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canard.c
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canard.c
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/*
* Copyright (c) 2016-2019 UAVCAN Team
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* Contributors: https://github.com/UAVCAN/libcanard/contributors
*
* Documentation: http://uavcan.org/Implementations/Libcanard
*/
#include "canard_internals.h"
#include <string.h>
#undef MIN
#undef MAX
#define MIN(a, b) (((a) < (b)) ? (a) : (b))
#define MAX(a, b) (((a) > (b)) ? (a) : (b))
#define TRANSFER_TIMEOUT_USEC 2000000U
#define IFACE_SWITCH_DELAY_USEC 1000000U
#define TRANSFER_ID_BIT_LEN 5U
#define ANON_MSG_DATA_TYPE_ID_BIT_LEN 2U
#define SOURCE_ID_FROM_ID(x) ((uint8_t) (((x) >> 0U) & 0x7FU))
#define SERVICE_NOT_MSG_FROM_ID(x) ((bool) (((x) >> 7U) & 0x1U))
#define REQUEST_NOT_RESPONSE_FROM_ID(x) ((bool) (((x) >> 15U) & 0x1U))
#define DEST_ID_FROM_ID(x) ((uint8_t) (((x) >> 8U) & 0x7FU))
#define PRIORITY_FROM_ID(x) ((uint8_t) (((x) >> 24U) & 0x1FU))
#define MSG_TYPE_FROM_ID(x) ((uint16_t)(((x) >> 8U) & 0xFFFFU))
#define SRV_TYPE_FROM_ID(x) ((uint8_t) (((x) >> 16U) & 0xFFU))
#define MAKE_TRANSFER_DESCRIPTOR(data_type_id, transfer_type, src_node_id, dst_node_id) \
(((uint32_t)(data_type_id)) | (((uint32_t)(transfer_type)) << 16U) | \
(((uint32_t)(src_node_id)) << 18U) | (((uint32_t)(dst_node_id)) << 25U))
#define TRANSFER_ID_FROM_TAIL_BYTE(x) ((uint8_t)((x) & 0x1FU))
// The extra cast to unsigned is needed to squelch warnings from clang-tidy
#define IS_START_OF_TRANSFER(x) ((bool)(((uint32_t)(x) >> 7U) & 0x1U))
#define IS_END_OF_TRANSFER(x) ((bool)(((uint32_t)(x) >> 6U) & 0x1U))
#define TOGGLE_BIT(x) ((bool)(((uint32_t)(x) >> 5U) & 0x1U))
/*
* API functions
*/
void canardInit(CanardInstance* out_ins,
void* mem_arena,
size_t mem_arena_size,
CanardOnTransferReception on_reception,
CanardShouldAcceptTransfer should_accept,
void* user_reference)
{
CANARD_ASSERT(out_ins != NULL);
/*
* Checking memory layout.
* This condition is supposed to be true for all 32-bit and smaller platforms.
* If your application fails here, make sure it's not built in 64-bit mode.
* Refer to the design documentation for more info.
*/
CANARD_ASSERT(CANARD_MULTIFRAME_RX_PAYLOAD_HEAD_SIZE >= 5);
memset(out_ins, 0, sizeof(*out_ins));
out_ins->node_id = CANARD_BROADCAST_NODE_ID;
out_ins->on_reception = on_reception;
out_ins->should_accept = should_accept;
out_ins->rx_states = NULL;
out_ins->tx_queue = NULL;
out_ins->user_reference = user_reference;
#if CANARD_ENABLE_TAO_OPTION
out_ins->tao_disabled = false;
#endif
size_t pool_capacity = mem_arena_size / CANARD_MEM_BLOCK_SIZE;
if (pool_capacity > 0xFFFFU)
{
pool_capacity = 0xFFFFU;
}
initPoolAllocator(&out_ins->allocator, mem_arena, (uint16_t)pool_capacity);
}
void* canardGetUserReference(const CanardInstance* ins)
{
CANARD_ASSERT(ins != NULL);
return ins->user_reference;
}
void canardSetLocalNodeID(CanardInstance* ins, uint8_t self_node_id)
{
CANARD_ASSERT(ins != NULL);
if ((ins->node_id == CANARD_BROADCAST_NODE_ID) &&
(self_node_id >= CANARD_MIN_NODE_ID) &&
(self_node_id <= CANARD_MAX_NODE_ID))
{
ins->node_id = self_node_id;
}
else
{
CANARD_ASSERT(false);
}
}
uint8_t canardGetLocalNodeID(const CanardInstance* ins)
{
return ins->node_id;
}
void canardForgetLocalNodeID(CanardInstance* ins) {
ins->node_id = CANARD_BROADCAST_NODE_ID;
}
void canardInitTxTransfer(CanardTxTransfer* transfer)
{
CANARD_ASSERT(transfer != NULL);
memset(transfer, 0, sizeof(*transfer));
}
int16_t canardBroadcast(CanardInstance* ins,
