as separate flows.
+}
+
+// tcpGROTable holds flow and coalescing information for the purposes of GRO.
+type tcpGROTable struct {
+	itemsByFlow map[flowKey][]tcpGROItem
+	itemsPool   [][]tcpGROItem
+}
+
+func newTCPGROTable() *tcpGROTable {
+	t := &tcpGROTable{
+		itemsByFlow: make(map[flowKey][]tcpGROItem, wgconn.IdealBatchSize),
+		itemsPool:   make([][]tcpGROItem, wgconn.IdealBatchSize),
+	}
+	for i := range t.itemsPool {
+		t.itemsPool[i] = make([]tcpGROItem, 0, wgconn.IdealBatchSize)
+	}
+	return t
+}
+
+func newFlowKey(pkt []byte, srcAddr, dstAddr, tcphOffset int) flowKey {
+	key := flowKey{}
+	addrSize := dstAddr - srcAddr
+	copy(key.srcAddr[:], pkt[srcAddr:dstAddr])
+	copy(key.dstAddr[:], pkt[dstAddr:dstAddr+addrSize])
+	key.srcPort = binary.BigEndian.Uint16(pkt[tcphOffset:])
+	key.dstPort = binary.BigEndian.Uint16(pkt[tcphOffset+2:])
+	key.rxAck = binary.BigEndian.Uint32(pkt[tcphOffset+8:])
+	return key
+}
+
+// lookupOrInsert looks up a flow for the provided packet and metadata,
+// returning the packets found for the flow, or inserting a new one if none
+// is found.
+func (t *tcpGROTable) lookupOrInsert(pkt []byte, srcAddrOffset, dstAddrOffset, tcphOffset, tcphLen, bufsIndex int) ([]tcpGROItem, bool) {
+	key := newFlowKey(pkt, srcAddrOffset, dstAddrOffset, tcphOffset)
+	items, ok := t.itemsByFlow[key]
+	if ok {
+		return items, ok
+	}
+	// TODO: insert() performs another map lookup. This could be rearranged to avoid.
+	t.insert(pkt, srcAddrOffset, dstAddrOffset, tcphOffset, tcphLen, bufsIndex)
+	return nil, false
+}
+
+// insert an item in the table for the provided packet and packet metadata.
+func (t *tcpGROTable) insert(pkt []byte, srcAddrOffset, dstAddrOffset, tcphOffset, tcphLen, bufsIndex int) {
+	key := newFlowKey(pkt, srcAddrOffset, dstAddrOffset, tcphOffset)
+	item := tcpGROItem{
+		key:       key,
+		bufsIndex: uint16(bufsIndex),
+		gsoSize:   uint16(len(pkt[tcphOffset+tcphLen:])),
+		iphLen:    uint8(tcphOffset),
+		tcphLen:   uint8(tcphLen),
+		sentSeq:   binary.BigEndian.Uint32(pkt[tcphOffset+4:]),
+		pshSet:    pkt[tcphOffset+tcpFlagsOffset]&tcpFlagPSH != 0,
+	}
+	items, ok := t.itemsByFlow[key]
+	if !ok {
+		items = t.newItems()
+	}
+	items = append(items, item)
+	t.itemsByFlow[key] = items
+}
+
+func (t *tcpGROTable) updateAt(item tcpGROItem, i int) {
+	items, _ := t.itemsByFlow[item.key]
+	items[i] = item
+}
+
+func (t *tcpGROTable) deleteAt(key flowKey, i int) {
+	items, _ := t.itemsByFlow[key]
+	items = append(items[:i], items[i+1:]...)
+	t.itemsByFlow[key] = items
+}
+
+// tcpGROItem represents bookkeeping data for a TCP packet during the lifetime
+// of a GRO evaluation across a vector of packets.
+type tcpGROItem struct {
+	key       flowKey
+	sentSeq   uint32 // the sequence number
+	bufsIndex uint16 // the index into the original bufs slice
+	numMerged uint16 // the number of packets merged into this item
+	gsoSize   uint16 // payload size
+	iphLen    uint8  // ip header len
+	tcphLen   uint8  // tcp header len
+	pshSet    bool   // psh flag is set
+}
+
+func (t *tcpGROTable) newItems() []tcpGROItem {
+	var items []tcpGROItem
+	items, t.itemsPool = t.itemsPool[len(t.itemsPool)-1], t.itemsPool[:len(t.itemsPool)-1]
+	return items
+}
+
+func (t *tcpGROTable) reset() {
+	for k, items := range t.itemsByFlow {
+		items = items[:0]
+		t.itemsPool = append(t.itemsPool, items)
+		delete(t.itemsByFlow, k)
+	}
+}
+
+// canCoalesce represents the outcome of checking if two TCP packets are
+// candidates for coalescing.
+type canCoalesce int
+
+const (
+	coalescePrepend     canCoalesce = -1
+	coalesceUnavailable canCoalesce = 0
+	coalesceAppend      canCoalesce = 1
+)
+
+// tcpPacketsCanCoalesce evaluates if pkt can be coalesced with the packet
+// described by item. This function makes considerations that match the kernel's
+// GRO self tests, which can be found in tools/testing/selftests/net/gro.c.
+func tcpPacketsCanCoalesce(pkt []byte, iphLen, tcphLen uint8, seq uint32, pshSet bool, gsoSize uint16, item tcpGROItem, bufs [][]byte, bufsOffset int) canCoalesce {
+	pktTarget := bufs[item.bufsIndex][bufsOffset:]
+	if tcphLen != item.tcphLen {
+		// cannot coalesce with unequal tcp options len
+		return coalesceUnavailable
+	}
+	if tcphLen > 20 {
+		if !bytes.Equal(pkt[iphLen+20:iphLen+tcphLen], pktTarget[item.iphLen+20:iphLen+tcphLen]) {
+			// cannot coalesce with unequal tcp options
+			return coalesceUnavailable
+		}
+	}
+	if pkt[0]>>4 == 6 {
+		if pkt[0] != pktTarget[0] || pkt[1]>>4 != pktTarget[1]>>4 {
+			// cannot coalesce with unequal Traffic class values
+			return coalesceUnavailable
+		}
+		if pkt[7] != pktTarget[7] {
+			// cannot coalesce with unequal Hop limit values
+			return coalesceUnavailable
+		}
+	} else {
+		if pkt[1] != pktTarget[1] {
+			// cannot coalesce with unequal ToS values
+			return coalesceUnavailable
+		}
+		if pkt[6]>>5 != pktTarget[6]>>5 {
+			// cannot coalesce with unequal DF or reserved bits. MF is checked
+			// further up the stack.
