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 }