uint64_t data_type_signature,
uint16_t data_type_id,
uint8_t* inout_transfer_id,
uint8_t priority,
const void* payload,
uint16_t payload_len
#if CANARD_ENABLE_DEADLINE
,uint64_t tx_deadline
#endif
#if CANARD_MULTI_IFACE
,uint8_t iface_mask
#endif
#if CANARD_ENABLE_CANFD
,bool canfd
#endif
)
{
// create transfer object
CanardTxTransfer transfer_object = {
.data_type_signature = data_type_signature,
.data_type_id = data_type_id,
.inout_transfer_id = inout_transfer_id,
.priority = priority,
.payload = (uint8_t*)payload,
.payload_len = payload_len,
#if CANARD_ENABLE_DEADLINE
.deadline_usec = tx_deadline,
#endif
#if CANARD_MULTI_IFACE
.iface_mask = iface_mask,
#endif
#if CANARD_ENABLE_CANFD
.canfd = canfd,
#endif
};
return canardBroadcastObj(ins, &transfer_object);
}
int16_t canardBroadcastObj(CanardInstance* ins, CanardTxTransfer* transfer_object)
{
if (transfer_object->payload == NULL && transfer_object->payload_len > 0)
{
return -CANARD_ERROR_INVALID_ARGUMENT;
}
if (transfer_object->priority > CANARD_TRANSFER_PRIORITY_LOWEST)
{
return -CANARD_ERROR_INVALID_ARGUMENT;
}
uint32_t can_id = 0;
uint16_t crc = 0xFFFFU;
if (canardGetLocalNodeID(ins) == 0)
{
if (transfer_object->payload_len > 7)
{
return -CANARD_ERROR_NODE_ID_NOT_SET;
}
static const uint16_t DTIDMask = (1U << ANON_MSG_DATA_TYPE_ID_BIT_LEN) - 1U;
if ((transfer_object->data_type_id & DTIDMask) != transfer_object->data_type_id)
{
return -CANARD_ERROR_INVALID_ARGUMENT;
}
// anonymous transfer, random discriminator
const uint16_t discriminator = (uint16_t)((crcAdd(0xFFFFU, transfer_object->payload, transfer_object->payload_len)) & 0x7FFEU);
can_id = ((uint32_t) transfer_object->priority << 24U) | ((uint32_t) discriminator << 9U) |
((uint32_t) (transfer_object->data_type_id & DTIDMask) << 8U) | (uint32_t) canardGetLocalNodeID(ins);
}
else
{
can_id = ((uint32_t) transfer_object->priority << 24U) | ((uint32_t) transfer_object->data_type_id << 8U) | (uint32_t) canardGetLocalNodeID(ins);
crc = calculateCRC(transfer_object);
}
const int16_t result = enqueueTxFrames(ins, can_id, crc, transfer_object);
if (result > 0) {
incrementTransferID(transfer_object->inout_transfer_id);
}
return result;
}
/*
the following FromIdx and ToIdx functions allow for the
CanardBufferBlock and CanartRxState structures to have the same size
on 32 bit and 64 bit platforms, which allows for easier testing in
simulator environments
*/
CANARD_INTERNAL CanardBufferBlock *canardBufferFromIdx(CanardPoolAllocator* allocator, canard_buffer_idx_t idx)
{
#if CANARD_64_BIT
if (idx == CANARD_BUFFER_IDX_NONE) {
return NULL;
}
return (CanardBufferBlock *)(uintptr_t)&((uint8_t *)allocator->arena)[idx-1];
#else
(void)allocator;
return (CanardBufferBlock *)idx;
#endif
}
CANARD_INTERNAL canard_buffer_idx_t canardBufferToIdx(CanardPoolAllocator* allocator, const CanardBufferBlock *buf)
{
#if CANARD_64_BIT
if (buf == NULL) {
return CANARD_BUFFER_IDX_NONE;
}
return 1U+((canard_buffer_idx_t)((uint8_t *)buf - (uint8_t *)allocator->arena));
#else
(void)allocator;
return (canard_buffer_idx_t)buf;
#endif
}
CANARD_INTERNAL CanardRxState *canardRxFromIdx(CanardPoolAllocator* allocator, canard_buffer_idx_t idx)
{
#if CANARD_64_BIT
if (idx == CANARD_BUFFER_IDX_NONE) {
return NULL;
}
return (CanardRxState *)(uintptr_t)&((uint8_t *)allocator->arena)[idx-1];
#else
(void)allocator;
return (CanardRxState *)idx;
#endif
}
CANARD_INTERNAL canard_buffer_idx_t canardRxToIdx(CanardPoolAllocator* allocator, const CanardRxState *rx)
{
#if CANARD_64_BIT
if (rx == NULL) {
