Try and solidify multicast interface behavior

This commit is contained in:
Neil Alexander 2019-06-20 15:11:55 +01:00
parent 2fd3ac6837
commit 54f1804101
No known key found for this signature in database
GPG Key ID: A02A2019A2BB0944
3 changed files with 76 additions and 73 deletions

View File

@ -5,7 +5,7 @@ import "github.com/yggdrasil-network/yggdrasil-go/src/admin"
func (m *Multicast) SetupAdminHandlers(a *admin.AdminSocket) { func (m *Multicast) SetupAdminHandlers(a *admin.AdminSocket) {
a.AddHandler("getMulticastInterfaces", []string{}, func(in admin.Info) (admin.Info, error) { a.AddHandler("getMulticastInterfaces", []string{}, func(in admin.Info) (admin.Info, error) {
var intfs []string var intfs []string
for _, v := range m.interfaces() { for _, v := range m.GetInterfaces() {
intfs = append(intfs, v.Name) intfs = append(intfs, v.Name)
} }
return admin.Info{"multicast_interfaces": intfs}, nil return admin.Info{"multicast_interfaces": intfs}, nil

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@ -5,6 +5,7 @@ import (
"fmt" "fmt"
"net" "net"
"regexp" "regexp"
"sync"
"time" "time"
"github.com/gologme/log" "github.com/gologme/log"
@ -22,11 +23,13 @@ type Multicast struct {
core *yggdrasil.Core core *yggdrasil.Core
config *config.NodeState config *config.NodeState
log *log.Logger log *log.Logger
reconfigure chan chan error
sock *ipv6.PacketConn sock *ipv6.PacketConn
groupAddr string groupAddr string
listeners map[string]*yggdrasil.TcpListener listeners map[string]*yggdrasil.TcpListener
listenPort uint16 listenPort uint16
interfaces map[string]net.Interface
interfacesMutex sync.RWMutex
interfacesTime time.Time
} }
// Init prepares the multicast interface for use. // Init prepares the multicast interface for use.
@ -34,25 +37,24 @@ func (m *Multicast) Init(core *yggdrasil.Core, state *config.NodeState, log *log
m.core = core m.core = core
m.config = state m.config = state
m.log = log m.log = log
m.reconfigure = make(chan chan error, 1)
m.listeners = make(map[string]*yggdrasil.TcpListener) m.listeners = make(map[string]*yggdrasil.TcpListener)
m.interfaces = make(map[string]net.Interface)
current, _ := m.config.Get() current, _ := m.config.Get()
m.listenPort = current.LinkLocalTCPPort m.listenPort = current.LinkLocalTCPPort
m.groupAddr = "[ff02::114]:9001"
// Perform our first check for multicast interfaces
if count := m.UpdateInterfaces(); count != 0 {
m.log.Infoln("Found", count, "multicast interface(s)")
} else {
m.log.Infoln("Multicast is not enabled on any interfaces")
}
// Keep checking quietly every minute in case they change
go func() { go func() {
for { for {
e := <-m.reconfigure time.Sleep(time.Minute)
// There's nothing particularly to do here because the multicast module m.UpdateInterfaces()
// already consults the config.NodeState when enumerating multicast
// interfaces on each pass. We just need to return nil so that the
// reconfiguration doesn't block indefinitely
e <- nil
} }
}() }()
m.groupAddr = "[ff02::114]:9001"
// Check if we've been given any expressions
if count := len(m.interfaces()); count != 0 {
m.log.Infoln("Found", count, "multicast interface(s)")
}
return nil return nil
} }
@ -60,11 +62,6 @@ func (m *Multicast) Init(core *yggdrasil.Core, state *config.NodeState, log *log
// listen for multicast beacons from other hosts and will advertise multicast // listen for multicast beacons from other hosts and will advertise multicast
// beacons out to the network. // beacons out to the network.
func (m *Multicast) Start() error { func (m *Multicast) Start() error {
current, _ := m.config.Get()
if len(current.MulticastInterfaces) == 0 {
m.log.Infoln("Multicast discovery is disabled")
} else {
m.log.Infoln("Multicast discovery is enabled")
addr, err := net.ResolveUDPAddr("udp", m.groupAddr) addr, err := net.ResolveUDPAddr("udp", m.groupAddr)
if err != nil { if err != nil {
return err return err
@ -85,7 +82,7 @@ func (m *Multicast) Start() error {
go m.multicastStarted() go m.multicastStarted()
go m.listen() go m.listen()
go m.announce() go m.announce()
}
return nil return nil
