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LoRaWAN: FRMPayload size validity #7459

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Merged
merged 2 commits into from
Jul 13, 2018
Merged

LoRaWAN: FRMPayload size validity #7459

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9a77b5d
FRMPayload size validity
Jul 10, 2018
ed9048f
Correcting unit for timeout
Jul 12, 2018
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2 changes: 1 addition & 1 deletion features/lorawan/LoRaRadio.h
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Original file line number Diff line number Diff line change
Expand Up @@ -281,7 +281,7 @@ class LoRaRadio
* @param iq_inverted Inverts IQ signals (LoRa only)
* FSK : N/A (set to 0).
* LoRa: [0: not inverted, 1: inverted]
* @param timeout The transmission timeout [us].
* @param timeout The transmission timeout [ms].
*/
virtual void set_tx_config(radio_modems_t modem, int8_t power, uint32_t fdev,
uint32_t bandwidth, uint32_t datarate,
Expand Down
96 changes: 58 additions & 38 deletions features/lorawan/lorastack/mac/LoRaMac.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1033,6 +1033,7 @@ lorawan_status_t LoRaMac::schedule_tx()
{
channel_selection_params_t next_channel;
lorawan_time_t backoff_time = 0;
uint8_t fopts_len = 0;

if (_params.sys_params.max_duty_cycle == 255) {
return LORAWAN_STATUS_DEVICE_OFF;
Expand Down Expand Up @@ -1090,9 +1091,25 @@ lorawan_status_t LoRaMac::schedule_tx()
_params.rx_window2_delay = _params.sys_params.join_accept_delay2
+ _params.rx_window2_config.window_offset;
} else {
if (validate_payload_length(_params.tx_buffer_len,

// if the outgoing message is a proprietary message, it doesn't include any
// standard message formatting except port and MHDR.
if (_ongoing_tx_msg.type == MCPS_PROPRIETARY) {
fopts_len = 0;
} else {
fopts_len = _mac_commands.get_mac_cmd_length() + _mac_commands.get_repeat_commands_length();
}

// A check was performed for validity of FRMPayload in ::prepare_ongoing_tx() API.
// However, owing to the asynch nature of the send() API, we should check the
// validity again, as datarate may have changed since we last attempted to transmit.
if (validate_payload_length(_ongoing_tx_msg.f_buffer_size,
_params.sys_params.channel_data_rate,
_mac_commands.get_mac_cmd_length()) == false) {
fopts_len) == false) {
tr_error("Allowed FRMPayload = %d, FRMPayload = %d, MAC commands pending = %d",
_lora_phy->get_max_payload(_params.sys_params.channel_data_rate,
_params.is_repeater_supported),
_ongoing_tx_msg.f_buffer_size, fopts_len);
return LORAWAN_STATUS_LENGTH_ERROR;
}
_params.rx_window1_delay = _params.sys_params.recv_delay1
Expand Down Expand Up @@ -1215,27 +1232,9 @@ int16_t LoRaMac::prepare_ongoing_tx(const uint8_t port,
uint8_t num_retries)
{
_ongoing_tx_msg.port = port;

uint8_t max_possible_size = get_max_possible_tx_size(length);

if (max_possible_size > MBED_CONF_LORA_TX_MAX_SIZE) {
max_possible_size = MBED_CONF_LORA_TX_MAX_SIZE;
}

if (max_possible_size < length) {
tr_info("Cannot transmit %d bytes. Possible TX Size is %d bytes",
length, max_possible_size);

_ongoing_tx_msg.pending_size = length - max_possible_size;
_ongoing_tx_msg.f_buffer_size = max_possible_size;
memcpy(_ongoing_tx_msg.f_buffer, data, _ongoing_tx_msg.f_buffer_size);
} else {
_ongoing_tx_msg.f_buffer_size = length;
_ongoing_tx_msg.pending_size = 0;
if (length > 0) {
memcpy(_ongoing_tx_msg.f_buffer, data, length);
}
}
uint8_t max_possible_size = 0;
uint8_t fopts_len = _mac_commands.get_mac_cmd_length()
+ _mac_commands.get_repeat_commands_length();

// Handles unconfirmed messages
if (flags & MSG_UNCONFIRMED_FLAG) {
Expand All @@ -1256,6 +1255,30 @@ int16_t LoRaMac::prepare_ongoing_tx(const uint8_t port,
_ongoing_tx_msg.type = MCPS_PROPRIETARY;
_ongoing_tx_msg.fport = port;
_ongoing_tx_msg.nb_trials = 1;
// a proprietary frame only includes an MHDR field which contains MTYPE field.
// Everything else is at the discretion of the implementer
fopts_len = 0;
}

max_possible_size = get_max_possible_tx_size(fopts_len);

if (max_possible_size > MBED_CONF_LORA_TX_MAX_SIZE) {
max_possible_size = MBED_CONF_LORA_TX_MAX_SIZE;
}

if (max_possible_size < length) {
tr_info("Cannot transmit %d bytes. Possible TX Size is %d bytes",
length, max_possible_size);

