1 /*
2 * Copyright (C) 2016 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 <errno.h>
18 #include <string.h>
19
20 #include <android-base/logging.h>
21 #include <sys/ioctl.h>
22
23 #include "fs_mgr_priv.h"
24 #include "fs_mgr_priv_dm_ioctl.h"
25
fs_mgr_verity_ioctl_init(struct dm_ioctl * io,const std::string & name,unsigned flags)26 void fs_mgr_verity_ioctl_init(struct dm_ioctl* io, const std::string& name, unsigned flags) {
27 memset(io, 0, DM_BUF_SIZE);
28 io->data_size = DM_BUF_SIZE;
29 io->data_start = sizeof(struct dm_ioctl);
30 io->version[0] = 4;
31 io->version[1] = 0;
32 io->version[2] = 0;
33 io->flags = flags | DM_READONLY_FLAG;
34 if (!name.empty()) {
35 strlcpy(io->name, name.c_str(), sizeof(io->name));
36 }
37 }
38
fs_mgr_create_verity_device(struct dm_ioctl * io,const std::string & name,int fd)39 bool fs_mgr_create_verity_device(struct dm_ioctl* io, const std::string& name, int fd) {
40 fs_mgr_verity_ioctl_init(io, name, 1);
41 if (ioctl(fd, DM_DEV_CREATE, io)) {
42 PERROR << "Error creating device mapping";
43 return false;
44 }
45 return true;
46 }
47
fs_mgr_destroy_verity_device(struct dm_ioctl * io,const std::string & name,int fd)48 bool fs_mgr_destroy_verity_device(struct dm_ioctl* io, const std::string& name, int fd) {
49 fs_mgr_verity_ioctl_init(io, name, 0);
50 if (ioctl(fd, DM_DEV_REMOVE, io)) {
51 PERROR << "Error removing device mapping";
52 return false;
53 }
54 return true;
55 }
56
fs_mgr_get_verity_device_name(struct dm_ioctl * io,const std::string & name,int fd,std::string * out_dev_name)57 bool fs_mgr_get_verity_device_name(struct dm_ioctl* io, const std::string& name, int fd,
58 std::string* out_dev_name) {
59 FS_MGR_CHECK(out_dev_name != nullptr);
60
61 fs_mgr_verity_ioctl_init(io, name, 0);
62 if (ioctl(fd, DM_DEV_STATUS, io)) {
63 PERROR << "Error fetching verity device number";
64 return false;
65 }
66
67 int dev_num = (io->dev & 0xff) | ((io->dev >> 12) & 0xfff00);
68 *out_dev_name = "/dev/block/dm-" + std::to_string(dev_num);
69
70 return true;
71 }
72
fs_mgr_resume_verity_table(struct dm_ioctl * io,const std::string & name,int fd)73 bool fs_mgr_resume_verity_table(struct dm_ioctl* io, const std::string& name, int fd) {
74 fs_mgr_verity_ioctl_init(io, name, 0);
75 if (ioctl(fd, DM_DEV_SUSPEND, io)) {
76 PERROR << "Error activating verity device";
77 return false;
78 }
79 return true;
80 }
81