conn, device: use UDP GSO and GRO on Linux

StdNetBind probes for UDP GSO and GRO support at runtime. UDP GSO is
dependent on checksum offload support on the egress netdev. UDP GSO
will be disabled in the event sendmmsg() returns EIO, which is a strong
signal that the egress netdev does not support checksum offload.

The iperf3 results below demonstrate the effect of this commit between
two Linux computers with i5-12400 CPUs. There is roughly ~13us of round
trip latency between them.

The first result is from commit 052af4a without UDP GSO or GRO.

Starting Test: protocol: TCP, 1 streams, 131072 byte blocks
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-10.00  sec  9.85 GBytes  8.46 Gbits/sec  1139   3.01 MBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  9.85 GBytes  8.46 Gbits/sec  1139  sender
[  5]   0.00-10.04  sec  9.85 GBytes  8.42 Gbits/sec        receiver

The second result is with UDP GSO and GRO.

Starting Test: protocol: TCP, 1 streams, 131072 byte blocks
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-10.00  sec  12.3 GBytes  10.6 Gbits/sec  232   3.15 MBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  12.3 GBytes  10.6 Gbits/sec  232   sender
[  5]   0.00-10.04  sec  12.3 GBytes  10.6 Gbits/sec        receiver

Reviewed-by: Adrian Dewhurst <adrian@tailscale.com>
Signed-off-by: Jordan Whited <jordan@tailscale.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
Jordan Whited 2023-10-02 13:53:07 -07:00 committed by Jason A. Donenfeld
parent 469159ecf7
commit 6a84778f2c
13 changed files with 672 additions and 146 deletions

