1 /*
   2  * Copyright (c) 2001, 2015, 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 /*
  27  * Solaris/Linux platform specific code to support the Prefs API.
  28  */
  29 
  30 #include <unistd.h>
  31 #include <sys/types.h>
  32 #include <sys/stat.h>
  33 #include <fcntl.h>
  34 #include <errno.h>
  35 #include <utime.h>
  36 #include "jni_util.h"
  37 
  38 /*
  39  * Declare library specific JNI_Onload entry if static build
  40  */
  41 DEF_STATIC_JNI_OnLoad
  42 
  43 JNIEXPORT jint JNICALL
  44 Java_java_util_prefs_FileSystemPreferences_chmod(JNIEnv *env,
  45                        jclass thisclass, jstring java_fname, jint permission) {
  46     const char *fname = JNU_GetStringPlatformChars(env, java_fname, NULL);
  47     int result = -1;
  48     if (fname) {
  49         result =  chmod(fname, permission);
  50         if (result != 0)
  51             result = errno;
  52         JNU_ReleaseStringPlatformChars(env, java_fname, fname);
  53     }
  54     return (jint) result;
  55 }
  56 
  57 #if defined(_ALLBSD_SOURCE)
  58 typedef struct flock FLOCK;
  59 #else
  60 typedef struct flock64 FLOCK;
  61 #endif
  62 
  63 /**
  64  * Try to open a named lock file.
  65  * The result is a cookie that can be used later to unlock the file.
  66  * On failure the result is zero.
  67  */
  68 JNIEXPORT jintArray JNICALL
  69 Java_java_util_prefs_FileSystemPreferences_lockFile0(JNIEnv *env,
  70     jclass thisclass, jstring java_fname, jint permission, jboolean shared) {
  71     const char *fname = JNU_GetStringPlatformChars(env, java_fname, NULL);
  72     int fd, rc;
  73     int result[2];
  74     jintArray javaResult = NULL;
  75     int old_umask;
  76     FLOCK fl;
  77 
  78     if (!fname)
  79         return javaResult;
  80 
  81     fl.l_whence = SEEK_SET;
  82     fl.l_len = 0;
  83     fl.l_start = 0;
  84     if (shared == JNI_TRUE) {
  85         fl.l_type = F_RDLCK;
  86     } else {
  87         fl.l_type = F_WRLCK;
  88     }
  89 
  90     if (shared == JNI_TRUE) {
  91         fd = open(fname, O_RDONLY, 0);
  92     } else {
  93         old_umask = umask(0);
  94         fd = open(fname, O_WRONLY|O_CREAT, permission);
  95         result[1] = errno;
  96         umask(old_umask);
  97     }
  98 
  99     if (fd < 0) {
 100         result[0] = 0;
 101     } else {
 102 #if defined(_ALLBSD_SOURCE)
 103         rc = fcntl(fd, F_SETLK, &fl);
 104 #else
 105         rc = fcntl(fd, F_SETLK64, &fl);
 106 #endif
 107         result[1] = errno;
 108         if (rc < 0) {
 109             result[0]= 0;
 110             close(fd);
 111         } else {
 112           result[0] = fd;
 113         }
 114     }
 115     JNU_ReleaseStringPlatformChars(env, java_fname, fname);
 116     javaResult = (*env)->NewIntArray(env,2);
 117     if (javaResult)
 118         (*env)->SetIntArrayRegion(env, javaResult, 0, 2, result);
 119     return javaResult;
 120 }
 121 
 122 
 123 /**
 124  * Try to unlock a lock file, using a cookie returned by lockFile.
 125  */
 126 JNIEXPORT jint JNICALL
 127 Java_java_util_prefs_FileSystemPreferences_unlockFile0(JNIEnv *env,
 128                                       jclass thisclass, jint fd) {
 129 
 130     int rc;
 131     FLOCK fl;
 132     fl.l_whence = SEEK_SET;
 133     fl.l_len = 0;
 134     fl.l_start = 0;
 135     fl.l_type = F_UNLCK;
 136 
 137 #if defined(_ALLBSD_SOURCE)
 138     rc = fcntl(fd, F_SETLK, &fl);
 139 #else
 140     rc = fcntl(fd, F_SETLK64, &fl);
 141 #endif
 142 
 143     if (rc < 0) {
 144         close(fd);
 145         return (jint)errno;
 146     }
 147     rc = close(fd);
 148     if (rc < 0) {
 149         return (jint) errno;
 150     }
 151     return 0;
 152 }