From 75e9232fd990a62cda6139b697bb738489545b07 Mon Sep 17 00:00:00 2001
From: "admin@komgo.io" <KomgoRocks2018!>
Date: Fri, 24 Apr 2020 17:09:25 +0200
Subject: [PATCH] p2p/discv5: bootnodes URLs using domain name

Since commit b90cdbaa79cfe438aab0f1389d35980f3d38ec84 enode url is able to manage domain name under URL,
But it still not the case for bootnodes parameter (invalid IP Address error) this change enable it.
---
 p2p/discv5/node.go      | 11 +++++++++--
 p2p/discv5/node_test.go | 36 ++++++++++++++++++++++++++++++++----
 2 files changed, 41 insertions(+), 6 deletions(-)

diff --git a/p2p/discv5/node.go b/p2p/discv5/node.go
index 44d3025b70..c9904d96c2 100644
--- a/p2p/discv5/node.go
+++ b/p2p/discv5/node.go
@@ -106,7 +106,10 @@ func (n *Node) String() string {
 	return u.String()
 }
 
-var incompleteNodeURL = regexp.MustCompile("(?i)^(?:enode://)?([0-9a-f]+)$")
+var (
+	incompleteNodeURL = regexp.MustCompile("(?i)^(?:enode://)?([0-9a-f]+)$")
+	lookupIPFunc      = net.LookupIP
+)
 
 // ParseNode parses a node designator.
 //
@@ -168,7 +171,11 @@ func parseComplete(rawurl string) (*Node, error) {
 		return nil, fmt.Errorf("invalid host: %v", err)
 	}
 	if ip = net.ParseIP(host); ip == nil {
-		return nil, errors.New("invalid IP address")
+		ips, err := lookupIPFunc(u.Hostname())
+		if err != nil {
+			return nil, errors.New("no such host")
+		}
+		ip = ips[0]
 	}
 	// Ensure the IP is 4 bytes long for IPv4 addresses.
 	if ipv4 := ip.To4(); ipv4 != nil {
diff --git a/p2p/discv5/node_test.go b/p2p/discv5/node_test.go
index 4e0fdbe3db..e20b3af1e6 100644
--- a/p2p/discv5/node_test.go
+++ b/p2p/discv5/node_test.go
@@ -17,6 +17,7 @@
 package discv5
 
 import (
+	"errors"
 	"fmt"
 	"math/big"
 	"math/rand"
@@ -31,6 +32,15 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 )
 
+func init() {
+	lookupIPFunc = func(name string) ([]net.IP, error) {
+		if name == "node.example.org" {
+			return []net.IP{{33, 44, 55, 66}}, nil
+		}
+		return nil, errors.New("no such host")
+	}
+}
+
 func ExampleNewNode() {
 	id := MustHexID("1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439")
 
@@ -68,7 +78,7 @@ var parseNodeTests = []struct {
 	// Complete nodes with IP address.
 	{
 		rawurl:    "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@hostname:3",
-		wantError: `invalid IP address`,
+		wantError: `no such host`,
 	},
 	{
 		rawurl:    "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@127.0.0.1:foo",
@@ -123,10 +133,12 @@ var parseNodeTests = []struct {
 		),
 	},
 	{
-		rawurl: "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439",
+		rawurl: "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@node.example.org:52150?discport=22334",
 		wantResult: NewNode(
 			MustHexID("0x1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439"),
-			nil, 0, 0,
+			net.IP{0x21, 0x2C, 0x37, 0x42},
+			22334,
+			52150,
 		),
 	},
 	// Invalid URLs
@@ -143,6 +155,15 @@ var parseNodeTests = []struct {
 		rawurl:    "://foo",
 		wantError: `missing protocol scheme`,
 	},
+	{
+		rawurl: "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@127.0.0.1:52150?discport=22334",
+		wantResult: NewNode(
+			MustHexID("0x1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439"),
+			net.IP{0x7f, 0x0, 0x0, 0x1},
+			22334,
+			52150,
+		),
+	},
 }
 
 func TestParseNode(t *testing.T) {
@@ -173,7 +194,14 @@ func TestNodeString(t *testing.T) {
 		if test.wantError == "" && strings.HasPrefix(test.rawurl, "enode://") {
 			str := test.wantResult.String()
 			if str != test.rawurl {
-				t.Errorf("test %d: Node.String() mismatch:\ngot:  %s\nwant: %s", i, str, test.rawurl)
+				if strings.Contains(test.rawurl, "node.example.org") {
+					resolvedurl := strings.Replace(test.rawurl, "node.example.org", "33.44.55.66", 1)
+					if str != resolvedurl {
+						t.Errorf("test %d: Node.String() mismatch:\ngot:  %s\nwant: %s", i, str, resolvedurl)
+					}
+				} else {
+					t.Errorf("test %d: Node.String() mismatch:\ngot:  %s\nwant: %s", i, str, test.rawurl)
+				}
 			}
 		}
 	}