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