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Add support for multi-frame responses (#4)
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* first test with multi-frame. storing data in handler. still need to free memory since using malloc.

* hardcode the IsoTpMessage payload size. copy the full multi-frame response into a complete isotpMessage once all frames have been received. otherwise, the returned isotpMessage is not complete.

* remove unnecessary debug statements.

* do not receive multi-frame message if it is larger than the payload buffer size.

* update changelog with multi-frame support

* fix the changelog version for proper semantic versioning. oops.

* move pointer intialization for testing purposes.

* add tests for multi-frame.

* try latest version of check

* fix syntax for version install.

* fix tests. no longer check for malloc pointer (not supported in Travis version of check.h - just test that flow control message has not been sent.

* add IsoTpMessage field for multi_frame. Need this upstream for doing timeout updates.

* add test multi_frame field.
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Zac Nelson authored Sep 14, 2016
1 parent 50722a2 commit 4e73753
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Showing 4 changed files with 177 additions and 13 deletions.
5 changes: 5 additions & 0 deletions CHANGELOG.mkd
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Original file line number Diff line number Diff line change
@@ -1,5 +1,10 @@
# ISO 15765-2 Support Library in C

## v0.2

* Add multi-frame support for diagnostic responses. An IsoTpMessage payload is
currently limited to 256 bytes.

## v0.1

* Initial release
16 changes: 12 additions & 4 deletions src/isotp/isotp_types.h
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Original file line number Diff line number Diff line change
Expand Up @@ -9,8 +9,14 @@
#define MAX_ISO_TP_MESSAGE_SIZE 4096
// TODO we want to avoid malloc, and we can't be allocated 4K on the stack for
// each IsoTpMessage, so for now we're setting an artificial max message size
// here - since we only handle single frame messages, 8 bytes is plenty.
#define OUR_MAX_ISO_TP_MESSAGE_SIZE 8
// here - for most multi-frame use cases, 256 bytes is plenty.
#define OUR_MAX_ISO_TP_MESSAGE_SIZE 256

/* Private: IsoTp nibble specifics for PCI and Payload.
*/
#define PCI_NIBBLE_INDEX 0
#define PAYLOAD_LENGTH_NIBBLE_INDEX 1
#define PAYLOAD_BYTE_INDEX 1

/* Private: The default timeout to use when waiting for a response during a
* multi-frame send or receive.
Expand All @@ -30,8 +36,9 @@ extern "C" {
* completed - An IsoTpMessage is the return value from a few functions - this
* attribute will be true if the message is actually completely received.
* If the function returns but is only partially through receiving the
* message, this will be false and you should not consider the other data
* to be valid.
* message, this will be false, the multi_frame attribute will be true,
* and you should not consider the other data to be valid.
* multi_frame - Designates the message is being built with multi-frame.
* arbitration_id - The arbitration ID of the message.
* payload - The optional payload of the message - don't forget to check the
* size!
Expand All @@ -42,6 +49,7 @@ typedef struct {
uint8_t payload[OUR_MAX_ISO_TP_MESSAGE_SIZE];
uint16_t size;
bool completed;
bool multi_frame;
} IsoTpMessage;

/* Public: The type signature for an optional logging function, if the user
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101 changes: 92 additions & 9 deletions src/isotp/receive.c
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Original file line number Diff line number Diff line change
@@ -1,6 +1,10 @@
#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) {
Expand All @@ -13,6 +17,26 @@ bool isotp_handle_single_frame(IsoTpReceiveHandle* handle, IsoTpMessage* 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 = {
Expand All @@ -31,6 +55,7 @@ IsoTpMessage isotp_continue_receive(IsoTpShims* shims,
IsoTpMessage message = {
arbitration_id: arbitration_id,
completed: false,
multi_frame: false,
payload: {0},
size: 0
};
Expand All @@ -53,30 +78,88 @@ IsoTpMessage isotp_continue_receive(IsoTpShims* shims,
IsoTpProtocolControlInformation pci = (IsoTpProtocolControlInformation)
get_nibble(data, size, 0);

uint8_t payload_length = get_nibble(data, size, 1);
uint8_t payload[payload_length];
if(payload_length > 0 && size > 0) {
memcpy(payload, &data[1], payload_length);
}

// 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, payload, payload_length);
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:
shims->log("Only single frame messages are supported");
break;
}
return message;
Expand Down
68 changes: 68 additions & 0 deletions tests/test_receive.c
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Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,8 @@
extern IsoTpShims SHIMS;
extern IsoTpReceiveHandle RECEIVE_HANDLE;

extern void message_sent(const IsoTpMessage* message, const bool success);

extern uint16_t last_can_frame_sent_arb_id;
extern uint8_t last_can_payload_sent;
extern uint8_t last_can_payload_size;
Expand Down Expand Up @@ -81,6 +83,70 @@ START_TEST (test_receive_single_frame)
}
END_TEST

