1 /*
2  * Copyright (c) 2001, 2004, 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 #include <nativehelper/JNIHelp.h>
39 
40 #define NATIVE_METHOD(className, functionName, signature) \
41 { #functionName, signature, (void*)(Java_java_util_prefs_ ## className ## _ ## functionName) }
42 
43 JNIEXPORT jint JNICALL
Java_java_util_prefs_FileSystemPreferences_chmod(JNIEnv * env,jclass thisclass,jstring java_fname,jint permission)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, JNI_FALSE);
47     int result;
48     result =  chmod(fname, permission);
49     if (result != 0)
50        result = errno;
51     JNU_ReleaseStringPlatformChars(env, java_fname, fname);
52     return (jint) result;
53 }
54 
55 // Android-changed: Fuchsia: Alias *64 on Fuchsia builds. http://b/119496969
56 // #if defined(_ALLBSD_SOURCE)
57 #if defined(_ALLBSD_SOURCE) || defined(__Fuchsia__)
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
Java_java_util_prefs_FileSystemPreferences_lockFile0(JNIEnv * env,jclass thisclass,jstring java_fname,jint permission,jboolean shared)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, JNI_FALSE);
72     int fd, rc;
73     int result[2];
74     jintArray javaResult;
75     int old_umask;
76     FLOCK fl;
77 
78     fl.l_whence = SEEK_SET;
79     fl.l_len = 0;
80     fl.l_start = 0;
81     if (shared == JNI_TRUE) {
82         fl.l_type = F_RDLCK;
83     } else {
84         fl.l_type = F_WRLCK;
85     }
86 
87     if (shared == JNI_TRUE) {
88         fd = open(fname, O_RDONLY, 0);
89     } else {
90         old_umask = umask(0);
91         fd = open(fname, O_WRONLY|O_CREAT, permission);
92         result[1] = errno;
93         umask(old_umask);
94     }
95 
96     if (fd < 0) {
97         result[0] = 0;
98     } else {
99 // Android-changed: Fuchsia: Alias *64 on Fuchsia builds. http://b/119496969
100 // #if defined(_ALLBSD_SOURCE)
101 #if defined(_ALLBSD_SOURCE) || defined(__Fuchsia__)
102         rc = fcntl(fd, F_SETLK, &fl);
103 #else
104         rc = fcntl(fd, F_SETLK64, &fl);
105 #endif
106         result[1] = errno;
107         if (rc < 0) {
108             result[0]= 0;
109             close(fd);
110         } else {
111           result[0] = fd;
112         }
113     }
114     JNU_ReleaseStringPlatformChars(env, java_fname, fname);
115     javaResult = (*env)->NewIntArray(env,2);
116     (*env)->SetIntArrayRegion(env, javaResult, 0, 2, result);
117     return javaResult;
118 }
119 
120 
121 /**
122  * Try to unlock a lock file, using a cookie returned by lockFile.
123  */
124 JNIEXPORT jint JNICALL
Java_java_util_prefs_FileSystemPreferences_unlockFile0(JNIEnv * env,jclass thisclass,jint fd)125 Java_java_util_prefs_FileSystemPreferences_unlockFile0(JNIEnv *env,
126                                       jclass thisclass, jint fd) {
127 
128     int rc;
129     FLOCK fl;
130     fl.l_whence = SEEK_SET;
131     fl.l_len = 0;
132     fl.l_start = 0;
133     fl.l_type = F_UNLCK;
134 // Android-changed: Fuchsia: Alias *64 on Fuchsia builds. http://b/119496969
135 // #if defined(_ALLBSD_SOURCE)
136 #if defined(_ALLBSD_SOURCE) || defined(__Fuchsia__)
137     rc = fcntl(fd, F_SETLK, &fl);
138 #else
139     rc = fcntl(fd, F_SETLK64, &fl);
140 #endif
141 
142     if (rc < 0) {
143         close(fd);
144         return (jint)errno;
145     }
146     rc = close(fd);
147     if (rc < 0) {
148         return (jint) errno;
149     }
150     return 0;
151 }
152 
153 static JNINativeMethod gMethods[] = {
154     NATIVE_METHOD(FileSystemPreferences, lockFile0, "(Ljava/lang/String;IZ)[I"),
155     NATIVE_METHOD(FileSystemPreferences, unlockFile0, "(I)I"),
156     NATIVE_METHOD(FileSystemPreferences, chmod, "(Ljava/lang/String;I)I"),
157 };
158 
register_java_util_prefs_FileSystemPreferences(JNIEnv * env)159 void register_java_util_prefs_FileSystemPreferences(JNIEnv* env) {
160     jniRegisterNativeMethods(env, "java/util/prefs/FileSystemPreferences", gMethods, NELEM(gMethods));
161 }
162