mv internal lib
This commit is contained in:
Jakob Borg
453
lib/discover/discover.go
Normal file
453
lib/discover/discover.go
Normal file
@@ -0,0 +1,453 @@
|
||||
// Copyright (C) 2014 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 discover
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"encoding/hex"
|
||||
"errors"
|
||||
"io"
|
||||
"net"
|
||||
"runtime"
|
||||
"strconv"
|
||||
"time"
|
||||
|
||||
"github.com/syncthing/protocol"
|
||||
"github.com/syncthing/syncthing/lib/beacon"
|
||||
"github.com/syncthing/syncthing/lib/events"
|
||||
"github.com/syncthing/syncthing/lib/sync"
|
||||
)
|
||||
|
||||
type Discoverer struct {
|
||||
myID protocol.DeviceID
|
||||
listenAddrs []string
|
||||
localBcastIntv time.Duration
|
||||
localBcastStart time.Time
|
||||
cacheLifetime time.Duration
|
||||
negCacheCutoff time.Duration
|
||||
beacons []beacon.Interface
|
||||
extPort uint16
|
||||
localBcastTick <-chan time.Time
|
||||
forcedBcastTick chan time.Time
|
||||
|
||||
registryLock sync.RWMutex
|
||||
registry map[protocol.DeviceID][]CacheEntry
|
||||
lastLookup map[protocol.DeviceID]time.Time
|
||||
|
||||
clients []Client
|
||||
mut sync.RWMutex
|
||||
}
|
||||
|
||||
type CacheEntry struct {
|
||||
Address string
|
||||
Seen time.Time
|
||||
}
|
||||
|
||||
var (
|
||||
ErrIncorrectMagic = errors.New("incorrect magic number")
|
||||
)
|
||||
|
||||
func NewDiscoverer(id protocol.DeviceID, addresses []string) *Discoverer {
|
||||
return &Discoverer{
|
||||
myID: id,
|
||||
listenAddrs: addresses,
|
||||
localBcastIntv: 30 * time.Second,
|
||||
cacheLifetime: 5 * time.Minute,
|
||||
negCacheCutoff: 3 * time.Minute,
|
||||
registry: make(map[protocol.DeviceID][]CacheEntry),
|
||||
lastLookup: make(map[protocol.DeviceID]time.Time),
|
||||
registryLock: sync.NewRWMutex(),
|
||||
mut: sync.NewRWMutex(),
|
||||
}
|
||||
}
|
||||
|
||||
func (d *Discoverer) StartLocal(localPort int, localMCAddr string) {
|
||||
if localPort > 0 {
|
||||
d.startLocalIPv4Broadcasts(localPort)
|
||||
}
|
||||
|
||||
if len(localMCAddr) > 0 {
|
||||
d.startLocalIPv6Multicasts(localMCAddr)
|
||||
}
|
||||
|
||||
if len(d.beacons) == 0 {
|
||||
l.Warnln("Local discovery unavailable")
|
||||
return
|
||||
}
|
||||
|
||||
d.localBcastTick = time.Tick(d.localBcastIntv)
|
||||
d.forcedBcastTick = make(chan time.Time)
|
||||
d.localBcastStart = time.Now()
|
||||
go d.sendLocalAnnouncements()
|
||||
}
|
||||
|
||||
func (d *Discoverer) startLocalIPv4Broadcasts(localPort int) {
|
||||
bb := beacon.NewBroadcast(localPort)
|
||||
d.beacons = append(d.beacons, bb)
|
||||
go d.recvAnnouncements(bb)
|
||||
bb.ServeBackground()
|
||||
}
|
||||
|
||||
func (d *Discoverer) startLocalIPv6Multicasts(localMCAddr string) {
|
||||
intfs, err := net.Interfaces()
|
||||
if err != nil {
|
||||
if debug {
|
||||
l.Debugln("discover: interfaces:", err)
|
||||
}
|
||||
l.Infoln("Local discovery over IPv6 unavailable")
|
||||
return
|
||||
}
|
||||
|
||||
v6Intfs := 0
|
||||
for _, intf := range intfs {
|
