syncthing/lib/relay/relay.go

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2015-06-28 19:09:53 +00:00
// Copyright (C) 2015 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at http://mozilla.org/MPL/2.0/.
package relay
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import (
"crypto/tls"
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"net/url"
"sort"
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"time"
"github.com/syncthing/syncthing/lib/config"
"github.com/syncthing/syncthing/lib/events"
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"github.com/syncthing/syncthing/lib/relay/client"
"github.com/syncthing/syncthing/lib/relay/protocol"
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"github.com/syncthing/syncthing/lib/sync"
"github.com/thejerf/suture"
)
const (
eventBroadcasterCheckInterval = 10 * time.Second
)
type Svc struct {
*suture.Supervisor
cfg *config.Wrapper
tlsCfg *tls.Config
tokens map[string]suture.ServiceToken
clients map[string]client.RelayClient
mut sync.RWMutex
invitations chan protocol.SessionInvitation
conns chan *tls.Conn
}
func NewSvc(cfg *config.Wrapper, tlsCfg *tls.Config) *Svc {
conns := make(chan *tls.Conn)
svc := &Svc{
Supervisor: suture.New("Svc", suture.Spec{
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Log: func(log string) {
Implement facility based logger, debugging via REST API This implements a new debug/trace infrastructure based on a slightly hacked up logger. Instead of the traditional "if debug { ... }" I've rewritten the logger to have no-op Debugln and Debugf, unless debugging has been enabled for a given "facility". The "facility" is just a string, typically a package name. This will be slightly slower than before; but not that much as it's mostly a function call that returns immediately. For the cases where it matters (the Debugln takes a hex.Dump() of something for example, and it's not in a very occasional "if err != nil" branch) there is an l.ShouldDebug(facility) that is fast enough to be used like the old "if debug". The point of all this is that we can now toggle debugging for the various packages on and off at runtime. There's a new method /rest/system/debug that can be POSTed a set of facilities to enable and disable debug for, or GET from to get a list of facilities with descriptions and their current debug status. Similarly a /rest/system/log?since=... can grab the latest log entries, up to 250 of them (hardcoded constant in main.go) plus the initial few. Not implemented in this commit (but planned) is a simple debug GUI available on /debug that shows the current log in an easily pasteable format and has checkboxes to enable the various debug facilities. The debug instructions to a user then becomes "visit this URL, check these boxes, reproduce your problem, copy and paste the log". The actual log viewer on the hypothetical /debug URL can poll regularly for new log entries and this bypass the 250 line limit. The existing STTRACE=foo variable is still obeyed and just sets the start state of the system.
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l.Debugln(log)
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},
FailureBackoff: 5 * time.Minute,
FailureDecay: float64((10 * time.Minute) / time.Second),
FailureThreshold: 5,
}),
cfg: cfg,
tlsCfg: tlsCfg,
tokens: make(map[string]suture.ServiceToken),
clients: make(map[string]client.RelayClient),
mut: sync.NewRWMutex(),
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invitations: make(chan protocol.SessionInvitation),
conns: conns,
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}
rcfg := cfg.Raw()
svc.CommitConfiguration(rcfg, rcfg)
cfg.Subscribe(svc)
receiver := &invitationReceiver{
tlsCfg: tlsCfg,
conns: conns,
invitations: svc.invitations,
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stop: make(chan struct{}),
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}
eventBc := &eventBroadcaster{
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svc: svc,
stop: make(chan struct{}),
}
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svc.Add(receiver)
svc.Add(eventBc)
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return svc
}
func (s *Svc) VerifyConfiguration(from, to config.Configuration) error {
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for _, addr := range to.Options.RelayServers {
_, err := url.Parse(addr)
if err != nil {
return err
}
}
return nil
}
func (s *Svc) CommitConfiguration(from, to config.Configuration) bool {
existing := make(map[string]*url.URL, len(to.Options.RelayServers))
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for _, addr := range to.Options.RelayServers {
uri, err := url.Parse(addr)
if err != nil {
Implement facility based logger, debugging via REST API This implements a new debug/trace infrastructure based on a slightly hacked up logger. Instead of the traditional "if debug { ... }" I've rewritten the logger to have no-op Debugln and Debugf, unless debugging has been enabled for a given "facility". The "facility" is just a string, typically a package name. This will be slightly slower than before; but not that much as it's mostly a function call that returns immediately. For the cases where it matters (the Debugln takes a hex.Dump() of something for example, and it's not in a very occasional "if err != nil" branch) there is an l.ShouldDebug(facility) that is fast enough to be used like the old "if debug". The point of all this is that we can now toggle debugging for the various packages on and off at runtime. There's a new method /rest/system/debug that can be POSTed a set of facilities to enable and disable debug for, or GET from to get a list of facilities with descriptions and their current debug status. Similarly a /rest/system/log?since=... can grab the latest log entries, up to 250 of them (hardcoded constant in main.go) plus the initial few. Not implemented in this commit (but planned) is a simple debug GUI available on /debug that shows the current log in an easily pasteable format and has checkboxes to enable the various debug facilities. The debug instructions to a user then becomes "visit this URL, check these boxes, reproduce your problem, copy and paste the log". The actual log viewer on the hypothetical /debug URL can poll regularly for new log entries and this bypass the 250 line limit. The existing STTRACE=foo variable is still obeyed and just sets the start state of the system.
