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-rw-r--r--mtp/ffs/MtpFfsHandle.cpp674
1 files changed, 674 insertions, 0 deletions
diff --git a/mtp/ffs/MtpFfsHandle.cpp b/mtp/ffs/MtpFfsHandle.cpp
new file mode 100644
index 000000000..01b6f2edb
--- /dev/null
+++ b/mtp/ffs/MtpFfsHandle.cpp
@@ -0,0 +1,674 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+#include <android-base/logging.h>
+#include <android-base/properties.h>
+#include <asyncio/AsyncIO.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <memory>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/eventfd.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/poll.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "PosixAsyncIO.h"
+#include "MtpDescriptors.h"
+#include "MtpFfsHandle.h"
+#include "mtp.h"
+#include "MtpDebug.h"
+
+namespace {
+
+constexpr unsigned AIO_BUFS_MAX = 128;
+constexpr unsigned AIO_BUF_LEN = 16384;
+
+constexpr unsigned FFS_NUM_EVENTS = 5;
+
+constexpr unsigned MAX_FILE_CHUNK_SIZE = AIO_BUFS_MAX * AIO_BUF_LEN;
+
+constexpr uint32_t MAX_MTP_FILE_SIZE = 0xFFFFFFFF;
+
+struct timespec ZERO_TIMEOUT = { 0, 0 };
+
+struct mtp_device_status {
+ uint16_t wLength;
+ uint16_t wCode;
+};
+
+} // anonymous namespace
+
+int MtpFfsHandle::getPacketSize(int ffs_fd) {
+ struct usb_endpoint_descriptor desc;
+ if (ioctl(ffs_fd, FUNCTIONFS_ENDPOINT_DESC, reinterpret_cast<unsigned long>(&desc))) {
+ MTPE("Could not get FFS bulk-in descriptor\n");
+ return MAX_PACKET_SIZE_HS;
+ } else {
+ return desc.wMaxPacketSize;
+ }
+}
+
+MtpFfsHandle::MtpFfsHandle(int controlFd) {
+ mControl.reset(controlFd);
+}
+
+MtpFfsHandle::~MtpFfsHandle() {}
+
+void MtpFfsHandle::closeEndpoints() {
+ mIntr.reset();
+ mBulkIn.reset();
+ mBulkOut.reset();
+}
+
+bool MtpFfsHandle::openEndpoints(bool ptp) {
+ if (mBulkIn < 0) {
+ mBulkIn.reset(TEMP_FAILURE_RETRY(open(ptp ? FFS_PTP_EP_IN : FFS_MTP_EP_IN, O_RDWR)));
+ if (mBulkIn < 0) {
+ MTPE("cannot open bulk in ep\n");
+ return false;
+ }
+ }
+
+ if (mBulkOut < 0) {
+ mBulkOut.reset(TEMP_FAILURE_RETRY(open(ptp ? FFS_PTP_EP_OUT : FFS_MTP_EP_OUT, O_RDWR)));
+ if (mBulkOut < 0) {
+ MTPE("cannot open bulk out ep\n");
+ return false;
+ }
+ }
+
+ if (mIntr < 0) {
+ mIntr.reset(TEMP_FAILURE_RETRY(open(ptp ? FFS_PTP_EP_INTR : FFS_MTP_EP_INTR, O_RDWR)));
+ if (mIntr < 0) {
+ MTPE("cannot open intr ep\n");
+ return false;
+ }
+ }
+ return true;
+}
+
+void MtpFfsHandle::advise(int fd) {
+ for (unsigned i = 0; i < NUM_IO_BUFS; i++) {
+ if (posix_madvise(mIobuf[i].bufs.data(), MAX_FILE_CHUNK_SIZE,
+ POSIX_MADV_SEQUENTIAL | POSIX_MADV_WILLNEED) < 0)
+ MTPE("Failed to madvise\n");
+ }
+ if (posix_fadvise(fd, 0, 0,
+ POSIX_FADV_SEQUENTIAL | POSIX_FADV_NOREUSE | POSIX_FADV_WILLNEED) < 0)
+ MTPE("Failed to fadvise\n");
+}
+
+bool MtpFfsHandle::writeDescriptors(bool ptp) {
+ return ::writeDescriptors(mControl, ptp);
+}
+
+void MtpFfsHandle::closeConfig() {
+ mControl.reset();
+}
+
