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.

4 files changed, 32 insertions, 29 deletions

diff --git a/p2p/simulations/adapters/docker.go b/p2p/simulations/adapters/docker.go
index d145c46b3..82eab0e9c 100644
--- a/p2p/simulations/adapters/docker.go
+++ b/p2p/simulations/adapters/docker.go
@@ -29,7 +29,7 @@ import (
 
 	"github.com/docker/docker/pkg/reexec"
 	"github.com/ethereum/go-ethereum/node"
-	"github.com/ethereum/go-ethereum/p2p/discover"
+	"github.com/ethereum/go-ethereum/p2p/enode"
 )
 
 var (
@@ -64,7 +64,7 @@ func NewDockerAdapter() (*DockerAdapter, error) {
 
 	return &DockerAdapter{
 		ExecAdapter{
-			nodes: make(map[discover.NodeID]*ExecNode),
+			nodes: make(map[enode.ID]*ExecNode),
 		},
 	}, nil
 }
diff --git a/p2p/simulations/adapters/exec.go b/p2p/simulations/adapters/exec.go
index e64cebc2a..dc7d277ca 100644
--- a/p2p/simulations/adapters/exec.go
+++ b/p2p/simulations/adapters/exec.go
@@ -38,7 +38,7 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/node"
 	"github.com/ethereum/go-ethereum/p2p"
-	"github.com/ethereum/go-ethereum/p2p/discover"
+	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/rpc"
 	"golang.org/x/net/websocket"
 )
@@ -54,7 +54,7 @@ type ExecAdapter struct {
 	// simulation node are created.
 	BaseDir string
 
-	nodes map[discover.NodeID]*ExecNode
+	nodes map[enode.ID]*ExecNode
 }
 
 // NewExecAdapter returns an ExecAdapter which stores node data in
@@ -62,7 +62,7 @@ type ExecAdapter struct {
 func NewExecAdapter(baseDir string) *ExecAdapter {
 	return &ExecAdapter{
 		BaseDir: baseDir,
-		nodes:   make(map[discover.NodeID]*ExecNode),
+		nodes:   make(map[enode.ID]*ExecNode),
 	}
 }
 
@@ -122,7 +122,7 @@ func (e *ExecAdapter) NewNode(config *NodeConfig) (Node, error) {
 // ExecNode starts a simulation node by exec'ing the current binary and
 // running the configured services
 type ExecNode struct {
-	ID     discover.NodeID
+	ID     enode.ID
 	Dir    string
 	Config *execNodeConfig
 	Cmd    *exec.Cmd
@@ -492,7 +492,7 @@ type wsRPCDialer struct {
 
 // DialRPC implements the RPCDialer interface by creating a WebSocket RPC
 // client of the given node
-func (w *wsRPCDialer) DialRPC(id discover.NodeID) (*rpc.Client, error) {
+func (w *wsRPCDialer) DialRPC(id enode.ID) (*rpc.Client, error) {
 	addr, ok := w.addrs[id.String()]
 	if !ok {
 		return nil, fmt.Errorf("unknown node: %s", id)
diff --git a/p2p/simulations/adapters/inproc.go b/p2p/simulations/adapters/inproc.go
index b0fdf49b9..52a662be6 100644
--- a/p2p/simulations/adapters/inproc.go
+++ b/p2p/simulations/adapters/inproc.go
@@ -27,7 +27,7 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/node"
 	"github.com/ethereum/go-ethereum/p2p"
-	"github.com/ethereum/go-ethereum/p2p/discover"
+	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/simulations/pipes"
 	"github.com/ethereum/go-ethereum/rpc"
 )
@@ -37,7 +37,7 @@ import (
 type SimAdapter struct {
 	pipe     func() (net.Conn, net.Conn, error)
 	mtx      sync.RWMutex
-	nodes    map[discover.NodeID]*SimNode
+	nodes    map[enode.ID]*SimNode
 	services map[string]ServiceFunc
 }
 
@@ -48,7 +48,7 @@ type SimAdapter struct {
 func NewSimAdapter(services map[string]ServiceFunc) *SimAdapter {
 	return &SimAdapter{
 		pipe:     pipes.NetPipe,
-		nodes:    make(map[discover.NodeID]*SimNode),
+		nodes:    make(map[enode.ID]*SimNode),
 		services: services,
 	}
 }
@@ -56,7 +56,7 @@ func NewSimAdapter(services map[string]ServiceFunc) *SimAdapter {
 func NewTCPAdapter(services map[string]ServiceFunc) *SimAdapter {
 	return &SimAdapter{
 		pipe:     pipes.TCPPipe,
-		nodes:    make(map[discover.NodeID]*SimNode),
+		nodes:    make(map[enode.ID]*SimNode),
 		services: services,
 	}
 }
@@ -115,14 +115,14 @@ func (s *SimAdapter) NewNode(config *NodeConfig) (Node, error) {
 