+			return coalesceUnavailable
+		}
+		if pkt[8] != pktTarget[8] {
+			// cannot coalesce with unequal TTL values
+			return coalesceUnavailable
+		}
+	}
+	// seq adjacency
+	lhsLen := item.gsoSize
+	lhsLen += item.numMerged * item.gsoSize
+	if seq == item.sentSeq+uint32(lhsLen) { // pkt aligns following item from a seq num perspective
+		if item.pshSet {
+			// We cannot append to a segment that has the PSH flag set, PSH
+			// can only be set on the final segment in a reassembled group.
+			return coalesceUnavailable
+		}
+		if len(pktTarget[iphLen+tcphLen:])%int(item.gsoSize) != 0 {
+			// A smaller than gsoSize packet has been appended previously.
+			// Nothing can come after a smaller packet on the end.
+			return coalesceUnavailable
+		}
+		if gsoSize > item.gsoSize {
+			// We cannot have a larger packet following a smaller one.
+			return coalesceUnavailable
+		}
+		return coalesceAppend
+	} else if seq+uint32(gsoSize) == item.sentSeq { // pkt aligns in front of item from a seq num perspective
+		if pshSet {
+			// We cannot prepend with a segment that has the PSH flag set, PSH
+			// can only be set on the final segment in a reassembled group.
+			return coalesceUnavailable
+		}
+		if gsoSize < item.gsoSize {
+			// We cannot have a larger packet following a smaller one.
+			return coalesceUnavailable
+		}
+		if gsoSize > item.gsoSize && item.numMerged > 0 {
+			// There's at least one previous merge, and we're larger than all
+			// previous. This would put multiple smaller packets on the end.
+			return coalesceUnavailable
+		}
+		return coalescePrepend
+	}
+	return coalesceUnavailable
+}
+
+func tcpChecksumValid(pkt []byte, iphLen uint8, isV6 bool) bool {
+	srcAddrAt := ipv4SrcAddrOffset
+	addrSize := 4
+	if isV6 {
+		srcAddrAt = ipv6SrcAddrOffset
+		addrSize = 16
+	}
+	tcpTotalLen := uint16(len(pkt) - int(iphLen))
+	tcpCSumNoFold := pseudoHeaderChecksumNoFold(unix.IPPROTO_TCP, pkt[srcAddrAt:srcAddrAt+addrSize], pkt[srcAddrAt+addrSize:srcAddrAt+addrSize*2], tcpTotalLen)
+	return ^checksum(pkt[iphLen:], tcpCSumNoFold) == 0
+}
+
+// coalesceResult represents the result of attempting to coalesce two TCP
+// packets.
+type coalesceResult int
+
+const (
+	coalesceInsufficientCap coalesceResult = 0
+	coalescePSHEnding       coalesceResult = 1
+	coalesceItemInvalidCSum coalesceResult = 2
+	coalescePktInvalidCSum  coalesceResult = 3
+	coalesceSuccess         coalesceResult = 4
+)
+
+// coalesceTCPPackets attempts to coalesce pkt with the packet described by
+// item, returning the outcome. This function may swap bufs elements in the
+// event of a prepend as item's bufs index is already being tracked for writing
+// to a Device.
+func coalesceTCPPackets(mode canCoalesce, pkt []byte, pktBuffsIndex int, gsoSize uint16, seq uint32, pshSet bool, item *tcpGROItem, bufs [][]byte, bufsOffset int, isV6 bool) coalesceResult {
+	var pktHead []byte // the packet that will end up at the front
+	headersLen := item.iphLen + item.tcphLen
+	coalescedLen := len(bufs[item.bufsIndex][bufsOffset:]) + len(pkt) - int(headersLen)
+
+	// Copy data
+	if mode == coalescePrepend {
+		pktHead = pkt
+		if cap(pkt)-bufsOffset < coalescedLen {
+			// We don't want to allocate a new underlying array if capacity is
+			// too small.
+			return coalesceInsufficientCap
+		}
+		if pshSet {
+			return coalescePSHEnding
+		}
+		if item.numMerged == 0 {
+			if !tcpChecksumValid(bufs[item.bufsIndex][bufsOffset:], item.iphLen, isV6) {
+				return coalesceItemInvalidCSum
+			}
+		}
+		if !tcpChecksumValid(pkt, item.iphLen, isV6) {
+			return coalescePktInvalidCSum
+		}
+		item.sentSeq = seq
+		extendBy := coalescedLen - len(pktHead)
+		bufs[pktBuffsIndex] = append(bufs[pktBuffsIndex], make([]byte, extendBy)...)
+		copy(bufs[pktBuffsIndex][bufsOffset+len(pkt):], bufs[item.bufsIndex][bufsOffset+int(headersLen):])
+		// Flip the slice headers in bufs as part of prepend. The index of item
+		// is already being tracked for writing.
+		bufs[item.bufsIndex], bufs[pktBuffsIndex] = bufs[pktBuffsIndex], bufs[item.bufsIndex]
+	} else {
+		pktHead = bufs[item.bufsIndex][bufsOffset:]
+		if cap(pktHead)-bufsOffset < coalescedLen {
+			// We don't want to allocate a new underlying array if capacity is
+			// too small.
+			return coalesceInsufficientCap
+		}
+		if item.numMerged == 0 {
+			if !tcpChecksumValid(bufs[item.bufsIndex][bufsOffset:], item.iphLen, isV6) {
+				return coalesceItemInvalidCSum
+			}
+		}
+		if !tcpChecksumValid(pkt, item.iphLen, isV6) {
+			return coalescePktInvalidCSum
+		}
+		if pshSet {
+			// We are appending a segment with PSH set.
