1 files changed, 263 insertions, 0 deletions

diff --git a/mtp/ffs/MtpUtils.cpp b/mtp/ffs/MtpUtils.cpp
new file mode 100644
index 000000000..80c01bf16
--- /dev/null
+++ b/mtp/ffs/MtpUtils.cpp
@@ -0,0 +1,263 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *		http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "MtpUtils"
+
+#include <android-base/logging.h>
+#include <android-base/unique_fd.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <string>
+#include <sys/sendfile.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <stdio.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "MtpUtils.h"
+
+using namespace std;
+
+constexpr unsigned long FILE_COPY_SIZE = 262144;
+
+static void access_ok(const char *path) {
+	if (access(path, F_OK) == -1) {
+		// Ignore. Failure could be common in cases of delete where
+		// the metadata was updated through other paths.
+	}
+}
+
+/*
+DateTime strings follow a compatible subset of the definition found in ISO 8601, and
+take the form of a Unicode string formatted as: "YYYYMMDDThhmmss.s". In this
+representation, YYYY shall be replaced by the year, MM replaced by the month (01-12),
+DD replaced by the day (01-31), T is a constant character 'T' delimiting time from date,
+hh is replaced by the hour (00-23), mm is replaced by the minute (00-59), and ss by the
+second (00-59). The ".s" is optional, and represents tenths of a second.
+This is followed by a UTC offset given as "[+-]zzzz" or the literal "Z", meaning UTC.
+*/
+
+bool parseDateTime(const char* dateTime, time_t& outSeconds) {
+	int year, month, day, hour, minute, second;
+	if (sscanf(dateTime, "%04d%02d%02dT%02d%02d%02d",
+			   &year, &month, &day, &hour, &minute, &second) != 6)
+		return false;
+
+	// skip optional tenth of second
+	const char* tail = dateTime + 15;
+	if (tail[0] == '.' && tail[1]) tail += 2;
+
+	// FIXME: "Z" means UTC, but non-"Z" doesn't mean local time.
+	// It might be that you're in Asia/Seoul on vacation and your Android
+	// device has noticed this via the network, but your camera was set to
+	// America/Los_Angeles once when you bought it and doesn't know where
+	// it is right now, so the camera says "20160106T081700-0800" but we
+	// just ignore the "-0800" and assume local time which is actually "+0900".
+	// I think to support this (without switching to Java or using icu4c)
+	// you'd want to always use timegm(3) and then manually add/subtract
+	// the UTC offset parsed from the string (taking care of wrapping).
+	// mktime(3) ignores the tm_gmtoff field, so you can't let it do the work.
+	bool useUTC = (tail[0] == 'Z');
+
+	struct tm tm = {};
+	tm.tm_sec = second;
+	tm.tm_min = minute;
+	tm.tm_hour = hour;
+	tm.tm_mday = day;
+	tm.tm_mon = month - 1;	// mktime uses months in 0 - 11 range
+	tm.tm_year = year - 1900;
+	tm.tm_isdst = -1;
+	outSeconds = useUTC ? timegm(&tm) : mktime(&tm);
+
+	return true;
+}
+
+void formatDateTime(time_t seconds, char* buffer, int bufferLength) {
+	struct tm tm;
+
+	localtime_r(&seconds, &tm);
+	snprintf(buffer, bufferLength, "%04d%02d%02dT%02d%02d%02d",
+		tm.tm_year + 1900,
+		tm.tm_mon + 1, // localtime_r uses months in 0 - 11 range
+		tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
+}
+
+int makeFolder(const char *path) {
+	mode_t mask = umask(0);
+	int ret = mkdir((const char *)path, DIR_PERM);
+	umask(mask);
+	if (ret && ret != -EEXIST) {
+		PLOG(ERROR) << "Failed to create folder " << path;
+		ret = -1;
+	} else {
+		chown((const char *)path, getuid(), FILE_GROUP);
+	}
+	access_ok(path);
+	return ret;
+}
+
+/**
+ * Copies target path and all children to destination path.
+ *
+ * Returns 0 on success or a negative value indicating number of failures
+ */
+int copyRecursive(const char *fromPath, const char *toPath) {
+	int ret = 0;
+	string fromPathStr(fromPath);
+	string toPathStr(toPath);
+
+	DIR* dir = opendir(fromPath);
+	if (!dir) {
+		PLOG(ERROR) << "opendir " << fromPath << " failed";
+		return -1;
+	}
+	if (fromPathStr[fromPathStr.size()-1] != '/')
+		fromPathStr += '/';
+	if (toPathStr[toPathStr.size()-1] != '/')
+		toPathStr += '/';
+
+	struct dirent* entry;
+	while ((entry = readdir(dir))) {
+		const char* name = entry->d_name;
+
+		// ignore "." and ".."
