p2p/discover: new package implementing the Node Discovery Protocol
This commit is contained in:
Felix Lange
parent
8c3095faf0
commit
12224c7f59
447
p2p/discover/table.go
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447
p2p/discover/table.go
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@ -0,0 +1,447 @@
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// Package discover implements the Node Discovery Protocol.
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//
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// The Node Discovery protocol provides a way to find RLPx nodes that
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// can be connected to. It uses a Kademlia-like protocol to maintain a
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// distributed database of the IDs and endpoints of all listening
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// nodes.
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package discover
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import (
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"crypto/ecdsa"
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"crypto/elliptic"
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"encoding/hex"
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"fmt"
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"io"
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"math/rand"
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"net"
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"sort"
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"strings"
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"sync"
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"time"
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"github.com/ethereum/go-ethereum/crypto/secp256k1"
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"github.com/ethereum/go-ethereum/rlp"
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)
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const (
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alpha = 3 // Kademlia concurrency factor
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bucketSize = 16 // Kademlia bucket size
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nBuckets = len(NodeID{})*8 + 1 // Number of buckets
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)
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type Table struct {
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mutex sync.Mutex // protects buckets, their content, and nursery
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buckets [nBuckets]*bucket // index of known nodes by distance
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nursery []*Node // bootstrap nodes
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net transport
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self *Node // metadata of the local node
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}
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// transport is implemented by the UDP transport.
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// it is an interface so we can test without opening lots of UDP
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// sockets and without generating a private key.
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type transport interface {
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ping(*Node) error
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findnode(e *Node, target NodeID) ([]*Node, error)
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close()
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}
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// bucket contains nodes, ordered by their last activity.
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type bucket struct {
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lastLookup time.Time
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entries []*Node
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}
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// Node represents node metadata that is stored in the table.
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type Node struct {
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Addr *net.UDPAddr
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ID NodeID
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active time.Time
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}
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type rpcNode struct {
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IP string
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Port uint16
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ID NodeID
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}
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func (n Node) EncodeRLP(w io.Writer) error {
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return rlp.Encode(w, rpcNode{IP: n.Addr.IP.String(), Port: uint16(n.Addr.Port), ID: n.ID})
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}
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func (n *Node) DecodeRLP(s *rlp.Stream) (err error) {
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var ext rpcNode
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if err = s.Decode(&ext); err == nil {
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n.Addr = &net.UDPAddr{IP: net.ParseIP(ext.IP), Port: int(ext.Port)}
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n.ID = ext.ID
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}
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return err
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}
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func newTable(t transport, ourID NodeID, ourAddr *net.UDPAddr) *Table {
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tab := &Table{net: t, self: &Node{ID: ourID, Addr: ourAddr}}
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for i := range tab.buckets {
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tab.buckets[i] = &bucket{}
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}
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return tab
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}
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// Bootstrap sets the bootstrap nodes. These nodes are used to connect
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// to the network if the table is empty. Bootstrap will also attempt to
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// fill the table by performing random lookup operations on the
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// network.
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func (tab *Table) Bootstrap(nodes []Node) {
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tab.mutex.Lock()
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// TODO: maybe filter nodes with bad fields (nil, etc.) to avoid strange crashes
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tab.nursery = make([]*Node, 0, len(nodes))
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for _, n := range nodes {
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cpy := n
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tab.nursery = append(tab.nursery, &cpy)
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}
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tab.mutex.Unlock()
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tab.refresh()
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}
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// Lookup performs a network search for nodes close
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// to the given target. It approaches the target by querying
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// nodes that are closer to it on each iteration.
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func (tab *Table) Lookup(target NodeID) []*Node {
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var (
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asked = make(map[NodeID]bool)
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seen = make(map[NodeID]bool)
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reply = make(chan []*Node, alpha)
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pendingQueries = 0
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)
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// don't query further if we hit the target.
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// unlikely to happen often in practice.
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asked[target] = true
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tab.mutex.Lock()
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// update last lookup stamp (for refresh logic)
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tab.buckets[logdist(tab.self.ID, target)].lastLookup = time.Now()
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// generate initial result set
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result := tab.closest(target, bucketSize)
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tab.mutex.Unlock()
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for {
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// ask the closest nodes that we haven't asked yet
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for i := 0; i < len(result.entries) && pendingQueries < alpha; i++ {
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n := result.entries[i]
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if !asked[n.ID] {
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asked[n.ID] = true
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pendingQueries++
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go func() {
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result, _ := tab.net.findnode(n, target)
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reply <- result
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}()
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}
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}
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if pendingQueries == 0 {
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// we have asked all closest nodes, stop the search
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break
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}
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// wait for the next reply
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for _, n := range <-reply {
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cn := n
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if !seen[n.ID] {
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seen[n.ID] = true
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result.push(cn, bucketSize)
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}
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}
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pendingQueries--
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}
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return result.entries
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}
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// refresh performs a lookup for a random target to keep buckets full.
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func (tab *Table) refresh() {
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ld := -1 // logdist of chosen bucket
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tab.mutex.Lock()
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for i, b := range tab.buckets {
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if i > 0 && b.lastLookup.Before(time.Now().Add(-1*time.Hour)) {
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ld = i
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break
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}
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}
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tab.mutex.Unlock()
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result := tab.Lookup(randomID(tab.self.ID, ld))
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if len(result) == 0 {
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// bootstrap the table with a self lookup
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tab.mutex.Lock()
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tab.add(tab.nursery)
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tab.mutex.Unlock()
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tab.Lookup(tab.self.ID)
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// TODO: the Kademlia paper says that we're supposed to perform
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// random lookups in all buckets further away than our closest neighbor.
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}
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}
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// closest returns the n nodes in the table that are closest to the
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// given id. The caller must hold tab.mutex.
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func (tab *Table) closest(target NodeID, nresults int) *nodesByDistance {
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// This is a very wasteful way to find the closest nodes but
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// obviously correct. I believe that tree-based buckets would make
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// this easier to implement efficiently.
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close := &nodesByDistance{target: target}
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for _, b := range tab.buckets {
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for _, n := range b.entries {
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close.push(n, nresults)
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}
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}
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return close
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}
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func (tab *Table) len() (n int) {
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for _, b := range tab.buckets {
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n += len(b.entries)
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}
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return n
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}
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// bumpOrAdd updates the activity timestamp for the given node and
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// attempts to insert the node into a bucket. The returned Node might
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// not be part of the table. The caller must hold tab.mutex.
