diff options
Diffstat (limited to 'libs/isotp-c/src/isotp/receive.c')
| -rw-r--r-- | libs/isotp-c/src/isotp/receive.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/libs/isotp-c/src/isotp/receive.c b/libs/isotp-c/src/isotp/receive.c new file mode 100644 index 0000000..35b7a2a --- /dev/null +++ b/libs/isotp-c/src/isotp/receive.c @@ -0,0 +1,166 @@ +#include <isotp/receive.h> +#include <isotp/send.h> +#include <bitfield/bitfield.h> +#include <string.h> +#include <stdlib.h> + +#define ARBITRATION_ID_OFFSET 0x8 + +static void isotp_complete_receive(IsoTpReceiveHandle* handle, IsoTpMessage* message) { + if(handle->message_received_callback != NULL) { + handle->message_received_callback(message); + } +} + +bool isotp_handle_single_frame(IsoTpReceiveHandle* handle, IsoTpMessage* message) { + isotp_complete_receive(handle, message); + return true; +} + +bool isotp_handle_multi_frame(IsoTpReceiveHandle* handle, IsoTpMessage* message) { + // call this once all consecutive frames have been received + isotp_complete_receive(handle, message); + return true; +} + +bool isotp_send_flow_control_frame(IsoTpShims* shims, IsoTpMessage* message) { + uint8_t can_data[CAN_MESSAGE_BYTE_SIZE] = {0}; + + if(!set_nibble(PCI_NIBBLE_INDEX, PCI_FLOW_CONTROL_FRAME, can_data, sizeof(can_data))) { + shims->log("Unable to set PCI in CAN data"); + return false; + } + + shims->send_can_message(message->arbitration_id - ARBITRATION_ID_OFFSET, can_data, + shims->frame_padding ? 8 : 1 + message->size); + return true; +} + + +IsoTpReceiveHandle isotp_receive(IsoTpShims* shims, + const uint32_t arbitration_id, IsoTpMessageReceivedHandler callback) { + IsoTpReceiveHandle handle = { + success: false, + completed: false, + arbitration_id: arbitration_id, + message_received_callback: callback + }; + + return handle; +} + +IsoTpMessage isotp_continue_receive(IsoTpShims* shims, + IsoTpReceiveHandle* handle, const uint32_t arbitration_id, + const uint8_t data[], const uint8_t size) { + IsoTpMessage message = { + arbitration_id: arbitration_id, + completed: false, + multi_frame: false, + payload: {0}, + size: 0 + }; + + if(size < 1) { + return message; + } + + if(handle->arbitration_id != arbitration_id) { + if(shims->log != NULL) { + // You may turn this on for debugging, but in normal operation it's + // very noisy if you are passing all received CAN messages to this + // handler. + /* shims->log("The arb ID 0x%x doesn't match the expected rx ID 0x%x", */ + /* arbitration_id, handle->arbitration_id); */ + } + return message; + } + + IsoTpProtocolControlInformation pci = (IsoTpProtocolControlInformation) + get_nibble(data, size, 0); + + // TODO this is set up to handle rx a response with a payload, but not to + // handle flow control responses for multi frame messages that we're in the + // process of sending + + switch(pci) { + case PCI_SINGLE: { + uint8_t payload_length = get_nibble(data, size, 1); + + if(payload_length > 0) { + memcpy(message.payload, &data[1], payload_length); + } + + message.size = payload_length; + message.completed = true; + handle->success = true; + handle->completed = true; + isotp_handle_single_frame(handle, &message); + break; + } + //If multi-frame, then the payload length is contained in the 12 + //bits following the first nibble of Byte 0. + case PCI_FIRST_FRAME: { + uint16_t payload_length = (get_nibble(data, size, 1) << 8) + get_byte(data, size, 1); + + if(payload_length > OUR_MAX_ISO_TP_MESSAGE_SIZE) { + shims->log("Multi-frame response too large for receive buffer."); + break; + } + + //Need to allocate memory for the combination of multi-frame + //messages. That way we don't have to allocate 4k of memory + //for each multi-frame response. + uint8_t* combined_payload = NULL; + combined_payload = (uint8_t*)malloc(sizeof(uint8_t)*payload_length); + + if(combined_payload == NULL) { + shims->log("Unable to allocate memory for multi-frame response."); + break; + } + + memcpy(combined_payload, &data[2], CAN_MESSAGE_BYTE_SIZE - 2); + handle->receive_buffer = combined_payload; + handle->received_buffer_size = CAN_MESSAGE_BYTE_SIZE - 2; + handle->incoming_message_size = payload_length; + + message.multi_frame = true; + handle->success = false; + handle->completed = false; + isotp_send_flow_control_frame(shims, &message); + break; + } + case PCI_CONSECUTIVE_FRAME: { + uint8_t start_index = handle->received_buffer_size; + uint8_t remaining_bytes = handle->incoming_message_size - start_index; + message.multi_frame = true; + + if(remaining_bytes > 7) { + memcpy(&handle->receive_buffer[start_index], &data[1], CAN_MESSAGE_BYTE_SIZE - 1); + handle->received_buffer_size = start_index + 7; + } else { + memcpy(&handle->receive_buffer[start_index], &data[1], remaining_bytes); + handle->received_buffer_size = start_index + remaining_bytes; + + if(handle->received_buffer_size != handle->incoming_message_size){ + free(handle->receive_buffer); + handle->success = false; + shims->log("Error capturing all bytes of multi-frame. Freeing memory."); + } else { + memcpy(message.payload,&handle->receive_buffer[0],handle->incoming_message_size); + free(handle->receive_buffer); + message.size = handle->incoming_message_size; + message.completed = true; + shims->log("Successfully captured all of multi-frame. Freeing memory."); + + handle->success = true; + handle->completed = true; + isotp_handle_multi_frame(handle, &message); + } + } + break; + } + default: + break; + } + return message; +} |