Exclude IP addresses from proxyless dialing (#1503)

* exclude IP addresses from proxyless dialing

Author: myleshorton

dialer/proxyless.go

@@ -142,6 +142,10 @@ func (d *proxylessDialer) onFailure(host string, err error) {
 // status checks the status of the dialer for the given address.
 // Returns SUCCEEDED, FAILED, or UNKNOWN.
 func (d *proxylessDialer) status(address string) int {
+	if isIPAddress(address) {
+		// If the address is an IP address, we can't use the proxyless dialer.
+		return FAILED
+	}
 	_, host, err := normalizeAddrHost(address)
 	if err != nil {
 		return FAILED
@@ -203,6 +207,16 @@ func normalizeAddrHost(address string) (string, string, error) {
 	return addr, host, nil
 }
 
+func isIPAddress(ip string) bool {
+	// First split the IP address by host and port
+	host, _, err := net.SplitHostPort(ip)
+	if err != nil { // If there's no port, we assume it's just an IP address
+		host = ip
+	}
+	parsedIP := net.ParseIP(host)
+	return parsedIP != nil
+}
+
 // configBytes returns the configuration bytes for the smart dialer
 // It uses the embedded file system to read the configuration file
 func configBytes() ([]byte, error) {

dialer/proxyless_test.go

@@ -148,3 +148,29 @@ func TestDialContext_DialStreamError(t *testing.T) {
 	assert.Nil(t, conn)
 	assert.Error(t, err)
 }
+func TestIsIPAddress(t *testing.T) {
+	tests := []struct {
+		input    string
+		expected bool
+	}{
+		{"127.0.0.1", true},
+		{"192.168.1.1", true},
+		{"192.168.1.1:90", true},
+		{"::1", true},
+		{"2001:db8::1", true},
+		{"example.com", false},
+		{"localhost", false},
+		{"", false},
+		{"256.256.256.256", false},        // invalid IP
+		{"1234:5678:9abc:defg::1", false}, // invalid IPv6
+		{"127.0.0.1:8080", true},          // port included
+		{"[2001:db8::1]:8080", true},      // IPv6 with port
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.input, func(t *testing.T) {
+			result := isIPAddress(tt.input)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}