||||
// Interface flags seem to always be 0 on Windows
|
||||
if runtime.GOOS != "windows" && (intf.Flags&net.FlagUp == 0 || intf.Flags&net.FlagMulticast == 0) {
|
||||
continue
|
||||
}
|
||||
|
||||
mb, err := beacon.NewMulticast(localMCAddr, intf.Name)
|
||||
if err != nil {
|
||||
if debug {
|
||||
l.Debugln("discover: Start local v6:", err)
|
||||
}
|
||||
continue
|
||||
}
|
||||
|
||||
d.beacons = append(d.beacons, mb)
|
||||
go d.recvAnnouncements(mb)
|
||||
v6Intfs++
|
||||
}
|
||||
|
||||
if v6Intfs == 0 {
|
||||
l.Infoln("Local discovery over IPv6 unavailable")
|
||||
}
|
||||
}
|
||||
|
||||
func (d *Discoverer) StartGlobal(servers []string, extPort uint16) {
|
||||
d.mut.Lock()
|
||||
defer d.mut.Unlock()
|
||||
|
||||
if len(d.clients) > 0 {
|
||||
d.stopGlobal()
|
||||
}
|
||||
|
||||
d.extPort = extPort
|
||||
pkt := d.announcementPkt()
|
||||
wg := sync.NewWaitGroup()
|
||||
clients := make(chan Client, len(servers))
|
||||
for _, address := range servers {
|
||||
wg.Add(1)
|
||||
go func(addr string) {
|
||||
defer wg.Done()
|
||||
client, err := New(addr, pkt)
|
||||
if err != nil {
|
||||
l.Infoln("Error creating discovery client", addr, err)
|
||||
return
|
||||
}
|
||||
clients <- client
|
||||
}(address)
|
||||
}
|
||||
|
||||
wg.Wait()
|
||||
close(clients)
|
||||
|
||||
for client := range clients {
|
||||
d.clients = append(d.clients, client)
|
||||
}
|
||||
}
|
||||
|
||||
func (d *Discoverer) StopGlobal() {
|
||||
d.mut.Lock()
|
||||
defer d.mut.Unlock()
|
||||
d.stopGlobal()
|
||||
}
|
||||
|
||||
func (d *Discoverer) stopGlobal() {
|
||||
for _, client := range d.clients {
|
||||
client.Stop()
|
||||
}
|
||||
d.clients = []Client{}
|
||||
}
|
||||
|
||||
func (d *Discoverer) ExtAnnounceOK() map[string]bool {
|
||||
d.mut.RLock()
|
||||
defer d.mut.RUnlock()
|
||||
|
||||
ret := make(map[string]bool)
|
||||
for _, client := range d.clients {
|
||||
ret[client.Address()] = client.StatusOK()
|
||||
}
|
||||
return ret
|
||||
}
|
||||
|
||||
func (d *Discoverer) Lookup(device protocol.DeviceID) []string {
|
||||
d.registryLock.RLock()
|
||||
cached := d.filterCached(d.registry[device])
|
||||
lastLookup := d.lastLookup[device]
|
||||
d.registryLock.RUnlock()
|
||||
|
||||
d.mut.RLock()
|
||||
defer d.mut.RUnlock()
|
||||
|
||||
if len(cached) > 0 {
|
||||
// There are cached address entries.
|
||||
addrs := make([]string, len(cached))
|
||||
for i := range cached {
|
||||
addrs[i] = cached[i].Address
|
||||
}
|
||||
return addrs
|
||||
}
|
||||
|
||||
if time.Since(lastLookup) < d.negCacheCutoff {
|
||||
// We have recently tried to lookup this address and failed. Lets
|
||||
// chill for a while.
|
||||
return nil
|
||||
}
|
||||
|
||||
if len(d.clients) != 0 && time.Since(d.localBcastStart) > d.localBcastIntv {
|
||||
// Only perform external lookups if we have at least one external
|
||||
// server client and one local announcement interval has passed. This is
|
||||
// to avoid finding local peers on their remote address at startup.
