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.annotation.UnsupportedAppUsage; 20 import android.util.Slog; 21 22 import java.io.File; 23 import java.io.FileDescriptor; 24 import java.io.IOException; 25 26 /** 27 * This class provides access to the centralized jni bindings for 28 * SELinux interaction. 29 * {@hide} 30 */ 31 public class SELinux { 32 private static final String TAG = "SELinux"; 33 34 /** Keep in sync with ./external/selinux/libselinux/include/selinux/android.h */ 35 private static final int SELINUX_ANDROID_RESTORECON_NOCHANGE = 1; 36 private static final int SELINUX_ANDROID_RESTORECON_VERBOSE = 2; 37 private static final int SELINUX_ANDROID_RESTORECON_RECURSE = 4; 38 private static final int SELINUX_ANDROID_RESTORECON_FORCE = 8; 39 private static final int SELINUX_ANDROID_RESTORECON_DATADATA = 16; 40 private static final int SELINUX_ANDROID_RESTORECON_SKIPCE = 32; 41 private static final int SELINUX_ANDROID_RESTORECON_CROSS_FILESYSTEMS = 64; 42 private static final int SELINUX_ANDROID_RESTORECON_SKIP_SEHASH = 128; 43 44 /** 45 * Get context associated with path by file_contexts. 46 * @param path path to the regular file to get the security context for. 47 * @return a String representing the security context or null on failure. 48 */ fileSelabelLookup(String path)49 public static final native String fileSelabelLookup(String path); 50 51 /** 52 * Determine whether SELinux is disabled or enabled. 53 * @return a boolean indicating whether SELinux is enabled. 54 */ 55 @UnsupportedAppUsage isSELinuxEnabled()56 public static final native boolean isSELinuxEnabled(); 57 58 /** 59 * Determine whether SELinux is permissive or enforcing. 60 * @return a boolean indicating whether SELinux is enforcing. 61 */ 62 @UnsupportedAppUsage isSELinuxEnforced()63 public static final native boolean isSELinuxEnforced(); 64 65 /** 66 * Sets the security context for newly created file objects. 67 * @param context a security context given as a String. 68 * @return a boolean indicating whether the operation succeeded. 69 */ setFSCreateContext(String context)70 public static final native boolean setFSCreateContext(String context); 71 72 /** 73 * Change the security context of an existing file object. 74 * @param path representing the path of file object to relabel. 75 * @param context new security context given as a String. 76 * @return a boolean indicating whether the operation succeeded. 77 */ setFileContext(String path, String context)78 public static final native boolean setFileContext(String path, String context); 79 80 /** 81 * Get the security context of a file object. 82 * @param path the pathname of the file object. 83 * @return a security context given as a String. 84 */ 85 @UnsupportedAppUsage getFileContext(String path)86 public static final native String getFileContext(String path); 87 88 /** 89 * Get the security context of a peer socket. 90 * @param fd FileDescriptor class of the peer socket. 91 * @return a String representing the peer socket security context. 92 */ getPeerContext(FileDescriptor fd)93 public static final native String getPeerContext(FileDescriptor fd); 94 95 /** 96 * Get the security context of a file descriptor of a file. 97 * @param fd FileDescriptor of a file. 98 * @return a String representing the file descriptor security context. 99 */ getFileContext(FileDescriptor fd)100 public static final native String getFileContext(FileDescriptor fd); 101 102 /** 103 * Gets the security context of the current process. 104 * @return a String representing the security context of the current process. 105 */ 106 @UnsupportedAppUsage getContext()107 public static final native String getContext(); 108 109 /** 110 * Gets the security context of a given process id. 111 * @param pid an int representing the process id to check. 112 * @return a String representing the security context of the given pid. 113 */ 114 @UnsupportedAppUsage getPidContext(int pid)115 public static final native String getPidContext(int pid); 116 117 /** 118 * Check permissions between two security contexts. 119 * @param scon The source or subject security context. 120 * @param tcon The target or object security context. 121 * @param tclass The object security class name. 122 * @param perm The permission name. 123 * @return a boolean indicating whether permission was granted. 124 */ 125 @UnsupportedAppUsage checkSELinuxAccess(String scon, String tcon, String tclass, String perm)126 public static final native boolean checkSELinuxAccess(String scon, String tcon, String tclass, String perm); 127 128 /** 129 * Restores a file to its default SELinux security context. 130 * If the system is not compiled with SELinux, then {@code true} 131 * is automatically returned. 132 * If SELinux is compiled in, but disabled, then {@code true} is 133 * returned. 134 * 135 * @param pathname The pathname of the file to be relabeled. 136 * @return a boolean indicating whether the relabeling succeeded. 137 * @exception NullPointerException if the pathname is a null object. 138 */ restorecon(String pathname)139 public static boolean restorecon(String pathname) throws NullPointerException { 140 if (pathname == null) { throw new NullPointerException(); } 141 return native_restorecon(pathname, 0); 142 } 143 144 /** 145 * Restores a file to its default SELinux security context. 146 * If the system is not compiled with SELinux, then {@code true} 147 * is automatically returned. 148 * If SELinux is compiled in, but disabled, then {@code true} is 149 * returned. 150 * 151 * @param pathname The pathname of the file to be relabeled. 152 * @return a boolean indicating whether the relabeling succeeded. 153 */ native_restorecon(String pathname, int flags)154 private static native boolean native_restorecon(String pathname, int flags); 155 156 /** 157 * Restores a file to its default SELinux security context. 158 * If the system is not compiled with SELinux, then {@code true} 159 * is automatically returned. 160 * If SELinux is compiled in, but disabled, then {@code true} is 161 * returned. 162 * 163 * @param file The File object representing the path to be relabeled. 164 * @return a boolean indicating whether the relabeling succeeded. 165 * @exception NullPointerException if the file is a null object. 166 */ restorecon(File file)167 public static boolean restorecon(File file) throws NullPointerException { 168 try { 169 return native_restorecon(file.getCanonicalPath(), 0); 170 } catch (IOException e) { 171 Slog.e(TAG, "Error getting canonical path. Restorecon failed for " + 172 file.getPath(), e); 173 return false; 174 } 175 } 176 177 /** 178 * Recursively restores all files under the given path to their default 179 * SELinux security context. If the system is not compiled with SELinux, 180 * then {@code true} is automatically returned. If SELinux is compiled in, 181 * but disabled, then {@code true} is returned. 182 * 183 * @return a boolean indicating whether the relabeling succeeded. 184 */ 185 @UnsupportedAppUsage restoreconRecursive(File file)186 public static boolean restoreconRecursive(File file) { 187 try { 188 return native_restorecon(file.getCanonicalPath(), 189 SELINUX_ANDROID_RESTORECON_RECURSE | SELINUX_ANDROID_RESTORECON_SKIP_SEHASH); 190 } catch (IOException e) { 191 Slog.e(TAG, "Error getting canonical path. Restorecon failed for " + 192 file.getPath(), e); 193 return false; 194 } 195 } 196 } 197