[Spice-devel] [PATCH 9/9] client/smartcard: libcacard dropped ReaderAddResponse

Hans de Goede hdegoede at redhat.com
Wed Feb 9 02:50:23 PST 2011


Hi,

On second look, my main comment was invalid, so Ack.

I still think that VSC_Error should be renamed to
VSC_Status and like wise the new handle_error function
should be renamed to handle_status. But that can be done in
a separate patch. Or you can disagree and just leave it as is :)

Regards,

Hans


On 02/09/2011 11:20 AM, Alon Levy wrote:
> uses VSC_Error with code==VSC_SUCCESS instead. This means that the VSC_Error
> message is overloaded. Instead of the other option of adding a message id,
> since the connection is TCP so no messages may be dropped or reordered, by
> having each message followed by a response there is no ambiguity. Still
> this commit adds a queue for messages that we only have one of which outstanding
> at a time, i.e. send, wait for response, send the next, etc. This further
> simplifies the logic, while not adding much overhead since only when spicec
> starts up it has a situation where it needs to send two events (ReaderAdd
> and ATR for Card Insert).
> ---
>   client/smartcard_channel.cpp |   87 +++++++++++++++++++++++++++++++++---------
>   client/smartcard_channel.h   |    9 ++++
>   2 files changed, 78 insertions(+), 18 deletions(-)
>
> diff --git a/client/smartcard_channel.cpp b/client/smartcard_channel.cpp
> index c57ecd5..98f24a8 100644
> --- a/client/smartcard_channel.cpp
> +++ b/client/smartcard_channel.cpp
> @@ -45,6 +45,7 @@ public:
>
>   SmartCardChannel::SmartCardChannel(RedClient&  client, uint32_t id)
>       : RedChannel(client, SPICE_CHANNEL_SMARTCARD, id, new SmartCardHandler(*this))
> +    , _next_sync_vevent(VEVENT_LAST)
>   {
>       SmartCardHandler* handler = static_cast<SmartCardHandler*>(get_message_handler());
>
> @@ -84,6 +85,7 @@ void SmartCardChannel::add_unallocated_reader(VReader* vreader, const char* name
>       data->reader_id = VSCARD_UNDEFINED_READER_ID;
>       data->name = spice_strdup(name);
>       _unallocated_readers_by_vreader.insert(std::pair<VReader*, ReaderData*>(vreader, data));
> +    LOG_INFO("adding unallocated reader %p", data);
>   }
>
>   /** called upon the VSC_ReaderAddResponse
> @@ -96,6 +98,7 @@ ReaderData* SmartCardChannel::add_reader(uint32_t reader_id)
>       assert(unallocated>  0);
>       data = _unallocated_readers_by_vreader.begin()->second;
>       data->reader_id = reader_id;
> +    LOG_INFO("adding %p->%d", data, reader_id);
>       _readers_by_vreader.insert(
>           std::pair<VReader*, ReaderData*>(data->vreader, data));
>       assert(_readers_by_vreader.count(data->vreader) == 1);
> @@ -179,6 +182,65 @@ void SmartCardChannel::remove_reader(ReaderData* data)
>       delete data;
>   }
>
> +/* Sync events need to be sent one by one, waiting for VSC_Error
> + * messages from the server in between. */
> +void SmartCardChannel::push_sync_event(VEventType type, Event *event)
> +{
> +    event->ref();
> +    _sync_events.push_back(SmartCardEvent(type, event));
> +    if (_next_sync_vevent != VEVENT_LAST) {
> +        return;
> +    }
> +    send_next_sync_event();
> +}
> +
> +void SmartCardChannel::send_next_sync_event()
> +{
> +    if (_sync_events.empty()) {
> +        _next_sync_vevent = VEVENT_LAST;
> +        return;
> +    }
> +    SmartCardEvent sync_event = _sync_events.front();
> +    _sync_events.pop_front();
> +    get_client().push_event(sync_event.second);
> +    sync_event.second->unref();
> +    _next_sync_vevent = sync_event.first;
> +}
> +
> +void SmartCardChannel::handle_reader_add_response(VSCMsgHeader *vheader,
> +                                                  VSCMsgError *error)
> +{
> +    ReaderData* data;
> +
> +    if (error->code == VSC_SUCCESS) {
> +        data = add_reader(vheader->reader_id);
> +        if (data->card_insert_pending) {
> +            data->card_insert_pending = false;
> +            send_atr(data->vreader);
> +        }
> +    } else {
> +        LOG_WARN("VSC Error: reader %d, code %d",
> +            vheader->reader_id, error->code);
> +    }
> +}
> +
> +void SmartCardChannel::handle_error_message(VSCMsgHeader *vheader,
> +    VSCMsgError *error)
> +{
