cloudflared-mirror/vendor/github.com/lucas-clemente/quic-go/client.go

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package quic
import (
"context"
"crypto/tls"
"errors"
"fmt"
"net"
"strings"
"github.com/lucas-clemente/quic-go/internal/protocol"
"github.com/lucas-clemente/quic-go/internal/utils"
"github.com/lucas-clemente/quic-go/logging"
)
type client struct {
conn sendConn
// If the client is created with DialAddr, we create a packet conn.
// If it is started with Dial, we take a packet conn as a parameter.
createdPacketConn bool
use0RTT bool
packetHandlers packetHandlerManager
tlsConf *tls.Config
config *Config
srcConnID protocol.ConnectionID
destConnID protocol.ConnectionID
initialPacketNumber protocol.PacketNumber
hasNegotiatedVersion bool
version protocol.VersionNumber
handshakeChan chan struct{}
session quicSession
tracer logging.ConnectionTracer
tracingID uint64
logger utils.Logger
}
var (
// make it possible to mock connection ID generation in the tests
generateConnectionID = protocol.GenerateConnectionID
generateConnectionIDForInitial = protocol.GenerateConnectionIDForInitial
)
// DialAddr establishes a new QUIC connection to a server.
// It uses a new UDP connection and closes this connection when the QUIC session is closed.
// The hostname for SNI is taken from the given address.
// The tls.Config.CipherSuites allows setting of TLS 1.3 cipher suites.
func DialAddr(
addr string,
tlsConf *tls.Config,
config *Config,
) (Session, error) {
return DialAddrContext(context.Background(), addr, tlsConf, config)
}
// DialAddrEarly establishes a new 0-RTT QUIC connection to a server.
// It uses a new UDP connection and closes this connection when the QUIC session is closed.
// The hostname for SNI is taken from the given address.
// The tls.Config.CipherSuites allows setting of TLS 1.3 cipher suites.
func DialAddrEarly(
addr string,
tlsConf *tls.Config,
config *Config,
) (EarlySession, error) {
return DialAddrEarlyContext(context.Background(), addr, tlsConf, config)
}
// DialAddrEarlyContext establishes a new 0-RTT QUIC connection to a server using provided context.
// See DialAddrEarly for details
func DialAddrEarlyContext(
ctx context.Context,
addr string,
tlsConf *tls.Config,
config *Config,
) (EarlySession, error) {
sess, err := dialAddrContext(ctx, addr, tlsConf, config, true)
if err != nil {
return nil, err
}
utils.Logger.WithPrefix(utils.DefaultLogger, "client").Debugf("Returning early session")
return sess, nil
}
// DialAddrContext establishes a new QUIC connection to a server using the provided context.
// See DialAddr for details.
func DialAddrContext(
ctx context.Context,
addr string,
tlsConf *tls.Config,
config *Config,
) (Session, error) {
return dialAddrContext(ctx, addr, tlsConf, config, false)
}
func dialAddrContext(
ctx context.Context,
addr string,
tlsConf *tls.Config,
config *Config,
use0RTT bool,
) (quicSession, error) {
udpAddr, err := net.ResolveUDPAddr("udp", addr)
if err != nil {
return nil, err
}
udpConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
if err != nil {
return nil, err
}
return dialContext(ctx, udpConn, udpAddr, addr, tlsConf, config, use0RTT, true)
}
// Dial establishes a new QUIC connection to a server using a net.PacketConn. If
// the PacketConn satisfies the OOBCapablePacketConn interface (as a net.UDPConn
// does), ECN and packet info support will be enabled. In this case, ReadMsgUDP
// and WriteMsgUDP will be used instead of ReadFrom and WriteTo to read/write
// packets. The same PacketConn can be used for multiple calls to Dial and
// Listen, QUIC connection IDs are used for demultiplexing the different
// connections. The host parameter is used for SNI. The tls.Config must define
// an application protocol (using NextProtos).
func Dial(
pconn net.PacketConn,
remoteAddr net.Addr,
host string,
tlsConf *tls.Config,
config *Config,
) (Session, error) {
return dialContext(context.Background(), pconn, remoteAddr, host, tlsConf, config, false, false)
}
// DialEarly establishes a new 0-RTT QUIC connection to a server using a net.PacketConn.
// The same PacketConn can be used for multiple calls to Dial and Listen,
// QUIC connection IDs are used for demultiplexing the different connections.
// The host parameter is used for SNI.
// The tls.Config must define an application protocol (using NextProtos).
func DialEarly(
pconn net.PacketConn,
remoteAddr net.Addr,
host string,
tlsConf *tls.Config,
config *Config,
) (EarlySession, error) {
return DialEarlyContext(context.Background(), pconn, remoteAddr, host, tlsConf, config)
}
// DialEarlyContext establishes a new 0-RTT QUIC connection to a server using a net.PacketConn using the provided context.
