Start of the changelog

Co-authored-by: Nate Brown <nbrown.us@gmail.com>

CHANGELOG.md

@@ -7,12 +7,64 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [1.10.0] - ????
+
+### Added
+
+- PKCS11 support for P256 keys when built with `pkcs11` tag (#1153)
+- ASN.1 based v2 nebula certificates with support for ipv6 and multiple ip addresses.
+  Certificates now have a unified interface for external implementations. (#1212, #1216, #1345)
+  **TODO: External documentation link!**
+- Add the ability to mark packets on linux to better target nebula packets in iptables/nftables. (#1331)
+- Add ECMP support for `unsafe_routes`. (#1332)
+
 ### Changed
 
 - `default_local_cidr_any` now defaults to false, meaning that any firewall rule
   intended to target an `unsafe_routes` entry must explicitly declare it via the
   `local_cidr` field. This is almost always the intended behavior. This flag is
-  deprecated and will be removed in a future release.
+  deprecated and will be removed in a future release. (#1373)
+
+### Fixed
+
+- Fix moving a udp address from one vpn address to another in the `static_host_map`
+  which could cause rapid re-handshaking with an incorrect remote. (#1259)
+- Improve smoke tests in environments where the docker network is not the default. (#1347)
+
+## [1.9.7] - 2025-10-10
+
+### Security
+
+- Fix an issue where Nebula could incorrectly accept and process a packet from an erroneous source IP when the sender's
+  certificate is configured with unsafe_routes (cert v1/v2) or multiple IPs (cert v2). (#1494)
+
+### Changed
+
+- Disable sending `recv_error` messages when a packet is received outside the allowable counter window. (#1459)
+- Improve error messages and remove some unnecessary fatal conditions in the Windows and generic udp listener. (#1543)
+
+## [1.9.6] - 2025-7-15
+
+### Added
+
+- Support dropping inactive tunnels. This is disabled by default in this release but can be enabled with `tunnels.drop_inactive`. See example config for more details. (#1413)
+
+### Fixed
+
+- Fix Darwin freeze due to presence of some Network Extensions (#1426)
+- Ensure the same relay tunnel is always used when multiple relay tunnels are present (#1422)
+- Fix Windows freeze due to ICMP error handling (#1412)
+- Fix relay migration panic (#1403)
+
+## [1.9.5] - 2024-12-05
+
+### Added
+
+- Gracefully ignore v2 certificates. (#1282)
+
+### Fixed
+
+- Fix relays that refuse to re-establish after one of the remote tunnel pairs breaks. (#1277)
 
 ## [1.9.4] - 2024-09-09
 
@@ -671,7 +723,11 @@ created.)
 
 - Initial public release.
 
-[Unreleased]: https://github.com/slackhq/nebula/compare/v1.9.4...HEAD
+[Unreleased]: https://github.com/slackhq/nebula/compare/v1.10.0...HEAD
+[1.10.0]: https://github.com/slackhq/nebula/releases/tag/v1.10.0
+[1.9.7]: https://github.com/slackhq/nebula/releases/tag/v1.9.7
+[1.9.6]: https://github.com/slackhq/nebula/releases/tag/v1.9.6
+[1.9.5]: https://github.com/slackhq/nebula/releases/tag/v1.9.5
 [1.9.4]: https://github.com/slackhq/nebula/releases/tag/v1.9.4
 [1.9.3]: https://github.com/slackhq/nebula/releases/tag/v1.9.3
 [1.9.2]: https://github.com/slackhq/nebula/releases/tag/v1.9.2

bits.go

@@ -9,14 +9,13 @@ 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 {
-	return &Bits{
+	b := &Bits{
 		length:             bits,
 		bits:               make([]bool, bits, bits),
 		current:            0,
@@ -24,34 +23,37 @@ 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.FieldLogger, i uint64) bool {
+func (b *Bits) Check(l *logrus.Logger, i uint64) bool {
 	// If i is the next number, return true.
-	if i > b.current || (i == 0 && b.firstSeen == false && b.current < b.length) {
+	if i > b.current {
 		return true
 	}
 
-	// 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 {
-		return !b.bits[i%b.length]
-	}
-
-	// If i is within the first window
-	if i < b.length {
+	// If i is within the window, check if it's been set already.
+	if i > b.current-b.length || i < b.length && b.current < b.length {
 		return !b.bits[i%b.length]
 	}
 
 	// Not within the window
-	l.Debugf("rejected a packet (top) %d %d delta %d\n", b.current, i, b.current-i)
+	if l.Level >= logrus.DebugLevel {
+		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 {
-		// Report missed packets, we can only understand what was missed after the first window has been gone through
-		if i > b.length && b.bits[i%b.length] == false {
+		// Check if the oldest bit was lost since we are shifting the window by 1 and occupying it with this counter
+		// The very first window can only be tracked as lost once we are on the 2nd window or greater
+		if b.bits[i%b.length] == false && i > b.length {
 			b.lostCounter.Inc(1)
 		}
 		b.bits[i%b.length] = true
@@ -59,61 +61,32 @@ func (b *Bits) Update(l *logrus.Logger, i uint64) bool {
 		return true
 	}
 
-	// If i packet is greater than current but less than the maximum length of our bitmap,
-	// flip everything in between to false and move ahead.
-	if i > b.current && i < b.current+b.length {
-		// In between current and i need to be zero'd to allow those packets to come in later
-		for n := b.current + 1; n < i; n++ {
+	// If i is a jump, adjust the window, record lost, update current, and return true
+	if i > b.current {
+		lost := int64(0)
+		// Zero out the bits between the current and the new counter value, limited by the window size,
+		// since the window is shifting
+		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
 		}
 
-		b.bits[i%b.length] = true
-		b.current = i
-		//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
-		}
-
+		// Only record any skipped packets as a result of the window moving further than the window length
+		// Any loss within the new window will be accounted for in future calls
+		lost += max(0, int64(i-b.current-b.length))
 		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
 	}
 
-	// Allow for the 0 packet to come in within the first window
-	if i == 0 && b.firstSeen == false && b.current < b.length {
-		b.firstSeen = 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 i is within the current window but below the current counter,
+	// Check to see if it's a duplicate
+	if i > b.current-b.length || i < b.length && b.current < b.length {
+		if b.current == i || b.bits[i%b.length] == true {
 			if l.Level >= logrus.DebugLevel {
 				l.WithField("receiveWindow", m{"accepted": false, "currentCounter": b.current, "incomingCounter": i, "reason": "duplicate"}).
 					Debug("Receive window")
@@ -122,18 +95,8 @@ 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.
@@ -147,11 +110,3 @@ 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

@@ -15,48 +15,41 @@ 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))
-	u := b.Update(l, 1)
-	assert.True(t, u)
+	assert.True(t, b.Update(l, 1))
 	assert.EqualValues(t, 1, b.current)
-	g := []bool{false, true, false, false, false, false, false, false, false, false}
+	g := []bool{true, true, false, false, false, false, false, false, false, false}
 	assert.Equal(t, g, b.bits)
 
 	// Receive two
 	assert.True(t, b.Check(l, 2))
-	u = b.Update(l, 2)
-	assert.True(t, u)
+	assert.True(t, b.Update(l, 2))
 	assert.EqualValues(t, 2, b.current)
-	g = []bool{false, true, true, false, false, false, false, false, false, false}
+	g = []bool{true, 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))
-	u = b.Update(l, 2)
-	assert.False(t, u)
+	assert.False(t, b.Update(l, 2))
 	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))
-	u = b.Update(l, 15)
-	assert.True(t, u)
+	assert.True(t, b.Update(l, 15))
 	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))
-	u = b.Update(l, 14)
-	assert.True(t, u)
+	assert.True(t, b.Update(l, 14))
 	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))
-	u = b.Update(l, 5)
-	assert.False(t, u)
+	assert.False(t, b.Update(l, 5))
 	assert.EqualValues(t, 15, b.current)
 	g = []bool{false, false, false, false, true, true, false, false, false, false}
 	assert.Equal(t, g, b.bits)
@@ -69,10 +62,29 @@ func TestBits(t *testing.T) {
 
 	// Walk through a few windows in order
 	b = NewBits(10)
-	for i := uint64(0); i <= 100; i++ {
+	for i := uint64(1); 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) {
@@ -124,8 +136,7 @@ func TestBitsOutOfWindowCounter(t *testing.T) {
 	assert.False(t, b.Update(l, 0))
 	assert.Equal(t, int64(1), b.outOfWindowCounter.Count())
 
-	//tODO: make sure lostcounter doesn't increase in orderly increment
-	assert.Equal(t, int64(20), b.lostCounter.Count())
+	assert.Equal(t, int64(19), b.lostCounter.Count()) // packet 0 wasn't lost
 	assert.Equal(t, int64(0), b.dupeCounter.Count())
 	assert.Equal(t, int64(1), b.outOfWindowCounter.Count())
 }
@@ -137,8 +148,6 @@ 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))
@@ -149,7 +158,7 @@ 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(20), b.lostCounter.Count())
+	assert.Equal(t, int64(19), b.lostCounter.Count()) // packet 0 wasn't lost
 	assert.Equal(t, int64(0), b.dupeCounter.Count())
 	assert.Equal(t, int64(0), b.outOfWindowCounter.Count())
 
@@ -158,8 +167,6 @@ 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
@@ -214,6 +221,62 @@ 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++ {

cmd/nebula-cert/ca.go

@@ -173,23 +173,26 @@ func ca(args []string, out io.Writer, errOut io.Writer, pr PasswordReader) error
 
 	var passphrase []byte
 	if !isP11 && *cf.encryption {
-		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
-			}
-		}
-
+		passphrase = []byte(os.Getenv("NEBULA_CA_PASSPHRASE"))
 		if len(passphrase) == 0 {
-			return fmt.Errorf("no passphrase specified, remove -encrypt flag to write out-key in plaintext")
+			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 {
+				return fmt.Errorf("no passphrase specified, remove -encrypt flag to write out-key in plaintext")
+			}
 		}
 	}
 

cmd/nebula-cert/ca_test.go

@@ -171,6 +171,17 @@ 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

@@ -5,10 +5,28 @@ 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

@@ -116,26 +116,28 @@ 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
-			for i := 0; i < 5; i++ {
-				out.Write([]byte("Enter passphrase: "))
-				passphrase, err = pr.ReadPassword()
-
-				if errors.Is(err, ErrNoTerminal) {
-					return fmt.Errorf("ca-key is encrypted and must be decrypted interactively")
-				} else if err != nil {
-					return fmt.Errorf("error reading password: %s", err)
-				}
-
-				if len(passphrase) > 0 {
-					break
-				}
-			}
+			passphrase = []byte(os.Getenv("NEBULA_CA_PASSPHRASE"))
 			if len(passphrase) == 0 {
-				return fmt.Errorf("cannot open encrypted ca-key without passphrase")
-			}
+				// ask for a passphrase until we get one
+				for i := 0; i < 5; i++ {
+					out.Write([]byte("Enter passphrase: "))
+					passphrase, err = pr.ReadPassword()
 
+					if errors.Is(err, ErrNoTerminal) {
+						return fmt.Errorf("ca-key is encrypted and must be decrypted interactively")
+					} else if err != nil {
+						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")
+				}
+			}
 			curve, caKey, _, err = cert.DecryptAndUnmarshalSigningPrivateKey(passphrase, rawCAKey)
 			if err != nil {
 				return fmt.Errorf("error while parsing encrypted ca-key: %s", err)

cmd/nebula-cert/sign_test.go

@@ -379,6 +379,15 @@ 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()
@@ -389,6 +398,17 @@ 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

@@ -4,6 +4,8 @@ import (
 	"flag"
 	"fmt"
 	"os"
+	"runtime/debug"
+	"strings"
 
 	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula"
@@ -18,6 +20,17 @@ 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

@@ -3,10 +3,9 @@ package main
 import (
 	"flag"
 	"fmt"
-	"log"
-	"net/http"
-	_ "net/http/pprof"
 	"os"
+	"runtime/debug"
+	"strings"
 
 	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula"
@@ -21,6 +20,17 @@ 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")
@@ -61,10 +71,6 @@ func main() {
 		os.Exit(1)
 	}
 
-	go func() {
-		log.Println(http.ListenAndServe("0.0.0.0:6060", nil))
-	}()
-
 	if !*configTest {
 		ctrl.Start()
 		notifyReady(l)

connection_state.go

@@ -13,7 +13,7 @@ import (
 	"github.com/slackhq/nebula/noiseutil"
 )
 
-const ReplayWindow = 4096
+const ReplayWindow = 1024
 
 type ConnectionState struct {
 	eKey           *NebulaCipherState

firewall.go

@@ -425,9 +425,9 @@ 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, now time.Time) 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, now) {
+	if f.inConns(fp, h, caPool, localCache) {
 		return nil
 	}
 
@@ -476,7 +476,7 @@ func (f *Firewall) Drop(fp firewall.Packet, incoming bool, h *HostInfo, caPool *
 	}
 
 	// We always want to conntrack since it is a faster operation
-	f.addConn(fp, incoming, now)
+	f.addConn(fp, incoming)
 
 	return nil
 }
@@ -505,7 +505,7 @@ 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, now time.Time) bool {
+func (f *Firewall) inConns(fp firewall.Packet, h *HostInfo, caPool *cert.CAPool, localCache firewall.ConntrackCache) bool {
 	if localCache != nil {
 		if _, ok := localCache[fp]; ok {
 			return true
@@ -517,7 +517,7 @@ func (f *Firewall) inConns(fp firewall.Packet, h *HostInfo, caPool *cert.CAPool,
 	// Purge every time we test
 	ep, has := conntrack.TimerWheel.Purge()
 	if has {
-		f.evict(ep, now)
+		f.evict(ep)
 	}
 
 	c, ok := conntrack.Conns[fp]
@@ -564,11 +564,11 @@ func (f *Firewall) inConns(fp firewall.Packet, h *HostInfo, caPool *cert.CAPool,
 
 	switch fp.Protocol {
 	case firewall.ProtoTCP:
-		c.Expires = now.Add(f.TCPTimeout)
+		c.Expires = time.Now().Add(f.TCPTimeout)
 	case firewall.ProtoUDP:
-		c.Expires = now.Add(f.UDPTimeout)
+		c.Expires = time.Now().Add(f.UDPTimeout)
 	default:
-		c.Expires = now.Add(f.DefaultTimeout)
+		c.Expires = time.Now().Add(f.DefaultTimeout)
 	}
 
 	conntrack.Unlock()
@@ -580,7 +580,7 @@ func (f *Firewall) inConns(fp firewall.Packet, h *HostInfo, caPool *cert.CAPool,
 	return true
 }
 
-func (f *Firewall) addConn(fp firewall.Packet, incoming bool, now time.Time) {
+func (f *Firewall) addConn(fp firewall.Packet, incoming bool) {
 	var timeout time.Duration
 	c := &conn{}
 
@@ -596,7 +596,7 @@ func (f *Firewall) addConn(fp firewall.Packet, incoming bool, now time.Time) {
 	conntrack := f.Conntrack
 	conntrack.Lock()
 	if _, ok := conntrack.Conns[fp]; !ok {
-		conntrack.TimerWheel.Advance(now)
+		conntrack.TimerWheel.Advance(time.Now())
 		conntrack.TimerWheel.Add(fp, timeout)
 	}
 
@@ -604,14 +604,14 @@ func (f *Firewall) addConn(fp firewall.Packet, incoming bool, now time.Time) {
 	// firewall reload
 	c.incoming = incoming
 	c.rulesVersion = f.rulesVersion
-	c.Expires = now.Add(timeout)
+	c.Expires = time.Now().Add(timeout)
 	conntrack.Conns[fp] = c
 	conntrack.Unlock()
 }
 
 // Evict checks if a conntrack entry has expired, if so it is removed, if not it is re-added to the wheel
 // Caller must own the connMutex lock!
-func (f *Firewall) evict(p firewall.Packet, now time.Time) {
+func (f *Firewall) evict(p firewall.Packet) {
 	// Are we still tracking this conn?
 	conntrack := f.Conntrack
 	t, ok := conntrack.Conns[p]
@@ -619,11 +619,11 @@ func (f *Firewall) evict(p firewall.Packet, now time.Time) {
 		return
 	}
 
-	newT := t.Expires.Sub(now)
+	newT := t.Expires.Sub(time.Now())
 
 	// Timeout is in the future, re-add the timer
 	if newT > 0 {
-		conntrack.TimerWheel.Advance(now)
+		conntrack.TimerWheel.Advance(time.Now())
 		conntrack.TimerWheel.Add(p, newT)
 		return
 	}

firewall_test.go

@@ -106,13 +106,13 @@ func TestFirewall_AddRule(t *testing.T) {
 	fw = NewFirewall(l, time.Second, time.Minute, time.Hour, c)
 	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{}, "", 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)

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 v0.25.0
+	github.com/gaissmai/bart v0.26.0
 	github.com/gogo/protobuf v1.3.2
 	github.com/google/gopacket v1.1.19
 	github.com/kardianos/service v1.2.4
@@ -50,6 +50,6 @@ require (
 	github.com/vishvananda/netns v0.0.5 // indirect
 	go.yaml.in/yaml/v2 v2.4.2 // indirect
 	golang.org/x/mod v0.24.0 // indirect
-	golang.org/x/time v0.7.0 // indirect
+	golang.org/x/time v0.5.0 // indirect
 	golang.org/x/tools v0.33.0 // indirect
 )

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 v0.25.0 h1:eqiokVPqM3F94vJ0bTHXHtH91S8zkKL+bKh+BsGOsJM=
-github.com/gaissmai/bart v0.25.0/go.mod h1:GREWQfTLRWz/c5FTOsIw+KkscuFkIV5t8Rp7Nd1Td5c=
+github.com/gaissmai/bart v0.26.0 h1:xOZ57E9hJLBiQaSyeZa9wgWhGuzfGACgqp4BE77OkO0=
+github.com/gaissmai/bart v0.26.0/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=
@@ -217,8 +217,8 @@ golang.org/x/term v0.37.0/go.mod h1:5pB4lxRNYYVZuTLmy8oR2BH8dflOR+IbTYFD8fi3254=
 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=
-golang.org/x/time v0.7.0 h1:ntUhktv3OPE6TgYxXWv9vKvUSJyIFJlyohwbkEwPrKQ=
-golang.org/x/time v0.7.0/go.mod h1:3BpzKBy/shNhVucY/MWOyx10tF3SFh9QdLuxbVysPQM=
+golang.org/x/time v0.5.0 h1:o7cqy6amK/52YcAKIPlM3a+Fpj35zvRj2TP+e1xFSfk=
+golang.org/x/time v0.5.0/go.mod h1:3BpzKBy/shNhVucY/MWOyx10tF3SFh9QdLuxbVysPQM=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20200130002326-2f3ba24bd6e7/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=

inside.go

@@ -2,18 +2,16 @@ package nebula
 
 import (
 	"net/netip"
-	"time"
 
 	"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/packet"
 	"github.com/slackhq/nebula/routing"
 )
 
-func (f *Interface) consumeInsidePacket(packet []byte, fwPacket *firewall.Packet, nb []byte, out *packet.Packet, q int, localCache firewall.ConntrackCache, now time.Time) {
+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 {
@@ -55,7 +53,7 @@ func (f *Interface) consumeInsidePacket(packet []byte, fwPacket *firewall.Packet
 	})
 
 	if hostinfo == nil {
-		f.rejectInside(packet, out.Payload, q) //todo vector?
+		f.rejectInside(packet, out, q)
 		if f.l.Level >= logrus.DebugLevel {
 			f.l.WithField("vpnAddr", fwPacket.RemoteAddr).
 				WithField("fwPacket", fwPacket).
@@ -68,11 +66,12 @@ func (f *Interface) consumeInsidePacket(packet []byte, fwPacket *firewall.Packet
 		return
 	}
 
-	dropReason := f.firewall.Drop(*fwPacket, false, hostinfo, f.pki.GetCAPool(), localCache, now)
+	dropReason := f.firewall.Drop(*fwPacket, false, hostinfo, f.pki.GetCAPool(), localCache)
 	if dropReason == nil {
-		f.sendNoMetricsDelayed(header.Message, 0, hostinfo.ConnectionState, hostinfo, netip.AddrPort{}, packet, nb, out, q)
+		f.sendNoMetrics(header.Message, 0, hostinfo.ConnectionState, hostinfo, netip.AddrPort{}, packet, nb, out, q)
+
 	} else {
-		f.rejectInside(packet, out.Payload, q) //todo vector?
+		f.rejectInside(packet, out, q)
 		if f.l.Level >= logrus.DebugLevel {
 			hostinfo.logger(f.l).
 				WithField("fwPacket", fwPacket).
@@ -219,7 +218,7 @@ func (f *Interface) sendMessageNow(t header.MessageType, st header.MessageSubTyp
 	}
 
 	// check if packet is in outbound fw rules
-	dropReason := f.firewall.Drop(*fp, false, hostinfo, f.pki.GetCAPool(), nil, time.Now())
+	dropReason := f.firewall.Drop(*fp, false, hostinfo, f.pki.GetCAPool(), nil)
 	if dropReason != nil {
 		if f.l.Level >= logrus.DebugLevel {
 			f.l.WithField("fwPacket", fp).
@@ -411,81 +410,3 @@ func (f *Interface) sendNoMetrics(t header.MessageType, st header.MessageSubType
 		}
 	}
 }
-
-func (f *Interface) sendNoMetricsDelayed(t header.MessageType, st header.MessageSubType, ci *ConnectionState, hostinfo *HostInfo, remote netip.AddrPort, p, nb []byte, out *packet.Packet, q int) {
-	if ci.eKey == nil {
-		return
-	}
-	useRelay := !remote.IsValid() && !hostinfo.remote.IsValid()
-	fullOut := out.Payload
-
-	if useRelay {
-		if len(out.Payload) < header.Len {
-			// out always has a capacity of mtu, but not always a length greater than the header.Len.
-			// Grow it to make sure the next operation works.
-			out.Payload = out.Payload[:header.Len]
-		}
-		// Save a header's worth of data at the front of the 'out' buffer.
-		out.Payload = out.Payload[header.Len:]
-	}
-
-	if noiseutil.EncryptLockNeeded {
-		// NOTE: for goboring AESGCMTLS we need to lock because of the nonce check
-		ci.writeLock.Lock()
-	}
-	c := ci.messageCounter.Add(1)
-
-	//l.WithField("trace", string(debug.Stack())).Error("out Header ", &Header{Version, t, st, 0, hostinfo.remoteIndexId, c}, p)
-	out.Payload = header.Encode(out.Payload, header.Version, t, st, hostinfo.remoteIndexId, c)
-	f.connectionManager.Out(hostinfo)
-
-	// Query our LH if we haven't since the last time we've been rebound, this will cause the remote to punch against
-	// all our addrs and enable a faster roaming.
-	if t != header.CloseTunnel && hostinfo.lastRebindCount != f.rebindCount {
-		//NOTE: there is an update hole if a tunnel isn't used and exactly 256 rebinds occur before the tunnel is
-		// finally used again. This tunnel would eventually be torn down and recreated if this action didn't help.
-		f.lightHouse.QueryServer(hostinfo.vpnAddrs[0])
-		hostinfo.lastRebindCount = f.rebindCount
-		if f.l.Level >= logrus.DebugLevel {
-			f.l.WithField("vpnAddrs", hostinfo.vpnAddrs).Debug("Lighthouse update triggered for punch due to rebind counter")
-		}
-	}
-
-	var err error
-	out.Payload, err = ci.eKey.EncryptDanger(out.Payload, out.Payload, p, c, nb)
-	if noiseutil.EncryptLockNeeded {
-		ci.writeLock.Unlock()
-	}
-	if err != nil {
-		hostinfo.logger(f.l).WithError(err).
-			WithField("udpAddr", remote).WithField("counter", c).
-			WithField("attemptedCounter", c).
-			Error("Failed to encrypt outgoing packet")
-		return
-	}
-
-	if remote.IsValid() {
-		err = f.writers[q].Prep(out, remote)
-		if err != nil {
-			hostinfo.logger(f.l).WithError(err).WithField("udpAddr", remote).Error("Failed to write outgoing packet")
-		}
-	} else if hostinfo.remote.IsValid() {
-		err = f.writers[q].Prep(out, hostinfo.remote)
-		if err != nil {
-			hostinfo.logger(f.l).WithError(err).WithField("udpAddr", remote).Error("Failed to write outgoing packet")
-		}
-	} 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
-			}
-			//todo vector!!
-			f.SendVia(relayHostInfo, relay, out.Payload, nb, fullOut[:header.Len+len(out.Payload)], true)
-			break
-		}
-	}
-}

interface.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"io"
 	"net/netip"
 	"os"
 	"runtime"
@@ -17,12 +18,10 @@ import (
 	"github.com/slackhq/nebula/firewall"
 	"github.com/slackhq/nebula/header"
 	"github.com/slackhq/nebula/overlay"
-	"github.com/slackhq/nebula/packet"
 	"github.com/slackhq/nebula/udp"
 )
 
 const mtu = 9001
-const batch = 1024 //todo config!
 
 type InterfaceConfig struct {
 	HostMap            *HostMap
@@ -87,18 +86,12 @@ type Interface struct {
 	conntrackCacheTimeout time.Duration
 
 	writers []udp.Conn
-	readers []overlay.TunDev
+	readers []io.ReadWriteCloser
 
 	metricHandshakes    metrics.Histogram
 	messageMetrics      *MessageMetrics
 	cachedPacketMetrics *cachedPacketMetrics
 
-	listenInN  int
-	listenOutN int
-
-	listenInMetric  metrics.Histogram
-	listenOutMetric metrics.Histogram
-
 	l *logrus.Logger
 }
 