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func (tab *Table) bumpOrAdd(node NodeID, from *net.UDPAddr) (n *Node) {
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b := tab.buckets[logdist(tab.self.ID, node)]
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if n = b.bump(node); n == nil {
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n = &Node{ID: node, Addr: from, active: time.Now()}
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if len(b.entries) == bucketSize {
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tab.pingReplace(n, b)
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} else {
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b.entries = append(b.entries, n)
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}
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}
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return n
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}
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func (tab *Table) pingReplace(n *Node, b *bucket) {
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old := b.entries[bucketSize-1]
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go func() {
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if err := tab.net.ping(old); err == nil {
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// it responded, we don't need to replace it.
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return
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}
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// it didn't respond, replace the node if it is still the oldest node.
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tab.mutex.Lock()
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if len(b.entries) > 0 && b.entries[len(b.entries)-1] == old {
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// slide down other entries and put the new one in front.
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copy(b.entries[1:], b.entries)
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b.entries[0] = n
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}
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tab.mutex.Unlock()
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}()
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}
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// bump updates the activity timestamp for the given node.
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// The caller must hold tab.mutex.
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func (tab *Table) bump(node NodeID) {
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tab.buckets[logdist(tab.self.ID, node)].bump(node)
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}
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// add puts the entries into the table if their corresponding
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// bucket is not full. The caller must hold tab.mutex.
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func (tab *Table) add(entries []*Node) {
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outer:
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for _, n := range entries {
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if n == nil || n.ID == tab.self.ID {
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// skip bad entries. The RLP decoder returns nil for empty
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// input lists.
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continue
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}
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bucket := tab.buckets[logdist(tab.self.ID, n.ID)]
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for i := range bucket.entries {
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if bucket.entries[i].ID == n.ID {
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// already in bucket
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continue outer
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}
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}
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if len(bucket.entries) < bucketSize {
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bucket.entries = append(bucket.entries, n)
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}
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}
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}
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func (b *bucket) bump(id NodeID) *Node {
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for i, n := range b.entries {
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if n.ID == id {
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n.active = time.Now()
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// move it to the front
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copy(b.entries[1:], b.entries[:i+1])
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b.entries[0] = n
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return n
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}
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}
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return nil
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}
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// nodesByDistance is a list of nodes, ordered by
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// distance to target.
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type nodesByDistance struct {
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entries []*Node
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target NodeID
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}
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// push adds the given node to the list, keeping the total size below maxElems.
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func (h *nodesByDistance) push(n *Node, maxElems int) {
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ix := sort.Search(len(h.entries), func(i int) bool {
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return distcmp(h.target, h.entries[i].ID, n.ID) > 0
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})
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if len(h.entries) < maxElems {
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h.entries = append(h.entries, n)
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}
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if ix == len(h.entries) {
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// farther away than all nodes we already have.
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// if there was room for it, the node is now the last element.
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} else {
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// slide existing entries down to make room
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// this will overwrite the entry we just appended.
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copy(h.entries[ix+1:], h.entries[ix:])
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h.entries[ix] = n
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}
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}
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// NodeID is a unique identifier for each node.
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// The node identifier is a marshaled elliptic curve public key.
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type NodeID [512 / 8]byte
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// NodeID prints as a long hexadecimal number.
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func (n NodeID) String() string {
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return fmt.Sprintf("%#x", n[:])
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}
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// The Go syntax representation of a NodeID is a call to HexID.
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func (n NodeID) GoString() string {
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return fmt.Sprintf("HexID(\"%#x\")", n[:])
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}
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// HexID converts a hex string to a NodeID.
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// The string may be prefixed with 0x.
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func HexID(in string) NodeID {
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if strings.HasPrefix(in, "0x") {
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in = in[2:]
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}
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var id NodeID
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b, err := hex.DecodeString(in)
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if err != nil {
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panic(err)
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} else if len(b) != len(id) {
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panic("wrong length")
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}
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copy(id[:], b)
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return id
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}
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func newNodeID(priv *ecdsa.PrivateKey) (id NodeID) {
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pubkey := elliptic.Marshal(priv.Curve, priv.X, priv.Y)
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if len(pubkey)-1 != len(id) {
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panic(fmt.Errorf("invalid key: need %d bit pubkey, got %d bits", (len(id)+1)*8, len(pubkey)))
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}
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copy(id[:], pubkey[1:])
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return id
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}
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// recoverNodeID computes the public key used to sign the
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// given hash from the signature.
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func recoverNodeID(hash, sig []byte) (id NodeID, err error) {
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pubkey, err := secp256k1.RecoverPubkey(hash, sig)
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if err != nil {
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return id, err
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}
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if len(pubkey)-1 != len(id) {
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return id, fmt.Errorf("recovered pubkey has %d bits, want %d bits", len(pubkey)*8, (len(id)+1)*8)
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}
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for i := range id {
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id[i] = pubkey[i+1]
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}
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return id, nil
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}
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// distcmp compares the distances a->target and b->target.
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// Returns -1 if a is closer to target, 1 if b is closer to target
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// and 0 if they are equal.
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func distcmp(target, a, b NodeID) int {
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for i := range target {
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da := a[i] ^ target[i]
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db := b[i] ^ target[i]
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if da > db {
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return 1
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} else if da < db {
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return -1
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}
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}
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return 0
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}
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// table of leading zero counts for bytes [0..255]
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var lzcount = [256]int{
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8, 7, 6, 6, 5, 5, 5, 5,
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4, 4, 4, 4, 4, 4, 4, 4,
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3, 3, 3, 3, 3, 3, 3, 3,
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3, 3, 3, 3, 3, 3, 3, 3,
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2, 2, 2, 2, 2, 2, 2, 2,
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2, 2, 2, 2, 2, 2, 2, 2,
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2, 2, 2, 2, 2, 2, 2, 2,
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2, 2, 2, 2, 2, 2, 2, 2,
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1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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}
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// logdist returns the logarithmic distance between a and b, log2(a ^ b).
