[Spice-devel] [PATCH spice-streaming-agent v3 3/4] Handle capabilities

[Lukáš Hrázký]

On Tue, 2018-02-20 at 20:48 +0000, Frediano Ziglio wrote:
> Do not bail if the server is attempting to communicate some extensions
> but just ignore as at the moment we support none.
> 
> Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> ---
>  src/spice-streaming-agent.cpp | 30 ++++++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
> 
> diff --git a/src/spice-streaming-agent.cpp b/src/spice-streaming-agent.cpp
> index 8d91f2d..31c655c 100644
> --- a/src/spice-streaming-agent.cpp
> +++ b/src/spice-streaming-agent.cpp
> @@ -40,6 +40,8 @@
>  
>  using namespace spice::streaming_agent;
>  
> +static size_t write_all(int fd, const void *buf, const size_t len);
> +
>  static ConcreteAgent agent;
>  
>  struct SpiceStreamFormatMessage
> @@ -77,6 +79,7 @@ static int have_something_to_read(int timeout)
>      return 0;
>  }
>  
> +static void handle_stream_capabilities(uint32_t len);
>  static void handle_stream_start_stop(uint32_t len);
>  
>  static void read_command_from_device(void)
> @@ -96,6 +99,8 @@ static void read_command_from_device(void)
>      }
>  
>      switch (hdr.type) {
> +    case STREAM_TYPE_CAPABILITIES:
> +        return handle_stream_capabilities(hdr.size);
>      case STREAM_TYPE_START_STOP:
>          return handle_stream_start_stop(hdr.size);
>      }
> @@ -124,6 +129,31 @@ static void handle_stream_start_stop(uint32_t len)
>      }
>  }
>  
> +static void handle_stream_capabilities(uint32_t len)
> +{
> +    uint8_t caps[STREAM_MSG_CAPABILITIES_MAX_BYTES];
> +
> +    if (len > sizeof(caps)) {
> +        throw std::runtime_error("capability message too long");
> +    }
> +    int n = read(streamfd, caps, len);
> +    if (n != len) {
> +        throw std::runtime_error("read command from device FAILED -- read " + std::to_string(n) +
> +                                 " expected " + std::to_string(len));
> +    }
> +
> +    // we currently do not support extensions so just reply so
> +    StreamDevHeader hdr = {
> +        STREAM_DEVICE_PROTOCOL,
> +        0,
> +        STREAM_TYPE_CAPABILITIES,
> +        0
> +    };
> +    if (write_all(streamfd, &hdr, sizeof(hdr)) != sizeof(hdr)) {
> +        throw std::runtime_error("error writing capabilities");
> +    }
> +}
> +
>  static int read_command(bool blocking)
>  {
>      int timeout = blocking?-1:0;

LGTM, I'm not entirely knowledgable of the capabilities interaction
though.

Reviewed-by: Lukáš Hrázký <lhrazky at redhat.com>