Datagram.cxx

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#include "openlcb/Datagram.hxx"
 
namespace openlcb
{
 
long long DATAGRAM_RESPONSE_TIMEOUT_NSEC = SEC_TO_NSEC(3);
 
DatagramService::DatagramService(If* iface,
                                 size_t num_registry_entries)
    : Service(iface->executor()), iface_(iface), dispatcher_(iface_, num_registry_entries)
{
    iface_->dispatcher()->register_handler(&dispatcher_, Defs::MTI_DATAGRAM, 0xffff
                                              );
}
 
DatagramService::~DatagramService()
{
    iface_->dispatcher()->unregister_handler(&dispatcher_, Defs::MTI_DATAGRAM, 0xffff
                                                );
}
 
StateFlowBase::Action DatagramService::DatagramDispatcher::entry()
{
    if (!nmsg()->dstNode)
    {
        return release_and_exit();
    }
    return allocate_and_call<IncomingDatagram>(nullptr, STATE(incoming_datagram_allocated), g_incoming_datagram_allocator);
}
 
StateFlowBase::Action
DatagramService::DatagramDispatcher::incoming_datagram_allocated()
{
    Buffer<IncomingDatagram>* b =
        get_allocation_result<IncomingDatagram>(nullptr);
    IncomingDatagram* d = b->data();
    d->src = nmsg()->src;
    d->dst = nmsg()->dstNode;
 
    // Takes over ownership of payload.
    d->payload.swap(nmsg()->payload);
 
    release();
 
    // Saves the datagram buffer pointer.
    d_ = b;
 
    unsigned datagram_id = -1;
    if (d->payload.empty())
    {
        LOG(WARNING,
            "Invalid arguments: incoming datagram from node %012" PRIx64
            " alias %x has no payload.",
            d->src.id, d->src.alias);
        resultCode_ = DatagramClient::PERMANENT_ERROR;
        return allocate_and_call(iface()->addressed_message_write_flow(),
                                 STATE(respond_rejection));
    }
    datagram_id = *reinterpret_cast<const uint8_t*>(d->payload.data());
 
    // Looks up the datagram handler.
    DatagramHandler* h = registry_.lookup(d->dst, datagram_id);
 
    if (!h)
    {
        LOG(VERBOSE, "No datagram handler found for node %p id %x", d->dst,
            datagram_id);
        resultCode_ = DatagramClient::PERMANENT_ERROR;
        return allocate_and_call(iface()->addressed_message_write_flow(),
                                 STATE(respond_rejection));
    }
 
    h->send(d_);
    d_ = nullptr;
    return exit();
}
 
StateFlowBase::Action
DatagramService::DatagramDispatcher::respond_rejection()
{
    auto* f = get_allocation_result(iface()->addressed_message_write_flow());
 
    f->data()->reset(Defs::MTI_DATAGRAM_REJECTED, d_->data()->dst->node_id(),
                     d_->data()->src, error_to_buffer(resultCode_));
    
    iface()->addressed_message_write_flow()->send(f);
    
    d_->unref();
    d_ = nullptr;
    return exit();
}
 
} // namespace openlcb