p2p/discv5: bootnodes URLs using domain name

Since commit b90cdbaa79 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

@@ -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 {

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)
+				}
 			}
 		}
 	}