Re: [Qemu-devel] [PATCH V2] net/traffic-mirror:Add traffic-mirror

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

On 01/28/2016 04:37 PM, Jason Wang wrote:
>
> On 01/28/2016 03:44 PM, Zhang Chen wrote:
>>
>> On 01/28/2016 01:44 PM, Jason Wang wrote:
>>> On 01/27/2016 10:40 AM, Zhang Chen wrote:
>>>> From: ZhangChen <zhangchen.fnst@cn.fujitsu.com>
>>>>
>>>> Traffic-mirror is a netfilter plugin.
>>>> It gives qemu the ability to copy and mirror guest's
>>>> net packet. we output packet to chardev.
>>>>
>>>> usage:
>>>>
>>>> -netdev tap,id=hn0
>>>> -chardev socket,id=mirror0,host=ip_primary,port=X,server,nowait
>>>> -traffic-mirror,id=m0,netdev=hn0,queue=tx/rx/all,outdev=mirror0
>>>>
>>>> Signed-off-by: ZhangChen <zhangchen.fnst@cn.fujitsu.com>
>>>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
>>>> Reviewed-by: Yang Hongyang <hongyang.yang@easystack.cn>
>>> Thanks for the patch. Several questions:
>>>
>>> - I'm curious about how the patch was tested? Simple setup e.g:
>>>
>>> -netdev tap,id=hn0 -device virtio-net-pci,netdev=hn0 -chardev
>>> socket,id=c0,host=localhost,port=4444,server,nowait -object
>>> traffic-mirror,netdev=hn0,outdev=c0,id=f0 -netdev
>>> socket,id=s0,connect=127.0.0.1:4444 -device e1000,netdev=s0
>>>
>>> does not works for me.
>> I test it in this way.
>> primary:
>> -netdev tap,id=hn0 -device e1000,netdev=hn0 -chardev
>> socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
>>   -object traffic-mirror,id=f0,netdev=hn0,queue=tx,outdev=mirror0
>>
>> secondary:
>> -netdev tap,id=hn0 -device e1000,netdev=hn0 -chardev
>> socket,id=mirror0,host=3.3.3.3,port=9003 -object
>> traffic-reader,id=f1,netdev=hn0,queue=rx,indev=mirror0
>>
>> I write a traffic-reader demo to read chardev socket and print it in
>> monitor.
> Ok, but maybe you can try socket backend. I think the protocol should be
> at least compatible with it.

Yes,I will try it.

>>
>>> - Is a reliable mirroring (e.g no packet drops during mirroring) is
>>> needed for COLO? If yes, this patch seems could not guarantee this.
>> I will fix it in V3
>>
>>> - Please consider to write a unit test for this patch.
>> write a unit test like tests/test-netfilter.c ?
> Even more for its basic function to work. E.g, start qemu with:
>
> -netdev socket,id=s0,listen=localhost:X -chardev
> socket,id=c0,host=localhost,pory=Y,server,nowait -object
> filter-mirror,netdev=hn0,outdev=c0
>
> Then you can inject packet from the socket connected to s0 and see if
> you can read it from socket that connected from c0 (or your traffic reader).

I got it~ will add test in next version.

>>> And see comments below.
>>>
>>> Thanks
>>>
>>>
>>>> ---
>>>>    net/Makefile.objs    |   1 +
>>>>    net/traffic-mirror.c | 173
>>>> +++++++++++++++++++++++++++++++++++++++++++++++++++
>>>>    qemu-options.hx      |   5 ++
>>>>    vl.c                 |   3 +-
>>>>    4 files changed, 181 insertions(+), 1 deletion(-)
>>>>    create mode 100644 net/traffic-mirror.c
>>>>
>>>> diff --git a/net/Makefile.objs b/net/Makefile.objs
>>>> index 5fa2f97..de06ebe 100644
>>>> --- a/net/Makefile.objs
>>>> +++ b/net/Makefile.objs
>>>> @@ -15,3 +15,4 @@ common-obj-$(CONFIG_VDE) += vde.o
>>>>    common-obj-$(CONFIG_NETMAP) += netmap.o
>>>>    common-obj-y += filter.o
>>>>    common-obj-y += filter-buffer.o
>>>> +common-obj-y += traffic-mirror.o
>>> Let's s/traffic-mirror/filter-mirror/g to be consistent with other
>>> filters.
>>>
>> OK~ I will fix it in V3
>>
>>>> diff --git a/net/traffic-mirror.c b/net/traffic-mirror.c
>>>> new file mode 100644
>>>> index 0000000..bed915c
>>>> --- /dev/null
>>>> +++ b/net/traffic-mirror.c
>>>> @@ -0,0 +1,173 @@
>>>> +/*
>>>> + * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
>>>> + * Copyright (c) 2016 FUJITSU LIMITED
>>>> + * Copyright (c) 2016 Intel Corporation
>>>> + *
>>>> + * Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
>>>> + *
>>>> + * This work is licensed under the terms of the GNU GPL, version 2 or
>>>> + * later.  See the COPYING file in the top-level directory.
>>>> + */
>>>> +
>>>> +#include "net/filter.h"
>>>> +#include "net/net.h"
>>>> +#include "qemu-common.h"
>>>> +#include "qapi/qmp/qerror.h"
>>>> +#include "qapi-visit.h"
>>>> +#include "qom/object.h"
>>>> +#include "qemu/main-loop.h"
>>>> +#include "qemu/error-report.h"
>>>> +#include "trace.h"
>>>> +#include "sysemu/char.h"
>>>> +#include "qemu/iov.h"
>>>> +
>>>> +#define FILTER_TRAFFIC_MIRROR(obj) \
>>>> +    OBJECT_CHECK(MirrorState, (obj), TYPE_FILTER_TRAFFIC_MIRROR)
>>>> +
>>>> +#define TYPE_FILTER_TRAFFIC_MIRROR "traffic-mirror"
>>>> +
>>>> +typedef struct MirrorState {
>>>> +    NetFilterState parent_obj;
>>>> +    char *outdev;
>>>> +    CharDriverState *chr_out;
>>>> +
>>>> +} MirrorState;
>>>> +
>>>> +static ssize_t traffic_mirror_send(NetFilterState *nf,
>>>> +                                   const struct iovec *iov,
>>>> +                                   int iovcnt)
>>>> +{
>>>> +    MirrorState *s = FILTER_TRAFFIC_MIRROR(nf);
>>>> +    ssize_t ret = 0;
>>>> +    ssize_t size = 0;
>>>> +    char *buf;
>>>> +
>>>> +    size = iov_size(iov, iovcnt);
>>>> +    if (!size) {
>>>> +        return 0;
>>>> +    }
>>>> +
>>>> +    buf = g_malloc0(size);
>>>> +    iov_to_buf(iov, iovcnt, 0, buf, size);
>>>> +    ret = qemu_chr_fe_write(s->chr_out, (uint8_t *)&size,
>>>> sizeof(size));
>>> htonl(size)?
>> We do not need this.
>>
> Why? Did you test your mirroring on the wire?

Oh, you are right. I will fix it.
I have test it in same endian computer.so it work.
but difference endian not.

Thanks
zhangchen

> Thanks
>
>
> .
>

-- 
Thanks
zhangchen