1 /*
   2  * Copyright (c) 2001, 2018, 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 #include "java_util_prefs_FileSystemPreferences.h"
  38 
  39 /*
  40  * Declare library specific JNI_Onload entry if static build
  41  */
  42 DEF_STATIC_JNI_OnLoad
  43 
  44 JNIEXPORT jint JNICALL
  45 Java_java_util_prefs_FileSystemPreferences_chmod(JNIEnv *env,
  46                        jclass thisclass, jstring java_fname, jint permission) {
  47     const char *fname = JNU_GetStringPlatformChars(env, java_fname, NULL);
  48     int result = -1;
  49     if (fname) {
  50         result =  chmod(fname, permission);
  51         if (result != 0)
  52             result = errno;
  53         JNU_ReleaseStringPlatformChars(env, java_fname, fname);
  54     }
  55     return (jint) result;
  56 }
  57 
  58 #if defined(_ALLBSD_SOURCE)
  59 typedef struct flock FLOCK;
  60 #else
  61 typedef struct flock64 FLOCK;
  62 #endif
  63 
  64 /**
  65  * Try to open a named lock file.
  66  * The result is a cookie that can be used later to unlock the file.
  67  * On failure the result is zero.
  68  */
  69 JNIEXPORT jintArray JNICALL
  70 Java_java_util_prefs_FileSystemPreferences_lockFile0(JNIEnv *env,
  71     jclass thisclass, jstring java_fname, jint permission, jboolean shared) {
  72     const char *fname = JNU_GetStringPlatformChars(env, java_fname, NULL);
  73     int fd, rc;
  74     int result[2];
  75     jintArray javaResult = NULL;
  76     int old_umask;
  77     FLOCK fl;
  78 
  79     if (!fname)
  80         return javaResult;
  81 
  82     fl.l_whence = SEEK_SET;
  83     fl.l_len = 0;
  84     fl.l_start = 0;
  85     if (shared == JNI_TRUE) {
  86         fl.l_type = F_RDLCK;
  87     } else {
  88         fl.l_type = F_WRLCK;
  89     }
  90 
  91     if (shared == JNI_TRUE) {
  92         fd = open(fname, O_RDONLY, 0);
  93     } else {
  94         old_umask = umask(0);
  95         fd = open(fname, O_WRONLY|O_CREAT, permission);
  96         result[1] = errno;
  97         umask(old_umask);
  98     }
  99 
 100     if (fd < 0) {
 101         result[0] = 0;
 102     } else {
 103 #if defined(_ALLBSD_SOURCE)
 104         rc = fcntl(fd, F_SETLK, &fl);
 105 #else
 106         rc = fcntl(fd, F_SETLK64, &fl);
 107 #endif
 108         result[1] = errno;
 109         if (rc < 0) {
 110             result[0]= 0;
 111             close(fd);
 112         } else {
 113           result[0] = fd;
 114         }
 115     }
 116     JNU_ReleaseStringPlatformChars(env, java_fname, fname);
 117     javaResult = (*env)->NewIntArray(env,2);
 118     if (javaResult)
 119         (*env)->SetIntArrayRegion(env, javaResult, 0, 2, result);
 120     return javaResult;
 121 }
 122 
 123 
 124 /**
 125  * Try to unlock a lock file, using a cookie returned by lockFile.
 126  */
 127 JNIEXPORT jint JNICALL
 128 Java_java_util_prefs_FileSystemPreferences_unlockFile0(JNIEnv *env,
 129                                       jclass thisclass, jint fd) {
 130 
 131     int rc;
 132     FLOCK fl;
 133     fl.l_whence = SEEK_SET;
 134     fl.l_len = 0;
 135     fl.l_start = 0;
 136     fl.l_type = F_UNLCK;
 137 
 138 #if defined(_ALLBSD_SOURCE)
 139     rc = fcntl(fd, F_SETLK, &fl);
 140 #else
 141     rc = fcntl(fd, F_SETLK64, &fl);
 142 #endif
 143 
 144     if (rc < 0) {
 145         close(fd);
 146         return (jint)errno;
 147     }
 148     rc = close(fd);
 149     if (rc < 0) {
 150         return (jint) errno;
 151     }
 152     return 0;
 153 }