1 /*
2  * Copyright (C) 2011, 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 #include <stdlib.h>
18 #include <stdio.h>
19 #include <string.h>
20 #include <sys/types.h>
21 #include <sys/stat.h>
22 #include <fcntl.h>
23 #include <unistd.h>
24 #include <sys/ioctl.h>
25 #include <linux/fs.h>
26 #include <errno.h>
27 
28 typedef unsigned long long u64;
29 
30 #ifndef BLKDISCARD
31 #define BLKDISCARD _IO(0x12,119)
32 #endif
33 
34 #ifndef BLKSECDISCARD
35 #define BLKSECDISCARD _IO(0x12,125)
36 #endif
37 
38 static u64 get_block_device_size(int fd)
39 {
40         u64 size = 0;
41         int ret;
42 
43         ret = ioctl(fd, BLKGETSIZE64, &size);
44 
45         if (ret)
46                 return 0;
47 
48         return size;
49 }
50 
51 static int wipe_block_device(int fd, u64 len, int secure)
52 {
53     u64 range[2];
54     int ret;
55     int req;
56 
57     range[0] = 0;
58     range[1] = len;
59     if (secure) {
60        req = BLKSECDISCARD;
61     } else {
62        req = BLKDISCARD;
63     }
64 
65     ret = ioctl(fd, req, &range);
66     if (ret < 0) {
67         fprintf(stderr, "%s discard failed, errno = %d\n",
68                 secure ? "Secure" : "Nonsecure", errno);
69     }
70 
71     return ret;
72 }
73 
74 static void usage(void)
75 {
76     fprintf(stderr, "Usage: wipe_blkdev [-s] <partition>\n");
77     exit(1);
78 }
79 
80 int main(int argc, char *argv[])
81 {
82     int secure = 0;
83     char *devname;
84     int fd;
85     u64 len;
86     struct stat statbuf;
87     int ret;
88 
89     if ((argc != 2) && (argc != 3)) {
90         usage();
91     }
92 
93     if (argc == 3) {
94         if (!strcmp(argv[1], "-s")) {
95             secure = 1;
96             devname = argv[2];
97         } else {
98             usage();
99         }
100     } else {
101         devname = argv[1];
102     }
103 
104     fd = open(devname, O_RDWR);
105     if (fd < 0) {
106         fprintf(stderr, "Cannot open device %s\n", devname);
107         exit(1);
108     }
109 
110     if (fstat(fd, &statbuf) < 0) {
111         fprintf(stderr, "Cannot stat %s\n", devname);
112         exit(1);
113     }
114 
115     if (!S_ISBLK(statbuf.st_mode)) {
116         fprintf(stderr, "%s is not a block device\n", devname);
117         exit(1);
118     }
119 
120     len = get_block_device_size(fd);
121 
122     if (! len) {
123         fprintf(stderr, "Cannot get size of block device %s\n", devname);
124         exit(1);
125     }
126 
127     ret = wipe_block_device(fd, len, secure);
128 
129     close(fd);
130 
131     return ret;
132 }
133