feat(ICMP): 添加 ICMP 报文的 RTT 计算功能

- 实现了 ICMP 报文的发送和接收
- 添加了 RTT（往返时间）的计算和显示
- 增加了超时处理机制

main.py

@@ -194,11 +194,33 @@ def send_packet():
         src_port = 12345
         dest_port = int(dest_port)
 
-        # 构造报文并发送
+        # ICMP报文需要添加 RTT 计算
         if packet_type == "ICMP":
             sock = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_ICMP)
             packet = construct_icmp()
-        elif packet_type == "UDP":
+
+            # 记录发送时间
+            start_time = time.time()
+
+            # 发送ICMP报文
+            sock.sendto(packet, (dest_ip, 0))
+
+            # 接收响应
+            sock.settimeout(2)  # 设置超时为2秒
+            try:
+                sock.recvfrom(1024)
+                end_time = time.time()
+                rtt = (end_time - start_time) * 1000  # 毫秒
+                result.set(f"ICMP请求成功，RTT: {rtt:.2f} 毫秒")
+            except socket.timeout:
+                result.set("ICMP请求超时")
+            finally:
+                sock.close()
+
+            return  # 结束函数
+
+        # 对于其他报文类型（UDP, TCP）
+        if packet_type == "UDP":
             sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
             packet = construct_udp(src_port, dest_port)
         elif packet_type == "TCP":