YARN-9728. Bugfix for escaping illegal xml characters for Resource Manager REST API.

           Contributed by Prabhu Joseph

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/conf/YarnConfiguration.java

@@ -3960,6 +3960,10 @@ public class YarnConfiguration extends Configuration {
   public static final boolean DEFAULT_DISPLAY_APPS_FOR_LOGGED_IN_USER =
       false;
 
+  public static final String FILTER_INVALID_XML_CHARS =
+      "yarn.webapp.filter-invalid-xml-chars";
+  public static final boolean DEFAULT_FILTER_INVALID_XML_CHARS = false;
+
   // RM and NM CSRF props
   public static final String REST_CSRF = "webapp.rest-csrf.";
   public static final String RM_CSRF_PREFIX = RM_PREFIX + REST_CSRF;

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/resources/yarn-default.xml

@@ -3793,6 +3793,15 @@
       </description>
   </property>
 
+  <property>
+    <name>yarn.webapp.filter-invalid-xml-chars</name>
+    <value>false</value>
+    <description>
+      Flag to enable filter of invalid xml 1.0 characters present in the
+      value of diagnostics field of apps output from RM WebService.
+    </description>
+  </property>
+
   <property>
     <description>
       The type of configuration store to use for scheduler configurations.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWebServices.java

@@ -242,6 +242,7 @@ public class RMWebServices extends WebServices implements RMWebServiceProtocol {
   @VisibleForTesting
   boolean isCentralizedNodeLabelConfiguration = true;
   private boolean filterAppsByUser = false;
+  private boolean filterInvalidXMLChars = false;
 
   public final static String DELEGATION_TOKEN_HEADER =
       "Hadoop-YARN-RM-Delegation-Token";
@@ -257,6 +258,9 @@ public class RMWebServices extends WebServices implements RMWebServiceProtocol {
     this.filterAppsByUser  = conf.getBoolean(
         YarnConfiguration.FILTER_ENTITY_LIST_BY_USER,
         YarnConfiguration.DEFAULT_DISPLAY_APPS_FOR_LOGGED_IN_USER);
+    this.filterInvalidXMLChars = conf.getBoolean(
+        YarnConfiguration.FILTER_INVALID_XML_CHARS,
+        YarnConfiguration.DEFAULT_FILTER_INVALID_XML_CHARS);
   }
 
   RMWebServices(ResourceManager rm, Configuration conf,
@@ -551,6 +555,38 @@ public class RMWebServices extends WebServices implements RMWebServiceProtocol {
     return ni;
   }
 
+  /**
+   * This method ensures that the output String has only
+   * valid XML unicode characters as specified by the
+   * XML 1.0 standard. For reference, please see
+   * <a href="http://www.w3.org/TR/2000/REC-xml-20001006#NT-Char">
+   * the standard</a>.
+   *
+   * @param str The String whose invalid xml characters we want to escape.
+   * @return The str String after escaping invalid xml characters.
+   */
+  public static String escapeInvalidXMLCharacters(String str) {
+    StringBuffer out = new StringBuffer();
+    final int strlen = str.length();
+    final String substitute = "\uFFFD";
+    int idx = 0;
+    while (idx < strlen) {
+      final int cpt = str.codePointAt(idx);
+      idx += Character.isSupplementaryCodePoint(cpt) ? 2 : 1;
+      if ((cpt == 0x9) ||
+          (cpt == 0xA) ||
+          (cpt == 0xD) ||
+          ((cpt >= 0x20) && (cpt <= 0xD7FF)) ||
+          ((cpt >= 0xE000) && (cpt <= 0xFFFD)) ||
+          ((cpt >= 0x10000) && (cpt <= 0x10FFFF))) {
+        out.append(Character.toChars(cpt));
+      } else {
+        out.append(substitute);
+      }
+    }
+    return out.toString();
+  }
+
   @GET
   @Path(RMWSConsts.APPS)
   @Produces({ MediaType.APPLICATION_JSON + "; " + JettyUtils.UTF_8,
@@ -629,6 +665,17 @@ public class RMWebServices extends WebServices implements RMWebServiceProtocol {
           WebAppUtils.getHttpSchemePrefix(conf), deSelectFields);
       allApps.add(app);
     }
+
+    if (filterInvalidXMLChars) {
+      final String format = hsr.getHeader(HttpHeaders.ACCEPT);
+      if (format != null &&
+          format.toLowerCase().contains(MediaType.APPLICATION_XML)) {
+        for (AppInfo appInfo : allApps.getApps()) {
+          appInfo.setNote(escapeInvalidXMLCharacters(appInfo.getNote()));
+        }
+      }
+    }
+
     return allApps;
   }
 