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l.Debugln("Failed to parse relay address", addr, err)
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continue
}
existing[uri.String()] = uri
}
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s.mut.Lock()
for key, uri := range existing {
_, ok := s.tokens[key]
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if !ok {
Implement facility based logger, debugging via REST API This implements a new debug/trace infrastructure based on a slightly hacked up logger. Instead of the traditional "if debug { ... }" I've rewritten the logger to have no-op Debugln and Debugf, unless debugging has been enabled for a given "facility". The "facility" is just a string, typically a package name. This will be slightly slower than before; but not that much as it's mostly a function call that returns immediately. For the cases where it matters (the Debugln takes a hex.Dump() of something for example, and it's not in a very occasional "if err != nil" branch) there is an l.ShouldDebug(facility) that is fast enough to be used like the old "if debug". The point of all this is that we can now toggle debugging for the various packages on and off at runtime. There's a new method /rest/system/debug that can be POSTed a set of facilities to enable and disable debug for, or GET from to get a list of facilities with descriptions and their current debug status. Similarly a /rest/system/log?since=... can grab the latest log entries, up to 250 of them (hardcoded constant in main.go) plus the initial few. Not implemented in this commit (but planned) is a simple debug GUI available on /debug that shows the current log in an easily pasteable format and has checkboxes to enable the various debug facilities. The debug instructions to a user then becomes "visit this URL, check these boxes, reproduce your problem, copy and paste the log". The actual log viewer on the hypothetical /debug URL can poll regularly for new log entries and this bypass the 250 line limit. The existing STTRACE=foo variable is still obeyed and just sets the start state of the system.
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l.Debugln("Connecting to relay", uri)
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c, err := client.NewClient(uri, s.tlsCfg.Certificates, s.invitations, 10*time.Second)
if err != nil {
l.Debugln("Failed to connect to relay", uri, err)
continue
}
s.tokens[key] = s.Add(c)
s.clients[key] = c
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}
}
for key, token := range s.tokens {
_, ok := existing[key]
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if !ok {
err := s.Remove(token)
delete(s.tokens, key)
delete(s.clients, key)
Implement facility based logger, debugging via REST API This implements a new debug/trace infrastructure based on a slightly hacked up logger. Instead of the traditional "if debug { ... }" I've rewritten the logger to have no-op Debugln and Debugf, unless debugging has been enabled for a given "facility". The "facility" is just a string, typically a package name. This will be slightly slower than before; but not that much as it's mostly a function call that returns immediately. For the cases where it matters (the Debugln takes a hex.Dump() of something for example, and it's not in a very occasional "if err != nil" branch) there is an l.ShouldDebug(facility) that is fast enough to be used like the old "if debug". The point of all this is that we can now toggle debugging for the various packages on and off at runtime. There's a new method /rest/system/debug that can be POSTed a set of facilities to enable and disable debug for, or GET from to get a list of facilities with descriptions and their current debug status. Similarly a /rest/system/log?since=... can grab the latest log entries, up to 250 of them (hardcoded constant in main.go) plus the initial few. Not implemented in this commit (but planned) is a simple debug GUI available on /debug that shows the current log in an easily pasteable format and has checkboxes to enable the various debug facilities. The debug instructions to a user then becomes "visit this URL, check these boxes, reproduce your problem, copy and paste the log". The actual log viewer on the hypothetical /debug URL can poll regularly for new log entries and this bypass the 250 line limit. The existing STTRACE=foo variable is still obeyed and just sets the start state of the system.
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l.Debugln("Disconnecting from relay", key, err)
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}
}
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s.mut.Unlock()
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return true
}
type Status struct {
URL string
OK bool
Latency int
}
// Relays return the list of relays that currently have an OK status.
func (s *Svc) Relays() []string {
if s == nil {
// A nil client does not have a status, really. Yet we may be called
// this way, for raisins...
return nil
}
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s.mut.RLock()
relays := make([]string, 0, len(s.clients))
for _, client := range s.clients {
relays = append(relays, client.URI().String())
}
s.mut.RUnlock()
sort.Strings(relays)
return relays
}
// RelayStatus returns the latency and OK status for a given relay.
func (s *Svc) RelayStatus(uri string) (time.Duration, bool) {
if s == nil {
// A nil client does not have a status, really. Yet we may be called
// this way, for raisins...
return time.Hour, false
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}
s.mut.RLock()
defer s.mut.RUnlock()
for _, client := range s.clients {
if client.URI().String() == uri {
return client.Latency(), client.StatusOK()
}
}
return time.Hour, false
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}
// Accept returns a new *tls.Conn. The connection is already handshaken.
