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connection.go
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connection.go
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/*
Package minq is a minimal implementation of QUIC, as documented at
https://quicwg.github.io/. Minq partly implements draft-04.
*/
package minq
import (
"bytes"
"crypto"
"crypto/rand"
"encoding/hex"
"fmt"
"io"
"time"
"github.com/bifurcation/mint"
// "github.com/bifurcation/mint/syntax"
)
// Role determines whether an endpoint is client or server.
type Role uint8
// These are roles.
const (
RoleClient = Role(1)
RoleServer = Role(2)
)
var HsEpochs = []mint.Epoch{mint.EpochClear, mint.EpochHandshakeData}
// State is the state of a QUIC connection.
type State uint8
// These are connection states.
const (
StateInit = State(1)
StateWaitClientInitial = State(2)
StateWaitServerInitial = State(3)
StateWaitServerFirstFlight = State(4)
StateWaitClientSecondFlight = State(5)
StateEstablished = State(6)
StateClosing = State(7)
StateClosed = State(8)
StateError = State(9)
)
const (
kMinimumClientInitialLength = 1200 // draft-ietf-quic-transport S 9.0
kLongHeaderLength = 12 // omits connection ID lengths
kInitialIntegrityCheckLength = 16 // Overhead.
kInitialMTU = 1252 // 1280 - UDP headers.
)
// The protocol version number.
type VersionNumber uint32
const (
kQuicDraftVersion = 15
kQuicVersion = VersionNumber(0xff000000 | kQuicDraftVersion)
kQuicGreaseVersion1 = VersionNumber(0x1a1a1a1a)
kQuicGreaseVersion2 = VersionNumber(0x2a2a2a2a)
)
const (
kQuicALPNToken = "hq-13"
)
// Interface for the handler object which the Connection will call
// to notify of events on the connection.
type ConnectionHandler interface {
// The connection has changed state to state |s|
StateChanged(s State)
// NewRecvStream indicates that a new unidirectional stream has been
// created by the remote peer. |s| contains the stream.
NewRecvStream(s RecvStream)
// NewStream indicates that a new bidirectional stream has been
// created by the remote peer. |s| contains the stream.
NewStream(s Stream)
// StreamReadable indicates that |s| is now readable.
StreamReadable(s RecvStream)
}
// Internal structures indicating ranges to ACK
type ackRange struct {
lastPacket uint64 // Packet with highest pn in range
count uint64 // Total number of packets in range
}
type ackRanges []ackRange
/*
Connection represents a QUIC connection. Clients can make
connections directly but servers should create a minq.Server
object which creates Connections as a side effect.
The control discipline is entirely operated by the consuming
application. It has two major responsibilities:
1. Deliver any incoming datagrams using Input()
2. Periodically call CheckTimer(). In future there will be some
way to know how often to call it, but right now it treats
every call to CheckTimer() as timer expiry.
The application provides a handler object which the Connection
calls to notify it of various events.
*/
type encryptionLevel struct {
epoch mint.Epoch
nextSendPacket uint64
sendCipher *cryptoState
recvCipher *cryptoState
sendCryptoStream SendStream
recvCryptoStream RecvStream
outputQ []*frame
recvd *recvdPackets
}
func (el *encryptionLevel) packetType() packetType {
return []packetType{
packetTypeInitial,
packetType0RTTProtected,
packetTypeHandshake,
packetTypeProtectedShort,
}[el.epoch]
}
type Connection struct {
handler ConnectionHandler
role Role
state State
version VersionNumber
clientConnectionId ConnectionId
serverConnectionId ConnectionId
transport Transport
tls *tlsConn
encryptionLevels []*encryptionLevel
recvCryptoEpoch mint.Epoch
mtu int
localBidiStreams *streamSet
remoteBidiStreams *streamSet
localUniStreams *streamSet
remoteUniStreams *streamSet
clientInitial []byte
sendFlowControl flowControl
recvFlowControl flowControl
amountRead uint64
sentAcks map[uint64]ackRanges
lastInput time.Time
idleTimeout time.Duration
tpHandler *transportParametersHandler
log loggingFunction
retransmitTime time.Duration
congestion CongestionController
lastSendQueuedTime time.Time
closingEnd time.Time
closePacket []byte
}
// Create a new QUIC connection. Should only be used with role=RoleClient,
// though we use it with RoleServer internally.