+			item.pshSet = pshSet
+			pktHead[item.iphLen+tcpFlagsOffset] |= tcpFlagPSH
+		}
+		extendBy := len(pkt) - int(headersLen)
+		bufs[item.bufsIndex] = append(bufs[item.bufsIndex], make([]byte, extendBy)...)
+		copy(bufs[item.bufsIndex][bufsOffset+len(pktHead):], pkt[headersLen:])
+	}
+
+	if gsoSize > item.gsoSize {
+		item.gsoSize = gsoSize
+	}
+	hdr := virtioNetHdr{
+		flags:      unix.VIRTIO_NET_HDR_F_NEEDS_CSUM, // this turns into CHECKSUM_PARTIAL in the skb
+		hdrLen:     uint16(headersLen),
+		gsoSize:    uint16(item.gsoSize),
+		csumStart:  uint16(item.iphLen),
+		csumOffset: 16,
+	}
+
+	// Recalculate the total len (IPv4) or payload len (IPv6). Recalculate the
+	// (IPv4) header checksum.
+	if isV6 {
+		hdr.gsoType = unix.VIRTIO_NET_HDR_GSO_TCPV6
+		binary.BigEndian.PutUint16(pktHead[4:], uint16(coalescedLen)-uint16(item.iphLen)) // set new payload len
+	} else {
+		hdr.gsoType = unix.VIRTIO_NET_HDR_GSO_TCPV4
+		pktHead[10], pktHead[11] = 0, 0                               // clear checksum field
+		binary.BigEndian.PutUint16(pktHead[2:], uint16(coalescedLen)) // set new total length
+		iphCSum := ^checksum(pktHead[:item.iphLen], 0)                // compute checksum
+		binary.BigEndian.PutUint16(pktHead[10:], iphCSum)             // set checksum field
+	}
+	hdr.encode(bufs[item.bufsIndex][bufsOffset-virtioNetHdrLen:])
+
+	// Calculate the pseudo header checksum and place it at the TCP checksum
+	// offset. Downstream checksum offloading will combine this with computation
+	// of the tcp header and payload checksum.
+	addrLen := 4
+	addrOffset := ipv4SrcAddrOffset
+	if isV6 {
+		addrLen = 16
+		addrOffset = ipv6SrcAddrOffset
+	}
+	srcAddrAt := bufsOffset + addrOffset
+	srcAddr := bufs[item.bufsIndex][srcAddrAt : srcAddrAt+addrLen]
+	dstAddr := bufs[item.bufsIndex][srcAddrAt+addrLen : srcAddrAt+addrLen*2]
+	psum := pseudoHeaderChecksumNoFold(unix.IPPROTO_TCP, srcAddr, dstAddr, uint16(coalescedLen-int(item.iphLen)))
+	binary.BigEndian.PutUint16(pktHead[hdr.csumStart+hdr.csumOffset:], checksum([]byte{}, psum))
+
+	item.numMerged++
+	return coalesceSuccess
+}
+
+const (
+	ipv4FlagMoreFragments uint8 = 0x20
+)
+
+const (
+	ipv4SrcAddrOffset = 12
+	ipv6SrcAddrOffset = 8
+	maxUint16         = 1<<16 - 1
+)
+
+// tcpGRO evaluates the TCP packet at pktI in bufs for coalescing with
+// existing packets tracked in table. It will return false when pktI is not
+// coalesced, otherwise true. This indicates to the caller if bufs[pktI]
+// should be written to the Device.
+func tcpGRO(bufs [][]byte, offset int, pktI int, table *tcpGROTable, isV6 bool) (pktCoalesced bool) {
+	pkt := bufs[pktI][offset:]
+	if len(pkt) > maxUint16 {
+		// A valid IPv4 or IPv6 packet will never exceed this.
+		return false
+	}
+	iphLen := int((pkt[0] & 0x0F) * 4)
+	if isV6 {
+		iphLen = 40
+		ipv6HPayloadLen := int(binary.BigEndian.Uint16(pkt[4:]))
+		if ipv6HPayloadLen != len(pkt)-iphLen {
+			return false
+		}
+	} else {
+		totalLen := int(binary.BigEndian.Uint16(pkt[2:]))
+		if totalLen != len(pkt) {
+			return false
+		}
+	}
+	if len(pkt) < iphLen {
+		return false
+	}
+	tcphLen := int((pkt[iphLen+12] >> 4) * 4)
+	if tcphLen < 20 || tcphLen > 60 {
+		return false
+	}
+	if len(pkt) < iphLen+tcphLen {
+		return false
+	}
+	if !isV6 {
+		if pkt[6]&ipv4FlagMoreFragments != 0 || pkt[6]<<3 != 0 || pkt[7] != 0 {
+			// no GRO support for fragmented segments for now
+			return false
+		}
+	}
+	tcpFlags := pkt[iphLen+tcpFlagsOffset]
+	var pshSet bool
+	// not a candidate if any non-ACK flags (except PSH+ACK) are set
+	if tcpFlags != tcpFlagACK {
+		if pkt[iphLen+tcpFlagsOffset] != tcpFlagACK|tcpFlagPSH {
+			return false
+		}
+		pshSet = true
+	}
+	gsoSize := uint16(len(pkt) - tcphLen - iphLen)
+	// not a candidate if payload len is 0
+	if gsoSize < 1 {
+		return false
+	}
+	seq := binary.BigEndian.Uint32(pkt[iphLen+4:])
+	srcAddrOffset := ipv4SrcAddrOffset
+	addrLen := 4
+	if isV6 {
+		srcAddrOffset = ipv6SrcAddrOffset
+		addrLen = 16
+	}
+	items, existing := table.lookupOrInsert(pkt, srcAddrOffset, srcAddrOffset+addrLen, iphLen, tcphLen, pktI)
+	if !existing {
+		return false
+	}
+	for i := len(items) - 1; i >= 0; i-- {
+		// In the best case of packets arriving in order iterating in reverse is
+		// more efficient if there are multiple items for a given flow. This
+		// also enables a natural table.deleteAt() in the
+		// coalesceItemInvalidCSum case without the need for index tracking.
