-
Notifications
You must be signed in to change notification settings - Fork 246
/
rendezvous.go
303 lines (275 loc) · 8.24 KB
/
rendezvous.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
package discovery
import (
"context"
"crypto/ecdsa"
"errors"
"math/rand"
"net"
"sync"
"time"
ma "github.com/multiformats/go-multiaddr"
"github.com/status-im/rendezvous"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/p2p/discv5"
"github.com/ethereum/go-ethereum/p2p/enode"
"github.com/ethereum/go-ethereum/p2p/enr"
)
const (
registrationPeriod = 10 * time.Second
requestTimeout = 5 * time.Second
bucketSize = 10
)
var (
errNodeIsNil = errors.New("node cannot be nil")
errIdentityIsNil = errors.New("identity cannot be nil")
errDiscoveryIsStopped = errors.New("discovery is stopped")
)
func NewRendezvous(servers []ma.Multiaddr, identity *ecdsa.PrivateKey, node *enode.Node) (*Rendezvous, error) {
r := new(Rendezvous)
r.node = node
r.identity = identity
r.servers = servers
r.registrationPeriod = registrationPeriod
r.bucketSize = bucketSize
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 {
mu sync.RWMutex
client *rendezvous.Client
// Root context is used to cancel running requests
// when Rendezvous is stopped.
rootCtx context.Context
cancelRootCtx context.CancelFunc
servers []ma.Multiaddr
registrationPeriod time.Duration
bucketSize int
node *enode.Node
identity *ecdsa.PrivateKey
recordMu sync.Mutex
record *enr.Record // record is set directly if rendezvous is used in proxy mode
}
func (r *Rendezvous) Running() bool {
r.mu.RLock()
defer r.mu.RUnlock()
return r.client != nil
}
// Start creates client with ephemeral identity.
func (r *Rendezvous) Start() error {
r.mu.Lock()
defer r.mu.Unlock()
client, err := rendezvous.NewEphemeral()
if err != nil {
return err
}
r.client = &client
r.rootCtx, r.cancelRootCtx = context.WithCancel(context.Background())
return nil
}
// Stop removes client reference.
func (r *Rendezvous) Stop() error {
r.mu.Lock()
defer r.mu.Unlock()
if r.client == nil {
return nil
}
r.cancelRootCtx()
if err := r.client.Close(); err != nil {
return err
}
r.client = nil
return nil
}
func (r *Rendezvous) MakeRecord(srv *ma.Multiaddr) (record enr.Record, err error) {
r.recordMu.Lock()
defer r.recordMu.Unlock()
if r.record != nil {
return *r.record, nil
}
if r.node == nil {
return record, errNodeIsNil
}
if r.identity == nil {
return record, errIdentityIsNil
}
ip := r.node.IP()
if srv != nil && (ip.IsLoopback() || IsPrivate(ip)) { // If AdvertiseAddr is not specified, 127.0.0.1 might be returned
ctx, cancel := context.WithTimeout(r.rootCtx, requestTimeout)
defer cancel()
ipAddr, err := r.client.RemoteIp(ctx, *srv)
if err != nil {
log.Error("could not obtain the external ip address", "err", err)
} else {
parsedIP := net.ParseIP(ipAddr)
if parsedIP != nil {
ip = parsedIP
log.Info("node's external IP address", "ipAddr", ipAddr)
} else {
log.Error("invalid ip address obtained from rendezvous server", "ipaddr", ipAddr, "err", err)
}
}
}
record.Set(enr.IP(ip))
record.Set(enr.TCP(r.node.TCP()))
record.Set(enr.UDP(r.node.UDP()))
// public key is added to ENR when ENR is signed
if err := enode.SignV4(&record, r.identity); err != nil {
return record, err
}
r.record = &record
return record, nil
}
func (r *Rendezvous) register(srv ma.Multiaddr, topic string, record enr.Record) error {
ctx, cancel := context.WithTimeout(r.rootCtx, requestTimeout)
defer cancel()
r.mu.RLock()
defer r.mu.RUnlock()
if r.client == nil {
return errDiscoveryIsStopped
}
err := r.client.Register(ctx, srv, topic, record, r.registrationPeriod)
if err != nil {
log.Error("error registering", "topic", topic, "rendezvous server", srv, "err", err)
}
return err
}
// Register renews registration in the specified server.
