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
52using android::base::StringPrintf;
53
54namespace android {
55namespace vold {
56namespace vfat {
57
58static const char* kMkfsPath = "/system/bin/newfs_msdos";
59static const char* kFsckPath = "/system/bin/fsck_msdos";
60
61bool IsSupported() {
62    return access(kMkfsPath, X_OK) == 0
63            && access(kFsckPath, X_OK) == 0
64            && IsFilesystemSupported("vfat");
65}
66
67status_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
126status_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 | MS_NOATIME;
137
138    flags |= (executable ? 0 : MS_NOEXEC);
139    flags |= (ro ? MS_RDONLY : 0);
140    flags |= (remount ? MS_REMOUNT : 0);
141
142    snprintf(mountData, sizeof(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
172status_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