Re: [Qemu-devel] [PATCH v3 4/4] net/filter: Add a default filter to each netdev

[Yang Hongyang]

On 02/01/2016 08:01 PM, zhanghailiang wrote:
> We add each netdev a default buffer filter, and
> the default buffer filter is disabled, so it has
> no side effect for packets delivering in qemu net layer.
>
> The default buffer filter can be used by COLO or Micro-checkpoint,
> The reason we add the default filter is we hope to support
> hot add network during COLO state in future.
>
> Signed-off-by: zhanghailiang <address@hidden>
> ---
> v2:
> - Add codes that generate id automatically for default filter
>    (Jason's suggestion)
> - Some other minor fixes.
> ---
>   include/net/filter.h |  4 ++++
>   net/net.c            | 23 +++++++++++++++++++++++
>   2 files changed, 27 insertions(+)
>
> diff --git a/include/net/filter.h b/include/net/filter.h
> index 661abef..8f5fa31 100644
> --- a/include/net/filter.h
> +++ b/include/net/filter.h
> @@ -22,6 +22,10 @@
>   #define NETFILTER_CLASS(klass) \
>       OBJECT_CLASS_CHECK(NetFilterClass, (klass), TYPE_NETFILTER)
>
> +#define DEFAULT_FILTER_TYPE "nop"
> +
> +#define TYPE_FILTER_BUFFER "filter-buffer"
> +
>   typedef void (FilterSetup) (NetFilterState *nf, Error **errp);
>   typedef void (FilterCleanup) (NetFilterState *nf);
>   /*
> diff --git a/net/net.c b/net/net.c
> index a49af48..998e90a 100644
> --- a/net/net.c
> +++ b/net/net.c
> @@ -77,6 +77,12 @@ const char *host_net_devices[] = {
>
>   int default_net = 1;
>
> +/*
> + * TODO: Export this with an option for users to control
> + * this with comand line ?
> + */
> +char default_netfilter_type[16] = TYPE_FILTER_BUFFER;
> +
>   /***********************************************************/
>   /* network device redirectors */
>
> @@ -1029,6 +1035,23 @@ static int net_client_init1(const void *object, int 
> is_netdev, Error **errp)
>           }
>           return -1;
>       }
> +
> +    if (is_netdev) {

If as I said earlier add a 'defult-filter' property to netdev, we
can use that property here to init default filter.

> +        const Netdev *netdev = object;
> +        char default_name[128];
> +
> +        snprintf(default_name, sizeof(default_name),
> +                "%s%s", netdev->id, DEFAULT_FILTER_TYPE);

name is "nop"

> +        /*
> +        * Here we add each netdev a default filter,
> +        * it will disabled by default, Users can enable it when necessary.
> +        */
> +        netdev_add_filter(netdev->id,
> +                          default_netfilter_type,
> +                          default_name,

type is filter-buffer, but name is "nop"?

> +                          true,
> +                          errp);
> +    }
>       return 0;
>   }

--
Thanks,
Yang