+		// This algorithm makes a best effort to coalesce in the event of
+		// unordered packets, where pkt may land anywhere in items from a
+		// sequence number perspective, however once an item is inserted into
+		// the table it is never compared across other items later.
+		item := items[i]
+		can := tcpPacketsCanCoalesce(pkt, uint8(iphLen), uint8(tcphLen), seq, pshSet, gsoSize, item, bufs, offset)
+		if can != coalesceUnavailable {
+			result := coalesceTCPPackets(can, pkt, pktI, gsoSize, seq, pshSet, &item, bufs, offset, isV6)
+			switch result {
+			case coalesceSuccess:
+				table.updateAt(item, i)
+				return true
+			case coalesceItemInvalidCSum:
+				// delete the item with an invalid csum
+				table.deleteAt(item.key, i)
+			case coalescePktInvalidCSum:
+				// no point in inserting an item that we can't coalesce
+				return false
+			default:
+			}
+		}
+	}
+	// failed to coalesce with any other packets; store the item in the flow
+	table.insert(pkt, srcAddrOffset, srcAddrOffset+addrLen, iphLen, tcphLen, pktI)
+	return false
+}
+
+func isTCP4NoIPOptions(b []byte) bool {
+	if len(b) < 40 {
+		return false
+	}
+	if b[0]>>4 != 4 {
+		return false
+	}
+	if b[0]&0x0F != 5 {
+		return false
+	}
+	if b[9] != unix.IPPROTO_TCP {
+		return false
+	}
+	return true
+}
+
+func isTCP6NoEH(b []byte) bool {
+	if len(b) < 60 {
+		return false
+	}
+	if b[0]>>4 != 6 {
+		return false
+	}
+	if b[6] != unix.IPPROTO_TCP {
+		return false
+	}
+	return true
+}
+
+// handleGRO evaluates bufs for GRO, and writes the indices of the resulting
+// packets into toWrite. toWrite, tcp4Table, and tcp6Table should initially be
+// empty (but non-nil), and are passed in to save allocs as the caller may reset
+// and recycle them across vectors of packets.
+func handleGRO(bufs [][]byte, offset int, tcp4Table, tcp6Table *tcpGROTable, toWrite *[]int) error {
+	for i := range bufs {
+		if offset < virtioNetHdrLen || offset > len(bufs[i])-1 {
+			return errors.New("invalid offset")
+		}
+		var coalesced bool
+		switch {
+		case isTCP4NoIPOptions(bufs[i][offset:]): // ipv4 packets w/IP options do not coalesce
+			coalesced = tcpGRO(bufs, offset, i, tcp4Table, false)
+		case isTCP6NoEH(bufs[i][offset:]): // ipv6 packets w/extension headers do not coalesce
+			coalesced = tcpGRO(bufs, offset, i, tcp6Table, true)
+		}
+		if !coalesced {
+			hdr := virtioNetHdr{}
+			err := hdr.encode(bufs[i][offset-virtioNetHdrLen:])
+			if err != nil {
+				return err
+			}
+			*toWrite = append(*toWrite, i)
+		}
+	}
+	return nil
+}
+
+// tcpTSO splits packets from in into outBuffs, writing the size of each
+// element into sizes. It returns the number of buffers populated, and/or an
+// error.
+func tcpTSO(in []byte, hdr virtioNetHdr, outBuffs [][]byte, sizes []int, outOffset int) (int, error) {
+	iphLen := int(hdr.csumStart)
+	srcAddrOffset := ipv6SrcAddrOffset
+	addrLen := 16
+	if hdr.gsoType == unix.VIRTIO_NET_HDR_GSO_TCPV4 {
+		in[10], in[11] = 0, 0 // clear ipv4 header checksum
+		srcAddrOffset = ipv4SrcAddrOffset
+		addrLen = 4
+	}
+	tcpCSumAt := int(hdr.csumStart + hdr.csumOffset)
+	in[tcpCSumAt], in[tcpCSumAt+1] = 0, 0 // clear tcp checksum
+	firstTCPSeqNum := binary.BigEndian.Uint32(in[hdr.csumStart+4:])
+	nextSegmentDataAt := int(hdr.hdrLen)
+	i := 0
+	for ; nextSegmentDataAt < len(in); i++ {
+		if i == len(outBuffs) {
+			return i - 1, ErrTooManySegments
+		}
+		nextSegmentEnd := nextSegmentDataAt + int(hdr.gsoSize)
+		if nextSegmentEnd > len(in) {
+			nextSegmentEnd = len(in)
+		}
+		segmentDataLen := nextSegmentEnd - nextSegmentDataAt
+		totalLen := int(hdr.hdrLen) + segmentDataLen
+		sizes[i] = totalLen
+		out := outBuffs[i][outOffset:]
+
+		copy(out, in[:iphLen])
+		if hdr.gsoType == unix.VIRTIO_NET_HDR_GSO_TCPV4 {
+			// For IPv4 we are responsible for incrementing the ID field,
+			// updating the total len field, and recalculating the header
+			// checksum.
+			if i > 0 {
+				id := binary.BigEndian.Uint16(out[4:])
+				id += uint16(i)
+				binary.BigEndian.PutUint16(out[4:], id)
+			}
+			binary.BigEndian.PutUint16(out[2:], uint16(totalLen))
+			ipv4CSum := ^checksum(out[:iphLen], 0)
+			binary.BigEndian.PutUint16(out[10:], ipv4CSum)
+		} else {
+			// For IPv6 we are responsible for updating the payload length field.
