/*
* Copyright (C) 2017 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 <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <linux/usb/ch9.h>
#include <linux/usb/functionfs.h>
#include <mutex>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/endian.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include "PosixAsyncIO.h"
#include "MtpFfsCompatHandle.h"
#include "mtp.h"
#define FUNCTIONFS_ENDPOINT_ALLOC _IOR('g', 231, __u32)
namespace {
// Must be divisible by all max packet size values
constexpr int MAX_FILE_CHUNK_SIZE = 3145728;
// Safe values since some devices cannot handle large DMAs
// To get good performance, override these with
// higher values per device using the properties
// sys.usb.ffs.max_read and sys.usb.ffs.max_write
constexpr int USB_FFS_MAX_WRITE = MTP_BUFFER_SIZE;
constexpr int USB_FFS_MAX_READ = MTP_BUFFER_SIZE;
static_assert(USB_FFS_MAX_WRITE > 0, "Max r/w values must be > 0!");
static_assert(USB_FFS_MAX_READ > 0, "Max r/w values must be > 0!");
constexpr unsigned int MAX_MTP_FILE_SIZE = 0xFFFFFFFF;
constexpr size_t ENDPOINT_ALLOC_RETRIES = 10;
} // anonymous namespace
MtpFfsCompatHandle::MtpFfsCompatHandle(int controlFd) :
MtpFfsHandle(controlFd),
mMaxWrite(USB_FFS_MAX_WRITE),
mMaxRead(USB_FFS_MAX_READ) {}
MtpFfsCompatHandle::~MtpFfsCompatHandle() {}
int MtpFfsCompatHandle::writeHandle(int fd, const void* data, size_t len) {
int ret = 0;
const char* buf = static_cast<const char*>(data);
while (len > 0) {
int write_len = std::min(mMaxWrite, len);
int n = TEMP_FAILURE_RETRY(::write(fd, buf, write_len));
if (n < 0) {
PLOG(ERROR) << "write ERROR: fd = " << fd << ", n = " << n;
return -1;
} else if (n < write_len) {
errno = EIO;
PLOG(ERROR) << "less written than expected";
return -1;
}
buf += n;
len -= n;
ret += n;
}
return ret;
}
int MtpFfsCompatHandle::readHandle(int fd, void* data, size_t len) {
int ret = 0;
char* buf = static_cast<char*>(data);
while (len > 0) {
int read_len = std::min(mMaxRead, len);
int n = TEMP_FAILURE_RETRY(::read(fd, buf, read_len));
if (n < 0) {
PLOG(ERROR) << "read ERROR: fd = " << fd << ", n = " << n;
return -1;
}
ret += n;
if (n < read_len) // done reading early
break;
buf += n;
len -= n;
}
return ret;
}
int MtpFfsCompatHandle::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);
posix_madvise(mIobuf[i].bufs.data(), MAX_FILE_CHUNK_SIZE,
POSIX_MADV_SEQUENTIAL | POSIX_MADV_WILLNEED);
}
// Get device specific r/w size
mMaxWrite = android::base::GetIntProperty("sys.usb.ffs.max_write", USB_FFS_MAX_WRITE);
mMaxRead = android::base::GetIntProperty("sys.usb.ffs.max_read", USB_FFS_MAX_READ);
size_t attempts = 0;
while (mMaxWrite >= USB_FFS_MAX_WRITE && mMaxRead >= USB_FFS_MAX_READ &&
attempts < ENDPOINT_ALLOC_RETRIES) {
// If larger contiguous chunks of memory aren't available, attempt to try
// smaller allocations.
if (ioctl(mBulkIn, FUNCTIONFS_ENDPOINT_ALLOC, static_cast<__u32>(mMaxWrite)) ||
ioctl(mBulkOut, FUNCTIONFS_ENDPOINT_ALLOC, static_cast<__u32>(mMaxRead))) {
if (errno == ENODEV) {
// Driver hasn't enabled endpoints yet.