View File

@ -8,6 +8,7 @@ package conn
import (
"context"
"errors"
"fmt"
"net"
"net/netip"
"runtime"
@ -29,16 +30,19 @@ var (
// methods for sending and receiving multiple datagrams per-syscall. See the
// proposal in https://github.com/golang/go/issues/45886#issuecomment-1218301564.
type StdNetBind struct {
mu sync.Mutex // protects all fields except as specified
ipv4 *net.UDPConn
ipv6 *net.UDPConn
ipv4PC *ipv4.PacketConn // will be nil on non-Linux
ipv6PC *ipv6.PacketConn // will be nil on non-Linux
mu sync.Mutex // protects all fields except as specified
ipv4 *net.UDPConn
ipv6 *net.UDPConn
ipv4PC *ipv4.PacketConn // will be nil on non-Linux
ipv6PC *ipv6.PacketConn // will be nil on non-Linux
ipv4TxOffload bool
ipv4RxOffload bool
ipv6TxOffload bool
ipv6RxOffload bool
// these three fields are not guarded by mu
udpAddrPool sync.Pool
ipv4MsgsPool sync.Pool
ipv6MsgsPool sync.Pool
// these two fields are not guarded by mu
udpAddrPool sync.Pool
msgsPool sync.Pool
blackhole4 bool
blackhole6 bool
@ -54,23 +58,14 @@ func NewStdNetBind() Bind {
},
},
ipv4MsgsPool: sync.Pool{
New: func() any {
msgs := make([]ipv4.Message, IdealBatchSize)
for i := range msgs {
msgs[i].Buffers = make(net.Buffers, 1)
msgs[i].OOB = make([]byte, srcControlSize)
}
return &msgs
},
},
ipv6MsgsPool: sync.Pool{
msgsPool: sync.Pool{
New: func() any {
// ipv6.Message and ipv4.Message are interchangeable as they are
// both aliases for x/net/internal/socket.Message.
msgs := make([]ipv6.Message, IdealBatchSize)
for i := range msgs {
msgs[i].Buffers = make(net.Buffers, 1)
msgs[i].OOB = make([]byte, srcControlSize)
msgs[i].OOB = make([]byte, controlSize)
}
return &msgs
},
@ -113,7 +108,7 @@ func (e *StdNetEndpoint) DstIP() netip.Addr {
return e.AddrPort.Addr()
}
// See sticky_default,linux, etc for implementations of SrcIP and SrcIfidx.
// See control_default,linux, etc for implementations of SrcIP and SrcIfidx.
func (e *StdNetEndpoint) DstToBytes() []byte {
b, _ := e.AddrPort.MarshalBinary()
@ -179,19 +174,21 @@ again:
}
var fns []ReceiveFunc
if v4conn != nil {
s.ipv4TxOffload, s.ipv4RxOffload = supportsUDPOffload(v4conn)
if runtime.GOOS == "linux" {
v4pc = ipv4.NewPacketConn(v4conn)
s.ipv4PC = v4pc
}
fns = append(fns, s.makeReceiveIPv4(v4pc, v4conn))
fns = append(fns, s.makeReceiveIPv4(v4pc, v4conn, s.ipv4RxOffload))
s.ipv4 = v4conn
}
if v6conn != nil {
s.ipv6TxOffload, s.ipv6RxOffload = supportsUDPOffload(v6conn)
if runtime.GOOS == "linux" {
v6pc = ipv6.NewPacketConn(v6conn)
s.ipv6PC = v6pc
}
fns = append(fns, s.makeReceiveIPv6(v6pc, v6conn))
fns = append(fns, s.makeReceiveIPv6(v6pc, v6conn, s.ipv6RxOffload))
s.ipv6 = v6conn
}
if len(fns) == 0 {
@ -201,69 +198,93 @@ again:
return fns, uint16(port), nil
}
func (s *StdNetBind) makeReceiveIPv4(pc *ipv4.PacketConn, conn *net.UDPConn) ReceiveFunc {
return func(bufs [][]byte, sizes []int, eps []Endpoint) (n int, err error) {
msgs := s.ipv4MsgsPool.Get().(*[]ipv4.Message)
defer s.ipv4MsgsPool.Put(msgs)
for i := range bufs {
(*msgs)[i].Buffers[0] = bufs[i]
}
var numMsgs int
if runtime.GOOS == "linux" {
numMsgs, err = pc.ReadBatch(*msgs, 0)
func (s *StdNetBind) putMessages(msgs *[]ipv6.Message) {
for i := range *msgs {
(*msgs)[i] = ipv6.Message{Buffers: (*msgs)[i].Buffers, OOB: (*msgs)[i].OOB}
}
s.msgsPool.Put(msgs)
}
