Re: [Qemu-devel] [PATCH v2 5/6] io: Ignore websocket PING and PONG frames

[Daniel P. Berrange]

On Fri, Sep 08, 2017 at 10:38:00AM -0700, Brandon Carpenter wrote:
> Keep pings and gratuitous pongs generated by web browsers from killing
> websocket connections.
> 
> Signed-off-by: Brandon Carpenter <address@hidden>
> ---
>  io/channel-websock.c | 21 +++++++++++++++++----
>  1 file changed, 17 insertions(+), 4 deletions(-)
> 
> diff --git a/io/channel-websock.c b/io/channel-websock.c
> index 3183aeff77..50387050d5 100644
> --- a/io/channel-websock.c
> +++ b/io/channel-websock.c
> @@ -86,6 +86,7 @@
>  #define QIO_CHANNEL_WEBSOCK_HEADER_FIELD_OPCODE 0x0f
>  #define QIO_CHANNEL_WEBSOCK_HEADER_FIELD_HAS_MASK 0x80
>  #define QIO_CHANNEL_WEBSOCK_HEADER_FIELD_PAYLOAD_LEN 0x7f
> +#define QIO_CHANNEL_WEBSOCK_CONTROL_OPCODE_MASK 0x8
>  
>  typedef struct QIOChannelWebsockHeader QIOChannelWebsockHeader;
>  
> @@ -565,8 +566,11 @@ static int 
> qio_channel_websock_decode_header(QIOChannelWebsock *ioc,
>              return -1;
>          }
>      } else {
> -        if (opcode != QIO_CHANNEL_WEBSOCK_OPCODE_BINARY_FRAME) {
> -            error_setg(errp, "only binary websocket frames are supported");
> +        if (opcode != QIO_CHANNEL_WEBSOCK_OPCODE_BINARY_FRAME &&
> +                opcode != QIO_CHANNEL_WEBSOCK_OPCODE_PING &&
> +                opcode != QIO_CHANNEL_WEBSOCK_OPCODE_PONG) {

Why would we need to ignore PONG ?  A client should only send a PONG in
response to a PING that we send, and we never send PINGs.  So if we
received a PONG that would be a serious error by the client, which should
cause us to close the connection IMHO>


Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|