static gboolean
aio_ctx_prepare(GSource *source, gint *timeout)
{
AioContext *ctx = (AioContext *) source;
/* We assume there is no timeout already supplied */
*timeout = qemu_timeout_ns_to_ms(aio_compute_timeout(ctx));
if (aio_prepare(ctx)) {
*timeout = 0;
}
return *timeout == 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;
}
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;
}