+			binary.BigEndian.PutUint16(out[4:], uint16(totalLen-iphLen))
+		}
+
+		// TCP header
+		copy(out[hdr.csumStart:hdr.hdrLen], in[hdr.csumStart:hdr.hdrLen])
+		tcpSeq := firstTCPSeqNum + uint32(hdr.gsoSize*uint16(i))
+		binary.BigEndian.PutUint32(out[hdr.csumStart+4:], tcpSeq)
+		if nextSegmentEnd != len(in) {
+			// FIN and PSH should only be set on last segment
+			clearFlags := tcpFlagFIN | tcpFlagPSH
+			out[hdr.csumStart+tcpFlagsOffset] &^= clearFlags
+		}
+
+		// payload
+		copy(out[hdr.hdrLen:], in[nextSegmentDataAt:nextSegmentEnd])
+
+		// TCP checksum
+		tcpHLen := int(hdr.hdrLen - hdr.csumStart)
+		tcpLenForPseudo := uint16(tcpHLen + segmentDataLen)
+		tcpCSumNoFold := pseudoHeaderChecksumNoFold(unix.IPPROTO_TCP, in[srcAddrOffset:srcAddrOffset+addrLen], in[srcAddrOffset+addrLen:srcAddrOffset+addrLen*2], tcpLenForPseudo)
+		tcpCSum := ^checksum(out[hdr.csumStart:totalLen], tcpCSumNoFold)
+		binary.BigEndian.PutUint16(out[hdr.csumStart+hdr.csumOffset:], tcpCSum)
+
+		nextSegmentDataAt += int(hdr.gsoSize)
+	}
+	return i, nil
+}
+
+func gsoNoneChecksum(in []byte, cSumStart, cSumOffset uint16) error {
+	cSumAt := cSumStart + cSumOffset
+	// The initial value at the checksum offset should be summed with the
+	// checksum we compute. This is typically the pseudo-header checksum.
+	initial := binary.BigEndian.Uint16(in[cSumAt:])
+	in[cSumAt], in[cSumAt+1] = 0, 0
+	binary.BigEndian.PutUint16(in[cSumAt:], ^checksum(in[cSumStart:], uint64(initial)))
+	return nil
+}

wgstack/tun/tun.go

@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: MIT
+//
+// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+
+package tun
+
+import (
+	"os"
+)
+
+type Event int
+
+const (
+	EventUp = 1 << iota
+	EventDown
+	EventMTUUpdate
+)
+
+type Device interface {
+	// File returns the file descriptor of the device.
+	File() *os.File
+
+	// Read one or more packets from the Device (without any additional headers).
+	// On a successful read it returns the number of packets read, and sets
+	// packet lengths within the sizes slice. len(sizes) must be >= len(bufs).
+	// A nonzero offset can be used to instruct the Device on where to begin
+	// reading into each element of the bufs slice.
+	Read(bufs [][]byte, sizes []int, offset int) (n int, err error)
+
+	// Write one or more packets to the device (without any additional headers).
+	// On a successful write it returns the number of packets written. A nonzero
+	// offset can be used to instruct the Device on where to begin writing from
+	// each packet contained within the bufs slice.
+	Write(bufs [][]byte, offset int) (int, error)
+
+	// MTU returns the MTU of the Device.
+	MTU() (int, error)
+
+	// Name returns the current name of the Device.
+	Name() (string, error)
+
+	// Events returns a channel of type Event, which is fed Device events.
+	Events() <-chan Event
+
+	// Close stops the Device and closes the Event channel.
+	Close() error
+
+	// BatchSize returns the preferred/max number of packets that can be read or
+	// written in a single read/write call. BatchSize must not change over the
+	// lifetime of a Device.
+	BatchSize() int
+}

wgstack/tun/tun_linux.go

@@ -0,0 +1,664 @@
+//go:build linux
+
+// SPDX-License-Identifier: MIT
+//
+// Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+
+package tun
+
+/* Implementation of the TUN device interface for linux
+ */
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"sync"
+	"syscall"
+	"time"
+	"unsafe"
+
+	wgconn "github.com/slackhq/nebula/wgstack/conn"
+	"golang.org/x/sys/unix"
+	"golang.zx2c4.com/wireguard/rwcancel"
+)
+
+const (
+	cloneDevicePath = "/dev/net/tun"
+	ifReqSize       = unix.IFNAMSIZ + 64
+)
+
+type NativeTun struct {
+	tunFile                 *os.File
+	index                   int32      // if index
+	errors                  chan error // async error handling
+	events                  chan Event // device related events
+	netlinkSock             int
+	netlinkCancel           *rwcancel.RWCancel
+	hackListenerClosed      sync.Mutex
+	statusListenersShutdown chan struct{}
+	batchSize               int
+	vnetHdr                 bool
+
+	closeOnce sync.Once
+
+	nameOnce  sync.Once // guards calling initNameCache, which sets following fields
+	nameCache string    // name of interface
+	nameErr   error
+
+	readOpMu sync.Mutex                    // readOpMu guards readBuff
+	readBuff [virtioNetHdrLen + 65535]byte // if vnetHdr every read() is prefixed by virtioNetHdr
+
+	writeOpMu                  sync.Mutex // writeOpMu guards toWrite, tcp4GROTable, tcp6GROTable
+	toWrite                    []int
+	tcp4GROTable, tcp6GROTable *tcpGROTable
+}
+
+func (tun *NativeTun) File() *os.File {
+	return tun.tunFile
+}
+
+func (tun *NativeTun) routineHackListener() {
+	defer tun.hackListenerClosed.Unlock()
+	/* This is needed for the detection to work across network namespaces
+	 * If you are reading this and know a better method, please get in touch.
+	 */
+	last := 0
+	const (
+		up   = 1
+		down = 2
+	)
+	for {
+		sysconn, err := tun.tunFile.SyscallConn()
+		if err != nil {
+			return
+		}
+		err2 := sysconn.Control(func(fd uintptr) {
+			_, err = unix.Write(int(fd), nil)
+		})
+		if err2 != nil {
+			return
+		}
+		switch err {
+		case unix.EINVAL:
+			if last != up {
+				// If the tunnel is up, it reports that write() is
+				// allowed but we provided invalid data.
+				tun.events <- EventUp
+				last = up
+			}
+		case unix.EIO:
+			if last != down {
+				// If the tunnel is down, it reports that no I/O
+				// is possible, without checking our provided data.