return CANARD_BUFFER_IDX_NONE;
}
return 1U+((canard_buffer_idx_t)((uint8_t *)rx - (uint8_t *)allocator->arena));
#else
(void)allocator;
return (canard_buffer_idx_t)rx;
#endif
}
CANARD_INTERNAL uint16_t calculateCRC(const CanardTxTransfer* transfer_object)
{
uint16_t crc = 0xFFFFU;
#if CANARD_ENABLE_CANFD
if ((transfer_object->payload_len > 7 && !transfer_object->canfd) ||
(transfer_object->payload_len > 63 && transfer_object->canfd))
#else
if (transfer_object->payload_len > 7)
#endif
{
crc = crcAddSignature(crc, transfer_object->data_type_signature);
crc = crcAdd(crc, transfer_object->payload, transfer_object->payload_len);
#if CANARD_ENABLE_CANFD
if (transfer_object->payload_len > 63 && transfer_object->canfd) {
uint8_t empty = 0;
uint8_t padding = (uint8_t)dlcToDataLength(dataLengthToDlc((uint16_t)((transfer_object->payload_len+2) % 63)+1))-1;
padding -= (uint8_t)((transfer_object->payload_len+2) % 63);
for (uint8_t i=0; i<padding; i++) {
crc = crcAddByte(crc, empty);
}
}
#endif
}
return crc;
}
int16_t canardRequestOrRespond(CanardInstance* ins,
uint8_t destination_node_id,
uint64_t data_type_signature,
uint8_t data_type_id,
uint8_t* inout_transfer_id,
uint8_t priority,
CanardRequestResponse kind,
const void* payload,
uint16_t payload_len
#if CANARD_ENABLE_DEADLINE
,uint64_t tx_deadline
#endif
#if CANARD_MULTI_IFACE
,uint8_t iface_mask
#endif
#if CANARD_ENABLE_CANFD
,bool canfd
#endif
)
{
CanardTxTransfer transfer_object = {
.data_type_signature = data_type_signature,
.data_type_id = data_type_id,
.inout_transfer_id = inout_transfer_id,
.priority = priority,
.transfer_type = kind == CanardRequest ? CanardTransferTypeRequest : CanardTransferTypeResponse,
.payload = payload,
.payload_len = payload_len,
#if CANARD_ENABLE_DEADLINE
.deadline_usec = tx_deadline,
#endif
#if CANARD_MULTI_IFACE
.iface_mask = iface_mask,
#endif
#if CANARD_ENABLE_CANFD
.canfd = canfd,
#endif
};
return canardRequestOrRespondObj(ins, destination_node_id, &transfer_object);
}
int16_t canardRequestOrRespondObj(CanardInstance* ins, uint8_t destination_node_id, CanardTxTransfer* transfer_object)
{
if (transfer_object->payload == NULL && transfer_object->payload_len > 0)
{
return -CANARD_ERROR_INVALID_ARGUMENT;
}
if (transfer_object->priority > CANARD_TRANSFER_PRIORITY_LOWEST)
{
return -CANARD_ERROR_INVALID_ARGUMENT;
}
if (canardGetLocalNodeID(ins) == 0)
{
return -CANARD_ERROR_NODE_ID_NOT_SET;
}
const uint32_t can_id = ((uint32_t) transfer_object->priority << 24U) | ((uint32_t) transfer_object->data_type_id << 16U) |
((uint32_t) transfer_object->transfer_type << 15U) | ((uint32_t) destination_node_id << 8U) |
(1U << 7U) | (uint32_t) canardGetLocalNodeID(ins);
uint16_t crc = calculateCRC(transfer_object);
const int16_t result = enqueueTxFrames(ins, can_id, crc, transfer_object);
if (result > 0 && transfer_object->transfer_type == CanardTransferTypeRequest) // Response Transfer ID must not be altered
{
incrementTransferID(transfer_object->inout_transfer_id);
}
return result;
}
CanardCANFrame* canardPeekTxQueue(const CanardInstance* ins)
{
if (ins->tx_queue == NULL)
{
return NULL;
}
return &ins->tx_queue->frame;
}
void canardPopTxQueue(CanardInstance* ins)
{
CanardTxQueueItem* item = ins->tx_queue;
ins->tx_queue = item->next;
freeBlock(&ins->allocator, item);
}
int16_t canardHandleRxFrame(CanardInstance* ins, const CanardCANFrame* frame, uint64_t timestamp_usec)
{
const CanardTransferType transfer_type = extractTransferType(frame->id);
const uint8_t destination_node_id = (transfer_type == CanardTransferTypeBroadcast) ?