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func logdist(a, b NodeID) int {
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lz := 0
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for i := range a {
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x := a[i] ^ b[i]
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if x == 0 {
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lz += 8
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} else {
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lz += lzcount[x]
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break
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}
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}
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return len(a)*8 - lz
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}
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// randomID returns a random NodeID such that logdist(a, b) == n
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func randomID(a NodeID, n int) (b NodeID) {
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if n == 0 {
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return a
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}
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// flip bit at position n, fill the rest with random bits
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b = a
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pos := len(a) - n/8 - 1
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bit := byte(0x01) << (byte(n%8) - 1)
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if bit == 0 {
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pos++
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bit = 0x80
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}
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b[pos] = a[pos]&^bit | ^a[pos]&bit // TODO: randomize end bits
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for i := pos + 1; i < len(a); i++ {
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b[i] = byte(rand.Intn(255))
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}
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return b
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}
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403
p2p/discover/table_test.go
Normal file
403
p2p/discover/table_test.go
Normal file
@ -0,0 +1,403 @@
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package discover
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import (
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"crypto/ecdsa"
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"errors"
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"fmt"
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"math/big"
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"math/rand"
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"net"
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"reflect"
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"testing"
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"testing/quick"
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"time"
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"github.com/ethereum/go-ethereum/crypto"
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)
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var (
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quickrand = rand.New(rand.NewSource(time.Now().Unix()))
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quickcfg = &quick.Config{MaxCount: 5000, Rand: quickrand}
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)
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func TestHexID(t *testing.T) {
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ref := NodeID{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 106, 217, 182, 31, 165, 174, 1, 67, 7, 235, 220, 150, 66, 83, 173, 205, 159, 44, 10, 57, 42, 161, 26, 188}
|
||||
id1 := HexID("0x000000000000000000000000000000000000000000000000000000000000000000000000000000806ad9b61fa5ae014307ebdc964253adcd9f2c0a392aa11abc")
|
||||
id2 := HexID("000000000000000000000000000000000000000000000000000000000000000000000000000000806ad9b61fa5ae014307ebdc964253adcd9f2c0a392aa11abc")
|
||||
|
||||
if id1 != ref {
|
||||
t.Errorf("wrong id1\ngot %v\nwant %v", id1[:], ref[:])
|
||||
}
|
||||
if id2 != ref {
|
||||
t.Errorf("wrong id2\ngot %v\nwant %v", id2[:], ref[:])
|
||||
}
|
||||
}
|
||||
|
||||
func TestNodeID_recover(t *testing.T) {
|
||||
prv := newkey()
|
||||
hash := make([]byte, 32)
|
||||
sig, err := crypto.Sign(hash, prv)
|
||||
if err != nil {
|
||||
t.Fatalf("signing error: %v", err)
|
||||
}
|
||||
|
||||
pub := newNodeID(prv)
|
||||
recpub, err := recoverNodeID(hash, sig)
|
||||
if err != nil {
|
||||
t.Fatalf("recovery error: %v", err)
|
||||
}
|
||||
if pub != recpub {
|
||||
t.Errorf("recovered wrong pubkey:\ngot: %v\nwant: %v", recpub, pub)
|
||||
}
|
||||
}
|
||||
|
||||
func TestNodeID_distcmp(t *testing.T) {
|
||||
distcmpBig := func(target, a, b NodeID) int {
|
||||
tbig := new(big.Int).SetBytes(target[:])
|
||||
abig := new(big.Int).SetBytes(a[:])
|
||||
bbig := new(big.Int).SetBytes(b[:])
|
||||
return new(big.Int).Xor(tbig, abig).Cmp(new(big.Int).Xor(tbig, bbig))
|
||||
}
|
||||
if err := quick.CheckEqual(distcmp, distcmpBig, quickcfg); err != nil {
|
||||
t.Error(err)
|
||||
}
|
||||
}
|
||||
|
||||
// the random tests is likely to miss the case where they're equal.
|
||||
func TestNodeID_distcmpEqual(t *testing.T) {
|
||||
base := NodeID{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}
|
||||
x := NodeID{15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0}
|
||||
if distcmp(base, x, x) != 0 {
|
||||
t.Errorf("distcmp(base, x, x) != 0")
|
||||
}
|
||||
}
|
||||
|
||||
func TestNodeID_logdist(t *testing.T) {
|
||||
logdistBig := func(a, b NodeID) int {
|
||||
abig, bbig := new(big.Int).SetBytes(a[:]), new(big.Int).SetBytes(b[:])
|
||||
return new(big.Int).Xor(abig, bbig).BitLen()
|
||||
}
|
||||
if err := quick.CheckEqual(logdist, logdistBig, quickcfg); err != nil {
|
||||
t.Error(err)
|
||||
}
|
||||
}
|
||||
|
||||
// the random tests is likely to miss the case where they're equal.
|
||||
func TestNodeID_logdistEqual(t *testing.T) {
|
||||
x := NodeID{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}
|
||||
if logdist(x, x) != 0 {
|
||||
t.Errorf("logdist(x, x) != 0")
|
||||
}
|
||||
}
|
||||
|
||||
func TestNodeID_randomID(t *testing.T) {
|
||||
// we don't use quick.Check here because its output isn't
|
||||
// very helpful when the test fails.
|
||||
for i := 0; i < quickcfg.MaxCount; i++ {
|
||||
a := gen(NodeID{}, quickrand).(NodeID)
|
||||
dist := quickrand.Intn(len(NodeID{}) * 8)
|
||||
result := randomID(a, dist)
|
||||
actualdist := logdist(result, a)
|
||||
|
||||
if dist != actualdist {
|
||||
t.Log("a: ", a)
|
||||
t.Log("result:", result)
|
||||
t.Fatalf("#%d: distance of result is %d, want %d", i, actualdist, dist)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func (NodeID) Generate(rand *rand.Rand, size int) reflect.Value {
|
||||
var id NodeID
|
||||
m := rand.Intn(len(id))
|
||||
for i := len(id) - 1; i > m; i-- {
|
||||
id[i] = byte(rand.Uint32())
|
||||
}
|
||||
return reflect.ValueOf(id)
|
||||
}
|
||||
|
||||
func TestTable_bumpOrAddPingReplace(t *testing.T) {
|
||||
pingC := make(pingC)
|
||||
tab := newTable(pingC, NodeID{}, &net.UDPAddr{})
|
||||
last := fillBucket(tab, 200)
|
||||
|
||||
// this bumpOrAdd should not replace the last node
|
||||
// because the node replies to ping.
|
||||
new := tab.bumpOrAdd(randomID(tab.self.ID, 200), nil)
|
||||
|
||||
pinged := <-pingC
|
||||
if pinged != last.ID {
|
||||
t.Fatalf("pinged wrong node: %v\nwant %v", pinged, last.ID)
|
||||
}
|
||||
|
||||
tab.mutex.Lock()
|
||||
defer tab.mutex.Unlock()
|
||||
if l := len(tab.buckets[200].entries); l != bucketSize {
|
||||
t.Errorf("wrong bucket size after bumpOrAdd: got %d, want %d", bucketSize, l)
|
||||
}
|
||||
if !contains(tab.buckets[200].entries, last.ID) {
|
||||
t.Error("last entry was removed")
|
||||
}
|
||||
if contains(tab.buckets[200].entries, new.ID) {
|
||||
t.Error("new entry was added")
|
||||
}
|
||||
}
|
||||
|
||||
func TestTable_bumpOrAddPingTimeout(t *testing.T) {
|
||||
tab := newTable(pingC(nil), NodeID{}, &net.UDPAddr{})
|
||||
last := fillBucket(tab, 200)
|
||||
|
||||
// this bumpOrAdd should replace the last node
|
||||
// because the node does not reply to ping.
