Proxy records found in ethereum discovery v5 (#1165)

Makefile

@@ -41,6 +41,7 @@ gotest_extraflags =
 
 DOCKER_IMAGE_NAME ?= statusteam/status-go
 BOOTNODE_IMAGE_NAME ?= statusteam/bootnode
+PROXY_IMAGE_NAME ?= statusteam/discovery-proxy
 STATUSD_PRUNE_IMAGE_NAME ?= statusteam/statusd-prune
 
 DOCKER_IMAGE_CUSTOM_TAG ?= $(shell BUILD_TAGS="$(BUILD_TAGS)" ./_assets/ci/get-docker-image-tag.sh)
@@ -87,6 +88,10 @@ bootnode: ##@build Build discovery v5 bootnode using status-go deps
 	go build -i -o $(GOBIN)/bootnode -v -tags '$(BUILD_TAGS)' $(BUILD_FLAGS) ./cmd/bootnode/
 	@echo "Compilation done."
 
+proxy: ##@build Build proxy for rendezvous servers using status-go deps
+	go build -i -o $(GOBIN)/proxy -v -tags '$(BUILD_TAGS)' $(BUILD_FLAGS) ./cmd/proxy/
+	@echo "Compilation done."
+
 mailserver-canary: ##@build Build mailserver canary using status-go deps
 	go build -i -o $(GOBIN)/mailserver-canary -v -tags '$(BUILD_TAGS)' $(BUILD_FLAGS) ./cmd/mailserver-canary/
 	@echo "Compilation done."
@@ -137,9 +142,19 @@ docker-image: ##@docker Build docker image (use DOCKER_IMAGE_NAME to set the ima
 bootnode-image:
 	@echo "Building docker image for bootnode..."
 	docker build --file _assets/build/Dockerfile-bootnode . \
+		--build-arg "build_tags=$(BUILD_TAGS)" \
+		--build-arg "build_flags=$(BUILD_FLAGS)" \
 		-t $(BOOTNODE_IMAGE_NAME):$(DOCKER_IMAGE_CUSTOM_TAG) \
 		-t $(BOOTNODE_IMAGE_NAME):latest
 
+proxy-image:
+	@echo "Building docker image for proxy..."
+	docker build --file _assets/build/Dockerfile-proxy . \
+		--build-arg "build_tags=$(BUILD_TAGS)" \
+		--build-arg "build_flags=$(BUILD_FLAGS)" \
+		-t $(PROXY_IMAGE_NAME):$(DOCKER_IMAGE_CUSTOM_TAG) \
+		-t $(PROXY_IMAGE_NAME):latest
+
 push-docker-images: docker-image bootnode-image
 	docker push $(BOOTNODE_IMAGE_NAME):$(DOCKER_IMAGE_CUSTOM_TAG)
 	docker push $(DOCKER_IMAGE_NAME):$(DOCKER_IMAGE_CUSTOM_TAG)

_assets/build/Dockerfile-proxy

@@ -0,0 +1,15 @@
+FROM golang:1.10-alpine as builder
+
+ARG build_tags
+
+RUN apk add --no-cache make gcc musl-dev linux-headers
+
+RUN mkdir -p /go/src/github.com/status-im/status-go
+ADD . /go/src/github.com/status-im/status-go
+RUN cd /go/src/github.com/status-im/status-go && make proxy BUILD_TAGS="$build_tags"
+
+FROM alpine:latest
+
+RUN apk add --no-cache ca-certificates bash
+
+COPY --from=builder /go/src/github.com/status-im/status-go/build/bin/proxy /usr/local/bin/

cmd/proxy/flags.go

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"errors"
+	"strconv"
+	"strings"
+)
+
+// ErrorEmpty returned when value is empty.
+var ErrorEmpty = errors.New("empty value not allowed")
+
+// StringSlice is a type of flag that allows setting multiple string values.
+type StringSlice []string
+
+func (s *StringSlice) String() string {
+	return "string slice"
+}
+
+// Set trims space from string and stores it.
+func (s *StringSlice) Set(value string) error {
+	trimmed := strings.TrimSpace(value)
+	if len(trimmed) == 0 {
+		return ErrorEmpty
+	}
+	*s = append(*s, trimmed)
+	return nil
+}
+
+// IntSlice is a type of flag that allows setting multiple int values.
+type IntSlice []int
+
+func (s *IntSlice) String() string {
+	return "int slice"
+}
+
+// Set trims space from string and stores it.
+func (s *IntSlice) Set(value string) error {
+	val, err := strconv.Atoi(value)
+	if err != nil {
+		return err
+	}
+	*s = append(*s, val)
+	return nil
+}

