Re: [Qemu-devel] [PATCH v4 06/11] netfilter: add an API to pass the packet to next filter

[Jason Wang <jasowang@redhat.com>]

On 08/04/2015 04:30 PM, Yang Hongyang wrote:
> add an API qemu_netfilter_pass_to_next_iov() to pass the packet
> to next filter, and a wrapper qemu_netfilter_pass_to_next().
>
> Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
> ---
>  include/net/filter.h | 12 ++++++++++++
>  net/filter.c         | 43 +++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 55 insertions(+)
>
> diff --git a/include/net/filter.h b/include/net/filter.h
> index c146be2..867d5aa 100644
> --- a/include/net/filter.h
> +++ b/include/net/filter.h
> @@ -54,4 +54,16 @@ void qemu_del_net_filter(NetFilterState *nf);
>  void netfilter_add(QemuOpts *opts, Error **errp);
>  void qmp_netfilter_add(QDict *qdict, QObject **ret, Error **errp);
>  
> +/* pass the packet to the next filter */
> +void qemu_netfilter_pass_to_next_iov(NetFilterState *nf,
> +                                     NetClientState *sender,
> +                                     unsigned flags,
> +                                     const struct iovec *iov,
> +                                     int iovcnt);
> +void qemu_netfilter_pass_to_next(NetFilterState *nf,
> +                                 NetClientState *sender,
> +                                 unsigned flags,
> +                                 const uint8_t *data,
> +                                 size_t size);

sender, flags, data and size were all could be inferred from packet. How
about just have a packet parameter?

> +
>  #endif /* QEMU_NET_FILTER_H */
> diff --git a/net/filter.c b/net/filter.c
> index 24ec4e1..166b851 100644
> --- a/net/filter.c
> +++ b/net/filter.c
> @@ -14,9 +14,11 @@
>  #include "qapi/dealloc-visitor.h"
>  #include "qemu/config-file.h"
>  #include "qmp-commands.h"
> +#include "qemu/iov.h"
>  
>  #include "net/filter.h"
>  #include "net/net.h"
> +#include "net/queue.h"
>  
>  static QTAILQ_HEAD(, NetFilterState) net_filters;
>  
> @@ -130,6 +132,47 @@ void qmp_netfilter_del(const char *id, Error **errp)
>      qemu_opts_del(opts);
>  }
>  
> +void qemu_netfilter_pass_to_next_iov(NetFilterState *nf,
> +                                     NetClientState *sender,
> +                                     unsigned flags,
> +                                     const struct iovec *iov,
> +                                     int iovcnt)
> +{
> +    int ret = 0;
> +    ssize_t size = iov_size(iov, iovcnt);
> +    NetFilterState *next = QTAILQ_NEXT(nf, next);
> +
> +    while (next) {
> +        if (next->chain == nf->chain || next->chain == NET_FILTER_ALL) {
> +            ret = next->info->receive_iov(next, sender, flags, iov, iovcnt);
> +            if (ret == size) {
> +                return;
> +            }
> +        }
> +        next = QTAILQ_NEXT(next, next);
> +    }
> +
> +    /* we have gone through all filters, pass it to receiver */
> +    if (sender && sender->peer) {
> +        qemu_net_queue_send_iov(sender->peer->incoming_queue, sender, flags,
> +                                iov, iovcnt, NULL);
> +    }
> +}
> +
> +void qemu_netfilter_pass_to_next(NetFilterState *nf,
> +                                 NetClientState *sender,
> +                                 unsigned flags,
> +                                 const uint8_t *data,
> +                                 size_t size)
> +{
> +    struct iovec iov = {
> +        .iov_base = (void *)data,
> +        .iov_len = size
> +    };
> +
> +    return qemu_netfilter_pass_to_next_iov(nf, sender, flags, &iov, 1);
> +}
> +
>  typedef int (NetFilterInit)(const NetFilterOptions *opts,
>                              const char *name, int chain,
>                              NetClientState *netdev, Error **errp);