func NewConnection(trans Transport, role Role, tls *TlsConfig, handler ConnectionHandler) *Connection {
mint.HkdfLabelPrefix = "quic "
c := &Connection{
handler: handler,
role: role,
state: StateInit,
version: kQuicVersion,
clientConnectionId: nil,
serverConnectionId: nil,
transport: trans,
tls: nil,
encryptionLevels: make([]*encryptionLevel, 4),
recvCryptoEpoch: mint.EpochClear,
mtu: kInitialMTU,
localBidiStreams: newStreamSet(streamTypeBidirectionalLocal, role, 1),
remoteBidiStreams: newStreamSet(streamTypeBidirectionalRemote, role, kConcurrentStreamsBidi),
localUniStreams: newStreamSet(streamTypeUnidirectionalLocal, role, 0),
remoteUniStreams: newStreamSet(streamTypeUnidirectionalRemote, role, kConcurrentStreamsUni),
clientInitial: nil,
sendFlowControl: flowControl{false, 0, 0},
recvFlowControl: flowControl{false, kInitialMaxData, 0},
amountRead: 0,
sentAcks: make(map[uint64]ackRanges, 0),
lastInput: time.Now(),
idleTimeout: time.Second * 5, // a pretty short time
tpHandler: nil,
log: nil,
retransmitTime: kDefaultInitialRtt,
congestion: nil,
lastSendQueuedTime: time.Now(),
closingEnd: time.Time{}, // Zero time
closePacket: nil,
}
c.log = newConnectionLogger(c)
c.tls = newTlsConn(c, tls, role)
//c.congestion = newCongestionControllerIetf(c)
c.congestion = &CongestionControllerDummy{}
c.congestion.setLostPacketHandler(c.handleLostPacket)
// TODO([email protected]): This isn't generic, but rather tied to
// Mint.
c.tpHandler = newTransportParametersHandler(c.log, role, kQuicVersion)
c.tls.setTransportParametersHandler(c.tpHandler)
for i := int(0); i < 4; i++ {
el := encryptionLevel{
nextSendPacket: 1,
epoch: mint.Epoch(i),
sendCipher: nil,
recvCipher: nil,
// We are using the streams data structures, but without flow control
sendCryptoStream: newSendStream(c, ^uint64(uint64(i)), ^uint64(0)),
recvCryptoStream: newRecvStream(c, ^uint64(uint64(i)), ^uint64(0)),
}
// TODO([email protected]): 0-RTT and 1-RTT should share these somehow.
el.outputQ = make([]*frame, 0)
el.recvd = newRecvdPackets(c.log)
c.encryptionLevels[i] = &el
}
var err error
if role == RoleClient {
c.serverConnectionId, err = c.randomConnectionId(8)
if err != nil {
return nil
}
c.clientConnectionId, err = c.randomConnectionId(kCidDefaultLength)
if err != nil {
return nil
}
err = c.setupAeadMasking(c.serverConnectionId)
if err != nil {
return nil
}
} else {
c.serverConnectionId, err = c.randomConnectionId(kCidDefaultLength)
if err != nil {
return nil
}
c.setState(StateWaitClientInitial)
}
return c
}
func (c *Connection) String() string {
return fmt.Sprintf("Conn: %v_%v: %s", c.clientConnectionId, c.serverConnectionId, c.role)
}
func (c *Connection) zeroRttAllowed() bool {
// Placeholder
return false
}
func (c *Connection) start() error {
return nil
}
func (c *Connection) Role() Role {
return c.role
}
func (r Role) String() string {
switch r {
case RoleClient:
return "client"
case RoleServer:
return "server"
default:
panic("invalid role")
}
}
func (c *Connection) setState(state State) {
if c.state == state {
return
}
c.log(logTypeConnection, "Connection state %v -> %v", c.state, state)
if c.handler != nil {
c.handler.StateChanged(state)
}
c.state = state
}
func (state State) String() string {
// TODO([email protected]): is there a way to get the name from the
// const value.
switch state {
case StateInit:
return "StateInit"
case StateWaitClientInitial:
return "StateWaitClientInitial"
case StateWaitServerInitial:
return "StateWaitServerInitial"
case StateWaitServerFirstFlight:
return "StateWaitServerFirstFlight"
case StateWaitClientSecondFlight:
return "StateWaitClientSecondFlight"
case StateEstablished:
return "StateEstablished"
case StateClosing:
return "StateClosing"
case StateClosed:
return "StateClosed"
case StateError:
return "StateError"
default:
return "Unknown state"
}
}
// ClientId returns the current identity, as dictated by the client.
func (c *Connection) ClientId() ConnectionId {
return c.clientConnectionId
}
// ServerId returns the current identity, as dictated by the server.
func (c *Connection) ServerId() ConnectionId {
return c.serverConnectionId
}
func (c *Connection) ensureRemoteBidi(id uint64) hasIdentity {
return c.remoteBidiStreams.ensure(id, func(x uint64) hasIdentity {
msd := uint64(c.tpHandler.peerParams.maxStreamDataBidiRemote)
return newStream(c, x, kInitialMaxStreamData, msd)
}, func(s hasIdentity) {
if c.handler != nil {
c.log(logTypeStream, "Created Stream %v", s.Id())
c.handler.NewStream(s.(Stream))
}
})
}
// This manages the creation of local and remote bidirectional streams as well
// as remote unidirectional streams.
func (c *Connection) ensureSendStream(id uint64) sendStreamPrivate {
var s hasIdentity
switch streamTypeFromId(id, c.role) {
case streamTypeBidirectionalLocal:
s = c.localBidiStreams.get(id)
case streamTypeBidirectionalRemote:
s = c.ensureRemoteBidi(id)
case streamTypeUnidirectionalLocal:
s = c.localUniStreams.get(id)
default:
// Local unidirectional streams can't receive.
return nil
}
if s == nil {
return nil
}
return s.(sendStreamPrivate)
}
// This manages the creation of local and remote bidirectional streams as well
// as remote unidirectional streams.
func (c *Connection) ensureRecvStream(id uint64) recvStreamPrivate {
var s hasIdentity
switch streamTypeFromId(id, c.role) {
case streamTypeBidirectionalLocal:
s = c.localBidiStreams.get(id)
case streamTypeBidirectionalRemote:
s = c.ensureRemoteBidi(id)
case streamTypeUnidirectionalRemote:
s = c.remoteUniStreams.ensure(id, func(x uint64) hasIdentity {
return newRecvStream(c, x, kInitialMaxStreamData)
}, func(s hasIdentity) {
if c.handler != nil {
c.log(logTypeStream, "Created RecvStream %v", s.Id())
c.handler.NewRecvStream(s.(RecvStream))
}
})
default:
// Local unidirectional streams can't receive.
return nil
}
if s == nil {
return nil
}
return s.(recvStreamPrivate)
}
func (c *Connection) forEachSend(f func(sendStreamPrivate)) {
c.localBidiStreams.forEach(func(s hasIdentity) {
f(s.(sendStreamPrivate))
})
c.remoteBidiStreams.forEach(func(s hasIdentity) {
f(s.(sendStreamPrivate))
})
c.localUniStreams.forEach(func(s hasIdentity) {
f(s.(sendStreamPrivate))
})
}
func (c *Connection) forEachRecv(f func(recvStreamPrivate)) {
c.localBidiStreams.forEach(func(s hasIdentity) {
f(s.(recvStreamPrivate))
})
c.remoteBidiStreams.forEach(func(s hasIdentity) {
f(s.(recvStreamPrivate))
})
c.remoteUniStreams.forEach(func(s hasIdentity) {
f(s.(recvStreamPrivate))
})
}
func (c *Connection) sendClientInitial() error {
panic("sendClientInitial API no longer exists")
}
func (c *Connection) determineEpoch(pt packetType) mint.Epoch {
switch pt {
case packetTypeInitial:
return mint.EpochClear
case packetType0RTTProtected:
return mint.EpochEarlyData
case packetTypeHandshake:
return mint.EpochHandshakeData
case packetTypeProtectedShort:
return mint.EpochApplicationData
default:
// TODO([email protected])": Check that packet decoding checks the types
panic("Internal error")
}
}
func (c *Connection) getEncryptionLevel(epoch mint.Epoch) *encryptionLevel {
if int(epoch) >= len(c.encryptionLevels) {
return nil
}
return c.encryptionLevels[epoch]
}
func (c *Connection) sendPacketRaw(el *encryptionLevel, pt packetType, version VersionNumber, pn uint64, payload []byte, containsOnlyAcks bool) ([]byte, error) {
c.log(logTypeConnection, "Sending packet PT=%v PN=%x: %s", pt, pn, dumpPacket(payload))
left := c.mtu // track how much space is left for payload
aead := el.sendCipher.aead
left -= aead.Overhead()
var destCid ConnectionId
var srcCid ConnectionId
if c.role == RoleClient {
destCid = c.serverConnectionId
srcCid = c.clientConnectionId
} else {
srcCid = c.serverConnectionId
destCid = c.clientConnectionId
}
p := newPacket(pt, destCid, srcCid, version, pn, payload, aead.Overhead())
c.logPacket("Sending", &p.packetHeader, pn, payload)
// Encode the header so we know how long it is.
