Re: [Qemu-devel] [RFC PATCH V2 2/3] filter-rewriter: track connection and parse packet

[Jason Wang <jasowang@redhat.com>]

On 2016年07月02日 14:22, Zhang Chen wrote:
> We use colo-base.h to track connection and parse packet
>
> Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
> ---
>   net/filter-rewriter.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 52 insertions(+)
>
> diff --git a/net/filter-rewriter.c b/net/filter-rewriter.c
> index 08b015d..c38ab24 100644
> --- a/net/filter-rewriter.c
> +++ b/net/filter-rewriter.c
> @@ -50,6 +50,20 @@ typedef struct RewriterState {
>       uint32_t hashtable_size;
>   } RewriterState;
>   
> +/*
> + * Return 1 on success, if return 0 means the pkt
> + * is not TCP packet
> + */
> +static int is_tcp_packet(Packet *pkt)
> +{
> +    if (!parse_packet_early(pkt) &&
> +        pkt->ip->ip_p == IPPROTO_TCP) {
> +        return 1;
> +    } else {
> +        return 0;
> +    }
> +}
> +
>   static ssize_t colo_rewriter_receive_iov(NetFilterState *nf,
>                                            NetClientState *sender,
>                                            unsigned flags,
> @@ -57,11 +71,49 @@ static ssize_t colo_rewriter_receive_iov(NetFilterState *nf,
>                                            int iovcnt,
>                                            NetPacketSent *sent_cb)
>   {
> +    RewriterState *s = FILTER_COLO_REWRITER(nf);
> +    Connection *conn;
> +    ConnectionKey key = {{ 0 } };
> +    Packet *pkt;
> +    ssize_t size = iov_size(iov, iovcnt);
> +    char *buf = g_malloc0(size);
> +
> +    iov_to_buf(iov, iovcnt, 0, buf, size);
> +    pkt = packet_new(buf, size);
> +
>       /*
>        * if we get tcp packet
>        * we will rewrite it to make secondary guest's
>        * connection established successfully
>        */
> +    if (is_tcp_packet(pkt)) {
> +        if (sender == nf->netdev) {
> +            fill_connection_key(pkt, &key, SECONDARY);
> +        } else {
> +            fill_connection_key(pkt, &key, PRIMARY);
> +        }
> +
> +        conn = connection_get(s->connection_track_table,
> +                              &key,
> +                              &s->hashtable_size);
> +        if (!conn->processing) {
> +            qemu_mutex_lock(&s->conn_list_lock);
> +            g_queue_push_tail(&s->conn_list, conn);
> +            qemu_mutex_unlock(&s->conn_list_lock);

conn_list was never used in this series, and I fail to understand why 
conn_list is needed?

> +            conn->processing = true;
> +        }
> +
> +        if (sender == nf->netdev) {
> +            /* NET_FILTER_DIRECTION_TX */
> +            /* handle_primary_tcp_pkt */
> +        } else {
> +            /* NET_FILTER_DIRECTION_RX */
> +            /* handle_secondary_tcp_pkt */
> +        }
> +    }
> +
> +    packet_destroy(pkt, NULL);
> +    pkt = NULL;
>       return 0;
>   }
>