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