harness-drone/vendor/github.com/lucas-clemente/quic-go/packet_unpacker.go
2017-07-24 19:15:25 -04:00

119 lines
3.2 KiB
Go

package quic
import (
"bytes"
"errors"
"fmt"
"github.com/lucas-clemente/quic-go/frames"
"github.com/lucas-clemente/quic-go/protocol"
"github.com/lucas-clemente/quic-go/qerr"
)
type unpackedPacket struct {
encryptionLevel protocol.EncryptionLevel
frames []frames.Frame
}
type quicAEAD interface {
Open(dst, src []byte, packetNumber protocol.PacketNumber, associatedData []byte) ([]byte, protocol.EncryptionLevel, error)
}
type packetUnpacker struct {
version protocol.VersionNumber
aead quicAEAD
}
func (u *packetUnpacker) Unpack(publicHeaderBinary []byte, hdr *PublicHeader, data []byte) (*unpackedPacket, error) {
buf := getPacketBuffer()
defer putPacketBuffer(buf)
decrypted, encryptionLevel, err := u.aead.Open(buf, data, hdr.PacketNumber, publicHeaderBinary)
if err != nil {
// Wrap err in quicError so that public reset is sent by session
return nil, qerr.Error(qerr.DecryptionFailure, err.Error())
}
r := bytes.NewReader(decrypted)
if r.Len() == 0 {
return nil, qerr.MissingPayload
}
fs := make([]frames.Frame, 0, 2)
// Read all frames in the packet
for r.Len() > 0 {
typeByte, _ := r.ReadByte()
if typeByte == 0x0 { // PADDING frame
continue
}
r.UnreadByte()
var frame frames.Frame
if typeByte&0x80 == 0x80 {
frame, err = frames.ParseStreamFrame(r)
if err != nil {
err = qerr.Error(qerr.InvalidStreamData, err.Error())
} else {
streamID := frame.(*frames.StreamFrame).StreamID
if streamID != 1 && encryptionLevel <= protocol.EncryptionUnencrypted {
err = qerr.Error(qerr.UnencryptedStreamData, fmt.Sprintf("received unencrypted stream data on stream %d", streamID))
}
}
} else if typeByte&0xc0 == 0x40 {
frame, err = frames.ParseAckFrame(r, u.version)
if err != nil {
err = qerr.Error(qerr.InvalidAckData, err.Error())
}
} else if typeByte&0xe0 == 0x20 {
err = errors.New("unimplemented: CONGESTION_FEEDBACK")
} else {
switch typeByte {
case 0x01:
frame, err = frames.ParseRstStreamFrame(r)
if err != nil {
err = qerr.Error(qerr.InvalidRstStreamData, err.Error())
}
case 0x02:
frame, err = frames.ParseConnectionCloseFrame(r)
if err != nil {
err = qerr.Error(qerr.InvalidConnectionCloseData, err.Error())
}
case 0x03:
frame, err = frames.ParseGoawayFrame(r)
if err != nil {
err = qerr.Error(qerr.InvalidGoawayData, err.Error())
}
case 0x04:
frame, err = frames.ParseWindowUpdateFrame(r)
if err != nil {
err = qerr.Error(qerr.InvalidWindowUpdateData, err.Error())
}
case 0x05:
frame, err = frames.ParseBlockedFrame(r)
if err != nil {
err = qerr.Error(qerr.InvalidBlockedData, err.Error())
}
case 0x06:
frame, err = frames.ParseStopWaitingFrame(r, hdr.PacketNumber, hdr.PacketNumberLen, u.version)
if err != nil {
err = qerr.Error(qerr.InvalidStopWaitingData, err.Error())
}
case 0x07:
frame, err = frames.ParsePingFrame(r)
default:
err = qerr.Error(qerr.InvalidFrameData, fmt.Sprintf("unknown type byte 0x%x", typeByte))
}
}
if err != nil {
return nil, err
}
if frame != nil {
fs = append(fs, frame)
}
}
return &unpackedPacket{
encryptionLevel: encryptionLevel,
frames: fs,
}, nil
}