TUN-8641: Expose methods to simplify V3 Datagram parsing on the edge

This commit is contained in:
Gonçalo Garcia 2024-11-04 15:23:36 -08:00
parent 589c198d2d
commit 3d33f559b1
5 changed files with 37 additions and 11 deletions

View File

@ -27,7 +27,7 @@ const (
maxDatagramPayloadLen = 1280
)
func parseDatagramType(data []byte) (DatagramType, error) {
func ParseDatagramType(data []byte) (DatagramType, error) {
if len(data) < datagramTypeLen {
return 0, ErrDatagramHeaderTooSmall
}
@ -140,7 +140,7 @@ func (s *UDPSessionRegistrationDatagram) MarshalBinary() (data []byte, err error
}
func (s *UDPSessionRegistrationDatagram) UnmarshalBinary(data []byte) error {
datagramType, err := parseDatagramType(data)
datagramType, err := ParseDatagramType(data)
if err != nil {
return err
}
@ -192,10 +192,10 @@ type UDPSessionPayloadDatagram struct {
}
const (
datagramPayloadHeaderLen = datagramTypeLen + datagramRequestIdLen
DatagramPayloadHeaderLen = datagramTypeLen + datagramRequestIdLen
// The maximum size that a proxied UDP payload can be in a [UDPSessionPayloadDatagram]
maxPayloadPlusHeaderLen = maxDatagramPayloadLen + datagramPayloadHeaderLen
maxPayloadPlusHeaderLen = maxDatagramPayloadLen + DatagramPayloadHeaderLen
)
// The datagram structure for UDPSessionPayloadDatagram is:
@ -230,7 +230,7 @@ func MarshalPayloadHeaderTo(requestID RequestID, payload []byte) error {
}
func (s *UDPSessionPayloadDatagram) UnmarshalBinary(data []byte) error {
datagramType, err := parseDatagramType(data)
datagramType, err := ParseDatagramType(data)
if err != nil {
return err
}
@ -332,7 +332,7 @@ func (s *UDPSessionRegistrationResponseDatagram) MarshalBinary() (data []byte, e
}
func (s *UDPSessionRegistrationResponseDatagram) UnmarshalBinary(data []byte) error {
datagramType, err := parseDatagramType(data)
datagramType, err := ParseDatagramType(data)
if err != nil {
return wrapUnmarshalErr(err)
}

View File

@ -122,7 +122,7 @@ func (c *datagramConn) Serve(ctx context.Context) error {
// Each incoming datagram will be processed in a new go routine to handle the demuxing and action associated.
go func() {
typ, err := parseDatagramType(datagram)
typ, err := ParseDatagramType(datagram)
if err != nil {
c.logger.Err(err).Msgf("unable to parse datagram type: %d", typ)
return

View File

@ -75,3 +75,15 @@ func (id RequestID) MarshalBinaryTo(data []byte) error {
binary.BigEndian.PutUint64(data[8:], id.lo)
return nil
}
func (id *RequestID) UnmarshalBinary(data []byte) error {
if len(data) != 16 {
return fmt.Errorf("invalid length slice provided to unmarshal: %d (expected 16)", len(data))
}
*id = RequestID{
binary.BigEndian.Uint64(data[:8]),
binary.BigEndian.Uint64(data[8:]),
}
return nil
}

View File

@ -5,6 +5,8 @@ import (
"slices"
"testing"
"github.com/stretchr/testify/require"
v3 "github.com/cloudflare/cloudflared/quic/v3"
)
@ -48,3 +50,15 @@ func TestRequestIDParsing(t *testing.T) {
t.Fatalf("buf1 != buf2: %+v %+v", buf1, buf2)
}
}
func TestRequestID_MarshalBinary(t *testing.T) {
buf := make([]byte, 16)
err := testRequestID.MarshalBinaryTo(buf)
require.NoError(t, err)
require.Len(t, buf, 16)
parsed := v3.RequestID{}
err = parsed.UnmarshalBinary(buf)
require.NoError(t, err)
require.Equal(t, testRequestID, parsed)
}

View File

@ -84,14 +84,14 @@ func (s *session) Serve(ctx context.Context) error {
go func() {
// QUIC implementation copies data to another buffer before returning https://github.com/quic-go/quic-go/blob/v0.24.0/session.go#L1967-L1975
// This makes it safe to share readBuffer between iterations
readBuffer := [maxOriginUDPPacketSize + datagramPayloadHeaderLen]byte{}
readBuffer := [maxOriginUDPPacketSize + DatagramPayloadHeaderLen]byte{}
// To perform a zero copy write when passing the datagram to the connection, we prepare the buffer with
// the required datagram header information. We can reuse this buffer for this session since the header is the
// same for the each read.
MarshalPayloadHeaderTo(s.id, readBuffer[:datagramPayloadHeaderLen])
MarshalPayloadHeaderTo(s.id, readBuffer[:DatagramPayloadHeaderLen])
for {
// Read from the origin UDP socket
n, err := s.origin.Read(readBuffer[datagramPayloadHeaderLen:])
n, err := s.origin.Read(readBuffer[DatagramPayloadHeaderLen:])
if errors.Is(err, net.ErrClosed) || errors.Is(err, io.EOF) || errors.Is(err, io.ErrUnexpectedEOF) {
s.log.Debug().Msg("Session (origin) connection closed")
}
@ -109,7 +109,7 @@ func (s *session) Serve(ctx context.Context) error {
}
// Sending a packet to the session does block on the [quic.Connection], however, this is okay because it
// will cause back-pressure to the kernel buffer if the writes are not fast enough to the edge.
err = s.eyeball.SendUDPSessionDatagram(readBuffer[:datagramPayloadHeaderLen+n])
err = s.eyeball.SendUDPSessionDatagram(readBuffer[:DatagramPayloadHeaderLen+n])
if err != nil {
s.closeChan <- err
return