@@ -184,7 +177,7 @@ func NewInterface(ctx context.Context, c *InterfaceConfig) (*Interface, error) {
 		routines:              c.routines,
 		version:               c.version,
 		writers:               make([]udp.Conn, c.routines),
-		readers:               make([]overlay.TunDev, c.routines),
+		readers:               make([]io.ReadWriteCloser, c.routines),
 		myVpnNetworks:         cs.myVpnNetworks,
 		myVpnNetworksTable:    cs.myVpnNetworksTable,
 		myVpnAddrs:            cs.myVpnAddrs,
@@ -203,8 +196,6 @@ func NewInterface(ctx context.Context, c *InterfaceConfig) (*Interface, error) {
 
 		l: c.l,
 	}
-	ifce.listenInMetric = metrics.GetOrRegisterHistogram("vhost.listenIn.n", nil, metrics.NewExpDecaySample(1028, 0.015))
-	ifce.listenOutMetric = metrics.GetOrRegisterHistogram("vhost.listenOut.n", nil, metrics.NewExpDecaySample(1028, 0.015))
 
 	ifce.tryPromoteEvery.Store(c.tryPromoteEvery)
 	ifce.reQueryEvery.Store(c.reQueryEvery)
@@ -234,7 +225,7 @@ func (f *Interface) activate() {
 	metrics.GetOrRegisterGauge("routines", nil).Update(int64(f.routines))
 
 	// Prepare n tun queues
-	var reader overlay.TunDev = f.inside
+	var reader io.ReadWriteCloser = f.inside
 	for i := 0; i < f.routines; i++ {
 		if i > 0 {
 			reader, err = f.inside.NewMultiQueueReader()
@@ -263,71 +254,40 @@ func (f *Interface) run() {
 	}
 }
 
-func (f *Interface) listenOut(q int) {
+func (f *Interface) listenOut(i int) {
 	runtime.LockOSThread()
 
 	var li udp.Conn
-	if q > 0 {
-		li = f.writers[q]
+	if i > 0 {
+		li = f.writers[i]
 	} else {
 		li = f.outside
 	}
 
 	ctCache := firewall.NewConntrackCacheTicker(f.conntrackCacheTimeout)
 	lhh := f.lightHouse.NewRequestHandler()
-
-	outPackets := make([]*packet.OutPacket, batch)
-	for i := 0; i < batch; i++ {
-		outPackets[i] = packet.NewOut()
-	}
-
+	plaintext := make([]byte, udp.MTU)
 	h := &header.H{}
 	fwPacket := &firewall.Packet{}
 	nb := make([]byte, 12, 12)
 
-	toSend := make([][]byte, batch)
-
-	li.ListenOut(func(pkts []*packet.Packet) {
-		toSend = toSend[:0]
-		for i := range outPackets {
-			outPackets[i].Valid = false
-			outPackets[i].SegCounter = 0
-		}
-
-		f.readOutsidePacketsMany(pkts, outPackets, h, fwPacket, lhh, nb, q, ctCache.Get(f.l), time.Now())
-		//we opportunistically tx, but try to also send stragglers
-		if _, err := f.readers[q].WriteMany(outPackets, q); err != nil {
-			f.l.WithError(err).Error("Failed to send packets")
-		}
-		//todo I broke this
-		//n := len(toSend)
-		//if f.l.Level == logrus.DebugLevel {
-		//	f.listenOutMetric.Update(int64(n))
-		//}
-		//f.listenOutN = n
-
+	li.ListenOut(func(fromUdpAddr netip.AddrPort, payload []byte) {
+		f.readOutsidePackets(fromUdpAddr, nil, plaintext[:0], payload, h, fwPacket, lhh, nb, i, ctCache.Get(f.l))
 	})
 }
 
-func (f *Interface) listenIn(reader overlay.TunDev, queueNum int) {
+func (f *Interface) listenIn(reader io.ReadWriteCloser, i int) {
 	runtime.LockOSThread()
 
+	packet := make([]byte, mtu)
+	out := make([]byte, mtu)
 	fwPacket := &firewall.Packet{}
 	nb := make([]byte, 12, 12)
 
 	conntrackCache := firewall.NewConntrackCacheTicker(f.conntrackCacheTimeout)
 
-	packets := make([]*packet.VirtIOPacket, batch)
-	outPackets := make([]*packet.Packet, batch)
-	for i := 0; i < batch; i++ {
-		packets[i] = packet.NewVIO()
-		outPackets[i] = packet.New(false) //todo?
-	}
-
 	for {
-		n, err := reader.ReadMany(packets, queueNum)
-
-		//todo!!
+		n, err := reader.Read(packet)
 		if err != nil {
 			if errors.Is(err, os.ErrClosed) && f.closed.Load() {
 				return
@@ -338,22 +298,7 @@ func (f *Interface) listenIn(reader overlay.TunDev, queueNum int) {
 			os.Exit(2)
 		}
 
-		if f.l.Level == logrus.DebugLevel {
-			f.listenInMetric.Update(int64(n))
-		}
-		f.listenInN = n
-
-		now := time.Now()
-		for i, pkt := range packets[:n] {
-			outPackets[i].OutLen = -1
-			f.consumeInsidePacket(pkt.Payload, fwPacket, nb, outPackets[i], queueNum, conntrackCache.Get(f.l), now)
-			reader.RecycleRxSeg(pkt, i == (n-1), queueNum) //todo handle err?
-			pkt.Reset()
-		}
-		_, err = f.writers[queueNum].WriteBatch(outPackets[:n])
-		if err != nil {
-			f.l.WithError(err).Error("Error while writing outbound packets")
-		}
+		f.consumeInsidePacket(packet[:n], fwPacket, nb, out, i, conntrackCache.Get(f.l))
 	}
 }
 
@@ -491,11 +436,6 @@ func (f *Interface) emitStats(ctx context.Context, i time.Duration) {
 			} else {
 				certMaxVersion.Update(int64(certState.v1Cert.Version()))
 			}
-			if f.l.Level != logrus.DebugLevel {
-				f.listenInMetric.Update(int64(f.listenInN))
-				f.listenOutMetric.Update(int64(f.listenOutN))
-			}
-
 		}
 	}
 }

main.go

@@ -5,6 +5,8 @@ import (
 	"fmt"
 	"net"
 	"net/netip"
+	"runtime/debug"
+	"strings"
 	"time"
 
 	"github.com/sirupsen/logrus"
@@ -27,6 +29,10 @@ func Main(c *config.C, configTest bool, buildVersion string, logger *logrus.Logg
 		}
 	}()
 
+	if buildVersion == "" {
+		buildVersion = moduleVersion()
+	}
+
 	l := logger
 	l.Formatter = &logrus.TextFormatter{
 		FullTimestamp: true,
@@ -296,3 +302,18 @@ 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

@@ -7,7 +7,6 @@ import (
 	"time"
 
 	"github.com/google/gopacket/layers"
-	"github.com/slackhq/nebula/packet"
 	"golang.org/x/net/ipv6"
 
 	"github.com/sirupsen/logrus"
@@ -20,7 +19,7 @@ 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, now time.Time) {
+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
@@ -62,7 +61,7 @@ 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, now) {
+			if !f.decryptToTun(hostinfo, h.MessageCounter, out, packet, fwPacket, nb, q, localCache) {
 				return
 			}
 		case header.MessageRelay:
@@ -97,7 +96,7 @@ func (f *Interface) readOutsidePackets(ip netip.AddrPort, via *ViaSender, out []
 			case TerminalType:
 				// If I am the target of this relay, process the unwrapped packet
 				// From this recursive point, all these variables are 'burned'. We shouldn't rely on them again.
-				f.readOutsidePackets(netip.AddrPort{}, &ViaSender{relayHI: hostinfo, remoteIdx: relay.RemoteIndex, relay: relay}, out[:0], signedPayload, h, fwPacket, lhf, nb, q, localCache, now)
+				f.readOutsidePackets(netip.AddrPort{}, &ViaSender{relayHI: hostinfo, remoteIdx: relay.RemoteIndex, relay: relay}, out[:0], signedPayload, h, fwPacket, lhf, nb, q, localCache)
 				return
 			case ForwardingType:
 				// Find the target HostInfo relay object
@@ -217,217 +216,6 @@ func (f *Interface) readOutsidePackets(ip netip.AddrPort, via *ViaSender, out []
 	f.connectionManager.In(hostinfo)
 }
 
-func (f *Interface) readOutsidePacketsMany(packets []*packet.Packet, out []*packet.OutPacket, h *header.H, fwPacket *firewall.Packet, lhf *LightHouseHandler, nb []byte, q int, localCache firewall.ConntrackCache, now time.Time) {
-	for i, pkt := range packets {
-		out[i].Scratch = out[i].Scratch[:0]
-		ip := pkt.AddrPort()
-
-		//l.Error("in packet ", header, packet[HeaderLen:])
-		if ip.IsValid() {
-			if f.myVpnNetworksTable.Contains(ip.Addr()) {
-				if f.l.Level >= logrus.DebugLevel {
-					f.l.WithField("udpAddr", ip).Debug("Refusing to process double encrypted packet")
-				}
-				return
-			}
-		}
-
-		//todo per-segment!
-		for segment := range pkt.Segments() {
-
-			err := h.Parse(segment)
-			if err != nil {
-				// Hole punch packets are 0 or 1 byte big, so lets ignore printing those errors
-				if len(segment) > 1 {
-					f.l.WithField("packet", pkt).Infof("Error while parsing inbound packet from %s: %s", ip, err)
-				}
-				return
-			}
-
-			var hostinfo *HostInfo
-			// verify if we've seen this index before, otherwise respond to the handshake initiation
-			if h.Type == header.Message && h.Subtype == header.MessageRelay {
-				hostinfo = f.hostMap.QueryRelayIndex(h.RemoteIndex)
-			} else {
-				hostinfo = f.hostMap.QueryIndex(h.RemoteIndex)
-			}
-
-			var ci *ConnectionState
-			if hostinfo != nil {
-				ci = hostinfo.ConnectionState
-			}
-
-			switch h.Type {
-			case header.Message:
-				// TODO handleEncrypted sends directly to addr on error. Handle this in the tunneling case.
-				if !f.handleEncrypted(ci, ip, h) {
-					return
-				}
-
-				switch h.Subtype {
-				case header.MessageNone:
-					if !f.decryptToTunDelayWrite(hostinfo, h.MessageCounter, out[i], pkt, segment, fwPacket, nb, q, localCache, now) {
-						return
-					}
-				case header.MessageRelay:
-					// The entire body is sent as AD, not encrypted.
-					// The packet consists of a 16-byte parsed Nebula header, Associated Data-protected payload, and a trailing 16-byte AEAD signature value.
-					// The packet is guaranteed to be at least 16 bytes at this point, b/c it got past the h.Parse() call above. If it's
-					// otherwise malformed (meaning, there is no trailing 16 byte AEAD value), then this will result in at worst a 0-length slice
-					// which will gracefully fail in the DecryptDanger call.
-					signedPayload := segment[:len(segment)-hostinfo.ConnectionState.dKey.Overhead()]
-					signatureValue := segment[len(segment)-hostinfo.ConnectionState.dKey.Overhead():]
-					out[i].Scratch, err = hostinfo.ConnectionState.dKey.DecryptDanger(out[i].Scratch, signedPayload, signatureValue, h.MessageCounter, nb)
-					if err != nil {
-						return
-					}
-					// Successfully validated the thing. Get rid of the Relay header.
-					signedPayload = signedPayload[header.Len:]
-					// Pull the Roaming parts up here, and return in all call paths.
-					f.handleHostRoaming(hostinfo, ip)
-					// Track usage of both the HostInfo and the Relay for the received & authenticated packet
-					f.connectionManager.In(hostinfo)
-					f.connectionManager.RelayUsed(h.RemoteIndex)
-
-					relay, ok := hostinfo.relayState.QueryRelayForByIdx(h.RemoteIndex)
-					if !ok {
-						// The only way this happens is if hostmap has an index to the correct HostInfo, but the HostInfo is missing
-						// its internal mapping. This should never happen.
-						hostinfo.logger(f.l).WithFields(logrus.Fields{"vpnAddrs": hostinfo.vpnAddrs, "remoteIndex": h.RemoteIndex}).Error("HostInfo missing remote relay index")
-						return
-					}
-
-					switch relay.Type {
-					case TerminalType:
-						// If I am the target of this relay, process the unwrapped packet
-						// From this recursive point, all these variables are 'burned'. We shouldn't rely on them again.
-						f.readOutsidePackets(netip.AddrPort{}, &ViaSender{relayHI: hostinfo, remoteIdx: relay.RemoteIndex, relay: relay}, out[i].Scratch[:0], signedPayload, h, fwPacket, lhf, nb, q, localCache, now)
-						return
-					case ForwardingType:
-						// Find the target HostInfo relay object
-						targetHI, targetRelay, err := f.hostMap.QueryVpnAddrsRelayFor(hostinfo.vpnAddrs, relay.PeerAddr)
-						if err != nil {
-							hostinfo.logger(f.l).WithField("relayTo", relay.PeerAddr).WithError(err).WithField("hostinfo.vpnAddrs", hostinfo.vpnAddrs).Info("Failed to find target host info by ip")
-							return
-						}
-
-						// If that relay is Established, forward the payload through it
-						if targetRelay.State == Established {
-							switch targetRelay.Type {
-							case ForwardingType:
-								// Forward this packet through the relay tunnel
-								// Find the target HostInfo
-								f.SendVia(targetHI, targetRelay, signedPayload, nb, out[i].Scratch, false)
-								return
-							case TerminalType:
-								hostinfo.logger(f.l).Error("Unexpected Relay Type of Terminal")
-							}
-						} else {
-							hostinfo.logger(f.l).WithFields(logrus.Fields{"relayTo": relay.PeerAddr, "relayFrom": hostinfo.vpnAddrs[0], "targetRelayState": targetRelay.State}).Info("Unexpected target relay state")
-							return
-						}
-					}
-				}
-
-			case header.LightHouse:
-				f.messageMetrics.Rx(h.Type, h.Subtype, 1)
-				if !f.handleEncrypted(ci, ip, h) {
-					return
-				}
-
-				d, err := f.decrypt(hostinfo, h.MessageCounter, out[i].Scratch, segment, h, nb)
-				if err != nil {
-					hostinfo.logger(f.l).WithError(err).WithField("udpAddr", ip).
-						WithField("packet", segment).
-						Error("Failed to decrypt lighthouse packet")
-					return
-				}
-
-				lhf.HandleRequest(ip, hostinfo.vpnAddrs, d, f)
-
-				// Fallthrough to the bottom to record incoming traffic
-
-			case header.Test:
-				f.messageMetrics.Rx(h.Type, h.Subtype, 1)
-				if !f.handleEncrypted(ci, ip, h) {
-					return
-				}
-
-				d, err := f.decrypt(hostinfo, h.MessageCounter, out[i].Scratch, segment, h, nb)
-				if err != nil {
-					hostinfo.logger(f.l).WithError(err).WithField("udpAddr", ip).
-						WithField("packet", segment).
-						Error("Failed to decrypt test packet")
-					return
-				}
-
-				if h.Subtype == header.TestRequest {
-					// This testRequest might be from TryPromoteBest, so we should roam
-					// to the new IP address before responding
-					f.handleHostRoaming(hostinfo, ip)
-					f.send(header.Test, header.TestReply, ci, hostinfo, d, nb, out[i].Scratch)
-				}
-
-				// Fallthrough to the bottom to record incoming traffic
-
-				// Non encrypted messages below here, they should not fall through to avoid tracking incoming traffic since they
-				// are unauthenticated
-
-			case header.Handshake:
-				f.messageMetrics.Rx(h.Type, h.Subtype, 1)
-				f.handshakeManager.HandleIncoming(ip, nil, segment, h)
-				return
-
-			case header.RecvError:
-				f.messageMetrics.Rx(h.Type, h.Subtype, 1)
-				f.handleRecvError(ip, h)
-				return
-
-			case header.CloseTunnel:
-				f.messageMetrics.Rx(h.Type, h.Subtype, 1)
-				if !f.handleEncrypted(ci, ip, h) {
-					return
-				}
-
-				hostinfo.logger(f.l).WithField("udpAddr", ip).
-					Info("Close tunnel received, tearing down.")
-
-				f.closeTunnel(hostinfo)
-				return
-
-			case header.Control:
-				if !f.handleEncrypted(ci, ip, h) {
-					return
-				}
-
-				d, err := f.decrypt(hostinfo, h.MessageCounter, out[i].Scratch, segment, h, nb)
-				if err != nil {
-					hostinfo.logger(f.l).WithError(err).WithField("udpAddr", ip).
-						WithField("packet", segment).
-						Error("Failed to decrypt Control packet")
-					return
-				}
-
-				f.relayManager.HandleControlMsg(hostinfo, d, f)
-
-			default:
-				f.messageMetrics.Rx(h.Type, h.Subtype, 1)
-				hostinfo.logger(f.l).Debugf("Unexpected packet received from %s", ip)
-				return
-			}
-
-			f.handleHostRoaming(hostinfo, ip)
-
-			f.connectionManager.In(hostinfo)
-
-		}
-		_, err := f.readers[q].WriteOne(out[i], false, q)
-		if err != nil {
-			f.l.WithError(err).Error("Failed to write packet")
-		}
-	}
-}
-
 // closeTunnel closes a tunnel locally, it does not send a closeTunnel packet to the remote
 func (f *Interface) closeTunnel(hostInfo *HostInfo) {
 	final := f.hostMap.DeleteHostInfo(hostInfo)
@@ -677,55 +465,7 @@ func (f *Interface) decrypt(hostinfo *HostInfo, mc uint64, out []byte, packet []
 	return out, nil
 }
 
-func (f *Interface) decryptToTunDelayWrite(hostinfo *HostInfo, messageCounter uint64, out *packet.OutPacket, pkt *packet.Packet, inSegment []byte, fwPacket *firewall.Packet, nb []byte, q int, localCache firewall.ConntrackCache, now time.Time) bool {
-	var err error
-
-	seg, err := f.readers[q].AllocSeg(out, q)
-	if err != nil {
-		f.l.WithError(err).Errorln("decryptToTunDelayWrite: failed to allocate segment")
-		return false
-	}
-
-	out.SegmentPayloads[seg] = out.SegmentPayloads[seg][:0]
-	out.SegmentPayloads[seg], err = hostinfo.ConnectionState.dKey.DecryptDanger(out.SegmentPayloads[seg], inSegment[:header.Len], inSegment[header.Len:], messageCounter, nb)
-	if err != nil {
-		hostinfo.logger(f.l).WithError(err).Error("Failed to decrypt packet")
-		return false
-	}
-
-	err = newPacket(out.SegmentPayloads[seg], true, fwPacket)
-	if err != nil {
-		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) {
-		hostinfo.logger(f.l).WithField("fwPacket", fwPacket).
-			Debugln("dropping out of window packet")
-		return false
-	}
-
-	dropReason := f.firewall.Drop(*fwPacket, true, hostinfo, f.pki.GetCAPool(), localCache, now)
-	if dropReason != nil {
-		// 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.SegmentPayloads[seg], hostinfo.ConnectionState, hostinfo, nb, inSegment, q)
-		if f.l.Level >= logrus.DebugLevel {
-			hostinfo.logger(f.l).WithField("fwPacket", fwPacket).
-				WithField("reason", dropReason).
-				Debugln("dropping inbound packet")
-		}
-		return false
-	}
-
-	f.connectionManager.In(hostinfo)
-	pkt.OutLen += len(inSegment)
-	out.Segments[seg] = out.Segments[seg][:len(out.SegmentHeaders[seg])+len(out.SegmentPayloads[seg])]
-	return true
-}
-
-func (f *Interface) decryptToTun(hostinfo *HostInfo, messageCounter uint64, out []byte, packet []byte, fwPacket *firewall.Packet, nb []byte, q int, localCache firewall.ConntrackCache, now time.Time) bool {
+func (f *Interface) decryptToTun(hostinfo *HostInfo, messageCounter uint64, out []byte, packet []byte, fwPacket *firewall.Packet, nb []byte, q int, localCache firewall.ConntrackCache) bool {
 	var err error
 
 	out, err = hostinfo.ConnectionState.dKey.DecryptDanger(out, packet[:header.Len], packet[header.Len:], messageCounter, nb)
@@ -747,7 +487,7 @@ func (f *Interface) decryptToTun(hostinfo *HostInfo, messageCounter uint64, out
 		return false
 	}
 
-	dropReason := f.firewall.Drop(*fwPacket, true, hostinfo, f.pki.GetCAPool(), localCache, now)
+	dropReason := f.firewall.Drop(*fwPacket, true, hostinfo, f.pki.GetCAPool(), localCache)
 	if dropReason != nil {
 		// 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

overlay/device.go

@@ -1,16 +1,17 @@
 package overlay
 
 import (
+	"io"
 	"net/netip"
 
 	"github.com/slackhq/nebula/routing"
 )
 
 type Device interface {
-	TunDev
+	io.ReadWriteCloser
 	Activate() error
 	Networks() []netip.Prefix
 	Name() string
 	RoutesFor(netip.Addr) routing.Gateways
-	NewMultiQueueReader() (TunDev, error)
+	NewMultiQueueReader() (io.ReadWriteCloser, error)
 }

overlay/eventfd/eventfd.go

@@ -1,91 +0,0 @@
-package eventfd
-
-import (
-	"encoding/binary"
-	"syscall"
-
-	"golang.org/x/sys/unix"
-)
-
-type EventFD struct {
-	fd  int
-	buf [8]byte
-}
-
-func New() (EventFD, error) {
-	fd, err := unix.Eventfd(0, unix.EFD_NONBLOCK)
-	if err != nil {
-		return EventFD{}, err
-	}
-	return EventFD{
-		fd:  fd,
-		buf: [8]byte{},
-	}, nil
-}
-
-func (e *EventFD) Kick() error {
-	binary.LittleEndian.PutUint64(e.buf[:], 1) //is this right???
-	_, err := syscall.Write(int(e.fd), e.buf[:])
-	return err
-}
-
-func (e *EventFD) Close() error {
-	if e.fd != 0 {
-		return unix.Close(e.fd)
-	}
-	return nil
-}
-
-func (e *EventFD) FD() int {
-	return e.fd
-}
-
-type Epoll struct {
-	fd     int
-	buf    [8]byte
-	events []syscall.EpollEvent
-}
-
-func NewEpoll() (Epoll, error) {
-	fd, err := unix.EpollCreate1(0)
-	if err != nil {
-		return Epoll{}, err
-	}
-	return Epoll{
-		fd:     fd,
-		buf:    [8]byte{},
-		events: make([]syscall.EpollEvent, 1),
-	}, nil
-}
-
-func (ep *Epoll) AddEvent(fdToAdd int) error {
-	event := syscall.EpollEvent{
-		Events: syscall.EPOLLIN,
-		Fd:     int32(fdToAdd),
-	}
-	return syscall.EpollCtl(ep.fd, syscall.EPOLL_CTL_ADD, fdToAdd, &event)
-}
-
-func (ep *Epoll) Block() (int, error) {
-	n, err := syscall.EpollWait(ep.fd, ep.events, -1)
-	if err != nil {
-		//goland:noinspection GoDirectComparisonOfErrors
-		if err == syscall.EINTR {
-			return 0, nil //??
-		}
-		return -1, err
-	}
-	return n, nil
-}
-
-func (ep *Epoll) Clear() error {
-	_, err := syscall.Read(int(ep.events[0].Fd), ep.buf[:])
-	return err
-}
-
-func (ep *Epoll) Close() error {
-	if ep.fd != 0 {
-		return unix.Close(ep.fd)
-	}
-	return nil
-}

overlay/tun.go

@@ -2,29 +2,16 @@ package overlay
 
 import (
 	"fmt"
-	"io"
 	"net"
 	"net/netip"
 
 	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula/config"
-	"github.com/slackhq/nebula/packet"
 	"github.com/slackhq/nebula/util"
 )
 
 const DefaultMTU = 1300
 
-type TunDev interface {
-	io.WriteCloser
-	ReadMany(x []*packet.VirtIOPacket, q int) (int, error)
-
-	//todo this interface sux
-	AllocSeg(pkt *packet.OutPacket, q int) (int, error)
-	WriteOne(x *packet.OutPacket, kick bool, q int) (int, error)
-	WriteMany(x []*packet.OutPacket, q int) (int, error)
-	RecycleRxSeg(pkt *packet.VirtIOPacket, kick bool, q int) error
-}
-
 // TODO: We may be able to remove routines
 type DeviceFactory func(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, routines int) (Device, error)
 
@@ -39,11 +26,11 @@ func NewDeviceFromConfig(c *config.C, l *logrus.Logger, vpnNetworks []netip.Pref
 	}
 }
 
-//func NewFdDeviceFromConfig(fd *int) DeviceFactory {
-//	return func(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, routines int) (Device, error) {
-//		return newTunFromFd(c, l, *fd, vpnNetworks)
-//	}
-//}
+func NewFdDeviceFromConfig(fd *int) DeviceFactory {
+	return func(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, routines int) (Device, error) {
+		return newTunFromFd(c, l, *fd, vpnNetworks)
+	}
+}
 
 func getAllRoutesFromConfig(c *config.C, vpnNetworks []netip.Prefix, initial bool) (bool, []Route, error) {
 	if !initial && !c.HasChanged("tun.routes") && !c.HasChanged("tun.unsafe_routes") {

overlay/tun_disabled.go

@@ -9,8 +9,6 @@ import (
 	"github.com/rcrowley/go-metrics"
 	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula/iputil"
-	"github.com/slackhq/nebula/overlay/virtqueue"
-	"github.com/slackhq/nebula/packet"
 	"github.com/slackhq/nebula/routing"
 )
 
@@ -24,10 +22,6 @@ type disabledTun struct {
 	l  *logrus.Logger
 }
 
-func (*disabledTun) RecycleRxSeg(pkt *packet.VirtIOPacket, kick bool, q int) error {
-	return nil
-}
-
 func newDisabledTun(vpnNetworks []netip.Prefix, queueLen int, metricsEnabled bool, l *logrus.Logger) *disabledTun {
 	tun := &disabledTun{
 		vpnNetworks: vpnNetworks,
@@ -46,10 +40,6 @@ func newDisabledTun(vpnNetworks []netip.Prefix, queueLen int, metricsEnabled boo
 	return tun
 }
 
-func (*disabledTun) GetQueues() []*virtqueue.SplitQueue {
-	return nil
-}
-
 func (*disabledTun) Activate() error {
 	return nil
 }
@@ -115,23 +105,7 @@ func (t *disabledTun) Write(b []byte) (int, error) {
 	return len(b), nil
 }
 
