all: new p2p node representation (#17643)

Package p2p/enode provides a generalized representation of p2p nodes
which can contain arbitrary information in key/value pairs. It is also
the new home for the node database. The "v4" identity scheme is also
moved here from p2p/enr to remove the dependency on Ethereum crypto from
that package.

Record signature handling is changed significantly. The identity scheme
registry is removed and acceptable schemes must be passed to any method
that needs identity. This means records must now be validated explicitly
after decoding.

The enode API is designed to make signature handling easy and safe: most
APIs around the codebase work with enode.Node, which is a wrapper around
a valid record. Going from enr.Record to enode.Node requires a valid
signature.

* p2p/discover: port to p2p/enode

This ports the discovery code to the new node representation in
p2p/enode. The wire protocol is unchanged, this can be considered a
refactoring change. The Kademlia table can now deal with nodes using an
arbitrary identity scheme. This requires a few incompatible API changes:

  - Table.Lookup is not available anymore. It used to take a public key
    as argument because v4 protocol requires one. Its replacement is
    LookupRandom.
  - Table.Resolve takes *enode.Node instead of NodeID. This is also for
    v4 protocol compatibility because nodes cannot be looked up by ID
    alone.
  - Types Node and NodeID are gone. Further commits in the series will be
    fixes all over the the codebase to deal with those removals.

* p2p: port to p2p/enode and discovery changes

This adapts package p2p to the changes in p2p/discover. All uses of
discover.Node and discover.NodeID are replaced by their equivalents from
p2p/enode.

New API is added to retrieve the enode.Node instance of a peer. The
behavior of Server.Self with discovery disabled is improved. It now
tries much harder to report a working IP address, falling back to
127.0.0.1 if no suitable address can be determined through other means.
These changes were needed for tests of other packages later in the
series.

* p2p/simulations, p2p/testing: port to p2p/enode

No surprises here, mostly replacements of discover.Node, discover.NodeID
with their new equivalents. The 'interesting' API changes are:

 - testing.ProtocolSession tracks complete nodes, not just their IDs.
 - adapters.NodeConfig has a new method to create a complete node.

These changes were needed to make swarm tests work.

Note that the NodeID change makes the code incompatible with old
simulation snapshots.

* whisper/whisperv5, whisper/whisperv6: port to p2p/enode

This port was easy because whisper uses []byte for node IDs and
URL strings in the API.

* eth: port to p2p/enode

Again, easy to port because eth uses strings for node IDs and doesn't
care about node information in any way.

* les: port to p2p/enode

Apart from replacing discover.NodeID with enode.ID, most changes are in
the server pool code. It now deals with complete nodes instead
of (Pubkey, IP, Port) triples. The database format is unchanged for now,
but we should probably change it to use the node database later.

* node: port to p2p/enode

This change simply replaces discover.Node and discover.NodeID with their
new equivalents.

* swarm/network: port to p2p/enode

Swarm has its own node address representation, BzzAddr, containing both
an overlay address (the hash of a secp256k1 public key) and an underlay
address (enode:// URL).

There are no changes to the BzzAddr format in this commit, but certain
operations such as creating a BzzAddr from a node ID are now impossible
because node IDs aren't public keys anymore.

Most swarm-related changes in the series remove uses of
NewAddrFromNodeID, replacing it with NewAddr which takes a complete node
as argument. ToOverlayAddr is removed because we can just use the node
ID directly.

1 files changed, 50 insertions, 52 deletions

diff --git a/p2p/dial.go b/p2p/dial.go
index 4baca7d93..359cdbcbb 100644
--- a/p2p/dial.go
+++ b/p2p/dial.go
@@ -18,14 +18,13 @@ package p2p
 
 import (
 	"container/heap"
-	"crypto/rand"
 	"errors"
 	"fmt"
 	"net"
 	"time"
 
 	"github.com/ethereum/go-ethereum/log"
-	"github.com/ethereum/go-ethereum/p2p/discover"
+	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/netutil"
 )
 
