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-rw-r--r--libs/isotp-c/src/isotp/receive.c166
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 00000000..35b7a2a6
--- /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;
+}