8274205: Handle KDC_ERR_SVC_UNAVAILABLE error code from KDC

jdk/src/share/classes/sun/security/krb5/KdcComm.java

@@ -257,9 +257,14 @@ private byte[] sendIfPossible(byte[] obuf, String tempKdc, boolean useTCP)
             } catch (Exception e) {
                 // OK
             }
-            if (ke != null && ke.getErrorCode() ==
+            if (ke != null) {
+                if (ke.getErrorCode() ==
                     Krb5.KRB_ERR_RESPONSE_TOO_BIG) {
-                ibuf = send(obuf, tempKdc, true);
+                    ibuf = send(obuf, tempKdc, true);
+                } else if (ke.getErrorCode() ==
+                        Krb5.KDC_ERR_SVC_UNAVAILABLE) {
+                    throw new KrbException("A service is not available");
+                }
             }
             KdcAccessibility.removeBad(tempKdc);
             return ibuf;

jdk/src/share/classes/sun/security/krb5/internal/Krb5.java

@@ -248,6 +248,7 @@ public class Krb5 {
     public static final int KDC_ERR_KEY_EXPIRED          = 23;   //Password has expired - change password to reset
     public static final int KDC_ERR_PREAUTH_FAILED       = 24;   //Pre-authentication information was invalid
     public static final int KDC_ERR_PREAUTH_REQUIRED     = 25;   //Additional pre-authentication required
+    public static final int KDC_ERR_SVC_UNAVAILABLE      = 29;   //A service is not available
     public static final int KRB_AP_ERR_BAD_INTEGRITY     = 31;   //Integrity check on decrypted field failed
     public static final int KRB_AP_ERR_TKT_EXPIRED       = 32;   //Ticket expired
     public static final int KRB_AP_ERR_TKT_NYV           = 33;   //Ticket not yet valid

jdk/test/sun/security/krb5/auto/TestHosts

@@ -0,0 +1,16 @@
+127.0.0.1 host.rabbit.hole
+127.0.0.1 kdc.rabbit.hole
+127.0.0.1 kdc.snake.hole
+127.0.0.1 kdc.web.domain
+127.0.0.1 host.web.domain
+127.0.0.1 host.proxy.domain
+127.0.0.1 kdc.proxy.domain
+127.0.0.1 client.rabbit.hole
+127.0.0.1 localhost
+127.0.0.1 host.r3.local
+127.0.0.1 kdc.r1
+127.0.0.1 kdc.r2
+127.0.0.1 kdc.r3
+127.0.0.1 host.realm
+127.0.0.1 realm
+127.0.0.1 irlga09

jdk/test/sun/security/krb5/auto/Unavailable.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8274205
+ * @summary Handle KDC_ERR_SVC_UNAVAILABLE error code from KDC
+ * @library /test/lib
+ * @compile -XDignore.symbol.file Unavailable.java
+ * @run main/othervm -Dsun.net.spi.nameservice.provider.1=ns,mock -Djdk.net.hosts.file=TestHosts Unavailable
+ */
+
+import sun.security.krb5.Config;
+import sun.security.krb5.PrincipalName;
+import sun.security.krb5.internal.KRBError;
+import sun.security.krb5.internal.KerberosTime;
+
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.Locale;
+
+public class Unavailable {
+
+    public static void main(String[] args) throws Exception {
+
+        // Good KDC
+        KDC kdc1 = KDC.create(OneKDC.REALM);
+        kdc1.addPrincipal(OneKDC.USER, OneKDC.PASS);
+        kdc1.addPrincipalRandKey("krbtgt/" + OneKDC.REALM);
+
+        // The "not available" KDC
+        KDC kdc2 = new KDC(OneKDC.REALM, "kdc." + OneKDC.REALM.toLowerCase(Locale.US), 0, true) {
+            @Override
+            protected byte[] processAsReq(byte[] in) throws Exception {
+                KRBError err = new KRBError(null, null, null,
+                        KerberosTime.now(), 0,
+                        29, // KDC_ERR_SVC_UNAVAILABLE
+                        null, new PrincipalName("krbtgt/" + OneKDC.REALM),
+                        null, null);
+                return err.asn1Encode();
+            }
+        };
+
+        Files.write(Paths.get(OneKDC.KRB5_CONF), String.format(
+                "[libdefaults]\n" +
+                "default_realm = RABBIT.HOLE\n" +
+                "\n" +
+                "[realms]\n" +
+                "RABBIT.HOLE = {\n" +
+                "    kdc = kdc.rabbit.hole:%d\n" +
+                "    kdc = kdc.rabbit.hole:%d\n" +
+                "}\n",
+                kdc2.getPort(), kdc1.getPort()).getBytes());
+        System.setProperty("java.security.krb5.conf", OneKDC.KRB5_CONF);
+        Config.refresh();
+
+        Context.fromUserPass(OneKDC.USER, OneKDC.PASS, false);
+    }
+}