|
||||
new := tab.bumpOrAdd(randomID(tab.self.ID, 200), nil)
|
||||
|
||||
// wait for async bucket update. damn. this needs to go away.
|
||||
time.Sleep(2 * time.Millisecond)
|
||||
|
||||
tab.mutex.Lock()
|
||||
defer tab.mutex.Unlock()
|
||||
if l := len(tab.buckets[200].entries); l != bucketSize {
|
||||
t.Errorf("wrong bucket size after bumpOrAdd: got %d, want %d", bucketSize, l)
|
||||
}
|
||||
if contains(tab.buckets[200].entries, last.ID) {
|
||||
t.Error("last entry was not removed")
|
||||
}
|
||||
if !contains(tab.buckets[200].entries, new.ID) {
|
||||
t.Error("new entry was not added")
|
||||
}
|
||||
}
|
||||
|
||||
func fillBucket(tab *Table, ld int) (last *Node) {
|
||||
b := tab.buckets[ld]
|
||||
for len(b.entries) < bucketSize {
|
||||
b.entries = append(b.entries, &Node{ID: randomID(tab.self.ID, ld)})
|
||||
}
|
||||
return b.entries[bucketSize-1]
|
||||
}
|
||||
|
||||
type pingC chan NodeID
|
||||
|
||||
func (t pingC) findnode(n *Node, target NodeID) ([]*Node, error) {
|
||||
panic("findnode called on pingRecorder")
|
||||
}
|
||||
func (t pingC) close() {
|
||||
panic("close called on pingRecorder")
|
||||
}
|
||||
func (t pingC) ping(n *Node) error {
|
||||
if t == nil {
|
||||
return errTimeout
|
||||
}
|
||||
t <- n.ID
|
||||
return nil
|
||||
}
|
||||
|
||||
func TestTable_bump(t *testing.T) {
|
||||
tab := newTable(nil, NodeID{}, &net.UDPAddr{})
|
||||
|
||||
// add an old entry and two recent ones
|
||||
oldactive := time.Now().Add(-2 * time.Minute)
|
||||
old := &Node{ID: randomID(tab.self.ID, 200), active: oldactive}
|
||||
others := []*Node{
|
||||
&Node{ID: randomID(tab.self.ID, 200), active: time.Now()},
|
||||
&Node{ID: randomID(tab.self.ID, 200), active: time.Now()},
|
||||
}
|
||||
tab.add(append(others, old))
|
||||
if tab.buckets[200].entries[0] == old {
|
||||
t.Fatal("old entry is at front of bucket")
|
||||
}
|
||||
|
||||
// bumping the old entry should move it to the front
|
||||
tab.bump(old.ID)
|
||||
if old.active == oldactive {
|
||||
t.Error("activity timestamp not updated")
|
||||
}
|
||||
if tab.buckets[200].entries[0] != old {
|
||||
t.Errorf("bumped entry did not move to the front of bucket")
|
||||
}
|
||||
}
|
||||
|
||||
func TestTable_closest(t *testing.T) {
|
||||
t.Parallel()
|
||||
|
||||
test := func(test *closeTest) bool {
|
||||
// for any node table, Target and N
|
||||
tab := newTable(nil, test.Self, &net.UDPAddr{})
|
||||
tab.add(test.All)
|
||||
|
||||
// check that doClosest(Target, N) returns nodes
|
||||
result := tab.closest(test.Target, test.N).entries
|
||||
if hasDuplicates(result) {
|
||||
t.Errorf("result contains duplicates")
|
||||
return false
|
||||
}
|
||||
if !sortedByDistanceTo(test.Target, result) {
|
||||
t.Errorf("result is not sorted by distance to target")
|
||||
return false
|
||||
}
|
||||
|
||||
// check that the number of results is min(N, tablen)
|
||||
wantN := test.N
|
||||
if tlen := tab.len(); tlen < test.N {
|
||||
wantN = tlen
|
||||
}
|
||||
if len(result) != wantN {
|
||||
t.Errorf("wrong number of nodes: got %d, want %d", len(result), wantN)
|
||||
return false
|
||||
} else if len(result) == 0 {
|
||||
return true // no need to check distance
|
||||
}
|
||||
|
||||
// check that the result nodes have minimum distance to target.
|
||||
for _, b := range tab.buckets {
|
||||
for _, n := range b.entries {
|
||||
if contains(result, n.ID) {
|
||||
continue // don't run the check below for nodes in result
|
||||
}
|
||||
farthestResult := result[len(result)-1].ID
|
||||
if distcmp(test.Target, n.ID, farthestResult) < 0 {
|
||||
t.Errorf("table contains node that is closer to target but it's not in result")
|
||||
t.Logf(" Target: %v", test.Target)
|
||||
t.Logf(" Farthest Result: %v", farthestResult)
|
||||
t.Logf(" ID: %v", n.ID)
|
||||
return false
|
||||
}
|
||||
}
|
||||
}
|
||||
return true
|
||||
}
|
||||
if err := quick.Check(test, quickcfg); err != nil {
|
||||
t.Error(err)
|
||||
}
|
||||
}
|
||||
|
||||
type closeTest struct {
|
||||
Self NodeID
|
||||
Target NodeID
|
||||
All []*Node
|
||||
N int
|
||||
}
|
||||
|
||||
func (*closeTest) Generate(rand *rand.Rand, size int) reflect.Value {
|
||||
t := &closeTest{
|
||||
Self: gen(NodeID{}, rand).(NodeID),
|
||||
Target: gen(NodeID{}, rand).(NodeID),
|
||||
N: rand.Intn(bucketSize),
|
||||
}
|
||||
for _, id := range gen([]NodeID{}, rand).([]NodeID) {
|
||||
t.All = append(t.All, &Node{ID: id})
|
||||
}
|
||||
return reflect.ValueOf(t)
|
||||
}
|
||||
|
||||
func TestTable_Lookup(t *testing.T) {
|
||||
self := gen(NodeID{}, quickrand).(NodeID)
|
||||
target := randomID(self, 200)
|
||||
transport := findnodeOracle{t, target}
|
||||
tab := newTable(transport, self, &net.UDPAddr{})
|
||||
|
||||
// lookup on empty table returns no nodes
|
||||
if results := tab.Lookup(target); len(results) > 0 {
|
||||
t.Fatalf("lookup on empty table returned %d results: %#v", len(results), results)
|
||||
}
|
||||
// seed table with initial node (otherwise lookup will terminate immediately)
|
||||
tab.bumpOrAdd(randomID(target, 200), &net.UDPAddr{Port: 200})
|
||||
|
||||
results := tab.Lookup(target)
|
||||
t.Logf("results:")
|
||||
for _, e := range results {
|
||||
t.Logf(" ld=%d, %v", logdist(target, e.ID), e.ID)
|
||||
}
|
||||
if len(results) != bucketSize {
|
||||
t.Errorf("wrong number of results: got %d, want %d", len(results), bucketSize)
|
||||
}
|
||||
if hasDuplicates(results) {
|
||||
t.Errorf("result set contains duplicate entries")
|
||||
}
|
||||
if !sortedByDistanceTo(target, results) {
|
||||
t.Errorf("result set not sorted by distance to target")
|
||||
}
|
||||
if !contains(results, target) {
|
||||
t.Errorf("result set does not contain target")
|
||||
}
|
||||
}
|
||||
|
||||
// findnode on this transport always returns at least one node
|
||||
// that is one bucket closer to the target.