+				tun.events <- EventDown
+				last = down
+			}
+		default:
+			return
+		}
+		select {
+		case <-time.After(time.Second):
+			// nothing
+		case <-tun.statusListenersShutdown:
+			return
+		}
+	}
+}
+
+func createNetlinkSocket() (int, error) {
+	sock, err := unix.Socket(unix.AF_NETLINK, unix.SOCK_RAW|unix.SOCK_CLOEXEC, unix.NETLINK_ROUTE)
+	if err != nil {
+		return -1, err
+	}
+	saddr := &unix.SockaddrNetlink{
+		Family: unix.AF_NETLINK,
+		Groups: unix.RTMGRP_LINK | unix.RTMGRP_IPV4_IFADDR | unix.RTMGRP_IPV6_IFADDR,
+	}
+	err = unix.Bind(sock, saddr)
+	if err != nil {
+		return -1, err
+	}
+	return sock, nil
+}
+
+func (tun *NativeTun) routineNetlinkListener() {
+	defer func() {
+		unix.Close(tun.netlinkSock)
+		tun.hackListenerClosed.Lock()
+		close(tun.events)
+		tun.netlinkCancel.Close()
+	}()
+
+	for msg := make([]byte, 1<<16); ; {
+		var err error
+		var msgn int
+		for {
+			msgn, _, _, _, err = unix.Recvmsg(tun.netlinkSock, msg[:], nil, 0)
+			if err == nil || !rwcancel.RetryAfterError(err) {
+				break
+			}
+			if !tun.netlinkCancel.ReadyRead() {
+				tun.errors <- fmt.Errorf("netlink socket closed: %w", err)
+				return
+			}
+		}
+		if err != nil {
+			tun.errors <- fmt.Errorf("failed to receive netlink message: %w", err)
+			return
+		}
+
+		select {
+		case <-tun.statusListenersShutdown:
+			return
+		default:
+		}
+
+		wasEverUp := false
+		for remain := msg[:msgn]; len(remain) >= unix.SizeofNlMsghdr; {
+
+			hdr := *(*unix.NlMsghdr)(unsafe.Pointer(&remain[0]))
+
+			if int(hdr.Len) > len(remain) {
+				break
+			}
+
+			switch hdr.Type {
+			case unix.NLMSG_DONE:
+				remain = []byte{}
+
+			case unix.RTM_NEWLINK:
+				info := *(*unix.IfInfomsg)(unsafe.Pointer(&remain[unix.SizeofNlMsghdr]))
+				remain = remain[hdr.Len:]
+
+				if info.Index != tun.index {
+					// not our interface
+					continue
+				}
+
+				if info.Flags&unix.IFF_RUNNING != 0 {
+					tun.events <- EventUp
+					wasEverUp = true
+				}
+
+				if info.Flags&unix.IFF_RUNNING == 0 {
+					// Don't emit EventDown before we've ever emitted EventUp.
+					// This avoids a startup race with HackListener, which
+					// might detect Up before we have finished reporting Down.
+					if wasEverUp {
+						tun.events <- EventDown
+					}
+				}
+
+				tun.events <- EventMTUUpdate
+
+			default:
+				remain = remain[hdr.Len:]
+			}
+		}
+	}
+}
+
+func getIFIndex(name string) (int32, error) {
+	fd, err := unix.Socket(
+		unix.AF_INET,
+		unix.SOCK_DGRAM|unix.SOCK_CLOEXEC,
+		0,
+	)
+	if err != nil {
+		return 0, err
+	}
+
+	defer unix.Close(fd)
+
+	var ifr [ifReqSize]byte
+	copy(ifr[:], name)
+	_, _, errno := unix.Syscall(
+		unix.SYS_IOCTL,
+		uintptr(fd),
+		uintptr(unix.SIOCGIFINDEX),
+		uintptr(unsafe.Pointer(&ifr[0])),
+	)
+
+	if errno != 0 {
+		return 0, errno
+	}
+
+	return *(*int32)(unsafe.Pointer(&ifr[unix.IFNAMSIZ])), nil
+}
+
+func (tun *NativeTun) setMTU(n int) error {
+	name, err := tun.Name()
+	if err != nil {
+		return err
+	}
+
+	// open datagram socket
+	fd, err := unix.Socket(
+		unix.AF_INET,
+		unix.SOCK_DGRAM|unix.SOCK_CLOEXEC,
+		0,
+	)
+	if err != nil {
+		return err
+	}
+	defer unix.Close(fd)
+
+	var ifr [ifReqSize]byte
+	copy(ifr[:], name)
+	*(*uint32)(unsafe.Pointer(&ifr[unix.IFNAMSIZ])) = uint32(n)
+
+	_, _, errno := unix.Syscall(
+		unix.SYS_IOCTL,
+		uintptr(fd),
+		uintptr(unix.SIOCSIFMTU),
+		uintptr(unsafe.Pointer(&ifr[0])),
+	)
+
+	if errno != 0 {
+		return errno
+	}
+	return nil
+}
+
+func (tun *NativeTun) routineNetlinkRead() {
+	defer func() {
+		unix.Close(tun.netlinkSock)
+		tun.hackListenerClosed.Lock()
+		close(tun.events)
+		tun.netlinkCancel.Close()
+	}()
+
+	for msg := make([]byte, 1<<16); ; {
+		var err error
+		var msgn int
+		for {
+			msgn, _, _, _, err = unix.Recvmsg(tun.netlinkSock, msg[:], nil, 0)
+			if err == nil || !rwcancel.RetryAfterError(err) {
+				break
+			}
+			if !tun.netlinkCancel.ReadyRead() {
+				tun.errors <- fmt.Errorf("netlink socket closed: %w", err)
+				return
+			}
+		}
+		if err != nil {
+			tun.errors <- fmt.Errorf("failed to receive netlink message: %w", err)
+			return
+		}
+
+		wasEverUp := false
+		for remain := msg[:msgn]; len(remain) >= unix.SizeofNlMsghdr; {
+
+			hdr := *(*unix.NlMsghdr)(unsafe.Pointer(&remain[0]))
+
+			if int(hdr.Len) > len(remain) {
+				break
+			}
+
+			switch hdr.Type {
+			case unix.NLMSG_DONE:
+				remain = []byte{}
+
+			case unix.RTM_NEWLINK:
+				info := *(*unix.IfInfomsg)(unsafe.Pointer(&remain[unix.SizeofNlMsghdr]))
+				remain = remain[hdr.Len:]
+
+				if info.Index != tun.index {
+					continue
+				}
+
+				if info.Flags&unix.IFF_RUNNING != 0 {
+					tun.events <- EventUp
+					wasEverUp = true
+				}
+
+				if info.Flags&unix.IFF_RUNNING == 0 {
+					if wasEverUp {
+						tun.events <- EventDown
+					}
+				}
+				tun.events <- EventMTUUpdate
+
+			default:
+				remain = remain[hdr.Len:]
+			}
+		}
+	}
+}
+
+func (tun *NativeTun) routineNetlink() {
+	var err error
+
+	tun.netlinkSock, err = createNetlinkSocket()
+	if err != nil {
+		tun.errors <- fmt.Errorf("failed to create netlink socket: %w", err)
+		return
+	}
+
+	tun.netlinkCancel, err = rwcancel.NewRWCancel(tun.netlinkSock)
+	if err != nil {
+		tun.errors <- fmt.Errorf("failed to create netlink cancel: %w", err)
+		return
+	}
+
+	go tun.routineNetlinkListener()
+}
+
+func (tun *NativeTun) Close() error {
+	var err1, err2 error
+	tun.closeOnce.Do(func() {
+		if tun.statusListenersShutdown != nil {
+			close(tun.statusListenersShutdown)
+			if tun.netlinkCancel != nil {
+				err1 = tun.netlinkCancel.Cancel()
+			}
+		} else if tun.events != nil {
+			close(tun.events)
+		}
+		err2 = tun.tunFile.Close()
+	})
+	if err1 != nil {
+		return err1
+	}
+	return err2
+}
+
+func (tun *NativeTun) BatchSize() int {
+	return tun.batchSize
+}
+
+const (
+	// TODO: support TSO with ECN bits
+	tunOffloads = unix.TUN_F_CSUM | unix.TUN_F_TSO4 | unix.TUN_F_TSO6
+)
+
+func (tun *NativeTun) initFromFlags(name string) error {
+	sc, err := tun.tunFile.SyscallConn()
+	if err != nil {
+		return err
+	}
+	if e := sc.Control(func(fd uintptr) {
+		var (
+			ifr *unix.Ifreq
+		)
+		ifr, err = unix.NewIfreq(name)
+		if err != nil {
+			return
+		}
+		err = unix.IoctlIfreq(int(fd), unix.TUNGETIFF, ifr)
+		if err != nil {
+			return
+		}
+		got := ifr.Uint16()
+		if got&unix.IFF_VNET_HDR != 0 {
+			err = unix.IoctlSetInt(int(fd), unix.TUNSETOFFLOAD, tunOffloads)
+			if err != nil {
+				return
+			}
+			tun.vnetHdr = true
+			tun.batchSize = wgconn.IdealBatchSize
+		} else {
+			tun.batchSize = 1
+		}
+	}); e != nil {
+		return e
+	}
+	return err
+}
+
+// CreateTUN creates a Device with the provided name and MTU.
+func CreateTUN(name string, mtu int) (Device, error) {
+	nfd, err := unix.Open(cloneDevicePath, unix.O_RDWR|unix.O_CLOEXEC, 0)
+	if err != nil {
+		return nil, fmt.Errorf("CreateTUN(%q) failed; %s does not exist", name, cloneDevicePath)
+	}
+	fd := os.NewFile(uintptr(nfd), cloneDevicePath)
+	tun, err := CreateTUNFromFile(fd, mtu)
+	if err != nil {
+		return nil, err
+	}
+	if name != "tun" {
+		if err := tun.(*NativeTun).initFromFlags(name); err != nil {
+			tun.Close()
+			return nil, fmt.Errorf("CreateTUN(%q) failed to set flags: %w", name, err)
+		}
+	}
+	return tun, nil
+}
+
+// CreateTUNFromFile creates a Device from an os.File with the provided MTU.
+func CreateTUNFromFile(file *os.File, mtu int) (Device, error) {
+	tun := &NativeTun{
+		tunFile: file,
+		errors:  make(chan error, 5),
+		events:  make(chan Event, 5),
+	}
+
+	name, err := tun.Name()
+	if err != nil {
+		return nil, fmt.Errorf("failed to determine TUN name: %w", err)
+	}
+
+	if err := tun.initFromFlags(name); err != nil {
+		return nil, fmt.Errorf("failed to query TUN flags: %w", err)
+	}
+
+	if tun.batchSize == 0 {
+		tun.batchSize = 1
+	}
+
+	tun.index, err = getIFIndex(name)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get TUN index: %w", err)
+	}
+
+	if err = tun.setMTU(mtu); err != nil {
+		return nil, fmt.Errorf("failed to set MTU: %w", err)
+	}
+
+	tun.statusListenersShutdown = make(chan struct{})
+	go tun.routineNetlink()
+
+	if tun.batchSize == 0 {
+		tun.batchSize = 1
+	}
+
+	tun.tcp4GROTable = newTCPGROTable()
+	tun.tcp6GROTable = newTCPGROTable()
+
+	return tun, nil
+}
+
+func (tun *NativeTun) Name() (string, error) {
+	tun.nameOnce.Do(tun.initNameCache)
+	return tun.nameCache, tun.nameErr
+}
+
+func (tun *NativeTun) initNameCache() {
+	sysconn, err := tun.tunFile.SyscallConn()
+	if err != nil {
+		tun.nameErr = err
+		return
+	}
+	err = sysconn.Control(func(fd uintptr) {
+		var ifr [ifReqSize]byte
+		_, _, errno := unix.Syscall(
+			unix.SYS_IOCTL,
+			fd,
+			uintptr(unix.TUNGETIFF),
+			uintptr(unsafe.Pointer(&ifr[0])),
+		)
+		if errno != 0 {
+			tun.nameErr = errno
+			return
+		}
+		tun.nameCache = unix.ByteSliceToString(ifr[:])