|
||||
results := make(chan []string, len(d.clients))
|
||||
wg := sync.NewWaitGroup()
|
||||
for _, client := range d.clients {
|
||||
wg.Add(1)
|
||||
go func(c Client) {
|
||||
defer wg.Done()
|
||||
results <- c.Lookup(device)
|
||||
}(client)
|
||||
}
|
||||
|
||||
wg.Wait()
|
||||
close(results)
|
||||
|
||||
cached := []CacheEntry{}
|
||||
seen := make(map[string]struct{})
|
||||
now := time.Now()
|
||||
|
||||
var addrs []string
|
||||
for result := range results {
|
||||
for _, addr := range result {
|
||||
_, ok := seen[addr]
|
||||
if !ok {
|
||||
cached = append(cached, CacheEntry{
|
||||
Address: addr,
|
||||
Seen: now,
|
||||
})
|
||||
seen[addr] = struct{}{}
|
||||
addrs = append(addrs, addr)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
d.registryLock.Lock()
|
||||
d.registry[device] = cached
|
||||
d.lastLookup[device] = time.Now()
|
||||
d.registryLock.Unlock()
|
||||
|
||||
return addrs
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
func (d *Discoverer) Hint(device string, addrs []string) {
|
||||
resAddrs := resolveAddrs(addrs)
|
||||
var id protocol.DeviceID
|
||||
id.UnmarshalText([]byte(device))
|
||||
d.registerDevice(nil, Device{
|
||||
Addresses: resAddrs,
|
||||
ID: id[:],
|
||||
})
|
||||
}
|
||||
|
||||
func (d *Discoverer) All() map[protocol.DeviceID][]CacheEntry {
|
||||
d.registryLock.RLock()
|
||||
devices := make(map[protocol.DeviceID][]CacheEntry, len(d.registry))
|
||||
for device, addrs := range d.registry {
|
||||
addrsCopy := make([]CacheEntry, len(addrs))
|
||||
copy(addrsCopy, addrs)
|
||||
devices[device] = addrsCopy
|
||||
}
|
||||
d.registryLock.RUnlock()
|
||||
return devices
|
||||
}
|
||||
|
||||
func (d *Discoverer) announcementPkt() *Announce {
|
||||
var addrs []Address
|
||||
if d.extPort != 0 {
|
||||
addrs = []Address{{Port: d.extPort}}
|
||||
} else {
|
||||
for _, astr := range d.listenAddrs {
|
||||
addr, err := net.ResolveTCPAddr("tcp", astr)
|
||||
if err != nil {
|
||||
l.Warnln("discover: %v: not announcing %s", err, astr)
|
||||
continue
|
||||
} else if debug {
|
||||
l.Debugf("discover: resolved %s as %#v", astr, addr)
|
||||
}
|
||||
if len(addr.IP) == 0 || addr.IP.IsUnspecified() {
|
||||
addrs = append(addrs, Address{Port: uint16(addr.Port)})
|
||||
} else if bs := addr.IP.To4(); bs != nil {
|
||||
addrs = append(addrs, Address{IP: bs, Port: uint16(addr.Port)})
|
||||
} else if bs := addr.IP.To16(); bs != nil {
|
||||
addrs = append(addrs, Address{IP: bs, Port: uint16(addr.Port)})
|
||||
}
|
||||
}
|
||||
}
|
||||
return &Announce{
|
||||
Magic: AnnouncementMagic,
|
||||
This: Device{d.myID[:], addrs},
|
||||
}
|
||||
}
|
||||
|
||||
func (d *Discoverer) sendLocalAnnouncements() {
|
||||
var addrs = resolveAddrs(d.listenAddrs)
|
||||
|
||||
var pkt = Announce{
|
||||
Magic: AnnouncementMagic,
|
||||
This: Device{d.myID[:], addrs},
|
||||
}
|
||||
msg := pkt.MustMarshalXDR()
|
||||
|
||||
for {
|
||||
for _, b := range d.beacons {
|
||||
b.Send(msg)
|
||||
}
|
||||
|
||||
select {
|
||||
case <-d.localBcastTick:
|
||||
case <-d.forcedBcastTick:
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func (d *Discoverer) recvAnnouncements(b beacon.Interface) {
|
||||
for {
|
||||
buf, addr := b.Recv()
|
||||
|
||||
var pkt Announce
|
||||
err := pkt.UnmarshalXDR(buf)
|
||||
if err != nil && err != io.EOF {
