1 /*
2 * Copyright (C) 2023 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15 #include "log.h"
16 #include "mount.h"
17
18 #include <sys/mount.h>
19 #include <securec.h>
20 #include <fcntl.h>
21 #include <unistd.h>
22 #include <sys/types.h>
23 #include <sys/stat.h>
24
25 using namespace Hdc;
26
FindMountDeviceByPath(const char * toQuery,char * dev)27 bool FindMountDeviceByPath(const char *toQuery, char *dev)
28 {
29 int ret = false;
30 int len = BUF_SIZE_DEFAULT2;
31 char buf[BUF_SIZE_DEFAULT2];
32
33 FILE *fp = fopen("/proc/mounts", "r");
34 if (fp == nullptr) {
35 WRITE_LOG(LOG_FATAL, "fopen /proc/mounts error:%d", errno);
36 return false;
37 }
38
39 while (fgets(buf, len, fp) != nullptr) {
40 char dir[BUF_SIZE_SMALL] = "";
41 int freq;
42 int passnno;
43 int res = 0;
44 // clang-format off
45 res = sscanf_s(buf, "%255s %255s %*s %*s %d %d\n", dev, BUF_SIZE_SMALL - 1,
46 dir, BUF_SIZE_SMALL - 1, &freq, &passnno);
47 // clang-format on
48 dev[BUF_SIZE_SMALL - 1] = '\0';
49 dir[BUF_SIZE_SMALL - 1] = '\0';
50 if (res == 4 && (strcmp(toQuery, dir) == 0)) { // 4 : The correct number of parameters
51 WRITE_LOG(LOG_DEBUG, "FindMountDeviceByPath dev:%s dir:%s", dev, dir);
52 ret = true;
53 break;
54 }
55 }
56 int rc = fclose(fp);
57 if (rc != 0) {
58 WRITE_LOG(LOG_WARN, "fclose rc:%d error:%d", rc, errno);
59 }
60 if (!ret) {
61 WRITE_LOG(LOG_FATAL, "FindMountDeviceByPath not found %s", toQuery);
62 }
63 return ret;
64 }
65
RemountPartition(const char * dir)66 bool RemountPartition(const char *dir)
67 {
68 int fd;
69 int off = 0;
70 int ret = 0;
71 char dev[BUF_SIZE_SMALL] = "";
72
73 if (!FindMountDeviceByPath(dir, dev) || strlen(dev) < 4) { // 4 : file count
74 WRITE_LOG(LOG_FATAL, "FindMountDeviceByPath dir:%s failed", dir);
75 return false;
76 }
77
78 if ((fd = open(dev, O_RDONLY | O_CLOEXEC)) < 0) {
79 WRITE_LOG(LOG_FATAL, "open dev:%s failed, error:%d", dev, errno);
80 return false;
81 }
82 ioctl(fd, BLKROSET, &off);
83 close(fd);
84
85 ret = mount(dev, dir, "none", MS_REMOUNT, nullptr);
86 if (ret < 0) {
87 WRITE_LOG(LOG_FATAL, "mount %s failed, reason is %s", dev, strerror(errno));
88 return false;
89 }
90 return true;
91 }
92
RemountDevice()93 bool RemountDevice()
94 {
95 if (getuid() != 0) {
96 return false;
97 }
98 struct stat info;
99 if (!lstat("/vendor", &info) && (info.st_mode & S_IFMT) == S_IFDIR) {
100 // has vendor
101 if (!RemountPartition("/vendor")) {
102 return false;
103 }
104 }
105 return true;
106 }