cmd/proxy/proxy.go

@@ -0,0 +1,103 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"strings"
+	"sync"
+
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/p2p/discv5"
+	"github.com/ethereum/go-ethereum/params"
+	ma "github.com/multiformats/go-multiaddr"
+	"github.com/status-im/status-go/discovery"
+	sparams "github.com/status-im/status-go/params"
+)
+
+var (
+	laddr           = flag.String("laddr", "0.0.0.0:31143", "Listening address for discovery v5.")
+	verbosity       = flag.String("v", "info", "Logger verbosity")
+	rendezvousNodes = StringSlice{}
+	bootnodes       = StringSlice{}
+	topics          = StringSlice{}
+	les             = IntSlice{}
+	useEthereum     = flag.Bool("use-ethereum-boot", false, "If true ethereum bootnodes will be used")
+)
+
+func main() {
+	flag.Var(&rendezvousNodes, "rendezvous-node", "Rendezvous server.")
+	flag.Var(&bootnodes, "bootnode", "Discovery v5 node.")
+	flag.Var(&les, "les", "Proxy les topic for a given network.")
+	flag.Var(&topics, "topic", "Topic that will be proxied")
+	flag.Parse()
+
+	level, err := log.LvlFromString(strings.ToLower(*verbosity))
+	if err != nil {
+		panic(fmt.Errorf("unable to get logger level from string %s: %v", *verbosity, err))
+	}
+	filteredHandler := log.LvlFilterHandler(level, log.StderrHandler)
+	log.Root().SetHandler(filteredHandler)
+
+	for _, net := range les {
+		if t := sparams.LesTopic(net); len(t) != 0 {
+			topics = append(topics, t)
+		}
+	}
+	key, err := crypto.GenerateKey()
+	if err != nil {
+		log.Crit("unable to generate a key", "error", err)
+	}
+	rst := []string(bootnodes)
+	if *useEthereum {
+		rst = append(rst, params.DiscoveryV5Bootnodes...)
+	}
+	v5 := discovery.NewDiscV5(key, *laddr, parseNodesV5(rst))
+	if err := v5.Start(); err != nil {
+		log.Crit("unable to start discovery v5", "address", *laddr, "error", err)
+	}
+	rendezvousServers := parseMultiaddrs(rendezvousNodes)
+	var wg sync.WaitGroup
+	stop := make(chan struct{})
+	defer close(stop)
+	for _, t := range topics {
+		log.Info("proxying records for", "topic", t, "bootnodes", rst, "rendezvous servers", rendezvousNodes)
+		t := t
+		wg.Add(1)
+		go func() {
+			if err := discovery.ProxyToRendezvous(v5, rendezvousServers, t, stop); err != nil {
+				log.Error("proxying to rendezvous servers failed", "servers", rendezvousNodes, "topic", t, "error", err)
+			}
+			wg.Done()
+		}()
+	}
+	wg.Wait()
+}
+
+func parseMultiaddrs(nodes []string) []ma.Multiaddr {
+	var (
+		rst = make([]ma.Multiaddr, len(nodes))
+		err error
+	)
+	for i := range nodes {
+		rst[i], err = ma.NewMultiaddr(nodes[i])
+		if err != nil {
+			log.Crit("unable to parse mutliaddr", "source", nodes[i], "error", err)
+		}
+	}
+	return rst
+}
+
+func parseNodesV5(nodes []string) []*discv5.Node {
+	var (
+		rst = make([]*discv5.Node, len(nodes))
+		err error
+	)
+	for i := range nodes {
+		rst[i], err = discv5.ParseNode(nodes[i])
+		if err != nil {
+			log.Crit("Failed to parse enode", "source", nodes[i], "err", err)
+		}
+	}
+	return rst
+}