std::this_thread::sleep_for(std::chrono::milliseconds(100));
attempts += 1;
continue;
}
mMaxWrite /= 2;
mMaxRead /=2;
} else {
return 0;
}
}
// Try to start MtpServer anyway, with the smallest max r/w values
mMaxWrite = USB_FFS_MAX_WRITE;
mMaxRead = USB_FFS_MAX_READ;
PLOG(ERROR) << "Functionfs could not allocate any memory!";
return 0;
}
int MtpFfsCompatHandle::read(void* data, size_t len) {
return readHandle(mBulkOut, data, len);
}
int MtpFfsCompatHandle::write(const void* data, size_t len) {
return writeHandle(mBulkIn, data, len);
}
int MtpFfsCompatHandle::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;
int packet_size = getPacketSize(mBulkOut);
unsigned char *data = mIobuf[0].bufs.data();
unsigned char *data2 = mIobuf[1].bufs.data();
struct aiocb aio;
aio.aio_fildes = mfr.fd;
aio.aio_buf = nullptr;
struct aiocb *aiol[] = {&aio};
int ret = -1;
size_t length;
bool read = false;
bool write = false;
posix_fadvise(mfr.fd, 0, 0, POSIX_FADV_SEQUENTIAL | POSIX_FADV_NOREUSE);
// Break down the file into pieces that fit in buffers
while (file_length > 0 || write) {
if (file_length > 0) {
length = std::min(static_cast<uint32_t>(MAX_FILE_CHUNK_SIZE), file_length);
// Read data from USB, handle errors after waiting for write thread.
ret = readHandle(mBulkOut, data, length);
if (file_length != MAX_MTP_FILE_SIZE && ret < static_cast<int>(length)) {
ret = -1;
errno = EIO;
}
read = true;
}
if (write) {
// get the return status of the last write request
aio_suspend(aiol, 1, nullptr);
int written = aio_return(&aio);
if (written == -1) {
errno = aio_error(&aio);
return -1;
}
if (static_cast<size_t>(written) < aio.aio_nbytes) {
errno = EIO;
return -1;
}
write = false;
}
// If there was an error reading above
if (ret == -1) {
return -1;
}
if (read) {
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 {
file_length -= ret;
}
// Enqueue a new write request
aio_prepare(&aio, data, length, offset);
aio_write(&aio);
offset += ret;
std::swap(data, data2);
write = true;
read = false;
}
}
// Receive an empty packet if size is a multiple of the endpoint size.
if (ret % packet_size == 0 || zero_packet) {
if (TEMP_FAILURE_RETRY(::read(mBulkOut, data, packet_size)) != 0) {
return -1;
}
}
return 0;
}
int MtpFfsCompatHandle::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);
unsigned char *data = mIobuf[0].bufs.data();
unsigned char *data2 = mIobuf[1].bufs.data();
posix_fadvise(mfr.fd, 0, 0, POSIX_FADV_SEQUENTIAL | POSIX_FADV_NOREUSE);
struct aiocb aio;
aio.aio_fildes = mfr.fd;
struct aiocb *aiol[] = {&aio};
int ret, length;
int error = 0;
bool read = false;
bool write = false;
// Send the header data
mtp_data_header *header = reinterpret_cast<mtp_data_header*>(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, reinterpret_cast<char*>(data) +
sizeof(mtp_data_header), init_read_len, offset))
!= init_read_len) return -1;
if (writeHandle(mBulkIn, data, sizeof(mtp_data_header) + init_read_len) == -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) {
if (read) {
// Wait for the previous read to finish
aio_suspend(aiol, 1, nullptr);
ret = aio_return(&aio);
if (ret == -1) {
errno = aio_error(&aio);
return -1;
}
if (static_cast<size_t>(ret) < aio.aio_nbytes) {
errno = EIO;
return -1;
}
file_length -= ret;
offset += ret;
std::swap(data, data2);
read = false;
write = true;
}
if (error == -1) {
return -1;
}
if (file_length > 0) {
length = std::min(static_cast<uint64_t>(MAX_FILE_CHUNK_SIZE), file_length);
// Queue up another read
aio_prepare(&aio, data, length, offset);
aio_read(&aio);
read = true;
}
if (write) {
if (writeHandle(mBulkIn, data2, ret) == -1) {
error = -1;
}
write = false;
}
}
if (ret % packet_size == 0) {
// If the last packet wasn't short, send a final empty packet
if (TEMP_FAILURE_RETRY(::write(mBulkIn, data, 0)) != 0) {
return -1;
}
}
return 0;
}