-func (t *disabledTun) AllocSeg(pkt *packet.OutPacket, q int) (int, error) {
-	return 0, fmt.Errorf("tun_disabled: AllocSeg not implemented")
-}
-
-func (t *disabledTun) WriteOne(x *packet.OutPacket, kick bool, q int) (int, error) {
-	return 0, fmt.Errorf("tun_disabled: WriteOne not implemented")
-}
-
-func (t *disabledTun) WriteMany(x []*packet.OutPacket, q int) (int, error) {
-	return 0, fmt.Errorf("tun_disabled: WriteMany not implemented")
-}
-
-func (t *disabledTun) ReadMany(b []*packet.VirtIOPacket, _ int) (int, error) {
-	return t.Read(b[0].Payload)
-}
-
-func (t *disabledTun) NewMultiQueueReader() (TunDev, error) {
+func (t *disabledTun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
 	return t, nil
 }
 

overlay/tun_linux.go

@@ -5,6 +5,7 @@ package overlay
 
 import (
 	"fmt"
+	"io"
 	"net"
 	"net/netip"
 	"os"
@@ -16,19 +17,15 @@ import (
 	"github.com/gaissmai/bart"
 	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula/config"
-	"github.com/slackhq/nebula/overlay/vhostnet"
-	"github.com/slackhq/nebula/packet"
 	"github.com/slackhq/nebula/routing"
 	"github.com/slackhq/nebula/util"
-	"github.com/slackhq/nebula/util/virtio"
 	"github.com/vishvananda/netlink"
 	"golang.org/x/sys/unix"
 )
 
 type tun struct {
-	file        *os.File
+	io.ReadWriteCloser
 	fd          int
-	vdev        []*vhostnet.Device
 	Device      string
 	vpnNetworks []netip.Prefix
 	MaxMTU      int
@@ -43,8 +40,7 @@ type tun struct {
 	useSystemRoutes           bool
 	useSystemRoutesBufferSize int
 
-	isV6 bool
-	l    *logrus.Logger
+	l *logrus.Logger
 }
 
 func (t *tun) Networks() []netip.Prefix {
@@ -106,7 +102,7 @@ func newTun(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, multiqueu
 	}
 
 	var req ifReq
-	req.Flags = uint16(unix.IFF_TUN | unix.IFF_NO_PI | unix.IFF_TUN_EXCL | unix.IFF_VNET_HDR | unix.IFF_NAPI)
+	req.Flags = uint16(unix.IFF_TUN | unix.IFF_NO_PI)
 	if multiqueue {
 		req.Flags |= unix.IFF_MULTI_QUEUE
 	}
@@ -116,47 +112,20 @@ func newTun(c *config.C, l *logrus.Logger, vpnNetworks []netip.Prefix, multiqueu
 	}
 	name := strings.Trim(string(req.Name[:]), "\x00")
 
-	if err = unix.SetNonblock(fd, true); err != nil {
-		_ = unix.Close(fd)
-		return nil, fmt.Errorf("make file descriptor non-blocking: %w", err)
-	}
-
 	file := os.NewFile(uintptr(fd), "/dev/net/tun")
-
-	err = unix.IoctlSetPointerInt(fd, unix.TUNSETVNETHDRSZ, virtio.NetHdrSize)
-	if err != nil {
-		return nil, fmt.Errorf("set vnethdr size: %w", err)
-	}
-
-	flags := 0
-	//flags = //unix.TUN_F_CSUM //| unix.TUN_F_TSO4 | unix.TUN_F_USO4 | unix.TUN_F_TSO6 | unix.TUN_F_USO6
-	err = unix.IoctlSetInt(fd, unix.TUNSETOFFLOAD, flags)
-	if err != nil {
-		return nil, fmt.Errorf("set offloads: %w", err)
-	}
-
 	t, err := newTunGeneric(c, l, file, vpnNetworks)
 	if err != nil {
 		return nil, err
 	}
-	t.fd = fd
-	t.Device = name
 
-	vdev, err := vhostnet.NewDevice(
-		vhostnet.WithBackendFD(fd),
-		vhostnet.WithQueueSize(8192), //todo config
-	)
-	if err != nil {
-		return nil, err
-	}
-	t.vdev = []*vhostnet.Device{vdev}
+	t.Device = name
 
 	return t, nil
 }
 
 func newTunGeneric(c *config.C, l *logrus.Logger, file *os.File, vpnNetworks []netip.Prefix) (*tun, error) {
 	t := &tun{
-		file:                      file,
+		ReadWriteCloser:           file,
 		fd:                        int(file.Fd()),
 		vpnNetworks:               vpnNetworks,
 		TXQueueLen:                c.GetInt("tun.tx_queue", 500),
@@ -164,9 +133,6 @@ func newTunGeneric(c *config.C, l *logrus.Logger, file *os.File, vpnNetworks []n
 		useSystemRoutesBufferSize: c.GetInt("tun.use_system_route_table_buffer_size", 0),
 		l:                         l,
 	}
-	if len(vpnNetworks) != 0 {
-		t.isV6 = vpnNetworks[0].Addr().Is6() //todo what about multi-IP?
-	}
 
 	err := t.reload(c, true)
 	if err != nil {
@@ -250,7 +216,7 @@ func (t *tun) reload(c *config.C, initial bool) error {
 	return nil
 }
 
-func (t *tun) NewMultiQueueReader() (TunDev, error) {
+func (t *tun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
 	fd, err := unix.Open("/dev/net/tun", os.O_RDWR, 0)
 	if err != nil {
 		return nil, err
@@ -263,17 +229,9 @@ func (t *tun) NewMultiQueueReader() (TunDev, error) {
 		return nil, err
 	}
 
-	vdev, err := vhostnet.NewDevice(
-		vhostnet.WithBackendFD(fd),
-		vhostnet.WithQueueSize(8192), //todo config
-	)
-	if err != nil {
-		return nil, err
-	}
+	file := os.NewFile(uintptr(fd), "/dev/net/tun")
 
-	t.vdev = append(t.vdev, vdev)
-
-	return t, nil
+	return file, nil
 }
 
 func (t *tun) RoutesFor(ip netip.Addr) routing.Gateways {
@@ -281,6 +239,29 @@ func (t *tun) RoutesFor(ip netip.Addr) routing.Gateways {
 	return r
 }
 
+func (t *tun) Write(b []byte) (int, error) {
+	var nn int
+	maximum := len(b)
+
+	for {
+		n, err := unix.Write(t.fd, b[nn:maximum])
+		if n > 0 {
+			nn += n
+		}
+		if nn == len(b) {
+			return nn, err
+		}
+
+		if err != nil {
+			return nn, err
+		}
+
+		if n == 0 {
+			return nn, io.ErrUnexpectedEOF
+		}
+	}
+}
+
 func (t *tun) deviceBytes() (o [16]byte) {
 	for i, c := range t.Device {
 		o[i] = byte(c)
@@ -693,14 +674,8 @@ func (t *tun) Close() error {
 		close(t.routeChan)
 	}
 
-	for _, v := range t.vdev {
-		if v != nil {
-			_ = v.Close()
-		}
-	}
-
-	if t.file != nil {
-		_ = t.file.Close()
+	if t.ReadWriteCloser != nil {
+		_ = t.ReadWriteCloser.Close()
 	}
 
 	if t.ioctlFd > 0 {
@@ -709,65 +684,3 @@ func (t *tun) Close() error {
 
 	return nil
 }
-
-func (t *tun) ReadMany(p []*packet.VirtIOPacket, q int) (int, error) {
-	n, err := t.vdev[q].ReceivePackets(p) //we are TXing
-	if err != nil {
-		return 0, err
-	}
-	return n, nil
-}
-
-func (t *tun) Write(b []byte) (int, error) {
-	maximum := len(b) //we are RXing
-
-	//todo garbagey
-	out := packet.NewOut()
-	x, err := t.AllocSeg(out, 0)
-	if err != nil {
-		return 0, err
-	}
-	copy(out.SegmentPayloads[x], b)
-	err = t.vdev[0].TransmitPacket(out, true)
-
-	if err != nil {
-		t.l.WithError(err).Error("Transmitting packet")
-		return 0, err
-	}
-	return maximum, nil
-}
-
-func (t *tun) AllocSeg(pkt *packet.OutPacket, q int) (int, error) {
-	idx, buf, err := t.vdev[q].GetPacketForTx()
-	if err != nil {
-		return 0, err
-	}
-	x := pkt.UseSegment(idx, buf, t.isV6)
-	return x, nil
-}
-
-func (t *tun) WriteOne(x *packet.OutPacket, kick bool, q int) (int, error) {
-	if err := t.vdev[q].TransmitPacket(x, kick); err != nil {
-		t.l.WithError(err).Error("Transmitting packet")
-		return 0, err
-	}
-	return 1, nil
-}
-
-func (t *tun) WriteMany(x []*packet.OutPacket, q int) (int, error) {
-	maximum := len(x) //we are RXing
-	if maximum == 0 {
-		return 0, nil
-	}
-
-	err := t.vdev[q].TransmitPackets(x)
-	if err != nil {
-		t.l.WithError(err).Error("Transmitting packet")
-		return 0, err
-	}
-	return maximum, nil
-}
-
-func (t *tun) RecycleRxSeg(pkt *packet.VirtIOPacket, kick bool, q int) error {
-	return t.vdev[q].ReceiveQueue.OfferDescriptorChains(pkt.Chains, kick)
-}

overlay/user.go

@@ -1,13 +1,11 @@
 package overlay
 
 import (
-	"fmt"
 	"io"
 	"net/netip"
 
 	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula/config"
-	"github.com/slackhq/nebula/packet"
 	"github.com/slackhq/nebula/routing"
 )
 
@@ -38,10 +36,6 @@ type UserDevice struct {
 	inboundWriter *io.PipeWriter
 }
 
-func (d *UserDevice) RecycleRxSeg(pkt *packet.VirtIOPacket, kick bool, q int) error {
-	return nil
-}
-
 func (d *UserDevice) Activate() error {
 	return nil
 }
@@ -52,7 +46,7 @@ func (d *UserDevice) RoutesFor(ip netip.Addr) routing.Gateways {
 	return routing.Gateways{routing.NewGateway(ip, 1)}
 }
 
-func (d *UserDevice) NewMultiQueueReader() (TunDev, error) {
+func (d *UserDevice) NewMultiQueueReader() (io.ReadWriteCloser, error) {
 	return d, nil
 }
 
@@ -71,19 +65,3 @@ func (d *UserDevice) Close() error {
 	d.outboundWriter.Close()
 	return nil
 }
-
-func (d *UserDevice) ReadMany(b []*packet.VirtIOPacket, _ int) (int, error) {
-	return d.Read(b[0].Payload)
-}
-
-func (d *UserDevice) AllocSeg(pkt *packet.OutPacket, q int) (int, error) {
-	return 0, fmt.Errorf("user: AllocSeg not implemented")
-}
-
-func (d *UserDevice) WriteOne(x *packet.OutPacket, kick bool, q int) (int, error) {
-	return 0, fmt.Errorf("user: WriteOne not implemented")
-}
-
-func (d *UserDevice) WriteMany(x []*packet.OutPacket, q int) (int, error) {
-	return 0, fmt.Errorf("user: WriteMany not implemented")
-}

overlay/vhost/README.md

@@ -1,23 +0,0 @@
-Significant portions of this code are derived from https://pkg.go.dev/github.com/hetznercloud/virtio-go
-
-MIT License
-
-Copyright (c) 2025 Hetzner Cloud GmbH
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.

overlay/vhost/doc.go

@@ -1,4 +0,0 @@
-// Package vhost implements the basic ioctl requests needed to interact with the
-// kernel-level virtio server that provides accelerated virtio devices for
-// networking and more.
-package vhost

overlay/vhost/ioctl.go

@@ -1,218 +0,0 @@
-package vhost
-
-import (
-	"fmt"
-	"unsafe"
-
-	"github.com/slackhq/nebula/overlay/virtqueue"
-	"github.com/slackhq/nebula/util/virtio"
-	"golang.org/x/sys/unix"
-)
-
-const (
-	// vhostIoctlGetFeatures can be used to retrieve the features supported by
-	// the vhost implementation in the kernel.
-	//
-	// Response payload: [virtio.Feature]
-	// Kernel name: VHOST_GET_FEATURES
-	vhostIoctlGetFeatures = 0x8008af00
-
-	// vhostIoctlSetFeatures can be used to communicate the features supported
-	// by this virtio implementation to the kernel.
-	//
-	// Request payload: [virtio.Feature]
-	// Kernel name: VHOST_SET_FEATURES
-	vhostIoctlSetFeatures = 0x4008af00
-
-	// vhostIoctlSetOwner can be used to set the current process as the
-	// exclusive owner of a control file descriptor.
-	//
-	// Request payload: none
-	// Kernel name: VHOST_SET_OWNER
-	vhostIoctlSetOwner = 0x0000af01
-
-	// vhostIoctlSetMemoryLayout can be used to set up or modify the memory
-	// layout which describes the IOTLB mappings in the kernel.
-	//
-	// Request payload: [MemoryLayout] with custom serialization
-	// Kernel name: VHOST_SET_MEM_TABLE
-	vhostIoctlSetMemoryLayout = 0x4008af03
-
-	// vhostIoctlSetQueueSize can be used to set the size of the virtqueue.
-	//
-	// Request payload: [QueueState]
-	// Kernel name: VHOST_SET_VRING_NUM
-	vhostIoctlSetQueueSize = 0x4008af10
-
-	// vhostIoctlSetQueueAddress can be used to set the addresses of the
-	// different parts of the virtqueue.
-	//
-	// Request payload: [QueueAddresses]
-	// Kernel name: VHOST_SET_VRING_ADDR
-	vhostIoctlSetQueueAddress = 0x4028af11
-
-	// vhostIoctlSetAvailableRingBase can be used to set the index of the next
-	// available ring entry the device will process.
-	//
-	// Request payload: [QueueState]
-	// Kernel name: VHOST_SET_VRING_BASE
-	vhostIoctlSetAvailableRingBase = 0x4008af12
-
-	// vhostIoctlSetQueueKickEventFD can be used to set the event file
-	// descriptor to signal the device when descriptor chains were added to the
-	// available ring.
-	//
-	// Request payload: [QueueFile]
-	// Kernel name: VHOST_SET_VRING_KICK
-	vhostIoctlSetQueueKickEventFD = 0x4008af20
-
-	// vhostIoctlSetQueueCallEventFD can be used to set the event file
-	// descriptor that gets signaled by the device when descriptor chains have
-	// been used by it.
-	//
-	// Request payload: [QueueFile]
-	// Kernel name: VHOST_SET_VRING_CALL
-	vhostIoctlSetQueueCallEventFD = 0x4008af21
-)
-
-// QueueState is an ioctl request payload that can hold a queue index and any
-// 32-bit number.
-//
-// Kernel name: vhost_vring_state
-type QueueState struct {
-	// QueueIndex is the index of the virtqueue.
-	QueueIndex uint32
-	// Num is any 32-bit number, depending on the request.
-	Num uint32
-}
-
-// QueueAddresses is an ioctl request payload that can hold the addresses of the
-// different parts of a virtqueue.
-//
-// Kernel name: vhost_vring_addr
-type QueueAddresses struct {
-	// QueueIndex is the index of the virtqueue.
-	QueueIndex uint32
-	// Flags that are not used in this implementation.
-	Flags uint32
-	// DescriptorTableAddress is the address of the descriptor table in user
-	// space memory. It must be 16-byte aligned.
-	DescriptorTableAddress uintptr
-	// UsedRingAddress is the address of the used ring in user space memory. It
-	// must be 4-byte aligned.
-	UsedRingAddress uintptr
-	// AvailableRingAddress is the address of the available ring in user space
-	// memory. It must be 2-byte aligned.
-	AvailableRingAddress uintptr
-	// LogAddress is used for an optional logging support, not supported by this
-	// implementation.
-	LogAddress uintptr
-}
-
-// QueueFile is an ioctl request payload that can hold a queue index and a file
-// descriptor.
-//
-// Kernel name: vhost_vring_file
-type QueueFile struct {
-	// QueueIndex is the index of the virtqueue.
-	QueueIndex uint32
-	// FD is the file descriptor of the file. Pass -1 to unbind from a file.
-	FD int32
-}
-
-// IoctlPtr is a copy of the similarly named unexported function from the Go
-// unix package. This is needed to do custom ioctl requests not supported by the
-// standard library.
-func IoctlPtr(fd int, req uint, arg unsafe.Pointer) error {
-	_, _, err := unix.Syscall(unix.SYS_IOCTL, uintptr(fd), uintptr(req), uintptr(arg))
-	if err != 0 {
-		return fmt.Errorf("ioctl request %d: %w", req, err)
-	}
-	return nil
-}
-
-// GetFeatures requests the supported feature bits from the virtio device
-// associated with the given control file descriptor.
-func GetFeatures(controlFD int) (virtio.Feature, error) {
-	var features virtio.Feature
-	if err := IoctlPtr(controlFD, vhostIoctlGetFeatures, unsafe.Pointer(&features)); err != nil {
-		return 0, fmt.Errorf("get features: %w", err)
-	}
-	return features, nil
-}
-
-// SetFeatures communicates the feature bits supported by this implementation
-// to the virtio device associated with the given control file descriptor.
-func SetFeatures(controlFD int, features virtio.Feature) error {
-	if err := IoctlPtr(controlFD, vhostIoctlSetFeatures, unsafe.Pointer(&features)); err != nil {
-		return fmt.Errorf("set features: %w", err)
-	}
-	return nil
-}
-
-// OwnControlFD sets the current process as the exclusive owner for the
-// given control file descriptor. This must be called before interacting with
-// the control file descriptor in any other way.
-func OwnControlFD(controlFD int) error {
-	if err := IoctlPtr(controlFD, vhostIoctlSetOwner, unsafe.Pointer(nil)); err != nil {
-		return fmt.Errorf("set control file descriptor owner: %w", err)
-	}
-	return nil
-}
-
-// SetMemoryLayout sets up or modifies the memory layout for the kernel-level
-// virtio device associated with the given control file descriptor.
-func SetMemoryLayout(controlFD int, layout MemoryLayout) error {
-	payload := layout.serializePayload()
-	if err := IoctlPtr(controlFD, vhostIoctlSetMemoryLayout, unsafe.Pointer(&payload[0])); err != nil {
-		return fmt.Errorf("set memory layout: %w", err)
-	}
-	return nil
-}
-
-// RegisterQueue registers a virtio queue with the kernel-level virtio server.
-// The virtqueue will be linked to the given control file descriptor and will
-// have the given index. The kernel will use this queue until the control file
-// descriptor is closed.
-func RegisterQueue(controlFD int, queueIndex uint32, queue *virtqueue.SplitQueue) error {
-	if err := IoctlPtr(controlFD, vhostIoctlSetQueueSize, unsafe.Pointer(&QueueState{
-		QueueIndex: queueIndex,
-		Num:        uint32(queue.Size()),
-	})); err != nil {
-		return fmt.Errorf("set queue size: %w", err)
-	}
-
-	if err := IoctlPtr(controlFD, vhostIoctlSetQueueAddress, unsafe.Pointer(&QueueAddresses{
-		QueueIndex:             queueIndex,
-		Flags:                  0,
-		DescriptorTableAddress: queue.DescriptorTable().Address(),
-		UsedRingAddress:        queue.UsedRing().Address(),
-		AvailableRingAddress:   queue.AvailableRing().Address(),
-		LogAddress:             0,
-	})); err != nil {
-		return fmt.Errorf("set queue addresses: %w", err)
-	}
-
-	if err := IoctlPtr(controlFD, vhostIoctlSetAvailableRingBase, unsafe.Pointer(&QueueState{
-		QueueIndex: queueIndex,
-		Num:        0,
-	})); err != nil {
-		return fmt.Errorf("set available ring base: %w", err)
-	}
-
-	if err := IoctlPtr(controlFD, vhostIoctlSetQueueKickEventFD, unsafe.Pointer(&QueueFile{
-		QueueIndex: queueIndex,
-		FD:         int32(queue.KickEventFD()),
-	})); err != nil {
-		return fmt.Errorf("set kick event file descriptor: %w", err)
-	}
-
-	if err := IoctlPtr(controlFD, vhostIoctlSetQueueCallEventFD, unsafe.Pointer(&QueueFile{
-		QueueIndex: queueIndex,
-		FD:         int32(queue.CallEventFD()),
-	})); err != nil {
-		return fmt.Errorf("set call event file descriptor: %w", err)
-	}
-
-	return nil
-}

overlay/vhost/ioctl_test.go

@@ -1,21 +0,0 @@
-package vhost_test
-
-import (
-	"testing"
-	"unsafe"
-
-	"github.com/slackhq/nebula/overlay/vhost"
-	"github.com/stretchr/testify/assert"
-)
-
-func TestQueueState_Size(t *testing.T) {
-	assert.EqualValues(t, 8, unsafe.Sizeof(vhost.QueueState{}))
-}
-
-func TestQueueAddresses_Size(t *testing.T) {
-	assert.EqualValues(t, 40, unsafe.Sizeof(vhost.QueueAddresses{}))
-}
-
-func TestQueueFile_Size(t *testing.T) {
-	assert.EqualValues(t, 8, unsafe.Sizeof(vhost.QueueFile{}))
-}

overlay/vhost/memory.go

@@ -1,73 +0,0 @@
-package vhost
-
-import (
-	"encoding/binary"
-	"fmt"
-	"unsafe"
-
-	"github.com/slackhq/nebula/overlay/virtqueue"
-)
-
-// MemoryRegion describes a region of userspace memory which is being made
-// accessible to a vhost device.
-//
-// Kernel name: vhost_memory_region
-type MemoryRegion struct {
-	// GuestPhysicalAddress is the physical address of the memory region within
-	// the guest, when virtualization is used. When no virtualization is used,
-	// this should be the same as UserspaceAddress.
-	GuestPhysicalAddress uintptr
-	// Size is the size of the memory region.
-	Size uint64
-	// UserspaceAddress is the virtual address in the userspace of the host
-	// where the memory region can be found.
-	UserspaceAddress uintptr
-	// Padding and room for flags. Currently unused.
-	_ uint64
-}
-
-// MemoryLayout is a list of [MemoryRegion]s.
-type MemoryLayout []MemoryRegion
-
-// NewMemoryLayoutForQueues returns a new [MemoryLayout] that describes the
-// memory pages used by the descriptor tables of the given queues.
-func NewMemoryLayoutForQueues(queues []*virtqueue.SplitQueue) MemoryLayout {
-	regions := make([]MemoryRegion, 0)
-	for _, queue := range queues {
-		for address, size := range queue.DescriptorTable().BufferAddresses() {
-			regions = append(regions, MemoryRegion{
-				// There is no virtualization in play here, so the guest address
-				// is the same as in the host's userspace.
-				GuestPhysicalAddress: address,
-				Size:                 uint64(size),
-				UserspaceAddress:     address,
-			})
-		}
-	}
-	return regions
-}
-
-// serializePayload serializes the list of memory regions into a format that is
-// compatible to the vhost_memory kernel struct. The returned byte slice can be
-// used as a payload for the vhostIoctlSetMemoryLayout ioctl.
-func (regions MemoryLayout) serializePayload() []byte {
-	regionCount := len(regions)
-	regionSize := int(unsafe.Sizeof(MemoryRegion{}))
-	payload := make([]byte, 8+regionCount*regionSize)
-
-	// The first 32 bits contain the number of memory regions. The following 32
-	// bits are padding.
-	binary.LittleEndian.PutUint32(payload[0:4], uint32(regionCount))
-
-	if regionCount > 0 {
-		// The underlying byte array of the slice should already have the correct
-		// format, so just copy that.
-		copied := copy(payload[8:], unsafe.Slice((*byte)(unsafe.Pointer(&regions[0])), regionCount*regionSize))
-		if copied != regionCount*regionSize {
-			panic(fmt.Sprintf("copied only %d bytes of the memory regions, but expected %d",
-				copied, regionCount*regionSize))
-		}
-	}
-
-	return payload
-}

overlay/vhost/memory_internal_test.go

@@ -1,42 +0,0 @@
-package vhost
-
-import (
-	"testing"
-	"unsafe"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestMemoryRegion_Size(t *testing.T) {
-	assert.EqualValues(t, 32, unsafe.Sizeof(MemoryRegion{}))
-}
-
-func TestMemoryLayout_SerializePayload(t *testing.T) {
-	layout := MemoryLayout([]MemoryRegion{
-		{
-			GuestPhysicalAddress: 42,
-			Size:                 100,
-			UserspaceAddress:     142,
-		}, {
-			GuestPhysicalAddress: 99,
-			Size:                 100,
-			UserspaceAddress:     99,
-		},
-	})
-	payload := layout.serializePayload()
-
-	assert.Equal(t, []byte{
-		0x02, 0x00, 0x00, 0x00, // nregions
-		0x00, 0x00, 0x00, 0x00, // padding
-		// region 0
-		0x2a, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // guest_phys_addr
-		0x64, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // memory_size
-		0x8e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // userspace_addr
-		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // flags_padding
-		// region 1
-		0x63, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // guest_phys_addr
-		0x64, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // memory_size
-		0x63, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // userspace_addr
-		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // flags_padding
-	}, payload)
-}

overlay/vhostnet/README.md

@@ -1,23 +0,0 @@
-Significant portions of this code are derived from https://pkg.go.dev/github.com/hetznercloud/virtio-go
-
-MIT License
-
-Copyright (c) 2025 Hetzner Cloud GmbH
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.