discovery/proxy.go

@@ -0,0 +1,86 @@
+package discovery
+
+import (
+	"fmt"
+	"sync"
+	"time"
+
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/p2p/discv5"
+	"github.com/ethereum/go-ethereum/p2p/enr"
+	ma "github.com/multiformats/go-multiaddr"
+)
+
+// ProxyToRendezvous proxies records discovered using original to rendezvous servers for specified topic.
+func ProxyToRendezvous(original Discovery, servers []ma.Multiaddr, topic string, stop chan struct{}) error {
+	var (
+		identities = map[discv5.NodeID]*Rendezvous{}
+		period     = make(chan time.Duration, 1)
+		found      = make(chan *discv5.Node, 10)
+		lookup     = make(chan bool)
+		wg         sync.WaitGroup
+	)
+	period <- 1 * time.Second
+	wg.Add(1)
+	go func() {
+		if err := original.Discover(topic, period, found, lookup); err != nil {
+			log.Error("discover request failed", "topic", topic, "error", err)
+		}
+		wg.Done()
+	}()
+	for {
+		select {
+		case <-stop:
+			close(period)
+			wg.Wait()
+			return nil
+		case <-lookup:
+		case n := <-found:
+			if _, exist := identities[n.ID]; exist {
+				continue
+			}
+			log.Info("proxying new record", "topic", topic, "identity", n.String())
+			record, err := makeProxiedENR(n)
+			if err != nil {
+				log.Error("error converting discovered node to ENR", "node", n.String(), "error", err)
+			}
+			r := NewRendezvousWithENR(servers, record)
+			identities[n.ID] = r
+			if err := r.Start(); err != nil {
+				log.Error("unable to start rendezvous proxying", "servers", servers, "error", err)
+			}
+			wg.Add(1)
+			go func() {
+				if err := r.Register(topic, stop); err != nil {
+					log.Error("register error", "topic", topic, "error", err)
+				}
+				wg.Done()
+			}()
+		}
+	}
+}
+
+func makeProxiedENR(n *discv5.Node) (enr.Record, error) {
+	record := enr.Record{}
+	record.Set(enr.IP(n.IP))
+	record.Set(enr.TCP(n.TCP))
+	record.Set(enr.UDP(n.UDP))
+	record.Set(Proxied(n.ID))
+	key, err := crypto.GenerateKey() // we need separate key for each identity, records are stored based on it
+	if err != nil {
+		return record, fmt.Errorf("unable to generate private key. error : %v", err)
+	}
+	if err := enr.SignV4(&record, key); err != nil {
+		return record, fmt.Errorf("unable to sign enr record. error: %v", err)
+	}
+	return record, nil
+}
+
+// Proxied is an Entry for ENR
+type Proxied discv5.NodeID
+
+// ENRKey returns unique key that is used by ENR.
+func (p Proxied) ENRKey() string {
+	return "proxied"
+}

discovery/proxy_test.go

@@ -0,0 +1,56 @@
+package discovery
+
+import (
+	"context"
+	"sync"
+	"testing"
+	"time"
+
+	ma "github.com/multiformats/go-multiaddr"
+	"github.com/status-im/rendezvous"
+	"github.com/stretchr/testify/require"
+)
+
+func TestProxyToRendezvous(t *testing.T) {
+	var (
+		topic    = "test"
+		id       = 101
+		reg      = newRegistry()
+		original = &fake{id: 110, registry: reg, started: true}
+		srv      = makeTestRendezvousServer(t, "/ip4/127.0.0.1/tcp/7788")
+		stop     = make(chan struct{})
+		wg       sync.WaitGroup
+	)
+	client, err := rendezvous.NewTemporary()
+	require.NoError(t, err)
+	reg.Add(topic, id)
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		require.NoError(t, ProxyToRendezvous(original, []ma.Multiaddr{srv.Addr()}, topic, stop))
+	}()
+	timer := time.After(3 * time.Second)
+	ticker := time.Tick(100 * time.Millisecond)
+	for {
+		select {
+		case <-timer:
+			close(stop)
+			wg.Wait()
+			require.FailNow(t, "failed waiting for record to be proxied")
+		case <-ticker:
+			records, err := client.Discover(context.TODO(), srv.Addr(), topic, 10)
+			if err != nil {
+				continue
+			}
+			if len(records) != 1 {
+				continue
+			}
+			var proxied Proxied
+			require.NoError(t, records[0].Load(&proxied))
+			require.Equal(t, proxied[0], byte(id))
+			close(stop)
+			wg.Wait()
+			return
+		}
+	}
+}

discovery/rendezvous.go

@@ -39,6 +39,15 @@ func NewRendezvous(servers []ma.Multiaddr, identity *ecdsa.PrivateKey, node *dis
 	return r, nil
 }
 