START_TEST (test_receive_multi_frame)
{
const uint8_t data0[CAN_MESSAGE_BYTE_SIZE] = {0x10, 0x14, 0x49, 0x02, 0x01, 0x31, 0x46, 0x4d};
IsoTpMessage message0 = isotp_continue_receive(&SHIMS, &RECEIVE_HANDLE, 0x2a, data0, 8);
fail_unless(!RECEIVE_HANDLE.completed);
fail_unless(!message0.completed);
fail_unless(!message_was_received);
fail_unless(message0.multi_frame);
//make sure flow control message has been sent.
ck_assert_int_eq(last_can_frame_sent_arb_id, 0x2a - 8);
ck_assert_int_eq(last_can_payload_sent, 0x30);

const uint8_t data1[CAN_MESSAGE_BYTE_SIZE] = {0x21, 0x43, 0x55, 0x39, 0x4a, 0x39, 0x34, 0x48};
IsoTpMessage message1 = isotp_continue_receive(&SHIMS, &RECEIVE_HANDLE, 0x2a, data1, 8);
fail_unless(!RECEIVE_HANDLE.completed);
fail_unless(!message1.completed);
fail_unless(!message_was_received);
fail_unless(message1.multi_frame);

const uint8_t data2[CAN_MESSAGE_BYTE_SIZE] = {0x22, 0x55, 0x41, 0x30, 0x34, 0x35, 0x32, 0x34};
IsoTpMessage message2 = isotp_continue_receive(&SHIMS, &RECEIVE_HANDLE, 0x2a, data2, 8);
fail_unless(RECEIVE_HANDLE.completed);
fail_unless(message2.completed);
fail_unless(message_was_received);
fail_unless(message2.multi_frame);

ck_assert_int_eq(last_message_received_arb_id, 0x2a);
ck_assert_int_eq(last_message_received_payload_size, 0x14);
ck_assert_int_eq(last_message_received_payload[0], 0x49);
ck_assert_int_eq(last_message_received_payload[1], 0x02);
ck_assert_int_eq(last_message_received_payload[2], 0x01);
ck_assert_int_eq(last_message_received_payload[3], 0x31);
ck_assert_int_eq(last_message_received_payload[4], 0x46);
ck_assert_int_eq(last_message_received_payload[5], 0x4d);
ck_assert_int_eq(last_message_received_payload[6], 0x43);
ck_assert_int_eq(last_message_received_payload[7], 0x55);
ck_assert_int_eq(last_message_received_payload[8], 0x39);
ck_assert_int_eq(last_message_received_payload[9], 0x4a);
ck_assert_int_eq(last_message_received_payload[10], 0x39);
ck_assert_int_eq(last_message_received_payload[11], 0x34);
ck_assert_int_eq(last_message_received_payload[12], 0x48);
ck_assert_int_eq(last_message_received_payload[13], 0x55);
ck_assert_int_eq(last_message_received_payload[14], 0x41);
ck_assert_int_eq(last_message_received_payload[15], 0x30);
ck_assert_int_eq(last_message_received_payload[16], 0x34);
ck_assert_int_eq(last_message_received_payload[17], 0x35);
ck_assert_int_eq(last_message_received_payload[18], 0x32);
ck_assert_int_eq(last_message_received_payload[19], 0x34);
}
END_TEST

START_TEST (test_receive_large_multi_frame)
{
const uint8_t data0[CAN_MESSAGE_BYTE_SIZE] = {0x11, 0x01, 0x49, 0x02, 0x01, 0x31, 0x46, 0x4d};
IsoTpMessage message = isotp_continue_receive(&SHIMS, &RECEIVE_HANDLE, 0x2a, data0, 8);
//Make sure we don't try to receive messages that are too large and don't send flow control.
fail_unless(!can_frame_was_sent);
fail_unless(!RECEIVE_HANDLE.completed);
fail_unless(!message.completed);
fail_unless(!message_was_received);
fail_unless(!message.multi_frame);
}
END_TEST

Suite* testSuite(void) {
Suite* s = suite_create("iso15765");
TCase *tc_core = tcase_create("receive");
Expand All @@ -90,6 +156,8 @@ Suite* testSuite(void) {
tcase_add_test(tc_core, test_receive_single_frame);
tcase_add_test(tc_core, test_receive_single_frame_empty_payload);
tcase_add_test(tc_core, test_receive_empty_can_message);
tcase_add_test(tc_core, test_receive_multi_frame);
tcase_add_test(tc_core, test_receive_large_multi_frame);
suite_add_tcase(s, tc_core);

return s;
Expand Down

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