1/*
2 * Copyright (C) 2010 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#define LOG_TAG "MtpUtils"
18
19#include <android-base/logging.h>
20#include <android-base/unique_fd.h>
21#include <dirent.h>
22#include <fcntl.h>
23#include <string>
24#include <sys/sendfile.h>
25#include <sys/stat.h>
26#include <sys/types.h>
27#include <stdio.h>
28#include <time.h>
29#include <unistd.h>
30
31#include "MtpUtils.h"
32
33using namespace std;
34
35namespace android {
36
37constexpr unsigned long FILE_COPY_SIZE = 262144;
38
39static void access_ok(const char *path) {
40    if (access(path, F_OK) == -1) {
41        // Ignore. Failure could be common in cases of delete where
42        // the metadata was updated through other paths.
43    }
44}
45
46/*
47DateTime strings follow a compatible subset of the definition found in ISO 8601, and
48take the form of a Unicode string formatted as: "YYYYMMDDThhmmss.s". In this
49representation, YYYY shall be replaced by the year, MM replaced by the month (01-12),
50DD replaced by the day (01-31), T is a constant character 'T' delimiting time from date,
51hh is replaced by the hour (00-23), mm is replaced by the minute (00-59), and ss by the
52second (00-59). The ".s" is optional, and represents tenths of a second.
53This is followed by a UTC offset given as "[+-]zzzz" or the literal "Z", meaning UTC.
54*/
55
56bool parseDateTime(const char* dateTime, time_t& outSeconds) {
57    int year, month, day, hour, minute, second;
58    if (sscanf(dateTime, "%04d%02d%02dT%02d%02d%02d",
59               &year, &month, &day, &hour, &minute, &second) != 6)
60        return false;
61
62    // skip optional tenth of second
63    const char* tail = dateTime + 15;
64    if (tail[0] == '.' && tail[1]) tail += 2;
65
66    // FIXME: "Z" means UTC, but non-"Z" doesn't mean local time.
67    // It might be that you're in Asia/Seoul on vacation and your Android
68    // device has noticed this via the network, but your camera was set to
69    // America/Los_Angeles once when you bought it and doesn't know where
70    // it is right now, so the camera says "20160106T081700-0800" but we
71    // just ignore the "-0800" and assume local time which is actually "+0900".
72    // I think to support this (without switching to Java or using icu4c)
73    // you'd want to always use timegm(3) and then manually add/subtract
74    // the UTC offset parsed from the string (taking care of wrapping).
75    // mktime(3) ignores the tm_gmtoff field, so you can't let it do the work.
76    bool useUTC = (tail[0] == 'Z');
77
78    struct tm tm = {};
79    tm.tm_sec = second;
80    tm.tm_min = minute;
81    tm.tm_hour = hour;
82    tm.tm_mday = day;
83    tm.tm_mon = month - 1;  // mktime uses months in 0 - 11 range
84    tm.tm_year = year - 1900;
85    tm.tm_isdst = -1;
86    outSeconds = useUTC ? timegm(&tm) : mktime(&tm);
87
88    return true;
89}
90
91void formatDateTime(time_t seconds, char* buffer, int bufferLength) {
92    struct tm tm;
93
94    localtime_r(&seconds, &tm);
95    snprintf(buffer, bufferLength, "%04d%02d%02dT%02d%02d%02d",
96        tm.tm_year + 1900,
97        tm.tm_mon + 1, // localtime_r uses months in 0 - 11 range
98        tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
99}
100
101int makeFolder(const char *path) {
102    mode_t mask = umask(0);
103    int ret = mkdir((const char *)path, DIR_PERM);
104    umask(mask);
105    if (ret && ret != -EEXIST) {
106        PLOG(ERROR) << "Failed to create folder " << path;
107        ret = -1;
108    } else {
109        chown((const char *)path, getuid(), FILE_GROUP);
110    }
111    access_ok(path);
112    return ret;
113}
114
115/**
116 * Copies target path and all children to destination path.
117 *
118 * Returns 0 on success or a negative value indicating number of failures
119 */
120int copyRecursive(const char *fromPath, const char *toPath) {
121    int ret = 0;
122    string fromPathStr(fromPath);
123    string toPathStr(toPath);
124
125    DIR* dir = opendir(fromPath);
126    if (!dir) {
127        PLOG(ERROR) << "opendir " << fromPath << " failed";
128        return -1;
129    }
130    if (fromPathStr[fromPathStr.size()-1] != '/')
131        fromPathStr += '/';
132    if (toPathStr[toPathStr.size()-1] != '/')
133        toPathStr += '/';
134
135    struct dirent* entry;
136    while ((entry = readdir(dir))) {
137        const char* name = entry->d_name;
138
139        // ignore "." and ".."
