1 /*
2  * Copyright (C) 2010 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 #include <android_runtime/AndroidRuntime.h>
18 #include <JNIHelp.h>
19 #include <jni.h>
20 #include <ScopedUtfChars.h>
21 
22 #include <utils/misc.h>
23 #include <sys/ioctl.h>
24 #include <sys/mount.h>
25 #include <utils/Log.h>
26 
27 
28 #include <inttypes.h>
29 #include <fcntl.h>
30 #include <errno.h>
31 #include <string.h>
32 
33 namespace android {
34 
get_block_device_size(int fd)35     uint64_t get_block_device_size(int fd)
36     {
37         uint64_t size = 0;
38         int ret;
39 
40         ret = ioctl(fd, BLKGETSIZE64, &size);
41 
42         if (ret)
43             return 0;
44 
45         return size;
46     }
47 
wipe_block_device(int fd)48     int wipe_block_device(int fd)
49     {
50         uint64_t range[2];
51         int ret;
52         uint64_t len = get_block_device_size(fd);
53 
54         range[0] = 0;
55         range[1] = len;
56 
57         if (range[1] == 0)
58             return 0;
59 
60         ret = ioctl(fd, BLKSECDISCARD, &range);
61         if (ret < 0) {
62             ALOGE("Something went wrong secure discarding block: %s\n", strerror(errno));
63             range[0] = 0;
64             range[1] = len;
65             ret = ioctl(fd, BLKDISCARD, &range);
66             if (ret < 0) {
67                 ALOGE("Discard failed: %s\n", strerror(errno));
68                 return -1;
69             } else {
70                 ALOGE("Wipe via secure discard failed, used non-secure discard instead\n");
71                 return 0;
72             }
73 
74         }
75 
76         return ret;
77     }
78 
com_android_server_PersistentDataBlockService_getBlockDeviceSize(JNIEnv * env,jclass,jstring jpath)79     static jlong com_android_server_PersistentDataBlockService_getBlockDeviceSize(JNIEnv *env, jclass, jstring jpath)
80     {
81         ScopedUtfChars path(env, jpath);
82         int fd = open(path.c_str(), O_RDONLY);
83 
84         if (fd < 0)
85             return 0;
86 
87         const uint64_t size = get_block_device_size(fd);
88 
89         close(fd);
90 
91         return size;
92     }
93 
com_android_server_PersistentDataBlockService_wipe(JNIEnv * env,jclass,jstring jpath)94     static int com_android_server_PersistentDataBlockService_wipe(JNIEnv *env, jclass, jstring jpath) {
95         ScopedUtfChars path(env, jpath);
96         int fd = open(path.c_str(), O_WRONLY);
97 
98         if (fd < 0)
99             return 0;
100 
101         const int ret = wipe_block_device(fd);
102 
103         close(fd);
104 
105         return ret;
106     }
107 
108     static const JNINativeMethod sMethods[] = {
109          /* name, signature, funcPtr */
110         {"nativeGetBlockDeviceSize", "(Ljava/lang/String;)J", (void*)com_android_server_PersistentDataBlockService_getBlockDeviceSize},
111         {"nativeWipe", "(Ljava/lang/String;)I", (void*)com_android_server_PersistentDataBlockService_wipe},
112     };
113 
register_android_server_PersistentDataBlockService(JNIEnv * env)114     int register_android_server_PersistentDataBlockService(JNIEnv* env)
115     {
116         return jniRegisterNativeMethods(env, "com/android/server/PersistentDataBlockService",
117                                         sMethods, NELEM(sMethods));
118     }
119 
120 } /* namespace android */