+int MtpFfsHandle::doAsync(void* data, size_t len, bool read, bool zero_packet) {
+ struct io_event ioevs[AIO_BUFS_MAX];
+ size_t total = 0;
+
+ while (total < len) {
+ size_t this_len = std::min(len - total, static_cast<size_t>(AIO_BUF_LEN * AIO_BUFS_MAX));
+ int num_bufs = this_len / AIO_BUF_LEN + (this_len % AIO_BUF_LEN == 0 ? 0 : 1);
+ for (int i = 0; i < num_bufs; i++) {
+ mIobuf[0].buf[i] = reinterpret_cast<unsigned char*>(data) + total + i * AIO_BUF_LEN;
+ }
+ int ret = iobufSubmit(&mIobuf[0], read ? mBulkOut : mBulkIn, this_len, read);
+ if (ret < 0) return -1;
+ ret = waitEvents(&mIobuf[0], ret, ioevs, nullptr);
+ if (ret < 0) return -1;
+ total += ret;
+ if (static_cast<size_t>(ret) < this_len) break;
+ }
+
+ int packet_size = getPacketSize(read ? mBulkOut : mBulkIn);
+ if (len % packet_size == 0 && zero_packet) {
+ int ret = iobufSubmit(&mIobuf[0], read ? mBulkOut : mBulkIn, 0, read);
+ if (ret < 0) return -1;
+ ret = waitEvents(&mIobuf[0], ret, ioevs, nullptr);
+ if (ret < 0) return -1;
+ }
+
+ for (unsigned i = 0; i < AIO_BUFS_MAX; i++) {
+ mIobuf[0].buf[i] = mIobuf[0].bufs.data() + i * AIO_BUF_LEN;
+ }
+ return total;
+}
+
+int MtpFfsHandle::read(void* data, size_t len) {
+ // Zero packets are handled by receiveFile()
+ return doAsync(data, len, true, false);
+}
+
+int MtpFfsHandle::write(const void* data, size_t len) {
+ return doAsync(const_cast<void*>(data), len, false, true);
+}
+
+int MtpFfsHandle::handleEvent() {
+
+ std::vector<usb_functionfs_event> events(FFS_NUM_EVENTS);
+ usb_functionfs_event *event = events.data();
+ int nbytes = TEMP_FAILURE_RETRY(::read(mControl, event,
+ events.size() * sizeof(usb_functionfs_event)));
+ if (nbytes == -1) {
+ return -1;
+ }
+ int ret = 0;
+ for (size_t n = nbytes / sizeof *event; n; --n, ++event) {
+ switch (event->type) {
+ case FUNCTIONFS_BIND:
+ case FUNCTIONFS_ENABLE:
+ ret = 0;
+ errno = 0;
+ break;
+ case FUNCTIONFS_UNBIND:
+ case FUNCTIONFS_DISABLE:
+ errno = ESHUTDOWN;
+ ret = -1;
+ break;
+ case FUNCTIONFS_SETUP:
+ if (handleControlRequest(&event->u.setup) == -1)
+ ret = -1;
+ break;
+ case FUNCTIONFS_SUSPEND:
+ case FUNCTIONFS_RESUME:
+ break;
+ default:
+ MTPE("Mtp Event (unknown)\n");
+ }
+ }
+ return ret;
+}
+
+int MtpFfsHandle::handleControlRequest(const struct usb_ctrlrequest *setup) {
+ uint8_t type = setup->bRequestType;
+ uint8_t code = setup->bRequest;
+ uint16_t length = setup->wLength;
+ uint16_t index = setup->wIndex;
+ uint16_t value = setup->wValue;
+ std::vector<char> buf;
+ buf.resize(length);
+ int ret = 0;
+
+ if (!(type & USB_DIR_IN)) {
+ if (::read(mControl, buf.data(), length) != length) {
+ MTPE("Mtp error ctrlreq read data");
+ }
+ }
+
+ if ((type & USB_TYPE_MASK) == USB_TYPE_CLASS && index == 0 && value == 0) {
+ switch(code) {
+ case MTP_REQ_RESET:
+ case MTP_REQ_CANCEL:
+ errno = ECANCELED;
+ ret = -1;
+ break;
+ case MTP_REQ_GET_DEVICE_STATUS:
+ {
+ if (length < sizeof(struct mtp_device_status) + 4) {
