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TUN-6584: Define QUIC datagram v2 format to support proxying IP packets

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This commit is contained in:
cthuang
2022-08-01 13:48:33 +01:00
committed by Chung-Ting Huang
parent d3fd581b7b
commit 278df5478a
12 changed files with 548 additions and 352 deletions
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92
quic/datagram.go
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@@ -1,6 +1,7 @@
package quic
import (
"context"
"fmt"
"github.com/google/uuid"
@@ -13,53 +14,88 @@ const (
sessionIDLen = len(uuid.UUID{})
)
type SessionDatagram struct {
ID uuid.UUID
Payload []byte
}
type BaseDatagramMuxer interface {
// MuxSession suffix the session ID to the payload so the other end of the QUIC connection can demultiplex the
// payload from multiple datagram sessions
MuxSession(sessionID uuid.UUID, payload []byte) error
// ServeReceive starts a loop to receive datagrams from the QUIC connection
ServeReceive(ctx context.Context) error
}
type DatagramMuxer struct {
session quic.Connection
logger *zerolog.Logger
session quic.Connection
logger *zerolog.Logger
demuxChan chan<- *SessionDatagram
}
func NewDatagramMuxer(quicSession quic.Connection, logger *zerolog.Logger) (*DatagramMuxer, error) {
func NewDatagramMuxer(quicSession quic.Connection, log *zerolog.Logger, demuxChan chan<- *SessionDatagram) *DatagramMuxer {
logger := log.With().Uint8("datagramVersion", 1).Logger()
return &DatagramMuxer{
session: quicSession,
logger: logger,
}, nil
session: quicSession,
logger: &logger,
demuxChan: demuxChan,
}
}
// SendTo suffix the session ID to the payload so the other end of the QUIC session can demultiplex
// the payload from multiple datagram sessions
func (dm *DatagramMuxer) SendTo(sessionID uuid.UUID, payload []byte) error {
if len(payload) > maxDatagramPayloadSize {
// Maximum application payload to send to / receive from QUIC datagram frame
func (dm *DatagramMuxer) mtu() int {
return maxDatagramPayloadSize
}
func (dm *DatagramMuxer) MuxSession(sessionID uuid.UUID, payload []byte) error {
if len(payload) > dm.mtu() {
// TODO: TUN-5302 return ICMP packet too big message
return fmt.Errorf("origin UDP payload has %d bytes, which exceeds transport MTU %d", len(payload), dm.MTU())
// drop packet for now, eventually reply with ICMP for PMTUD
return fmt.Errorf("origin UDP payload has %d bytes, which exceeds transport MTU %d", len(payload), dm.mtu())
}
msgWithID, err := suffixSessionID(sessionID, payload)
payloadWithMetadata, err := suffixSessionID(sessionID, payload)
if err != nil {
return errors.Wrap(err, "Failed to suffix session ID to datagram, it will be dropped")
}
if err := dm.session.SendMessage(msgWithID); err != nil {
if err := dm.session.SendMessage(payloadWithMetadata); err != nil {
return errors.Wrap(err, "Failed to send datagram back to edge")
}
return nil
}
// ReceiveFrom extracts datagram session ID, then sends the session ID and payload to session manager
// which determines how to proxy to the origin. It assumes the datagram session has already been
// registered with session manager through other side channel
func (dm *DatagramMuxer) ReceiveFrom() (uuid.UUID, []byte, error) {
msg, err := dm.session.ReceiveMessage()
if err != nil {
return uuid.Nil, nil, err
func (dm *DatagramMuxer) ServeReceive(ctx context.Context) error {
for {
// Extracts datagram session ID, then sends the session ID and payload to receiver
// which determines how to proxy to the origin. It assumes the datagram session has already been
// registered with receiver through other side channel
msg, err := dm.session.ReceiveMessage()
if err != nil {
return err
}
if err := dm.demux(ctx, msg); err != nil {
dm.logger.Error().Err(err).Msg("Failed to demux datagram")
if err == context.Canceled {
return err
}
}
}
sessionID, payload, err := extractSessionID(msg)
if err != nil {
return uuid.Nil, nil, err
}
return sessionID, payload, nil
}
// Maximum application payload to send to / receive from QUIC datagram frame
func (dm *DatagramMuxer) MTU() int {
return maxDatagramPayloadSize
func (dm *DatagramMuxer) demux(ctx context.Context, msg []byte) error {
sessionID, payload, err := extractSessionID(msg)
if err != nil {
return err
}
sessionDatagram := SessionDatagram{
ID: sessionID,
Payload: payload,
}
select {
case dm.demuxChan <- &sessionDatagram:
return nil
case <-ctx.Done():
return ctx.Err()
}
}
// Each QUIC datagram should be suffixed with session ID.