func (s *Svc) Accept() *tls.Conn {
return <-s.conns
}
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type invitationReceiver struct {
invitations chan protocol.SessionInvitation
tlsCfg *tls.Config
conns chan<- *tls.Conn
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stop chan struct{}
}
func (r *invitationReceiver) Serve() {
for {
select {
case inv := <-r.invitations:
Implement facility based logger, debugging via REST API This implements a new debug/trace infrastructure based on a slightly hacked up logger. Instead of the traditional "if debug { ... }" I've rewritten the logger to have no-op Debugln and Debugf, unless debugging has been enabled for a given "facility". The "facility" is just a string, typically a package name. This will be slightly slower than before; but not that much as it's mostly a function call that returns immediately. For the cases where it matters (the Debugln takes a hex.Dump() of something for example, and it's not in a very occasional "if err != nil" branch) there is an l.ShouldDebug(facility) that is fast enough to be used like the old "if debug". The point of all this is that we can now toggle debugging for the various packages on and off at runtime. There's a new method /rest/system/debug that can be POSTed a set of facilities to enable and disable debug for, or GET from to get a list of facilities with descriptions and their current debug status. Similarly a /rest/system/log?since=... can grab the latest log entries, up to 250 of them (hardcoded constant in main.go) plus the initial few. Not implemented in this commit (but planned) is a simple debug GUI available on /debug that shows the current log in an easily pasteable format and has checkboxes to enable the various debug facilities. The debug instructions to a user then becomes "visit this URL, check these boxes, reproduce your problem, copy and paste the log". The actual log viewer on the hypothetical /debug URL can poll regularly for new log entries and this bypass the 250 line limit. The existing STTRACE=foo variable is still obeyed and just sets the start state of the system.
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l.Debugln("Received relay invitation", inv)
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conn, err := client.JoinSession(inv)
if err != nil {
Implement facility based logger, debugging via REST API This implements a new debug/trace infrastructure based on a slightly hacked up logger. Instead of the traditional "if debug { ... }" I've rewritten the logger to have no-op Debugln and Debugf, unless debugging has been enabled for a given "facility". The "facility" is just a string, typically a package name. This will be slightly slower than before; but not that much as it's mostly a function call that returns immediately. For the cases where it matters (the Debugln takes a hex.Dump() of something for example, and it's not in a very occasional "if err != nil" branch) there is an l.ShouldDebug(facility) that is fast enough to be used like the old "if debug". The point of all this is that we can now toggle debugging for the various packages on and off at runtime. There's a new method /rest/system/debug that can be POSTed a set of facilities to enable and disable debug for, or GET from to get a list of facilities with descriptions and their current debug status. Similarly a /rest/system/log?since=... can grab the latest log entries, up to 250 of them (hardcoded constant in main.go) plus the initial few. Not implemented in this commit (but planned) is a simple debug GUI available on /debug that shows the current log in an easily pasteable format and has checkboxes to enable the various debug facilities. The debug instructions to a user then becomes "visit this URL, check these boxes, reproduce your problem, copy and paste the log". The actual log viewer on the hypothetical /debug URL can poll regularly for new log entries and this bypass the 250 line limit. The existing STTRACE=foo variable is still obeyed and just sets the start state of the system.
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l.Debugf("Failed to join relay session %s: %v", inv, err)
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continue
}
var tc *tls.Conn
if inv.ServerSocket {
tc = tls.Server(conn, r.tlsCfg)
} else {
tc = tls.Client(conn, r.tlsCfg)
}
err = tc.Handshake()
if err != nil {
l.Infof("TLS handshake (BEP/relay %s): %v", inv, err)
tc.Close()
continue
}
r.conns <- tc
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case <-r.stop:
return
}
}
}
func (r *invitationReceiver) Stop() {
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close(r.stop)
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}
// The eventBroadcaster sends a RelayStateChanged event when the relay status
// changes. We need this somewhat ugly polling mechanism as there's currently
// no way to get the event feed directly from the relay lib. This may be
// something to revisit later, possibly.
type eventBroadcaster struct {
svc *Svc
stop chan struct{}
}
func (e *eventBroadcaster) Serve() {
timer := time.NewTicker(eventBroadcasterCheckInterval)
defer timer.Stop()
var prevOKRelays []string
for {
select {
case <-timer.C:
curOKRelays := e.svc.Relays()
changed := len(curOKRelays) != len(prevOKRelays)
if !changed {
for i := range curOKRelays {
if curOKRelays[i] != prevOKRelays[i] {
changed = true
break
}
}
}
if changed {
events.Default.Log(events.RelayStateChanged, map[string][]string{
"old": prevOKRelays,
"new": curOKRelays,
})
}
prevOKRelays = curOKRelays
case <-e.stop:
return
}
}
}
func (e *eventBroadcaster) Stop() {
close(e.stop)
}