Add DHTCrawler module

cmd/yggdrasil/main.go

@@ -25,6 +25,7 @@ import (
 	"github.com/yggdrasil-network/yggdrasil-go/src/admin"
 	"github.com/yggdrasil-network/yggdrasil-go/src/config"
 	"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
+	"github.com/yggdrasil-network/yggdrasil-go/src/dhtcrawler"
 	"github.com/yggdrasil-network/yggdrasil-go/src/module"
 	"github.com/yggdrasil-network/yggdrasil-go/src/multicast"
 	"github.com/yggdrasil-network/yggdrasil-go/src/tuntap"
@@ -38,6 +39,7 @@ type node struct {
 	tuntap     module.Module // tuntap.TunAdapter
 	multicast  module.Module // multicast.Multicast
 	admin      module.Module // admin.AdminSocket
+	dhtcrawler module.Module // dhtcrawler.Crawler
 }
 
 func readConfig(useconf *bool, useconffile *string, normaliseconf *bool) *config.NodeConfig {
@@ -284,6 +286,7 @@ func main() {
 	n.admin = &admin.AdminSocket{}
 	n.multicast = &multicast.Multicast{}
 	n.tuntap = &tuntap.TunAdapter{}
+	n.dhtcrawler = &dhtcrawler.Crawler{}
 	// Start the admin socket
 	n.admin.Init(&n.core, n.state, logger, nil)
 	if err := n.admin.Start(); err != nil {
@@ -310,6 +313,10 @@ func main() {
 	} else {
 		logger.Errorln("Unable to get Listener:", err)
 	}
+
+	n.dhtcrawler.Init(&n.core, n.state, logger, nil)
+	n.dhtcrawler.SetupAdminHandlers(n.admin.(*admin.AdminSocket))
+
 	// Make some nice output that tells us what our IPv6 address and subnet are.
 	// This is just logged to stdout for the user.
 	address := n.core.Address()
@@ -337,6 +344,7 @@ func main() {
 				n.core.UpdateConfig(cfg)
 				n.tuntap.UpdateConfig(cfg)
 				n.multicast.UpdateConfig(cfg)
+				n.dhtcrawler.UpdateConfig(cfg)
 			} else {
 				logger.Errorln("Reloading config at runtime is only possible with -useconffile")
 			}