@@ -985,8 +1032,18 @@ public class RMWebServices extends WebServices implements RMWebServiceProtocol {
     DeSelectFields deSelectFields = new DeSelectFields();
     deSelectFields.initFields(unselectedFields);
 
-    return new AppInfo(rm, app, hasAccess(app, hsr), hsr.getScheme() + "://",
-        deSelectFields);
+    AppInfo appInfo =  new AppInfo(rm, app, hasAccess(app, hsr),
+        hsr.getScheme() + "://", deSelectFields);
+
+    if (filterInvalidXMLChars) {
+      final String format = hsr.getHeader(HttpHeaders.ACCEPT);
+      if (format != null &&
+          format.toLowerCase().contains(MediaType.APPLICATION_XML)) {
+        appInfo.setNote(escapeInvalidXMLCharacters(appInfo.getNote()));
+      }
+    }
+
+    return appInfo;
   }
 
   @GET

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/dao/AppInfo.java

@@ -390,6 +390,10 @@ public class AppInfo {
     return this.diagnostics;
   }
 
+  public void setNote(String diagnosticsMsg) {
+    this.diagnostics = diagnosticsMsg;
+  }
+
   public FinalApplicationStatus getFinalStatus() {
     return this.finalStatus;
   }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/TestRMWebServices.java

@@ -22,6 +22,7 @@ import static org.apache.hadoop.yarn.webapp.WebServicesTestUtils.assertResponseS
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.isA;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
@@ -30,11 +31,17 @@ import java.io.File;
 import java.io.StringReader;
 import java.security.Principal;
 import java.util.Arrays;
+import java.util.ArrayList;
 import java.util.Collections;
+import java.util.List;
 import java.util.Set;
+import java.util.HashMap;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
 
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
+import javax.ws.rs.core.HttpHeaders;
 import javax.ws.rs.core.MediaType;
 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
@@ -49,12 +56,21 @@ import org.apache.hadoop.util.VersionInfo;
 import org.apache.hadoop.yarn.api.protocolrecords.GetApplicationsRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.GetApplicationsResponse;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
+import org.apache.hadoop.yarn.api.records.ApplicationAttemptId;
+import org.apache.hadoop.yarn.api.records.ApplicationSubmissionContext;
 import org.apache.hadoop.yarn.api.records.ApplicationReport;
+import org.apache.hadoop.yarn.api.records.FinalApplicationStatus;
+import org.apache.hadoop.yarn.api.records.Priority;
 import org.apache.hadoop.yarn.api.records.QueueACL;
 import org.apache.hadoop.yarn.api.records.QueueState;
+import org.apache.hadoop.yarn.api.records.Resource;
+import org.apache.hadoop.yarn.api.records.YarnApplicationState;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
+import org.apache.hadoop.yarn.event.Dispatcher;
 import org.apache.hadoop.yarn.server.resourcemanager.*;
 import org.apache.hadoop.yarn.server.resourcemanager.nodelabels.RMNodeLabelsManager;
+import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMApp;
+import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMAppMetrics;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.QueueMetrics;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceScheduler;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler;
@@ -870,6 +886,72 @@ public class TestRMWebServices extends JerseyTestBase {
     verifyClusterUserInfo(userInfo, "yarn", "admin");
   }
 