// TODO([email protected]): this is gross.
hdr, err := encode(&p.packetHeader)
if err != nil {
return nil, err
}
hdrx := append(hdr, encodePacketNumber(pn, 4)...) // Always use the 4-byte PN
left -= len(hdrx)
assert(left >= len(payload))
p.payload = payload
protected := aead.Seal(nil, c.packetNonce(p.PacketNumber), p.payload, hdrx)
packet := append(hdrx, protected...)
// Encrypt the packet number in place.
err = xorPacketNumber(&p.packetHeader, len(hdr), packet[len(hdr):len(hdr)+4], packet, el.sendCipher.pne)
assert(err == nil)
c.log(logTypeTrace, "Sending packet len=%d, len=%v", len(packet), hex.EncodeToString(packet))
c.congestion.onPacketSent(pn, containsOnlyAcks, len(packet)) //TODO([email protected]) check isackonly
c.transport.Send(packet)
return packet, nil
}
// Send a packet with whatever PT seems appropriate now.
func (c *Connection) sendPacketNow(tosend []*frame, containsOnlyAcks bool) ([]byte, error) {
return c.sendPacket(c.encryptionLevels[mint.EpochApplicationData], packetTypeProtectedShort, tosend, containsOnlyAcks)
}
// Send a packet with a specific PT.
func (c *Connection) sendPacket(el *encryptionLevel, pt packetType, tosend []*frame, containsOnlyAcks bool) ([]byte, error) {
sent := 0
payload := make([]byte, 0)
for _, f := range tosend {
_, err := f.length()
if err != nil {
return nil, err
}
c.log(logTypeTrace, "Frame=%v", hex.EncodeToString(f.encoded))
{
msd, ok := f.f.(*maxStreamDataFrame)
if ok {
c.log(logTypeFlowControl, "EKR: PT=%x Sending maxStreamDate %v %v", el.nextSendPacket, msd.StreamId, msd.MaximumStreamData)
}
}
payload = append(payload, f.encoded...)
sent++
}
// Pad out client Initial
if pt == packetTypeInitial && c.role == RoleClient && !containsOnlyAcks {
topad := kMinimumClientInitialLength - (len(payload) +
c.packetOverhead(el))
payload = append(payload, make([]byte, topad)...)
}
pn := el.nextSendPacket
el.nextSendPacket++
return c.sendPacketRaw(el, pt, c.version, pn, payload, containsOnlyAcks)
}
func (c *Connection) makeAckFrame(el *encryptionLevel, acks ackRanges, left int) (*frame, int, error) {
c.log(logTypeConnection, "Making ack frame, room=%d", left)
af, rangesSent, err := newAckFrame(el.recvd, acks, left)
if err != nil {
c.log(logTypeConnection, "Couldn't prepare ACK frame %v", err)
return nil, 0, err
}
return af, rangesSent, nil
}
func (c *Connection) sendQueued(bareAcks bool) (int, error) {
c.log(logTypeConnection, "Calling sendQueued state=%s", c.GetState())
c.lastSendQueuedTime = time.Now()
if c.state == StateInit {
return 0, nil
}
sent := 0
// Send CRYPTO_HS and associated
for _, el := range c.encryptionLevels {
if el.sendCipher != nil {
s, err := c.sendCryptoFrames(el, bareAcks)
if err != nil {
return sent, err
}
sent += s
}
}
// Send application data
el := c.streamEncryptionLevel()
if el != nil {
err := c.queueStreamFrames(el)
if err != nil {
return sent, err
}
// Send enqueued data from protected streams
s, err := c.sendQueuedFrames(el, bareAcks)
if err != nil {
return sent, err
}
sent += s
}
return sent, nil
}
// Send a packet of stream frames, plus whatever acks fit.
