static int
pn53x_usb_send(nfc_device *pnd, const uint8_t *pbtData, const size_t szData, const int timeout)
{
uint8_t abtFrame[PN53X_USB_BUFFER_LEN] = { 0x00, 0x00, 0xff }; // Every packet must start with "00 00 ff"
size_t szFrame = 0;
int res = 0;
if ((res = pn53x_build_frame(abtFrame, &szFrame, pbtData, szData)) < 0) {
pnd->last_error = res;
return pnd->last_error;
}
if ((res = pn53x_usb_bulk_write(DRIVER_DATA(pnd), abtFrame, szFrame, timeout)) < 0) {
pnd->last_error = res;
return pnd->last_error;
}
uint8_t abtRxBuf[PN53X_USB_BUFFER_LEN];
if ((res = pn53x_usb_bulk_read(DRIVER_DATA(pnd), abtRxBuf, sizeof(abtRxBuf), timeout)) < 0) {
// try to interrupt current device state
pn53x_usb_ack(pnd);
pnd->last_error = res;
return pnd->last_error;
}
if (pn53x_check_ack_frame(pnd, abtRxBuf, res) == 0) {
// The PN53x is running the sent command
} else {
// For some reasons (eg. send another command while a previous one is
// running), the PN533 sometimes directly replies the response packet
// instead of ACK frame, so we send a NACK frame to force PN533 to resend
// response packet. With this hack, the nextly executed function (ie.
// pn53x_usb_receive()) will be able to retreive the correct response
// packet.
// FIXME Sony reader is also affected by this bug but NACK is not supported
if ((res = pn53x_usb_bulk_write(DRIVER_DATA(pnd), (uint8_t *)pn53x_nack_frame, sizeof(pn53x_nack_frame), timeout)) < 0) {
pnd->last_error = res;
// try to interrupt current device state
pn53x_usb_ack(pnd);
return pnd->last_error;
}
}
return NFC_SUCCESS;
}
int
pn53x_usb_receive (nfc_device *pnd, uint8_t *pbtData, const size_t szDataLen, const int timeout)
{
size_t len;
off_t offset = 0;
uint8_t abtRxBuf[PN53X_USB_BUFFER_LEN];
int res;
/*
* If no timeout is specified but the command is blocking, force a 200ms (USB_TIMEOUT_PER_PASS)
* timeout to allow breaking the loop if the user wants to stop it.
*/
int usb_timeout;
int remaining_time = timeout;
read:
if (timeout == USB_INFINITE_TIMEOUT) {
usb_timeout = USB_TIMEOUT_PER_PASS;
} else {
// A user-provided timeout is set, we have to cut it in multiple chunk to be able to keep an nfc_abort_command() mecanism
remaining_time -= USB_TIMEOUT_PER_PASS;
if (remaining_time <= 0) {
pnd->last_error = NFC_ETIMEOUT;
return pnd->last_error;
} else {
usb_timeout = MIN(remaining_time, USB_TIMEOUT_PER_PASS);
}
}
res = pn53x_usb_bulk_read (DRIVER_DATA (pnd), abtRxBuf, sizeof (abtRxBuf), usb_timeout);
if (res == -USB_TIMEDOUT) {
if (DRIVER_DATA (pnd)->abort_flag) {
DRIVER_DATA (pnd)->abort_flag = false;
pn53x_usb_ack (pnd);
pnd->last_error = NFC_EOPABORTED;
return pnd->last_error;
} else {
goto read;
}
}
if (res < 0) {
pnd->last_error = res;
// try to interrupt current device state
pn53x_usb_ack(pnd);
return pnd->last_error;
}
const uint8_t pn53x_preamble[3] = { 0x00, 0x00, 0xff };
if (0 != (memcmp (abtRxBuf, pn53x_preamble, 3))) {
log_put (LOG_CATEGORY, NFC_PRIORITY_ERROR, "%s", "Frame preamble+start code mismatch");
pnd->last_error = NFC_EIO;
return pnd->last_error;
}
offset += 3;
if ((0x01 == abtRxBuf[offset]) && (0xff == abtRxBuf[offset + 1])) {
// Error frame
log_put (LOG_CATEGORY, NFC_PRIORITY_ERROR, "%s", "Application level error detected");
pnd->last_error = NFC_EIO;
return pnd->last_error;
} else if ((0xff == abtRxBuf[offset]) && (0xff == abtRxBuf[offset + 1])) {
// Extended frame
offset += 2;
// (abtRxBuf[offset] << 8) + abtRxBuf[offset + 1] (LEN) include TFI + (CC+1)
len = (abtRxBuf[offset] << 8) + abtRxBuf[offset + 1] - 2;
if (((abtRxBuf[offset] + abtRxBuf[offset + 1] + abtRxBuf[offset + 2]) % 256) != 0) {
// TODO: Retry
log_put (LOG_CATEGORY, NFC_PRIORITY_ERROR, "%s", "Length checksum mismatch");
pnd->last_error = NFC_EIO;
return pnd->last_error;
}
offset += 3;
} else {
// Normal frame
if (256 != (abtRxBuf[offset] + abtRxBuf[offset + 1])) {
// TODO: Retry
log_put (LOG_CATEGORY, NFC_PRIORITY_ERROR, "%s", "Length checksum mismatch");
pnd->last_error = NFC_EIO;
return pnd->last_error;
}
// abtRxBuf[3] (LEN) include TFI + (CC+1)
len = abtRxBuf[offset] - 2;
offset += 2;
}
if (len > szDataLen) {
log_put (LOG_CATEGORY, NFC_PRIORITY_ERROR, "Unable to receive data: buffer too small. (szDataLen: %zu, len: %zu)", szDataLen, len);
pnd->last_error = NFC_EIO;
return pnd->last_error;
}
// TFI + PD0 (CC+1)
if (abtRxBuf[offset] != 0xD5) {
log_put (LOG_CATEGORY, NFC_PRIORITY_ERROR, "%s", "TFI Mismatch");
pnd->last_error = NFC_EIO;
return pnd->last_error;
}
offset += 1;
if (abtRxBuf[offset] != CHIP_DATA (pnd)->last_command + 1) {
log_put (LOG_CATEGORY, NFC_PRIORITY_ERROR, "%s", "Command Code verification failed");
pnd->last_error = NFC_EIO;
return pnd->last_error;
}
offset += 1;
memcpy (pbtData, abtRxBuf + offset, len);
offset += len;
uint8_t btDCS = (256 - 0xD5);
btDCS -= CHIP_DATA (pnd)->last_command + 1;
for (size_t szPos = 0; szPos < len; szPos++) {
btDCS -= pbtData[szPos];
}
if (btDCS != abtRxBuf[offset]) {
log_put (LOG_CATEGORY, NFC_PRIORITY_ERROR, "%s", "Data checksum mismatch");
pnd->last_error = NFC_EIO;
return pnd->last_error;
}
offset += 1;
if (0x00 != abtRxBuf[offset]) {
log_put (LOG_CATEGORY, NFC_PRIORITY_ERROR, "%s", "Frame postamble mismatch");
pnd->last_error = NFC_EIO;
return pnd->last_error;
}
// The PN53x command is done and we successfully received the reply
pnd->last_error = 0;
return len;
}