@@ -50,7 +49,7 @@ const (
 // NodeDialer is used to connect to nodes in the network, typically by using
 // an underlying net.Dialer but also using net.Pipe in tests
 type NodeDialer interface {
-	Dial(*discover.Node) (net.Conn, error)
+	Dial(*enode.Node) (net.Conn, error)
 }
 
 // TCPDialer implements the NodeDialer interface by using a net.Dialer to
@@ -60,8 +59,8 @@ type TCPDialer struct {
 }
 
 // Dial creates a TCP connection to the node
-func (t TCPDialer) Dial(dest *discover.Node) (net.Conn, error) {
-	addr := &net.TCPAddr{IP: dest.IP, Port: int(dest.TCP)}
+func (t TCPDialer) Dial(dest *enode.Node) (net.Conn, error) {
+	addr := &net.TCPAddr{IP: dest.IP(), Port: dest.TCP()}
 	return t.Dialer.Dial("tcp", addr.String())
 }
 
@@ -74,22 +73,22 @@ type dialstate struct {
 	netrestrict *netutil.Netlist
 
 	lookupRunning bool
-	dialing       map[discover.NodeID]connFlag
-	lookupBuf     []*discover.Node // current discovery lookup results
-	randomNodes   []*discover.Node // filled from Table
-	static        map[discover.NodeID]*dialTask
+	dialing       map[enode.ID]connFlag
+	lookupBuf     []*enode.Node // current discovery lookup results
+	randomNodes   []*enode.Node // filled from Table
+	static        map[enode.ID]*dialTask
 	hist          *dialHistory
 
-	start     time.Time        // time when the dialer was first used
-	bootnodes []*discover.Node // default dials when there are no peers
+	start     time.Time     // time when the dialer was first used
+	bootnodes []*enode.Node // default dials when there are no peers
 }
 
 type discoverTable interface {
-	Self() *discover.Node
+	Self() *enode.Node
 	Close()
-	Resolve(target discover.NodeID) *discover.Node
-	Lookup(target discover.NodeID) []*discover.Node
-	ReadRandomNodes([]*discover.Node) int
+	Resolve(*enode.Node) *enode.Node
+	LookupRandom() []*enode.Node
+	ReadRandomNodes([]*enode.Node) int
 }
 
 // the dial history remembers recent dials.
@@ -97,7 +96,7 @@ type dialHistory []pastDial
 
 // pastDial is an entry in the dial history.
 type pastDial struct {
-	id  discover.NodeID
+	id  enode.ID
 	exp time.Time
 }
 
@@ -109,7 +108,7 @@ type task interface {
 // fields cannot be accessed while the task is running.
 type dialTask struct {
 	flags        connFlag
-	dest         *discover.Node
+	dest         *enode.Node
 	lastResolved time.Time
 	resolveDelay time.Duration
 }
@@ -118,7 +117,7 @@ type dialTask struct {
 // Only one discoverTask is active at any time.
 // discoverTask.Do performs a random lookup.
 type discoverTask struct {
-	results []*discover.Node
+	results []*enode.Node
 }
 
 // A waitExpireTask is generated if there are no other tasks
@@ -127,15 +126,15 @@ type waitExpireTask struct {
 	time.Duration
 }
 
-func newDialState(static []*discover.Node, bootnodes []*discover.Node, ntab discoverTable, maxdyn int, netrestrict *netutil.Netlist) *dialstate {
+func newDialState(static []*enode.Node, bootnodes []*enode.Node, ntab discoverTable, maxdyn int, netrestrict *netutil.Netlist) *dialstate {
 	s := &dialstate{
 		maxDynDials: maxdyn,
 		ntab:        ntab,
 		netrestrict: netrestrict,
-		static:      make(map[discover.NodeID]*dialTask),
-		dialing:     make(map[discover.NodeID]connFlag),
-		bootnodes:   make([]*discover.Node, len(bootnodes)),
-		randomNodes: make([]*discover.Node, maxdyn/2),
+		static:      make(map[enode.ID]*dialTask),
+		dialing:     make(map[enode.ID]connFlag),
+		bootnodes:   make([]*enode.Node, len(bootnodes)),
+		randomNodes: make([]*enode.Node, maxdyn/2),
 		hist:        new(dialHistory),
 	}
 	copy(s.bootnodes, bootnodes)
@@ -145,32 +144,32 @@ func newDialState(static []*discover.Node, bootnodes []*discover.Node, ntab disc
 	return s
 }
 