(uint8_t)CANARD_BROADCAST_NODE_ID :
DEST_ID_FROM_ID(frame->id);
// TODO: This function should maintain statistics of transfer errors and such.
if ((frame->id & CANARD_CAN_FRAME_EFF) == 0 ||
(frame->id & CANARD_CAN_FRAME_RTR) != 0 ||
(frame->id & CANARD_CAN_FRAME_ERR) != 0 ||
(frame->data_len < 1))
{
return -CANARD_ERROR_RX_INCOMPATIBLE_PACKET;
}
if (transfer_type != CanardTransferTypeBroadcast &&
destination_node_id != canardGetLocalNodeID(ins))
{
return -CANARD_ERROR_RX_WRONG_ADDRESS;
}
const uint8_t priority = PRIORITY_FROM_ID(frame->id);
const uint8_t source_node_id = SOURCE_ID_FROM_ID(frame->id);
const uint16_t data_type_id = extractDataType(frame->id);
const uint32_t transfer_descriptor =
MAKE_TRANSFER_DESCRIPTOR(data_type_id, transfer_type, source_node_id, destination_node_id);
const uint8_t tail_byte = frame->data[frame->data_len - 1];
uint64_t data_type_signature = 0;
CanardRxState* rx_state = NULL;
if (IS_START_OF_TRANSFER(tail_byte))
{
if (ins->should_accept(ins, &data_type_signature, data_type_id, transfer_type, source_node_id))
{
rx_state = traverseRxStates(ins, transfer_descriptor);
if(rx_state == NULL)
{
return -CANARD_ERROR_OUT_OF_MEMORY;
}
}
else
{
return -CANARD_ERROR_RX_NOT_WANTED;
}
}
else
{
rx_state = findRxState(ins, transfer_descriptor);
if (rx_state == NULL)
{
return -CANARD_ERROR_RX_MISSED_START;
}
}
CANARD_ASSERT(rx_state != NULL); // All paths that lead to NULL should be terminated with return above
// Resolving the state flags:
const bool not_initialized = rx_state->timestamp_usec == 0;
const bool tid_timed_out = (timestamp_usec - rx_state->timestamp_usec) > TRANSFER_TIMEOUT_USEC;
const bool same_iface = frame->iface_id == rx_state->iface_id;
const bool first_frame = IS_START_OF_TRANSFER(tail_byte);
const bool not_previous_tid =
computeTransferIDForwardDistance((uint8_t) rx_state->transfer_id, TRANSFER_ID_FROM_TAIL_BYTE(tail_byte)) > 1;
const bool iface_switch_allowed = (timestamp_usec - rx_state->timestamp_usec) > IFACE_SWITCH_DELAY_USEC;
const bool non_wrapped_tid = computeTransferIDForwardDistance(TRANSFER_ID_FROM_TAIL_BYTE(tail_byte), (uint8_t) rx_state->transfer_id) < (1 << (TRANSFER_ID_BIT_LEN-1));
const bool incomplete_frame = rx_state->buffer_blocks != CANARD_BUFFER_IDX_NONE;
const bool need_restart =
(not_initialized) ||
(tid_timed_out) ||
(same_iface && first_frame && (not_previous_tid || incomplete_frame)) ||
(iface_switch_allowed && first_frame && non_wrapped_tid);
if (need_restart)
{
rx_state->transfer_id = TRANSFER_ID_FROM_TAIL_BYTE(tail_byte);
rx_state->next_toggle = 0;
releaseStatePayload(ins, rx_state);
rx_state->iface_id = frame->iface_id;
if (!IS_START_OF_TRANSFER(tail_byte))
{
rx_state->transfer_id++;
return -CANARD_ERROR_RX_MISSED_START;
}
}
if (frame->iface_id != rx_state->iface_id)
{
// drop frame if coming from unexpected interface
return CANARD_OK;
}
if (IS_START_OF_TRANSFER(tail_byte) && IS_END_OF_TRANSFER(tail_byte)) // single frame transfer
{
rx_state->timestamp_usec = timestamp_usec;
CanardRxTransfer rx_transfer = {
.timestamp_usec = timestamp_usec,
.payload_head = frame->data,
.payload_len = (uint8_t)(frame->data_len - 1U),
.data_type_id = data_type_id,
.transfer_type = (uint8_t)transfer_type,