func (s *StdNetBind) getMessages() *[]ipv6.Message {
return s.msgsPool.Get().(*[]ipv6.Message)
}
var (
// If compilation fails here these are no longer the same underlying type.
_ ipv6.Message = ipv4.Message{}
)
type batchReader interface {
ReadBatch([]ipv6.Message, int) (int, error)
}
type batchWriter interface {
WriteBatch([]ipv6.Message, int) (int, error)
}
func (s *StdNetBind) receiveIP(
br batchReader,
conn *net.UDPConn,
rxOffload bool,
bufs [][]byte,
sizes []int,
eps []Endpoint,
) (n int, err error) {
msgs := s.getMessages()
for i := range bufs {
(*msgs)[i].Buffers[0] = bufs[i]
(*msgs)[i].OOB = (*msgs)[i].OOB[:cap((*msgs)[i].OOB)]
}
defer s.putMessages(msgs)
var numMsgs int
if runtime.GOOS == "linux" {
if rxOffload {
readAt := len(*msgs) - (IdealBatchSize / udpSegmentMaxDatagrams)
numMsgs, err = br.ReadBatch((*msgs)[readAt:], 0)
if err != nil {
return 0, err
}
numMsgs, err = splitCoalescedMessages(*msgs, readAt, getGSOSize)
if err != nil {
return 0, err
}
} else {
msg := &(*msgs)[0]
msg.N, msg.NN, _, msg.Addr, err = conn.ReadMsgUDP(msg.Buffers[0], msg.OOB)
numMsgs, err = br.ReadBatch(*msgs, 0)
if err != nil {
return 0, err
}
numMsgs = 1
}
for i := 0; i < numMsgs; i++ {
msg := &(*msgs)[i]
sizes[i] = msg.N
addrPort := msg.Addr.(*net.UDPAddr).AddrPort()
ep := &StdNetEndpoint{AddrPort: addrPort} // TODO: remove allocation
getSrcFromControl(msg.OOB[:msg.NN], ep)
eps[i] = ep
} else {
msg := &(*msgs)[0]
msg.N, msg.NN, _, msg.Addr, err = conn.ReadMsgUDP(msg.Buffers[0], msg.OOB)
if err != nil {
return 0, err
}
return numMsgs, nil
numMsgs = 1
}
for i := 0; i < numMsgs; i++ {
msg := &(*msgs)[i]
sizes[i] = msg.N
if sizes[i] == 0 {
continue
}
addrPort := msg.Addr.(*net.UDPAddr).AddrPort()
ep := &StdNetEndpoint{AddrPort: addrPort} // TODO: remove allocation
getSrcFromControl(msg.OOB[:msg.NN], ep)
eps[i] = ep
}
return numMsgs, nil
}
func (s *StdNetBind) makeReceiveIPv4(pc *ipv4.PacketConn, conn *net.UDPConn, rxOffload bool) ReceiveFunc {
return func(bufs [][]byte, sizes []int, eps []Endpoint) (n int, err error) {
return s.receiveIP(pc, conn, rxOffload, bufs, sizes, eps)
}
}
func (s *StdNetBind) makeReceiveIPv6(pc *ipv6.PacketConn, conn *net.UDPConn) ReceiveFunc {
func (s *StdNetBind) makeReceiveIPv6(pc *ipv6.PacketConn, conn *net.UDPConn, rxOffload bool) ReceiveFunc {
return func(bufs [][]byte, sizes []int, eps []Endpoint) (n int, err error) {
msgs := s.ipv6MsgsPool.Get().(*[]ipv6.Message)
defer s.ipv6MsgsPool.Put(msgs)
for i := range bufs {
(*msgs)[i].Buffers[0] = bufs[i]
}
var numMsgs int
if runtime.GOOS == "linux" {
numMsgs, err = pc.ReadBatch(*msgs, 0)
if err != nil {
return 0, err
}
} else {
msg := &(*msgs)[0]
msg.N, msg.NN, _, msg.Addr, err = conn.ReadMsgUDP(msg.Buffers[0], msg.OOB)
if err != nil {
return 0, err
}
numMsgs = 1
}
for i := 0; i < numMsgs; i++ {
msg := &(*msgs)[i]
sizes[i] = msg.N
addrPort := msg.Addr.(*net.UDPAddr).AddrPort()
ep := &StdNetEndpoint{AddrPort: addrPort} // TODO: remove allocation
getSrcFromControl(msg.OOB[:msg.NN], ep)
eps[i] = ep
}
return numMsgs, nil
return s.receiveIP(pc, conn, rxOffload, bufs, sizes, eps)
}
}
@ -293,28 +314,42 @@ func (s *StdNetBind) Close() error {
}
s.blackhole4 = false
s.blackhole6 = false
s.ipv4TxOffload = false
s.ipv4RxOffload = false
s.ipv6TxOffload = false
s.ipv6RxOffload = false
if err1 != nil {
