Re: [Qemu-devel] [PATCH V3 1/2] net/filter-mirror:Add filter-mirror

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

On 02/15/2016 01:23 PM, Jason Wang wrote:
>
> On 02/04/2016 05:00 PM, Zhang Chen wrote:
>>
>> On 02/04/2016 03:43 PM, Zhang Chen wrote:
>>> From: ZhangChen <zhangchen.fnst@cn.fujitsu.com>
>>>
>>> Filter-mirror is a netfilter plugin.
>>> It gives qemu the ability to copy and mirror guest's
>>> net packet. we output packet to chardev.
> To make it compact, how about "It gives qemu the ability to mirror
> packets to a chardev."?

OK, will fix it in next version.

>>> usage:
>>>
>>> -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,outdev=mirror0
> An issue with mirror (and dump) is that it can not work correctly with
> the netdev that has a vnet header. Need to fix this, a possible solution
> is to checksum the buffer and strip the header before passing it to a
> chardev.
>

Thanks, I don't consider about vnet, we will fix it in next version.

>>> 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>
>>> Reviewed-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
>>> ---
>>>    net/Makefile.objs   |   1 +
>>>    net/filter-mirror.c | 171
>>> ++++++++++++++++++++++++++++++++++++++++++++++++++++
>>>    qemu-options.hx     |   5 ++
>>>    vl.c                |   3 +-
>>>    4 files changed, 179 insertions(+), 1 deletion(-)
>>>    create mode 100644 net/filter-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
>> s/traffic-mirror.o/filter-mirror.o/     rebase error....
>>
>>> diff --git a/net/filter-mirror.c b/net/filter-mirror.c
>>> new file mode 100644
>>> index 0000000..87ccaf5
>>> --- /dev/null
>>> +++ b/net/filter-mirror.c
>>> @@ -0,0 +1,171 @@
>>> +/*
>>> + * 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_MIRROR(obj) \
>>> +    OBJECT_CHECK(MirrorState, (obj), TYPE_FILTER_MIRROR)
>>> +
>>> +#define TYPE_FILTER_MIRROR "filter-mirror"
>>> +
>>> +typedef struct MirrorState {
>>> +    NetFilterState parent_obj;
>>> +    char *outdev;
>>> +    CharDriverState *chr_out;
>>> +} MirrorState;
>>> +
>>> +static ssize_t filter_mirror_send(NetFilterState *nf,
>>> +                                   const struct iovec *iov,
>>> +                                   int iovcnt)
>>> +{
>>> +    MirrorState *s = FILTER_MIRROR(nf);
>>> +    ssize_t ret = 0;
>>> +    ssize_t size = 0;
>>> +    uint32_t len =  0;
>>> +    char *buf;
>>> +
>>> +    size = iov_size(iov, iovcnt);
>>> +    len = htonl(size);
>>> +    if (!size) {
>>> +        return 0;
>>> +    }
>>> +
>>> +    buf = g_malloc0(size);
>>> +    iov_to_buf(iov, iovcnt, 0, buf, size);
>>> +    ret = qemu_chr_fe_write_all(s->chr_out, (uint8_t *)&len,
>>> sizeof(len));
>>> +    if (ret < 0) {
> I believe we should also fail when ret < sizeof(len) and modify the
> caller check in filter_mirror_iov(). To make this a little bit easier,
> there's no need to return ssize_t here (otherwise, caller need to call
> iov_size() before checking the return value), just return 0 for success
> and -EFXXX for failure.

OK, will fix it in next version

Thanks
zhangchen

> Other looks good.
>
>
>
> .
>

-- 
Thanks
zhangchen