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, 7 insertions, 3 deletions

diff --git a/p2p/discover/table_test.go b/p2p/discover/table_test.go
index e8631024b..6b4cd2d18 100644
--- a/p2p/discover/table_test.go
+++ b/p2p/discover/table_test.go
@@ -141,7 +141,7 @@ func TestTable_IPLimit(t *testing.T) {
 	defer db.Close()
 
 	for i := 0; i < tableIPLimit+1; i++ {
-		n := nodeAtDistance(tab.self.ID(), i, net.IP{172, 0, 1, byte(i)})
+		n := nodeAtDistance(tab.self().ID(), i, net.IP{172, 0, 1, byte(i)})
 		tab.add(n)
 	}
 	if tab.len() > tableIPLimit {
@@ -158,7 +158,7 @@ func TestTable_BucketIPLimit(t *testing.T) {
 
 	d := 3
 	for i := 0; i < bucketIPLimit+1; i++ {
-		n := nodeAtDistance(tab.self.ID(), d, net.IP{172, 0, 1, byte(i)})
+		n := nodeAtDistance(tab.self().ID(), d, net.IP{172, 0, 1, byte(i)})
 		tab.add(n)
 	}
 	if tab.len() > bucketIPLimit {
@@ -240,7 +240,7 @@ func TestTable_ReadRandomNodesGetAll(t *testing.T) {
 
 		for i := 0; i < len(buf); i++ {
 			ld := cfg.Rand.Intn(len(tab.buckets))
-			tab.stuff([]*node{nodeAtDistance(tab.self.ID(), ld, intIP(ld))})
+			tab.stuff([]*node{nodeAtDistance(tab.self().ID(), ld, intIP(ld))})
 		}
 		gotN := tab.ReadRandomNodes(buf)
 		if gotN != tab.len() {
@@ -510,6 +510,10 @@ type preminedTestnet struct {
 	dists     [hashBits + 1][]encPubkey
 }
 
+func (tn *preminedTestnet) self() *enode.Node {
+	return nullNode
+}
+
 func (tn *preminedTestnet) findnode(toid enode.ID, toaddr *net.UDPAddr, target encPubkey) ([]*node, error) {
 	// current log distance is encoded in port number
 	// fmt.Println("findnode query at dist", toaddr.Port)