diff --git a/src/sqlmap-master/lib/techniques/dns/test.py b/src/sqlmap-master/lib/techniques/dns/test.py
index 1a8fe6a..baf23ab 100644
--- a/src/sqlmap-master/lib/techniques/dns/test.py
+++ b/src/sqlmap-master/lib/techniques/dns/test.py
@@ -5,6 +5,7 @@ Copyright (c) 2006-2024 sqlmap developers (https://sqlmap.org/)
 See the file 'LICENSE' for copying permission
 """
 
+# 导入Backend、randomInt、conf、kb、logger、FROM_DUMMY_TABLE、SqlmapNotVulnerableException、dnsUse模块
 from lib.core.common import Backend
 from lib.core.common import randomInt
 from lib.core.data import conf
@@ -14,19 +15,31 @@ from lib.core.dicts import FROM_DUMMY_TABLE
 from lib.core.exception import SqlmapNotVulnerableException
 from lib.techniques.dns.use import dnsUse
 
+# 定义dnsTest函数，用于测试通过DNS通道获取数据
+    # 打印日志，表示正在测试通过DNS通道获取数据
+    # 打印信息，表示正在测试通过DNS通道获取数据
 def dnsTest(payload):
     logger.info("testing for data retrieval through DNS channel")
+    # 生成一个随机整数
 
+    # 将kb.dnsTest设置为通过dnsUse函数获取的数据是否等于randInt
     randInt = randomInt()
     kb.dnsTest = dnsUse(payload, "SELECT %d%s" % (randInt, FROM_DUMMY_TABLE.get(Backend.getIdentifiedDbms(), ""))) == str(randInt)
+    # 如果kb.dnsTest为False，表示通过DNS通道获取数据失败
 
+        # 构造错误信息
     if not kb.dnsTest:
+        # 如果没有强制使用DNS通道
         errMsg = "data retrieval through DNS channel failed"
+            # 将conf.dnsDomain设置为None
         if not conf.forceDns:
+            # 构造错误信息
             conf.dnsDomain = None
             errMsg += ". Turning off DNS exfiltration support"
             logger.error(errMsg)
+        # 如果强制使用DNS通道
         else:
+            # 抛出SqlmapNotVulnerableException异常
             raise SqlmapNotVulnerableException(errMsg)
     else:
         infoMsg = "data retrieval through DNS channel was successful"
diff --git a/src/sqlmap-master/lib/techniques/dns/use.py b/src/sqlmap-master/lib/techniques/dns/use.py
index 4592d73..5bf872e 100644
--- a/src/sqlmap-master/lib/techniques/dns/use.py
+++ b/src/sqlmap-master/lib/techniques/dns/use.py
@@ -46,9 +46,12 @@ def dnsUse(payload, expression):
     count = 0
     offset = 1
 
+    # 如果配置了dnsDomain，并且数据库类型为MSSQL、ORACLE、MYSQL、PGSQL
     if conf.dnsDomain and Backend.getIdentifiedDbms() in (DBMS.MSSQL, DBMS.ORACLE, DBMS.MYSQL, DBMS.PGSQL):
+        # 使用hashDBRetrieve函数获取SQL查询的输出
         output = hashDBRetrieve(expression, checkConf=True)
 
+        # 如果输出中包含PARTIAL_VALUE_MARKER，或者kb.dnsTest为None，则将输出置为None
         if output and PARTIAL_VALUE_MARKER in output or kb.dnsTest is None:
             output = None
 
@@ -98,10 +101,15 @@ def dnsUse(payload, expression):
 
             kb.dnsMode = False
 
+        # 如果output不为None
+        # 如果output不为None
         if output is not None:
+            # 将output赋值给retVal
             retVal = output
 
+            # 如果kb.dnsTest不为None
             if kb.dnsTest is not None:
+                # 将output输出到标准输出
                 dataToStdout("[%s] [INFO] %s: %s\n" % (time.strftime("%X"), "retrieved" if count > 0 else "resumed", safecharencode(output)))
 
                 if count > 0: