Support notifying components for config reload, listen for SIGHUP

cmd/yggdrasil/main.go

@@ -314,7 +314,9 @@ func main() {
 	logger.Printf("Your IPv6 subnet is %s", subnet.String())
 	// Catch interrupts from the operating system to exit gracefully.
 	c := make(chan os.Signal, 1)
+	r := make(chan os.Signal, 1)
 	signal.Notify(c, os.Interrupt, syscall.SIGTERM)
+	signal.Notify(r, os.Interrupt, syscall.SIGHUP)
 	// Create a function to capture the service being stopped on Windows.
 	winTerminate := func() {
 		c <- os.Interrupt
@@ -322,5 +324,13 @@ func main() {
 	minwinsvc.SetOnExit(winTerminate)
 	// Wait for the terminate/interrupt signal. Once a signal is received, the
 	// deferred Stop function above will run which will shut down TUN/TAP.
-	<-c
+	for {
+		select {
+		case _ = <-r:
+			n.core.UpdateConfig(cfg)
+		case _ = <-c:
+			goto exit
+		}
+	}
+exit:
 }

src/yggdrasil/admin.go

@@ -23,6 +23,7 @@ import (
 
 type admin struct {
 	core        *Core
+	reconfigure chan bool
 	listenaddr  string
 	listener    net.Listener
 	handlers    []admin_handlerInfo
@@ -53,6 +54,21 @@ func (a *admin) addHandler(name string, args []string, handler func(admin_info)
 // init runs the initial admin setup.
 func (a *admin) init(c *Core, listenaddr string) {
 	a.core = c
+	a.reconfigure = make(chan bool, 1)
+	go func() {
+		for {
+			select {
+			case _ = <-a.reconfigure:
+				a.core.configMutex.RLock()
+				a.core.log.Println("Notified: admin")
+				if a.core.config.AdminListen != a.core.configOld.AdminListen {
+					a.core.log.Println("AdminListen has changed!")
+				}
+				a.core.configMutex.RUnlock()
+				continue
+			}
+		}
+	}()
 	a.listenaddr = listenaddr
 	a.addHandler("list", []string{}, func(in admin_info) (admin_info, error) {
 		handlers := make(map[string]interface{})

src/yggdrasil/core.go

@@ -7,6 +7,7 @@ import (
 	"log"
 	"net"
 	"regexp"
+	"sync"
 
 	"github.com/yggdrasil-network/yggdrasil-go/src/address"
 	"github.com/yggdrasil-network/yggdrasil-go/src/config"
@@ -17,14 +18,26 @@ import (
 var buildName string
 var buildVersion string
 
+type module interface {
+	init(*config.NodeConfig) error
+	start() error
+}
+
 // The Core object represents the Yggdrasil node. You should create a Core
 // object for each Yggdrasil node you plan to run.
 type Core struct {
 	// This is the main data structure that holds everything else for a node
+	// We're going to keep our own copy of the provided config - that way we can
+	// guarantee that it will be covered by the mutex
+	config      config.NodeConfig // Active config
+	configOld   config.NodeConfig // Previous config
+	configMutex sync.RWMutex      // Protects both config and configOld
+	// Core-specific config
 	boxPub  crypto.BoxPubKey
 	boxPriv crypto.BoxPrivKey
 	sigPub  crypto.SigPubKey
 	sigPriv crypto.SigPrivKey
+	// Modules
 	switchTable switchTable
 	peers       peers
 	sessions    sessions
@@ -35,6 +48,7 @@ type Core struct {
 	multicast   multicast
 	nodeinfo    nodeinfo
 	tcp         tcpInterface
+	// Other bits
 	log      *log.Logger
 	ifceExpr []*regexp.Regexp // the zone of link-local IPv6 peers must match this
 }
@@ -62,8 +76,26 @@ func (c *Core) init(bpub *crypto.BoxPubKey,
 	c.switchTable.init(c, c.sigPub) // TODO move before peers? before router?
 }
 
-// Get the current build name. This is usually injected if built from git,
+// UpdateConfig updates the configuration in Core and then signals the
-// or returns "unknown" otherwise.
+// various module goroutines to reconfigure themselves if needed
+func (c *Core) UpdateConfig(config *config.NodeConfig) {
+	c.configMutex.Lock()
+	c.configOld = c.config
+	c.config = *config
+	c.configMutex.Unlock()
+
+	c.admin.reconfigure <- true
+	c.searches.reconfigure <- true
+	c.dht.reconfigure <- true
+	c.sessions.reconfigure <- true
+	c.multicast.reconfigure <- true
+	c.peers.reconfigure <- true
+	c.router.reconfigure <- true
+	c.switchTable.reconfigure <- true
+}
+
+// GetBuildName gets the current build name. This is usually injected if built
+// from git, or returns "unknown" otherwise.
 func GetBuildName() string {
 	if buildName == "" {
 		return "unknown"
@@ -96,6 +128,11 @@ func (c *Core) Start(nc *config.NodeConfig, log *log.Logger) error {
 
 	c.log.Println("Starting up...")
 