overlay/vhostnet/device.go

@@ -1,427 +0,0 @@
-package vhostnet
-
-import (
-	"context"
-	"errors"
-	"fmt"
-	"os"
-	"runtime"
-
-	"github.com/slackhq/nebula/overlay/vhost"
-	"github.com/slackhq/nebula/overlay/virtqueue"
-	"github.com/slackhq/nebula/packet"
-	"github.com/slackhq/nebula/util/virtio"
-	"golang.org/x/sys/unix"
-)
-
-// ErrDeviceClosed is returned when the [Device] is closed while operations are
-// still running.
-var ErrDeviceClosed = errors.New("device was closed")
-
-// The indexes for the receive and transmit queues.
-const (
-	receiveQueueIndex  = 0
-	transmitQueueIndex = 1
-)
-
-// Device represents a vhost networking device within the kernel-level virtio
-// implementation and provides methods to interact with it.
-type Device struct {
-	initialized bool
-	controlFD   int
-
-	fullTable     bool
-	ReceiveQueue  *virtqueue.SplitQueue
-	TransmitQueue *virtqueue.SplitQueue
-}
-
-// NewDevice initializes a new vhost networking device within the
-// kernel-level virtio implementation, sets up the virtqueues and returns a
-// [Device] instance that can be used to communicate with that vhost device.
-//
-// There are multiple options that can be passed to this constructor to
-// influence device creation:
-//   - [WithQueueSize]
-//   - [WithBackendFD]
-//   - [WithBackendDevice]
-//
-// Remember to call [Device.Close] after use to free up resources.
-func NewDevice(options ...Option) (*Device, error) {
-	var err error
-	opts := optionDefaults
-	opts.apply(options)
-	if err = opts.validate(); err != nil {
-		return nil, fmt.Errorf("invalid options: %w", err)
-	}
-
-	dev := Device{
-		controlFD: -1,
-	}
-
-	// Clean up a partially initialized device when something fails.
-	defer func() {
-		if err != nil {
-			_ = dev.Close()
-		}
-	}()
-
-	// Retrieve a new control file descriptor. This will be used to configure
-	// the vhost networking device in the kernel.
-	dev.controlFD, err = unix.Open("/dev/vhost-net", os.O_RDWR, 0666)
-	if err != nil {
-		return nil, fmt.Errorf("get control file descriptor: %w", err)
-	}
-	if err = vhost.OwnControlFD(dev.controlFD); err != nil {
-		return nil, fmt.Errorf("own control file descriptor: %w", err)
-	}
-
-	// Advertise the supported features. This isn't much for now.
-	// TODO: Add feature options and implement proper feature negotiation.
-	getFeatures, err := vhost.GetFeatures(dev.controlFD) //0x1033D008000 but why
-	if err != nil {
-		return nil, fmt.Errorf("get features: %w", err)
-	}
-	if getFeatures == 0 {
-
-	}
-	//const funky = virtio.Feature(1 << 27)
-	//features := virtio.FeatureVersion1 | funky // | todo virtio.FeatureNetMergeRXBuffers
-	features := virtio.FeatureVersion1 | virtio.FeatureNetMergeRXBuffers
-	if err = vhost.SetFeatures(dev.controlFD, features); err != nil {
-		return nil, fmt.Errorf("set features: %w", err)
-	}
-
-	itemSize := os.Getpagesize() * 4 //todo config
-
-	// Initialize and register the queues needed for the networking device.
-	if dev.ReceiveQueue, err = createQueue(dev.controlFD, receiveQueueIndex, opts.queueSize, itemSize); err != nil {
-		return nil, fmt.Errorf("create receive queue: %w", err)
-	}
-	if dev.TransmitQueue, err = createQueue(dev.controlFD, transmitQueueIndex, opts.queueSize, itemSize); err != nil {
-		return nil, fmt.Errorf("create transmit queue: %w", err)
-	}
-
-	// Set up memory mappings for all buffers used by the queues. This has to
-	// happen before a backend for the queues can be registered.
-	memoryLayout := vhost.NewMemoryLayoutForQueues(
-		[]*virtqueue.SplitQueue{dev.ReceiveQueue, dev.TransmitQueue},
-	)
-	if err = vhost.SetMemoryLayout(dev.controlFD, memoryLayout); err != nil {
-		return nil, fmt.Errorf("setup memory layout: %w", err)
-	}
-
-	// Set the queue backends. This activates the queues within the kernel.
-	if err = SetQueueBackend(dev.controlFD, receiveQueueIndex, opts.backendFD); err != nil {
-		return nil, fmt.Errorf("set receive queue backend: %w", err)
-	}
-	if err = SetQueueBackend(dev.controlFD, transmitQueueIndex, opts.backendFD); err != nil {
-		return nil, fmt.Errorf("set transmit queue backend: %w", err)
-	}
-
-	// Fully populate the receive queue with available buffers which the device
-	// can write new packets into.
-	if err = dev.refillReceiveQueue(); err != nil {
-		return nil, fmt.Errorf("refill receive queue: %w", err)
-	}
-	if err = dev.refillTransmitQueue(); err != nil {
-		return nil, fmt.Errorf("refill receive queue: %w", err)
-	}
-
-	dev.initialized = true
-
-	// Make sure to clean up even when the device gets garbage collected without
-	// Close being called first.
-	devPtr := &dev
-	runtime.SetFinalizer(devPtr, (*Device).Close)
-
-	return devPtr, nil
-}
-
-// refillReceiveQueue offers as many new device-writable buffers to the device
-// as the queue can fit. The device will then use these to write received
-// packets.
-func (dev *Device) refillReceiveQueue() error {
-	for {
-		_, err := dev.ReceiveQueue.OfferInDescriptorChains()
-		if err != nil {
-			if errors.Is(err, virtqueue.ErrNotEnoughFreeDescriptors) {
-				// Queue is full, job is done.
-				return nil
-			}
-			return fmt.Errorf("offer descriptor chain: %w", err)
-		}
-	}
-}
-
-func (dev *Device) refillTransmitQueue() error {
-	//for {
-	//	desc, err := dev.TransmitQueue.DescriptorTable().CreateDescriptorForOutputs()
-	//	if err != nil {
-	//		if errors.Is(err, virtqueue.ErrNotEnoughFreeDescriptors) {
-	//			// Queue is full, job is done.
-	//			return nil
-	//		}
-	//		return fmt.Errorf("offer descriptor chain: %w", err)
-	//	} else {
-	//		dev.TransmitQueue.UsedRing().InitOfferSingle(desc, 0)
-	//	}
-	//}
-	return nil
-}
-
-// Close cleans up the vhost networking device within the kernel and releases
-// all resources used for it.
-// The implementation will try to release as many resources as possible and
-// collect potential errors before returning them.
-func (dev *Device) Close() error {
-	dev.initialized = false
-
-	// Closing the control file descriptor will unregister all queues from the
-	// kernel.
-	if dev.controlFD >= 0 {
-		if err := unix.Close(dev.controlFD); err != nil {
-			// Return an error and do not continue, because the memory used for
-			// the queues should not be released before they were unregistered
-			// from the kernel.
-			return fmt.Errorf("close control file descriptor: %w", err)
-		}
-		dev.controlFD = -1
-	}
-
-	var errs []error
-
-	if dev.ReceiveQueue != nil {
-		if err := dev.ReceiveQueue.Close(); err == nil {
-			dev.ReceiveQueue = nil
-		} else {
-			errs = append(errs, fmt.Errorf("close receive queue: %w", err))
-		}
-	}
-
-	if dev.TransmitQueue != nil {
-		if err := dev.TransmitQueue.Close(); err == nil {
-			dev.TransmitQueue = nil
-		} else {
-			errs = append(errs, fmt.Errorf("close transmit queue: %w", err))
-		}
-	}
-
-	if len(errs) == 0 {
-		// Everything was cleaned up. No need to run the finalizer anymore.
-		runtime.SetFinalizer(dev, nil)
-	}
-
-	return errors.Join(errs...)
-}
-
-// ensureInitialized is used as a guard to prevent methods to be called on an
-// uninitialized instance.
-func (dev *Device) ensureInitialized() {
-	if !dev.initialized {
-		panic("device is not initialized")
-	}
-}
-
-// createQueue creates a new virtqueue and registers it with the vhost device
-// using the given index.
-func createQueue(controlFD int, queueIndex int, queueSize int, itemSize int) (*virtqueue.SplitQueue, error) {
-	var (
-		queue *virtqueue.SplitQueue
-		err   error
-	)
-	if queue, err = virtqueue.NewSplitQueue(queueSize, itemSize); err != nil {
-		return nil, fmt.Errorf("create virtqueue: %w", err)
-	}
-	if err = vhost.RegisterQueue(controlFD, uint32(queueIndex), queue); err != nil {
-		return nil, fmt.Errorf("register virtqueue with index %d: %w", queueIndex, err)
-	}
-	return queue, nil
-}
-
-// truncateBuffers returns a new list of buffers whose combined length matches
-// exactly the specified length. When the specified length exceeds the length of
-// the buffers, this is an error. When it is smaller, the buffer list will be
-// truncated accordingly.
-func truncateBuffers(buffers [][]byte, length int) (out [][]byte) {
-	for _, buffer := range buffers {
-		if length < len(buffer) {
-			out = append(out, buffer[:length])
-			return
-		}
-		out = append(out, buffer)
-		length -= len(buffer)
-	}
-	if length > 0 {
-		panic("length exceeds the combined length of all buffers")
-	}
-	return
-}
-
-func (dev *Device) GetPacketForTx() (uint16, []byte, error) {
-	var err error
-	var idx uint16
-	if !dev.fullTable {
-
-		idx, err = dev.TransmitQueue.DescriptorTable().CreateDescriptorForOutputs()
-		if err == virtqueue.ErrNotEnoughFreeDescriptors {
-			dev.fullTable = true
-			idx, err = dev.TransmitQueue.TakeSingle(context.TODO())
-		}
-	} else {
-		idx, err = dev.TransmitQueue.TakeSingle(context.TODO())
-	}
-	if err != nil {
-		return 0, nil, fmt.Errorf("transmit queue: %w", err)
-	}
-	buf, err := dev.TransmitQueue.GetDescriptorItem(idx)
-	if err != nil {
-		return 0, nil, fmt.Errorf("get descriptor chain: %w", err)
-	}
-	return idx, buf, nil
-}
-
-func (dev *Device) TransmitPacket(pkt *packet.OutPacket, kick bool) error {
-	if len(pkt.SegmentIDs) == 0 {
-		return nil
-	}
-	for idx := range pkt.SegmentIDs {
-		segmentID := pkt.SegmentIDs[idx]
-		dev.TransmitQueue.SetDescSize(segmentID, len(pkt.Segments[idx]))
-	}
-	err := dev.TransmitQueue.OfferDescriptorChains(pkt.SegmentIDs, false)
-	if err != nil {
-		return fmt.Errorf("offer descriptor chains: %w", err)
-	}
-	pkt.Reset()
-	if kick {
-		if err := dev.TransmitQueue.Kick(); err != nil {
-			return err
-		}
-	}
-
-	return nil
-}
-
-func (dev *Device) TransmitPackets(pkts []*packet.OutPacket) error {
-	if len(pkts) == 0 {
-		return nil
-	}
-
-	for i := range pkts {
-		if err := dev.TransmitPacket(pkts[i], false); err != nil {
-			return err
-		}
-	}
-	if err := dev.TransmitQueue.Kick(); err != nil {
-		return err
-	}
-	return nil
-}
-
-// TODO: Make above methods cancelable by taking a context.Context argument?
-// TODO: Implement zero-copy variants to transmit and receive packets?
-
-// processChains processes as many chains as needed to create one packet. The number of processed chains is returned.
-func (dev *Device) processChains(pkt *packet.VirtIOPacket, chains []virtqueue.UsedElement) (int, error) {
-	//read first element to see how many descriptors we need:
-	pkt.Reset()
-
-	err := dev.ReceiveQueue.GetDescriptorInbuffers(uint16(chains[0].DescriptorIndex), &pkt.ChainRefs)
-	if err != nil {
-		return 0, fmt.Errorf("get descriptor chain: %w", err)
-	}
-	if len(pkt.ChainRefs) == 0 {
-		return 1, nil
-	}
-
-	// The specification requires that the first descriptor chain starts
-	// with a virtio-net header. It is not clear, whether it is also
-	// required to be fully contained in the first buffer of that
-	// descriptor chain, but it is reasonable to assume that this is
-	// always the case.
-	// The decode method already does the buffer length check.
-	if err = pkt.Header.Decode(pkt.ChainRefs[0][0:]); err != nil {
-		// The device misbehaved. There is no way we can gracefully
-		// recover from this, because we don't know how many of the
-		// following descriptor chains belong to this packet.
-		return 0, fmt.Errorf("decode vnethdr: %w", err)
-	}
-
-	//we have the header now: what do we need to do?
-	if int(pkt.Header.NumBuffers) > len(chains) {
-		return 0, fmt.Errorf("number of buffers is greater than number of chains %d", len(chains))
-	}
-	if int(pkt.Header.NumBuffers) != 1 {
-		return 0, fmt.Errorf("too smol-brain to handle more than one chain right now: %d chains", len(chains))
-	}
-	if chains[0].Length > 16000 {
-		//todo!
-		return 1, fmt.Errorf("too big packet length: %d", chains[0].Length)
-	}
-
-	//shift the buffer out of out:
-	pkt.Payload = pkt.ChainRefs[0][virtio.NetHdrSize:chains[0].Length]
-	pkt.Chains = append(pkt.Chains, uint16(chains[0].DescriptorIndex))
-	return 1, nil
-
-	//cursor := n - virtio.NetHdrSize
-	//
-	//if uint32(n) >= chains[0].Length && pkt.Header.NumBuffers == 1 {
-	//	pkt.Payload = pkt.Payload[:chains[0].Length-virtio.NetHdrSize]
-	//	return 1, nil
-	//}
-	//
-	//i := 1
-	//// we used chain 0 already
-	//for i = 1; i < len(chains); i++ {
-	//	n, err = dev.ReceiveQueue.GetDescriptorChainContents(uint16(chains[i].DescriptorIndex), pkt.Payload[cursor:], int(chains[i].Length))
-	//	if err != nil {
-	//		// When this fails we may miss to free some descriptor chains. We
-	//		// could try to mitigate this by deferring the freeing somehow, but
-	//		// it's not worth the hassle. When this method fails, the queue will
-	//		// be in a broken state anyway.
-	//		return i, fmt.Errorf("get descriptor chain: %w", err)
-	//	}
-	//	cursor += n
-	//}
-	////todo this has to be wrong
-	//pkt.Payload = pkt.Payload[:cursor]
-	//return i, nil
-}
-
-func (dev *Device) ReceivePackets(out []*packet.VirtIOPacket) (int, error) {
-	//todo optimize?
-	var chains []virtqueue.UsedElement
-	var err error
-	//if len(dev.extraRx) == 0 {
-	chains, err = dev.ReceiveQueue.BlockAndGetHeadsCapped(context.TODO(), len(out))
-	if err != nil {
-		return 0, err
-	}
-	if len(chains) == 0 {
-		return 0, nil
-	}
-	//} else {
-	//	chains = dev.extraRx
-	//}
-
-	numPackets := 0
-	chainsIdx := 0
-	for numPackets = 0; chainsIdx < len(chains); numPackets++ {
-		if numPackets >= len(out) {
-			return numPackets, fmt.Errorf("dropping %d packets, no room", len(chains)-numPackets)
-		}
-		numChains, err := dev.processChains(out[numPackets], chains[chainsIdx:])
-		if err != nil {
-			return 0, err
-		}
-		chainsIdx += numChains
-	}
-
-	// Now that we have copied all buffers, we can recycle the used descriptor chains
-	//if err = dev.ReceiveQueue.OfferDescriptorChains(chains); err != nil {
-	//	return 0, err
-	//}
-
-	return numPackets, nil
-}

overlay/vhostnet/doc.go

@@ -1,3 +0,0 @@
-// Package vhostnet implements methods to initialize vhost networking devices
-// within the kernel-level virtio implementation and communicate with them.
-package vhostnet

overlay/vhostnet/ioctl.go

@@ -1,31 +0,0 @@
-package vhostnet
-
-import (
-	"fmt"
-	"unsafe"
-
-	"github.com/slackhq/nebula/overlay/vhost"
-)
-
-const (
-	// vhostNetIoctlSetBackend can be used to attach a virtqueue to a RAW socket
-	// or TAP device.
-	//
-	// Request payload: [vhost.QueueFile]
-	// Kernel name: VHOST_NET_SET_BACKEND
-	vhostNetIoctlSetBackend = 0x4008af30
-)
-
-// SetQueueBackend attaches a virtqueue of the vhost networking device
-// described by controlFD to the given backend file descriptor.
-// The backend file descriptor can either be a RAW socket or a TAP device. When
-// it is -1, the queue will be detached.
-func SetQueueBackend(controlFD int, queueIndex uint32, backendFD int) error {
-	if err := vhost.IoctlPtr(controlFD, vhostNetIoctlSetBackend, unsafe.Pointer(&vhost.QueueFile{
-		QueueIndex: queueIndex,
-		FD:         int32(backendFD),
-	})); err != nil {
-		return fmt.Errorf("set queue backend file descriptor: %w", err)
-	}
-	return nil
-}

overlay/vhostnet/options.go

@@ -1,69 +0,0 @@
-package vhostnet
-
-import (
-	"errors"
-
-	"github.com/slackhq/nebula/overlay/virtqueue"
-)
-
-type optionValues struct {
-	queueSize int
-	backendFD int
-}
-
-func (o *optionValues) apply(options []Option) {
-	for _, option := range options {
-		option(o)
-	}
-}
-
-func (o *optionValues) validate() error {
-	if o.queueSize == -1 {
-		return errors.New("queue size is required")
-	}
-	if err := virtqueue.CheckQueueSize(o.queueSize); err != nil {
-		return err
-	}
-	if o.backendFD == -1 {
-		return errors.New("backend file descriptor is required")
-	}
-	return nil
-}
-
-var optionDefaults = optionValues{
-	// Required.
-	queueSize: -1,
-	// Required.
-	backendFD: -1,
-}
-
-// Option can be passed to [NewDevice] to influence device creation.
-type Option func(*optionValues)
-
-// WithQueueSize returns an [Option] that sets the size of the TX and RX queues
-// that are to be created for the device. It specifies the number of
-// entries/buffers each queue can hold. This also affects the memory
-// consumption.
-// This is required and must be an integer from 1 to 32768 that is also a power
-// of 2.
-func WithQueueSize(queueSize int) Option {
-	return func(o *optionValues) { o.queueSize = queueSize }
-}
-
-// WithBackendFD returns an [Option] that sets the file descriptor of the
-// backend that will be used for the queues of the device. The device will write
-// and read packets to/from that backend. The file descriptor can either be of a
-// RAW socket or TUN/TAP device.
-// Either this or [WithBackendDevice] is required.
-func WithBackendFD(backendFD int) Option {
-	return func(o *optionValues) { o.backendFD = backendFD }
-}
-
-//// WithBackendDevice returns an [Option] that sets the given TAP device as the
-//// backend that will be used for the queues of the device. The device will
-//// write and read packets to/from that backend. The TAP device should have been
-//// created with the [tuntap.WithVirtioNetHdr] option enabled.
-//// Either this or [WithBackendFD] is required.
-//func WithBackendDevice(dev *tuntap.Device) Option {
-//	return func(o *optionValues) { o.backendFD = int(dev.File().Fd()) }
-//}

overlay/virtqueue/README.md

@@ -1,23 +0,0 @@
-Significant portions of this code are derived from https://pkg.go.dev/github.com/hetznercloud/virtio-go
-
-MIT License
-
-Copyright (c) 2025 Hetzner Cloud GmbH
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.

overlay/virtqueue/available_ring.go

@@ -1,140 +0,0 @@
-package virtqueue
-
-import (
-	"fmt"
-	"unsafe"
-)
-
-// availableRingFlag is a flag that describes an [AvailableRing].
-type availableRingFlag uint16
-
-const (
-	// availableRingFlagNoInterrupt is used by the guest to advise the host to
-	// not interrupt it when consuming a buffer. It's unreliable, so it's simply
-	// an optimization.
-	availableRingFlagNoInterrupt availableRingFlag = 1 << iota
-)
-
-// availableRingSize is the number of bytes needed to store an [AvailableRing]
-// with the given queue size in memory.
-func availableRingSize(queueSize int) int {
-	return 6 + 2*queueSize
-}
-
-// availableRingAlignment is the minimum alignment of an [AvailableRing]
-// in memory, as required by the virtio spec.
-const availableRingAlignment = 2
-
-// AvailableRing is used by the driver to offer descriptor chains to the device.
-// Each ring entry refers to the head of a descriptor chain. It is only written
-// to by the driver and read by the device.
-//
-// Because the size of the ring depends on the queue size, we cannot define a
-// Go struct with a static size that maps to the memory of the ring. Instead,
-// this struct only contains pointers to the corresponding memory areas.
-type AvailableRing struct {
-	initialized bool
-
-	// flags that describe this ring.
-	flags *availableRingFlag
-	// ringIndex indicates where the driver would put the next entry into the
-	// ring (modulo the queue size).
-	ringIndex *uint16
-	// ring references buffers using the index of the head of the descriptor
-	// chain in the [DescriptorTable]. It wraps around at queue size.
-	ring []uint16
-	// usedEvent is not used by this implementation, but we reserve it anyway to
-	// avoid issues in case a device may try to access it, contrary to the
-	// virtio specification.
-	usedEvent *uint16
-}
-
-// newAvailableRing creates an available ring that uses the given underlying
-// memory. The length of the memory slice must match the size needed for the
-// ring (see [availableRingSize]) for the given queue size.
-func newAvailableRing(queueSize int, mem []byte) *AvailableRing {
-	ringSize := availableRingSize(queueSize)
-	if len(mem) != ringSize {
-		panic(fmt.Sprintf("memory size (%v) does not match required size "+
-			"for available ring: %v", len(mem), ringSize))
-	}
-
-	return &AvailableRing{
-		initialized: true,
-		flags:       (*availableRingFlag)(unsafe.Pointer(&mem[0])),
-		ringIndex:   (*uint16)(unsafe.Pointer(&mem[2])),
-		ring:        unsafe.Slice((*uint16)(unsafe.Pointer(&mem[4])), queueSize),
-		usedEvent:   (*uint16)(unsafe.Pointer(&mem[ringSize-2])),
-	}
-}
-
-// Address returns the pointer to the beginning of the ring in memory.
-// Do not modify the memory directly to not interfere with this implementation.
-func (r *AvailableRing) Address() uintptr {
-	if !r.initialized {
-		panic("available ring is not initialized")
-	}
-	return uintptr(unsafe.Pointer(r.flags))
-}
-
-// offer adds the given descriptor chain heads to the available ring and
-// advances the ring index accordingly to make the device process the new
-// descriptor chains.
-func (r *AvailableRing) offerElements(chains []UsedElement) {
-	//always called under lock
-	//r.mu.Lock()
-	//defer r.mu.Unlock()
-
-	// Add descriptor chain heads to the ring.
-	for offset, x := range chains {
-		// The 16-bit ring index may overflow. This is expected and is not an
-		// issue because the size of the ring array (which equals the queue
-		// size) is always a power of 2 and smaller than the highest possible
-		// 16-bit value.
-		insertIndex := int(*r.ringIndex+uint16(offset)) % len(r.ring)
-		r.ring[insertIndex] = x.GetHead()
-	}
-
-	// Increase the ring index by the number of descriptor chains added to the
-	// ring.
-	*r.ringIndex += uint16(len(chains))
-}
-
-func (r *AvailableRing) offer(chains []uint16) {
-	//always called under lock
-	//r.mu.Lock()
-	//defer r.mu.Unlock()
-
-	// Add descriptor chain heads to the ring.
-	for offset, x := range chains {
-		// The 16-bit ring index may overflow. This is expected and is not an
-		// issue because the size of the ring array (which equals the queue
-		// size) is always a power of 2 and smaller than the highest possible
-		// 16-bit value.
-		insertIndex := int(*r.ringIndex+uint16(offset)) % len(r.ring)
-		r.ring[insertIndex] = x
-	}
-
-	// Increase the ring index by the number of descriptor chains added to the
-	// ring.
-	*r.ringIndex += uint16(len(chains))
-}
-
-func (r *AvailableRing) offerSingle(x uint16) {
-	//always called under lock
-	//r.mu.Lock()
-	//defer r.mu.Unlock()
-
-	offset := 0
-	// Add descriptor chain heads to the ring.
-
-	// The 16-bit ring index may overflow. This is expected and is not an
-	// issue because the size of the ring array (which equals the queue
-	// size) is always a power of 2 and smaller than the highest possible
-	// 16-bit value.
-	insertIndex := int(*r.ringIndex+uint16(offset)) % len(r.ring)
-	r.ring[insertIndex] = x
-
-	// Increase the ring index by the number of descriptor chains added to the ring.
-	*r.ringIndex += 1
-}

overlay/virtqueue/available_ring_internal_test.go

@@ -1,71 +0,0 @@
-package virtqueue
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestAvailableRing_MemoryLayout(t *testing.T) {
-	const queueSize = 2
-
-	memory := make([]byte, availableRingSize(queueSize))
-	r := newAvailableRing(queueSize, memory)
-
-	*r.flags = 0x01ff
-	*r.ringIndex = 1
-	r.ring[0] = 0x1234
-	r.ring[1] = 0x5678
-
-	assert.Equal(t, []byte{
-		0xff, 0x01,
-		0x01, 0x00,
-		0x34, 0x12,
-		0x78, 0x56,
-		0x00, 0x00,
-	}, memory)
-}
-
-func TestAvailableRing_Offer(t *testing.T) {
-	const queueSize = 8
-
-	chainHeads := []uint16{42, 33, 69}
-
-	tests := []struct {
-		name              string
-		startRingIndex    uint16
-		expectedRingIndex uint16
-		expectedRing      []uint16
-	}{
-		{
-			name:              "no overflow",
-			startRingIndex:    0,
-			expectedRingIndex: 3,
-			expectedRing:      []uint16{42, 33, 69, 0, 0, 0, 0, 0},
-		},
-		{
-			name:              "ring overflow",
-			startRingIndex:    6,
-			expectedRingIndex: 9,
-			expectedRing:      []uint16{69, 0, 0, 0, 0, 0, 42, 33},
-		},
-		{
-			name:              "index overflow",
-			startRingIndex:    65535,
-			expectedRingIndex: 2,
-			expectedRing:      []uint16{33, 69, 0, 0, 0, 0, 0, 42},
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			memory := make([]byte, availableRingSize(queueSize))
-			r := newAvailableRing(queueSize, memory)
-			*r.ringIndex = tt.startRingIndex
-
-			r.offer(chainHeads)
-
-			assert.Equal(t, tt.expectedRingIndex, *r.ringIndex)
-			assert.Equal(t, tt.expectedRing, r.ring)
-		})
-	}
-}