+  @Test
+  public void testInvalidXMLChars() throws Exception {
+    ResourceManager mockRM = mock(ResourceManager.class);
+
+    ApplicationId applicationId = ApplicationId.newInstance(1234, 5);
+    ApplicationReport appReport = ApplicationReport.newInstance(
+        applicationId, ApplicationAttemptId.newInstance(applicationId, 1),
+        "user", "queue", "appname", "host", 124, null,
+        YarnApplicationState.FAILED, "java.lang.Exception: \u0001", "url",
+        0, 0, 0, FinalApplicationStatus.FAILED, null, "N/A", 0.53789f, "YARN",
+        null, null, false, Priority.newInstance(0), "high-mem", "high-mem");
+    List<ApplicationReport> appReports = new ArrayList<ApplicationReport>();
+    appReports.add(appReport);
+
+    GetApplicationsResponse response = mock(GetApplicationsResponse.class);
+    when(response.getApplicationList()).thenReturn(appReports);
+    ClientRMService clientRMService = mock(ClientRMService.class);
+    when(clientRMService.getApplications(any(GetApplicationsRequest.class)))
+        .thenReturn(response);
+    when(mockRM.getClientRMService()).thenReturn(clientRMService);
+
+    RMContext rmContext = mock(RMContext.class);
+    when(rmContext.getDispatcher()).thenReturn(mock(Dispatcher.class));
+
+    ApplicationSubmissionContext applicationSubmissionContext = mock(
+        ApplicationSubmissionContext.class);
+    when(applicationSubmissionContext.getUnmanagedAM()).thenReturn(true);
+
+    RMApp app = mock(RMApp.class);
+    RMAppMetrics appMetrics = new RMAppMetrics(Resource.newInstance(0, 0),
+        0, 0, new HashMap<>(), new HashMap<>());
+    when(app.getDiagnostics()).thenReturn(
+        new StringBuilder("java.lang.Exception: \u0001"));
+    when(app.getApplicationId()).thenReturn(applicationId);
+    when(app.getUser()).thenReturn("user");
+    when(app.getName()).thenReturn("appname");
+    when(app.getQueue()).thenReturn("queue");
+    when(app.getRMAppMetrics()).thenReturn(appMetrics);
+    when(app.getApplicationSubmissionContext()).thenReturn(
+        applicationSubmissionContext);
+
+    ConcurrentMap<ApplicationId, RMApp> applications =
+        new ConcurrentHashMap<>();
+    applications.put(applicationId, app);
+
+    when(rmContext.getRMApps()).thenReturn(applications);
+    when(mockRM.getRMContext()).thenReturn(rmContext);
+
+    Configuration conf = new YarnConfiguration();
+    conf.setBoolean(YarnConfiguration.FILTER_INVALID_XML_CHARS, true);
+    RMWebServices webSvc = new RMWebServices(mockRM, conf, mock(
+        HttpServletResponse.class));
+
+    HttpServletRequest mockHsr = mock(HttpServletRequest.class);
+    when(mockHsr.getHeader(HttpHeaders.ACCEPT)).
+         thenReturn(MediaType.APPLICATION_XML);
+    Set<String> emptySet = Collections.unmodifiableSet(Collections.emptySet());
+
+    AppsInfo appsInfo = webSvc.getApps(mockHsr, null, emptySet, null,
+        null, null, null, null, null, null, null, emptySet, emptySet, null);
+
+    assertEquals("Incorrect Number of Apps", 1, appsInfo.getApps().size());
+    assertEquals("Invalid XML Characters Present",
+        "java.lang.Exception: \uFFFD", appsInfo.getApps().get(0).getNote());
+  }
+
   public void verifyClusterUserInfo(ClusterUserInfo userInfo,
             String rmLoginUser, String requestedUser) {
     assertEquals("rmLoginUser doesn't match: ",