|
||||
type findnodeOracle struct {
|
||||
t *testing.T
|
||||
target NodeID
|
||||
}
|
||||
|
||||
func (t findnodeOracle) findnode(n *Node, target NodeID) ([]*Node, error) {
|
||||
t.t.Logf("findnode query at dist %d", n.Addr.Port)
|
||||
// current log distance is encoded in port number
|
||||
var result []*Node
|
||||
switch port := n.Addr.Port; port {
|
||||
case 0:
|
||||
panic("query to node at distance 0")
|
||||
case 1:
|
||||
result = append(result, &Node{ID: t.target, Addr: &net.UDPAddr{Port: 0}})
|
||||
default:
|
||||
// TODO: add more randomness to distances
|
||||
port--
|
||||
for i := 0; i < bucketSize; i++ {
|
||||
result = append(result, &Node{ID: randomID(t.target, port), Addr: &net.UDPAddr{Port: port}})
|
||||
}
|
||||
}
|
||||
return result, nil
|
||||
}
|
||||
|
||||
func (t findnodeOracle) close() {}
|
||||
|
||||
func (t findnodeOracle) ping(n *Node) error {
|
||||
return errors.New("ping is not supported by this transport")
|
||||
}
|
||||
|
||||
func hasDuplicates(slice []*Node) bool {
|
||||
seen := make(map[NodeID]bool)
|
||||
for _, e := range slice {
|
||||
if seen[e.ID] {
|
||||
return true
|
||||
}
|
||||
seen[e.ID] = true
|
||||
}
|
||||
return false
|
||||
}
|
||||
|
||||
func sortedByDistanceTo(distbase NodeID, slice []*Node) bool {
|
||||
var last NodeID
|
||||
for i, e := range slice {
|
||||
if i > 0 && distcmp(distbase, e.ID, last) < 0 {
|
||||
return false
|
||||
}
|
||||
last = e.ID
|
||||
}
|
||||
return true
|
||||
}
|
||||
|
||||
func contains(ns []*Node, id NodeID) bool {
|
||||
for _, n := range ns {
|
||||
if n.ID == id {
|
||||
return true
|
||||
}
|
||||
}
|
||||
return false
|
||||
}
|
||||
|
||||
// gen wraps quick.Value so it's easier to use.
|
||||
// it generates a random value of the given value's type.
|
||||
func gen(typ interface{}, rand *rand.Rand) interface{} {
|
||||
v, ok := quick.Value(reflect.TypeOf(typ), rand)
|
||||
if !ok {
|
||||
panic(fmt.Sprintf("couldn't generate random value of type %T", typ))
|
||||
}
|
||||
return v.Interface()
|
||||
}
|
||||
|
||||
func newkey() *ecdsa.PrivateKey {
|
||||
key, err := crypto.GenerateKey()
|
||||
if err != nil {
|
||||
panic("couldn't generate key: " + err.Error())
|
||||
}
|
||||
return key
|
||||
}
|
||||
422
p2p/discover/udp.go
Normal file
422
p2p/discover/udp.go
Normal file
@ -0,0 +1,422 @@
|
||||
package discover
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"crypto/ecdsa"
|
||||
"errors"
|
||||
"fmt"
|
||||
"net"
|
||||
"time"
|
||||
|
||||
"github.com/ethereum/go-ethereum/crypto"
|
||||
"github.com/ethereum/go-ethereum/logger"
|
||||
"github.com/ethereum/go-ethereum/rlp"
|
||||
)
|
||||
|
||||
var log = logger.NewLogger("P2P Discovery")
|
||||
|
||||
// Errors
|
||||
var (
|
||||
errPacketTooSmall = errors.New("too small")
|
||||
errBadHash = errors.New("bad hash")
|
||||
errExpired = errors.New("expired")
|
||||
errTimeout = errors.New("RPC timeout")
|
||||
errClosed = errors.New("socket closed")
|
||||
)
|
||||
|
||||
// Timeouts
|
||||
const (
|
||||
respTimeout = 300 * time.Millisecond
|
||||
sendTimeout = 300 * time.Millisecond
|
||||
expiration = 3 * time.Second
|
||||
|
||||
refreshInterval = 1 * time.Hour
|
||||
)
|
||||
|
||||
// RPC packet types
|
||||
const (
|
||||
pingPacket = iota + 1 // zero is 'reserved'
|
||||
pongPacket
|
||||
findnodePacket
|
||||
neighborsPacket
|
||||
)
|
||||
|
||||
// RPC request structures
|
||||
type (
|
||||
ping struct {
|
||||
IP string // our IP
|
||||
Port uint16 // our port
|
||||
Expiration uint64
|
||||
}
|
||||
|
||||
// reply to Ping
|
||||
pong struct {
|
||||
ReplyTok []byte
|
||||
Expiration uint64
|
||||
}
|
||||
|
||||
findnode struct {
|
||||
// Id to look up. The responding node will send back nodes
|
||||
// closest to the target.
|
||||
Target NodeID
|
||||
Expiration uint64
|
||||
}
|
||||
|
||||
// reply to findnode
|
||||
neighbors struct {
|
||||
Nodes []*Node
|
||||
Expiration uint64
|
||||
}
|
||||
)
|
||||
|
||||
// udp implements the RPC protocol.
|
||||
type udp struct {
|
||||
conn *net.UDPConn
|
||||
priv *ecdsa.PrivateKey
|
||||
addpending chan *pending
|
||||
replies chan reply
|
||||
closing chan struct{}
|
||||
|
||||
*Table
|
||||
}
|
||||
|
||||
// pending represents a pending reply.
|
||||
//
|
||||
// some implementations of the protocol wish to send more than one
|
||||
// reply packet to findnode. in general, any neighbors packet cannot
|
||||
// be matched up with a specific findnode packet.