func (c *Connection) sendCombinedPacket(pt packetType, el *encryptionLevel, frames []*frame, acks ackRanges, left int) (int, error) {
asent := int(0)
var err error
containsOnlyAcks := len(frames) == 0
if len(acks) > 0 && (left-kMaxAckHeaderLength) >= 0 {
var af *frame
af, asent, err = c.makeAckFrame(el, acks, left)
if err != nil {
return 0, err
}
if af != nil {
frames = append(frames, af)
}
}
// Record which packets we sent ACKs in.
c.sentAcks[el.nextSendPacket] = acks[0:asent]
_, err = c.sendPacket(el, pt, frames, containsOnlyAcks)
if err != nil {
return 0, err
}
return asent, nil
}
func (c *Connection) queueFrame(q *[]*frame, f *frame) {
*q = append(*q, f)
}
// TODO([email protected]): Coalesce the frames, either here or in Mint.
func (c *Connection) sendCryptoFrames(el *encryptionLevel, bareAcks bool) (int, error) {
s := el.sendCryptoStream
q := &el.outputQ
for _, ch := range s.(sendStreamPrivate).outputWritable() {
f := newCryptoHsFrame(ch.offset, ch.data)
c.queueFrame(q, f)
}
n, err := c.sendQueuedFrames(el, bareAcks)
if err != nil {
return 0, err
}
return n, err
}
func (c *Connection) enqueueStreamFrames(s sendStreamPrivate, q *[]*frame) {
logf(logTypeStream, "Stream %v: enqueueing", s.Id())
if s == nil {
return
}
for _, ch := range s.outputWritable() {
logf(logTypeStream, "Stream %v is writable", s.Id())
f := newStreamFrame(s.Id(), ch.offset, ch.data, ch.last)
c.queueFrame(q, f)
}
}
// Send all the queued data on a set of streams with the current app data encryption
// level.
func (c *Connection) queueStreamFrames(el *encryptionLevel) error {
c.log(logTypeConnection, "%v: queueStreamFrames", c.role)
// Output all the stream frames that are now permitted by stream flow control
c.forEachSend(func(s sendStreamPrivate) {
c.enqueueStreamFrames(s, &el.outputQ)
})
return nil
}
func (c *Connection) sendFrame(f *frame) error {
if c.state != StateEstablished {
return ErrorWouldBlock
}
c.queueFrame(&c.encryptionLevels[mint.EpochApplicationData].outputQ, f)
_, err := c.sendQueued(false)
return err
}
func (c *Connection) packetOverhead(el *encryptionLevel) int {
overhead := el.sendCipher.aead.Overhead()
if el.epoch < mint.EpochApplicationData {
overhead += kLongHeaderLength
if c.role == RoleClient {
overhead += len(c.clientConnectionId)
} else {
overhead += len(c.serverConnectionId)
}
} else {
overhead += 5
}
if c.role == RoleClient {
overhead += len(c.serverConnectionId)
} else {
overhead += len(c.clientConnectionId)
}
return overhead
}
func (c *Connection) suppressRetransmission(f *frame) bool {
switch inner := f.f.(type) {
case *paddingFrame, *pathChallengeFrame, *pathResponseFrame:
return true
case *streamIdBlockedFrame:
switch streamTypeFromId(inner.StreamId, c.role) {
case streamTypeBidirectionalLocal:
return c.localBidiStreams.nstreams > len(c.localBidiStreams.streams)
case streamTypeUnidirectionalLocal:
return c.localUniStreams.nstreams > len(c.localUniStreams.streams)
default:
panic("shouldn't be complaining about this")
}
case *blockedFrame:
return c.sendFlowControl.max > inner.Offset
case *streamBlockedFrame:
fc := c.ensureSendStream(inner.StreamId).flowControl()
return fc.max > inner.Offset
default:
return false
}
}
// maybeRemoveFromQueue is run after a packet is sent.