overlay/virtqueue/descriptor.go

@@ -1,43 +0,0 @@
-package virtqueue
-
-// descriptorFlag is a flag that describes a [Descriptor].
-type descriptorFlag uint16
-
-const (
-	// descriptorFlagHasNext marks a descriptor chain as continuing via the next
-	// field.
-	descriptorFlagHasNext descriptorFlag = 1 << iota
-	// descriptorFlagWritable marks a buffer as device write-only (otherwise
-	// device read-only).
-	descriptorFlagWritable
-	// descriptorFlagIndirect means the buffer contains a list of buffer
-	// descriptors to provide an additional layer of indirection.
-	// Only allowed when the [virtio.FeatureIndirectDescriptors] feature was
-	// negotiated.
-	descriptorFlagIndirect
-)
-
-// descriptorSize is the number of bytes needed to store a [Descriptor] in
-// memory.
-const descriptorSize = 16
-
-// Descriptor describes (a part of) a buffer which is either read-only for the
-// device or write-only for the device (depending on [descriptorFlagWritable]).
-// Multiple descriptors can be chained to produce a "descriptor chain" that can
-// contain both device-readable and device-writable buffers. Device-readable
-// descriptors always come first in a chain. A single, large buffer may be
-// split up by chaining multiple similar descriptors that reference different
-// memory pages. This is required, because buffers may exceed a single page size
-// and the memory accessed by the device is expected to be continuous.
-type Descriptor struct {
-	// address is the address to the continuous memory holding the data for this
-	// descriptor.
-	address uintptr
-	// length is the amount of bytes stored at address.
-	length uint32
-	// flags that describe this descriptor.
-	flags descriptorFlag
-	// next contains the index of the next descriptor continuing this descriptor
-	// chain when the [descriptorFlagHasNext] flag is set.
-	next uint16
-}

overlay/virtqueue/descriptor_internal_test.go

@@ -1,12 +0,0 @@
-package virtqueue
-
-import (
-	"testing"
-	"unsafe"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestDescriptor_Size(t *testing.T) {
-	assert.EqualValues(t, descriptorSize, unsafe.Sizeof(Descriptor{}))
-}

overlay/virtqueue/descriptor_table.go

@@ -1,641 +0,0 @@
-package virtqueue
-
-import (
-	"errors"
-	"fmt"
-	"math"
-	"unsafe"
-
-	"golang.org/x/sys/unix"
-)
-
-var (
-	// ErrDescriptorChainEmpty is returned when a descriptor chain would contain
-	// no buffers, which is not allowed.
-	ErrDescriptorChainEmpty = errors.New("empty descriptor chains are not allowed")
-
-	// ErrNotEnoughFreeDescriptors is returned when the free descriptors are
-	// exhausted, meaning that the queue is full.
-	ErrNotEnoughFreeDescriptors = errors.New("not enough free descriptors, queue is full")
-
-	// ErrInvalidDescriptorChain is returned when a descriptor chain is not
-	// valid for a given operation.
-	ErrInvalidDescriptorChain = errors.New("invalid descriptor chain")
-)
-
-// noFreeHead is used to mark when all descriptors are in use and we have no
-// free chain. This value is impossible to occur as an index naturally, because
-// it exceeds the maximum queue size.
-const noFreeHead = uint16(math.MaxUint16)
-
-// descriptorTableSize is the number of bytes needed to store a
-// [DescriptorTable] with the given queue size in memory.
-func descriptorTableSize(queueSize int) int {
-	return descriptorSize * queueSize
-}
-
-// descriptorTableAlignment is the minimum alignment of a [DescriptorTable]
-// in memory, as required by the virtio spec.
-const descriptorTableAlignment = 16
-
-// DescriptorTable is a table that holds [Descriptor]s, addressed via their
-// index in the slice.
-type DescriptorTable struct {
-	descriptors []Descriptor
-
-	// freeHeadIndex is the index of the head of the descriptor chain which
-	// contains all currently unused descriptors. When all descriptors are in
-	// use, this has the special value of noFreeHead.
-	freeHeadIndex uint16
-	// freeNum tracks the number of descriptors which are currently not in use.
-	freeNum uint16
-
-	bufferBase uintptr
-	bufferSize int
-	itemSize   int
-}
-
-// newDescriptorTable creates a descriptor table that uses the given underlying
-// memory. The Length of the memory slice must match the size needed for the
-// descriptor table (see [descriptorTableSize]) for the given queue size.
-//
-// Before this descriptor table can be used, [initialize] must be called.
-func newDescriptorTable(queueSize int, mem []byte, itemSize int) *DescriptorTable {
-	dtSize := descriptorTableSize(queueSize)
-	if len(mem) != dtSize {
-		panic(fmt.Sprintf("memory size (%v) does not match required size "+
-			"for descriptor table: %v", len(mem), dtSize))
-	}
-
-	return &DescriptorTable{
-		descriptors: unsafe.Slice((*Descriptor)(unsafe.Pointer(&mem[0])), queueSize),
-		// We have no free descriptors until they were initialized.
-		freeHeadIndex: noFreeHead,
-		freeNum:       0,
-		itemSize:      itemSize, //todo configurable? needs to be page-aligned
-	}
-}
-
-// Address returns the pointer to the beginning of the descriptor table in
-// memory. Do not modify the memory directly to not interfere with this
-// implementation.
-func (dt *DescriptorTable) Address() uintptr {
-	if dt.descriptors == nil {
-		panic("descriptor table is not initialized")
-	}
-	//should be same as dt.bufferBase
-	return uintptr(unsafe.Pointer(&dt.descriptors[0]))
-}
-
-func (dt *DescriptorTable) Size() uintptr {
-	if dt.descriptors == nil {
-		panic("descriptor table is not initialized")
-	}
-	return uintptr(dt.bufferSize)
-}
-
-// BufferAddresses returns a map of pointer->size for all allocations used by the table
-func (dt *DescriptorTable) BufferAddresses() map[uintptr]int {
-	if dt.descriptors == nil {
-		panic("descriptor table is not initialized")
-	}
-
-	return map[uintptr]int{dt.bufferBase: dt.bufferSize}
-}
-
-// initializeDescriptors allocates buffers with the size of a full memory page
-// for each descriptor in the table. While this may be a bit wasteful, it makes
-// dealing with descriptors way easier. Without this preallocation, we would
-// have to allocate and free memory on demand, increasing complexity.
-//
-// All descriptors will be marked as free and will form a free chain. The
-// addresses of all descriptors will be populated while their length remains
-// zero.
-func (dt *DescriptorTable) initializeDescriptors() error {
-	numDescriptors := len(dt.descriptors)
-
-	// Allocate ONE large region for all buffers
-	totalSize := dt.itemSize * numDescriptors
-	basePtr, err := unix.MmapPtr(-1, 0, nil, uintptr(totalSize),
-		unix.PROT_READ|unix.PROT_WRITE,
-		unix.MAP_PRIVATE|unix.MAP_ANONYMOUS)
-	if err != nil {
-		return fmt.Errorf("allocate buffer memory for descriptors: %w", err)
-	}
-
-	// Store the base for cleanup later
-	dt.bufferBase = uintptr(basePtr)
-	dt.bufferSize = totalSize
-
-	for i := range dt.descriptors {
-		dt.descriptors[i] = Descriptor{
-			address: dt.bufferBase + uintptr(i*dt.itemSize),
-			length:  0,
-			// All descriptors should form a free chain that loops around.
-			flags: descriptorFlagHasNext,
-			next:  uint16((i + 1) % len(dt.descriptors)),
-		}
-	}
-
-	// All descriptors are free to use now.
-	dt.freeHeadIndex = 0
-	dt.freeNum = uint16(len(dt.descriptors))
-
-	return nil
-}
-
-// releaseBuffers releases all allocated buffers for this descriptor table.
-// The implementation will try to release as many buffers as possible and
-// collect potential errors before returning them.
-// The descriptor table should no longer be used after calling this.
-func (dt *DescriptorTable) releaseBuffers() error {
-	for i := range dt.descriptors {
-		descriptor := &dt.descriptors[i]
-		descriptor.address = 0
-	}
-
-	// As a safety measure, make sure no descriptors can be used anymore.
-	dt.freeHeadIndex = noFreeHead
-	dt.freeNum = 0
-
-	if dt.bufferBase != 0 {
-		// The pointer points to memory not managed by Go, so this conversion
-		// is safe. See https://github.com/golang/go/issues/58625
-		dt.bufferBase = 0
-		//goland:noinspection GoVetUnsafePointer
-		err := unix.MunmapPtr(unsafe.Pointer(dt.bufferBase), uintptr(dt.bufferSize))
-		if err != nil {
-			return fmt.Errorf("release buffer memory: %w", err)
-		}
-	}
-
-	return nil
-}
-
-// createDescriptorChain creates a new descriptor chain within the descriptor
-// table which contains a number of device-readable buffers (out buffers) and
-// device-writable buffers (in buffers).
-//
-// All buffers in the outBuffers slice will be concatenated by chaining
-// descriptors, one for each buffer in the slice. The size of the single buffers
-// must not exceed the size of a memory page (see [os.Getpagesize]).
-// When numInBuffers is greater than zero, the given number of device-writable
-// descriptors will be appended to the end of the chain, each referencing a
-// whole memory page.
-//
-// The index of the head of the new descriptor chain will be returned. Callers
-// should make sure to free the descriptor chain using [freeDescriptorChain]
-// after it was used by the device.
-//
-// When there are not enough free descriptors to hold the given number of
-// buffers, an [ErrNotEnoughFreeDescriptors] will be returned. In this case, the
-// caller should try again after some descriptor chains were used by the device
-// and returned back into the free chain.
-func (dt *DescriptorTable) createDescriptorChain(outBuffers [][]byte, numInBuffers int) (uint16, error) {
-	// Calculate the number of descriptors needed to build the chain.
-	numDesc := uint16(len(outBuffers) + numInBuffers)
-
-	// Descriptor chains must always contain at least one descriptor.
-	if numDesc < 1 {
-		return 0, ErrDescriptorChainEmpty
-	}
-
-	// Do we still have enough free descriptors?
-	if numDesc > dt.freeNum {
-		return 0, ErrNotEnoughFreeDescriptors
-	}
-
-	// Above validation ensured that there is at least one free descriptor, so
-	// the free descriptor chain head should be valid.
-	if dt.freeHeadIndex == noFreeHead {
-		panic("free descriptor chain head is unset but there should be free descriptors")
-	}
-
-	// To avoid having to iterate over the whole table to find the descriptor
-	// pointing to the head just to replace the free head, we instead always
-	// create descriptor chains from the descriptors coming after the head.
-	// This way we only have to touch the head as a last resort, when all other
-	// descriptors are already used.
-	head := dt.descriptors[dt.freeHeadIndex].next
-	next := head
-	tail := head
-	for i, buffer := range outBuffers {
-		desc := &dt.descriptors[next]
-		checkUnusedDescriptorLength(next, desc)
-
-		if len(buffer) > dt.itemSize {
-			// The caller should already prevent that from happening.
-			panic(fmt.Sprintf("out buffer %d has size %d which exceeds desc length %d", i, len(buffer), dt.itemSize))
-		}
-
-		// Copy the buffer to the memory referenced by the descriptor.
-		// The descriptor address points to memory not managed by Go, so this
-		// conversion is safe. See https://github.com/golang/go/issues/58625
-		//goland:noinspection GoVetUnsafePointer
-		copy(unsafe.Slice((*byte)(unsafe.Pointer(desc.address)), dt.itemSize), buffer)
-		desc.length = uint32(len(buffer))
-
-		// Clear the flags in case there were any others set.
-		desc.flags = descriptorFlagHasNext
-
-		tail = next
-		next = desc.next
-	}
-	for range numInBuffers {
-		desc := &dt.descriptors[next]
-		checkUnusedDescriptorLength(next, desc)
-
-		// Give the device the maximum available number of bytes to write into.
-		desc.length = uint32(dt.itemSize)
-
-		// Mark the descriptor as device-writable.
-		desc.flags = descriptorFlagHasNext | descriptorFlagWritable
-
-		tail = next
-		next = desc.next
-	}
-
-	// The last descriptor should end the chain.
-	tailDesc := &dt.descriptors[tail]
-	tailDesc.flags &= ^descriptorFlagHasNext
-	tailDesc.next = 0 // Not necessary to clear this, it's just for looks.
-
-	dt.freeNum -= numDesc
-
-	if dt.freeNum == 0 {
-		// The last descriptor in the chain should be the free chain head
-		// itself.
-		if tail != dt.freeHeadIndex {
-			panic("descriptor chain takes up all free descriptors but does not end with the free chain head")
-		}
-
-		// When this new chain takes up all remaining descriptors, we no longer
-		// have a free chain.
-		dt.freeHeadIndex = noFreeHead
-	} else {
-		// We took some descriptors out of the free chain, so make sure to close
-		// the circle again.
-		dt.descriptors[dt.freeHeadIndex].next = next
-	}
-
-	return head, nil
-}
-
-func (dt *DescriptorTable) CreateDescriptorForOutputs() (uint16, error) {
-	//todo just fill the damn table
-	// Do we still have enough free descriptors?
-
-	if 1 > dt.freeNum {
-		return 0, ErrNotEnoughFreeDescriptors
-	}
-
-	// Above validation ensured that there is at least one free descriptor, so
-	// the free descriptor chain head should be valid.
-	if dt.freeHeadIndex == noFreeHead {
-		panic("free descriptor chain head is unset but there should be free descriptors")
-	}
-
-	// To avoid having to iterate over the whole table to find the descriptor
-	// pointing to the head just to replace the free head, we instead always
-	// create descriptor chains from the descriptors coming after the head.
-	// This way we only have to touch the head as a last resort, when all other
-	// descriptors are already used.
-	head := dt.descriptors[dt.freeHeadIndex].next
-	desc := &dt.descriptors[head]
-	next := desc.next
-
-	checkUnusedDescriptorLength(head, desc)
-
-	// Give the device the maximum available number of bytes to write into.
-	desc.length = uint32(dt.itemSize)
-	desc.flags = 0 // descriptorFlagWritable
-	desc.next = 0  // Not necessary to clear this, it's just for looks.
-
-	dt.freeNum -= 1
-
-	if dt.freeNum == 0 {
-		// The last descriptor in the chain should be the free chain head
-		// itself.
-		if next != dt.freeHeadIndex {
-			panic("descriptor chain takes up all free descriptors but does not end with the free chain head")
-		}
-
-		// When this new chain takes up all remaining descriptors, we no longer
-		// have a free chain.
-		dt.freeHeadIndex = noFreeHead
-	} else {
-		// We took some descriptors out of the free chain, so make sure to close
-		// the circle again.
-		dt.descriptors[dt.freeHeadIndex].next = next
-	}
-
-	return head, nil
-}
-
-func (dt *DescriptorTable) createDescriptorForInputs() (uint16, error) {
-	// Do we still have enough free descriptors?
-	if 1 > dt.freeNum {
-		return 0, ErrNotEnoughFreeDescriptors
-	}
-
-	// Above validation ensured that there is at least one free descriptor, so
-	// the free descriptor chain head should be valid.
-	if dt.freeHeadIndex == noFreeHead {
-		panic("free descriptor chain head is unset but there should be free descriptors")
-	}
-
-	// To avoid having to iterate over the whole table to find the descriptor
-	// pointing to the head just to replace the free head, we instead always
-	// create descriptor chains from the descriptors coming after the head.
-	// This way we only have to touch the head as a last resort, when all other
-	// descriptors are already used.
-	head := dt.descriptors[dt.freeHeadIndex].next
-	desc := &dt.descriptors[head]
-	next := desc.next
-
-	checkUnusedDescriptorLength(head, desc)
-
-	// Give the device the maximum available number of bytes to write into.
-	desc.length = uint32(dt.itemSize)
-	desc.flags = descriptorFlagWritable
-	desc.next = 0 // Not necessary to clear this, it's just for looks.
-
-	dt.freeNum -= 1
-
-	if dt.freeNum == 0 {
-		// The last descriptor in the chain should be the free chain head
-		// itself.
-		if next != dt.freeHeadIndex {
-			panic("descriptor chain takes up all free descriptors but does not end with the free chain head")
-		}
-
-		// When this new chain takes up all remaining descriptors, we no longer
-		// have a free chain.
-		dt.freeHeadIndex = noFreeHead
-	} else {
-		// We took some descriptors out of the free chain, so make sure to close
-		// the circle again.
-		dt.descriptors[dt.freeHeadIndex].next = next
-	}
-
-	return head, nil
-}
-
-// TODO: Implement a zero-copy variant of createDescriptorChain?
-
-// getDescriptorChain returns the device-readable buffers (out buffers) and
-// device-writable buffers (in buffers) of the descriptor chain that starts with
-// the given head index. The descriptor chain must have been created using
-// [createDescriptorChain] and must not have been freed yet (meaning that the
-// head index must not be contained in the free chain).
-//
-// Be careful to only access the returned buffer slices when the device has not
-// yet or is no longer using them. They must not be accessed after
-// [freeDescriptorChain] has been called.
-func (dt *DescriptorTable) getDescriptorChain(head uint16) (outBuffers, inBuffers [][]byte, err error) {
-	if int(head) > len(dt.descriptors) {
-		return nil, nil, fmt.Errorf("%w: index out of range", ErrInvalidDescriptorChain)
-	}
-
-	// Iterate over the chain. The iteration is limited to the queue size to
-	// avoid ending up in an endless loop when things go very wrong.
-	next := head
-	for range len(dt.descriptors) {
-		if next == dt.freeHeadIndex {
-			return nil, nil, fmt.Errorf("%w: must not be part of the free chain", ErrInvalidDescriptorChain)
-		}
-
-		desc := &dt.descriptors[next]
-
-		// The descriptor address points to memory not managed by Go, so this
-		// conversion is safe. See https://github.com/golang/go/issues/58625
-		//goland:noinspection GoVetUnsafePointer
-		bs := unsafe.Slice((*byte)(unsafe.Pointer(desc.address)), desc.length)
-
-		if desc.flags&descriptorFlagWritable == 0 {
-			outBuffers = append(outBuffers, bs)
-		} else {
-			inBuffers = append(inBuffers, bs)
-		}
-
-		// Is this the tail of the chain?
-		if desc.flags&descriptorFlagHasNext == 0 {
-			break
-		}
-
-		// Detect loops.
-		if desc.next == head {
-			return nil, nil, fmt.Errorf("%w: contains a loop", ErrInvalidDescriptorChain)
-		}
-
-		next = desc.next
-	}
-
-	return
-}
-
-func (dt *DescriptorTable) getDescriptorItem(head uint16) ([]byte, error) {
-	if int(head) > len(dt.descriptors) {
-		return nil, fmt.Errorf("%w: index out of range", ErrInvalidDescriptorChain)
-	}
-
-	desc := &dt.descriptors[head] //todo this is a pretty nasty hack with no checks
-
-	// The descriptor address points to memory not managed by Go, so this
-	// conversion is safe. See https://github.com/golang/go/issues/58625
-	//goland:noinspection GoVetUnsafePointer
-	bs := unsafe.Slice((*byte)(unsafe.Pointer(desc.address)), desc.length)
-	return bs, nil
-}
-
-func (dt *DescriptorTable) getDescriptorInbuffers(head uint16, inBuffers *[][]byte) error {
-	if int(head) > len(dt.descriptors) {
-		return fmt.Errorf("%w: index out of range", ErrInvalidDescriptorChain)
-	}
-
-	// Iterate over the chain. The iteration is limited to the queue size to
-	// avoid ending up in an endless loop when things go very wrong.
-	next := head
-	for range len(dt.descriptors) {
-		if next == dt.freeHeadIndex {
-			return fmt.Errorf("%w: must not be part of the free chain", ErrInvalidDescriptorChain)
-		}
-
-		desc := &dt.descriptors[next]
-
-		// The descriptor address points to memory not managed by Go, so this
-		// conversion is safe. See https://github.com/golang/go/issues/58625
-		//goland:noinspection GoVetUnsafePointer
-		bs := unsafe.Slice((*byte)(unsafe.Pointer(desc.address)), desc.length)
-
-		if desc.flags&descriptorFlagWritable == 0 {
-			return fmt.Errorf("there should not be an outbuffer in %d", head)
-		} else {
-			*inBuffers = append(*inBuffers, bs)
-		}
-
-		// Is this the tail of the chain?
-		if desc.flags&descriptorFlagHasNext == 0 {
-			break
-		}
-
-		// Detect loops.
-		if desc.next == head {
-			return fmt.Errorf("%w: contains a loop", ErrInvalidDescriptorChain)
-		}
-
-		next = desc.next
-	}
-
-	return nil
-}
-
-func (dt *DescriptorTable) getDescriptorChainContents(head uint16, out []byte, maxLen int) (int, error) {
-	if int(head) > len(dt.descriptors) {
-		return 0, fmt.Errorf("%w: index out of range", ErrInvalidDescriptorChain)
-	}
-
-	// Iterate over the chain. The iteration is limited to the queue size to
-	// avoid ending up in an endless loop when things go very wrong.
-
-	length := 0
-	//find length
-	next := head
-	for range len(dt.descriptors) {
-		if next == dt.freeHeadIndex {
-			return 0, fmt.Errorf("%w: must not be part of the free chain", ErrInvalidDescriptorChain)
-		}
-
-		desc := &dt.descriptors[next]
-
-		if desc.flags&descriptorFlagWritable == 0 {
-			return 0, fmt.Errorf("receive queue contains device-readable buffer")
-		}
-		length += int(desc.length)
-
-		// Is this the tail of the chain?
-		if desc.flags&descriptorFlagHasNext == 0 {
-			break
-		}
-
-		// Detect loops.
-		if desc.next == head {
-			return 0, fmt.Errorf("%w: contains a loop", ErrInvalidDescriptorChain)
-		}
-
-		next = desc.next
-	}
-	if maxLen > 0 {
-		//todo length = min(maxLen, length)
-	}
-	//set out to length:
-	out = out[:length]
-
-	//now do the copying
-	copied := 0
-	for range len(dt.descriptors) {
-		desc := &dt.descriptors[next]
-
-		// The descriptor address points to memory not managed by Go, so this
-		// conversion is safe. See https://github.com/golang/go/issues/58625
-		//goland:noinspection GoVetUnsafePointer
-		bs := unsafe.Slice((*byte)(unsafe.Pointer(desc.address)), min(uint32(length-copied), desc.length))
-		copied += copy(out[copied:], bs)
-
-		// Is this the tail of the chain?
-		if desc.flags&descriptorFlagHasNext == 0 {
-			break
-		}
-
-		// we did this already, no need to detect loops.
-		next = desc.next
-	}
-	if copied != length {
-		panic(fmt.Sprintf("expected to copy %d bytes but only copied %d bytes", length, copied))
-	}
-
-	return length, nil
-}
-
-// freeDescriptorChain can be used to free a descriptor chain when it is no
-// longer in use. The descriptor chain that starts with the given index will be
-// put back into the free chain, so the descriptors can be used for later calls
-// of [createDescriptorChain].
-// The descriptor chain must have been created using [createDescriptorChain] and
-// must not have been freed yet (meaning that the head index must not be
-// contained in the free chain).
-func (dt *DescriptorTable) freeDescriptorChain(head uint16) error {
-	if int(head) > len(dt.descriptors) {
-		return fmt.Errorf("%w: index out of range", ErrInvalidDescriptorChain)
-	}
-
-	// Iterate over the chain. The iteration is limited to the queue size to
-	// avoid ending up in an endless loop when things go very wrong.
-	next := head
-	var tailDesc *Descriptor
-	var chainLen uint16
-	for range len(dt.descriptors) {
-		if next == dt.freeHeadIndex {
-			return fmt.Errorf("%w: must not be part of the free chain", ErrInvalidDescriptorChain)
-		}
-
-		desc := &dt.descriptors[next]
-		chainLen++
-
-		// Set the length of all unused descriptors back to zero.
-		desc.length = 0
-
-		// Unset all flags except the next flag.
-		desc.flags &= descriptorFlagHasNext
-
-		// Is this the tail of the chain?
-		if desc.flags&descriptorFlagHasNext == 0 {
-			tailDesc = desc
-			break
-		}
-
-		// Detect loops.
-		if desc.next == head {
-			return fmt.Errorf("%w: contains a loop", ErrInvalidDescriptorChain)
-		}
-
-		next = desc.next
-	}
-	if tailDesc == nil {
-		// A descriptor chain longer than the queue size but without loops
-		// should be impossible.
-		panic(fmt.Sprintf("could not find a tail for descriptor chain starting at %d", head))
-	}
-
-	// The tail descriptor does not have the next flag set, but when it comes
-	// back into the free chain, it should have.
-	tailDesc.flags = descriptorFlagHasNext
-
-	if dt.freeHeadIndex == noFreeHead {
-		// The whole free chain was used up, so we turn this returned descriptor
-		// chain into the new free chain by completing the circle and using its
-		// head.
-		tailDesc.next = head
-		dt.freeHeadIndex = head
-	} else {
-		// Attach the returned chain at the beginning of the free chain but
-		// right after the free chain head.
-		freeHeadDesc := &dt.descriptors[dt.freeHeadIndex]
-		tailDesc.next = freeHeadDesc.next
-		freeHeadDesc.next = head
-	}
-
-	dt.freeNum += chainLen
-
-	return nil
-}
-
-// checkUnusedDescriptorLength asserts that the length of an unused descriptor
-// is zero, as it should be.
-// This is not a requirement by the virtio spec but rather a thing we do to
-// notice when our algorithm goes sideways.
-func checkUnusedDescriptorLength(index uint16, desc *Descriptor) {
-	if desc.length != 0 {
-		panic(fmt.Sprintf("descriptor %d should be unused but has a non-zero length", index))
-	}
-}

