cloudflared/connection/observer.go
Sudarsan Reddy 99f39225f1 TUN-6617: Dont fallback to http2 if QUIC conn was successful.
cloudflared falls back aggressively to HTTP/2 protocol if a connection
attempt with QUIC failed. This was done to ensure that machines with UDP
egress disabled did not stop clients from connecting to the cloudlfare
edge. This PR improves on that experience by having cloudflared remember
if a QUIC connection was successful which implies UDP egress works. In
this case, cloudflared does not fallback to HTTP/2 and keeps trying to
connect to the edge with QUIC.
2022-08-12 08:40:03 +00:00

113 lines
2.8 KiB
Go

package connection
import (
"net"
"strings"
"github.com/rs/zerolog"
)
const (
LogFieldLocation = "location"
LogFieldIPAddress = "ip"
observerChannelBufferSize = 16
)
type Observer struct {
log *zerolog.Logger
logTransport *zerolog.Logger
metrics *tunnelMetrics
tunnelEventChan chan Event
addSinkChan chan EventSink
}
type EventSink interface {
OnTunnelEvent(event Event)
}
func NewObserver(log, logTransport *zerolog.Logger) *Observer {
o := &Observer{
log: log,
logTransport: logTransport,
metrics: newTunnelMetrics(),
tunnelEventChan: make(chan Event, observerChannelBufferSize),
addSinkChan: make(chan EventSink, observerChannelBufferSize),
}
go o.dispatchEvents()
return o
}
func (o *Observer) RegisterSink(sink EventSink) {
o.addSinkChan <- sink
}
func (o *Observer) logServerInfo(connIndex uint8, location string, address net.IP, msg string) {
o.sendEvent(Event{Index: connIndex, EventType: Connected, Location: location})
o.log.Info().
Uint8(LogFieldConnIndex, connIndex).
Str(LogFieldLocation, location).
IPAddr(LogFieldIPAddress, address).
Msg(msg)
o.metrics.registerServerLocation(uint8ToString(connIndex), location)
}
func (o *Observer) sendRegisteringEvent(connIndex uint8) {
o.sendEvent(Event{Index: connIndex, EventType: RegisteringTunnel})
}
func (o *Observer) sendConnectedEvent(connIndex uint8, protocol Protocol, location string) {
o.sendEvent(Event{Index: connIndex, EventType: Connected, Protocol: protocol, Location: location})
}
func (o *Observer) SendURL(url string) {
o.sendEvent(Event{EventType: SetURL, URL: url})
if !strings.HasPrefix(url, "https://") {
// We add https:// in the prefix for backwards compatibility as we used to do that with the old free tunnels
// and some tools (like `wrangler tail`) are regexp-ing for that specifically.
url = "https://" + url
}
o.metrics.userHostnamesCounts.WithLabelValues(url).Inc()
}
func (o *Observer) SendReconnect(connIndex uint8) {
o.sendEvent(Event{Index: connIndex, EventType: Reconnecting})
}
func (o *Observer) sendUnregisteringEvent(connIndex uint8) {
o.sendEvent(Event{Index: connIndex, EventType: Unregistering})
}
func (o *Observer) SendDisconnect(connIndex uint8) {
o.sendEvent(Event{Index: connIndex, EventType: Disconnected})
}
func (o *Observer) sendEvent(e Event) {
select {
case o.tunnelEventChan <- e:
break
default:
o.log.Warn().Msg("observer channel buffer is full")
}
}
func (o *Observer) dispatchEvents() {
var sinks []EventSink
for {
select {
case sink := <-o.addSinkChan:
sinks = append(sinks, sink)
case evt := <-o.tunnelEventChan:
for _, sink := range sinks {
sink.OnTunnelEvent(evt)
}
}
}
}
type EventSinkFunc func(event Event)
func (f EventSinkFunc) OnTunnelEvent(event Event) {
f(event)
}