src/dhtcrawler/crawler.go

@@ -0,0 +1,273 @@
+package dhtcrawler
+
+import (
+	"encoding/hex"
+	"encoding/json"
+	"math/rand"
+	"net"
+	"sync"
+	"time"
+
+	"github.com/gologme/log"
+
+	"github.com/yggdrasil-network/yggdrasil-go/src/address"
+	"github.com/yggdrasil-network/yggdrasil-go/src/admin"
+	"github.com/yggdrasil-network/yggdrasil-go/src/config"
+	"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
+	"github.com/yggdrasil-network/yggdrasil-go/src/yggdrasil"
+)
+
+const (
+	DefaultRetryCount int           = 5
+	DefaultExpiration time.Duration = 5 * time.Minute
+)
+
+type ApiCache struct {
+	networkMap      admin.Info
+	networkMapMutex sync.RWMutex
+	expiration      int64
+}
+
+func (a *ApiCache) Get(crawler *Crawler) admin.Info {
+	a.networkMapMutex.Lock()
+	defer a.networkMapMutex.Unlock()
+
+	if a.networkMap == nil || time.Now().UnixNano() > a.expiration {
+		json_value := crawler.getNetworkMap()
+		a.networkMap = admin.Info{"networkMap": json_value}
+		a.expiration = time.Now().Add(DefaultExpiration).UnixNano()
+	}
+
+	return a.networkMap
+}
+
+type Crawler struct {
+	core    *yggdrasil.Core
+	config  *config.NodeState
+	log     *log.Logger
+	started bool
+
+	apiCache          ApiCache
+	dhtWaitGroup      sync.WaitGroup
+	dhtVisited        map[string]attempt
+	dhtMutex          sync.RWMutex
+	nodeInfoWaitGroup sync.WaitGroup
+	nodeInfoVisited   map[string]interface{}
+	nodeInfoMutex     sync.RWMutex
+}
+
+// This is the structure that we marshal at the end into JSON results
+type results struct {
+	Meta struct {
+		GeneratedAtUTC     int64 `json:"generated_at_utc"`
+		NodesAttempted     int   `json:"nodes_attempted"`
+		NodesSuccessful    int   `json:"nodes_successful"`
+		NodesFailed        int   `json:"nodes_failed"`
+		NodeInfoSuccessful int   `json:"nodeinfo_successful"`
+		NodeInfoFailed     int   `json:"nodeinfo_failed"`
+	} `json:"meta"`
+	Topology *map[string]attempt     `json:"topology"`
+	NodeInfo *map[string]interface{} `json:"nodeinfo"`
+}
+
+type attempt struct {
+	NodeID     string   `json:"node_id"`     // the node ID
+	IPv6Addr   string   `json:"ipv6_addr"`   // the node address
+	IPv6Subnet string   `json:"ipv6_subnet"` // the node subnet
+	Coords     []uint64 `json:"coords"`      // the coordinates of the node
+	Found      bool     `json:"found"`       // has a search for this node completed successfully?
+}
+
+func (s *Crawler) Init(core *yggdrasil.Core, config *config.NodeState, log *log.Logger, options interface{}) error {
+	s.core = core
+	s.config = config
+	s.log = log
+	s.started = false
+
+	return nil
+}
+
+func (s *Crawler) Stop() error {
+	return nil
+}
+
+func (s *Crawler) Start() error {
+	return nil
+}
+
+func (s *Crawler) IsStarted() bool {
+	return s.started
+}
+
+func (s *Crawler) UpdateConfig(config *config.NodeConfig) {}
+
+func (s *Crawler) SetupAdminHandlers(a *admin.AdminSocket) {
+	a.AddHandler("getNetworkMap", []string{}, func(in admin.Info) (admin.Info, error) {
+		return s.apiCache.Get(s), nil
+	})
+}
+
+func (s *Crawler) getNetworkMap() string {
+	starttime := time.Now()
+	s.dhtVisited = make(map[string]attempt)
+	s.nodeInfoVisited = make(map[string]interface{})
+
+	if key, err := hex.DecodeString(s.core.EncryptionPublicKey()); err == nil {
+		var pubkey crypto.BoxPubKey
+		copy(pubkey[:], key)
+		s.dhtWaitGroup.Add(1)
+		go s.dhtPing(pubkey, s.core.Coords())
+	} else {
+		panic("failed to decode pub key")
+	}
+
+	s.dhtWaitGroup.Wait()
+	s.nodeInfoWaitGroup.Wait()
+
+	s.dhtMutex.Lock()
+	defer s.dhtMutex.Unlock()
+	s.nodeInfoMutex.Lock()
+	defer s.nodeInfoMutex.Unlock()
+
+	s.log.Infoln("The crawl took", time.Since(starttime))
+
+	attempted := len(s.dhtVisited)
+	found := 0
+	for _, attempt := range s.dhtVisited {
+		if attempt.Found {
+			found++
+		}
+	}
+
+	res := results{
+		Topology: &s.dhtVisited,
+		NodeInfo: &s.nodeInfoVisited,