+ errno = EINVAL;
+ return -1;
+ }
+ struct mtp_device_status *st = reinterpret_cast<struct mtp_device_status*>(buf.data());
+ st->wLength = htole16(sizeof(st));
+ if (mCanceled) {
+ st->wLength += 4;
+ st->wCode = MTP_RESPONSE_TRANSACTION_CANCELLED;
+ uint16_t *endpoints = reinterpret_cast<uint16_t*>(st + 1);
+ endpoints[0] = ioctl(mBulkIn, FUNCTIONFS_ENDPOINT_REVMAP);
+ endpoints[1] = ioctl(mBulkOut, FUNCTIONFS_ENDPOINT_REVMAP);
+ mCanceled = false;
+ } else {
+ st->wCode = MTP_RESPONSE_OK;
+ }
+ length = st->wLength;
+ break;
+ }
+ default:
+ MTPE("Unrecognized Mtp class request!\n");
+ }
+ } else {
+ MTPE("Unrecognized request type\n");
+ }
+
+ if (type & USB_DIR_IN) {
+ if (::write(mControl, buf.data(), length) != length) {
+ MTPE("Mtp error ctrlreq write data");
+ }
+ }
+ return 0;
+}
+
+int MtpFfsHandle::start(bool ptp) {
+ if (!openEndpoints(ptp))
+ return -1;
+
+ for (unsigned i = 0; i < NUM_IO_BUFS; i++) {
+ mIobuf[i].bufs.resize(MAX_FILE_CHUNK_SIZE);
+ mIobuf[i].iocb.resize(AIO_BUFS_MAX);
+ mIobuf[i].iocbs.resize(AIO_BUFS_MAX);
+ mIobuf[i].buf.resize(AIO_BUFS_MAX);
+ for (unsigned j = 0; j < AIO_BUFS_MAX; j++) {
+ mIobuf[i].buf[j] = mIobuf[i].bufs.data() + j * AIO_BUF_LEN;
+ mIobuf[i].iocb[j] = &mIobuf[i].iocbs[j];
+ }
+ }
+
+ memset(&mCtx, 0, sizeof(mCtx));
+ if (io_setup(AIO_BUFS_MAX, &mCtx) < 0) {
+ MTPE("unable to setup aio");
+ return -1;
+ }
+ mEventFd.reset(eventfd(0, EFD_NONBLOCK));
+ mPollFds[0].fd = mControl;
+ mPollFds[0].events = POLLIN;
+ mPollFds[1].fd = mEventFd;
+ mPollFds[1].events = POLLIN;
+
+ mCanceled = false;
+ return 0;
+}
+
+void MtpFfsHandle::close() {
+ io_destroy(mCtx);
+ closeEndpoints();
+ closeConfig();
+}
+
+int MtpFfsHandle::waitEvents(__attribute__((unused)) struct io_buffer *buf, int min_events, struct io_event *events,
+ int *counter) {
+ int num_events = 0;
+ int ret = 0;
+ int error = 0;
+
+ while (num_events < min_events) {
+ if (poll(mPollFds, 2, 0) == -1) {
+ MTPE("Mtp error during poll()\n");
+ return -1;
+ }
+ if (mPollFds[0].revents & POLLIN) {
+ mPollFds[0].revents = 0;
+ if (handleEvent() == -1) {
+ error = errno;
+ }
+ }
+ if (mPollFds[1].revents & POLLIN) {
+ mPollFds[1].revents = 0;
+ uint64_t ev_cnt = 0;
+
+ if (::read(mEventFd, &ev_cnt, sizeof(ev_cnt)) == -1) {
+ MTPE("Mtp unable to read eventfd\n");
+ error = errno;
+ continue;
+ }
+
+ // It's possible that io_getevents will return more events than the eventFd reported,
+ // since events may appear in the time between the calls. In this case, the eventFd will
+ // show up as readable next iteration, but there will be fewer or no events to actually
+ // wait for. Thus we never want io_getevents to block.
+ int this_events = TEMP_FAILURE_RETRY(io_getevents(mCtx, 0, AIO_BUFS_MAX, events, &ZERO_TIMEOUT));
+ if (this_events == -1) {
+ MTPE("Mtp error getting events");
+ error = errno;
+ }
+ // Add up the total amount of data and find errors on the way.
