void network_dispatch_response(Packet *response) {
EnumerateCallback *enumerate_callback;
char packet_signature[PACKET_MAX_SIGNATURE_LENGTH];
int i;
Client *client;
Node *pending_request_global_node;
PendingRequest *pending_request;
if (packet_header_get_sequence_number(&response->header) == 0) {
if (response->header.function_id == CALLBACK_ENUMERATE) {
enumerate_callback = (EnumerateCallback *)response;
if (enumerate_callback->enumeration_type == ENUMERATION_TYPE_CONNECTED ||
enumerate_callback->enumeration_type == ENUMERATION_TYPE_DISCONNECTED) {
network_drop_pending_requests(response->header.uid);
}
}
if (_clients.count == 0) {
log_packet_debug("No clients connected, dropping %s (%s)",
packet_get_response_type(response),
packet_get_response_signature(packet_signature, response));
return;
}
log_packet_debug("Broadcasting %s (%s) to %d client(s)",
packet_get_response_type(response),
packet_get_response_signature(packet_signature, response),
_clients.count);
for (i = 0; i < _clients.count; ++i) {
client = array_get(&_clients, i);
client_dispatch_response(client, NULL, response, true, false);
}
} else if (_clients.count + _zombies.count > 0) {
log_packet_debug("Dispatching response (%s) to %d client(s) and %d zombies(s)",
packet_get_response_signature(packet_signature, response),
_clients.count, _zombies.count);
pending_request_global_node = _pending_request_sentinel.next;
while (pending_request_global_node != &_pending_request_sentinel) {
pending_request = containerof(pending_request_global_node,
PendingRequest, global_node);
if (packet_is_matching_response(response, &pending_request->header)) {
if (pending_request->client != NULL) {
client_dispatch_response(pending_request->client, pending_request,
response, false, false);
} else {
zombie_dispatch_response(pending_request->zombie, pending_request);
}
return;
}
pending_request_global_node = pending_request_global_node->next;
}
log_warn("Broadcasting response (%s) because no client/zombie has a matching pending request",
packet_get_response_signature(packet_signature, response));
for (i = 0; i < _clients.count; ++i) {
client = array_get(&_clients, i);
client_dispatch_response(client, NULL, response, true, false);
}
} else {
log_packet_debug("No clients/zombies connected, dropping response (%s)",
packet_get_response_signature(packet_signature, response));
}
}
// If data should just be polled, set packet_send to NULL.
//
// If no packet is received from slave the length in packet_recv will be set to 0,
// the exact reason for that is encoded in the return value.
//
// For the return value see RED_STACK_TRANSCEIVE_RESULT_* at the top of this file.
static int red_stack_spi_transceive_message(REDStackPacket *packet_send, Packet *packet_recv, REDStackSlave *slave) {
int retval = 0;
uint8_t length, length_send;
uint8_t checksum;
int rc;
uint8_t sequence_number_master = 0xFF;
uint8_t sequence_number_slave = 0xFF;
uint8_t tx[RED_STACK_SPI_PACKET_SIZE] = {0};
uint8_t rx[RED_STACK_SPI_PACKET_SIZE] = {0};
// We assume that we don't receive anything. If we receive a packet the
// length will be overwritten again
packet_recv->header.length = 0;
// Preamble is always the same
tx[RED_STACK_SPI_PREAMBLE] = RED_STACK_SPI_PREAMBLE_VALUE;
if (packet_send == NULL) {
// If packet_send is NULL
// we send a message with empty payload (4 byte)
tx[RED_STACK_SPI_LENGTH] = RED_STACK_SPI_PACKET_EMPTY_SIZE;
retval = RED_STACK_TRANSCEIVE_RESULT_SEND_NONE;
} else if (slave->status == RED_STACK_SLAVE_STATUS_AVAILABLE) {
length = packet_send->packet.header.length;
if (length > sizeof(Packet)) {
retval |= RED_STACK_TRANSCEIVE_RESULT_SEND_ERROR;
log_error("Send length is greater then allowed (actual: %d > maximum: %d)",
length, (int)sizeof(Packet));
goto ret;
}
retval = RED_STACK_TRANSCEIVE_DATA_SEND;
tx[RED_STACK_SPI_LENGTH] = length + RED_STACK_SPI_PACKET_EMPTY_SIZE;
memcpy(tx+2, &packet_send->packet, length);
} else {
retval = RED_STACK_TRANSCEIVE_RESULT_SEND_ERROR;
log_error("Slave with stack address %d is not present in stack", slave->stack_address);
goto ret;
}
length = tx[RED_STACK_SPI_LENGTH];
// Set master and slave sequence number
tx[RED_STACK_SPI_INFO(length)] = slave->sequence_number_master | slave->sequence_number_slave;
// Calculate checksum
tx[RED_STACK_SPI_CHECKSUM(length)] = red_stack_spi_calculate_pearson_hash(tx, length-1);
struct spi_ioc_transfer spi_transfer = {
.tx_buf = (unsigned long)&tx,
.rx_buf = (unsigned long)&rx,
.len = RED_STACK_SPI_PACKET_SIZE,
};
red_stack_spi_select(slave);
rc = ioctl(_red_stack_spi_fd, SPI_IOC_MESSAGE(1), &spi_transfer);
red_stack_spi_deselect(slave);
if (rc < 0) {
// Overwrite current return status with error,
// it seems ioctl itself didn't work.
