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

[Zhang Chen <zhangchen.fnst@cn.fujitsu.com>]

On 07/04/2016 11:04 AM, Jason Wang wrote:
>
>
> 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?

When filter-rewriter work with colo-frame we need this do some 
synchronization job.
like colo do checkpoint,we will flush connection.
Maybe I should move this lock to other patch (like filter-rewriter work 
with colo-frame).

Thanks
Zhang Chen

>
>> +            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;
>>   }
>
>
>
> .
>

-- 
Thanks
zhangchen