Re: [Qemu-devel] [PATCH V3 04/10] net/filter-mirror.c: Add filter-mirror and filter-redirector vnet support.

[Jason Wang <jasowang@redhat.com>]

On 2017年05月03日 11:18, Zhang Chen wrote:
>
>
> On 05/02/2017 12:47 PM, Jason Wang wrote:
>>
>>
>> On 2017年04月28日 17:47, Zhang Chen wrote:
>>> In this patch, we change the send packet format from
>>> struct {int size; const uint8_t buf[];} to {int size; int 
>>> vnet_hdr_len; const uint8_t buf[];}.
>>> make other module(like colo-compare) know how to parse net packet 
>>> correctly.
>>>
>>> Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
>>> ---
>>>   net/filter-mirror.c | 28 +++++++++++++++++++++++-----
>>>   1 file changed, 23 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/net/filter-mirror.c b/net/filter-mirror.c
>>> index 72fa7c2..bb9ecf3 100644
>>> --- a/net/filter-mirror.c
>>> +++ b/net/filter-mirror.c
>>> @@ -43,12 +43,14 @@ typedef struct MirrorState {
>>>       SocketReadState rs;
>>>   } MirrorState;
>>>   -static int filter_mirror_send(CharBackend *chr_out,
>>> +static int filter_mirror_send(MirrorState *s,
>>>                                 const struct iovec *iov,
>>>                                 int iovcnt)
>>>   {
>>> +    NetFilterState *nf = NETFILTER(s);
>>>       int ret = 0;
>>>       ssize_t size = 0;
>>> +    ssize_t vnet_hdr_len;
>>>       uint32_t len = 0;
>>>       char *buf;
>>>   @@ -58,14 +60,30 @@ static int filter_mirror_send(CharBackend 
>>> *chr_out,
>>>       }
>>>         len = htonl(size);
>>> -    ret = qemu_chr_fe_write_all(chr_out, (uint8_t *)&len, 
>>> sizeof(len));
>>> +    ret = qemu_chr_fe_write_all(&s->chr_out, (uint8_t *)&len, 
>>> sizeof(len));
>>> +    if (ret != sizeof(len)) {
>>> +        goto err;
>>> +    }
>>> +
>>> +    /*
>>> +     * We send vnet header len make other module(like colo-compare)
>>> +     * know how to parse net packet correctly.
>>> +     */
>>> +    if (qemu_get_using_vnet_hdr(nf->netdev)) {
>>> +        vnet_hdr_len = qemu_get_vnet_hdr_len(nf->netdev);
>>> +    } else {
>>> +        vnet_hdr_len = qemu_get_vnet_hdr_len(nf->netdev->peer);
>>> +    }
>>
>> Any reason to query peer here?
>
> That's depend on using NetClientState, If we using nf->netdev that 
> need to query,
> Otherwise we query nf->netdev->peer, then we can get the real 
> vnet_hdr_len in my test.
>
> Thanks
> Zhang Chen 

Confused, I think nf->netdev won't be a nic?

Thanks