-func (s *dialstate) addStatic(n *discover.Node) {
+func (s *dialstate) addStatic(n *enode.Node) {
 	// This overwrites the task instead of updating an existing
 	// entry, giving users the opportunity to force a resolve operation.
-	s.static[n.ID] = &dialTask{flags: staticDialedConn, dest: n}
+	s.static[n.ID()] = &dialTask{flags: staticDialedConn, dest: n}
 }
 
-func (s *dialstate) removeStatic(n *discover.Node) {
+func (s *dialstate) removeStatic(n *enode.Node) {
 	// This removes a task so future attempts to connect will not be made.
-	delete(s.static, n.ID)
+	delete(s.static, n.ID())
 	// This removes a previous dial timestamp so that application
 	// can force a server to reconnect with chosen peer immediately.
-	s.hist.remove(n.ID)
+	s.hist.remove(n.ID())
 }
 
-func (s *dialstate) newTasks(nRunning int, peers map[discover.NodeID]*Peer, now time.Time) []task {
+func (s *dialstate) newTasks(nRunning int, peers map[enode.ID]*Peer, now time.Time) []task {
 	if s.start.IsZero() {
 		s.start = now
 	}
 
 	var newtasks []task
-	addDial := func(flag connFlag, n *discover.Node) bool {
+	addDial := func(flag connFlag, n *enode.Node) bool {
 		if err := s.checkDial(n, peers); err != nil {
-			log.Trace("Skipping dial candidate", "id", n.ID, "addr", &net.TCPAddr{IP: n.IP, Port: int(n.TCP)}, "err", err)
+			log.Trace("Skipping dial candidate", "id", n.ID(), "addr", &net.TCPAddr{IP: n.IP(), Port: n.TCP()}, "err", err)
 			return false
 		}
-		s.dialing[n.ID] = flag
+		s.dialing[n.ID()] = flag
 		newtasks = append(newtasks, &dialTask{flags: flag, dest: n})
 		return true
 	}
@@ -196,8 +195,8 @@ func (s *dialstate) newTasks(nRunning int, peers map[discover.NodeID]*Peer, now
 		err := s.checkDial(t.dest, peers)
 		switch err {
 		case errNotWhitelisted, errSelf:
-			log.Warn("Removing static dial candidate", "id", t.dest.ID, "addr", &net.TCPAddr{IP: t.dest.IP, Port: int(t.dest.TCP)}, "err", err)
-			delete(s.static, t.dest.ID)
+			log.Warn("Removing static dial candidate", "id", t.dest.ID, "addr", &net.TCPAddr{IP: t.dest.IP(), Port: t.dest.TCP()}, "err", err)
+			delete(s.static, t.dest.ID())
 		case nil:
 			s.dialing[id] = t.flags
 			newtasks = append(newtasks, t)
@@ -260,18 +259,18 @@ var (
 	errNotWhitelisted   = errors.New("not contained in netrestrict whitelist")
 )
 
