chore(selftest): Add tc Query test case

The bpf_tc_query/bpf_tc_detach interface should init the parameter
first, sometimes it may be confused for us, so add the case to reduce
the confusion.

#421
#420

Signed-off-by: Tao Chen <chen.dylane@gmail.com>

selftest/tc/main.go

@@ -56,12 +56,40 @@ func main() {
 
 	var tcOpts bpf.TcOpts
 	tcOpts.ProgFd = int(tcProg.GetFd())
+	tcOpts.Flags = bpf.BpfTcFReplace
+	tcOpts.Handle = 1
 	err = hook.Attach(&tcOpts)
 	if err != nil {
 		fmt.Fprintln(os.Stderr, err)
 		os.Exit(-1)
 	}
 
+	// test for query
+	tcOpts.Flags = 0
+	tcOpts.ProgFd = 0
+	tcOpts.ProgId = 0
+	err = hook.Query(&tcOpts)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(-1)
+	}
+	if tcOpts.Handle != 1 {
+		fmt.Fprintln(os.Stderr, "query info error, handle:%d", tcOpts.Handle)
+		os.Exit(-1)
+	}
+
+	// test for detach
+	defer func() {
+		tcOpts.Flags = 0
+		tcOpts.ProgFd = 0
+		tcOpts.ProgId = 0
+		err = hook.Detach(&tcOpts)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			os.Exit(-1)
+		}
+	}()
+
 	eventsChannel := make(chan []byte)
 	rb, err := bpfModule.InitRingBuf("events", eventsChannel)
 	if err != nil {