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