1 /*
2  * Copyright (C) 2012 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package android.os;
18 
19 import android.util.Slog;
20 
21 import java.io.IOException;
22 import java.io.File;
23 import java.io.FileDescriptor;
24 
25 /**
26  * This class provides access to the centralized jni bindings for
27  * SELinux interaction.
28  * {@hide}
29  */
30 public class SELinux {
31     private static final String TAG = "SELinux";
32 
33     /** Keep in sync with ./external/libselinux/include/selinux/android.h */
34     private static final int SELINUX_ANDROID_RESTORECON_NOCHANGE = 1;
35     private static final int SELINUX_ANDROID_RESTORECON_VERBOSE = 2;
36     private static final int SELINUX_ANDROID_RESTORECON_RECURSE = 4;
37     private static final int SELINUX_ANDROID_RESTORECON_FORCE = 8;
38     private static final int SELINUX_ANDROID_RESTORECON_DATADATA = 16;
39 
40     /**
41      * Determine whether SELinux is disabled or enabled.
42      * @return a boolean indicating whether SELinux is enabled.
43      */
isSELinuxEnabled()44     public static final native boolean isSELinuxEnabled();
45 
46     /**
47      * Determine whether SELinux is permissive or enforcing.
48      * @return a boolean indicating whether SELinux is enforcing.
49      */
isSELinuxEnforced()50     public static final native boolean isSELinuxEnforced();
51 
52     /**
53      * Set whether SELinux is permissive or enforcing.
54      * @param value representing whether to set SELinux to enforcing
55      * @return a boolean representing whether the desired mode was set
56      */
setSELinuxEnforce(boolean value)57     public static final native boolean setSELinuxEnforce(boolean value);
58 
59     /**
60      * Sets the security context for newly created file objects.
61      * @param context a security context given as a String.
62      * @return a boolean indicating whether the operation succeeded.
63      */
setFSCreateContext(String context)64     public static final native boolean setFSCreateContext(String context);
65 
66     /**
67      * Change the security context of an existing file object.
68      * @param path representing the path of file object to relabel.
69      * @param context new security context given as a String.
70      * @return a boolean indicating whether the operation succeeded.
71      */
setFileContext(String path, String context)72     public static final native boolean setFileContext(String path, String context);
73 
74     /**
75      * Get the security context of a file object.
76      * @param path the pathname of the file object.
77      * @return a security context given as a String.
78      */
getFileContext(String path)79     public static final native String getFileContext(String path);
80 
81     /**
82      * Get the security context of a peer socket.
83      * @param fd FileDescriptor class of the peer socket.
84      * @return a String representing the peer socket security context.
85      */
getPeerContext(FileDescriptor fd)86     public static final native String getPeerContext(FileDescriptor fd);
87 
88     /**
89      * Gets the security context of the current process.
90      * @return a String representing the security context of the current process.
91      */
getContext()92     public static final native String getContext();
93 
94     /**
95      * Gets the security context of a given process id.
96      * @param pid an int representing the process id to check.
97      * @return a String representing the security context of the given pid.
98      */
getPidContext(int pid)99     public static final native String getPidContext(int pid);
100 
101     /**
102      * Gets a list of the SELinux boolean names.
103      * @return an array of strings containing the SELinux boolean names.
104      */
getBooleanNames()105     public static final native String[] getBooleanNames();
106 
107     /**
108      * Gets the value for the given SELinux boolean name.
109      * @param name The name of the SELinux boolean.
110      * @return a boolean indicating whether the SELinux boolean is set.
111      */
getBooleanValue(String name)112     public static final native boolean getBooleanValue(String name);
113 
114     /**
115      * Sets the value for the given SELinux boolean name.
116      * @param name The name of the SELinux boolean.
117      * @param value The new value of the SELinux boolean.
118      * @return a boolean indicating whether or not the operation succeeded.
119      */
setBooleanValue(String name, boolean value)120     public static final native boolean setBooleanValue(String name, boolean value);
121 
122     /**
123      * Check permissions between two security contexts.
124      * @param scon The source or subject security context.
125      * @param tcon The target or object security context.
126      * @param tclass The object security class name.
127      * @param perm The permission name.
128      * @return a boolean indicating whether permission was granted.
129      */
checkSELinuxAccess(String scon, String tcon, String tclass, String perm)130     public static final native boolean checkSELinuxAccess(String scon, String tcon, String tclass, String perm);
131 
132     /**
133      * Restores a file to its default SELinux security context.
134      * If the system is not compiled with SELinux, then {@code true}
135      * is automatically returned.
136      * If SELinux is compiled in, but disabled, then {@code true} is
137      * returned.
138      *
139      * @param pathname The pathname of the file to be relabeled.
140      * @return a boolean indicating whether the relabeling succeeded.
141      * @exception NullPointerException if the pathname is a null object.
142      */
restorecon(String pathname)143     public static boolean restorecon(String pathname) throws NullPointerException {
144         if (pathname == null) { throw new NullPointerException(); }
145         return native_restorecon(pathname, 0);
146     }
147 
148     /**
149      * Restores a file to its default SELinux security context.
150      * If the system is not compiled with SELinux, then {@code true}
151      * is automatically returned.
152      * If SELinux is compiled in, but disabled, then {@code true} is
153      * returned.
154      *
155      * @param pathname The pathname of the file to be relabeled.
156      * @return a boolean indicating whether the relabeling succeeded.
157      */
native_restorecon(String pathname, int flags)158     private static native boolean native_restorecon(String pathname, int flags);
159 
160     /**
161      * Restores a file to its default SELinux security context.
162      * If the system is not compiled with SELinux, then {@code true}
163      * is automatically returned.
164      * If SELinux is compiled in, but disabled, then {@code true} is
165      * returned.
166      *
167      * @param file The File object representing the path to be relabeled.
168      * @return a boolean indicating whether the relabeling succeeded.
169      * @exception NullPointerException if the file is a null object.
170      */
restorecon(File file)171     public static boolean restorecon(File file) throws NullPointerException {
172         try {
173             return native_restorecon(file.getCanonicalPath(), 0);
174         } catch (IOException e) {
175             Slog.e(TAG, "Error getting canonical path. Restorecon failed for " +
176                     file.getPath(), e);
177             return false;
178         }
179     }
180 
181     /**
182      * Recursively restores all files under the given path to their default
183      * SELinux security context. If the system is not compiled with SELinux,
184      * then {@code true} is automatically returned. If SELinux is compiled in,
185      * but disabled, then {@code true} is returned.
186      *
187      * @return a boolean indicating whether the relabeling succeeded.
188      */
restoreconRecursive(File file)189     public static boolean restoreconRecursive(File file) {
190         try {
191             return native_restorecon(file.getCanonicalPath(), SELINUX_ANDROID_RESTORECON_RECURSE);
192         } catch (IOException e) {
193             Slog.e(TAG, "Error getting canonical path. Restorecon failed for " +
194                     file.getPath(), e);
195             return false;
196         }
197     }
198 }
199