retval = RED_STACK_TRANSCEIVE_RESULT_SEND_ERROR | RED_STACK_TRANSCEIVE_RESULT_READ_ERROR;
if(packet_send == NULL) {
slave->next_packet_empty = true;
}
log_error("ioctl failed: %s (%d)", get_errno_name(errno), errno);
goto ret;
}
length_send = rc;
if (length_send != RED_STACK_SPI_PACKET_SIZE) {
// Overwrite current return status with error,
// it seems ioctl itself didn't work.
retval = RED_STACK_TRANSCEIVE_RESULT_SEND_ERROR | RED_STACK_TRANSCEIVE_RESULT_READ_ERROR;
if(packet_send == NULL) {
slave->next_packet_empty = true;
}
log_error("ioctl has unexpected result (actual: %d != expected: %d)",
length_send, RED_STACK_SPI_PACKET_SIZE);
goto ret;
}
if (rx[RED_STACK_SPI_PREAMBLE] != RED_STACK_SPI_PREAMBLE_VALUE) {
// Do not log by default, an "unproper preamble" is part of the protocol
// if the slave is too busy to fill the DMA buffers fast enough
// log_error("Received packet without proper preamble (actual: %d != expected: %d)",
// rx[RED_STACK_SPI_PREAMBLE], RED_STACK_SPI_PREAMBLE_VALUE);
retval = (retval & (~RED_STACK_TRANSCEIVE_RESULT_MASK_READ)) | RED_STACK_TRANSCEIVE_RESULT_READ_ERROR;
if(packet_send == NULL) {
slave->next_packet_empty = true;
}
goto ret;
}
// Check length
length = rx[RED_STACK_SPI_LENGTH];
if ((length != RED_STACK_SPI_PACKET_EMPTY_SIZE) &&
((length < (RED_STACK_SPI_PACKET_EMPTY_SIZE + sizeof(PacketHeader))) ||
(length > RED_STACK_SPI_PACKET_SIZE))) {
log_error("Received packet with malformed length: %d", length);
retval = (retval & (~RED_STACK_TRANSCEIVE_RESULT_MASK_READ)) | RED_STACK_TRANSCEIVE_RESULT_READ_ERROR;
if(packet_send == NULL) {
slave->next_packet_empty = true;
}
goto ret;
}
// Calculate and check checksum
checksum = red_stack_spi_calculate_pearson_hash(rx, length-1);
if (checksum != rx[RED_STACK_SPI_CHECKSUM(length)]) {
log_error("Received packet with wrong checksum (actual: %x != expected: %x)",
checksum, rx[RED_STACK_SPI_CHECKSUM(length)]);
retval = (retval & (~RED_STACK_TRANSCEIVE_RESULT_MASK_READ)) | RED_STACK_TRANSCEIVE_RESULT_READ_ERROR;
if(packet_send == NULL) {
slave->next_packet_empty = true;
}
goto ret;
}
// If we send data and the master sequence number matches to the one
// set in the packet we know that the slave received the packet!
if ((packet_send != NULL) /*&& (packet_send->status == RED_STACK_PACKET_STATUS_SEQUENCE_NUMBER_SET)*/) {
sequence_number_master = rx[RED_STACK_SPI_INFO(length)] & RED_STACK_SPI_INFO_SEQUENCE_MASTER_MASK;
if (sequence_number_master == slave->sequence_number_master) {
retval = (retval & (~RED_STACK_TRANSCEIVE_RESULT_MASK_SEND)) | RED_STACK_TRANSCEIVE_RESULT_SEND_OK;
// Increase sequence number for next packet
red_stack_increase_master_sequence_number(slave);
}
} else {
// If we didn't send anything we can always increase the sequence number,
// it doesn't matter if the slave actually received it.