// Here we assume that toRemove is in the same order as the queue.
func (c *Connection) maybeRemoveFromQueue(queue *[]*frame, toRemove []*frame) {
q := make([]*frame, 0, len(*queue)-len(toRemove))
next := 0
for _, f := range *queue {
maybeRemove := (next < len(toRemove)) && (f == toRemove[next])
if maybeRemove && c.suppressRetransmission(f) {
c.log(logTypeTrace, "frame sent, suppressing retransmission: %v", f)
} else {
q = append(q, f)
}
if maybeRemove {
next++
}
}
*queue = q
}
/* Transmit all the frames permitted by connection level flow control and
* the congestion controller. We're going to need to be more sophisticated
* when we actually do connection level flow control. */
func (c *Connection) sendQueuedFrames(el *encryptionLevel, bareAcks bool) (int, error) {
pt := el.packetType()
c.log(logTypeConnection, "sendQueuedFrames, pt=%v, epoch=%v", pt, el.epoch)
acks := el.recvd.prepareAckRange(el.epoch, false)
now := time.Now()
txAge := c.retransmitTime
sent := int(0)
spaceInCongestionWindow := c.congestion.bytesAllowedToSend()
// Select the queue we will send from
queue := &el.outputQ
/* Iterate through the queue, and append frames to packet, sending
* packets when the maximum packet size is reached, or we are not
* allowed to send more from the congestion controller */
// Calculate available space in the next packet.
overhead := c.packetOverhead(el)
spaceInPacket := c.mtu - overhead
spaceInCongestionWindow -= overhead
// Save a copy of the queue because this removes frames if they don't
// need be sent again.
originalQueue := *queue
congested := false
for index := 0; index < len(originalQueue); {
// Store frames that will be sent in the next packet
toSend := make([]*frame, 0)
toRemove := make([]*frame, 0)
spaceInPacket = c.mtu - overhead
spaceInCongestionWindow -= overhead
c.log(logTypeStream, "Building packet with %d and %d octets left",
spaceInPacket, spaceInCongestionWindow)
for ; index < len(originalQueue); index++ {
f := originalQueue[index]
frameLength, err := f.length()
if err != nil {
return sent, err
}
cAge := now.Sub(f.time)
if f.needsTransmit {
c.log(logTypeStream, "Frame %v requires transmission", f)
} else if cAge < txAge {
c.log(logTypeStream, "Skipping frame %v because sent too recently (%v < %v)", f, cAge, txAge)
continue
}
// if there is no more space in the congestion window, this frame
// can't be sent.
if spaceInCongestionWindow < frameLength {
congested = true
break
}
// if there is no more space for the next frame in the packet,
// send what we have and start forming a new packet
if spaceInPacket < frameLength {
break
}
c.log(logTypeFrame, "Sending frame %v, age = %v", f, cAge)
// add the frame to the packet
toSend = append(toSend, f)
toRemove = append(toRemove, f)
spaceInPacket -= frameLength
spaceInCongestionWindow -= frameLength
}
// Now send the packet if there is anything worth sending.
if len(toSend) == 0 {
break
}
acksSent, err := c.sendCombinedPacket(pt, el, toSend, acks, spaceInPacket)
if err != nil {
return sent, err
}
// Record what was sent.
sent++
acks = acks[acksSent:]
for _, f := range toSend {
f.time = now
f.needsTransmit = false
f.pns = append(f.pns, el.nextSendPacket-1)
}
c.maybeRemoveFromQueue(queue, toRemove)
if congested {
break
}
}
// Now send any bare acks that didn't fit in earlier packets.
if len(acks) > 0 {
if bareAcks {
_, err := c.sendCombinedPacket(pt, el, nil, acks, c.mtu-overhead)
if err != nil {
return sent, err
}
sent++
} else {
c.log(logTypeAck, "Acks to send, but suppressing bare acks")
return sent, nil
}
}
return sent, nil
}
func (c *Connection) handleLostPacket(lostPn uint64) {
panic("Unimplemented")
/*
queues := [][]*frame{c.outputClearQ, c.outputProtectedQ}
for _, queue := range queues {
for _, frame := range queue {
for _, pn := range frame.pns {
if pn == lostPn {
// If the packet is considered lost, remember that.
