MTP FFS updates:
This update splits old MTP code and new MTP code from Google
into two trees, legacy and ffs. Depending on the SDK level,
the build system will select the correct version. The reason
for separating the versions out are due to older android trees
not supporting the updated MTP code from Google.
Most MTP code is from Google, with additions needed from
implementing the Java functions in C++ for TWRP and FFS.
We assume if you are in android-9.0 or above, your kernel
has support for FFS over MTP. Verify that your init.rc
is mounting the MTP FFS driver to the proper location.
Change-Id: I4b107b239bd9bc5699527f9c8c77d9079f264a7e
diff --git a/mtp/ffs/MtpStringBuffer.cpp b/mtp/ffs/MtpStringBuffer.cpp
new file mode 100644
index 0000000..e2302df
--- /dev/null
+++ b/mtp/ffs/MtpStringBuffer.cpp
@@ -0,0 +1,108 @@
+/*
+ * 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 "MtpStringBuffer"
+
+#include <codecvt>
+#include <locale>
+#include <string>
+#include <vector>
+
+#include "MtpDataPacket.h"
+#include "MtpStringBuffer.h"
+
+namespace {
+
+std::wstring_convert<std::codecvt_utf8_utf16<char16_t>,char16_t> gConvert;
+
+static std::string utf16ToUtf8(std::u16string input_str) {
+ return gConvert.to_bytes(input_str);
+}
+
+static std::u16string utf8ToUtf16(std::string input_str) {
+ return gConvert.from_bytes(input_str);
+}
+
+} // namespace
+
+MtpStringBuffer::MtpStringBuffer(const char* src)
+{
+ set(src);
+}
+
+MtpStringBuffer::MtpStringBuffer(const uint16_t* src)
+{
+ set(src);
+}
+
+MtpStringBuffer::MtpStringBuffer(const MtpStringBuffer& src)
+{
+ mString = src.mString;
+}
+
+void MtpStringBuffer::set(const char* src) {
+ mString = std::string(src);
+}
+
+void MtpStringBuffer::set(const uint16_t* src) {
+ mString = utf16ToUtf8(std::u16string((const char16_t*)src));
+}
+
+bool MtpStringBuffer::readFromPacket(MtpDataPacket* packet) {
+ uint8_t count;
+ if (!packet->getUInt8(count))
+ return false;
+ if (count == 0)
+ return true;
+
+ std::vector<char16_t> buffer(count);
+ for (int i = 0; i < count; i++) {
+ uint16_t ch;
+ if (!packet->getUInt16(ch))
+ return false;
+ buffer[i] = ch;
+ }
+ if (buffer[count-1] != '\0') {
+ MTPE("Mtp string not null terminated\n");
+ return false;
+ }
+ mString = utf16ToUtf8(std::u16string(buffer.data()));
+ return true;
+}
+
+void MtpStringBuffer::writeToPacket(MtpDataPacket* packet) const {
+ std::u16string src16 = utf8ToUtf16(mString);
+ int count = src16.length();
+
+ if (count == 0) {
+ packet->putUInt8(0);
+ return;
+ }
+ packet->putUInt8(std::min(count + 1, MTP_STRING_MAX_CHARACTER_NUMBER));
+
+ int i = 0;
+ for (char16_t &c : src16) {
+ if (i == MTP_STRING_MAX_CHARACTER_NUMBER - 1) {
+ // Leave a slot for null termination.
+ MTPD("Mtp truncating long string\n");
+ break;
+ }
+ packet->putUInt16(c);
+ i++;
+ }
+ // only terminate with zero if string is not empty
+ packet->putUInt16(0);
+}