// required, this must send a single CAN message with the given arbitration
// ID (i.e. the CAN message ID) and data. The size will never be more than 8
// bytes.
bool send_can(const uint32_t arbitration_id, const uint8_t* data,
        const uint8_t size) {
    ...
}

// optional, provide to receive debugging log messages
void debug(const char* format, ...) {
    ...
}


// not used in the current version
bool set_timer(uint16_t time_ms, void (*callback)) {
    ...
}

IsoTpShims shims = isotp_init_shims(debug, send_can, set_timer);

// Optional: This is your callback that will be called when the message is
// completely sent. If it was single frame (the only type supported right
// now), this will be called immediately.
void message_sent(const IsoTpMessage* message, const bool success) {
    // You received the message! Do something with it.
}

IsoTpSendHandle handle = isotp_send(&shims, 0x100, NULL, 0, message_sent);

if(handle.completed) {
    if(!handle.success) {
        // something happened and it already failed - possibly we aren't able to
        // send CAN messages
        return;
    } else {
        // If the message fit in a single frame, it's already been sent
        // and you're done
    }
} else {
    while(true) {
        // Continue to read from CAN, passing off each message to the handle
        // this will return true when the message is completely sent (which
        // may take more than one call if it was multi frame and we're waiting
        // on flow control responses from the receiver)
        bool complete = isotp_continue_send(&shims, &handle, 0x100, data, size);

        if(complete && handle.completed) {
            if(handle.success) {
                // All frames of the message have now been sent, following
                // whatever flow control feedback it got from the receiver
            } else {
                // the message was unable to be sent and we bailed - fatal
                // error!
            }
        }
    }
}

// Optional: This is your callback for when a complete ISO-TP message is
// received at the arbitration ID you specify. The completed message is
// also returned by isotp_continue_receive, which can sometimes be more
// useful since you have more context.
void message_received(const IsoTpMessage* message) {
}

IsoTpReceiveHandle handle = isotp_receive(&shims, 0x100, message_received);
if(!handle.success) {
    // something happened and it already failed - possibly we aren't able to
    // send CAN messages
} else {
    while(true) {
        // Continue to read from CAN, passing off each message to the handle
        IsoTpMessage message = isotp_continue_receive(&shims, &handle, 0x100, data, size);

        if(message.completed && handle.completed) {
            if(handle.success) {
                // A message has been received successfully
            } else {
                // Fatal error - we weren't able to receive a message and
                // gave up trying. A message using flow control may have
                // timed out.
            }
        }
    }
}

$ make test

$ BROWSER=google-chrome-stable make coverage