.transfer_id = TRANSFER_ID_FROM_TAIL_BYTE(tail_byte),
.priority = priority,
.source_node_id = source_node_id,
#if CANARD_ENABLE_CANFD
.canfd = frame->canfd,
.tao = !(frame->canfd || ins->tao_disabled)
#elif CANARD_ENABLE_TAO_OPTION
.tao = !ins->tao_disabled
#endif
};
ins->on_reception(ins, &rx_transfer);
prepareForNextTransfer(rx_state);
return CANARD_OK;
}
if (TOGGLE_BIT(tail_byte) != rx_state->next_toggle)
{
return -CANARD_ERROR_RX_WRONG_TOGGLE;
}
if (TRANSFER_ID_FROM_TAIL_BYTE(tail_byte) != rx_state->transfer_id)
{
return -CANARD_ERROR_RX_UNEXPECTED_TID;
}
if (IS_START_OF_TRANSFER(tail_byte) && !IS_END_OF_TRANSFER(tail_byte)) // Beginning of multi frame transfer
{
if (frame->data_len <= 3)
{
return -CANARD_ERROR_RX_SHORT_FRAME;
}
// take off the crc and store the payload
rx_state->timestamp_usec = timestamp_usec;
rx_state->payload_len = 0;
const int16_t ret = bufferBlockPushBytes(&ins->allocator, rx_state, frame->data + 2,
(uint8_t) (frame->data_len - 3));
if (ret < 0)
{
releaseStatePayload(ins, rx_state);
prepareForNextTransfer(rx_state);
return -CANARD_ERROR_OUT_OF_MEMORY;
}
rx_state->payload_crc = (uint16_t)(((uint16_t) frame->data[0]) | (uint16_t)((uint16_t) frame->data[1] << 8U));
rx_state->calculated_crc = crcAddSignature(0xFFFFU, data_type_signature);
rx_state->calculated_crc = crcAdd((uint16_t)rx_state->calculated_crc,
frame->data + 2, (uint8_t)(frame->data_len - 3));
}
else if (!IS_START_OF_TRANSFER(tail_byte) && !IS_END_OF_TRANSFER(tail_byte)) // Middle of a multi-frame transfer
{
const int16_t ret = bufferBlockPushBytes(&ins->allocator, rx_state, frame->data,
(uint8_t) (frame->data_len - 1));
if (ret < 0)
{
releaseStatePayload(ins, rx_state);
prepareForNextTransfer(rx_state);
return -CANARD_ERROR_OUT_OF_MEMORY;
}
rx_state->calculated_crc = crcAdd((uint16_t)rx_state->calculated_crc,
frame->data, (uint8_t)(frame->data_len - 1));
}
else // End of a multi-frame transfer
{
const uint8_t frame_payload_size = (uint8_t)(frame->data_len - 1);
uint8_t tail_offset = 0;
if (rx_state->payload_len < CANARD_MULTIFRAME_RX_PAYLOAD_HEAD_SIZE)
{
// Copy the beginning of the frame into the head, point the tail pointer to the remainder
for (size_t i = rx_state->payload_len;
(i < CANARD_MULTIFRAME_RX_PAYLOAD_HEAD_SIZE) && (tail_offset < frame_payload_size);
i++, tail_offset++)
{
rx_state->buffer_head[i] = frame->data[tail_offset];
}
}
else
{
// Like above, except that the beginning goes into the last block of the storage
CanardBufferBlock* block = canardBufferFromIdx(&ins->allocator, rx_state->buffer_blocks);
if (block != NULL)
{
size_t offset = CANARD_MULTIFRAME_RX_PAYLOAD_HEAD_SIZE; // Payload offset of the first block
while (block->next != NULL)
{
block = block->next;
offset += CANARD_BUFFER_BLOCK_DATA_SIZE;
}
CANARD_ASSERT(block != NULL);
const size_t offset_within_block = rx_state->payload_len - offset;
CANARD_ASSERT(offset_within_block <= CANARD_BUFFER_BLOCK_DATA_SIZE);
for (size_t i = offset_within_block;
(i < CANARD_BUFFER_BLOCK_DATA_SIZE) && (tail_offset < frame_payload_size);
i++, tail_offset++)
{
block->data[i] = frame->data[tail_offset];
}
}
}
CanardRxTransfer rx_transfer = {
.timestamp_usec = timestamp_usec,