+ for (unsigned j = 0; j < static_cast<unsigned>(this_events); j++) {
+ if (events[j].res < 0) {
+ errno = -events[j].res;
+ MTPE("Mtp got error event\n");
+ error = errno;
+ }
+ ret += events[j].res;
+ }
+ num_events += this_events;
+ if (counter)
+ *counter += this_events;
+ }
+ if (error) {
+ errno = error;
+ ret = -1;
+ break;
+ }
+ }
+ return ret;
+}
+
+void MtpFfsHandle::cancelTransaction() {
+ // Device cancels by stalling both bulk endpoints.
+ if (::read(mBulkIn, nullptr, 0) != -1 || errno != EBADMSG)
+ MTPE("Mtp stall failed on bulk in\n");
+ if (::write(mBulkOut, nullptr, 0) != -1 || errno != EBADMSG)
+ MTPE("Mtp stall failed on bulk out\n");
+ mCanceled = true;
+ errno = ECANCELED;
+}
+
+int MtpFfsHandle::cancelEvents(struct iocb **iocb, struct io_event *events, unsigned start,
+ unsigned end) {
+ // Some manpages for io_cancel are out of date and incorrect.
+ // io_cancel will return -EINPROGRESS on success and does
+ // not place the event in the given memory. We have to use
+ // io_getevents to wait for all the events we cancelled.
+ int ret = 0;
+ unsigned num_events = 0;
+ int save_errno = errno;
+ errno = 0;
+
+ for (unsigned j = start; j < end; j++) {
+ if (io_cancel(mCtx, iocb[j], nullptr) != -1 || errno != EINPROGRESS) {
+ MTPE("Mtp couldn't cancel request\n");
+ } else {
+ num_events++;
+ }
+ }
+ if (num_events != end - start) {
+ ret = -1;
+ errno = EIO;
+ }
+ int evs = TEMP_FAILURE_RETRY(io_getevents(mCtx, num_events, AIO_BUFS_MAX, events, nullptr));
+ if (static_cast<unsigned>(evs) != num_events) {
+ MTPE("Mtp couldn't cancel all requests\n");
+ ret = -1;
+ }
+
+ uint64_t ev_cnt = 0;
+ if (num_events && ::read(mEventFd, &ev_cnt, sizeof(ev_cnt)) == -1)
+ MTPE("Mtp Unable to read event fd\n");
+
+ if (ret == 0) {
+ // Restore errno since it probably got overriden with EINPROGRESS.
+ errno = save_errno;
+ }
+ return ret;
+}
+
+int MtpFfsHandle::iobufSubmit(struct io_buffer *buf, int fd, unsigned length, bool read) {
+ int ret = 0;
+ buf->actual = AIO_BUFS_MAX;
+ for (unsigned j = 0; j < AIO_BUFS_MAX; j++) {
+ unsigned rq_length = std::min(AIO_BUF_LEN, length - AIO_BUF_LEN * j);
+ io_prep(buf->iocb[j], fd, buf->buf[j], rq_length, 0, read);
+ buf->iocb[j]->aio_flags |= IOCB_FLAG_RESFD;
+ buf->iocb[j]->aio_resfd = mEventFd;
+
+ // Not enough data, so table is truncated.
+ if (rq_length < AIO_BUF_LEN || length == AIO_BUF_LEN * (j + 1)) {
+ buf->actual = j + 1;
+ break;
+ }
+ }
+
+ ret = io_submit(mCtx, buf->actual, buf->iocb.data());
+ if (ret != static_cast<int>(buf->actual)) {
+ MTPE("Mtp io_submit\n");
+ if (ret != -1) {
+ errno = EIO;
+ }
+ ret = -1;
+ }
+ return ret;
+}
+
+int MtpFfsHandle::receiveFile(mtp_file_range mfr, bool zero_packet) {
+ // When receiving files, the incoming length is given in 32 bits.
+ // A >=4G file is given as 0xFFFFFFFF
+ uint32_t file_length = mfr.length;
+ uint64_t offset = mfr.offset;
+
+ struct aiocb aio;
+ aio.aio_fildes = mfr.fd;
+ aio.aio_buf = nullptr;
+ struct aiocb *aiol[] = {&aio};
+
+ int ret = -1;
+ unsigned i = 0;
+ size_t length;
+ struct io_event ioevs[AIO_BUFS_MAX];
+ bool has_write = false;
+ bool error = false;
+ bool write_error = false;
+ int packet_size = getPacketSize(mBulkOut);
+ bool short_packet = false;
+ advise(mfr.fd);
+
+ // Break down the file into pieces that fit in buffers
+ while (file_length > 0 || has_write) {
+ // Queue an asynchronous read from USB.