overlay/virtqueue/descriptor_table_internal_test.go

@@ -1,407 +0,0 @@
-package virtqueue
-
-import (
-	"os"
-	"testing"
-	"unsafe"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestDescriptorTable_InitializeDescriptors(t *testing.T) {
-	const queueSize = 32
-
-	dt := DescriptorTable{
-		descriptors: make([]Descriptor, queueSize),
-	}
-
-	assert.NoError(t, dt.initializeDescriptors())
-	t.Cleanup(func() {
-		assert.NoError(t, dt.releaseBuffers())
-	})
-
-	for i, descriptor := range dt.descriptors {
-		assert.NotZero(t, descriptor.address)
-		assert.Zero(t, descriptor.length)
-		assert.EqualValues(t, descriptorFlagHasNext, descriptor.flags)
-		assert.EqualValues(t, (i+1)%queueSize, descriptor.next)
-	}
-}
-
-func TestDescriptorTable_DescriptorChains(t *testing.T) {
-	// Use a very short queue size to not make this test overly verbose.
-	const queueSize = 8
-
-	pageSize := os.Getpagesize() * 2
-
-	// Initialize descriptor table.
-	dt := DescriptorTable{
-		descriptors: make([]Descriptor, queueSize),
-	}
-	assert.NoError(t, dt.initializeDescriptors())
-	t.Cleanup(func() {
-		assert.NoError(t, dt.releaseBuffers())
-	})
-
-	// Some utilities for easier checking if the descriptor table looks as
-	// expected.
-	type desc struct {
-		buffer []byte
-		flags  descriptorFlag
-		next   uint16
-	}
-	assertDescriptorTable := func(expected [queueSize]desc) {
-		for i := 0; i < queueSize; i++ {
-			actualDesc := &dt.descriptors[i]
-			expectedDesc := &expected[i]
-			assert.Equal(t, uint32(len(expectedDesc.buffer)), actualDesc.length)
-			if len(expectedDesc.buffer) > 0 {
-				//goland:noinspection GoVetUnsafePointer
-				assert.EqualValues(t,
-					unsafe.Slice((*byte)(unsafe.Pointer(actualDesc.address)), actualDesc.length),
-					expectedDesc.buffer)
-			}
-			assert.Equal(t, expectedDesc.flags, actualDesc.flags)
-			if expectedDesc.flags&descriptorFlagHasNext != 0 {
-				assert.Equal(t, expectedDesc.next, actualDesc.next)
-			}
-		}
-	}
-
-	// Initial state: All descriptors are in the free chain.
-	assert.Equal(t, uint16(0), dt.freeHeadIndex)
-	assert.Equal(t, uint16(8), dt.freeNum)
-	assertDescriptorTable([queueSize]desc{
-		{
-			// Free head.
-			flags: descriptorFlagHasNext,
-			next:  1,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  2,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  3,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  4,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  5,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  6,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  7,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  0,
-		},
-	})
-
-	// Create the first chain.
-	firstChain, err := dt.createDescriptorChain([][]byte{
-		makeTestBuffer(t, 26),
-		makeTestBuffer(t, 256),
-	}, 1)
-	assert.NoError(t, err)
-	assert.Equal(t, uint16(1), firstChain)
-
-	// Now there should be a new chain next to the free chain.
-	assert.Equal(t, uint16(0), dt.freeHeadIndex)
-	assert.Equal(t, uint16(5), dt.freeNum)
-	assertDescriptorTable([queueSize]desc{
-		{
-			// Free head.
-			flags: descriptorFlagHasNext,
-			next:  4,
-		},
-		{
-			// Head of first chain.
-			buffer: makeTestBuffer(t, 26),
-			flags:  descriptorFlagHasNext,
-			next:   2,
-		},
-		{
-			buffer: makeTestBuffer(t, 256),
-			flags:  descriptorFlagHasNext,
-			next:   3,
-		},
-		{
-			// Tail of first chain.
-			buffer: make([]byte, pageSize),
-			flags:  descriptorFlagWritable,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  5,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  6,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  7,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  0,
-		},
-	})
-
-	// Create a second chain with only a single in buffer.
-	secondChain, err := dt.createDescriptorChain(nil, 1)
-	assert.NoError(t, err)
-	assert.Equal(t, uint16(4), secondChain)
-
-	// Now there should be two chains next to the free chain.
-	assert.Equal(t, uint16(0), dt.freeHeadIndex)
-	assert.Equal(t, uint16(4), dt.freeNum)
-	assertDescriptorTable([queueSize]desc{
-		{
-			// Free head.
-			flags: descriptorFlagHasNext,
-			next:  5,
-		},
-		{
-			// Head of the first chain.
-			buffer: makeTestBuffer(t, 26),
-			flags:  descriptorFlagHasNext,
-			next:   2,
-		},
-		{
-			buffer: makeTestBuffer(t, 256),
-			flags:  descriptorFlagHasNext,
-			next:   3,
-		},
-		{
-			// Tail of the first chain.
-			buffer: make([]byte, pageSize),
-			flags:  descriptorFlagWritable,
-		},
-		{
-			// Head and tail of the second chain.
-			buffer: make([]byte, pageSize),
-			flags:  descriptorFlagWritable,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  6,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  7,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  0,
-		},
-	})
-
-	// Create a third chain taking up all remaining descriptors.
-	thirdChain, err := dt.createDescriptorChain([][]byte{
-		makeTestBuffer(t, 42),
-		makeTestBuffer(t, 96),
-		makeTestBuffer(t, 33),
-		makeTestBuffer(t, 222),
-	}, 0)
-	assert.NoError(t, err)
-	assert.Equal(t, uint16(5), thirdChain)
-
-	// Now there should be three chains and no free chain.
-	assert.Equal(t, noFreeHead, dt.freeHeadIndex)
-	assert.Equal(t, uint16(0), dt.freeNum)
-	assertDescriptorTable([queueSize]desc{
-		{
-			// Tail of the third chain.
-			buffer: makeTestBuffer(t, 222),
-		},
-		{
-			// Head of the first chain.
-			buffer: makeTestBuffer(t, 26),
-			flags:  descriptorFlagHasNext,
-			next:   2,
-		},
-		{
-			buffer: makeTestBuffer(t, 256),
-			flags:  descriptorFlagHasNext,
-			next:   3,
-		},
-		{
-			// Tail of the first chain.
-			buffer: make([]byte, pageSize),
-			flags:  descriptorFlagWritable,
-		},
-		{
-			// Head and tail of the second chain.
-			buffer: make([]byte, pageSize),
-			flags:  descriptorFlagWritable,
-		},
-		{
-			// Head of the third chain.
-			buffer: makeTestBuffer(t, 42),
-			flags:  descriptorFlagHasNext,
-			next:   6,
-		},
-		{
-			buffer: makeTestBuffer(t, 96),
-			flags:  descriptorFlagHasNext,
-			next:   7,
-		},
-		{
-			buffer: makeTestBuffer(t, 33),
-			flags:  descriptorFlagHasNext,
-			next:   0,
-		},
-	})
-
-	// Free the third chain.
-	assert.NoError(t, dt.freeDescriptorChain(thirdChain))
-
-	// Now there should be two chains and a free chain again.
-	assert.Equal(t, uint16(5), dt.freeHeadIndex)
-	assert.Equal(t, uint16(4), dt.freeNum)
-	assertDescriptorTable([queueSize]desc{
-		{
-			flags: descriptorFlagHasNext,
-			next:  5,
-		},
-		{
-			// Head of the first chain.
-			buffer: makeTestBuffer(t, 26),
-			flags:  descriptorFlagHasNext,
-			next:   2,
-		},
-		{
-			buffer: makeTestBuffer(t, 256),
-			flags:  descriptorFlagHasNext,
-			next:   3,
-		},
-		{
-			// Tail of the first chain.
-			buffer: make([]byte, pageSize),
-			flags:  descriptorFlagWritable,
-		},
-		{
-			// Head and tail of the second chain.
-			buffer: make([]byte, pageSize),
-			flags:  descriptorFlagWritable,
-		},
-		{
-			// Free head.
-			flags: descriptorFlagHasNext,
-			next:  6,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  7,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  0,
-		},
-	})
-
-	// Free the first chain.
-	assert.NoError(t, dt.freeDescriptorChain(firstChain))
-
-	// Now there should be only a single chain next to the free chain.
-	assert.Equal(t, uint16(5), dt.freeHeadIndex)
-	assert.Equal(t, uint16(7), dt.freeNum)
-	assertDescriptorTable([queueSize]desc{
-		{
-			flags: descriptorFlagHasNext,
-			next:  5,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  2,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  3,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  6,
-		},
-		{
-			// Head and tail of the second chain.
-			buffer: make([]byte, pageSize),
-			flags:  descriptorFlagWritable,
-		},
-		{
-			// Free head.
-			flags: descriptorFlagHasNext,
-			next:  1,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  7,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  0,
-		},
-	})
-
-	// Free the second chain.
-	assert.NoError(t, dt.freeDescriptorChain(secondChain))
-
-	// Now all descriptors should be in the free chain again.
-	assert.Equal(t, uint16(5), dt.freeHeadIndex)
-	assert.Equal(t, uint16(8), dt.freeNum)
-	assertDescriptorTable([queueSize]desc{
-		{
-			flags: descriptorFlagHasNext,
-			next:  5,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  2,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  3,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  6,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  1,
-		},
-		{
-			// Free head.
-			flags: descriptorFlagHasNext,
-			next:  4,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  7,
-		},
-		{
-			flags: descriptorFlagHasNext,
-			next:  0,
-		},
-	})
-}
-
-func makeTestBuffer(t *testing.T, length int) []byte {
-	t.Helper()
-	buf := make([]byte, length)
-	for i := 0; i < length; i++ {
-		buf[i] = byte(length - i)
-	}
-	return buf
-}

overlay/virtqueue/doc.go

@@ -1,7 +0,0 @@
-// Package virtqueue implements the driver-side for a virtio queue as described
-// in the specification:
-// https://docs.oasis-open.org/virtio/virtio/v1.2/csd01/virtio-v1.2-csd01.html#x1-270006
-// This package does not make assumptions about the device that consumes the
-// queue. It rather just allocates the queue structures in memory and provides
-// methods to interact with it.
-package virtqueue

overlay/virtqueue/eventfd_test.go

@@ -1,45 +0,0 @@
-package virtqueue
-
-import (
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-	"gvisor.dev/gvisor/pkg/eventfd"
-)
-
-// Tests how an eventfd and a waiting goroutine can be gracefully closed.
-// Extends the eventfd test suite:
-// https://github.com/google/gvisor/blob/0799336d64be65eb97d330606c30162dc3440cab/pkg/eventfd/eventfd_test.go
-func TestEventFD_CancelWait(t *testing.T) {
-	efd, err := eventfd.Create()
-	require.NoError(t, err)
-	t.Cleanup(func() {
-		assert.NoError(t, efd.Close())
-	})
-
-	var stop bool
-
-	done := make(chan struct{})
-	go func() {
-		for !stop {
-			_ = efd.Wait()
-		}
-		close(done)
-	}()
-	select {
-	case <-done:
-		t.Fatalf("goroutine ended early")
-	case <-time.After(500 * time.Millisecond):
-	}
-
-	stop = true
-	assert.NoError(t, efd.Notify())
-	select {
-	case <-done:
-		break
-	case <-time.After(5 * time.Second):
-		t.Error("goroutine did not end")
-	}
-}

overlay/virtqueue/size.go

@@ -1,33 +0,0 @@
-package virtqueue
-
-import (
-	"errors"
-	"fmt"
-)
-
-// ErrQueueSizeInvalid is returned when a queue size is invalid.
-var ErrQueueSizeInvalid = errors.New("queue size is invalid")
-
-// CheckQueueSize checks if the given value would be a valid size for a
-// virtqueue and returns an [ErrQueueSizeInvalid], if not.
-func CheckQueueSize(queueSize int) error {
-	if queueSize <= 0 {
-		return fmt.Errorf("%w: %d is too small", ErrQueueSizeInvalid, queueSize)
-	}
-
-	// The queue size must always be a power of 2.
-	// This ensures that ring indexes wrap correctly when the 16-bit integers
-	// overflow.
-	if queueSize&(queueSize-1) != 0 {
-		return fmt.Errorf("%w: %d is not a power of 2", ErrQueueSizeInvalid, queueSize)
-	}
-
-	// The largest power of 2 that fits into a 16-bit integer is 32768.
-	// 2 * 32768 would be 65536 which no longer fits.
-	if queueSize > 32768 {
-		return fmt.Errorf("%w: %d is larger than the maximum possible queue size 32768",
-			ErrQueueSizeInvalid, queueSize)
-	}
-
-	return nil
-}

overlay/virtqueue/size_test.go

@@ -1,59 +0,0 @@
-package virtqueue
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestCheckQueueSize(t *testing.T) {
-	tests := []struct {
-		name        string
-		queueSize   int
-		containsErr string
-	}{
-		{
-			name:        "negative",
-			queueSize:   -1,
-			containsErr: "too small",
-		},
-		{
-			name:        "zero",
-			queueSize:   0,
-			containsErr: "too small",
-		},
-		{
-			name:        "not a power of 2",
-			queueSize:   24,
-			containsErr: "not a power of 2",
-		},
-		{
-			name:        "too large",
-			queueSize:   65536,
-			containsErr: "larger than the maximum",
-		},
-		{
-			name:      "valid 1",
-			queueSize: 1,
-		},
-		{
-			name:      "valid 256",
-			queueSize: 256,
-		},
-
-		{
-			name:      "valid 32768",
-			queueSize: 32768,
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			err := CheckQueueSize(tt.queueSize)
-			if tt.containsErr != "" {
-				assert.ErrorContains(t, err, tt.containsErr)
-			} else {
-				assert.NoError(t, err)
-			}
-		})
-	}
-}

overlay/virtqueue/split_virtqueue.go

@@ -1,530 +0,0 @@
-package virtqueue
-
-import (
-	"context"
-	"errors"
-	"fmt"
-	"os"
-	"syscall"
-
-	"github.com/slackhq/nebula/overlay/eventfd"
-	"golang.org/x/sys/unix"
-)
-
-// SplitQueue is a virtqueue that consists of several parts, where each part is
-// writeable by either the driver or the device, but not both.
-type SplitQueue struct {
-	// size is the size of the queue.
-	size int
-	// buf is the underlying memory used for the queue.
-	buf []byte
-
-	descriptorTable *DescriptorTable
-	availableRing   *AvailableRing
-	usedRing        *UsedRing
-
-	// kickEventFD is used to signal the device when descriptor chains were
-	// added to the available ring.
-	kickEventFD eventfd.EventFD
-	// callEventFD is used by the device to signal when it has used descriptor
-	// chains and put them in the used ring.
-	callEventFD eventfd.EventFD
-
-	// stop is used by [SplitQueue.Close] to cancel the goroutine that handles
-	// used buffer notifications. It blocks until the goroutine ended.
-	stop func() error
-
-	itemSize int
-
-	epoll eventfd.Epoll
-	more  int
-}
-
-// NewSplitQueue allocates a new [SplitQueue] in memory. The given queue size
-// specifies the number of entries/buffers the queue can hold. This also affects
-// the memory consumption.
-func NewSplitQueue(queueSize int, itemSize int) (_ *SplitQueue, err error) {
-	if err = CheckQueueSize(queueSize); err != nil {
-		return nil, err
-	}
-
-	if itemSize%os.Getpagesize() != 0 {
-		return nil, errors.New("split queue size must be multiple of os.Getpagesize()")
-	}
-
-	sq := SplitQueue{
-		size:     queueSize,
-		itemSize: itemSize,
-	}
-
-	// Clean up a partially initialized queue when something fails.
-	defer func() {
-		if err != nil {
-			_ = sq.Close()
-		}
-	}()
-
-	// There are multiple ways for how the memory for the virtqueue could be
-	// allocated. We could use Go native structs with arrays inside them, but
-	// this wouldn't allow us to make the queue size configurable. And including
-	// a slice in the Go structs wouldn't work, because this would just put the
-	// Go slice descriptor into the memory region which the virtio device will
-	// not understand.
-	// Additionally, Go does not allow us to ensure a correct alignment of the
-	// parts of the virtqueue, as it is required by the virtio specification.
-	//
-	// To resolve this, let's just allocate the memory manually by allocating
-	// one or more memory pages, depending on the queue size. Making the
-	// virtqueue start at the beginning of a page is not strictly necessary, as
-	// the virtio specification does not require it to be continuous in the
-	// physical memory of the host (e.g. the vhost implementation in the kernel
-	// always uses copy_from_user to access it), but this makes it very easy to
-	// guarantee the alignment. Also, it is not required for the virtqueue parts
-	// to be in the same memory region, as we pass separate pointers to them to
-	// the device, but this design just makes things easier to implement.
-	//
-	// One added benefit of allocating the memory manually is, that we have full
-	// control over its lifetime and don't risk the garbage collector to collect
-	// our valuable structures while the device still works with them.
-
-	// The descriptor table is at the start of the page, so alignment is not an
-	// issue here.
-	descriptorTableStart := 0
-	descriptorTableEnd := descriptorTableStart + descriptorTableSize(queueSize)
-	availableRingStart := align(descriptorTableEnd, availableRingAlignment)
-	availableRingEnd := availableRingStart + availableRingSize(queueSize)
-	usedRingStart := align(availableRingEnd, usedRingAlignment)
-	usedRingEnd := usedRingStart + usedRingSize(queueSize)
-
-	sq.buf, err = unix.Mmap(-1, 0, usedRingEnd,
-		unix.PROT_READ|unix.PROT_WRITE,
-		unix.MAP_PRIVATE|unix.MAP_ANONYMOUS)
-	if err != nil {
-		return nil, fmt.Errorf("allocate virtqueue buffer: %w", err)
-	}
-
-	sq.descriptorTable = newDescriptorTable(queueSize, sq.buf[descriptorTableStart:descriptorTableEnd], sq.itemSize)
-	sq.availableRing = newAvailableRing(queueSize, sq.buf[availableRingStart:availableRingEnd])
-	sq.usedRing = newUsedRing(queueSize, sq.buf[usedRingStart:usedRingEnd])
-
-	sq.kickEventFD, err = eventfd.New()
-	if err != nil {
-		return nil, fmt.Errorf("create kick event file descriptor: %w", err)
-	}
-	sq.callEventFD, err = eventfd.New()
-	if err != nil {
-		return nil, fmt.Errorf("create call event file descriptor: %w", err)
-	}
-
-	if err = sq.descriptorTable.initializeDescriptors(); err != nil {
-		return nil, fmt.Errorf("initialize descriptors: %w", err)
-	}
-
-	sq.epoll, err = eventfd.NewEpoll()
-	if err != nil {
-		return nil, err
-	}
-	err = sq.epoll.AddEvent(sq.callEventFD.FD())
-	if err != nil {
-		return nil, err
-	}
-
-	// Consume used buffer notifications in the background.
-	sq.stop = sq.startConsumeUsedRing()
-
-	return &sq, nil
-}
-
-// Size returns the size of this queue, which is the number of entries/buffers
-// this queue can hold.
-func (sq *SplitQueue) Size() int {
-	return sq.size
-}
-
-// DescriptorTable returns the [DescriptorTable] behind this queue.
-func (sq *SplitQueue) DescriptorTable() *DescriptorTable {
-	return sq.descriptorTable
-}
-
-// AvailableRing returns the [AvailableRing] behind this queue.
-func (sq *SplitQueue) AvailableRing() *AvailableRing {
-	return sq.availableRing
-}
-
-// UsedRing returns the [UsedRing] behind this queue.
-func (sq *SplitQueue) UsedRing() *UsedRing {
-	return sq.usedRing
-}
-
-// KickEventFD returns the kick event file descriptor behind this queue.
-// The returned file descriptor should be used with great care to not interfere
-// with this implementation.
-func (sq *SplitQueue) KickEventFD() int {
-	return sq.kickEventFD.FD()
-}
-
-// CallEventFD returns the call event file descriptor behind this queue.
-// The returned file descriptor should be used with great care to not interfere
-// with this implementation.
-func (sq *SplitQueue) CallEventFD() int {
-	return sq.callEventFD.FD()
-}
-
-// startConsumeUsedRing starts a goroutine that runs [consumeUsedRing].
-// A function is returned that can be used to gracefully cancel it. todo rename
-func (sq *SplitQueue) startConsumeUsedRing() func() error {
-	return func() error {
-
-		// The goroutine blocks until it receives a signal on the event file
-		// descriptor, so it will never notice the context being canceled.
-		// To resolve this, we can just produce a fake-signal ourselves to wake
-		// it up.
-		if err := sq.callEventFD.Kick(); err != nil {
-			return fmt.Errorf("wake up goroutine: %w", err)
-		}
-		return nil
-	}
-}
-
-// BlockAndGetHeads waits for the device to signal that it has used descriptor chains and returns all [UsedElement]s
-func (sq *SplitQueue) BlockAndGetHeads(ctx context.Context) ([]UsedElement, error) {
-	var n int
-	var err error
-	for ctx.Err() == nil {
-
-		// Wait for a signal from the device.
-		if n, err = sq.epoll.Block(); err != nil {
-			return nil, fmt.Errorf("wait: %w", err)
-		}
-		if n > 0 {
-			stillNeedToTake, out := sq.usedRing.take(-1)
-			sq.more = stillNeedToTake
-			if stillNeedToTake == 0 {
-				_ = sq.epoll.Clear() //???
-			}
-			return out, nil
-		}
-	}
-	return nil, ctx.Err()
-}
-
-func (sq *SplitQueue) TakeSingle(ctx context.Context) (uint16, error) {
-	var n int
-	var err error
-	for ctx.Err() == nil {
-		out, ok := sq.usedRing.takeOne()
-		if ok {
-			return out, nil
-		}
-		// Wait for a signal from the device.
-		if n, err = sq.epoll.Block(); err != nil {
-			return 0, fmt.Errorf("wait: %w", err)
-		}
-
-		if n > 0 {
-			out, ok = sq.usedRing.takeOne()
-			if ok {
-				_ = sq.epoll.Clear() //???
-				return out, nil
-			} else {
-				continue //???
-			}
-		}
-	}
-	return 0, ctx.Err()
-}
-
-func (sq *SplitQueue) BlockAndGetHeadsCapped(ctx context.Context, maxToTake int) ([]UsedElement, error) {
-	var n int
-	var err error
-	for ctx.Err() == nil {
-
-		//we have leftovers in the fridge
-		if sq.more > 0 {
-			stillNeedToTake, out := sq.usedRing.take(maxToTake)
-			sq.more = stillNeedToTake
-			return out, nil
-		}
-		//look inside the fridge
-		stillNeedToTake, out := sq.usedRing.take(maxToTake)
-		if len(out) > 0 {
-			sq.more = stillNeedToTake
-			return out, nil
-		}
-		//fridge is empty I guess
-
-		// Wait for a signal from the device.
-		if n, err = sq.epoll.Block(); err != nil {
-			return nil, fmt.Errorf("wait: %w", err)
-		}
-		if n > 0 {
-			_ = sq.epoll.Clear() //???
-			stillNeedToTake, out = sq.usedRing.take(maxToTake)
-			sq.more = stillNeedToTake
-			return out, nil
-		}
-	}
-
-	return nil, ctx.Err()
-}
-
-// OfferDescriptorChain offers a descriptor chain to the device which contains a
-// number of device-readable buffers (out buffers) and device-writable buffers
-// (in buffers).
-//
-// All buffers in the outBuffers slice will be concatenated by chaining
-// descriptors, one for each buffer in the slice. When a buffer is too large to
-// fit into a single descriptor (limited by the system's page size), it will be
-// split up into multiple descriptors within the chain.
-// When numInBuffers is greater than zero, the given number of device-writable
-// descriptors will be appended to the end of the chain, each referencing a
-// whole memory page (see [os.Getpagesize]).
-//
-// When the queue is full and no more descriptor chains can be added, a wrapped
-// [ErrNotEnoughFreeDescriptors] will be returned. If you set waitFree to true,
-// this method will handle this error and will block instead until there are
-// enough free descriptors again.
-//
-// After defining the descriptor chain in the [DescriptorTable], the index of
-// the head of the chain will be made available to the device using the
-// [AvailableRing] and will be returned by this method.
-// Callers should read from the [SplitQueue.UsedDescriptorChains] channel to be
-// notified when the descriptor chain was used by the device and should free the
-// used descriptor chains again using [SplitQueue.FreeDescriptorChain] when
-// they're done with them. When this does not happen, the queue will run full
-// and any further calls to [SplitQueue.OfferDescriptorChain] will stall.
-
-func (sq *SplitQueue) OfferInDescriptorChains() (uint16, error) {
-	// Create a descriptor chain for the given buffers.
-	var (
-		head uint16
-		err  error
-	)
-	for {
-		head, err = sq.descriptorTable.createDescriptorForInputs()
-		if err == nil {
-			break
-		}
-
-		// I don't wanna use errors.Is, it's slow
-		//goland:noinspection GoDirectComparisonOfErrors
-		if err == ErrNotEnoughFreeDescriptors {
-			return 0, err
-		} else {
-			return 0, fmt.Errorf("create descriptor chain: %w", err)
-		}
-	}
-
-	// Make the descriptor chain available to the device.
-	sq.availableRing.offerSingle(head)
-
-	// Notify the device to make it process the updated available ring.
-	if err := sq.kickEventFD.Kick(); err != nil {
-		return head, fmt.Errorf("notify device: %w", err)
-	}
-
-	return head, nil
-}
-
-func (sq *SplitQueue) OfferOutDescriptorChains(prepend []byte, outBuffers [][]byte) ([]uint16, error) {
-	// TODO change this
-	// Each descriptor can only hold a whole memory page, so split large out
-	// buffers into multiple smaller ones.
-	outBuffers = splitBuffers(outBuffers, sq.itemSize)
-
-	chains := make([]uint16, len(outBuffers))
-
-	// Create a descriptor chain for the given buffers.
-	var (
-		head uint16
-		err  error
-	)
-	for i := range outBuffers {
-		for {
-			bufs := [][]byte{prepend, outBuffers[i]}
-			head, err = sq.descriptorTable.createDescriptorChain(bufs, 0)
-			if err == nil {
-				break
-			}
-
-			// I don't wanna use errors.Is, it's slow
-			//goland:noinspection GoDirectComparisonOfErrors
-			if err == ErrNotEnoughFreeDescriptors {
-				// Wait for more free descriptors to be put back into the queue.
-				// If the number of free descriptors is still not sufficient, we'll
-				// land here again.
-				//todo should never happen
-				syscall.Syscall(syscall.SYS_SCHED_YIELD, 0, 0, 0) // Cheap barrier
-				continue
-			}
-			return nil, fmt.Errorf("create descriptor chain: %w", err)
-		}
-		chains[i] = head
-	}
-
-	// Make the descriptor chain available to the device.
-	sq.availableRing.offer(chains)
-
-	// Notify the device to make it process the updated available ring.
-	if err := sq.kickEventFD.Kick(); err != nil {
-		return chains, fmt.Errorf("notify device: %w", err)
-	}
-
-	return chains, nil
-}
-
-// GetDescriptorChain returns the device-readable buffers (out buffers) and
-// device-writable buffers (in buffers) of the descriptor chain with the given
-// head index.
-// The head index must be one that was returned by a previous call to
-// [SplitQueue.OfferDescriptorChain] and the descriptor chain must not have been
-// freed yet.
-//
-// Be careful to only access the returned buffer slices when the device is no
-// longer using them. They must not be accessed after
-// [SplitQueue.FreeDescriptorChain] has been called.
-func (sq *SplitQueue) GetDescriptorChain(head uint16) (outBuffers, inBuffers [][]byte, err error) {
-	return sq.descriptorTable.getDescriptorChain(head)
-}
-
-func (sq *SplitQueue) GetDescriptorItem(head uint16) ([]byte, error) {
-	sq.descriptorTable.descriptors[head].length = uint32(sq.descriptorTable.itemSize)
-	return sq.descriptorTable.getDescriptorItem(head)
-}
-
-func (sq *SplitQueue) GetDescriptorChainContents(head uint16, out []byte, maxLen int) (int, error) {
-	return sq.descriptorTable.getDescriptorChainContents(head, out, maxLen)
-}
-
-func (sq *SplitQueue) GetDescriptorInbuffers(head uint16, inBuffers *[][]byte) error {
-	return sq.descriptorTable.getDescriptorInbuffers(head, inBuffers)
-}
-
-// FreeDescriptorChain frees the descriptor chain with the given head index.
-// The head index must be one that was returned by a previous call to
-// [SplitQueue.OfferDescriptorChain] and the descriptor chain must not have been
-// freed yet.
-//
-// This creates new room in the queue which can be used by following
-// [SplitQueue.OfferDescriptorChain] calls.
-// When there are outstanding calls for [SplitQueue.OfferDescriptorChain] that
-// are waiting for free room in the queue, they may become unblocked by this.
-func (sq *SplitQueue) FreeDescriptorChain(head uint16) error {
-	//not called under lock
-	if err := sq.descriptorTable.freeDescriptorChain(head); err != nil {
-		return fmt.Errorf("free: %w", err)
-	}
-
-	return nil
-}
-
-func (sq *SplitQueue) SetDescSize(head uint16, sz int) {
-	//not called under lock
-	sq.descriptorTable.descriptors[int(head)].length = uint32(sz)
-}
-
-func (sq *SplitQueue) OfferDescriptorChains(chains []uint16, kick bool) error {
-	//todo not doing this may break eventually?
-	//not called under lock
-	//if err := sq.descriptorTable.freeDescriptorChain(head); err != nil {
-	//	return fmt.Errorf("free: %w", err)
-	//}
-
-	// Make the descriptor chain available to the device.
-	sq.availableRing.offer(chains)
-
-	// Notify the device to make it process the updated available ring.
-	if kick {
-		return sq.Kick()
-	}
-
-	return nil
-}
-
-func (sq *SplitQueue) Kick() error {
-	if err := sq.kickEventFD.Kick(); err != nil {
-		return fmt.Errorf("notify device: %w", err)
-	}
-	return nil
-}
-
-// Close releases all resources used for this queue.
-// The implementation will try to release as many resources as possible and
-// collect potential errors before returning them.
-func (sq *SplitQueue) Close() error {
-	var errs []error
-
-	if sq.stop != nil {
-		// This has to happen before the event file descriptors may be closed.
-		if err := sq.stop(); err != nil {
-			errs = append(errs, fmt.Errorf("stop consume used ring: %w", err))
-		}
-
-		// Make sure that this code block is executed only once.
-		sq.stop = nil
-	}
-
-	if err := sq.kickEventFD.Close(); err != nil {
-		errs = append(errs, fmt.Errorf("close kick event file descriptor: %w", err))
-	}
-	if err := sq.callEventFD.Close(); err != nil {
-		errs = append(errs, fmt.Errorf("close call event file descriptor: %w", err))
-	}
-
-	if err := sq.descriptorTable.releaseBuffers(); err != nil {
-		errs = append(errs, fmt.Errorf("release descriptor buffers: %w", err))
-	}
-
-	if sq.buf != nil {
-		if err := unix.Munmap(sq.buf); err == nil {
-			sq.buf = nil
-		} else {
-			errs = append(errs, fmt.Errorf("unmap virtqueue buffer: %w", err))
-		}
-	}
-
-	return errors.Join(errs...)
-}
-
-// ensureInitialized is used as a guard to prevent methods to be called on an
-// uninitialized instance.
-func (sq *SplitQueue) ensureInitialized() {
-	if sq.buf == nil {
-		panic("used ring is not initialized")
-	}
-}
-
-func align(index, alignment int) int {
-	remainder := index % alignment
-	if remainder == 0 {
-		return index
-	}
-	return index + alignment - remainder
-}
-
-// splitBuffers processes a list of buffers and splits each buffer that is
-// larger than the size limit into multiple smaller buffers.
-// If none of the buffers are too big though, do nothing, to avoid allocation for now
-func splitBuffers(buffers [][]byte, sizeLimit int) [][]byte {
-	for i := range buffers {
-		if len(buffers[i]) > sizeLimit {
-			return reallySplitBuffers(buffers, sizeLimit)
-		}
-	}
-	return buffers
-}
-
-func reallySplitBuffers(buffers [][]byte, sizeLimit int) [][]byte {
-	result := make([][]byte, 0, len(buffers))
-	for _, buffer := range buffers {
-		for added := 0; added < len(buffer); added += sizeLimit {
-			if len(buffer)-added <= sizeLimit {
-				result = append(result, buffer[added:])
-				break
-			}
-			result = append(result, buffer[added:added+sizeLimit])
-		}
-	}
-
-	return result
-}

