allow to parse ipv6 localhost "[::]:4601" (#2430)dili

Allow parsing of ipv6 localhost -colon- port address.
"[::]:4601" was failing to parse. This and other forms pass ParseHostOrURL() now.

2 files changed, 73 insertions, 6 deletions

diff --git a/network/wsNetwork.go b/network/wsNetwork.go
index 21306eb34..49eacf331 100644
--- a/network/wsNetwork.go
+++ b/network/wsNetwork.go
@@ -1911,18 +1911,35 @@ var errBcastInvalidArray = errors.New("invalid broadcast array")
 
 var errBcastQFull = errors.New("broadcast queue full")
 
-// HostColonPortPattern matches "^[^:]+:\\d+$" e.g. "foo.com.:1234"
-var HostColonPortPattern = regexp.MustCompile("^[^:]+:\\d+$")
+var errURLNoHost = errors.New("could not parse a host from url")
+
+// HostColonPortPattern matches "^[a-zA-Z0-9.]+:\\d+$" e.g. "foo.com.:1234"
+var HostColonPortPattern = regexp.MustCompile("^[a-zA-Z0-9.]+:\\d+$")
 
 // ParseHostOrURL handles "host:port" or a full URL.
 // Standard library net/url.Parse chokes on "host:port".
 func ParseHostOrURL(addr string) (*url.URL, error) {
-	var parsedURL *url.URL
+	// If the entire addr is "host:port" grab that right away.
+	// Don't try url.Parse() because that will grab "host:" as if it were "scheme:"
 	if HostColonPortPattern.MatchString(addr) {
-		parsedURL = &url.URL{Scheme: "http", Host: addr}
-		return parsedURL, nil
+		return &url.URL{Scheme: "http", Host: addr}, nil
+	}
+	parsed, err := url.Parse(addr)
+	if err == nil {
+		if parsed.Host == "" {
+			return nil, errURLNoHost
+		}
+		return parsed, nil
+	}
+	if strings.HasPrefix(addr, "http:") || strings.HasPrefix(addr, "https:") || strings.HasPrefix(addr, "ws:") || strings.HasPrefix(addr, "wss:") || strings.HasPrefix(addr, "://") || strings.HasPrefix(addr, "//") {
+		return parsed, err
+	}
+	// This turns "[::]:4601" into "http://[::]:4601" which url.Parse can do
+	parsed, e2 := url.Parse("http://" + addr)
+	if e2 == nil {
+		return parsed, nil
 	}
-	return url.Parse(addr)
+	return parsed, err /* return original err, not our prefix altered try */
 }
 
 // addrToGossipAddr parses host:port or a URL and returns the URL to the websocket interface at that address.
diff --git a/network/wsNetwork_test.go b/network/wsNetwork_test.go
index 1ccdfb0d1..e1670a7ba 100644
--- a/network/wsNetwork_test.go
+++ b/network/wsNetwork_test.go
@@ -24,6 +24,7 @@ import (
 	"math/rand"
 	"net"
 	"net/http"
+	"net/url"
 	"os"
 	"runtime"
 	"sort"
@@ -1969,3 +1970,52 @@ func BenchmarkVariableTransactionMessageBlockSizes(t *testing.B) {
 		txnCount += txnCount/4 + 1
 	}
 }
+
+type urlCase struct {
+	text string
+	out  url.URL
+}
+
+func TestParseHostOrURL(t *testing.T) {
+	urlTestCases := []urlCase{
+		{"localhost:123", url.URL{Scheme: "http", Host: "localhost:123"}},
+		{"http://localhost:123", url.URL{Scheme: "http", Host: "localhost:123"}},
+		{"ws://localhost:9999", url.URL{Scheme: "ws", Host: "localhost:9999"}},
+		{"wss://localhost:443", url.URL{Scheme: "wss", Host: "localhost:443"}},
+		{"https://localhost:123", url.URL{Scheme: "https", Host: "localhost:123"}},
+		{"https://somewhere.tld", url.URL{Scheme: "https", Host: "somewhere.tld"}},
+		{"http://127.0.0.1:123", url.URL{Scheme: "http", Host: "127.0.0.1:123"}},
+		{"//somewhere.tld", url.URL{Scheme: "", Host: "somewhere.tld"}},
+		{"//somewhere.tld:4601", url.URL{Scheme: "", Host: "somewhere.tld:4601"}},
+		{"http://[::]:123", url.URL{Scheme: "http", Host: "[::]:123"}},
+		{"1.2.3.4:123", url.URL{Scheme: "http", Host: "1.2.3.4:123"}},
+		{"[::]:123", url.URL{Scheme: "http", Host: "[::]:123"}},
+	}
+	badUrls := []string{
+		"justahost",
+		"localhost:WAT",
+		"http://localhost:WAT",
+		"https://localhost:WAT",
+		"ws://localhost:WAT",
+		"wss://localhost:WAT",
+		"//localhost:WAT",
+		"://badaddress", // See rpcs/blockService_test.go TestRedirectFallbackEndpoints
+		"://localhost:1234",
+	}
+	for _, tc := range urlTestCases {
+		t.Run(tc.text, func(t *testing.T) {
+			v, err := ParseHostOrURL(tc.text)
+			require.NoError(t, err)
+			if tc.out != *v {
+				t.Errorf("url wanted %#v, got %#v", tc.out, v)
+				return
+			}
+		})
+	}
+	for _, addr := range badUrls {
+		t.Run(addr, func(t *testing.T) {
+			_, err := ParseHostOrURL(addr)
+			require.Error(t, err, "url should fail", addr)
+		})
+	}
+}