Re: [Qemu-devel] [PATCH] net/filter-redirector:Add filter-redirector

[Jason Wang <jasowang@redhat.com>]

On 02/18/2016 03:50 PM, Zhang Chen wrote:
>
>
> On 02/18/2016 10:41 AM, Jason Wang wrote:
>>
>> On 02/05/2016 02:50 PM, Zhang Chen wrote:
>>> From: ZhangChen <zhangchen.fnst@cn.fujitsu.com>
>>>
>>> Filter-redirector is a netfilter plugin.
>>> It gives qemu the ability to redirect net packet.
>>> redirector can redirect filter's net packet to outdev.
>>> and redirect indev's packet to filter.
>>>
>>>                               filter
>>>                                 +
>>>                                 |
>>>                                 |
>>>                redirector       |
>>>                 +-------------------------+
>>>                 |               |         |
>>>                 |               |         |
>>>                 |               |         |
>>>    indev +----------------+     +---------------->  outdev
>>>                 |         |               |
>>>                 |         |               |
>>>                 |         |               |
>>>                 +-------------------------+
>>>                           |
>>>                           |
>>>                           v
>>>                        filter
>
>                                   v
>
> change it to           filter ........ filter ...... guest
> It's may more clearly expressed.
>
>>> usage:
>>>
>>> -netdev tap,id=hn0
>>> -chardev socket,id=s0,host=ip_primary,port=X,server,nowait
>>> -chardev socket,id=s1,host=ip_primary,port=Y,server,nowait
>>> -filter-redirector,id=r0,netdev=hn0,queue=tx/rx/all,indev=s0,outdev=s1
>>>
>>> Signed-off-by: ZhangChen <zhangchen.fnst@cn.fujitsu.com>
>>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
>>> ---
>> Thanks a lot for the patch. Like mirror, let's design a unit-test for
>> this. And what's more, is there any chance to unify the codes? (At least
>> parts of the codes could be reused).
>
> We can make filter-redirector based on filter-mirror.
> if you want to use redirector ,you must open mirror before.
> like this:
>
> -netdev tap,id=hn0
> -chardev socket,id=mirror0,host=ip_primary,port=X,server,nowait
> -filter-mirror,id=m0,netdev=hn0,queue=tx/rx/all,redirector=on,outdev=mirror0
>
> -filter-redirector,id=r0,netdev=hn0,queue=tx/rx/all,indev=s0
>
> How about this?

This looks like a burden for user who just want to use redirector. Maybe
we can do :

- Still two type of filters but sharing a single state.
- Using a internal flag to differ mirrors from redirectors?

>
>
>>>   net/Makefile.objs       |   1 +
>>>   net/filter-redirector.c | 245
>>> ++++++++++++++++++++++++++++++++++++++++++++++++
>>>   qemu-options.hx         |   6 ++
>>>   vl.c                    |   3 +-
>>>   4 files changed, 254 insertions(+), 1 deletion(-)
>>>   create mode 100644 net/filter-redirector.c
>>>
>>> diff --git a/net/Makefile.objs b/net/Makefile.objs
>>> index 5fa2f97..f4290a5 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 += filter-redirector.o
>>> diff --git a/net/filter-redirector.c b/net/filter-redirector.c
>>> new file mode 100644
>>> index 0000000..364e463
>>> --- /dev/null
>>> +++ b/net/filter-redirector.c
>>> @@ -0,0 +1,245 @@
>>> +/*
>>> + * 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"
>>> +#include "qemu/sockets.h"
>>> +
>>> +#define FILTER_REDIRECTOR(obj) \
>>> +    OBJECT_CHECK(RedirectorState, (obj), TYPE_FILTER_REDIRECTOR)
>>> +
>>> +#define TYPE_FILTER_REDIRECTOR "filter-redirector"
>>> +#define REDIRECT_HEADER_LEN sizeof(uint32_t)
>>> +
>>> +typedef struct RedirectorState {
>>> +    NetFilterState parent_obj;
>>> +    NetQueue *incoming_queue;/* guest normal net queue */
>> The comment looks unless and maybe even wrong when queue=rx?
>
> We design redirector that indev's data always be passed to guest finally.
> so, It's no relation between the queue=rx/tx/all. just related to
> indev = xxx.
> we need incoming_queue to inject packet from indev.

So what happens if queue=rx or you want to forbid queue=rx for redirector?