|
||||
if debug {
|
||||
l.Debugf("discover: Failed to unmarshal local announcement from %s:\n%s", addr, hex.Dump(buf))
|
||||
}
|
||||
continue
|
||||
}
|
||||
|
||||
if debug {
|
||||
l.Debugf("discover: Received local announcement from %s for %s", addr, protocol.DeviceIDFromBytes(pkt.This.ID))
|
||||
}
|
||||
|
||||
var newDevice bool
|
||||
if bytes.Compare(pkt.This.ID, d.myID[:]) != 0 {
|
||||
newDevice = d.registerDevice(addr, pkt.This)
|
||||
}
|
||||
|
||||
if newDevice {
|
||||
select {
|
||||
case d.forcedBcastTick <- time.Now():
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func (d *Discoverer) registerDevice(addr net.Addr, device Device) bool {
|
||||
var id protocol.DeviceID
|
||||
copy(id[:], device.ID)
|
||||
|
||||
d.registryLock.Lock()
|
||||
defer d.registryLock.Unlock()
|
||||
|
||||
current := d.filterCached(d.registry[id])
|
||||
|
||||
orig := current
|
||||
|
||||
for _, a := range device.Addresses {
|
||||
var deviceAddr string
|
||||
if len(a.IP) > 0 {
|
||||
deviceAddr = net.JoinHostPort(net.IP(a.IP).String(), strconv.Itoa(int(a.Port)))
|
||||
} else if addr != nil {
|
||||
ua := addr.(*net.UDPAddr)
|
||||
ua.Port = int(a.Port)
|
||||
deviceAddr = ua.String()
|
||||
}
|
||||
for i := range current {
|
||||
if current[i].Address == deviceAddr {
|
||||
current[i].Seen = time.Now()
|
||||
goto done
|
||||
}
|
||||
}
|
||||
current = append(current, CacheEntry{
|
||||
Address: deviceAddr,
|
||||
Seen: time.Now(),
|
||||
})
|
||||
done:
|
||||
}
|
||||
|
||||
if debug {
|
||||
l.Debugf("discover: Caching %s addresses: %v", id, current)
|
||||
}
|
||||
|
||||
d.registry[id] = current
|
||||
|
||||
if len(current) > len(orig) {
|
||||
addrs := make([]string, len(current))
|
||||
for i := range current {
|
||||
addrs[i] = current[i].Address
|
||||
}
|
||||
events.Default.Log(events.DeviceDiscovered, map[string]interface{}{
|
||||
"device": id.String(),
|
||||
"addrs": addrs,
|
||||
})
|
||||
}
|
||||
|
||||
return len(current) > len(orig)
|
||||
}
|
||||
|
||||
func (d *Discoverer) filterCached(c []CacheEntry) []CacheEntry {
|
||||
for i := 0; i < len(c); {
|
||||
if ago := time.Since(c[i].Seen); ago > d.cacheLifetime {
|
||||
if debug {
|
||||
l.Debugf("discover: Removing cached address %s - seen %v ago", c[i].Address, ago)
|
||||
}
|
||||
c[i] = c[len(c)-1]
|
||||
c = c[:len(c)-1]
|
||||
} else {
|
||||
i++
|
||||
}
|
||||
}
|
||||
return c
|
||||
}
|
||||
|
||||
func addrToAddr(addr *net.TCPAddr) Address {
|
||||
if len(addr.IP) == 0 || addr.IP.IsUnspecified() {
|
||||
return Address{Port: uint16(addr.Port)}
|
||||
} else if bs := addr.IP.To4(); bs != nil {
|
||||
return Address{IP: bs, Port: uint16(addr.Port)}
|
||||
} else if bs := addr.IP.To16(); bs != nil {
|
||||
return Address{IP: bs, Port: uint16(addr.Port)}
|
||||
}
|
||||
return Address{}
|
||||
}
|
||||
|
||||
func resolveAddrs(addrs []string) []Address {
|
||||
var raddrs []Address
|
||||
for _, addrStr := range addrs {
|
||||
addrRes, err := net.ResolveTCPAddr("tcp", addrStr)
|
||||
if err != nil {
|
||||
continue
|
||||
}
|
||||
addr := addrToAddr(addrRes)
|
||||
if len(addr.IP) > 0 {
|
||||
raddrs = append(raddrs, addr)
|
||||
} else {
|
||||
raddrs = append(raddrs, Address{Port: addr.Port})
|
||||
}
|
||||
}
|
||||
return raddrs
|
||||
}
|
||||
Reference in New Issue
Block a user