.payload_head = rx_state->buffer_head,
.payload_middle = canardBufferFromIdx(&ins->allocator, rx_state->buffer_blocks),
.payload_tail = (tail_offset >= frame_payload_size) ? NULL : (&frame->data[tail_offset]),
.payload_len = (uint16_t)(rx_state->payload_len + frame_payload_size),
.data_type_id = data_type_id,
.transfer_type = (uint8_t)transfer_type,
.transfer_id = TRANSFER_ID_FROM_TAIL_BYTE(tail_byte),
.priority = priority,
.source_node_id = source_node_id,
#if CANARD_ENABLE_CANFD
.canfd = frame->canfd,
.tao = !(frame->canfd || ins->tao_disabled)
#elif CANARD_ENABLE_TAO_OPTION
.tao = !ins->tao_disabled
#endif
};
rx_state->buffer_blocks = CANARD_BUFFER_IDX_NONE; // Block list ownership has been transferred to rx_transfer!
// CRC validation
rx_state->calculated_crc = crcAdd((uint16_t)rx_state->calculated_crc, frame->data, frame->data_len - 1U);
if (rx_state->calculated_crc == rx_state->payload_crc)
{
ins->on_reception(ins, &rx_transfer);
}
// Making sure the payload is released even if the application didn't bother with it
canardReleaseRxTransferPayload(ins, &rx_transfer);
prepareForNextTransfer(rx_state);
if (rx_state->calculated_crc == rx_state->payload_crc)
{
return CANARD_OK;
}
else
{
return -CANARD_ERROR_RX_BAD_CRC;
}
}
rx_state->next_toggle = rx_state->next_toggle ? 0 : 1;
return CANARD_OK;
}
void canardCleanupStaleTransfers(CanardInstance* ins, uint64_t current_time_usec)
{
CanardRxState* prev = ins->rx_states, * state = ins->rx_states;
while (state != NULL)
{
if ((current_time_usec - state->timestamp_usec) > TRANSFER_TIMEOUT_USEC)
{
if (state == ins->rx_states)
{
releaseStatePayload(ins, state);
ins->rx_states = canardRxFromIdx(&ins->allocator, ins->rx_states->next);
freeBlock(&ins->allocator, state);
state = ins->rx_states;
prev = state;
}
else
{
releaseStatePayload(ins, state);
prev->next = state->next;
freeBlock(&ins->allocator, state);
state = canardRxFromIdx(&ins->allocator, prev->next);
}
}
else
{
prev = state;
state = canardRxFromIdx(&ins->allocator, state->next);
}
}
#if CANARD_MULTI_IFACE || CANARD_ENABLE_DEADLINE
// remove stale TX transfers
CanardTxQueueItem* prev_item = ins->tx_queue, * item = ins->tx_queue;
while (item != NULL)
{
#if CANARD_MULTI_IFACE && CANARD_ENABLE_DEADLINE
if ((current_time_usec > item->frame.deadline_usec) || item->frame.iface_mask == 0)
#elif CANARD_MULTI_IFACE
if (item->frame.iface_mask == 0)
#else
if (current_time_usec > item->frame.deadline_usec)
#endif
{
if (item == ins->tx_queue)
{
ins->tx_queue = ins->tx_queue->next;
freeBlock(&ins->allocator, item);
item = ins->tx_queue;
prev_item = item;
}
else
{
prev_item->next = item->next;
freeBlock(&ins->allocator, item);
item = prev_item->next;
}
}
else
{
prev_item = item;
item = item->next;
}
}
#endif
}
int16_t canardDecodeScalar(const CanardRxTransfer* transfer,
uint32_t bit_offset,
uint8_t bit_length,
bool value_is_signed,
void* out_value)
{
if (transfer == NULL || out_value == NULL)
{
return -CANARD_ERROR_INVALID_ARGUMENT;
}
if (bit_length < 1 || bit_length > 64)
{
return -CANARD_ERROR_INVALID_ARGUMENT;
}
if (bit_length == 1 && value_is_signed)
{
return -CANARD_ERROR_INVALID_ARGUMENT;
}
/*
* Reading raw bytes into the temporary storage.
