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, 19 insertions, 19 deletions

diff --git a/swarm/network/fetcher.go b/swarm/network/fetcher.go
index 413b40cb5..5b4b61c7e 100644
--- a/swarm/network/fetcher.go
+++ b/swarm/network/fetcher.go
@@ -22,7 +22,7 @@ import (
 	"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/swarm/storage"
 )
 
@@ -32,7 +32,7 @@ var searchTimeout = 1 * time.Second
 // Also used in stream delivery.
 var RequestTimeout = 10 * time.Second
 
-type RequestFunc func(context.Context, *Request) (*discover.NodeID, chan struct{}, error)
+type RequestFunc func(context.Context, *Request) (*enode.ID, chan struct{}, error)
 
 // Fetcher is created when a chunk is not found locally. It starts a request handler loop once and
 // keeps it alive until all active requests are completed. This can happen:
@@ -41,18 +41,18 @@ type RequestFunc func(context.Context, *Request) (*discover.NodeID, chan struct{
 // Fetcher self destroys itself after it is completed.
 // TODO: cancel all forward requests after termination
 type Fetcher struct {
-	protoRequestFunc RequestFunc           // request function fetcher calls to issue retrieve request for a chunk
-	addr             storage.Address       // the address of the chunk to be fetched
-	offerC           chan *discover.NodeID // channel of sources (peer node id strings)
+	protoRequestFunc RequestFunc     // request function fetcher calls to issue retrieve request for a chunk
+	addr             storage.Address // the address of the chunk to be fetched
+	offerC           chan *enode.ID  // channel of sources (peer node id strings)
 	requestC         chan struct{}
 	skipCheck        bool
 }
 
 type Request struct {
-	Addr        storage.Address  // chunk address
-	Source      *discover.NodeID // nodeID of peer to request from (can be nil)
-	SkipCheck   bool             // whether to offer the chunk first or deliver directly
-	peersToSkip *sync.Map        // peers not to request chunk from (only makes sense if source is nil)
+	Addr        storage.Address // chunk address
+	Source      *enode.ID       // nodeID of peer to request from (can be nil)
+	SkipCheck   bool            // whether to offer the chunk first or deliver directly
+	peersToSkip *sync.Map       // peers not to request chunk from (only makes sense if source is nil)
 }
 
 // NewRequest returns a new instance of Request based on chunk address skip check and
@@ -112,14 +112,14 @@ func NewFetcher(addr storage.Address, rf RequestFunc, skipCheck bool) *Fetcher {
 	return &Fetcher{
 		addr:             addr,
 		protoRequestFunc: rf,
-		offerC:           make(chan *discover.NodeID),
+		offerC:           make(chan *enode.ID),
 		requestC:         make(chan struct{}),
 		skipCheck:        skipCheck,
 	}
 }
 
 // Offer is called when an upstream peer offers the chunk via syncing as part of `OfferedHashesMsg` and the node does not have the chunk locally.
-func (f *Fetcher) Offer(ctx context.Context, source *discover.NodeID) {
+func (f *Fetcher) Offer(ctx context.Context, source *enode.ID) {
 	// First we need to have this select to make sure that we return if context is done
 	select {
 	case <-ctx.Done():
@@ -156,13 +156,13 @@ func (f *Fetcher) Request(ctx context.Context) {
 // it keeps the Fetcher alive within the lifecycle of the passed context
 func (f *Fetcher) run(ctx context.Context, peers *sync.Map) {
 	var (
-		doRequest bool               // determines if retrieval is initiated in the current iteration
-		wait      *time.Timer        // timer for search timeout
-		waitC     <-chan time.Time   // timer channel
-		sources   []*discover.NodeID // known sources, ie. peers that offered the chunk
-		requested bool               // true if the chunk was actually requested
+		doRequest bool             // determines if retrieval is initiated in the current iteration
+		wait      *time.Timer      // timer for search timeout
+		waitC     <-chan time.Time // timer channel
+		sources   []*enode.ID      // known sources, ie. peers that offered the chunk
+		requested bool             // true if the chunk was actually requested
 	)
-	gone := make(chan *discover.NodeID) // channel to signal that a peer we requested from disconnected
+	gone := make(chan *enode.ID) // channel to signal that a peer we requested from disconnected
 
 	// loop that keeps the fetching process alive
 	// after every request a timer is set. If this goes off we request again from another peer
@@ -251,9 +251,9 @@ func (f *Fetcher) run(ctx context.Context, peers *sync.Map) {
 // * the peer's address is added to the set of peers to skip
 // * the peer's address is removed from prospective sources, and
 // * a go routine is started that reports on the gone channel if the peer is disconnected (or terminated their streamer)
-func (f *Fetcher) doRequest(ctx context.Context, gone chan *discover.NodeID, peersToSkip *sync.Map, sources []*discover.NodeID) ([]*discover.NodeID, error) {
+func (f *Fetcher) doRequest(ctx context.Context, gone chan *enode.ID, peersToSkip *sync.Map, sources []*enode.ID) ([]*enode.ID, error) {
 	var i int
-	var sourceID *discover.NodeID
+	var sourceID *enode.ID
 	var quit chan struct{}
 
 	req := &Request{