 // Dial implements the p2p.NodeDialer interface by connecting to the node using
 // an in-memory net.Pipe
-func (s *SimAdapter) Dial(dest *discover.Node) (conn net.Conn, err error) {
-	node, ok := s.GetNode(dest.ID)
+func (s *SimAdapter) Dial(dest *enode.Node) (conn net.Conn, err error) {
+	node, ok := s.GetNode(dest.ID())
 	if !ok {
-		return nil, fmt.Errorf("unknown node: %s", dest.ID)
+		return nil, fmt.Errorf("unknown node: %s", dest.ID())
 	}
 	srv := node.Server()
 	if srv == nil {
-		return nil, fmt.Errorf("node not running: %s", dest.ID)
+		return nil, fmt.Errorf("node not running: %s", dest.ID())
 	}
 	// SimAdapter.pipe is net.Pipe (NewSimAdapter)
 	pipe1, pipe2, err := s.pipe()
@@ -138,7 +138,7 @@ func (s *SimAdapter) Dial(dest *discover.Node) (conn net.Conn, err error) {
 
 // DialRPC implements the RPCDialer interface by creating an in-memory RPC
 // client of the given node
-func (s *SimAdapter) DialRPC(id discover.NodeID) (*rpc.Client, error) {
+func (s *SimAdapter) DialRPC(id enode.ID) (*rpc.Client, error) {
 	node, ok := s.GetNode(id)
 	if !ok {
 		return nil, fmt.Errorf("unknown node: %s", id)
@@ -151,7 +151,7 @@ func (s *SimAdapter) DialRPC(id discover.NodeID) (*rpc.Client, error) {
 }
 
 // GetNode returns the node with the given ID if it exists
-func (s *SimAdapter) GetNode(id discover.NodeID) (*SimNode, bool) {
+func (s *SimAdapter) GetNode(id enode.ID) (*SimNode, bool) {
 	s.mtx.RLock()
 	defer s.mtx.RUnlock()
 	node, ok := s.nodes[id]
@@ -163,7 +163,7 @@ func (s *SimAdapter) GetNode(id discover.NodeID) (*SimNode, bool) {
 // pipe
 type SimNode struct {
 	lock         sync.RWMutex
-	ID           discover.NodeID
+	ID           enode.ID
 	config       *NodeConfig
 	adapter      *SimAdapter
 	node         *node.Node
@@ -177,9 +177,9 @@ func (sn *SimNode) Addr() []byte {
 	return []byte(sn.Node().String())
 }
 
-// Node returns a discover.Node representing the SimNode
-func (sn *SimNode) Node() *discover.Node {
-	return discover.NewNode(sn.ID, net.IP{127, 0, 0, 1}, 30303, 30303)
+// Node returns a node descriptor representing the SimNode
+func (sn *SimNode) Node() *enode.Node {
+	return sn.config.Node()
 }
 
 // Client returns an rpc.Client which can be used to communicate with the
diff --git a/p2p/simulations/adapters/types.go b/p2p/simulations/adapters/types.go
index 2c4b9dd8f..6681726e4 100644
--- a/p2p/simulations/adapters/types.go
+++ b/p2p/simulations/adapters/types.go
@@ -29,7 +29,7 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/node"
 	"github.com/ethereum/go-ethereum/p2p"
-	"github.com/ethereum/go-ethereum/p2p/discover"
+	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/rpc"
 )
 
@@ -78,7 +78,7 @@ type NodeAdapter interface {
 type NodeConfig struct {
 	// ID is the node's ID which is used to identify the node in the
 	// simulation network
-	ID discover.NodeID
+	ID enode.ID
 
 	// PrivateKey is the node's private key which is used by the devp2p
 	// stack to encrypt communications
@@ -97,7 +97,7 @@ type NodeConfig struct {
 	Services []string
 
 	// function to sanction or prevent suggesting a peer
-	Reachable func(id discover.NodeID) bool
+	Reachable func(id enode.ID) bool
 
 	Port uint16
 }
@@ -138,11 +138,9 @@ func (n *NodeConfig) UnmarshalJSON(data []byte) error {
 	}
 
 	if confJSON.ID != "" {
-		nodeID, err := discover.HexID(confJSON.ID)
-		if err != nil {
+		if err := n.ID.UnmarshalText([]byte(confJSON.ID)); err != nil {
 			return err
 		}
-		n.ID = nodeID
 	}
 
 	if confJSON.PrivateKey != "" {
@@ -165,6 +163,11 @@ func (n *NodeConfig) UnmarshalJSON(data []byte) error {
 	return nil
 }
 
+// Node returns the node descriptor represented by the config.
+func (n *NodeConfig) Node() *enode.Node {
+	return enode.NewV4(&n.PrivateKey.PublicKey, net.IP{127, 0, 0, 1}, int(n.Port), int(n.Port))
+}
+
 // RandomNodeConfig returns node configuration with a randomly generated ID and
 // PrivateKey
 func RandomNodeConfig() *NodeConfig {
@@ -173,7 +176,7 @@ func RandomNodeConfig() *NodeConfig {
 		panic("unable to generate key")
 	}
 
-	id := discover.PubkeyID(&key.PublicKey)
+	id := enode.PubkeyToIDV4(&key.PublicKey)
 	port, err := assignTCPPort()
 	if err != nil {
 		panic("unable to assign tcp port")
@@ -218,7 +221,7 @@ type ServiceContext struct {
 // other nodes in the network (for example a simulated Swarm node which needs
 // to connect to a Geth node to resolve ENS names)
 type RPCDialer interface {
-	DialRPC(id discover.NodeID) (*rpc.Client, error)
+	DialRPC(id enode.ID) (*rpc.Client, error)
 }
 
 // Services is a collection of services which can be run in a simulation