overlay/virtqueue/split_virtqueue_internal_test.go

@@ -1,105 +0,0 @@
-package virtqueue
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-func TestSplitQueue_MemoryAlignment(t *testing.T) {
-	tests := []struct {
-		name      string
-		queueSize int
-	}{
-		{
-			name:      "minimal queue size",
-			queueSize: 1,
-		},
-		{
-			name:      "small queue size",
-			queueSize: 8,
-		},
-		{
-			name:      "large queue size",
-			queueSize: 256,
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			sq, err := NewSplitQueue(tt.queueSize)
-			require.NoError(t, err)
-
-			assert.Zero(t, sq.descriptorTable.Address()%descriptorTableAlignment)
-			assert.Zero(t, sq.availableRing.Address()%availableRingAlignment)
-			assert.Zero(t, sq.usedRing.Address()%usedRingAlignment)
-		})
-	}
-}
-
-func TestSplitBuffers(t *testing.T) {
-	const sizeLimit = 16
-	tests := []struct {
-		name     string
-		buffers  [][]byte
-		expected [][]byte
-	}{
-		{
-			name:     "no buffers",
-			buffers:  make([][]byte, 0),
-			expected: make([][]byte, 0),
-		},
-		{
-			name: "small",
-			buffers: [][]byte{
-				make([]byte, 11),
-			},
-			expected: [][]byte{
-				make([]byte, 11),
-			},
-		},
-		{
-			name: "exact size",
-			buffers: [][]byte{
-				make([]byte, sizeLimit),
-			},
-			expected: [][]byte{
-				make([]byte, sizeLimit),
-			},
-		},
-		{
-			name: "large",
-			buffers: [][]byte{
-				make([]byte, 42),
-			},
-			expected: [][]byte{
-				make([]byte, 16),
-				make([]byte, 16),
-				make([]byte, 10),
-			},
-		},
-		{
-			name: "mixed",
-			buffers: [][]byte{
-				make([]byte, 7),
-				make([]byte, 30),
-				make([]byte, 15),
-				make([]byte, 32),
-			},
-			expected: [][]byte{
-				make([]byte, 7),
-				make([]byte, 16),
-				make([]byte, 14),
-				make([]byte, 15),
-				make([]byte, 16),
-				make([]byte, 16),
-			},
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			actual := splitBuffers(tt.buffers, sizeLimit)
-			assert.Equal(t, tt.expected, actual)
-		})
-	}
-}

overlay/virtqueue/used_element.go

@@ -1,21 +0,0 @@
-package virtqueue
-
-// usedElementSize is the number of bytes needed to store a [UsedElement] in
-// memory.
-const usedElementSize = 8
-
-// UsedElement is an element of the [UsedRing] and describes a descriptor chain
-// that was used by the device.
-type UsedElement struct {
-	// DescriptorIndex is the index of the head of the used descriptor chain in
-	// the [DescriptorTable].
-	// The index is 32-bit here for padding reasons.
-	DescriptorIndex uint32
-	// Length is the number of bytes written into the device writable portion of
-	// the buffer described by the descriptor chain.
-	Length uint32
-}
-
-func (u *UsedElement) GetHead() uint16 {
-	return uint16(u.DescriptorIndex)
-}

overlay/virtqueue/used_element_internal_test.go

@@ -1,12 +0,0 @@
-package virtqueue
-
-import (
-	"testing"
-	"unsafe"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestUsedElement_Size(t *testing.T) {
-	assert.EqualValues(t, usedElementSize, unsafe.Sizeof(UsedElement{}))
-}

overlay/virtqueue/used_ring.go

@@ -1,184 +0,0 @@
-package virtqueue
-
-import (
-	"fmt"
-	"unsafe"
-)
-
-// usedRingFlag is a flag that describes a [UsedRing].
-type usedRingFlag uint16
-
-const (
-	// usedRingFlagNoNotify is used by the host to advise the guest to not
-	// kick it when adding a buffer. It's unreliable, so it's simply an
-	// optimization. Guest will still kick when it's out of buffers.
-	usedRingFlagNoNotify usedRingFlag = 1 << iota
-)
-
-// usedRingSize is the number of bytes needed to store a [UsedRing] with the
-// given queue size in memory.
-func usedRingSize(queueSize int) int {
-	return 6 + usedElementSize*queueSize
-}
-
-// usedRingAlignment is the minimum alignment of a [UsedRing] in memory, as
-// required by the virtio spec.
-const usedRingAlignment = 4
-
-// UsedRing is where the device returns descriptor chains once it is done with
-// them. Each ring entry is a [UsedElement]. It is only written to by the device
-// and read by the driver.
-//
-// Because the size of the ring depends on the queue size, we cannot define a
-// Go struct with a static size that maps to the memory of the ring. Instead,
-// this struct only contains pointers to the corresponding memory areas.
-type UsedRing struct {
-	initialized bool
-
-	// flags that describe this ring.
-	flags *usedRingFlag
-	// ringIndex indicates where the device would put the next entry into the
-	// ring (modulo the queue size).
-	ringIndex *uint16
-	// ring contains the [UsedElement]s. It wraps around at queue size.
-	ring []UsedElement
-	// availableEvent is not used by this implementation, but we reserve it
-	// anyway to avoid issues in case a device may try to write to it, contrary
-	// to the virtio specification.
-	availableEvent *uint16
-
-	// lastIndex is the internal ringIndex up to which all [UsedElement]s were
-	// processed.
-	lastIndex uint16
-
-	//mu sync.Mutex
-}
-
-// newUsedRing creates a used ring that uses the given underlying memory. The
-// length of the memory slice must match the size needed for the ring (see
-// [usedRingSize]) for the given queue size.
-func newUsedRing(queueSize int, mem []byte) *UsedRing {
-	ringSize := usedRingSize(queueSize)
-	if len(mem) != ringSize {
-		panic(fmt.Sprintf("memory size (%v) does not match required size "+
-			"for used ring: %v", len(mem), ringSize))
-	}
-
-	r := UsedRing{
-		initialized:    true,
-		flags:          (*usedRingFlag)(unsafe.Pointer(&mem[0])),
-		ringIndex:      (*uint16)(unsafe.Pointer(&mem[2])),
-		ring:           unsafe.Slice((*UsedElement)(unsafe.Pointer(&mem[4])), queueSize),
-		availableEvent: (*uint16)(unsafe.Pointer(&mem[ringSize-2])),
-	}
-	r.lastIndex = *r.ringIndex
-	return &r
-}
-
-// Address returns the pointer to the beginning of the ring in memory.
-// Do not modify the memory directly to not interfere with this implementation.
-func (r *UsedRing) Address() uintptr {
-	if !r.initialized {
-		panic("used ring is not initialized")
-	}
-	return uintptr(unsafe.Pointer(r.flags))
-}
-
-// take returns all new [UsedElement]s that the device put into the ring and
-// that weren't already returned by a previous call to this method.
-// had a lock, I removed it
-func (r *UsedRing) take(maxToTake int) (int, []UsedElement) {
-	//r.mu.Lock()
-	//defer r.mu.Unlock()
-
-	ringIndex := *r.ringIndex
-	if ringIndex == r.lastIndex {
-		// Nothing new.
-		return 0, nil
-	}
-
-	// Calculate the number new used elements that we can read from the ring.
-	// The ring index may wrap, so special handling for that case is needed.
-	count := int(ringIndex - r.lastIndex)
-	if count < 0 {
-		count += 0xffff
-	}
-
-	stillNeedToTake := 0
-
-	if maxToTake > 0 {
-		stillNeedToTake = count - maxToTake
-		if stillNeedToTake < 0 {
-			stillNeedToTake = 0
-		}
-		count = min(count, maxToTake)
-	}
-
-	// The number of new elements can never exceed the queue size.
-	if count > len(r.ring) {
-		panic("used ring contains more new elements than the ring is long")
-	}
-
-	elems := make([]UsedElement, count)
-	for i := range count {
-		elems[i] = r.ring[r.lastIndex%uint16(len(r.ring))]
-		r.lastIndex++
-	}
-
-	return stillNeedToTake, elems
-}
-
-func (r *UsedRing) takeOne() (uint16, bool) {
-	//r.mu.Lock()
-	//defer r.mu.Unlock()
-
-	ringIndex := *r.ringIndex
-	if ringIndex == r.lastIndex {
-		// Nothing new.
-		return 0xffff, false
-	}
-
-	// Calculate the number new used elements that we can read from the ring.
-	// The ring index may wrap, so special handling for that case is needed.
-	count := int(ringIndex - r.lastIndex)
-	if count < 0 {
-		count += 0xffff
-	}
-
-	// The number of new elements can never exceed the queue size.
-	if count > len(r.ring) {
-		panic("used ring contains more new elements than the ring is long")
-	}
-
-	if count == 0 {
-		return 0xffff, false
-	}
-
-	out := r.ring[r.lastIndex%uint16(len(r.ring))].GetHead()
-	r.lastIndex++
-
-	return out, true
-}
-
-// InitOfferSingle is only used to pre-fill the used queue at startup, and should not be used if the device is running!
-func (r *UsedRing) InitOfferSingle(x uint16, size int) {
-	//always called under lock
-	//r.mu.Lock()
-	//defer r.mu.Unlock()
-
-	offset := 0
-	// Add descriptor chain heads to the ring.
-
-	// The 16-bit ring index may overflow. This is expected and is not an
-	// issue because the size of the ring array (which equals the queue
-	// size) is always a power of 2 and smaller than the highest possible
-	// 16-bit value.
-	insertIndex := int(*r.ringIndex+uint16(offset)) % len(r.ring)
-	r.ring[insertIndex] = UsedElement{
-		DescriptorIndex: uint32(x),
-		Length:          uint32(size),
-	}
-
-	// Increase the ring index by the number of descriptor chains added to the ring.
-	*r.ringIndex += 1
-}

overlay/virtqueue/used_ring_internal_test.go

@@ -1,136 +0,0 @@
-package virtqueue
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestUsedRing_MemoryLayout(t *testing.T) {
-	const queueSize = 2
-
-	memory := make([]byte, usedRingSize(queueSize))
-	r := newUsedRing(queueSize, memory)
-
-	*r.flags = 0x01ff
-	*r.ringIndex = 1
-	r.ring[0] = UsedElement{
-		DescriptorIndex: 0x0123,
-		Length:          0x4567,
-	}
-	r.ring[1] = UsedElement{
-		DescriptorIndex: 0x89ab,
-		Length:          0xcdef,
-	}
-
-	assert.Equal(t, []byte{
-		0xff, 0x01,
-		0x01, 0x00,
-		0x23, 0x01, 0x00, 0x00,
-		0x67, 0x45, 0x00, 0x00,
-		0xab, 0x89, 0x00, 0x00,
-		0xef, 0xcd, 0x00, 0x00,
-		0x00, 0x00,
-	}, memory)
-}
-
-//func TestUsedRing_Take(t *testing.T) {
-//	const queueSize = 8
-//
-//	tests := []struct {
-//		name      string
-//		ring      []UsedElement
-//		ringIndex uint16
-//		lastIndex uint16
-//		expected  []UsedElement
-//	}{
-//		{
-//			name: "nothing new",
-//			ring: []UsedElement{
-//				{DescriptorIndex: 1},
-//				{DescriptorIndex: 2},
-//				{DescriptorIndex: 3},
-//				{DescriptorIndex: 4},
-//				{},
-//				{},
-//				{},
-//				{},
-//			},
-//			ringIndex: 4,
-//			lastIndex: 4,
-//			expected:  nil,
-//		},
-//		{
-//			name: "no overflow",
-//			ring: []UsedElement{
-//				{DescriptorIndex: 1},
-//				{DescriptorIndex: 2},
-//				{DescriptorIndex: 3},
-//				{DescriptorIndex: 4},
-//				{},
-//				{},
-//				{},
-//				{},
-//			},
-//			ringIndex: 4,
-//			lastIndex: 1,
-//			expected: []UsedElement{
-//				{DescriptorIndex: 2},
-//				{DescriptorIndex: 3},
-//				{DescriptorIndex: 4},
-//			},
-//		},
-//		{
-//			name: "ring overflow",
-//			ring: []UsedElement{
-//				{DescriptorIndex: 9},
-//				{DescriptorIndex: 10},
-//				{DescriptorIndex: 3},
-//				{DescriptorIndex: 4},
-//				{DescriptorIndex: 5},
-//				{DescriptorIndex: 6},
-//				{DescriptorIndex: 7},
-//				{DescriptorIndex: 8},
-//			},
-//			ringIndex: 10,
-//			lastIndex: 7,
-//			expected: []UsedElement{
-//				{DescriptorIndex: 8},
-//				{DescriptorIndex: 9},
-//				{DescriptorIndex: 10},
-//			},
-//		},
-//		{
-//			name: "index overflow",
-//			ring: []UsedElement{
-//				{DescriptorIndex: 9},
-//				{DescriptorIndex: 10},
-//				{DescriptorIndex: 3},
-//				{DescriptorIndex: 4},
-//				{DescriptorIndex: 5},
-//				{DescriptorIndex: 6},
-//				{DescriptorIndex: 7},
-//				{DescriptorIndex: 8},
-//			},
-//			ringIndex: 2,
-//			lastIndex: 65535,
-//			expected: []UsedElement{
-//				{DescriptorIndex: 8},
-//				{DescriptorIndex: 9},
-//				{DescriptorIndex: 10},
-//			},
-//		},
-//	}
-//	for _, tt := range tests {
-//		t.Run(tt.name, func(t *testing.T) {
-//			memory := make([]byte, usedRingSize(queueSize))
-//			r := newUsedRing(queueSize, memory)
-//
-//			copy(r.ring, tt.ring)
-//			*r.ringIndex = tt.ringIndex
-//			r.lastIndex = tt.lastIndex
-//
-//			assert.Equal(t, tt.expected, r.take())
-//		})
-//	}
-//}

packet/outpacket.go

@@ -1,70 +0,0 @@
-package packet
-
-import (
-	"github.com/slackhq/nebula/util/virtio"
-	"golang.org/x/sys/unix"
-)
-
-type OutPacket struct {
-	Segments        [][]byte
-	SegmentPayloads [][]byte
-	SegmentHeaders  [][]byte
-	SegmentIDs      []uint16
-	//todo virtio header?
-	SegSize      int
-	SegCounter   int
-	Valid        bool
-	wasSegmented bool
-
-	Scratch []byte
-}
-
-func NewOut() *OutPacket {
-	out := new(OutPacket)
-	out.Segments = make([][]byte, 0, 64)
-	out.SegmentHeaders = make([][]byte, 0, 64)
-	out.SegmentPayloads = make([][]byte, 0, 64)
-	out.SegmentIDs = make([]uint16, 0, 64)
-	out.Scratch = make([]byte, Size)
-	return out
-}
-
-func (pkt *OutPacket) Reset() {
-	pkt.Segments = pkt.Segments[:0]
-	pkt.SegmentPayloads = pkt.SegmentPayloads[:0]
-	pkt.SegmentHeaders = pkt.SegmentHeaders[:0]
-	pkt.SegmentIDs = pkt.SegmentIDs[:0]
-	pkt.SegSize = 0
-	pkt.Valid = false
-	pkt.wasSegmented = false
-}
-
-func (pkt *OutPacket) UseSegment(segID uint16, seg []byte, isV6 bool) int {
-	pkt.Valid = true
-	pkt.SegmentIDs = append(pkt.SegmentIDs, segID)
-	pkt.Segments = append(pkt.Segments, seg) //todo do we need this?
-
-	vhdr := virtio.NetHdr{ //todo
-		Flags:      unix.VIRTIO_NET_HDR_F_DATA_VALID,
-		GSOType:    unix.VIRTIO_NET_HDR_GSO_NONE,
-		HdrLen:     0,
-		GSOSize:    0,
-		CsumStart:  0,
-		CsumOffset: 0,
-		NumBuffers: 0,
-	}
-
-	hdr := seg[0 : virtio.NetHdrSize+14]
-	_ = vhdr.Encode(hdr)
-	if isV6 {
-		hdr[virtio.NetHdrSize+14-2] = 0x86
-		hdr[virtio.NetHdrSize+14-1] = 0xdd
-	} else {
-		hdr[virtio.NetHdrSize+14-2] = 0x08
-		hdr[virtio.NetHdrSize+14-1] = 0x00
-	}
-
-	pkt.SegmentHeaders = append(pkt.SegmentHeaders, hdr)
-	pkt.SegmentPayloads = append(pkt.SegmentPayloads, seg[virtio.NetHdrSize+14:])
-	return len(pkt.SegmentIDs) - 1
-}

packet/packet.go

@@ -1,119 +0,0 @@
-package packet
-
-import (
-	"encoding/binary"
-	"iter"
-	"net/netip"
-	"slices"
-	"syscall"
-	"unsafe"
-
-	"golang.org/x/sys/unix"
-)
-
-const Size = 0xffff
-
-type Packet struct {
-	Payload []byte
-	Control []byte
-	Name    []byte
-	SegSize int
-
-	//todo should this hold out as well?
-	OutLen int
-
-	wasSegmented bool
-	isV4         bool
-}
-
-func New(isV4 bool) *Packet {
-	return &Packet{
-		Payload: make([]byte, Size),
-		Control: make([]byte, unix.CmsgSpace(2)),
-		Name:    make([]byte, unix.SizeofSockaddrInet6),
-		isV4:    isV4,
-	}
-}
-
-func (p *Packet) AddrPort() netip.AddrPort {
-	var ip netip.Addr
-	// Its ok to skip the ok check here, the slicing is the only error that can occur and it will panic
-	if p.isV4 {
-		ip, _ = netip.AddrFromSlice(p.Name[4:8])
-	} else {
-		ip, _ = netip.AddrFromSlice(p.Name[8:24])
-	}
-	return netip.AddrPortFrom(ip.Unmap(), binary.BigEndian.Uint16(p.Name[2:4]))
-}
-
-func (p *Packet) updateCtrl(ctrlLen int) {
-	p.SegSize = len(p.Payload)
-	p.wasSegmented = false
-	if ctrlLen == 0 {
-		return
-	}
-	if len(p.Control) == 0 {
-		return
-	}
-	cmsgs, err := unix.ParseSocketControlMessage(p.Control)
-	if err != nil {
-		return // oh well
-	}
-
-	for _, c := range cmsgs {
-		if c.Header.Level == unix.SOL_UDP && c.Header.Type == unix.UDP_GRO && len(c.Data) >= 2 {
-			p.wasSegmented = true
-			p.SegSize = int(binary.LittleEndian.Uint16(c.Data[:2]))
-			return
-		}
-	}
-}
-
-// Update sets a Packet into "just received, not processed" state
-func (p *Packet) Update(ctrlLen int) {
-	p.OutLen = -1
-	p.updateCtrl(ctrlLen)
-}
-
-func (p *Packet) SetSegSizeForTX() {
-	p.SegSize = len(p.Payload)
-	hdr := (*unix.Cmsghdr)(unsafe.Pointer(&p.Control[0]))
-	hdr.Level = unix.SOL_UDP
-	hdr.Type = unix.UDP_SEGMENT
-	hdr.SetLen(syscall.CmsgLen(2))
-	binary.NativeEndian.PutUint16(p.Control[unix.CmsgLen(0):unix.CmsgLen(0)+2], uint16(p.SegSize))
-}
-
-func (p *Packet) CompatibleForSegmentationWith(otherP *Packet, currentTotalSize int) bool {
-	//same dest
-	if !slices.Equal(p.Name, otherP.Name) {
-		return false
-	}
-
-	//don't get too big
-	if len(p.Payload)+currentTotalSize >= 0xffff {
-		return false
-	}
-
-	//same body len
-	//todo allow single different size at end
-	if len(p.Payload) != len(otherP.Payload) {
-		return false //todo technically you can cram one extra in
-	}
-	return true
-}
-
-func (p *Packet) Segments() iter.Seq[[]byte] {
-	return func(yield func([]byte) bool) {
-		//cursor := 0
-		for offset := 0; offset < len(p.Payload); offset += p.SegSize {
-			end := offset + p.SegSize
-			if end > len(p.Payload) {
-				end = len(p.Payload)
-			}
-			if !yield(p.Payload[offset:end]) {
-				return
-			}
-		}
-	}
-}

packet/virtio.go

@@ -1,37 +0,0 @@
-package packet
-
-import (
-	"github.com/slackhq/nebula/util/virtio"
-)
-
-type VirtIOPacket struct {
-	Payload   []byte
-	Header    virtio.NetHdr
-	Chains    []uint16
-	ChainRefs [][]byte
-	// OfferDescriptorChains(chains []uint16, kick bool) error
-}
-
-func NewVIO() *VirtIOPacket {
-	out := new(VirtIOPacket)
-	out.Payload = nil
-	out.ChainRefs = make([][]byte, 0, 4)
-	out.Chains = make([]uint16, 0, 8)
-	return out
-}
-
-func (v *VirtIOPacket) Reset() {
-	v.Payload = nil
-	v.ChainRefs = v.ChainRefs[:0]
-	v.Chains = v.Chains[:0]
-}
-
-type VirtIOTXPacket struct {
-	VirtIOPacket
-}
-
-func NewVIOTX(isV4 bool) *VirtIOTXPacket {
-	out := new(VirtIOTXPacket)
-	out.VirtIOPacket = *NewVIO()
-	return out
-}

udp/conn.go

@@ -4,13 +4,13 @@ import (
 	"net/netip"
 