_ongoing_tx_msg.pending_size = length - max_possible_size;
_ongoing_tx_msg.f_buffer_size = max_possible_size;
memcpy(_ongoing_tx_msg.f_buffer, data, _ongoing_tx_msg.f_buffer_size);
} else {
_ongoing_tx_msg.f_buffer_size = length;
_ongoing_tx_msg.pending_size = 0;
if (length > 0) {
memcpy(_ongoing_tx_msg.f_buffer, data, length);
}
}

tr_info("RTS = %u bytes, PEND = %u, Port: %u",
Expand Down Expand Up @@ -1566,8 +1589,10 @@ lorawan_status_t LoRaMac::prepare_frame(loramac_mhdr_t *machdr,

_mac_commands.parse_mac_commands_to_repeat();

// We always add Port Field. Spec leaves it optional.
_params.tx_buffer[pkt_header_len++] = frame_port;

if ((payload != NULL) && (_params.tx_buffer_len > 0)) {
_params.tx_buffer[pkt_header_len++] = frame_port;

uint8_t *key = _params.keys.app_skey;
uint32_t key_length = sizeof(_params.keys.app_skey) * 8;
Expand Down Expand Up @@ -1759,35 +1784,30 @@ void LoRaMac::disconnect()
reset_mcps_indication();
}

uint8_t LoRaMac::get_max_possible_tx_size(uint8_t size)
uint8_t LoRaMac::get_max_possible_tx_size(uint8_t fopts_len)
{
uint8_t max_possible_payload_size = 0;
uint8_t current_payload_size = 0;
uint8_t fopt_len = _mac_commands.get_mac_cmd_length()
+ _mac_commands.get_repeat_commands_length();
uint8_t allowed_frm_payload_size = 0;

if (_params.sys_params.adr_on) {
_lora_phy->get_next_ADR(false, _params.sys_params.channel_data_rate,
_params.sys_params.channel_tx_power,
_params.adr_ack_counter);
}

current_payload_size = _lora_phy->get_max_payload(_params.sys_params.channel_data_rate, _params.is_repeater_supported);
allowed_frm_payload_size = _lora_phy->get_max_payload(_params.sys_params.channel_data_rate,
_params.is_repeater_supported);

if (current_payload_size >= fopt_len) {
max_possible_payload_size = current_payload_size - fopt_len;
if (allowed_frm_payload_size >= fopts_len) {
max_possible_payload_size = allowed_frm_payload_size - fopts_len;
} else {
max_possible_payload_size = current_payload_size;
fopt_len = 0;
max_possible_payload_size = allowed_frm_payload_size;
fopts_len = 0;
_mac_commands.clear_command_buffer();
_mac_commands.clear_repeat_buffer();
}

if (validate_payload_length(size, _params.sys_params.channel_data_rate,
fopt_len) == false) {
return max_possible_payload_size;
}
return current_payload_size;
return max_possible_payload_size;
}

bool LoRaMac::nwk_joined()
Expand Down
29 changes: 17 additions & 12 deletions features/lorawan/lorastack/mac/LoRaMac.h
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Original file line number Diff line number Diff line change
Expand Up @@ -93,18 +93,18 @@ class LoRaMac {
void disconnect(void);

/**
* @brief Queries the LoRaMAC whether it is possible to send the next frame with
* a given payload size. The LoRaMAC takes the scheduled MAC commands into
* account and returns corresponding value.
* @brief Queries the LoRaMAC the maximum possible FRMPayload size to send.
* The LoRaMAC takes the scheduled MAC commands into account and returns
* corresponding value.
*
* @param size [in] The size of the applicable payload to be sent next.
* @param fopts_len [in] Number of mac commands in the queue pending.
*
* @return Size of the biggest packet that can be sent.
* Please note that if the size of the MAC commands in the queue do
* not fit into the payload size on the related datarate, the LoRaMAC will
* omit the MAC commands.
*/
uint8_t get_max_possible_tx_size(uint8_t size);
uint8_t get_max_possible_tx_size(uint8_t fopts_len);

/**
* @brief nwk_joined Checks if device has joined to network
Expand Down Expand Up @@ -316,13 +316,18 @@ class LoRaMac {

/**
* @brief prepare_ongoing_tx This will prepare (and override) ongoing_tx_msg.
* @param port The application port number.
* @param data A pointer to the data being sent. The ownership of the
* buffer is not transferred.
* @param length The size of data in bytes.
* @param flags A flag used to determine what type of
* message is being sent.
* @param num_retries Number of retries for a confirmed type message
* @param port The application port number.
*
* @param data A pointer to the data being sent. The ownership of the
* buffer is not transferred.
*
* @param length The size of data in bytes.
*
* @param flags A flag used to determine what type of
* message is being sent.
*
* @param num_retries Number of retries for a confirmed type message
*
* @return The number of bytes prepared for sending.
*/
int16_t prepare_ongoing_tx(const uint8_t port, const uint8_t *data,
Expand Down