Re: [Qemu-devel] [RFC PATCH 9/9] net/colo-proxy: add packet compare and notify checkpoint

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Zhang Chen (zhangchen.fnst@cn.fujitsu.com) wrote:
> From: zhangchen <zhangchen.fnst@cn.fujitsu.com>
> 
> Lookup same connection's primary and secondary packet
> to compare,if same we will send primary packet and
> drop secondary packet,else send all of primary
> packets be queued,drop secondary queue and notify
> colo to do checkpoint
> 
> Signed-off-by: zhangchen <zhangchen.fnst@cn.fujitsu.com>
> ---
>  net/colo-proxy.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 74 insertions(+)
> 
> diff --git a/net/colo-proxy.c b/net/colo-proxy.c
> index 5f1852a..847f7f2 100644
> --- a/net/colo-proxy.c
> +++ b/net/colo-proxy.c
> @@ -70,6 +70,41 @@ static Connection *connection_new(void)
>      return connection;
>  }
>  
> +static void colo_send_primary_packet(void *opaque, void *user_data)
> +{
> +    Packet *pkt = opaque;
> +    qemu_net_queue_send(pkt->s->incoming_queue, pkt->sender, 0,
> +                    (const uint8_t *)pkt->data, pkt->size, NULL);
> +}
> +
> +static void colo_flush_connection(void *opaque, void *user_data)
> +{
> +    Connection *connection = opaque;
> +    g_queue_foreach(&connection->primary_list, colo_send_primary_packet, NULL);
> +    g_queue_foreach(&connection->secondary_list, packet_destroy, NULL);
> +}
> +
> +static void colo_proxy_notify_checkpoint(void)
> +{
> +    DEBUG("colo_proxy_notify_checkpoint\n");
> +}
> +
> +static void colo_proxy_do_checkpoint(NetFilterState *nf)
> +{
> +    ColoProxyState *s = FILTER_COLO_PROXY(nf);
> +
> +    g_queue_foreach(&s->unprocessed_connections, colo_flush_connection, NULL);
> +}
> +
> +/*
> + * colo failover flag
> + */
> +static ssize_t colo_has_failover(NetFilterState *nf)
> +{
> +    ColoProxyState *s = FILTER_COLO_PROXY(nf);
> +    return s->has_failover;
> +}
> +
>  /* Return 0 on success, or return -1 if the pkt is corrpted */
>  static int parse_packet_early(Packet *pkt, Connection_key *key)
>  {
> @@ -136,6 +171,45 @@ static void packet_destroy(void *opaque, void *user_data)
>      g_slice_free(Packet, pkt);
>  }
>  
> +/*
> + * The sent IP packets comparison between primary
> + * and secondary
> + * TODO： support ip fragment
> + * return:    true  means packet same
> + *            false means packet different
> + */
> +static bool colo_packet_compare(Packet *ppkt, Packet *spkt)
> +{
> +    int i;
> +    DEBUG("colo_packet_compare lens ppkt %d,spkt %d\n", ppkt->size,
> +                spkt->size);
> +    DEBUG("primary pkt data=%s,  pkt->ip->ipsrc=%x,pkt->ip->ipdst=%x\n",
> +                (char *)ppkt->data, ppkt->ip->ip_src, ppkt->ip->ip_dst);
> +    DEBUG("seconda pkt data=%s,  pkt->ip->ipsrc=%x,pkt->ip->ipdst=%x\n",
> +                (char *)spkt->data, spkt->ip->ip_src, spkt->ip->ip_dst);

Is it always IP packets we're comparing at this point?

> +    if (ppkt->size == spkt->size) {
> +        DEBUG("colo_packet_compare data   ppkt\n");
> +        for (i = 0; i < spkt->size; i++) {
> +            DEBUG("%x", ((char *)ppkt->data)[i]);
> +            DEBUG("|");
> +        }
> +        DEBUG("\ncolo_packet_compare data   spkt\n");
> +        for (i = 0; i < spkt->size; i++) {
> +            DEBUG("%x", ((char *)spkt->data)[i]);
> +            DEBUG("|");
> +        }
> +        DEBUG("\ncolo_packet_compare data   ppkt %s\n", (char *)ppkt->data);
> +        DEBUG("colo_packet_compare data   spkt %s\n", (char *)spkt->data);

It's probably better to make these a helper debug routine to dump
a packet;  I bet you'll wnat to sometimes do it when the sizes
are different.

> +        if (!memcmp(ppkt->data, spkt->data, spkt->size)) {
> +            return true;
> +        } else {
> +            return false;
> +        }
> +    } else {
> +        return false;
> +    }
> +}
> +
>  static Connection *colo_proxy_enqueue_packet(GHashTable *unprocessed_packets,
>                                            Connection_key *key,
>                                            Packet *pkt, packet_type type)
> -- 
> 1.9.1
> 
> 
> 

Dave

--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK