更新

dns_server.py

@@ -0,0 +1,74 @@
+import socket
+import struct
+
+class DNSServer:
+    def __init__(self, host='0.0.0.0', port=53):
+        self.host = host
+        self.port = port
+        self.socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        self.socket.bind((self.host, self.port))
+        print(f"DNS Server started on {self.host}:{self.port}")
+    
+    def run(self):
+        while True:
+            try:
+                data, addr = self.socket.recvfrom(512)
+                print(f"Received query from {addr}")
+                response = self.handle_query(data)
+                self.socket.sendto(response, addr)
+            except Exception as e:
+                print(f"Error: {e}")
+    
+    def handle_query(self, data):
+        # 解析查询
+        header = data[:12]
+        query_id, flags, qdcount, ancount, nscount, arcount = struct.unpack('!HHHHHH', header)
+        
+        # 构建响应头部
+        # 设置响应标志
+        flags = 0x8400  # 标准查询响应，无错误
+        
+        # 解析查询部分
+        offset = 12
+        queries = []
+        for _ in range(qdcount):
+            qname, offset = self._parse_name(data, offset)
+            qtype, qclass = struct.unpack('!HH', data[offset:offset+4])
+            offset += 4
+            queries.append((qname, qtype, qclass))
+        
+        # 构建响应
+        response = header[:2]  # 保留查询ID
+        response += struct.pack('!H', flags)
+        response += struct.pack('!HHHH', qdcount, 0, 0, 0)  # 暂时没有回答、权威和附加记录
+        
+        # 添加查询部分
+        for qname, qtype, qclass in queries:
+            response += self._encode_name(qname)
+            response += struct.pack('!HH', qtype, qclass)
+        
+        return response
+    
+    def _parse_name(self, data, offset):
+        parts = []
+        while True:
+            length = data[offset]
+            if length == 0:
+                offset += 1
+                break
+            offset += 1
+            parts.append(data[offset:offset+length].decode('utf-8'))
+            offset += length
+        return '.'.join(parts), offset
+    
+    def _encode_name(self, name):
+        encoded = b''
+        for part in name.split('.'):
+            encoded += struct.pack('!B', len(part))
+            encoded += part.encode('utf-8')
+        encoded += b'\x00'  # 结束标记
+        return encoded
+
+if __name__ == '__main__':
+    server = DNSServer()
+    server.run()