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 #ifdef __solaris__
  32 #include <sys/systeminfo.h>
  33 #include <strings.h>
  34 #endif
  35 
  36 #if defined(__linux__) || defined(_ALLBSD_SOURCE)
  37 #include <string.h>
  38 #endif
  39 
  40 #include "jni.h"
  41 
  42 #ifndef MAXDNAME
  43 #define MAXDNAME                1025
  44 #endif
  45 
  46 
  47 /*
  48  * Class:     sun_net_dns_ResolverConfgurationImpl
  49  * Method:    localDomain0
  50  * Signature: ()Ljava/lang/String;
  51  */
  52 JNIEXPORT jstring JNICALL
  53 Java_sun_net_dns_ResolverConfigurationImpl_localDomain0(JNIEnv *env, jclass cls)
  54 {
  55     /*
  56      * On Solaris the LOCALDOMAIN environment variable has absolute
  57      * priority.
  58      */
  59 #ifdef __solaris__
  60     {
  61         char *cp = getenv("LOCALDOMAIN");
  62         if (cp != NULL) {
  63             jstring s = (*env)->NewStringUTF(env, cp);
  64             return s;
  65         }
  66     }
  67 #endif
  68     return (jstring)NULL;
  69 }
  70 
  71 /*
  72  * Class:     sun_net_dns_ResolverConfgurationImpl
  73  * Method:    loadConfig0
  74  * Signature: ()Ljava/lang/String;
  75  */
  76 JNIEXPORT jstring JNICALL
  77 Java_sun_net_dns_ResolverConfigurationImpl_fallbackDomain0(JNIEnv *env, jclass cls)
  78 {
  79     char buf[MAXDNAME];
  80 
  81     /*
  82      * On Solaris if domain or search directives aren't specified
  83      * in /etc/resolv.conf then sysinfo or gethostname is used to
  84      * determine the domain name.
  85      *
  86      * On Linux if domain or search directives aren't specified
  87      * then gethostname is used.
  88      */
  89 
  90 #ifdef __solaris__
  91     {
  92         int ret = sysinfo(SI_SRPC_DOMAIN, buf, sizeof(buf));
  93 
  94         if ((ret > 0) && (ret<sizeof(buf))) {
  95             char *cp;
  96             jstring s;
  97 
  98             if (buf[0] == '+') {
  99                 buf[0] = '.';
 100             }
 101             cp = strchr(buf, '.');
 102             if (cp == NULL) {
 103                 s = (*env)->NewStringUTF(env, buf);
 104             } else {
 105                 s = (*env)->NewStringUTF(env, cp+1);
 106             }
 107             return s;
 108         }
 109     }
 110 #endif
 111 
 112     if (gethostname(buf, sizeof(buf)) == 0) {
 113         char *cp;
 114 
 115         /* gethostname doesn't null terminate if insufficient space */
 116         buf[sizeof(buf)-1] = '\0';
 117 
 118         cp = strchr(buf, '.');
 119         if (cp != NULL) {
 120             jstring s = (*env)->NewStringUTF(env, cp+1);
 121             return s;
 122         }
 123     }
 124 
 125     return (jstring)NULL;
 126 }