 	"github.com/slackhq/nebula/config"
-	"github.com/slackhq/nebula/packet"
 )
 
 const MTU = 9001
 
 type EncReader func(
-	[]*packet.Packet,
+	addr netip.AddrPort,
+	payload []byte,
 )
 
 type Conn interface {
@@ -19,8 +19,6 @@ type Conn interface {
 	ListenOut(r EncReader)
 	WriteTo(b []byte, addr netip.AddrPort) error
 	ReloadConfig(c *config.C)
-	Prep(pkt *packet.Packet, addr netip.AddrPort) error
-	WriteBatch(pkt []*packet.Packet) (int, error)
 	Close() error
 }
 

udp/udp_linux.go

@@ -14,22 +14,22 @@ import (
 	"github.com/rcrowley/go-metrics"
 	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula/config"
-	"github.com/slackhq/nebula/packet"
 	"golang.org/x/sys/unix"
 )
 
-const iovMax = 128 //1024 //no unix constant for this? from limits.h
-//todo I'd like this to be 1024 but we seem to hit errors around ~130?
-
 type StdConn struct {
-	sysFd     int
-	isV4      bool
-	l         *logrus.Logger
-	batch     int
-	enableGRO bool
+	sysFd int
+	isV4  bool
+	l     *logrus.Logger
+	batch int
+}
 
-	msgs []rawMessage
-	iovs [][]iovec
+func maybeIPV4(ip net.IP) (net.IP, bool) {
+	ip4 := ip.To4()
+	if ip4 != nil {
+		return ip4, true
+	}
+	return ip, false
 }
 
 func NewListener(l *logrus.Logger, ip netip.Addr, port int, multi bool, batch int) (Conn, error) {
@@ -69,20 +69,7 @@ func NewListener(l *logrus.Logger, ip netip.Addr, port int, multi bool, batch in
 		return nil, fmt.Errorf("unable to bind to socket: %s", err)
 	}
 
-	const batchSize = 8192
-	msgs := make([]rawMessage, 0, batchSize) //todo configure
-	iovs := make([][]iovec, batchSize)
-	for i := range iovs {
-		iovs[i] = make([]iovec, iovMax)
-	}
-	return &StdConn{
-		sysFd: fd,
-		isV4:  ip.Is4(),
-		l:     l,
-		batch: batch,
-		msgs:  msgs,
-		iovs:  iovs,
-	}, err
+	return &StdConn{sysFd: fd, isV4: ip.Is4(), l: l, batch: batch}, err
 }
 
 func (u *StdConn) Rebind() error {
@@ -132,7 +119,9 @@ func (u *StdConn) LocalAddr() (netip.AddrPort, error) {
 }
 
 func (u *StdConn) ListenOut(r EncReader) {
-	msgs, packets := u.PrepareRawMessages(u.batch, u.isV4)
+	var ip netip.Addr
+
+	msgs, buffers, names := u.PrepareRawMessages(u.batch)
 	read := u.ReadMulti
 	if u.batch == 1 {
 		read = u.ReadSingle
@@ -146,12 +135,13 @@ func (u *StdConn) ListenOut(r EncReader) {
 		}
 
 		for i := 0; i < n; i++ {
-			packets[i].Payload = packets[i].Payload[:msgs[i].Len]
-			packets[i].Update(getRawMessageControlLen(&msgs[i]))
-		}
-		r(packets[:n])
-		for i := 0; i < n; i++ { //todo reset this in prev loop, but this makes debug ez
-			msgs[i].Hdr.Controllen = uint64(unix.CmsgSpace(2))
+			// Its ok to skip the ok check here, the slicing is the only error that can occur and it will panic
+			if u.isV4 {
+				ip, _ = netip.AddrFromSlice(names[i][4:8])
+			} else {
+				ip, _ = netip.AddrFromSlice(names[i][8:24])
+			}
+			r(netip.AddrPortFrom(ip.Unmap(), binary.BigEndian.Uint16(names[i][2:4])), buffers[i][:msgs[i].Len])
 		}
 	}
 }
@@ -204,147 +194,6 @@ func (u *StdConn) WriteTo(b []byte, ip netip.AddrPort) error {
 	return u.writeTo6(b, ip)
 }
 
-func (u *StdConn) WriteToBatch(b []byte, ip netip.AddrPort) error {
-	if u.isV4 {
-		return u.writeTo4(b, ip)
-	}
-	return u.writeTo6(b, ip)
-}
-
-func (u *StdConn) Prep(pkt *packet.Packet, addr netip.AddrPort) error {
-	nl, err := u.encodeSockaddr(pkt.Name, addr)
-	if err != nil {
-		return err
-	}
-	pkt.Name = pkt.Name[:nl]
-	pkt.OutLen = len(pkt.Payload)
-	return nil
-}
-
-func (u *StdConn) WriteBatch(pkts []*packet.Packet) (int, error) {
-	if len(pkts) == 0 {
-		return 0, nil
-	}
-
-	u.msgs = u.msgs[:0]
-	//u.iovs = u.iovs[:0]
-
-	sent := 0
-	var mostRecentPkt *packet.Packet
-	mostRecentPktSize := 0
-	//segmenting := false
-	idx := 0
-	for _, pkt := range pkts {
-		if len(pkt.Payload) == 0 || pkt.OutLen == -1 {
-			sent++
-			continue
-		}
-		lastIdx := idx - 1
-		if mostRecentPkt != nil && pkt.CompatibleForSegmentationWith(mostRecentPkt, mostRecentPktSize) && u.msgs[lastIdx].Hdr.Iovlen < iovMax {
-			u.msgs[lastIdx].Hdr.Controllen = uint64(len(mostRecentPkt.Control))
-			u.msgs[lastIdx].Hdr.Control = &mostRecentPkt.Control[0]
-
-			u.iovs[lastIdx][u.msgs[lastIdx].Hdr.Iovlen].Base = &pkt.Payload[0]
-			u.iovs[lastIdx][u.msgs[lastIdx].Hdr.Iovlen].Len = uint64(len(pkt.Payload))
-			u.msgs[lastIdx].Hdr.Iovlen++
-
-			mostRecentPktSize += len(pkt.Payload)
-			mostRecentPkt.SetSegSizeForTX()
-		} else {
-			u.msgs = append(u.msgs, rawMessage{})
-			u.iovs[idx][0] = iovec{
-				Base: &pkt.Payload[0],
-				Len:  uint64(len(pkt.Payload)),
-			}
-
-			msg := &u.msgs[idx]
-			iov := &u.iovs[idx][0]
-			idx++
-
-			msg.Hdr.Iov = iov
-			msg.Hdr.Iovlen = 1
-			setRawMessageControl(msg, nil)
-			msg.Hdr.Flags = 0
-
-			msg.Hdr.Name = &pkt.Name[0]
-			msg.Hdr.Namelen = uint32(len(pkt.Name))
-			mostRecentPkt = pkt
-			mostRecentPktSize = len(pkt.Payload)
-		}
-	}
-
-	if len(u.msgs) == 0 {
-		return sent, nil
-	}
-
-	offset := 0
-	for offset < len(u.msgs) {
-		n, _, errno := unix.Syscall6(
-			unix.SYS_SENDMMSG,
-			uintptr(u.sysFd),
-			uintptr(unsafe.Pointer(&u.msgs[offset])),
-			uintptr(len(u.msgs)-offset),
-			0,
-			0,
-			0,
-		)
-
-		if errno != 0 {
-			if errno == unix.EINTR {
-				continue
-			}
-			//for i := 0; i < len(u.msgs); i++ {
-			//	for j := 0; j < int(u.msgs[i].Hdr.Iovlen); j++ {
-			//		u.l.WithFields(logrus.Fields{
-			//			"msg_index": i,
-			//			"iov idx":   j,
-			//			"iov":       fmt.Sprintf("%+v", u.iovs[i][j]),
-			//		}).Warn("failed to send message")
-			//	}
-			//
-			//}
-			u.l.WithFields(logrus.Fields{
-				"errno":   errno,
-				"idx":     idx,
-				"len":     len(u.msgs),
-				"deets":   fmt.Sprintf("%+v", u.msgs),
-				"lastIOV": fmt.Sprintf("%+v", u.iovs[len(u.msgs)-1][u.msgs[len(u.msgs)-1].Hdr.Iovlen-1]),
-			}).Error("failed to send message")
-			return sent + offset, &net.OpError{Op: "sendmmsg", Err: errno}
-		}
-
-		if n == 0 {
-			break
-		}
-		offset += int(n)
-	}
-
-	return sent + len(u.msgs), nil
-}
-
-func (u *StdConn) encodeSockaddr(dst []byte, addr netip.AddrPort) (uint32, error) {
-	if u.isV4 {
-		if !addr.Addr().Is4() {
-			return 0, fmt.Errorf("Listener is IPv4, but writing to IPv6 remote")
-		}
-		var sa unix.RawSockaddrInet4
-		sa.Family = unix.AF_INET
-		sa.Addr = addr.Addr().As4()
-		binary.BigEndian.PutUint16((*[2]byte)(unsafe.Pointer(&sa.Port))[:], addr.Port())
-		size := unix.SizeofSockaddrInet4
-		copy(dst[:size], (*(*[unix.SizeofSockaddrInet4]byte)(unsafe.Pointer(&sa)))[:])
-		return uint32(size), nil
-	}
-
-	var sa unix.RawSockaddrInet6
-	sa.Family = unix.AF_INET6
-	sa.Addr = addr.Addr().As16()
-	binary.BigEndian.PutUint16((*[2]byte)(unsafe.Pointer(&sa.Port))[:], addr.Port())
-	size := unix.SizeofSockaddrInet6
-	copy(dst[:size], (*(*[unix.SizeofSockaddrInet6]byte)(unsafe.Pointer(&sa)))[:])
-	return uint32(size), nil
-}
-
 func (u *StdConn) writeTo6(b []byte, ip netip.AddrPort) error {
 	var rsa unix.RawSockaddrInet6
 	rsa.Family = unix.AF_INET6
@@ -445,27 +294,6 @@ func (u *StdConn) ReloadConfig(c *config.C) {
 			u.l.WithError(err).Error("Failed to set listen.so_mark")
 		}
 	}
-	u.configureGRO(true)
-}
-
-func (u *StdConn) configureGRO(enable bool) {
-	if enable == u.enableGRO {
-		return
-	}
-
-	if enable {
-		if err := unix.SetsockoptInt(u.sysFd, unix.SOL_UDP, unix.UDP_GRO, 1); err != nil {
-			u.l.WithError(err).Warn("Failed to enable UDP GRO")
-			return
-		}
-		u.enableGRO = true
-		u.l.Info("UDP GRO enabled")
-	} else {
-		if err := unix.SetsockoptInt(u.sysFd, unix.SOL_UDP, unix.UDP_GRO, 0); err != nil && err != unix.ENOPROTOOPT {
-			u.l.WithError(err).Warn("Failed to disable UDP GRO")
-		}
-		u.enableGRO = false
-	}
 }
 
 func (u *StdConn) getMemInfo(meminfo *[unix.SK_MEMINFO_VARS]uint32) error {

udp/udp_linux_64.go

@@ -7,7 +7,6 @@
 package udp
 
 import (
-	"github.com/slackhq/nebula/packet"
 	"golang.org/x/sys/unix"
 )
 
@@ -34,59 +33,25 @@ type rawMessage struct {
 	Pad0 [4]byte
 }
 
-func setRawMessageControl(msg *rawMessage, buf []byte) {
-	if len(buf) == 0 {
-		msg.Hdr.Control = nil
-		msg.Hdr.Controllen = 0
-		return
-	}
-	msg.Hdr.Control = &buf[0]
-	msg.Hdr.Controllen = uint64(len(buf))
-}
-
-func getRawMessageControlLen(msg *rawMessage) int {
-	return int(msg.Hdr.Controllen)
-}
-
-func setCmsgLen(h *unix.Cmsghdr, l int) {
-	h.Len = uint64(l)
-}
-
-func (u *StdConn) PrepareRawMessages(n int, isV4 bool) ([]rawMessage, []*packet.Packet) {
+func (u *StdConn) PrepareRawMessages(n int) ([]rawMessage, [][]byte, [][]byte) {
 	msgs := make([]rawMessage, n)
-	packets := make([]*packet.Packet, n)
+	buffers := make([][]byte, n)
+	names := make([][]byte, n)
 
 	for i := range msgs {
-		packets[i] = packet.New(isV4)
+		buffers[i] = make([]byte, MTU)
+		names[i] = make([]byte, unix.SizeofSockaddrInet6)
 
 		vs := []iovec{
-			{Base: &packets[i].Payload[0], Len: uint64(packet.Size)},
+			{Base: &buffers[i][0], Len: uint64(len(buffers[i]))},
 		}
 
 		msgs[i].Hdr.Iov = &vs[0]
 		msgs[i].Hdr.Iovlen = uint64(len(vs))
 
-		msgs[i].Hdr.Name = &packets[i].Name[0]
-		msgs[i].Hdr.Namelen = uint32(len(packets[i].Name))
-
-		if u.enableGRO {
-			msgs[i].Hdr.Control = &packets[i].Control[0]
-			msgs[i].Hdr.Controllen = uint64(len(packets[i].Control))
-		} else {
-			msgs[i].Hdr.Control = nil
-			msgs[i].Hdr.Controllen = 0
-		}
+		msgs[i].Hdr.Name = &names[i][0]
+		msgs[i].Hdr.Namelen = uint32(len(names[i]))
 	}
 
-	return msgs, packets
-}
-
-func setIovecSlice(iov *iovec, b []byte) {
-	if len(b) == 0 {
-		iov.Base = nil
-		iov.Len = 0
-		return
-	}
-	iov.Base = &b[0]
-	iov.Len = uint64(len(b))
+	return msgs, buffers, names
 }

util/virtio/doc.go

@@ -1,3 +0,0 @@
-// Package virtio contains some generic types and concepts related to the virtio
-// protocol.
-package virtio

util/virtio/features.go

@@ -1,136 +0,0 @@
-package virtio
-
-// Feature contains feature bits that describe a virtio device or driver.
-type Feature uint64
-
-// Device-independent feature bits.
-//
-// Source: https://docs.oasis-open.org/virtio/virtio/v1.2/csd01/virtio-v1.2-csd01.html#x1-6600006
-const (
-	// FeatureIndirectDescriptors indicates that the driver can use descriptors
-	// with an additional layer of indirection.
-	FeatureIndirectDescriptors Feature = 1 << 28
-
-	// FeatureVersion1 indicates compliance with version 1.0 of the virtio
-	// specification.
-	FeatureVersion1 Feature = 1 << 32
-)
-
-// Feature bits for networking devices.
-//
-// Source: https://docs.oasis-open.org/virtio/virtio/v1.2/csd01/virtio-v1.2-csd01.html#x1-2200003
-const (
-	// FeatureNetDeviceCsum indicates that the device can handle packets with
-	// partial checksum (checksum offload).
-	FeatureNetDeviceCsum Feature = 1 << 0
-
-	// FeatureNetDriverCsum indicates that the driver can handle packets with
-	// partial checksum.
-	FeatureNetDriverCsum Feature = 1 << 1
-
-	// FeatureNetCtrlDriverOffloads indicates support for dynamic offload state
-	// reconfiguration.
-	FeatureNetCtrlDriverOffloads Feature = 1 << 2
-
-	// FeatureNetMTU indicates that the device reports a maximum MTU value.
-	FeatureNetMTU Feature = 1 << 3
-
-	// FeatureNetMAC indicates that the device provides a MAC address.
-	FeatureNetMAC Feature = 1 << 5
-
-	// FeatureNetDriverTSO4 indicates that the driver supports the TCP
-	// segmentation offload for received IPv4 packets.
-	FeatureNetDriverTSO4 Feature = 1 << 7
-
-	// FeatureNetDriverTSO6 indicates that the driver supports the TCP
-	// segmentation offload for received IPv6 packets.
-	FeatureNetDriverTSO6 Feature = 1 << 8
-
-	// FeatureNetDriverECN indicates that the driver supports the TCP
-	// segmentation offload with ECN for received packets.
-	FeatureNetDriverECN Feature = 1 << 9
-
-	// FeatureNetDriverUFO indicates that the driver supports the UDP
-	// fragmentation offload for received packets.
-	FeatureNetDriverUFO Feature = 1 << 10
-
-	// FeatureNetDeviceTSO4 indicates that the device supports the TCP
-	// segmentation offload for received IPv4 packets.
-	FeatureNetDeviceTSO4 Feature = 1 << 11
-
-	// FeatureNetDeviceTSO6 indicates that the device supports the TCP
-	// segmentation offload for received IPv6 packets.
-	FeatureNetDeviceTSO6 Feature = 1 << 12
-
-	// FeatureNetDeviceECN indicates that the device supports the TCP
-	// segmentation offload with ECN for received packets.
-	FeatureNetDeviceECN Feature = 1 << 13
-
-	// FeatureNetDeviceUFO indicates that the device supports the UDP
-	// fragmentation offload for received packets.
-	FeatureNetDeviceUFO Feature = 1 << 14
-
-	// FeatureNetMergeRXBuffers indicates that the driver can handle merged
-	// receive buffers.
-	// When this feature is negotiated, devices may merge multiple descriptor
-	// chains together to transport large received packets. [NetHdr.NumBuffers]
-	// will then contain the number of merged descriptor chains.
-	FeatureNetMergeRXBuffers Feature = 1 << 15
-
-	// FeatureNetStatus indicates that the device configuration status field is
-	// available.
-	FeatureNetStatus Feature = 1 << 16
-
-	// FeatureNetCtrlVQ indicates that a control channel virtqueue is
-	// available.
-	FeatureNetCtrlVQ Feature = 1 << 17
-
-	// FeatureNetCtrlRX indicates support for RX mode control (e.g. promiscuous
-	// or all-multicast) for packet receive filtering.
-	FeatureNetCtrlRX Feature = 1 << 18
-
-	// FeatureNetCtrlVLAN indicates support for VLAN filtering through the
-	// control channel.
-	FeatureNetCtrlVLAN Feature = 1 << 19
-
-	// FeatureNetDriverAnnounce indicates that the driver can send gratuitous
-	// packets.
-	FeatureNetDriverAnnounce Feature = 1 << 21
-
-	// FeatureNetMQ indicates that the device supports multiqueue with automatic
-	// receive steering.
-	FeatureNetMQ Feature = 1 << 22
-
-	// FeatureNetCtrlMACAddr indicates that the MAC address can be set through
-	// the control channel.
-	FeatureNetCtrlMACAddr Feature = 1 << 23
-
-	// FeatureNetDeviceUSO indicates that the device supports the UDP
-	// segmentation offload for received packets.
-	FeatureNetDeviceUSO Feature = 1 << 56
-
-	// FeatureNetHashReport indicates that the device can report a per-packet
-	// hash value and type.
-	FeatureNetHashReport Feature = 1 << 57
-
-	// FeatureNetDriverHdrLen indicates that the driver can provide the exact
-	// header length value (see [NetHdr.HdrLen]).
-	// Devices may benefit from knowing the exact header length.
-	FeatureNetDriverHdrLen Feature = 1 << 59
-
-	// FeatureNetRSS indicates that the device supports RSS (receive-side
-	// scaling) with configurable hash parameters.
-	FeatureNetRSS Feature = 1 << 60
-
-	// FeatureNetRSCExt indicates that the device can process duplicated ACKs
-	// and report the number of coalesced segments and duplicated ACKs.
-	FeatureNetRSCExt Feature = 1 << 61
-
-	// FeatureNetStandby indicates that the device may act as a standby for a
-	// primary device with the same MAC address.
-	FeatureNetStandby Feature = 1 << 62
-
-	// FeatureNetSpeedDuplex indicates that the device can report link speed and
-	// duplex mode.
-	FeatureNetSpeedDuplex Feature = 1 << 63
-)

util/virtio/net_hdr.go

@@ -1,77 +0,0 @@
-package virtio
-
-import (
-	"errors"
-	"unsafe"
-
-	"golang.org/x/sys/unix"
-)
-
-// Workaround to make Go doc links work.
-var _ unix.Errno
-
-// NetHdrSize is the number of bytes needed to store a [NetHdr] in memory.
-const NetHdrSize = 12
-
-// ErrNetHdrBufferTooSmall is returned when a buffer is too small to fit a
-// virtio_net_hdr.
-var ErrNetHdrBufferTooSmall = errors.New("the buffer is too small to fit a virtio_net_hdr")
-
-// NetHdr defines the virtio_net_hdr as described by the virtio specification.
-type NetHdr struct {
-	// Flags that describe the packet.
-	// Possible values are:
-	//   - [unix.VIRTIO_NET_HDR_F_NEEDS_CSUM]
-	//   - [unix.VIRTIO_NET_HDR_F_DATA_VALID]
-	//   - [unix.VIRTIO_NET_HDR_F_RSC_INFO]
-	Flags uint8
-	// GSOType contains the type of segmentation offload that should be used for
-	// the packet.
-	// Possible values are:
-	//   - [unix.VIRTIO_NET_HDR_GSO_NONE]
-	//   - [unix.VIRTIO_NET_HDR_GSO_TCPV4]
-	//   - [unix.VIRTIO_NET_HDR_GSO_UDP]
-	//   - [unix.VIRTIO_NET_HDR_GSO_TCPV6]
-	//   - [unix.VIRTIO_NET_HDR_GSO_UDP_L4]
-	//   - [unix.VIRTIO_NET_HDR_GSO_ECN]
-	GSOType uint8
-	// HdrLen contains the length of the headers that need to be replicated by
-	// segmentation offloads. It's the number of bytes from the beginning of the
-	// packet to the beginning of the transport payload.
-	// Only used when [FeatureNetDriverHdrLen] is negotiated.
-	HdrLen uint16
-	// GSOSize contains the maximum size of each segmented packet beyond the
-	// header (payload size). In case of TCP, this is the MSS.
-	GSOSize uint16
-	// CsumStart contains the offset within the packet from which on the
-	// checksum should be computed.
-	CsumStart uint16
-	// CsumOffset specifies how many bytes after [NetHdr.CsumStart] the computed
-	// 16-bit checksum should be inserted.
-	CsumOffset uint16
-	// NumBuffers contains the number of merged descriptor chains when
-	// [FeatureNetMergeRXBuffers] is negotiated.
-	// This field is only used for packets received by the driver and should be
-	// zero for transmitted packets.
-	NumBuffers uint16
-}
-
-// Decode decodes the [NetHdr] from the given byte slice. The slice must contain
-// at least [NetHdrSize] bytes.
-func (v *NetHdr) Decode(data []byte) error {
-	if len(data) < NetHdrSize {
-		return ErrNetHdrBufferTooSmall
-	}
-	copy(unsafe.Slice((*byte)(unsafe.Pointer(v)), NetHdrSize), data[:NetHdrSize])
-	return nil
-}
-
-// Encode encodes the [NetHdr] into the given byte slice. The slice must have
-// room for at least [NetHdrSize] bytes.
-func (v *NetHdr) Encode(data []byte) error {
-	if len(data) < NetHdrSize {
-		return ErrNetHdrBufferTooSmall
-	}
-	copy(data[:NetHdrSize], unsafe.Slice((*byte)(unsafe.Pointer(v)), NetHdrSize))
-	return nil
-}

util/virtio/net_hdr_test.go

@@ -1,43 +0,0 @@
-package virtio
-
-import (
-	"testing"
-	"unsafe"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-	"golang.org/x/sys/unix"
-)
-
-func TestNetHdr_Size(t *testing.T) {
-	assert.EqualValues(t, NetHdrSize, unsafe.Sizeof(NetHdr{}))
-}
-
-func TestNetHdr_Encoding(t *testing.T) {
-	vnethdr := NetHdr{
-		Flags:      unix.VIRTIO_NET_HDR_F_NEEDS_CSUM,
-		GSOType:    unix.VIRTIO_NET_HDR_GSO_UDP_L4,
-		HdrLen:     42,
-		GSOSize:    1472,
-		CsumStart:  34,
-		CsumOffset: 6,
-		NumBuffers: 16,
-	}
-
-	buf := make([]byte, NetHdrSize)
-	require.NoError(t, vnethdr.Encode(buf))
-
-	assert.Equal(t, []byte{
-		0x01, 0x05,
-		0x2a, 0x00,
-		0xc0, 0x05,
-		0x22, 0x00,
-		0x06, 0x00,
-		0x10, 0x00,
-	}, buf)
-
-	var decoded NetHdr
-	require.NoError(t, decoded.Decode(buf))
-
-	assert.Equal(t, vnethdr, decoded)
-}