140        if (name[0] == '.' && (name[1] == 0 || (name[1] == '.' && name[2] == 0))) {
141            continue;
142        }
143        string oldFile = fromPathStr + name;
144        string newFile = toPathStr + name;
145
146        if (entry->d_type == DT_DIR) {
147            ret += makeFolder(newFile.c_str());
148            ret += copyRecursive(oldFile.c_str(), newFile.c_str());
149        } else {
150            ret += copyFile(oldFile.c_str(), newFile.c_str());
151        }
152    }
153    return ret;
154}
155
156int copyFile(const char *fromPath, const char *toPath) {
157    auto start = std::chrono::steady_clock::now();
158
159    android::base::unique_fd fromFd(open(fromPath, O_RDONLY));
160    if (fromFd == -1) {
161        PLOG(ERROR) << "Failed to open copy from " << fromPath;
162        return -1;
163    }
164    android::base::unique_fd toFd(open(toPath, O_CREAT | O_WRONLY, FILE_PERM));
165    if (toFd == -1) {
166        PLOG(ERROR) << "Failed to open copy to " << toPath;
167        return -1;
168    }
169    off_t offset = 0;
170
171    struct stat sstat = {};
172    if (stat(fromPath, &sstat) == -1)
173        return -1;
174
175    off_t length = sstat.st_size;
176    int ret = 0;
177
178    while (offset < length) {
179        ssize_t transfer_length = std::min(length - offset, (off_t) FILE_COPY_SIZE);
180        ret = sendfile(toFd, fromFd, &offset, transfer_length);
181        if (ret != transfer_length) {
182            ret = -1;
183            PLOG(ERROR) << "Copying failed!";
184            break;
185        }
186    }
187    auto end = std::chrono::steady_clock::now();
188    std::chrono::duration<double> diff = end - start;
189    LOG(DEBUG) << "Copied a file with MTP. Time: " << diff.count() << " s, Size: " << length <<
190        ", Rate: " << ((double) length) / diff.count() << " bytes/s";
191    chown(toPath, getuid(), FILE_GROUP);
192    access_ok(toPath);
193    return ret == -1 ? -1 : 0;
194}
195
196void deleteRecursive(const char* path) {
197    string pathStr(path);
198    if (pathStr[pathStr.size()-1] != '/') {
199        pathStr += '/';
200    }
201
202    DIR* dir = opendir(path);
203    if (!dir) {
204        PLOG(ERROR) << "opendir " << path << " failed";
205        return;
206    }
207
208    struct dirent* entry;
209    while ((entry = readdir(dir))) {
210        const char* name = entry->d_name;
211
212        // ignore "." and ".."
213        if (name[0] == '.' && (name[1] == 0 || (name[1] == '.' && name[2] == 0))) {
214            continue;
215        }
216        string childPath = pathStr + name;
217        int success;
218        if (entry->d_type == DT_DIR) {
219            deleteRecursive(childPath.c_str());
220            success = rmdir(childPath.c_str());
221        } else {
222            success = unlink(childPath.c_str());
223        }
224        access_ok(childPath.c_str());
225        if (success == -1)
226            PLOG(ERROR) << "Deleting path " << childPath << " failed";
227    }
228    closedir(dir);
229}
230
231bool deletePath(const char* path) {
232    struct stat statbuf;
233    int success;
234    if (stat(path, &statbuf) == 0) {
235        if (S_ISDIR(statbuf.st_mode)) {
236            // rmdir will fail if the directory is non empty, so
237            // there is no need to keep errors from deleteRecursive
238            deleteRecursive(path);
239            success = rmdir(path);
240        } else {
241            success = unlink(path);
242        }
243    } else {
244        PLOG(ERROR) << "deletePath stat failed for " << path;
245        return false;
246    }
247    if (success == -1)
248        PLOG(ERROR) << "Deleting path " << path << " failed";
249    access_ok(path);
250    return success == 0;
251}
252
253int renameTo(const char *oldPath, const char *newPath) {
254    int ret = rename(oldPath, newPath);
255    access_ok(oldPath);
256    access_ok(newPath);
257    return ret;
258}
259
260// Calls access(2) on the path to update underlying filesystems,
261// then closes the fd.
262void closeObjFd(int fd, const char *path) {
263    close(fd);
264    access_ok(path);
265}
266
267}  // namespace android
268