> +    switch (_next_sync_vevent) {
> +        case VEVENT_READER_INSERT:
> +            handle_reader_add_response(vheader, error);
> +            break;
> +        case VEVENT_CARD_INSERT:
> +        case VEVENT_CARD_REMOVE:
> +        case VEVENT_READER_REMOVE:
> +            break;
> +        default:
> +            LOG_WARN("Unexpected Error message: %d", error->code);
> +    }
> +    send_next_sync_event();
> +}
> +
>   void SmartCardChannel::cac_card_events_thread_main()
>   {
>       VEvent *vevent = NULL;
> @@ -194,28 +256,28 @@ void SmartCardChannel::cac_card_events_thread_main()
>               LOG_INFO("VEVENT_READER_INSERT");
>               {
>                   AutoRef<ReaderAddEvent>  event(new ReaderAddEvent(this, vevent));
> -                get_client().push_event(*event);
> +                push_sync_event(vevent->type, *event);
>               }
>               break;
>           case VEVENT_READER_REMOVE:
>               LOG_INFO("VEVENT_READER_REMOVE");
>               {
>                   AutoRef<ReaderRemoveEvent>  event(new ReaderRemoveEvent(this, vevent));
> -                get_client().push_event(*event);
> +                push_sync_event(vevent->type, *event);
>               }
>               break;
>           case VEVENT_CARD_INSERT:
>               LOG_INFO("VEVENT_CARD_INSERT");
>               {
>                   AutoRef<CardInsertEvent>  event(new CardInsertEvent(this, vevent));
> -                get_client().push_event(*event);
> +                push_sync_event(vevent->type, *event);
>               }
>               break;
>           case VEVENT_CARD_REMOVE:
>               LOG_INFO("VEVENT_CARD_REMOVE");
>               {
>                   AutoRef<CardRemoveEvent>  event(new CardRemoveEvent(this, vevent));
> -                get_client().push_event(*event);
> +                push_sync_event(vevent->type, *event);
>               }
>               break;
>           case VEVENT_LAST:
> @@ -390,25 +452,14 @@ void VSCMessageEvent::response(AbstractProcessLoop&  loop)
>       uint8_t pbRecvBuffer[APDUBufSize+sizeof(uint32_t)];
>       VReaderStatus reader_status;
>       uint32_t rv;
> -    ReaderData* data;
>
>       switch (_vheader->type) {
> -        case (VSC_ReaderAddResponse):
> -            data = _smartcard_channel->add_reader(_vheader->reader_id);
> -            if (data->card_insert_pending) {
> -                data->card_insert_pending = false;
> -                _smartcard_channel->send_atr(data->vreader);
> -            }
> -            return;
> -            break;
>           case VSC_APDU:
>               break;
>           case VSC_Error:
> -            {
> -                VSCMsgError *error = (VSCMsgError*)_vheader->data;
> -                LOG_WARN("VSC Error: reader %d, code %d",
> -                    _vheader->reader_id, error->code);
> -            }
> +            _smartcard_channel->handle_error_message(
> +                            _vheader,
> +                            (VSCMsgError*)_vheader->data);
>               return;
>           case VSC_Init:
>               break;
> diff --git a/client/smartcard_channel.h b/client/smartcard_channel.h
> index 1d512a6..752713b 100644
> --- a/client/smartcard_channel.h
> +++ b/client/smartcard_channel.h
> @@ -86,6 +86,8 @@ public:
>       virtual void response(AbstractProcessLoop&  events_loop);
>   };
>
> +typedef std::pair<VEventType, Event*>  SmartCardEvent;
> +
>   class SmartCardChannel : public RedChannel {
>
>   public:
> @@ -114,6 +116,13 @@ private:
>       typedef std::map<VReader*, ReaderData*>  readers_by_vreader_t;
>       readers_by_vreader_t _readers_by_vreader;
>       readers_by_vreader_t _unallocated_readers_by_vreader;
> +    VEventType _next_sync_vevent;
> +    std::list<SmartCardEvent>  _sync_events;
> +
> +    void push_sync_event(VEventType type, Event *event);
> +    void send_next_sync_event();
> +    void handle_reader_add_response(VSCMsgHeader *vheader, VSCMsgError *error);
> +    void handle_error_message(VSCMsgHeader *vheader, VSCMsgError *error);
>
>       ReaderData* reader_data_from_vreader(VReader* vreader);
>       ReaderData* reader_data_from_reader_id(uint32_t reader_id);


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