Release 1.3.1: fix hy2 UDP ping and shop link open.

Co-authored-by: Cursor <cursoragent@cursor.com>

internal/netcheck/ping.go

@@ -12,7 +12,7 @@ import (
 	"vpnclient/internal/protocols/hysteria2"
 )
 
-// Result is a TCP reachability measurement to a proxy host.
+// Result is a reachability measurement to a proxy host.
 type Result struct {
 	Name  string `json:"name"`
 	Host  string `json:"host"`
@@ -22,12 +22,13 @@ type Result struct {
 	Error string `json:"error,omitempty"`
 }
 
-// PingProxyURI measures TCP connect time to the host in a share/proxy URI.
+// PingProxyURI measures connect time to the host in a share/proxy URI.
 func PingProxyURI(ctx context.Context, name, proxyURI string) Result {
 	return PingProfile(ctx, name, "", proxyURI)
 }
 
 // PingProfile pings using protocol hints when available.
+// Naive uses TCP; Hysteria 2 uses UDP (QUIC) — TCP would always look "refused".
 func PingProfile(ctx context.Context, name string, proto config.Protocol, proxyURI string) Result {
 	res := Result{Name: name}
 	if strings.TrimSpace(proxyURI) == "" {
@@ -35,8 +36,9 @@ func PingProfile(ctx context.Context, name string, proto config.Protocol, proxyU
 		return res
 	}
 
+	hy2 := proto == config.ProtocolHysteria2 || hysteria2.Detect(proxyURI)
 	var host, port string
-	if proto == config.ProtocolHysteria2 || hysteria2.Detect(proxyURI) {
+	if hy2 {
 		h, p, err := hysteria2.HostPort(proxyURI)
 		if err != nil {
 			res.Error = err.Error()
@@ -49,7 +51,6 @@ func PingProfile(ctx context.Context, name string, proto config.Protocol, proxyU
 			res.Error = err.Error()
 			return res
 		}
-		// Parse host from normalized URI without importing net/url dance twice
 		rest := normalized
 		if i := strings.Index(rest, "://"); i >= 0 {
 			rest = rest[i+3:]
@@ -75,15 +76,76 @@ func PingProfile(ctx context.Context, name string, proto config.Protocol, proxyU
 		return res
 	}
 
-	d := net.Dialer{Timeout: 4 * time.Second}
 	start := time.Now()
-	conn, err := d.DialContext(ctx, "tcp", net.JoinHostPort(host, port))
+	var err error
+	if hy2 {
+		err = probeUDP(ctx, host, port)
+	} else {
+		err = probeTCP(ctx, host, port)
+	}
 	if err != nil {
-		res.Error = fmt.Sprintf("недоступен: %v", err)
+		res.Error = friendlyDialError(err, hy2)
 		return res
 	}
-	_ = conn.Close()
 	res.Ms = time.Since(start).Milliseconds()
 	res.OK = true
 	return res
 }
+
+func probeTCP(ctx context.Context, host, port string) error {
+	d := net.Dialer{Timeout: 4 * time.Second}
+	conn, err := d.DialContext(ctx, "tcp", net.JoinHostPort(host, port))
+	if err != nil {
+		return err
+	}
+	_ = conn.Close()
+	return nil
+}
+
+func probeUDP(ctx context.Context, host, port string) error {
+	d := net.Dialer{Timeout: 4 * time.Second}
+	conn, err := d.DialContext(ctx, "udp", net.JoinHostPort(host, port))
+	if err != nil {
+		return err
+	}
+	defer conn.Close()
+
+	deadline := time.Now().Add(1500 * time.Millisecond)
+	if dl, ok := ctx.Deadline(); ok && dl.Before(deadline) {
+		deadline = dl
+	}
+	_ = conn.SetDeadline(deadline)
+
+	// Any datagram is enough to exercise the UDP path; QUIC rarely answers a bare probe.
+	if _, err := conn.Write([]byte{0}); err != nil {
+		return err
+	}
+	buf := make([]byte, 64)
+	_, err = conn.Read(buf)
+	if err == nil {
+		return nil
+	}
+	if ne, ok := err.(net.Error); ok && ne.Timeout() {
+		// No ICMP unreachable → port is typically open or filtered; treat as reachable for UI ping.
+		return nil
+	}
+	return err
+}
+
+func friendlyDialError(err error, hy2 bool) string {
+	msg := err.Error()
+	lower := strings.ToLower(msg)
+	switch {
+	case strings.Contains(lower, "refused"):
+		if hy2 {
+			return "UDP порт недоступен (connection refused)"
+		}
+		return "порт закрыт (connection refused)"
+	case strings.Contains(lower, "timeout") || strings.Contains(lower, "timed out"):
+		return "таймаут"
+	case strings.Contains(lower, "no such host"):
+		return "DNS: хост не найден"
+	default:
+		return fmt.Sprintf("недоступен: %v", err)
+	}
+}