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

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

On 02/24/2016 11:39 AM, Jason Wang wrote:
>
> 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?

Good idea~ I will change it in next version.

>
>>
>>>>    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?
>

If queue=rx, filter-redirector will get the packet that guest send, then 
redirect
to outdev(if none, do nothing). but queue=rx/tx/all not related to 
indev. please
look the flow chart below. queue=xxx just work for one way(filter->outdev).

                               filter
                                 +
                                 |
                                 |
                redirector       |
                 +-------------------------+
                 |               |         |
                 |               |         |
                 |               |         |
    indev +----------------+     +---------------->  outdev
                 |         |               |
                 |         |               |
                 |         |               |
                 +-------------------------+
                           |
                           |
                           v
                        filter

                           |

                           |

                           v
                        filter ........ filter ...... guest

>
> .
>

-- 
Thanks
zhangchen