+func NewRendezvousWithENR(servers []ma.Multiaddr, record enr.Record) *Rendezvous {
+	r := new(Rendezvous)
+	r.servers = servers
+	r.registrationPeriod = registrationPeriod
+	r.bucketSize = bucketSize
+	r.record = record
+	return r
+}
+
 // Rendezvous is an implementation of discovery interface that uses
 // rendezvous client.
 type Rendezvous struct {
@@ -148,6 +157,7 @@ func (r *Rendezvous) Discover(
 			}
 			for i := range records {
 				n, err := enrToNode(records[i])
+				log.Debug("converted enr to", "ENODE", n.String())
 				if err != nil {
 					log.Warn("error converting enr record to node", "err", err)
 				}
@@ -159,13 +169,21 @@ func (r *Rendezvous) Discover(
 
 func enrToNode(record enr.Record) (*discv5.Node, error) {
 	var (
-		key   enr.Secp256k1
+		key     enr.Secp256k1
-		ip    enr.IP
+		ip      enr.IP
-		tport enr.TCP
+		tport   enr.TCP
-		uport enr.UDP
+		uport   enr.UDP
+		proxied Proxied
+		nodeID  discv5.NodeID
 	)
-	if err := record.Load(&key); err != nil {
+	if err := record.Load(&proxied); err == nil {
-		return nil, err
+		nodeID = discv5.NodeID(proxied)
+	} else {
+		if err := record.Load(&key); err != nil {
+			return nil, err
+		}
+		ecdsaKey := ecdsa.PublicKey(key)
+		nodeID = discv5.PubkeyID(&ecdsaKey)
 	}
 	if err := record.Load(&ip); err != nil {
 		return nil, err
@@ -175,6 +193,5 @@ func enrToNode(record enr.Record) (*discv5.Node, error) {
 	}
 	// ignore absence of udp port, as it is optional
 	_ = record.Load(&uport)
-	ecdsaKey := ecdsa.PublicKey(key)
+	return discv5.NewNode(nodeID, net.IP(ip), uint16(uport), uint16(tport)), nil
-	return discv5.NewNode(discv5.PubkeyID(&ecdsaKey), net.IP(ip), uint16(uport), uint16(tport)), nil
 }

discovery/rendezvous_test.go

@@ -1,7 +1,6 @@
 package discovery
 
 import (
-	"fmt"
 	"net"
 	"testing"
 	"time"
@@ -18,17 +17,21 @@ import (
 	"github.com/syndtr/goleveldb/leveldb/storage"
 )
 
-func TestRendezvousDiscovery(t *testing.T) {
+func makeTestRendezvousServer(t *testing.T, addr string) *server.Server {
 	priv, _, err := lcrypto.GenerateKeyPair(lcrypto.Secp256k1, 0)
 	require.NoError(t, err)
-	laddr, err := ma.NewMultiaddr(fmt.Sprintf("/ip4/127.0.0.1/tcp/7777"))
+	laddr, err := ma.NewMultiaddr(addr)
 	require.NoError(t, err)
 	db, err := leveldb.Open(storage.NewMemStorage(), nil)
 	require.NoError(t, err)
 	srv := server.NewServer(laddr, priv, server.NewStorage(db))
 	require.NoError(t, srv.Start())
-	defer srv.Stop()
+	return srv
+}
 
+func TestRendezvousDiscovery(t *testing.T) {
+	srv := makeTestRendezvousServer(t, "/ip4/127.0.0.1/tcp/7777")
+	defer srv.Stop()
 	identity, err := crypto.GenerateKey()
 	require.NoError(t, err)
 	node := discover.NewNode(discover.PubkeyID(&identity.PublicKey), net.IP{10, 10, 10, 10}, 10, 20)

params/config.go

@@ -13,10 +13,12 @@ import (
 	"path/filepath"
 	"strings"
 
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/p2p/discv5"
+	"github.com/ethereum/go-ethereum/params"
 )
 
 // errors
@@ -687,7 +689,7 @@ func (c *NodeConfig) updateRelativeDirsConfig() error {
 
 // updatePeerLimits will set default peer limits expectations based on enabled services.
 func (c *NodeConfig) updatePeerLimits() {
-	if c.NoDiscovery {
+	if c.NoDiscovery && !c.Rendezvous {
 		return
 	}
 	if c.WhisperConfig.Enabled {
@@ -722,6 +724,18 @@ func GetStatusHome() string {
 	if gopath == "" {
 		gopath = build.Default.GOPATH
 	}
-
 	return path.Join(gopath, "/src/github.com/status-im/status-go/")
 }
+
+// LesTopic returns discovery v5 topic derived from genesis of the provided network.
+// 1 - mainnet, 4 - ropsten
+func LesTopic(netid int) string {
+	switch netid {
+	case 1:
+		return "LES2@" + common.Bytes2Hex(params.MainnetGenesisHash.Bytes()[:8])
+	case 3:
+		return "LES2@" + common.Bytes2Hex(params.TestnetGenesisHash.Bytes()[:8])
+	default:
+		return ""
+	}
+}