+ if (file_length > 0) {
+ length = std::min(static_cast<uint32_t>(MAX_FILE_CHUNK_SIZE), file_length);
+ if (iobufSubmit(&mIobuf[i], mBulkOut, length, true) == -1)
+ error = true;
+ }
+
+ // Get the return status of the last write request.
+ if (has_write) {
+ aio_suspend(aiol, 1, nullptr);
+ int written = aio_return(&aio);
+ if (static_cast<size_t>(written) < aio.aio_nbytes) {
+ errno = written == -1 ? aio_error(&aio) : EIO;
+ MTPE("Mtp error writing to disk\n");
+ write_error = true;
+ }
+ has_write = false;
+ }
+
+ if (error) {
+ return -1;
+ }
+
+ // Get the result of the read request, and queue a write to disk.
+ if (file_length > 0) {
+ unsigned num_events = 0;
+ ret = 0;
+ unsigned short_i = mIobuf[i].actual;
+ while (num_events < short_i) {
+ // Get all events up to the short read, if there is one.
+ // We must wait for each event since data transfer could end at any time.
+ int this_events = 0;
+ int event_ret = waitEvents(&mIobuf[i], 1, ioevs, &this_events);
+ num_events += this_events;
+
+ if (event_ret == -1) {
+ cancelEvents(mIobuf[i].iocb.data(), ioevs, num_events, mIobuf[i].actual);
+ return -1;
+ }
+ ret += event_ret;
+ for (int j = 0; j < this_events; j++) {
+ // struct io_event contains a pointer to the associated struct iocb as a __u64.
+ if (static_cast<__u64>(ioevs[j].res) <
+ reinterpret_cast<struct iocb*>(ioevs[j].obj)->aio_nbytes) {
+ // We've found a short event. Store the index since
+ // events won't necessarily arrive in the order they are queued.
+ short_i = (ioevs[j].obj - reinterpret_cast<uint64_t>(mIobuf[i].iocbs.data()))
+ / sizeof(struct iocb) + 1;
+ short_packet = true;
+ }
+ }
+ }
+ if (short_packet) {
+ if (cancelEvents(mIobuf[i].iocb.data(), ioevs, short_i, mIobuf[i].actual)) {
+ write_error = true;
+ }
+ }
+ if (file_length == MAX_MTP_FILE_SIZE) {
+ // For larger files, receive until a short packet is received.
+ if (static_cast<size_t>(ret) < length) {
+ file_length = 0;
+ }
+ } else if (ret < static_cast<int>(length)) {
+ // If file is less than 4G and we get a short packet, it's an error.
+ errno = EIO;
+ MTPE("Mtp got unexpected short packet\n");
+ return -1;
+ } else {
+ file_length -= ret;
+ }
+
+ if (write_error) {
+ cancelTransaction();
+ return -1;
+ }
+
+ // Enqueue a new write request
+ aio_prepare(&aio, mIobuf[i].bufs.data(), ret, offset);
+ aio_write(&aio);
+
+ offset += ret;
+ i = (i + 1) % NUM_IO_BUFS;
+ has_write = true;
+ }
+ }
+ if ((ret % packet_size == 0 && !short_packet) || zero_packet) {
+ // Receive an empty packet if size is a multiple of the endpoint size
+ // and we didn't already get an empty packet from the header or large file.
+ if (read(mIobuf[0].bufs.data(), packet_size) != 0) {
+ return -1;
+ }
+ }
+ return 0;
+}
+
+int MtpFfsHandle::sendFile(mtp_file_range mfr) {
+ uint64_t file_length = mfr.length;
+ uint32_t given_length = std::min(static_cast<uint64_t>(MAX_MTP_FILE_SIZE),
+ file_length + sizeof(mtp_data_header));
+ uint64_t offset = mfr.offset;
+ int packet_size = getPacketSize(mBulkIn);
+
+ // If file_length is larger than a size_t, truncating would produce the wrong comparison.
+ // Instead, promote the left side to 64 bits, then truncate the small result.