return err1
}
return err2
}
type ErrUDPGSODisabled struct {
onLaddr string
RetryErr error
}
func (e ErrUDPGSODisabled) Error() string {
return fmt.Sprintf("disabled UDP GSO on %s, NIC(s) may not support checksum offload", e.onLaddr)
}
func (e ErrUDPGSODisabled) Unwrap() error {
return e.RetryErr
}
func (s *StdNetBind) Send(bufs [][]byte, endpoint Endpoint) error {
s.mu.Lock()
blackhole := s.blackhole4
conn := s.ipv4
var (
pc4 *ipv4.PacketConn
pc6 *ipv6.PacketConn
)
offload := s.ipv4TxOffload
br := batchWriter(s.ipv4PC)
is6 := false
if endpoint.DstIP().Is6() {
blackhole = s.blackhole6
conn = s.ipv6
pc6 = s.ipv6PC
br = s.ipv6PC
is6 = true
} else {
pc4 = s.ipv4PC
offload = s.ipv6TxOffload
}
s.mu.Unlock()
@ -324,25 +359,56 @@ func (s *StdNetBind) Send(bufs [][]byte, endpoint Endpoint) error {
if conn == nil {
return syscall.EAFNOSUPPORT
}
msgs := s.getMessages()
defer s.putMessages(msgs)
ua := s.udpAddrPool.Get().(*net.UDPAddr)
defer s.udpAddrPool.Put(ua)
if is6 {
return s.send6(conn, pc6, endpoint, bufs)
as16 := endpoint.DstIP().As16()
copy(ua.IP, as16[:])
ua.IP = ua.IP[:16]
} else {
return s.send4(conn, pc4, endpoint, bufs)
as4 := endpoint.DstIP().As4()
copy(ua.IP, as4[:])
ua.IP = ua.IP[:4]
}
ua.Port = int(endpoint.(*StdNetEndpoint).Port())
var (
retried bool
err error
)
retry:
if offload {
n := coalesceMessages(ua, endpoint.(*StdNetEndpoint), bufs, *msgs, setGSOSize)
err = s.send(conn, br, (*msgs)[:n])
if err != nil && offload && errShouldDisableUDPGSO(err) {
offload = false
s.mu.Lock()
if is6 {
s.ipv6TxOffload = false
} else {
s.ipv4TxOffload = false
}
s.mu.Unlock()
retried = true
goto retry
}
} else {
for i := range bufs {
(*msgs)[i].Addr = ua
(*msgs)[i].Buffers[0] = bufs[i]
setSrcControl(&(*msgs)[i].OOB, endpoint.(*StdNetEndpoint))
}
err = s.send(conn, br, (*msgs)[:len(bufs)])
}
if retried {
return ErrUDPGSODisabled{onLaddr: conn.LocalAddr().String(), RetryErr: err}
}
return err
}
func (s *StdNetBind) send4(conn *net.UDPConn, pc *ipv4.PacketConn, ep Endpoint, bufs [][]byte) error {
ua := s.udpAddrPool.Get().(*net.UDPAddr)
as4 := ep.DstIP().As4()
copy(ua.IP, as4[:])
ua.IP = ua.IP[:4]
ua.Port = int(ep.(*StdNetEndpoint).Port())
msgs := s.ipv4MsgsPool.Get().(*[]ipv4.Message)
for i, buf := range bufs {
(*msgs)[i].Buffers[0] = buf
(*msgs)[i].Addr = ua
setSrcControl(&(*msgs)[i].OOB, ep.(*StdNetEndpoint))
}
func (s *StdNetBind) send(conn *net.UDPConn, pc batchWriter, msgs []ipv6.Message) error {
var (
n int
err error
@ -350,59 +416,128 @@ func (s *StdNetBind) send4(conn *net.UDPConn, pc *ipv4.PacketConn, ep Endpoint,
)
if runtime.GOOS == "linux" {
for {
n, err = pc.WriteBatch((*msgs)[start:len(bufs)], 0)
if err != nil || n == len((*msgs)[start:len(bufs)]) {
n, err = pc.WriteBatch(msgs[start:], 0)
if err != nil || n == len(msgs[start:]) {
break
}
start += n
}
} else {
for i, buf := range bufs {
_, _, err = conn.WriteMsgUDP(buf, (*msgs)[i].OOB, ua)
for _, msg := range msgs {
_, _, err = conn.WriteMsgUDP(msg.Buffers[0], msg.OOB, msg.Addr.(*net.UDPAddr))
if err != nil {
break
}
}
}
s.udpAddrPool.Put(ua)
s.ipv4MsgsPool.Put(msgs)
return err
}
func (s *StdNetBind) send6(conn *net.UDPConn, pc *ipv6.PacketConn, ep Endpoint, bufs [][]byte) error {
ua := s.udpAddrPool.Get().(*net.UDPAddr)
as16 := ep.DstIP().As16()
copy(ua.IP, as16[:])
ua.IP = ua.IP[:16]