|
||||
//
|
||||
// our implementation handles this by storing a callback function for
|
||||
// each pending reply. incoming packets from a node are dispatched
|
||||
// to all the callback functions for that node.
|
||||
type pending struct {
|
||||
// these fields must match in the reply.
|
||||
from NodeID
|
||||
ptype byte
|
||||
|
||||
// time when the request must complete
|
||||
deadline time.Time
|
||||
|
||||
// callback is called when a matching reply arrives. if it returns
|
||||
// true, the callback is removed from the pending reply queue.
|
||||
// if it returns false, the reply is considered incomplete and
|
||||
// the callback will be invoked again for the next matching reply.
|
||||
callback func(resp interface{}) (done bool)
|
||||
|
||||
// errc receives nil when the callback indicates completion or an
|
||||
// error if no further reply is received within the timeout.
|
||||
errc chan<- error
|
||||
}
|
||||
|
||||
type reply struct {
|
||||
from NodeID
|
||||
ptype byte
|
||||
data interface{}
|
||||
}
|
||||
|
||||
// ListenUDP returns a new table that listens for UDP packets on laddr.
|
||||
func ListenUDP(priv *ecdsa.PrivateKey, laddr string) (*Table, error) {
|
||||
net, realaddr, err := listen(priv, laddr)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
net.Table = newTable(net, newNodeID(priv), realaddr)
|
||||
log.DebugDetailf("Listening on %v, my ID %x\n", realaddr, net.self.ID[:])
|
||||
return net.Table, nil
|
||||
}
|
||||
|
||||
func listen(priv *ecdsa.PrivateKey, laddr string) (*udp, *net.UDPAddr, error) {
|
||||
addr, err := net.ResolveUDPAddr("udp", laddr)
|
||||
if err != nil {
|
||||
return nil, nil, err
|
||||
}
|
||||
conn, err := net.ListenUDP("udp", addr)
|
||||
if err != nil {
|
||||
return nil, nil, err
|
||||
}
|
||||
realaddr := conn.LocalAddr().(*net.UDPAddr)
|
||||
|
||||
udp := &udp{
|
||||
conn: conn,
|
||||
priv: priv,
|
||||
closing: make(chan struct{}),
|
||||
addpending: make(chan *pending),
|
||||
replies: make(chan reply),
|
||||
}
|
||||
go udp.loop()
|
||||
go udp.readLoop()
|
||||
return udp, realaddr, nil
|
||||
}
|
||||
|
||||
func (t *udp) close() {
|
||||
close(t.closing)
|
||||
t.conn.Close()
|
||||
// TODO: wait for the loops to end.
|
||||
}
|
||||
|
||||
// ping sends a ping message to the given node and waits for a reply.
|
||||
func (t *udp) ping(e *Node) error {
|
||||
// TODO: maybe check for ReplyTo field in callback to measure RTT
|
||||
errc := t.pending(e.ID, pongPacket, func(interface{}) bool { return true })
|
||||
t.send(e, pingPacket, ping{
|
||||
IP: t.self.Addr.String(),
|
||||
Port: uint16(t.self.Addr.Port),
|
||||
Expiration: uint64(time.Now().Add(expiration).Unix()),
|
||||
})
|
||||
return <-errc
|
||||
}
|
||||
|
||||
// findnode sends a findnode request to the given node and waits until
|
||||
// the node has sent up to k neighbors.
|
||||
func (t *udp) findnode(to *Node, target NodeID) ([]*Node, error) {
|
||||
nodes := make([]*Node, 0, bucketSize)
|
||||
nreceived := 0
|
||||
errc := t.pending(to.ID, neighborsPacket, func(r interface{}) bool {
|
||||
reply := r.(*neighbors)
|
||||
for i := 0; i < len(reply.Nodes); i++ {
|
||||
nreceived++
|
||||
n := reply.Nodes[i]
|
||||
if validAddr(n.Addr) && n.ID != t.self.ID {
|
||||
nodes = append(nodes, n)
|
||||
}
|
||||
}
|
||||
return nreceived == bucketSize
|
||||
})
|
||||
|
||||
t.send(to, findnodePacket, findnode{
|
||||
Target: target,
|
||||
Expiration: uint64(time.Now().Add(expiration).Unix()),
|
||||
})
|
||||
err := <-errc
|
||||
return nodes, err
|
||||
}
|
||||
|
||||
func validAddr(a *net.UDPAddr) bool {
|
||||
return !a.IP.IsMulticast() && !a.IP.IsUnspecified() && a.Port != 0
|
||||
}
|
||||
|
||||
// pending adds a reply callback to the pending reply queue.
|
||||
// see the documentation of type pending for a detailed explanation.
|
||||
func (t *udp) pending(id NodeID, ptype byte, callback func(interface{}) bool) <-chan error {
|
||||
ch := make(chan error, 1)
|
||||
p := &pending{from: id, ptype: ptype, callback: callback, errc: ch}
|
||||
select {
|
||||
case t.addpending <- p:
|
||||
// loop will handle it
|
||||
case <-t.closing:
|
||||
ch <- errClosed
|
||||
}
|
||||
return ch
|
||||
}
|
||||
|
||||
// loop runs in its own goroutin. it keeps track of
|
||||
// the refresh timer and the pending reply queue.
|
||||
func (t *udp) loop() {
|
||||
var (
|
||||
pending []*pending
|
||||
nextDeadline time.Time
|
||||
timeout = time.NewTimer(0)
|
||||
refresh = time.NewTicker(refreshInterval)
|
||||
)
|
||||
<-timeout.C // ignore first timeout
|
||||
defer refresh.Stop()
|
||||
defer timeout.Stop()
|
||||
|
||||
rearmTimeout := func() {
|
||||
if len(pending) == 0 || nextDeadline == pending[0].deadline {
|
||||
return
|
||||
}
|
||||
nextDeadline = pending[0].deadline
|
||||
timeout.Reset(nextDeadline.Sub(time.Now()))
|
||||
}
|
||||
|
||||
for {
|
||||
select {
|
||||
case <-refresh.C:
|
||||
go t.refresh()
|
||||
|
||||
case <-t.closing:
|
||||
for _, p := range pending {
|
||||
p.errc <- errClosed
|
||||
}
|
||||
return
|
||||
|
||||
case p := <-t.addpending:
|
||||
p.deadline = time.Now().Add(respTimeout)
|
||||
pending = append(pending, p)
|
||||
rearmTimeout()
|
||||
|
||||
case reply := <-t.replies:
|
||||
// run matching callbacks, remove if they return false.