+	}
+	res.Meta.GeneratedAtUTC = time.Now().UTC().Unix()
+	res.Meta.NodeInfoSuccessful = len(s.nodeInfoVisited)
+	res.Meta.NodeInfoFailed = found - len(s.nodeInfoVisited)
+	res.Meta.NodesAttempted = attempted
+	res.Meta.NodesSuccessful = found
+	res.Meta.NodesFailed = attempted - found
+
+	if j, err := json.MarshalIndent(res, "", "\t"); err == nil {
+		return string(j)
+	} else {
+		return "json marshaling error"
+	}
+}
+
+func (s *Crawler) dhtPing(pubkey crypto.BoxPubKey, coords []uint64) {
+	// Notify the main goroutine that we're done working
+	defer s.dhtWaitGroup.Done()
+
+	// Generate useful information about the node, such as it's node ID, address
+	// and subnet
+	key := hex.EncodeToString(pubkey[:])
+	nodeid := crypto.GetNodeID(&pubkey)
+	addr := net.IP(address.AddrForNodeID(nodeid)[:])
+	upper := append(address.SubnetForNodeID(nodeid)[:], 0, 0, 0, 0, 0, 0, 0, 0)
+	subnet := net.IPNet{IP: upper, Mask: net.CIDRMask(64, 128)}
+
+	// If we already have an entry of this node then we should stop what we're
+	// doing - it either means that a search is already taking place, or that we
+	// have already processed this node
+	s.dhtMutex.RLock()
+	if info := s.dhtVisited[key]; info.Found {
+		s.dhtMutex.RUnlock()
+		return
+	}
+	s.dhtMutex.RUnlock()
+
+	// Make a record of this node and the coordinates so that future goroutines
+	// started by a rumour of this node will not repeat this search
+	var res yggdrasil.DHTRes
+	var err error
+	for idx := 0; idx < DefaultRetryCount; idx++ {
+		// Randomized delay between attempts, increases exponentially
+		time.Sleep(time.Millisecond * time.Duration(rand.Intn(1000)*(1<<idx)))
+		// Send out a DHT ping request into the network
+		res, err = s.core.DHTPing(
+			pubkey,
+			coords,
+			&crypto.NodeID{},
+		)
+		if err == nil {
+			break
+		}
+	}
+
+	// Write our new information into the list of visited DHT nodes
+	info := attempt{
+		NodeID:     nodeid.String(),
+		IPv6Addr:   addr.String(),
+		IPv6Subnet: subnet.String(),
+		Coords:     coords,
+		Found:      err == nil,
+	}
+
+	// If we successfully found the node then update dhtVisited to say so
+	s.dhtMutex.Lock()
+	defer s.dhtMutex.Unlock()
+	oldInfo := s.dhtVisited[key]
+	if info.Found || !oldInfo.Found {
+		s.dhtVisited[key] = info
+	}
+
+	// If this was the first response from this node then request nodeinfo
+	if !oldInfo.Found && info.Found {
+		s.nodeInfoWaitGroup.Add(1)
+		go s.nodeInfo(pubkey, coords)
+	} else {
+		// This isn't our first response from the node, so don't do anything
+		return
+	}
+
+	// Start new DHT search goroutines based on the rumours included in the DHT
+	// ping response
+	for _, info := range res.Infos {
+		s.dhtWaitGroup.Add(1)
+		go s.dhtPing(info.PublicKey, info.Coords)
+	}
+}
+
+func (s *Crawler) nodeInfo(pubkey crypto.BoxPubKey, coords []uint64) {
+	// Notify the main goroutine that we're done working
+	defer s.nodeInfoWaitGroup.Done()
+
+	// Store information that says that we attempted to query this node for
+	// nodeinfo
+	key := hex.EncodeToString(pubkey[:])
+	s.nodeInfoMutex.RLock()
+	if _, ok := s.nodeInfoVisited[key]; ok {
+		s.nodeInfoMutex.RUnlock()
+		return
+	}
+	s.nodeInfoMutex.RUnlock()
+
+	// send the nodeinfo request to the given coordinates
+	var res yggdrasil.NodeInfoPayload
+	var err error
+	for idx := 0; idx < DefaultRetryCount; idx++ {
+		time.Sleep(time.Millisecond * time.Duration(rand.Intn(1000)*(1<<idx)))
+		res, err = s.core.GetNodeInfo(pubkey, coords, false)
+		if err == nil {
+			break
+		}
+	}
+	if err != nil {
+		return
+	}
+
+	s.nodeInfoMutex.Lock()
+	defer s.nodeInfoMutex.Unlock()
+
+	// If we received nodeinfo back then try to unmarshal it and store it in our
+	// received nodeinfos
+	var j interface{}
+	if err := json.Unmarshal(res, &j); err != nil {
+		s.log.Debugln(err)
+	} else {
+		s.nodeInfoVisited[key] = j
+	}
+}