ua.Port = int(ep.(*StdNetEndpoint).Port())
msgs := s.ipv6MsgsPool.Get().(*[]ipv6.Message)
for i, buf := range bufs {
(*msgs)[i].Buffers[0] = buf
(*msgs)[i].Addr = ua
setSrcControl(&(*msgs)[i].OOB, ep.(*StdNetEndpoint))
}
const (
// Exceeding these values results in EMSGSIZE. They account for layer3 and
// layer4 headers. IPv6 does not need to account for itself as the payload
// length field is self excluding.
maxIPv4PayloadLen = 1<<16 - 1 - 20 - 8
maxIPv6PayloadLen = 1<<16 - 1 - 8
// This is a hard limit imposed by the kernel.
udpSegmentMaxDatagrams = 64
)
type setGSOFunc func(control *[]byte, gsoSize uint16)
func coalesceMessages(addr *net.UDPAddr, ep *StdNetEndpoint, bufs [][]byte, msgs []ipv6.Message, setGSO setGSOFunc) int {
var (
n int
err error
start int
base = -1 // index of msg we are currently coalescing into
gsoSize int // segmentation size of msgs[base]
dgramCnt int // number of dgrams coalesced into msgs[base]
endBatch bool // tracking flag to start a new batch on next iteration of bufs
)
if runtime.GOOS == "linux" {
for {
n, err = pc.WriteBatch((*msgs)[start:len(bufs)], 0)
if err != nil || n == len((*msgs)[start:len(bufs)]) {
break
maxPayloadLen := maxIPv4PayloadLen
if ep.DstIP().Is6() {
maxPayloadLen = maxIPv6PayloadLen
}
for i, buf := range bufs {
if i > 0 {
msgLen := len(buf)
baseLenBefore := len(msgs[base].Buffers[0])
freeBaseCap := cap(msgs[base].Buffers[0]) - baseLenBefore
if msgLen+baseLenBefore <= maxPayloadLen &&
msgLen <= gsoSize &&
msgLen <= freeBaseCap &&
dgramCnt < udpSegmentMaxDatagrams &&
!endBatch {
msgs[base].Buffers[0] = append(msgs[base].Buffers[0], buf...)
if i == len(bufs)-1 {
setGSO(&msgs[base].OOB, uint16(gsoSize))
}
dgramCnt++
if msgLen < gsoSize {
// A smaller than gsoSize packet on the tail is legal, but
// it must end the batch.
endBatch = true
}
continue
}
start += n
}
} else {
for i, buf := range bufs {
_, _, err = conn.WriteMsgUDP(buf, (*msgs)[i].OOB, ua)
if err != nil {
break
if dgramCnt > 1 {
setGSO(&msgs[base].OOB, uint16(gsoSize))
}
// Reset prior to incrementing base since we are preparing to start a
// new potential batch.
endBatch = false
base++
gsoSize = len(buf)
setSrcControl(&msgs[base].OOB, ep)
msgs[base].Buffers[0] = buf
msgs[base].Addr = addr
dgramCnt = 1
}
return base + 1
}
type getGSOFunc func(control []byte) (int, error)
func splitCoalescedMessages(msgs []ipv6.Message, firstMsgAt int, getGSO getGSOFunc) (n int, err error) {
for i := firstMsgAt; i < len(msgs); i++ {
msg := &msgs[i]
if msg.N == 0 {
return n, err
}
var (
gsoSize int
start int
end = msg.N
numToSplit = 1
)
gsoSize, err = getGSO(msg.OOB[:msg.NN])
if err != nil {
return n, err
}
if gsoSize > 0 {
numToSplit = (msg.N + gsoSize - 1) / gsoSize
end = gsoSize
}
for j := 0; j < numToSplit; j++ {
if n > i {
return n, errors.New("splitting coalesced packet resulted in overflow")
}
copied := copy(msgs[n].Buffers[0], msg.Buffers[0][start:end])
msgs[n].N = copied
msgs[n].Addr = msg.Addr
start = end
end += gsoSize
if end > msg.N {
end = msg.N
}
n++
}
if i != n-1 {
// It is legal for bytes to move within msg.Buffers[0] as a result
// of splitting, so we only zero the source msg len when it is not
// the destination of the last split operation above.
msg.N = 0
}
}
s.udpAddrPool.Put(ua)
s.ipv6MsgsPool.Put(msgs)
return err
return n, nil
}

