feat(watchdog): implement keepalive mechanism and enhance connection handling

watchdog/keepalive.go

@@ -1,2 +1,62 @@
 package watchdog
 
+import (
+	"fmt"
+	"time"
+
+	"super-frpc/global"
+	"super-frpc/postLog"
+)
+
+func StartKeepAlive() error {
+	ticker := time.NewTicker(3 * time.Second)
+	defer ticker.Stop()
+
+	for {
+		<-ticker.C
+
+		if err := isProcessAlive(); err != nil {
+			global.Is.WatchdogConnected = false
+			postLog.Warning(fmt.Sprintf("[watchdog] keepalive check failed: %v", err))
+
+			_ = Disconnect()
+
+			var lastErr error
+			for i := 0; i < 5; i++ {
+				if err := ensureWatchdogProcess(); err != nil {
+					lastErr = err
+					time.Sleep(500 * time.Millisecond)
+					continue
+				}
+
+				if Connect("127.0.0.1", global.CurrentConfig.Watchdog.Port) {
+					global.Is.WatchdogConnected = true
+					postLog.Info("[watchdog] successfully reconnected to watchdog")
+					lastErr = nil
+					break
+				}
+
+				lastErr = fmt.Errorf("failed to connect to watchdog")
+				time.Sleep(500 * time.Millisecond)
+			}
+
+			if lastErr != nil {
+				postLog.Error(fmt.Sprintf("[watchdog] failed to recover watchdog connection: %v", lastErr))
+				return fmt.Errorf("watchdog recovery failed after 5 attempts: %w", lastErr)
+			}
+		}
+	}
+}
+
+func isProcessAlive() error {
+	if watchdogName, err := getWatchdogBinaryName(); err == nil && isWatchdogProcessRunning(watchdogName) {
+		resp, err := sendMsg("watchdogAgentConnectionTest", 3)
+		if err != nil || resp != "success" {
+			return fmt.Errorf("watchdog not responding to connection test")
+		}
+	} else {
+		return fmt.Errorf("watchdog process not running")
+	}
+
+	return nil
+}