-func (s *dialstate) checkDial(n *discover.Node, peers map[discover.NodeID]*Peer) error {
-	_, dialing := s.dialing[n.ID]
+func (s *dialstate) checkDial(n *enode.Node, peers map[enode.ID]*Peer) error {
+	_, dialing := s.dialing[n.ID()]
 	switch {
 	case dialing:
 		return errAlreadyDialing
-	case peers[n.ID] != nil:
+	case peers[n.ID()] != nil:
 		return errAlreadyConnected
-	case s.ntab != nil && n.ID == s.ntab.Self().ID:
+	case s.ntab != nil && n.ID() == s.ntab.Self().ID():
 		return errSelf
-	case s.netrestrict != nil && !s.netrestrict.Contains(n.IP):
+	case s.netrestrict != nil && !s.netrestrict.Contains(n.IP()):
 		return errNotWhitelisted
-	case s.hist.contains(n.ID):
+	case s.hist.contains(n.ID()):
 		return errRecentlyDialed
 	}
 	return nil
@@ -280,8 +279,8 @@ func (s *dialstate) checkDial(n *discover.Node, peers map[discover.NodeID]*Peer)
 func (s *dialstate) taskDone(t task, now time.Time) {
 	switch t := t.(type) {
 	case *dialTask:
-		s.hist.add(t.dest.ID, now.Add(dialHistoryExpiration))
-		delete(s.dialing, t.dest.ID)
+		s.hist.add(t.dest.ID(), now.Add(dialHistoryExpiration))
+		delete(s.dialing, t.dest.ID())
 	case *discoverTask:
 		s.lookupRunning = false
 		s.lookupBuf = append(s.lookupBuf, t.results...)
@@ -323,7 +322,7 @@ func (t *dialTask) resolve(srv *Server) bool {
 	if time.Since(t.lastResolved) < t.resolveDelay {
 		return false
 	}
-	resolved := srv.ntab.Resolve(t.dest.ID)
+	resolved := srv.ntab.Resolve(t.dest)
 	t.lastResolved = time.Now()
 	if resolved == nil {
 		t.resolveDelay *= 2
@@ -336,7 +335,7 @@ func (t *dialTask) resolve(srv *Server) bool {
 	// The node was found.
 	t.resolveDelay = initialResolveDelay
 	t.dest = resolved
-	log.Debug("Resolved node", "id", t.dest.ID, "addr", &net.TCPAddr{IP: t.dest.IP, Port: int(t.dest.TCP)})
+	log.Debug("Resolved node", "id", t.dest.ID, "addr", &net.TCPAddr{IP: t.dest.IP(), Port: t.dest.TCP()})
 	return true
 }
 
@@ -345,7 +344,7 @@ type dialError struct {
 }
 
 // dial performs the actual connection attempt.
-func (t *dialTask) dial(srv *Server, dest *discover.Node) error {
+func (t *dialTask) dial(srv *Server, dest *enode.Node) error {
 	fd, err := srv.Dialer.Dial(dest)
 	if err != nil {
 		return &dialError{err}
@@ -355,7 +354,8 @@ func (t *dialTask) dial(srv *Server, dest *discover.Node) error {
 }
 
 func (t *dialTask) String() string {
-	return fmt.Sprintf("%v %x %v:%d", t.flags, t.dest.ID[:8], t.dest.IP, t.dest.TCP)
+	id := t.dest.ID()
+	return fmt.Sprintf("%v %x %v:%d", t.flags, id[:8], t.dest.IP(), t.dest.TCP())
 }
 
 func (t *discoverTask) Do(srv *Server) {
@@ -367,9 +367,7 @@ func (t *discoverTask) Do(srv *Server) {
 		time.Sleep(next.Sub(now))
 	}
 	srv.lastLookup = time.Now()
-	var target discover.NodeID
-	rand.Read(target[:])
-	t.results = srv.ntab.Lookup(target)
+	t.results = srv.ntab.LookupRandom()
 }
 
 func (t *discoverTask) String() string {
@@ -391,11 +389,11 @@ func (t waitExpireTask) String() string {
 func (h dialHistory) min() pastDial {
 	return h[0]
 }
-func (h *dialHistory) add(id discover.NodeID, exp time.Time) {
+func (h *dialHistory) add(id enode.ID, exp time.Time) {
 	heap.Push(h, pastDial{id, exp})
 
 }
-func (h *dialHistory) remove(id discover.NodeID) bool {
+func (h *dialHistory) remove(id enode.ID) bool {
 	for i, v := range *h {
 		if v.id == id {
 			heap.Remove(h, i)
@@ -404,7 +402,7 @@ func (h *dialHistory) remove(id discover.NodeID) bool {
 	}
 	return false
 }
-func (h dialHistory) contains(id discover.NodeID) bool {
+func (h dialHistory) contains(id enode.ID) bool {
 	for _, v := range h {
 		if v.id == id {
 			return true