func (r *Rendezvous) Register(topic string, stop chan struct{}) error {
srv := r.getRandomServer()
record, err := r.MakeRecord(&srv)
if err != nil {
return err
}
// sending registration more often than the whole registraton period
// will ensure that it won't be accidentally removed
ticker := time.NewTicker(r.registrationPeriod / 2)
defer ticker.Stop()
if err := r.register(srv, topic, record); err == context.Canceled {
return err
}
for {
select {
case <-stop:
return nil
case <-ticker.C:
if err := r.register(r.getRandomServer(), topic, record); err == context.Canceled {
return err
} else if err == errDiscoveryIsStopped {
return nil
}
}
}
}
func (r *Rendezvous) discoverRequest(srv ma.Multiaddr, topic string) ([]enr.Record, error) {
ctx, cancel := context.WithTimeout(r.rootCtx, requestTimeout)
defer cancel()
r.mu.RLock()
defer r.mu.RUnlock()
if r.client == nil {
return nil, errDiscoveryIsStopped
}
return r.client.Discover(ctx, srv, topic, r.bucketSize)
}
// Discover will search for new records every time period fetched from period channel.
func (r *Rendezvous) Discover(
topic string, period <-chan time.Duration, found chan<- *discv5.Node, lookup chan<- bool,
) error {
ticker := time.NewTicker(<-period)
for {
select {
case newPeriod, ok := <-period:
ticker.Stop()
if !ok {
return nil
}
ticker = time.NewTicker(newPeriod)
case <-ticker.C:
srv := r.servers[rand.Intn(len(r.servers))] // nolint: gosec
records, err := r.discoverRequest(srv, topic)
if err == context.Canceled {
return err
} else if err == errDiscoveryIsStopped {
return nil
} else if err != nil {
log.Debug("error fetching records", "topic", topic, "rendezvous server", srv, "err", err)
} else {
for i := range records {
n, err := enrToNode(records[i])
if err != nil {
log.Warn("error converting enr record to node", "err", err)
} else {
log.Debug("converted enr to", "ENODE", n.String())
select {
case found <- n:
case newPeriod, ok := <-period:
// closing a period channel is a signal to producer that consumer exited
ticker.Stop()
if !ok {
return nil
}
ticker = time.NewTicker(newPeriod)
}
}
}
}
}
}
}
func (r *Rendezvous) getRandomServer() ma.Multiaddr {
return r.servers[rand.Intn(len(r.servers))] // nolint: gosec
}
func enrToNode(record enr.Record) (*discv5.Node, error) {
var (
key enode.Secp256k1
ip enr.IPv4
tport enr.TCP
uport enr.UDP
nodeID discv5.NodeID
)
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
}
if err := record.Load(&tport); err != nil {
return nil, err
}
// ignore absence of udp port, as it is optional
_ = record.Load(&uport)
return discv5.NewNode(nodeID, net.IP(ip), uint16(uport), uint16(tport)), nil
}
// IsPrivate reports whether ip is a private address, according to
// RFC 1918 (IPv4 addresses) and RFC 4193 (IPv6 addresses).
// Copied/Adapted from https://go-review.googlesource.com/c/go/+/272668/11/src/net/ip.go
// Copyright (c) The Go Authors. All rights reserved.
// @TODO: once Go 1.17 is released in Q42021, remove this function as it will become part of the language
func IsPrivate(ip net.IP) bool {
if ip4 := ip.To4(); ip4 != nil {
// Following RFC 4193, Section 3. Local IPv6 Unicast Addresses which says:
// The Internet Assigned Numbers Authority (IANA) has reserved the
// following three blocks of the IPv4 address space for private internets:
// 10.0.0.0 - 10.255.255.255 (10/8 prefix)
// 172.16.0.0 - 172.31.255.255 (172.16/12 prefix)
// 192.168.0.0 - 192.168.255.255 (192.168/16 prefix)
return ip4[0] == 10 ||
(ip4[0] == 172 && ip4[1]&0xf0 == 16) ||
(ip4[0] == 192 && ip4[1] == 168)
}
// Following RFC 4193, Section 3. Private Address Space which says:
// The Internet Assigned Numbers Authority (IANA) has reserved the
// following block of the IPv6 address space for local internets:
// FC00:: - FDFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF (FC00::/7 prefix)
return len(ip) == net.IPv6len && ip[0]&0xfe == 0xfc
}