|
||||
for i, p := range pending {
|
||||
if reply.from == p.from && reply.ptype == p.ptype && p.callback(reply.data) {
|
||||
p.errc <- nil
|
||||
copy(pending[i:], pending[i+1:])
|
||||
pending = pending[:len(pending)-1]
|
||||
i--
|
||||
}
|
||||
}
|
||||
rearmTimeout()
|
||||
|
||||
case now := <-timeout.C:
|
||||
// notify and remove callbacks whose deadline is in the past.
|
||||
i := 0
|
||||
for ; i < len(pending) && now.After(pending[i].deadline); i++ {
|
||||
pending[i].errc <- errTimeout
|
||||
}
|
||||
if i > 0 {
|
||||
copy(pending, pending[i:])
|
||||
pending = pending[:len(pending)-i]
|
||||
}
|
||||
rearmTimeout()
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
const (
|
||||
macSize = 256 / 8
|
||||
sigSize = 520 / 8
|
||||
headSize = macSize + sigSize // space of packet frame data
|
||||
)
|
||||
|
||||
var headSpace = make([]byte, headSize)
|
||||
|
||||
func (t *udp) send(to *Node, ptype byte, req interface{}) error {
|
||||
b := new(bytes.Buffer)
|
||||
b.Write(headSpace)
|
||||
b.WriteByte(ptype)
|
||||
if err := rlp.Encode(b, req); err != nil {
|
||||
log.Errorln("error encoding packet:", err)
|
||||
return err
|
||||
}
|
||||
|
||||
packet := b.Bytes()
|
||||
sig, err := crypto.Sign(crypto.Sha3(packet[headSize:]), t.priv)
|
||||
if err != nil {
|
||||
log.Errorln("could not sign packet:", err)
|
||||
return err
|
||||
}
|
||||
copy(packet[macSize:], sig)
|
||||
// add the hash to the front. Note: this doesn't protect the
|
||||
// packet in any way. Our public key will be part of this hash in
|
||||
// the future.
|
||||
copy(packet, crypto.Sha3(packet[macSize:]))
|
||||
|
||||
log.DebugDetailf(">>> %v %T %v\n", to.Addr, req, req)
|
||||
if _, err = t.conn.WriteToUDP(packet, to.Addr); err != nil {
|
||||
log.DebugDetailln("UDP send failed:", err)
|
||||
}
|
||||
return err
|
||||
}
|
||||
|
||||
// readLoop runs in its own goroutine. it handles incoming UDP packets.
|
||||
func (t *udp) readLoop() {
|
||||
defer t.conn.Close()
|
||||
buf := make([]byte, 4096) // TODO: good buffer size
|
||||
for {
|
||||
nbytes, from, err := t.conn.ReadFromUDP(buf)
|
||||
if err != nil {
|
||||
return
|
||||
}
|
||||
if err := t.packetIn(from, buf[:nbytes]); err != nil {
|
||||
log.Debugf("Bad packet from %v: %v\n", from, err)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func (t *udp) packetIn(from *net.UDPAddr, buf []byte) error {
|
||||
if len(buf) < headSize+1 {
|
||||
return errPacketTooSmall
|
||||
}
|
||||
hash, sig, sigdata := buf[:macSize], buf[macSize:headSize], buf[headSize:]
|
||||
shouldhash := crypto.Sha3(buf[macSize:])
|
||||
if !bytes.Equal(hash, shouldhash) {
|
||||
return errBadHash
|
||||
}
|
||||
fromID, err := recoverNodeID(crypto.Sha3(buf[headSize:]), sig)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
var req interface {
|
||||
handle(t *udp, from *net.UDPAddr, fromID NodeID, mac []byte) error
|
||||
}
|
||||
switch ptype := sigdata[0]; ptype {
|
||||
case pingPacket:
|
||||
req = new(ping)
|
||||
case pongPacket:
|
||||
req = new(pong)
|
||||
case findnodePacket:
|
||||
req = new(findnode)
|
||||
case neighborsPacket:
|
||||
req = new(neighbors)
|
||||
default:
|
||||
return fmt.Errorf("unknown type: %d", ptype)
|
||||
}
|
||||
if err := rlp.Decode(bytes.NewReader(sigdata[1:]), req); err != nil {
|
||||
return err
|
||||
}
|
||||
log.DebugDetailf("<<< %v %T %v\n", from, req, req)
|
||||
return req.handle(t, from, fromID, hash)
|
||||
}
|
||||
|
||||
func (req *ping) handle(t *udp, from *net.UDPAddr, fromID NodeID, mac []byte) error {
|
||||
if expired(req.Expiration) {
|
||||
return errExpired
|
||||
}
|
||||
t.mutex.Lock()
|
||||
// Note: we're ignoring the provided IP/Port right now.
|
||||
e := t.bumpOrAdd(fromID, from)
|
||||
t.mutex.Unlock()
|
||||
|
||||
t.send(e, pongPacket, pong{
|
||||
ReplyTok: mac,
|
||||
Expiration: uint64(time.Now().Add(expiration).Unix()),
|
||||
})
|
||||
return nil
|
||||
}
|
||||
|
||||
func (req *pong) handle(t *udp, from *net.UDPAddr, fromID NodeID, mac []byte) error {
|
||||
if expired(req.Expiration) {
|
||||
return errExpired
|
||||
}
|
||||
t.mutex.Lock()
|
||||
t.bump(fromID)
|
||||
t.mutex.Unlock()
|
||||
|
||||
t.replies <- reply{fromID, pongPacket, req}
|
||||
return nil
|
||||
}
|
||||
|
||||
func (req *findnode) handle(t *udp, from *net.UDPAddr, fromID NodeID, mac []byte) error {
|
||||
if expired(req.Expiration) {
|
||||
return errExpired
|
||||
}
|
||||
t.mutex.Lock()
|
||||
e := t.bumpOrAdd(fromID, from)
|
||||
closest := t.closest(req.Target, bucketSize).entries
|
||||
t.mutex.Unlock()
|
||||
|
||||
t.send(e, neighborsPacket, neighbors{
|
||||
Nodes: closest,
|
||||
Expiration: uint64(time.Now().Add(expiration).Unix()),
|
||||
})
|
||||
return nil
|
||||
}
|
||||
|
||||
func (req *neighbors) handle(t *udp, from *net.UDPAddr, fromID NodeID, mac []byte) error {
|
||||
if expired(req.Expiration) {
|
||||
return errExpired
|
||||
}
|
||||
t.mutex.Lock()
|
||||
t.bump(fromID)
|
||||
t.add(req.Nodes)
|
||||
t.mutex.Unlock()
|
||||
|
||||
t.replies <- reply{fromID, neighborsPacket, req}
|
||||