+		if (name[0] == '.' && (name[1] == 0 || (name[1] == '.' && name[2] == 0))) {
+			continue;
+		}
+		string oldFile = fromPathStr + name;
+		string newFile = toPathStr + name;
+
+		if (entry->d_type == DT_DIR) {
+			ret += makeFolder(newFile.c_str());
+			ret += copyRecursive(oldFile.c_str(), newFile.c_str());
+		} else {
+			ret += copyFile(oldFile.c_str(), newFile.c_str());
+		}
+	}
+	return ret;
+}
+
+int copyFile(const char *fromPath, const char *toPath) {
+	auto start = std::chrono::steady_clock::now();
+
+	android::base::unique_fd fromFd(open(fromPath, O_RDONLY));
+	if (fromFd == -1) {
+		PLOG(ERROR) << "Failed to open copy from " << fromPath;
+		return -1;
+	}
+	android::base::unique_fd toFd(open(toPath, O_CREAT | O_WRONLY, FILE_PERM));
+	if (toFd == -1) {
+		PLOG(ERROR) << "Failed to open copy to " << toPath;
+		return -1;
+	}
+	off_t offset = 0;
+
+	struct stat sstat = {};
+	if (stat(fromPath, &sstat) == -1)
+		return -1;
+
+	off_t length = sstat.st_size;
+	int ret = 0;
+
+	while (offset < length) {
+		ssize_t transfer_length = std::min(length - offset, (off_t) FILE_COPY_SIZE);
+		ret = sendfile(toFd, fromFd, &offset, transfer_length);
+		if (ret != transfer_length) {
+			ret = -1;
+			PLOG(ERROR) << "Copying failed!";
+			break;
+		}
+	}
+	auto end = std::chrono::steady_clock::now();
+	std::chrono::duration<double> diff = end - start;
+	LOG(DEBUG) << "Copied a file with MTP. Time: " << diff.count() << " s, Size: " << length <<
+		", Rate: " << ((double) length) / diff.count() << " bytes/s";
+	chown(toPath, getuid(), FILE_GROUP);
+	access_ok(toPath);
+	return ret == -1 ? -1 : 0;
+}
+
+void deleteRecursive(const char* path) {
+	string pathStr(path);
+	if (pathStr[pathStr.size()-1] != '/') {
+		pathStr += '/';
+	}
+
+	DIR* dir = opendir(path);
+	if (!dir) {
+		PLOG(ERROR) << "opendir " << path << " failed";
+		return;
+	}
+
+	struct dirent* entry;
+	while ((entry = readdir(dir))) {
+		const char* name = entry->d_name;
+
+		// ignore "." and ".."
+		if (name[0] == '.' && (name[1] == 0 || (name[1] == '.' && name[2] == 0))) {
+			continue;
+		}
+		string childPath = pathStr + name;
+		int success;
+		if (entry->d_type == DT_DIR) {
+			deleteRecursive(childPath.c_str());
+			success = rmdir(childPath.c_str());
+		} else {
+			success = unlink(childPath.c_str());
+		}
+		access_ok(childPath.c_str());
+		if (success == -1)
+			PLOG(ERROR) << "Deleting path " << childPath << " failed";
+	}
+	closedir(dir);
+}
+
+bool deletePath(const char* path) {
+	struct stat statbuf;
+	int success;
+	if (stat(path, &statbuf) == 0) {
+		if (S_ISDIR(statbuf.st_mode)) {
+			// rmdir will fail if the directory is non empty, so
+			// there is no need to keep errors from deleteRecursive
+			deleteRecursive(path);
+			success = rmdir(path);
+		} else {
+			success = unlink(path);
+		}
+	} else {
+		PLOG(ERROR) << "deletePath stat failed for " << path;
+		return false;
+	}
+	if (success == -1)
+		PLOG(ERROR) << "Deleting path " << path << " failed";
+	access_ok(path);
+	return success == 0;
+}
+
+int renameTo(const char *oldPath, const char *newPath) {
+	int ret = rename(oldPath, newPath);
+	access_ok(oldPath);
+	access_ok(newPath);
+	return ret;
+}
+
+// Calls access(2) on the path to update underlying filesystems,
+// then closes the fd.
+void closeObjFd(int fd, const char *path) {
+	close(fd);
+	access_ok(path);
+}