} }
@ -102,34 +99,37 @@ func (m *Multicast) UpdateConfig(config *config.NodeConfig) {
m.config.Replace(*config) m.config.Replace(*config)
errors := 0
components := []chan chan error{
m.reconfigure,
}
for _, component := range components {
response := make(chan error)
component <- response
if err := <-response; err != nil {
m.log.Errorln(err)
errors++
}
}
if errors > 0 {
m.log.Warnln(errors, "multicast module(s) reported errors during configuration reload")
} else {
m.log.Infoln("Multicast configuration reloaded successfully") m.log.Infoln("Multicast configuration reloaded successfully")
if count := m.UpdateInterfaces(); count != 0 {
m.log.Infoln("Found", count, "multicast interface(s)")
} else {
m.log.Infoln("Multicast is not enabled on any interfaces")
} }
} }
func (m *Multicast) interfaces() map[string]net.Interface { // GetInterfaces returns the currently known/enabled multicast interfaces. It is
// expected that UpdateInterfaces has been called at least once before calling
// this method.
func (m *Multicast) GetInterfaces() map[string]net.Interface {
m.interfacesMutex.RLock()
defer m.interfacesMutex.RUnlock()
return m.interfaces
}
// UpdateInterfaces re-enumerates the available multicast interfaces on the
// system, using the current MulticastInterfaces config option as a template.
// The number of selected interfaces is returned.
func (m *Multicast) UpdateInterfaces() int {
m.interfacesMutex.Lock()
defer m.interfacesMutex.Unlock()
// Get interface expressions from config // Get interface expressions from config
current, _ := m.config.Get() current, _ := m.config.Get()
exprs := current.MulticastInterfaces exprs := current.MulticastInterfaces
// Ask the system for network interfaces // Ask the system for network interfaces
interfaces := make(map[string]net.Interface) for i := range m.interfaces {
delete(m.interfaces, i)
}
allifaces, err := net.Interfaces() allifaces, err := net.Interfaces()
if err != nil { if err != nil {
panic(err) panic(err)
@ -156,11 +156,12 @@ func (m *Multicast) interfaces() map[string]net.Interface {
} }
// Does the interface match the regular expression? Store it if so // Does the interface match the regular expression? Store it if so
if e.MatchString(iface.Name) { if e.MatchString(iface.Name) {
interfaces[iface.Name] = iface m.interfaces[iface.Name] = iface
} }
} }
} }
return interfaces m.interfacesTime = time.Now()
return len(m.interfaces)
} }
func (m *Multicast) announce() { func (m *Multicast) announce() {
@ -173,7 +174,7 @@ func (m *Multicast) announce() {
panic(err) panic(err)
} }
for { for {
interfaces := m.interfaces() interfaces := m.GetInterfaces()
// There might be interfaces that we configured listeners for but are no // There might be interfaces that we configured listeners for but are no
// longer up - if that's the case then we should stop the listeners // longer up - if that's the case then we should stop the listeners
for name, listener := range m.listeners { for name, listener := range m.listeners {
@ -307,9 +308,11 @@ func (m *Multicast) listen() {
if addr.IP.String() != from.IP.String() { if addr.IP.String() != from.IP.String() {
continue continue
} }
if _, ok := m.GetInterfaces()[from.Zone]; ok {
addr.Zone = "" addr.Zone = ""
if err := m.core.CallPeer("tcp://"+addr.String(), from.Zone); err != nil { if err := m.core.CallPeer("tcp://"+addr.String(), from.Zone); err != nil {
m.log.Debugln("Call from multicast failed:", err) m.log.Debugln("Call from multicast failed:", err)
} }
} }
}
} }

View File

@ -35,12 +35,12 @@ func (m *Multicast) multicastStarted() {
if awdlGoroutineStarted { if awdlGoroutineStarted {
return return
} }
m.log.Infoln("Multicast discovery will wake up AWDL if required")
awdlGoroutineStarted = true awdlGoroutineStarted = true
for { for {
C.StopAWDLBrowsing() C.StopAWDLBrowsing()
for _, intf := range m.interfaces() { for _, intf := range m.GetInterfaces() {
if intf.Name == "awdl0" { if intf.Name == "awdl0" {
m.log.Infoln("Multicast discovery is using AWDL discovery")
C.StartAWDLBrowsing() C.StartAWDLBrowsing()
break break
} }