1 /*
2 * Copyright (C) 2008 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 <stdio.h>
18 #include <stdlib.h>
19 #include <fcntl.h>
20 #include <unistd.h>
21 #include <errno.h>
22 #include <string.h>
23 #include <dirent.h>
24 #include <errno.h>
25 #include <fcntl.h>
26
27 #include <sys/types.h>
28 #include <sys/stat.h>
29 #include <sys/types.h>
30 #include <sys/mman.h>
31 #include <sys/mount.h>
32 #include <sys/wait.h>
33 #include <linux/fs.h>
34 #include <sys/ioctl.h>
35
36 #include <linux/kdev_t.h>
37
38 #define LOG_TAG "Vold"
39
40 #include <android-base/logging.h>
41 #include <android-base/stringprintf.h>
42 #include <cutils/log.h>
43 #include <cutils/properties.h>
44 #include <selinux/selinux.h>
45
46 #include <logwrap/logwrap.h>
47
48 #include "Vfat.h"
49 #include "Utils.h"
50 #include "VoldUtil.h"
51
52 using android::base::StringPrintf;
53
54 namespace android {
55 namespace vold {
56 namespace vfat {
57
58 static const char* kMkfsPath = "/system/bin/newfs_msdos";
59 static const char* kFsckPath = "/system/bin/fsck_msdos";
60
IsSupported()61 bool IsSupported() {
62 return access(kMkfsPath, X_OK) == 0
63 && access(kFsckPath, X_OK) == 0
64 && IsFilesystemSupported("vfat");
65 }
66
Check(const std::string & source)67 status_t Check(const std::string& source) {
68 if (access(kFsckPath, X_OK)) {
69 SLOGW("Skipping fs checks\n");
70 return 0;
71 }
72
73 int pass = 1;
74 int rc = 0;
75 do {
76 std::vector<std::string> cmd;
77 cmd.push_back(kFsckPath);
78 cmd.push_back("-p");
79 cmd.push_back("-f");
80 cmd.push_back(source);
81
82 // Fat devices are currently always untrusted
83 rc = ForkExecvp(cmd, sFsckUntrustedContext);
84
85 if (rc < 0) {
86 SLOGE("Filesystem check failed due to logwrap error");
87 errno = EIO;
88 return -1;
89 }
90
91 switch(rc) {
92 case 0:
93 SLOGI("Filesystem check completed OK");
94 return 0;
95
96 case 2:
97 SLOGE("Filesystem check failed (not a FAT filesystem)");
98 errno = ENODATA;
99 return -1;
100
101 case 4:
102 if (pass++ <= 3) {
103 SLOGW("Filesystem modified - rechecking (pass %d)",
104 pass);
105 continue;
106 }
107 SLOGE("Failing check after too many rechecks");
108 errno = EIO;
109 return -1;
110
111 case 8:
112 SLOGE("Filesystem check failed (no filesystem)");
113 errno = ENODATA;
114 return -1;
115
116 default:
117 SLOGE("Filesystem check failed (unknown exit code %d)", rc);
118 errno = EIO;
119 return -1;
120 }
121 } while (0);
122
123 return 0;
124 }
125
Mount(const std::string & source,const std::string & target,bool ro,bool remount,bool executable,int ownerUid,int ownerGid,int permMask,bool createLost)126 status_t Mount(const std::string& source, const std::string& target, bool ro,
127 bool remount, bool executable, int ownerUid, int ownerGid, int permMask,
128 bool createLost) {
129 int rc;
130 unsigned long flags;
131 char mountData[255];
132
133 const char* c_source = source.c_str();
134 const char* c_target = target.c_str();
135
136 flags = MS_NODEV | MS_NOSUID | MS_DIRSYNC;
137
138 flags |= (executable ? 0 : MS_NOEXEC);
139 flags |= (ro ? MS_RDONLY : 0);
140 flags |= (remount ? MS_REMOUNT : 0);
141
142 sprintf(mountData,
143 "utf8,uid=%d,gid=%d,fmask=%o,dmask=%o,shortname=mixed",
144 ownerUid, ownerGid, permMask, permMask);
145
146 rc = mount(c_source, c_target, "vfat", flags, mountData);
147
148 if (rc && errno == EROFS) {
149 SLOGE("%s appears to be a read only filesystem - retrying mount RO", c_source);
150 flags |= MS_RDONLY;
151 rc = mount(c_source, c_target, "vfat", flags, mountData);
152 }
153
154 if (rc == 0 && createLost) {
155 char *lost_path;
156 asprintf(&lost_path, "%s/LOST.DIR", c_target);
157 if (access(lost_path, F_OK)) {
158 /*
159 * Create a LOST.DIR in the root so we have somewhere to put
160 * lost cluster chains (fsck_msdos doesn't currently do this)
161 */
162 if (mkdir(lost_path, 0755)) {
163 SLOGE("Unable to create LOST.DIR (%s)", strerror(errno));
164 }
165 }
166 free(lost_path);
167 }
168
169 return rc;
170 }
171
Format(const std::string & source,unsigned long numSectors)172 status_t Format(const std::string& source, unsigned long numSectors) {
173 std::vector<std::string> cmd;
174 cmd.push_back(kMkfsPath);
175 cmd.push_back("-F");
176 cmd.push_back("32");
177 cmd.push_back("-O");
178 cmd.push_back("android");
179 cmd.push_back("-c");
180 cmd.push_back("64");
181 cmd.push_back("-A");
182
183 if (numSectors) {
184 cmd.push_back("-s");
185 cmd.push_back(StringPrintf("%lu", numSectors));
186 }
187
188 cmd.push_back(source);
189
190 int rc = ForkExecvp(cmd);
191 if (rc < 0) {
192 SLOGE("Filesystem format failed due to logwrap error");
193 errno = EIO;
194 return -1;
195 }
196
197 if (rc == 0) {
198 SLOGI("Filesystem formatted OK");
199 return 0;
200 } else {
201 SLOGE("Format failed (unknown exit code %d)", rc);
202 errno = EIO;
203 return -1;
204 }
205 return 0;
206 }
207
208 } // namespace vfat
209 } // namespace vold
210 } // namespace android
211