Separation Generator to a dedicated repo

Change-Id: Id94831651c3266861435272a6e36c7884bef2c45
Signed-off-by: Romain Forlot <romain.forlot@iot.bzh>

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;
+}