* Luckily, C guarantees that every element is aligned at the beginning (lower address) of the union.
*/
union
{
bool boolean; ///< sizeof(bool) is implementation-defined, so it has to be handled separately
uint8_t u8; ///< Also char
int8_t s8;
uint16_t u16;
int16_t s16;
uint32_t u32;
int32_t s32; ///< Also float, possibly double, possibly long double (depends on implementation)
uint64_t u64;
int64_t s64; ///< Also double, possibly float, possibly long double (depends on implementation)
uint8_t bytes[8];
} storage;
memset(&storage, 0, sizeof(storage)); // This is important
const int16_t result = descatterTransferPayload(transfer, bit_offset, bit_length, &storage.bytes[0]);
if (result <= 0)
{
return result;
}
CANARD_ASSERT((result > 0) && (result <= 64) && (result <= bit_length));
/*
* The bit copy algorithm assumes that more significant bits have lower index, so we need to shift some.
* Extra most significant bits will be filled with zeroes, which is fine.
* Coverity Scan mistakenly believes that the array may be overrun if bit_length == 64; however, this branch will
* not be taken if bit_length == 64, because 64 % 8 == 0.
*/
if ((bit_length % 8) != 0)
{
// coverity[overrun-local]
storage.bytes[bit_length / 8U] = (uint8_t)(storage.bytes[bit_length / 8U] >> ((8U - (bit_length % 8U)) & 7U));
}
/*
* Determining the closest standard byte length - this will be needed for byte reordering and sign bit extension.
*/
uint8_t std_byte_length = 0;
if (bit_length == 1) { std_byte_length = sizeof(bool); }
else if (bit_length <= 8) { std_byte_length = 1; }
else if (bit_length <= 16) { std_byte_length = 2; }
else if (bit_length <= 32) { std_byte_length = 4; }
else if (bit_length <= 64) { std_byte_length = 8; }
else
{
CANARD_ASSERT(false);
return -CANARD_ERROR_INTERNAL;
}
CANARD_ASSERT((std_byte_length > 0) && (std_byte_length <= 8));
/*
* Flipping the byte order if needed.
*/
if (isBigEndian())
{
swapByteOrder(&storage.bytes[0], std_byte_length);
}
#if WORD_ADDRESSING_IS_16BITS
/*
* Copying 8-bit array to 64-bit storage
*/
{
uint64_t temp = 0;
for(uint16_t i=0; i<std_byte_length; i++)
{
temp |= (((uint64_t)storage.bytes[i] & 0xFFU) << (8*i));
}
storage.u64 = temp;
}
#endif
/*
* Extending the sign bit if needed. I miss templates.
* Note that we operate on unsigned values in order to avoid undefined behaviors.
*/
if (value_is_signed && (std_byte_length * 8 != bit_length))
{
if (bit_length <= 8)
{
if ((storage.u8 & (1U << (bit_length - 1U))) != 0) // If the sign bit is set...
{
storage.u8 |= (uint8_t) 0xFFU & (uint8_t) ~((1U << bit_length) - 1U); // ...set all bits above it.
}
}
else if (bit_length <= 16)
{
if ((storage.u16 & (1U << (bit_length - 1U))) != 0)
{
storage.u16 |= (uint16_t) 0xFFFFU & (uint16_t) ~((1U << bit_length) - 1U);
}
}
else if (bit_length <= 32)
{
if ((storage.u32 & (((uint32_t) 1) << (bit_length - 1U))) != 0)
{
storage.u32 |= (uint32_t) 0xFFFFFFFFUL & (uint32_t) ~((((uint32_t) 1) << bit_length) - 1U);
}
}
else if (bit_length < 64) // Strictly less, this is not a typo
{
if ((storage.u64 & (((uint64_t) 1) << (bit_length - 1U))) != 0)
{
storage.u64 |= (uint64_t) 0xFFFFFFFFFFFFFFFFULL & (uint64_t) ~((((uint64_t) 1) << bit_length) - 1U);
}
}
else
{
CANARD_ASSERT(false);
return -CANARD_ERROR_INTERNAL;
}
}
/*
* Copying the result out.