+	c.configMutex.Lock()
+	c.config = *nc
+	c.configOld = c.config
+	c.configMutex.Unlock()
+
 	var boxPub crypto.BoxPubKey
 	var boxPriv crypto.BoxPrivKey
 	var sigPub crypto.SigPubKey

src/yggdrasil/dht.go

@@ -66,6 +66,7 @@ type dhtReqKey struct {
 // The main DHT struct.
 type dht struct {
 	core        *Core
+	reconfigure chan bool
 	nodeID      crypto.NodeID
 	peers       chan *dhtInfo                  // other goroutines put incoming dht updates here
 	reqs        map[dhtReqKey]time.Time        // Keeps track of recent outstanding requests
@@ -78,6 +79,18 @@ type dht struct {
 // Initializes the DHT.
 func (t *dht) init(c *Core) {
 	t.core = c
+	t.reconfigure = make(chan bool, 1)
+	go func() {
+		for {
+			select {
+			case _ = <-t.reconfigure:
+				t.core.configMutex.RLock()
+				t.core.log.Println("Notified: dht")
+				t.core.configMutex.RUnlock()
+				continue
+			}
+		}
+	}()
 	t.nodeID = *t.core.GetNodeID()
 	t.peers = make(chan *dhtInfo, 1024)
 	t.callbacks = make(map[dhtReqKey]dht_callbackInfo)

src/yggdrasil/multicast.go

@@ -11,12 +11,25 @@ import (
 
 type multicast struct {
 	core        *Core
+	reconfigure chan bool
 	sock        *ipv6.PacketConn
 	groupAddr   string
 }
 
 func (m *multicast) init(core *Core) {
 	m.core = core
+	m.reconfigure = make(chan bool, 1)
+	go func() {
+		for {
+			select {
+			case _ = <-m.reconfigure:
+				m.core.configMutex.RLock()
+				m.core.log.Println("Notified: multicast")
+				m.core.configMutex.RUnlock()
+				continue
+			}
+		}
+	}()
 	m.groupAddr = "[ff02::114]:9001"
 	// Check if we've been given any expressions
 	if len(m.core.ifceExpr) == 0 {

src/yggdrasil/peer.go

@@ -19,6 +19,7 @@ import (
 // In other cases, it's link protocol traffic used to build the spanning tree, in which case this checks signatures and passes the message along to the switch.
 type peers struct {
 	core                        *Core
+	reconfigure                 chan bool
 	mutex                       sync.Mutex   // Synchronize writes to atomic
 	ports                       atomic.Value //map[switchPort]*peer, use CoW semantics
 	authMutex                   sync.RWMutex
@@ -31,6 +32,18 @@ func (ps *peers) init(c *Core) {
 	defer ps.mutex.Unlock()
 	ps.putPorts(make(map[switchPort]*peer))
 	ps.core = c
+	ps.reconfigure = make(chan bool, 1)
+	go func() {
+		for {
+			select {
+			case _ = <-ps.reconfigure:
+				ps.core.configMutex.RLock()
+				ps.core.log.Println("Notified: peers")
+				ps.core.configMutex.RUnlock()
+				continue
+			}
+		}
+	}()
 	ps.allowedEncryptionPublicKeys = make(map[crypto.BoxPubKey]struct{})
 }
 

src/yggdrasil/router.go

@@ -38,6 +38,7 @@ import (
 // The router's mainLoop goroutine is responsible for managing all information related to the dht, searches, and crypto sessions.
 type router struct {
 	core        *Core
+	reconfigure chan bool
 	addr        address.Address
 	subnet      address.Subnet
 	in          <-chan []byte          // packets we received from the network, link to peer's "out"
@@ -61,6 +62,7 @@ type router_recvPacket struct {
 // Initializes the router struct, which includes setting up channels to/from the tun/tap.
 func (r *router) init(core *Core) {
 	r.core = core
+	r.reconfigure = make(chan bool, 1)
 	r.addr = *address.AddrForNodeID(&r.core.dht.nodeID)
 	r.subnet = *address.SubnetForNodeID(&r.core.dht.nodeID)
 	in := make(chan []byte, 32) // TODO something better than this...
@@ -124,6 +126,11 @@ func (r *router) mainLoop() {
 			}
 		case f := <-r.admin:
 			f()
+		case _ = <-r.reconfigure:
+			r.core.configMutex.RLock()
+			r.core.log.Println("Notified: router")
+			r.core.configMutex.RUnlock()
+			continue
 		}
 	}
 }

src/yggdrasil/search.go

@@ -43,12 +43,25 @@ type searchInfo struct {
 // This stores a map of active searches.
 type searches struct {
 	core        *Core
+	reconfigure chan bool
 	searches    map[crypto.NodeID]*searchInfo
 }
 
