1 /*
   2  * Copyright (c) 2002, 2012, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <unistd.h>
  29 #include <errno.h>
  30 
  31 #include <string.h>
  32 
  33 #include "jni.h"
  34 
  35 #ifndef MAXDNAME
  36 #define MAXDNAME                1025
  37 #endif
  38 
  39 
  40 /*
  41  * Class:     sun_net_dns_ResolverConfigurationImpl
  42  * Method:    loadConfig0
  43  * Signature: ()Ljava/lang/String;
  44  */
  45 JNIEXPORT jstring JNICALL
  46 Java_sun_net_dns_ResolverConfigurationImpl_fallbackDomain0(JNIEnv *env, jclass cls)
  47 {
  48     char buf[MAXDNAME];
  49 
  50     /*
  51      * If domain or search directives aren't specified
  52      * then gethostname is used.
  53      */
  54 
  55     if (gethostname(buf, sizeof(buf)) == 0) {
  56         char *cp;
  57 
  58         /* gethostname doesn't null terminate if insufficient space */
  59         buf[sizeof(buf)-1] = '\0';
  60 
  61         cp = strchr(buf, '.');
  62         if (cp != NULL) {
  63             jstring s = (*env)->NewStringUTF(env, cp+1);
  64             return s;
  65         }
  66     }
  67 
  68     return (jstring)NULL;
  69 }