red_stack_increase_master_sequence_number(slave);
}
// If the slave sequence number matches we already processed this packet
sequence_number_slave = rx[RED_STACK_SPI_INFO(length)] & RED_STACK_SPI_INFO_SEQUENCE_SLAVE_MASK;
if (sequence_number_slave == slave->sequence_number_slave) {
retval = (retval & (~RED_STACK_TRANSCEIVE_RESULT_MASK_READ)) | RED_STACK_TRANSCEIVE_RESULT_READ_NONE;
} else {
// Otherwise we save the new sequence number
slave->sequence_number_slave = sequence_number_slave;
if (length == RED_STACK_SPI_PACKET_EMPTY_SIZE) {
// Do not log by default, will produce 2000 log entries per second
// log_packet_debug("Received empty packet over SPI (w/ header)");
retval = (retval & (~RED_STACK_TRANSCEIVE_RESULT_MASK_READ)) | RED_STACK_TRANSCEIVE_RESULT_READ_NONE;
} else {
// Everything seems OK, we can copy to buffer
memcpy(packet_recv, rx+2, length - RED_STACK_SPI_PACKET_EMPTY_SIZE);
log_packet_debug("Received packet over SPI (%s)",
packet_get_response_signature(packet_signature, packet_recv));
retval = (retval & (~RED_STACK_TRANSCEIVE_RESULT_MASK_READ)) | RED_STACK_TRANSCEIVE_RESULT_READ_OK;
retval |= RED_STACK_TRANSCEIVE_DATA_RECEIVED;
}
}
ret:
return retval;
}
// Creates the "routing table", which is just the
// array of REDStackSlave structures.
static void red_stack_spi_create_routing_table(void) {
char base58[BASE58_MAX_LENGTH];
int tries, ret, i;
uint8_t stack_address = 0;
uint8_t uid_counter = 0;
log_debug("Starting to discover SPI stack slaves");
while (stack_address < RED_STACK_SPI_MAX_SLAVES) {
REDStackSlave *slave = &_red_stack.slaves[stack_address];
Packet packet;
StackEnumerateResponse *response;
REDStackPacket red_stack_packet = {
slave,
{{
0, // UID 0
sizeof(StackEnumerateRequest),
FUNCTION_STACK_ENUMERATE,
0x08, // Return expected
0
}, {0}, {0}},
RED_STACK_PACKET_STATUS_ADDED,
};
// We have to assume that the slave is available
slave->status = RED_STACK_SLAVE_STATUS_AVAILABLE;
// Send stack enumerate request
for (tries = 0; tries < RED_STACK_SPI_ROUTING_TRIES; tries++) {
ret = red_stack_spi_transceive_message(&red_stack_packet, &packet, slave);
if ((ret & RED_STACK_TRANSCEIVE_RESULT_MASK_SEND) == RED_STACK_TRANSCEIVE_RESULT_SEND_OK) {
break;
}
SLEEP_NS(0, RED_STACK_SPI_ROUTING_WAIT); // Give slave some more time
}
if (tries == RED_STACK_SPI_ROUTING_TRIES) {
// Slave does not seem to be available,
slave->status = RED_STACK_SLAVE_STATUS_ABSENT;
// This means that there can't be any more slaves above
// and we are actually done here already!
break;
}
// Receive stack enumerate response
for (tries = 0; tries < RED_STACK_SPI_ROUTING_TRIES; tries++) {
// We first check if we already received an answer before we try again
if ((ret & RED_STACK_TRANSCEIVE_RESULT_MASK_READ) == RED_STACK_TRANSCEIVE_RESULT_READ_OK) {
break;
}
// Here we sleep before transceive so that there is some time
// between the sending of stack enumerate and the receiving
// of the answer
SLEEP_NS(0, RED_STACK_SPI_ROUTING_WAIT); // Give slave some more time
ret = red_stack_spi_transceive_message(NULL, &packet, slave);
}
if (tries == RED_STACK_SPI_ROUTING_TRIES) {
// Slave does not seem to be available,
slave->status = RED_STACK_SLAVE_STATUS_ABSENT;
// This means that there can't be any more slaves above
// and we are actually done here already!
break;
}
response = (StackEnumerateResponse *)&packet;
for (i = 0; i < PACKET_MAX_STACK_ENUMERATE_UIDS; i++) {
if (response->uids[i] != 0) {
uid_counter++;
stack_add_recipient(&_red_stack.base, response->uids[i], stack_address);
log_debug("Found UID number %d of slave %d with UID %s",
i, stack_address,
base58_encode(base58, uint32_from_le(response->uids[i])));
} else {
break;
}
}
stack_address++;
}
_red_stack.slave_num = stack_address;
log_info("SPI stack slave discovery done. Found %d slave(s) with %d UID(s) in total",
stack_address, uid_counter);
}