View File

@ -1,6 +1,12 @@
package conn
import "testing"
import (
"encoding/binary"
"net"
"testing"
"golang.org/x/net/ipv6"
)
func TestStdNetBindReceiveFuncAfterClose(t *testing.T) {
bind := NewStdNetBind().(*StdNetBind)
@ -20,3 +26,225 @@ func TestStdNetBindReceiveFuncAfterClose(t *testing.T) {
fn(bufs, sizes, eps)
}
}
func mockSetGSOSize(control *[]byte, gsoSize uint16) {
*control = (*control)[:cap(*control)]
binary.LittleEndian.PutUint16(*control, gsoSize)
}
func Test_coalesceMessages(t *testing.T) {
cases := []struct {
name string
buffs [][]byte
wantLens []int
wantGSO []int
}{
{
name: "one message no coalesce",
buffs: [][]byte{
make([]byte, 1, 1),
},
wantLens: []int{1},
wantGSO: []int{0},
},
{
name: "two messages equal len coalesce",
buffs: [][]byte{
make([]byte, 1, 2),
make([]byte, 1, 1),
},
wantLens: []int{2},
wantGSO: []int{1},
},
{
name: "two messages unequal len coalesce",
buffs: [][]byte{
make([]byte, 2, 3),
make([]byte, 1, 1),
},
wantLens: []int{3},
wantGSO: []int{2},
},
{
name: "three messages second unequal len coalesce",
buffs: [][]byte{
make([]byte, 2, 3),
make([]byte, 1, 1),
make([]byte, 2, 2),
},
wantLens: []int{3, 2},
wantGSO: []int{2, 0},
},
{
name: "three messages limited cap coalesce",
buffs: [][]byte{
make([]byte, 2, 4),
make([]byte, 2, 2),
make([]byte, 2, 2),
},
wantLens: []int{4, 2},
wantGSO: []int{2, 0},
},
}
for _, tt := range cases {
t.Run(tt.name, func(t *testing.T) {
addr := &net.UDPAddr{
IP: net.ParseIP("127.0.0.1").To4(),
Port: 1,
}
msgs := make([]ipv6.Message, len(tt.buffs))
for i := range msgs {
msgs[i].Buffers = make([][]byte, 1)
msgs[i].OOB = make([]byte, 0, 2)
}
got := coalesceMessages(addr, &StdNetEndpoint{AddrPort: addr.AddrPort()}, tt.buffs, msgs, mockSetGSOSize)
if got != len(tt.wantLens) {
t.Fatalf("got len %d want: %d", got, len(tt.wantLens))
}
for i := 0; i < got; i++ {
if msgs[i].Addr != addr {
t.Errorf("msgs[%d].Addr != passed addr", i)
}
gotLen := len(msgs[i].Buffers[0])
if gotLen != tt.wantLens[i] {
t.Errorf("len(msgs[%d].Buffers[0]) %d != %d", i, gotLen, tt.wantLens[i])
}
gotGSO, err := mockGetGSOSize(msgs[i].OOB)
if err != nil {
t.Fatalf("msgs[%d] getGSOSize err: %v", i, err)
}
if gotGSO != tt.wantGSO[i] {
t.Errorf("msgs[%d] gsoSize %d != %d", i, gotGSO, tt.wantGSO[i])
}
}
})
}
}
func mockGetGSOSize(control []byte) (int, error) {
if len(control) < 2 {
return 0, nil
}
return int(binary.LittleEndian.Uint16(control)), nil
}
func Test_splitCoalescedMessages(t *testing.T) {
newMsg := func(n, gso int) ipv6.Message {
msg := ipv6.Message{
Buffers: [][]byte{make([]byte, 1<<16-1)},
N: n,
OOB: make([]byte, 2),
}
binary.LittleEndian.PutUint16(msg.OOB, uint16(gso))
if gso > 0 {
msg.NN = 2
}
return msg
}
cases := []struct {
name string
msgs []ipv6.Message
firstMsgAt int
wantNumEval int
wantMsgLens []int
wantErr bool
}{
{
name: "second last split last empty",
msgs: []ipv6.Message{
newMsg(0, 0),
newMsg(0, 0),
newMsg(3, 1),
newMsg(0, 0),
},
firstMsgAt: 2,
wantNumEval: 3,
wantMsgLens: []int{1, 1, 1, 0},
wantErr: false,
},
{
name: "second last no split last empty",
msgs: []ipv6.Message{
newMsg(0, 0),
newMsg(0, 0),
newMsg(1, 0),
newMsg(0, 0),
},
firstMsgAt: 2,
wantNumEval: 1,
wantMsgLens: []int{1, 0, 0, 0},
wantErr: false,
},
{
name: "second last no split last no split",
msgs: []ipv6.Message{
newMsg(0, 0),
newMsg(0, 0),
newMsg(1, 0),
newMsg(1, 0),
},
firstMsgAt: 2,
wantNumEval: 2,
wantMsgLens: []int{1, 1, 0, 0},
wantErr: false,
},
{
name: "second last no split last split",
msgs: []ipv6.Message{
newMsg(0, 0),
newMsg(0, 0),
newMsg(1, 0),
newMsg(3, 1),
},
firstMsgAt: 2,
wantNumEval: 4,
wantMsgLens: []int{1, 1, 1, 1},
wantErr: false,
},
{
name: "second last split last split",
msgs: []ipv6.Message{
newMsg(0, 0),
newMsg(0, 0),
newMsg(2, 1),
newMsg(2, 1),
},
firstMsgAt: 2,
wantNumEval: 4,
wantMsgLens: []int{1, 1, 1, 1},
wantErr: false,
},
{
name: "second last no split last split overflow",
msgs: []ipv6.Message{
newMsg(0, 0),
newMsg(0, 0),
newMsg(1, 0),
newMsg(4, 1),
},
firstMsgAt: 2,
wantNumEval: 4,
wantMsgLens: []int{1, 1, 1, 1},
wantErr: true,
},
}
for _, tt := range cases {
t.Run(tt.name, func(t *testing.T) {
got, err := splitCoalescedMessages(tt.msgs, 2, mockGetGSOSize)
if err != nil && !tt.wantErr {
t.Fatalf("err: %v", err)
}
if got != tt.wantNumEval {
t.Fatalf("got to eval: %d want: %d", got, tt.wantNumEval)
}
for i, msg := range tt.msgs {
if msg.N != tt.wantMsgLens[i] {
t.Fatalf("msg[%d].N: %d want: %d", i, msg.N, tt.wantMsgLens[i])
}
}
})
}
}

