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.

2 files changed, 13 insertions, 1 deletions

diff --git a/p2p/enr/enr.go b/p2p/enr/enr.go
index 251caf458..444820c15 100644
--- a/p2p/enr/enr.go
+++ b/p2p/enr/enr.go
@@ -156,7 +156,7 @@ func (r *Record) Set(e Entry) {
 }
 
 func (r *Record) invalidate() {
-	if r.signature == nil {
+	if r.signature != nil {
 		r.seq++
 	}
 	r.signature = nil
diff --git a/p2p/enr/enr_test.go b/p2p/enr/enr_test.go
index 9bf22478d..449c898a8 100644
--- a/p2p/enr/enr_test.go
+++ b/p2p/enr/enr_test.go
@@ -169,6 +169,18 @@ func TestDirty(t *testing.T) {
 	}
 }
 
+func TestSeq(t *testing.T) {
+	var r Record
+
+	assert.Equal(t, uint64(0), r.Seq())
+	r.Set(UDP(1))
+	assert.Equal(t, uint64(0), r.Seq())
+	signTest([]byte{5}, &r)
+	assert.Equal(t, uint64(0), r.Seq())
+	r.Set(UDP(2))
+	assert.Equal(t, uint64(1), r.Seq())
+}
+
 // TestGetSetOverwrite tests value overwrite when setting a new value with an existing key in record.
 func TestGetSetOverwrite(t *testing.T) {
 	var r Record