*/
if (value_is_signed)
{
if (bit_length <= 8) { *( (int8_t*) out_value) = storage.s8; }
else if (bit_length <= 16) { *((int16_t*) out_value) = storage.s16; }
else if (bit_length <= 32) { *((int32_t*) out_value) = storage.s32; }
else if (bit_length <= 64) { *((int64_t*) out_value) = storage.s64; }
else
{
CANARD_ASSERT(false);
return -CANARD_ERROR_INTERNAL;
}
}
else
{
if (bit_length == 1) { *( (bool*) out_value) = storage.boolean; }
else if (bit_length <= 8) { *( (uint8_t*) out_value) = storage.u8; }
else if (bit_length <= 16) { *((uint16_t*) out_value) = storage.u16; }
else if (bit_length <= 32) { *((uint32_t*) out_value) = storage.u32; }
else if (bit_length <= 64) { *((uint64_t*) out_value) = storage.u64; }
else
{
CANARD_ASSERT(false);
return -CANARD_ERROR_INTERNAL;
}
}
CANARD_ASSERT(result <= bit_length);
CANARD_ASSERT(result > 0);
return result;
}
void canardEncodeScalar(void* destination,
uint32_t bit_offset,
uint8_t bit_length,
const void* value)
{
/*
* This function can only fail due to invalid arguments, so it was decided to make it return void,
* and in the case of bad arguments try the best effort or just trigger an CANARD_ASSERTion failure.
* Maybe not the best solution, but it simplifies the API.
*/
CANARD_ASSERT(destination != NULL);
CANARD_ASSERT(value != NULL);
if (bit_length > 64)
{
CANARD_ASSERT(false);
bit_length = 64;
}
if (bit_length < 1)
{
CANARD_ASSERT(false);
bit_length = 1;
}
/*
* Preparing the data in the temporary storage.
*/
union
{
bool boolean;
uint8_t u8;
uint16_t u16;
uint32_t u32;
uint64_t u64;
uint8_t bytes[8];
} storage;
memset(&storage, 0, sizeof(storage));
uint8_t std_byte_length = 0;
// Extra most significant bits can be safely ignored here.
if (bit_length == 1) { std_byte_length = sizeof(bool); storage.boolean = (*((bool*) value) != 0); }
else if (bit_length <= 8) { std_byte_length = 1; storage.u8 = *((uint8_t*) value); }
else if (bit_length <= 16) { std_byte_length = 2; storage.u16 = *((uint16_t*) value); }
else if (bit_length <= 32) { std_byte_length = 4; storage.u32 = *((uint32_t*) value); }
else if (bit_length <= 64) { std_byte_length = 8; storage.u64 = *((uint64_t*) value); }
else
{
CANARD_ASSERT(false);
}
CANARD_ASSERT(std_byte_length > 0);
#if WORD_ADDRESSING_IS_16BITS
/*
* Copying 64-bit storage to 8-bit array
*/
{
uint64_t temp = storage.u64;
for(uint16_t i=0; i<std_byte_length; i++)
{
storage.bytes[i] = (temp >> (8*i)) & 0xFFU;
}
}
#endif
if (isBigEndian())
{
swapByteOrder(&storage.bytes[0], std_byte_length);
}
/*
* The bit copy algorithm assumes that more significant bits have lower index, so we need to shift some.
* Extra least significant bits will be filled with zeroes, which is fine.
* Extra most significant bits will be discarded here.
* Coverity Scan mistakenly believes that the array may be overrun if bit_length == 64; however, this branch will
* not be taken if bit_length == 64, because 64 % 8 == 0.
*/
if ((bit_length % 8) != 0)
{
// coverity[overrun-local]
storage.bytes[bit_length / 8U] = (uint8_t)(storage.bytes[bit_length / 8U] << ((8U - (bit_length % 8U)) & 7U));
}
/*
* Now, the storage contains properly serialized scalar. Copying it out.
*/
copyBitArray(&storage.bytes[0], 0, bit_length, (uint8_t*) destination, bit_offset);
}
void canardReleaseRxTransferPayload(CanardInstance* ins, CanardRxTransfer* transfer)
{
while (transfer->payload_middle != NULL)
{