View File

@ -21,8 +21,9 @@ func (e *StdNetEndpoint) SrcToString() string {
return ""
}
// TODO: macOS, FreeBSD and other BSDs likely do support this feature set, but
// use alternatively named flags and need ports and require testing.
// TODO: macOS, FreeBSD and other BSDs likely do support the sticky sockets
// {get,set}srcControl feature set, but use alternatively named flags and need
// ports and require testing.
// getSrcFromControl parses the control for PKTINFO and if found updates ep with
// the source information found.
@ -34,8 +35,17 @@ func getSrcFromControl(control []byte, ep *StdNetEndpoint) {
func setSrcControl(control *[]byte, ep *StdNetEndpoint) {
}
// srcControlSize returns the recommended buffer size for pooling sticky control
// data.
const srcControlSize = 0
// getGSOSize parses control for UDP_GRO and if found returns its GSO size data.
func getGSOSize(control []byte) (int, error) {
return 0, nil
}
// setGSOSize sets a UDP_SEGMENT in control based on gsoSize.
func setGSOSize(control *[]byte, gsoSize uint16) {
}
// controlSize returns the recommended buffer size for pooling sticky and UDP
// offloading control data.
const controlSize = 0
const StdNetSupportsStickySockets = false

View File

@ -8,6 +8,7 @@
package conn
import (
"fmt"
"net/netip"
"unsafe"
@ -105,6 +106,54 @@ func setSrcControl(control *[]byte, ep *StdNetEndpoint) {
*control = append(*control, ep.src...)
}
var srcControlSize = unix.CmsgSpace(unix.SizeofInet6Pktinfo)
const (
sizeOfGSOData = 2
)
// getGSOSize parses control for UDP_GRO and if found returns its GSO size data.
func getGSOSize(control []byte) (int, error) {
var (
hdr unix.Cmsghdr
data []byte
rem = control
err error
)
for len(rem) > unix.SizeofCmsghdr {
hdr, data, rem, err = unix.ParseOneSocketControlMessage(rem)
if err != nil {
return 0, fmt.Errorf("error parsing socket control message: %w", err)
}
if hdr.Level == unix.SOL_UDP && hdr.Type == unix.UDP_GRO && len(data) >= sizeOfGSOData {
var gso uint16
copy(unsafe.Slice((*byte)(unsafe.Pointer(&gso)), sizeOfGSOData), data[:sizeOfGSOData])
return int(gso), nil
}
}
return 0, nil
}
// setGSOSize sets a UDP_SEGMENT in control based on gsoSize. It leaves existing
// data in control untouched.
func setGSOSize(control *[]byte, gsoSize uint16) {
existingLen := len(*control)
avail := cap(*control) - existingLen
space := unix.CmsgSpace(sizeOfGSOData)
if avail < space {
return
}
*control = (*control)[:cap(*control)]
gsoControl := (*control)[existingLen:]
hdr := (*unix.Cmsghdr)(unsafe.Pointer(&(gsoControl)[0]))
hdr.Level = unix.SOL_UDP
hdr.Type = unix.UDP_SEGMENT
hdr.SetLen(unix.CmsgLen(sizeOfGSOData))
copy((gsoControl)[unix.SizeofCmsghdr:], unsafe.Slice((*byte)(unsafe.Pointer(&gsoSize)), sizeOfGSOData))
*control = (*control)[:existingLen+space]
}
// controlSize returns the recommended buffer size for pooling sticky and UDP
// offloading control data.
var controlSize = unix.CmsgSpace(unix.SizeofInet6Pktinfo) + unix.CmsgSpace(sizeOfGSOData)
const StdNetSupportsStickySockets = true

View File

@ -60,7 +60,7 @@ func Test_setSrcControl(t *testing.T) {
}
setSrc(ep, netip.MustParseAddr("127.0.0.1"), 5)
control := make([]byte, srcControlSize)
control := make([]byte, controlSize)
setSrcControl(&control, ep)
@ -89,7 +89,7 @@ func Test_setSrcControl(t *testing.T) {
}
setSrc(ep, netip.MustParseAddr("::1"), 5)
control := make([]byte, srcControlSize)
control := make([]byte, controlSize)
setSrcControl(&control, ep)
@ -113,7 +113,7 @@ func Test_setSrcControl(t *testing.T) {
})
t.Run("ClearOnNoSrc", func(t *testing.T) {
control := make([]byte, unix.CmsgLen(0))
control := make([]byte, controlSize)
hdr := (*unix.Cmsghdr)(unsafe.Pointer(&control[0]))
hdr.Level = 1
hdr.Type = 2
@ -129,7 +129,7 @@ func Test_setSrcControl(t *testing.T) {
func Test_getSrcFromControl(t *testing.T) {
t.Run("IPv4", func(t *testing.T) {
control := make([]byte, unix.CmsgSpace(unix.SizeofInet4Pktinfo))
control := make([]byte, controlSize)
hdr := (*unix.Cmsghdr)(unsafe.Pointer(&control[0]))
hdr.Level = unix.IPPROTO_IP
hdr.Type = unix.IP_PKTINFO
@ -149,7 +149,7 @@ func Test_getSrcFromControl(t *testing.T) {
}
})
t.Run("IPv6", func(t *testing.T) {
control := make([]byte, unix.CmsgSpace(unix.SizeofInet6Pktinfo))
control := make([]byte, controlSize)
hdr := (*unix.Cmsghdr)(unsafe.Pointer(&control[0]))
hdr.Level = unix.IPPROTO_IPV6
hdr.Type = unix.IPV6_PKTINFO

