Re: [Qemu-devel] [PATCH 1/2] nbd: Handle fixed new-style clients.

[Paolo Bonzini]

Il 25/05/2014 11:50, Hani Benhabiles ha scritto:
> @@ -236,9 +236,10 @@ static int nbd_receive_options(NBDClient *client)
>          LOG("read failed");
>          goto fail;
>      }
> -    TRACE("Checking reserved");
> -    if (tmp != 0) {
> -        LOG("Bad reserved received");
> +    TRACE("Checking client flags");
> +    tmp = be32_to_cpu(tmp);
> +    if (tmp != 0 && tmp != NBD_FLAG_C_FIXED_NEWSTYLE) {
> +        LOG("Bad client flags received");
>          goto fail;
>      }
>
> @@ -246,7 +247,7 @@ static int nbd_receive_options(NBDClient *client)
>          LOG("read failed");
>          goto fail;
>      }
> -    TRACE("Checking reserved");
> +    TRACE("Checking opts magic");
>      if (magic != be64_to_cpu(NBD_OPTS_MAGIC)) {
>          LOG("Bad magic received");
>          goto fail;

Here, if the client used "fixed new-style negotiation" you should reply 
with NBD_REP_ERR_UNSUP.  You also need to turn this into a while loop. 
With these changes here, the logic in patch 2 should be okay.

Thanks,

Paolo