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