// See DialEarly for details.
func DialEarlyContext(
ctx context.Context,
pconn net.PacketConn,
remoteAddr net.Addr,
host string,
tlsConf *tls.Config,
config *Config,
) (EarlySession, error) {
return dialContext(ctx, pconn, remoteAddr, host, tlsConf, config, true, false)
}
// DialContext establishes a new QUIC connection to a server using a net.PacketConn using the provided context.
// See Dial for details.
func DialContext(
ctx context.Context,
pconn net.PacketConn,
remoteAddr net.Addr,
host string,
tlsConf *tls.Config,
config *Config,
) (Session, error) {
return dialContext(ctx, pconn, remoteAddr, host, tlsConf, config, false, false)
}
func dialContext(
ctx context.Context,
pconn net.PacketConn,
remoteAddr net.Addr,
host string,
tlsConf *tls.Config,
config *Config,
use0RTT bool,
createdPacketConn bool,
) (quicSession, error) {
if tlsConf == nil {
return nil, errors.New("quic: tls.Config not set")
}
if err := validateConfig(config); err != nil {
return nil, err
}
config = populateClientConfig(config, createdPacketConn)
packetHandlers, err := getMultiplexer().AddConn(pconn, config.ConnectionIDLength, config.StatelessResetKey, config.Tracer)
if err != nil {
return nil, err
}
c, err := newClient(pconn, remoteAddr, config, tlsConf, host, use0RTT, createdPacketConn)
if err != nil {
return nil, err
}
c.packetHandlers = packetHandlers
c.tracingID = nextSessionTracingID()
if c.config.Tracer != nil {
c.tracer = c.config.Tracer.TracerForConnection(
context.WithValue(ctx, SessionTracingKey, c.tracingID),
protocol.PerspectiveClient,
c.destConnID,
)
}
if c.tracer != nil {
c.tracer.StartedConnection(c.conn.LocalAddr(), c.conn.RemoteAddr(), c.srcConnID, c.destConnID)
}
if err := c.dial(ctx); err != nil {
return nil, err
}
return c.session, nil
}
func newClient(
pconn net.PacketConn,
remoteAddr net.Addr,
config *Config,
tlsConf *tls.Config,
host string,
use0RTT bool,
createdPacketConn bool,
) (*client, error) {
if tlsConf == nil {
tlsConf = &tls.Config{}
}
if tlsConf.ServerName == "" {
sni := host
if strings.IndexByte(sni, ':') != -1 {
var err error
sni, _, err = net.SplitHostPort(sni)
if err != nil {
return nil, err
}
}
tlsConf.ServerName = sni
}
// check that all versions are actually supported
if config != nil {
for _, v := range config.Versions {
if !protocol.IsValidVersion(v) {
return nil, fmt.Errorf("%s is not a valid QUIC version", v)
}
}
}
srcConnID, err := generateConnectionID(config.ConnectionIDLength)
if err != nil {
return nil, err
}
destConnID, err := generateConnectionIDForInitial()
if err != nil {
return nil, err
}
c := &client{
srcConnID: srcConnID,
destConnID: destConnID,
conn: newSendPconn(pconn, remoteAddr),
createdPacketConn: createdPacketConn,
use0RTT: use0RTT,
tlsConf: tlsConf,
config: config,
version: config.Versions[0],
handshakeChan: make(chan struct{}),
logger: utils.DefaultLogger.WithPrefix("client"),
}
return c, nil
}
func (c *client) dial(ctx context.Context) error {
c.logger.Infof("Starting new connection to %s (%s -> %s), source connection ID %s, destination connection ID %s, version %s", c.tlsConf.ServerName, c.conn.LocalAddr(), c.conn.RemoteAddr(), c.srcConnID, c.destConnID, c.version)
c.session = newClientSession(
c.conn,
c.packetHandlers,
c.destConnID,
c.srcConnID,
c.config,
c.tlsConf,
c.initialPacketNumber,
c.use0RTT,
c.hasNegotiatedVersion,
c.tracer,
c.tracingID,
c.logger,
c.version,
)
c.packetHandlers.Add(c.srcConnID, c.session)
errorChan := make(chan error, 1)
go func() {
err := c.session.run() // returns as soon as the session is closed
if e := (&errCloseForRecreating{}); !errors.As(err, &e) && c.createdPacketConn {
c.packetHandlers.Destroy()
}
errorChan <- err
}()
// only set when we're using 0-RTT
// Otherwise, earlySessionChan will be nil. Receiving from a nil chan blocks forever.
var earlySessionChan <-chan struct{}
if c.use0RTT {
earlySessionChan = c.session.earlySessionReady()
}
select {
case <-ctx.Done():
c.session.shutdown()
return ctx.Err()
case err := <-errorChan:
var recreateErr *errCloseForRecreating
if errors.As(err, &recreateErr) {
c.initialPacketNumber = recreateErr.nextPacketNumber
c.version = recreateErr.nextVersion
c.hasNegotiatedVersion = true
return c.dial(ctx)
}
return err
case <-earlySessionChan:
// ready to send 0-RTT data
return nil
case <-c.session.HandshakeComplete().Done():
// handshake successfully completed
return nil
}
}