View File

@ -57,5 +57,13 @@ func init() {
}
return err
},
// Attempt to enable UDP_GRO
func(network, address string, c syscall.RawConn) error {
c.Control(func(fd uintptr) {
_ = unix.SetsockoptInt(int(fd), unix.IPPROTO_UDP, unix.UDP_GRO, 1)
})
return nil
},
)
}

12
conn/errors_default.go Normal file
View File

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

26
conn/errors_linux.go Normal file
View File

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

15
conn/features_default.go Normal file
View File

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

35
conn/features_linux.go Normal file
View File

@ -0,0 +1,35 @@
/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
*/
package conn
import (
"net"
"golang.org/x/sys/unix"
)
func supportsUDPOffload(conn *net.UDPConn) (txOffload, rxOffload bool) {
rc, err := conn.SyscallConn()
if err != nil {
return
}
err = rc.Control(func(fd uintptr) {
_, errSyscall := unix.GetsockoptInt(int(fd), unix.IPPROTO_UDP, unix.UDP_SEGMENT)
if errSyscall != nil {
return
}
txOffload = true
opt, errSyscall := unix.GetsockoptInt(int(fd), unix.IPPROTO_UDP, unix.UDP_GRO)
if errSyscall != nil {
return
}
rxOffload = opt == 1
})
if err != nil {
return false, false
}
return txOffload, rxOffload
}

View File

@ -17,6 +17,7 @@ import (
"golang.org/x/crypto/chacha20poly1305"
"golang.org/x/net/ipv4"
"golang.org/x/net/ipv6"
"golang.zx2c4.com/wireguard/conn"
"golang.zx2c4.com/wireguard/tun"
)
@ -525,6 +526,13 @@ func (peer *Peer) RoutineSequentialSender(maxBatchSize int) {
device.PutOutboundElement(elem)
}
device.PutOutboundElementsSlice(elems)
if err != nil {
var errGSO conn.ErrUDPGSODisabled
if errors.As(err, &errGSO) {
device.log.Verbosef(err.Error())
err = errGSO.RetryErr
}
}
if err != nil {
device.log.Errorf("%v - Failed to send data packets: %v", peer, err)
continue

2
go.mod
View File

@ -5,7 +5,7 @@ go 1.20
require (
golang.org/x/crypto v0.6.0
golang.org/x/net v0.7.0
golang.org/x/sys v0.5.1-0.20230222185716-a3b23cc77e89
golang.org/x/sys v0.12.0
golang.zx2c4.com/wintun v0.0.0-20230126152724-0fa3db229ce2
gvisor.dev/gvisor v0.0.0-20221203005347-703fd9b7fbc0
)

4
go.sum
View File

@ -4,8 +4,8 @@ golang.org/x/crypto v0.6.0 h1:qfktjS5LUO+fFKeJXZ+ikTRijMmljikvG68fpMMruSc=
golang.org/x/crypto v0.6.0/go.mod h1:OFC/31mSvZgRz0V1QTNCzfAI1aIRzbiufJtkMIlEp58=
golang.org/x/net v0.7.0 h1:rJrUqqhjsgNp7KqAIc25s9pZnjU7TUcSY7HcVZjdn1g=
golang.org/x/net v0.7.0/go.mod h1:2Tu9+aMcznHK/AK1HMvgo6xiTLG5rD5rZLDS+rp2Bjs=
golang.org/x/sys v0.5.1-0.20230222185716-a3b23cc77e89 h1:260HNjMTPDya+jq5AM1zZLgG9pv9GASPAGiEEJUbRg4=
golang.org/x/sys v0.5.1-0.20230222185716-a3b23cc77e89/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.12.0 h1:CM0HF96J0hcLAwsHPJZjfdNzs0gftsLfgKt57wWHJ0o=
golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/time v0.0.0-20191024005414-555d28b269f0 h1:/5xXl8Y5W96D+TtHSlonuFqGHIWVuyCkGJLwGh9JJFs=
golang.org/x/time v0.0.0-20191024005414-555d28b269f0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
golang.zx2c4.com/wintun v0.0.0-20230126152724-0fa3db229ce2 h1:B82qJJgjvYKsXS9jeunTOisW56dUokqW/FOteYJJ/yg=