+	})
+	if err != nil && tun.nameErr == nil {
+		tun.nameErr = err
+	}
+}
+
+func (tun *NativeTun) MTU() (int, error) {
+	name, err := tun.Name()
+	if err != nil {
+		return 0, err
+	}
+
+	// open datagram socket
+	fd, err := unix.Socket(
+		unix.AF_INET,
+		unix.SOCK_DGRAM|unix.SOCK_CLOEXEC,
+		0,
+	)
+	if err != nil {
+		return 0, err
+	}
+	defer unix.Close(fd)
+
+	var ifr [ifReqSize]byte
+	copy(ifr[:], name)
+
+	_, _, errno := unix.Syscall(
+		unix.SYS_IOCTL,
+		uintptr(fd),
+		uintptr(unix.SIOCGIFMTU),
+		uintptr(unsafe.Pointer(&ifr[0])),
+	)
+
+	if errno != 0 {
+		return 0, errno
+	}
+
+	return int(*(*uint32)(unsafe.Pointer(&ifr[unix.IFNAMSIZ]))), nil
+}
+
+func (tun *NativeTun) Events() <-chan Event {
+	return tun.events
+}
+
+func (tun *NativeTun) Write(bufs [][]byte, offset int) (int, error) {
+	tun.writeOpMu.Lock()
+	defer func() {
+		tun.tcp4GROTable.reset()
+		tun.tcp6GROTable.reset()
+		tun.writeOpMu.Unlock()
+	}()
+	var (
+		errs  error
+		total int
+	)
+	tun.toWrite = tun.toWrite[:0]
+	if tun.vnetHdr {
+		err := handleGRO(bufs, offset, tun.tcp4GROTable, tun.tcp6GROTable, &tun.toWrite)
+		if err != nil {
+			return 0, err
+		}
+		offset -= virtioNetHdrLen
+	} else {
+		for i := range bufs {
+			tun.toWrite = append(tun.toWrite, i)
+		}
+	}
+	for _, bufsI := range tun.toWrite {
+		n, err := tun.tunFile.Write(bufs[bufsI][offset:])
+		if errors.Is(err, syscall.EBADFD) {
+			return total, os.ErrClosed
+		}
+		if err != nil {
+			errs = errors.Join(errs, err)
+		} else {
+			total += n
+		}
+	}
+	return total, errs
+}
+
+// handleVirtioRead splits in into bufs, leaving offset bytes at the front of
+// each buffer. It mutates sizes to reflect the size of each element of bufs,
+// and returns the number of packets read.
+func handleVirtioRead(in []byte, bufs [][]byte, sizes []int, offset int) (int, error) {
+	var hdr virtioNetHdr
+	if err := hdr.decode(in); err != nil {
+		return 0, err
+	}
+	in = in[virtioNetHdrLen:]
+	if hdr.gsoType == unix.VIRTIO_NET_HDR_GSO_NONE {
+		if hdr.flags&unix.VIRTIO_NET_HDR_F_NEEDS_CSUM != 0 {
+			if err := gsoNoneChecksum(in, hdr.csumStart, hdr.csumOffset); err != nil {
+				return 0, err
+			}
+		}
+		if len(in) > len(bufs[0][offset:]) {
+			return 0, fmt.Errorf("read len %d overflows bufs element len %d", len(in), len(bufs[0][offset:]))
+		}
+		n := copy(bufs[0][offset:], in)
+		sizes[0] = n
+		return 1, nil
+	}
+	if hdr.gsoType != unix.VIRTIO_NET_HDR_GSO_TCPV4 && hdr.gsoType != unix.VIRTIO_NET_HDR_GSO_TCPV6 {
+		return 0, fmt.Errorf("unsupported virtio GSO type: %d", hdr.gsoType)
+	}
+
+	ipVersion := in[0] >> 4
+	switch ipVersion {
+	case 4:
+		if hdr.gsoType != unix.VIRTIO_NET_HDR_GSO_TCPV4 {
+			return 0, fmt.Errorf("ip header version: %d, GSO type: %d", ipVersion, hdr.gsoType)
+		}
+	case 6:
+		if hdr.gsoType != unix.VIRTIO_NET_HDR_GSO_TCPV6 {
+			return 0, fmt.Errorf("ip header version: %d, GSO type: %d", ipVersion, hdr.gsoType)
+		}
+	default:
+		return 0, fmt.Errorf("invalid ip header version: %d", ipVersion)
+	}
+
+	if len(in) <= int(hdr.csumStart+12) {
+		return 0, errors.New("packet is too short")
+	}
+	tcpHLen := uint16(in[hdr.csumStart+12] >> 4 * 4)
+	if tcpHLen < 20 || tcpHLen > 60 {
+		return 0, fmt.Errorf("tcp header len is invalid: %d", tcpHLen)
+	}
+	hdr.hdrLen = hdr.csumStart + tcpHLen
+	if len(in) < int(hdr.hdrLen) {
+		return 0, fmt.Errorf("length of packet (%d) < virtioNetHdr.hdrLen (%d)", len(in), hdr.hdrLen)
+	}
+	if hdr.hdrLen < hdr.csumStart {
+		return 0, fmt.Errorf("virtioNetHdr.hdrLen (%d) < virtioNetHdr.csumStart (%d)", hdr.hdrLen, hdr.csumStart)
+	}
+	cSumAt := int(hdr.csumStart + hdr.csumOffset)
+	if cSumAt+1 >= len(in) {
+		return 0, fmt.Errorf("end of checksum offset (%d) exceeds packet length (%d)", cSumAt+1, len(in))
+	}
+
+	return tcpTSO(in, hdr, bufs, sizes, offset)
+}
+
+func (tun *NativeTun) Read(bufs [][]byte, sizes []int, offset int) (int, error) {
+	tun.readOpMu.Lock()
+	defer tun.readOpMu.Unlock()
+	select {
+	case err := <-tun.errors:
+		return 0, err
+	default:
+		readInto := bufs[0][offset:]
+		if tun.vnetHdr {
+			readInto = tun.readBuff[:]
+		}
+		n, err := tun.tunFile.Read(readInto)
+		if errors.Is(err, syscall.EBADFD) {
+			err = os.ErrClosed
+		}
+		if err != nil {
+			return 0, err
+		}
+		if tun.vnetHdr {
+			return handleVirtioRead(readInto[:n], bufs, sizes, offset)
+		}
+		sizes[0] = n
+		return 1, nil
+	}
+}