// Do *not* remove the PN from the list, because
// the packet might pop up later anyway, and then
// we want to mark this frame as received.
frame.lostPns = append(frame.lostPns, lostPn)
}
if len(frame.pns) == len(frame.lostPns) {
// if we consider all packets that this frame was send in as lost,
// we have to retransmit it.
frame.needsTransmit = true
break
}
}
}
}*/
}
// Walk through all the streams and see how many bytes are outstanding.
// Right now this is very expensive.
func (c *Connection) outstandingQueuedBytes() (n int) {
c.forEachSend(func(s sendStreamPrivate) {
n += s.outstandingQueuedBytes()
})
cd := func(frames []*frame) int {
ret := 0
for _, f := range frames {
sf, ok := f.f.(*streamFrame)
if ok {
ret += len(sf.Data)
}
}
return ret
}
for _, el := range c.encryptionLevels {
n += cd(el.outputQ)
}
return
}
// Input provides a packet to the connection.
//
// TODO([email protected]): when is error returned?
func (c *Connection) Input(p []byte) error {
return c.handleError(c.input(p))
}
func (c *Connection) fireReadable() {
if c.handler == nil {
return
}
c.forEachRecv(func(s recvStreamPrivate) {
if s.clearReadable() {
c.handler.StreamReadable(s)
}
})
}
func (c *Connection) input(payload []byte) error {
c.log(logTypeTrace, "Input packet length=%d", len(payload))
fullLength := len(payload)
if c.isClosed() {
return ErrorConnIsClosed
}
if c.state == StateClosing {
c.log(logTypeConnection, "Discarding packet while closing (closePacket=%v)", c.closePacket != nil)
if c.closePacket != nil {
c.transport.Send(c.closePacket)
}
return ErrorConnIsClosing
}
c.lastInput = time.Now()
hdr := packetHeader{shortCidLength: kCidDefaultLength}
c.log(logTypeTrace, "Receiving packet len=%v %v", len(payload), hex.EncodeToString(payload))
hdrlen, err := decode(&hdr, payload)
if err != nil {
c.log(logTypeConnection, "Could not decode packet: %v", hex.EncodeToString(payload))
return wrapE(ErrorInvalidPacket, err)
}
assert(int(hdrlen) <= len(payload))
hdrbytes := payload[:hdrlen]
if hdr.Type.isLongHeader() && hdr.Version != c.version {
if c.role == RoleServer {
c.log(logTypeConnection, "Received unsupported version %v, expected %v", hdr.Version, c.version)
err = c.sendVersionNegotiation(hdr)
if err != nil {
return err
}
if c.state == StateWaitClientInitial {
return ErrorDestroyConnection
}
return nil
} else {
// If we're a client, choke on unknown versions, unless
// they come in version negotiation packets.
if hdr.Version != 0 {
return fmt.Errorf("Received packet with unexpected version %v", hdr.Version)
}
}
}
typ := hdr.getHeaderType()
c.log(logTypeConnection, "Packet header %v, %d", hdr, typ)
if hdr.Type.isLongHeader() && hdr.Version == 0 {
return c.processVersionNegotiation(&hdr, hdrbytes)
}
if c.state == StateWaitClientInitial {
if typ != packetTypeInitial {
c.log(logTypeConnection, "Received unexpected packet before client initial")
return ErrorDestroyConnection
}
// Now check the size.
if fullLength < kMinimumClientInitialLength {
c.log(logTypeConnection, "Discarding too short client Initial")
return nil
}
err := c.setupAeadMasking(hdr.DestinationConnectionID)
if err != nil {
return err
}
c.serverConnectionId, err = c.randomConnectionId(kCidDefaultLength)
if err != nil {
return err
}
c.clientConnectionId = hdr.SourceConnectionID
}
// Figure out the epoch
epoch := c.determineEpoch(typ)
el := c.getEncryptionLevel(epoch)
if el == nil || el.recvCipher == nil {
c.log(logTypeConnection, "Received protected data before crypto state is ready")
return nil