p2p, p2p/discover: add signed ENR generation (#17753)

This PR adds enode.LocalNode and integrates it into the p2p
subsystem. This new object is the keeper of the local node
record. For now, a new version of the record is produced every
time the client restarts. We'll make it smarter to avoid that in
the future.

There are a couple of other changes in this commit: discovery now
waits for all of its goroutines at shutdown and the p2p server
now closes the node database after discovery has shut down. This
fixes a leveldb crash in tests. p2p server startup is faster
because it doesn't need to wait for the external IP query
anymore.

1 files changed, 4 insertions, 3 deletions

diff --git a/p2p/dial.go b/p2p/dial.go
index 359cdbcbb..d228514fc 100644
--- a/p2p/dial.go
+++ b/p2p/dial.go
@@ -71,6 +71,7 @@ type dialstate struct {
 	maxDynDials int
 	ntab        discoverTable
 	netrestrict *netutil.Netlist
+	self        enode.ID
 
 	lookupRunning bool
 	dialing       map[enode.ID]connFlag
@@ -84,7 +85,6 @@ type dialstate struct {
 }
 
 type discoverTable interface {
-	Self() *enode.Node
 	Close()
 	Resolve(*enode.Node) *enode.Node
 	LookupRandom() []*enode.Node
@@ -126,10 +126,11 @@ type waitExpireTask struct {
 	time.Duration
 }
 
-func newDialState(static []*enode.Node, bootnodes []*enode.Node, ntab discoverTable, maxdyn int, netrestrict *netutil.Netlist) *dialstate {
+func newDialState(self enode.ID, static []*enode.Node, bootnodes []*enode.Node, ntab discoverTable, maxdyn int, netrestrict *netutil.Netlist) *dialstate {
 	s := &dialstate{
 		maxDynDials: maxdyn,
 		ntab:        ntab,
+		self:        self,
 		netrestrict: netrestrict,
 		static:      make(map[enode.ID]*dialTask),
 		dialing:     make(map[enode.ID]connFlag),
@@ -266,7 +267,7 @@ func (s *dialstate) checkDial(n *enode.Node, peers map[enode.ID]*Peer) error {
 		return errAlreadyDialing
 	case peers[n.ID()] != nil:
 		return errAlreadyConnected
-	case s.ntab != nil && n.ID() == s.ntab.Self().ID():
+	case n.ID() == s.self:
 		return errSelf
 	case s.netrestrict != nil && !s.netrestrict.Contains(n.IP()):
 		return errNotWhitelisted