+ int init_read_len = std::min(
+ static_cast<uint64_t>(packet_size - sizeof(mtp_data_header)), file_length);
+
+ advise(mfr.fd);
+
+ struct aiocb aio;
+ aio.aio_fildes = mfr.fd;
+ struct aiocb *aiol[] = {&aio};
+ int ret = 0;
+ int length, num_read;
+ unsigned i = 0;
+ struct io_event ioevs[AIO_BUFS_MAX];
+ bool error = false;
+ bool has_write = false;
+
+ // Send the header data
+ mtp_data_header *header = reinterpret_cast<mtp_data_header*>(mIobuf[0].bufs.data());
+ header->length = htole32(given_length);
+ header->type = htole16(2); // data packet
+ header->command = htole16(mfr.command);
+ header->transaction_id = htole32(mfr.transaction_id);
+
+ // Some hosts don't support header/data separation even though MTP allows it
+ // Handle by filling first packet with initial file data
+ if (TEMP_FAILURE_RETRY(pread(mfr.fd, mIobuf[0].bufs.data() +
+ sizeof(mtp_data_header), init_read_len, offset))
+ != init_read_len) return -1;
+ if (doAsync(mIobuf[0].bufs.data(), sizeof(mtp_data_header) + init_read_len,
+ false, false /* zlps are handled below */) == -1)
+ return -1;
+ file_length -= init_read_len;
+ offset += init_read_len;
+ ret = init_read_len + sizeof(mtp_data_header);
+
+ // Break down the file into pieces that fit in buffers
+ while(file_length > 0 || has_write) {
+ if (file_length > 0) {
+ // Queue up a read from disk.
+ length = std::min(static_cast<uint64_t>(MAX_FILE_CHUNK_SIZE), file_length);
+ aio_prepare(&aio, mIobuf[i].bufs.data(), length, offset);
+ aio_read(&aio);
+ }
+
+ if (has_write) {
+ // Wait for usb write. Cancel unwritten portion if there's an error.
+ int num_events = 0;
+ if (waitEvents(&mIobuf[(i-1)%NUM_IO_BUFS], mIobuf[(i-1)%NUM_IO_BUFS].actual, ioevs,
+ &num_events) != ret) {
+ error = true;
+ cancelEvents(mIobuf[(i-1)%NUM_IO_BUFS].iocb.data(), ioevs, num_events,
+ mIobuf[(i-1)%NUM_IO_BUFS].actual);
+ }
+ has_write = false;
+ }
+
+ if (file_length > 0) {
+ // Wait for the previous read to finish
+ aio_suspend(aiol, 1, nullptr);
+ num_read = aio_return(&aio);
+ if (static_cast<size_t>(num_read) < aio.aio_nbytes) {
+ errno = num_read == -1 ? aio_error(&aio) : EIO;
+ MTPE("Mtp error reading from disk\n");
+ cancelTransaction();
+ return -1;
+ }
+
+ file_length -= num_read;
+ offset += num_read;
+
+ if (error) {
+ return -1;
+ }
+
+ // Queue up a write to usb.
+ if (iobufSubmit(&mIobuf[i], mBulkIn, num_read, false) == -1) {
+ return -1;
+ }
+ has_write = true;
+ ret = num_read;
+ }
+
+ i = (i + 1) % NUM_IO_BUFS;
+ }
+
+ if (ret % packet_size == 0) {
+ // If the last packet wasn't short, send a final empty packet
+ if (write(mIobuf[0].bufs.data(), 0) != 0) {
+ return -1;
+ }
+ }
+ return 0;
+}
+
+int MtpFfsHandle::sendEvent(mtp_event me) {
+ // Mimic the behavior of f_mtp by sending the event async.
+ // Events aren't critical to the connection, so we don't need to check the return value.
+ char *temp = new char[me.length];
+ memcpy(temp, me.data, me.length);
+ me.data = temp;
+ std::thread t([this, me]() { return this->doSendEvent(me); });
+ t.detach();
+ return 0;
+}
+
+void MtpFfsHandle::doSendEvent(mtp_event me) {
+ unsigned length = me.length;
+ int ret = ::write(mIntr, me.data, length);
+ if (static_cast<unsigned>(ret) != length)
+ MTPE("Mtp error sending event thread!\n");
+ delete[] reinterpret_cast<char*>(me.data);
+}
+