 // Intializes the searches struct.
 func (s *searches) init(core *Core) {
 	s.core = core
+	s.reconfigure = make(chan bool, 1)
+	go func() {
+		for {
+			select {
+			case _ = <-s.reconfigure:
+				s.core.configMutex.RLock()
+				s.core.log.Println("Notified: searches")
+				s.core.configMutex.RUnlock()
+				continue
+			}
+		}
+	}()
 	s.searches = make(map[crypto.NodeID]*searchInfo)
 }
 

src/yggdrasil/session.go

@@ -18,6 +18,7 @@ import (
 // This includes coords, permanent and ephemeral keys, handles and nonces, various sorts of timing information for timeout and maintenance, and some metadata for the admin API.
 type sessionInfo struct {
 	core         *Core
+	reconfigure  chan bool
 	theirAddr    address.Address
 	theirSubnet  address.Subnet
 	theirPermPub crypto.BoxPubKey
@@ -101,6 +102,7 @@ func (s *sessionInfo) timedout() bool {
 // Additionally, stores maps of address/subnet onto keys, and keys onto handles.
 type sessions struct {
 	core        *Core
+	reconfigure chan bool
 	lastCleanup time.Time
 	// Maps known permanent keys to their shared key, used by DHT a lot
 	permShared map[crypto.BoxPubKey]*crypto.BoxSharedKey
@@ -124,6 +126,22 @@ type sessions struct {
 // Initializes the session struct.
 func (ss *sessions) init(core *Core) {
 	ss.core = core
+	ss.reconfigure = make(chan bool, 1)
+	go func() {
+		for {
+			select {
+			case newConfig := <-ss.reconfigure:
+				ss.core.configMutex.RLock()
+				ss.core.log.Println("Notified: sessions")
+				ss.core.configMutex.RUnlock()
+
+				for _, sinfo := range ss.sinfos {
+					sinfo.reconfigure <- newConfig
+				}
+				continue
+			}
+		}
+	}()
 	ss.permShared = make(map[crypto.BoxPubKey]*crypto.BoxSharedKey)
 	ss.sinfos = make(map[crypto.Handle]*sessionInfo)
 	ss.byMySes = make(map[crypto.BoxPubKey]*crypto.Handle)
@@ -271,6 +289,7 @@ func (ss *sessions) createSession(theirPermKey *crypto.BoxPubKey) *sessionInfo {
 	}
 	sinfo := sessionInfo{}
 	sinfo.core = ss.core
+	sinfo.reconfigure = make(chan bool, 1)
 	sinfo.theirPermPub = *theirPermKey
 	pub, priv := crypto.NewBoxKeys()
 	sinfo.mySesPub = *pub
@@ -539,6 +558,11 @@ func (sinfo *sessionInfo) doWorker() {
 			} else {
 				return
 			}
+		case _ = <-sinfo.reconfigure:
+			sinfo.core.configMutex.RLock()
+			sinfo.core.log.Println("Notified: sessionInfo")
+			sinfo.core.configMutex.RUnlock()
+			continue
 		}
 	}
 }

src/yggdrasil/switch.go

@@ -162,6 +162,7 @@ type switchData struct {
 // All the information stored by the switch.
 type switchTable struct {
 	core              *Core
+	reconfigure       chan bool
 	key               crypto.SigPubKey           // Our own key
 	time              time.Time                  // Time when locator.tstamp was last updated
 	drop              map[crypto.SigPubKey]int64 // Tstamp associated with a dropped root
@@ -184,6 +185,7 @@ const SwitchQueueTotalMinSize = 4 * 1024 * 1024
 func (t *switchTable) init(core *Core, key crypto.SigPubKey) {
 	now := time.Now()
 	t.core = core
+	t.reconfigure = make(chan bool, 1)
 	t.key = key
 	locator := switchLocator{root: key, tstamp: now.Unix()}
 	peers := make(map[switchPort]peerInfo)
@@ -808,6 +810,11 @@ func (t *switchTable) doWorker() {
 			}
 		case f := <-t.admin:
 			f()
+		case _ = <-t.reconfigure:
+			t.core.configMutex.RLock()
+			t.core.log.Println("Notified: switchTable")
+			t.core.configMutex.RUnlock()
+			continue
 		}
 	}
 }