return nil
|
||||
}
|
||||
|
||||
func expired(ts uint64) bool {
|
||||
return time.Unix(int64(ts), 0).Before(time.Now())
|
||||
}
|
||||
156
p2p/discover/udp_test.go
Normal file
156
p2p/discover/udp_test.go
Normal file
@ -0,0 +1,156 @@
|
||||
package discover
|
||||
|
||||
import (
|
||||
logpkg "log"
|
||||
"net"
|
||||
"os"
|
||||
"testing"
|
||||
"time"
|
||||
|
||||
"github.com/ethereum/go-ethereum/logger"
|
||||
)
|
||||
|
||||
func init() {
|
||||
logger.AddLogSystem(logger.NewStdLogSystem(os.Stdout, logpkg.LstdFlags, logger.DebugLevel))
|
||||
}
|
||||
|
||||
func TestUDP_ping(t *testing.T) {
|
||||
t.Parallel()
|
||||
|
||||
n1, _ := ListenUDP(newkey(), "127.0.0.1:0")
|
||||
n2, _ := ListenUDP(newkey(), "127.0.0.1:0")
|
||||
defer n1.net.close()
|
||||
defer n2.net.close()
|
||||
|
||||
if err := n1.net.ping(n2.self); err != nil {
|
||||
t.Fatalf("ping error: %v", err)
|
||||
}
|
||||
if find(n2, n1.self.ID) == nil {
|
||||
t.Errorf("node 2 does not contain id of node 1")
|
||||
}
|
||||
if e := find(n1, n2.self.ID); e != nil {
|
||||
t.Errorf("node 1 does contains id of node 2: %v", e)
|
||||
}
|
||||
}
|
||||
|
||||
func find(tab *Table, id NodeID) *Node {
|
||||
for _, b := range tab.buckets {
|
||||
for _, e := range b.entries {
|
||||
if e.ID == id {
|
||||
return e
|
||||
}
|
||||
}
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
func TestUDP_findnode(t *testing.T) {
|
||||
t.Parallel()
|
||||
|
||||
n1, _ := ListenUDP(newkey(), "127.0.0.1:0")
|
||||
n2, _ := ListenUDP(newkey(), "127.0.0.1:0")
|
||||
defer n1.net.close()
|
||||
defer n2.net.close()
|
||||
|
||||
entry := &Node{ID: NodeID{1}, Addr: &net.UDPAddr{IP: net.IP{1, 2, 3, 4}, Port: 15}}
|
||||
n2.add([]*Node{entry})
|
||||
|
||||
target := randomID(n1.self.ID, 100)
|
||||
result, _ := n1.net.findnode(n2.self, target)
|
||||
if len(result) != 1 {
|
||||
t.Fatalf("wrong number of results: got %d, want 1", len(result))
|
||||
}
|
||||
if result[0].ID != entry.ID {
|
||||
t.Errorf("wrong result: got %v, want %v", result[0], entry)
|
||||
}
|
||||
}
|
||||
|
||||
func TestUDP_replytimeout(t *testing.T) {
|
||||
t.Parallel()
|
||||
|
||||
// reserve a port so we don't talk to an existing service by accident
|
||||
addr, _ := net.ResolveUDPAddr("udp", "127.0.0.1:0")
|
||||
fd, err := net.ListenUDP("udp", addr)
|
||||
if err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
defer fd.Close()
|
||||
|
||||
n1, _ := ListenUDP(newkey(), "127.0.0.1:0")
|
||||
defer n1.net.close()
|
||||
n2 := n1.bumpOrAdd(randomID(n1.self.ID, 10), fd.LocalAddr().(*net.UDPAddr))
|
||||
|
||||
if err := n1.net.ping(n2); err != errTimeout {
|
||||
t.Error("expected timeout error, got", err)
|
||||
}
|
||||
|
||||
if result, err := n1.net.findnode(n2, n1.self.ID); err != errTimeout {
|
||||
t.Error("expected timeout error, got", err)
|
||||
} else if len(result) > 0 {
|
||||
t.Error("expected empty result, got", result)
|
||||
}
|
||||
}
|
||||
|
||||
func TestUDP_findnodeMultiReply(t *testing.T) {
|
||||
t.Parallel()
|
||||
|
||||
n1, _ := ListenUDP(newkey(), "127.0.0.1:0")
|
||||
n2, _ := ListenUDP(newkey(), "127.0.0.1:0")
|
||||
udp2 := n2.net.(*udp)
|
||||
defer n1.net.close()
|
||||
defer n2.net.close()
|
||||
|
||||
nodes := make([]*Node, bucketSize)
|
||||
for i := range nodes {
|
||||
nodes[i] = &Node{
|
||||
Addr: &net.UDPAddr{IP: net.IP{1, 2, 3, 4}, Port: i + 1},
|
||||
ID: randomID(n2.self.ID, i+1),
|
||||
}
|
||||
}
|
||||
|
||||
// ask N2 for neighbors. it will send an empty reply back.
|
||||
// the request will wait for up to bucketSize replies.
|
||||
resultC := make(chan []*Node)
|
||||
go func() {
|
||||
ns, err := n1.net.findnode(n2.self, n1.self.ID)
|
||||
if err != nil {
|
||||
t.Error("findnode error:", err)
|
||||
}
|
||||
resultC <- ns
|
||||
}()
|
||||
|
||||
// send a few more neighbors packets to N1.
|
||||
// it should collect those.
|
||||
for end := 0; end < len(nodes); {
|
||||
off := end
|
||||
if end = end + 5; end > len(nodes) {
|
||||
end = len(nodes)
|
||||
}
|
||||
udp2.send(n1.self, neighborsPacket, neighbors{
|
||||
Nodes: nodes[off:end],
|
||||
Expiration: uint64(time.Now().Add(10 * time.Second).Unix()),
|
||||
})
|
||||
}
|
||||
|
||||
// check that they are all returned. we cannot just check for
|
||||
// equality because they might not be returned in the order they
|
||||
// were sent.
|
||||
result := <-resultC
|
||||
if hasDuplicates(result) {
|
||||
t.Error("result slice contains duplicates")
|
||||
}
|
||||
if len(result) != len(nodes) {
|
||||
t.Errorf("wrong number of nodes returned: got %d, want %d", len(result), len(nodes))
|
||||
}
|
||||
matched := make(map[NodeID]bool)
|
||||
for _, n := range result {
|
||||
for _, expn := range nodes {
|
||||
if n.ID == expn.ID { // && bytes.Equal(n.Addr.IP, expn.Addr.IP) && n.Addr.Port == expn.Addr.Port {
|
||||
matched[n.ID] = true
|
||||
}
|
||||
}
|
||||
}
|
||||
if len(matched) != len(nodes) {
|
||||
t.Errorf("wrong number of matching nodes: got %d, want %d", len(matched), len(nodes))
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user